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高中英语学术论文研究方法练习题40题1.Which of the following topics is most suitable for a high school English academic paper?A.The history of video games.B.The influence of social media on teenagers' language learning.C.The development of artificial intelligence in the medical field.D.The architecture of ancient Rome.答案：B。
解析：选项 A 视频游戏历史与高中英语学术论文关联不大。
选项C 人工智能在医疗领域的发展与英语学科不相关。
选项D 古罗马建筑也与英语学科没有直接关系。
而选项B 社交媒体对青少年语言学习的影响既与英语语言相关，也适合高中学生进行研究。
2.In choosing a topic for an English academic paper, what should be considered first?A.Personal interest.B.Availability of resources.C.Relevance to the curriculum.D.Popularity of the topic.答案：C。
解析：选项 A 个人兴趣虽然重要，但不是首先要考虑的。
选项 B 资源的可获得性在确定选题后再考虑。
选项 D 话题的流行度不是关键因素。
首先应考虑与课程的相关性，这样才能确保论文在学科范围内有意义。
3.Which of the following is NOT a good criterion for choosing anacademic paper topic?A.Being too broad.B.Having enough research materials available.C.Being relevant to current events.D.Being easy to research.答案：A。
2023年9月第39卷㊀第5期外国语文(双月刊)Foreign Languages and Literature(bimonthly)Sep.,2023Vol.39㊀No.5收稿日期:2023-03-27基金项目:教育部人文社会科学规划基金项目 多模态能源舆情话语的认知批评研究 (21YJA740055)㊁北京市社会科学基金规划项目 多模态视域下中西能源话语比较研究 (21YYB006)的阶段性成果作者简介:赵秀凤,女,中国石油大学(北京)外国语学院教授,博士,博士生导师,主要从事认知诗学与多模态认知批评研究㊂崔亚霄,女,中国石油大学(北京)外国语学院副教授,博士,硕士生导师,主要从事认知诗学与文体学研究㊂引用格式:赵秀凤,崔亚霄.多模态体认诗学 基于体认语言学的研究[J].外国语文,2023(5):82-92.多模态体认诗学基于体认语言学的研究赵秀凤㊀崔亚霄(中国石油大学外国语学院,北京㊀102249)摘㊀要:本文把多模态文学的认知研究置于体认语言学理论视域,考察多模态文学交流的体认性特征,提出构建和推动 多模态体认诗学 的研究设想㊂多模态文学的认知研究结合具体文学作品揭示了多模态文学交流过程的多维体认特征㊂一方面,多模态文学符号也与语言符号一样,具有认知性㊁社会性和文化性,其交流过程也涉及身体体验和认知加工的循环互动;另一方面,多模态文学交流过程中的体认特征也体现出一定的独特性,即体认的多模态性㊁多维交互性和复杂系统性㊂为此,本文提出应从拓宽体认语言学的外延㊁丰富体认语言学的理论蕴含㊁推动体认语言学和诗学的交叉融合三个方面,推动 多模态体认诗学 研究㊂本研究从文学和语言学跨学科视野,探讨人类符号交际的体认性,有助于在后现代语境下切实推动多领域的互动交流对话,践行体认语言学的后现代主义哲学观,推动学术研究的开放多元㊂关键词:多模态认知诗学;体认语言学;多模态文学;体认诗学中图分类号:H0-05㊀㊀㊀文献标志码:A㊀㊀㊀文章编号:1674-6414(2023)05-0082-110㊀引言近年来,在欧美兴起了一种新的文学研究动向 多模态认知诗学研究,从认知的角度考察多种模态协同表征的文学的交流过程和效果㊂这一研究动向由以英国谢菲尔德大学艾莉森㊃吉本斯(Alison Gibbons)为代表的一批学者推动,他们把研究对象从纯文字小说拓展到运用多种模态符号创作的各类文学如后现代实验文学(Page,2009;Gibbons,2012;Caracciolo,2014)㊂该研究动向关注语言和非语言符号协同构成的多模态实验文学对读者认知体验和接受产生的影响,反过来,也考察读者的认知体验对后现代实验文学创作发挥的制约性作用,即关注多模态文学与读者之间的互动体验㊂多种模态符号协同互动所创建的文学作品对读者的常规阅读图式,包括感知体验㊁认知解读㊁理解和情感反应,都带来了新的改变或挑战,其突出特点就是后现代多模态文学高度彰显文学作品自身的物质性㊁互文指涉㊁排版的新奇性等,对读者在文学体验过程中的涉身参与提出了新要求㊂不同于传统纯文字小说,多模态小说不但需要读者想象性参与虚构小说故事世界,而且需要切实调动身体器官实施相应行为,需要不断在小说创建的文本世界和作者及读者所在的话语世界之间穿插切换,这种新型文学交流得以顺畅进行的前提正是多模态符号的体认性㊂㊃28㊃㊀赵秀凤㊀崔亚霄㊀多模态体认诗学 基于体认语言学的研究㊀正是基于对后现代实验文学多模态交互体认特征的认识,吉本斯于2012年出版了‘多模态认知诗学和实验文学“(Multimodality,Cognition,and Experimental Literature)一书,整合认知语言学㊁神经认知科学㊁视觉感知㊁多模态符号学等多领域研究成果,强调沿用广义认知原则,如多感官感知原则㊁涉身体验原则等,探究多模态叙事对读者叙事体验和情感反应的影响㊂在该书中,吉本斯以四部后现代实验小说为例,详细阐述了读者的阅读感知体验㊂之后,吉本斯沿用这一研究路径,发表了系列研究成果(Bray et al.,2012;Gibbons,2016;Gibbons,2021),使多模态认知诗学成为文学认知研究领域的后起之秀㊂纵观已有的多模态认知诗学研究,笔者发现无论其理论阐述还是应用实践都与王寅(2014)提出的 体认语言学 (Embodied-cognitive Linguistics,简称:ECL)的核心观点不谋而合㊂本文意在基于体认语言学的理论视域,梳理并考察多模态认知诗学阐述的多模态体认观,加强两个不同研究领域之间的互动,进一步推动文学和语言学研究在 后现代哲学 语境下的 同堂对话 (贾娟等, 2020:32),丰富 体认 内涵,拓展体认语言学的应用范畴,推动构建 多模态体认诗学 ㊂另一方面来看,体认语言学(王寅,2014)无论是在理论建构,还是个案分析及应用方面,都得到了蓬勃发展㊂体认语言学对语言的各个层面都展示出了强大的阐释力,如转喻(魏在江,2019)㊁指类句(雷卿,2019)㊁兼语构式(刘云飞,2019)㊁名谓句(帖伊等,2019)㊁虚拟位移(张克定,2020)㊁歇后语(王寅,2020)等㊂笔者认为,体认语言学不但精确概括了语言的本质,其基本观点和核心原则对其他社会符号也有强大的阐释力㊂例如,在特定社会文化语境中,人们用于社会交往的各类手势㊁视觉符号乃至声音,更是在人与现实世界体验互动和认知加工过程中形成的,兼具认知性和社会性㊂之所以能够进入社会交际,正是因为这类对复杂现实进行简约性表征的非语言符号也是 来自人与人㊁人与自然的互动,来自人对这些互动的体验和认知加工 (牛保义,2021:28)㊂正是在这层意义上,我们赞同王铭钰等(2021)的主张,应把体认语言学上升为 体认符号学 ,有必要结合多种符号组合和应用实例,阐述 体认 在更广泛符号层面的普遍意义和价值㊂基于以上考虑,本文试图结合已有研究,从多模态文学交流的体认特征入手,阐述借鉴体认语言学的核心理论和方法,针对多模态文学的语类特征,推动 多模态体认诗学 研究㊂1㊀多模态文学交流的体认特征1.1体认的多模态性王寅(2014)在认知语言学涉身体验基础上,结合中国传统哲学和后现代哲学的基本立场,提出了语言意义的 体认观 ,将其哲学立场命名为 体认哲学 ,强调 人本性 和 唯物论 的辩证统一㊂体认观一方面坚持了乔姆斯基和认知语言学从人的心智角度研究语言的基本取向(王铭玉等, 2021:2),另一方面又与后现代哲学的人本主义立场一脉相承,突出强调语言和语言研究中的人本性(贾娟等,2020:33),主张语言研究必须强调人对现实世界进行的体验(王寅,2014:61-67),因此,体认哲学观更加全面综合,更接近人类语言交际的现实㊂体认的人本观决定体认的多模态本质㊂ (黄萍等,2021:118)正如顾曰国(2013:3)所言: 人类在正常情况下跟外部世界(包括人与人之间)的互动都是多模态的㊂ 由视觉㊁听觉㊁触觉㊁嗅觉㊁味觉组成的多模态感官系统参与到人体察世界的过程中,形成人与世界的多模态互动体验,经由认㊃38㊃㊀外国语文2023年第5期㊀知系统的认知加工,形成理性认识(顾曰国,2015)㊂这一过程说明体认本身蕴含多模态性,体认是多模态感官系统和认知系统互动的产物㊂有学者指出: 语言的产生和使用是基于 多模态感官系统 的 互动体验 与基于 认知系统 的 认知加工 进行互动的结果㊂ (黄萍等,2021:118)事实上,多模态互动体认不限于语言的产生和使用,而是体现于人类话语交际的全过程㊂在实际的话语交际过程中,交际双方往往是多感官协同参与,并不断互动㊂多模态感官的协同联动不但刺激产生互动感知体验,而且诱发对意义的认知加工升华㊂人类交际过程的 多模态 性,不仅体现于面对面交际中的身体姿势㊁手势㊁声音㊁语调㊁表情,还体现在书面交际中的字体㊁排版㊁颜色㊁物质性媒介等多模态特征㊂也就是说,在实际交际过程中,多模态既是人类用于交际的符号手段,又是人类多种感官协同参与的体认通道㊂正是基于这一认识,我们认为有必要探讨多模态交际的体认性特征,丰富体认语言学的理论体系,拓展其应用范畴㊂在这一方面,多模态认知诗学先行一步,结合后现代实验文学的多模态特征,进行了开创性研究㊂吉本斯运用认知-叙事学研究路径(cognitive-narratological approach),不但把模态视为表意资源,还把不同表意系统所诱发的多感官感知㊁体验和认知方式纳入研究视野,她所建构的多模态认知诗学综合性分析框架旨在剖析阐释多模态文学交流的体认过程㊂当然,多模态体认过程研究的前提是认知诗学的基本主张 文学是 人类经验的一种具体形式 (Gavinset al.,2003:1), 文学研究可向我们揭示认知实践,借此我们不但可以阅读文学作品,还可以感知和理解世界 (Gibbons, 2012:26)㊂多模态认知诗学认为 人们不仅通过语言,而且也通过视觉㊁听觉和心理等其他方式接触世界 (Gibbons,2012:38),因此,多模态认知诗学把研究焦点确定为读者对多模态进行理解和体验的复杂动态过程,并运用科学的方法对该过程进行动态描述㊂多模态文学倾向于突出符号的物质性和意义理解的多模态性,往往通过调动读者的身体参与,诱发和强化心理体验㊂因此,多模态文学的认知研究高度关注读者在字体㊁排版㊁图像形状㊁颜色㊁布局等视觉因素的刺激或操控下作出的行为反应或注意力变化㊂如吉本斯(Gibbons,2012:45)运用图形-背景理论,解释眼睛如何在一个视域内部或跨视域之间移动㊂ 在阅读视觉语篇时,意义的理解尤其需要阅读路径的动态调整 (Gibbons,2012:25),眼睛在阅读文本中的移动路径是在视觉结构诱发下人所做出的主体性反应,如图1(见下页)㊂读者在阅读到该页时,会主动做出选择,调整阅读路径㊂在‘书页之屋“这一多模态小说中,有很多类似的视觉操控手段,调动和激发读者的阅读行为,读者需要根据对故事世界的理解自动调整阅读顺序,甚至需要手动调整书页的方向,这类设计突出了图书作为阅读对象的物理属性,赋予读者更多自主性,可以自行选择阅读顺序和路径㊂这种在物理行为上的 身体 介入,往往会诱发读者心理上的自我投射(projection)㊁自我暗示(self-implication)㊁情感或认知反应(emotional response) (Gibbons,2012:27),从而直接影响读者对故事世界的体验和认知㊂再如,在托马苏拉(Tomasula)小说‘VAS:平地上的歌剧“(VAS:An Opera in Flatland:A Novel,文后简称:VAS)中,作者通过排版设计等视觉化手段使符号的物质性被高度前景化,调动读者的身体器官实施相应行为(赵秀凤, 2021:xiii),如翻页㊁调整书本方向㊁调控阅读视角等行为反应㊂由此,读者直接参与叙事进程,从而 高度彰显了读者在文本体验过程中的涉身参与性 强化阅读㊁存在㊁认知和想象等过程的涉身本质 (赵秀凤,2021:xiii)㊂㊃48㊃㊀赵秀凤㊀崔亚霄㊀多模态体认诗学 基于体认语言学的研究㊀图1㊀‘书页之屋“(Danielewski,2000:133)节选多模态小说VAS中的主题隐喻是运用多模态符号调动多感官参与,彰显动态性体认的典型实例㊂该部小说以多种方式反复建构和表征一个主题隐喻[人类是书籍]㊂一方面,这一隐喻体现为故事内聚焦人物感知觉的语言表达㊂如主人公 四边形 (小说中主人公的名字)把手术视为 对自己身体的改写 (Tomasula,2002:193)和 一次简单的编辑 (Tomasula,2002:312),以下段落更清晰地表征了人物感知和认知域中的[人体 书籍隐喻]:四边形(小说内主人公的名字)停下了笔,看了看指尖的涡纹,这些由线构成的巧妙图像是祖祖辈辈,世世代代,甚至是经过125,000代追溯到类人猿时期传承下来的,它可以由AGCT四个基本字母来表示,这四个字母又可以构成单词GAT㊁ATA㊁AGG,然后这些单词构成了基因的双螺旋句子,进而填充细胞内染色体,最后由这些细胞构成躯体这本书㊂(Tomasula,2002:312;吉本斯,2021:80)该段中关于身体的医学术语 双螺旋㊁基因㊁染色体㊁细胞 与关于书籍/写作的常用词语 句子㊁文章㊁书籍 整合编织在一起,最后直接用 躯体这本书 更加显性表征[书籍 身体隐喻]㊂另一方面,该书还刻意创建物理相似性,激活读者的视知觉感知,亲身体会 书籍 域与 身体域 的整合:封面主色调为桃红色,数条蓝灰色横线隐约穿插而过,隐喻皮肤及皮下静脉;书页以肉色为主,其中的㊃58㊃㊀外国语文2023年第5期㊀文本和图片渐变为红色㊁黑色和米黄色,使整本书的视觉构造仿佛人的躯体,随着读者阅读的深入(即人的年龄的增大),皮肤日渐失去光泽,布满皱纹㊂在文字和视觉模态的协同作用下,读者 多模态器官 体验且认识到身体与书籍之间不仅是概念上的跨域映射关系,也是自己身体和心理互动体验下的 合二为一 ㊂这一实例完美地揭示了多模态文学对多模态体认的 前景化 调用,突出了体认的多模态性㊂1.2体认的交互性体认语言学在阐述其核心原则 现实 认知 语言 时,格外强调体认的 互动性 :一是人通过对外部现实世界(包括自然㊁社会㊁文化等)直接感性接触所产生的互动体验,二是人在外界感性接触基础上进行的认知加工㊂从 体的互动体验 到 认的认知加工 ,再返回到体验,循环升华(王寅,2020:22)㊂从语言的产生㊁语言的发展到语言的习得都是以人的体认为基础的(林正军等, 2021), 现实 认知 和 语言 之间的互动推动了语言的产生和使用㊂体认语言学在阐释各类语言现象时所使用的理论工具,如概念隐喻㊁认知参照点㊁意象图式㊁理想认知模型㊁识解等都是围绕人与世界的互动展开的理论阐述,都强调人与人㊁人与自然互动过程中身体感知觉体验的规律性特征对于语言符号的产生㊁表达和理解的作用㊂例如,王寅(2020)结合大量实例,阐述了隐藏在歇后语背后统一的体认型式:歇后语的前项描写人较为直观的感性生活体验,后项揭示由该体验所引发的认识, 反映了人们从 感性到理性 ,从 具体到抽象 ,从 外延到内涵 ,从 参照点到目标 ,从 明示到推理 ,从 背景到图形 ,从 表层到深层 (由表及里)的体认过程 (王寅,2020:2)㊂体认语言学关于互动性的论述主要阐释语言产生和使用的规律性特征㊂其实,体认的互动性理论能更充分地阐释读者在阅读多模态文学过程中的身心交互特征,如多模态小说VAS中第139页末端的文字为( Still,it moves )在排版上颠倒了文字的方向(图2)㊂图2㊀VAS(Tomasula,2002:139)节选要识读这些文字,读者必须把书旋转过来㊂这种设计配合该部分表达的主题 宇宙的本质一直处于运动之中,呼应该句 一直在动 的语义,因为读者必须做出翻转书本的身体行为,才能读到 一直在动 这句话㊂在该情况下,读者的身体机能与语言对行为的触发双向互动, 执行一个动作有助于理解包含行为动词的修辞短语和文学短语 (Gibbs,2005:88)㊂因此,读者翻动图书的身体动作同时启动了 移动/运动 这一概念,使读者得以身心协同体验 移动/运动 ,加深对 一直在动 这句话的理解㊂此外,该页配有众多箭头和线条组织成的旋转图像,视觉㊁行为动作㊁感知和文字理解多路径协同,创造关于宇宙旋转移动的感性体验和理性认知㊂关于身心体认及其与世界的互动,认知科学家莱德曼(Lederman)和克莱茨(Klatzy)曾指出: 人们使用触觉系统来感知真实物体和虚拟物体同时存在的世界,并与其进行互动㊂ (2001:71)同㊃68㊃㊀赵秀凤㊀崔亚霄㊀多模态体认诗学 基于体认语言学的研究㊀样,马克斯(Marks,2002:2)也指出: 我们正是通过协同触觉㊁动觉和本体感受,才同时在阅读书籍的过程中获得身体感知和内心体验㊂ 从这一意义来说,通过调动读者的身体与书本在实体意义上的直接接触,VAS成功激活并强化了读者的交互性体认㊂体认的交互性还体现为读者与人物之间的 协同共振 ㊂与常规文字小说不同,多模态小说往往借助多模态符号,频繁调动读者对故事世界的身体参与,这一点在叙述人物行为动作时,表现得尤为突出㊂例如,在‘书页之屋“第440-441页,作者通过排版(见图3)设计出如具象诗般的文字,描述人物戴维森(Davison)攀爬探险的行为过程:图3㊀‘书页之屋“(Danielewski,2000:400)节选戴维森步伐缓慢,但是十分坚定,双手交互爬行上了梯子 他仍然继续攀爬,最终他的坚持不懈有了回报,爬行了大概半个小时后,他终于爬完了梯子的最后一根㊂几秒钟过后,他站在一个非常 (Danielewski,2000:400;吉本斯,2021:58)显然,这段文字被排列为一个梯子的形状,从底部一行开始,每个横档错落排开,在空白周边的映衬下,深黑色字体形成的横档越发突显,如同一架梯子斜依在墙上㊂文字的排列顺序和空间摆放方式,决定了读者的阅读方向和顺序:自下而上,从左到右,这一顺序与人物的攀爬动作一致 从低到高㊂可以说,读者在视觉符号的引导下,眼睛紧随人物攀爬的动作,拾级而上,与人物 亦步亦趋 ,一起 攀爬 ㊂梯子横档一级级向上,迫使眼睛不时穿过空白处,形成视觉跳跃(Gibbons,2021: 60)㊂眼睛发挥 动能闭合 (kinetic occlusion)作用,戴维森 不断换手 攀爬梯子㊂从侧面来看,当他在前面的那只手抓到高一级横档时,后面的手便跟着向前,这个动作类似于眼睛的动能闭合 读完一段文字后,空白处便进入眼帘㊂该例同时充分体现了两类互动:读者的身心互动及读者与人物的协同共振㊂当然,这种双维互动的前提是多模态符号对读者体认感知的诱发性潜势㊂从一般抽象意义来说,是不同模态之间的符号互动激发了读者的身心互动及读者与人物的互动㊂正如吉布斯(Gibbs,2005:66-67)所言: 认知是身体与物理/文化世界互动的产物㊂思维并不是存在于人的身体内部,而是存在于大脑㊁身体㊁世界 交织形成的网络㊂ 涉身 就是指大脑㊁身体和物理/文化环境之间的动态交互㊂ 约翰逊(Johnson,1987:5)也指出: 我们所认识的现实由以下因素所塑造:身体运动型式㊁时空定位轨迹㊁我们与物体的互动形式;它绝不仅仅是抽象的概念和命题判断㊂ 为此,吉本斯(Gibbons,2012:42)强调: 既然涉身是人类理解和体验的奠基之本,那么我们似乎可以做出这样的逻辑推演:身体在阅读中的参与度越多,阅读就越有意义,影响就越深远㊂㊃78㊃㊀外国语文2023年第5期㊀以上实例分析表明,多模态文学语篇充分运用多种模态符号,调动读者的多维交互体验,无论是人与符号资源在物理意义上的本体互动,还是文本内多种模态符号之间互动所引发的读者在身体感知和心理认识之间的互动,都反映了多模态符号对读者整体体认过程的影响㊂1.3㊀体认的复杂系统性从复杂动态系统理论视角来看(Complex Dynamic Systems,简称:CDS),在多模态文学的交流过程中,读者的体认也呈现出复杂动态系统性特征㊂根据CDS理论,复杂系统具有以下突出特征: 复杂性,即构成元素和施动体丰富多样㊁互动方式多元;动态性,即构成元素与施动体始终变化,互动方式亦始终在变;开放性,即新元素和施动体随时可进入系统;非线性,即系统的整体变化不可预测,无法以变量分析法找到规律;此外,系统可具自发组织性和共适性,有时体现为相对稳定的状态㊂ (单理扬,2019:94)就多模态文学交流而言,一方面,读者的体认具有多模态感官联动性,另一方面,多模态文学的构成要素丰富多样,这些都对多模态文学的理解体认过程产生直接影响,使体认本身成为一种复杂的动态系统,呈现出复杂系统的一般特征㊂首先,多模态文学交流的对象,文学作品本身就是一个由多个子模态符号系统构成的复杂系统,如后现代实验小说系统往往包含图像㊁图形㊁页面设计㊁空间布局㊁字体㊁颜色㊁词汇㊁语法㊁篇章结构㊁文学常规等等多个子系统㊂多模态小说尤其是后现代实验文学达到了高度的形式自觉,大量运用元小说和互文指涉手段㊁彰显实体性㊁创新文本排版形式等㊂吉本斯(Gibbons,2012:2)把这种形式自觉在符号上的主要体现概括为以下八类:存在明显的文本布局和页面设计;排印方式多样,在文字和图像中运用色彩;类似于具象诗,把文本文字具象化;使用包括元小说写作在内的多种手段;吸引读者关注文本的物质属性;使用脚注和其他形式传递自我质疑;使用翻页书技巧设计部分章节;混合使用多种文学样类,包括文学创作风格上的混搭,如恐怖,也包括视觉效果的混搭,如剪报和剧本对白㊂每个子系统之间相互联系,相互制约,表征和建构小说世界,创建文学意义㊂其次,读者个体也可以看作一个高度复杂的动态系统,对多模态符号的阅读理解过程本身也受个体㊁社会㊁认知㊁文化和环境等多因素的影响㊂如在识读鲁宾(Robin)的花瓶图像(图4)时,某人可能第一眼倾向于解读为 看到了一个置于白色背景的黑色花瓶 ,而另一个人则解读为 黑色背景下的两张白色面孔 ; 图像阅读并没有线性结构的强制要求,即读者具有主体性选择,当然即使有个体差异,在特定社会文化群体中,也一定有规律性体验阅读路径 (Gibbons,2012:14)㊂因此,他们又都可以在这两种解读之间任意切换,体现了读者体验的个体性差异㊂图4㊀鲁宾的花瓶图像(吉本斯,2021:35,源自Rubin,1958/1915:201)㊃88㊃㊀赵秀凤㊀崔亚霄㊀多模态体认诗学 基于体认语言学的研究㊀多模态文学交流是一个多要素相互作用的系统,文学构成要素和认知主体要素的多样性和动态变化性,使文学意义的理解和体悟过程本身也呈现出复杂动态系统特征,多模态符号系统内部诸要素与读者的多模态感官系统及认知系统之间存在 竞争㊁互补㊁对立和适应等多种交错叠加的互动关系 (曾小燕,2017:35)㊂在真实交际活动中,体认的复杂动态性既体现于读者与文学作品及其环境之间的互动,又存在于读者个体多种素质和能力的互动,多维互动在多模态文学符号的诱发下呈现出高度的动态性和自组织性㊂例如,当读者翻开多模态小说‘书页之屋“,读到的开篇之句是 This is not for you (这不是为你写的)(Danielewski,2000:ix)㊂该句的否定语法结构 not 和指向故事外读者的第二人称代词 you ,都令读者感到某种 不适 ,该句似乎在实施一种禁止性言语行为,阻止读者进入小说世界㊂这显然违背小说常规,与读者固有阅读体验及打开小说的阅读冲动和欲望之间形成直接冲突,令读者感到 认知失调 (cognitive dissonance)㊂事实上,作者是 希望借此激将法诱使读者深入阅读 (Gibbons,2012:51)㊂ 失调给人带来心理不适感,会促使人们努力减少不适,达到协调㊂ (Festinger,1957:3)当人们的行为和认知发生冲突时,内心急求缓解这种失调的愿望便会异常强烈(Gibbons,2012:53),因此,读到这句阻止性否定句后,读者反而往往会做出 认知对抗 (cognitive reactance)反应,即产生强烈的反抗心理,就会反其道而行之㊂可见,常规㊁语言㊁读者的阅读欲望㊁心理预期及其个体心理调整适应等多要素联动,相互作用与制衡㊂该句的阅读理解过程 从体会到符号意义表层上的被排斥,经认知对抗,做出逆反性继续阅读行为 充分体现了体认的动态性㊁复杂性和自组织性,是多种子系统连接互动的结果㊂此外,该句单独构成一页,位于按照常规应该是献词页的位置,这一空间位置本身又形成了激活文学常规的符号要素,与文学作品的语类结构及其相应的阅读常规图式形成联动关系,直接影响阅读个体的体验和认知,以及随之产生的对抗认知反应㊂2㊀走向多模态体认诗学综上所述, 多模态体认观 拓宽了 语言体认观 的适用视域㊂多模态文学实例表明,语言符号具有认知性㊁社会性和文化性,多模态符号更是如此;多模态符号的协同㊁组合㊁应用更涉及身体体验和认知加工的循环互动㊂多模态文学交流也遵循 现实 认知 符号 这一核心原则,也大量启用图形-背景㊁意象图式㊁概念隐喻等体认机制㊂因此,我们可以说,体认语言学理论为我们阐释多模态文学的交流过程提供了强有力的理论工具㊂我们可以通过拓展体认语言学的应用范畴,从多模态符号的体认性出发,阐释读者与文学作品之间的互动体验,推动 多模态体认诗学 研究㊂笔者认为可以从以下三个方面展开:首先,拓宽体认语言学的外延㊂体认语言学侧重从语言生产角度论述体认的作用,阐述 现实 认知 符号 三者之间的关系㊂作为揭示语言人本性的体认语言学,理应从语言产生的一般规律出发探讨本源问题,但事实上人类用于交际的所有符号都具有体认性特征㊂21世纪起的后现代实验文学,充分利用各类图文符号,激活人的感知体验㊁情感和认知加工;这类文学的日渐兴盛也充分说明了多模态符号体认性对文学的影响㊂因此,我们有必要拓宽体认语言学的外延,从广义的符号层面,考察体认的过程;如针对后现代实验文学的多模态组合特征,阐释该类文学得以产生㊁接受㊁形成独特文学样类背后的体认机制;通过透视读者的阅读体验和认知加工过程,揭示多模态文㊃98㊃。
分子生物学学科的英语意思The English Meaning of the Discipline of Molecular BiologyDefinition and BackgroundMolecular biology is a branch of science that explores the structure, function, and interactions of biological macromolecules, such as DNA, RNA, and proteins, at the molecular level. It involves the study of various processes within cells, including replication, transcription, translation, and gene expression. Through understanding the fundamental mechanisms of life, molecular biology provides insights into genetic diseases, evolutionary relationships, and the development of new therapeutic interventions.Etymology and OriginsThe term "molecular biology" originated in the early 20th century. The word "molecular" refers to the smallest fundamental units of a substance, while "biology" pertains to the study of life. The combination of these two concepts reflects the focus of molecular biology on elucidating the molecular basis of biological phenomena.Historical MilestonesThe history of molecular biology can be traced back to numerous key discoveries and technological advancements. In 1953, James Watson and Francis Crick proposed the double-helix structure of DNA, which revolutionized the field and provided a framework for understanding how genetic information is stored and transmitted. In the following years, the development of techniques such as polymerase chain reaction (PCR), DNAsequencing, and recombinant DNA technology allowed scientists to manipulate and analyze genetic material with unprecedented precision. These breakthroughs paved the way for significant advancements in the understanding of molecular biology.Interdisciplinary NatureMolecular biology draws upon various scientific disciplines, including genetics, biochemistry, biophysics, and cell biology. The integration of knowledge from these fields enables researchers to comprehend the complex mechanisms underlying biological processes at the molecular level. By combining theoretical concepts with experimental approaches, scientists in molecular biology can unravel the intricate details of cellular functions.Application in BiotechnologyThe knowledge gained from molecular biology research has numerous practical applications. In the field of biotechnology, molecular biology techniques are utilized for the production of recombinant proteins, development of genetically modified organisms (GMOs), and gene therapy. Through genetic engineering, scientists are able to manipulate and modify the genetic makeup of organisms, leading to advancements in agriculture, medicine, and environmental conservation.Disease Research and Drug DevelopmentIn the context of human health, molecular biology plays a crucial role in disease research and drug development. By studying the molecular mechanisms underlying diseases, scientists can identify genetic markers, develop diagnostic tests, and design targeted therapies. Additionally,molecular biology techniques contribute to the identification and characterization of potential drug targets, facilitating the discovery of new treatments for various disorders.Evolutionary StudiesMolecular biology also contributes to our understanding of evolutionary processes. By comparing DNA sequences among different species, scientists can reconstruct evolutionary relationships and study the factors driving genetic variation and adaptation. This field, known as molecular evolution, sheds light on the origins of life and the diversification of species across time.Future PerspectivesAs technology continues to advance, the field of molecular biology is likely to witness further progress. Emerging techniques, such as next-generation sequencing, genome editing, and single-cell analysis, offer unprecedented opportunities to delve deeper into the molecular intricacies of life. Moreover, the integration of molecular biology with other fields, such as artificial intelligence and nanotechnology, may open up new avenues for scientific exploration and innovation.In conclusion, the discipline of molecular biology focuses on understanding the molecular basis of life, encompassing the study of DNA, RNA, proteins, and their interactions within cells. With its interdisciplinary nature and practical applications, molecular biology plays a pivotal role in various scientific and technological advancements. By continuously unraveling the mysteries of the molecular world, researchers in this field contribute to the progress of science and the betterment of human life.。
_______________________________________The paper presents an application of reassigned wavelet scalogram for rotor system fault diagnosis. It is a topic of interest to the researchers in the related areas but the paper needs very significant improvement before acceptance for publication. My detailed comments are as follows:1. The wavelet method (reassigned wavelet scalogram) used in the paper works very well for the underlying fault diagnosis problem. On the other hand, this wavelet method is awell-established method, and the present research is a direct application of this method without new contribution in methodological research.2. For the above reason, the presentation should be focused on the results. Unfortunately, the presentation is far from acceptable for publication. The material was not properly organized and it is strongly suggested that the authors check carefully the English writing and use standard terminologies in the technical area.3. The title of the paper should be more specific since numerous studies have been done on the fault diagnosis of rotor systems using wavelets and time-frequency methods. Also, remove the word "research".4. On Section 1:· This section listed many references that are mainly related to rotor dynamics and are not directly related to rotor system diagnosis. If the authors would like to keep these references, some discussions on the relevance of these refs to the present research are needed.· Review on the directly relevant refs will be more helpful for the reader. Also, time-frequency and wavelets are mainly for non-stationary and transient analysis. The author may discuss in more detail what types of transients and non-stationary components would appear in rotor system vibration.· A few sentences on the organization of the paper will be helpful.5. On Section 2:· Since the major method used in the application is reassigned wavelet scalogram, it is not needed to give the details of three other methods (only give a few words and give the refs). Instead, the authors may discuss more on the relationship between traditional wavelet scalogram and the reassigned wavelet scalogram, and explain why the latter is better than the former.· Eq (2): the right-hand-side is wrong and "2" is missed.· The description after Eq (2) is not clear. See Cohen's book for details about the cross-terms.6. On Sections 3 and 4:The description needs to be improved. The material in Section 3 should be organized in several paragraphs.7. On Section 5:· The authors did a good experiment and some of the phenomena presented in thetime-frequency planes are also very interesting. However, the observations should be described concisely, and the authors should focus more on: 1) whether these phenomena are general characteristics, and 2) if possible, explain the reason of the phenomena and the advantages of reassigned wavelet scalogram over other time-frequency methods.· In fact, it is possible to interpret most of the phenomena in the time-frequency planes usingrotor dynamics. For example, shaft rub causes broadband vibration and will result in nearly horizontal lines in the phase planes.· Some of the paragraphs are too long.8. The conclusion should be concise and only summarize the most important contribution of the research.Reviewer #2: This paper presents the results of time-frequency analysis applied to a table top rotating machinery test rig under a set of fault conditions. The title of the paper is very misleading because no automated methods for either fault detection or diagnosis/isolation are discussed in the paper. Rather, under different fault scenarios, several time-frequency methods available in the literature are evaluated for their ability to generate visually discriminating features associated with the fault conditions. Hence, this paper provides a characterization of time-frequency features associated with rotating machinery faults as opposed to the development of any type of fault diagnosis methodology. Hence, the paper must be judged solely on the quality of the experimentation, the presentation of the results, and how the time-frequency features identified in the various fault cases relates to the dynamical operating conditions of the rig.The main problem with the paper is that it is very poorly written, and this makes the evaluation and interpretation of the main contributions of the paper obscure. The paper requires a complete rewrite to improve the grammar, style and readability. Also consider:In equation (1) on page 2, what does it mean that h(t) is centered at t=0 and f=0? h(t) is a windowing function in the time domain!What is the point of the simulation experiments, what do they add to what is already known about the time-frequency techniques from the literature?Since the only contribution of the paper is the time-frequency analysis, the results of these computations need to be explained in detail in the text and the graphical results need to be properly annotated so that readers can comprehend and understand which distinguishing features are associated with the faults. Currently, the graphical results are poorly displayed and it is difficult to correlate the figures with the text.以下是从一个朋友转载来的，关于英文投稿过程中编辑给出的意见。
LncRNAs在胶质瘤免疫治疗作用摘要：胶质瘤是中枢神经系统最常见的恶性肿瘤，尽管进行了手术联合同步放化疗的多模式治疗，但是胶质瘤患者的预后依然很差，因此，深入挖掘胶质瘤发生和进展的分子机制，并以此为基础开发新型靶向治疗药物显得尤为重要。
LncRNA是指长度超过200个核苷酸的非编码RNA，序列上保守性差，功能上具有一定保守性[1]。
根据lncRNA在基因组上的位置，可以分为如下五类：1、基因间区长链非编码（large intergenic lncRNA），2、内含子区长链非编码RNA （intronic transcript），3、正义链长链非编码RNA（sense lncRNA），4、反义链长链非编码RNA（antisense lncRNA），5、双向长链非编码RNA （bidirectional lncRNA）。
LncRNA的功能机制主要包括五个方面：1、介导染色质重塑和组蛋白修饰，调控其下游基因的表达；2、通过碱基互补配对，与编码蛋白质的基因的转录本形成双链结构，干扰编码基因转录本的剪接或者形成内源性小干扰RNA（small interfering RNA，siRNA）；3、与特定的蛋白质结合，调控该蛋白的活性或者组成核酸-蛋白质复合体；4、与特定蛋白质锚定后，改变该蛋白质的亚细胞定位；5、进一步代谢成小分子RNA，如miRNAs和piRNAs等[2-4]。
关键词：胶质瘤；miRNAs；诊断；预后；标志性作用胶质瘤是中枢神经系统中最常见的一种原发性肿瘤，约占中枢神经系统恶性肿瘤的80%[5]。
目前，临床中针对胶质瘤的各种治疗手段均取得了一定的进展，但恶性胶质瘤的5年生存率仍然很低[6]。
因此，研究和探索胶质瘤发病机制和有效治疗方法是神经外科领域的前沿课题。
目前认为，胶质瘤的发病机制本质上是一种多基因、多个分子信号通路调节异常，从而使得肿瘤细胞表现出各种恶性表型[7,8]。
神经胶质瘤是中枢神经系统中起源于大脑和脊髓中的神经胶质细胞的肿瘤,占中枢神经系统恶性肿瘤的80%左右[9]。
英语作文影评常用词汇积累Film Review Vocabulary。
When writing a film review, it is important to use a variety of vocabulary to effectively convey your thoughts and opinions. Here are some commonly used words and phrases to help you write a compelling film review:Plot the sequence of events in a story。
Characterization the way a character is developed throughout the story。
Cinematography the art of photography and camera work in film。
Editing the process of selecting and arranging shots to create a cohesive story。
Direction the way the film is guided and brought tolife by the director。
Acting the performance of the actors in the film。
Dialogue the spoken words between characters。
Soundtrack the music and sound effects used in the film。
Special effects the use of technology to create visual and audio effects。
Screenplay the written script of the film。
覆铜板的分类（Classification of copper clad laminate）Classification and variety of copper clad laminate for PCB substrate materialAccording to the different requirements and grades of PCB, the main substrate material - CCL has many product varieties. They are classified according to different rules.(1) according to the mechanical rigidity of copper clad laminate, the rigid copper clad laminate and flexible copper clad laminate can be divided according to the mechanical rigidity of copper clad laminate. Usually rigid copper clad laminates are intermittently laminated. Flexible copper clad laminates are heavily used to form copper foil on polyimide or polyester films. The finished product is soft and has excellent folding resistance. In recent years, with the load type semiconductor package (TBA) and other development, with its need for organic resin ribbon packaging substrate, also appeared in the glass fiber cloth, epoxy resin and liquid crystal polymer film and other thin copper clad zone shape products.(2) according to the different insulation material, the structure is dividedAccording to different insulation materials and structures, they can be divided into organic resin CCL, metal base (core) copper clad plate and ceramic base copper clad laminate. The structure and material composition of these three types of copper clad laminate are shown in figure 2-1.Metal clad copper clad plate is usually composed of three parts: metal substrate, insulating medium and conductive layer (usually copper foil). One or both surfaces of a metal substrate to be chemically or electrochemically treated are coated with an insulating dielectric layer and a copper foil, which is compounded by hot pressing. According to the structure, composition and properties of metal clad copper clad laminate, there are many kinds of copper clad laminates. The structure is divided into metal substrate, clad metal substrate and metal core substrate. From the composition of the metal substrate is divided into aluminum based copper clad laminate, iron based copper clad laminate, copper based copper clad laminate, molybdenum based copper clad laminate and so on. Divided from the performance for a metal base copper clad laminate; flame retardant metal base copper clad laminate; high heat-resistant metal base copper clad laminate; high thermal conductivity type metal base copper clad laminate; superconducting heat type metal base copper clad laminate; high frequency type metal base copper clad laminate; multilayer metal base copper clad laminate. Metal clad copper clad laminate has excellent heat dissipation, good mechanical properties, excellent dimensional stability, electromagnetic shielding, electromagnetic property, etc..Ceramic based copper clad laminate (DBC) consists of ceramic substrate, bonding bond layer and conductive layer (copper foil). There are many kinds of ceramics, which can be classified according to the types of materials used. If there are Al2O3, SiO, MgO, Al2O3, SiC, AIN, ZnO, BeO, MgO, Cr2O3 and other kinds of ceramic films. At present, the most widely used and is "ceramic. It can also be divided into two categories: directkey method and bonding lamination key.(3) according to the thickness of different insulation layerAccording to the thickness of CCL, it can be divided into regular plate and thin plate. Generally, the thickness of copper (not including copper foil) is less than 0.8mm of epoxy resin clad laminate, called sheet (IPC standard is 0.5mm). Epoxy glass cloth CCL thickness below 0.8mm thin board is suitable for punching processing, and it can also be used as the core material required in the fabrication of multilayer board.(4) divided by different reinforcementIn this division, when the copper plate uses some reinforcing material, the copper clad sheet is called a material substrate. Different from the commonly used reinforced rigid organic resin laminate has three types of woven glass laminate; paper base copper clad laminate; composite base copper clad laminate. In addition, there are special reinforcing material composed of copper plate, as well as: aramid fiber non-woven fabrics, copper clad laminates, synthetic fiber based copper clad laminate.For fiber reinforced materials, there are differences between organic fiber reinforced materials and inorganic reinforcing materials. In recent years, the development of CO2 laser manufacturing in hole processing PCB, using organic fiber reinforced materials (such as: aramid fiber reinforced material), due to the laser light absorption ability, and isconducive to the laser hole machining. Most of the reinforcement materials used for CCL are still inorganic reinforcing materials. The common inorganic materials with enhanced electronic grade (also called E) (referred to as glass fiber cloth, glass fiber cloth) electronic grade glass fiber paper (E) (hereinafter referred to as the glass paper, also known as glass fiber non-woven, glass mat, glass paper).The so-called composite copper clad laminate, mainly refers to the insulating substrate, is the surface layer and core layer using two different reinforcing materials composed of copper clad laminate. In the composite base copper clad laminate, the most common is CEM-1 (flame retardant copper clad modified epoxy glass fiber cloth, paper core composite material laminate (CEM-3) and flame retardant copper clad epoxy glass fiber cloth, glass fiber paper core composite laminate substrate) two types.(5) according to the insulation resinThe resin of the copper clad plate is made of some kind of resin, and the copper clad plate is called a copper clad plate of a resin type. At present, the most common are the main resin: phenolic resin, epoxy resin (EP), polyimide (PI) resin, polyester resin (PET) and polyphenylene ether resin (PPO) and cyanate ester resin (CE), PTFE resin (PTFE), bismaleimide resin (BT) was three.Based on the above two principles of using different reinforcing materials and different insulating resins, the rigid CCL can be divided into five categories. These five categories are: paper base copper clad laminate; CCLS basedcomposite; base copper clad laminate; lamination plywood substrate materials; special base copper clad laminate. The classification of these five types of substrate materials and their respective specific mainFigure 2-2 a variety of substrate materials classified by different reinforcing materials and different insulating resins is shown in figure 2-2.[the last line is red leaf dance, Fragrant Hill at 2008-6-13, 10:53 editing]Attachment: your user group cannot download or view attachmentsUID27641 post 11366, essence 6 points 11819, read permissions 150, online time 2205 hours, registration time 2007-1-1, finally login 2008-8-7, view detailsTOPTerminator reassert divinity, successfully intercepted Ravdm stealing Trojan QNew technology analysis of Windows Server 2008Red maple danceSuper ModeratorPersonal space sends short message plus friend, current offline 2# large, medium and small, published in 2008-6-13, 10:38, onlysee the authorYou can delete the "worm" Mobo manual (6) according to the classification of flame retardant propertiesUL standard (UL94, UL746E, etc.) can be divided into different flame retardant grades for the flame retardant properties of substrate materials. That is, UL standards will be divided into four kinds of substrate materials, different flame retardant grades are: UL-94VO class; UL-94V1 class; UL-94V2 class and UL-HB class. Generally speaking, according to the UL Standard Test methods, testing, to achieve flame retardant UL-HB grade CCL, known as non flame retardant copper clad laminate (commonly known as HB board). To meet the flammability requirements of the vertical combustion method in the UL standard (the best flame retardant grade is grade UL-94VO), and to call it a flame retardant copper clad laminate (commonly known as VO board). This kind of "HB board" and "VO board" popular term, in our country on paper based copper clad laminate flame retardant classification of the appellation is still very popular.(7) according to a special performance of CClAccording to the special performance of CCL, the copper clad boards of different grades are divided, which are mainly displayed on some high-grade plates. Here are only a few varieties of this classification.1., according to the different classification of TgThe glass transition temperature (Tg) is a description of the organic insulating resin reaching a certain temperature point, and the molecular morphology changes from glassy to rubbery. The temperature at which this point is known is called the glass transition temperature. Tg is an important project of heat resistance measurement, some characterization of CCLS based. When the insulating resin of the base material rises above Tg, many properties change dramatically. Therefore, the higher the Tg, the better the stability of the various properties of the insulating material. On the other hand, materials with high Tg generally have better dimensional stability and mechanical strength retention than those with low Tg. In addition, the excellent performance can be maintained in a larger temperature range, which is very important for the manufacture of printed circuit boards with high density, high accuracy and high reliability.According to the different grades of CCL $%, divided into different heat resistance. For example, in the IPC 4101 A standard, the general copper-clad laminates, epoxy glass cloth laminates (including halogen based FR-4) are divided into three grades according to different Tg characteristics. Namely: IPC-4101/21 for Tg, FR-4 at, IPC-4101/24 for Tg, FR-4 at 150-200 DEG C, and IPC-4101/26 for Tg, and FR-4 for at 170-220 degrees.2. classification according to whether there is halogen or notThe world's research experiments show that in the halogen containing compounds or resins as flame retardant electrical products (including printed circuit board substrate), in the incineration after the waste will produce dioxin harmfulsubstances. Therefore, the development and use of halogen-free PCB substrate materials is an important task in the CCL industry and PCB industry. Since the late 1990s, there has been a "green" substrate material - halogen-free substrate material. According to this characteristic, the substrate material can be divided into halogen base material and halogen-free substrate material.Evaluation of non halogenated substrate material is mainly based on the Japanese printed circuit board (JPCA) industry will be defined as compiled and published in November 1999 on the proposed CCL standards "halogen-free" feature. Namely: the non halogenated base material is in its resin the chlorine content or the bromine content is less than 0.09wt%. In the IPC-4101 standard, more specifically, the halogenated PCB base material is divided into three different halogen-free varieties depending on the type of flame retardant used in the resin. Non halogen, non antimony, phosphorus containing, halogen-free base material (inorganic filler), non halogen, non antimony containing phosphorous containing halogen-free base material (containing inorganic filler), non halogen non antimony non phosphorus non halogen base plate material. And the last one is more conducive to environmental protection requirements.In view of the current development of copper clad flame retardant technology, it will be a good way to realize this kind of high performance "green" substrate material in the future using nano materials and new technologies.3. classification of the coefficient of linear expansionaccording to the substrate materialIn PCB processing and use, in order to ensure its reliability and stability, ensure the hole size of substrate material in the machining process, some PCB in the design and manufacture of low substrate material for the expansion of the more stringent requirements (especially in a semiconductor package substrate for material). Therefore, a new substrate material, low thermal expansion substrate material, has been rising rapidly in recent years. Thus, it is generally customary to have the thermal expansion coefficient (CTE) at 12ppm/ DEG C (plate X, Y direction) below the characteristic substrate material, designated as low CTE substrate material.4. paper base plate according to the punching preheating temperature classificationThe hole processing of paper based copper clad laminate is mostly punched processing. In order to ensure the quality of the punching process of the substrate (no cracks between the holes, no separation between layers, the hole does not appear around the white circle, the hole smooth and so on), it is necessary to pre process the plate before punching. The temperature of the preheating treatment directly affects the size accuracy of the substrate, the flatness of the plate and the shrinkage of the bore bore. For example, Japan Matsushita Electric Company R-8700 paper base copper clad laminate (FR-1) product, on the surface of the plate punching processing temperature for punching processing under 30 DEG C, the hole shrinkage of 0.138mm (diameter of 0.10mm); punching at 50 DEG C, hole shrinkage of 0.150mm; punching in 70 C, hole shrinkageof 0.165mm. In the punching process of paper base copper clad laminate, according to the board can achieve the excellent quality and the punching preheating temperature before punching in (to plate surface temperature meter), production of paper-based cover copper varieties draw two different characteristics of punching out. Traditionally, the surface temperature of the plate before the punching process is 30-70 DEG C for punching. The copper plate with excellent punching quality can be called the low temperature punching plate. The plate which is preheated and punched at more than 70 degrees is called a high temperature punching plate. Under the condition that the quality of punching can be reached, the lower the preheating temperature, the better the punching characteristics are.5. according to the classification of the resistance to leakageTrackings substrate material refers to the electronic products in use, in the PCB line surface of the space position, and the formation of carbide conductive circuit traces for a long time by the dust accumulation, water condensation and other effects, such trackings, in applied voltage, sparks, cause damage to the insulation performance. Therefore, the leakage resistance of copper clad laminate is an important safety characteristic item. Especially for high humidity, exposure, high pressure and other harsh conditions, PCB has more requirements in this regard.Resistance to leakage traces, generally compared with CTI Tracking (Commparative Index index) to express. In the IEC112 standard of CTI index is defined as: in the process of experiment, material by 50 drops of electrolyte (water solutionof ammonium chloride 0.1% general) maximum voltage without leakage phenomenon (generally traces value V said). IEC950 also sets out the three CTI grades of the substrate material according to the different voltage values that the substrate is subjected to under the above experimental conditions. That is, class I (CTI>=600V), level II (600V>CTI>=400V), class III (400V>CTI>=175V). The smaller the grade of%05 of a substrate material, the higher its resistance to leakage.[at last, this line is red autumnal dance, Fragrant Hill at 2008-6-13, 10:54。
An Editing-Based Characterization of theDesign Space of Collaborative ApplicationsPrasun DewanUniversity of North CarolinaRajiv ChoudharyIntel CorporationHonghai ShenIBM CorporationThe design space of collaborative applications is characterized using the notion of generalized multiuser editing.Gen-eralized multiuser editing allows users to view interactive applications as editors of data structures.It offers several collaboration functions,which allow users to collaboratively edit application data structures.These functions include coupling,concurrency control,access control,and multiuser undo.Coupling allows the users to share editing changes,access control and concurrency control prevent them from making unauthorized and inconsistent changes, respectively,and multiuser undo allows them to collaboratively undo/redo changes.These functions must be per-formedflexibly to accommodate different applications,users,phases of collaboration,and bandwidths of the commun-ication links.In this paper,we define and motivate the notion of generalized multiuser editing and describe some of the issues,approaches,tradeoffs,principles,and requirements related to the design of the functions offered by it.1.IntroductionA large number of applications have recently been developed that allow users,interacting possibly from geo-graphically dispersed sites,to collaborate with each other1-3.These applications,called collaborative,multiuser,or groupware applications,have the potential for automating the large amount of group work carried out in current organizations4.In particular,they have the potential for supporting group decision making5,team software develop-ment6,a national‘‘collaboratory’’7,distributed concurrent engineering8,and distributed classrooms3.First author’s address:Department of Computer Science,University of North Carolina,Chapel Hill,N.C.27599;dewan@.Second author’s address:Mail Stop HF3-02Intel Corporation,5200N.E.Elam Young Parkway,Hillsboro,Oregon97124; rajiv_choudhary@.Third Author’s address:IBM/Advantis,HCP3C130,1311Mamaroneck Ave.,White Plains,NY10605; hhs@.This research was supported in part by National Science Foundation grants IRI-9015442and IRI-9208319and in part by a grant from the Software Engineering Research Center at Purdue University,a National Science Foundation Industry/University Cooperative Research Center(NSF Grant No.ECD-8913133).Some important questions raised by the design of these applications are:d What are the dimensions of the design space of collaborative applications?d What are the design choices along each of these dimensions?d What are the advantages and disadvantages of making each of these choices?d What are the design principles and requirements of collaborative applications?We refer to a set of answers to these questions as a‘‘characterization of the design space of collaborative applica-tions’’.Such a characterization would improve the understanding,design,and automation of collaborative applica-tions:d Understanding:It would allow those studying this area to understand the nature and scope of collaborativeapplications and what distinguishes these applications from single-user applications.d Design:It would tell designers of these applications the design decisions they need to make,the tradeoffs inchoosing among these decisions,and the design principles and requirements they must support.d Automation:Implementation of collaborative applications from scratch is difficult and typically takes severalperson years9.Therefore,system support for automating their implementation is an attractive idea.It is not possible to provide such support without knowing the design space of collaborative applications.In this paper,we do a preliminary,high-level characterization of the design space of collaborative applications based on the notion of generalized multiuser editing.Generalized multiuser editing is an extension of generalized single-user editing10,which allows a user to view an interactive application as an editor of the data structures of the application.It offers several functions to allow users to collaboratively edit these data structures.These functions include coupling,concurrency control,access control,and multiuser undo.Coupling allows the users to share editing changes,access control and concurrency control prevent them from making unauthorized and inconsistent changes, respectively,and multiuser undo allows them to collaboratively undo/redo changes.We characterize the design space of collaborative applications by characterizing the design space of each of these functions.Our characterization is not complete,for two main reasons.First,not all issues,design choices,tradeoffs,prin-ciples and requirements are currently known for all functions.Our characterization reflects the state-of-the art in this area.Second,we focus mainly on high-level concepts in the characterization—lower-level,more specific,concepts required to support some these ideas are given elsewhere11-13.See2,14-16for alternative characterizations of colla-borative applications,which are not based on the notion of generalized multiuser editing.Our approach represents a method for dimensionalizing the design space of collaborative applications that addresses collaboration at the‘‘com-mon object perception’’level in Malone and Crowston’s collaboration hierarchy of coordination,group decision mak-ing,communication,and common object perception16.The particular technical dimensions we have chosen at this level are consistent with the ones identified by other researchers2,14-16.The rest of the paper is organized as follows:Section2identifies and motivates two important properties of an effective design space characterization—generality and detail.Section3explains the ideas of single-user and mul-tiuser generalized editing and introduces the collaboration functions.Section4characterizes the design space of eachof the collaboration functions.Finally,Section 5provides conclusions and directions for future work.2.Defining a Collaborative ApplicationIn this section,we propose and evaluate two simple but extreme definitions of collaborative applications to motivate a more complex,editing-based definition of these applications.A general definition :A collaborative application is a software application that (a)interacts with multiple users,that is,receives input from multiple users and displays output to multiple users,and (b)couples these users,that is,allows one user’s input to influence the output displayed to another user (Figure 1).This definition covers all possible collaborative applications since it leaves the nature of coupling supported by a collaborative application undefined.It contributes somewhat to the understanding,design,and automation of colla-borative applications.It tells those (a)understanding collaborative applications that multiuser interaction and coupling are the essential differences between collaborative and single-user applications,(b)designing these applications that,in addition to single-user issues,they must address issues in multi-user input/output and coupling,and (c)automating collaborative applications that they must provide facilities that allow an application to interact with multiple,possibly distributed,users.On the other hand,because it leaves the nature of coupling and associated functions unspecified,it does not convey any information about the issues,choices,tradeoffs,principles and requirements related to the design of colla-borative applications.As a result,it is not possible to use this definition to gain a detailed understanding of the design space of collaborative applications or to provide high-level support for implementing these applications.The next definition meets these requirements.A detailed definition :A collaborative application is a software application that interacts with multiple users and creates one or more shared windows,which are replicated on the screens of all users of the application.Coupling between the users ensures WYSIWIS (What You See Is What I See)17interaction,that is,keeps the contents of the windows identical (Figure 2).CouplingApplicationSoftwareUser 2User 1Figure 1:A General Definition of a Collaborative ApplicationThis definition allows collaborative applications to be understood in terms of the specific notion of WYSIWIS. It also precisely states how coupling between users should be designed.Finally,this definition can be used to build a system such as a shared window system18that completely automates multiuser interaction and coupling without mak-ing the applications collaboration-aware.The second definition leads to these benefits because it qualifies the nature of collaboration in a collaborative application.However,a serious drawback is that it overqualifies the nature of collaboration since several applications such as traditional mail programs and recent collaborative applications such as the GROVE group editor2do not sup-port WYSIWIS.Thus,while the definition is detailed,it is not general.In the rest of the paper,we develop a definition that is both general in that it does not preclude useful colla-borative applications and detailed.Like the second definition above,our definition has afixed part that defines the invariants of collaboration and like thefirst definition above,it has a set of variables which define the collaboration design space.3.An Editing-based DefinitionBefore we can model the interaction between multiple users and an interactive application,we should be able to model the interaction between a single user and an interactive application.Generalized single-user editing10(Fig-ure3)allows us to model the simpler case of single-user interaction.According to this model,an interactive applica-tion can be considered an editor of a display of the data structures of the application.A user interacts with the appli-cation by editing the display using text/graphics editing commands.Thus,interaction with an interactive application is similar to interaction with a text or graphics editor.The difference is that the display is‘‘active’’,that is,changes to it can trigger computations in the application,which can update the display and send messages to other applica-tions.Generalized single-user editing is a simple but general model of single-user interaction.It models a variety of popular contemporary interactive application:A text or graphics editor can be considered an editor of a text orSoftwareApplicationWYSIWISWindow 1Window 2Window CommandsUser 2User 1Figure2:A Detailed Definition of a Collaborative Applicationgraphicsfile;a language-oriented editor can be considered an editor of a program syntax tree;a spreadsheet can be considered an editor of a matrix that responds to an editing of an entry in the matrix by updating related entries;and a debugger can be considered an editor of a debugging history that responds to the insertion of a new command in the history by computing the command and appending the output to the history.At some level of abstraction,any single-user interactive application can be considered a single-user generalized editor.The challenge,then,is to introduce multiuser interaction into this model.Figure4shows how this can be done.As before,a user interacts with an application by editing an active display of the data structures of the applica-tion.Different users,however,edit different versions of the active display.Coupling between the displays allows them to share editing changes;multiuser undo allows them to collaboratively undo/redo changes;and access and con-currency control prevent unauthorized and inconsistent changes,respectively.Moreover,in the multiuser case,the application is persistent.In the single-user case,it is possible to tie a single-user session with an application so that when the user quits the session the application terminates.In the multiuser case,it is not possible to do so since a user may start and terminate a session at any time.Thus the application must persist beyond any particular user ses-sion to allow users to dynamically enter and leave collaborative sessions.Together,coupling,undo,concurrency control,and access control define a new multiuser transaction model designed for interactive multiuser applications.The model is an alternative to the query-based transaction model sup-ported by traditional databases,which has been designed mainly for batch applications.The arrows withing the cir-cles of Figure4represent user-/application-controlled dials and indicate that the collaboration functions must be per-formedflexibly.We characterize below the design space of each of these functions.4.Collaboration FunctionsSome of the general principles for designing collaboration functions are independent of the function:ApplicationActive DisplayEditingCmdsUserFigure3:Generalized Single-User EditingActive Display Version 1Active DisplayVersion 2 ApplicationEditingCmdsEditing CmdsPersistentUndo Redo ConcurrencyControl AccessControlCplngUser 1User 2Figure4:Generalized Multiuser Editingd Specification:The model should make it easy for users to specify how a collaboration function should be per-formed.d Grouping:A corollary of the specification principle is that the model should allow users to specify a collabora-tion parameter once for a group of objects that share its definition instead of once for each member of the group.d Performance:The model must not make the response time of programs unacceptable.d Automation:The model should make it easy for programmers to implement a collaboration function.We shall see below(functions-specific)principles that require the collaboration functions to be performed flexibly.The principles above require thatflexibility not be introduced at the expense of easy specification,perfor-mance,and automation—otherwise,users and programmers would be unwilling to use the model.4.1.CouplingCoupling determines how coupled interaction occurs among the users of a collaborative application.In partic-ular,it determines which users share a change made by a user and when the change is communicated to them.Two main alternatives for coupling are WYSIWIS coupling,mentioned earlier,and WYSINWIS(What You See Is Not What I See)coupling.WYSIWIS ensures that any change made by a user is communicated immediately to all other users.In partic-ular,it ensures all users share the same sizes,positions,cursors,and contents of their edit windows.There are several advantages of supporting WYSIWIS coupling:First,it is the ideal coupling in meetings that require very close colla-boration.For instance,in a group demonstration of a program,the demonstrees might want WYSIWIS coupling so that they can see every action made by the demonstrator.Second,WYSIWIS is easy to understand in that each user knows what the other user is seeing.Finally,WYSIWIS can be defined in an application-independent fashion,and thus can be automatically supported by a general system such as a shared window system18,which collects input from all users and broadcasts output to them.Clients of such a system do not have to be aware that they are interactingwith multiple coupled users.However,WYSIWIS coupling has two main disadvantages.Researchers have found that it can lead to‘‘win-dow wars’’and‘‘scroll wars’’as users position windows and scrollbars at different positions17.Similarly,it can lead to‘‘view wars’’and‘‘format wars’’as they try to create different views and formats for the editable data structures. In general,it can lead to wars whenever users are forced to share changes they do not want to share.Second, WYSIWIS requires the overhead of communicating all user changes to all of the other users,which is inefficient,spe-cially when the users do not wish to share some of these changes.WYSINWIS does not have these disadvantages but does not have any of the advantages of WYSIWIS either. What is necessary,then,is a coupling model that allows the coupling between users to be tailored to the level of the collaboration among the users.Specifically,the design of a coupling model should be based on the following princi-ples:d Need to tell:Local editing changes sent to remote users should contain no more than the information that thelocal users wants to tell the remote users.Otherwise,the coupling is not secure and remote users may take actions based on information that was not meant for them.This principle is in the spirit of the‘‘need to know’’or‘‘least privilege’’principle in access control mentioned later.d Need to learn:Local editing changes sent to remote users should contain no more than the information that theremote users want to learn about.Otherwise,they get information overload.Moreover,the information received sometimes destroys some of receiver’s information,and therefore getting unwanted information can cause undesired information destruction.d Need to collaborate:Local editing changes sent to remote users should contain no less than the intersection ofthe information the local and remote users want to tell and know,respectively.Otherwise,some collaboration that the participants are interested in may not be facilitated.We can summarize these three principles by the following sharing principle:Sharing principle:Local editing changes sent to remote users should contain the intersection of the information the local and remote users want to tell and know,respectively.The principles above address which changes made by a user should be communicated to other users.The fol-lowing analogous principles address when these changes should be communicated:d Time to tell:Local changes should not be seen by remote users sooner than the time the local users wants themseen.Otherwise,the coupling is not secure and the remote user may take actions earlier than wanted.d Time to learn:Local changes should not be seen by remote users sooner than the time the remote users wantsto see them.Otherwise,they get information overload and premature destruction of local editing state.d Time to collaborate:Local changes should not be seen by remote users later than the later of the times whenthe remote and local users wants to tell/know about the contained information.Otherwise,some possible col-laboration will be unnecessarily delayed.These three principles are summarized by the following principle:d Timing principle:Local changes should be seen by remote users at the later of the times the remote and localusers wants to tell/know about the contained information.As designers of coupling models,we do not know what particular users would like communicated and when they would like the communication to occur.So one approach to meet these principles is to require them to manually define the desired coupling,but this approach violates the specification principle.Another extreme approach is to define a single rigid coupling,which is easy to specify but in several situations may be not beflexible enough.What we need is a set of concrete requirements that,based on collaboration scenarios,describe the kind offlexibility users would want.We give below an initial set offlexibility requirements:d Data independence:It should be possible for users to couple different data structures differently.Dataindependence allows users to collaborate differently on different data structures.In particular,it allows them to create both private and public data structures.For instance,it allows a group of users to create a shared list of procedures but private comments on these procedures.d Property independence:Users should be able to determine which properties of an editable data structure areshared among them.In particular,they should have the choice of determining if the viewing and formatting properties of the data structure are shared.For instance,users of a multiuser debugger may wish to display the same image of a single shared state on all workstations so that each of them can see the cause-effect relation-ships,while users of a multiuser program editor may wish to see different views of the program.d Asymmetric coupling:It should be possible for a user to share certain kinds of changes with another userwithout requiring the latter to share the same kinds of changes with the former.This requirement would allow for instance,managers to observe the work of employees but not vice versa.d Sender and receiver control:Both the local and remote user should be able to determine the content and timingof the information communicated from the former to the latter—a direct consequence of the need to tell and need to know principles.d User independence:It should be possible for a user to be coupled differently with different users since differentusers may wish to collaborate at different levels.For instance,a programming-language tutor interacting witha multiuser program editor may wish to see raw values input by beginning students;syntactically correctvalues input by intermediate students,who may not need help with the syntax of the programming language;and semantically correct values input by advanced students,who may not need help with the semantics of the language.d Dynamic coupling:It should be possible for the coupling among users to be changed dynamically.Dynamiccoupling is useful since users may want to couple at different levels during different phases of the collabora-tion.For instance,during the‘‘outline phase’’of a requirements document,users interacting with a multiuser document editor may wish to see a change as soon as it is made since they would be collaborating closely on defining the outline of the document;during the‘‘writing phase’’,they may wish to see a change only after it has been committed since they would be working on separate tasks;andfinally,during the‘‘integrationphase’’,they may wish to again see a change as soon as it is made.It also allows the coupling level to be adapted to support minimum performance levels.The response time of multiuser programs depends on the kind of coupling among its users—decreasing the level of coupling decreases the number of notification events generated and thus also decreases the response time of the program.This phenomenon can be used to dynamically‘‘tune’’the coupling of a multiuser program based on the maximum response time acceptable to its users.For instance,parts of the design of a software module created by a user of a multiuser program edi-tor can be shared with other users as soon as they are created or after the design is completed,depending on the maximum response time acceptable to the users of the editor.d Recognizing dependencies:The requirements above indicate the kind of independences a generic couplingmodel should support.However,in specific situations,not all of these independences are relevant.For instance,in some situations,listeners may be willing to receive any information sent by senders of the infor-mation.When such dependencies exist,the coupling model should not force the users to enter,duplicate, redundant information—a direct consequence of the specification principle.For instance,in some situations, listeners may be willing to receive any information sent by senders of the information whenever the informa-tion is made available to them.In these situations,the model should not require the listeners to enumerate the the information they are willing to receive and when they are willing to receive it.This information should be automatically derived from the specifications made by the senders.Similarly,the model should allow specifications to be made for groups of data,properties,and users.Thus,a generic collaboration model must give users greatflexibility in choosing the nature of the coupling while also meeting the generic principles of easy specification,performance,and automation.4.2.Concurrency ControlConcurrency control prevents concurrent,possibly distributed,inconsistent changes to the editable data struc-tures of a collaborative application.It is similar to access control in that it may control access to data structures.The difference is that access control prevents unauthorized changes while concurrency control prevents inconsistent (authorized)changes.There are two main principles a concurrency model must follow in addition to the function-independent princi-ples of specification,grouping,automation,and performance:d Consistency:It must disallow inconsistent concurrent interaction.Otherwise,users are forced to manuallydetect and resolve inconsistencies.d Concurrency:It must allow consistent concurrent interaction.Otherwise,users are forced to wait unneces-sarily.Different systems put different emphasis on these principles.For instance,classical database systems emphasize the consistency principle by supporting serializable transactions19.The serializable model ensures that systems support only those concurrent transaction schedules that are equivalent to serial execution of the transactions.However,in several emerging applications,it is too conservative in that it precludes concurrent schedules that satisfy application-specific consistency requirements20.Groupware systems,on the other hand,emphasize the concurrency and perfor-mance principles.They often take the approach of not supporting any concurrency control17.In traditional database applications,it is difficult to imagine a scenario that does not require concurrency control,but in collaborative applica-tions,there are situations in which no control is acceptable.If the number of collaborators is small and each user can instantly see changes made by other users to shared objects,each collaborator can be completely aware of the poten-tially conflicting actions of other users,and thus social protocol can prevent inconsistent changes.Experience of researchers has shown that under these two conditions few collisions occur2,17.In these circumstances,it is more desirable to use the computing resources to provide real-time communication of users’changes than to check for inconsistent concurrent changes.Thus,this approach supports the concurrency and performance principles by com-pletely sacrificing the consistency principle.If either the number of collaborators is large or the coupling is not WYSIWIS,it is useful to provide system support for ensuring consistent interaction.As with coupling,the concurrency control model must allow tailoring of the concurrency control scheme.We have identified the following set offlexibility requirements that define the kind of tailoring that should be provided:d Isolation:Transactions should be allowed to make a set of changes in isolation before allowing others to viewthem21.While the classical database systems support this requirement,few groupware systems do so.d Sharing of partial results:Transactions should be able to share‘‘partial results’’with selected sets of transac-tions,called their domains,before they share‘‘final results’’with the set of all transactions22.This require-ment is not supported by classical database systems and has been identified in the context of software engineer-ing to allow,for example,a team of programmers to share intermediate versions of a module before they com-mit thefinal version to the testing team.d Hierarchy of partial results:A hierarchy of partial results,each with its domain,should be supported to cap-ture the notion that some partial results are‘‘morefinal’’than others.For instance,it should be possible for the team of programmers to share their changes with the testers before they share them with the customers.d Flexible inconsistency detection time:An important issue in concurrency control is inconsistency detectiontime.Should the optimistic approach be used to detect inconsistencies at commit time or the pessimistic, locking-based approach be used to detect them at access time?Optimistic concurrency control has two main advantages:First,it does not lock out users from doing their work.This is important when the transactions made by users are long,since when such transactions lock data,they may cause other concurrent transactions to wait for an unacceptable time.In several collaborative situations such as group software development and writing,transactions typically span several days.Second,optimistic concurrency control does not require incremental consistency checking,thereby improving the interactive response.Its main disadvantage is that it may require users to(i)abort inconsistent changes detected at commit time,thereby losing possibly several days of work,or(ii)merge their changes,which in general is labour-intensive,even though it can be automated in some cases23.In summary,pessimistic concurrency control is desirable when inconsistent, difficult to merge changes are frequently made and optimistic concurrency control is desirable in other。
