社会信息化水平测度模型及其应用_陈昆玉
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云南行政学院学报2021年第6期
·43·地方政府数据开放平台服务质量评价研究*——基于群AHP-熵权法组合权重的TOPSIS实证分析阮霁阳1,2(1.复旦大学 国际关系与公共事务学院,上海 杨浦 200433; 2.云南中医药大学 人文与管理学院,云南 昆明 650500)
摘 要:地方政府数据开放平台充分、优质、高效的数据开放服务,对推进科学治理、协同治理、高效治理等方面的作用日益凸显。建构科学实用的平台服务质量评价指标体系,既是促进服务质量提升的“指挥棒”,也是规范地方政府数据开放平台建设的关键环节。本文在SERVOUAL理论模型的基础上构建了一个中国地方政府数据开放服务质量评价指标体系,选取更加严谨的群AHP-熵权组合赋值法进行权重判断,结合TOPSIS法对10个具有代表性的省级地方政府数据开放平台进行实证研究。结果表明,功能性与可靠性成为影响地方政府数据开放平台的关键因素,10个省级地方政府数据开放平台服务质量存在较为明显的差距。推进省级平台平衡协调发展,重视以功能性、可靠性为主的平台优化建设,是不断提高地方政府数据开放平台服务质量的必然选择。关键词:数据开放平台;服务质量;群AHP-熵权法;TOPSIS;评价指标中图分类号:D63 文献标识码:A 文章编号:1671-0681(06)-043-010作者简介:阮霁阳,复旦大学国际关系与公共事务学院博士研究生,云南中医药大学人文与管理学院讲师,主要研究方向为公共政策、数字治理。
一、文献综述与问题的提出大数据时代,数字政府治理成为实现国家治理体系与治理能力现代化目标的关键举措,数字政府治理的关键是发挥数字赋能的效用,政府数据开放进一步释放政府数据的社会价值与经济价值,搭建了公众和政府信息沟通的重要桥梁,是数字赋能的重要体现。自2012年我国首个政府数据开放平台——“上海市政府数据服务网”正式上线运行以来,截至2020年10月已有142个省级、副省级和地级政府上线了数据开放平台,与2019年下半年相比,新增了4个省级平台和36个地级(含副省级)平台,平台总数增长近4成a。
ResearchCybersecurity—ReviewSocial Influence Analysis:Models,Methods,andEvaluationKan Li ⇑,Lin Zhang,Heyan HuangSchool of Computer Science and Technology,Beijing Institute of Technology,Beijing 100081,Chinaa r t i c l e i n f o Article history:Received 10December 2017Revised 5January 2018Accepted 8January 2018Available online 16February 2018Keywords:Social influence analysis Online social networksSocial influence analysis models Influence evaluationa b s t r a c tSocial influence analysis (SIA)is a vast research field that has attracted research interest in many areas.In this paper,we present a survey of representative and state-of-the-art work in models,methods,and eval-uation aspects related to SIA.We divide SIA models into two types:microscopic and macroscopic models.Microscopic models consider human interactions and the structure of the influence process,whereas macroscopic models consider the same transmission probability and identical influential power for all users.We analyze social influence methods including influence maximization,influence minimization,flow of influence,and individual influence.In social influence evaluation,influence evaluation metrics are introduced and social influence evaluation models are then analyzed.The objectives of this paper are to provide a comprehensive analysis,aid in understanding social behaviors,provide a theoretical basis for influencing public opinion,and unveil future research directions and potential applications.Ó 2018 THE AUTHORS. Published by Elsevier LTD on behalf of Chinese Academy of Engineering and Higher Education Press Limited Company. This is an open access article under the CC BY-NC-ND license1.IntroductionOnline social networks such as Weibo,Twitter,and Facebook provide valuable platforms for information diffusion among their users.During this process,social influence occurs when a person’s opinions,emotions,or behaviors are affected by other people [1].Thus,changes occur in an individual’s attitudes,thoughts,feelings,or behaviors as a result of interaction with other people or groups.Social influence analysis (SIA)is becoming an impor-tant research field in social networks.SIA mainly studies how to model the influence diffusion process in networks,and how to propose an efficient method to identify a group of target nodes in a network [2].Studied questions include:Who influences whom;who is influenced;who are the most influential users,and so forth.SIA has important social significance and has been applied in many fields.Viral marketing [3–10],online recommen-dation [11],healthcare communities [12–14],expert finding [15–17],rumor spreading [18],and other applications all depend on the social influence effect [19–21].Analyzing social influence can help us to understand peoples’social behaviors,provide the-oretical support for making public decisions and influencing pub-lic opinion,and promote exchanges and dissemination of various activities [22].This paper provides a comprehensive view of SIA from the aspects of models,methods,and evaluation.To this end,we iden-tify the strengths and weaknesses of existing models and methods,as well as those of the evaluation of social influence.First,we review existing social influence models.Next,we summarize social influence methods.Finally,we analyze the evaluation of social influence.The rest of this paper is organized as follows.In Section 2,we discuss SIA models.In Section 3,we analyze SIA methods,includ-ing influence maximization,influence minimization,flow of influ-ence,and individual influence.We then detail social influence evaluation in Section 4.Finally,we summarize the reviewed mod-els and methods of social influence,and discuss open questions.2.Social influence analysis modelsSIA models have been widely studied in the literature.We clas-sify these models into two categories:microscopic and macro-scopic models.2.1.Microscopic modelsMicroscopic models focus on the role of human interactions,and examine the structure of the influence process.The two fre-quently used influence analysis models in this category are the independent cascade (IC)[23–25]and linear threshold (LT)⇑Corresponding author.E-mail address:likan@ (K.Li).Engineering 4(2018)40–46Contents lists available at ScienceDirectEngineering[23,26]models.Since Kempe et al.[23]used these two models,they are still mainly used to assess social influence diffusion.2.1.1.The IC and LT modelsThe IC model.In a social network G ¼ðV ;E Þwith a seed set S (S #V ),where V is the set of nodes and E is the set of edges,and S t (S t #V )is the set of nodes that are activated at step t (t P 0).At step t þ1,every node v i 2S t can activate its out-neighbors v j 2V n [06i 6t S i with an independent probability P ij .The process ends when no node can be activated.Note that a node has only one chance to activate its out-neighbors after it has been activated,and the node remains an activated node after it is activated.The LT model.In a social network G ¼ðV ;E Þ,the sum of the influ-ence weights of all the neighbors of node v i meets Pv j 2N gact iw ij 61,where w ij is the influence weight between node v i and its neighbor node v j ,and N g act iis the set of its neighbor nodes activated by nodev i .Node v i randomly selects its own threshold h i ,uniformly chosenfrom 0to 1.Only when the sum of the influence weights of its neigh-bor nodes exceeds this threshold will v i be activated.2.1.2.VariationsFor both the IC and LT models,it is usually necessary to run the Monte Carlo simulation in order to estimate a node’s influence for a sufficient time period.However,this is time-consuming and unsuitable for large-scale social networks.Many researchers have proposed methods to improve the IC and LT models.Here,we divide these improvements into four categories:variations of the IC model,variations of the LT model,variations of both the IC and LT models,and models that differ from the IC or LT models and their variations.We only list representative works in this paper.(1)Variations of the IC model.Some researchers have consid-ered time delay and time-critical constraints for influence diffu-sion.Chen et al.[27]extended the IC model and proposed an IC model with meeting events (IC-M model).In the IC-M model,the activated node has the probability to meet the inactive -pared with the general IC model,the calculation results from this model are closer to the actual situation,although the calculation of time consumption is slightly above that of the IC model.Feng et al.[28]incorporated novelty decay into the IC model.Based on previous studies,they found that repeated exposures have diminishing influence on users.Therefore,they developed a prop-agation path-based algorithm to assess the influence spread of seed nodes.There are two values on each edge of a social network:influence probability and expected influence delay time.Mohamadi-Baghmolaei et al.[29]considered important time and trust factors,and proposed the trust-based latency-aware indepen-dent cascade (TLIC)model.This is the first time trust has been studied in a classic IC model.In the TLIC model,a node can change its state (i.e.,as active or inactive)with different probabilities for a trusted neighbor node than for a distrusted neighbor.Budak et al.[30]introduced the multi-campaign IC model,which models the diffusion of two cascades evolving simultaneously.They studied the notion of competing campaigns,in which the good campaign counteracts the effect of a bad campaign in a social network.(2)Variations of the LT model.Liu et al.[31]considered the containment of competitive influence diffusion in social networks,and extended the LT model to construct the diffusion-containment (D-C)model.The traditional LT model is not applicable to that a situation concerns both the diffusion and the containment of the influence.In the D-C model,the state of a node is described by the activation probability;each node is only influenced by a neigh-bor with a higher probability,and the sum of the probabilities of possible node states is not greater than 1.Borodin et al.[32]analyzed the competitive influence diffusion of different models based on the LT model.(3)Variations of both the IC and LT models.Mohammadi et al.[33]considered the time delay and proposed two diffusion models:the delayed independent cascade (DIC)model and the delayed lin-ear threshold (DLT)model.In these two models,nodes have three states:active,inactive,and latent active.To pass from an inactive state to an active state,a node must pass through the middle pro-cess of being in a latent active pared with the traditional IC and LT models,the effect of influence diffusion in this model is better.However,because more than one state is possible,the cal-culation complexity is relatively high.In the IC and LT models,information diffusion is treated as a series of node state changes that occur in a synchronous way.However,the actual diffusion takes place in an asynchronous way,and the time stamps of the observed data are not evenly spaced out.Some models relax the synchronicity assumption of traditional IC and LT models and extend these two models to make the state change asyn-chronously.Saito et al.[34]proposed the asynchronous exten-sions:asynchronous IC (AsIC)and asynchronous LT (AsLT)models.Their learning algorithm can estimate the influence degrees of nodes in a network from relatively few information dif-fusion results,which avoids the overfitting problem.Guille and Hacid [35]also presented an asynchronous model—time-based AsIC model—to model the diffusion process.Other studies [30,32,36–44]have improved the classical models in specific direc-tions.Fan et al.[38]introduced two models:the opportunistic one-activate-one (OPOAO)model,in which each person can only com-municate with another person simultaneously;and the determin-istic one-activate-many (DOAM)model,which has a mechanism that is similar to an information broadcast procedure.For the OPOAO model,they used the classical greedy algorithm to produce a (1À1=e)approximation ratio;for the DOAM model,they pro-posed a set cover-based greedy (SCBG)algorithm to achieve an O ðln n Þ(n is the number of vertices)factor solution.The transmis-sion probabilities in these two models are the same for all users.Galam [45]proposed a model that investigates opinion dynamics,followed by Lee et al.[39],who proposed a new scheme to improve Galam’s model.Nevertheless,these models are confined to word-of-mouth information-exchanging process.(4)Models that differ from the IC or LT models and their variations.Some models are different from the IC or LT models and their variations,and have solved information influence diffu-sion from a new point of view.Lin et al.[46]proposed a data-driven model to maximize the expected influence in the long run using meta-learning concepts.However,this model needs large amounts of data,and the accuracy of its results requires fur-ther improvement.Golnari et al.[47]proposed a heat conduction (HC)model.It considers a non-progressive propagation process,and is completely different from the previous IC or LT models,which only consider the progressive propagation process.In the HC model,the influence cascade is initiated from a set of seeds and arbitrary values for other nodes.Wang et al.[48]studied emotion influence in large-scale image social networks,and pro-posed an emotion influence model.They designed a factor graph model to infer emotion influence from images in social networks.Gao [49]proposed a read-write (RW)model to describe the detailed processes of opinion forming,influence,and diffusion.However,there are three main issues that this model needs to consider further:the many parameters of the model that must be inferred,the proper collection of datasets about opinion influ-ence and diffusion,and the evaluation metrics that are suitable for this task.Whether a classical IC or LT model or a new model,the ultimate goal for a model of social influence is to achieve faster computing speed and more accurate results,while using less memory.K.Li et al./Engineering 4(2018)40–4641However,these microscopic models are lacking in some major details.Firstly,because of the difference in characteristics (i.e.,educational background and individual consciousness),differ-ent people identify with the same information to different degrees. Secondly,different individuals have different capabilities to influ-ence other users;also,spreaders with different degrees of author-ity have different impacts on their neighbors and on society. Thirdly,the probability that an individual will transmit a piece of information to others is not constant,and should depend on the individual’s attraction to the information.Moreover,these models use a binary variable to record whether an individual becomes infected.In addition,they assume that once an individual is infected,the individual never changes its state;however,this assumption does not reflect the realistic smoothness of the transi-tion of individuals from one state to another.2.2.Macroscopic modelsMacroscopic models consider all users to have the same attrac-tion to information,the same transmission probability,and identi-cal influential power.However,since macroscopic models do not take individuals into account,the accuracy of these models’results is lower.To improve such models,therefore,the differences between individuals should be considered.Macroscopic models divide nodes into different classes(i.e.,states)and focus on the state evolution of the nodes in each class.The percentage of nodes in each class is expressed by simple differential equations.Epi-demic models are the most common models that are used to study social influence from a macroscopic perspective.These models were mainly developed to model epidemiological processes.How-ever,they neglect the topological characteristics of social net-works.The percentage of nodes in each class is computed by mean-field rate equations,which are too simple to depict such a complex evolution accurately.Daley and Kendall[50]analyzed the similarity between the diffusion of an infectious disease and the dissemination of a piece of information,and proposed the clas-sic Daley–Kendall model.Since then,researchers have improved these epidemic models in general to overcome their weaknesses. Refs.[50–53]consider the topological characteristics of underlying networks in their methods.However,these scholars have ignored the impact of human behaviors in the influence diffusion process.Researchers have recently begun to consider the role of human behaviors and different mechanisms during information influence diffusion[54–60].Zhao et al.[59,60]proposed the susceptible–in fected–hibernator–removed model as an extension from the classi-cal susceptible–infected–removed(SIR)model in order to incorpo-rate the forgetting and remembering mechanism;they investigated this problem in homogeneous and inhomogeneous networks.Wang et al.[54]proposed a variation of the rumor-diffusion model in online social networks that considers negative or positive social reinforcements in the acceptant probability model.They analyzed how social reinforcement affects the spread-ing rate.Wang et al.[55]proposed an SIR model by introducing the trust mechanism between nodes.This mechanism can reduce the ultimate rumor size and the velocity of rumor diffusion.Xia et al.[56]presented a modified susceptible–exposed–infected–removed (SEIR)model to discuss the impact of the hesitating mechanism on the rumor-spreading model.They took into account the attractive-ness and fuzziness of the contents of rumors,and concluded that the more clarity a rumor has,the smaller its effects will be.Su et al.[57]proposed the microblog-susceptible–infected–removed model for information diffusion by explicitly considering users’incomplete reading behavior.In Ref.[58],motivated by the work in Refs.[56,57],Liu et al.extended the model in Ref.[56]and pro-posed a new SEIR model on heterogeneous networks in order to study the diffusion dynamics in a microblog.3.Social influence analysis methodsSIA methods are used to solve the sub-problems of social net-work influence analysis,such as influence maximization,influence minimization,flow of influence,and individual influence.All these problems involve influence diffusion,so the same influence model can apply to all of them in some cases.However,the ultimate goal of using the model is different for each problem.3.1.Influence maximizationInfluence maximization requiresfinding the most influential group of members in social networks.Kempe et al.[23]formulated this problem.Given a directed graph with users as nodes,edge weights that reflect the influence between users,and a budget/ threshold number k,the purpose of influence maximization is to find k nodes in a social network,so that the expected spread of the influence can be maximized by activating these nodes.This is a discrete optimization problem that is non-deterministic polynomial-time(NP)-hard for both the IC and LT models.Influ-ence maximization is the most widely studied problem in SIA.Les-kovec et al.[10]and Rogers[20]studied this problem as an algorithmic problem,and proposed some probabilistic methods. Influence maximization must achieve fast calculation,high accu-racy,and low storage capacity.Most of the algorithms that con-sider the differences between individuals are based on greedy algorithms or heuristic algorithms.3.1.1.Greedy algorithmsGreedy algorithms‘‘greedily”select the active node with the maximum marginal gain toward the existing seeds in each itera-tion.The study of greedy algorithms is based on the hill-climbing greedy algorithm,in which each choice can provide the greatest impact value of the node using the local optimal solution to approximate the global optimal solution.The advantage of this algorithm is that the accuracy is relatively high,reaching (1À1=eÀe)for any e>0.However,the algorithm has high com-plexity and high execution time,so the efficiency is relatively poor. Kempe et al.[23]were thefirst to establish the influence of the maximum refinement as a discrete optimization problem,and pro-posed a greedy climbing approximation algorithm.Leskovec et al.[61]proposed a greedy optimization method,the cost-effective lazy forward(CELF)method.Chen et al.[27]put forward new greedy algorithms,the NewGreedy and MixGreedy methods.Zhou et al.[62]proposed the upper bound-based lazy forward(UBLF) algorithm to discover top-k influential nodes.They established new upper bounds in order to significantly reduce the number of Monte Carlo simulations in greedy algorithms,especially at the ini-tial step.Some of the algorithms that are used to study the differ-ences between individuals are based on these greedy algorithms.3.1.2.Heuristic algorithmsDue to the high computational complexity of greedy algorithms, many excellent heuristic algorithms have been proposed to reduce the solution-solving time and pursue higher algorithm efficiency. These heuristic algorithms iteratively select nodes based on a specific heuristic,such as degree or PageRank,rather than comput-ing the marginal gain of the nodes in each iteration.Their draw-back is that the accuracy is relatively low.The most basic heuristic algorithms are the Random,Degree,and Centrality heuristic algorithms proposed by Kempe et al.[23].Based on the degree of the heuristic algorithm,Chen et al.[41]proposed a heuristic algorithm for the IC model:DegreeDiscount.They then proposed a new heuristic algorithm,prefix excluding maximum influence arborescence(PMIA)[63].For the LT model,Chen et al.42K.Li et al./Engineering4(2018)40–46[63]proposed local directed acyclic graph(LDAG)heuristic algo-rithm.Of course,other heuristic algorithms are also based on these heuristic algorithms,such as SIMPATH[64]and IRIE[65].Borgs et al.[66]made a theoretical breakthrough and presented a quasi-linear time algorithm for influence maximization under the IC model.Tang et al.[67]proposed a two-phase influence maximiza-tion(TIM)algorithm for influence maximization.The expected time of the algorithm is O½ðkþ‘ÞðnþmÞlog n=e2 ,and it returns a (1À1=eÀe)approximate solution with at leastð1ÀnÀ‘Þprobability.The time complexity of the abovementioned algorithms is shown in Table1[23,41,61,63–67].Here,we describe some representative studies that take into account individual differences or the user’s own attributes.Li et al.[68]considered the behavioral relationships between humans(i.e.,regular and rare behaviors)in order to simulate the effects of heterogeneous social networks to solve the influence maximization problem.They proposed two entropy-based heuris-tic algorithms to identify the communicators in the network,and then maximized the impact of the propagation.Although the entropy-based heuristic performance is better than those of Degree [23]and DegreeDiscount[41],this method is still based on heuris-tic ideas,so its accuracy is inadequate.Subbian et al.[69]proposed the individual social value:Existing influence maximization algo-rithms cannot model individual social value,which is usually the real motivation for nodes to connect to each other.Subbian et al.[69]used the concept of social capital to propose a framework in which the social value of the network is calculated by the number of bindings and bridging connections.The performance of the algo-rithm is better than that of PMIA[63],PageRank,and the weighted degree method.Li et al.[70]proposed a conformity-aware cascade (C2)model and a conformity-aware greedy algorithm to solve the influence maximization problem.This algorithm works well when applied to the distributed platform.However,because it is based on the greedy algorithm and considers the conformity-aware cal-culation,the complexity of the calculation still requires improve-ment.Lee and Chung[71]formulated the influence maximization problem as a query processing problem for distinguishing specific users from others.Since influence maximization query processing is NP-hard,and since solving the objective function is also NP-hard,they focused on how to approximate optimal seeds effi-ciently.Node features are always overlooked when estimating the impact of different users.Deng et al.[72]addressed influence maximization while considering this factor.They presented three quantitative measures to respectively evaluate node features:user activity,user sensitivity,and user affinity.They combined node features into users’static effects,and then used the continuous exponential decay function to convert the strength of a user’s dynamic influence between two adjacent users.They also pro-posed the credit distribution with node features(CD-NF)model, which redefines the credit,and designed the greedy algorithm with node features(GNF)based on the CD-NF model.When considering a certain class or influence maximization,the individual’s attributes will have a great impact on the results; therefore,individual differences or the user’s attributes need to be taken into account.From the descriptions above of the studies on individual differences,it is clear that most studies are based on the greedy algorithm in order to improve the accuracy.How-ever,heuristic algorithms will be improved by a pursuit of high efficiency and low complexity,because the greedy algorithm is computationally complex.In order to reduce the running time,a considerable amount of work will be carried out on a distributed platform.Due to the individual differences,the computational complexity will be further increased compared with the original. So,for the time being,it is necessary to improve the complexity of the calculation and the accuracy of the results.3.2.Influence minimizationAssuming that the negative information propagates in a net-work G¼ðV;EÞwith the initially infected node set S#V,the goal of influence minimization is to minimize the number offinal infected nodes by blocking k nodes(or vertices)of the set D#V, where k((|V|)is a given constant.It can be expressed as the fol-lowing optimization problem:Düarg minD#V;j D j6krðS V n DjÞð1Þwhere rðS V n DjÞdenotes the influence of set S when nodes in the set D are blocked.From this notion[73],we know that influence minimization is a dual problem of influence maximization.Influence minimization mainly used to curb rumors,monitor public opinion,and so on. Yao et al.[73]proposed a method to minimize adverse effects in the network by preventing a limited number of nodes from the perspective of the topic model.When rumors and other adverse events occur in social networks and some users are already infected,the purpose of this model is to minimize the number of final infected users.Wang et al.[74]proposed a dynamic rumor influence minimization model with user experience.This model minimizes the influence of rumors(i.e.,the number of users who accept and send rumors)by preventing part of the nodes from acti-vating.Groeber et al.[75]designed a general framework of social influence inspired by the social psychological concept of cognitive dissonance,in which individuals minimize the preconditions for disharmony arising from disagreements with neighbors in a given social network.Chang et al.[76]explored thefirst solution to esti-mate the probability of successfully bounding the infected count below the out-of-control threshold;this can be logically mapped to outbreak risk,and can allow authorities to adaptively adjust the intervention cost to meet necessary risk control.They then pro-posed an influence minimization model to effectively prevent the proliferation of epidemic-prone diseases on the network.3.3.Flow of influenceWhen information spreads,it is accompanied by influenceflow [77].In recent years,theflow of influence methods has been stud-ied by many researchers.Subbian et al.[78]proposed aflowTable1The time complexity of different algorithms.Algorithm Time complexityHill-climbing greedy[23]OðknRmÞCELF[61]OðknRmÞNewGreedyIC[41]OðkRmÞNewGreedyWC[41]OðkRTmÞMixGreedyIC[41]OðkRmÞMixGreedyWC[41]OðkRTmÞDegreeDiscountIC[41]Oðk log nþmÞPMIA[63]O½nt i hþkn o h n i hðn i hþlog nÞLDAG[63]Oð‘vþn log‘vÞSIMPATH[64]OðkmnÞIRIE[65]OðkmnÞQuasilinear time algorithm[66]O½k eÀ2ðmþnÞlog nTIM[67]O½ðkþ‘ÞðmþnÞlog n=e2n:number of vertices in G;m:number of edges in G;k:number of seeds to beselected;R:number of rounds of simulations;T:number of iterations;t i h,n o h,n i h:constants decided by h;h:the influence threshold;n i h¼max v2V fj MIIAðv;hÞjg;n o h¼max v2V fj MIOAðv;hÞjg;MIIAðv;hÞ=MIOAðv;hÞ:the maximum influence inarborescence/out arborescence of a node v;t i h:the maximum running time tocompute MIIAðv;hÞ;‘:number of communities in the network;e:any constantlarger than0;‘v:the volume of LDAGðv;hÞ.K.Li et al./Engineering4(2018)40–4643pattern mining approach with the condition of specificflow valid-ity constraints.Kutzkov et al.[79]proposed a streaming method called STRIP to compute the influence strength along each link of a social network.Teng et al.[80]examined real-world information flows in various platforms,including the American Physical Soci-ety,Facebook,Twitter,and LiveJournal,and then leveraged the behavioral patterns of users to construct virtual information influ-ence diffusion processes.Chintakunta and Gentimis[81]discussed the relationships between the topological structures of social net-works and the informationflows within them.However,unlike microblogging platforms,most social networks cannot provide suf-ficient context to mine theflow pattern.3.4.Individual influenceIndividual influence is a relatively microscopic assessment that models the influence of a user on other users or on the whole social network.Chintakunta and Gentimis[81]proposed a method called SoCap tofind influencers in a social network.They modeled influ-encerfinding in a social network as a value-allocation problem,in which the allocated value represents the individual social capital. Subbian et al.[82]proposed an approach to identify influential agents in open multi-agent systems using the matrix factorization method to measure the influence of nodes in a network.Liu et al.[83]presented the trust-oriented social influence(TOSI)method, which considers social contexts(i.e.,social relationships and social trust between participants)and preferences in order to assess indi-vidual influence.The TOSI method greatly outperforms SoCap in terms of effectiveness,efficiency,and robustness.Deng et al.[84] incorporated the time-critical aspect and the characteristics of the nodes when evaluating the influence of different users.The results showed that their approach is efficient and reasonable for identifying seed nodes,and its prediction of influence spread is more accurate than that of the original method,which disregards node features in the diffusion process.In conclusion,considering more comprehensive user character-istics and user interaction information results in higher result accuracy.4.Social influence evaluation4.1.Influence evaluation metricsRunning time is a very intuitive measure of model efficiency that is easy to calculate.In general,under the same conditions,the faster a model runs,the better it is.However,the traditional greedy algo-rithm calculates the range of influence spreading for a given node set by a large number of repeated Monte Carlo simulations,result-ing in a considerable running time.Especially in the face of current large-scale social networks,the existing algorithms cannot meet the application requirements for efficiency.Therefore,running time is an important measure of social influence evaluation.Since the influence-spreading problem is NP-hard,it is difficult to obtain an optimal solution of the objective function.Most of the existing algorithms rely on monotonicity and submodularity of the function to achieve(1À1=e)approximation[23].However, attempts to achieve a higher approximation ratio have never stopped.Zhu et al.[85]proposed semidefinite-based algorithms in their model considering influence transitivity and limiting prop-agation distance.Another metric is the number of Monte Carlo calls.Because there is no way to obtain an optimal solution,a Monte Carlo sim-ulation is usually used to estimate the real value.Existing greedy-based algorithms demand heavy Monte Carlo simulations of the spread functions for each node at the initial step,greatly reducing the efficiency of the models.The UBLF algorithm proposed by Zhou et al.[62]can reduce the number of Monte Carlo simulations of CELF method by more than95%,and achieved a speedup of2–10 times when the seed set is small.The expected spread indicates the number of nodes that the seed set can ultimately affect—and the larger the better.There are many applications in real-life scenarios where the influence spread needs to be maximized as much as possible.Typical exam-ples of such applications are marketing and advertising.In both applications,thefinal expected spread represents the benefits of product promotion or the profitability of product.Therefore, exploring high expected spread algorithms is an important prob-lem for SIA.Robustness refers to the characteristics of a certain parameter perturbation(i.e.,structure and size)that is used to maintain some other performances.Both Jung et al.[65]and Liu et al.[83]men-tioned robustness in their algorithms.The IRIE algorithm proposed by Jung et al.[65]is more robust and stable in terms of running time and memory usage across various density networks and cas-cades of different sizes.The experimental results showed that the IRIE algorithm runs two orders of magnitude faster than existing methods such as PMIA[63]on a large-scale network,and only uses part of the memory.The TOSI evaluation method proposed by Liu et al.[83]shows superior performance in terms of robustness over the state-of-the-art SoCap[81].Scalability refers to the ability to continuously expand or enhance the functionality of the system with minimal impact on existing systems.In social networks,scalability usually refers to the ability to expand from a small-scale network to a large-scale network.It is a common indicator used to evaluate the quality of a model.Due to the complexity of the algorithm and the long run-ning time,the current solution algorithms only apply to small and medium-sized social networks with nodes below one million. Given today’s large-scale social networks,influence analysis algo-rithms with good scalability must be designed to deal with the challenges posed by massive social network data.4.2.Social influence evaluation modelThe evaluation of social influence is a complex process.As a subjective attribute,a social relationship has many characteristics, including dynamics,event disparity,asymmetry,transitivity,etc. In social networks,frequent user interaction and changes in the structure of the network make the evaluation of social influence more difficult.The literature contains a few studies on the social influence evaluation model.He et al.[86]designed an influence-measuring model on the theme of online complaints;based on the entropy weight model,this model monitors and analyzes the static and dynamic properties of complaint information in real time.Enterprises can use this model to manage online group com-plaints.Wang et al.[12]proposed afine-grained feature-based social influence(FBI)evaluation model,which explores the impor-tance of a user and the possibility of a user impacting others.They then designed a PageRank algorithm-based social influence adjust-ment model by identifying the influence contributions of friends. The FBI evaluation model can identify the social influences of all users with much less duplication(less than7%with the model), while having a larger influence spread with top-k influential users; it was evaluated on three datasets:HEPTH[87],DBLP[88],and ArnetMiner[89].5.Conclusions and future workIn this paper,we survey state-of-the-art research on SIA from the aspects of influence models,methods,and evaluation.We also44K.Li et al./Engineering4(2018)40–46。
• 1.第一个提出大数据概念的公司是()。
(单选题1分)得分:1分o A.脸谱公司o B.谷歌公司o C.麦肯锡公司o D.微软公司• 2.根据涂子沛先生所讲,以下说法错误的是哪项?(单选题1分)得分:1分o A.个人要把数据当做自己的遗产o B.数据垃圾对商业公司是一个挑战o C.国家要制定合适的法律来规范数据遗产继承的问题o D.中国社会不会面临数据遗产问题• 3.科学范式的发展路径:从观察到演绎分析、模型推导,到计算机分析、仿真模拟,再到()时期。
(单选题1分)得分:0分o A.数据计算o B.理论科技o C.数据科学o D.数据推导• 4.2015年,贵阳市的呼叫服务产业达到()坐席。
(单选题1分)得分:1分o A.5万o B.10万o C.3万o D.20万• 5.2015年“双11”:阿里平台每秒钟订单创建()笔。
(单选题1分)得分:1分o A.14万o B.24万o C.34万o D.4万• 6.关于大数据在社会综合治理中的作用,以下理解不正确的是(单选题1分)得分:1分o A.大数据的运用有利于走群众路线o B.大数据的运用能够加强交通管理o C.大数据的运用能够维护社会治安o D.大数据的运用能够杜绝抗生素的滥用•7.根据涂子沛先生所讲,社交媒体是在哪一年出现的?(单选题1分)得分:1分o A.1965年o B.1989年o C.2004年o D.1988年•8.()指利用计算机处理信息的技术,是现代信息技术的核心。
(单选题1分)得分:1分o A.感测技术o B.通信技术o C.计算机技术o D.微电子技术•9.医疗健康数据的基本情况不包括以下哪项?(单选题1分)得分:1分o A.个人健康管理数据o B.诊疗数据o C.公共安全数据o D.健康档案数据•10.2014年,阿里平台完成农产品销售()元。
(单选题1分)得分:1分o A.283亿o B.383亿o C.183亿o D.483亿•11.根据周琦老师所讲,以下哪项不属于数据挖掘的内容?(单选题1分)得分:1分o A.高德地图导航有躲避拥堵功能o B.建立道路拥堵概率与拥堵趋势变化模型o C.多维分析统计用户出行规律o D.补充与完善路网属性•12.根据周琦老师所讲,高德早在()就开始投入资源来做全国交通信息的采集和发布。
协同治理视角下城市韧性评估理论模型及实践研究!陈玉梅黄颖欣"摘要:城市韧性理念在城市建设和发展中的应用可以帮助降低城市面对风险和灾害时的损失,将协同治理这一社会治理的新实践方式引入城市韧性建设中,能更加系统性地推进城市的防灾减灾工作。
本文基于协同治理视角,运用文献计量法和文献归纳法对城市韧性评估的相关文献进行分析和比较,构建城市韧性评估的理论模型,包含社会、经济、制度、基础设施、社区资本和环境6个一级维度和33个二级维度。
然后结合实践以广州市为例,运用评估模型分析其城市韧性建设的实践并提出建议,在此基础上对评估模型的维度做进一步优化整合,提出6个一级维度和12个二级维度构建的城市韧性评估!基金项目:国家社科一般项目"粵港澳大湾区政府大应急协调机制下的基层社区韧性评估与优化策略研究"(编号:19BZZ070**作者筒介:陈玉,大学/应急管理学院副教授、电子高工,政务大数据开放与社会创新研究中心主任,应急管理研究中研究员,美国大学奥尔巴尼校区政府技术研究中心CTG研究员,博士,研究方向为数据开放、应急、情韧性城&,暨南大学/应急管理学院制硕士研究生$90|他险t t1机硏愛•第十二辑理论模型,希望能为新时代下中国的城市尤其是粤港澳大湾区的韧性提升、完善与发展提供借鉴,并为政府的城市治理和防灾减灾工作的绩效评估提供参考。
关键词:协同治理城市韧性广州—弓I言随着城市化进程的加快,城市在应对洪水、地震、台风和恐怖袭击等灾害时显得极度脆弱,传统的应急管理工作重心也逐渐从响应处置转变为减灾准备。
与此同时,城市韧性概念在灾害管理和城市安全上的应用也受到越来越多的重视,并被学术界和实践界广泛用于解决城市风险问题。
城市韧性概念应用的最终目的是提升一个城市抵御风险的能力和自恢复能力,而城市韧性概念的发展和应用逐渐提出了要构建多主体的社会治理体系,即在政府主导的同时,多个主体(如企业、个人和社会组织等)共同参与到城市韧性建设和发展过程中,并且引入绩效评估等公共管理的方法和手段。
社会信息化水平测度模型及其应用陈昆玉(云南大学经济学院,昆明650091)摘 要 社会信息化水平是对一个区域内社会信息化发展程度的定量描述;信息化测度方法比较流行的有
美国波拉特模型和日本的信息化指数模型,二者均存在不足。本文在日本指数模型的基础上进行了一系列改善,重构了较为科学、合理的信息化测度模型。关键词 信息化测度 波拉特模型 信息化指数模型
TheModelofSocialInformationizationMeasureandItsApplication
ChenKunyu(EconomicSchoolofYunnanUniversity,Kunming650091)
Abstract
Thesocialinformationizationdegreenumericallydescribesanarea'ssocialinformationization
situation.BothAmericanM·U·porat'smodelandJapaneseindexmodelaremorePopularthanothermeasuremethods,butbothofthemaresomeshortcomings.AnewmeasuremodeliscreatedbyimprovingJapaneseindexmodel,whichismorescientificandresonable.Keywords Informationizationmeasure M·U·poratmodel Informationizationindexmodel
* 本文为云南大学“学生科技创新,创业行动计划”资助项目研究成果。收稿日期:2000-9-21
1 社会信息化水平及其测度社会信息化是指社会信息资源开发与利用的产业化和社会化,它是现代社会经济发展中出现的一种新现象。社会信息化水平是对一个区域内社会信息化发展程度的定量描述。它能够从数量上反映一个国家或地区的信息环境、信息化现有水平、信息发展潜力和揭示社会信息化发展的一些基本规律。其主要作用至少体现在两个方面:其一,从纵向上看,它将使人们认识到信息化是人类社会发展的必然趋势,同时有助于人们了解不同历史时期的社会信息化发展程度,从而使各国能充分考虑自己的国情国力,制定适宜的信息化政策;其二,从横向上看,它便于人们通过比较研究各国社会信息化发展的不同措施和不同模式,寻找社会信息化发展的一般规律。对社会信息化水平的测度,目前国际上还没有建立一套科学、权威和系统的方法体系。其原因就在于,这种测度存在一系列困难。主要表现为: 1.1 社会信息化界线的不明确性社会信息化是一个界线不确定、不分明的范畴,这主要是由于信息本身的特点决定的。信息是一个内涵丰富、外延广阔、具有普遍联系的概念,它广泛渗透到社会生活的各个领域和各个方面,与其活动相互交叉融合,难分彼此;信息对社会发展的作用与影响往往与其他物质因素结合在一起,要从中分析出信息要素的作用份额或效力难度较大。因此,社会信息化的界定标准、表征因素和计算方法都十分难以选择。
1.2 现行经济统计指标的局限性现行的国民经济统计指标和统计方法是面向物质经济的,信息和信息活动的贡献被分散到物质经济的各产业部门和活动领域,没有独立列项分类统计。因而,在对社会信息化水平测度时必须考虑其他产业部门或经济活动的信息化情况,必须采用一定的统计处理方法获取这些数据,而这种数据的获取可能本身就存在问题。因此,科学的测度需要建立起包括信息活动在内的国民经济核算体系。
1.3 社会信息化因素贡献程度的难以衡量性衡量社会信息化水平的因素是多重的,在这些众多因素中,其对社会信息化的贡献程度是不一样的。如何来确定各因素贡献的权重大小是个十分棘手的问题。另外,随着社会的发展,信息化程度的进一步加深,衡量社会信息化水平的因素无论从构
第19卷第1期2001年1月 情 报 科 学 Vol.19,No.1January,2001成内容上还是从贡献权重上,可能都会有所变化,这种变化相应增加了社会信息化水平测度的困难。2 国外信息化水平测度模型评析国外在对社会信息化水平测度的研究中,影响较大、应用较广的有两个主要分支:一是从经济学范畴出发的以信息经济为对象的宏观计量,以此来反映社会信息化水平。代表人物是美国经济学家F·马克卢普、M·U·波拉特、M·F·鲁宾等人,其中波拉特创立的测度模型最为出名。二是从衡量社会的信息流量和信息能力等来反映社会的信息化程度,主要依据某些综合的社会统计数字来构造测度模型。其颇具典型的代表就是日本提出的信息化指数模型。 2.1 美国:波拉特模型20世纪70年代后期,波拉特在马克卢普开创的有关知识产业的理论基础上提出了该模型。其基本要点是:首先,将信息产业单列为第四产业。为了测算信息产业,定义了信息活动概念。根据信息活动的情况将国民经济信息部门划分为一级信息部门和二级信息部门。前者专指向市场提供信息产品和信息服务的企业,其产值测度可采用测度国民生产总值的一般方法。后者主要指政府或非信息企业创造的一切信息服务,以该部门的信息劳动者收入和信息设备折旧之和作为其产值。其次,把与信息的生产、流通和处理有实质性关联的职业列为信息职业。从美国442种职业中归纳出五大类属于信息职业。同时还对一些具有“复合性质”的职业采用典型调查法确定出28种“半信息职业”,以此来统计从事信息职业的人数。最后,使用信息活动产值占GNP或GDP的比重大小、信息部门就业人数占总就业人数的比重大小和信息部门就业者收入占国民收入的比重大小三项指标来衡量社会信息化水平。波拉特模型的优点在于首次从国民经济各部门中识别出信息行业,并开拓性地以定量方式反映出信息行业或信息劳动力在整个经济部门中的比重及其变化。特别是对二级信息部门的明确划分和测度更具创造性。该模型对于研究信息产业与国民经济结构及其它产业部门间的内在联系等问题具有重大意义。但该模型尚存在以下不足:它对信息活动、信息行业和信息职业等的划分尚缺乏统一的科学标准,测度中所采用的某些方法和某些数据欠合理。如二级信息部门信息劳动者创造的价值在时间和空间上都存在不小的差异,因而使测度的结果可比性受到影响。此外,该模型运算非常繁复,对统计资料的要求较高。该模型的测度值大致可用来表示“经济信息化”(它是信息产业化和产业信息化的互补共进过程)程度,并不能全面和准确地描述社会信息化水平。
2.2 日本:信息化指数模型20世纪70年代,日本学者尝试建立了一个衡量社会信息化水平的指数模型。该模型共有42项指标,同时为了便于测度,又按一定的标准将它们分解为11个分指标。其模型结构如图1:
图1测度社会信息化指数的基本思路是:把基年各项指标的指数取作100,用被测年度指标实际值比上基年指标实际值,再把这一比值乘上100%,得到被测年度的各项指标指数,然后再采用算术平均法相继求出每组指标指数的平均值和最终社会信息化指数平均值。测度过程可用公式表示如下:
A=14·∑4i=1Bi
Bi
=1Ni·∑Nij=1(
Cij
Cij(基)×100%) (i=1~4)
式中:A为社会信息化指数的总体评价值;Bi
为第一层第i个指标的评价值;Ni为影响第一层第i
个指标的第二层指标的个数;Cij为影响第一层第i
个指标的第二层第j个指标的实际值;Cij(基)为影响第一层i个指标的第二层第j个指标的基期标准值。日本的信息化指数模型侧重从与社会信息活动相关的多个方面来进行测度。其优点是该模型中所
151期 社会信息化水平测度模型及其应用需的统计资料较易获得,参数少,计算较简单,因此实用性较强。同时它将信息化发展进程的相对阶段和相对差距用量化的方式反映出来。在有较完整的时间序列数据的情况下,既能发现一些信息化过程中的结构性失衡或缺陷,又能对今后的信息化发展趋势作出预测。该方法的主要缺点是:从理论上分析,该模型显得过于简单,不够全面。在信息环境评估的完整意义上,它只反映了某几个方面的信息环境状况(主要是社会信息流量、社会信息能力等)。而信息活动的有些重要方面(如信息需求满足程度等)未能充分体现和包括在模型之中。此外,该模型采用算术平均得出综合的测度结果(信息化指数),未能适当区分出不同参数或不同因子的贡献大小,简单平均的算法其结果可能掩盖实质上的差异。同时,该测度模型是20世纪70年代提出的,时值30年后的今天,模型中的指标内容和结构已经不能全面和准确反映社会信息化水平。所以,应该考虑重新修正。 3 信息化水平测度模型的改善及其应用 通过对以上国外两种社会信息化水平测度模型的比较分析可知,日本的信息化指数模型在对社会信息化发展水平的测度分析上更具优势。但考虑到其不足之处,应该对其进行一系列相应的改善,重构社会信息化水平测度的模型。改善后的模型分为3个层次,相应有5个主要指标和16个具体指标。如图2:图2 3.1 该模型的应用方法(1)类似日本的信息化指数模型,把基年各项指标的指数取作100,用被测年度指标实际值比上基年指标实际值,再把这一比值乘上100%,得到被测年度的各项指标指数。(2)引入权重系数,对应每一层的每一指标,都有其相应的权重系数。权重系数是某一指标下同一层的各指标对该上属指标的贡献程度。权重系数的取值可采用“德尔菲法”(又称专家打分法)确定,然后采用加权平均法相继求出每组指标指数的加权平均值和最终的社会信息化指数加权平均值。(3)其测度过程可用公式表示如下:
A=∑2i=1Bi·WBi
Bi=∑Nij=1Cj·WCj
Cj=∑MjK=1(Djk
Djk(基)×100%)·WDk (i=1~
2)式中:A为社会信息化指数的总体评价值;B
i
为第一层第i个指标的评价值;WBi为第一层第i个
指标的权重值(其中:WB1+WB2=1);Ni为影响第一层第i个指标的第二层指标的个数;Cj为第二层第j个指标的评价值;WCj为第二层第j个指标的权重值(其中:WC1+WC2+WC3=1,WC4+WC
5
=1);Mj为影响第二层第j个指标的第三层指标的
个数;Djk为影响第二层第j个指标的第三层第k个指标的实际值;Djk(基)为影响第二层第j个指标的第三层第k个指标的基期标准值;WDk为第三层第k个指标的权重值(其中:WD1+WD2+WD3+WD4
=1,WD5+WD6+WD7+WD8+WD9=1,WD10=
1,WD11+WD12+WD13=1,WD14+WD15+WD16=1。
3.2 该模型的应用说明(1)物力资源指标的选择。电讯产业是信息化发展的基础,只有在电讯产业的发展得以巩固的前提下,才谈得上信息化的充分发展,而在电讯产业中,起支柱作用的是软件产业、电信产业和电子工业。因此,模型选用该三项的潜力指数作为物力资源的衡量标准。(2)对于物力资源指标各下属指标的计算。①软件产业潜力指数的计算: 被测年度软件产业相对增长速率=软件产业较上一年增加产值GDP较上一年增加值×100%