International Journal of Cooperative Information Systems

EXtensible Access Control Markup Language (XACML) is one of the standardized languages for specifying access control policies. Policies described by the XACML are used to express the security requirement in the network and information system when we study authorization access control. With the aim to improve the Policy Decision Point (PDP) evaluation performance, we put forward a Graph and Clustering-Based Framework, employing the aggregate function. First, we partition the rule set into subsets. For the single value, we select the best partition quantity based on the aggregate function. As for the interval value, we handle with the start point and the finish point, respectively, in the same way as single value. Second, the policy set is split according to the partition of rule set. In this way, not only single values, but also interval values are taken into consideration. After that, we explore the searching tree to obtain the possibly matched rules. Finally, we construct the combining tree and output the policy decision on the basis of it. The experimental results show that our approach is orders of magnitude better than the Sun PDP. A comparison in evaluation performance between the redundancy detecting and eliminating engine and the Sun PDP, as well as XEngine and SBA-XACML, is made. Experimental results show that the evaluation performance of the PDP can be prominently improved by eliminating redundancies.

In this study, we examine how the monetary rewards and competitive constraints that organizers of innovation tournaments incorporate are associated with participation. These two aspects of innovation tournaments are crucial because they represent critical design decisions that the organizers must make beforehand. We show that the reward amount is negatively associated with participation, while the presence of competitive constraints, which “make the competitive landscape less asymmetric”, is positively associated with participation. Furthermore, the study shows that competitive constraints moderate the negative association between reward amount and participation. These findings provide insights into contestant motivation as well as the interdependencies between tournament design choices.

Quality control is a critical design goal for crowdsourcing. However, when measuring the long-term quality of workers, the existing strategies do not make effective use of workers’ historical information, whereas others regard workers’ conditions as fixed values, even if they do not consider the impact of workers’ quality. This paper proposes a long-term quality perception incentive model (called QAI model) in a crowdsourcing environment with budget constraints. In this work, QAI divides the entire long-term activity cycle into multiple stages based on proportional allocation rules. Each stage treats the interaction between the requester and the worker as a reverse auction process. At each stage, a truthful, individually rational, budget feasible, quality-aware task allocation algorithm is designed. At the end of each stage, according to hidden Markov model (HMM), this paper proposes a new framework for quality prediction and parameter learning framework, which can make use of workers’ historical information efficiently. Experiments have verified the feasibility of our algorithm and showed that the proposed QAI model leads to improved results.

As a new design and manufacture paradigm, Cloud-Based Collaborative Design (CBCD) has motivated designers to outsource their product data and design computation onto the cloud service. Despite non-negligible benefits of CBCD, there are potential security threats for the outsourced product data, such as intellectual property, design intentions and private identity, which has become an interest point. This paper presents a novel secure product data exchange (PDE) in the processes of CBCD. Different from general cloud security mechanism, our method is content-based. We first show an outline of the collaborative scenario to describe the architecture of the proposed secure CBCD, in which a security mechanism is combined with the data exchange service to achieve secure PDE. Second, we present a novel grid-based geometric deformation method for the security mechanism with three processes: the original shapes of a source Computer Aided Design (CAD) model can be hidden by deforming the control grid; then the deformed grid can be exchanged to target system where a deformed target CAD model can be reconstructed; at last, the deformed target CAD model can be recovered to the original shape after recovering the deformed grid. Finally, typical CAD model tests demonstrate that our method can keep the sensitive information of source model and also maintain the same level of data exchange error.

The characteristic of multi-shop scheduling is that the processing equipment is scattered in multiple workshops in different geographical locations. To solve this problem, a multi-shop comprehensive scheduling algorithm considering migration dual-objective is proposed of migration of a single complex product in multi-shop equipment, and the workpiece is migrated from one device to another during the processing. The algorithm first uses the leaf nodes of the process tree as a set of schedulable operations; second, the pre-scheduled operation set is determined according to the long path first strategy and the short time strategy; third, the actual scheduling set of the same idle equipment is determined according to the same equipment procedure selection strategy in the workshop; finally, considering the migration time and cost of the process to be processed, a two-objective optimization strategy for process shop selection is proposed. The example results show that the algorithm in this paper consumes less time and cost during the migration process, and can obtain a relatively compromised solution of the total time and total cost of product scheduling.

The development of crowd intelligence makes the structure of social network more complex and changeable. Research on social network should be more in-depth and focus on the changes of structure. Ego-network, which represents the relationship between specific individual and the related people, is a hot issue among the research of dynamic social network. The evolution of ego-network is highly dynamic and pluralistic, it is hard to capture its evolutionary pattern over time. To help users analyze the individual characteristics and hidden patterns in multivariate ego-network, we present EgoVis, an interactive visual analysis system for exploring and analyzing complex structural relationships in dynamic network. Based on the task requirements of network evolution analysis, we propose a task taxonomy which is suitable for ego-network research and analysis, design novel visual fonts, and analyze the evolution of dynamic ego-network relations from the three dimensions: overview, subgroup, and detail-ego. Finally, the validity and practicability of EgoVis are verified on DBLP citation network dataset.

The Multi-choice machine reading comprehension, selecting the correct answer in the candidate answers, requires obtaining the interaction semantics between the given passage and the question. In this paper, we propose an end-to-end deep learning model. It employs Bi-GRU to contextually encode passages and question, and specifically models complex interactions between the given passage and the question by six kinds of attention functions, including the concatenated attention, the bilinear attention, the element-wise dot attention, minus attention and bi-directional attentions of Query2Context, Context2Query. Then, we use the multi-level attention transfer reasoning mechanism to focus on further obtaining more accurate comprehensive semantics. To demonstrate the validity of our model, we performed experiments on the large reading comprehension data set RACE. The experimental results show that our model surpasses many state-of-the-art systems on the RACE data set and has good reasoning ability.

When an earthquake occurs, disaster relief is an urgent, complex and critical mission. High on the list is communication network recovery within the disaster area. Unmanned aerial vehicles (UAVs) are often used in this regard. Some of them are used as collective repeaters to provide the required network coverage. Their timely, efficient, and collaborative deployment to specific locations is a big challenge. To meet this challenge, this paper formalizes and solves the problem of UAV deployment for signal relays via group role assignment (GRA). The minimum spanning tree algorithm is used to model a rapidly deployed optimal relay network. It can help establish the minimum number of relay points necessary to ensure communication stability. In this scenario, UAVs (agents) adopt roles as communication relays. The task of distributing UAVs to relay points can be solved quickly via the assignment process of GRA, which can solve the x-ILP problem with the help of the PuLP package of Python. Results from thousands of experimental simulations indicate that our solutions are effective, robust and practical. The process can be used to establish an optimal, efficient, and collaborative relay network using UAVs. Their rapid deployment can be a significant contribution to earthquake disaster relief.

This paper studies the flexible integrated scheduling problem, which is an extension of job-shop scheduling considering the assembly and the machining stages at the same time, with networked devices (FISND). The completion time of the entire product may be impacted by the uncertainty of the process constraint structure and flexible equipment, so we take machining structure evaluation (MSE) into account. We proposed an improved artificial bee colony algorithm considering MSE (ABC${}_{\mathrm{\text{MSE}}}$) with two new strategies: one is a dynamic perturbation step strategy and the other is double-chain similarity and migration time factor strategy to evaluate the product processing structure, and then we computed the selection probability of the followers by it. Finally, the experimental results show that ABC${}_{\mathrm{\text{MSE}}}$ has a better performance and faster convergence than the algorithm ABC, hyABC, GA. It can not only solve the flexible integrated scheduling problem with networked devices, but also yield better solutions to the typical flexible integrated scheduling problem than the flexible equipment integrated scheduling algorithm based on device-driven.

Recently, deep learning has introduced new prospects to numerous practical applications such as image recognition, robot navigation, gene engineering, language processing, and traffic sign identification. Several network models including AlexNet, VGGNet, GoogLenet and ResNet, have achieved milestone contributions while relying on massive computing resources. However, when faced with a small number of labeled examples, especially in the case of unbalanced datasets, the cumulative error and time-consuming convergence reduce their efficacy. Inspired by the convolutional output layer with a $1\times 1$ kernel, a convolutional nonlinear transfer approach with partial cooperating (CNN-COL) is proposed to address this challenge. Meanwhile, a novel method for data augmented balance can enhance the influence of small and unbalanced samples in the CNN-COL. Related experiments show that the proposed CNN-COL can effectively improve the quality of a dataset and achieve superior performance with respect to traffic sign identification based on a small and type-unbalanced dataset.

Crowdsourced software testing (CST) is an emerging trend in software testing. Companies and developers assign testing tasks through CST platforms to thousands of online testers. Currently, CST platform managers are trying to find and resolve challenges in order to reach the best CST practice. Many features have been applied by CST platforms to improve CST activities, including notification emails, online chat rooms, forums and, most importantly, a CST platform dashboard to view all testing projects and tasks; these features have enabled CST to operate efficiently. Still, CST users find it difficult to stay abreast of test project updates, maintain their motivation, and avoid frustration. This aligns with the increasing studies in the literature that call for more efficient solutions to support CST process. This research aims to support CST by searching for potential process limitations and overcoming them. In order to do so, a five-stage approach is used: first, the current process of CST is investigated through reviewing 15 CST platforms. Second, the review has resulted in identifying eight possible activities to improve CST; among them six have been selected after a survey distributed to 30 domain experts in Stage 3. In Stage 4, we have designed and implemented five process models in a web-based system that can fulfill the requirements of the six activities identified earlier. In Stage 5, we have evaluated these process models through interviews with representatives of two CST platforms and an expert tester, and through making scenario-based evaluation with 20 domain experts who used the system and rated the value of the processes. The results show that the new improvements are sound and can strengthen the CST practice.