CRiBAC: Community-centric role interaction based access control model

As one of the most efficient solutions to complex and large-scale problems, multi-agent cooperation has been in the limelight for the past few decades. Recently, many research projects have focused on context-aware cooperation to dynamically provide complex services. As cooperation in the multi-agent systems (MASs) becomes more common, guaranteeing the security of such cooperation takes on even greater importance. However, existing security models do not reflect the agents' unique features, including cooperation and context-awareness. In this paper, we propose a Community-based Role interaction-based Access Control model (CRiBAC) to allow secure cooperation in MASs. To do this, we refine and extend our preliminary RiBAC model, which was proposed earlier to support secure interactions among agents, by introducing a new concept of interaction permission, and then extend it to CRiBAC to support community-based cooperation among agents. We analyze potential problems related to interaction permissions and propose two approaches to address them. We also propose an administration model to facilitate administration of CRiBAC policies. Finally, we present the implementation of a prototype system based on a sample scenario to assess the proposed work and show its feasibility. © 2012 Elsevier Ltd. All rights reserved

A survey of security issue in multi-agent systems

Multi-agent systems have attracted the attention of researchers because of agents' automatic, pro-active, and dynamic problem solving behaviors. Consequently, there has been a rapid development in agent technology which has enabled us to provide or receive useful and convenient services in a variety of areas such as banking, transportation, e-business, and healthcare. In many of these services, it is, however, necessary that security is guaranteed. Unless we guarantee the security services based on agent-based systems, these services will face significant deployment problems. In this paper, we survey existing work related to security in multi-agent systems, especially focused on access control and trust/reputation, and then present our analyses. We also present existing problems and discuss future research challenges. © Springer Science+Business Media B.V 2011

Situation-Aware Community Computing Model for Developing Dynamic Ubiquitous Computing Systems

For many complex and dynamic ubiquitous services, context-aware cooperation can be a solution. However, the way is not yet clear to make individual objects cooperate with each other as situations change. In addition, in the present environment in which many smart agents are already deployed, we are able to quickly develop ubiquitous services by utilizing existing agents. In the case of urgent but unavailable services, such fast development is required but there is no existing work to provide a path. To meet such requirements, in this paper, we thus introduce community computing as a new paradigm in which ubiquitous services are provided through context-aware cooperation among existing agents. To design such systems intuitively, we propose an abstraction model, called the situation-aware community computing model which includes the community situation model and the situation-aware cooperation model. In addition, for fast and convenient system development, we propose a development process based on the MDA (Model-Driven Architecture) approach [OMG, 03]. Following the development steps of MDA, we propose three models each having different abstraction levels and the model transformation process from the high-level model, CCM, to the source code. To make such transformation semi-automatic, we develop a toolkit, called CDTK. By using CDTK, we are able to implement a community computing system conveniently and systematically. To verify the proposed work, we implemented two small systems based on motivated scenarios; CHILDCARE and COEX-Mall. Through the simulated results of those systems, we examined the possibility of community computing as a new development paradigm

984 Ubiquitous Mobile Information and Collaboration Systems Community based Ubiquitous System Development in Multi-agent Environment

Abstract. Ubiquitous system can be considered as the intelligent space, in which many kinds of component are connected by networks and also each component recognizes their connection and cooperates with others for achieving some goals. In many case of ubiquitous computing environments, users and devices interact and cooperate each other to attain some goals. To develop such a ubiquitous system, we should model a ubiquitous system in a cooperation view. To do this, in this paper, we model a ubiquitous system using community metaphor consistently. In the proposed high-level abstraction model, we can represent mission-oriented organizations and interrelationships between members or organizations. In addition, so far, a developer of a ubiquitous system should start from scratch and think about the action as an individual component and also the action as a member of cooperative organization at same time. Therefore, we also introduce the development process, which make it possible concerning the cooperative action and the individual action separately. To examine the proposed community computing model and the development process, we trying to implement a small system in JADE Platform.

Emergency Response using Ephemeral Social Communities across Online Social Networks

In an emergency situation, receiving prompt and organized help from nearby people is of critical importance. The growing use of online social networks (OSNs) in emergency situations is a clear indication of the natural applicability of online social networking technologies to emergency responses. Despite this intense interest, a number of fundamental limitations still exist, such as lack of conceptual models and limitations on group organization and cooperation. To address existing limitations, we propose Whistle+ – a cooperation framework for OSN users which can 1) dynamically organize an emergency community with nearby eligible users who are distributed in heterogeneous online social networks, and 2) guarantee secure communication, unrestricted cooperation and resource sharing by leveraging the SocialVPN virtual network and the Jitsi communicator. To test the feasibility and applicability of Whistle+, we present a prototype implementation and demonstrate its applicability to an example use case

A Systematic Review on Comparative Analyses between Ureteroscopic Lithotripsy and Shock-Wave Lithotripsy for Ureter Stone According to Stone Size

Background and Objectives: This systematic review and meta-analysis was conducted to analyze the treatment outcomes of shock wave lithotripsy (SWL) and ureteroscopic lithotripsy (URSL) according to the ureteral stone size. Materials and Methods: In this systematic review, relevant articles that compared SWL and URSL for treatment of ureteral stones were identified. Articles were selected from four English databases including Ovid-Medline, Ovid-EMBASE, the Cochrane Central Register of controlled Trials (Central), and Google Scholar. A quality assessment was carried out by our researchers independently using the Scottish Intercollegiate Guidelines Network (SIGN). A total of 1325 studies were identified, but after removing duplicates, there remained 733 studies. Of these studies, 439 were excluded, 294 were screened, and 18 met the study eligibility criteria. Results: In randomized control trial (RCT) studies, URSL showed significantly higher SFR than SWL (p < 0.01, OR= 0.40, 95% CI 0.30–0.55, I² = 29%). The same results were shown in sub-group analysis according to the size of the stone (<1 cm: p < 0.01, OR = 0.40, 95% CI 0.25–0.63; >1 cm: p < 0.01, OR = 0.38, 95% CI 0.19–0.74, I² = 55%; not specified: p < 0.01, OR = 0.43, 95% CI 0.25–0.72, I² = 70%). In the non-RCT studies, the effectiveness of the URSL was significantly superior to that of SWL (p < 0.01, OR = 0.33, 95% CI 0.21–0.52, I² = 83%). Retreatment rate was significantly lower in URSL than in SWL regardless of stone size (p < 0.01, OR = 10.22, 95% CI 6.76–15.43, I² = 54%). Conclusions: Meta-analysis results show that SFR was higher than SWL in URSL and that URSL was superior to SWL in retreatment rate. However, more randomized trials are required to identify definitive conclusions

Case series of branch retinal vein occlusion secondary to rhegmatogenous retinal detachment and its surgical management

Abstract Background To review cases of branch retinal vein occlusion (BRVO) secondary to rhegmatogenous retinal detachment (RRD) and its surgical management and presume their mechanism. Methods Medical records of patients who underwent surgery for RRD between 2015 and 2019 at a single tertiary care center were retrospectively reviewed. New BRVO secondary to RRD or its surgical procedure was diagnosed based on the fundus examination and its clinical course. Results A total of 734 RRD surgeries were performed for five years, and six cases of new BRVOs were noticed in the first year after surgery (incidence was 0.68%: six cases of BRVO / 734 cases of surgical RRD); five cases occurred after vitrectomy, and one occurred after scleral buckling. In three cases, retinal veins were presumed to already be partially occluded related due to a kink of the retinal vein seen before surgery. In the other three cases, the retinal veins were presumed to have incurred damage during vitrectomy. Conclusion In the present cohort, RRD or its related procedures caused BRVO within a year of surgery at an incidence of 0.68%. The proposed mechanisms are kinks of the retinal vein on the detached retina and damage to the retinal vein during vitrectomy