• Journal of Electrical Engineering and Technology
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• v.6 no.6
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• pp.806-816
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• 2011

Interest about social security has recently increased in favor of safety for infrastructure. In addition, advances in computer vision and pattern recognition research are leading to video-based surveillance systems with improved scene analysis capabilities. However, such video surveillance systems, which are controlled by human operators, cannot actively cope with dynamic and anomalous events, such as having an invader in the corporate, commercial, or public sectors. For this reason, intelligent surveillance systems are increasingly needed to provide active social security services. In this study, we propose a core technique for intelligent surveillance system that is based on swarm robot technology. We present techniques for invader enclosing using swarm robots based on multiple distributed object environment. The proposed methods are composed of three main stages: location estimation of the object, specified object tracking, and decision of the cooperative behavior of the swarm robots. By using particle filter, object tracking and location estimation procedures are performed and a specified enclosing point for the swarm robots is located on the interactive positions in their coordinate system. Furthermore, the cooperative behaviors of the swarm robots are determined via the result of path navigation based on the combination of potential field and wall-following methods. The results of each stage are combined into the swarm robot-based invader-enclosing technique on multiple distributed object environments. Finally, several simulation results are provided to further discuss and verify the accuracy and effectiveness of the proposed techniques.

• Journal of The Korean Association For Science Education
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• v.39 no.6
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• pp.695-706
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• 2019

This study conducted a case study on the process-centered evaluation competency of a middle-school/high-school science teacher using Teacher's Process-centered Evaluation Competency (T-PEC) measurement tool. The case analysis shows that teacher A in a middle school represents high competency of process-centered evaluation planning and cooperative communication while the competency of utilizing process-centered evaluation results is low owing to the characteristics of non-standardized areas. Teacher B in a high school shows high level of cooperative communication competency whereas low level of process-centered evaluation execution competency because the freedom given to students is not enough during the process of evaluation. The teacher also shows very low level of utilizing process-centered evaluation results due to the lack of time and the school culture not giving feedback to the students. According to cross-case analysis, teacher A and B both represent the highest level of collaborative communication competency and the lowest level of utilization process-centered evaluation results competency. And the lack of clear criteria for process-centered evaluation leads to different understanding of process-centered evaluation between the two teachers, and teacher B shows low the level of utilizing process-centered evaluation affects results due to the students not being concerned on feedback, security problem, and the reality focusing on the university entrance examination in high schools. Based on the results, this study suggests providing clear guidelines of process-centered evaluation to teachers, introducing an application in order to solve the time-lack problem pointed out as the biggest problem of process-centered evaluation, ensuring objectivity and security about process-centered evaluation results, and building the school culture such as the expanded application of standardized areas in order to implementing process-centered evaluation.

• Journal of Information Technology Services
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• v.13 no.3
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• pp.93-110
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• 2014

With the explosive proliferation of smart devices that may be connected to the fast Internet, virtual desktop interfaces(VDI) are being implemented in enterprises allowing employees to work anywhere anytime in the same technological environment. As this kind of systems are intended to raise the work performance, a research model is constructed from the review of research literature on service quality and work design. The model consists of VDI system service quality (ubiquity, availability, compatibility, security and ease of use), system satisfaction, task performance and job satisfaction. As VDI is designed as a support system for cooperative work, the task interdependence adopted from the work design theory is postulated here as moderating the effect of user satisfaction on task performance and job satisfaction. 147 data points were collected by a survey of VDI users in a global firm and subjected to PLS analysis. Interestingly, ubiquity and compatibility seem to be not statistically significant for user satisfaction while availability, security and ease of use of VDI system are statistically significant. Task interdependence is found to be a relatively strong mediator between system user satisfaction and task performance, however, interestingly, the coefficient come out as negative. This may indicate that the influence of VDI user satisfaction on task performance would not be high in highly interdependent tasks. Considering that VDI is intended for supporting 'interdependence' in cooperative work, this finding is a bit surprising. In-depth discussions are made in the discussion followed by future research directions.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.11
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• pp.339-344
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• 2020

During COVID-19, education industry is organizing the concept of 'Edutech', which has evolved one step further from the existing e-Learning, by introducing various intelligent information technologues based on the core technology of the 4th industrial revolution and spreading it through diverse contents. Meanwhile, each industries are creating new industries by applying new technology to existing businesses and ask for needs of cultivating human resources who understand the existing traditional ICT technology and industrial business which can solve a newly rising problems. However, it is difficult to build contents for cultivating such human resources with the existing e-learning of transferring knowledge by one-way or some two-way commnication system which has established some interactive conversational system. Accordingly, this study conducted a research on a cooperative e-learning system that enables educators to communicate with learners in real time and allows problem-solving education based on the existing two-way communication system. As a result, frame for contents and prototype was developedp and artially applied to the actual class and conducted an efficiency analysis, which resulted in the validation of being applied to the actual class as a simulation-based cooperative content.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.67-74
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• 2023

In this study, the risk of landslides was analyzed for planned development sites in mountainous areas. Field survey was conducted on the research area with the slope and valley site. The criteria for evaluating the risk of landslides in the field survey were based on the risk assessment table of the Korea Forest Service Notice No. 2023-10. The research area has 13 slopes and 11 valleys. As a result of evaluating the risk area, two slopes and two valley were found to be dangerous sites in each. Numerical simulation was performed on the investigated risk areas to predict the spread of damage. The debris flow was simulated to have an affect on roads and buildings located in the lower part of the basin, and it was determined that a disaster prevention facility was nacessary to minimize damage. This information can be used to determine the impact of disasters before carrying out mountain development.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.3
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• pp.1057-1073
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• 2015

In this paper, we consider cooperative D2D communications in cellular networks. More precisely, a cellular user leases part of its spectrum to facilitate the D2D communication with a goal of improving the energy efficiency of a D2D pair. However the D2D pair is untrusted to the cellular user, such resource sharing may result in the information of this cellular user unsecured. In order to motivate the cellular user's generosity, this D2D pair needs to help the cellular user maintain a target secrecy rate. To address this issue, we formulate a joint spectrum and power allocation problem to maximize the energy efficiency of the D2D communication while guaranteeing the physical layer security of the cellular user. Then, a theorem is proved to indicate the best resource allocation strategy, and accordingly, an algorithm is proposed to find the best solution to this resource allocation problem. Numerical results are finally presented to verify the validity and effectiveness of the proposed algorithm.

• Journal of Korea Multimedia Society
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• v.17 no.7
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• pp.769-777
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• 2014

With the rapid interest in Geographic Information System (GIS) contents, a large volume of valuable GIS dataset has been distributed illegally by pirates, hackers, or unauthorized users. Therefore the problem focus on how to protect the copyright of GIS vector map data for storage and transmission. At this point, GIS security techniques focusing on secure network and data encryption have been studied and developed to solve the copyright protection and illegal copy prevention for GIS digital map. But GIS vector map data is very large and current data encryption techniques often encrypt all components of data. That means we have encrypted large amount of data lead to the long encrypting time and high complexity computation. This paper presents a novel selective encryption scheme for GIS vector map data protection to store, transmit or distribute to authorized users using K-means algorithm. The proposed algorithm only encrypts a small part of data based on properties of polylines and polygons in GIS vector map but it can change whole data of GIS vector map. Experimental results verified the proposed algorithm effectively and error in decryption is approximately zero.

• Journal of Korea Multimedia Society
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• v.17 no.7
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• pp.778-786
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• 2014

Buyer-seller watermarking protocol is one of the copyright protection techniques which combine a cryptographic protocol used in electronic commerce with a digital wetermarking scheme aiming at proving the ownership of multimedia contents and preventing the illegal reproduction and redistribution of digital contents. In this paper, it is proposed a new watermarking scheme in an encrypted domain in an image that is based on the block-DCT framework. In order to implement watermarking scheme in a public-key cryptosystem, it is divided that frequency coefficients exist as real number into integer and decimal layer. And the decimal layer is modified integer type through integral-processing. Also, for robustness and invisibility required in watermarking scheme, it is designed a direction-adaptive watermarking scheme based on locally edge-properties of each block in an image through analyzing distribution property of the frequency coefficients in a block using JND threshold.

• Convergence Security Journal
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• v.11 no.6
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• pp.37-44
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• 2011

VANET(Vehicular Ad-hoc Network) is a kind of ad hoc networks consist of intelligence vehicular ad nodes, and has become a hot emerging research project in many field. It provide traffic safety, cooperative driving and etc. but has also some security problems that can be occurred in general ad hoc networks. Also, in VANET, vehicles shoul d be able to authenticate each other to securely communicate with network-based infrastructure, and their locations and identifiers should not be exposed from the communication messages. This paper proposes V2I(Vehicular to Infra structure) authentication protocol that anonymity and untraceability of vehicular using Error Correcting Code that ge nerate encoding certification using generation matrix. The proposed scheme based on ECC resolves overhead problems of vehicular secure key management of KDC.

• Journal of Internet Computing and Services
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• v.15 no.4
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• pp.103-110
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• 2014

In study we analyze the network about the legislators in Korean National Assembly. We focused on 17th National Assembly since there were full of important changes in composition. Mutual cooperation is necessary to pass the bills beyond their given mission in legislation. In order to find out the relationship of legislators based on the introducing bills, total 5728 bills in 17th National Assembly, we used bipartite network projection. We can find who is a highly influential legislator and the difference between a ruling party and a main opposition party in aspects of cooperative behavior.