• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.1
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• pp.455-472
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• 2020

As a user in modern societies with the rapid growth of Internet environment and more complicated business flow processes in order to be effective at work and accomplish things on time when the manager of the company went for a business trip, he/she need to delegate his/her signing authorities to someone such that, the delegatee can act as a manager and sign a message on his/her behalf. In order to make the delegation process more secure and authentic, we proposed a secure and efficient identity-based proxy signcryption in cloud data sharing (SE-IDPSC-CS), which provides a secure privilege delegation mechanism for a person to delegate his/her signcryption privilege to his/her proxy agent. Our scheme allows the manager of the company to delegate his/her signcryption privilege to his/her proxy agent and the proxy agent can act as a manager and generate signcrypted messages on his/her behalf using special information called "proxy key". Then, the proxy agent uploads the signcrypted ciphertext to a cloud service provider (CSP) which can only be downloaded, decrypted and verified by an authorized user at any time from any place through the Internet. Finally, the security analysis and experiment result determine that the proposed scheme outperforms previous works in terms of functionalities and computational time.

• The KIPS Transactions:PartC
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• v.11C no.7 s.96
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• pp.999-1008
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• 2004

The Jini system provides an infrastructure to facilitate a programmer to develop distributed systems. As one of the Jini services, JavaSpare has been used as a repository which is accessible publicly in the Java distributed environment. Although JavaSpace could give a useful method for saving and sharing java object, it would not be applicable to develop a distributed system requiring access securities for the objects because JavaSpare does not support secure access control. In this paper, we present a secure JavaSpare service based on Jini2.0 named SeureJS, which strengthens the security weakness of JavaSpare. The system consists of ObjectStore to store Java objects, AccessManager to control access of ObjectStore and KeyManager to manage public keys.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.5
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• pp.598-606
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• 2002

We suggest a distributed communication and management methodology using PC to PC Query multicasting strategy for efficient management of medical images produced by DICOM(Digital Imaging and Communications in Medicine) Modalities. It is absolutely necessary to reduce strict degradation of PACS system due to large sire of medical images and their very high transport rates. DICOM PC to PC Component is composed of a Service Manager to execute requested queries, a Communication Manager to take charge of file transmission, and a DICOM Manager to manage stored data and system behavior Each Manager itself is a component to search for requested file by interaction or to transmit the file to other PCs. Distributed management and transformation of medical information based on PC to PC Query multicasting methodology will enhance performance of central server and network capacity, reducing overload on both. We organize three major components for system operation. Each component is implemented as Agent. Communication between agents uses XML encoded Agent Communication Language.

• International Journal of Contents
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• v.16 no.4
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• pp.16-25
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• 2020

The size of observation data in astronomy has been increasing exponentially with the advents of wide-field optical telescopes. This means the needs of changes to the way used for large-scale astronomy data analysis. The complexity of analysis tools and the lack of extensibility of computing environments, however, lead to the difficulty and inefficiency of dealing with the huge observation data. To address this problem, this paper proposes a workflow execution system for analyzing large-scale astronomy data efficiently. The proposed system is composed of two parts: 1) a workflow execution manager and its RESTful endpoints that can automate and control data analysis tasks based on workflow templates and 2) an elastic resource manager as an underlying mechanism that can dynamically add/remove virtualized computing resources (i.e., virtual machines) according to the analysis requests. To realize our workflow execution system, we implement it on a testbed using OpenStack IaaS (Infrastructure as a Service) toolkit and HTCondor workload manager. We also exhaustively perform a broad range of experiments with different resource allocation patterns, system loads, etc. to show the effectiveness of the proposed system. The results show that the resource allocation mechanism works properly according to the number of queued and running tasks, resulting in improving resource utilization, and the workflow execution manager can handle more than 1,000 concurrent requests within a second with reasonable average response times. We finally describe a case study of data reduction system as an example application of our workflow execution system.

• Journal of Korea Port Economic Association
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• v.21 no.3
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• pp.259-270
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• 2005

This study applies the Analytic Hierarchy Process (AHP) to evaluate service quality of Third-Party Logistics (3PL) providers. For this, 3PL service quality is conceptualized and measured using SERVQUAL's five dimensions such as tangibles, reliability, responsiveness, assurance and empathy. Then, the AHP method is applied to determining the relative importance of five service quality dimensions and eventually selecting the best 3PL provider. Finally, this study conducts an empirical case study on four companies providing 3PL services in Korea to demonstrate the basic idea suggested in this paper. The results obtained in the present study indicate that responsiveness to customers is the most important factor perceived by 3PL customers and 3PL C is the best 3PL provider according to the overall service quality scores. In contrast to some previous researches, this study examined issues of service quality from the perspective of 3PL customers as opposed to the perspective of 3PL providers. In order for this study to be more complete, future research is needed in establishing a set of metrics to quantify each dimension of 3PL service quality proposed.

• Journal of Korea Multimedia Society
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• v.2 no.1
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• pp.69-79
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• 1999

We have implemented the telecommunication management functions based on TMN (Telecommunications Management Network) architecture that is standardized by ISO/ITU-T. TMN has been developed to manage heterogeneous networks, services and equipment. In this paper, we first analyze the detailed functions of EMS (Element Management System) that performs core functions in the subnetwork management of TMN architecture. We propose an implementation method of EMS for efficient subnetwork management and verify its performance and functionality through detailed implementation and various testing. The proposed EMS consists of EML-Manager module and NML-Agent module. The EML-Manager module controls NEL (Network Element Layer) through the CMIP operations on the managed-objects. The NML-Agent module processes the requests from NMS (Network Management System) in upper layer. We have implemented NMS that performs only the NML-Manager function to test the proposed EMS, and we have used NE-Agent that was designed and implemented by the B-ISDN Lab. of Yeungnam University. The implemented EMS has three management functions: configuration management function, performance management function, and fault management function. We confirmed that the EMS operated normally as we tested the EMS. As further research works, the implementation of NMS with both NML-Manager function and SML-Agent function is required.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7C
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• pp.971-984
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• 2004

In the coming age of information warfare, information security patterns need to be changed such as to the active approach using offensive security mechanisms rather than traditional passive approach just protecting the intrusions. In an active security environment, it is essential that, when detecting an intrusion, the immediate confrontation such as analysing the intrusion situation in realtime, protecting information from the attacks, and even tracing the intruder. This paper presents an active intrusion-confronting system using a fake session and a honeypot. Through the fake session, the attacks like Dos(Denial of Service) and port scan can be intercepted. By monitoring honeypot system, in which the intruders are migrated from the protected system and an intrusion rule manager is being activated, new intrusion rules are created and activated for confronting the next intrusions.

• Journal of the Korea Institute of Building Construction
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• v.11 no.2
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• pp.108-115
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• 2011

This study investigates the construction management selection methods for fair competition within the construction management market by analyzing the current status of domestic construction management, the 2010 publication on the status of construction management, and the construction management evaluation criteria. Also, the 2009 publication of top CM service establishments, the average proportion of tender for 120 CM services from 2002 to 2010, and six assessment results which are open to the parties directly involved were statistically analyzed to review the adequacy of the evaluation criteria. This analysis shows that the evaluation criteria for the CM service impedes the development of the construction management industry and companies, since the criteria are decided by the service payment, and the technical skills assessed by technical proposals have no ties with contract prices. Therefore, this study proposes an improvement of the selection methods in accordance with the project characteristics and the technical requirements. However, more research is still needed to derive a detailed classification method of the technical requirement, the owner's evaluation criteria selection, and the preparation of an institutional foundation for the construction manager's post-evaluation.

• Korean Journal of Social Welfare
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• v.54
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• pp.273-294
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• 2003

The outcome of study has shown that team approach in case management in the community welfare center has shown a fair amount of effectiveness in increasing the quality of life for the elderly. 30 elderly people who had complex difficulties in life were selected and given case management for a 6 month period. The student volunteers supervised by a case manager visited the clients once a week and arranged a series of community resources following assessment of the clients' needs. A group of professionals active in the community was invited for supervision. Compared to the clients in the comparison group, those clients who case management showed the increase in the quality of life and life satisfaction scale. The results of the study suggest that face-to-face service for the elderly is one important factor for successful case management intervention. Also, a team approach in case management utilizing professionals and volunteers can be useful for the case manager in the community welfare center who is overwhelmed with too many case loads.

• The Journal of the Korea Contents Association
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• v.13 no.1
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• pp.221-233
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• 2013

This study aims to explore how to cognize and perform case management process to community psychiatric rehabilitation center in Busan area. The case of case manager for 12 people obtained by conducting focus group interviews were in-depth analysis. Many commissioned by a variety of human service organizations in the contract and the client-centric intake has been received. Assessment, rather than a function of mental disabilities center service needs, planning difficulties in securing resource discovery and felt. Intervention phase focuses on direct service and when several agencies responsible for the case management approach. The possession of responsibility was unclear. Mainly monthly facilities within the checking step checks are being made, there was a desire for the realistic-supervision. Completion stage expectations showed a performance evaluation oriented, and individualized case management that can be represented well on the rating scale.