• Journal of information and communication convergence engineering
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• v.20 no.4
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• pp.273-279
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• 2022

Owing to the need to establish a cooperative-intelligent transport system (C-ITS) environment in the transportation sector locally and abroad, various research and development efforts such as high-tech road infrastructure, connection technology between road components, and traffic information systems are currently underway. However, the current central control center-oriented information collection and provision service structure and the insufficient road infrastructure limit the realization of the C-ITS, which requires a diversity of traffic information, real-time data, advanced traffic safety management, and transportation convenience services. In this study, a network construction method based on the existing received signal strength indicator (RSSI) selected as a comparison target, and the experimental target and the proposed intelligent edge network compared and analyzed. The result of the analysis showed that the data transmission rate in the intelligent edge network was 97.48%, the data transmission time was 215 ms, and the recovery time of network failure was 49,983 ms.

• Asia Marketing Journal
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• v.4 no.4
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• pp.1-27
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• 2002

본 연구는 Critical Incident Technique(CIT)를 이용하여 음식점에서 서비스 실패를 야기하는 결정적인 사건과 서비스 실패/복구수준과의 관계를 고찰해 보았다. 이와 더불어 불만족한 고객을 만족한 고객으로 전환시키는 데에 중요한 역할을 하는 고객이 바라는 복구와 점포 개선사항을 추가로 제시함으로써 실용적인 마케팅 접근을 시도하였다. 본 연구에서는 고객 불만족 원인이 서비스상품의 결함에 대부분 기인한다는 Hoffman et al. (1995)과 Tax et al. (1998)의 결과와는 달리 서비스 실패를 일으키는 주원인은 서비스제공자에게 있다는 흥미로운 결과를 얻을 수 있었다. 그 동안 국내의 많은 서비스관련 연구들이 서비스 만족과 불만족에 대해 양적 (quantitative)으로 접근한 것과는 달리 본 연구는 질적(qualitative) 접근을 시도하였다. 또한 본 연구는 CIT를 이용한 최초의 서비스 복구에 대한 연구이며, 기존의 연구들이 단순히 서비스 실패의 유형을 범주화하고 복구의 종류를 알아보는 것에 그치고 있는 데 반해 본 연구에서는 고객이 바라는 복구종류와 서비스 제공자의 개선 사항, 서비스 실패를 경험한 고객들의 구전활동에 관한 조사결과와 전략적 시사점도 함께 제시함으로써, 일선 관리자들이 본 연구의 결과를 기업의 마케팅전략 수립에 효과적으로 활용이 가능하다는 점에서 그 의의가 크다고 할 수 있다.

• Journal of Information Processing Systems
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• v.10 no.2
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• pp.176-192
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• 2014

The realization of Wireless Multimedia Sensor Networks (WMSNs) has been fostered by the availability of low cost and low power CMOS devices. However, the transmission of bulk video data requires adequate bandwidth, which cannot be promised by single path communication on an intrinsically low resourced sensor network. Moreover, the distortion or artifacts in the video data and the adherence to delay threshold adds to the challenge. In this paper, we propose a two stage Quality of Service (QoS) guaranteeing scheme called Prioritized Multipath WMSN (PMW) for transmitting H.264 encoded video. Multipath selection based on QoS metrics is done in the first stage, while the second stage further prioritizes the paths for sending H.264 encoded video frames on the best available path. PMW uses two composite metrics that are comprised of hop-count, path energy, BER, and end-to-end delay. A color-coded assisted network maintenance and failure recovery scheme has also been proposed using (a) smart greedy mode, (b) walking back mode, and (c) path switchover. Moreover, feedback controlled adaptive video encoding can smartly tune the encoding parameters based on the perceived video quality. Computer simulation using OPNET validates that the proposed scheme significantly outperforms the conventional approaches on human eye perception and delay.

• Journal of Korea Spatial Information System Society
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• v.8 no.3
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• pp.1-14
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• 2006

Recently, to efficiently support the real-time requirements of LBS and Telematics services, interest in the spatial main memory DBMS is rising. In the spatial main memory DBMS, because all spatial data can be lost when the system failure happens, the recovery system is very important for the stability of the database. Especially, disk I/O in executing the log and the checkpoint becomes the bottleneck of letting down the total system performance. Therefore, it is urgently necessary to research about the recovery system to reduce disk I/O in the spatial main memory DBMS. In this paper, we study an efficient recovery system for the spatial main memory DBMS. First, the pre-commit log method is used for the decrement of disk I/O and the improvement of transaction concurrency. In addition, we propose the fuzzy-shadow checkpoint method for the recovery system of the spatial main memory DBMS. This method can solve the problem of duplicated disk I/O on the same page of the existing fuzzy-pingpong checkpoint method for the improvement of the whole system performance. Finally, we also report the experimental results confirming the benefit of the proposed recovery system.

• The KIPS Transactions:PartC
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• v.12C no.6 s.102
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• pp.891-900
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• 2005

This paper studies network recovery methods for WDM optical mesh networks, concentrating on improving spare resource utilization. The resource efficiency can be obtained by sharing spare resources needed for network recovery. To improve the sharability of spare resources in WDM networks, methods to share backup paths us well as spare capacity should be studied. The proposed method in this paper uses multiple ring-covers and this method provides fast and simple recovery operation by exploiting the characteristics of logical ring topology, and also provides efficient resource utilization by using multiple distributed backup paths to improve the sharability of overall spare resources in the networks. This method can provide layered reliability to network service by enabling hierarchical robustness against multiple failures. The performance results show that the proposed method provide improved resource efficiency for single failure and enhanced robustness for multiple failures.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.7
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• pp.421-428
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• 2006

In this paper, the way of remote installation and back-up of 3-tier structure is introduced for efficient utilizing the cluster system resources distributed at several places. Recently, cluster system is constructed as the system of over hundreds nodes under complex network system mixed with public networks and private networks. Therefore, the as installation method suitable for the large scale cluster system and the remote recovery of failure nodes are important. However the previous researches which are based on 2-tier architecture may not provide the efficient cluster installation and image back-up method when the network of cluster system is composed of several private networks and public networks. In this paper, RISE (Remote Installation Service and Environment) based on the 3-tier architecture is proposed to solve this problem. In our approach, the managing node's role is divided into the global master node (GRISE) and the local master node (LRISE) to provide the efficient initial system deployment and remote failure recovery of distributed cluster system under the various network systems. Also, LRISE's availability is ensured under the complex network environments by adopting the auto-synchronization mechanism between GRISE and LRISE. In this work, a 64-node cluster system with gigabit network system is utilized for the experiment. From the experimental result, the system image with 1.86GB data can be obtained in 5 minutes and 53 seconds and the image-based installation of 64-node system can be carried out in 17 minutes and 53 seconds.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.366-369
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• 2014

Recently been viewed as a core technology of the IT industry, cloud computing services. It is expected that the market for cloud services industry showed a growth rate of 18.9% annually, to form a scale of $ 1,330 billion dollars in 2013, and to form a 1,768 billion dollars in 2015. Growth of cloud computing services industry, provides the operational efficiency and reduce costs for many companies, but the risks associated with it is also increasing. There is a problem that phenomenon is to lose control of the data on features of the cloud service, more data is gathered in one place, when a failure occurs, it is removed simultaneously the data of all devices. therefore, in the present paper is investigate the area a quick recovery with up to the problem and secure data storage INT the cloud computing service is available in only the data in the cloud service possible.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.1895-1904
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• 2014

This study explores the way to improve service quality with the application of Service Blueprint and Analytic Hierarchy Process (hereafter, "AHP") in medical tourism. Service Blueprint has been widely accepted to identify the possible fail points in service delivery system, and AHP analysis has been recognized as beneficial method to rate relative importance in multi-criteria decision making process. We try to understand possible pitfalls to enhance Chinese medical tourists, and propose the priority in the resolution process. In the first step, we reviewed the extant literatures about medical tourism of South Korea, and built initial Service Blueprint. Experts who experienced service delivery process towards Chinese patients participated to review the proposed Service Blueprint in the second step. Thirdly, after extracting the possible fail points from revised Service Blueprint, we asked experts to guess the relative importance of Chinese patient by AHP methodology. Four domains (Arrival and Welcoming, Hospitalization, Process before, operations, and after surgery, Recovery and discharge) were emerged with detail criteria. Results show that operations and treatment is the most important domain not to lose Chinese patient's loyalty with following hospitalization process domain. Also, we suggest the priority among sixteen criteria to prevent service failure.

• Journal of the Korea Society of Computer and Information
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• v.17 no.3
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• pp.41-50
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• 2012

In the monitoring system based on web service application, it is faced with the problems like code reproduction, difficult scalability and error recovery derived from the frequent change of data structure. So we propose a technique of monitoring system by DTD(Document Type Definition) automatic generation. This technique is to use dynamic server-side script to cope with the change of sensor data structure, generate the DTD dynamically. An it also adapt the AJAX(Asynchronous JavaScript and XML) for XML data parsing, it can support mass data transmission and exception processing for data loss and damage. This technique shows the result of recovery time is decreased about 44.8ms in case of temporary data failure by comparing to the conventional XML method.

• Journal of the Korea Society of Computer and Information
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• v.28 no.12
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• pp.105-114
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• 2023

In this paper, we propose a deployment and operation scheme of UxNB network toward mobile IAB. By operating a UxNB network based on SDN(Software Defined Network), UxNBs are deployed in areas where mobile communication services are desired. After deploying UxNB in the service area, IAB can be set up to perform mobile communication services. For this purpose, this paper first proposes a UxNB Network Controller consisting of a UAV Controller and an SDN Controller, and proposes the necessary functions. Next, we present a scenario in which a UxNB network can be deployed and operated in detail step by step. We also discuss the location of the UxNB network controller, how to deliver control commands from the UAV controller to the UxNB, how to apply IAB for UxNB networks, optimization of UxNB networks, RLF(radio link failure) recovery in UxNB networks, and future research on security in UxNB networks. It is expected that the proposed UxNB Network Controller architecture and UxNB network deployment and operation will enable seamless integration of UxNB networks into Mobile IAB.