• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.2
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• pp.239-250
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• 2022

LoRa is a physical layer technology designed to secure highly reliable long-range communication with introducing loco parentis tree network and chirp spreading spectrum. Since since a leaf can send message to more than one parents simultaneously with a single transmission in a region, packet delivery ratio increases logarithmically as the number of gateways increases. The delivery ratio, however, dramatically collapses even under loco parentis tree topology due to the limitations of ALOHA-like primitive MAC, . The proposed method is intended to exploit SDMA approach to reuse frequency in an area. With the view, TxPower of each sender for each message in a concurrent transmission is elaborately controlled to survive the collision at different gateway. Thus, the gain from the capture effect improves the capacity of resource-hungry Low Power and Wide Area Networks.

• Journal of the Korea Society of Computer and Information
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• v.27 no.10
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• pp.105-113
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• 2022

In this paper, we present and analyze 5G system and IEEE time-sensitive networking(TSN) and propose a novel mobility management scheme for time sensitive communications in 5G-TSN to support ultra-low latency networks. Time-sensitive networking(TSN) has a promising future in the Industrial Automation and Industrial Internet of Things(IIoT), as a key technology that is able to provide low-latency, high-reliable and deterministic communications over the Ethernet. When a TSN capable UE moves the TSN service coverage from the non-TSN service coverage, the UE cannot get the TSN service promptly because the related mobility management is not performed appropriately. For the mobility situation with the TSN service coverage, the proposed scheme reports TSN capability to the network and triggers the initial registration in order to be provided the TSN service immediately and ultra-low latency communications compared to existing schemes in 5G mobile networks.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2000.11a
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• pp.397-406
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• 2000

대부분의 국방정보시스템의 소프트웨어는 높은 가용성, 신뢰성, 신속성, 정확성 등을 요구하는 대규모이면서 복잡한 실시간 시스템이다. 이러한 국방정보시스템의 소프트웨어 개발사업에 있어서 저비용 고효율의 미개국방경영 건설을 위하고 강한 전투력을 육성하기 위해서는 국방정보시스템의 효율적인 소프트웨어 개발사법이 요구된다. 따라서, 국방정보시스템의 소프트웨어 사업관리자가 개발사업을 관리하고 감독하는데 있어서 개발자와 사용자간의 조정 및 통제 기능을 수행하고 해당 국방정보시스템의 특성을 파악하여 성공적인 사업수행을 할 수 있도록 기술적인 사업관리 측면에서 구체적이고 상세화된 방안/지침을 제공하기 위한 전문가시스템의 지식베이스 도메인 지식개발에 관한 연구이다. 기존의 국방정보시스템의 사업관리자가 경험을 동해 축적해 온 기술, 정책, 아이디어, 노하우 등에 대한 지식을 습득하고 사업 관련자료에서 제시한 소프트웨어 생명주기 단계별 방안이나 지침 등을 바탕으로 하여 식별된 사실이나 내용을 지식베이스로 구축하여 국방정보시스템의 사업관리자가 필요로 할 때 설명모듈을 거쳐 임무 및 세부활동사항을 게시하여 줌으로써 사업관리 경험이 부족하거나 사업관리자가 교체되었을 때 사업관리자들이 업무를 지속적으로 연계시켜 임무수행이 가능하도록 기초/기반 여건을 제공하고자 한다. 본 논문은 국방정보시스템의 소프트웨어 개발사업에서 소프트웨어 생명주기 단계별 사업관리자의 임무 및 세부활동사항 지원용 전문가시스템을 개발할 때 이용할 수 있도록 도메인 지식을 개발하는 것이며 논문의 결과를 활용시 기대되는 효과는 본문을 참고 바란다.의 장점을 취합하여 설계되었다. 본 시스템은 기존의 UN/EDIFACT표준을 사용하고 있는 EDI환경과 기존 VAN 방식의 EDI 중계 시스템과 연동되며, 향후 관세청의 XML/EDI 표준 시행을 미리 대비하는 선도연구로서 자리매김이 된다. 본 연구에서는 개발된 XML/EDI 통관시스템은 향후, 서비스의 최대 걸림돌이 되어왔던 값비싼 EDI 사용료의 부담에서 벗어날 수 있게 할 것이며, 저렴한 EDI구축/운영 비용으로 전자문서교환의 활성화와 XML이 인터넷 기반의 문서유통 표준으로 자리매김할 수 있는 중요한 계기가 될 것이다.재무/비재무적 지표를 고려한 인공신경망기법의 예측적중률이 높은 것으로 나타났다. 즉, 로지스틱회귀 분석의 재무적 지표모형은 훈련, 시험용이 84.45%, 85.10%인 반면, 재무/비재무적 지표모형은 84.45%, 85.08%로서 거의 동일한 예측적중률을 가졌으나 인공신경망기법 분석에서는 재무적 지표모형이 92.23%, 85.10%인 반면, 재무/비재무적 지표모형에서는 91.12%, 88.06%로서 향상된 예측적중률을 나타내었다.ting LMS according to increasing the step-size parameter $\mu$ in the experimentally computed. learning curve. Also we find that convergence speed of proposed algorithm is increased by (B+1) time proportional to B which B is

• Journal of Korea Game Society
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• v.4 no.4
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• pp.11-18
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• 2004

The on-line games in the past were played by only two persons exchanging data based on one-to-one connections, whereas recent ones (e.g. MMORPG: Massively Multi-player Online Role-playings Game) enable tens of thousands of people to be connected simultaneously. Specifically, Korea has established an excellent network infrastructure that can't be found anywhere in the world. Almost every household has a high-speed Internet access. What made this possible was, in part, high density of population that has accelerated the formation of good Internet infrastructure. However, this rapid increase in the use of on-line games may lead to surging traffics exceeding the limited Internet communication capacity so that the connection to the games is unstable or the server fails. expanding the servers though this measure is very costly could solve this problem. To deal with this problem, the present study proposes the load distribution technology that connects in the form of local clustering the game servers divided by their contents used in each on-line game reduces the loads of specific servers using the load balancer, and enhances performance of sewer for their efficient operation. In this paper, a cluster system is proposed where each Game server in the system has different contents service and loads are distributed efficiently using the game server resource information such as CPU utilization. Game sewers having different contents are mutually connected and managed with a network file system to maintain information consistency required to support resource information updates, deletions, and additions. Simulation studies show that our method performs better than other traditional methods. In terms of response time, our method shows shorter latency than RR (Round Robin) and LC (Least Connection) by about 12%, 10% respectively.

• Korean Security Journal
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• no.17
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• pp.157-172
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• 2008

The purpose of this research is to suggest a construction device that can transform a public safety, security service, security system on counter- terrorism device system, from government leading type to private management type. There are purpose on this thesis to research for the bringing up counter-terrorism experts certification system and about all sorts of developed device among our country's counter-terrorism situation and through comparing developed country's private security's developing device. This summary of thesis is like below. First we need to establish total counter-terrorism center, like developed country on national corresponding strategy. Second, we need to make an organization as a country security department unified as an America's President directly belonging organization. Third, it is to legislate about an counter-terrorism. Fourth, we need to make a coorperate system according to counter-terrorism duty come under private management, so that can recover a trust among people. Fifth, a terror warning system is necessary. Private security's mutual relationship and developing devices is First, it is necessary to bring up counter-terrorism expert. Second, it is necessary to bring in counter-terrorism experts certification system. Third, counter-terrorism research center that come under private management is necessary. It is considered that various research need to be continued after by bringing up counter-terrorism experts, transforming a consciousness, counter- terrorism education, building an equipment and education center, not for a special group, that can minimize human infringement.

• Journal of Korean Home Economics Education Association
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• v.24 no.4
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• pp.59-75
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• 2012

This study investigated the self-perception of body image and awareness of diet of high school students in Zibo city, China. The data were collected from 260 high school students through the self-administered questionnaires. Frequency analysis, t tests, one-way ANOVA, Duncan's multiple range tests, factor analysis and Cronbach's alpha test were conducted by SPSS Windows V.19.0. The results were as follows. In the self-perception of body image, two fifths of the respondents thought of themselves as standard body image. More female respondents thought of themselves as fat persons compared with male respondents. The level of concern about diet was generally low and the mean for pursuit of skinny figure was highest in the awareness of diet. The percentage of correct answers of knowledge about diet was not that high, and one fifths of respondents had experience of diet. The respondents practiced fasting therapy, exercise therapy, food therapy, sweat therapy, drug/appliance therapy, and therapy using professional organization in order for diet.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.5
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• pp.147-156
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• 2022

Industrial control systems that manage and maintain various industries were mainly operated in closed environment without external connection, but with the recent development of the Internet and the introduction of ICT technology, the access to the industrial control system of external or attackers has become easier. Such incorrect approaches or attacks can undermine the availability, a major attribute of the industrial control system, and violation of availability can cause great damage. In this paper, when issuing commands in an industrial control system, a verification group is formed using a random list to verify and execute commands, and a trust score technique is introduced that applies feedback to the verification group that conducted verification using the command execution result. This technique can reduce overhead generated by random generation in the process of requesting command verification, give flexibility to the verification process, and ensure system availability. For the performance analysis of the system, we measured the time and gas usage when deploying a smart contract, gas usage when verifying a command. As a result, we confirmed that although the proposed system generates a random list compared to the legacy system, there was little difference in the time when it took to deploy smart contract and that the gas used to deploy smart contract increased by about 1.4 times in the process of generating a random list. However, the proposed system does not perform random operations even though the operation of command verification and confidence score technique is performed together during the command verification process, thus it uses about 9% less gas per verification, which ensures availability in the verification process.

• Journal of KIISE
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• v.43 no.10
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• pp.1085-1093
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• 2016

Community-based Question Answering system is a system which provides answers for each question from the documents uploaded on web communities. In order to enhance the capacity of question analysis, former methods have developed specific rules suitable for a target region or have applied machine learning to partial processes. However, these methods incur an excessive cost for expanding fields or lead to cases in which system is overfitted for a specific field. This paper proposes a multiple machine learning method which automates the overall process by adapting appropriate machine learning in each procedure for efficient processing of community-based Question Answering system. This system can be divided into question analysis part and answer selection part. The question analysis part consists of the question focus extractor, which analyzes the focused phrases in questions and uses conditional random fields, and the question type classifier, which classifies topics of questions and uses support vector machine. In the answer selection part, the we trains weights that are used by the similarity estimation models through an artificial neural network. Also these are a number of cases in which the results of morphological analysis are not reliable for the data uploaded on web communities. Therefore, we suggest a method that minimizes the impact of morphological analysis by using character features in the stage of question analysis. The proposed system outperforms the former system by showing a Mean Average Precision criteria of 0.765 and R-Precision criteria of 0.872.

• Journal of Internet Computing and Services
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• v.11 no.4
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• pp.11-22
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• 2010

In case that group communication protocols assume every process is interested in all events occurring in a large scale group, the events multicasting to a subset of a large process group, such as a sensor network, potentially varying for every event based on their interests might lead to very high communication overhead on each individual process. Moreover, despite the importance of both guaranteeing message delivery order and supporting overlapped group using gossip based group communication for multicasting in sensor or P2P networks, there exist little research works on development of gossip-based protocols to satisfy all these requirements. In this paper, we present a new gossip-based causal message order guaranteeing multicast protocol based on local views and delegates representing subgroups and fully utilizing multi-group features to improve scalability. In the proposed protocol, the message delivery order in overlapped groups has been guaranteed consistently by all corresponding members of the groups including delegates. Therefore, these features of the proposed protocol might be significantly scalable rather than those of the protocols guaranteeing atomic order dependencies between multicast messages by hierarchical membership list of dedicated groups like traditional committee protocols and much stronger rather than fully decentralized protocols guaranteeing dependencies between multicast messages based on only local views. And the proposed protocol is a hybrid approach improving the inherent scalability of multicast nature by gossip-based technique in all communications.

• Journal of Internet Computing and Services
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• v.10 no.5
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• pp.195-209
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• 2009

The embedded software has been become more important than the hardware in mobile systems in ubiquitous society. The improvement models such as CMMI(Capability Maturity Model Integration) and SPICE(Software Process Improvement and Capability dEtermination) are used to improve the quality of software in general systems. Software process improvement is also necessary for mobile embedded software development to improve its quality. It is not easy to apply the general software improvement model to the mobile embedded software development due to the high cost effectiveness and heavy process. On the other hand, XP has the characteristics on focused communications with customers and iteration development. It is specially suitable for mobile embedded software development as depending on customer's frequent requirement changes and hardware attributes. In this paper, we propose a framework for development small process improvement based XP(eXtreme Programming)'s practice in order to accomplish CMMI level 2 or 3 in mobile embedded software development at the small organizations. We design and implement the Mobile Embedded Software Process Improvement System(MESPIS) to support process improvement. We also suggest the evaluation method for the mobile embedded software development process improvement framework with CMMI coverage check by comparing other process improvement model. In the future, we need to apply this proposed framework to real project for practical effectiveness and the real cases quantitative. It also include the enhance the functionality of MESPIS.