• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.51-54
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• 2012

본 논문에서는 스테레오스코픽 비디오 응용 포맷(Stereoscopic video Application Format)을 기반으로 IP환경에서 3차원 광고, 홍보 및 교육 등에 직접적으로 적용될 수 있는 3D Push 서비스 시스템을 제안한다. 스테레오스코픽 비디오 응용 포맷은 모바일 및 고정형 환경에서 스테레오스코픽 비디오 저장 및 전송을 위한 파일 포맷으로서 다양한 3D 디바이스에 공통으로 적용될 수 있으며 국제표준(ISO/IEC 23000-11)으로 채택되었다. 제안한 시스템은 스테레오스코픽 콘텐츠를 토대로 프로그램 저작을 위한 저작 및 저장을 위한 저작도구, 저작된 프로그램을 스케줄링하고 각 클라이언트의 요청에 따라 전송 관리하는 서버 및 프로그램에 따라 자동 3D 디스플레이 및 사용자 인터랙션을 제공하는 플레이어로 구성된다. 또한, 제안하는 시스템은 국제표준을 토대로 다양한 3D 디바이스와 호환성을 제공하며 모바일 및 고화질 3차원 서비스를 제공할 수 있으며, 각 사이트 과금에 따라 3D 프리미엄 서비스 및 Non-tapeless기반의 원격관리 3D Push 서비스를 제공하는 장점을 가진다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.421-423
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• 2001

본 논문은 IETF에서 제안한 차등화서비스모델(Differentiated Service Model)을 지원하는 라우터를 리눅스상에 구현하였다. 구현한 라우터는 기존의 리눅스에서 지원하는 에지 라우터의 단점을 개선하기 위하여 구현한 ingress marker를 사용하였다. 구현된 ingress marker는 AF 클래스의 트래픽을 미터링하고 마킹하기 위해 사용되는 trTCM을 포함하고 있으며, 이 ingress marker를 사용한 에지 라우터는 병목이 발생한 경우에도 각 클래스간 독립적으로 서비스를 보장해 줄 수 있다. 각 클래스간 성능보장은 AF PHB를 통해 기존 라우터와 비교 실험하여 검증하였다.

• Journal of the Korean Society for Library and Information Science
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• v.15
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• pp.141-173
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• 1988

The focuses and methods in Library science have been changed abreast with the development af library facilities and with the expansion and diversification of its functions. One of current trends in Library science is focussed on the social functions of library: its relations to the public, effective service for the users. and efficieniencies of the management policies, and so. on. To. deal with these issues, we need to borrow methodology from other disciplines such as management, marketing, statistics, etc. This paper is mainly concerned with how we approach to the measurement af services and thus provide tentative standard for evaluating library services. To do. this work properly, we'd better consider the users' needs and expectations. But it is not an easy work since too many factors are involved in the study of the users' needs. Users' needs and expectations are so. varying that it is difficult to find out some general and objective data. That is the reason why although many scholars have urged time after time the necessity of library's effectiveness measurement, few studies demonstrated substantial method for measuring the effectiveness of service. In this paper I propose a device for measuring service: i. e, Conjoint Analysis. Conjoint Analysis, which has originally been developed and applied in marketing research, is used to measure the priorities and preferences of purchasers on the new item. So far as Conjoint Analysis, concerning users' physical and psychological necessities, can numeralize people's needs, it may also be applied to measure service provided by nonprofit organization like library. If this approach prove to be sucessful, I hope this study to make any contribution to the appropriate direction on improving library facilities based on the result from a concret reference evaluation.

• Korean Circulation Journal
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• v.54 no.5
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• pp.256-267
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• 2024

Background and Objectives: Accumulating evidence shows that sodium-glucose cotransporter 2 inhibitors (SGLT2is) reduce adverse cardiovascular outcomes. However, whether SGLT2i, compared with other antidiabetic drugs, reduce the new development of atrial fibrillation (AF) is unclear. In this study, we compared SGLT2i with dipeptidyl peptidase-4 inhibitors (DPP-4is) in terms of reduction in the risk of AF in individuals with type 2 diabetes. Methods: We included 42,786 propensity score-matched pairs of SGLT2i and DPP-4i users without previous AF diagnosis using the Korean National Health Insurance Service database between May 1, 2016, and December 31, 2018. Results: During a median follow-up of 1.3 years, SGLT2i users had a lower incidence of AF than DPP-4i users (1.95 vs. 2.65 per 1,000 person-years; hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.55-0.97; p=0.028]). In individuals without heart failure, SGLT2i users was associated with a decreased risk of AF incidence (HR, 0.70; 95% CI, 0.52-0.94; p=0.019) compared to DPP-4i users. However, individuals with heart failure, SGLT2i users was not significantly associated with a change in risk (HR, 1.04; 95% CI, 0.44-2.44; p=0.936). Conclusions: In this nationwide cohort study of individuals with type 2 diabetes, treatment with SGLT2i was associated with a lower risk of AF compared with treatment with DPP-4i.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1116-1122
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• 2009

ATS(Automatic Train Stop) system makes train stop when it runs over the speed limit and ensure the safe operation of train. Seoul Metro line 2 in Korea, which started its passenger service in 1982, has adopted ATS system for its signaling system. The ATS system has only a train stop function at the time of emergency, and Seoul Metro is planning to replaced them with ATC(Automatic Train Control)/ATO(Automatic Train Operation) system which can provide the dedicated speed control for headway reduction and automatic operation of train. Until all the ATS system is replaced with the new ATC system, both systems are to operate simultaneously at the same metro line. In this situation, ATS system sometimes reveals improper operation: train stops suddenly without any obstacles in front of it. These emergency stops cause interruption of passenger service, and abnormal abrasion of wheels and rail. This paper makes it clear that these interruptions are caused by EMI phenomena between ATS on-board device and ATC wayside device : Signal current flowing in AF track circuit of ATC is turn out to be a EMI source that prevent normal operation of the ATS on-board device. Although the two systems have different frequency-ranges (ATS system has frequency range between $78{\sim}130$[kHz] and ATC system has frequency range between $9.5{\sim}16.5$[kHz]), it turned out that EMI phenomena appears between the both systems. This is investigated by measuring the output signal from ATS on-board device passing over ATC wayside device. The FFT(Fast Fourier Transform) analysis of the signal reveals that AF track circuit signal is transmitted to the ATS on-board device and induce noise causing improper operation. The countermeasures to the EMI phenomena are examined in three ways; blocking EMI transmission, enforcement of EMS (Electromagnetic Susceptibility) of ATS on-board device, and blocking the EMI source. It is suggested that the practical solution be blocking EMI source temporarily, that is breaking AF track circuit signal when the trains with ATS on-board device pass over it. To this purpose, TODS(Train Occupation Detection System) is developed, and has made a success in preventing the EMI problem of Seoul Metro line 2.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.2
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• pp.566-578
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• 2018

In this paper, we design a segment training based individual channel estimation (STICE) scheme for the classical two-way relay network (TWRN) with multi-pair sources (MPS) and amplify-and-forward (AF). We adopt the linear minimum mean square error (LMMSE) channel estimator to minimize the mean square error (MSE) without channel estimation error, where the optimal power allocation strategy from the relay for different sources is obtained. Then the MSE gains are given with different source pairs among the proposed power allocation scheme and the existing power allocation schemes. Numerical results show that the proposed method outperforms the existing ones.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.325-338
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• 2004

As the recent rapid development of internet technology and the wide spread of multimedia communication, massive increase of network traffic causes some problems such as the lack of network paths and the bad quality of service. To resolve these problems, this paper presents a traffic control agent that can perform the dynamic resource allocation by controlling traffic flows on a DiffServ network. In addition, this paper presents a router that can support DiffServ on Linux to support selective QoS in IP network environment. To implement a method for selective traffic transmission based on priority on a DiffServ router, this paper changes the queuing discipline in Linux, and presents the traffic control agent so that it can efficiently control routers, efficiently allocates network resources according to service requests, and relocate resources in response to state changes of the network. Particularly for the efficient processing of Assured Forwarding(AF) Per Hop Behavior(PHB), this paper proposes an ACWF$^2$Q$^{+}$ packet scheduler on a DiffServ router to enhance the throughput of packet transmission and the fairness of traffic services.s.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.293-297
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• 2004

Recently, with the spread of digital camera and PC cam, need of tools for display and manipulation of digital images have increased remarkably. These tools are called as digital album. Af now, people want to see picture not alone in home but share with someone else. The purpose of this study is to develop a digital album, which is easy to use, easy to approach and has more function. Therefore people can see picture everywhere he want and management it. If computer is connected In Internet.

• Journal of Advanced Navigation Technology
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• v.10 no.1
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• pp.70-78
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• 2006

This paper has addressed the scheme to design single rate Rate Adaptive Shaper (srRAS) proposed in RFC2963. srRAS is the shaper used in conjugation with downstream single rate Three Color Marker (srTCM) described in RFC269. it is tail-drop First Input First Out (FIFO) queue that is drained at a variable rate. srTCM meters IP packet streams from srRAS and marks its packets to be either green, yellow, or red. This shaper has been proposed to use at the ingress of differentiated services networks providing AF PHB. And then srRAS can reduce the burstiness of the upstream traffic of srTCM. This paper addresses algorithm, architecture of srRAS, and the scheme to implement srRAS using Field-Programmable Gate Arrays (FPGA) and the related technology.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.6
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• pp.2686-2708
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• 2020

This paper investigates the energy efficiency of energy harvesting (EH) bidirectional cooperative sensor networks, in which the considered system model enables the uplink information transmission from the sensor (SN) to access point (AP) and the energy supply for the amplify-and-forward (AF) relay and SN using power-splitting (PS) or time-switching (TS) protocol. Considering the minimum EH activation constraint and quality of service (QoS) requirement, energy efficiency is maximized by jointly optimizing the resource division ratio and transmission power. To cope with the non-convexity of the optimizations, we propose the low complexity iterative algorithm based on fractional programming and alternative search method (FAS). The key idea of the proposed algorithm first transforms the objective function into the parameterized polynomial subtractive form. Then we decompose the optimization into two convex sub-problems, which can be solved by conventional convex programming. Simulation results validate that the proposed schemes have better output performance and the iterative algorithm has a fast convergence rate.