• 경영과학
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• 제27권1호
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• pp.45-60
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• 2010

This study evaluates life annuity plans based on two different types of measures : financial benefit and utility on consumption. The financial benefit is measured by Money's Worth (MW) ratio and return on annuity. For the measure of utility, an optimization problem is formulated with the objective of maximizing utility on consumption. To solve the optimization model, we use Dynamic Programming (DP) technique. The both types of measures are applied to cases of Korean pre-retirees at age 40 with different accumulation years of annuity (i.e. level of annuity asset at the age of retirement) and different timings of annuitization. Our results generally indicate that the utility based optimization model is superior to the financial measures in terms of providing a better evaluation of an annuity plan due to its capability to consider an individual's financial situation during his/her retirement period. Also, they suggest that the level of annuity asset is an important factor when an individual determines the optimal annuitization timing.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.297-301
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• 2009

The impact of adding additional Multi-Criteria Decision Analysis (MCDA) criteria is demonstrated because current research shows MCDA for flood damage has been applied using only a few criteria but for better results the MCDA approach needs to apply more criteria for evaluating the alternatives. By adding additional criteria into MCDA, the capability to make the best alternatives more diverse and show the decision maker more differences in the scores of the alternatives to allow the decision maker to discriminate is significantly improved. The target region for a demonstration application of the methodology was the Suyoung River Basin in Korea. The 1991 Gladys flood event and five different return periods were used as a case study to demonstrate the proposed methodology of evaluation of various flood damage reduction alternatives.

• 한국군사과학기술학회지
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• 제11권3호
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• pp.40-49
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• 2008

In this paper, we have described a Simulated Radar Target Generation Equipment(SRTGE) for evaluating the performance of a developed radar system. In order to change a simulated target range(or time delay), the variable optical delay line structure is used in SRTGE, In addition, SRTGE is required to generate a target return signal which is composed of variable amplitude and Doppler velocity. The interference such as noise jamming and clutter is also produced from SRTGE for evaluating ECCM(Electronic-Counter-Counter Measure) capability of radar.

• East Asian Economic Review
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• 제19권2호
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• pp.189-220
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• 2015

Multi-scale representations are effective in characterising the time-frequency characteristics of financial return series. They have the capability to reveal the properties not evident with typical time domain analysis. Given the aforesaid, this study derives crucial insights from multi scale analysis to investigate the co-movements between Indian and emerging Asian equity markets using wavelet correlation and wavelet coherence measures. It is reported that the Indian equity market is strongly integrated with Asian equity markets at lower frequency scales and relatively less blended at higher frequencies. On the other hand the results from cross correlations suggest that the lead-lag relationship becomes substantial as we turn to lower frequency scales and finally, wavelet coherence demonstrates that this correlation eventually grows strong in the interim of the crises period at lower frequency scales. Overall the findings are relevant and have strong policy and practical implications.

• 센서학회지
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• 제29권3호
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• pp.149-155
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• 2020

In this study, we employed Manchester code for illumination control and flicker prevention of the light-emitting diode (LED) used in a visible light communication (VLC) system. In the VLC transmitter, the duty factor of the Manchester code was utilized for illumination control; in the VLC receiver, the spike signal from an RC-high pass filter was utilized to recover the transmitted signal whilst suppressing the 120-Hz noise arising from adjacent lighting lamps. Instead of the clock being transmitted in a separate channel, a syncmark signal was transmitted in front of each data byte and used as the reference time for transforming the Manchester code to non-return-to-zero (NRZ) data in the receiver. In experiments, the LED illumination was controlled in the range of approximately 12-84% of the constant wave (CW) light via changing of the duty factor from 10% to 90%. This scheme is useful for constructing indoor wireless sensor networks using LED light that is flicker-free and presents capability for illumination control.

• 센서학회지
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• 제28권3호
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• pp.191-197
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• 2019

In this study, we propose a dimming control method for a visible light communication (VLC) system, in which the subcarrier on-off keying (OOK) modulation of Manchester code is used for data transmission. In the VLC transmitter, non-return-to-zero (NRZ) code data is transformed to Manchester code, which is OOK modulated with a subcarrier. Manchester code is used for flicker-free lighting; the duty factor is changed for dimming control, and the subcarrier is used for preventing the adjacent noise light interference. In the experiments, the dimming control was carried out from about 8%-92% of the continuous wave (CW) LED light. This configuration is simple and effective in constructing a VLC system for indoor wireless sensor networks with flicker-free illumination and dimming control capability without adjacent noise light interference.

• 한국건축시공학회지
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• 제11권1호
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• pp.35-44
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• 2011

기업 활동에 있어 성과측정은 경영성과의 평가, 인적 자원의 관리 및 전략이행의 중요한 도구로 사용된다. 기업의 경영성과 측정은 당기 순이익, 투자수익률, 자기자본 이익률과 같이 단순히 재무적 관점에서 측정할 수 있으나 기업의 내부프로세스나 정보화와 같은 재무외적 성과를 측정할 수 없어 부족함이 있다. 따라서 본 연구는 국내의 시공능력순위 30위 이내의 건설기업에 적용 가능한 핵심 성과지표(KPI:Key Performance Indicators)를 도출하였으며, 기존의 연구와 기업 전문가의 설문을 반영하여 보다 현실적인 기업의 경영을 반영하며 기존의 연구와 차별된 결과를 도출하였다.

• 한국정보과학회논문지:정보통신
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• 제31권5호
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• pp.429-437
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• 2004

IETF의 mobileip 작업 그룹에서는 경로 최적화를 위해 절차가 간단하고 이동 노드의 낮은 연산 처리 능력을 고려해 암호학적 연산을 대폭 줄인 보안 기능으로서 RR(Return Routability)를 제공하지만 실질적으로 제공하는 보안 강도는 매우 낮으므로 이를 개선하기 위해 현재 CGA(Cryptographically Generated Address), IPsec(Internet Protocol Security)등의 암호학적 처리 방법과 PKI(Public Key Infrastructure), AAA(Authentication, Authorization and Account)등의 기존 인프라와 통합하는 강력한 보안 서비스 방법이 연구되고 있다. 본 논문에서는 유선망 및 802.11, 3GPP(3rd Generation Partnership Project)등의 무선망에서 성공적으로 사용되고 있는 AAA 인프라 기반의 노드 인증 및 안전한 경로 최적화를 위한 키 분배 방안을 제안하고 제안된 방법에 대한 비용 분석 모델을 통해 RR과 효율성을 비교하였는데 결과적으로 최대 20 퍼센트의 성능 향상을 보였다.

• 한국통신학회논문지
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• 제31권7B호
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• pp.660-667
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• 2006

본 연구에서는 무선 LAN 시장의 새로운 돌파구로 기대되는 VoWLAN의 투자 수익률 분석을 위해 구체적이고 실용적인 방법론을 제시하고자 한다. 이를 위하여 먼저 국내외 VoWLAN 시장의 동향을 분석한다. 다음으로는 투자수익률 분석을 위해 구축유형에 따라 VoWLAN에의 비용항목과 VoWLAN과 경쟁하는 대안서비스(유선랜과 유선전화서비스)의 비용항목을 산정한 후 대안서버스와 비교한 VoWLAN의 혜택 항목과 투자수익률 분석 시 필요한 기타 입력항목을 선정한다. 또한, 대상 기업의 다양한 상황에 맞는 구축 시나리오를 제시하고 각 시나리오 별로 비용/혜택 분석 프레임워크에 따라 경제성 분석을 실시한다. 본 연구에서는 개발된 투자 수익률 분석 프레임워크의 유용성을 검증하기 위해 VBA 프로그램으로 구현하여 실제 사례에 적용한다.

• Strategy21
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• 통권41호
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• pp.52-84
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• 2017

After finishing Cold War, the U.S. Navy's ability to Sea control has been gradually eroded last 15-20 years. The global security environment demands that the surface Navy rededicate itself to sea control, as a new group of potential adversaries is working to deny U.S. navy command of the sea. China has been increasing their sea denial capability, such as extended anti-surface cruise missile and anti-surface ballistic missile. To cope with this situation, the U.S. Naval Surface Forces Command has announced Surface Forces Strategy: Return to Sea Control. It is a new operating and organizing concept for the U.S. surface fleet called 'distributed lethality'. Under distributed lethality, offensive weapons such as new ASCMs are to be distributed more widely across all types of Navy surface ships, and new operational concept for Navy surface fleet's capability for attacking enemy ships and make it less possible for an enemy to cripple the U.S. fleet by concentrating its attack on a few very high-value Navy surface ships. By increasing the lethality of the surface ships and distributing them across wide areas, the Navy forces potential adversaries to not only consider the threat from our carrier-based aircraft and submarines, but they now consider the threat form all of those surface ships. This idea of using the distributed lethality template to generate surface action groups and adaptive force package and to start thinking about to increase the lethal efficacy of these ships. The U.S. Navy believes distributed lethality increases the Navy's sea control capability and expands U.S. conventional deterrence. Funding new weapons and renovated operating concept to field a more lethal and distributed force will enable us to establish sea control, even in contested area. The U.S. Navy's Surface Forces Strategy provides some useful implications for The ROK Navy. First the ROK Navy need to reconsider sea control mission. securing sea control and exploiting sea control are in a close connection. However, recently the ROK Navy only focuses on exploiting sea control, for instance land attack mission. the ROK Navy is required to reinvigorate sea control mission, such as anti-surface warfare and anti-air warfare. Second, the ROK Navy must seek the way to improve its warfighting capability. It can be achieved by developing high-edge weapons and designing renewed operating concept and embraced new weapon's extended capabilities.