• 한국HCI학회:학술대회논문집
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• 2007.02c
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• pp.158-163
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• 2007

본 논문의 목적은 PC 용으로 구축되어 있는 웹 컨텐츠를 PDA나 휴대폰과 같은 다양한 멀티플랫폼 단말기에도 제공할 수 있도록 하는 것이다. 기존의 대부분 방식은 모든 단말기에 서비스 할 수 없으므로 단말기용으로 모바일 컨텐츠를 미리 생성해 놓고 그 제한된 단말기에만 서비스하였다. 이때 가장 큰 문제점은 하나의 PC 웹 컨텐츠를 이용하여 다양한 하드웨어 특성을 가지는 모바일 단말기 마다 재생 가능한 모바일 컨텐츠를 모두 생성하는 것이다. 본 논문에서는 MPEG-21 멀티미디어 프레임워크를 이용하여 유선 웹 컨텐츠를 다양한 멀티 플랫폼 단말기에 실시간으로 맞추어 서비스하는 시스템을 제안한다. 제안한 시스템은 다양한 단말기별로 모바일 컨텐츠를 생성하는 것이 아니라 모바일 컨텐츠의 구성 및 표현방법을 MEPG-21 의 DIDL 을 이용하여 중간언어로써 기술한다. 그리고 멀티미디어 데이터 부분(Resource)만 Off-line으로 미리 변환한다. 이동단말기 접속 시 멀티미디어 서술(Description)부분을 실시간으로 변환하고 그 단말기가 사용 가능한 변환된 리소스를 통하여 단말기에 적합한 모바일 컨텐츠를 실시간으로 생성하여 서비스한다. 본 논문은 추가적으로 모바일 웹 서비스를 제공하는 과정에서 발생할 수 있는 응답시간 지연 현상을 최소화 하기 위하여 선 서비스 후 변환 방법을 제안한다.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.2
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• pp.69-76
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• 2006

TRISO(tri-isotropic)-coated fuel particle technology is utilized owing to its higher stability at a high temperature and Its efficient retention capability for fission products In the HTGR(high temperature gas-reeled reactor). The typical spherical TRISO fuel panicle with a diameter of about 1mm is composed of a nuclear fuel kernel and outer coating layers. The outer coating layers consist of a buffer PyC(pyrolytic carbon) layer, Inner PyC(1-PyC) layer, SiC layer, and outer PyC(O-PyC) layer Most of the Inspection Items for the TRTSO-coated fuel particle depend on destructive methods. The coating thickness of the TRISO fuel particle can be nondestructively measured by the X-ray radiography without generating radioactive wastel. In this study, the coaling thickness for the simulated TRISO-coated fuel particle with $ZrO_2$ kernel Instead of $%UO_2$ kernel was measured by using micro-focus X-ray radiography with micro-focus X-ray generator and flat panel detector The radiographic image was also enhanced by image processing technique to acquire clear boundary lines between coating layers. The coaling thickness wat effectively measured by applying the micro-focus X-ray radiography The inspection process for the TRISO-coated fuel particles will be improved by the developed micro-focus X-ray radiography and digital image processing technology.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.6
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• pp.69-77
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• 2002

To acquire the dynamic response and design the controller of the airship, the longitudinal motion of the airship with respect to the vertical gust, which is the nonlinear system, was studied. The effects of the apparent mass and moment of the airship delay the dynamic response and the settling time, which are slower than those of conventional airplanes. The current object of the airship is designed to cruise at 500~1000m altitude. At that height, the atmospheric conditions are generally unstable by wind gust. In this paper, it has been studied for the case of vertical gust, since the apparent mass effects are dominant in has been studied for the case of vertical gust, since the apparent mass effects are dominant in that plane. In addition to the study of the dynamic responses of the airship, the controller was designed using the PID-controller. When the gust was applied, airship responses were recovered of equilibrium states. However, it takes too ling time for recovery and the speed of airship is reduced. So, the aim in this paper was to fasten the recovery speed and to get back the cruising velocity. The control parameters were determined from the stability mode analysis, and the control inputs were the thrust and the elevator deflection angle.

• Journal of Navigation and Port Research
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• v.48 no.1
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• pp.62-77
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• 2024

In the maritime shipping industry, imbalance between supply and demand has persistently increased, leading to the utilization of blank sailings by major shipping companies worldwide as a key means of flexibly adjusting vessel capacity in response to shipping market conditions. Traditionally, blank sailings have been frequently implemented around the Chinese New Year period. However, due to unique circumstances such as the global pandemic starting in 2020 and trade tensions between the United States and China, shipping companies have recently conducted larger-scale blank sailings compared to the past. As blank sailings directly impact freight transport delays, they can have negative repercussions from perspectives of both businesses and consumers. Therefore, this study employed Poisson regression models and negative binomial regression models to analyze the influence of maritime freight rate determinants on shipping companies' decisions regarding blank sailings, aiming to proactively address potential consequences. Results of the analysis indicated that, in Poisson regression analysis for 2M, significant variables included global container shipping volume, container vessel capacity, container ship scrapping volume, container ship newbuilding index, and OECD inflation. In negative binomial regression analysis, ocean alliance showed significance with global container shipping volume and container ship order volume, the alliance with container ship capacity and interest rates, non-alliance with international oil prices, global supply chain pressure index, container ship capacity, OECD inflation, and total alliance with container ship capacity and interest rates.

• Journal of the Korean Chemical Society
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• v.39 no.1
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• pp.40-46
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• 1995

A new analytical luminescence method for the Tb+3 and Eu+3 ions was studied using the fluorescence enhancement of the ions on the TLC plate. Compared to the specific emission intensities of the ions in aqueous or ethanol solution, if spotted on the TLC plate, the line intensities were extremely enhanced. There was additional enhancement effect of the lines from the ions on the TLC plate, if treated with ο-phenanthroline. Based on the luminescence enhancement, the detection limit of the ions was lowered more than 6 order of magnitude compared to the luminescence method using solution samples. The energy-transfer mechanism was also explained for the theoretical back ground of the luminescence enhancement.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.514-519
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• 1990

Some chemical constituents were monitored to evaluate the biochemical and nutritional aspects of ${\gamma}-irradiated$ mushrooms associated with shelf-life extension. Volatile components identified by GC and GC-MS were composed primarily of 1-octen-3-ol(68%)). benzaldehyde(13%), 3-octanone(8%), benzyl alcohol(5%), 3-octanol(2%)). 1-octen-3one(1%). etc. Treatment with 2kGy-irradiation and subsequent storage for 17 days at $(9{\pm}1^{\circ}C\;and\;80{\pm}7%$ RH resulted in appreciable changes In their contents. even though negligible changes were observed in GC patterns between the nonirradiated and 2 kGy-irradiated samples. Most of the amino acids were resistant to ionizing energy of 2 kGy, while sulfur-containing free amino acids were affected significantly by ${\gamma}-irradiation$.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.2
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• pp.41-46
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• 2019

The application of series compensator in a power system affects other devices such as circuit breakers transient recovery voltage (TRV) problem. In this paper, we analyze the TRV effect on a line circuit breaker in the cases with and without thyristor-controlled series capacitor (TCSC) via simulation, and suggest an effective method to overcome the increase of TRV due to the TCSC installation. It also discusses the impact of proposed protection on metal oxide varistor (MOV). A 345 kV transmission line in Korea was selected as a study case. Grid system was modelled using PSCAD (Power Systems Computer Aided Design) / EMTDC(Electro Magnetic Transient Direct Current). The TRV was analyzed by implementing a short circuit fault along the transmission line and at the breaker terminal. The proposed protection scheme, the TRV satisfies the standard. However, the MOV energy capacity increased as the delay time increased. This result can solve the TRV problem caused by the expected transmission line fault in a practical power system.

• Journal of Digital Policy
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• v.1 no.2
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• pp.1-8
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• 2022

In case of a dangerous situation, the roof, which serves as an emergency exit, must be open in case of fire according to the Fire Act. However, when the roof door is opened, it has become a place of various incidents and accidents such as illegal entry, crime, and suicide. As a result, it is a reality to close the roof door in terms of facility management to prevent crime, various incidents, and accidents. Accordingly, the government is pushing to legislate regulations on housing construction standards, etc. that mandate the installation of electronic automatic opening and closing devices on rooftop doors. Therefore, in this paper, an intelligent emergency door opening/closing device system is proposed. To this end, an intelligent emergency door opening and closing system was developed by linking wired and wireless access counting and AI image analysis. Finally, it is possible to build a wireless communication-based integrated management platform that provides remote control and history management in a centralized method of device status real-time monitoring and event alarm.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.1
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• pp.1-10
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• 2012

Mobility and quality of service (QoS) are becoming the more important issues in wireless communications. The traditional Internet service is expanding into new access media and applications. Since wireless communication services are accompanied by frequent handovers at remote sites, scalable and fast handover has become a prerequisite for ubiquitous communication. In this paper, the differentiated service (Diffserv) model is deployed in heterogeneous proxy mobile IPv6 (PMIPv6) networks to satisfy the QoS guaranteed service and fast handover requirements. The operational procedures for QoS guaranteed global roaming are presented. In addition, QoS management and handover cost evaluation schemes based on a mobile host's movement scope are proposed. This paper analyzes the reduction in handover delay in a network-based localized mobility management framework. We propose and analyze a PMIPv6 optimized with a global mobile access gateway (G-MAG), which is a network-based entity, to further improve the handover performance in terms of handover delay while maintaining minimal signaling overhead in the air interface among converged heterogeneous wireless networks. The handover signaling procedures with host-based MIPv6 are compared with network-based proxy MIPv6 (PMIPv6) and fast PMIPv6 assisted by G-MAG to show how much handover delay reduction can be achieved. Analytical results show that the handover delay is significantly reduced.

• Journal of Power System Engineering
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• v.12 no.2
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• pp.62-70
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• 2008

The paper made a description of the method for numerical analysis and modeling of a proportional pressure control valve by bondgraph. The valve is a three port pressure regulator valve, consists of two subsystems; a proportional solenoid and a spool assembly. A purpose of this study is to analysis the dynamic characteristics of the valve using bondgraph method and to verified results that each of parameters has an effect on modeling. It considered the effect which the presence of solenoid, flow coefficient and non-linearity of resistance causes in the valve modeling. In particular, it is analyzed the effect that the solenoid interacted with modeling results and characteristics of the nonlinear resistance through orifice on the supply and discharge side of valve. Thus this paper described method to present nonlinear characteristics by bondgraph modeling method, so that we could know easily result that each parameters has an effect on the modeling.