• KIEAE Journal
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• v.9 no.5
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• pp.105-113
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• 2009

Daylighting provides the opportunity for both energy savings and improved visual comfort. An accurate estimation of the amount of daylight entering a building is the key step for daylight designing. This research aims to assess comparative daylighting performance of four different configurations of fenestration in case of unilateral windows and their variation under clear and overcast sky conditions. The selected window openings in this study were single punched, double punched, multiple punched and clerestory, and the area was same for each type of window. The experiment was designed for an office space using 1/10 scale model. Daylighting performance was evaluated by measuring the illuminance on work-plane height using Agilent data logger and photometric sensor Li-Cor. Thecomputer program ECOTECT was also used to simulate the pattern of interior illuminance distribution. Clerestory window showed the best performance in term of both illuminance level and distribution in the experiment. Multiple punched window provided more uniform illuminance distribution than single punched window. Lowest daylighting performance in the experiment was shown by double punched window.

• International Commerce and Information Review
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• v.7 no.4
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• pp.157-177
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• 2005

In many countries, a Single Window system for simplifications is establishing in order to reduce works submitted double data and compliance costs. A Single Window is defined as a facility that allows parties involved in trade and transport to lodge standardized information and documents with a single entry point to fulfil all import, export, and transit-related regulatory requirements. A Single window can bring improved level of security, faster clearance and reduced compliance costs. UN/CEFACT released "Recommendation and Guidelines on establishing a Single Window to enhance the efficient exchange of information between trade and government". Also, WCO has made progress several projects to assist effective establishing a single window, i.e. CDM, UCR, ICT. Korea has being established a single window system, "e-trade platform" connected with trade, clearance, logistics, marketing and payment system. Some suggestions to establish a effective single window system in Korea are as follows. Firstly, it is necessary to clearly define roles and responsibilities of a lead agency in a single window system and form a organic relationship with PGA. Secondly, a single window system has to be progressed by stages, namely, customs clearance portal system should be established first, and later established e-trade platform. Lastly, the Korean government has to take part in CDM project to gain an advantage over other countries.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.9
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• pp.3110-3125
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• 2014

Network coding improves TCP's performance in lossy wireless networks. However, the complex congestion window evolution of network coded TCP (TCP-NC) makes the analysis of end-to-end throughput challenging. This paper analyzes the evolutionary process of TCP-NC against lossy links. An analytic model is established by applying a two-dimensional Markov chain. With maximum window size, end-to-end erasure rate and redundancy parameter as input parameters, the analytic model can reflect window evolution and calculate end-to-end throughput of TCP-NC precisely. The key point of our model is that by the novel definition of the states of Markov chain, both the number of related states and the computation complexity are substantially reduced. Our work helps to understand the factors that affect TCP-NC's performance and lay the foundation of its optimization. Extensive simulations on NS2 show that the analytic model features fairly high accuracy.

• Atmosphere
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• v.20 no.3
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• pp.287-306
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• 2010

An ensemble Kalman filter (EnKF) with Weather Research and Forecasting (WRF) Model is applied for Typhoon Wukong (200610) to investigate the performance of ensemble forecasts depending on experimental configurations of the EnKF. In addition, the ensemble sensitivity analysis is applied to the forecast and analysis ensembles generated in EnKF, to investigate the possibility of using the ensemble sensitivity analysis as the adaptive observation guidance. Various experimental configurations are tested by changing model error, ensemble size, assimilation time window, covariance relaxation, and covariance localization in EnKF. First of all, experiments using different physical parameterization scheme for each ensemble member show less root mean square error compared to those using single physics for all the forecast ensemble members, which implies that considering the model error is beneficial to get better forecasts. A larger number of ensembles are also beneficial than a smaller number of ensembles. For the assimilation time window, the experiment using less frequent window shows better results than that using more frequent window, which is associated with the availability of observational data in this study. Therefore, incorporating model error, larger ensemble size, and less frequent assimilation window into the EnKF is beneficial to get better prediction of Typhoon Wukong (200610). The covariance relaxation and localization are relatively less beneficial to the forecasts compared to those factors mentioned above. The ensemble sensitivity analysis shows that the sensitive regions for adaptive observations can be determined by the sensitivity of the forecast measure of interest to the initial ensembles. In addition, the sensitivities calculated by the ensemble sensitivity analysis can be explained by dynamical relationships established among wind, temperature, and pressure.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.73-80
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• 2005

Both theoretical and experimental investigations were conducted to analyze defrosting behavior of a window heater operating in the low outdoor temperature($-20^{\circ}C$). To achieve this purpose, first a warm-chamber experiment($23^{\circ}C$) was performed to measure inner and outer surface temperature of the rear window(heated by the electric heater supplying 195 W) as functions of both time and position. Secondly, a cold chamber experiment was made to continuously record defrosting process of the frosted window. From the comparisons of the two experimental results, it was found that there was a similarity between the spatial distributions of both temperature and remaining frost. Thus, the temperature data from the warm-chamber experiments can be utilized to predict an expected zone covered with remaining frosts, and this approach can also be adopted in the inspection process in order to economically guarantee optimized performance of the window heater. Finally, an analytical model based on one-dimensional, steady-state heat transfer theories was proposed and successfully predicted the outer surface temperature of the rear window surrounded by cold air($-20^{\circ}C$) for the given operating conditions(heater power, inside and outside heat transfer coefficients, and surrounding air temperature, etc.).

• KIEAE Journal
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• v.12 no.6
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• pp.123-128
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• 2012

A window increases the lighting quality of a space by allowing daylight into the space, and maintains visual contact with the outside. Moreover, the window with a preferred view provides many benefits such as psychological satisfaction, occupants' health and improved environmental quality. This study aimed to investigate how view elements and window luminance influence occupants' seating preference in a living room. The experiment was carried out in a mock-up model with thirty-two subjects (17 men and 15 women). The nine seating positions in a living room have different view such as natural view (trees or sky) and man-made view (paving and roof top). Subjects were asked to select a position in the room where they felt most visual comfort. Simultaneously Photolux 2.1 software was used to analyze the window luminance. The experiment results indicated that subjects prefer to be seated near a window and feel comfort in a seating overlooking the trees and sky. This would indicate that the natural elements of the view and a distance to the window affect seating preference to the occupants.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.3
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• pp.301-309
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• 2007

Netherlands had suggested a uniform system to standardize and simplify EDI systems relating to the Arrival/Departure, stay, and clearance of ships, persons, and cargoes for the Facilitation of International Maritime Transport to the International Maritime Organization(IMO). Republic of Korea proposed the Framework of XML-based Single Window System for the simplified clearance of ships to the 32nd session of Facilitation Committee of the IMO. Accordingly the authors studied that the XML Infrastructure for Single Window efficiently supports the Single Window service and the business collaboration between business entities of logistics. The proposed XML Infrastructure designs to support the various document format translation and to easily manage. Therefore business entity using the proposed system has the effect of downing the resource and costs on using Single Window.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.101-102
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• 2006

XML 기반의 Single Window은 국제 표준에 입각하여 해운 분야의 전자문서를 사용하여 국제해사기구와 전세계적으로 공통된 양식을 사용한다. 이는 동일한 양식의 전자문서를 사용하는 사용자들 간은 통용될 수 있다는 의미이며, 민원인 입장에서는 정보의 재사용성과 중복 입력의 불합리함을 줄일 수 있다. 이로써 민원인들은 입출항 수속 간소화 뿐만 아니라 해운 업무 자체에 많은 업무 개선 효과를 볼 수 있다. 본 고에서 제안한 XML 인프라스트럭처(XML infrastructure for Single Window)는 ebXML 기반의 Single Window에 적합하도록 설계 및 구현되었으며, 자원의 재사용성과 중복 투자를 방지할 수 있도록 하였다. 즉, 사용 환경에 유동적으로 적용가능 하도록 컴포넌트 방식으로 구성되었으며, 기존 시스템을 최대한 활용하도록 구성할 수 있도록 하였다.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.4
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• pp.342-349
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• 2011

This paper considers the inbound and outbound truck scheduling problem in a cross docking terminal. The unloading process from inbound trucks and loading process to outbound trucks are assumed to be performed within a time window. If some items are not able to be loaded to their scheduled outbound trucks within the time window, they are stored in the terminal and shipped using the truck visiting the next time window. The objective of this paper is to schedule inbound and outbound trucks to minimize the number of items unable to ship within the time window. A mathematical model for an optimal solution is derived, and a rule-based local search heuristic algorithm and genetic algorithm (GA) are proposed. The performance of the algorithms are evaluated using randomly generated several examples.

• Journal of Sensor Science and Technology
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• v.28 no.3
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• pp.146-151
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• 2019

This paper reports a sliding window filtering approach for ground moving targets with cross-correlated sensor noise and uncertainty. In addition, the effect of uncertain parameters during a tracking error on the model performance is considered. A distributed fusion sliding window filter is also proposed. The distributed fusion filtering algorithm represents the optimal linear combination of local filters under the minimum mean-square error criterion. The derivation of the error cross-covariances between the local sliding window filters is the key to the proposed method. Simulation results of the motion of the ground moving target a demonstrate high accuracy and computational efficiency of the distributed fusion sliding window filter.