• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.860-865
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• 2006

The traditional Korean Ondol System that is a radiant floor heating system was made as warm floor and cool indoor temperature. Nowaday, Ondol is developed as the hydronic floor heating system. But unbalance of floor temperature and indoor temperature is occurred bocause strengthen thermal insulation and airtightness in building changes thermal performance. To solve these problems, we examine actual indoor environment of heating system methods in existing apartments and present the new method of floor heating system. The existing heating system made definite indoor temperatures but floor temperatures that is $22^{\circ}C-26^{\circ}C$ was maintained. To solve these problems, we adopted the differential heating system which made warm area and cool area. A differential heating system was made different pitches of heating pipe in single zone and ratio of warm area to cool area is 1 to 2. As a result of experiments, warm area temperature is $40.7^{\circ}C$, cool area temperature is $36.1^{\circ}C$. A difference of temperature between both area is 4K. A distribution of indoor vertical temperature is similar to both warm area and cool area.

• Journal of Environmental Health Sciences
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• v.5 no.1
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• pp.76-85
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• 1978

This survey was undertaken for the period seven month beginning January 15, 1977 and ending July 31, 1977 to detect the general sanitary status of the villages and the villagers and, at the same time, analyse quality of water sources with emphasis on a total of 1,256 households dividing into three different groups: such as, 280 households were selected as random samples from the area of the sophisticated piped water supply system, 122 households from the area of the simplified water supply system and finally 854 households from the area of nonpi-ped water supply system. The following results were concluded after quality of water sources had been analysed and conditions of the environmental sanitation had been reviewed: 1. 11.2% of the respondents from the area of the sophisticated piped water supply system responded that quantity of drinking water lacked to meet their demand while 30.6% of the villagers from the area of nonpi-ped water supply system responded quantity of drinking water didn't meet their demand. 2. 30.8% of the.respondents from the area of the sophisticated water supply system responded that contaminating source located within 15 meters from the water source while 54.4% of the respondents from the non-piped water supply system claimed the same. 3. It was found that water from all sampling areas were positive in coliform group with exception of Moonsan which is one of the sophisticated piped water supply system groups and the number of general bacteria exceeded the government standard criteria of water quality in the area of the nonpi-ped water supply system. 4. In relation with time requirement to draw water in the area of non-piped water supply system, 76 respondents claimed it requires less than 15 minutes to draw water, 15.0% claimed 15 to 30 minutes and 9.0% claimed more than 30 minutes. 5. In relation with knowledge on sanitation of drinking water, 30.8% of respondents from the area of the sophisticated piped water supply system and 41.8% of respondents from the area of nonpiped water supply system denied possible existence of germ in drinking water they drink, while 17.4% of the respondents from the area of the sophisticated water supply system and 50.2% of non-peped water supply system thought it safe to drink water without any treatment. 6. 60.0% of the respondents from the area of non-piped water supply system and many of them believed that their health status will be improved by installation of a sophisticated water supply system in their area. 7. The respondents from the areas of piped water supply sytem expressed greater concern over drinking water sanitation than those from the areas of non-piped water supply system and sanitary conditions were found the same. It was, therefore, proved that knowledge of environmnntal sanitation contributed a great deal to improve sanitary conditions of the villages and villagers and at the same time health education, especially environmental sanitation, will be played a important role to improve their sanitary conditions.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.8
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• pp.437-443
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• 2003

In this paper an expert system is developed to decide the resetting area of protective devices in power transmission systems. A configuration change in power transmission networks from a substation extension such as new line or bus addition need resetting of protective devices around the point of configuration changes. To find the resetting area in complex power system is very difficult, especially when the distance protective relays are considered to be reset. The proposed expert system, in this paper to find the resetting area has many rules based on the changes of fault currents and apparent factors from the power system alteration. It solves the problem to find relay resetting area using the network information in the database and the rule-base. The case study shows a result of the problem to find relay resetting area in KEPCO system when there is any configuration change.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.3
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• pp.307-314
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• 2023

Wide-Area Differential Global Positioning System (WADGPS) is a system that operates a number of reference stations to provide correction information to improve the accuracy of GPS users, and it is available to service users within the area where the wide-area reference stations are installed. Recently, as positioning information has been used in various applications, the need for WADGPS for precise navigation in long-distance spaced areas where the wide-area reference stations cannot be installed has been raised. This paper tested the user navigation performance outside the wide-area reference stations of the WADGPS system, which serves both GPS Precise Positioning Service (PPS) and Standard Positioning Service (SPS) users. Static and dynamic tests were conducted using vehicles, and as a result, position accuracy improvement through WADGPS was confirmed even at points hundreds of kilometers outside the network area of the wide-area reference stations. Through this, the performance of the PPS/SPS correction system and the possibility of expanding the service area were confirmed.

• Journal of Korea Port Economic Association
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• v.31 no.3
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• pp.121-140
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• 2015

The present study examines how to construct a transport system for tourism in the marine city area of Yeosu. An effective tourism transport system is needed in Yeosu to promote ocean tourism in Korea's southern coastal region. The problems in Yeosu's transport system for ocean tourism were identified by comparing it with the Bay Area in the United States; future improvement methods were deduced accordingly. The transport support system for ocean tourism in Yeosu area was insufficient in many aspects compared with the Bay Area, such as intercity transportation, urban transport systems, and transport information systems. Thus, this study suggests various approaches to building a new ocean tourism transport support system in Yeosu. Connecting transport modes and ocean tourism resources, such as linking intercity and urban transport modes with ocean tourism transport modes, is suggested. It is also recommended that a cooperative transport support system be established for ocean tourism in the neighboring regions of Yeosu. Furthermore, an integrated transport information system for ocean tourism needs to be provided to connect the system efficiently with ocean tourists. This integrated transport support system could lead to a decrease in the cost and time needed for travel.

• Land and Housing Review
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• v.11 no.2
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• pp.69-74
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• 2020

The purpose of this study is to investigate the effect of floor area ratio incentive system for Long-life housing certification system by simulation of five recently built apartment complexes. Apartments that are certified as superior in Long-life housing can receive 10% of the floor are incentive in Seoul. However, the difference between base and permitted floor area ratio are in general residential area of class 2 and 3 is not more than 20%. limit of feasible allowance incentive is limited. Even if there is an unrealized permitted floor area ratio, there is no reason to apply the Long-life housing certification system preferentially. Because the items of the floor area ratio incentive provided by the District Unit Plan are various, it shows that the floor space ratio incentive for Long-life housing certification system has little effectiveness. To enhance the feasibility of incentives for the Long-life housing certification system, improvement in the urban planning level, including district unit planning, including the design criteria for apartments in Seoul, is needed.

• Journal of the Korea Society for Simulation
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• v.14 no.3
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• pp.79-90
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• 2005

There are plenty of optimization models for the signal-system of a single intersection and area traffic. Some of those models are adopted for the real traffic signal control system. The simulators for a single crossroad have been developed, so that we could evaluate optimization models and traffic control systems. However, the simulators for the area traffic are still being developed. Therefore, there are many limitations in the analysis and evaluation for area traffic control system. The area traffic is consisted of several intersections which are very complicated and many traffic strategies are adopted for the control system. This paper features an effective area traffic control system based on the High Lever Architecture(HLA). In this paper, we discuss the design of HLA-based area traffic control simulation. We describe technical motivations for the HLA, the key elements of the architecture and how they are minimum and essential to the goal of reuse and interoperability. A distributed simulation with HLA/RTI provides stable and satisfactory experimental results. Moreover, the prototype traffic control system provides reliable accomplishment compared to the NETSIM and TRANSYT-7F models.

• Proceedings of the KIEE Conference
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• summer
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• pp.33-35
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• 2004

The secondary voltage control is the method the pilot bus controls the voltage of the voltage control area sufficiently uncoupled form its neighbours within a area to k slightly influenced by the actions carried out in the other areas. This paper presents the comparison of three methods which determines the voltage control area for the secondary voltage control in power system. Additionally, this paper selects the fitted thing of three methods determining the voltage control area, VSSA, and using it applies the procedure determining the voltage control area to KEPCO system.

• Journal of Electrical Engineering and Technology
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• v.8 no.3
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• pp.472-477
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• 2013

An internet-based, real-time GPS synchronized wide-area power system frequency monitoring network(FNET) has been monitoring wide-area power system frequency in continuous time in the United States. This paper analyzes the FNET measurement to the verified disturbances in the US eastern interconnected power system and simulates it using the dynamic system model. By comparing the frequency measurements with its simulation results to the same disturbances in detail, this paper finds that the sequence of monitoring points to detect the frequency fluctuation caused by the disturbances is matched well in the measured data and the simulation results. The similarity comparison index is also proposed to quantify the similarity of the compared cases. The dynamic model based simulation result is expected to compensate for the lack of FNET measurement in its applications.