• Advances in aircraft and spacecraft science
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• 제5권2호
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• pp.205-223
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• 2018

During launch a spacecraft is subjected to a variety of dynamical loads transmitted through the launcher to spacecraft interface or air-born transmission excitations in the acoustic pressure field inside the fairing. As a result, spacecraft are tested on ground to ensure and demonstrate the global integrity of the structure against these loads, to screen the flight hardware for quality of workmanship and to validate mathematical models. This paper addresses the numerical modelling and simulation of the low frequency sine and random vibration tests performed on electrodynamic shaker facilities to comprise the mechanical-borne transmission loads through the launcher to spacecraft interface. Consequently, the paper reviews techniques and methodologies to derive a reliable and representative coupled virtual vibration testing simulation environment based on experimental data. These technologies are explored with the main objectives to ensure a stable, reliable and accurate control while testing. As a result, the use of the derived simulation models in combination with the added value of improved control and signal processing algorithms can lead to a safer and smoother vibration test control of the entire environmental test campaign.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년도 추계학술발표대회 논문집
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• pp.121-125
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• 2009

The nursing-care insurance system started in April, 2000 in Japan. It was a kind of business opportunities for a lot of private entrepreneurs. They came into this care service business from another type of business rapidly. They opened the pay nursing homes with 24 hour nursing. However, the expense load of the nursing-care insurance system was large, local governments started controlling on total numbers of facilities with 24 hours nursing in 2006. So the group houses besides the pay nursing home without nursing care are paid to attention. The pay nursing home has been often managed by the nursing business. Most of the group houses are managed by community based NPO. This study is a case study by the visit and the interview form for one of the group houses. The group house "Shalom Tsukimino" in Kanagawa started operations comparatively at early time among them. Through the study we recognized that a lot of people were helping the NPO as a community service. So they can manage the group house and people who live there get the services with low cost. They show that they separate residence and nursing and use the community service efficiently. We can find a new direction in this case for the life in elderly.

• 한국안전학회지
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• 제28권5호
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• pp.35-40
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• 2013

Recently reclamation land is largely developed to utilize the land according to economic growth. The soil of landfill is soft, low shear strength, which makes it difficult to use the equipment. A large movement is occurred on the utility tunnel under construction. The inclined land with high water level and underground facilities are widely distributed and the excess pore water pressure may occur under construction similarly to this study. Some different conditions are made to design result, such as 4m of soil piling near the construction area, heavy rainfall during 2nd excavation that may cause flow liquefaction. To analyze the cause of transverse lateral movement, Three dimensional analysis are performed to four load cases, which is original design condition, flow liquefaction by heavy rainfall, unsymmetric lateral soil pressure, and both of them simultaneously. Ten steps of full construction stage, 1st excavation for utility tunnel, construction of utility tunnel, 1st refill, piling soil from 1m to 4 m, 2nd excavation for drainage culvert, liquefaction around the utility tunnel, construction of drainage culvert and 2nd refill, are take into account to investigate the cause of movement.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.390-393
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• 2007

The reliability as well as the power capability of the UPS system can be increased by replacing a single UPS unit with multiple small UPS units in parallel, resulting in a so-called module UPS. This module UPS system allows that a new module can be added or replaced while maintaining power to loads, which is a hot-swappable operation. In addition, it has desirable features such as ease of output power expandability, convenience of maintenance and repair, and high reliability. To realize the module UPS, load sharing without interconnection among parallel connecting modules as well as a small scale and lightweight topology is necessary. The frequency and voltage droop method is applied to parallel operation control to achieve load sharing. 5kVA modules are designed and implemented to confirm the effectiveness of the proposed approaches. Experimental results show that the module UPS system has a high power factor, a low distortion of output voltage and input current, hot-swappable operations and good load sharing characteristics.

• 한국항해항만학회지
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• 제44권5호
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• pp.430-437
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• 2020

This paper analyzes the profitability of the Private Finance Initiative(PFI) ports and proposes the application plans of the R-project(Rehabilitate project) for old ports to attract and activate private investment in the port industry. The R-project of old ports can reduce the government's financial budget and provide improved facilities for users more quickly than the public sector comparator. Before suggesting the R-project for old ports, the profitability of the currently operating 11 companies of the PFI ports are analyzed using the four ratios of profitability, and the results show that all the companies indicate low profitability, except for the top three companies. To apply the R-project, the three types of R-project ports are categorized as maintaining the function of the port, changing the function of the port, and mixing the function of the port. Additionally, three obstacles and improvement measures are suggested; attracting private business, legal issues, and administrative procedures. This study is conducive to the policy making for the port renewal and the activating PFI for the port industry.

• 전기학회논문지
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• 제65권9호
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• pp.1571-1576
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• 2016

A Tesla coil is an electrical resonant transformer circuit invented by Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high frequency alternating-current electricity. Tesla coil can generate a long streamer with several million volts of electricity as a high voltage device. It is basically consists of a voltage transformer, high voltage capacitor, spark gap, primary coil, secondary coil and toroid. It is difficult to appear in the output size of the streamer is controlled by the spark gap. The general decision method of the length of streamer is to display the electric output in accordance with the design specifications in initial development plan. Design specifications and the electric output is determined by the application of facilities. In this paper the spark gap is replaced with periodic switching semiconductor device to control output voltage easily in order to apply overvoltage protective circuit due to a secondary coil and a performance test. In these days, their main use is for entertainment and educational displays of the museum, although small coils are still used as leak detectors for high vacuum systems.

• 수산경영론집
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• 제26권1호
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• pp.55-77
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• 1995

This study analyzed the structure of imported fisheries, focusing especially on the following factors of live fisheries import : First of all, it is confirmed that the import of live fisheries expands when domestic production decreases. To put it concretely, the structure of domestic live fish supply is based upon the production of aquaculture, the shift from export to domestic use, and imported live fisheries. These all coexist, expand, and grow together. Secondly, the structure of the consumer's market - the background of expanding and growing live fisheries-is currently diversifying with quality and quantity from a local area consumer system based upon regional markets, to a wider ranged system based upon the food industry and retailing market. The existence of the consumer markets is premised upon a stable supply structure, in terms of material and price. Thirdly, in terms of trade policy, control of imports instantly reduces import goods. But it is reasonable to say that there is not any logical effectiveness of denying the stable growth of low market capital under the background of strong consummer expansion. Fourthly, the attitude of the import related managener organization is directly related to the degree to which it is connected to live fish import. It is demanded that such a managing organization possess suitable facilities, specializaed knowledge, and management skill of live fisheries. So it is predicted that newly introducing the importing of live fisheries is not simple. It indirectly shows that the capital which relates to live fisheries are connected with the importing og live fish fisheries.

• 한국공작기계학회논문집
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• 제10권2호
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• pp.29-37
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• 2001

The application of laser in pipelines was started from the base of using laser in nuclear facilities industries and power plants. Because laser can be delivered to a remote area without any difficulties, the application of laser in many industries can solve many difficulties from limitation of access in danger area and reduced the risks of workers. Therefore, we developed a new experimental technique to measure internal defects of pressure vessels with a combination of shearog-raphy and image processing technique. Conventional NDT methods have been taken relatively much time, money and manpower because of performing as the method of contact with objects to be inspected. But digital shearography is laser-based optical method which allows full-field observation of surface displacement derivatives. This method has many advantages in practical use, such as low sensitivity to environmental noise, simple optical configuration and real time mea-surement. In this paper, we find the optimum shearing magnitude with EFM and experiment and measured internal crack length of the pressure vessels at a real time and estimated the error of the results.

• 환경영향평가
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• 제22권5호
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• pp.397-408
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• 2013

The purpose of this study is to analyze water cycle area ratio and spatial evaluation of water cycle in urban area of Changwon-si, Gyeongsangnam-do. Water cycle area ratio are analyzed by using spatial data of land-cover and land-use, and Hot spot analysis of GIS program was used for spatial evaluation of water cycle. The results are as below. Firstly, the high water cycle area ratio areas were forests, parks, and rivers, but urban areas covered asphalt and concrete were low under 40%. Public institutions and co-residential of urban areas were higher than others because of high area ratio of pervious land-cover. Spatial evaluation of water cycle was analyzed to vulnerable areas there are dense residential and commercial area. These areas are really occurring frequently flooding and immersion, therefore, is required water management facilities and improvement of land-cover from impervious to pervious. In the future, it will require additionally analysis of water cycle area ratio supplemented data of water management facility and ground water.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.54-59
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• 2008

The poor maintenance and management of HVAC systems finally lead to the shortening of the life expectancy and result in the increase of operating costs and energy consumptions due to low efficiencies. Also, it is essential to try to develop ways to adequately maintain and to use the building facilities efficiently in order to preserve earth environment and the limited resource. In this study, an analysis on the maintenance and management cost for HVAC systems was carried out with the capacity of equipment. Besides, the LCC(Life Cycle Cost) based analysis was carried out to verify the effect of the doing maintenance and management. As the results, the case of the good maintenance and management is able to save LCC to 11 % than the case of the poor method.