• Journal of Korean Society of Transportation
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• v.29 no.2
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• pp.111-121
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• 2011

This paper discusses a method for optimizing the semi-actuated traffic signal control system by adjusting the initial interval according to the number of vehicles waiting for the green light in the actuated phase. We also present a Left-Turn actuated traffic signal control strategy that examines the vehicular noise in the detection area and determines the phase extension and the gap-out. In order to detect the vehicles in real-time, an image detector's Video Image Tracking technology was adopted. A 'Zone in Zone'method was implemented, and the image detection area is segmented into three zones: 1) Zone1 for verifying a vehicles obligatory presence, 2) Zone2 for counting the standby vehicles, and 3) Zone3 for examining the number of vehicles that have passed. The on-site assessment of the Left Turn Actuated Control is carried out using CORSIM, and the results show that the Control Delay decreased by 23.10%, 15.06%, and 4.34% compared to the delays resulted from pre-timed control, semi-actuated control-1 and semi-actuated control-2 traffic signal control systems respectively. The Queue Time also decreased by 36.24%, 20.10% and the Total Time by 14.36%, 7.02% for the same scenario. Which clearly demonstrates the operational efficiency. A sensitivity analysis reveals that the improvement from the propose traffic control strategy tends to increase as the through traffic volume reaches a saturated condition and the left-turn traffic volume decreases.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.163-172
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• 2016

This study conducts an analysis of a problem on internet reservation of e-haneul funeral total information system by disqualified fee imposition standard in public cremation facilities through research and investigation focusing on the operational realities and an ordinance related to public cremation facilities made by each local government across the country, and then is to suggest a policy proposal to improve the drawn problem. As a result of the analysis, as a way to improve the drawn problems, this study suggests a policy proposal that prevents an illegal camouflaged move-in to reduce fee by restricting residence period in requirement of local residents inside the jurisdiction who can use public cremation facilities, raises fee of public cremation facilities of local residents inside the jurisdiction into the optimum level that is set cheaper than production cost, and unifies age norm of an object to apply adult fee in the central government about a difference of age norm of an object to apply fee of adult with the highest availability of public cremation facilities between local governments, resolving a fee difference through fee cutting of local residents outside the jurisdiction priced higher than production cost.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.6
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• pp.1133-1143
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• 2016

The purpose of this study is to improve project performance analysis indicators for BTL sewer rehabilitation projects. Among the assessment indicators for BTL sewer rehabilitation projects, an infiltration assessment indicator is given a high score of 17.5 points as a single assessment item. This infiltration assessment indicator is assessed focusing on the amount of infiltration, and presently calculated according to 'Nighttime Domestic Flow Evaluation' method. However, this assessment indicator's failure to reflect the geological features of Jeju region is emerging as a problem in the operational stage. Thus, this study intended to compare and analyze the calculation result depending on the assessment indicators and the actual amount of infiltration, centering on Jeju region. To this end, this study analyzed the amount of infiltration in five areas of Jeju Province calculated according to 'Nighttime Domestic Flow Evaluation' method. Also, a complete enumeration survey was carried out about the conditions for actual infiltration occurrence. According to the results of this survey, ground water level is distributed lower than the level of sewer pipes. The results of a sewer pipe function test show there was no infiltration occurrence caused by sewer pipe defect. So, it is concluded that 'Nighttime Domestic Flow Evaluation' method, which is utilized for the current assessment indicator, is not appropriate to apply to Jeju region, and it is thought that there is a need to establish infiltration criteria specialized for Jeju region.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.5
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• pp.92-102
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• 2016

While there have many completions of large parks recently under development, there has been a dearth of quality assessments. Studies focused on post-evaluation have been made to resolve this, but most of these are biased toward user satisfaction after completion and therefore behaviour analysis has limitations on solving problemsduring the actual design implementation processes. Therefore, this study examined the internal phenomenon and structure of the implementation process of design competition through the ground theory and microscopic independent perspective. As a result, maintaining the identity and differentiation of parks derived from the preserved design competition scheme contributed greatly to completeness and satisfaction. Outcomes were mainly caused by the trust of public officials as the ordering organization, the will of policy decision-makers, and the competence of operational enterprises, etc. Negative factors such as undermining the whole concept of the park and landscape occurred as external pressure and related subjects intruded on change design factors due to variations in social conditions. Additionally, illogical construction processes occurred, such as a reinvestigation of the budget for restoration after damaging on original landscape. There have been needs for the improvement of the work processing system. On balance, an interventional role is very important in the park construction process, especially the PA and operation committee in terms of maintaining the basic direction, landscape design supervision for detailed designs, and expert construction management on LA in terms of rational work management in the field. The study, using the microscopic perspective of the designer and ground theory, deliver significant meaning as an early study by suggesting alternative methods for the after-evaluation of large parks and structurally looking into main influence factors driven during the construction process.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.10
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• pp.791-799
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• 2020

Launched in October 2019, Northrop Grumman's MEV-1 was the world's first unmanned mission demonstrating the practical feasibility of on-orbit servicing. Although the concept of on-orbit servicing was proposed several decades ago, it has been developed to various mission concepts providing services such as orbit change, station keeping, propellant and equipment supply, upgrade, repair, on-orbit assembly and production, and space debris removal. The historical success of MEV-1 is expected to expand the market of on-orbit servicing for government agencies and commercial sectors worldwide. The on-orbit servicing essentially requires the utilization of a highly propellant efficient electric propulsion system due to the nature of the mission. In this study, the space mission analysis for a simple on-orbit mission involving Hall thruster is conducted, which is life extension mission for geostationary orbit satellites. In order to analyze the mission, design space exploration for various Hall thruster design variable combinations is performed. The values of design variables and operational parameters of Hall thruster suitable for the mission are proposed through design space analysis and optimization, and mission performance is derived. In addition, the direction of further improvement for the current on-orbit mission analysis process and space mission analysis involving Hall thruster is reviewed.

• Journal of Cadastre & Land InformatiX
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• v.44 no.2
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• pp.209-230
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• 2014

There are three forms of REITs company in Korea that was first introduced in 2002. Each REITs have been listed on the KRX, its characteristics are different, but it is classified as a REITs company in all events. REITs current methods are applied uniformly manner that does not reflect the characteristics of the individual. REITs some, that is not seen unlike legislative intent, it is delisted, such as generating an investment loss of investors. In this study it is an object of the invention from the point of view of REITs business validity, to draw up operational support aggressive plans of the scheme. By improving the PF assesment system, to improve the relevance of REIT business and presenting policy direction to the activation of REITs. Through the sophistication of real estate finance utilizing REITs, policy for proper investment of general investors REITs funds were listed with the smooth flow must be realized. The results of this study, it can be utilized as basic data for policy to reflect the real estate policy for activation of the indirect financial investments.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.4
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• pp.105-119
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• 2014

With its growing awareness by public today, along with our heritage gaining higher standing - such as being listed as World Heritage - the needs for managing cultural heritage that meet global standard is required, and public's interest towards national heritage growing higher, Cultural Heritage Administration is actively pursuing related projects for scenic amenity that include systematic preserve/manage/restore the heritage including surrounding environment, also propose harmonious landscape. 1,834 cases of allowance limit for state-designated cultural heritage change are prepared as part of the plan, and the standards are being expanded actively towards designated cultural heritage across the country, contributing towards administrative efficiency and living conditions of the locals significantly. However, some definitions are unclear and possible complaints might arise when applied due to choice of the law, this research prepares the base material for efficient management of the establishment by diagnosing overall operational status and proposing alternatives towards the limit and improvements after reviewing the result. Through this, we expect to see establishment of policies for better management of cultural heritage and its scenic amenity via maximizing administrative efficiency, whilst positively enhance resident satisfaction around the heritage area as well as settling the regulations in short term.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.419-427
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• 2020

In the case of large combined weapon systems, such as submarines, the application, and verification of methods of setting the reliability, availability, and maintainability (RAM) target values for conventional weapon systems are limited. Submarines are complex weapon systems with the characteristics of the diversity of operation mode summary and mission profiles (OMS/MP) as well as equipment complexity because they are composed of multiple weapon systems, such as sonar systems and armed systems. Therefore, this study analyzed the development cases of existing weapon systems, i.e., the RAM target value-setting cases, and derived the problems and limitations of the cases to present measures to improve the setting and verification of the ram target values of submarines. In addition, submarines operate around the world and have different operating and maintenance conditions. Therefore, a submarine's ram target values should be set and verified centering on the mission essential equipment and mission critical equipment, instead of all components that constitute weapon systems. This study examined a method to verify the required performance RAM target-value setting, considering the characteristics of submarines as well as the physical performance requirements for the systems and equipment of submarines that must be considered when implementing national defense acquisition projects for submarines.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.223-229
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• 2020

The current technological advances are changing the way people live. In the history of war in the past, nations or people with an edge in military science and technology have always been the victor. The emergence of new technologies not only alters war patterns drastically but also affects military operational concepts and organizational systems. As the paradigm of the security environment changes, developed countries are investing heavily in defense R & D for their security. Therefore, the importance of professionalism of the defense acquisition personnel who perform their tasks from the exploration and development of weapon systems to mass production, deployment, and logistics support cannot be overemphasized. In the United States, an advanced country in this field, to improve the work efficiency of acquisition personnel in the defense field, the Directive of Ministry of Defense issued a law on education and training career development for personnel in 1990. The present study refers to related materials, such as the Desk Guide for the main education requirements for the US acquisition personnel in the military field, which contributes to the improvement of the workforce of the acquired manpower after the systematic education system.

• Journal of Biosystems Engineering
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• v.8 no.1
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• pp.17-29
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• 1983

The milling process is considered as causing one of the greatest grain losses among all the processes in rice post-production. Major source of grain losses in the rice milling is considered as the whitening process. This study was attempted to develop an abrasive-type whitener, the whitening chamber of which being supplied by jet-air evenly and continuously. To investigate the milling performance by the new whitener, three kind of emery-stone grit(#36, #41, and #46), and three levels of rotational speed of emery stone roller (950, 1070, and 1200 rpm) were tested. The jet-air abrasive-type whitener was also compared with the conventional abrasive-type having no jet-air blower in terms of their milling performance. In addition, the effect of different combinations of sequential uses of the abrasive- and friction-type whiteners on the milling performance was also experimentally evaluated. The results of this study are summarized as follows; 1. In general, the whitening system combined with the abrasive type whitener with jet-air supply, which was newly designed, and the existing jet-air friction type whiteners produces more milled- and head-rice by about 0.3% points and 2.8% points, respectively than the system combined with the existing abrasive type without the jet-air supply under the same operational conditions. The former also consumed less electricity by 0.024 KwH per 100kg of milled rice production and gave more milling capacity by about 35 kg/hr. As compared with the conventional whitening system consisting of jet-air friction type whiteners only, the former yielded more milled- and head-rice by 1.5% points and 4.4% points, respectively. 2. The abrasive roller having 46 grit emery was better than the roller having 36 grit in aspects of milling performance and machine efficiency, in general. 3. With regard to the effect of combination method of abrasive type and friction type whiteners, one pass in abrasive type plus three passes in friction type gave better milling performance and energy efficiency than the two passes in abrasive type plus two passes in friction type regardless of the designs of the emery stone rollers. 4. The increase in rotational speed of the emery stone roller from 950 rpm to 1200 rpm presented negative effects on milled and head-rice yields and machine efficiency, but slightly positive effect on milling capacity.