• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1289-1292
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• 2006

The demand on a turnout layed on a bridge is rising owing to the increasing number of stations on the viaduct. And also the demand on a turnout with CWR is rising to upgrade running speed of the passing train. A CWR connected with turnout is subjected to additional axial force induced by the actions due to change in temperature, braking and starting force, and bending of the deck. But magnitude and distribution of the axial force in rails of turnout is not clear yet. So, in this study, a field measurement was conducted to know them. The strain gage method was adopted for field test. The FBG sensor for the strain measurement was used to ensure stability of test value and durability of gage for long term. It is expected that we can get data on the axial force in rail connected with turnout with respect to seasonal temperature change by the established field test system.

• 자원ㆍ환경경제연구
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• 제30권2호
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• pp.237-268
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• 2021

에너지전환 정책의 가속화로 변동성 재생에너지가 가파르게 증가하면서 계통수용비용이 빠르게 상승하고 있다. 변동성 재생에너지 증가는 기존 전통적 발전자원의 이용률을 하락시켜서 전력공급에 비효율성을 가중시키는데 이에 대한 해결책으로 수요자원이 주목받고 있다. 본 연구에서는 수요자원 중 큰 잠재력을 가지고 있는 전기차 수요가 재생발전에 대한 유연성 자원으로 활용될 경우 전력공급비용을 얼마나 경감시킬 수 있는지 9차 전력수급계획을 반영하여 분석하였다. 분석모형으로 재생발전의 확률적 특성을 사실적으로 반영할 수 있는 확률적 전력시스템 최적화 모형을 적용해서 재생에너지가 유발하는 비용과 전기차 수요자원의 편익을 분석하였다. 분석결과 계시별 요금제보다 가상발전소 기반의 직접제어방식이 편익이 더 높고, 발전구성에서 재생에너지의 비중이 높아질수록 편익이 더 높아지는 것으로 나타났다. 전기차 수요자원의 구현비용인 중개사업자 수수료와 배터리마모비용을 고려한 순편익 추정결과, 충방전이 가능한 가상발전소 방식의 경우 월평균 운행비용의 67~85% 수준으로 나타났다. 이러한 수요자원 순편익이 소비자에게 효과적으로 분배되는 요금체계가 적용될 경우 시장참여유인이 높을 것으로 추정된다.

• Journal of Preventive Medicine and Public Health
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• 제22권4호
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• pp.542-554
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• 1989

The skyrocketing inflation of medical costs has become a major health problem among most developed countries. Korea, which recently covered the entire population with National Health Insurance, is facing the same problem. The proportion of health expenditure to GNP has increased from 3% to 4.8% during the last decade. This was remarkable, if we consider the rapid economic growth during that time. A few policy analysts began to raise cost containment as an agenda, after recognizing the importance of medical cost inflation. In order to Prepare an appropriate alternative for the agenda, it is necessary to find out reasons for the cost inflation. Then, we should focus on the reasons which are controllable, and those whose control are socially desirable. This study is designed to articulate the theory of medical cost inflation through literature reviews, to find out reasons for cost inflation, by analyzing aggregated data with a deterministic model. Finally to identify determinants of changes in both medical demand and service intensity which are major reasons for cost inflation. The reasons for cost inflation are classified into cost push inflation and demand pull inflation, The former consists of increases in price and intensity of services, while the latter is made of consumer derived demand and supplier induced demand. We used a time series (1983-1987), and cross sectional (over regions) data of health insurance. The deterministic model reveals, that an increase in service intensity is a major cause of inflation in the case of inpatient care, while, more utilization, is a primary attribute in the case of physician visits. Multiple regression analysis shows that an increase in hospital beds is a leading explanatory variable for the increase in hospital care. It also reveals, that an introduction of a deductible clause, an increase in hospital beds and degree of urbanization, are statistically significant variables explaining physician visits. The results are consistent with the existing theory, The magnitude of service intensity is influenced by the level of co-payment, the proportion of old age and an increase in co-payment. In short, an increase in co-payment reduced the utilization, but it induced more intensities or services. We can conclude that the strict fee regulation or increase in the level of co-payment can not be an effective measure for cost containment under the fee for service system. Because the provider can react against the regulation by inducing more services.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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• pp.288-295
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• 2000

As the level of earthquake intensity in Korea is considered to be moderate, some structures or structural elements may be subjected to the reduced ductility demand, in contrast to the structures in high seismicity, due to the large inherent strength induced by gravity loads. New Zealand Standard(NZS) deals with these structures within the category of structures of limited ductility. This paper briefly reviews the concept of structures of limited ductility in NZS, and its applicability to Korean case. A structural wall system which is used as the structural system for typical apartments is taken as an example for the illustration.

• 통상정보연구
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• 제9권4호
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• pp.127-139
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• 2007

There are three methods to examine import structures : 1) look at import coefficient, 2) import dependency, and 3) composition ratio of imported products. Therefore, this study analyses the import structure of Korea using the three methods above and when final demand occurs on produced goods and services in each industrial section, it divides import induction coefficients that indicate size of induced import directly and indirectly into consumption, investment and export to identify the effect of export on import induction.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.219-220
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• 2003

The success of recirculating system depends largely on the treatment efficiency of waste generated in the system. fine solids were suspected to be responsible for fish kill in a recirculating system. Clogging of biofilter may be induced by high solids concentration in recirculating systems. Also, the solids could generate more ammonia nitrogen and oxygen demand if not removed out of recirculating system as soon as possible (Weeks et al., 1992). (omitted)

• 한국전기전자재료학회논문지
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• 제33권5호
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• pp.360-366
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• 2020

Focused electron beams with high energy acceleration are versatile probes. Focused electron beams can be used for high-resolution imaging and multi-mode nanofabrication, in combination with, molecular precursor delivery, in an electron microscopy environment. A high degree of control with atomic-to-microscale resolution, a focused electron beam allows for precise engineering of a graphene-based field-effect transistor (FET). In this study, the effect of electron irradiation on a graphene FET was systematically investigated. A separate evaluation of the electron beam induced transport properties at the graphene channel and the graphene-metal contacts was conducted. This provided on-demand strategies for tuning transfer characteristics of graphene FETs by focused electron beam irradiation.

• 전기학회논문지P
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• 제65권1호
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• pp.1-6
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• 2016

Recently, proportion of the induction motor load is gradually increased. When a contingency in the power systems, it has been discovered phenomenon that the voltage is delayed recover caused mechanical characteristics of the induction motor load. It can be a serious impact on the voltage stability of the power system considering induction motor load. The scheme to mitigate this phenomenon tripping off the motors to prevent voltage drop and delayed voltage recovery on the load demand side. Fault induced delayed voltage recovery phenomenon is caused by stalling of small induction motor load in transmission level contingencies. In this paper, fault induced delayed voltage recovery phenomenon mitigation method implementation under voltage load shedding on the korean power system considering induction motor load.

• 소성∙가공
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• 제17권6호
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• pp.443-448
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• 2008

Fiber reinforced injection molded parts are widely used in recent years because of their improved properties of materials such as specific stiffness, specific strength, and specific toughness. The demand for products with high precision is increasing and it is important to minimize the warpage of the products. The warpage of short-fiber reinforced product is caused by anisotropy induced by fiber orientation as well as the residual stresses induced during the molding process. In order to reduce the warpage of the part, it is important to achieve successful mold design, processing control, and part design. In the present study, the design of gating system, molding condition, and part structure were carried out and verified with numerical analysis using a commercial CAE code Moldflow. The numbers and locations of gates were iteratively determined, and the molding conditions which can decrease the warpage of the part were investigated. Finally, slight structural modification of the part was conducted to reduce the locally concentrated warpage.

• 한국레이저가공학회지
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• 제11권2호
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• pp.33-38
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• 2008

Laser micromachining has increasingly been adopted in various advanced industries where the high-precision machining of large-area, high-density and multi-layered components is in a strong demand. To effectively meet the requirements, the laser micromachining process must be carefully monitored. In order to facilitate the development of a new laser micromachining process and/or a new system, we have fabricated a UV laser micromachining platform that is equipped with optical modules for monitoring the process online. They include a laser power stabilizing module, a module for laser-induced breakdown spectroscopy, and an auto-focusing module.