• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.119-124
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• 2005

순로구분 자동화 시스템이 상용화를 앞두게 됨에 따라 실제 순로구분기의 운영계획을 비롯한 자동화 방안 등에 대한 연구가 활발히 진행되고 있다. 또한 순로구분기의 유형의 결정과 운영 방식을 고려한 자동화 효과를 분석하여 실제로 어느 정도의 경제적 효익이 발생할 수 있는가에 대한 청사진이 제시되어야 할 필요성이 있다. 그러나, 이제까지 순로구분의 자동화와 순로구분 시스템의 효율적인 운영을 위한 사업의 타당한 당위성이나 최적의 사업 및 운영에 대한 목표 등의 구체적인 모델링이 없었으며, 이러한 모델링을 위한 분석체계가 미흡했던 것이 사실이다. 이에 본 연구는 순로구분의 자동화 효과에 대한 경제성을 인건비 절감을 통하여 분석하고, 우편물량과 순로구분기 유형, 운영 일정에 대한 시나리오를 설정하여 각각 소요되는 자동화 비용을 분석하고, 현재의 수작업 순로구분에 비하여 경제적인 이득이 얼마나 발생하는가에 대하여 분석한다. 본 연구는 학술적으로는 순로구분 자동화라는 새로운 시스템이 도입됨에 따라 설정되는 정성적인 변수들을 계량화하여 이를 경제성 분석에 반영함으로써 상호 배타적인 투자안에 대한 결론을 도출하려고 노력하였다. 또한 우편업무 개선을 위한 실무적 측면에서는 순로구분기의 도입과 시스템이 실제로 상용화되는 과정에 따라 구체화되는 여러 요인에 따라서 요구되는 의사결정을 위한 기초 자료로써 활용될 수 있다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.404-409
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• 2007

To change rail tracks from main track to another track, it needs some device that is called turnout point. If the point which is composed of accurate parts and complex sensors does not work, serious problems will be arisen. However, there serious problems by the failure of the point. In this paper, after analyzing the failures of the conventional points, a new point is presented. The proposed point is not affected by surge caused by lighting.

• The Transactions of the Korea Information Processing Society
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• v.5 no.10
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• pp.2676-2685
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• 1998

In order to improve the branch prediction accuracy and to reduce the BTB miss rate, this paper proposes a two-level BTB structure that adds small-sized victim BTB to the convetional BTB. With small cost, two-level BTB can reduce the BTB miss rate as well as improve the prediction accuracy of the hybrid branch prediction strategy which combines dynamic prediction and static prediction. Through the trace-driven simulation of four bechmark programs, the performance improvement by the proposed two-level BTB structure is analysed and validated. Our proposed BTB structure can improve the BTB miss rate by 26.5% and the misprediction rate by 26.75%

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.735-741
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• 2007

A turnout system which permits trains to pass from one track to another is a combination of the switch, the crossing, lead rails which are necessary to connect the switch and the crossing, two guard rails and a switch machine for operating the switch. In Korea, it has been planned to adopt the high speed tilting train which is suitable for the circumstance of Korea and operates at the maximum speed of 180 km/h, at conventional lines by the year of 2010. For the present, the prototype of the tilting train has been fabricated, and has undergoing a trial run. In this study, evaluation of noise around the turnout system induced by the tilting train has been implemented through the field measurements.

• 주택과사람들
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• no.5 s.22
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• pp.72-85
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• 1992

[ $\bullet$ ] ''91 년간 전국평균지가상승률은 $12.78{\%}$로서 전년대비 $7.8{\%}$포인트 감소. $\bullet$ 서울의 지가상승은 $11.15{\%}$로서 ''90년의 $31.18{\%}$보다 무려 $20.03{\%}$ 포인트 감소하여 전국의 지가안정을 주도하고 있음. ${\cdot}$ 지역별로는 6대도시 : $13.57{\%}$, 중소도시 : $13.69{\%}$, 군지역 : $10.19{\%}$. ${\cdot}$ 용도지역별로는 주거지역 : $13.57{\%}$, 상업지역 : $12.22{\%}$, 공업지역 : $15.96{\%}$, 녹지지역 : $13.80{\%}$, 비도시지역 : $9.42{\%}$. $\bullet$ 특이사항으로는 ${\cdot}$ ''91. 4/4분기중 지가가 하락한 지역이 29개 시${\cdot}$군${\cdot}$구로서 이중에서 중요한 지역을 보면 서울 중구($-2.92{\%}$), 용산구($-2.02{\%}$), 강남구($-1.94{\%}$), 대구 수성구($-3.11{\%}$), 대전의 유성구($-3.18{\%}$), 충남 태안군($-3.83{\%}$), 전남 순천시($-2.36{\%}$)), 나주군($-2.42{\%}$등이며, ${\cdot}$ 대전($23.25{\%}$) 및 인천($22.81{\%}$) 지역은 년간 $20{\%}$를 상회하고 있으나 이들 지역에서도 ''91 4/4분기에는 크게 둔화되고 있음. $\bullet$ 전반적으로 ''87년 수준의 지가안정세를 보이고 있으며 분기별 상승률은 ''87. 4/4분기 이래 최소치를 시현하고 있음.

• Environmental and Resource Economics Review
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• v.14 no.3
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• pp.753-773
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• 2005

This paper is a study of the investment dynamics focusing on crude oil supply by OPEC and non-OPEC. Oil supply capacity is first determined by a leader, OPEC, and by an aggregate that represents non-OPEC producers. OPEC wants to increase a gain from oil price increase while keeping its market share relative to non-OPEC's share. An investment rule model is developed for OPEC crude oil supply capacity in response to non-OPEC's decision. In presence of oil price uncertainty, oil price threshold is derived above which it is optimal for OPEC to expand oil supply capacity since otherwise the increased supply of non-OPEC results in weakening of OPEC market share in the world oil market. In addition, a lower threshold price is derived below which OPEC triggers a capacity reduction to regain its otherwise forgone profits. A simulation is provided for calculating the capacity expansion and reduction thresholds.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.2
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• pp.107-116
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• 2012

The experiment was performed to analyze the intersectional ventilation efficiency by intersection structure and Jet Fan in network-form road tunnel. For this, the size of real road tunnel was reduced by 1/45. To apply traffic inertia force when driving, blower fan was used to form an airflow in model tunnel and the intersectional efficiency was also investigated by measuring the speed at local point of the tunnel. To improve the reduction of ventilation caused by the structure character, Jet Fan was installed to optimize ventilation efficiency in tunnel.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.306-313
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• 1994

In order to estimate the degree of genetic divergence between the two types of finespotted flounder, Pleuronichthys cornutus which is important commercially in Japan, isozyme analysis was carried out by starch gel electrophoresis. Twenty two loci coding for fourteen enzymes were scored in two types of finespotted flounder and three completely divergent loci (Acp, Idh-2 and Mdh-2), with no common alleles, were observed between these two types. Nei's genetic distance between two types was 0.46592. However, the expected average heterozygosity was 0.120 in type A (Hon meitagarei) and 0.095 in type B (Bake meitagarei) These results mean that the existence of two types of finespotted flounder was established in this study which may have had genetic divergence and the divergence time of these two types may have been about $2.3{\times}10^6$ years ago.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.479-486
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• 2011

In image-based CFD modeling of carotid bifurcation hemodynamics, it is often not possible (or at least not convenient) to impose measured velocity profiles at the common carotid artery inlet. Instead, fully-developed velocity profiles are usually imposed based on measured flow rates. However, some studies reported a pronounced influence of inflow boundary conditions that were based on actual velocity profiles measured by magnetic resonance imaging which showing the unusual presence of a high velocity band in the middle of the vessel during early diastole inconsistent with a Dean-type velocity profile. We demonstrated that those velocity profiles were induced by the presence of modest secondary curvature of the inlet and set about to test whether such more "realistic" velocity profiles might indeed have a more pronounced influence on the carotid bifurcation hemodynamics. We found that inlet boundary condition with axisymmetric fully-developed velocity profile(Womersley flow) is reasonable as long as sufficient CCA inlet length of realistic geometry is applied.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.393-404
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• 2018

The tunnel can be planned to connect to underground roadway and surface road. The large tunnel and branch section are made when the ramp tunnel access to the main tunnel. In the branch section, stress concentration can be assigned and it can be very important for the stability of the tunnel. This study assessed the behavior of rock pillar in double deck tunnel diverging area by using a two dimensional numerical analysis. This study evaluated different safety factors according to pillar width and the ramp tunnel position in branch. By the assessment of the strength-stress ratio, tunnel pillar width is suggested in order to secure the safety factor 1.5.