In this paper, we present a new way to derive the mean cycle time of the G/G/m failure prone queue when the loading of the system approaches to zero. The loading is the relative ratio of the arrival rate to the service rate multiplied by the number of servers. The system with low loading means the busy fraction of the system is low. The queueing system with low loading can be found in the semiconductor manufacturing process. Cluster tools in semiconductor manufacturing need a setup whenever the types of two successive lots are different. To setup a cluster tool, all wafers of preceding lot should be removed. Then, the waiting time of the next lot is zero excluding the setup time. This kind of situation can be regarded as the system with low loading. By employing absorbing Markov chain model and renewal theory, we propose a new way to derive the exact mean cycle time. In addition, using the proposed method, we present the cycle times of other types of queueing systems. For a queueing model with phase type service time distribution, we can obtain a two dimensional Markov chain model, which leads us to calculate the exact cycle time. The results also can be applied to a queueing model with batch arrivals. Our results can be employed to test the accuracy of existing or newly developed approximation methods. Furthermore, we provide intuitive interpretations to the results regarding the expected waiting time. The intuitive interpretations can be used to understand logically the characteristics of systems with low loading.

PURPOSES : This study aims to examine the differences between the existing traffic demand forecasting method and the traffic demand forecasting method considering future regional development plans and new road construction and expansion plans using a four-step traffic demand forecast for a more objective and sophisticated national highway maintenance. This study ultimately aims to present future pavement deterioration and budget forecasting planning based on the examination. METHODS: This study used the latest data offered by the Korea Transport Data Base (KTDB) as the basic data for demand forecast. The analysis scope was set using the Daejeon Metropolitan City’s O/D and network data. This study used a traffic demand program called TransCad, and performed a traffic assignment by vehicle type through the application of a user equilibrium-based multi-class assignment technique. This study forecasted future traffic demand by verifying whether or not a realistic traffic pattern was expressed similarly by undertaking a calibration process. This study performed a life cycle cost analysis based on traffic using the forecasted future demand or existing past pattern, or by assuming the constant traffic demand. The maintenance criteria were decided according to equivalent single axle loads (ESAL). The maintenance period in the concerned section was calculated in this study. This study also computed the maintenance costs using a construction method by applying the maintenance criteria considering the ESAL. The road user costs were calculated by using the user cost calculation logic applied to the Korean Pavement Management System, which is the existing study outcome. RESULTS : This study ascertained that the increase and decrease of traffic occurred in the concerned section according to the future development plans. Furthermore, there were differences from demand forecasting that did not consider the development plans. Realistic and accurate demand forecasting supported an optimized decision making that efficiently assigns maintenance costs, and can be used as very important basic information for maintenance decision making. CONCLUSIONS : Therefore, decision making for a more efficient and sophisticated road management than the method assuming future traffic can be expected to be the same as the existing pattern or steady traffic demand. The reflection of a reliable forecasting of the future traffic demand to life cycle cost analysis (LCCA) can be a very vital factor because many studies are generally performed without considering the future traffic demand or with an analysis through setting a scenario upon LCCA within a pavement management system.

인도네시아는 전체 도로의 약 96%가 아스팔트 포장으로 되어 있으며, 최근 지역 간의 경제교류 활성화 및 국민에 삶에 질을 높이기 위해 기초 기반시설인 도로 건설에 많은 예산을 투자하고 있다. 하지만 년 중 약 6개월 동안 비가 내리는 몬순기후 및 과적차량, 그리고 급격한 교통량 증가로 인해 소성변형과 포트홀, 골재 박리와 같은 수분에 의한 조기 파손이 빈번히 발생하고 있다. 또한 인도네시아는 아스팔트 플랜트가 인도네시아 전역에 고르게 분포되어 있지 않아 원거리 공사의 경우, 아스팔트 혼합물의 포설 및 시공온도를 관리하는데 어려움이 있다. 본 연구에서는 인도네시아의 기후 및 교통하중을 고려하여 아스팔트 포장의 성 능 및 공용수명을 향상시키고, 특히 수분에 대한 저항성을 증진시켜, 몬순기후에 적합한 중온 개질 첨가제 를 개발하였으며, 인도네시아 현지에 적용하여 현장 적용성 평가를 수행하였다. 본 연구는 한국건설기술연 구원과 인도네시아 국가 연구기관인 도로연구소(IRE, Institute of Road Engineering)와 국제 공동연구로 추진되었으며, 연구 결과, 몬순기후용 중온 개질 아스팔트 포장 기술은 인도네시아의 고온다습한 기후에서 아스팔트 포장의 소성변형 및 포트홀과 같은 수분에 대한 저항성이 높은 것으로 평가 되었다. 인도네시아에서 사용 중인 일반 아스팔트 바인더는 고온 등급이 64℃이며 수분에 대한 저항성이 낮아 인도네시아에 적용하기에는 한계가 있다. 이를 극복하기 위해 본 연구에서는 인도네시아 일반 아스팔트 바인더에 수분에 대한 저항성 증진을 위한 화학적 요소와 폴리머 그리고 중온화 첨가제를 혼합하여 고온 및 수분에 대한 저항성이 높은 기술을 개발하였다(그림 1). 개발 기술의 현지 적용성 평가를 위해 WEST JAVA 섬에 위치한 Jatibarang 및 Subang 지역에 시험포장을 수행하였으며, 동시에 인도네시아 현지에 서 품질평가를 수행하였다. 인도네시아 현지 품질 평가 수행 결과 몬순기후용 중온 개질 아스팔트 기술이 인도네시아 현지 개질 아스팔트 품질기준에 부합하였으며, 시험포장 또한 성공적으로 수행되었다. 시험포 장 배합설계는 아스팔트 함량이 5.2%,시, 생산온도 144℃, 다짐온도 120℃였다. 향후 지속적인 추적조사 를 통해 소성변형, 포트홀 등 수분에 대한 파손에 대한 평가가 필요할 것으로 판단된다.

최근 일본 구마모토 및 에콰도르 등 지진뿐만 아니라 크고 작은 사회적･인적재난의 피해와 빈도가 점차 증가함에 따라 재난관리에 대한 관심과 필요성이 증가하고 있다. 외국의 경우, 재난 대책 매뉴얼이나 주요 도로를 선정하여 대피 계획을 세움으로써 재난에 대비하고 있으나 우리나라의 경우, 그렇지 못한 실정이다. 따라서, 본 연구에서는 세종시를 대상으로 네트워크 내 영향력이 큰 도로를 선정하고자 하였다. 먼저, 네트워크 구축을 위해 국가교통DB센터(KTDB)에서 제공하는 행정경계, 도로망 및 도로경계 등의 자료를 바탕으로 GIS 공간데이터를 구축하였으며, Arc GIS S/W의 네트워크 분석(Network Analysis) 기능을 이용하여 연결정도 중심성 및 근접 중심성 지표를 산정하였다. 또한, 재난 후 라이프라인 복구에 있어 영 향력이 큰 도로를 중심으로 도로네트워크의 기능 및 특성, 교통량 등을 고려하여 유지보수가 우선적으로 필요한 도로 인프라(교량, 터널, 도로구간 등)를 선정하였다. 나아가, 재난 발생으로 인해 네트워크 연결성이 저하될 경우의 통행패턴 변화와 통행시간 변화를 분석 하였으며, 재난 발생 후의 유입 교통량에 대한 통행패턴 및 통행시간 특성을 분석하기 위해 재난 발생 이 후의 방재도로에 대한 긴급 복구 시나리오를 가정하였으며 추가적으로 공사 기간, 공사구간(Work-zone) 의 연장, 이용자 비용의 산정 등 다양한 요소를 고려하였다. 본 연구를 통해 향후 도시지역 방재계획 및 재난 대응 방안을 위한 의사결정시 기초자료로 사용될 수 있을 것이라 판단된다.

The objective of this study is to apply performance-based seismic design to high-rise apartment buildings in Korean considering collapse prevention level. The possible issues during its application were studied and the suggestions were made based on the findings from the performance-based seismic design of a building with typical residential multi-unit layout. The lateral-force-resisting system of the building is ordinary shear walls system with a code exception of height limit. In order to allow the exception, the serviceability and the stability of the ordinary shear wall structure need to be evaluated to confirm that it has the equivalent performance as the one designed under the Korean Building Code 2009. The structure was evaluated whether it satisfied its performance objectives to withstand Service Level and Maximum Considered Earthquake.

This study analyzed annual catch trend during 45 years and monthly catch of the least 10 years (2005∼2014) for chub mackerel caught in the Korean coastal waters. To determine fishing status of chub mackerel, fork length measurements were conducted at least twice every week for 100 individuals randomly selected at the Busan Cooperative Fish Market from January of 2012 to December of 2014; and biological characteristics and proximate composition (moisture, protein, fat, ash) were analyzed by length class (I∼IV) on a monthly basis from January to December of 2014. Monthly catch trend showed low level below 5,000 mt from February to July, whereas high level above 15,000 mt from October to December. For the period between 2012 and 2014, annual average catch proportion of juvenile were relatively high at 68.1%, 53.1% and 53.2% from January to April, before spawning season, while those were low at 21.5%, 20.7% and 29.12% from June to November. As for the change in the proximate composition per 100 g of muscle, protein and ash did not change much by seasons and length class, whereas fat and moisture contents showed large fluctuations and complementary relationship between the two factors. Regardless of length class, monthly average fat content, containing Omega-3, showed the lowest at 7.18 g in April and highest at 19.27 g in December, which exhibited 2.6 times difference from one another. Regardless of fishing seasons, fat content by length class were 19.06 g for the class I and 6.43 g for the class IV, which showed three times difference. Fat contents of the class I were high at 26.97 g and 27.19 g in November and December, while low at 8.37 g and 9.99 g in April and May. Especially, fat contents from January to May were 5.0 g, which was the lowest. Therefore, it is expected that consumer could indirectly contribute fisheries management through their understanding and wise consumption based on fishing status and fluctuation of proximate composition.

Shelter that communication equipment and on-equipment material are mounted on is transported by airplane, vehicle and has a function such as waterproof and shielding EMI. Maintaining proper inside temperature of shelter is important in order to operate equipment. Accordingly proper cooling capacity of cooling equipment which installed on the shelter is important for equipment and operator. To calculate proper cooling capacity, There are some considerations such as environmental factors and equipment in the shelter. In Korea solar irradiation and outdoor temperature is difference in accordance with geological characteristic. Also electric equipment mounted on the shelter is increased by development of technology. But the capacity of air conditioner is not changed thus there is a problem about operating equipment. In this paper, Compare cooling capacity of shelter when using air conditioner that is not enough cooling capacity and calculate proper cooling capacity to consider geological solar irradiation and outdoor temperature.

In this study, analysis on the stiffness of the headrest, the stiffness of front-rear load and the torsion of cushion frame was performed using finite element method in order to investigate the properties of the stress-deformation by material characteristics according to the test requirements of FMVSS (Federal Motor Vehicle Safety Standard). The results are shown that AZ31 (Mg alloy) and A365 (Al alloy) with low modulus of elasticity and density have higher strain rate than steel in terms of stress-deformation and meet the standards for safety within 108 mm of the maximum amount of deformation. Considering it’s safety and durability, however, the selection of AZ31 for light weight seems difficult to gain the reliability because it causes an excessive deformation, and therefore it is not expected to be used for recliner where stress is concentrated and also the bracket linking rail and cushion frame.

철근콘크리트 슬라브의 휨강도 보강을 위해 제안된 섬유보강폴리머(Fiber Reinforced Polymer, FRP)와 초 고거동 콘크리트(Ultra High Performance Concrete, UHPC)의 합성구조의 파괴 시 거동을 살펴 본 결과, 과다한 휨 보강으로 인한 전단파괴와 보강된 FRP의 탈착에 의한 파괴가 발생하였다. 전단강도와 휨 강도의 크기를 고려한 설계 기준을 제시하여 휨 보강 한도를 제한하고, 전단 철근을 추가하여 탈착에 의한 파괴를 보강하였다. 휨 강도의 보강을 제한 하고 부착 철근이 보강된 슬라브의 실험 결과, 휨에 의한 연성파괴가 유도되었다.

PURPOSES: This paper investigates behavior and performance of concrete pavement in tunnel based on temperature data from field. METHODS : In this study, there are 4 contents to evaluate concrete pavement in tunnel, First, Comparison for distress was conducted at outside, transition, and inside part of tunnel. Secondly, temperature data was collected in air and inside concrete pavement in outside and inside tunnel. Thirdly, FEM analysis was performed to evaluate stress condition, based on temperature data from field. Finally, performance prediction was done with KPRP program. RESULTS: From the distress evaluation, failure of inside tunnel was much less than it of outside tunnel, Temperature change in tunnel was less than out side, and also it was more stable. According to result of FEM analysis, both curling stress status of inside tunnel was lower than it of outside tunnel. Based on KPRP program analysis, performance of inside tunnel was longer than outside. CONCLUSIONS : Through all study about behavior and performance of concrete pavement in tunnel, condition in tunnel has more advantages from environmental and distress point of view. Therefore, performance of inside tunnel was better than outside.

Chest lateral decubitus is a chest examination to determine the persence of pleural fluid in thorax. In this study, we prepare recumbent holding position time standard of chest lateral decubitus. The records of 15 patients with chest lateral decubitus between May and Jun. Recumbent holding time is 30, 60, 90, 120, 180, 210, 240 seconds. The result is fluid level change between 0.88mm to 9.63. Fluid heigh change between 9.9 percent to 42.5 percent. We can confirm fluid level change with chest decubitus image. The proper time for fluid level change is 180 seconds.

Resonance occurrence conditions are explored by performing dynamic interaction analysis of arch bridge and KTX trains. The target bridge is a 3D tied-arch bridge having span length of 120m. KTX trains consist of two power carriages, two power and passenger carriages and sixteen passenger carriages. When KTX trains run on the target bridge with the uniform speed of 100 to 500km/h, the dynamic responses of the bridge induced by moving trains are obtained from railway arch bridge-train interaction analysis. Two resonance conditions are presented and whether the resonance phenomena occur or not at the suspicious resonance velocities is rigorously investigated through bridge deflections and accelerations and their FFT analysis.

This study is the compared seismic performance that are difference between the performance of structures on various site classes and beam-column connection. this analysis model was designed the previous earthquake load. To compare the performance levels of the structure was subjected to nonlinear static and nonlinear dynamic analysis. Nonlinear analysis was used to The Perform 3D program. Nonlinear static analysis was compared with the performance point and Nonlinear dynamic analysis was compared the drift ratio(%). Analysis results, the soft site class of the displacement was more increase than rock site classes of the displacement. Also The smaller the displacement was increased beam-column connection stiffness.

If scour is occurred at shallow foundation of bridge, seismic performance of the bridge will be reduced. In order to evaluate accurate seismic response of bridge according to scour depths, modeling of foundation reflecting scour effect is important. In this study, taking into account the effect of the reduction in embedment depth of the shallow foundation by scouring, the soil around the foundation is modelled as an equivalent soil spring with various stiffness. Seismic fragility analyses for 3 types of bridges subjected to 4 types of ground motions classified into Site Class A, B, C, D are evaluated according to several scour depths. From the fragility analysis results, it can be observed that the deeper the scour depth, the higher probability of exceeding damage states. Also, seismic failure probability of asymmetric bridge is higher than that of symmetric bridge.

국내의 중저준위 방사성폐기물 처분시설에 대한 핵종량은 대부분의 방사성핵종에 대한 규명이 요구되어 진다. 본 논문에 서는 국내 경주 처분시설 부지에서 방사성폐기물의 처분을 위한 처분시설의 활용도 및 효율성 그리고 신분류기준을 반영한 핵종재고량을 예측하였다. 장기 방사성폐기물의 예측하기 위해 2014년까지 다양한 발생원별 방사성폐기물의 발생량과 발 생전망을 분석하였다. 예측된 핵종재고량 결과는 처분시설에 대한 안정적인 개발 및 Safety case의 구축하는데 기여할 것으 로 판단된다.

We investigate the records related to the reign style and the calendar day from the epigraphs of the Goryeo dynasty (918 - 1392) in Korea in order to verify and supplement the sexagenary cycle data of the first day in the lunar month of the dynasty. The database of the National Research Institute of Culture Heritage contains a rubbed-copy image, transcription statement, and translation statement for Korean epigraphs as well as 775 epigraphs corresponding to the Goryeo dynasty. The epigraph records are valuable in that, during this time, they were written differently from other historical literature such as the Goryeosa (History of the Goryeo Dynasty), which was compiled in the next dynasty. We find that the Goryeo dynasty, in general, had adopted the reign styles of Chinese dynasties at that time. We also find 159 calendar day records all showing good agreement with the work of Ahn et al. except for dozens of records. Through this study, we can verify the reign styles and the calendar days of the Goryeo dynasty.