• 유공압시스템학회논문집
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• 제5권4호
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• pp.1-9
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• 2008

In this paper, an energy regeneration algorithm is proposed to make the maximum use of the regenerative braking energy for a parallel hybrid electric vehicle(HEV) equipped with a continuous variable transmission(CVT). The regenerative algorithm is developed by considering the battery state of charge(SOC), vehicle velocity and motor capacity. The hydraulic module consists of a reducing valve and a power unit to supply the front wheel brake pressure according to the control algorithm. In order to evaluate the performance of the regenerative braking algorithm and the hydraulic module, a hardware-in-the-loop simulation (HILS) is performed. In the HILS system, the brake system consists of four wheel brakes and the hydraulic module. Dynamic characteristics of the HEV are simulated using an HEV simulator. In the HEV simulator, each element of the HEV powertrain such as internal combustion engine, motor, battery and CVT is modelled using MATLAB/$Simulink^{(R)}$. In the HILS, a driver operates the brake pedal with his or her foot while the vehicle speed is displayed on the monitor in real time. It is found from the HILS that the regenerative braking algorithm and the hydraulic module suggested in this paper provide a satisfactory braking performance in tracking the driving schedule and maintaining the battery state of charge.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.1447-1454
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• 2009

Currently, geothermal heat pump systems are being installed in new official and commercial building, welfare facilities, and school but there are a few cases for the housing heat sink in Korea. The reason is that there are no progressive taxes for the household electrical use, no actual output for the application of geothermal technology, high initial investment. For the overall use in multi family apartment such as the Green Home etc, technology development and building of the relevant research team need to be done through preliminary study. Core subjects for overall use include cooling heating load estimation for the multi family apartment, economical efficiency of the geothermal cooling and heating system, design and construction technology of the geothermal cooling and heating system for the multi family apartment, commercialization plan, and state of the art analysis. Selection of the detailed subjects with respect to core subject, driving schedule and commercialization plan, driving system, presentation of the utilization plan.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.770-771
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• 2015

본 논문에서는 발전소 전기설비 및 구축비용의 상당부분을 차지하는 케이블의 손실자원을 최소화하고, 효율적인 케이블 자재관리가 가능한 케이블 드럼 스케줄링 자동화를 제안하고 구현하였다. 구현된 케이블 드럼 스케줄링은 기존 수기방식의 케이블 드럼 계산에 소요되는 소비시간을 최소화하고, 종류별 케이블들을 케이블 드럼 총용량에 최적화함으로써 전기설비 생산성을 향상시킬 수 있다.

• 전기학회논문지
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• 제64권3호
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• pp.384-392
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• 2015

This paper presents an economic assessment of large-scale Li-ion battery energy storage systems applied to Korean power system. There are many applications of the battery energy storage systems (BESSs) and they can provide various benefits to power systems. We consider BESSs to the energy time-shift application to Korean power system and evaluate the benefits from the application of BESS in the social perspective. The mixed integer programming (MIP) algorithm is used to resolve the optimal operation schedule of the BESS. The social benefits can include the savings of the fuel cost from generating units, deferral effects of the generation capacity, delay of transmission and distribution infra construction, and incremental CO2 emission cost impacts, etc. The economic evaluation of the BESS is separately applied into Korean power systems of the Main-land and Jeju island to reflect the differences of the load and generation patterns.

• Spatial Information Research
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• 제7권2호
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• pp.237-253
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• 1999

서울시는 95년도에 수립된 GIS 구축 기본계획에 따라 각종 수치지형도를 포함한 기본적인 GIS 데이터의 제작과 함께 다양한 응용 시스템의 구축사업을 수행해오고 있다. 그러나 최근 서울시 업무환경의 변화와 정보화 근로사업의 우선 추진으로 사업추진 일정의 변화를 가져오고 있고 대단위 정보시스템의 통합을 통한 정보의 공동 이용 및 업무에의 활용성 증대와 시민편의 지향적 정보서비스 추구를 주요한 내용으로 삼고 있는 서울시 정보화 기본방향이 정립됨에 따라 GIS기본방향의 재정립이 요구되고 있다. 본 연구에서는 최신의 GIS의 기술에 바탕을 둔 종합적인 도시정보시스템(UIS) 구현을 위해 새로운 각도의 서울시 지리정보시스템 구축 기본방향과 접근방법에 대해 논의하고 이에 따른 최적의 시스템구조를 제안하고자 한다.

• Corrosion Science and Technology
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• 제16권2호
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• pp.76-84
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• 2017

In the construction of subsea oil and gas developments, it is increasingly common that subsea oil and gas equipment will be installed in subsea well before final hookup and production. Installation of wellheads, subsea hardware, pipelines, and surface facilities (platforms, FPSO, FLNG, connected terminals, or gas plants) are increasingly driven by independent cost and vessel availability schedules; this gives rise to requirements that the subsea facilities must be stored in the seabed for a specific time. In addition, schedule delays, particularly in the installation or startup of the connected platform, FPSO, FLNG, or onshore plant may cause unexpected extensions of the intended storage period. Currently, there are two methods commonly used for storage subsea facilities in the seabed: dry parking and wet parking. Each method has its own risks, challenges, and implications for the facility life and its integrity. The corrosion management and preservation method selection is a crucial factor to be considered in choosing the appropriate storage method and achieving a successful seabed storage. An overview of those factors is presented, along with a discussion on the internal corrosion threats and assessments.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권2호
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• pp.219-226
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• 2017

These days, the great part of design processes in the field of ship or offshore manufacturing are planned and implemented using the CAD system customized for shipbuilding companies. It means that all information for design and production could be extracted and reused at the other useful fields which need cost considerable time and efforts. The typical example is the field of welding material quantity evaluation which is demanded during the construction of ship or offshore structures. The proper evaluation of welding material to be used and the usage of them at the stage of schedule planning are mostly important to achieve the seamless process of production and costing in advance. This study is related to the calculation of welding length and needed welding material quantity at the stage of design completion utilizing the customized CAD system. The calculated welding material quantity would be classified according to welding posture, assembly stage, block, bevel and welding type so as to improve the accuracy of total cost evaluation. Moreover it is possible to predict the working time for welding operation and could be used efficiently for the cost management using the results of this research.

• 대한조선학회논문집
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• 제55권3호
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• pp.243-251
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• 2018

In the shipyard, a lot of data is generated, stored, and managed during design, construction, and operation phases to build ships and offshore structures. However, it is difficult to handle such big data efficiently using existing data-handling technologies. As the big data technology is developed, the ship and offshore industries start to focus on the existing big data to find valuable information from it. In this paper, the material requirement estimation method of offshore structure piping materials using big data analysis is proposed. A big data platform for the data analysis in the shipyard is introduced and it is applied to the analysis of material requirement estimation to solve the problems in piping design by a designer. The regression model is developed from the big data of piping materials and verified using the existing data. This analysis can help a piping designer to estimate the exact amount of material requirement and schedule the purchase time.

• International Journal of Knowledge Content Development & Technology
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• 제10권3호
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• pp.51-68
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• 2020

The library provides its services to satisfy the user's approach. Naturally, the development of library services may determine by considering the satisfaction of users. It traces users' perceptions regarding subject access highlighting problems in the retrieval of Bengali documents by subject. This study has designed to assess users' attitudes towards the retrievals of Bengali documents in OPAC through subject headings. For a collection of data, a representative sample has drawn from a large and heterogeneous population consisting of users in university libraries of West Bengal using a stratified sampling technique. Subsequently, under each of the universities, users' community was stratified into students, research scholars, and faculty members. Under each stratum, the sample selected on a random basis. The users met personally to collect relevant data, while they came to the library and went on to search OPAC. A structured schedule, prepared for the purpose, was presented before library users and consequently, interviews and interpretations recorded systematically. In this manner, several factors have identified concerning subject searching and retrieval performance for Bengali documents. This study explores the access using subject headings in multilingual information retrieval systems. Moreover, the suitability of subject headings for retrieval of Bengali resources has ascertained from the users' point of view. The findings demand standard principles and rules for the construction of Bengali subject headings to maintain uniformity and consistency.

• KIEAE Journal
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• 제7권6호
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• pp.113-118
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• 2007

The composite beam adopted in the study was designed to reduce the floor height as well as to embed the top flange of steel frame into the slab that will enable to avoid applying the fire-resistant coating and to unify the joint method with a steel frame-type. As the steel frame and bottom concrete of the beam is pre-fabricated at the factory it could reduce the overall schedule at the jobsite. Applying such composite beam system to the work is expected to provide the efficient and enhanced performance, given the current tendency of the building construction that tends to be getting higher, larger and dense. The study focused on combining the composite beam with various column systems in a bid to propose the details thereof. A desirable composite girder can be adopted depending on site conditions through the evaluation of various beam and jointing approaches. Among the column systems applied to the study are steel column, SRC column, RC-PC column and RC column. The ways of combining with the columns addressed in the study were categorized into the rigid joint, pin joint, steel frame joint and bracket type joint. Besides, the instruction for site fabrication of beam-column was added in an effort to help set up the site fabrication procedures.