• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 동계학술발표대회 논문집
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• pp.551-556
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• 2008

This study analyzed operation characteristics of air-condition piping is made by quick disconnect coupling. Air-conditioning consists of central compressor 3HP capacity and R22 refrigerant. We experimented with two operation cycles of air-condition under the same environment; one is with quick disconnect coupling. The other is without quick disconnect coupling. As a result, we can observe whether the condensation temperature of former increased by about 3-5. Furthermore, COP decreased by about 10%.

• 지역연구
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• 제40권2호
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• pp.39-55
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• 2024

이 연구는 사례조사와 인터뷰를 통해 청춘조치원 프로젝트의 주민공동이용시설의 현황과 운영실태를 파악하여 지속적인 운영을 위한 방안을 도출하고자 하였다. 현황 및 운영실태를 살펴보면, 첫째, 조치원읍에는 2025년까지 13개의 시설이 조성예정이지만, 상당수의 시설은 아직 구체적인 운영방안이 마련되지 않고 있다. 둘째, 다른 시설과의 연계를 통한 일자리 및 수익 창출 가능, 유료화 시스템 도입 등을 근거로 지속운영 가능성에 대해 긍정적으로 평가하고 있다. 셋째, 다양한 측면에서 행정지원이 이루어지고 있지만 예산의 한계로 아쉬움이 존재하였다. 지속가능한 운영을 위해 보건복지와 여가문화 기능을 강화하고, 행정지원 측면에서의 지원이 필요하며, 도시재생지원센터 활용하여 지원 및 관리 기능을 강화할 수 있을 것으로 기대된다.

• 대한수학회보
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• 제41권3호
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• pp.493-505
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• 2004

We introduce certain local Thomsen condition in a 3-web and prove that it is equivalent to the equation a－(a－b)＝b in its corresponding loop, where we denote the loop operation additively for convenience and simplicity, even though the loop is neither associative nor commutative. Also we interpret such local Thomsen condition using orthogonality of chains in a web.

• 한국생산제조학회지
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• 제6권3호
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• pp.36-43
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• 1997

In order to make unmanned machining systems with satisfactory performances, it is necessary to incorporate appropriate condition monitoring systems in the machining workstations to provide the required intelligence of the expert. This paper deals with condition monitoring for tool wear and breakage during turning operation. Developing economic sensing and identification methods for turning processes, sound pressure measurement and digital signal processing technique are proposed. The validity of the proposed system is confirmed through the large number of cutting tests.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.2215-2222
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• 2010

Advanced EMU have been enhanced in terms of safe transport and maintainability. It is a new urban railway technology that enables an operation institution to cut repair and maintenance costs and customers to use convenient service at lower costs based on IT technology. If a development vehicle of Advanced EMU is completed, it will be used to test the entire advanced EMU system through sufficient performance check and reliability check prior to operation in commercial line. It will also verify efficiency, safety, punctuality and energy efficiency of transport. Accordingly, it is necessary to figure how to repair and maintain vehicles to enhance safety of Advanced EMU system in cooperation with operation during the period of comprehensive evaluation on the operation of a development vehicle in a test line. In this paper, we investigated the maintenance program of Advanced EMU on test operation in Dabul line. The test condition and operation environment of Advanced EMU in Daebul line was analyzed.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.537-539
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• 2015

considerate operation is a major issue in the equipment-intensive operation. Identifying an optimal equipment combination is important to achieve low-energy operations. An Earthwork operation planning system, which measures the energy consumption of construction operations by taking into account construction equipments' engineering attributes (e.g., weight, capacity, energy consumption rate, etc.) and operation conditions (e.g., road condition, attributes of materials to be moved, geometric information, etc.), is essential to achieve the low-energy consumption. This study develops an automated computerized system which identifies an optimal earthmoving equipment fleet minimizing the energy consumption. The system imports a standard template of earthmoving operation model and compares numerous scenarios using alternative equipment allocation plans. It finds the fleet that minimizes the energy consumption by enumerating all cases using sensitivity analysis. A case study is presented to verify the validity of the system.

• 상하수도학회지
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• 제13권4호
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• pp.54-61
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• 1999

SBR process used to evaluate the removal of organics, nitrogen and phosphorus on the basis of a report of research on a precedence at various operation cycle and condition change. Effluent concentration of COD were 50mg/l, 50mg/l, 90mg/l respectively, The removal rates of COD were nearly over 95% at Run 1, 2 and 4. But at Run 3, Effluent concentration of COD was 255.0mg/l, The removal rate of COD was 87% at Run 3. As Oxic/Anoxic rate was fixed and operating cycle of Oxic/Anoxic was changed, the removal rates of T-N were 74.7%, 46.9%, 28.5%, 63.3% respectively at Run 1~4. The case of Run 1 was best result. The removal rates of T-P was appeared in proportion to T-N removal rates and rest of $NO_2-N$. The removal rates of T-P were 51.2%, 35.5%, 41.5%, 51.9% respectively. The removal rates of COD, T-N, T-P were influenced on the change of SBR operation cycle. As organic loading rate was $1.43kgCOD/m^3day$ and C/N ratio was 3.0, operation cycle of Run 1 was best condition of T-N removal rates and T-P removal.

• 대한기계학회논문집
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• 제18권11호
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• pp.2913-2921
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• 1994

In SMA(shape memory alloy), the degradation by fatigue is one of the most important problems to be overcome, when SMA is used for robot-actuator material. The actuator is operated repeatitively for long time and its repeating operation develops the fatigue degradation of SMA. The fatigue degradation changes the transformation temperature and deformation behavior and results in inaccurate operation control of robot. Accordingly, the changing behavior of transformation temperature and deformation which results from repeating operation is to be investigated in advance and the scheme to resolve those problems have to be made for the design of actuator. In this study, the fatigue tests were carried out on SMA specimens prepared to have different condition of aging time and pre-strain with the direct-current heating-cooling method, which was a general method of operation in robot actuators. The behavior of transformation temperature and deformation were examined and analyzed in each specimen and the study was performed to establish the optimistic manufacturing condition of SMA against the fatigue degradation.

• Nuclear Engineering and Technology
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• 제44권7호
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• pp.773-780
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• 2012

The article presented is concerned with an evaluation of the corrosion behavior of SA-508 low alloy steel (LAS) and Type 309L stainless steel (SS) cladding of a reactor pressure vessel under the simulated primary water chemistry of a pressurized water reactor (PWR). The uniform corrosion and galvanic corrosion rates of SA-508 LAS and Type 309L SS were measured in three different control conditions: power operation, shutdown, and power operation followed by shutdown. In all conditions, the dissimilar metal coupling of SA-508 LAS and Type 309L SS exhibited higher corrosion rates than the SA-508 base metal itself due to severe galvanic corrosion near the cladding interface, while the corrosion of Type 309L in the primary water environment was minimal. The galvanic corrosion rate of the SA-508 LAS and Type 309L SS couple measured under the simulated power operation condition was much lower than that measured in the simulated shutdown condition due to the formation of magnetite on the metal surface in a reducing environment. Based on the experimental results, the corrosion rate of SA-508 LAS clad with Type 309L SS was estimated as a function of operating cycle simulated for a typical PWR.

• 대한치과의사협회지
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• 제17권2호통권117호
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• pp.129-135
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• 1979

This 27 year-old male patient had severe mandibular prognathism (right and left mesio-occlusion were 0.4㎝ and 1.2㎝ , respectively). He had good oral health relatively exception of missing teeth. We examined all of his oral and skeletal status with full mouth x-ray taking, study model, and cephalogram. His general condition was good but above examination indicated the surgical operation for the mandibular prognathism. His laboratory tests were within normal limits. We determined surgical operation which was done by extraoral approach bilaterally. Incisions were made bilaterally 1.5㎝ beneath the inferior border of the mandible in the selected area and then the inferior border of the ascending rami was exposed. Retracting the periosteum to the lingual and buccal a slight amount, the cut in the bone was performed by use of bone drill. Avoiding T.M.J. troubles, the proximal segmant was not fixed to anterior segment, being in overlapping state buccally, in order to expect a natural healing by the environmental muscles and ligaments. We had immobilization with intermaxillary fixation by using the multiple Stout's method. He was discharged 17 days after operation. His general condition and operation results were good and satisfactory.