• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.608-609
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• 2011

In this study, we tried to validate FLUENT solver model and domain setting for the problem of convective heat transfer in multiple tube bank under transitional zone. We have paid special attention to verify proper boundary conditions and the grid convergence. Through validation work, it is found that unsteady solution method with two-dimensional simulation domain can produce reasonable accurate results compared with existing experimental data. Simulation results with steady solution generates relatively large error. We found that both steady and unsteady method for three-dimensional domain shows acceptable accuracy. Further parametric study for deriving correlation from transverse and longitudinal pitch is currently underway.

• 한국기계가공학회지
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• 제11권4호
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• pp.13-19
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• 2012

There are many dynamic properties in measured end-milling force. So, it is difficult to predict the real static property of end-milling force. Also the behavior of end-milling force is very complex to predict with the measured one. To extract the static property from measured force, it must be filtered and its problem is closely related to a de-noising one. Also this paper presents alternative de-noising method of end-milling force using wavelet filter bank, based on the wavelet transform and its inverse one. In this paper, by comparing the measured force and its wavelet filtered one, the fundamental end-milling force property after wavelet transform is well reviewed and analyzed. This result of wavelet filtering with filter bank shows the static force of end-milling which has severe dynamic properties occurring in entry and exit state of edge emersion into the workpiece.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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• pp.62-63
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• 2017

According to the rapid development of digital technology, the free formed buildings with complex and various curved surfaces are being constructed. Most of the external cladding of free formed buildings have been applied materials such as metal, glass, FRP, GFRC, etc. However, these materials have many disadvantages such as a complicated manufacturing process for realizing 3D irregular shape and an increase in production period and cost. Therefore, the studies for UHPC which is an optimized material for overcoming this problem for a long time in overseas. This study reviewed the remodeling construction of Samsung-dong KEB Hana Bank appling the exterior curved UHPC panel for the first time in Korea. As a result, we confirmed the possibility of UHPC panels with various free formed shapes.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권1호
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• pp.24-29
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• 2004

A new low cost hybrid active filter for thyristor-controlled rectifier load is presented to overcome the high cost problem of the active or the other hybrid active filters. The proposed hybrid active filter which consists of tuned (5th and 7th harmonics) LC passive filters, power factor improvement(PFI) capacitor bank, and active filter compensates power factor as well as harmonic currents. Since most of harmonic currents are filtered by the passive filter and most of reactive power is compensated by the PFI capacitor bank, the power rating of active filter can be minimized, resulting in cost minimization of the proposed hybrid active filter. A 300kVA hybrid active filter system is implemented and tested using 1MVA thyristor rectifier load to verify the operation and performance.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.275-278
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• 2001

다중비 필터뱅크의 합성 필터 설계 문제에 H$_{\infty}$ 제어기법을 적용한다. 순수한 시간 지연 시스템을 기준 모델로 선정하여 이 지연 시스템과 다중비 필터 뱅크와의 오차 시스템을 고려한다. 설계 하고자 하는 합성 필터는 오차 시스템의 ι$_2$-유도된 노름을 최소화하도록 설계한다.

• Journal of Advanced Marine Engineering and Technology
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• 제23권2호
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• pp.131-139
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• 1999

An experimental study was conducted to investigate the fouling effects of geothermal water scale deposited onto a heating surface upon its forced convection heat transfer characteristics. Scales deposited onto the heating surfaces of heat exchangers seriously reduce the heat transfer perfor-mance and also increase the hydrodynamic drag. Accordingly fouling is an important problem in the design and operation of heat exchangers. The cylinders were settled in tandem with equal dis-tance between neighbouring cylinders and only the test cylinder was heated under the condition of constant heat flux. The Reynolds number was varied from 13000310 through 50003100. It is found that the heat transfer of the in-line tube banks greatly varies with the fouling of geothermal water scale especially its scale height. Further the local and average Nusselt numbers strongly depend upon the cylinder spacing and the Reynolds number.

• 한국조경학회:학술대회논문집
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• 한국조경학회 2007년도 Journal of Landscape Architecture in Asia Vol.3
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• pp.30-37
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• 2007

Modern cities are weak in traditional culture with the lack of characteristics and the problem of environmental deterioration. As the important carrier of urban culture, landscape architecture should be responsible for solving these problems. The urban need is paid much attention in the design of South Bank Linear Park in Meizhou city. Following the principle of inheriting and developing urban traditional culture, the design of the whole park is integrated with Hakka culture in Meizhou, which forms the landscape with local features and modern landscape architecture culture, and promotes the urban culture construction.

• 대한공간정보학회지
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• 제20권4호
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• pp.3-9
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• 2012

화석연료 사용의 급격한 상승은 연료의 고갈과 막대한 온실가스배출을 초래했다. 특히, 건설 분야는 전체 이산화탄소 배출량의 약 1/4 이상을 차지하는 환경문제의 원천이다. 이에 본 연구에서는 건설 현장의 탄소배출량 감소를 위한 GIS기법의 적용 강화를 목표로 사토장 선정에 네트워크분석기법을 적용하였다. 그 결과 후보지별로 최단거리 및 최소시간에 따라 예상되는 탄소배출량 및 운반단가를 구할 수 있었다. 이 결과를 바탕으로 사토장을 선정할 경우 소나무 한그루를 심는 것과 비슷한 효과의 탄소배출량을 감소할 수 있을 것이다. 또한, 건설 분야 전반에서 발생하는 탄소배출에 영향을 주는 복합적인 요소들을 고려하여 적용한다면 탄소배출량을 획기적으로 줄일 수 있을 것이다.

• 한국인터넷방송통신학회논문지
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• 제23권3호
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• pp.167-173
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• 2023

자금 흐름 일치 문제(CFMP)는 T년도 간 지불해야 할 총액을 전액 현금으로 지불하지 않고 채권이나 은행 예금의 원금과 이자로 지급하여 초기 투자액을 최소화시키는 것이 목적이다. CFMP를 풀 수 있는 방법으로는 선형계획법(LP)이 유일하게 알려져 있다. 선형계획법은 T개의 선형함수를 최적화시키는 문제로 수기 식으로는 해결이 불가하여 선형계획법 해결사인 LINGO 등을 활용하는 실정이다. 본 논문은 LINGO의 도움 없이 오로지 수기 식으로 CFMP의 해를 구하는 알고리즘을 제안한다. 제안된 알고리즘은 만기 도래 일자가 최장기부터 단기의 내림차순으로 해당 채권이 차기 만기 도래 채권의 이전 년도까지 지급액을 커버하는 방법으로 채권 매수 량을 결정한다. 또한 최 단기 채권 만기 도래 이전 년도까지는 은행 예금의 원금과 이자로 충당하는 예금액을 결정하였다. 2개의 실험 데이터에 제안된 알고리즘을 적용한 결과 선형계획법에 비해 보다 정확한 결과를 얻을 수 있음을 보였다.

• 제어로봇시스템학회논문지
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• 제17권10호
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• pp.960-966
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• 2011

In this paper, an $\mathfrak{H}$_/$\mathfrak{H}_{\infty}$ fault detection and isolation (FDI) observer design problem is investigated for discrete-time delayed systems. To that end, a bank consisting of the sensor's number of observers is introduced. Each residual should be sensitive to a certain partial group of faults, but robust against the disturbance as far as possible. We formulate this multiobjective FDI problem as $\mathfrak{H}$_/$\mathfrak{H}_{\infty}$ observers design problem. Sufficient design condition is expressed as iterative linear matrix inequalities. The fault is then detected and isolated by evaluating the residuals through an FDI decision logic. A computer simulation is provided for verification of the proposed technique.