• Annals of Laboratory Medicine
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• 제38권6호
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• pp.616-618
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• 2018

• 한국세라믹학회지
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• 제51권5호
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• pp.406-412
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• 2014

In this study, flat-tubular-type alumina filters were manufactured using alumina powder of two sizes ($2.4{\mu}m$ ALM-44 and $0.4{\mu}m$ AP 400) by an extrusion process. The manufactured alumina filter was sintered at $1200-1600^{\circ}C$ for 1 h. As particle size increased, the largest pore size, average pore size and porosity increased; but density and linear shrinkage decreased. The alumina filter fabricated using ALM-44 powder sintered at $1500^{\circ}C$ was confirmed as the best water treatment filter after investigation of the bending strength, water permeability and impurity-removal efficiency of the experimental filters. This flat-tubular-type alumina filter is expected to be useful not only for direct water treatment, but also for use as a support filter during coating processes, to control pore size.

• 대한기계학회논문집B
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• 제23권8호
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• pp.978-986
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• 1999

In this study, the general thermal and flow characteristics of flat tube with micro-channels has been studied and the correlation of Nusselt number and friction factor is proposed. The optimal flat tube geometry is determined by optimal design process. It is assumed to be a three dimensional laminar flow in the analysis of thermal and flow characteristics. The periodic boundary condition is applied since the geometry of flat tube with micro-channels shows uniform cross-section in primary flow direction. Local Nusselt number is examined for thermal characteristics of each membrane, and module average Nusselt number and friction factor are calculated to determine the characteristics of the heat transfer and pressure drop in overall flat tube with microchannels. The correlations between Nusselt number and friction factor are given by Reynolds number, aspect ratio of membranes, and the width of flat tube. ALM (Augmented Lagrangian Multiplier) method is applied to the correlations to determine an optimal shape of flat tube. It is shown that the optimal aspect ratio of flat tube is approximately 1.0, irrespective of the width of flat tube and Reynolds number.

• 한국전산유체공학회지
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• 제16권1호
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• pp.30-35
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• 2011

In this paper, our effort to apply 3-D Virtual Reality system for stereoscopic visualization of mesh data on the web is briefly described. This study is an extension of our previous and on-going research efforts to develop an automatic grid generation program specialized for wing mesh, named as eGWing. The program is developed by using JAVA programming language, and it can be used either as an application program on a local computer or as an applet in the network environment. In this research advancing layer method(ALM) augmented by elliptic smoothing method is used for the structured grid generation. And to achieve a stereoscopic viewing capability, two graphic windows are used to render its own viewing image for the left and right eye respectively. These two windows are merged into one image using 3D monitor and the viewers can see the mesh data visualization results with stereoscopic depth effects by using polarizing glasses. In this paper three dimensional mesh data visualization with stereoscopic technique combined with 3D monitor is demonstrated, and the current achievement would be a good start-up for further development of low-cost high-quality stereoscopic mesh data visualization system which can be shared by many users through the web.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.335-340
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• 2010

In this paper development of an automatic grid generation program for flow field calculation around 3D wing is described and its application is also introduced. The program is developed by using JAVA programming language and a graphic library, JOGL, and it can be usee either as an application program on a local computer or as a applet in the network environment. Currently, The program provides NACA series 4-digit airfoils as the wing cross-section shape and it offers a non-complicated GUI program which can easily generate structured grids for wings based on user's parameter input. Grid generated by the program can be selected as one of two types; O-type and C-type. In this research advancing layer method(ALM) augmented by elliptic smoothing method is used for the FLUENT. It is shown that by using current program high-quality structured grids around 3D wings can be easily generated, and typical grid generation results and flow solutions are demonstrated. Study on effects of geometric parameters on flow field is also tried by changing major wing parameters such as incidence angle type of wing-tip and sweepback angle.

• Journal of Mechanical Science and Technology
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• 제15권8호
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• pp.1143-1155
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• 2001

In order to reduce the expensive CPU time for design sensitivity analysis in dynamic response optimization, this study introduces the design sensitivities approximated within estimated confidence radius in dynamic response optimization with ALM method. The confidence radius is estimated by the linear approximation with Hessian of quasi-Newton formula and qualifies the approximate gradient to be validly used during optimization process. In this study, if the design changes between consecutive iterations are within the estimated confidence radius, then the approximate gradients are accepted. Otherwise, the exact gradients are used such as analytical or finite differenced gradients. This hybrid design sensitivity analysis method is embedded in an in-house ALM based dynamic response optimizer, which solves three typical dynamic response optimization problems and one practical design problem for a tracked vehicle suspension system. The optimization results are compared with those of the conventional method that uses only exact gradients throughout optimization process. These comparisons show that the hybrid method is more efficient than the conventional method. Especially, in the tracked vehicle suspension system design, the proposed method yields 14 percent reduction of the total CPU time and the number of analyses than the conventional method, while giving similar optimum values.

• Genomics & Informatics
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• 제12권4호
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• pp.156-164
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• 2014

Cancer is the most dreaded disease in human and also major health problem worldwide. Despite its high occurrence, the exact molecular mechanisms of the development and progression are not fully understood. The existing cancer therapy based on allopathic medicine is expensive, exhibits side effects; and may also alter the normal functioning of genes. Thus, a non-toxic and effective mode of treatment is needed to control cancer development and progression. Some medicinal plants offer a safe, effective and affordable remedy to control the cancer progression. Nimbolide, a limnoid derived from the neem (Azadirachta indica) leaves and flowers of neem, is widely used in traditional medical practices for treating various human diseases. Nimbolide exhibits several pharmacological effects among which its anticancer activity is the most promising. The previous studies carried out over the decades have shown that nimbolide inhibits cell proliferation and metastasis of cancer cells. This review highlights the current knowledge on the molecular targets that contribute to the observed anticancer activity of nimbolide related to induction of apoptosis and cell cycle arrest; and inhibition of signaling pathways related to cancer progression.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 에너지변화시스템부문
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• pp.225-227
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• 2009

The conventional fixed gain PI controller is very sensitive to step change of command speed, parameter variation and load disturbances. The precise speed control of interior permanent magnet synchronous motor(IPMSM) drive becomes a complex issue due to nonlinear coupling among its winding currents and the rotor speed as well as the nonlinear electromagnetic developed torque. Therefore, there exists a need to tune the PI controller parameters on-line to ensure optimum drive performance over a wide range of operating conditions. This paper is proposed artificial intelligent-PI(AIPI) controller of IPMSM drive using adaptive learning mechanism(ALM) and fuzzy neural network(FNN). The proposed controller is developed to ensure accurate speed control of IPMSM drive under system disturbances and estimation of speed using artificial neural network(ANN) controller. The PI controller parameters are optimized by ALM-FNN at all possible operating condition in a closed loop vector control scheme. The validity of the proposed controller is verified by results at different dynamic operating conditions.

• 한국컴퓨터정보학회논문지
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• 제28권9호
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• pp.1-8
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• 2023

본 논문에서는 임베디드 시스템을 이용한 차량용 다기능 레이다(Multi-Function Radar, MFR) 수평구동장치(Auto-Leveling Equipment, ALE) 구동 전략을 제안한다. 차량용 레이다는 일정 속도로 회전하며 지대공 유도미사일, 유인/무인 전투기 감시정찰 임무를 수행한다. 수평구동장치는 수평구동모듈 4세트로 구성하고 레이다 차량의 수평을 유지하여 시스템의 안정성을 확보한다. 차량의 수평은 임베디드 시스템을 이용하여 경사도를 측정하고, 구동모터를 이용하여 차량의 수평각을 유지한다. 본 논문에서는 수평구동모듈 1세트를 모델링하여 수평구동장치를 축소 구현하여 수평구동장치 설계 향상에 기여한다. 제안하는 구동 전략의 타당성은 MATLAB/Simulink 시뮬레이션으로 입증한다.

• 한국초지조사료학회지
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• 제6권2호
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• pp.91-96
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• 1986

본(本) 시험(試驗)은 자연초지(自然草地) 식물군락(植物群落)의 사료가치(飼料價値)를 평가(評價)하고, 이들 군락(群落)을 식물사회학적(植物社會學的)인 면(面)에서 초지(草地) 식생도(植生圖)를 작성(作成)하기 위(爲)하여 1982년(年)부터 1983년(年)까지 독일(獨逸)의 남부(南部) Bavarian Alps 지역(地域)에서 수행(遂行)되었다. 1. 자연초지(自然草地) 식물군락(植物群落)의 타발적천이(他發的遷移)는 면양방목(緬羊放牧)보다 토양수분(土壤水分)이나 지표수(地表水)가 더 큰 영향(影響)을 미쳤다. 2. Rehberg-Alm의 초지식물(草地植物) 군락(群落)은 Nardetum apligenum, Poo-Prunelletum, Cirsium arvense-Cirsium vulgare-Association, Caricetum davalltanae, Rumicetum alpini, Caricetum paniculatae 및 Disturbed lowland bog-Stand였다. 3. 초지(草地)의 사료가(飼料價)가 낮은 식물군락(植物群落)인 Nardetum alpigenum은 면양방목(緬羊放牧)에 의(依)해 점차적(漸次的)으로 산지초지(山地草地)에서 가장 우수(優秀)한 식물군락(植物群落)인 Poo-Prunelletum으로 개량(改良)될 수 있을 것으로 사료(思料)된다. 4. 이 지역(地域)의 초지사료가(草地飼料價)는 식물군락(植物群落)의 식생구성(植生構成)에 따라 많은 차이(差異)가 있었는데, 가장 높은 사료가(飼料價)를 가진 군락(群落)은 Poo-Prunelletum으로 4.4였고 그 다음은 Nardetum alpigenum으로서 2.5였다. 이 외(外)의 식물군락(植物群落)들은 초지(草地)의 사료가(飼料價)가 낮아 방목지(放牧地)로서는 부적합(不適合)하였다.