• 산업공학
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• 제12권2호
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• pp.166-173
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• 1999

In this paper, a load balancing problem among operators is considered, when one or more identical machines can be assigned to an operator. The operations of a job are separated into three categories : machine-controlled elements, operator-controlled elements and machine/operator-controlled elements. Machining or forming operations are included into the first category. The second category includes inspection and moving to another machine, and the last category includes setup and loading/unloading operation. The objective is to balance the workloads among operators under the constraints of available machine-time and operator-time. A hierarchical heuristic solution procedure is suggested for allocating jobs to each machine and allocating machines to each operator. The performance of the algorithm is evaluated with various data set.

• Bulletin of the Korean Chemical Society
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• 제7권2호
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• pp.102-105
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• 1986

Samples with the nominal composition of $Co_{9-x}M_xS_8$(M = Ni, Rh, Ru, and Fe) were prepared, and their magnetic properties were measured. X-ray diffraction analysis showed that small amount of the elements Ni, Rh, and Fe could be incorporated into $Co_9S_8$ forming a homogeneous ${\pi}$-phase, whereas the Ru-incorporated sample could not be prepared in a single phase. The lattice parameter was observed to increase as other elements were incorporated into $Co_9S_8$. Samples incorporated with the elements of Ni, Rh, and Ru showed Pauli-paramagnetism while the Fe-incorporated sample exhibited weak ferromagnetism. The values of magnetic susceptibility for the Ni, Rh, Ru-incorporated samples were nearly the same as that of pure $Co_9S_8$.

• 한국실내디자인학회논문집
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• 제21권5호
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• pp.34-45
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• 2012

In these days, restaurants are not simply used as a physical space but used as a cultural space in which people can enjoy and experience different cultures and traditional images. Moreover, from the restaurants design elements which help to form the atmosphere of the restaurants which serve food of specific country, we can see the history and traditions of that country. The additional value of the traditional decorative components which are the main factors forming the atmosphere of the restaurant will be different according to the various expressions used in the restaurant space. For this article, 12 restaurants, Norangjugory korean restaurant, Yongsusan korean restaurant, Best well-bing food restaurant, Awoolim, Mugunhwa, Ondal in Korea, and Songhelou, South Beauty, Xuxian restaurant & lounge, Beijing dadong roast duck restaurant, The horizon chinese restaurant, Dynasty jade garden in China, were selected for the field study. This study focused on a comparative analysis of the traditional decorative elements, especially, the application rate of the traditional decorative elements. The analyzed elements are nature, religious beliefs, history and culture for the intangible elements and facade, courtyard, trademark, ground, wall, ceiling, door, window, furniture and adornment for the tangible elements. After that, we analyzed the rates of the use of traditional decorative elements and modern decorative elements. Through the survey result and ratio analysis, we concluded as below. In Korean restaurant, traditionality is expressed in furnitures while, in Chinese restaurant, traditionality is expressed in decorative pattern. When it comes to the intangible elements among the traditional decorative components of the Korean and Chinese restaurants, Chinese and Korean restaurants have similarities in emphasizing the natural elements. Korean restaurants focus much on the environmentally friendly parts, while Chinese restaurants focus much on the fantastic natural atmospheres like those shown and expressed in the poems. As for religion characteristics, Chinese restaurants emphasize "geomancy" more than Korean restaurant. When it comes to the visible elements among the traditional decorative components of the Korean and Chinese restaurants, in Korean restaurants, the interior part has more traditionality than exterior part, while in Chinese restaurants, the exterior part has more traditionality than the interior part.

• 한국산학기술학회논문지
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• 제12권6호
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• pp.2777-2784
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• 2011

본 논문에서는 비변수 추정 알고리즘을 토대로 선형배열 안테나와 원형배열 안테나로부터 수신되는 다중신호의 DOA와 적응 빔성형 알고리즘을 연구하고 분석하였다. 비변수 추정 알고리즘에서는 입사각의 함수로써 신호에너지를 추정하기 위하여 고분해능과 잡음억압을 도출하도록 비이차놈을 사용하여 규칙화 목적함수를 최소화하였다. 그리고 나서, 신호와 잡음공간 조정벡터로부터 DOA를 추정하였고, 공간벡터에 의하여 도출된 가중치 벡터를 적용하여 적응 빔성형 패턴을 개선하였다. 특히, 안테나 배열방법과 배열소자의 수에 따라 입사되는 다중신호의 방향성 판별 능력과 적응빔을 성형하는 능력을 비교하고 고찰하였다.

• 열처리공학회지
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• 제25권6호
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• pp.283-291
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• 2012

In order to increase the anti-oxidation property during the tailor welding blanked hot press forming process for a high strength boron steel sheet, we performed a different coating method on the boron-steel sheet such as 87% Al - 13% Si and Fe - 8.87 Zn dipping plating procedure. However, during laser welding process, the Al-Si coated steel sheet has showed a low tensile strength and about half value of elongation than the original boron-steel sheet. Aluminum and silicon, elements of coating layer were diffused into the boron-steel matrix and have shown a low strength result than non-coated specimen. On the other hand, Zinc-coated boron-steel has expectedly showed a excellent tensile strength and micro-harness value in the welded area like original boron-steel.

• Ocean and Polar Research
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• 제26권2호
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• pp.231-243
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• 2004

Sequential extraction was carried out on twenty two subsamples of three ferromanganese crusts from three seamounts (Lemkein, Lomilik, and Litakpooki) near the Marshall Islands in the western Pacific. The extraction was designed to fractionate Fe-Mn crust forming elements into low defined groups: (1) exchangeable and carbornate, (2) Mn-oxide, (3) Fe-oxyhyd.oxide, and (4) residual fraction. X-ray diffraction result shows that target material were well removed by each extraction step except for CFA in phosphatized crusts generation. According to chemical analysis of each leachate, most of elements in the Fe-Mn crusts are bound with two major phases. Mn, Ba, Co, Ni, Zn, (Fe, Sr, Cu, and V) are strongly bounded with Mn-oxide $({\delta}-MnO_2)$ phase, whereas Fe, Ti, Zr, Mo, Pb, Al, Cu,(V, P, and Zn) show chemical affinity with Fe-oxyhydroxide phase. This result indicates that significant amount of Al, Ti, and Zr can not be explained by detrital origin. Ca, Mg, K, and Sr mainly occur as exchangeable elements and/or carbonate phase. Outermost layer 1 and inner layer 2 which are both young crusts generations are similar in chemical speciations of elements. However, some of Fe-oxyhydroxide bounded elements (Pb, Y, Mo, Ba, Al, and V) in phosphatized innermost layer 3 are released during phosphatization and incorporated into phosphate (Pb, Y, Mo, and Ba) or Mn-oxide phase (Al and V). Our sequential extraction results reveal that chemical speciations of elements in the hydrogenetic crusts are more or less different from interelemental relationship calculated by statistical method based on bulk chemistry.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.337-337
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• 2004

As one of researches for the P ＆ T purposes, a basic experiment on the recovery of actinide elements from the mixture with rare earth elements by means of electrorefining using a liquid cadmium cathode in the LiCl-KC1 eutectic melt was carried out. In order to examine the behaviors of electrodeposition of metal ions on a liquid electrode, recovery experiments of rare earth metals resulting from forming electrodeposits were performed by a galvanostatic electrolysis method at various current densities. A cyclic voltammetric technique was applied to determine reduction-oxidation potential of each metal element in the melt and to detect the changes of the multi component melt composition for on-line monitoring. Also, a collaboration study with RIAR was completed to test the preliminary feasibility on a recovery of actinide elements from the mixture with rare earth elements using a liquid cadmium cathode and actinide metals. Experimental results showed that the ratio of actinides to rare earths, 9: 0.5∼1 led to the rare earth content of about 5∼10 wt% in the deposit.

• 한국자동차공학회논문집
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• 제4권6호
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• pp.27-38
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• 1996

A two-dimensional FEM program, which considers bending effects in the membrane fromulation, was developed under plane strain assumption for analyzing forming processes of an arbitrarily shaped draw-die of automotive panels. For the evaluation of bending effects with membrane elements, the bending equivalent forces and stiffnesses are calculated from the bending moment computed using the changes in curvature of the formed shape of two membrane ones. The curves depicted with 3 nodes are described by a circle, a quadratic equation, and a cubic equation, respectively, and in the simulation of the stretch/draw sections of an automotive inner panel, three different description results are compared each other. Also, the bending results are compared with membrane results and measurements in order to verify the validity of the developed program.

• 디지털산업정보학회논문지
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• 제5권1호
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• pp.83-88
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• 2009

This paper consider the problem of direction of arrival(DOA) estimation in the presence of multipath propagation. The sensor elements are assumed to be linear and uniformly spaced. Numerous authors have advocated the use of a beamforming preprocessor to facilitate application of high resolution direction finding algorithms The benefits cited include reduced computation, improved performance in environments that include spatially colored noise, and enhanced resolution. Performance benefits typically have been demonstrated via specific example. The purpose of this paper is to provide an analysis of a beamspace version of the MUSIC algorithm applicable to two closely spaced emitters in diverse scenarios. Specifically, the analysis is applicable to uncorrelated far field emitters of any relative power level, confined to a known plane, and observed by an arbitrary array of directional antenna. In this paper, we researched about optimize beam forming to smart antenna system. The covariance matrix obtained using fourth order cumulant function. Simulations illustrate the performance of the techniques.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.195-199
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• 1993

In the analysis of metal forming processes by the finite element method, there are many numerical instabilities such as element locking, hourglass mode, shear locking. These instabilities may have a bad effect upon accuracy and convergence. The present work is concerned with improvement of stability and efficiency in two dimensional rigid-plastic finite element method using various type of elements and numerical integration schemes. AS metal forming examples, upsetting and backward extrusion are taken for comparison among the methods : various element types and numerical integration schemes. comparison is made in terms of stability and efficiency. As a result, it has been shown that the finite element computation is stabilized from the viewpoint of computational time, convergency, and numerical instability.