• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 추계학술발표회
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• pp.404-408
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• 2003

In this study, we examined the influences of pH and total concentration on the speciation of heavy metals (Cd, Cu, Zn) in acid mine drainage. Their labile concentrations were analyzed by Anodic Stripping Voltammetry (ASV) at both natural pH and adjusted pHs (from 2 to 8). We obtained regression equations for predicting labile concentrations as a function of the water pH and contamination level (total dissolved metal concentration). Our data show that labile Cu depends on both the total concentration and pH, while labile Cd and Zn concentrations are controlled mainly by their total concentration rather than pH. Therefore, the pH variation of AMD may significantly change the toxicity and bioavailability especially of Cu, owing to its speciation change.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권5호
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• pp.511-515
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• 2013

A Monte Carlo (MC) simulation study has been done in order to investigate the effects of line-edge-roughness (LER) induced by either 1P1E (single-patterning and single-etching) or 2P2E (double-patterning and double-etching) on fully-depleted silicon-on-insulator (FDSOI) tri-gate metal-oxide-semiconductor field-effect transistors (MOSFETs). Three parameters for characterizing the LER profile [i.e., root-mean square deviation (${\sigma}$), correlation length (${\zeta}$), and fractal dimension (D)] are extracted from the image-processed scanning electron microscopy (SEM) image for each photolithography method. It is experimentally verified that two parameters (i.e., ${\sigma}$ and D) are almost the same in each case, but the correlation length in the 2P2E case is longer than that in the 1P1E case. The 2P2E-LER-induced $V_TH$ variation in FDSOI tri-gate MOSFETs is smaller than the 1P1E-LER-induced $V_TH$ variation. The total random variation in $V_TH$, however, is very dependent on the other major random variation sources, such as random dopant fluctuation (RDF) and work-function variation (WFV).

• BMB Reports
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• 제36권2호
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• pp.154-158
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• 2003

Collagen is a family of proteins which consists of several genetically distinct molecular species and is intimately involved in tissue organization, function, differentiation and development. The purpose of this study was to investigate the concentration of different hydroxyproline (Hyp) fractions viz., total, free, peptide-bound, protein-bound, soluble- and insoluble-collagen hydroxyproline (Hyp) in various bovine tissues. Results showed that liver had the highest concentration of free Hyp followed by kidney, brain, spleen, lungs, muscle and heart. Liver also had the highest concentration of peptide-bound collagen Hyp followed by kidney, heart, spleen, lungs, brain and muscle. The concentration of protein-bound collagen Hyp was highest in the liver, followed by kidney, spleen, lungs, muscle, brain and heart. Total Hyp was highest in the liver, followed by kidney, spleen, brain, heart, muscle and lungs. Liver also had significantly high concentration of collagen as compared to other tissues examined (P<0.001). Spleen had the significantly higher concentration of soluble-collagen Hyp when compared to other tissues (P<0.001). This was followed by heart, muscle, lungs, brain, kidney and liver. Heart had the highest concentration of insoluble-collagen Hyp followed by lungs, kidney, liver, muscle, spleen and brain. The variation among the insoluble-collagen Hyp concentration of heart and muscle, spleen and brain was significant (P<0.001). We speculate that these differences could be due to the variation in turn over of rate of collagen metabolism in this species.

• Structural Engineering and Mechanics
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• 제52권1호
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• pp.115-136
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• 2014

In this study, an extended Kantorovich method, employing multi-term displacement functions, is applied to analyze the vibration problem of symmetrically laminated plates with arbitrary boundary conditions. The vibration behaviors of laminated plates are determined based on the variational principle of total energy minimization and the iterative Kantorovich method. The out-of-plane displacement is represented in the form of a series of a sum of products of functions in x and y directions. With a known function in the x or y directions, the formulation for the variation of total potential energy is transformed to a set of governing equations and a set of boundary conditions. The equations and boundary conditions are then numerically solved for the natural frequency and vibration mode shape. The solutions are verified with available solutions from the literature and solutions from the Ritz and finite element analysis. In most cases, the natural frequencies compare very well with the reference solutions. The vibration mode shapes are also very well modeled using the multi-term assumed displacement function in the terms of a power series. With the method used in this study, it is possible to solve the angle-ply plate problem, where the Kantorovich method with single-term displacement function is ineffective.

• 한국컴퓨터정보학회논문지
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• 제18권3호
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• pp.119-126
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• 2013

본 논문에서는 영화나 소설과 같이 스토리를 갖는 콘텐츠에 대해 스토리를 가시화해서 보여주는 시스템에 대해 제안하고 설명한다. 스토리를 가시화 해주기 위해 등장인물들 간의 관계를 모형화 하는 Character-net 방법론을 스토리 모형으로 적용하였다. 하지만 Character-net은 전체 스토리를 누적된 형태로 표현하기 때문에 스토리 진행에 따른 변화를 보여주기 한계가 있다. 이의 개선을 위해 Character-net의 변화와 등장인물들의 변화를 분석하여 보여주는 시스템을 개발하였다. 시스템은 Character-net 변화 실행 및 분석창과 등장인물 중심성 변화 시계열 그래프 창으로 구성하였다. 두 가지 창을 통해 주요 등장인물들이 처음 등장하거나 처음 만나는 장면과 같은 등장인물들 사이에서 나타나는 주요 변화지점을 찾는 기능과 인디그리와 아웃디그리의 변화 패턴을 통해 등장인물의 성향이나 성향의 변화를 추적할 수 있도록 지원하는 기능을 구현하였다. 본 논문에서는 이러한 스토리 가시화 시스템에 대해 설명하고 추가적으로 필요한 사항들에 대해 논의한다.

• 대한산업공학회지
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• 제19권3호
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• pp.11-23
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• 1993

A basic problem of sequencing a set of independent tasks at a single facility with the objective of minimizing total tardiness is considered. A variation of beam search, called knowledge-based beam search, has been studied which uses domain knowledge to reduce the problem size with an evaluation function to generate nodes probable to include the optimal solution. Its performance behavior is compared with some existing algorithms.

• 대한기계학회논문집
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• 제17권1호
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• pp.182-189
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• 1993

본 연구에서는 한곳에 적응효과가 중복되는 것을 피하고 해의 변화율이 상대 적으로 큰 곳에 대해 대등한 격자 적응효과를 주는 방법을 연구하였다. 전 유동장에 서 해의 변화율을 계산하여 하한값(threshold) 보다 큰 값을 갖는 cell에 대해 같은 크기의 가중함수(weight function) 값을 갖게 한다. 하한값(threshold)은 전체 cell 수에 대해 상위의 변화율을 갖는 cell의 백분율(percentage)로부터 구한다. 이 방법 은 하한값을 직접 대입해야 한다는 단점은 있으나 변황율이 상대적으로 큰 영역에 대 해 고른 격자 적응 효과를 줌으로 해서 격자 적응의 회수를 줄일 수 있으며 해의 발달 에 긍정적인 격자를 생성할 수 있다.

• Nuclear Engineering and Technology
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• 제51권3호
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• pp.719-722
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• 2019

Gamma-ray images generally suffer from a lot of noise because of low photon detection in the gamma camera system. The purpose of this study is to improve the image quality in gamma-ray images using a gamma camera system with a fast nonlocal means (FNLM) noise reduction algorithm with an acceleration function. The designed FNLM algorithm is based on local region considerations, including the Euclidean distance in the gamma-ray image and use of the encoded information. To evaluate the noise characteristics, the normalized noise power spectrum (NNPS), contrast-to-noise ratio (CNR), and coefficient of variation (COV) were used. According to the NNPS result, the lowest values can be obtained using the FNLM noise reduction algorithm. In addition, when the conventional methods and the FNLM noise reduction algorithm were compared, the average CNR and COV using the proposed algorithm were approximately 2.23 and 7.95 times better than those of the noisy image, respectively. In particular, the image-processing time of the FNLM noise reduction algorithm can achieve the fastest time compared with conventional noise reduction methods. The results of the image qualities related to noise characteristics demonstrated the superiority of the proposed FNLM noise reduction algorithm in a gamma camera system.

• 재활치료과학
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• 제2권2호
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• pp.47-59
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• 2013

목적 : 뇌졸중 환자를 대상으로 과제 지향적 훈련을 집단과 개별로 실시하게 하여 상지 기능, 인지 기능과 일상생활 수행력에 미치는 영향을 알아보고자 실시하였다. 연구방법 : 2012년 6월부터 11월까지 약 5개월간 A병원에 입원하여 뇌졸중 진단을 받은 사람 중에 재활치료를 받은 환자를 대상으로 하였다. 과제 훈련군과 개별 훈련군은 각각 13명씩 무작위 배정 하였다. 두 군 모두 동일한 내용의 과제 지향 훈련을 1일 30분씩 3주간 시행하도록 하였다. 결과 : 훈련 전 두 군의 상지 기능과 인지 기능은 유의한 차이를 보이지 않았다. 훈련 전 일상생활 영역에서 목욕하기(p<.001), 식사하기, 개인위생과 총점(p<.05)이 집단 훈련군에서 더 높은 것으로 나타났고 훈련 후 상지 기능은 개별 훈련군에서 유의하게 높았다(p<.001). 두 그룹 모두 훈련 전후 상지 기능 식사하기, 개인위생,목욕하기, 옷 입기, 용변처리, 이동, 보행, 계단, 총점(p<.05)에 유의한 향상이 있었다. 두 그룹의 훈련 전후 변화량 비교에서 개별 훈련군이 상지 기능(p<.001)과 일상생활 영역에서 식사하기와 총점에서 더 유의한 향상을 나타냈다(p<.05). 결론 : 과제 지향적 훈련을 시행 시 집단 훈련군과 개별 훈련군 모두 상지기능, 일상생활 수행력에 향상을 가져오며, 특히 상지 기능의 향상이 클 경우에 더 높은 일상생활 수행력의 변화를 가져 올 수 있다. 앞으로 보다 많은 환자를 대상으로 장기간에 걸친 종단적인 사례 연구가 필요하다.

• 산업공학
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• 제16권spc호
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• pp.39-44
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• 2003

As one of many design variables, the role of dimension tolerances is to restrict the amount of size variation in a manufactured feature while ensuring functionality. In this study, a nonlinear integer model has been modeled to allocate the optimal tolerance to each individual feature at a minimum manufacturing cost. While a normal distribution determines statistically worst tolerances with its symmetrical property in many previous tolerance allocation studies, a asymmetrical distribution is more realistic because its mean is not always coincident with a process center. A nonlinear integer model is modeled to allocate the optimal tolerance to a feature based on a beta distribution at a minimum total cost. The total cost as a function of tolerances is defined by machining cost and quality loss. After the convexity of manufacturing cost is checked by the Hessian matrix, the model is solved by the Complex Method. Finally, a numerical example is presented demonstrating successful model implementation for a nonlinear design case.