• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1995년도 추계학술대회 논문집
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• pp.64-67
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• 1995

Transfer Molding is currently the most widely used process for encapsulation integrated circuits(;IC). Although the process has been introduced over 20 years ago, generating billions of parts each year, it is far from being optimized. With each new mold, epoxy mold, epoxy mold compound, and lead-frame, lengthy period and expensive qualification runs have to be performed to minimized defects ranging from wire sweep, incomplete fill, and internal voids etc. This studies describes how simulation can be applied to transfer molding to yield acceptable design and processing parameter. The non-isothermal filling of non-newtonian reactive epoxy molding compound(;EMC) in a multi-cavity mold is analyzed. Sensitivity analysis is conducted to investigate the influence of process deviations on the final molded profile. This study trend is carried out by following some heuristic process guidelines.

• Journal of applied mathematics & informatics
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• 제22권1_2호
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• pp.307-316
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• 2006

Incomplete LU factorization preconditioning techniques often have difficulty on indefinite sparse matrices. We present hybrid reordering strategies to deal with such matrices, which include new diagonal reorderings that are in conjunction with a symmetric nondecreasing degree algorithm. We first use the diagonal reorderings to efficiently search for entries of single element rows and columns and/or the maximum absolute value to be placed on the diagonal for computing a nonsymmetric permutation. To augment the effectiveness of the diagonal reorderings, a nondecreasing degree algorithm is applied to reduce the amount of fill-in during the ILU factorization. With the reordered matrices, we achieve a noticeable improvement in enhancing the stability of incomplete LU factorizations. Consequently, we reduce the convergence cost of the preconditioned Krylov subspace methods on solving the reordered indefinite matrices.

• 한국정보처리학회논문지
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• 제2권6호
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• pp.960-968
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• 1995

이 논문에서 우리는 CRAY-2에서 편미분방정식에서 발생하는 대형희귀 연립방정 식의 효과적인 벡터준비행렬을 만들기 위한 재배열방법을 제시한다. 이 재배열방법은 종래의 빨강/검정 배열의 선형 형태로써, ILU 준비행렬의 변형에 사용될 경우 필인 (fill-in)을 크게 하면 종래의 빨강/검정 재배열의 약점이던 수렴율의 감소를 극복할 수 있다. 우리는 CRAY-2에서 여러 가지 실험을 통해 우리의 주장을 입증한다. 또, 에러 행렬의 후로베니우스 놈을 계산한 결과도 우리의 주장과 일치한다.

• Journal of the Korean Data and Information Science Society
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• 제26권4호
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• pp.971-984
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• 2015

Imputation procedures fill-in missing values, thereby enabling complete data analyses. Fully efficient fractional imputation (FEFI) and multiple imputation (MI) create multiple versions of the missing observations, thereby reflecting uncertainty about their true values. Methods have been described for hypothesis testing with multiple imputation. Fractional imputation assigns weights to the observed data to compensate for missing values. The focus of this article is the development of tests of independence using FEFI for partially classified two-way contingency tables. Wald and deviance tests of independence under FEFI are proposed. Simulations are used to compare type I error rates and Power. The partially observed marginal information is useful for estimating the joint distribution of cell probabilities, but it is not useful for testing association. FEFI compares favorably to other methods in simulations.

• 한국정밀공학회지
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• 제22권3호
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• pp.107-114
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• 2005

A new approach which combines implicit surface scheme and point projection method is presented in order to fill the arbitrarily shaped holes in the polygon model. In the method a trimmed surface which has an outer boundary curve is generated by using the implicit surface scheme and normal projection of point onto the base surface. The base surface is constructed by creating smooth implicit surface from the incomplete polygon model through which the surface should pass. In this paper an implicit surface is defined by a radial basis function, a continuous scalar-valued function over the domain $R^3$. The base surface is the set of all points at which this scalar function takes on the value zero and is created by placing zero-valued constraints at the vertices of the polygon model. In order to show the validity of the present study, various hole fillings are carried out for the complex polygon model of arbitrary topology.

• International Journal of Precision Engineering and Manufacturing
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• 제8권1호
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• pp.3-10
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• 2007

A new approach based on implicit surface interpolation combined with domain decomposition is proposed for filling complex-shaped holes in a large polygon model, A surface was constructed by creating a smooth implicit surface from an incomplete polygon model through which the actual surface would pass. The implicit surface was defined by a radial basis function, which is a continuous scalar-value function over the domain $R^{3}$. The generated surface consisted of the set of all points at which this scalar function is zero. It was created by placing zero-valued constraints at the vertices of the polygon model. The well-known domain decomposition method was used to treat the large polygon model. The global domain of interest was divided into smaller domains in which the problem could be solved locally. The LU decomposition method was used to solve the set of small local problems; the local solutions were then combined using weighting coefficients to obtain a global solution. The validity of this new approach was demonstrated by using it to fill various holes in large and complex polygon models with arbitrary topologies.

• 한국의료질향상학회지
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• 제4권2호
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• pp.174-183
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• 1997

Background : Medical records thought to be reflecting the quality of medicine. By this ground, examination of medical records can be served to evaluate, and to improve the quality of medical care. To examine the medical records, we need some standards or checklists which can be used to sort out the problems. Methods: We developed checklists for medical records evaluation. We studied 1,677 medical records about its completeness using this checklists in one educational hospital. Survey was completed by 5 well trained staffs of medical record department. Results are analyzed. SPSS/PC+ program was used for statistics. Results : 13.8% of discharge summary was incomplete. Recording of the demographic information was also poor in incomplete medical records compared to complete ones. Progress note was recorded average 4.16 times during 11.9 hospital days. After 4th hospital day, recording rate of progress note dropped sharply. Rate of professor's signature on operation records was poor(27%). He or she who described the discharge summary well also wrote progress note well. Conclusions: Fill-up of demographic date should be stressed during medical record education program. Strategy to create the environment emphasizing the responsibility of professor on quality medical record should be made. We suggest new index (number of records/hospital stay) for the evaluation of completeness of progress note.

• 대한화학회지
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• 제60권1호
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• pp.48-58
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• 2016

이 연구는 중학생들의 전해질과 이온 개념에서 나타나는 개념 변화 유형을 조사한 것이다. 자료수집은 9학년 학생들을 대상으로 전해질과 이온 수업 전후의 개념을 조사하고, 9명의 학생들을 대상으로 반구조화된 면담을 통해 이루어졌다. 면담내용을 모두 녹음하고 전사하였으며, 그리고 학생들의 응답을 유형별로 분류하였다. 연구 결과는 다음과 같다. 첫째, 이온의 개념 변화 유형은 단순한 개념에서 정교화된 개념, 불완전한 개념에서 과학적 개념, 오개념에서 혼동된 개념, 오개념에서 오개념 등의 4가지로 분류되었다. 많은 학생들이 수업 전후 이온 개념 형성에 어려움을 겪고 있으며, 원자와 원자의 구성입자를 정확하게 구별하지 못하고 있었다. 둘째, 전해질 개념 변화 유형은 부분적 과학 개념에서 정교화된 개념, 오개념에서 부분적 오개념, 불완전한 개념에서 불완전한 개념, 오개념에서 오개념 등의 4가지로 분류되었다. 또한 다수의 학생들은 전해질과 비전해질의 차이점을 구분하는 것을 어려워하였다. 셋째, 연구 단원인 전해질과 이온은 교육과정에 따라 9학년 2학기에 편성되어 있고, 진학을 위한 내신성적 산출 등 바쁜 시기의 학습으로 학생들이 입자 개념 형성에 더욱 곤란을 겪고 있음을 알 수 있었다. 연구 결과를 바탕으로 학생들이 입자의 과학적 개념을 변화시킬 수 있는 교수전략을 제시하였다.

• 한국정밀공학회지
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• 제23권1호
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• pp.174-184
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• 2006

In order to fill the holes with complex shapes in the large polygon model, a new approach which is based on the implicit surface interpolation method combined with domain decomposition method is presented. In the present study, a surface is constructed by creating smooth implicit surface from the incomplete polygon model through which the surface should pass. In the method an implicit surface is defined by a radial basis function, a continuous scalar-valued function over the domain $R^3$ The generated surface is the set of all points at which this scalar function takes on the value zero and is created by placing zero-valued constraints at the vertices of the polygon model. In this paper the well-known domain decomposition method is used in order to treat the large polygon model. The global domain of interest is divided into smaller domains where the problem can be solved locally. LU decomposition method is used to solve a set of small local problems and their local solutions are combined together using the weighting coefficients to obtain a global solution. In order to show the validity of the present study, various hole fillings are carried out fur the large and complex polygon model of arbitrary topology.

• Water Engineering Research
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• 제5권1호
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• pp.47-54
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• 2004

Several computer programs have been developed to make stochastically generated weather data from observed daily data. But they require fully dataset to run WGEN. Mostly, meterological data frequently have sporadic missing data as well as totally missing data. The modified WGEN has data filling algorithm for incomplete meterological datasets. Any other WGEN models have not the function of data filling. Modified WGEN with data filling algorithm is processing from the equation of Matalas for first order autoregressive process on a multi dimensional state with known cross and auto correlations among state variables. The parameters of the equation of Matalas are derived from existing dataset and derived parameters are adopted to fill data. In case of WGEN (Richardson and Wright, 1984), it is one of most widely used weather generators. But it has to be modified and added. It uses an exponential distribution to generate precipitation amounts. An exponential distribution is easier to describe the distribution of precipitation amounts. But precipitation data with using exponential distribution has not been expressed well. In this paper, generated precipitation data from WGEN and Modified WGEN were compared with corresponding measured data as statistic parameters. The modified WGEN adopted a formula of CLIGEN for WEPP (Water Erosion Prediction Project) in USDA in 1985. In this paper, the result of other parameters except precipitation is not introduced. It will be introduced through study of verification and review soon