• 한국경영과학회지
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• 제36권3호
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• pp.91-105
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• 2011

In this paper, we analyze a logistic system involving a supplier who produces and delivers multiple types of items and a buyer who receives and sells the products to end customers. The buyer controls the inventory level by replenishing each product item up to a given order-up-to-level to cope with stochastic demand of end customers. In response to the buyer's order, the supplier produces or outsources the ordered item and delivers them at the start of each period. For the system described above, a mathematical model for a single type of item was developed from the buyer's perspective. Based on the model, an efficient method to find the cycle length and safety factor which correspond to a local minimum solution is proposed. This single product model was extended to cover a multiple item situation. From the model, algorithms to decide the base cycle length and order interval of each item were proposed. The results of the computational experiment show that the algorithms were able to determine the global optimum solution for all tested cases within a reasonable amount of time.

• 한국지역지리학회지
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• 제11권5호
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• pp.474-487
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• 2005

본 연구 목적은 2001년에 시행된 미국 NAEP 지리 평가에 대한 학생들의 문항반응경향성을 분석하여 귀납적으로 성취수준을 기술하는데 있다. NAEP 지리 평가는 4 8 12학년 학생을 대상으로 실시되는데, 평가영역은 내용영역과 행동영역으로 구분된다. 내용영역은 공간과 장소 환경과 사회 공간직 역동성과 연계성이고, 행동영역은 지식 이해 적용이다. 성취수준은 기초 숙달 수월수준으로 구분된다. 본 연구에서는 각 수준과 대표 문항을 연계하는 방법(item mapping method)을 사용하여 성취수준에 대하여 분석하였다. 그 결과 NAEP 지리 성취수준 설정위원회에서 제시한 성취수준과 대표 문항 분석에 기초한 성취수준은 큰 차이가 있는 것으로 나타났다. 대표 문항 분석을 기초로 도출된 성취수준은 실제 학생들의 문항반응에 기초하여 도출되었기 때문에 지리교육과정 개선을 위한 효과적인 송환 역할을 할 수 있을 것이다.

• 비교교육연구
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• 제28권5호
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• pp.1-19
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• 2018

국제 수학 과학 성취도 추이 연구와 같은 교육평가의 목적은 국가와 같은 집단을 비교하는 것이다. 이와 같이 평가의 단위가 학생보다 상위 수준일 때 집단을 비교하기 위해서는 다층 문항반응이론 기반의 집단 수준 진단평가 모형을 고려할 수 있다. 이 연구에서는 Park과 Bolt(2008)가 제안한 문항특성모형을 수정하여 새로운 다층 문항반응이론 기반의 집단 수준 진단평가 모형을 제안하였다. 이 수정된 모형은 2015년에 실시된 국제 수학 과학 성취도 추이 연구의 8학년 수학 평가 자료에 적용되었다. 그 결과 9개의 인지적 요소에 대한 국가들의 프로파일을 구할 수 있었다. 이 연구 결과는 국가 간 비교 또는 요소 간 상호 비교에 이용될 수 있다. 이와 같이 잔차항을 설명할 수 있도록 수정된 모형은 보다 높은 신뢰도를 지니며 국가 간 비교에 보다 정확한 정보를 제공할 수 있을 것으로 기대된다. 예를 이용하여 연구 결과를 어떻게 해석할 수 있는지 제시하였으며, 연구의 제한점과 후속 연구에 대해서도 논의하였다.

• 대한안전경영과학회지
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• 제8권2호
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• pp.115-128
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• 2006

The study analyzes those relations of customer service level of each sales branch, level of cooperations among branches, and overall system-wide service level for an item. Under the continuous review method, each sales branch places an order to the outside supplier, and the each branch receives the order quantity after elapsing a certain lead time. Under these circumstances, those branches with stockout condition may be supplied by other branches with keeping stocks to cover the shortages. This policy generally increases the system-wide customer service level for an item throughout cooperations for the safety plan among branches. Therefore, in the context of inventory policy, the decision rules to determine the proper branch levels of service and cooperation levels of service are important goals in terms of attaining desired system-wide service level. This research has suggested the method and procedure to reach above goals.

• 대한산업공학회지
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• 제19권3호
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• pp.25-35
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• 1993

Economic screening procedures using a correlated variable are proposed to assure that the proportion of conforming items is above a desired level after screening. It is assumed that the performance variable and the screening variable are jointly normally distributed. Two screening procedures are considered. In the first screening procedure, all of the items are inspected on the screening variable. If an item fails to meet the screening specifications, it is rejected and excluded from shipment without inspection of the performance variable. In the second screening procedure, the item which fails to meet the screening specifications is inspected on the performance variable. If the value of the performance variable is within specifications the item is accepted, and the item is rejected otherwise. Cost models are constructed which involve cast from an accepted nonconforming item, cost from a rejected item, and quality inspection cost. Methods of finding optimal cutoff value on a screening variable are presented and numerical examples are given.

• 산업경영시스템학회지
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• 제10권16호
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• pp.129-132
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• 1987

Multi-item inventory problems can be well characterized by the nature of interaction of the quantities and timing. This interaction may be due to the effect of certain combination of orders. It is that the set-up cost of ordering individual items can be saved by jointly ordering at a time. This study finds a decision criteria of optimum inventory policy through the comparisons of individual multi-item order policy(IMP), joint multi-item order policy(JMP), augmented multi-item order policy(AMP) in cost ratio. Subsequently we assume that there exists a unique optimum order level corresponding to an optimum reorder range for the augmented multi-item order, at which a cost saying is maximum.

• 한국의류학회지
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• 제15권4호
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• pp.405-416
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• 1991

This paper examined the risks perceived by consumers in apparel buying situation by 1) measuring the contents and perception level of risk, 2) categorizing each risk into meaningful factors (risk types), 3) analyzing the relationships between risk types and consumers' demo-graphic variables. 224 respondents deliberately selected to include each level of S demographic variables were contacted with 37-item question3.ire. Factor analysis showed that 32-item perceived risk could be categorized into 6 risk types: psychological. social, economic, time/convenience loss, fashionability loss, performance risk. Psychological risk were perceived highest in terms of perception level while social and performance risk showed relatively low perception level. 4 of 5 demographic variables including sex, education level, income, occupa-tion showed partial relationship with each risk type after ANOVA and Duncan test. Sex had the greatest influence on risk perception level and each age level (20's, 30's, 40's) showed different risk structure.

• 한국과학교육학회지
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• 제11권2호
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• pp.161-178
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• 1991

This study was designed to investigate the effect of test anxiety, intelligence, and item arrangement order on test performance in Earth Science. The main purposes in this study were to investigate (1) (2) (3) (4) on test performance.: (1) the effect of test anxiety components on test performance in Earth Science. (2) the effect of item arrangement order on test performance in Earth Science. (3) the effect of test anxiety This study was designed to investigate the effect of test anxiety, intelligence, and item arrangement order on test performance in Earth Science. The main purposes in this study were to investigate (1) (2) (3) (4) on test performance.: (1) the effect of test anxiety components on test performance in Earth Science. (2) the effect of item arrangement order on test performance in Earth Science. (3) the effect of test anxiety components on test performance in Earth Science according to learner's intelligence levels. (4) test effect of item arrangement order on learner's intelligence. The hypothesis was that there is difference among test achievements scores according to (1) test anxiety-worry levels. (2) item arrangement orders. (3) item arrangement orders on test anxiety-worry levels. (4) test anxiety-worry levels on intelligence levels. (5) test anxiety-emotionality levels. (6) item arrangement orders on test anxiety-emotionality levels. (7) test anxiety-emotionality levels on intelligence levels. (8) item arrangement orders on intelligence levels. The test items selected for this study were derived from the text Science (part 1) first grade of high school. The subjects of this study were 164 of high school first grade boy students in Pusan. They were assigned to one of the three groups, according to test anxiety levels.: (1) upper 25% of total subjects designated to high group (2) middle 50% (3) low group, lower 25% of total subjects And according to LQ. (1) upper 25% of total subjects designated to high group. (2) middle 50%. (3) low group, lower 25% of total subjects Analysis of variance was used in this study for hypothesis examination. The dependent variable was the achievement scores of Earth Science test and independent variables were test anxiety(worry, emotionality) level, LQ. level, item arrangement orders. The principal findings of the present study are as follows: (1)Test achievement score trend decreases as the test anxiety (worry, emotionality) increases although the result is not statistically significant. (2)There is no significant difference among test achievement scores according to item arrangement orders. (3)The higher the LQ. is, the more effective test anxiety. And the LQ. has significant interaction effect with test anxiety. (4)There is significant interaction effect between the LQ. levels and itemqr arrangement orders.

• 한국전문물리치료학회지
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• 제23권4호
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• pp.71-80
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• 2016

Background: Functional capacity evaluations (FCEs) are designed to systematically assess the capacity to perform work-related tasks and to determine worker's ability to return to the previous job following work-related injuries. These evaluations may be rated either by clinician or worker. There has been a lack of consensus between the two scoring methods. Objects: This study aimed: 1) to confirm if the data are fit to the Rasch rating scale model and 2) to investigate the item-level concordance rate between the ratings of clinician and injured worker of the FCE. Methods: A cross-sectional study was conducted with a sample (n=124) of a rehabilitation program with the Occupational Rehabilitation Data Base for workers with low back pain. The functional capacity evaluation at admission and discharge was administered to clinicians and workers. The data were analyzed using both classical test theory-based Pearson's r and intra-class coefficient followed by item-level analysis with Rasch rating scale model. Results: All items of the FCE, except sitting items rated by clinician at admission and handling items rated by both clinician and worker throughout admission and discharge, were acceptable fit statistics with minor out of ranges for a misfit criterion. This may indicate that the items of the FCE overall fit to the Rasch rating scale model. Few problematic items responding differently to clinician and worker both at admission and discharge were detected with the differential item functioning analysis despite the excellent concordance rate using the two conventional statistics-sitting and handling items at admission and handling item at discharge. Conclusion: The item-level speculations using Rasch analysis of the FCE demonstrate that the ratings of clinician and self ratings of worker were psychometrically acceptable though there was an apparent discrepancy between the raters both at admission and discharge.

• 정보교육학회논문지
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• 제5권2호
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• pp.268-278
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• 2001

본 연구는 웹기반 교수 시스템을 이용하는 학습자의 지식 수준을 지능적으로 진단하기 위하여 문항 반응을 이용한 진단 모듈의 설계와 구현에 관하여 다룬다. 문항 반응 이론은 기존의 학습자 검사 방법처럼 전체 문항에서 정답 문항의 총점에 근거를 두고 학습자를 진단하는 것이 아니라 문항 하나 하나에 근거를 두고 학습자의 지식 수준을 검사하는 것이다. 기존의 웹기반 교수 시스템의 경우 학습자의 지식 수준은 고려하지 않고 검사의 총점 결과만을 가지고 진단한 뒤 그 결과를 토대로 이분법적인 학습을 진행하는 오류를 범하고 있다. 이는 학습자의 올바른 진단이 될 수 없으며 학습자 모델을 구성하기가 어려워 진보한 지능형 교수 학습 시스템에 적용하기 어렵다. 따라서 본 연구에서는 기존에 연구된 문항 반응 이론을 수학 학습에 응용하여 학습자의 지식 수준을 진단하기 위한 학습자 진단 모듈의 설계 및 구현에 대한 방향을 제시하고자 한다.