• 한국응급구조학회지
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• 제28권2호
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• pp.7-19
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• 2024

Purpose: To adjust item numbers in a national test, this study used item response theory to examine changes in average scores, reliability, difficulty, and discrimination according to the adjustment of item numbers. Methods: We analyzed the dichotomous coding of correct and incorrect answers of 473 examinees in a mock test conducted in 2023. Additionally, as an explanatory pilot study, we used an online questionnaire to survey experts on their perceptions of the appropriate item numbers for each test subject from January 18, 2024, to February 15, 2024. Results: Regarding the item numbers on the national exam, experts preferred to reduce the number of management of emergency patients (33.14±6.09, p<.05) and advanced emergency medical care: subtopics (104.49±11.55, p<.05), and the total number of questions (217.82±20.95, p<.05). In a simulation set in which items with low item fit were removed after fitting a two-parameter item response theory model, reliability was maintained at .910 until the 5th test consisting of 185 questions with little loss of difficulty, discrimination, and average score, and there was no correlation between item numbers and average score. Conclusion: Experts responded that reducing the number of items on the national exam was appropriate. As a result of the item reduction simulation, there was no significant loss in the average score, difficulty, discrimination, or reliability. More reliable results could be obtained if the results were based on a validity analysis and analyzed using actual national exams.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제7권3호
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• pp.163-189
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• 2003

The purpose of this study is to develop a test, which can be used in creative problem solving ability in mathematics of the mathematically gifted and the regular students. This test tool is composed of three categories; fluency (number of responses), flexibility (number of different kinds of responses), and originality (degree of uniqueness of responses) which are the factors of the creativity. After applying to 462 middle school students, this test was analyzed into item analysis. As a results of item analysis, it turned out to be meaningful (reliability: 0.80, validity: item 1(1.05), item 2(1.10), item 3(0.85), item 4(0.90), item 5(1.08), item difficulty: item 1(-0.22), item 2(-0.41), item 3(0.23), item 4(0.40), item 5(-0.01), item discriminating power: item 1(0.73), item 2(0.73), item 3(0.67), item 4(0.51), item 5(0.56), over the level of a standard basis. This means that the test tool was useful in the test process of creative problem solving ability in mathematics

• 한국게임학회 논문지
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• 제7권4호
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• pp.125-134
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• 2007

아이템 거래의 속성에 대해서는 그동안 많은 연구가 진행되어 왔으나, 막상 아이템 거래의 발생 원인에 대해서는 설문조사 등의 방법만 수행되어 왔고, 온라인 게임 내에서의 경제 분석 에 의한 연구는 이루어지지 못하였다. 따라서 본 연구는 온라인 게임 내에서의 아이템 수요와 공급에 대해 역할참석, 직접관찰, 관련자 면담 등의 방법을 사용하여 게임 내에서의 아이템 거래의 원인을 분석하였다. 분석 결과 아이템 거래가 일반 게이머들 사이에서 차지하는 비중은 크지 않으며, 인챈트를 즐기는 소수의 게이머, 혈전 및 공성전을 수행하는 사람들 사이에서 중점적으로 발생한다. 또 주된 아이템 공급자는 일반게이머가 아니라 작업장이다. 즉 아이템 거래는 소량으로 적은 액수를 거래하는 다수의 게이머와, 대량으로 많은 액수를 거래하는 소수의 매니아 게이머에 의해서 발생한다. 이러한 아이템 거래의 소수 집중적 속성을 파악하는 것은 아이템 거래와 관련된 제반 정책 및 사회적 영향을 검토하는 데에 기반 지식으로 활용될 수 있을 것이다.

• Industrial Engineering and Management Systems
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• 제12권3호
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• pp.172-180
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• 2013

We herein consider a stochastic multi-item inventory management problem in which a warehouse sells multiple items with stochastic demand and periodic replenishment from a supplier. Inventory management requires the timing and amounts of orders to be determined. For inventory replenishment, trucks of finite capacity are available. Most inventory management models consider either a single item or assume that multiple items are ordered independently, and whether there is sufficient space in trucks. The order cost is commonly calculated based on the number of carriers and the usage fees of carriers. In this situation, we can reduce future shipments by supplementing items to an order, even if the item is not scheduled to be ordered. On the other hand, we can reduce the average number of items in storage by reducing the order volume and at the risk of running out of stock. The primary variables of interest in the present research are the average number of items in storage, the stock-out volume, and the number of carriers used. We formulate this problem as a multi-objective optimization problem. In a numerical experiment based on actual shipment data, we consider the item shipping characteristics and simulate the warehouse replenishing items coordinately. The results of the simulation indicate that applying a conventional ordering policy individually will not provide effective inventory management.

• 한방안이비인후피부과학회지
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• 제27권3호
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• pp.1-25
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• 2014

Objective : For activation of study on filed of odontology in Korean medicine academia, we analyzed the trend of articles that published in journals of Korean medicine. Methods : Using search words of odontology, in internet reference sites we collected papers and classified those into three categories like as review article, original article, case report. Observation points of each item are as follows. Inclusive item of papers; publication year, journal, number of authors, disease. Item of review article; subject of paper, Item of original article; number of patients, period of research, remedy. Item of case report; remedy, valuation of criteria, number of cases. Results : The total number of articles searched was 88, consisting of 23 review articles, 46 original articles and 19 case reports. The percentage of 'TMJ diseases' ranked highest(47.7%) in classification by disease. The most reviewed subject was 'Remedy' (16 times). '25 or less' person ranked highest(50%) in the number of patient in original articles. Acupuncture, chuna manual medicine and herbal medicine were mostly applied in case reports. The number of 'one case' reported case reports was highest(52.6%).

• Management Science and Financial Engineering
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• 제19권1호
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• pp.25-28
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• 2013

Consider the inverse bin-packing number problem. Given a set of items and a prescribed number K of bins, the inverse bin-packing number problem, IBPN for short, is concerned with determining the minimum perturbation to the item-size vector so that all the items can be packed into K bins or less. It is known that this problem is NP-hard (Chung, 2012). In this paper, we investigate some special cases of IBPN that can be solved in polynomial time. We propose an optimal algorithm for solving the IBPN instances with two distinct item sizes and the instances with large items.

• 산업경영시스템학회지
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• 제19권39호
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• pp.19-26
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• 1996

A solution procedure to minimize the number of storage carousels has been developed under the carousel throughput rate and total storage capacity requirements. The number of carousels can be reduced by increasing the throughput rate of carousels which depends upon the size of carousels, the storage item allocation to carousels, and the item position assignments in each carousel. Since the problem is very complicated and hard to solve optimally, the following solution procedure to solve the problem hierarchically is proposed: With a given number of carousels, the storage items are allocated to carousels so that the slowest average transaction time among carousels may be minimized, and then the position of each item is assigned in the allocated carousel so that the throughput of the carousel can be maximized.

• 한국수학교육학회지시리즈A:수학교육
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• 제46권4호
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• pp.407-421
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• 2007

The purpose of this study is to identify the item characteristics that are supposed to affect item difficulty and to estimate the regression equations for predicting item difficulty of mathematics in the College Scholastic Ability Test(CSAT). We selected six variables related to item characteristics based on learning theories: contents, cognitive domain, novelty, item type, number of concepts, and the amount of computation. With data of the CSAT mathematics test administered in 2004-2006, item difficulty was regressed on the six variables, the location of an item, and the item writer's judgment on difficulty. The novelty of an item was found to be a statistically insignificant variable in explaining item difficulty. Four regression equations with different sets of independent variables could explain $70%{\sim}80%$ of the item difficulty variance and were validated as predicting item difficulty of the mock CSAT in 2006.

• 한국수학교육학회지시리즈A:수학교육
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• 제37권1호
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• pp.1-13
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• 1998

In this paper, we have represented the efficient way how to enumerate the optimal number-right scores to adjust the item difficulty and to improve item discrimination. To estimate the optimal number-right scores in two equivalent math-tests by linear score equating a measurement error model was applied to the true scores observed from a pair of equivalent math-tests assumed to measure same trait. The model specification for true scores which is represented by the bivariate model is a simple regression model to inference the optimal number-right scores and we assume again that the two simple regression lines of raw scores and true scores are independent each other in their error models. We enumerated the difference between mean value of $\chi$＊ and ${\mu}$$\_$$\chi$/ and the difference between the mean value of y＊and a＋b${\mu}$$\_$$\chi$/ by making an inference the estimates from 2 error variable regression model. Furthermore, so as to distinguish from the original score points, the estimated number-right scores y’$\^$*/ as the estimated regression values of true scores with the same coordinate were moved to center points that were composed of such difference values with result of such parallel score moving procedure as above mentioned. We got the asymptotically normal distribution in Figure 5 that was represented as the optimal distribution of the optimal number-right scores so that we could decide the optimal proportion of number-right score in each item. Also by assumption that equivalence of two tests is closely connected to unidimensionality of a student’s ability. we introduce new definition of trait score to evaluate such ability in each item. In this study there are much limitations in getting the real true scores and in analyzing data of the bivariate error model. However, even with these limitations we believe that this study indicates that the estimation of optimal number right scores by using this enumeration procedure could be easily achieved.

• 산업경영시스템학회지
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• 제21권48호
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• pp.15-23
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• 1998

This paper concerns the problem of determining the spare inventory level for multi-echelon repairable-item inventory system with finite number of operating items. We consider the system which has several bases and a central depot. When an item fails, it is dispatched to a repair facility and, a spare, if available, is plugged in immediately. When the failed item is repaired, it is sent to the base and either is used to fill a backorder or is stored at a spare inventory point. Using queueing network, we develop an algorithm to find the spare inventory level which minimizes the total expected cost and, simultaneously, satisfies a specified minimum fill rate. The results of the algorithm clearly indicate that the algorithm successfully generate output with optimal solution.