• The Pure and Applied Mathematics
• /
• v.3 no.2
• /
• pp.141-154
• /
• 1996

A data-driven index of dimensionality for an educational or psychological test - DETECT, short for Dimensionality Evaluation To Enumerate Contributing Traits, is proposed in this paper. It is based on estimated conditional covariances of item pairs, given score on remaining test items. Its purpose is to detect whatever multidimensionality structure exists, especially in the case of approximate simple structure. It does so by assigning items to relatively dimensionally homogeneous clusters via attempted maximization of the DETECT over all possible item cluster partitions. The performance of DETECT is studied through real and simulated data analyses.

• The Journal of the Korea Contents Association
• /
• v.13 no.12
• /
• pp.321-327
• /
• 2013

Impaired naming difficulty is common in normal elderly as well as in patients with neurological impairment. The 60-item Korean version-Boston Naming Test(K-BNT) is one of the most commonly used test for measuring confrontational naming ability. However, age-related cognitive decline may make the elderly difficult concentrating during the 60-item test, therefore, item reduction of the K-BNT would improve test validity and reliability. Thus, the purpose of this study was to develop a short form of the K-BNT based on Item Response Theory(IRT). Considering item-fit index, sex factor, and item difficulty through Rasch analysis, the 15-item K-BNT(i.e., K-BNT-15) was developed. Via administration of the K-BNT-15, we observed age-related decline in naming ability and significantly different performance between the normal elderly and patients with mild cognitive impairment. This study demonstrates the utility of IRT for developing a short-form language evaluation tool. The K-BNT-15 can be effective as a language screening tool to differentiate between normal aging and pathological diseases.

• Korean Management Science Review
• /
• v.27 no.1
• /
• pp.91-105
• /
• 2010

We proposed and stratified a selection standard model on Open Source Functional Board which could be found in Web. So we could grasp the weight about Performance Evaluation from the viewpoints of planners, developers, and web disigner professional of views. We suggested applying diverse measurement types in case of item which could chart Evaluation Standards on chosen sample boards. In case of item which couldn't do that, we compared and analyzed it by using selective type of 9 point scaling method on professionalists in every sample board. As a result of weight on upper estimate section of evaluation model chart, the order of importance was convenience(0.334), performance(0.333), function(0.240) and design(0.093) respectively. It indicates that there is more weight on performance and convenience which are hard to be structurally modified than designs and functions that are directly shown to the users. Also, it was evident that opposite results came out when using 9-point scale survey and measurement with objective data such as function and performance. The reason is because the surveyed subject can have his or her own subjectivity and bias unlike objective data. However, objectivity of the administrator is also an important factor thus both two perspectives have to be all considered when selecting the bulletin board.

• Quality Improvement in Health Care
• /
• v.5 no.2
• /
• pp.296-310
• /
• 1998

Background : Performance evaluation of medical care providers has become more important than before in Korea. Especially in university hospitals, job contents of medical staffs are so complicated that evaluation is not easily performed. In addition, in order that the feedback of evaluation be successful, acceptance of staffs to be evaluated is essential. This study is aimed at the development of items for evaluation and weighting of each item in one university hospital, and clustering departments by different weight given by medical staffs. Methods : Through resource group meeting. performance items were listed up by categories of education, research, medical services, and other activities in and out of the hospital. For each item, all the medical staffs were asked how important they thought, compared with publishing one original article. By factor analysis, the items in each category were grouped into a few subgroups. In turn, cluster analysis was done for the purpose of grouping departments by priority the medical staffs gave. Results and Conclusion : Among five major categories, medical staffs regard education, research, and medical services more important than other activities in and out of the hospital. Five categories consisted of two or three components. Departments in hospital were grouped into three. However, characteristics of each group was not clearly delineated. This result suggests that more comprehensive tool should be developed and applied in the process of performance evaluation in university hospitals.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.27 no.1
• /
• pp.33-41
• /
• 2016

Radio Frequency Identification(RFID) can provide visibility and efficiency throughout the entire supply chain in fashion apparel and footwear. The technical analysis of RFID performance is necessarily required to create a sealess omni-channel service using customer experience. Especially, several tagged-item performance specifications, for example read range and multi-read rate, strongly depend on the attached material and real-operating environment. This paper suggests minimum performance requirements for RFID tags embedded inside a pair of shoes to negotiate tagged-item performance between retailers and suppliers.

• Journal of Korean Critical Care Nursing
• /
• v.15 no.3
• /
• pp.1-11
• /
• 2022

Purpose : The purpose of this study was to not only examine the importance and performance status of patient safety nursing activities in the intensive care unit but also to understand nurses' educational needs in this respect. Methods : In this descriptive study, 196 nurses working in the intensive care units of university hospitals located at B City and G Province were enrolled. They completed the Importance-Performance Analysis (IPA) questionnaire, and the data were statistically analyzed. Results : Mean±standard deviation item scores of importance and performance of patient safety nursing activities were 4.75±0.33 and 4.48±0.38, respectively. In the IPA results, a total of 10 items were included in the second quadrant, including 1 item related to 'transfer,' 1 to 'infection,' and 1 to 'firefighting surveillance.' As the second quadrant contains the high-importance, low-performance items, these 10 items resemble the nurses' educational needs that should be prioritized. Conclusion : The results of this study can be used as a basis for the development of nursing educational programs for patient safety in the intensive care unit.

• Management Science and Financial Engineering
• /
• v.11 no.3
• /
• pp.137-153
• /
• 2005

Collaborative filtering-based recommendation systems make personalized recommendations based on users' ratings on products. Recommender systems must collect sufficient rating information from users to provide relevant recommendations because less user rating information results in poorer performance of recommender systems. To learn about new users, recommendation systems must first present users with an initial item list. In this study, we designed and analyzed seven selection strategies including the popularity, favorite, clustering, genre, and entropy methods. We investigated how these strategies performed using MovieLens, a public dataset. While the favorite and popularity methods tended to produce the highest average score and greatest average number of ratings, respectively, a hybrid of both favorite and popularity methods or a hybrid of demographic, favorite, and popularity methods also performed within acceptable ranges for both rating scores and numbers of ratings.

• International Journal of Reliability and Applications
• /
• v.3 no.4
• /
• pp.185-198
• /
• 2002

In the traditional life testing model, it is assumed that a certain number of identical items are tested under identical condition. This is due to statistical rather than practical considerations. The proportional hazards model can be used to develop a realistic approach to determine the performance of an item. That is also capable of modeling the failure rates of accelerated life testing when the covariates are applied stresses. The proportional hazards model is typically applied for a group of items to assess the importance of factors that may influence the reliability of an item. In this paper we considered the interarrival times of an item rather than the time to first failure for grouped items and provided the availability estimation for the determination of maintenance policy and overhaul time. In order to demonstrate the proposed approach, an example is presented.

• Journal of Korean Institute of Industrial Engineers
• /
• v.24 no.3
• /
• pp.359-365
• /
• 1998

An economic process monitoring procedure is presented when the major quality characteristic of the item is dichotomous. Every item is inspected and decided whether it is conforming or not. If an item is found to be nonconforming, the previous number of the successive conforming items is compared with a predetermined number r to check the process for existence of any assignable cause of variation. A cost model is constructed on the basis of costs of inspection, illegal signal, undetected out-of-control state and corrective action. By minimizing the expected total cost per unit time, the optimal value of r is obtained. The effects of cost coefficients are studied numerically.

• Journal of Information Processing Systems
• /
• v.15 no.1
• /
• pp.127-136
• /
• 2019

User-based and item-based approaches have been developed as the solutions of the movie recommendation problem. However, the user-based approach is faced with the problem of sparsity, and the item-based approach is faced with the problem of not reflecting users' preferences. In order to solve these problems, there is a research on the combination of the two methods using the concept of similarity. In reality, it is not free from the problem of sparsity, since it has a lot of parameters to be calculated. In this study, we propose a combining method that simplifies the combination equation of prior study. This method is relatively free from the problem of sparsity, since it has less parameters to be calculated. Thus, it can get more accurate results by reflecting the users rating to calculate the parameters. It is very fast to predict new movie ratings as well. In experiments for the proposed method, the initial error is large, but the performance gets quickly stabilized after. In addition, it showed about 6% lower average error rate than the existing method using similarity.