• International Journal of Reliability and Applications
• /
• v.12 no.2
• /
• pp.131-143
• /
• 2011

In most of literatures of age replacement policy, the authors consider the case that a new item starts operating at time zero and is to be replaced by new one at time T. It is, however, often to purchase used items because of the limited budget. In this paper, we consider age replacement policy of a used item whose age is $t_0$. The mathematical formulas of the expected cost rate per unit time are derived for both infinite-horizon case and finite-horizon case. For each case, we show that the optimal replacement age exists and is finite and investigate the effect of the age of the used item.

• International Journal of Reliability and Applications
• /
• v.10 no.1
• /
• pp.33-42
• /
• 2009

In most of literatures of age replacement policy, the authors consider the case that a new item starts operating at time zero and is to be replaced by new one at time T. It is, however, often to purchase used items because of the limited budget. In this paper, we consider age replacement policy of a used item whose age is $t_0$. The mathematical formulas of the expected cost rate per unit time are derived for both infinite-horizon case and finite-horizon case. For each case, we show that the optimal replacement age exists and is finite and investigate the effect of the age of the used item.

• The Journal of Korean Medicine
• /
• v.34 no.3
• /
• pp.96-105
• /
• 2013

Objectives: Bi Jeung (비증) is a pain syndrome derivative of pathological patterns of East Asian medicine. The purpose of this study was to develop a self-rated questionnaire for Bi Jeung. Methods: Twelve questionnaire items for Bi Jeung (3 items for the Wind Bi, 5 items for the Cold Bi, and 4 items for the Dampness Bi) were extracted through the literature review. These items were presented to the 18 Korean medical doctors who specialized in pain medicine to conduct two sessions of the Delphi method. The Korean medical doctors were asked to rate the importance of each item for the corresponding Bi syndromes, using a Likert 7-point scale, and were asked to propose which item should be additionally included to increase determinant power to each Bi syndrome. We determined the 4 points of the importance as a cut-off point of each item. Results: Through two sessions of the Delphi method, two items were deleted because their mean values of the importance were below 4 point. Korean medical doctors proposed to add three items for the Bi Jeung. However, the mean values of only two among the three items were over 4 points, so finally 12 items (3 items for the Wind Bi, 5 items for the Cold Bi, and 4 items for the Damp Bi) were determined for the Bi Jeung questionnaire. Conclusions: It is concluded that a 12 item-Bi Jeung questionnaire comprising the three subcategories of the Bi Jeung (Wind, Cold, and Dampness Bis) possesses contents validity through literature review and Delphi methods.

• The Mathematical Education
• /
• v.37 no.1
• /
• pp.1-13
• /
• 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.

• Physical Therapy Korea
• /
• v.15 no.2
• /
• pp.44-53
• /
• 2008

The purpose of this preliminary study was to develop a measurement for assessing risk factors for falling in community-dwelling elderly persons. Rasch analysis and principal component analysis were performed to examine whether items on the Activities-Specific Balance Confidence (ABC), assessing self-efficacy, and items on the Berg Balance Scale (BBS), assessing balance function, contribute jointly to a unidimensional construct in the elderly. A total of 35 elderly persons (4 men, 31 women) participated. In this study, each item of ABC (16 items) and BBS (14 items) was scored on a 5-point ordinal rating scale from 0 to 4. The initial Rasch and principal component analysis indicated that 3 of the ABC items and 2 of the BBS items were misfit for this study. These 5 items were excluded from further study. After combining ABC and BBS, Rasch and principal component analyses were examined and finally 23 items selected; 12 items from ABC, 11 items from BBS. The 23 combined ABC-BBC items were arranged in order of difficulty. The hardest item was 'walk outside on icy sidewalks' and the easiest item was 'pivot transfer'. Although structural calibration of each 5 rating scale categories was not ordered, the other three essential criteria of Linacre's optimal rating scale were satisfied. Overall, the ABC-BBS showed sound item psychometric properties. Each of the 5 rating scale categories appeared to distinctly identify subjects at different ability levels. The findings of this study support that the new ABC-BBS scale measure balance function and self-efficacy. It will be a clinically useful assessment of risk factors for falling in the elderly. However, the number of subjects was too small to generalize our results. Further study is needed to develop a new assessment considering more risk factors of falling in elderly.

• The Journal of Korean Physical Therapy
• /
• v.21 no.3
• /
• pp.103-108
• /
• 2009

Purpose: The purpose of this survey was to assess the satisfaction of patients suffering from musculoskeletal pain with physical therapy (PT) in Busan, Daegu, and Kyeongsang provinces using a Korean-language version of the patient satisfaction questionnaire with physical therapy service (PSPT). Methods: A total of 654 patients, having PT for their musculoskeletal pains, participated. Consenting subjects completed a 20-item PSPT on their $6^{th}$ or last treatment day. Simple descriptive statistics were used for respondent characteristics, and mean of satisfaction score in each item. Regression analysis was performed on each item of the questionnaire. Results: 654 subjects responded during or after their PT services. 297 (45.5%) of them were male and the most common site of pain was the spine. The mean of each item score (1-5) ranged from 2.14 for "my therapist did not listen to my concerns" to 4.12 for "my therapist treated me respectfully". Receptionist's attitude, registration process, service time of the hospital, and answer to the patient's questions greatly affected the general satisfaction of the respondents. Conclusion: The results showed high levels of satisfaction to the general process for obtaining treatment as well as the therapist's attitudes toward their patients. They may provide valuable patients' feedback regarding PT service for musculoskeletal pain. Therefore, it may be used by physical therapists to improve future patient experiences with a view to improving the patient's attendance and compliance with the PT service protocols for patients suffering from musculoskeletal pain.

• Journal of Korean Clinical Health Science
• /
• v.9 no.2
• /
• pp.1493-1501
• /
• 2021

Purpose: The purpose of this study is to classify the characteristics of each item of CIST evaluation and to find out the degree of recognition of the characteristics of the cognitive tool. Methods: This study was conducted for occupational therapy majors at M University located in Gyeongsangnam-do. The data collection from May to June 2021. Total of 25 copies of the data were finally analyzed, SPSS Statistics 26 was used for data analysis. Results: As a result of the study, the significance level was visual reasoning 1 test strip and the visual reasoning 1 tool. In the relationship between the correspondence 1 figure simulation sheet and the figure simulation tool for each item and statistically significant, and the correspondence 2 visual reasoning 2 sheet. Visual reasoning 2 sheet and visual reasoning tool also showed that was found to be statistically significant. The correlation for visual reasoning 1 sheet and the visual reasoning 1 tool, reasoning 2 tool and visual reasoning 1 sheet, and the visual reasoning 2 tool and the verbal reasoning sheet. Conclusion: In this study, in the CIST items that may be difficult, it is better to attach the actual tool rather than the verbal explanation of the test paper to increase the efficiency of the test and the understanding of subjects with mild cognitive impairment. It was implemented by applying the tool, and it was found that the use of the tool in the visual reasoning item showed a high correlation by item. Furthermore, based on this study, it will be possible to suggest a method to control the difficulty of each subject of the cognitive evaluation tool, and to prepare a standard for future research.

• Journal of Korean Institute of Industrial Engineers
• /
• v.37 no.4
• /
• pp.358-366
• /
• 2011

Multi-criteria ABC inventory classification, which aims to classify inventory items by considering more than one criterion, is one of the most widely employed techniques for inventory control. The weighted linear optimization (WLO) model proposed by Ramanathan (2006) solves the problem of multi-criteria ABC inventory classification by generating a set of criterion weights for each inventory item and assigning a normalized score to the item for ABC analysis. However, the WLO model has some limitations. First, many inventory items can share the same optimal score, which can hinder a precise classification of inventory items. Second, the model allows too much flexibility in weighting multiple criteria; each item is allowed to choose its own weights so that it can maximize its score. As a result, if an item dominates the others in terms of a certain criterion, it may be classified into a higher class regardless of other criteria by assigning an overwhelming weight to the criterion. Consequently, an item with a high value in an unimportant criterion and low values in others may be inappropriately classified as class A, leading to an inaccurate classification of inventory items. To overcome these shortcomings, we extend the WLO model by using the cross-efficiency method in data envelopment analysis. We claim that the proposed model can provide a more reasonable and accurate classification of inventory items by mitigating the adverse effect of flexibility in the choice of weights and yielding a unique ordering of inventory items.

• YAKHAK HOEJI
• /
• v.59 no.5
• /
• pp.235-244
• /
• 2015

The goal of this study is to help for the utilization the national pharmacists test through the analysis of item development management to the foreign pharmacists examination. The United States is going to NABP (National Association of Boards of Pharmacy) initiative under the curriculum in question on the basis of this assessment and develop standards and unified, systematic system to conduct tests pharmacist. Practice oriented (patient scenario, the participation of a pharmacist or perform work, clinical practice) examination is doing in Canada, The UK is asking the for more than 70 percent and the prescription needed for actual calculation in practice prior to testing program, and by the including that allows references use. Our country may introduce the job as a clinical pharmacist, positively. Item management system is integrated into four regions based on the six-year curriculum should be done in harmony proportion of each region. Integration of fusion of each region in accordance with the duties should be come out. It has gradually been able to item management system developed by the United States or Canada. This item notice pharmacist judging the results of the work must be carried out for management upgrading to a form of management with an emphasis on clinical practice in developed countries. Foundation design, development, production and management and test after actively reviewing ways to improve management system for to management systems, a pharmacist to improve the quality of the national examination could be contributing are involved.

• Journal of KIISE:Software and Applications
• /
• v.29 no.9
• /
• pp.669-675
• /
• 2002

In recent years most of personalized recommender systems in electronic commerce utilize collaborative filtering algorithm in order to recommend more appropriate items. User-based collaborative filtering is based on the ratings of other users who have similar preferences to a user in order to predict the rating of an item that the user hasn't seen yet. This nay decrease the accuracy of prediction because the similarity between two users is computed with respect to the two users and only when an item has been rated by the users. In item-based collaborative filtering, the preference of an item is predicted based on the similarity between the item and each of other items that have rated by users. This method, however, uses the ratings of users who are not the neighbors of a user for computing the similarity between a pair of items. Hence item-based collaborative filtering may degrade the accuracy of a recommender system. In this paper, we present a new approach that a user's neighborhood is used when we compute the similarity between the items in traditional item-based collaborative filtering in order to compensate the weak points of the current item-based collaborative filtering and to improve the prediction accuracy. We empirically evaluate the accuracy of our approach to compare with several different collaborative filtering approaches using the EachMovie collaborative filtering data set. The experimental results show that our approach provides better quality in prediction and recommendation list than other collaborative filtering approaches.