• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.47 no.2
• /
• pp.30-39
• /
• 2024

This study introduces a novel approach for identifying potential failure risks in missile manufacturing by leveraging Quality Inspection Management (QIM) data to address the challenges presented by a dataset comprising 666 variables and data imbalances. The utilization of the SMOTE for data augmentation and Lasso Regression for dimensionality reduction, followed by the application of a Random Forest model, results in a 99.40% accuracy rate in classifying missiles with a high likelihood of failure. Such measures enable the preemptive identification of missiles at a heightened risk of failure, thereby mitigating the risk of field failures and enhancing missile life. The integration of Lasso Regression and Random Forest is employed to pinpoint critical variables and test items that significantly impact failure, with a particular emphasis on variables related to performance and connection resistance. Moreover, the research highlights the potential for broadening the scope of data-driven decision-making within quality control systems, including the refinement of maintenance strategies and the adjustment of control limits for essential test items.

• Journal of Acupuncture Research
• /
• v.24 no.1
• /
• pp.127-135
• /
• 2007

Objectives: To evaluate the methodological quality of Korean Acupuncture Clinical trials Methods : Two independent researchers reviewed 12 protocols of Acupuncture clinical trials which were conducted in Korea 2006. Also, Survey Principal Investigator of those was conducted. We compare the results of protocol review with investigator reponses of actual practice. Quality assessment consisted of 5 items including random sequence generation, randomization method, allocation concealment, subject blinding, assessor blinding. Results : Randomization was performed using the proper procedure to insure that treatment assignment is unbiased and concealed from subjects in all clinical trials, According to protocols, 6(50%) of 12 clinical trials used computer-generated random numbers, 6(50%) remaining trials didn't describe the randomization method. Also all trials used appropriate randomization methods on the basis of the survey results: 8 trials used computer-generated random number, 2 used random table. Of 7 protocols in which allocation concealment was stated, 5(71%) reported appropriate method (Calling a central office or statisticians, Sealed opaque envelopes). However according to survey, 5(42%) of 12 trials used inappropriate allocation concealment (Keeping a master randomization list and referring to when subject entered the trial). In addition, the result of protocol review and survey response was not coincident in 5(42%) trials. Subject blinding was conducted in all except 1 clinical trials. Although 11(92%) of 12 trials were conducted using assessor blinding in actual practice, only 7(58%) reported that in protocol. Conclusion : Although randomization and blinding were conducted adequately, allocation concealment was used inadequately, Not only appropriate allocation concealment, but also every quality assessment item including randomization, blinding should be stated in more detail in protocol.

• Journal of Korean Academy of Nursing
• /
• v.7 no.1
• /
• pp.73-79
• /
• 1977

This study was carried on between June first and July thirty-first 1976 using as subjects women living in the areas of Pusan, Kyoung Sang Buk Do and Kyoung Sang Nam Do. The subjects were divided into 3 groups according to different environments and styles of life, namely married life, widowhood and religious life and according to ages ranging between 45 and 55. Each of these 3 groups of women of .menopausal age consisted of 50 persons and totalling a group of 150. The subjects were chosen according to random sampling and the Cornell Medical Index was applied to discover physical and mental health status with the following results : 1. The total mean scores for complaints in the group of widows was 46.00, in the group of Married women was 37.10 and in the Sisters was 34.30 showing highest scores for the widows and lowest for the Sisters. 2. The mean score percentages for physical and mental complaints 28.80 and 16.50 respectively for the Widows:27.00 and 10.80 for the Married and 24.30 and 10.20 for the Sisters. 3. The highest number of mean scores for physical items was for digestive system complaints which showed a score of 5.04, 4.78 and 4.90 respectively for Widows, Married women and Sisters among the psychic status items all 3 groups showed highest scores for complaints of inadequacy: 5.52, 3.40 and 3.64 respectively. 4. In comparing the 2 groups of Married women and Widows, the highest significant differences appeared in the items of depression and sensitivity but there was also some significant difference in the items of inadequacy, anger, miscellaneous diseases and genito-urinary system complaints. 5. In comparing the Married women and Religious groups the highest significant differences according from the highest were as follows : cardiovascular system, sensitivity, tension, nervous system, frequent illnesses and anxiety.

• Korean Journal of Health Education and Promotion
• /
• v.25 no.4
• /
• pp.13-28
• /
• 2008

Objectives: The purpose of this study was to assess general population' AIDS knowledge and attitudes towards AIDS. Methods: Using a multistage area sampling and random digit dialing method, a random sample of individuals aged 19-59 years, living in 16 different area in Korea during September 2007 were interviewed by telephone. Results: In all, 1,087 respondents completed the survey. In most items, respondents displayed a fairly good degree of knowledge about AIDS. However it was lower than that in developed countries. Respondents' attitudes towards AIDS were found to be negative. The knowledge and attitudes towards AIDS were more positive for respondents who were young, educated, office worker or students, higher in income. The higher level of knowledge, the more positive attitudes towards AIDS. Conclusions: In general AIDS related knowledge was relatively low and people showed negative attitudes towards AIDS. Incorrect knowledge and lack of information on AIDS would lead to unnecessary negative attitudes and there need to be addressed by health education programs and campaigns using mass media.

• Journal of Korean Society for Quality Management
• /
• v.47 no.1
• /
• pp.87-96
• /
• 2019

Purpose: The purpose of this paper is to determine an optimal production time for economic production quantity model with preventive maintenance and random defective rate as the function of a machinery deteriorates. Methods: If a machinery shifts from "in-control" state to "out-of-control" state, a proportion of defective items being produced increases. It is assumed that time to state shift is a random variable and follows an arbitrary distribution. The elapsed time until process shift decreases stochastically as a production cycle repeats and quasi-renewal process is used to implement for production facilities to deteriorate. Results: When the exponential parameter for exponential distribution increases, the optimal production time increases. When Weibull distribution is considered, the optimal production time is closely affected by the shape parameter of Weibull distribution. Conclusion: A mathematical model is suggested to find optimal production time and optimal number of production cycles and numerical examples are implemented to validate the patterns for changes of optimal times under different parameters assumptions. The real application is implemented using the proposed approach.

• Knowledge Management Research
• /
• v.11 no.2
• /
• pp.95-109
• /
• 2010

The objectives of this study are to identify the survival function (hazard function) of small and medium enterprises by using technology rating data for the companies guaranteed by Korea Technology Finance Corporation (KOTEC), and to figure out the factors that affects their survival. To serve the purposes, this study uses Kaplan-Meier Analysis as a non-parametric method and Cox proportional hazards model as a semi-parametric one. The 17,396 guaranteed companies that assessed from July 1st in 2005 to December 31st in 2009 are selected as samples (16,504 censored data and 829 accident data). The survival time is computed with random censoring (Type III) from July in 2005 as a starting point. The results of the analysis show that Kaplan-Meier Analysis and Cox proportional hazards model are able to readily estimate survival and hazard function and to perform comparative study among group variables such as industry and technology rating level. In particular, Cox proportional hazards model is recognized that it is useful to understand which technology rating items are meaningful to company's survival and how much they affect it. It is considered that these results will provide valuable knowledge for practitioners to find and manage the significant items for survival of the guaranteed companies through future technology rating.

• Women's Health Nursing
• /
• v.9 no.4
• /
• pp.499-508
• /
• 2003

Purpose: This study analyzed the effects of a CD- ROM educational program for the prevention of sexual violence in relation to the sexual knowledge of middle school students. Method: A one group, pre-test-post-test design was used. The subjects of this study were 171 middle school students in Kangwon Province, Korea. The questionnaire included 34 items relating to overall sexual knowledge, and included questions on sexual violence. The collected data were analyzed using the mean, standard deviation and paired- t tests. Result: There were significant differences in the sexual knowledge by demographic characteristics between the pre- and post- tests. Of the 34 items, 20 showed significant differences in the sexual knowledge between the pre- and post- tests. Conclus ion: The overall level of sexual knowledge of the students increased after taking the CD- ROM educational program. Further testing will be required to determine the effects of the CD- ROM using a control group and random sampling.

• Journal of the Korea Safety Management & Science
• /
• v.9 no.1
• /
• pp.77-84
• /
• 2007

This study was planned to investigate what the main factor of the regulation compliance of inspection on harmful machine, instrument and equipment by industrial safety and health act is. This study subject was composed of three groups as employers, employees of manufacturing and using the harmful machine and safety inspectors. Manufacturing workplace were 236 places, using workplace were 201 places and the safety inspectors were 100 people. The study subject was sampled by stratified random sampling considering the type of harmful Machine. Data for analysis is collected from each sample using interview with structured questionnaires. Compliance is measured by 2, 3, and 4 point scale composed by 8 sub items such as general perception, understanding, clearness, necessity, relevancy, implementation, penalty, and general compliance of the regulation. The level of 8 items of employer's compliance are not differentiated among three groups. The determining factors for inspection observance of the workplace using the harmful Machine were understanding, penalty and cognized compliance. The determining factors for inspection observance of the workplace manufacturing the harmful Machine were understanding and object conformity. These results show that the strategy to adapt the regulated group to inspection regulation will be the elevation of understanding for regulation first of all.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.45 no.3
• /
• pp.439-452
• /
• 2021

The purpose of this thesis is to compare the efficiency of 3D digital design technology with traditional hand-drawn designs of a transformable dress for a small wedding. After reviewing the literature, this empirical study analyzed the tendencies of small wedding dress design, concluding that a transformable dress for a small wedding consists of a bodice, skirt, and outer skirt or gown with train, each of which has five possible designs, resulting in 15 virtual items within the 3D program. The 3D program provides the benefit of easy design development as well as reduced costs and design time. Specifically, the random combination of 15 items with layers in the 3D program produced 150 different styles in 5 hours, while hand-drawing 150 dresses took 50 hours. Moreover, the 3D program does not need any material, but 150 physical drawings required a sketchbook, pencil, eraser, and marker, total cost 31,100 won. Additionally, the 3D whole-body scan helps the bride decide which design she prefers through virtual try-ons. Eventually, the 3D program could help a bride decide what she prefers and produce it with virtual simulation, resulting in reduced time and costs.

• Korea Trade Review
• /
• v.42 no.2
• /
• pp.277-296
• /
• 2017

More than 95% of imports and exports in the World are being transported by vessels. In other words, marine transportation accounts for a large portion of share in the world trade. The purpose of this study is to analyze factors of seaborne trade volume according to items affecting on the world economy. This study conducted a linear regression analysis between seaborne trade volume and the world economy (world GDP) to estimate the correlation between them. Panel data analysis and random effects model analysis have been applied to examine the effect of seaborne trade volume. For this study, the seaborne trade volume is categorized into 10 items, and estimated how much global GDP will be affected when the trade volume changes. In addition, the granger causality test was conducted to verify the relationship between seaborne trade volume and the world GDP. As a result, seaborne trade volume and the world GDP were mutually influenced each other. However, seaborne trade volume affects the world economy more significantly. The items affecting world economic growth include petroleum products, crude oil, chemical products, and so on. The estimated value of the coefficients of petroleum products, crude oil and chemical products were 1.014, 1.013 and 1.010, respectively. The estimated value 1.014 of petroleum products means that the growth rate is 1.014 times higher than the current world GDP growth rate when the seaborne trade volume of petroleum products increased by one unit Lastly, this study examines the seaborne trade volume of 10 categories and then verifies whether the growth rate of world GDP will increase when the volume of seaborne trade increased. This study is expected to provide policy-makers with useful information about formulating policies related to international trade.