• Journal of the Korea Society for Simulation
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• v.28 no.3
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• pp.57-63
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• 2019

This study suggests the level of guaranteed reserves that should be accumulated in order to provide guaranteed interest contracts to pension members. To calculate the guaranteed reserve, this study employs the method using variable insurance contracts with guaranteed interest options. The average return of three major pensions (national pension, private teacher's pension, civil servants pension) funds, from 2010 to 2018, is set as the target rate of return and then we establish 0%, 1.0%, 1.5% and 2.0% each as our minimum guaranteed returns for their respective guaranteed reserves. Our results firstly show that gaps between each guaranteed reserves are increasing as times goes on. Second, the probability of shortfall reserve is on the decrease as the pension fund is mature. Conclusively, a long-term conservative balance between risk and return is one of the best investing strategies in pension funds providing the guaranteed interest.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1605-1618
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• 2020

The purpose of this study was to investigate the effect of beauty healthcare behaviors of middle-aged women on physical esteem and psychological well-being. The subjects of this study were middle-aged women in Seoul and Gyeonggi area, and surveyed for 6 weeks starting from October 26, 2020, and 334 words were used for analysis. The analysis method used the SPSS 26.0 program to perform frequency analysis, factor analysis, and reliability analysis. To find out the correlation between beauty healthcare, physical esteem, and psychological well-being for middle-aged women, correlation analysis and multi-regression analysis were performed. the statistical significance level was set to p<.05. It was confirmed that beauty healthcare behavior had a statistically significant effect on physical esteem and psychological well-being.

• Korean Journal of Applied Biomechanics
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• v.34 no.1
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• pp.25-33
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• 2024

Objective: The purpose of this study was to compare the lower extremity muscle activity and knee joint load according to movement speed conditions during the barbell back squat. Method: Nine males with resistance training experience participated in this study. Participants performed the barbell back squat in three conditions (Standard, Fast, and Slow) differing movement speed. During the barbell back squat, muscle activity of the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), biceps femoris long head (BFL), semitendinosus (ST), gluteus maximus (GM), gastrocnemius (GCN), and tibialis anterior (TA) was collected using an 8 channel wireless EMG system. The peak flexion angle of the lower extremity joints and the peak resultant joint force in each direction of the knee joint were calculated using eight motion capture cameras and ground reaction force plates. This study was to used the Friedman test and the Wilcoxon signed rank test, to compare lower extremity muscle activity and peak resultant joint force at knee joint according to movement speed conditions during the barbell back squat, and the statistical significance level was set at .01. Results: In the downward phase of the barbell back squat, the RF and TA showed the higher muscle activity in the fast condition, and in the upward phase, RF, VL, VM, BFL, ST, GM, and TA showed the higher muscle activity in the fast condition. As a results, analyzing of the load on the knee joint, in the downward phase, and in the upward phase, the higher peak compressive force of the knee joint was showed in the fast condition. Conclusion: The barbell back squat with fast movement speed was more effective due to increased muscle activity of lower extremity, but one must be careful of knee joint injuries because the load on the knee joint may increase during the barbell back squat with fast movement speed.

• Korean Journal of Applied Biomechanics
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• v.34 no.2
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• pp.53-62
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• 2024

Objective: The purpose of this study was to analyze the differences in kinematic factors according to stretching treatment, myofascial release treatment, and static stretching treatment conditions during squat. Method: Twelve males with resistance training experience participated in this study. Participants performed squats without treatment (Pre-Test), and performed squats after treatment with the myofascial release technique (MRT) and static stretching (SS) on different days (post-test). Squat movements were captured using eight motion capture cameras (sampling rate: 250 Hz), and the peak joint angles of the ankle, knee, hip, and pelvis were calculated for each direction. One-way repeated ANOVA and Bonferroni post hoc analyses using SPSS 27 (IBM Corp. Armonk NY, USA) were used to compare the peak joint angle of the lower extremity joints and pelvis among the normal condition (squat without treatment), MRT condition (squat after MRT treatment) and SS condition (squat after static stretching). The statistical significance level was set at .05. Results: It was observed that the maximum ankle joint flexion angle during squats was statistically reduced under conditions of myofascial release and static stretching (p<.05), in comparison to the scenario where no stretching was performed. Furthermore, static stretching was found to enhance the maximum hip flexion angle during squat (p<.05), whereas the myofascial release stretching technique resulted in the minimal posterior pelvic tilt angle (p<.05). Conclusion: Employing myofascial release stretching as a preparatory exercise proved to be more efficacious in maintaining body stability throughout the execution of high-intensity squat movements by effectively managing the posterior tilt of the pelvis, as opposed to foregoing stretching or engaging in static stretching.

• Journal of the Korean earth science society
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• v.41 no.3
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• pp.291-306
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• 2020

In this study, we developed a learning progression for the structure of the solar system using multi-tier supply form items and validated its appropriateness. To this end, by applying Wilson's (2005) construct modeling approach, we set up 'solar system components,' 'size and distance pattern of solar system planets,' and 'solar system modeling' as the progress variables of the learning progression and constructed multi-tier supply form items for each of these variables. The items were applied to 150 fifth graders before and after the classes that dealt with the 'solar system and star' unit. To describe the results of the assessment, the students' responses to each item were categorized into five levels. By analyzing the Wright map that was created by applying the partial credit Rasch model, we validated the appropriateness of the learning progression based on the students' responses. In addition, the validity of the hypothetical pathway that was established in the learning progression was verified by tracking changes in the developmental level of students before and after the classes. The results of the research are as follows. The bottom-up research method that used multi-tier supply form items was able to elaborately set the empirical learning progression for the conceptualization of the structure of the solar system that is taught in elementary school. In addition, the validity of the learning progression was high, and the development of students was found to change with the learning progression.

• Journal of Korea Water Resources Association
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• v.50 no.10
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• pp.681-690
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• 2017

This study estimated the daily maximum snow depth using the Artificial Neural Network (ANN) model in Korean Peninsula. First, the optimal ANN model structure was determined through the trial-and-error approach. As a result, daily precipitation, daily mean temperature, and daily minimum temperature were chosen as the input data of the ANN. The number of hidden layer was set to 1 and the number of nodes in the hidden layer was set to 10. In case of using the observed value as the input data of the ANN model, the cross validation correlation coefficient was 0.87, which is higher than that of the case in which the daily maximum snow depth was spatially interpolated using the Ordinary Kriging method (0.40). In order to investigate the performance of the ANN model for estimating the daily maximum snow depth of the ungauged area, the input data of the ANN model was spatially interpolated using Ordinary Kriging. In this case, the correlation coefficient of 0.49 was obtained. The performance of the ANN model in mountainous areas above 200m above sea level was found to be somewhat lower than that in the rest of the study area. This result of this study implies that the ANN model can be used effectively for the accurate and immediate estimation of the maximum snow depth over the whole country.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.426-426
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• 1999

;There are many sources of uncertainty in a typical production and inventory system. There is uncertainty as to how many items customers will demand during the next day, week, month, or year. There is uncertainty about delivery times of the product. Uncertainty exacts a toll from management in a variety of ways. A spurt in a demand or a delay in production may lead to stockouts, with the potential for lost revenue and customer dissatisfaction. Firms typically hold inventory to provide protection against uncertainty. A cushion of inventory on hand allows management to face unexpected demands or delays in delivery with a reduced chance of incurring a stockout. The proposed strategies are used for the design of a probabilistic inventory system. In the traditional approach to the design of an inventory system, the goal is to find the best setting of various inventory control policy parameters such as the re-order level, review period, order quantity, etc. which would minimize the total inventory cost. The goals of the analysis need to be defined, so that robustness becomes an important design criterion. Moreover, one has to conceptualize and identify appropriate noise variables. There are two main goals for the inventory policy design. One is to minimize the average inventory cost and the stockouts. The other is to the variability for the average inventory cost and the stockouts The total average inventory cost is the sum of three components: the ordering cost, the holding cost, and the shortage costs. The shortage costs include the cost of the lost sales, cost of loss of goodwill, cost of customer dissatisfaction, etc. The noise factors for this design problem are identified to be: the mean demand rate and the mean lead time. Both the demand and the lead time are assumed to be normal random variables. Thus robustness for this inventory system is interpreted as insensitivity of the average inventory cost and the stockout to uncontrollable fluctuations in the mean demand rate and mean lead time. To make this inventory system for robustness, the concept of utility theory will be used. Utility theory is an analytical method for making a decision concerning an action to take, given a set of multiple criteria upon which the decision is to be based. Utility theory is appropriate for design having different scale such as demand rate and lead time since utility theory represents different scale across decision making attributes with zero to one ranks, higher preference modeled with a higher rank. Using utility theory, three design strategies, such as distance strategy, response strategy, and priority-based strategy. for the robust inventory system will be developed.loped.

• 대한공업교육학회지
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• v.44 no.1
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• pp.114-140
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• 2019

The purpose of this research is to analyze a principal's job at a Vocational High School using DACUM Task Analysis Method. The contents of this research are to set the order after deriving the duties and tasks of the principal., then to verify as the importance, difficulty, and frequency of each task, and also to indicate whether it is an essential capability to have in the early stages of one's duty. Finally, based on the job analysis results, a DACUM chart was developed by the principal of the Vocational High School. The DACUM Task Analysis Workshop was attended by one DACUM analyst with LEVEL - 1 license, seven DACUM members with more than four years experience, one secretary and two administrative assistants for a two-day period. The results of the research are as follows; First, the Vocational High School Principal is defined as a school administrator who operate the vocational education curriculum of in the specialized and customized high schools of industrial demand development and the job area. The analysis derived 11 duties and 95 tasks of the Principal. Second, the importance, difficulties, and frequency of each task were divided respectively into high (A), moderate (B), and low (C), and the consensus of the experts was made to determine whether the core capabilities are acquired early on the job. Third, based on the analysis results, a DACUM Task Analysis chart of the Vocational High School principals was presented. In addition, while engaged on the job of the vocational high school principal, a list of 49 general knowledge and abilities, 16 tools, Integrated data and fixtures are required. Along with 28 attitudes 33 future prospects and characteristics of the Vocational High School principal was presented.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.29 no.1
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• pp.369-391
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• 2018

The purpose of this study was to develop a measurement scheme that assesses organizational performances in library department unit level by applying PCSI model, a Public-service Customer Satisfaction Index. Specifically, this study adopted the Antecedent Model, a component of the PCSI's three-part model, that consists of a total of 12 service quality indices. The study selected a large-scale library as a case to analyze and design a method. We analyzed the library's organizational missions and goals set by each of its six departments, and then mapped them with each of the 12 service quality indices. This mapping was further developed as a work analysis scheme of the library and as a measurement tool. A total of 341 library users participated in a survey that was designed to assess 12 service quality indices. As a result service quality was measured for each index, which in turn, calculated the library's service performance index for both entire and individual units of the library. The results reveled the measurement tool useful in assessing service performances for both individual unit and the entire library.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.9
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• pp.441-450
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• 2016

In this study, we investigate the effect of the level of cognitive affordance which explains an explicit interaction method on the interest of viewers. Viewer's recognition of the interaction method is associated with cognitive affordance as a matter of visual-perceptual exposure of the input device and viewer's cognition of it. The final goal of the research on affordance is to enhance the audience participation rather than the smooth interation. Many interactive media artworks have been designed with hiding the explicit explanation to the artwork due to worry that the explicit explanation may also hinder the induction of impressions leading the viewer to an aesthetic experience and the retainment of interest. In this context, we set up two hypotheses for study on cognitive affordance. First, the more explicit the explanation of interaction method is, the higher the viewer' understanding of interaction method is. Second, the more explicit the explanation of interaction method is, the lower the interest of the viewer is. An interactive media art work was manufactured with three versions which vary in the degree of visual-perceptual information suggestion and we analyzed the participation and interest level of audience in each version. As a result of the experiments, the version with high explicitness of interaction was found to have long time spent on watching and high participation and interest of viewers. On the contrary, the version with an unexplicit interaction method was found to have low interest and satisfaction of viewers. Therefore, regarding usability, the hypothesis that a more explicit explanation of interaction would lower the curiosity and interest in exploration of the viewer was dismissed. It was confirmed that improvement of cognitive affordance raised the interaction of the work of art and interest of the viewer in the proposed interactive content. This study implies that interactive media art work should be designed in view of that the interaction and interest of audience can be lowered when cognitive affordance is low.