• Korean Journal of Applied Biomechanics
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• v.28 no.2
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• pp.109-117
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• 2018

Objective: To compare head and hand movement patterns during squash forehand motions between experts and less-skilled squash players. Method: Four experts and four less-skilled squash players participated in this study. They performed squash forehand swings and a VICON motion analysis system was used to obtain displacement and velocity data of the head and right hand during the movement. Mann-Whitney U-tests were performed to compare head and hand range of motion and peak velocity, and cross-correlation was performed to analyze the head-hand coordination pattern between groups in three movement directions. Results: In terms of head and hand kinematic data, experts had greater head range of motion during down swings than less-skilled squash players. Experts seemed to reach peak hand velocity at impact by reaching peak head velocity followed by hand peak velocity within a given temporal sequence. In terms of head-hand coordination patterns, both groups revealed high positive correlations in the medial-lateral direction, indicating a dominant allocentric coordination pattern. However, experts had uncoupled coordination patterns in the vertical direction and less-skilled squash players had high positive correlations. These results indicate that the head-hand movement pattern likely an important factor squash forehand movement. Conclusion: Analysis of head and hand movement patterns could be a key variable in squash training to reach expert-level performance.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.231-234
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• 2009

Based on combined continuum-fracture mechanics, fracture criterion was utilized to predict impact performance of advanced high-strength steel sheets: 340R and TWIP940. The macro-crack propagation behavior at high stress triaxiality was characterized by V-notch tests while deformation behavior at high strain rate was characterized by simple tension tests with various cross head speeds. The characterized mechanical properties were incorporated into the FE program ABAQUS/Explicit to simulate the charpy impact tests, which showed good agreement with experiments.

• Journal of Auto-vehicle Safety Association
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• v.3 no.2
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• pp.22-27
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• 2011

The side impact test in the Korean New Car Assessment program (KNCAP) has been conducted since 2003. The side impact test method has been contributed to the improvement of the vehicle side structure and the enhancement of the occupant protection performance for the domestic vehicles. The pole side impact test method introduced in the KNCAP in 2010 to enhance the head protection under the severe side crash environment. The pole side impact test is optional for the additional score to be added to the overall rating score. The test results of side and pole side impact test for five vehicles were introduced and compared.

• Journal of Audiology & Otology
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• v.24 no.2
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• pp.61-70
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• 2020

Background and Objectives: To assess the academic performance, communication skills, and psychosocial development of prelingual deaf children with cochlear implants (CIs) attending mainstream schools, and to evaluate the impact of auditory speech perception on their classroom performance. Subjects and Methods: As participant, 67 children with CI attending mainstream schools were included. A survey was conducted using a structured questionnaire on academic performance in the native language, second language, mathematics, social studies, science, art, communication skills, self-esteem, and social relations. Additionally, auditory and speech performances on the last follow-up were reviewed retrospectively. Results: Most implanted children attending mainstream school appeared to have positive self-esteem and confidence, and had little difficulty in conversing in a quiet classroom. Also, half of the implanted children (38/67) scored above average in general academic achievement. However, academic achievement in the second language (English), social studies, and science were usually poorer than general academic achievement. Furthermore, half of the implanted children had difficulty in understanding the class content (30/67) or conversing with peers in a noisy classroom (32/67). These difficulties were significantly associated with poor speech perception. Conclusions: Improving the listening environment for implanted children attending mainstream schools is necessary.

• Korean Journal of Audiology
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• v.24 no.2
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• pp.61-70
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• 2020

Background and Objectives: To assess the academic performance, communication skills, and psychosocial development of prelingual deaf children with cochlear implants (CIs) attending mainstream schools, and to evaluate the impact of auditory speech perception on their classroom performance. Subjects and Methods: As participant, 67 children with CI attending mainstream schools were included. A survey was conducted using a structured questionnaire on academic performance in the native language, second language, mathematics, social studies, science, art, communication skills, self-esteem, and social relations. Additionally, auditory and speech performances on the last follow-up were reviewed retrospectively. Results: Most implanted children attending mainstream school appeared to have positive self-esteem and confidence, and had little difficulty in conversing in a quiet classroom. Also, half of the implanted children (38/67) scored above average in general academic achievement. However, academic achievement in the second language (English), social studies, and science were usually poorer than general academic achievement. Furthermore, half of the implanted children had difficulty in understanding the class content (30/67) or conversing with peers in a noisy classroom (32/67). These difficulties were significantly associated with poor speech perception. Conclusions: Improving the listening environment for implanted children attending mainstream schools is necessary.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.1
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• pp.71-79
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• 2020

Balanced Scorecard (BSC) is one of basic contents of managerial accounting. Balanced Scorecard (BSC) will help the manager to measure and evaluate the operating performance in enterprises. Therefore, providing the theory base as well as in fact with regards to apply with Balanced Scorecard, impact of applying with Balanced Scorecard on the performance of company, from then providing for the managers with the base to promote on applying the Balanced Scorecard in Vietnamese Enterprises aimed to improve the operating performance of enterprises meaningfully and neccessary. However, balanced scorecard in general is a very new content in both theoretical and practice in Viet Nam. The study aims to explore the application with Balanced Scorecard in enterprises according to 4 perspective of Balanced Scorecard in Vietnamese commercial banks. In the dimension of this paper, SPSS 22 was used to collect and analysis data, basing on the results of 109 questionnaires of managers and head of department from Vietnamese commercial banks. Research have shown impact of Balanced Scorecard on the performance of Vietnamese commercial banks. This is the scientific basis for enterprises of Vietnam in general and Vietnamese commercial banks firms in particular have a successful application of balanced scorecard to improve the business performance.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.6
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• pp.837-846
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• 2005

The purpose of this study is to suggest a standard of guidance for testing the performance and safety of motorcycle jacket with built-in airbag. The method of testing were as follows: The effects of the motorcycle jacket with built-in airbag are experimentaly investigated according to neck injury of FMVSS 208. The experiment consists of the crash simulation test by shield and the impact test. The head and neck injuries are evaluated based on industrial standards. Also, the displacements of the head and neck and chest are observed by film analysis. Using the results of the crash simulation test, neck injury$(N_ij)$ is discussed and the peak chest deflection of the results of the impact test, chest injury is pursued. Neck injury$(N_ij)$ of the result of the crash test show that the chance of a serious wound is $18\%$ if rider wear the R&D motorcycle jacket with built-in airbag(Type A). Chest injury is expected by peak chest deflection of the result of the impact test. The result of the peak chest deflection show that the reduction effect in chest injury of Type A motorcycle jacket is $10.3\%$.

• Journal of Families and Better Life
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• v.28 no.2
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• pp.27-37
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• 2010

The purpose of the study was to analyze the constraints that are normally experienced before moving in the context of the household characteristics of households that had recently moved to newly-built apartments. The data for the analysis was collected through a self-administered questionnaire from July 1, 2008 to August 10, 2008. The sample consisted of 251 households in Ulsan living in an apartment complex who had moved within a year. The data from the sample was analyzed by descriptive statistics, factor analysis, and analysis of variance with Duncan's multiple range tests. The results are as follows. The constraints were categorized into information gathering, attractive housing characteristics, expectations of residential mobility, housing development and policies, and resources. Overall, the constraints did not have a huge impact on the performance of the residential mobility of the sample households. Resources, however, were the most influential factors among the five constraints followed by attractive housing characteristics, information gathering, etc. The constraints varied based on the demographic characteristics, such as the household size, duration of marriage, age of the household head, and the socio-economic characteristics, such as the education level of the household head, household income, and the number of mobility. As the number of family members increased, the age of the household head went up, or the level of education went down, the constraints on information gathering were affected in terms of performing residential mobility. Households with a middle aged head with a professional occupation were more constrained by the attractive characteristics of the housing. The impact of the resources related constraints was significantly different based on the number of family members, marriage duration, and the household head's age and occupation, and the number of mobility.

• Structural Engineering and Mechanics
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• v.85 no.6
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• pp.755-764
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• 2023

The article examines the impact response of the sandwich beam furnished by a novel bilayer core as inspired by the woodpecker's head architecture under different repeatedly exerted low-velocity impact loadings by employing the finite element package, ABAQUS. The sandwich beam forms four essential parts comprising bottom and top carbon fiber reinforced polymer laminates encasing bilayer core made of laterally arched solid hot melt adhesive material and aluminum honeycomb. Impact loadings are implemented repeatedly with a steel hemisphere impactor for various impact energies, 7.28 J, 9.74 J, and 12.63 J. Essentially, the commonly concentrated stresses at the impact region are regulated away by the arched core in all considered cases thus reducing the threat of failure. The sandwich beam can resist up to 5 continual impacts at 7.28 J and 9.74 J but only up to 3 times repeated loads at 12.63 J before visible failure is noticed. In the examination of several key impact performance indicators under numerous loading cases, the proposed beam demonstrates favorably up to 1.3-11.2 higher impact resistance efficacies compared to existing designs, therefore displaying an improvement in repeated impact resistance of the new design.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.2
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• pp.27-37
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• 2019

The shell and tube heat exchangers installed in the propulsion system test complex (PSTC) at the Naro Space Center heats cryogenic helium to 500 K with a heat transfer oil. As the experimental helium outlet temperature was lower than expected (less than 100 K), the boundary layer effect of the heat transfer oil is predicted to be the cause of the performance deterioration. A computational fluid dynamics (CFD) analysis was performed to verify where the boundary layer effect exists; however, the boundary layer effect has no significant impact on the performance of the heat exchanger. An alternative method to improve the performance of the heat exchanger by changing the heat transfer oil has been discussed in this paper. The low viscosity and high thermal conductivity at high temperature (~500 K) of heat transfer oil at the shell-side are required to improve the thermal performance of the heat exchanger. The experimental performance of the heat exchanger, used to exchange heat between the cryogenic helium and hot heat transfer oil at the PSTC are summarized in this paper.