• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.743-750
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• 2017

It is important to ensure a uniform temperature distribution in greenhouses for the mushroom cultivation. The air temperature of the mushroom cultivation greenhouse is made uniform by supplying a constant air temperature with the underground air. The mushroom cultivation array in a greenhouse in seven columns and four rows can make smooth air flows between the rows and prevent air differences between the top and bottom. The buoyancy effect in the entering air of 0.5m/s based on following density difference depending on initial internal temperature needs to be considered. The locations of the Fan Coil Unit (FCU) and fan were defined through flow analysis in a greenhouse to distribute the optimal uniform temperature. In this study, the air conditioning system of a greenhouse with a sandwich heat insulting panel shape which is composed of a FCU and fan was designed by flow analysis. A relatively uniform temperature distribution can be formed because the circulation path of air becomes longer in the different locations of the FCU (inlet) and fan (outlet) through the internal temperature and flow analysis. The cultivation and quality uniformity of the mushrooms could be promoted through these environmental improvements.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.378-385
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• 2017

This study investigated the design of a snap fit, which is widely used for fastening plastic parts. We analyzed the assembly mechanism of a lock snapfit, measured the assembly force and separation force based on the design of experiments, and derived a regression equation through an analysis of variance. The response surface methodology was also used. Polybutylene terephthalate was used to fabricate specimens, and the assembly force and separation force were measured using a micro-tensile tester. The length, width, thickness, and interference were considered as factors. A second-order regression model was used to derive the regression equation. The assembly force decreased with increasing length and width, but it increased with increasing thickness and interference. The finite element method was used to analyze the assembly mechanics. The width decreased the assembly force by increasing the ductility. The influences of the factors for low assembly force and high release force were shown to be opposite to each other. It was necessary to design a structure that minimized the assembly force while maintaining an appropriate level of separation force.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.675-684
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• 2020

The purpose of this study is to identify the influence of the GRIT of teenagers on their career preparation behaviors and verify whether there is a mediating effect between GRIT and the career preparation behaviors with a view to assisting such career preparation behaviors. For this study, an analysis was conducted using AMO 22.0 and SPSS Statistics 22.0, with 426 teenagers in general middle schools. The findings of the analysis were as follows. First, the GRIT of teenagers had a significant impact on social support and career preparation behaviors. Social support had a significant effect on career preparation behaviors, as well. Second, in the relationship between the GRIT of the teenagers and their career preparation behaviors, social support, and the sub-elements of the social supports, which are emotional support, information support, evaluatory support, and material support, all had mediating effects. These study findings showed that GRIT and social support were influential factors upon career preparation behaviors. Therefore, in order to promote career preparation behaviors among teenagers, it is necessary to provide social support in the family and school environments, and it is also helpful to enhance the GRIT, which is an individual trait.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.308-316
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• 2020

This paper describes the relationship and influencing factors among academic stress, university life adaptation, and health promotion behaviors of health college students. Data were collected from October 2017 to May 2018 using a structural questionnaire, which was completed by 223 health college students in D metropolitan city. The collected data were analyzed by descriptive statistics, T-test, ANOVA, correlation, and multiple regression using an IBM SPSS 20.0. As a result, the mean scores were as follows: academic stress, 3.02±0.89; university life adaptation, 3.16±0.48; health promotion behavior, 2.14±0.45. Correlation analysis of the variables revealed a negative relationship between academic stress and health promotion behavior and a positive relationship between university life adaptation and health promotion behavior. The factors affecting the health promotion behavior were the economic level, satisfaction with major, academic stress, and university life adaptation, which explained approximately 37.5% of the total. In conclusion, to increase the health promotion behavior of health-related college students, it is necessary to develop programs that reduce academic stress and improve university life adaptation. In addition, systematic efforts to identify the general characteristics of the subjects are needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5989-5997
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• 2015

The purpose of this study is to identify consumers' perceived consumption values and to examine the causal relationship between perceived consumption values, brand identification, emotional Absorption and behavioral commitment. Undergraduate students(N=210) were participated in the survey and the structural equation modeling was utilized for data analysis. The results of this study show that; first, psychological value and personality value have positive effects on brand identification but there was no significant relationship between functional value and brand identification; second, brand identification have positive effects on emotional commitment and behavioral commitment; third, the relationship between emotional commitment and behavioral commitment was not significant; fourth, the effect of psychological value on brand identification was higher than the effect of personality value on brand identification. Based on these results, several recommendations for company are discussed and future research directions are outlined.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6027-6035
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• 2015

The purpose of this study was to examine influential factors for the transition to college life and career identity of nursing students and what changes social support from parents brought about to them by academic year. The subjects in this study were 542 selected students who majored in nursing in four-year universities located in Seoul and the provinces. A self-administered survey was conducted to find out their general characteristics, social support from fathers and mothers, college adjustment and career identity. A hierarchical regression analysis was made to determine how social support from parents affected the college adjustment and career identity of the nursing students. Social support from parents had an impact on their college adjustment and career identity. The factors that affected college adjustment were academic year, satisfaction level with major and emotional support from mothers, and the factors that impacted on career identity were academic year, satisfaction level with major and informative support from fathers. In order to facilitate the college adjustment of nursing students, professors should try to develop efficient learning methods, meet with parents to inform them of the necessity of social support, share information on the major field of study and learning methods, and provide an opportunity for students to communicate with graduates or students who are years ahead of them in college so that they could have a better understanding of majoring in nursing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5810-5818
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• 2015

The dissertation presents the portfolio construction method using the score sheet so that general investors can utilize it easily. This study draws the significant variables to contribute the enterprise value and suggests the combined models by applying the single methodology, which private investors can easily utilize. The results of the research can be classified into 2 areas. Firstly, the significantly affecting variables were selected for analyzing the enterprise value. The variables and the method for the enterprise value analysis were studied from the existing researches to choose the optimal variables. The variables were identified by using AHP method and the structure equation method from the investigation of the previous researches. And the critical variables were added extracted from the common denominator of variables which the 3 grue investors used for their investment. The final variables identified are dividend yield, PER, PBR, PCR, EV/EBITDA, ROE, net income, sales growth rate, net current asset, debt ratio, current ratio, rate of operating profits, ratio of operating profit to net sales, ratio of net income to net sales, net profit to total assets, EPS growth rate, inventory turnover ratio, and receivables turnover. Second, the new methodologies for forecasting enterprise value modifying the existing methods were developed. The result of the Logistic regression analysis for forecasting showed that the equation could not be suitable as the accuracy with 91.98%.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1403-1413
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• 2015

An information System Audit by the recognition of a problem and suggestions for solutions for overall matters about constructing and managing information systems is needed in order to contribute to the improvement of an information system's quality and improving the performance of projects. In reality, however, the general cognition is that audit is biased by subjective opinions. For this, an auditor needs to measure the level of recognition of the usability and convenience of the technologies of automating audit by applying TAM in the information system audit, and to analyze the relationship with recognition and availability of the interested parties for the technology (tool) of the audit. By the hypothesis verification result, an auditor needs to present objective corroborative facts that back up the level of recognition and usability for the information technology in the field of audit. This study verified that the phenomenon of technology application can be explained and predicted by applying TAM in the field of audit. Through an empirical study of the recognition level of audit and contractor, the developer suggests that the audit plan stage is similar to the audit corrective action stage, but the audit action stage is different from the audit review stage. This research can verify the audit technology preferred for the availability and intention of use and usability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3370-3377
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• 2015

FMECA(Failure Mode, Effects and Criticality Analysis) techniques to make quantitative evaluation of failure effects severity and criticality have been applied to systematic failure analysis for reliability improvement of train which should provide regular service and secure high level of safety as a mass transportation system. These FMECA techniques do not fully reflect the inherent train operation and maintenance circumstances because they are based on the FMECA standards devised for other industries such as automobile industry and FMECA standard dedicated to train industry has not been established yet. This paper analyzes FMECA standards for various industries, and suggests a FMECA technique dedicated to train industry which makes failure effect analysis and criticality analysis step by step and makes criticality analysis placing emphasis on the severity of the failure effect. The proposed technique is applied to FMECA of high-speed current breaker which is a core safety device of train using field failure data for 15 years of train maintenance. The FMECA results show that breakage of arc chute has the highest risk with 3rd severity class and 5th criticality class among all the components of high-speed circuit breaker. Damage and poor contact of electronic valve, and cylinder breakage with 3rd severity class and 4th criticality class are followed by. These results can be applied to improvement of design and maintenance process for high-speed circuit breaker of train.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4125-4130
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• 2015

This paper presents the communication performance for the radiation pattern reconfigurable antenna in the wearable device measuring bio signal (temperature, blood pressure, pulse etc.) of human body. The operational frequency is 2.4 - 2.5 GHz, which covers Bluetooth communication bandwidth. The maximum gain of the antennas is 1.96 dBi. The proposed antenna is efficiently transmitting and receiving signal by generating two opposite beam directions using two RF switches (PIN diode). Also, we investigated how radiation pattern changes according to three angles ($30^{\circ}$, $90^{\circ}$, $150^{\circ}$) of Top Loading. In this paper, we measured and compared the SNR (Signal-to-Noise Ratio) and BER (Bit Error Rate) performances of the proposed antennas in the condition between an ideal environment of anechoic chamber and smart house existing practical electromagnetic interferences (Universal Software Radio Peripheral, USRP). Throughout the comparing the results of the measurement of two cases, we found that the SNR is degraded over 5dB in average and BER is increased over ten times in maximum, therefore, it is confirmed that the error rate of receiving signal is increased. The measured results of SNR and BER value in this paper able to expect the performance degrading by the interference from the electromagnetic devices.