• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.1-7
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• 2018

In a microcolumn, a miniaturized electrostatic deflector is often adopted to scan an electron beam. Usually, a double octupole deflector is used because it can avoid excessive spherical aberrations by controlling the electron beam path close to the optical axis of the objective lens and has a wide scan field. Studies on microcolumns have been performed to improve the low throughput of an electron column through multiple column applications. On the other hand, as the number of microcolumns increases, the number of wires connected to the components of the microcolumn increases. This will result in practical problems during the process of connecting the wires to electronic controllers outside of the vacuum chamber. To reduce this problem, modified quadrupole and octupole deflectors were examined through simulation analysis by selecting an ultraminiaturized microcolumn with the Einzel lens eliminated. The modified deflectors were designed changing the size of each electrode of the conventional Si octupole deflector. The variations of the scan field and electric field strength were studied by changing the size of active electrodes to which the deflection voltage was to be applied. The scan field increased linearly with increasing deflection voltage. The scan field of the quadrupole deflector and the electric field strength at the center were calculated to be approximately 1.3 ~ 2.0 times larger than those of the octupole deflector depending on the electrode size.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.15-22
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• 2019

Awireless sensor network utilizes small sensors with a low cost and low power being deployed over a wide area. They monitor the surrounding environment and gather the associated information to transmit it to a base station via multi-hop transmission. Most of the research has mainly focused on static sensors that are located in a fixed position. Unlike a wireless sensor network based on static sensors, we can exploit drone-based technologies for more efficient wireless networks in terms of coverage and energy. In this paper, we introduce a transmission power model and a video encoding power model to design the network environment. We also explain a priority mapping scheme, and deploy drones oriented for network coverage and energy consumption. Through our simulations, this research shows coverage and energy improvements in adrone-based wireless sensor network with fewer sensors, compared to astatic sensor-based wireless sensor network. Concretely, coverage increases by 30% for thedrone-based wireless sensor network with the same number of sensors. Moreover, we save an average of 25% with respect to the total energy consumption of the network while maintaining the coverage required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.560-569
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• 2019

This study examined the factors influencing the burnout of correctional workers via a survey conducted in February 2018 for the employees working at the Korea Rehabilitation Agency. The final analysis used data from 290 survey responses. In order to investigate the factors affecting burnout, personal and job-related characteristics, job stress, and interpersonal stress factors were analysed. For the analysis, Baslach burnout scale, Korean occupational stress scale (KOSS), Korean interpersonal relationship stress (KIRS), descriptive analysis, correlation analysis, and hierarchical regression analysis were all used. The correlation analysis showed statistically significant relationships between the factors(p<.01). From the regression analysis results, the influences of job stress (job demand ${\beta}=.308$, p<.001, degree of autonomy ${\beta}=.124$, p<.001, relationship conflict ${\beta}=.169$, p<.001) and interpersonal stress (relationships with supervisors ${\beta}=.402$, p<.001, relationships with clients ${\beta}=.155$, p<.01) were stronger than job-related characteristics (employment type, working hours, working years) and personal characteristics (gender ${\beta}=.173$, p<.01). Although personal and job-related characteristics influence the workers' burnout, levels of job stress and interpersonal stress affect burnout levels more strongly. Based on the study results, further study and suggestions for reducing the burnout of the correctional workers were discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.313-320
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• 2019

This study compared and analyzed the levels of expectations of specialized hospitals, and the recognition of professional competency in specialized hospitals for the general public aged 20 years or older and those professionals on the hospital staffs who had more than three years of experience. The research period ran from July 2018 to May 2019. T-test and regression analysis were used for the analysis of the data. Research result; There was no difference in the level of expectations for the specialized hospitals between the general public and the hospital staffs. It was shown that the professional factor affecting subjective expectations of the specialized hospitals was a difference in the way of thinking between the general public and the hospital staff. The professional factor affecting the expected level of hospital use for the general public and hospital staffs was confidence in the doctors. However, the professional factors affecting the credibility of doctors differed between the general public and the hospital staff. The factor for the general public was excellent technical skill in the field, and the factor for the hospital staff was the specialized ability of doctor and their years of medical service. It is thought that efforts are needed to reduce the difference between the perception of hospital staff and that of the general public in order for specialized hospitals to continue to develop.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.565-572
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• 2019

As a public research institute, government-supported institutes have led the industrial development and the advancement of science and technology in Korea. Robert Levering has annually selected 'Fortune 100 GPTW(Great Place to Work)' by measuring the Trust Index which was originated by himself. The objectives of this study are to attempt newly to analyze the inter-relations among 5 elements of GPTW trust index such as credibility, respect, fairness, camaraderie, and pride perceived by the K institute's 262 employees; to verify that GPTW trust index is valid for the selection of the fortune 100 GPTW. Amart PLS 2.0 and SPSS 18 were utilized for the statistical analysis. The results of this study are as follows. Credibility has positive effect to pride; respect has positive effect to pride and camaraderie; fairness has positive effect to camaraderie; and camaraderie has positive to pride. Pride and camaraderie have positive effect to the perceived GPTW. Recent studies mainly focused on the relations between GPTW trust index as independent, mediating variables or parameters and organizational performances. It is meaningful that this study has firstly tried to analyze the inter-relations among 5 elements of the trust index for the employees of research institute. This study has implication that the in order to enhance the performance the institute has to manage GPTW trust index perceived by the employees.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.28-34
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• 2019

Solar energy is one of the most abundant renewable energy sources on Earth but there are restrictions on the use of solar thermal energy due to the time-discrepancy between the solar-rich season and heating demand. In Europe and Canada, a seasonal solar thermal energy storage (SSTES), which stores the abundant solar heat in the summer and uses the heat for the winter heating load, is used. Recently, SSTES has been introduced in Korea and empirical studies are actively underway. In this study, a $2,000m^2$ flat plate type solar collector and $20,000m^2$ of borehole thermal energy storage (BTES) were studied for a greenhouse in Hwaseong City, which has a heating load of 2,164 GJ/year. To predict the dynamic performance of the system over time, it was simulated using the TRNSYS 18 program, and the solar fraction of the system with the control conditions was investigated. As a result, the solar BTES system proposed in this study showed an average solar fraction of approximately 60% for 5 years when differential temperature control was applied to both collecting solar thermal energy and discharging BTES. The proposed system simplified the configuration and control method of the solar BTES system and secured its performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.329-338
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• 2019

In this study, we analyze consumer preferences based on the agricultural box scheme attributes, and make a suggestion for business revival. We estimate the marginal willingness to pay (MWTP) for box scheme attributes using a choice experiment. Attributes include the bundle method, the delivery method, and price. To select an efficient model for statistical analysis, we evaluate the conditional logit model, heteroscedastic extreme value model(HEV model), multinomial probit model, and mixed logit model under different assumptions. The results of these four models show that the bundle method, the delivery method, and price are statistically significant in explaining the probability of participation in a box scheme. The results of likelihood ratio tests show that the heteroscedastic extreme value model is the most appropriate for our survey data. The results also indicate that MWTP for a change from fixed type to selection type is KRW 7,096.6. MWTP for a change from parcel service to direct delivery and cold-chain delivery are KRW 3,497.5 and KRW 7,532.7, respectively. The results of this study may contribute to the government's local food policies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.644-648
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• 2019

This study examined effects of the wall thermal conductivity coefficients on the thermal fluid phenomenon of a compartment fire. The reduced scale compartment was 0.4 m in width, 0.6 m in length and 0.6 m in height with a fire-board, which has a thermal conductivity coefficient of $0.18W/m{\cdot}K$. The local temperature at a 0.37 m height and the overall heat release rate were measured under the following experiment conditions: a $0.12m^2$ opening area and $0.01m^2$ pool size of a gasoline fire. The numerical results obtained by the Fire Dynamic Simulation were compared with the experimentally measured temperature. The deviations were within 10 % in the period of the steady state for maximum heat release rate (4.8 kW). The numerical results show that the average temperature of the compartment wall decreases by approximately 71 % with increasing thermal conductivity coefficient from $0.1W/m{\cdot}K$ to $100.0W/m{\cdot}K$ on the fixed heat release rate.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.290-298
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• 2019

This study investigated a total of 22 types (15 types of natural disasters and seven types of social disasters) of disaster and safety data based on the National Daily Situation Report, Disaster Yearbook and annual Disaster Annals issued by the Ministry of Public Administration and Security. Disaster safety data were collected from the daily situation report of MOIS (Ministry of the Interior and Safety). The number of total data cases were 1,760, of which 656 were natural disasters and 1,104 were social disasters. The disasters were then patternized according to their characteristics. The patterning was conducted to set up the disaster and safety data system designed to keep disaster situations under prompt and effective management. The study analyzed the data associated with the activities in the response and recovery stages according to the disaster type. Furthermore, based on the management activities performed with the flow of time following a disaster, this study classified and proposed disaster and safety data patterns to achieve effective disaster management work by analyzing the characteristics of a disaster and safety data and disaster and safety management procedures. Disasters of high similarity were classified by merging and deleting them. This was done to consider the scalability and mutual linkage so that it can be used in the establishment of national statistical data, such as the disaster annual report and disaster annuity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.20-28
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• 2019

This study comparatively analyzes general walking shoes on the conical top foundation of the ground condition and the pressure distribution during walking with shoes that are currently under development. Two categories of footwear were used: general footwear and a footwear conical top foundation that is currently under development. Experiments were carried out on hard ground and sandy soil in 15 male twenties that satisfy the conditions of normal foot wearing 260 mm. The pressure during walking was measured using Techstorm's Wireless Insole System, and foot pressure was measured in 7 zones of the foot. Studies have shown different maximum forces, average pressures, and pressure distributions depending on the shoe and ground conditions. This study shows that shoes with general low pressure dispersion effects depending on the feet in hard ground and sand ground are different from shoes with the conical top foundation that is currently under development. It is expected that it will be useful for the development of shoes that can be worn in all hard ground and sandy ground by selecting various rubber materials through further research.