• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.180-189
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• 2019

The purpose of this study is to analyze the factors that affect the entrepreneurial satisfaction of entrepreneurs, based on the characteristics of entrepreneurial firms. For this purpose, we tried to derive the psychological factors besides the personal characteristics of the entrepreneurs as the factors affecting the entrepreneurial satisfaction, which is the result of much research. Psychological factors were empirically analyzed by satisfaction with job and work environment through entrepreneurship, satisfaction with economic employment stability and income factors, and individual development potential, autonomy, and social reputation. The results of this study are as follows: First, the sample consists of entrepreneurs who have been engaged in entrepreneurship activity in Busan for 3 years. Through technical statistical analysis, correlation analysis and multiple regression analysis, The hypotheses about entrepreneurship satisfaction were verified and meaningful results and implications could be derived. Based on this, it can be extended to include research on firm capacity variables such as financial indicators and technological power that were not reflected in this study in the future.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.9
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• pp.745-751
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• 2014

For the multi-nozzle propulsion, the rupture pressure of nozzle closure has an effect on the initial strain rate of ignition. Moreover, the deviation of rupture pressure for each nozzle closure leads to side forces which can disturb the attitude control of rocket. When designed, it should be considered whether nozzle closures are ruptured equally and exactly in the intented pressure. In this paper, the rupture behavior is analyzed by analytical and experimental methods for plate and "+" notched nozzle closures. The rupture pressure and deviation for operating temperature, whether notched or not and notched directions are analyzed. This paper provides a comparison between rupture pressure prediction of finite elements method which tool is Abaqus/Explicit and results of the rupture test. Jonson-Cook shear failure model which corresponds to the damage initiation criterion were used in this simulation.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.26 no.3
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• pp.27-50
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• 2015

The top thirty universities in 2014 by the college rankings of the Korea Joongang Daily were chosen for the samples of this study to find how much academic libraries affect the competitiveness of universities. Evaluation scores of the universities in four areas, and building size, budgets, the number of collections and personnels were also decided as the variables in this study. The influence to the universities' evaluation and rankings of their libraries through average and correlation analysis was studied. The major findings of the study are: (1) Average analysis between metropolitan and non-metropolitan areas found that there were significant differences in globalization indicators, reputation, and social advance degree. Also, (2) Correlation analysis found that library budgets and the number of personnel highly affected the university evaluations or rankings compared to the other variables.

• Journal of the Korean GEO-environmental Society
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• v.16 no.6
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• pp.5-11
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• 2015

Recently the necessity of developing the Load and Resistance Factor Design (LRFD) for shallow foundation has been raised to implement to the domestic design codes related to geotechnical engineering since the limit state design is requested as international technical standard for the foundation of structures. In this study, applicability of LRFD for shallow foundation on weathered soils was investigated and resistance factor for this case was proposed. The quantitative analyses on the uncertainty and resistance bias for shallow foundation on weathered soil ground were performed by collecting the statistical data about domestic case studies for design and construction of shallow foundation. Reliability analyses for shallow foundation were first performed using FDA (First-order Design value Approach) method. Resistance factors were calibrated using the load factors obtained from the specifications of shallow foundations on weathered soil ground. The influence of the load factors developed in this study on the resistance factors were discussed by comparing with the resistance factor obtained from using AASHTO load factors.

• Information Systems Review
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• v.22 no.4
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• pp.41-58
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• 2020

This study addresses the issue of which factors make domestic works have turnover intention. To pursue this research issue, we utilized a public database "2017 Occupational Migration Path Survey", administerd by Korea Employment Information Service (KEIS). Decision tree method was applied to extract crucial factors influencing workers' turnover intention. They include 'the degree of matching the level of education with the level of work', 'the possibility of individual development', 'the job-related education and training', 'the promotion system', 'wage and income', 'social reputation for work' and 'the stability of employment'.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.577-585
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• 2010

This paper is a part of developing a software that predicts the infrared signal emitted from a ground object by considering solar irradiation. The radiance emitted from a surface can be calculated by using the temperature and optical characteristics of the surface object. The bidirectional reflectance distribution function (BRDF) is defined as the ratio of reflected radiance to incident irradiance. It is a very important surface reflection property that decides the reflected radiance from the object. In this paper, the spectral radiance received by a remote sensor over the mid-wave infrared(MWIR), and the long-wave infrared(LWIR) regions are computed and compared each other for several different materials. The results show that the optical surface properties such as the BRDF and the emissivity of the object surface can play a major role in generating the infrared signatures of various objects, and the largest infrared signal may reach up to 10 times the smallest one when the infrared signals obtained from a flat plate with different surface conditions under the sun light.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.363-367
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• 2016

A test section of a supersonic wind tunnel was designed for the analysis of flow characteristics over a backward-facing step with Mach 1.0 slot injection in a supersonic flow of Mach 2.5. The cavity flow of a high-speed vehicle is very complex at supersonic speed, so it is necessary to do experiments using supersonic wind tunnels to verify numerical analysis methods. The previous 2D symmetrical nozzle was replaced with an asymmetrical nozzle. The inviscid nozzle contour was designed using Method of Characteristics (MOC), and the boundary layer thickness correction was reflected by experimental data from the wind tunnel. The results were compared with a CFD analysis. The PID control system was changed to be based on the change of tank pressure. This improved the control efficiency, and the run times of supersonic flow increased by about 1 second. The flow characteristics over a backward facing step with slot injection were visualized by a Schlieren device. This equipment will be used for an experimental study of the film cooling effectiveness over a cavity with various velocities, mass flows, and temperatures.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.11
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• pp.1285-1294
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• 2010

This study describes the design and verification of short range UWB(Ultra Wideband) imaging radar that is able to display high resolution radar image for front area of a UGV(Unmanned Ground Vehicle). This radar can help a UGV to navigate autonomously as it detects and avoids obstacles through foliage. We describe the relationship between bandwidth of transmitting signal and range resolution. A vivaldi antenna is designed and it's radiation pattern and reflection are measured. It is easy to make array antenna because of small size and thin shape. Aperture size of receiving array antenna is determined by azimuth resolution of radar image. The relation of interval of receiving antenna array, image resolution and aliasing of target on a radar image is analyzed. A vector network analyzer is used to obtain the reflected signal and corner reflectors as targets are positioned at grass field. Applicability of the proposed radar to UGV is proved by analysis of image resolution and penetrating capability for grass in the experiment.

• Analytical Science and Technology
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• v.6 no.2
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• pp.149-156
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• 1993

The formation of the graphite spherulites has been studied experimentally in the Ni-C liquid under high pressure and temperature. In the diamond-stable region the graphite spherulites were formed and grew stably. They were not the polycrystalline particles but the single crystals of the fullerene-type, respectively, grown spirally with much imperfection. And they were proved to be in a mixture state of carbon atoms with $sp^2$- and $sp^3$-bonding by an Auger electron spectroscope and a high resolution transmission electron microscope. As the pressure decreased from the diamond-stable region to the graphite-stable region, the shape of the graphite particles changed gradually from the sphere to the flaky shape. The formation of the graphite spherulites was attributed to the stable existence of the carbon atoms with $sp^3$ bonding in the diamond-stable region. The formation of the large fullerene-type graphite spherulites with much imperfection is well agreed with Kroto's prediction for growth of the giant fullerene.

• Journal of Broadcast Engineering
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• v.15 no.2
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• pp.290-303
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• 2010

Recently, researches to improve a quality and a color of a display are being actively studied because of the prosperous growth of the flat panel displays such as LCD, PDP and OLED. Automatically adjusting color temperatures based on user preferences is the one of the researches to provide the optimum display color. In this paper, along with defining the problems of prior methods, the user preferences against the priori defined ranges proposed by the MPEG-7 color temperature descriptor are inspected. Based on the analysis of user preferences, an optimal color temperature conversion curve is proposed. As a result of an analysis by ANOVA, tendencies of the user preferences against each range are proven to be similar to the prior research results. The repetition of the color temperature conversion against an image is not statistically significant.