• Title/Summary/Keyword: Difference equation

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Distribution Analysis of Land Surface Temperature about Seoul Using Landsat 8 Satellite Images and AWS Data (Landsat 8 위성영상과 AWS 데이터를 이용한 서울특별시의 지표면 온도 분포 분석)

  • Lee, Jong-Sin;Oh, Myoung-Kwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.434-439
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    • 2019
  • Recently, interest in urban temperature change and ground surface temperature change has been increasing due to weather phenomenon due to global warming, heat island phenomenon caused by urbanization in urban areas. In Korea, weather data such as temperature and precipitation have been collected since 1904. In recent years, there are 96 ASOS stations and 494 AWS weather observation stations. However, in the case of terrestrial networks, terrestrial meteorological data except measurement points are predicted through interpolation because they provide point data for each installation point. In this study, to improve the resolution of ground surface temperature measurement, the surface temperature using satellite image was calculated and its applicability was analyzed. For this purpose, the satellite images of Landsat 8 OLI TIRS were obtained for Seoul Metropolitan City by seasons and transformed to surface temperature by applying NASA equation to the thermal bands. The ground measurement data was based on the temperature data measured by AWS. Since the AWS temperature data is station based point data, interpolation is performed by Kriging interpolation method for comparison with Landsat image. As a result of comparing the satellite image base surface temperature with the AWS temperature data, the temperature difference according to the season was calculated as fall, winter, summer, based on the RMSE value, Spring, in order of applicability of Landsat satellite image. The use of that attribute and AWS support starts at $2.11^{\circ}C$ and RMSE ${\pm}3.84^{\circ}C$, which reflects information from the extended NASA.

The effect of parental rearing behavior on self-esteem and gender role Stereotypes in Adolescents: Mediating effect of self-esteem -The use of Latent Growth Model-

  • Ju, Sunyoung
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.6
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    • pp.189-197
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    • 2019
  • The purpose of this study was to investigate about the effects of parental rearing behavior on self-esteem and gender role stereotype during adolescence and to reveal the mediating effect of self-esteem on adolescents' gender role strerotype. Also investigated the relationship among these variables and condition variables. For this purpose, used the Second Grade longitudianl Panel data of Middle School from the Korea Youth Panel Survay(KYPS). And the latent growth model was analyzed 3,449 men and women adolescents' cases of the first, the fourth and the sixth wave of the Korea Youth Panel Survey(KYPS) administered by Korea Institute for Youth development. And the structural equation model was used to investigate whether self-esteem mediates parental rearing behavior and male and female gender role Strerotype. The results of this study, the direct effect between variable factors showed that the more positive the parenting behavior of the second grader of middle school is, the more positive the self-esteem of male adolescents and the initial value of stereotypes of male gender role. It also affects the self-esteem of female adolescents and stereotypes of female gender roles but not statistically significant. The male gender role stereotypes were decreased in influence by the rate of change of parental rearing behaviors, and the initial value and the rate of change of self-esteem were statistically influenced to the male gender role stereotypes and the higher the self-esteem, the higher the self-esteem. However, there was no significant effect on stereotypes of female gender roles. As a result of analyzing the mediating effect of self-esteem, partially mediated between the initial value of parental rearing behavior and initial stereotype of male gender role, but there was no longitudinal mediation effect. There was no mediating effect of self-esteem between parental rearing behaviors and stereotypes of female gender roles and there was no longitudinal mediation effect. The effect of condition variable gender was found that female adolescents are more affected by paretal rearing behavior than male adolescents and also affected by the growth process. The monthly income of households influenced the initial value of parental rearing behaviors and showed a difference in parental rearing behavior according to household income. And the higher the mother 's educational level, the more the self-esteem of male adolescents was affected.

Molecular Dynamics Simulation on the Thermal Boundary Resistance of a Thin-film and Experimental Validation (분자동역학을 이용한 박막의 열경계저항 예측 및 실험적 검증)

  • Suk, Myung Eun;Kim, Yun Young
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.32 no.2
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    • pp.103-108
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    • 2019
  • Non-equilibrium molecular dynamics simulation on the thermal boundary resistance(TBR) of an aluminum(Al)/silicon(Si) interface was performed in the present study. The constant heat flux across the Si/Al interface was simulated by adding the kinetic energy in hot Si region and removing the same amount of the energy from the cold Al region. The TBR estimated from the sharp temperature drop at the interface was independent of heat flux and equal to $5.13{\pm}0.17K{\cdot}m^2/GW$ at 300K. The simulation result was experimentally confirmed by the time-domain thermoreflectance technique. A 90nm thick Al film was deposited on a Si(100) wafer using an e-beam evaporator and the TBR on the film/substrate interface was measured using the time-domain thermoreflectance technique based on a femtosecond laser system. A numerical solution of the transient heat conduction equation was obtained using the finite difference method to estimate the TBR value. Experimental results were compared to the prediction and discussions on the nanoscale thermal transport phenomena were made.

A Study on the Influence of Government Support on Corporate Ability and Opportunist Behavior: Focusing on Socially Disadvantaged Business (정부지원이 기업역량과 기회주의행동에 미치는 영향에 관한 연구: 사회적약자기업을 중심으로)

  • An, Yuk-Bong;Kim, Young-Soo;Kim, Sang-Yon
    • The Journal of the Korea Contents Association
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    • v.21 no.10
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    • pp.378-387
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    • 2021
  • This study aims to confirm the effect of government support on the capability of socially disadvantaged enterprises (SDBs) and to explain the opportunistic behavior of SDBs to acquire more external resources such as government support. By dividing government support into policies and procedures, the difference in influence on corporate ability is analyzed by clarifying government support, and the impact of corporate capability on opportunistic behavior is analyzed using the structural equation (SEM) to provide government support The purpose of this study is to present the policy direction, the necessity of procedural development of government support, and the preceding factors to avoid opportunistic behavior. As a result of analyzing 261 questionnaires targeting SDB executives and employees, the relationship between government support policy and corporate ability was rejected. It was found that the government support procedure had a positive (+) effect on corporate ability, and that corporate ability had a negative (-) effect on opportunistic behavior. The implication is that, among the two components of government support, only the government support procedure was found to be significant. There should be publicity and in-depth consideration of government support policies.

Development of Pressure Correction System for Surface Vessel to Ensure Reliability of Compartment Test Result (수상함 격실기밀시험 결과의 신뢰성 확보를 위한 압력 보정 시스템 개발)

  • Min, Il-Hong;Kim, Jun-Woo;Son, Gi-Joong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.1
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    • pp.409-414
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    • 2021
  • Tightness performance that blocks compartments is important for surface ships to achieve superior mission performance and survivability in combat environments. To meet the above requirements, airtightness of the structural elements and the appropriate strength to specific areas are checked during a test run after ship construction. In particular, air tests of compartments adjacent to the water surface are performed. In an air test, air is injected into the compartment up to the test pressure of the test memo. The pressure drop value is checked after 10 minutes to determine if the requirements of the corresponding area are satisfied. In summer, however, when the influence of the outside temperature is large, a phenomenon in which the internal pressure increases during the air test was identified. This phenomenon reduces the reliability of the test result. Therefore, a system was designed to compensate for temperature changes in the compartments through this study. The developed system calculates the amount of pressure change caused by a temperature change in the compartment and outputs a correction value. The pressure change was calculated using the ideal gas equation, reflecting the maintenance, increase, and decrease in temperature during the test process. A comparison of the calculated pressure correction value with the database of NIST REFPROP revealed a difference of 0.126% to a maximum of 0.253%.

The Relationship between Basic Psychological Needs and Postpartum Depression: Focused on the Mediating Effects of Spousal Support and Marital Satisfaction (기본심리욕구와 산후우울의 관계: 배우자지지, 결혼만족도의 매개 효과)

  • Bae, Yeon Wook;Yu, Kum Lan
    • The Journal of the Korea Contents Association
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    • v.21 no.3
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    • pp.518-528
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    • 2021
  • Based on the Self-Determination Theory and previous studies, this study confirmed that basic psychological needs among Self-Determination Theory have an indirect influence on the postpartum depression through mediation of spousal support and marital satisfaction. A sample of 313 mothers who raises her child within a year of giving birth completed a questionnaire survey, and a structural equation model was utilized to analyze the data. Results indicated that both the measurement model, and the hypothesized structural model fit to the data. Meanwhile, when compared with the hypothesized model in which the path between all variables is established, the competitive model excluding the path from spousal support to postpartum depression has no difference in fitness, and was relatively simple and adopted as the final model. In the final model, the link between basic psychological needs and postpartum depression was partially mediated by spousal support and marital satisfaction. In addition, marital satisfaction was found to mediate completely the relationship between spousal support and postpartum depression. Based on the results, it would be helpful to identify the status of basic psychological needs, spouse support, and marriage satisfaction in counseling related to postpartum depression.

A Study on Innovation Capability and Business Performance: Multi-Group Analysis by Company Location (혁신역량과 경영성과에 관한 연구: 기업 소재지별 다중집단분석)

  • Choi, Kyu-Sun
    • The Journal of the Korea Contents Association
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    • v.22 no.10
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    • pp.703-722
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    • 2022
  • The concentration of local businesses in the capital region promotes a decrease in the local population and polarization between the capital region and non-capital regions. It affects the competitiveness of local industries and creates a vicious cycle throughout the local economy, society and culture. Therefore, this study classified the companies in the capital region and non-capital regions by group and examined the effect of the innovation capability factors of companies on the creation of business performance. We analyzed the effects of R&D capabilities, which are elements of innovation capability, and open innovation and convergence capabilities on business performance. Smart PLS 3.0 was used for analysis including direct and indirect mediating and moderating effects, multi-group analysis, and structural equation model analysis. As a result, R&D capability did not have a significant effect on business performance, but it has a positive influence towards business performance through convergence capability and open innovation. However, the effectiveness of open innovation in non-capital regions and convergence capabilities in capital region were not statistically significant. In particular, in terms of open innovation, as the difference between groups is statistically clear, follow-up measures are suggested especially in non-capital regions.

The Effect of Job Environmental Factors on Job Satisfaction and Turnover Intention of Container Shipping Workers -Focused on the Difference between Land and Maritime Workers of 'H' Liner Shipping Company- (컨테이너 선사 종사자의 직무환경 요인이 직무만족도와 이직의도에 미치는 영향 - H사의 육상직과 해상직간 차이를 중심으로-)

  • Lee, Won-woo;Ryu, Hee-chan;Lee, Choong-bae
    • Journal of Korea Port Economic Association
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    • v.38 no.1
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    • pp.143-158
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    • 2022
  • The shipping industry has experienced significantly fluctuated while decline in long-term and boom in short-term period due to the continuous recession of the shipping industry since the 2010s and during the recent COVID-19 pandemic. This study aims to suggest implications for securing manpower and personnel policy by analyzing the effects of job environmental factors of a liner shipping company on job satisfaction and turnover intention and differences between land and marine workers. For the analysis, the job environmental factors of a liner shipping company were divided into work character, relational factors, personnel characters, and remuneration factors, and then structural equation model and t-test were conducted to test the relationship between job satisfaction and turnover intention. As a result of the study, it was found that job environmental factors, such as work, relationship, personnel, and remuneration, had a positive (+) effect on job satisfaction, and job satisfaction had a negative (-) effect on turnover intention. In a comparative analysis between groups such as land and sea workers, it was found that the maritime workers group had higher job satisfaction and lower turnover intention than the land workers.

Oxygen Transfer Rate from Liquid Free Surface in Reciprocally Shaking Vessel (왕복요동 교반조의 자유 표면에서의 산소흡수속도)

  • Koh, Seung-Tae
    • Korean Chemical Engineering Research
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    • v.59 no.2
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    • pp.276-280
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    • 2021
  • The oxygen transfer rate at the liquid surface of the reciprocally shaking vessel was studied. The required power of the reciprocally shaking vessel was not proportional to the shaking frequency, unlike the rotational shaking vessel, and the liquid level suddenly fluctuated greatly at a certain frequency as the flow pattern in the vessel was a left and right wave flow different from that of the rotational shaking that has a rotational flow. The effect of the shaking frequency on the required power in the reciprocally shaking vessel was very complex, such as less power required than the rotational shaking vessel when the shaking frequency is more than 3 s-1, but the required power for the range of the generated rotational flow in the reciprocally shaking vessel could be correlated with the equation that was reported for the rotational shaking vessel. The kLa (mass transfer capacity coefficient) in the reciprocally shaking vessel also increased in a complex pattern because the required power for shaking was not consumed in a simple pattern, unlike kLa in the rotational shaking vessel, which increases linearly with increasing frequency. The kLa of the reciprocally shaking vessel was larger than the kLa of the rotational shaking vessel, and as the kLa value increased, the difference between them increased sharply. As a result, the oxygen transfer rate in the reciprocal motion was greater than that of the rotational motion, and could be correlated with the required power per unit volume.

The Effect of Parents' Educational Involvement and Parental Efficacy on Students' School Life Satisfaction and School Achievement According to Family Type and School Level (학부모의 교육 참여, 부모효능감, 학교생활 만족도, 학업성취 간 관계: 가족 유형 및 학교급에 따른 차이를 중심으로)

  • Yeon, Eun Mo;Choi, Hyo-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.5
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    • pp.71-80
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    • 2021
  • The purpose of this study is to explore the structural relationships among parents' educational involvement and parental efficacy on students' school life satisfaction and school achievement and to determine whether there are any differences depending on family type and school level. Using data from 2,497 families that participated in the 2018 National Survey on Children's Life, t-tests and structural equation modeling were conducted. The results of this study demonstrated that two-parent families reported higher levels of educational involvement than single-parent families and custodial grandparent families. Also, two-parent families raising children in elementary schools showed higher educational involvement than two-parent families raising children attending middle schools. Second, parental efficacy was found to mediate the effects of parents' educational involvement on students' school life satisfaction and school achievement. Third, the path coefficients between parents' educational involvement, students' school life satisfaction, and school achievement showed statistically significant differences depending on family type, with two-parent families having greater involvement than single-parent families and custodial grandparent families. Fourth, multiple group analysis reported a statistically significant difference in the relationship between parents' educational involvement and school achievement as well as parental efficacy and school achievement depending on the school level.