• Title/Summary/Keyword: 구조적 인과 모델

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A Design Method of Three-phase IPMSM and Clamping Force Control of EMB for High-speed Train (고속철도차량의 EMB 적용을 위한 3상 IPMSM의 설계 및 제동압부력 제어)

  • Baek, Seung-Koo;Oh, Hyuck-Keun;Kwak, Min-ho;Kim, Seog-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.578-585
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    • 2018
  • This paper proposes a design method for a 3-phase interior permanent magnet synchronous motor (IPMSM) and clamping force control method for an electro-mechanical brake (EMB) using co-simulation for a high-speed train (HST). A traditional pneumatic brake system needs much space for the compressor, brake reservoir, and air pipe. However, an EMB system uses up to 50% less space due to the use of a motor and electric wires for controlling the brake caliper. In addition, it can reduce the latency time for brake control because of the fast response and precise control. A train that has many brakes is advantageous for safety because of the control by sharing the braking force. In this paper, a driving method for a cam-shaft-type EMB is modeled. It is different from the ball-screw-type brakes that are widely used in automobiles. In addition, a co-simulation method is proposed using JMAG and Matlab/Simulink. The IPMSM was designed and analyzed with the JMAG tool, and the control system was simulated using Matlab/Simulink. The effectiveness of the co-simulation results of the mechanical clamping force and braking force was verified by comparison with the clamping force specifications of a HEMU-430X HST.

Development of Air Flow Simulator in Agricultural Facility based on Virtual Reality (가상현실 기반 농업시설 공기유동 시뮬레이터의 개발)

  • Noh, Jae Seung;Kim, Yu Yong;Yoo, Young Ji;Kwon, Jin Kyung;Lee, In Bok;Kim, Rack Woo;Kim, Jun Gyu
    • Journal of Bio-Environment Control
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    • v.28 no.1
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    • pp.16-27
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    • 2019
  • Using virtual reality technology, users can learn and experience many interactions in virtual space like the actual physical space. This study was conducted to develop air flow simulator that allows farmers and consultants to consult air flow through VR devices by creating a greenhouse or pigpen model. It can help educate farmers about the importance of ventilation effects for agricultural facilities. We proposed CFD visualization system by building a virtual reality environment and constructing database of CFD and structure of agricultural facilities. After consultants can set up situations according to environmental conditions, the users experience the visualized air flow of agricultural facility according to the ventilation effects. Also it can provide a quantified environmental distribution in the agricultural facility. Currently, the CFD data in agricultural facilities are established during winter and summer. In order to experience various environmental conditions in the developed system, The experts need to run CFD data under various environmental conditions and register them in the system requirements.

Effects of Ego integrity on QoL of Elderly Living Alone: Focused on Moderating Role of SF36 Health Factors (독거노인의 자아통합감이 삶의 질에 미치는 영향: 주관적 건강요인별 조절효과를 중심으로)

  • Shin, Hakgene;Jeon, Sang-Nam;You, Gil-Jun;Lee, Eun-Yong
    • 한국노년학
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    • v.30 no.4
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    • pp.1179-1195
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    • 2010
  • In this study, we investigated the effects of ego integrity on QoL(Quality of Life) of elderly living alone, where we focused on moderating role of SF36 health factors. To investigate the cause and effect of factors, we purposively collected 282 samples from senior welfare centers in Jeonju city and exploited reliability analysis, confirmatory factor analysis and SEM(Structural Equation Modeling) for 265 cases excluding some cases with missing values. As the results, first, we confirmed ego integrity was positive predictor of QoL. Second, it was proven that the effect of ego integrity on QoL of elderly living alone was stronger in the lower physical functioning group than higher physical functioning group. Third, we also verified that the group with more difficulties in activities or work as a result of poor physical health showed higher effect of ego integrity on QoL. Based on the results, we could explain the reason of conflicts regarding how elderly's health influenced on ego integrity. Also, in the practice of intervention to elderly's problem, we found the health factors could be an indicator of direction or effect of the intervention

Impact of Relationship Quality and Attribution on Service Recovery Expectation and Word of Mouth (관계 품질과 귀인이 서비스 복구 기대와 구전에 미치는 영향)

  • Yoon, Sungwook;Park, Seongil
    • Journal of Service Research and Studies
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    • v.9 no.4
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    • pp.97-114
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    • 2019
  • The relationship quality and recovery of service failures perceived by consumers play an essential role in affecting the service provider's image and sales in terms of the highly involved service industry. In particular, implementation of successful relationship marketing strategies and effective recovery of service failures provide greater satisfaction for customers expecting customized services and reinforce the relationships between the companies and consumers. Based on these previous studies, this research conducted to find out the causal relationship between the variables influencing service recovery expectations and word of mouth(WOM) by approaching the severity of service failures from the perspective of relationship marketing and attribution theory. For the empirical analysis of this research, we conducted a questionnaire surveys of 360 service users of beauty salons, who have experienced in high-involvement services, and utilized 333 questionnaires for the final analysis. The hypothesis was experimented using the Structural Equation Model(SEM), and the results are as follows. First, we identified that the higher the customer perceived the severity of the service failure, the lower the quality of the relationship. Second, we verified that service users observed service failure as a temporary and uncontrollable factor as they distinguished service quality as higher. Third, the hypothesis that customers recognize service failures as a temporary one has a positive impact on service recovery expectation level is determined through empirical analysis. Forth, it was figured out that the higher the perceived quality of the relationship with the service provider, the higher the service recovery level expected by the consumers. At the same time, the hypothesis that optimism for service recovery expectation affects positive word of mouth has been verified. The results of this study help develop the customer-oriented business model of the service companies. Furthermore, the academic significance in that it suggested a new direction for the research of high-involvement service marketing.

A Study on the Distribution of Heavy Metal Elements in Arc Welding Fume (아크용접 Fume의 중금속 분포에 관한 연구)

  • 채현병;김정한
    • Proceedings of the Safety Management and Science Conference
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    • 1999.11a
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    • pp.343-343
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    • 1999
  • 아크용접은 산업전반에 걸쳐 그 생산기반에 없어서는 안될 필수기술로써 자동차 및 조선, 항공우주산업에 이르기까지 경제기반에 미치는 파급효과가 매우 크다. 그러나 이 아크용접을 하게 되면 각종 가스와 미세입자로 이루어진 흄이 발생하게 되는데 이들은 작업자들의 건강에 많은 영향을 미치는 것으로 보고되어 있다. 용접흄에는 용접재료 및 용접공정에 따라 다양한 유해원소가 포함되어 있고 그 종류에 따라 인체에 미치는 잠재적 독성효과도 매우 광범위하다. 최근 국내에서는 용접사들 중에 용접흄에 포함된 중금속 중 Mn중독에 의한 파킨스씨병 환자들과 Cr중독에 의하여 콧속 연골에 구멍이 뚫리는 비중격천공(鼻中隔穿孔) 환자들이 직업병으로 판정 받아 산재요양이 승인된 사례가 있다. 이러한 계기로 인하여 용접사들의 용접기피 현상이 심화되고 작업환경에 대한 법적규제는 선진 외국뿐만 아니라 국내에서도 한층 엄격하게 강화되고 있는 실정이다. 따라서 이제는 작업자와 사용자 모두 용접흄에 대한 인식의 전환이 요구되는 때이며 여러 분야에서 이러한 용접흄에 대한 연구가 활발히 진행되어야 한다. 해외에서는 이미 용접흄에 대한 연구가 활발히 진행되어 왔으나 국내의 경우는 매우 미비한 상태이며 용접산업의 미래 영향력이나 필요성을 고려할 때 국내에서도 적극적인 관심을 가져야 할 부분으로 판단된다. 본 연구에서는 아크용접공정에서 발생하는 흄의 특정 중금속 성분이 인체에 치명적인 악영향을 미치는 것에 착안하여 여러 종류의 용접재료에서 발생되는 용접흄의 중금속 분포를 조사하여 비교하였다. 이것은 향후 용접재료별 및 용접공정별 발생되는 흄의 유해원소를 저감시킬 수 있고 또한 각종 유해원소의 노출기준 및 평가기준을 마련할 수 있는 기초data로써 도움이 되리라 사료된다.동, 공정중재고가 줄어드는 결과를 보였고, 가동률 수준이 높을수록 ORR 방법간의 차이가 크게 나타났다. 그리고 부하평준화 기능은 Order Release 정책의 유효성에 별 영향을 주지 않는 것으로 나타났다. 결론적으로, Order Release 방법은 우선순위규칙간의 성능차이를 줄이거나, 대체할 수 통제 기법이라기보다는 우선순위규칙을 보완하여 공정중재고와 작업현장에서의 리드타임, 리드타임의 편차를 줄여주는 역할을 한다고 볼 수 있다. 그리고, 계획시스템이 존재하여 계획오더가 일정기간간격으로 이송되는 환경에서 특히 유용하다는 결론을 얻었다. 알 수 있었다. 것인데, 제조업에서의 심각한 고비용, 저효율 문제 를 해결하기 위해 필수적으로 도입해야만 하는 실정이다. 또한 소비자의 다양한 요구로 인 하여 제품의 종류와 사양면에서 심한 변동을 보이는 시장 수요에, 신속한 정보처리로 대응 하는데도 크게 기여하고 있다. 이에 본 연구에서는, 자동차 Job Shop의 동기화 생산방식을 지원하는 동기화 생산시스템의 구축 모델을 제시하고자 한다.과로 여겨지며, 또한 혈청중의 ALT, ALP 및 LDH활성을 유의성있게 감소시키므로서 감잎 phenolic compounds가 에탄올에 의한 간세포 손상에 대한 해독 및 보호작용이 있는 것으로 사료된다.반적으로 홍삼 제조시 내공의 발생은 제조공정에서 나타나는 경우가 많으며, 내백의 경우는 홍삼으로 가공되면서 발생하는 경우가 있고, 인삼이 성장될 때 부분적인 영양상태의 불충분이나 기후 등에 따른 영향을 받을 수 있기 때문에 앞으로 이에 대한 많은 연구가 이루어져야할 것으로 판단된다.태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(min

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A Inquiry of the Perception of Death in School Age (학령기 아동의 죽음인식에 관한 탐색적 연구)

  • Joun, Young-Ran
    • Korean Journal of Hospice Care
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    • v.8 no.1
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    • pp.13-28
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    • 2008
  • Purpose: This paper aims to examine the subjective structures and types of school age children's perception of death through an investigative study on their perception of death in order to provide a basic material for them to understand death, and develop and carry out an effective death education program. Methods: The study method used the Q Methodology which can investigate the subjective structures and types of school age children's perception of death. For Q-population, 20 school age children were used as subjects for neutral interviews and open surveys, and through documentary research, a total of 132 statements were collected, For Q-samples, 23 statements (Q-samples) were derived through a non-structural method. P-samples were 31 school age children (8-13 year olds), Q-sorting was carried out using Q-cards, and the collected data was analyzed using the PC QUANL program. Results: As a result of the study, children's perception of death was divided into five types. The first type was functional type, characterized by prominent subjective perception regarding the elements of death, such as non-reversibility, universality, non-functionality, and causality. The second was after-life type, characterized by a strong, focus on life after death in one's perception of death, and it included children with Christian background and those who had experienced death in their immediate family. The third was religious type, characterized by a strong belief in being able to still watch over one's family and friends after one's death, resulting in a positive faith in the after-life. The fourth was fearful type, characterized by a deeper fear of death in comparison to other types. The fifth was realistic type, characterized by a strong and positive assent to the perception of good death. Conclusion: The significance of the results of this paper's study to Nursing is as follows. In terms of understanding the subjectivity of school age children's perception of death in nursing practice, and understanding the compositional elements of death presented with strong emphasis in existing literature and studies, the results will expand these understandings and allow us to understand the level of perception in school age children regarding the definition of death, after-life, and good death, be utilized as useful material in developing an effective death education program for them according to their type characteristics, and become the fertilizer for enabling the children to live a proper life and preventing the tendency to make light of death that occur in adolescence and the spread of suicides. In terms of nursing theory, the description and examination of the subjective structures and the characteristics of the different, types of school age children's perception of death can be utilized as useful material for building a model of school age children's perception of death, and be further used for teaching respect for life. In terms of nursing research, the results can contribute to research describing the effects of nursing intervention strategies and developing tools for providing psychosocial nursing in terms of giving school age children a positive perception of death according to their types as well respect for life.

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Condensation processes in transonic two-phase flows of saturated humid air using a small-disturbance model (미교란 모델을 이용한 포화 습공기 천음속 2상 유동에서의 응축현상)

  • Lee, Jang-Chang;Zvi Rusak
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.6
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    • pp.23-29
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    • 2003
  • Transonic two-phase flow of Saturated humid air, in which relative humidity is 100%, with various condensation processes around thin airfoils is investigated. The study uses an extended transonic small-disturbance(TSD) model of Rusak and Lee [11, 12] which includes effects of heat addition to the flow due to condensation. Two possible limit types of condensation processes are considered. In the nonequilibrium and homogeneous process, the condensate mass fraction is calculated according to classical nucleation and droplet growth rate models. In the equilibrium process, the condensate mass fraction is calculated by assuming an isentropic process. The flow and condensation equations are solved numerical1y by iterative computations. Results under same upstream conditions describe the flow structure, field of condensate, and pressure distribution on airfoil's surfaces. It is found that flow characteristics, such as position and strength of shock waves and airfoil’s pressure distribution, are different for the two condensation processes. Yet, in each case, heat addition as a result of condensation causes significant changes in flow behavior and affects the aerodynamic performance of airfoils.

The Search of Pig Pheromonal Odorants for Biostimulation Control System Technologies: III. Comparative Molecular Field Analysis (CoMFA) on Binding Affinities between Ligands of 2-(Cyclohexyloxy) Tetrahydrofurane Derivatives and Porcine Odorant Binding Protein (생물학적 자극 통제 수단으로 활용하기 위한 돼지 페로몬성 냄새 물질의 탐색: III. 2-(Cyclohexyloxy) Tetrahydrofurane 유도체와 Porcine Odorant Binding Protein 사이의 결합 친화력에 관한 비교 분자장 분석)

  • Sung Nack-Do;Park Chang-Sik;Jung Hoon-Sung;Seong Min-Kyu
    • Reproductive and Developmental Biology
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    • v.30 no.1
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    • pp.13-19
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    • 2006
  • To search of new porcine pheromonal odorants for biostimulation control system technologies to improve reproductive efficiency in livestock species, the comparative molecular field analysis (CoMFA) for binding affinity constant $(p(Od)_{50})$ between porcine odorant binding protein (pOBP) and ligands of odorant 2-(cyclohexyloxy) tetrahydrofurane derivatives as substrate molecule was conducted and discussed. In the optimized CoMFA model AIV with chirality $(C_1'(R),\;C_2(S))$ in substrate molecule and atom based fit alignment (A) of odorants, the statistical results showed the best predictability of the binding affinities $(p(Od)_{50})$ based on the LOO cross-validated value $r^2_{cv}.\;(q^2=0.886)$ and non-cross-validated conventional coefficient $(r^2_{ncv}.=0.984)$. the binding affinity constants exhibited a good correlation with steric (40.8%), electrostatic (14.6%) and hydrophobic (44.6%) factors of the substrate molecules. from the analytical results of the contour maps, which may give us some valuable informations to the modification of odorants for effective binding affinity.

Investigating the Use of Energy Performance Indicators in Korean Industry Sector (한국 산업부문의 에너지성과 지표 이용에 관한 연구)

  • Shim, Hong-Souk;Lee, Sung-Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.707-725
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    • 2021
  • Energy management systems (EnMS) contribute to sustainable energy saving and greenhouse gas reduction by emphasizing the role of energy management in production-oriented economies. Although understanding the methods used to measure energy performance is a key factor in constructing successful EnMS, few attempts have been made to examine these methods, their applicability, and their utility in practice. To fill this research gap, this study aimed to deepen the understanding of energy performance measures by focusing on four energy performance indicators (EnPIs) proposed by ISO 50006, namely the measured energy value, ratio between measured values, linear regression model, and nonlinear regression model. This paper presents policy and managerial implications to facilitate the effective use of these measures. An analytic hierarchy process (AHP) analysis was conducted with 41 experts to analyze the preference for EnPIs and their key selection criteria by the industry sector, and organization and user type. The findings suggest that the most preferred EnPI is the ratio between the measured values followed by the measured energy value. The ease of use was considered to be most important while choosing EnPIs.

A Study on Satisfaction on Use of VR Tourism Program (VR관광콘텐츠의 이용만족에 대한 연구)

  • Yang, Sung-Soo
    • The Journal of the Korea Contents Association
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    • v.19 no.8
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    • pp.184-193
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    • 2019
  • With the development of the information and communication technology, tourism items or products based on new technology is created or developed for tourists. This study examines tourist's satisfaction about VR program, "Secret Wind Forest", which is the story of Gotjawal, one of famous Jeju eco-tourism attraction. In order to achieve the study goal, it identified a study model from the previous studies. It collected data using survey from visitors who used VR program. The total of 227 questionnaires was utilized for data analysis. Based on the study model, it accepted five hypotheses (H1~H5), which are as follows. Firstly, individual innovativeness has a significant effect on perceived usefulness. Secondly, individual innovativeness influenced perceived usefulness, and perceived usefulness and ease influenced usage satisfaction. These results have both theoretical and practical contribution in terms of the development to tourist products using VR program. Academics can provide basic theories such as tourism activities, behaviors, and attitudes to tourism consumer-related studies on VR tourism program in terms of content application. Practically, it can help tourist marketers who want to use VR tourism program and content developers who use VR devices to construct VR program stories using tourism resources and to plan and execute contents considering the target market.