• Title/Summary/Keyword: Theoretical model

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A Prediction Model on Adaptation to University Life among Chinese International Students in Korea (중국 유학생의 한국 대학생활 적응 예측모형)

  • Lin, Qin Lan;Kim, Hee-Kyung
    • The Journal of Korean Academic Society of Nursing Education
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    • v.17 no.3
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    • pp.501-513
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    • 2011
  • Purpose: On the basis of the theoretical framework of a combination of Roy's adaptation theory and Lazarus & Folkman's theory of stress - appraise coping, the purpose of this study was to predict effect factors of adaptation to university life of Chinese international students in Korea. After this, a model of adaptation to university life of Chinese international students in Korea was constructed. Methods: A questionnaire was used to survey 369 Chinese international students from one university in Korea, which was analyzed by using PASW Statistics 18.0 and LISREL 8.7. Results: This theoretical model explained adaptation to university life of Chinese international students at 75.0% in Korea. Physical symptoms, loneliness, acculturation stress and self-efficacy directly affected the adaptation to university life. Korean language proficiency indirectly affected adaptation to university life through self-efficacy. Conclusion: Results of this study provided theoretical basis for the future health care of university- centered health centers. For improving adaptation to university life of Chinese international students in Korea, education and nursing measures for reducing physical symptoms, loneliness and acculturation stress, and improving Korean language proficiency and self-efficacy are proposed for further research and development.

A study on the transient characteristics during speed up of inverter heat pump (회전수 상승폭 변화에 따른 인버터열펌프의 비정상 운전특성)

  • 황윤제;김호영
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.4
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    • pp.495-507
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    • 1998
  • The transient characteristics of a 4.0㎾ inverter driven heat pump was investigated by theoretical and experimental studies. The heat pump used in this study consists of a high side scroll compressor and $\Phi$7 compact heat exchangers with two capillary tubes. A series of tests was peformed to examine the transient characteristics of heat pump in heating and cooling mode when the operating speed was varied from 30Hz to 102Hz. One of the major issues that has not been addressed so far is transient characteristics during speed modulation. A cycle simulation model has been developed to predict the cycle performance under frequency rise-up conditions, and the results of theoretical study were compared with the results of experimental study. The theoretical model was driven from mass conservation and energy conservation equations to predict the operation points of refrigerant cycle and the performances at various operating speeds. For transient conditions, the simulated results are in good agreement with the experimental results within 10%. The transient cycle migration of the liquid state refrigerant causes a significant dynamic change in system. Thus, the migration of refrigerant is the most important factor whenever An experimental analysis is performed or A simulation model is developed.

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The Existence of Mispriced Futures Contracts in the Korean Financial Market (빅데이터 분석을 통한 보유비용모형에 근거한 주가지수선물의 가격괴리에 대한 분석)

  • Kim, Hyun Kyung;Nam, Seung Oh
    • Journal of Information Technology Applications and Management
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    • v.21 no.4
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    • pp.97-125
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    • 2014
  • This study investigates the relationship between stock index and its associated nearby futures markets based on the cost-of-carry model. The purpose of this study is to explore the existence of mispriced futures contracts, and to test whether traders can earn trading profits in real financial market using the information about the mispriced futures contracts. This study suggests the concordance correlation coefficient to investigate the existence of mispriced futures contracts. The concordance correlation coefficient gives a desirable result for trading profits that results from a comparative analysis among profits from trading at the time to indicate trading opportunities determined by the degree of the difference between the observed market price and the theoretical price of a futures contract. In addition, this study also explains that the concordance correlation coefficient developed from the mean square error (MSE) has a statistically theoretical meaning. In conclusion, this study shows that the concordance correlation coefficient is appropriate for analyzing the relationship between the observed stock index futures market price and the theoretical stock index futures price derived from the cost-of-carry model.

Theoretical study on compression wave propagating in a sudden reduction duct (급축소관을 전파하는 압축파에 관한 이론적 연구)

  • Kim, Hui-Dong;Kim, Tae-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.1
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    • pp.89-98
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    • 1997
  • Compression waves propagating in a high speed railway tunnel impose large pressure fluctuations on the train body or tunnel structures. The pressure fluctuations can cause ear discomfort for the passengers and increase the aerodynamic resistance of trains. As a fundamental research to resolve the pressure wave phenomenon in the tunnel, a steady theory of Chester-Chisnell- Whitham was applied to a simple shock tube with a sudden cross-sectional area reduction to model trains inside the tunnel. The results of the present theoretical analysis were compared with the experiments of the shock tube. The results show that the reflected compression wave from the model becomes stronger as the strength of incident compression wave and the blockage ratio increase. However, the compression wave passing through the model is not strongly dependent on the blockage ratio. The theoretical results are in good agreement with the experiments.

Factors affecting the Success of Smoking Cessation for Six Months in the Smoking Cessation Clinic of a Public Health Center Based on the Trans?theoretical Model (범이론적 모형을 기초로 한 보건소 금연클리닉 등록자의 6개월 금연성공요인)

  • Kim, Yun-Hee
    • Research in Community and Public Health Nursing
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    • v.20 no.4
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    • pp.433-442
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    • 2009
  • Purpose: The purpose of this study was to identify factors affecting on the successful cessation of smoking for six months in the smoking cessation clinic of a public health center. Methods: The subjects of this study were 568 adult smokers who had registered in the smoking cessation clinic of a public health center in B City. Data were analyzed through $x^2$-test, t-test, and logistic regression using the SPSS/WIN 12.0 program. Results: Identified factors affecting the successful cessation of smoking for six months were service type, number of counseling, alcohol problem, previous quit-smoking trial, dependency on nicotine, CO level in expiration at the first visit time, self-reevaluation, helping relationship, negative/affective situational temptation, and Cons. Conclusion: Trans-theoretical Model variables were confirmed as factors affecting the success of smoking cessation. Based on the results of this study, a smoking cessation program was suggested, which uses Trans-theoretical Model variables affecting smoking cessation for six months in a public health center.

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Model to Predict Absorbed Amino Acid Supply at the Proximal Duodenum in Growing Beef Cattle

  • Yan, Xianghua;Xu, Zirong;Zhang, Wen-ju;Wang, Jiaqi
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.3
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    • pp.358-363
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    • 2005
  • Five crossbred beef cattle (Simmental${\times}$yellow cattle, Shantung Province) fitted with permanent cannulae in the rumen and T-type cannulae at the proximal duodenum and terminal ileum, were fed five different diets containing corn, cotton meal or soybean meal and ammoniated straw to determine the dry matter, crude protein and amino acid flows in duodenal and ileum digesta, and to calculate the regression equations between theoretical and experimental concentration of AA in duodenal digesta. The results showed that there was a strong correlation between experimental (g/d, y) and theoretical CP flows (g/d, x) at the proximal duodenum, the $R^2$-value regression equation of crude protein is very high (0.9636). The $R^2$-value regression equation of the limiting amino acid (such as Met or Lys) is high (0.7573 or 0.9252 respectively). This results indicated that we can formulate better diets fed to beef cattle according to the theoretical amino acid concentration. A mathematical model has been successfully constructed for predicting the supply of absorbed amino acids at the proximal duodenum in growing beef cattle.

A Study on the Factors Affecting E-logistics Systems in the Chinese Logistics Industry

  • Yu, Liu;Bae, Jung-Han
    • International Commerce and Information Review
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    • v.2 no.1
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    • pp.25-48
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    • 2009
  • With the rapid growth of e-logistics in the global logistics industry, it is important to gain further insight into this growing segment of Chinese logistics industry. The current situation in China consists of many small and medium-sized logistics firms. Furthermore, e-logistics is still relatively undeveloped in the majority of the Chinese logistics companies and presently there are still many problems unresolved. This paper attempted to review the concepts and theoretical background of e-logistics systems from previous studies. After acknowledging the essential issues related to e-logistics systems, a research model based on the theory acceptance model was designed and tested. The key factors to the e-logistics system (reliability, maintainability, software, facility and transportation) were validated through the modeling and testing process. Included in the modelling and testing process are other related factors of e-logistics process, logistics information system and added value as dependent variables in this model. The results of this study confirm that the e-logistics Process is affected by transportation, while maintainability and software factors influence logistics information system. reliability, maintainability, facility and transportation are significant factors associated with added value. This research aimed to provide theoretical and practical contribution to Chinese logistics companies and to give some insights into e-logistics system as a whole. The paper also provided some useful theoretical implication and practical guidelines for the development of e-logistics system in the chinese logistics industry.

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Theoretical Study on Interfacial Stresses at RC Beam Repair-Purpose Overlayed by Latex Modified Concrete (LMC로 덧씌우기 보수된 RC보의 계면응력에 관한 연구)

  • Kim, Hyun-Oh;Kim, Seong-Hwan;Kim, Dong-Ho;Lee, Bong-Hak
    • Journal of Industrial Technology
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    • v.24 no.A
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    • pp.179-184
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    • 2004
  • Each year, new technological advancements for repair-purpose are being introduced to overlay the old deterioration of RC bridge deck at highway by latex-modified concrete. The days may come when this old problem will be successfully resolved. While the experimental works and researches are very active at both laboratory and field, only a few theoretical studies were performed on interfacial problems, especially on stress distribution and concentration of RC beam overlayed by latex-modified concrete. The repaired and strengthened structures would induce a premature failure due to the stress concentration at the adhesive layer of different material before the design expected failure. This paper investigated and proposed an analytical model for predicting interfacial shear and normal stresses of RC beam repair-purpose overlayed by latex-modified concrete. This would be used for predicting interfacial stresses and preventing premature failure at interfaces. This study modified Smith-Teng method for applying to cementitious repairing material, which was based on a direct governing equation and linear-elastic approach for interfacial normal and shear stresses. The proposed theoretical model was verified using commercial FEA program, LUSAS, in terms of interfacial stresses predicted by the proposed model and calculated by LUSAS.

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A Study on the Factors Affecting E-logistics Systems in the Chinese Logistics Industry

  • Yu, Liu;Bae, Jung-Han
    • International Commerce and Information Review
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    • v.11 no.2
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    • pp.3-26
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    • 2009
  • With the rapid growth of e-logistics in the global logistics industry, it is important to gain further insight into this growing segment of Chinese logistics industry. The current situation in China consists of many small and medium-sized logistics firms. Furthermore, e-logistics is still relatively undeveloped in the majority of the Chinese logistics companies and presently there are still many problems unresolved. This paper attempted to review the concepts and theoretical background of e-logistics systems from previous studies. After acknowledging the essential issues related to e-logistics systems, a research model based on the theory acceptance model was designed and tested. The key factors to the e-logistics system (reliability, maintainability, software, facility and transportation) were validated through the modeling and testing process. Included in the modelling and testing process are other related factors of e-logistics process, logistics information system and added value as dependent variables in this model. The results of this study confirm that the e-logistics Process is affected by transportation, while maintainability and software factors influence logistics information system. reliability, maintainability, facility and transportation are significant factors associated with added value. This research aimed to provide theoretical and practical contribution to Chinese logistics companies and to give some insights into e-logistics system as a whole. The paper also provided some useful theoretical implication and practical guidelines for the development of e-logistics system in the chinese logistics industry.

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Analysis on mechanical behavior of dovetail mortise-tenon joints with looseness in traditional timber buildings

  • Li, Yizhu;Cao, Shuangyin;Xue, Jianyang
    • Structural Engineering and Mechanics
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    • v.60 no.5
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    • pp.903-921
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    • 2016
  • To study the effect of looseness on mechanical behavior of dovetail mortise-tenon joints, five dovetail mortise-tenon joints, including one intact joint and four loose joints, were fabricated and tested under cycle lateral loadings, and non-linear finite element models using the software ABAQUS were also developed. The effects of looseness on stress distribution, rotational stiffness and bearing capacity of joints were studied based on the analysis of test and simulation results. The results indicate that the hysteretic loops are anti-Z-shaped and present typical characteristics of pinching and slippage, the envelop curves of joints are classified as following two stages: elastic and strengthening stage. The peak stress, rotational stiffness and bearing capacity of joints were reduced due to looseness. The moment-rotation theoretical model of intact joint was simplified in terms of the relation of construction dimensions for buildings, and the moment-rotation theoretical model considering the effect of looseness was proposed and validated.