• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.459-465
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• 2009

This paper considers the influence of internal heat exchangers to the efficiency of a refrigerating system. These internal heat exchangers(liquid-suction or suction-line heat exchangers) can, in some cases, yield improved system performance while in other cases they degrade system performance. A steady state mathematical model is used to analysis the performance characteristics of refrigeration system with internal heat exchanger. The influence of operating conditions, such as gas cooler pressure and evaporation temperatures, superheat in the evaporator and temperature of gas cooler outlet, to optimal dimensions of the heat exchanger is also analyzed in the paper. The main results were summarized as follows : the mass flowrate of R744, inner diameter tube and length of internal heat exchanger, and effectiveness have an effect on the cooling capacity, compressor work and RCI(Relative capacity index) of this system. With a thorough grasp of these effect, it is necessary to design the R744 compression refrigeration cycle using internal heat exchanger.

• The Journal of the Korea Contents Association
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• v.14 no.1
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• pp.374-385
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• 2014

The purpose of this study is to examine the effects of implementing internal marketing on the internal satisfaction and on the cognitive organization performance in the K-water by using the logistic regression analysis. The results of test are as follows. First, three internal marketing factors such as reward system, education and training, and internal communication have a significant influence on employee's job satisfaction of the K-water. Second, two internal marketing factors such as education and training, and internal communication have a significant influence on organization performance of the K-water. In conclusion, internal marketing enhances job satisfaction and organization performance, and satisfied employees provide good customer service, thus resulting in enhanced customer satisfaction and improved organization performance.

• Journal of Distribution Science
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• v.17 no.11
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• pp.53-62
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• 2019

Purpose: This research aims to study the internal and external social practices of supply chain management along with economic and social performance of eight Portuguese companies from different industrial sectors. Through empirical data derived from eight case studies, five research propositions are suggested and tested. Research, design, data and methodology: The data was collected through 22 semi-structured interviews with general, procurement, and environmental/safety managers from eight companies from different industrial sectors. Secondary data was collected from reports, websites, and companies' internal documentation. Results: The analysis identifies the most important social practices considered by managers, as well as the performance measures that are most appropriate and most widely used to evaluate the influence of social practices on corporate economic and social performance. The results support four of the five propositions of this research. Companies' economic and social performance are affected by the implementation of social practices into the supply chain, namely the internal social practices. Conclusions: The findings confirmed that there is a positive relationship between internal social practices and economic performance. Internal social supply chain practices contribute to improve social performance. It also identifies the social practices which have negative effects on focal company performance.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.3
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• pp.209-215
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• 2005

Since a transcritical $CO_2$ cycle shows lower performance than conventional air conditioners in the cooling mode operation, it is required to enhance the performance of the $CO_2$ cycle by applying advanced technologies and optimizing components. In this study, the cooling performance of a $CO_2$ system measured by varying refrigerant charge amount, compressor frequency, EEV opening and length of internal heat exchanger. As a result, the cooling COP of the basic system without internal heat exchanger was 2.1. The cooling performance of the modified cycle applying internal heat exchanger improved by $4-9\%$ over the basic cycle.

• Journal of Power System Engineering
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• v.20 no.5
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• pp.78-85
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• 2016

This paper considers the influence of internal heat exchangers to the efficiency of a refrigerating system using R170. These liquid-gas heat exchangers(internal or suction-line heat exchangers) can, in some cases, yield improved system performance while in other cases they degrade system performance. A steady state mathematical model is used to analysis the performance characteristics of refrigeration system with internal heat exchanger. The influence of operating conditions, such as the mass flowrate of R170, inner diameter tube and length of internal heat exchanger, to optimal dimensions of the heat exchanger is also analyzed in the paper. The main results were summarized as follows : the mass flowrate of R170, inner diameter tube and length of internal heat exchanger, and effectiveness have an effect on the cooling capacity, compressor work and RCI(Relative Capacity Index) of this system. Exception for the effect of inner diameter, the RCI of R170 with respect to refrigerant mass flowrate, the length and effectiveness of internal heat exchanger is about 2.1~3.3% higher than that of R13 at the same experimental conditions. With a thorough grasp of these effect, it is necessary to design the R170 compression refrigeration cycle using internal heat exchanger.

• Asia-Pacific Journal of Business
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• v.14 no.1
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• pp.1-19
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• 2023

Purpose - The purpose of this study was to examine the internal relevance between digital transformation, manipulation of asset evaluation and corporate M&A performance and further explores the impact path of manipulation of asset valuation on corporate M&A performance. Design/methodology/approach - This study based on the financial data of A-share listed companies in Shanghai and Shenzhen Stock Exchanges from 2013 to 2021. Findings - First, manipulation of asset evaluation is negatively correlated with M&A performance. Second, Digital transformation significantly weakens the negative correlation between manipulation of asset evaluation and corporate M&A performance. Third, The effectiveness of internal control plays a partially intermediary role in the process of manipulation of asset evaluation affecting M&A performance. Research implications or Originality - Enriching the existing literature on the subject, the study can also provide useful reference for improving the performance of corporate mergers and acquisitions, regulating asset valuation, promoting the digital transformation of enterprises and improving internal control mechanisms, with both theoretical and practical implications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.69-73
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• 2013

Internal heat exchanger (IHX) apparatus using the temperature difference between high and low pressure lines in vehicle air conditioning system is a good method to enhance the cooling performance. In this study, we designed various double-pipe internal heat exchangers which have inner fins between the internal pipe and external pipe. We also measured the performance characteristic (pressure drop, cooling capacity, compressor work and coefficient of performance (COP)) of the modified internal heat exchangers that had the change of the fin height and the inside shape of the internal pipe. This experimental results indicated that the liner and serration type internal heat exchanger was the best cooling performance. In addition, the air conditioning system with the liner and serration type internal heat exchanger showed the improved performances of about 6.4% and 9.2%, respectively, for the cooling capacity and COP.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.7
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• pp.531-542
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• 2002

Transcritical$CO_2$ systems are under consideration for use as residential/mobile air conditioners. In these systems, an internal heat exchanger is usually adopted to improve both capacity and/or COP of the $CO_2$ system in lower operating pressure range of gas cooler. A program has been developed to analyse the performance of internal heat exchangers using the section-by-section method. The internal heat exchanger of coaxial configuration is first analyzed and fairly good agreements with the data are obtained, And then the internal heat exchanger of multiple circular coil configuration has been investigated. The results obtained from the parametric study provide the guidelines for the initial design and manufacturing concepts of the internal heat exchanger in transcritical $CO_2$ system. Further studies are necessary to develop the heat transfer correlations of carbon dioxide in the tubes to obtain more accurate results.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.426-437
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• 2012

The purpose of this study is to investigate the relationship between internal service quality, internal customer satisfaction and management outcome of airport security agents. This study had selected special securities from Incheon airport of October, 2011 for population. Using judgment sampling method, 282 samples were drawn and were used for the final analysis. Questionnaire used in study is composed of total 43 questions and using SPSSWIN 18.0, frequency analysis, factor analysis, reliability analysis, multiple regression analysis and path analysis were performed. Cronbach's ${\alpha}$ value which shows the reliability of the survey came out to be over .686. The conclusion is following: First, internal service quality of airport security agents affects internal customer satisfaction. That is, as corporality, responsiveness and empathy increase, internal supply satisfaction and job satisfaction also increase. Second, internal service quality of airport security agent affects job performance. That is, as corporality, reliability and responsiveness increase, non-financial performance and financial performance also increase. However, when empathy is not activated well, financial performance is decreased. Third, airport security agent…s internal customer satisfaction affects job performance. That is, as activation of internal supply satisfaction increases, nonfinancial performance and financial performance are increased. Fourth, airport special security agent…s inside quality of service exerts direction indirect effect in inside customers satisfaction and management result. That is, inside customers satisfaction is an important variable that mediate inside quality of service and management result.

• Journal of Korean Academy of Nursing Administration
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• v.11 no.1
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• pp.1-12
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• 2005

Purpose: The purpose was to analyze the effects of internal marketing activity factors on nurse's turnover intention, nursing task performance and nursing productivity. Methods: The subjects were 355 nurses who were working at the 3 universities hospital over 1 year. The instruments were used of internal marketing activity factors(Lee, 2001), turnover intension(Lee, 1995), nursing task performance(Park, 1988) and nursing productivity(McNeese-Smith, 1996). Results: The mean score of internal marketing activity factors was 2.79, education and training 2.97, individualization 2.93, communication 2.87, promotion 2.76, work environment 2.63, reward system 2.62, and management vision for employee 2.61. The turnover intention was 3.12, nursing task performance 3.49, and nursing productivity 3.38. The internal marketing activity factors were negatively correlated with turnover intention(r=-0.37, p<0.0001), and positively correlated with nursing task performance(r=0.29, p<0.0001) and nursing productivity(r=0.30, p<0.0001). The key predictor of turnover intension was reward system, education and training, communication, and salary. They explained 35.0% of the total variance. In nursing task performance, communication, management vision for employee, salary and unit explained 26.0% of the total variance. In nursing productivity, communication, reward, education and training, salary, and position explained 24.0%. Conclusions: To increase nurse's nursing task performance and nursing productivity and to decrease turnover intention, it is necessary to concentrate on improving communication and reward system in the internal marketing activity factors. Through these activities, the effectiveness of internal marketing strategies will be enhanced and finally, nursing organizational outcome will be increased.