• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.8
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• pp.629-635
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• 2008

Recently, microturbines have received attention as a small-scale distributed power generator. Since the exhaust gas carries all of the heat release, the microturbine CHP (combined heat and power) system is relatively compact and easy to maintain. Generating hot water or steam is usual method of heat recovery from the microturbine. In this work, a heat recovery unit producing hot water was installed at the exhaust side of a 30 kW class microturbine and its performance characteristics following microturbine power variation was investigated. Heat recovery performance has been compared for different operating conditions such as constant hot water temperature and constant water flow rate. In particular, the influence of water flow rate and hot water temperature on the recovered heat was analyzed.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.10
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• pp.18-25
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• 2000

In this paper, we analyze TCP congestion control algorithm over ATM-UBR network. TCP congestion control algorithm consists of slow start, congestion avoidance, fast recovery, fast retransmit. We analyze the ATM-UBR network service using the BSD 4.3 TCP Reno, Vanilla. However we found the fact that the characteristic of fast retransmit, recovery algorithm makes a serious degradation of Performance in multiple losses of packets. We propose new fast retransmit, recovery algorithm to improve the problem. The results of performance analysis improve the multiple losses of packets using a proposed fast retransmit, recovery algorithm.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.191-196
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• 2005

A low-cost, high-performance 40 Gb/s clock recovery module using a phase-locked loop(PLL) for a 40 Gb/s optical receiver has been designed and implemented. It consists of a clock recovery circuit, a RF mixer and frequency discriminator for phase/frequency detection, a DR-VCO, a phase shifter, and a hold circuit. The recovered 40 GHz clock is synchronized with a stable 10 GHz DR-VCO. The clock stability and jitter characteristics of the implemented PLL-based clock recovery module has shown to significantly improve the performance of the conventional open-loop type clock recovery module with DR filter. The measured peak-to-peak RMS jitter is about 230 fs. When input signal is dropped, the 40 GHz clock is generated continuously by hold circuit. The implemented clock recovery module can be used as a low-cost and high-performance receiver module for 40 Gb/s commercial optical network.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.12
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• pp.875-880
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• 2012

The field of the large volume heat exchanger for wasted heat recovery ventilation system is being expanded enormously seeing as the fact that the quantity of reducing energies are huge due to the large volume heat exchanger for wasted heat recovery system at large buildings and factories, which consume large amount of energies while it has been arising huge amount of losses in Korea because of the lack of technology. To develop large volume waste heat recovery heat exchanger, rotor type heat exchanger was simulated for the surface corrugation. Based on the simulation results produced $30,000m^3/h$ grade waste heat recovery, heat exchanger was performed for the actual experiment. In addition, performance tests exceed the capacity of a large waste heat recovery heat exchanger performance test methods proposed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.11
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• pp.541-546
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• 2014

The present study was conducted to determine whether ESCO Business is success or not. ESCO Business recovers the investment costs by the energy savings resulting from complementing existing energy facilities. The guaranteed parameters are Quantity of Heat Recovery, and Generator output drop. The results of the Performance Test show that the Quantity of Heat Recovery increased by 11.52 Gcal/h, and Generator output decreased by 0.234 MW, which satisfied the guarantee value.

• The Journal of Information Systems
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• v.24 no.1
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• pp.169-191
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• 2015

Green supply chain management(GSCM) has emerged as an organizational system which helps organizations and their parter to achieve corporate profit by reducing environmental risk and cost. The main objective of this study is to investigate the relationship among organizational factors(manager support and organizational learning), GSCM practices(investment recovery and eco-design) and GSCM performance based on the BSC. Using a sample of 125 Korean companies, path analysis is used to test the research model. The results shows that the manager support has a positive effect on the investment recovery and eco-design. The results also suggest that the organizational learning directly affect the investment recovery, but do not affect the eco-design. The investment recovery and eco-design have effect on the GSCM performance. In addition, the competitive pressure has moderating effects on most of the relationships between the organizational factors and GSCM practices. This findings provides useful insights for managers seeking to adopt GSCM practices, and also provide useful guidelines for researchers to study GSCM performance.

• Journal of Korean Academy of Nursing Administration
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• v.18 no.4
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• pp.434-441
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• 2012

Purpose: The purpose of this study was to identify perception of recovery, self-esteem, role performance, job satisfaction and factors influencing job satisfaction of psychiatric mental heath nurses. Methods: Data were collected from 161 psychiatric nurses from G city & J province who understood the purpose of the study and agreed to participate. Data were analyzed using descriptive statistics, t-test, Pearson correlation coefficient, and multiple regression with SPSS 18.0. Results: There were significant differences in job satisfaction between upper 25% and lower 25% group for perception of recovery, self-esteem, and role performance. Results from the multiple regression analysis revealed difference in the related factors and in the magnitude of the relationship evaluated by standardized beta coefficients. Significant factors, listed by the magnitude of beta coefficients, were role performance, self esteem, roles and responsibilities in recovery, expectations regarding recovery in perception of recovery. These variables accounted for 16% of job satisfaction. Conclusion: Results indicate that to improve psychiatric nurses' job satisfaction, there is a need to develop programs including personal qualities and perception of recovery. Further research is necessary in order to establish consensus on roles of the related factors of job satisfaction.

• Journal of Digital Convergence
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• v.14 no.4
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• pp.267-276
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• 2016

This paper aims to examine the effects of perceived justice of service recovery efforts on the customer relationship performance in mobile social commerce. To this end, we classified cognitive-affective trusts and post-recovery satisfaction into the customer relationship performance. This research employs a field survey of customers who experienced service failures in mobile social commerce and a covariance structural model analysis in order to test hypotheses of our research model. The findings present that all justices of service recovery efforts positively affect the cognitive trust, whereas the only procedural justice significantly influences the affective trust. In addition, the results show that cognitive-affective trusts have a positive effect on the post-recovery satisfaction. Our results suggest practical implications that are used to help managers maintain and improve relations with the customers who experienced service failures and to increase the post-recovery satisfaction.

• Culinary science and hospitality research
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• v.18 no.2
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• pp.118-133
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• 2012

The purpose of this study is to investigate the relationships of core-self evaluation, service recovery performance, job satisfaction and turnover intention among frontline staff in the Korean hotel industry. In order to examine the proposed hypotheses, descriptive statistics analysis, frequency analysis, confirmatory factor analysis, reliability analysis, correlation analysis and covariance structure analysis were undertaken using SPSS(10.0) and AMOS(4.0) to explore the relationships among variables. The results showed that core-self evaluation had a significantly positive effect on service recovery performance. In addition, service recovery performance had a significantly positive effect on job satisfaction, while there was no evidence of relationship between service recovery performance and turnover intention. Job satisfaction was explored to have a significant negative effect on turnover intention.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.3
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• pp.240-246
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• 2012

The supply and use of exhaust heat recovery ventilation system as effective energy saving equipment has been increasing steadily. The exhaust heat recovery ventilation system can be installed at ceiling of balcony or emergency space. However, ventilation system can not be installed at emergency space because where have to remain as empty space by law. Therefore, the proper installation space of ventilation system is needed. In this study, to install heat recovery ventilation system in the light weight wall, thickness of heat exchanger was assembled below 140 mm. One or two paper heat exchangers were installed in the ventilation system. The efficiency of heat recovery was analyzed through performance experiment on case of cooling and heating mode.