• Title/Summary/Keyword: enhancing factor

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A Study on Effective Enhancement of Load Power Factor Using the Load Power Factor Sensitivity of Generation Cost

  • Lee Byung Ha;Kim Jung-Hoon
    • KIEE International Transactions on Power Engineering
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    • v.5A no.3
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    • pp.252-259
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    • 2005
  • Various problems such as increase of power loss and voltage instability may often occur in the case of low load power factor. The demand of reactive power increases continuously with the growth of active power and restructuring of electric power companies makes the comprehensive management of reactive power a troublesome problem, so that the systematic control of load power factor is required. In this paper, the load power factor sensitivity of generation cost is derived and it is used for effectively determining the locations of reactive power compensation devices and for enhancing the load power factor appropriately. In addition, voltage variation penalty cost is introduced and integrated costs including voltage variation penalty cost are used for determining the value of load power factor from the point of view of economic investment and voltage regulation. It is shown through application to a large-scale power system that the load power factor can be enhanced effectively using the load power factor sensitivity and the integrated cost.

Clinical Utility of Pre-B-Cell Colony-Enhancing Factor in Bronchoalveolar Lavage Fluid of Acute Critical Ill Patients with Lung Infiltrates (폐 침윤을 동반한 급성 중증 환자의 기관지 폐포 세척액에서 측정한 Pre-B-Cell Colony-Enhancing Factor의 임상적 유용성)

  • Lee, Kwangha;Hong, Sang-Bum
    • Tuberculosis and Respiratory Diseases
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    • v.67 no.5
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    • pp.402-408
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    • 2009
  • Background: Pre-B-cell colony enhancing factor (PBEF) has been suggested as a novel biomarker in sepsis and acute lung injury. We measured the PBEF in bronchoalveolar lavage (BAL) fluid of acute critically ill patients with lung infiltrates in order to evaluate the clinical utility of measuring PBEF in BAL fluid. Methods: BAL fluid was collected by bronchoscope from 185 adult patients with lung infiltrates. An enzyme-linked immunosorbent assay was then performed on the collected fluids to measure the PBEF. Results: Mean patient age was 59.9 ${\pm}$14.5 years and 63.8% of patients were males. The mean concentration of PBEF in BAL fluid was 17.5 ${\pm}$88.3 ng/mL, and patients with more than 9 ng/mL of PBEF concentration (n=26, 14.1%) had higher Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores on the BAL exam day. However, there were no significant differences in clinical characteristics between survivors and non-survivors. In patients with leukocytosis (n=93) seen on the BAL exam day, the linear regression analysis revealed a significant, positive relationship between PBEF and APACHE II ($r^2$=0.06), SOFA score ($r^2$=0.08), Clinical Pulmonary Infection Score ($r^2$=0.05), and plateau pressure in patients on ventilators ($r^2$=0.07) (p<0.05, respectively). In addition, multivariate regression analysis with PBEF as a dependent variable showed that the plateau pressure ($r^2$=0.177, p<0.05) was correlated positively with PBEF. Conclusion: The PBEF level in the BAL fluid may be a useful, new biomarker for predicting the severity of illness and ventilator-induced lung injury in critically ill patients with lung infiltates and leukocytosis.

A Study on the Effective Enhancement of the Load Power Factor Using the Load Power Factor Sensitivity of Generation Cost (발전비용의 부하역률 감도를 이용한 효율적인 역률 개선 연구)

  • Lee, B.H.;Oh, M.H.;Kim, J.H.;Shim, K.B.
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.196-198
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    • 2003
  • The low load power factor causes various problems such as the increase of the power loss and the voltage instability. The demand of reactive power increases continuously with the growth of active power and the restructuring of electric power companies makes the integrated management of ractive power troublesome, from which the systematic control of load power factor is required. In this paper, the load power factor sensitivity of the generation cost is derived and its effects in supplying the reactive power and enhancing the load power factor are analyzed in a small-scale power system. The load power factor sensitivity of the generation cost is applied for determining the locations and capacities of reactive power compensation devices. It is shown that the generation cost can be reduced and the system power factor can be enhanced effectively using the load power factor sensitivity.

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A Study on the Effective Enhancement of the Load Power Factor Using the Load Power Factor Sensitivity of Generation Cost and Integrated Costs (발전비용의 부하역률 감도와 종합비용을 활용한 효과적인 역률개선 방안 연구)

  • Lee, B.H.;Oh, M.H.;Kim, J.H.;Shim, K.B.
    • Proceedings of the KIEE Conference
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    • 2003.11a
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    • pp.284-286
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    • 2003
  • The low load power factor causes various problems such as the Increase of the power loss and the voltage instability. The demand of reactive power increases continuously with the growth of active power and the restructuring of electric power companies makes the integrated management of ractive power troublesome, from which the systematic control of load power factor is required. In this paper, the load power factor sensitivity of the generation cost and integrated costs are used for determining the locations and capacities of reactive power compensation devices effectively and for enhancing the load power factor appropriately. It is shown through the application to a small-scale power system that the system power factor can be enhanced effectively and appropriately using the load power factor sensitivity and integrated costs.

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A Study on Enhancing Load Power Factor Effectively Using Load Duration Curves and the Power Factor Sensitivity of Generation Cost (부하지속곡선과 부하역률 감도기법 적용에 의한 효과적인 부하역률개선 연구)

  • Lee, Byung-Ha;Kim, Jung-Hoon
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.480-482
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    • 2005
  • In this paper, utilization of load duration curves is presented for analyzing the effect of load power factor and determining the value of load power factor effectively. In addition, the power factor sensitivity of generation cost and integrated costs including voltage variation penalty cost are used for determining the value of the load power factor from the point of view of voltage regulation and economic investment. It is shown through the application to the KEPCO power system that the load power factor can be enhanced effectively and appropriately using the load duration curve.

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Sportswear customers' level of involvement, satisfaction with functionality, and repurchase intentions - A review of sports participation motives - (스포츠웨어에 대한 소비자의 관여도, 기능성 만족도 및 재구매의도에 관한 연구 - 스포츠 참여동기를 중심으로 -)

  • Rhee, YoungJu
    • The Research Journal of the Costume Culture
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    • v.22 no.3
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    • pp.468-480
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    • 2014
  • This study aimed to identify the effects of sports participation motives, the involvement in choosing sportswear, and the satisfaction with/perceived importance of sportswear functionality, on customers' repurchase intentions. A total of 185 survey questionnaires were analyzed after surveying 200 female undergraduates in their 20s. The research results are as follows. First, the participation motives for sports were categorized as follows. A factor analysis conducted on 13 questions yielded 4 factors. Factor 1 included consideration about socializing and pleasure, factor 2 privileged ostentation, factor 3 was concerned with enhancing health, and factor 4 was about maintaining appearance. Second, the various effects of different sports participation motives, of the satisfaction with functionality, and of the involvement in buying sportswear on customers' repurchase intentions were analyzed. The intention to repurchase sportswear was considered as a dependent variable, while the motives for participating in sports, the satisfaction with functionality, and the level of involvement were treated as independent variables. A multiple regression analysis using these variables showed that the satisfaction with functionality and involvement in choosing sportswear had a significant impact on the intention to repurchase sportswear. Third, looking at how different participation motives for sports affected the importance of sportswear functionality, the motives related to socializing and pleasure and ostentation, the sub-factors in sports participation motives, significantly increased the importance of comfort. Motives related to enhancing health and maintaining appearance, on the other hand, were found to affect the importance of sports performance. Fourth, a MANOVA was performed to examine the difference in the importance of functionality between those consumers highly involved in sportswear-buying and those less involved. Those with a high level of involvement were found to prioritize sports performance over comfort. Those with a low level of involvement were shown to place a greater emphasis on comfort.

Comparison of Resonance Characteristics in FBAR Devices by Thermal Treatments

  • Mai Linh;Song Hae-il;Yoon Giwan
    • Journal of information and communication convergence engineering
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    • v.3 no.3
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    • pp.137-141
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    • 2005
  • The paper presents some methods to improve characteristics of film bulk acoustic resonator (FBAR) devices. The FBAR devices were fabricated on Bragg reflectors. Thermal treatments were done by sintering and/or annealing processes. The measurement showed a considerable improvement of return loss $(S_{11})$ and quality factor $(Q_{s/p}).$ These thermal treatment techniques seem very promising for enhancing FBAR resonance performance.

A Study on the Effective Enhancement of the Load Power Factor Using the Load Power Factor Sensitivity of Generation Cost (부하역률 감도기법 적용에 의한 효율적인 부하역률 개선에 관한 연구)

  • Lee Byung Ha;Kim Jung-Hoon
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.54 no.1
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    • pp.18-24
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    • 2005
  • Various problems such as the increase of the power loss and the voltage instability may often occur in the case of low load power factor. The demand of reactive power increases continuously with the growth of active power and the restructuring of electric power companies makes the comprehensive management of reactive power a troublesome problem, so that the systematic control of load power factor is required. In this paper, the load power factor sensitivity of the generation cost is derived and it is used for determining the locations of reactive power compensation devices effectively and for enhancing the load power factor appropriately. In addition, the voltage variation penalty cost is introduced and the integrated costs including the voltage variation penalty cost are used for determining the value of the load power factor from the point of view of the economic investment and voltage regulation. It is shown through the application to a large-scale power system that the load power factor can be enhanced effectively and appropriately using the load power factor sensitivity and integrated costs.