• 한국유체기계학회 논문집
• /
• 제19권2호
• /
• pp.27-35
• /
• 2016

The purpose of this study is to develop a method to predict the performance and economics of a micro gas turbine cogeneration system using performance correction curves. The variables of correction curves are ambient temperature, ambient pressure, relative humidity and load fraction. All of the values of correction factors were expressed as relative values with respect to design values at the ISO conditions. Once the correction curves are obtained, system performance can be predicted relatively easily compared to a detailed performance analysis method through a simple multiplication of the correction factors of various variables at any operating conditions. The predicted results using the correction curve method were compared with those by the detailed and more complex performance analysis in a wide operating range, and its feasibility was confirmed. To illustrate the usability of the correction curve method, the results of an economic analysis of a cogeneration system considering varying operating ambient condition and load was presented.

• 재무관리연구
• /
• 제20권1호
• /
• pp.331-339
• /
• 2003

본 연구는 분리공모(ECO)를 통한 장기 주식성과가 기업집중 내지 영업성과와 어떤 관련이 있는지를 분석하였다. 분석결과, 동업종 ECO의 자회사의 12개월간 CAR과 BHAR은 각각 26.52%와 22.19%로 양(+)의 성과를 보였으며 CAR은 5% 수준에서 의하였다. 이업종 ECO의 자회사의 12개월간 CAR과 BHAR은 각각 35.14%와 39.64%로 1% 수준에서 유의한 양(+)의 값을 보여 기업집중을 높이는 이업종 ECO가 동업종 ECO보다 고성과를 보였다. 반면, 모회사는 어떤 경우에도 유의한 성과를 보이지 않았다. ECO 자회사의 3년간 초과 영업성과를 분석한 결과, 첫 연도는 유의한 양(+)의 값을 보였으며 그 이후는 유의하지 않아 주식성과의 패턴과 일치하였다. 회귀분석 결과, 공모비율이 낮을수록 영업성과가 좋을수록 자회사의 주식성과가 좋았다.

• 디지털융복합연구
• /
• 제15권4호
• /
• pp.309-316
• /
• 2017

본 연구의 목적은 수술실 간호사의 목표관리특성과 직무몰입이 간호업무성과에 미치는 영향을 파악하기 위함이다. 연구대상은 서울에 소재한 3차 의료기관 수술간호팀의 자발적 참여의사가 있는 간호사 226명을 대상으로 자료수집을 하였고, 수술실 간호사의 간호업무성과에 미치는 영향을 파악하기 위하여 다중회귀분석을 실시하였다. 본 연구의 결과 수술실 간호사의 간호업무성과에 관계하는 영향요인은 목표관리특성중 목표구체성, 직무몰입, 측정가능성 순으로 나타났으며, 간호업무성과의 25.8%를 설명하였다. 따라서 간호업무성과를 높이기 위하여 수술실 간호의 직무특성상 수술상황에 몰입되어 간호를 할 수 있는 업무환경을 만들기 위해 노력해야 한다. 또한 수술실 간호사의 간호업무성과를 향상시키기 위해서는 목표관리특성 중에서 목표구체성과 목표의 측정가능성 부분에 대하여 이들의 영향력을 더욱 높일 수 있는 전략을 개발하여야 한다.

• 상하수도학회지
• /
• 제32권4호
• /
• pp.357-361
• /
• 2018

Forward osmosis (FO) process has been attracting attention for its potential applications such as industrial wastewater treatment, wastewater reclamation and seawater desalination. Particularly, in terms of fouling reversibility and operating energy consumption, the FO process is assumed to be preferable to the reverse osmosis (RO) process. Despite these advantages, there is a difficulty in the empirical step due to the lack of separation and recovery techniques of the draw solution. Therefore, rather than using FO alone, recent developments of the FO process have adapted a hybrid system without draw solution separation/recovery systems, such as the FO-RO osmotic dilution system. In this study, we investigated the performance of the hollow fiber FO module according to various operating conditions. The change of permeate flow rate according to the flow rates of the draw and feed solutions in the process operation is a factor that increases the permeate flow rate, one of the performance factors in the positive osmosis process. Our results reveal that flow rates of draw and feed solutions affect the membrane performance, such as the water flux and the reverse solute flux. Moreover, use of hydraulic pressure on the feed side was shown to yield slightly higher flux than the case without applied pressure. Thus, optimizing the operating conditions is important in the hollow fiber FO system.

• 국제학술발표논문집
• /
• The 3th International Conference on Construction Engineering and Project Management
• /
• pp.914-919
• /
• 2009

The research investigates for the relationship between the operating performances of the make-ready process and project production performance. To this end, the researchers proposed a metric of PCR (Percentage of Constraint Removal) to measure the make-ready performance. The study measured the production performance in two ways: production planning reliability and progress performance. We hypothesized that how well the make-ready process is performed has an impact on the degree of production performance. The statistical analyses are used to investigate that how operating performance of the make-ready process affects project production performance. The results of the regression analysis support our hypotheses (p<0.25) and correlation coefficients for the relationship between project production performance and make-ready performance are also significant (p<0.05).

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2005년도 연구개발 발표회 논문집
• /
• pp.378-383
• /
• 2005

The performances of side channel type regenerative blowers were evaluated by the blower performance test, 1-D performance prediction and CFD. The performance prediction method was modified using the results of the performance test and CFD and applied to the design of the new regenerative blowers. The major geometric parameters such as channel height, channel area and expansion angle were decided from the performance prediction method for the improved models and the predicted results were compared with CFD and experimental data. Both of the modified models showed improved efficiency at the operating condition. Especially, model3 could be possible to reduce operating rotating speed, that is benefit to noise performance, because of the high head performance at the design point. The CFD results showed that the performance of the regenerative blower was influenced by the secondary circulatory flow in the channel.

• 연구논문집
• /
• 통권30호
• /
• pp.5-13
• /
• 2000

The computation scheme of simulating gas turbine transient behavior was developed. The basic principles of this scheme and main input data required are described. Calculation results are presented in terms of whole operating regime of the cycle. The influence of main initial parameters such as starting engine power, moment of inertia of the rotor, fuel supplying schedule etc. on performance characteristics of has turbine during transient operation is studied In addition, bleeding air influence on transient behavior was also considered For validation of the developed code, comparison of present calculation with that of measurement data of the experimental data for the range of operating period studied.

• International Journal of Computer Science & Network Security
• /
• 제23권7호
• /
• pp.165-170
• /
• 2023

Scheduling algorithms plays a significant role in optimizing the CPU in operating system. Each scheduling algorithms schedules the processes in the ready queue with its own algorithm design and its properties. In this paper, the performance analysis of First come First serve scheduling, Non preemptive scheduling, Preemptive scheduling, Shortest Job scheduling and Round Robin algorithm has been discussed with an example and the results has been analyzed with the performance parameters such as minimum waiting time, minimum turnaround time and Response time.

• 아태비즈니스연구
• /
• 제14권3호
• /
• pp.167-186
• /
• 2023

Purpose - The purpose of this study is to empirically investigate whether the auditor accreditation system for IPO firms improves the efficiency of the KOSDAQ IPO market. To verify the effectiveness of the auditor designation system, we time series compare four measures of IPO firms (earnings management, long-term stock performance, change in operating performance, and possibility of delisting). Design/methodology/approach - We test the hypothesis through event research method and regression analysis. Specifically, the dependent variables of the regression model are discretionary accruals in the year of IPO, 36-month holding period excess return after IPO, change in operating performance for 3 years after IPO, and dummy variable for delisting. And the explanatory variable is a dummy variable that separates the period before and after the implementation of the auditor designation system. Findings - We find that earnings management and delisting risks decreased more in the period after the implementation of the auditor accreditation system than in the previous period. In addition, we find that long-term stock performance and operating performance after IPO increase further after the implementation of the auditor accreditation system. Research implications or Originality - Overall, the results of this study suggest that the implementation of the auditor accreditation system for IPO firms contributes to improving market efficiency in the KOSDAQ market, where information asymmetry is high. Our study differs from previous studies in that it demonstrates the effectiveness of the auditor designation system using various measures.

• 한국유체기계학회 논문집
• /
• 제6권3호
• /
• pp.36-43
• /
• 2003

Operating performance of industrial gas turbines in combined cycle power plants depends upon atmospheric conditions. Compressor fouling caused by airborne particles in the atmosphere and their adhesions on compressor blades is one of critical phenomena related to the performance degradation of industrial gas turbines. Compressor fouling provokes increase of pressure loss in inlet duct, decrease of mass flow rate of intake air and decrease of compressor stage efficiency. In this study, impacts of compressor fouling on the performance of an industrial gas turbine operating at design point condition are investigated analytically. As results, it is found that the reduction of produced power with decreased mass flow rate of intake air caused by narrowed flow area by the adhesion of airborne particles on compressor blades is the most dominant impact on the gas turbine performance by the compressor fouling phenomena.