• Title/Summary/Keyword: Effects on Performances

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The Static Performances of Air-Lubricated Tilting Pad Bearings With Inlet Pressure (선단압력을 고려한 공기윤활 틸팅패드베어링의 정특성)

  • 김성국;김경웅
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.04a
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    • pp.235-240
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    • 1998
  • The inlet pressure build-up at the leading edge of bearings and its effects on the static performances are investigated theoretically. The performance analyses of air-lubricated tilting pad bearings are carried out considering the inlet pressure which is obtained by means of momentum conservation method. The results show that inlet pressure is above atmosphere pressure in front of leading edge of tilting pad bearing and there is a significant influence of the inlet pressure on the performance of bearings.

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Rainfall Effects on Discharged Pollution Load in Unit Watershed Area for the Management of TMDLs (수질오염총량관리 배출부하량에 대한 강우영향 분석연구)

  • Park, Jun Dae;Oh, Seung Young
    • Journal of Korean Society on Water Environment
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    • v.26 no.4
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    • pp.648-653
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    • 2010
  • Discharged pollution load for the management of Total Maximum Daily Loads (TMDLs) is calculated on the basis of rainfall data for reference year. Rainfall has an influence on discharged pollution load in unit watershed with combined sewer system. This study reviewed the status of discharged pollution load and rainfall conditions. We also investigated rainfall effects on discharged pollution load by analyzing change of the load in accordance with increase of rainfall. The change ratio of discharged pollution load was 18.6% while inflow load only 5.8% for 5 years from 2004 to 2008 in Daejeon district. The greatest rainfall and rain days were over 2 times than the least during the period. This change in rainfall could have great effect on discharged pollution load. The analysis showed that discharged pollution load increased 2.1 times in case rainfall increased 2 times and 1.2 times in case rain days increased 2 times. Rainfall effects, therefore, should be considered to make resonable evaluation of discharged pollution load in the assessment of annual performances.

An Empirical Study on the Management Performances of Korean Tourism Firms : Focusing on the Economic Effects caused by FTA (FTA의 경제적 효과가 한국 관광기업의 경영성과에 미치는 영향에 관한 연구)

  • Shin, Kwang-Ha;Park, Myung-Chan
    • International Area Studies Review
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    • v.14 no.1
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    • pp.221-254
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    • 2010
  • This study is for analyzing the mgmt performances of Korean tourism firms, operating as preparing strategically against FTA, one of the most importantly external environment in int'l mgmt since in the mid of 1990s. The main purpose can be mentioned to test empirically some relations between the mgmt performances of Korean tourism ones and the economic effects originated from FTA. The dependent variables of mgmt performances are classified with sales, profits and mgmt satisfaction, while the independent one regarding with economic effects from FTA are sorted based on the previous studies with the 2 following factors like direct with inbound/outbound and indirect effects. This study is conducted in two stages. Firstly, the research model is designed by the reviewing relevant theories and previous studies. Secondly, the survey of Korean tourism firms engaging in mgmt activities is implemented by collecting questionnaires. And for testing the hypothesis, the analyzing tools are used for correlation, reliability, validity and multi-regression on SPSS 12.0 and the path analysis of structural equation modeling is activated with AMOS 11.0.

Numericla Study on the Aerodynamic Performances of the Turbo Blower Using Fluid-Structure Interaction Method (유체 구조 연계 해석기법을 적용한 터보블로워 공력성능 해석에 관한 수치적 연구)

  • Park, T.G.;Chung, H.T.;Kim, H.B.;Park, J.Y.
    • Journal of Power System Engineering
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    • v.15 no.6
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    • pp.35-40
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    • 2011
  • The present study aims at investigating the effect of the fluid-structure interaction on the aerodynamic performances in the turbo blower. The design specifications of the reference model driven by 400kW power were given as 7.43kg/s of mass flow rate, 1.66 of pressure ratio with 12000rpm of impeller rotating speed. Numerical simulation has been performed on the three cases based on the tip clearance between the impeller blade and the shroud. The CFX-turbo for flow fields and ANSYS-mechanical for structure domain were applied to solve the present FSI problems inside the turbo blower. Through the numerical results, the performances corrected by the FSI effects were proposed for the more reliable predictions.

A Study on the Effects of Core Competencies of the University-Industry Cooperation on Technology Transfer & Education Performances (산학협력단 핵심역량이 기술이전과 교육성과에 미치는 영향에 관한 연구)

  • Kwon, Hyukje;Yoon, Jaehong
    • Journal of Technology Innovation
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    • v.23 no.2
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    • pp.55-80
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    • 2015
  • This Study's topic is to study on the effects of core competencies as such as leadership, strategic competences' influence towards the university-industry cooperation on technology transfer and education performances. First, the existing studies and literatures have been reviewed. Second, the nationwide surveys were conducted. In results, the leadership competence did not have any impact on the operation performances. Strategic competence did not have any impact on the technology transfer, but it influenced the education performance. Human resource competence also did not have any influence on the managing performances, but it has been analyzed that the R&D competence had an influence over the technology transfer part of the managing performance. The University-Industry Cooperations create an opportunity and secures competencies for the enterprise, it also enhances the R&D competency of University and provides supports in nurturing the human resources. Especially, the strategic competency amongst the independent variables has influenced the education performance.

Effect of Environmental Dynamics on the Business Performance of Franchise Distribution Industry (프랜차이즈 유통산업에서 환경 동태성이 가맹점의 경영성과에 미치는 영향에 관한 연구)

  • Park, Han-Seong;Kim, Joon-Ho;Yu, Jong-Pil
    • Journal of Distribution Science
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    • v.16 no.3
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    • pp.59-68
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    • 2018
  • Purpose - This study empirically examines the effects of environmental dynamics(dynamics of one's own company, dynamics of competitors, and dynamics of customers), within the franchise industry, on the dependence and conflict(dysfunctional conflict and functional conflicts) and the business performances(financial and non-financial). Furthermore, we empirically examined the effects of the dependence of franchise on the conflicts(dysfunctional conflict and functional conflict) and business performances(financial and non-financial). Finally, we empirically examined the effects of the conflicts of franchise (dysfunctional conflict and functional conflict) on the business performances(financial and non-financial). Research design, data, and methodology - Our study conducted a survey on the managers and owners of the franchises located in Seoul, Gyeonggi, and Incheon. The total number of valid samples was 230, and the structural equation model was analyzed by using AMOS program. Results - First, the environmental dynamics(dynamics of one's own company, dynamics of competitors, and dynamics of customers) in the franchise industry were shown to have statistically significant positive effect on the dependence of franchise. Second, among the environmental dynamics in the franchise industry, the dynamics of one's own company and the dynamics of the customers were shown to have a statistically significant positive effect on the dysfunctional conflicts of franchisees. However, in the franchise industry, the dynamics of competitors did not have a statistically significant effect on the dysfunctional conflict of the franchise. Third, in the franchise industry, the environmental dynamics(dynamics of one's own company, dynamics of competitors, and dynamics of customers) did not have a statistically significant effect on the functional conflicts of the franchises. Fourth, the dependence of franchise was shown to have a statistically significant positive effect on the conflicts(dysfunctional conflict and functional conflict). Fifth, the dysfunctional conflict of franchisees was shown to have a statistically significant negative effect on the business performances(financial and non-financial). Sixth, the functional conflicts of franchises was shown to have a statistically significant positive effect on business performances(financial and non-financial). Conclusions - From the franchise industry researches, the environmental dynamics were selected as the preceding factors and the relationship leading to dependence, conflict, and business performance were constructed into model.

Measuring the Impact of Change Orders on Project Performances by Building Type

  • Juarez, Marcus;Kim, Joseph J.
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.179-187
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    • 2022
  • The project performances can be measured in terms of meeting the project schedule, budget, and conformance to functional and technical specifications. Numerous studies have been conducted to examine the causes and effects of change orders for both vertical and horizontal construction, respectively. However, these studies mainly focus on a single project type, so this paper examines the impact of change order for cost growth and schedule overruns using four different building types to close the gap in the change order research area. A total of 211 building projects are collected from four building types: healthcare, residential, office, and education. Statistical analyses using ANOVA tests and linear regression models are used to examine the created metric $CO/day on the cost and schedule impacts. The results found that mean $CO/day values were not statistically different among building types, and that the sum of change orders is a statistically significant predictor of $CO/day. The results will help project stakeholders mitigate the negative change orders effects can be a challenge for project managers and researchers alike.

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The Effect of Foreign Direct Investment on Corporate Financial Performances: Focused on Comparison between Korean SMEs and Large Enterprises (해외직접투자가 기업의 재무성과에 미치는 영향: 한국의 중소기업과 대기업 비교를 중심으로)

  • Maeng, Seon Bae;Kim, Soon Choul
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.6
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    • pp.11-26
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    • 2023
  • This study aimed to empirically analyze the effect of Korean companies' FDI(Foreign Direct Investment) on their financial performances, particularly divided into profitability, stability, growth and activity, while comparing distinct financial performances between SMEs(small and medium-sized enterprises) and large enterprises whose corporate attributes are different from each other. As research subjects, this study selected FDI Korean companies from the directory of oversea-expanded companies of KOTRA(Korea Trade-Investment Promotion Agency) and used financial data from a total of 409 companies(136 SMEs and 273 large enterprises) with complete financial data for the first five years after the initial investment out of all the financial data from 1990 to 2021. The analysis results can be summarized as follows; In the profitability sector, FDI had positive effects on ROA(Return on Assets) and ROS(Return on Sales) of SMEs, while having negative effects on those of large enterprises to the contrary. In the stability sector, FDI had no statistical significance for SMEs, while having significantly negative effect on LEV(Debt to Equity Ratio) of large enterprises. In the growth sector, FDI had significantly negative effect on AGR(Asset Growth) of SMEs, but showed no significant results for large enterprises. In the activity sector, FDI showed no statistical significance for SMEs, while having positive effects on ATR(Asset Turnover Ratio) and FATA(Fixed Asset Turnover Ratio) of large enterprises. In conclusion, it was found that when having made FDI, SMEs and large enterprises showed different financial performances from each other in terms of profitability, stability, growth and activity.

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Effects of Swirl on Flame Development and Late Combustion Characteristic in a High Speed Single-Shot Visualized SI Engine (고속 단발 가시화 스파크 점화 엔진에서의 연소 특성에 대한 선회효과 연구)

  • Kim, S.S.;Kim, S.S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.1
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    • pp.54-64
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    • 1995
  • The effects of swirl on early flame development and late combustion characteristic were investigated using a high speed single-shot visualized 51 engine. LDV measurements were performed to get better understanding of the flow field in this combustion chamber. Spark plugs were located at half radius (R/2) and central location of bore. High speed schlieren photographs at 20,000 frames/sec were taken to visualize the detailed formation and development of the flame kernel with cylinder pressure measurements. This study showed that high swirl gave favorable effects on combustion-related performances in terms of the maximum cylinder pressure and flame growth rate regardless of spark position. However, at R/2 ignition the low swirl shown desirable effects at low engine speed gave worse performances as engine speed increased than without swirl. There were distinct signs of slow-down in flame growth during the period when the flame front expanded from 2.5mm in radius until it reached 5.0mm apparently due to the presence of ground electrode. There seemed to be heat transfer effect on the flame expansion speed which was evidenced in high swirl case by the slowdown of the late flame front presumably caused by relatively large heat loss from burned gas to wall compared with low- or no-swirl cases.

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Li Ion Diffusivity and Improved Electrochemical Performances of the Carbon Coated LiFePO4

  • Park, Chang-Kyoo;Park, Sung-Bin;Oh, Si-Hyung;Jang, Ho;Cho, Won-Il
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.836-840
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    • 2011
  • This study examines the effects of a carbon coating on the electrochemical performances of $LiFePO_4$. The results show that the capacity of bare $LiFePO_4$ decreased sharply, whereas the $LiFePO_4$/C shows a well maintained initial capacity. The Li ion diffusivity of the bare and carbon coated $LiFePO_4$ is calculated using cyclic voltammetry (CV) to determine the correlation between the electrochemical performance of $LiFePO_4$ and Li diffusion. The diffusion constants for $LiFePO_4$ and $LiFePO_4$/C measured from CV are $6.56{\times}10^{-16}$ and $2.48{\times}10^{-15}\;cm^2\;s^{-1}$, respectively, indicating considerable increases in diffusivity after modifications. The Li ion diffusivity (DLi) values as a function of the lithium content in the cathode are estimated by electrochemical impedance spectroscopy (EIS). The effects of the carbon coating as well as the mechanisms for the improved electrochemical performances after modification are discussed based on the diffusivity data.