• Title/Summary/Keyword: sensitively analysis

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A Study on the Derivation and Sensitivity Analysis of the Adjustment Factor in the Software Cost Estimation Guidelines (소프트웨어 사업대가기준 보정계수의 유도 및 민감도 분석)

  • Byun, Boon-Hee;Kwon, Ki-Tae
    • The KIPS Transactions:PartD
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    • v.15D no.1
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    • pp.61-72
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    • 2008
  • One of the most significant tasks of software development project is to know how much it will be the software development cost in the early stage of software development cycle. The software development environment and technology are changing very rapidly. For accuracy, we should apply those to the software cost estimation. And it is important that we select the suitable adjustment factor and the value of a suitable adjustment factor. For that, this paper have applied the method of AHP. And we have also analyzed the sensitivity of the adjustment factor which is influenced by decision metrics. In conclusion, the value of the application type adjustment factor is responded more sensitively to the data complexity and the control complexity than processing complexity. And the value of the language adjustment factor is responded more sensitively to the supplying manpower and the time of the coding than the time of the debugging. In the future, we will research the selection of an additional adjustment factor and a suitable value of the adjustment factor which are influenced by the environment and the technology of the domestic software development. And then, in the language adjustment factor, we will try to calculate the value about the individual programming language.

Characteristics of Thermodynamic Performance of Heat Exchanger in Organic Rankine Cycle Depending on Pinch Temperature Difference (유기랭킨사이클에서 핀치온도차의 변화에 따른 열교환기의 열역학적 성능특성)

  • KIM, KYOUNG HOON;JUNG, YOUNG GUAN;PARK, SANG HEE
    • Journal of Hydrogen and New Energy
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    • v.26 no.6
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    • pp.590-599
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    • 2015
  • In this paper a performance analysis is carried out based on the first and second laws of thermodynamics for heat exchanger in organic Rankine cycle (ORC) for the recovery of low-temperature finite thermal energy source. In the analysis, effects of the selection of working fluid and pinch temperature difference are investigated on the performance of the heat exchanger including the effectiveness of the heat exchanger, exergy destruction, second-law efficiency, number of transfer unit (NTU), and pinch point. The temperature distribution are shown depending on the working fluids and the pinch temperature difference. The results show that the performance of the heat exchanger depends on the pinch temperature difference sensitively. As the pinch temperature increases, the exergy destruction in the evaporator increases but the effectiveness, second law efficiency and NTU decreases.

Sound Quality Evaluation for the Vehicle HVAC System Using Optimum Layout of Damping material (제진재의 최적배치를 이용한 차량공조시스템의 음질평가)

  • Hwang, Dong-Kun;Abu, Aminudin Bin;Lee, Jung-Youn;Oh, Jae-Eung;Yoo, Dong-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.629-633
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    • 2005
  • The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. In particular, the HVAC sound among the vehicle interior noise has been reflected sensitively in the side of psychology. In previous study, we have developed to verify identification of source for the vehicle HVAC system through multiple-dimensional spectral analysis. Also we carried out objective assessments on the vehicle HVAC noises and subjective assessments have been already performed with 30 subjects. In this study, the linear regression models were obtained for the subjective evaluation and the sound quality metrics. The regression procedure also allows you to produce diagnostic statistics to evaluate the regression estimates including appropriation and accuracy. Appropriation of regression model is necessary to $R^2$ value and F-value. And testing for regression model is necessary to Independence, Homoscedesticity and Normality. Also we selected optimum layout of damping material using Taguchi method. As a result of application, sound quality is improved by more quiet, powerful, expensive, smooth.

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The Effects of the STS 304 Hollow Cylinder Property Variations on the Non-Steady Heat Conduction (STS 304 중공 원통의 물성치 변화가 비정상 열전도에 미치는 영향)

  • Lee, S.C.;Choi, H.G.;Seo, J.S.;Jeong, H.M.;Chung, H.S.
    • Journal of Power System Engineering
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    • v.8 no.2
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    • pp.39-44
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    • 2004
  • The effects of the STS 304 hollow cylinder property variations on the non-steady heat conduction are considered in this paper. In the non steady state, the specific heat and conductivity are depended on the temperature variations, and these properties affect to the governing equation on heat conduction. But the most of numerical analysis on heat conduction is assumed to constant properties which is conductivity and specific heat. Assuming that the properties are reacted sensitively, the numerical results can have the difference of between constant properties with non constant properties. The main parameters are specific heat and conductivity. The temperature distributions of the STS 304 hollow cylinder became in steady state after 4 minutes in case of the constant properties. As the conductivity is varied with temperature, the temperature distributions became in steady state after 15 minutes. Therefore, a numerical analysis of the non steady state heat transfer is so important in case of varying temperature.

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Isolation of a Hypoxia/Reoxygenation Regulatory Factor in Rat Astrocytes (흰쥐 성상세포에서 산소농도의존성 유전자의 분리)

  • Park Jeong-Ae;Song Hyun-Seok;Lee Hye-Shin;Kim Kyu-Won
    • YAKHAK HOEJI
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    • v.50 no.2
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    • pp.124-128
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    • 2006
  • Astrocyte has emerged as an active regulator of brain function, which connects between blood vessels and neurons as well as is a structural component of the blood-brain barrier, From its structural characteristics, astrocyte seems to sensitively respond to oxygen tension, and, in turn, generate diverse cellular cascades. Therefore, to reveal astrocytlc events by oxygen change, we screened genes whose expressions are upregulated under reoxygenation after hypoxic stress using cDNA representational difference analysis (RDA) technique. Meteorin that regulates glial differentiation was isolated from primary cultured rat astrocytes as a hypoxia/reoxygenation regulatory factor. We cloned rat version of Meteorin (rMe-teorin) and determined full-size sequences of rMeteorin. In addition, RT-PCR analysis revealed that Meteorin was increased under reoxygenation in astrocytes and highly expressed in the developing brain. Collectively, these results suggest that Meteorin may regulate astrocyte-mediated effects in response to the change of oxygen tension in the pathophysiological states.

A Study on Purchase Satisfaction and Repurchase Intention accoding to Usage Motivation when Purchasing Fashion Products in Social Commerce (소셜커머스에서 패션제품 구매시 이용동기에 따른 구매만족도와 재구매의도에 관한 연구)

  • Lee, Hyun Ji
    • Fashion & Textile Research Journal
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    • v.16 no.4
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    • pp.596-603
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    • 2014
  • The purpose of this study was to find affecting consumer's usage motivation on purchase satisfaction and repurchase intension when purchasing fashion products in social commerce. The data were collected via a self-administered questionnaire from 239 male and female who living in Busan with experience in social commerce purchasing fashion products. Using SPSS 20.0 and AMOS 20.0 package, Cronbach's ${\alpha}$, a confirmotory factor analysis and a structural equation modeling analysis were performed. The results are as follows. Hedonic, economical efficiency and interaction without information provide subjective norms significantly influenced the purchase satisfaction. And aforementioned subjective norms significantly influenced repurchase intension, too. The purchase satisfaction positively influenced the repurchase intension. Therefore, social commerce sellers of fashion products ought to offer variety price benift and promotion to raise the purchase satisfaction and repurchase intension. To offer variety price benift, they should respond sensitively to the price set by comparing prices with other sellers. And promotion to raise the purchase satisfaction and repurchase intension need to consider such variety of missions, discount coupons or event and mileage. In addition, they should develop customer service system for interaction with customer and connect to the repurchase increases the purchass satisfaction through faster customer response to the product information or sales, service.

Improvement of Sound Quality for the Vehicle HVAC System Using Optimum Layout of Damping Material (제진재의 최적배치를 이용한 차량공조시스템의 음질개선)

  • Oh Jae-Eung;Hwang Dong-Kun;Park Sang-Gil;Yoon Tae-Kun;Sim Hyoun-Jin;Lee Jung-Youn
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.6 s.249
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    • pp.728-733
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    • 2006
  • The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. In particular, the HVAC sound among the vehicle interior noise has been reflected sensitively in the side of psychology. In previous study, we have developed to verify identification of source for the vehicle HVAC system through multiple-dimensional spectral analysis. Also we carried out objective assessments on the vehicle HVAC noises and subjective assessments have been already performed with 30 subjects. In this study, the linear regression models were obtained for the subjective evaluation and the sound quality metrics. The regression procedure also allows you to produce diagnostic statistics to evaluate the regression estimates including appropriation and accuracy. Appropriation of regression model is necessary to $R^2$ value and F-value. And testing for regression model is necessary to independence, homoscedesticity and normality. Also we selected optimum layout of damping material using Taguchi method. As a result of application, sound quality is improved more quietly, powerfully, even though costly, and smoothly.

The Effects of Welding Parameters on Quality in Lap Joint Fillet Welds of Thin Plate by Plasma Welding (Plasma 용접에 의한 박판 겹치기 이음 필릿 용접부의 품질에 미치는 용접 변수의 영향)

  • Park, Kun-Gi;Yang, Jong-Soo;Cho, Sang-Myung;Yoon, Hun-Sung
    • Special Issue of the Society of Naval Architects of Korea
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    • 2006.09a
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    • pp.122-127
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    • 2006
  • In case of lap joint fillet welds of thin plate, the example which is applicable to Plasma Welding increases substituting for the exiting TIG Welding but the quality of Plasma arc welding has a special feature influenced sensitively by the condition of welding caused by controlling the various parts of welding torch. This research is purposed to improve lap joint fillet welds of thin plate in high quality and attain the high productivity and it is examined that how the change of electrode tip angle and Setback has an effect on the quality of welding and it is investigated how the change of Setback and Standoff has an effect on Melting efficiency using Response Surface Analysis.

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The Flow Analysis of Supercavitating Cascade by Nonlinear Theory (비선형이론에 의한 Supercavitation 익렬의 유동해석)

  • Pak, Ee-Tong;Hwang, Yoon
    • Solar Energy
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    • v.17 no.1
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    • pp.35-46
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    • 1997
  • In this study comparison of experiment results with the computed results of linear theory and nonlinear theory using singularity method was obtainable. Specially singularity points like sources and vortexes on hydrofoil and freestreamline were distributed to analyze two dimensional flow field of supercavitating cascade using nonlinear theory, and governing equations of flow field were derived and hydraulic characteristics of cascade were calculated by numerical analysis of the governing equations. The results compared linear theory and nonlinear theory with the experiment results of the study are as follows: The tolerances of nonlinear theory were larger than those of linear theory in case of ${\alpha}<10^{\circ}$. Moreover the computational range of attack angles could be expanded from ${\alpha}=10^{\circ}$ to ${\alpha}=25^{\circ}$, the flow field of supercavitating cascade could be analyzed in the condition which the wake thickness and the length of cavity are a variable. The shapes of cavity were changed sensitively according to various variable such as attack angles, pitches and wake thickness, and the pressure distribution of hydrofoil surface was identical almost disregarding wake thickness but changed largely according to attack angle and the length of cavity. Lift coefficient and drag coefficient were reduced according to increasing of wake thickness but the influences of wake thickness were very little in the situation of small pitch and long cavity.

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Process Design and Forming Analysis of Permalloy Shielding Can for Instrument Cluster (자동차 계기판용 퍼멀로이 실딩 캔의 성형해석 및 공정설계)

  • Kim, Dong-Hwan;Lee, Seon-Bong;Kim, Byung-Min
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.2
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    • pp.177-185
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    • 2001
  • This study shows the process design and forming analysis of permalloy shielding can that support the automobile multi-display parts to indicate the accurate information of car. This study is particularly important, since the strain and thickness of permalloy shielding can is known to affect the magnetic properties such as coercivity and permeability quite thickness of permalloy shielding can is known to affect the magnetic properties such as coercivity and permeability quite sensitively. The objective functions are strain and thickness deviation. The punch radius, die radius and blank holding force are considered as design parameters. Orthogonal array (OA) table and characteristics are applied to neural network (NN) as train data. After training, the optimal and robust condition of design parameters is selected. This study shows the correlation between the design methodology of NN and the statistical design of experiments (DOE) approach.

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