• Title/Summary/Keyword: Pressure contribution analysis

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The Discriminant Analysis of Blood Pressure - Including the Risk Factors - (혈압 판별 분석 -위험요인을 중심으로-)

  • 오현수;서화숙
    • Journal of Korean Academy of Nursing
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    • v.28 no.2
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    • pp.256-269
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    • 1998
  • The purpose of this study was to evaluate the usefulness of variables which were known to be related to blood pressure for discriminating between hypertensive and normotensive groups. Variables were obesity, serum lipids, life style-related variables such as smoking, alcohol, exercise, and stress, and demographic variables such as age, economical status, and education. The data were collected from 400 male clients who visited one university hospital located in Incheon, Republic of Korea, from May 1996 to December 1996 for a regular physical examination. Variables which showed significance for discriminating systolic blood pressure in this study were age, serum lipids, education, HDL, exercise, total cholesterol, body fat percent, alcohol, stress, and smoking(in order of significance). By using the combination of these variables, the possibility of proper prediction for a high-systolic pressure group was 2%, predicting a normal-systolic pressure group was 70.3%, and total Hit Ratio was 70%. Variables which showed significance for discriminating diastolic blood pressure were exercise, triglyceride, alcohol, smoking, economical status, age, and BMI (in order of significance). By using the combination of these variables, the possibility of proper prediction for a high-diastolic pressure group was 71.2%, predicting a normal-diastolic pressure group was 71.3%, and total Hit Ratio was 71.3%. Multiple regression analysis was performed to examine the association of systolic blood pressure with life style-related variables after adjustment for obesity, serum lipids, and demographic variables. First, the effect of demographic variable alone on the systolic blood pressure was statistically significant (p=.000) and adjusted $R^2$was 0.09. Adding the variable obesity on demographic variables resulted in raising adjusted $R^2$to 0.11 (p=.000) : therefore, the contribution rate of obesity on the systolic blood pressure was 2.0%. On the next step, adding the variable serum lipids on the obesity and demographic variables resulted in raising adjusted R2 to 0.12(P=.000) : therefore, the contribution rate of serum lipid on the systolic pressure was 1.0%. Finally, adding life style-related variables on all other variables resulted in raising the adjusted $R^2$to 0.18(p=.000) ; therefore, the contribution rate of life style-related variables on the systolic blood pressure after adjustment for obesity, serum lipids, and demographic variables was 6.0%. Multiple regression analysis was also performed to examine the association of diastolic blood pressure with life style-related variables after adjustment for obesity, serum lipids, and demographic variables. First, the effect of demographic variable alone on the diastolic blood pressure was statistically significant (p=.01) and adjusted $R^2$was 0.03. Adding the variable obesity on demographic variables resulted in raising adjusted $R^2$to 0.06 (p=.000) ; therefore, the contribution rate of obesity on the diastolic blood pressure was 3.0%. On the next step, adding the variable serum lipids on the obesity and demographic variables resulted in raising the adjusted $R^2$ to 0.09(p=.000) ; therefore, the contribution rate of serum lipid on the diastolic pressure was 3.0%. Finally, adding life style-related variables on all other variables resulted in raising the adjusted $R^2$ to 0.12 (p=.000) : therefore, the contribution rate of life style-related variables on the systolic blood pressure after adjustment for obesity, serum lipids, and demographic variables was 3.0%.

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Application of the Determination Method of Monitoring Location in Real Water Distribution System (실제 상수관망에 대한 모니터링 지점선정방법의 적용)

  • Park, Yong-Gyun;Jung, Sung-Gyun;Kwon, Hyuk-Jae
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.6
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    • pp.617-623
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    • 2015
  • In this study, determination methods of monitoring location in water distribution system were suggested and applied to real test bed. Small block of Gwangtan water distribution system is consisted of 582 pipes, 564 junctions, 1 reservoir, and 1 pump station. Small block of Ho Chi Minh water distribution system is consisted of 162 pipes, 148 junctions, and 1 reservoir. Two small block water distribution systems were analyzed by pressure contribution analysis method to determine the optimum monitoring locations. The pressure change was estimated at each junctions by the additional demand at a junction. From the results, the optimum monitoring location can be determined by rank of pressure contribution index at each junctions due to demand change at a junction.

Determination Methods of Pressure Monitoring Location in Water Distribution System (상수관망에서 수압모니터링지점 선정방법)

  • Kwon, Hyuk Jae
    • Journal of Korea Water Resources Association
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    • v.46 no.11
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    • pp.1103-1113
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    • 2013
  • In this study, determination methods of the pressure monitoring location in water distribution system were introduced and applied to sample pipe network. The best determination method of the pressure monitoring location was suggested and applied to the real city pipe network. Three kinds of determination methods of pressure monitoring locations are categorized such as the sensitivity analysis according to changing roughness coefficient, pressure contribution analysis, and sensitivity analysis according to changing demand. Further-more, pressure contribution analysis and sensitivity analysis from the results of unsteady analysis were conducted and compared each other. From the results, the most accurate and simplest method was selected in this study. Therefore, the best method can be applied for the pressure management or leakage detection as a determination method of pressure monitoring location in water distribution system.

Interior Noise Reduction of Wheel Loader Using Transfer Path Analysis and Panel Contribution Analysis (전달 경로 분석과 패널 기여도 분석을 이용한 휠로더의 실내소음 저감에 관한 연구)

  • Kim, Bo-Yong;Shin, Chang-Woo;Jeong, Won-Tae;Park, Sung-Yong;Jang, Han-Kee;Kim, Seong-Jae;Kang, Yeong-June
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.8
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    • pp.805-815
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    • 2008
  • Transfer path analysis(TPA) and panel contribution analysis(PCA) have been used widely to reduce interior noise of mechanical systems. TPA enables us to decompose interior noise into air-borne and structure-borne noises and estimate the path contribution of noise sources. PCA is also used to identify the noise contribution of each sub-panel in vibro-acoustic systems. In this paper, TPA and PCA are applied to wheel loader, one of the heavy construction equipments. Firstly, TPA for air-borne noise is conducted to estimate the contribution of air-borne sources using pressure transfer function. Thereafter, TPA for structure -borne noise is employed to verify the results of air-borne source quantification through the synthesis of two results. Secondly, PCA is performed by both TPA using pressure transfer function between panels inside the cabin and boundry element method(BEM) for the cabin of wheel loader with various boundary conditions. As a results, it was found that TPA conducted by experiments and PCA accomplished by both experiments and BEM are very effective methods in analyzing the path and contribution of the noises for reducing an interior noise level in the wheel loader system.

Analysis of a Panel Contribution of a Vehicle Compartment Using the Acoustic Reciprocal Theorem (음향 상호성 이론을 이용한 승용차 차실 판넬의 기여도 해석)

  • Kim, M.G.;Park, T.W.;Lee, S.H.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.2
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    • pp.59-72
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    • 1994
  • For a panel contribution of the passenger vehicle compartment, a model was created for acoustic analysis of the passenger vehicle compartment and through the acoustic normal modal analysis, frequencies and mode shapes of the resonance modes were calculated. Also, the contribution analysis of each panel was executed using acoustic reciprocal theorem, and through this analysis, normalized responses at the particular point indicate the relative contribution of each panel for generating noise and vibration

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A Study on the Interior Noise Reduction of EMU by Contribution Analysis (기여도 분석에 의한 전기동차 실내소음 저감대책 연구)

  • 문경호;김재철;유원희
    • Proceedings of the KSR Conference
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    • 1999.05a
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    • pp.218-225
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    • 1999
  • Speed-up and mass reduction of EMU(Electrical multiple unit) causes increase of interior noise. One of the best ways to reduce the interior noise is to identify noise sources. In this study, we evaluated interior noise by contribution analysis. This method is to predict the interior noise contribution of carbody by using transfer function between acceleration and sound pressure. The plan of the interior noise reduction based on the test results was also presented.

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Interior Noise Reduction of a Passenger Car using Panel Contribution Analysis (패널 기여도 분석에 의한 승용차의 실내 소음 저감)

  • 이두호;김태정
    • Journal of KSNVE
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    • v.9 no.4
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    • pp.785-794
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    • 1999
  • The panel contribution analysis to reduce interior booming noise of a passenger car is carried out using both experimental method and numerical one. The accelerations of panels are measured on the outer surface of car body during operation. The acoustic characteristic of cavity is represented by two different ways. One is the acoustic transfer function obtained by experiment with reciprocal manner. The other is the boundary element model and numerical results of the model are calculated using SYSNOISE. The results from numerical method show more good agreement with measured sound pressure levels than the experimental one. Contributions of panels for interior noise are ranked and structure of the car is reinforced according to the results, which shows that the panel contribution analysis is a powerful tool to lessen structure-borne noise of passenger vehicle.

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A Study on Structural Design of Pressure Hull of Submerible (잠수정 내압선체의 구조설계에 관한 연구)

  • Gang, Byeong-Yun;Wi, Jae-Yong
    • 한국기계연구소 소보
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    • s.16
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    • pp.95-109
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    • 1986
  • The pressure hull of submersible is a unique structure which requires sophisti¬cated technology in its design and fabrication aspects. In this contribution an attempt has been made to review and analysis the pressure hull design such the most important subject as various geometrical shape, materials, and strength of pressure hull. Comparative study to theoritical analysis through the experimental measure¬ments are also carried out.

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Interior noise prediction of the Korean high speed train using sound source contribution analysis and sensitivity analysis of wall′s transmission loss (소음원 기여도 해석 및 벽면 투과손실에 대한 민감도 해석에 의한 한국형 고속철도의 실내소음 예측)

  • 김관주;박진규
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.1093-1098
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    • 2001
  • The interior sound pressure level of the Korean high speed train is predicted using ray acoustic method. The motor car, motorized car and passenger cabin are investigated under the environment of passing open countryside and inside tunnel Calculated sound levels of KHST are compared with the those of KTX prototype which vehicle shows similar acoustic behavior with KHST for the purpose of assuring the calculated data. In order to reduce the calculated SPL in systematic way, contribution analysis of sound sources and sensitivity analysis of concerning wall's transmission loss on the SPL of the designated receiving points are carried out. Finally, practical design suggestions are proposed.

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A Design Process for Structural Borne Noise using Panel Contribution and Design Sensitivity (판넬기여도와 설계민감도를 이용한 구조기인소음 설계프로세스)

  • Kim, Hyo-Sig;Kim, Heon-Hee;Cho, Hyo-Jin;Yoon, Seong-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.806-811
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    • 2007
  • In this study, we propose a more systematic design process for the structure-borne noise. The proposed way consists of 4 steps: Problem definition, Cause analysis, Development of counter-measure and Validation. Especially, we improved the second step: Cause analysis. According to the PCA(Panel Contribution Analysis), a reduction in vibration of the panels of which panel contribution is positive and larger, results in a reduction in structure-borne noise. We have, however, met the case in which the concept of PCA is no valid in a few vehicle tests. In order to understand this phenomenon, we compared the major panels selected by PCA with the one chosen by DSA(Design Sensitivity Analysis). After investigating the difference between the two results, a more improved process is suggested. The proposed one for the second step in the design process consists of not only the previous way: PCA with deformation analysis results but also DSA. It is finally validated that the proposed design process decreases the sound pressure of the concerned noise transfer function more than 3.5 dB.

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