• Title/Summary/Keyword: pressure relation

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Study on the Undrained Shear Strength Characteristics (반월지역 해성점토의 비배수 전단강도 특성에 관한 연구)

  • 장병욱;박영곤
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.36 no.3
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    • pp.90-99
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    • 1994
  • To investigate the undrained shear strength characteristics of marine soils with high water content, high compressibility and weak bearing capacity, a series of undrained triaxial tests with pore pressure measurements on undisturbed and disturbed Banwol marine clay in normally consolidated and overconsolidated states is carried out. The results and main conclusions of this study are summarized as follows : 1 . When the consolidation pressure is increased, the maximum deviator stress of disturbed and undistubed clay in normally consolidated state is increased. Pore pressure parameters and internal friction angle of undisturbed clay are greater than those of disturbed clay. 2. The relationship between pore pressure and axial strain of undisturbed clay in normally consolidated state can be expressed as a hyperbolic function like stress-strain relation proposed by Kondner. 3. In the pore pressure-axial strain relation of disturbed clay in normally consolidated state, failure ratio R'f is greatly deviated in the range of 0.7~0.9 proposed by Christian and Desai. 4. For overconsolided clay, when overconsolidation ratio (OCR) is increased, normalized maximum deviator stress is increased and maximum pore pressure is decreased gradually. 5. Cohesion of overconsolidated clay is greater than that of nomally consolidated clay and internal friction angle slightly is decreased. 6. Pore pressure parameter at failure (Af) of overconsolidated clay is varied with OCR, Af becomes negative values with increment in OCR

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Development of a Vent Analysis Method for Multiple Compartments Connected Through Multiple Ports (다중 Port로 연결된 다중 격실 Vent 해석 기법 개발)

  • Ok, Ho-Nam;Kim, In-Sun
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.547-550
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    • 2006
  • An analysis method is developed for the prediction of venting in multiple compartments which are connected in series or parallel through multiple ports. The existing method by the authors is modified to remove the limitation in number of ports and compartments, and the more general polytropic relation or solution of the additional energy equation replaces the previous isentropic relation allowing the prediction of pressure rise in addition to pressure drop. The accuracy of the method is verified by comparison with the results by NASA Flap code for the problem of pressure drop in a payload in the Space Shuttle cargo bay. It is expected that this method will be a useful tool in prediction of the pressure variation in a payload or payload capsule without mentioning the payload fairing itself.

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The Investigation on Results from Mass Health Examination of Partial Healthy Public Officials -First Health Examination Results- (일부 공무원을 대상으로 한 집단건강진단 결과 분석 -1차 결과를 중심으로-)

  • Sohn, Seok-Joon;Kim, Byong-Woo
    • Journal of agricultural medicine and community health
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    • v.18 no.1
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    • pp.65-75
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    • 1993
  • This study was conducted to compare the frequency and to find epidemiologic characteristics of the diseases by analyzing the results of routine first health examination for partial healthy public officials. The total number of the examined was 1.128(876 male, 252 female) The results were as follow; 1. The prevalence rate of suspicious disease was liver disease 5.9% hypertension 5.4%, hyperlipemic disease 3.8%, pulmonary tuberculosis 1.2% by order. 2. The mean systolic blood pressure and diastolic blood pressure showed increasing trend by age increasing. The mean of blood pressure in man was rather higher than that in woman. 3. The prevalence rate of suspicious borderline hypertension increased by aging. And the distribution of high cholesterol group and over than overweight group increased by aging. 4. In male, significant relation among age, systolic blood pressure, diastolic blood pressure, relative body weight was found. And significant relation between total cholesterol level and relative body weight was found. In female, age and relative body weight was related to systolic blood pressure, diastolic blood pressure and total cholesterol level. 5. According to the retrospective follow-up for those who had suspicious disease, correspondence rate of results was 5.2% in circulatory disease and 1.5% in liver disease.

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Studied on Garment Restraint(III) - Relation between Clothing Pressure and Muscular Activity of Foundation - (의복의 구속성에 관한 연구(III) - 화운데이션의 의복압과 근활동과의 관계를 중심으로 -)

  • Shim, Boo Ja;Choi, Seon Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.2
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    • pp.197-206
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    • 1993
  • We studied relation between the clothing pressure applied by foundations(waist nipper, girdle, body suit) on the waist of bodies and muscular activity, feeling of tightness. The main results were summerized as follows ; 1. Clothing pressure applied by foundations was high in order of girdle>waist nipper>body suit, also clothing pressure was higher back than front and side, sitting on the chair than standing posture, ventral flection than repose. Individual differences, even if size of body was equal, were shown in clothing pressure applied by foundations with subcutaneous fat's amount in measuring region. 2. The muscular activity of rectus abdominis than obliquus externus abdominis was more affected by foundations in all kinds of postures and motions. Amplitude of electromyogram was high sitting on the chair than standing posture, but there was little difference with motion variation. The wearing girdle strongly affected on the muscular activities of rectus abdominis and obliquus externus abdominis as compared with waist nipper and body suit. 3. The value for feeling of tightness by wearing waist nipper was higher than girdle and body suit. Also the case when sitting on the chair and ventral flection, the value for feeling of tightness was high. When the foundations were on the body, most tightened on the region of the body was anterior abdominal region.

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A Study on Relation of Job Stress, Heart Rate Variability, Blood Pressure and Lifestyle on White-Collar Workers (사무직 근로자들의 직무 스트레스, 심박 변이성, 혈압 및 생활 습관과의 관계)

  • Choi, Young-Sil
    • Korean Journal of Occupational Health Nursing
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    • v.17 no.2
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    • pp.250-259
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    • 2008
  • Purpose: The purpose of this study was to identify the relation of Job Stress, Heart Rate Variability, Blood Pressure and Lifestyle on White-Collar Workers. Method: Data were collected from August to December in 2007. HRV was measured using Freeze-Framer. WSRI and Lifestyle data were collected from the self-reported questionnaire. Result: 1) Total score of WSRI was 32.88, H score was 47.92, L score was 16.90, systolic blood pressure was 138.88mmHg, diastolic blood pressure was 81.20 mmHg. 2) WSRI correlated with L score of HRV, BP, smoking, drinking positively. WSRI correlated with H score, exercise times negatively. H correlated with exercise positively and had negative correlation with BP and L. Systolic pressure correlated with smoking and drinking positively. Conclusion: WSRI, HRV, BP and lifestyle are interrelated strongly and they need to be monitor continually. It is considered that education of health and intervention with HRV make white-collar workers concern more about their health and care.

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Salt Intake Behavior and Blood Pressure: the effect of taste sensitivity and preference (소금 섭취 행태와 혈압: 맛에 대한 민감도와 선호도의 영향)

  • Kim, Jin-Hee;Choi, Man-Kyu
    • Korean Journal of Human Ecology
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    • v.16 no.4
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    • pp.837-848
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    • 2007
  • The literature suggested that a small reduction in overall blood pressure can have a large effect on overall prevalence of hypertension, and therefore, the affect of taste preferences of the population on salt intake should be considered for long-term blood pressure intervention programs. The purpose of this study is to investigate the influence of salt taste preference and salt taste sensitivity on salt intake behavior as risk factors for high blood pressure. We collected information on blood pressure, diet and lifestyle behaviors, salt taste preference and salt taste sensitivity from 540 respondents from Suseo-dong, Seoul. Salt taste sensitivity was assessed by administering a 1% NaCl solution to the subject's tongue and measuring the perceived intensity on 10 level scale. Salt intake behavior was classified into 3 categories: frequency of high-sodium foods, practice of salt-reducing behavior and frequency of vegetable and fruit intake. Salt taste preference showed a significant relation to the subjects' blood pressure, i.e. subjects with a higher salt preference had higher blood pressure. Salt taste sensitivity did not show a significant relation to blood pressure. However, there was a positive correlation between salt taste preference and salt taste sensitivity. Among the 3 indicators used to measure salt intake behavior, the practice of salt-reducing behavior remained significantly correlated to blood pressure. Moreover, salt-reducing behavior and salt taste preference showed a significant correlation, i.e. people who do not like salty foods tend to practice more salt-reducing behavior, leading to reduced levels in blood pressure. In a population, a small reduction in overall blood pressure can have large effects in overall prevalence of hypertension, in contrast to clinical studies where achievement of an individual's normal blood pressure is emphasized. Therefore, taste preference of the population should be considered for long-term blood pressure intervention programs.

Thermodynamic Analysis of the Hammett Reaction Parameter and Free Energy Relationship for the Pressure Change

  • Hwang, Jung-Ui
    • Bulletin of the Korean Chemical Society
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    • v.8 no.4
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    • pp.237-242
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    • 1987
  • Pressure dependance of Hammett reaction parameter was analyzed and the free energy relationship for the pressure change derived thermodynamically. There are insufficient data in the literature to test the relation derived but from some limited previous data it could be concluded that the parameter ${\rho}$ is dependent on pressure and increase or decrease as pressure increase for a given reaction series.

Combustion Characteristics of High Pressure Gas Generator for Liquid Rocket Engine (액체로켓엔진용 가스발생기의 고압연소특성)

  • Han Yeoung-Min;Lee Kwang-Jin;Moon Il-Yoon;Seo Seong-Hyeon;Choi Hwan-Seok;Lee Soo-Yong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2005.11a
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    • pp.341-345
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    • 2005
  • This paper is for the combustion characteristics of gas generator which drive 1.5MW-class turbo pump and runs in fuel-rich combustion regime with LOx/kerosene as propellant. The outline of development procedure of real scale high pressure gas generator is introduced and the relation between O/F ratio and outlet temperature and the molecular weight and specific heat ratio of combustion gas are described. The relation between O/F ratio and temperature is newly obtained at higher pressure and the molecular weight and specific heat ratio is modified and their validity is confirmed by the mass relation equation.

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Influence of User-Motivation on User-Commitment in Social Media: Moderating Effects of Social Pressure (소셜미디어 이용 동기가 이용자 몰입에 미치는 영향: 사회적 압력의 조절효과)

  • Bae, Jee-Woo;Park, Cheong-Yeul
    • The Journal of the Korea Contents Association
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    • v.15 no.1
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    • pp.462-474
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    • 2015
  • This article is aimed to investigate the role of social pressure in the influential relationship of user motivation on user commitment in social media. On this purpose, user motivation in social media was divided into 3 sub-dimensions as social motivation, functional motivation and hedonic motivation and social pressure was also categorized into informational isolation pressure and conformity pressure and then it was explored that how the social pressure makes differential effects in the relationship of each dimensions of user motivation and user commitment. Major findings are as follows. First, user's social motivation and hedonic motivation in social media had significant positive influence on user commitment. Second, the informational isolation pressure showed moderating effect in the relation of functional motivation and commitment. Third, conformity pressure displayed moderating effect in the relation of social motivation and commitment. This article suggests empirical supports about the role of social pressure in the phenomena of social media use and commitment, but requires to explore more specific factors and multi-dimensional studies in regard of social pressure in social media.

Cycle Resolved NO Emissions and Its Relation with Combustion Chamber Pressure in an S.I. Engine with Fast Response NO Analyzer

  • Sung, Jung-Min;Kim, Hyun-Woo;Lee, Kyung-Hwan
    • Journal of Mechanical Science and Technology
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    • v.17 no.10
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    • pp.1563-1571
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    • 2003
  • A fast response NO analyzer was applied to investigate the relation between cycle-by-cycle NO emissions and combustion chamber pressure. NO emissions were sampled at an isolated exhaust manifold of 4-stroke spark ignition engine to avoid the interference of exhaust gas from other cylinders. The linear correlation analysis was performed with collected data of NO emissions and combustion chamber pressure with respect to the various air-fuel mixture ratios and engine loads. The sampled data sets were obtained during 200 cycles at each operating condition. The results showed that there was a typical pattern in NO emissions from an exhaust port through a cycle. It was possible to set a block of crank angle in which the linear correlation coefficient between NO emissions and combustion chamber pressure was high. As the engine load increased, NO emissions were more dependent on combustion chamber pressure after TDC. It was also analyzed that the correlation between two parameters with respect to air-fuel mixture ratio tended to increase as mixture went leaner. Furthermore, this correlation coefficient for the mixture near the lean limit seemed to be kept high even though combustion was unstable.