• Title/Summary/Keyword: Pressure estimation

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Study on Effect of Aromatherapy on Physiological and Psychological Aspect of Patients with Pain (향기요법이 통증환자의 생리적 및 심리적 측면에 미치는 효과)

  • Song, Min-Sun;Suh, Young-Sook;Choi, Chan-Hun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.4
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    • pp.748-754
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    • 2011
  • The purpose of this study was to investigate the effect of aromatherapy on pain level, blood pressure, pulse rate, sleep, anxiety and depression of patients with pain. This study used a non equivalent quasi-experimental design. Aromatherapy was the inhalation of blending oils with lavender, eucalyptus, peppermint for 3 weeks. As the estimation for the physiological aspect, the visual analogy scale (VAS) for the pain level, blood pressure and pulse rate were measured. Also, as the estimation for the psychological aspect, Sleep of Snyder-Halpern & Verra, anxiety of Spielbeger and depression of Beck were used. The data were analyzed by SAS program using $x^2$ test, Fisher's exact test, Cronbach ${\alpha}$ and t-test. The results of this study were as follows. Pain level(p=0.001), state anxiety(p=0.018), trait anxiety(p=0.002), and depression(p<0.001) improved significantly in the experimental group. Also, there was significant difference between the experimental group and the control group on the depression(p=0.012). Aromatherapy was effective in physiological and psychological therapy. Also it can be applied in combination with existing Oriental medical therapy.

Holding Mechanism of Anchor System for Fisheries Facilities (계류기초의 파주력 산정에 관한 연구)

  • Jung, Jin-Ho;Ryu, Cheong-Ro;Kim, Jong-Gyu
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.2
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    • pp.132-147
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    • 1996
  • The optimal design of floating type fisheries facilities in the open sea is demanded considering with the severe hydrodynamic forces on floating body, mooring tension and holding force of anchor. For conserving the facilities in most effective state, design and selection of anchor system is one of the most important fundamental subject. To enhance the design procedure of anchor system the holding forces of anchor are investigated by the hydraulic model test and are compared with the typical conventional results for various anchors. Applicability of previous estimation methods of holding force are checked and holding mechanism of anchor is discussed. Using the results a new computational concept of holding force is suggested considering mainly the effects of passive soil pressure (resistance), steady soil pressure, and surface friction etc. The new estimation method is proved as a feasible one by comparing the results of hydraulic model experiments. Applicability of various anchors to the anchor system on open sea fisheries structures is comprehensively reviewed using the present model tests and previous study results in the viewpoint of economy, construction and stability etc. Using the results, fundamental anchoring system design procedures are suggested to apply huge marine ranching complex with increase of the holding capacity of anchor under the optimum cost.

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Development of Propulsion Subsystem for KOMPSAST (다목적 실용위성의 추진시스템 개발)

  • 최진철;윤효철
    • Journal of the Korean Society of Propulsion Engineers
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    • v.2 no.3
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    • pp.80-89
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    • 1998
  • Propulsion subsystem transfers KOMPSAT into mission orbit and controls its attitude. Design factor consists of structure safety, electrical circuit design, consumable power estimation of thermal hardwares, damping device design of fuel transient pressure, and system configuration design by considering plume effect from thruster firing. System level analysis should be performed for verification of system design under launch vehicle and orbital environment. Electrical functional test of thermal control hardware, proof pressure test, cleanliness verification test, and internal/external leakage test of fuel feeding system should be carried out for performance estimation of propulsion system. Design and assembly process of propulsion subsystem was depicted and reliability of system was verified by test analysis in this paper.

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Reliability Estimation of Buried Gas Pipelines in terms of Various Types of Random Variable Distribution

  • Lee Ouk Sub;Kim Dong Hyeok
    • Journal of Mechanical Science and Technology
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    • v.19 no.6
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    • pp.1280-1289
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    • 2005
  • This paper presents the effects of corrosion environments of failure pressure model for buried pipelines on failure prediction by using a failure probability. The FORM (first order reliability method) is used in order to estimate the failure probability in the buried pipelines with corrosion defects. The effects of varying distribution types of random variables such as normal, lognormal and Weibull distributions on the failure probability of buried pipelines are systematically investigated. It is found that the failure probability for the MB31G model is larger than that for the B31G model. And the failure probability is estimated as the largest for the Weibull distribution and the smallest for the normal distribution. The effect of data scattering in corrosion environments on failure probability is also investigated and it is recognized that the scattering of wall thickness and yield strength of pipeline affects the failure probability significantly. The normalized margin is defined and estimated. Furthermore, the normalized margin is used to predict the failure probability using the fitting lines between failure probability and normalized margin.

A Study on the Estimation of Continuous Blood Pressure using PIT and Biometric Parameters

  • Park Eun-Kyoung;Cho Baek-Hwan;Park Sang-Hae;Lee Jong-Youn;Hwang Hwan-Sik;Park Hun-Ki;Lee Jong-Shill;Kim In-Young;Kim Sun-I
    • Journal of Biomedical Engineering Research
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    • v.27 no.1
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    • pp.1-5
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    • 2006
  • In this paper, we propose a subject-independent regression model to estimate systolic blood pressures (SBP) conveniently and continuously. There have been several researches on estimating SBP with pulse transit time (PTT) and they showed promising results. However, previous studies used only PTT as the estimation parameter, and their models were generated with just one person's PTT data which is not applicable to estimating other person's SBP. Therefore, we collected several additional biometric parameters with 202 healthy subjects. After statistical analysis of measured biometric parameters with SBP, we chose final estimating parameters including PTT to generate a multiple linear regression model for estimating SBP. Comparing the results of our study with approvable standards of automated sphygmomanometers developed by Association for the Advancement of Medical Instrumentation and approved by American National Standards Institute (ANSI/AAMI) indicates that our proposed method for continuously blood pressures monitoring gives an acceptable error.

Prediction and improvement of the solid particles transfer rate for the bulk handing system design of offshore drilling vessels

  • Ryu, Mincheol;Jeon, Dong Soo;Kim, Yooil
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.6
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    • pp.964-978
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    • 2015
  • Numerous experiments with a scaled pilot facility were carried out to compare the relative bulk transfer performance of three special devices for applications to drilling systems. The pipe diameter for bulk transportation was 3 in., which corresponds to around half of the actual system dimensions. Two different pressures, 3 and 4 bar, were considered to check the relative performance under different pressure conditions at a bulk storage tank. And to make a practical estimation method of the bulk transfer rate at the early design stages of the bulk handling system, a series of experiments were conducted for real scaled bulk handing systems of two drilling vessels. The pressure drops at each pipe element as well as the bulk transfer rates were measured under different operating conditions. Using the measured results, the friction factor for each pipe element was calculated and a procedure for transfer rate estimation was developed. Compared to the measured transfer rate results for other drilling vessels, the estimated transfer rates were within a maximum 15% error bound.

Development of a one-dimensional system code for the analysis of downward air-water two-phase flow in large vertical pipes

  • Donkoan Hwang;Soon Ho Kang;Nakjun Choi;HangJin Jo
    • Nuclear Engineering and Technology
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    • v.56 no.1
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    • pp.19-33
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    • 2024
  • In nuclear thermal-hydraulic system codes, most correlations used for vertical pipes, under downward two-phase flow, have been developed considering small pipes or pool systems. This suggests that there could be uncertainties in applying the correlations to accident scenarios involving large vertical pipes owing to the difference in the characteristics of two-phase flows, or flow conditions, between large and small pipes. In this study, we modified the Multi-dimensional Analysis of Reactor Safety KINS Standard (MARS-KS) code using correlations, such as the drift-flux model and two-phase multiplier, developed in a plant-scale air-inflow experiment conducted for a pipe of diameter 600 mm under downward two-phase flow. The results were then analyzed and compared with those based on previous correlations developed for small pipes and pool conditions. The modified code indicated a good estimation performance in two plant-scale experiments with large pipes. For the siphon-breaking experiment, the maximum errors in water flow for modified and original codes were 2.2% and 30.3%, respectively. For the air-inflow accident experiment, the original code could not predict the trend of frictional pressure gradient in two-phase flow as / increased, while the modified MARS-KS code showed a good estimation performance of the gradient with maximum error of 3.5%.

A Discussion on the Improvement of Pseudo-Static Seismic Design Criteria of Retaining Wall in Domestic (국내 옹벽의 유사정적 내진설계기준 개선방향에 대한 고찰)

  • Jo, Seong-Bae;Ha, Jeong Gon;Lee, Jin-Sun;Kim, Dong-Soo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.2
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    • pp.45-53
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    • 2015
  • This paper reviews the current seismic design code and research for dynamic earth pressure on retaining structures. Domestic design codes do not clearly define the estimation of dynamic earth pressure and give different comments for seismic coefficient, wall inertia and distribution of dynamic earth pressure using Mononobe-Okabe method. AASHTO has been revised reflecting current research and aims for effective seismic design. Various design codes are analyzed to compare their performance and economic efficiency. The results are used to make improvement of current domestic seismic design code. Further, it is concluded that the experimental investigation is also needed to verify and improve domestic seismic code for dynamic earth pressure.

Neutron Flux Evaluation on the Reactor Pressure Vessel by Using Neural Network (인공신경 회로망을 이용한 압력용기 중성자 조사취화 평가)

  • Yoo, Choon-Sung;Park, Jong-Ho
    • Journal of Radiation Protection and Research
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    • v.32 no.4
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    • pp.168-177
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    • 2007
  • A neural network model to evaluate the neutron exposure on the reactor pressure vessel inner diameter was developed. By using the three dimensional synthesis method described in Regulatory Guide 1.190, a simple linear equation to calculate the neutron spectrum on the reactor pressure vessel was constructed. This model can be used in a quick estimation of fast neutron flux which is the most important parameter in the assessment of embrittlement of reactor pressure vessel. This model also used in the selection of an optimum core loading pattern without the neutron transport calculation. The maximum relative error of this model was less than 3.4% compared to the transport calculation for the calculations from cycle 1 to cycle 23 of Kori unit 1.

An Engineering Method for Non-Linear Fracture Mechanics Analysis of Circumferential Through-Wall Cracked Pipes Under Internal Pressure (내압이 작용하는 원주방향 관통균열 배관의 비선형 파괴역학 해석법)

  • Huh, Nam-Su;Kim, Yun-Jae;Kim, Young-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.6
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    • pp.1099-1106
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    • 2002
  • This paper provides engineering J-integral and crack opening displacement (COD) estimation equations for circumferential through-wall cracked pipes under internal pressure and under combined internal pressure and bending. Based on selected 3-D finite element calculations for the circumferential through-wall cracked pipes under internal pressure using the idealized power law materials, the elastic and plastic influence functions for fully plastic J-integral and COD solutions are found as a function of the normalized crack length and the mean radius-to-thickness ratio. These developed GE/EPRI-type solutions are then re-formulated based on the enhanced reference stress method. Such re-formulation not only provides simpler equations for J-integral and COD estimations, but also can be easily extended to combined internal pressure and bending. The proposed equations are compared with elastic-plastic finite element results using actual stress-strain data, which shows overall excellent agreement.