• Journal of Korean Vacuum Science & Technology
• /
• 제6권3호
• /
• pp.109-115
• /
• 2002

This paper describes a CCM key comparison of low absolute-pressure standards at seven National Measurement Institutes that was carried out during the period March 1998 to September 1999 in order to determine their degrees of equivalence at pressures in the range 1 Pa to 1000 Pa. The Korea Research Institutes of Standards and Science(KRISS) participated from 10 Pa to 1000 Pa pressure range in 1999. The primary standards, which represent two principal measurement methods, included five liquid-column manometers and four static expansion systems. The transfer standard package consisted of four high-precision pressure transducers, two capacitance diaphragm gauges to provide high resolution at low pressures, and two resonant silicon gauges to provide the required calibration stability.

• 제어로봇시스템학회논문지
• /
• 제15권3호
• /
• pp.273-279
• /
• 2009

In this paper, we address the problem of detecting incorrect sonar measurements. We use ideas from the inconsistency of information among sonar measurements together with the sound pressure of the wave from the sonar sensor to develop a new method, called the comparison of the sound pressure (CSP), to detect incorrect sonar readings. The inconsistency of information in cells can be a clue that indicates candidates for incorrect measurements, and the sound pressure of the wave from the sonar sensor determines incorrect readings among the candidates. From various experiments, the proposed method is confirmed that it is better than existing method at deciding the state of sonar measurements.

• 제어로봇시스템학회논문지
• /
• 제9권9호
• /
• pp.707-713
• /
• 2003

We investigate the ultrasonic gas flow meter for the measurement of gas volume quantity, which passing through pipe, using the transit time difference method. We have designed a receiving system of an ultrasonic signal and hardware system of a flow meter Also, we have designed an experimental system for the characteristic test and calibration of a gas flow meter system. We have developed an ultrasonic gas flow meter, which has a measurement uncertainty within $\pm$ 1.7 %. For the test, we have compared our system with a difference pressure type flow meter for a few months in the real field. Through the test, we have confirmed that our system have a good reliability and durability. Also, we have confirmed that our system follows very well the variation of gas volume quantity, which was measured by a difference pressure type flow meter.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2011년도 춘계학술대회 논문집
• /
• pp.588-593
• /
• 2011

The Main design parameters of ship HVAC systems are pressure drop and noise analysis of ducts. The Noise prediction for HVAC(Heating, Ventilating and Air Conditioning) systems are normally performed by empirical method suggested by NEBB(National Environmental Balancing Bureau, 1994), but NEBB's method is not suitable for the ship HVAC systems. In this paper, numerical analysis methods are used to develop a noise prediction method for the ship HVAC systems, especially for large ducts. To develop regression formula of attenuation of sound pressure level in large duct, Boundary Element Method(BEM) is used. Using dynamic loss coefficient which is suggested by ASHRAE fitting data base and numerical methods of HVAC noise analysis, integrated HVAC noise analysis of Program is developed. The developed program can present pressure drop and noise analysis of the ship HVAC systems. To verify the accuracy and convenience of the developed program, prediction of HVAC system for Semi-Submersible Drilling RIG is carried out and the results are compared with measurement of noise level during sea trial.

• 상하수도학회지
• /
• 제37권6호
• /
• pp.437-446
• /
• 2023

We propose a transient evaluation scheme using a pressure measurement in a complicate pipeline systems. Conservation of mass and momentum equations in time domain can be transformed into a pressure head and flowrate relationship between upstream and downstream point in frequency domain. The impedance formulations were derived to address measured pressure at downstream to evaluate of flowrate or pressure head at any point of system. Both branched pipeline element and looped pipeline element can be generally addressed in the platform of the basic reservoir pipeline valve system. The convolution of time domain response function with measured pressure head from a downstream point provides flowrate or pressure head response in any point of the designated pipeline system. The proposed method was validated through comparison between traditional method of characteristics and the proposed method in several hypothetical systems.

• 한국유체기계학회 논문집
• /
• 제3권3호
• /
• pp.25-30
• /
• 2000

Thermodynamic method of pump performance measurement calculates pump efficiency and flowrate by measuring fluid temperature increase and pressure rise through the pump. The theory of this method is investigated and precise comparison experiment with classical hydraulic method was conducted to verify the accuracy. Classical hydraulic pump performance measurement results and Yatesmeter results based on the thermodynamic method showed good agreement in measured performance.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권12호
• /
• pp.1099-1110
• /
• 2020

This research tests the effects of institutional pressures, the use of performance measurement systems and accountability, and moderation effects of human resource capability between institutional pressures and the use of performance measurement systems in the Local Government institutions in Indonesia. The research aims to provide empirical evidence both quantitatively and qualitatively that isomorphism institutional pressures occurred in the scope of implementation of the performance measurement system and accountability in the public sector organizations and to show the importance of human resource capability enhancement in reducing external pressure impact. In addition, it tries to develop the correlation model of institutional pressures, human resource capability, implementation of the performance measurement system, and accountability of public sector organizations. The research used mixed methods with sequential explanatory design. The data collection used surveys and interviews in 209 regency/Special Region of Yogyakarta and Central Java local governments as samples. The research result indicated that the institutionalization process of the performance measurement is influenced by institutional pressures, especially coercive and mimetic pressures. Human resource capability was unable to weaken institutional pressures effects in the performance measurement system implementation. The research also proved that the use of a performance measurement system was able to improve local government institution accountability.

• 정보저장시스템학회논문집
• /
• 제8권1호
• /
• pp.16-21
• /
• 2012

SAW device is widely used as filters, sensors, actuators in various technologies. And capacitive sensor is tremendously used to measure pressure, gap, etc. The application of SAW device as signal conditioner of capacitive sensor reduces noise level and enables high precision measurement. The response increase of SAW based capacitive sensor is produced just before the two capacitive electrode contacts by the existence of parasitic resistance of capacitive electrode. In this paper, we analyze the effects of parasitic resistance and propose the calibrating method using lumped component and execute the high precision gap measurement using calibrated system. And xx nm resolution and yy ${\mu}m$ stroke was attained.

• 한국전문물리치료학회지
• /
• 제8권3호
• /
• pp.35-41
• /
• 2001

In-shoe measurement systems allow the clinician and researcher to examine the pressure parameters within the shoe. The purpose of this study was to investigate the test-retest reliability of plantar pressures using the Parotec system over speeds and plantar regions. Seventeen healthy subjects were recruited for the study. Sampling rate was 100 Hz, and data of six variables (pressure on medial heel, lateral heel, 1st metatarsal head, 5th metatarsal head, and great toe and total impulse) were collected in four different gait speed (1.0 m/sec, 1.5 m/sec, 2.0 m/sec, and comfortable walking speed) in each day. The result indicates fair to excellent reliability between the two day test. Intraclass correlation coefficients (ICCs) ranged from .693 to .979, and range of reliability was similar depending on the speed and plantar region. In most cases, data recorded by the Parotec systems provide good evidence for the reliability.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1030-1033
• /
• 2003

The packing-free piston has become widely distributed in certain branches of instrument making and precision machine building. A large number of the most diversified instruments are now being constructed on the principle of the packing-free piston like piston manometers, vacuum manometers, hydraulic machines, dynamometers. hardness measuring instruments. power indicators, hydraulic scales, and many others. In spite of the widespread application of systems with a packing-free piston, there were practically no special papers to the theory and practice of the application of such systems. This paper describes the theoretical approaching method to get the pressure distribution profile between the piston and cylinder using finite element method.