• 한국재료학회지
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• 제29권5호
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• pp.336-341
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• 2019

The gas adsorption isotherm requires accurate measurement for the analysis of porous materials and is used as an index of surface area, pore distribution, and adsorption amount of gas. Basically, adsorption isotherms of porous materials are measured conventionally at 77K and 87K using liquid nitrogen and liquid argon. The cold volume calibration in this conventional method is done simply by splitting a sample cell into two zones (cold and warm volumes) by controlling the level sensor in a Dewar filled with liquid nitrogen or argon. As a result, BET measurement for textural properties is mainly limited to liquefied gases (i.e. $N_2$ or Ar) at atmospheric pressure. In order to independently investigate other gases (e.g. hydrogen isotopes) at cryogenic temperature, a novel temperature control system in the sample cell is required, and consequently cold volume calibration at various temperatures becomes more important. In this study, a cryocooler system is installed in a commercially available BET device to control the sample cell temperature, and the automated cold volume calibration method of temperature variation is introduced. This developed calibration method presents a reliable and reproducible method of cryogenic measurement for hydrogen isotope separation in porous materials, and also provides large flexibility for evaluating various other gases at various temperature.

• 한국조경학회지
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• 제25권3호
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• pp.56-65
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• 1997

This research was conducted to suggest some directions for desirable urban green space planning through 1) establishing a new classification system by examining the existing concept, problems and characteristics of green space and 2) defining the essence of green space environment and finding some analytical and evaluative methods through a clear establishment of functions, indicators of green space. In the research, measurements of the amount of green space was accompanied with measurements of green covered space, green volume, and the structure of greenery within the frame of vision. As result, three-dimensional measurement was possible, three-dimensional measurement was possible, which turned out to be more effective than the existing 2-dimensional measuring method. It is found that the ratio of green covered space is to proportional to the ratio of green volume in this study. Therefore in green space planning process it is desirable to consider the ratio of green volume all together.

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

• International Journal of Automotive Technology
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• 제7권2호
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• pp.173-177
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• 2006

A noise transfer function(NTF) is the frequency response function between an input force applied to an exterior point of a vehicle body and the resultant interior sound pressure usually measured at the driver's ear position. It represents the measure of noise sensitivity for the output force transmitted to the joints between the body and chassis. The principle of vibro-acoustic reciprocity is often utilized in the measurement of NTF. One difficulty in using the volume source is that most of the previously proposed methods require the knowledge of the volume velocity of the acoustic source in advance. A new method proposed in the present work does not require any calculation related with the volume velocity of the acoustic source, but still yields even more accurate results both in the amplitude and phase of the NTF. In the present work, the new method is applied to obtain NTF data for a midsize sedan.

• Bulletin of the Korean Chemical Society
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• 제8권3호
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• pp.150-155
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• 1987

A new method of measurement of pore volume distribution in a porous material by adsorption of gases is proposed. In the newly proposed method the use of spherical molecules with relatively large molecular weight as adsorbates is strongly recommended to eliminate the troubles caused by stereospecificity and low boiling point of widely used $N_2$. It is also claimed that the universal t-curves that have been widely used since proposed by de Boer et al. must be replaced by the flat-surface isotherms that can be derived from the theory proposed by Chang et al. The results of analysis of pore volume distribution based on the method described in this paper are found to be reasonable and satisfactory.

• 대한의용생체공학회:의공학회지
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• 제37권1호
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• pp.31-38
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• 2016

For the patients with bladder dysfunction, measurement of urine volume inside the bladder is very critical to avoid bladder failure. In measuring urine volume inside a bladder, low-resolution 3D ultrasound images are widely used. However, urine volume estimation from 3D ultrasound images is prone to big errors and inconsistency because of low spatial resolution and low signal-to-noise ratio of ultrasound images. We developed a new robust volume estimation algorithm which is not computationally expensive. We tested the algorithm on a lab-built ultrasound bladder phantom and volunteers. The average error rate of the human bladder volume estimation was 5.9% which was better than the commercial machine.

• 한국진공학회지
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• 제20권5호
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• pp.313-321
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• 2011

한국표준과학연구원(Korea Research Institute of Standards and Science, KRISS)에는 초음파간섭 수은주압력계(ultrasonic interferometer manometer, UIM), 정적형표준기(static volume expansion system, SVES), 오리피스형 정압표준기(orifice-type dynamic expansion system, ODES) 등 세 개의 주요한 국가 진공표준기가 있다. 이 장치들의 불확도 평가를 위해 각각 변수들의 측정 및 계산 모델을 개발하였다. 국제표준화기구(International Organization for Standardization, ISO) 지침에 따라 표준기들의 확장불확도(expanded uncertainty, U)를 계산하였다.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.2154-2161
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• 2014

Growth analysis and selection of sea cucumbers (Stichopus japonicas) is typically performed through length or weight measurements. However, because sea cucumbers continuously change shape depending on the external environment, weight measurement has been the preferred approach. Weight measurements require extensive time and labor, moreover it is often difficult to accurately weigh sea cucumbers because of their wet surface. The present study measured sea cucumber features, including the body length, width, and thickness, by using a vision system and regression analysis to generate $R^2$ values that were used to develop a weight estimation algorithm. The $R^2$ value between the actual volume and weight of the sea cucumbers was 0.999, which was relatively high. Evaluation of the performance of this algorithm using cross-validation showed that the root mean square error and worst-case prediction error were 1.434 g and ${\pm}5.879g$, respectively. In addition, the present study confirmed that the proposed weight estimation algorithm and single slide rail device for weight measurement can measure weights at approximately 4,500 sea cucumbers per hour.

• 대한핵의학회지
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• 제21권1호
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• pp.33-37
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• 1987

Attenuated end-diastolic and end-systolic left ventricular counts which obtained from cardiac gated blood pool scan were corrected using experimentally calculated attenuation coefficient $(\mu=0.13/cm)$ and depth of center of left ventricle. This method was confirmed to be correct experimentally using phantom balloon. To compare the accuracy of attenuated and attenuation-corrected left ventricular volume measurement, authors studied 10 patients with ischemic heart disease who underwent both gated blood pool scan and X-ray contrast ventriculography within a week. The attenuated and attenuation-corrected left ventricular volume measured by count method correlated with contrast ventriculographic volumes; however, attenuation corrected measurement was correlated more closely.

• Journal of International Society for Simulation Surgery
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• 제1권2호
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• pp.71-74
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• 2014

Purpose The prominent mandible angle, otherwise known as "square face", has been recognized as an aesthetic problem that needs correction by many in the Asian community. Many surgeons considered that mandible angle ostectomy alone, brings about hypotrophy of the masseter muscle. However, it was only proven indirectly (by clinical experience and histological animal experiments) and not objectively. In this study, we evaluated the volume of masseter muscle to prove the effect, objectively. Materials and method Computed tomography (CT) images were used to measure the masseter muscle volume of normal female group (n=6), and of female patient group n=8, preoperative and early & late postoperative volumes) presenting the symptom of prominent mandible angle. The data was analyzed statistically by two-sample t-test and paired t-test using SAS (version 8.2). Results In normal female group, volume average was $16,142{\pm}2,829.8mm^3$. In patient group, preoperative volume averaged $24,447{\pm}4,544.5mm^3$ (p<0.0001), early postoperative volume measured average of $31,966{\pm}50,421mm^3$ which is a 30% increase from the preoperative volume (p<0.0001). Late postoperative measurement was $20,202{\pm}4,092.3mm^3$, which is a 20% decrease from the preoperative volume (p<0.0006). Conclusion The bone reduction of prominent mandible angle induce the hypotrophic effect of masseter muscle after long term follow up (5 more months). This result mean that the result of mandible angle contouring surgery can be considered as combined effect of bony angle reduction and subsequent masseter muscle hypotrophy.