• 천문학논총
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• 제30권2호
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• pp.83-86
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• 2015

We present observational results characterizing molecular outflows from very low-mass objects in ${\rho}$ Ophiuchi and Taurus. Our results provide us with important implications that clarify the formation process of very low-mass objects.

• Physical Therapy Rehabilitation Science
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• 제10권1호
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• pp.64-68
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• 2021

Objective: In clinical practice, there are a lot of exercise to reduce body weight or reduce the amount of body fat in order to solve back pain. However, many studies have contradicted the relationship between back pain and weight or body fat mass. The purpose of this study was to investigate the relationship between fat mass, body mass index and low back pain of office worker. Design: Crossed-sectional study Methods: Among the white-collar workers diagnosed with non-specific back pain by doctors, subjects who were not included in the exclusion criteria were selected to measure the subject's body fat mass, body mass index, pain intensity, and disability index due to back pain. The NPRS was used for the intensity of back pain of office workers, and the ODI was used for the degree of disability due to back pain. A body composition analyzer was used to measure the body fat mass and body mass index of white-collar workers. Results: There was no significant difference between the two groups in the comparison between the normal group and the excessive group according to the criteria of fat mass and body mass index. In the correlation analysis of fat mass, body mass index, pain intensity, and disability index, it was found that there was a significant correlation between fat mass and body mass index. However, neither fat mass nor body mass index had a significant correlation with pain intensity and disability index. Conclusions: The fat mass and body mass index of office worker do not affect low back pain.

• Journal of Astronomy and Space Sciences
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• 제23권3호
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• pp.189-198
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• 2006

BVRI CCD 측광 관측에 의하여 질량비가 작은 접촉쌍성 HN UMa와 II UMa의 새로운 광도곡선을 얻었다. 새로운 광도곡선과 이미 발표된 분광관측으로부터 Wilson-Devinney 프로그램을 이용하여 이 두 별의 궤도요소와 절대 물리량을 얻었다. HN UMa와 II UMa를 포함한 절대물리량이 잘 알려진 21개의 질량비가 작은 접촉쌍성들의 진화 상태를 조사하였다. 그 결과 질랑비가 작은 접촉쌍성의 반성은 영년주계열 아래 놓이며, 이러한 현상은 질량이 작은 접촉쌍성의 반성에서의 질량손실을 가정할 경우, 비록 작의 양의 질량이지만 반성에서의 질량 감소는 상대적으로 광도의 감소가 현저히 작아지기 때문일 것으로 예상된다.

• Journal of Microbiology and Biotechnology
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• 제29권6호
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• pp.887-896
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• 2019

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based pathogen identification relies on the ribosomal protein spectra provided in the proprietary database. Although these mass spectra can discern various pathogens at species level, the spectra-based method still has limitations in identifying closely-related microbial species. In this study, to overcome the limits of the current MALDI-TOF MS identification method using ribosomal protein spectra, we applied MALDI-TOF MS of low-mass profiling to the identification of two genetically related Bacillus species, the food-borne pathogen Bacillus cereus, and the insect pathogen Bacillus thuringiensis. The mass spectra of small molecules from 17 type strains of two bacilli were compared to the morphological, biochemical, and genetic identification methods of pathogens. The specific mass peaks in the low-mass range (m/z 500-3,000) successfully identified various closely-related strains belonging to these two reference species. The intensity profiles of the MALDI-TOF mass spectra clearly revealed the differences between the two genetically-related species at strain level. We suggest that small molecules with low molecular weight, 714.2 and 906.5 m/z can be potential mass biomarkers used for reliable identification of B. cereus and B. thuringiensis.

• 융복합기술연구소 논문집
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• 제7권2호
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• pp.25-30
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• 2017

This paper presents the effects of a virtual mass with a low-pass filter on the stability boundary of a virtual spring in the haptic system. In general, a haptic system consists of a haptic device, a sampler, a virtual impedance model and zero-order-hold. The virtual impedance is modeled as a virtual spring and a virtual mass. However the high-frequency noise due to the sampling time and the quantization error of sampled data may be generated when an acceleration is measured to compute the inertia force of the virtual mass. So a low-pass filter is needed to prevent the unstable behavior due to the high-frequency noise. A finite impulse response (FIR) filter is added to the measurement process of the acceleration and the effects on the haptic stability are simulated. According to the virtual mass with the FIR filter and the sampling time, the stability boundary of the virtual spring is analyzed through the simulation. The maximum available stiffness to guarantee the stable behavior is reduced, but simulation results still show that the stability boundary of the haptic system with the virtual mass is larger than that of the haptic system without the virtual mass.

• 한국대기환경학회지
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• 제21권5호
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• pp.547-555
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• 2005

In this study, an analytical expression for aerosol mass transfer at spherical collector in the low Knudsen number region was obtained. Happel's zero shear stress cell model was extended in the low Knudsen number region and the result was compared with numerical solution results. The zero vorticity model based on the Kuwabara's cell model was also extended in the low Knudsen number region and compared with Happel's results. The results showed that both analytic and numerical solution agree very well with each other in low Knudsen number region. Happel's zero shear stress model also agrees with Kuwabara's zero vorticity model without significant loss of accuracy. The obtained solution converges to the original solution of Lee et al. (1999) when Knudsen number approaches to zero. Subsequently, this study derived most general type of analytic solution for aerosol mass transfer of spherical collector including the finite Knudsen number region.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.1889-1893
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• 2000

During the test drive of developing vehicle, a low frequency vibration of sprung mass on front outer wheel has been frequently observed in cornering with some speed. The purpose of this paper is to investigate the low frequency vibration of the sprung mass. The analysis result shows that the low frequency vibration is caused by sudden migration of the center of gravity of vihicle and it is determined by geometric points of suspension.

• Food Science and Biotechnology
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• 제14권5호
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• pp.667-671
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• 2005

The aim of this study is to investigate the effects of the muscle mass and fiber number on post-mortem metabolic rates and pork quality. Carcass traits, muscle fiber characteristics, and type of fiber composition were evaluated using a sample of 200 cross-bred pigs. The muscle mass was divided into two groups according to carcass weight and loin-eye area measurements (heavy or light). In addition, the muscle histological characteristics were divided into two groups according to the muscle fiber density and total number of muscle fibers (high or low). All the carcass traits were significantly different in the muscle mass groups. Increasing weight significantly affected the cross-sectional area (CSA) of all fibers. The low group, which had a low muscle fiber number indicating a larger CSA of fibers, and especially the heavy-low group had the highest CSA levels of fibers. The fiber number percentage and the area percentage were significantly different in the groups categorized by fiber number. The heavy-high group indicated a normal rate of pH decline and the R-value. In addition, pigs with a heavy muscle mass and high muscle fiber number indicated normal drip loss, lightness, and protein denaturation. The present results suggest that increasing the total muscle fiber number has a beneficial effect on increasing the muscle mass without deteriorating the meat quality.

• 한국초전도ㆍ저온공학회논문지
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• 제14권1호
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• pp.38-43
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• 2012

In the extreme conditions of launch vehicle in a space, such as cryogenic temperature and low-gravity environment, the mass gauging of remaining propellants becomes a difficult problem. Pressure-volume-temperature (PVT) method is one of the attractive mass gauging methods under low-gravity due to its simplicity and reliability. PVT gauging experiment with various mass flow rates of helium injection is carried out with the experimental apparatus creating cryogenic homogeneous condition as the condition of low-gravity. Experimental results are analyzed by a novel PVT gauging analysis method which considers all instantaneous changes of pressure and temperature in the ullage volume with small time intervals. It is observed that the gauging error from the novel PVT gauging analysis is -0.11% with 2 slpm mass flow rate of helium injection.

• Structural Engineering and Mechanics
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• 제88권3호
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• pp.209-220
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• 2023

This study investigates the effectiveness of tuned mass dampers (TMDs) in controlling vibrations in low-rise reinforced concrete buildings. It examines both linear and nonlinear behaviors of concrete structures subjected to strong ground motions from the PEER database. The research follows the ASCE 7-16 provisions to model structural nonlinearity. Additionally, the study explores the effect of varying TMD mass ratios on the performance of these systems in real-world conditions. The findings emphasize the importance of accounting for structural nonlinearity in low-rise buildings, highlighting its significant influence on the controlled response under severe seismic excitations. The study suggests including nonlinear analysis in seismic design practices and recommends customizing TMD designs to optimize vibration control. These recommendations have practical implications for enhancing the safety and effectiveness of seismic design practices for low-rise buildings.