• Geophysics and Geophysical Exploration
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• v.11 no.3
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• pp.263-270
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• 2008

The Gas Hydrate Research and Development Organization (KGHDO) of Korea accomplished successfully geophysical logging (LWD: Logging While Drilling, MWD: Measurement While Drilling) for five sites in 2007, in order to investigate the presence of gas hydrate in the Ulleung Basin, the East Sea of Korea. The togging parameters acquired from LWD/MWD dre electrical resistivity, acoustic velocity, neutron density and porosity, and natural gamma. In addition, pressure, temperature, and diameter of borehole were measured. LWD/MWD data showed several evidences indicating the presence of gas hydrate. Based on LWD/MWD data, three coring sites were selected for sampling of gas hydrate. Subsequently, various gas hydrate samples were collected directly from three sites. Therefore. the presence of gas hydrates was verified by coring. LWD/MWD data will be significantly used to estimate the amount of gas hydrate. Also, they will provide important information to elucidate about sedimentologic characteristics of gas-hydrate bearing formation and sedimentary environment of the Ulleung Basin.

• Polymer(Korea)
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• v.31 no.6
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• pp.532-537
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• 2007

The rheological properties of the solutions of atactic poly(vinyl alcohol)(PVA) in dimethyl sulfoxide (DMSO) were investigated in terms of molecular weight distribution (MWD) of the polymer. The dynamic viscosity (${\eta}#$) and loss modulus (G") for the PVA/DMSO solutions with broader MWD were lower than those with narrower MWD at the similar $M_w$. It could be explained by the fact that the free volume for the solution with broader MWD at the similar $M_w$ was increased. The storage modulus(G#) of 14 wt% PVA/DMSO solutions with broader MWD was higher than that with narrower MWD at a lower frequency than 1.3 rad/sec, but lower than that with narrower MWD at a higher frequency (>1.3 rad/sec). The slopes of modified Cole-Cole plots of the 14 wt% solutions showed that as the MWD was broadened, the phase transition with frequency was more noticeable.

• Tuberculosis and Respiratory Diseases
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• v.76 no.6
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• pp.269-275
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• 2014

Background: The six-minute walk test has been widely used in people with chronic cardiopulmonary disorders as an outcome assessment with regards to therapeutic or prognostic determinants. This study was undertaken to determine the six-minute walk distance (6MWD) in a sample of healthy Koreans and to create a reference equation. We also compared the 6MWD of our cohort with previously published equations. Methods: Two hundred fifty-nine healthy subjects (95 males) aged 22-59 years performed two walking tests using a standardized protocol. 6MWD was defined as the greatest distance achieved from the two tests. The effect of anthropometrics on the 6MWD was also investigated. Results: The average 6MWD was $598.5{\pm}57.92m$, with significantly longer distances by males ($628.9{\pm}59.51m$) than females ($580.9{\pm}47.80m$) (p<0.001). Age, height, weight, and body mass index were significantly correlated with 6MWD in univariate analysis. Stepwise multiple regression showed height to be single independent predictor of 6MWD ($r^2$=0.205, p<0.001). The reference equations derived in Caucasian and North African populations tend to overestimate the distance walked by Korean subjects, while Asian equations underestimate it. Conclusion: The average 6MWD in these Korean populations was 600 m. The regression equation revealed that individual's height was the most significant predictor of distance, explaining 20.5% of the distance variance.

• Journal of the Korean Wood Science and Technology
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• v.45 no.4
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• pp.471-481
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• 2017

As the molecular weight (MW) of urea-formaldehyde (UF) resins had a great impact on their properties, this work was conducted to study effect of analytical parameters of gel permeation chromatography (GPC) on the MW measurement of UF resins. GPC parameters such as flow rate, column, detector temperature, and sample injection temperature were selected to compare number-average molecular weight (Mn), weight-average molecular weight (Mw), molecular weight distribution (MWD) and polydispersity index (PDI) of two UF resins with different viscosities. As expected, UF resin with higher viscosity resulted in greater Mn and Mw than those of low viscosity UF resin. When the flow rate increased, both Mn and Mw of UF resins decreased and MWD became narrower. By contrast, both Mn and Mw increased and MWD became wide when the column, detector, and sample injection temperature increased. The column, detector, and sample injection temperature of $50^{\circ}C$ at a flow rate of $0.5m{\ell}/min$ resulted in the highest MW and broadest MWD for the GPC analysis. These results suggest that the apparent molecular size or a hydrodynamic radius of UF resin molecules dissolved in the mobile phase affect to Mn, Mw and MWD.

• Korean Journal of Remote Sensing
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• v.16 no.1
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• pp.87-98
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• 2000

Image merging techniques have been developed to integrate the advantage of different data type. The objective of this study is to present the optimal method for merging high spatial resolution panchromatic image, such as the latest commercial satellite data, and low spatial resolution mulitspectral images. For this study, a set of 2m resolution panchromatic and 8m resolution mulitspectral data were simulated by using airborne mulitspectral data. Five merging methods of MWD, IHS, PCA, HPF, and CN were applied to produce four bands of high spatial resolution mulitspectral data. Merging results were evaluated by visual interpretation, image statistics, semivariogram, and spectral characteristics. From the aspects of both spatial resolution and spectral information, the wavelet-based MWD merging method have shown very similar results compared with the original data used for the merging.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.311-316
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• 1997

무붕산 노심의 부하추종운전을 위하여 출력제어기법을 개발하였다. 무붕산 노심의 출력제어 논리는 출력 준위와 제어봉의 위치에 따라 제어군의 역할을 반응도 제어에 사용되는 제어군과 출력분포 제어에 사용되는 제어군으로 구분하여 8가지의 제어군 구동 형태를 가지며, ASI 편차를 입력으로 구동할 제어군이 결정된다. 무붕산 노심의 출력제어 논리를 적용하여 ONED94 코드로 일일 부하추종운전을 모사하였다. 모사 결과 주기초(0 MWD/MTU)와 주기중(7000 MWD/MTU)에는 ASI 편차 $\pm$10% 내에서 부하추종운전이 가능하며, 85% 주기말(11000 MWD/MTU)에서는 $\pm$12% 내에서 부하추종운전이 가능한 것으로 나타났다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.130-134
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• 2003

The quantity of solid waste produced during HANARO operation for the years from 1996 to 2002 has been investigated and the interrelation with the reactor power output has been analysed. The waste amount produced during this period was $69, 598{\ell}$ and the processing expense was 1, 878, 000 won. The waste amount and processing expense per reactor power output are $3.01{\ell}/MWD$ and 811 won/MWD, respectively. A dry equipment for the spent resin was developed and the spent resin volume has been reduced by about 40% by using it.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.135-140
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• 2003

The quantity of liquid waste produced during HANARO operation for the years from 1996 to 2002 has been investigated and the interrelation with the reactor power output has been analysed. The waste amount produced during this period was $263, 530{\ell}$ and the processing expense was 81, 690, 000 won. The waste amount and processing expense per reactor power output are $11.38{\ell}/MWD$ and 157 won/MWD, respectively. The waste has been reduced by improving repair work procedure and experiment process in the reactor hall.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.147.1-147.1
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• 2011

지식경제부 가스 하이드레이트 개발사업의 일환으로 동해 울릉분지 가스 하이드레이트 2차 시추(Ulleung Basin Gas Hydrate Drilling Expedition: UBGH2)가 2010년 7월 8일부터 9월 30일까지 D/V Fugro Synergy를 이용하여 수행되었다. UBGH2 수행을 위해 선정된 13개 site에서 약 1개월 동안 Schlumberger사의 장비를 이용 Logging-While-Drilling/Measurement-While-Drilling(LWD/MWD) 자료를 취득하였다. LWD/MWD 자료는 선상에서 분석되었으며, 이 결과는 coring 및 borehole plan 수립을 위하여 활용되었다. Coring Phase 동안 10개 site의 18개 hole로부터 퇴적물 코어 시료를 채취하고 선상에서 퇴적학, 지구화학, 생지화학, 물리적 특성 등 각종 분석과 측정 작업을 수행하였다. 약 2개월에 걸쳐 수행된 coring phase 동안에 2개 site에서 FAOL(Fugro Alluvial Offshore Limited)사의 장비를 이용 Wireline Logging/Vertical Seismic Profile(WL/VSP) 자료도 취득하였다. LWD/MWD phase와 coring phase 동안 12개 site에서 무인잠수정(remotely operated vehicle: ROV)를 이용하여 퇴적물 시료 채취, 해저면 관찰, 용존메탄 측정 등의 작업을 수행하였으며, 선상에서 취득된 이들 자료를 분석하였다. Coring을 수행한 모든 site에서 가스 하이드레이트 부존을 확인하였으며, 다양한 산상의 가스 하이드레이트 실물을 회수하고 분석하였다.

• The Journal of Korean Physical Therapy
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• v.29 no.5
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• pp.281-286
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• 2017

Purpose: The purpose of this study was to examine the correlations among the resting physical factors related to a six-minute walk test (6MWT) and to determine the effects of the resting physical factors on the distance and intensity related to the 6MWT in healthy female subjects. Methods: A total of 43 healthy female subjects ($22.84{\pm}3.90yrs$) participated in this study. They performed the 6MWT, and the physical factors related to the 6MWT were assessed. SPSS 20.0 was used to analyze the data, and the mean and standard deviation were calculated, and the collected data were analyzed by the Pearson's correlation coefficient (among physical factors related to 6MWT) and independent t-test (between six-minute walk distance [6MWD] groups and six-minute walk intensity [6MWI] groups). Results: The 6MWD had a significant negative correlation with the resting HR (beat/min) in healthy female subjects (r=-0.49, p<0.05). The 6MWI had a significant negative correlation with the resting systolic blood pressure (SBP) (r=-0.45, p<0.01). A comparison of the 6MWD revealed the long distance group (LDG, 700-799 m) to be significantly higher than the middle distance group (MDG, 600-699 m) in the 6MWI (%), %predicted distance (%), predicted VO2max (mL/kg/min), resting HR (beat/min), and resting SBP (mmHg)(p<0.05). In the comparison of 6MWI, the moderate intensity group (MIG, 64-75%HRmax) was significantly lower than the low intensity group (LIG, 50-63%HRmax) in the resting SBP (mmHg) (p<0.05). Conclusion: These results suggest that the resting physical factors are related to the 6MWD and 6MWI of the 6MWT in healthy females. In particular, SBP is associated with not only the 6MWD but also the 6MWI in 6MWT.