• Progress in Medical Physics
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• v.17 no.1
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• pp.6-16
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• 2006

The goal of this study was to develop new indices for effectively evaluating the dose coverage and homogeneity based on the target-volume dose-volume histogram (TV-DVH) of intensity-modulated radio-therapy treatment plans. A new coverage Index and a new homogeneity index were developed by integrating a modified TV-DVH and by fitting a TV-DVH with a modified step function, respectively. The coverage index, named the l-index, indicates whether the dose coverage for the target volume is adequate based on user-defined criteria. A lower l-index indicates higher dose coverage of the tumor volume. The index for assessing dose homogeneity in a target volume, named the n-index, is more accurate than the conventional method in evaluating the dose homogeneity in a tumor volume. The baseline treatment plan for a target volume coverage and homogeneity is discussed. The proposed simple indices have been demonstrated to be effective in evaluating the dose coverage and homogeneity for TV-DVHs.

• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.310-319
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• 2006

The objective of study was to evaluate ecological health from seven sampling locations of Yoogu Stream, one of the tributaries of Guem River, July and September 2005. The research approach was based on the Index of Biological Integrity (IBI) using fish assemblage and Qualitative Habitat Evaluation Index (QHEI) using fish assemblage. The models of IBI and QHEI were modified as 10 metric model and 11 metric model, respectively, for the regional applications. In Yoogu Stream, value of IBI were averaged 29.5 (n=7) which is judged as a 'fair condition'. The IBI model scores, at the site 3 and 7, were estimated as 23 and 24, indicating a 'poor${\sim}$fair condition' while, site 5 was estimated as 28, 'fair condition'. The remaining sites were between 31 and 34, indicating 'fair${\sim}$good condition'. According to the analysis of QHEI, the average was estimated as 136, 'fair${\sim}$good condition'. Spatial variation the QHEI were evident; site 1 and site 4 were 186 and 120 respectively, indicating an 'excellent and fair${\sim}$good conditions'. Site 3 was 69, fair condition while the other sites were 128${\sim}$156, good condition.

• Geophysics and Geophysical Exploration
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• v.18 no.3
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• pp.125-132
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• 2015

The water saturation ($S_w$), which is very important to estimate hydrocarbon reserves in the reservoir, has been determined from resistivity index (RI) by using the Archie's formula. However, in many cases, it has been reported that n is not constant for a given formation and it could be varied with water saturation. In addition, it frequently happens that the line obtained by linear regression analysis on log-log scale does not pass through the origin. In order to overcome these drawbacks, we suggested a modified Archie's formula, which can handle almost all the RI vs. $S_w$ cross-plots whether the trend is straight or curved and whether it passes through the origin or not. We also demonstrated that how to determine conductivity exponent ${\mu}$, critical water saturation $S_c$, and saturation distribution factor b in the laboratory to use the modified Archie's formula. Since the modified Archie's formula takes into account pore structure, pore water distribution, and wettability of reservoir such as clean sandstone and carbonate rocks, it might improve field applicability.

• Explosives and Blasting
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• v.22 no.2
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• pp.33-43
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• 2004

The six grades weathering system is normally used in weathered rock classification. In this study. fresh and weathered rock block of grade I to V were sampled in Jang-soo ana but samples of the grade VI was omitted from this study. The variation quantities of chemical weathering indices with weathering degree are smaller than those of physical and mechanical properties. Increase of Weathering degree is well indicated by physical and mechanical properties such as strength, hardness, ultrasonic velocity and slake durability result. Especially, absorption and porosity ratio is a good indicator. As weathering proceeds. a number of the cracks affect the rock deformation. Therefore, stress-strain curves of weathered rocks in unconfined state are quite different from ones of fresh rocks.

• Progress in Medical Physics
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• v.7 no.1
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• pp.25-35
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• 1996

Optical measurements of turbid biological tissue have provided a means to study tissue metabolism, tissue blood perfusion and blood oxygenation non-invasively. We used the red light of 660nm and infrared of 880nm to measure the blood fractional volume and oxygen saturation of biological tissue. In vivo reflectance data were obtained the physiological change from the deep tissue in human subject. The data evaluation was assessed by examining the slopes of the plotter index for the changes in oxygen saturation and blood fraction volume. The index is the natural logarithm of the ratio of reflected light intensity from measured medium to reference intensity at each wavelength. According to the experimental results, oxygen index changes significantly in the muscle of calf during exercise.

• Ecology and Resilient Infrastructure
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• v.4 no.2
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• pp.105-114
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• 2017

This study performed physical habitat simulation for fish and macroinvertebrate species in the Gongneung River. Target fishes were selected as Rhinogobius brunneus and Zacco platypus. Target macroinvertebrate species were selected as Hydropsyche kozhantschikovi and Chironomidae. Habitat suitability curves were constructed by using monitoring data from the monitoring project which is called "the survey and evaluation of aquatic ecosystem health". For calculation of CSI, weighted mean method was used. For macroinvertebrates species, the weighting factor derived from analytic hierarchy method was considered. River2D, which is capable to simulate flow in two-dimensional space, was selected for flow computation. Composite suitability index was simulated for target fish and macroinvertebrate species for discharge of drought, low, normal, and averaged-wet flow. Simulation results show that Chironomidae and Hydropsyche kozhantschikovi prefer the pool and riffle habitat, respectively. Rhinogobius brunneus and Zacco platypus show high suitability in riffle habitat.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.419-419
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• 2018

기후변화로 인한 홍수피해의 빈도와 규모가 증가함에 따라 미래 홍수취약성은 갈수록 증가할 것으로 전망된다. 이를 대비하기 위해서는 지역별 기후변화를 고려한 홍수취약성 평가를 통해 적절한 적응 정책을 수립하여야 한다. 본 연구에서는 지역별 홍수취약성을 평가하기 위해 홍수취약성지수(Flood Vulnerability Index, FVI)를 새롭게 선정하였다. FVI는 3가지 구성요소의 결합으로 산정되며, 피해의 원인이 되는 압력지수(Pressure Index), 물리적 피해 현황을 나타내는 현상지수(State Index), 대응할 수 있는 능력인 대책지수(Response Index)의 함수로 나타낸다. 압력지수는 기후, 유역, 사회특성에 따라 세부지표를 구분하였고, 현상지수는 홍수피해 비율, 대책지수는 기술 및 사회적 특성을 기준으로 하였다. 따라서, 압력지수 및 현상지수가 클수록 홍수피해에 취약함을 나타내고, 대책지수가 클수록 취약성이 저감되게 된다. 연구 대상 지역은 최근 집중호우로 인해 많은 홍수피해가 발생한 금강유역을 선정하였고, 과거 홍수 피해액 자료를 사용하여 선정된 지수의 적용성을 검토하였다. 또한, 기후변화를 고려하기 위해 27개의 GCMs (Global Climate Models) 중 홍수를 가장 잘 설명하는 5개의 대표시나리오와 2개의 배출시나리오(RCP4.5, RCP8.5)를 사용하였으며, 과거(2010년대) 및 2030년대, 2050년대, 2080년대의 홍수취약성지수를 산정하여 결과를 분석하였다. Spearmans's rank correlation coefficient를 사용하여 과거 10년간 실제 홍수 피해액의 평균값과 FVI를 비교한 결과 선정된 지수가 홍수피해를 적절히 설명하는 것으로 나타났다. 대표시나리오를 사용한 미래 홍수취약성 분석 결과, 용담댐 유역에서 홍수취약성이 증가하는 것으로 나타났으며 지역별 상대적 취약성전망 결과는 대부분 과거와 비슷하였다.

• Physical Therapy Korea
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• v.8 no.4
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• pp.63-69
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• 2001

이 연구는 성인 편마비 환자를 대상으로 PLS (Posterior Leaf Spring) 착용이 기립 균형에 미치는 영향을 알아보는 것이었다. 신발만 착용하였을 때의 기립조건과 신발과 PLS를 동시에 착용한 기립조건의 평균평형지수가 맨발로 서 있을 때의 기립조건에 비하여 높았다. 그러나 신발만 착용한 기립조건과 신발과 PLS를 함께 착용한 기립조건하에서의 평균평형지수의 차이는 없었다. 따라서 편마비 환자의 기립균형과 관련하여 PLS만을 착용한 효과와 신발만을 착용한 효과를 비교하는 연구가 필요하다.

• Journal of Industrial Technology
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• v.34
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• pp.53-59
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• 2014

The single regression method was used to analyze the correlationship between the compression index with mechanical properties for reclaimed marine clays in the southern coast of Korea. As results of performing regression analysis for 200 samples about reclaimed marine clays in the southern coast of Korea, linear regression lines between compression index and natural water content, void ratio in situ, and liquid limit respectively wer obtained. The changed properties of soil due to disturbance during dredging and reclaiming could be investigated by comparing with the existing empirical correlation equations for the original ground where dredging was performed. These regression equations might be rationally used in the preliminary evaluation of settlement of dredged and reclaimed marine clayey ground in the southern coast of Korea.

• KIEAE Journal
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• v.8 no.1
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• pp.31-36
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• 2008

For the comfortable housing life, comfortable and pleasant urban environment should be created for the people living in house and in city. There are lots of environmental conditions in city affecting house and life. Also most of all the noise pollution have been become major factor that makes people's life uncomfortable. Recently soundscape researches have been performed to create comfortable urban environment and various studies on the evaluation of urban environmental sounds are now undergoing. This study aimed to analyse the subjective characteristics through the subjective evaluation to the sounds measured with physical parameters and eventually to find out alternative evaluation method for urban environmental sounds. Adjectives applied to previous studies were used for the subjective evaluation and sound sources recorded in specific places were presented with picture at the same time. As a result, new physical parameters such as Lmax, Unbiased Annoyance, G, N and EmT have a feasibility to evaluation of urban environment sounds in terms of acoustic comfort.