• 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.

• The Korean Journal of Ecology
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• 제26권3호
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• pp.123-127
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• 2003

Cubic-meter volumes estimated from two proxy taper functions were compared to observed volumes of Japanese red cedar trees (Cryptomeria japonica D. Don) to evaluate accuracy and precision in the centroid method. Centroid volume estimates were also compared to volume estimates from existing whole-tree volume equations developed for another geographic region. This study found that one proxy function produced unbiased volume estimates while the other was biased. Volume estimates from the whole-tree equations were also biased. However, the volume estimates from the whole-tree equations were more precise than those from the centroid method. These results support previous studies that the centroid method can produce reliable volumes of trees when no other reliable volume equations exist.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.311-315
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• 1987

In this paper an efficient algorithm to estimate the volume and surface area and the reconstruction algorithm for 3-dimensional graphics are presented. The graph theory is used to estimate the optimal quantitative factors. To improve the computing efficiency, the algorithm to get proper contour points is performed by applying several tolerances. The search and the given arc cost is limited according to the change of curvature of the cross-sectional contour. For mathematical model, these algorithms for volume estimation based on polyhedral approximation are applied to the selected optimal surface. The results show that the values of the volume and surface area for tolerances 1.0005, 1.001 and 1.002 approximate to values for tolerances 1.000 resulting in small errors. The reconstructed three-dimensional images are sparse and consist of larger triangular tiles between two cross sections as tolerance is increasing.

• 대한토목학회논문집
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• 제28권2D호
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• pp.155-162
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• 2008

본 연구에서는 전체 시간대별 교통량을 관측하지 못하여 설계시간교통량을 구할 수 없는 지점에 대하여 설계시간계수를 추정하는 방법에 대하여 분석하였다. 수시조사는 연 1~5회 조사되며, 이러한 지점에서는 설계시간교통량을 구할 수 없어 설계시간계수를 구할 수 없다. 분석을 위하여 2006년 일반국도 상시조사 지점의 시간대별 교통량을 이용하여 분석하였다. 설계시간계수를 추정하기 위하여 시간대별 교통량의 변동을 반영하는 시간대별 교통량의 변동계수(Coefficient of Variance), 시간대별 교통량의 표준편차, 첨두시간교통량(peak hour volume)과 도로의 특성을 파악할 수 있는 중차량비율, 주야율, AADT와 중방향계수 등의 변수를 독립변수로 하여 각 변수들과 설계시간계수와의 상관분석 및 회귀분석을 이용하여 설계시간교통량을 추정하였다. 산점도를 통하여 독립변수와 종속변수의 관계를 분석한 결과 대부분의 변수들이 곡선의 형태를 띠는 것으로 나타나 선형회귀분석보다 곡선회귀분석이 더 적합한 것으로 나타났다. 곡선회귀분석으로 분석한 결과 AADT를 독립변수로 하여 분석한 대수모형이 결정계수가 가장 높은 것으로 나타났다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.114-117
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• 2002

To develop an effective geometric modeling is essential in order that precise material properties of the 3-D braided composite can be estimated. in this study RVE(representative volume element) which is the smallest volume element representing whole material properties is developed to estimate the mechanical properties of 3-D flat board shaped braided composite using volume averaging method.

• 한국대기환경학회지
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• 제11권3호
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• pp.273-278
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• 1995

This study is to estimate the ventilation volume by the traffic that originated from driving automobiles for two tunnels (Kugi tunnel and Kumhwa tunnel) that adopted natural ventilation system among tunnels of Seoul, and on the basis of which, we estimated the ventilation velume at various conditions. With the result of the estimation, we will present the basic method that can be operated with the optimum condition for the ventilation system. Estimating the predicted ventilation volume in the tennel by the pollutant concentration, we used traffic volume and CO emission data by the automobile speed and CO concentration in the tunnel. And, when we estimated the traffic ventilation volume by natural and traffic ventilation force, we used traffic volume, automobile speed, tunnel area, automobile area data and so on. As the result of simple regression between predicted ventilation volume and traffic ventilation volume, we attained the regression coefficient 0.88, and achieved the relation form that predicted ventilation volume equal 0.12x traffic ventilation volume-92, 000. Using this equation, we estimated the ventilation volume to satisfy the enviromnental standards of several space, and calculated the required volume for mechanical ventilation. Incase of Kumhwa Tunnel, there is a need of mechanical ventilation all day long to satisfy air quality standard 9 ppm for 8 hours average and 10 ppm for the indoor air quality standard of public facilities.

• 한국막학회:학술대회논문집
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• 한국막학회 1997년도 추계 총회 및 학술발표회
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• pp.27-30
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• 1997

1. Introduction : Molecular diffusion of small molecules in polymers plays an important role in many areas where polymers are acting as barriers, and in separation processes, such as selective diffusion. Different applications of polymers have different requirements on their transport properties. Therefore, reliable predictions of diffusion coefficients for small molecules in polymeric materials could be a useful tool to design appropriate materials. For many years, the theories based on free-volume concepts have been widely used to correlate and predict diffusion behavior in polymer/solvent systems. In the theory derived by Vrentas and Duda, the empty space between molecules that is available for molecular transport, referred to as hole free-volume, is being redistributed. Molecular transport will occur only when a free-volume of sufficient size appears adjacent to a molecule and the molecule has enough energy to jump into this void. The diffusive jump is considered complete when the void left behind is closed before the molecule returns to its original position. In this paper, the Vrentas-Duda free-volume theory is presented and the methods to estimate free-volume parameters for predicting polymer/ solvent diffusion coefficients are described in detail.

• 한국산림과학회지
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• 제18권1호
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• pp.1-7
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• 1973

본시험(本試驗)은 리기다소나무 인공단순림(인공단순림)에 있어서 임분재적추정(林分材積推定)을 단급법(單級法) 단순임의추출법(單純任意抽出法) 복합비추정법(複合比推定法) 분리비추정법(分離比推定法) 표준목비추정법(標準木比推定法)등의 방법(方法)으로 조사비교(調査比較)한 것이다. 비추정(比推定)에 의하여 얻은 결과(結果)는 표(表) 8과 같아 실제임분재적(實際林分材積)이 추정임분재적내(推定林分材積內)에 포함(包含)되어 있는 것은 단순임의추출법(單純任意抽出法)과 복합비추정법(複合比推定法)뿐이다. 단순임의추출법(單純任意抽出法)이 좋은 결과(結果)를 갖어온 것은 임분(林分)의 구성상태(構成狀態)가 단순동령림(單純同齡林)이기 때문이라 추측(推測)된다. 추정시(推定時) 측정(測定)이나 계산(計算)이 간편한것은 (1) 단급법(單級法) (2) 단순임의추출법(單純任意抽出法) (3) 표준목비추정법(標準木比推定法) (4) 분리비추정법(分離比推定法) (5) 복합비추정법(複合比推定法)의 순(順)으로 되어 정도면(精度面)이나 실제임분(實際林分) 재적(材積) 측정시(測定時) 시간경비(時間經費) 노력(勞力)을 비교적(比較的) 적게 들이고 측정(測定)할수 있는 방법(方法)은 적어도 인공일제림(人工一齊林)에서는 단순임의추출법(單純任意抽出法)이 가장 좋은 결과(結果)를 가져왔다고 본다.

• 한국농공학회지
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• 제8권1호
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• pp.1011-1034
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• 1966

This thesis is the final report which has long been studied by the author to obtain the design basis for various hydrological constructions with the specific system suitable to the natural environmental conditions in Korea. This report is divided into two parts: one is to estimate runoff volume from watersheds and the other to estimate the peak discharge for a single storm. According to the result of observed runoff record from watersheds, it is known that Kajiyama formula is useful instrument in estimating runoff volume from watersheds in this country. But it has been found that this formula shows us 20-30% less than the actual flow. Therefore, when wihed to bring a better result, the watershed characteristics coefficient in this formula, that is, f-value, should be corrected to 0.5-0.8. As for the method to estimate peak discharge from drainage basin, the author proposes to classify it in two ways; one is small size watershed and the other large size watershed. The maximum -flood discharge rate $Q_p$ and time to peak Pt obtained from the observed record on the small size watershed are compared by various methods and formulas which are based upon the modern hydrological knowledge. But it was fou.d that it. was not a satisfied result. Therefore, the author proposes. tocomputate $Q_p$, to present 4.0-5.0% for the total runoff volume ${\Sigma}Q$.${\Sigma}Q$ is computed under the assumption of 30mm 103s in watershed per day and to change the theoritical total flow volume to one hour dura tion total flow rate when design daily storm is given. Time to peak Pt is derived from three parameters which are u,w,k. These are computed by relationship between total runoff volume (ha-m unit)and $Q_p$. (C.M.S. unit). Finally, the author checked out these results obtained from 51 hydrographs and got a satisfied result. Therefore the author suggested the model of design dimensionless unit-hydrograph. And the author believes that this model will be much available at none runoff record river site. In the large size watersheds in Korea when the maximum discharge occurs, the effective rainfall is two consequtive stormy days. So the loss in watershed was assutned as 6Omm/2days,and the author proposed 3-hour-daration hydrograph flow distribution percentage. This distribution percentage will be sure to form the hydrograph coordinate.

• International Journal of Precision Engineering and Manufacturing
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• 제8권4호
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• pp.45-49
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• 2007

When drilling using electrical-discharge machining (EDM), severe electrode wear makes in-process measurements of the depth of the drilled hole and the volume of material removed impossible. To estimate the volume of material removed a reliable real-time discharge pulse counting method is proposed by assuming that the volume removed in EDM is proportional to the number of discharge pulses from an iso-energy pulse generator. The geometry of machined holes, including depths and cross-sectional profiles, is estimated using geometric analysis. A proportional relationship between the volume of material removed and the number of discharge pulses was developed and verified by experiments.