• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.49 no.2
• /
• pp.102-112
• /
• 2012

In this paper, we propose a texture classification using wavelet-domain BDIP (block difference of inverse probabilities) and BVLC (block variance of local correlation coefficients) features with WPCA (whitened principal component analysis) classifier. In the proposed method, the wavelet transform is first applied to a query image. The BDIP and BVLC operators are next applied to the wavelet subbands. Global moments for each subband of BDIP and BVLC are then computed and fused into a feature vector. In classification, the WPCA classifier, which is usually adopted in the face identification, searches the training feature vector most similar to the query feature vector. Experimental results show that the proposed method yields excellent texture classification with low feature dimension for test texture image DBs.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.39 no.5
• /
• pp.425-433
• /
• 2015

In this paper, we have numerically investigated two-dimensional dielectrophoretic (DEP) motions of a single particle suspended freely in a viscous fluid, interacting with a nearby nonconducting planar wall, under an externally applied uniform direct-current electric field. Particularly, we solve the Maxwell equation with a large sharp jump in the electric conductivity at the particle-fluid interface and then integrate the Maxwell stress tensor to compute the DEP force on the particle. Results show that, under an electric field parallel to the wall, one particle is always repelled to move far away from the wall and the motion depends strongly on the particle-wall spacing and the particle conductivity. The motion strength vanishes when the particle is as conductive as the fluid and increases as the conductivity deviates further from that of the fluid.

• Nuclear Engineering and Technology
• /
• v.25 no.1
• /
• pp.166-177
• /
• 1993

A simplified thermal analysis method to evaluate the maximum temperature of the CANDU 37-element fuel bundle within a fuel basket in a given spent fuel dry storage canister has been presented along with the results of sample analyses performed to examine the parametric effects of the ambient conditions on the maximum fuel temperature within a canister. To solve the multi-dimensional heat transfer problem of the complex geometry of rod bundles within a canister where three modes of heat transfer are superimposed, the CANDU spent fuel bundles stored in the dry storage canister are first replaced by equivalent concentric fuel cylinders. The simplified axi-symmetric two-dimensional multi-mode heat transfer problem of the equivalent fuel cylinders is then analyzed with an existing computer code, HEATING5, using additional input data and heat transfer correlations. A comparison between the predicted temperature profile and the mock-up test results shows that the agreement is quite satisfactory.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.19 no.2
• /
• pp.155-161
• /
• 2001

When determining a three dimensional position for engineering purposes, we can use the GPS survey to find position. According to the enhancement of precision for domestic Geoid model, the positional accuracy of GPS about precise method of vertical position has been also increased. But by considering Geoid undulation, it is difficult to measure GPS-derived elevations. Because Geoid undulation has changed little in local sites, GPS-derived elevations are similar to orthometric height. By ignoring Geoid undulation, it is possible to measure GLT-derived elevations at the local. small construction sites. GLT(GPS Leveling Technique) provides a method for computing orthometric heights. GLT processes the data more rapidly than conventional measurement devices. We only considered the weight factors affecting accuracy between the points. That is, the GPS procedures to produce satisfactory elevation accuracy depends on the method of observations, receivers and conditions of the local environment. A comparison was performed between the GPS survey using Geoid model and GLT at a part within Pusan National University and construction model sites in South Korea. And the writers proved the GPS surveying is efficient in positioning accuracy, time, and cost on a construction sites.

• Geotechnical Engineering
• /
• v.5 no.1
• /
• pp.27-34
• /
• 1989

This study presents a probabilistic analysis of the stability of homogeneous soil slopes during earthquakes. The stability of the slope is measured through its probability of failure rather than the customary factor of safety. The maximum horizontal ground acceleration is deterimined with Donovan and McGuire equation. The earthquake magnitude (m) is a random variable the Probability density function f(m) has been obtained with a use of Richter law. The potential failure surfaces are taken to be of an exponential shape (log-spiral) , Uncertainties of the shear strength parameters along potential failure surface are expressed by one-dimensional random field model. From a first order analysis the mean and variance of safety margin is osculated. The dependence on significant seismic parameters of the probability of failure of the slope is examined and the results are presented in a number of graphs and tables. On the base of the results obtained in this study, it is concluled that (1) the present model is useful in assessing the reliability of soil slopes under both static and seismic conditions: and (2) the probability of failure of a soil slope is greatly affected by the values of the seismic parameters that are associated with it.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.22 no.3
• /
• pp.319-327
• /
• 2012

In this paper, we present a sign language recognition model which does not use any wearable devices for object tracking. The system design issues and implementation issues such as data representation, feature extraction and pattern classification methods are discussed. The proposed data representation method for sign language patterns is robust for spatio-temporal variances of feature points. We present a feature extraction technique which can improve the computation speed by reducing the amount of feature data. A neural network model which is capable of incremental learning is described and the behaviors and learning algorithm of the model are introduced. We have defined a measure which reflects the relevance between the feature values and the pattern classes. The measure makes it possible to select more effective features without any degradation of performance. Through the experiments using six types of sign language patterns, the proposed model is evaluated empirically.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2004.11a
• /
• pp.805-808
• /
• 2004

본 논문에서는 두 단백질의 구조적 유사성을 기반으로 한 단백질 비교를 위해서 전처리 기법으로서의 주성분분석기법을 소개한다. 기존의 백본 및 알파탄소 간의 거리행렬(distance matrix), 2차 구조 비교기법, 구역(segment)단위의 비교 기법과 같은 단백질 비교 기법들은 위치이동(translation)와 회전(rotation)에 불변한(invariant) 차이를 구하기 위하여 거리행렬을 이용하였다. 그리고, 난 다음 이들의 최적화 과정을 거쳤다. 그러나, 본 논문에서 제시하는 전처리 기법으로서의 주성분분석기법은 단백질 구조를 전체적인 구조 관점에서 위치를 정렬시킨 후에 단백질 간의 구조를 비교하는 방식이다. 단백질의 구조의 방향성(Orientation)을 맞춘 다음에는 다양한 단백질 표현으로 구를 비교할 수 있다. 본 논문에서는 두 단백질의 구조의 유사성을 측정하기 위한 간결한 단백질 표현(representation)으로 3 차원 에지 히스토그램을 사용하였다. 이 기법은 방향성을 정렬하기 위하여 기존의 방법에서 사용되었던 반복적인 거리계산을 통한 최적화하는 과정을 없앰으로써 단백질 구조 비교 시간을 단축할 수 있는 새로운 단백질 구조 비교 패러다임을 가능하게 한다. 따라서, 이 패러다임을 통하여 적절한 단백질 구조 방향성 정렬과 단백질 구조 표현을 이용한 단백질 구조 비교 검색 시스템은 많은 양의 단백질 구조 정보로부터 원하는 형태의 단백질 구조를 빠른 시간에 검색할 수 있는 장점을 가질 수 있다.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.11 no.1
• /
• pp.41-49
• /
• 1999

The horizontal two-dimensional model which can predict the long-term water quality(WQ) change is setup for the environmental management. For the model calibration and verification, we measured the pollutants load at 22 streams and the WQ at 16 stations monthly and/or seasonally in Chinhae . Masan Bay. The pollutants release rate from the sediment was also measured to consider the regionally different sediment pollution level. From the model application results, it is shown that the WQ concentrations in most of the regions adjacent to land and river inflow are considerably high, but rapidly decrease along the seaward direction. In Masan Bay, the particulate inflow-pollutants were substantially deposited and gradually contaminated the bottom sediment on account of the excessive pollutants load and flow stagnancy. Eutrophication in the effluent discharge region was also being slowly progressed by the inefficiently treated wastewater containing amount of Nand P constituents.

• Economic and Environmental Geology
• /
• v.28 no.5
• /
• pp.503-512
• /
• 1995

Groundwater flow in fracture networks is simulated using a discrete fracture (DF) model which assume that groundwater flows only through the fracture network. This assumption is available if the permeability of rock matrix is very low. It is almost impossible to describe fracture networks perfectly, so a stochastic approach is used. The stochastic approach assumes that the characteristic parameters in fracture network have special distribution patterns. The stochastic model generates fracture networks with some characteristic parameters. The finite element method is used to compute fracture flows. One-dimensional line element is the element type of the finite elements. The simulation results are shown by dominant flow paths in the fracture network. The dominant flow path can be found from the simulated groundwater flow field. The model developed in this study provides the tool to estimate the influences of characteristic parameters on groundwater flow in fracture networks. The influences of some characteristic parameters on the frcture flow are estimated by the Monte Carlo simulation based on 30 realizations.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2012.05a
• /
• pp.142-142
• /
• 2012

지금까지 국내 연구에서 EFDC 모형의 활용은 WASP 모형과 연계하여 저수지 수리해석에 주로 이용되었으며, 하천의 수리해석에서도 많이 활용되었다. 이에 본 연구에서는 EFDC 모형의 Full 버전을 이용하여 하천 수질모델링을 수행하고 적용성과 수질해석의 재현성을 검토하고자 한다. 국립환경과학원의 8일 간격 실측자료를 사용하기 위하여 대상구간을 낙동강 본류 C에서 낙동강 본류 K까지를 선정하였고, 2차원 수리해석과 수질해석을 수행하였다. 수리해석의 결과를 확인하기 위하여 유량을 실측자료와 비교하였으며, 수질인자는 수온, COD, TOC, DO, TN, TP에 대해 모의하였으며, 모형에서 직접 계산되지 않는 BOD는 COD와 환산을 통해 간접적인 방법으로 산정하여 실측자료와 비교하였다. EFDC 모형의 하천에서의 수질해석 적용성을 평가하기 위하여 모의 결과와 실측자료를 이용하여 통계분석을 수행하여 수리 수질해석의 재현성을 평가하였다. 본 연구에서 수행한 EFDC를 이용한 수리 및 수질 모델링의 모의의 예측결과는 우수한 것으로 판단되나, BOD의 경우 다른 인자들의 모의결과에 비해 다소 낮게 나타나고 있는데, 이는 COD나 TOC와 관련된 BOD의 환산에 대한 연구의 부족으로 인한 결과로 보이며, 향후 보다 향상된 기법을 이용한다면 이러한 문제는 개선될 것으로 판단된다. 검증을 위한 실측치로 8일 간격 실측치를 이용하였는데 이 자료의 경우 8일 간격이므로 실제로 결측치가 많이 발생을 하고, 또한 유량이 많이 발생하는 홍수기시에는 관측을 하지 않는 문제가 있어 실제로 자료의 변동이 큰 경우에는 모의 결과가 실측치의 경향을 잘 쫓아가지 못하는 문제가 발생하게 된다. 따라서 모의결과 신뢰도 향상을 위해 일간격의 실측치를 확보하거나 또는 결측치를 보완할 수 있는 기법에 대한 선행 연구가 필요할 것으로 판단된다.