• Journal of Korea Water Resources Association
• /
• v.50 no.5
• /
• pp.347-358
• /
• 2017

This study examined characteristic differences by the rainfall direction on the runoff responses. The directional characteristics of hydrological components in a basin were quantified by von Mises distribution. The runoff hydrograph was derived using the result of convolution integration of each distribution and this hydrograph was compared with GIUH model and observed data. As a result, it was found that runoff response by rainfall direction was more similar the observed rainfall-runoff data than the runoff result using GIUH model. These results implies that runoff modeling could be improved by considering directional components in hydrologic analysis. This study would be helpful to reduce uncertainties of hydrologic analysis considering a non-linearity of rainfall-runoff process by the rainfall direction.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.3
• /
• pp.401-409
• /
• 1997

In this paper, a pattern spectrum component function is introduced for an oriented shape analysis and its properties are discussed. It can represent directional information of shape more precisely than the conventional oriented pattern spectrum. An adaptive distance function between two pattern spectrum component functions is presented to recognize different shapes in noise. As a practical application, the pattern spectrum component function is applied to warning traffic sign recognitions utilizing the adaptive distance functions. Favorable results are obtained compared to the oriented pattern spectrum.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.9
• /
• pp.1965-1970
• /
• 2011

This paper proposes the method of switching function implementation using switching function extraction based on graph over finite fields. After we deduce the matrix equation from path number of directional graph, we propose the switching function circuit algorithm, also we propose the code assignment algorithm for nodes which is satisfied the directional graph characteristics with designed circuits. We can implement more optimal switching function compare with former algorithm, also we can design the switching function circuit which have any natural number path through the proposed switching function circuit implementation algorithms. Also the proposed switching function implementation using graph theory over finite fields have decrement number of input-output, circuit construction simplification, increment arithmetic speed and decrement cost etc.

• Tunnel and Underground Space
• /
• v.18 no.3
• /
• pp.194-201
• /
• 2008

In order to investigate the characteristics in tensile strength of transversely isotropic rock, a new anisotropic tensile failure function was suggested. According to the function, the tensile strength is minimum in the normal direction to a weakness plane and rises exponentially to its maximum on a plane perpendicular to the weakness plane. The anisotropic function is defined in terms of three strength parameters which can be identified trom direct tensile tests of transversely isotropic rocks. By incorporating the suggested function into the critical plane approach, a numerical procedure which enables to search the tensile strength and the direction of critical plane at failure was presented. The validity of the suggested numerical procedure was checked through the simulation of direct tensile tests reported in a literature. The numerical results from the simulation were in good agreements with those from the laboratory tests.

• Environmental and Resource Economics Review
• /
• v.16 no.1
• /
• pp.171-197
• /
• 2007

In this paper we provide a methodology that permits test of feasibility of Porter hypothesis under limited data environment by utilizing two types of output distance function: Shephard distance function and directional distance function. The production technology supported by Porter hypothesis is embodied in the directional distance function. The average annual marginal abatement cost for $SO_2$ obtained by estimating the directional distance function is higher than the one obtained with the Shephard distance function by about 50 percent in the Korean electric power industry over the period 1970~1998. This result implies that feasibility of Porter hypothesis depends upon whether investment in production capital and process can bring more than a 50 percent increase in the average productivity.

• Annual Conference of KIPS
• /
• 2017.04a
• /
• pp.459-460
• /
• 2017

해시 함수는 데이터의 위변조를 확인하기 위해 사용하는 일방향 함수로, 현재 많은 기술 및 논문에서 해시 함수를 사용하고 있다. 대표적인 해시 함수에는 MD와 SHA가 있으며 다양한 버전을 가지고 있다. 본 논문에서는 해시 알고리즘들의 안전성과 관련된 동향과 취약점을 파악하고 향후 방향성을 알아보고자 한다.

• Environmental and Resource Economics Review
• /
• v.19 no.3
• /
• pp.633-658
• /
• 2010

In this paper, we estimate the Translog cost function in Korean manufacturing, using capital (K), labor (L), material (M), electricity (E), fuel (F) data over the period from 1970 to 2005. Especially, this paper investigates the impact of imposing concavity in the estimation of a Translog cost function. Although the value of log-likelihood is somewhat reduced in a concavity imposed function rather than a function which is not, a concavity imposed function satisfies regularity conditions (monotonicity, positivity, concavity) at all data points. We also calculate price elasticities using a concavity imposed Translog cost function. Electricity complements capital so electricity demand increases as capital demand increases. Meanwhile, electricity substitutes labor, fuel, and material. These results show that Korean manufacturing experienced a structural change of increase in electricity demand.

• Tunnel and Underground Space
• /
• v.26 no.2
• /
• pp.100-109
• /
• 2016

This study suggests three spatial distribution functions of strength parameters, which can be adopted in the derivation of failure conditions for transversely isotropic rocks. All three proposed functions, which are the oblate spheroidal function, the exponential function, and the function based on the directional projection of the strength parameter tensor, consist of two model parameters. With assumption that the cohesion and friction angle can be described by the proposed distribution functions, the transversely isotropic Mohr-Coulomb criterion is formulated and used as a failure condition in the simulation of the conventional triaxial tests. The simulation results confirm that the failure criteria incorporating the proposed distribution functions could reproduce the general trend in the variations of the axial stress at failure and the directions of failure planes with varying inclination of the weankness planes and confining pressure. Among three distribution functions, the function based on the directional projection of the strength parameter tensor yields the highest axial strength, while the axial strength estimated by the oblate spheroidal distribution function is the lowest.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2000.08a
• /
• pp.337-340
• /
• 2000

조명 및 반사광의 성질에 의해 블러링이 발생하고 이런 영상을 인식하는 경우 정확한 에지 검출이 어렵게 된다. 이를 최적으로 검출하기 위해 일정하게 에지를 검출할 수 있는 가우시안 함수와 2차 미분 함수를 합성한 새로운 하이브리드 함수를 제안하고 실제 영상과 컨볼루션 한 후 함수의 $\sigma$값을 변화시키면서, Canny 알고리즘의 방향성 에지 검출 방법을 적용하여 에지를 검출하였다. 그 결과 Sobel, Robert, Canny 에지 검출방법보다 0.2~14㏈ 정도 안정적으로 에지가 검출되었다.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.20 no.5
• /
• pp.665-671
• /
• 2010

This paper propose the DDEGST(divergent-direction-emphasis generalized symmetry transform) which emphasis the symmetry of divergent intensity orientation for effective target extraction in FLIR(forward looking infra-red) images. In the proposed method, we use the exponential function instead of cosine function as a phase weight function in the generalized symmetry transform for effective target extraction in FLIR images which contain a target with higher intensity than a background intensity. To evaluate the performance of the proposed method, we compare the proposed mehtod with conventional GST method in experiments. We prove that the proposed method have better performance in IR images.