• 대한지리학회지
• /
• 제29권3호
• /
• pp.253-265
• /
• 1994

본 연구에서는 하상이 주로 모래로 이루어진 우리 나라 충적하천에서 종단 하상경 사와 하천수리량과의 관계를 조사하였다. 조사대상 하천들은 주로 대하천의 1차 지류 중에 서 평형상태에 있다고 보여지는 하천들이다. 평형상태를 검토하기 위해서 Richards의 평형 하천의 조건을 참고하였다. 본 연구에서 채택된 방법은 Leopold와 Maddock식 형태와 Garde식 형태 두 가지이며, 이를 위하여 유역면적 100-2,000$ extrm{km}^2$ 까지의 18개 하천에 대해 상 류로부터 하천거리에 따른 하상경사, 유역면적, 하상재료 크기의 변화 등을 조사하였다. 조 사대상 충적하천에서 하상경사와 유역면적 및 하상재료의 크기 변화를 7개 하천자료를 이용 하여 Garde식 형태로 표시한 결과는 하상재료 크기의 변화에 대한 신뢰성 있는 자료의 부 족으로 현단계로서는 객관성이 부족한 것으로 보여진다. 14개 하천자료를 이용하여 얻어진 Leopold와 Maddock식 형태로 표시한 하상경사 S는 유역면적 A와 유역면적의 변화계수 0.0063 0.0063 $eta$를 이용하면 S = $S_{0}$ $A_{0}$$^{-------- +0.51}$A-$^{-------- -0.51}$로 $\beta$ $\beta$ 표시할 수 있다. 이 식에 의하면 조사대상 충적하천의 종단하상경사는 개략 적으로 유역면적의 -0.6승 정도에 비례하는 것으로 나타났다.

• 한국정보과학회논문지:소프트웨어및응용
• /
• 제36권2호
• /
• pp.122-130
• /
• 2009

기존의 번호판 검출 기법들은 대부분 일정한 거리와 방향에서 촬영되어 번호판의 크기가 유사하고, 배경이 단순한 차량 전면 영상에 적용되는 한계를 가지고 있어서 번호판의 위치가 변하거나 조명 혹은 크기의 변화에 매우 취약하다. 본 논문에서는 이러한 기존 기법들의 문제점들을 극복하기 위하여 에지기반 영역확장 기법을 사용하는 번호판 검출기법을 제안한다. 1단계에서는 입력영상에서 예지영상을 얻고 번호판의 기하학적 특성을 갖는 에지 영역들을 검출하여 이들을 번호판 검색영역으로 정한다. 검색영역의 에지들을 기반으로 주변의 화소들을 색상을 기반으로 영역확장을 통해 분할하여 번호판의 기하학적 특성을 만족하는 영역들을 번호판 후보영역으로 정한다. 후보영역들은 자동차의 조명등과 같은 구조물과의 위상특성을 고려하여 최종결정한다. 본 논문에서 제안하는 기법은 번호판의 문자가 검출되지 않는 경우에도 번호판 위치의 검출이 가능하고 특히 작은 크기의 번호판 검출에 유리하며, 크기와 상관없이 번호판을 검출할 수 있음을 실험을 통해 입증하였다.

• Steel and Composite Structures
• /
• 제7권2호
• /
• pp.87-103
• /
• 2007

This paper presents some of the results from an experimental research project on the behavior of extended end-plate connections subjected to moment conducted at the Structural Laboratory of Jordan University of Science and Technology. Since the connection behavior affects the structural frame response, it must be included in the global analysis and design. In this study, the behavior of six full-scale stiffened and unstiffened cantilever connections of HEA- and IPE-sections has been investigated. Eight high strength bolts were used to connect the extended end-plate to the column flange in each case. Strain gauges were installed inside each of the top six bolts in order to obtain experimentally the actual tension force induced within each bolt. Then the connection behavior is characterized by the tension force in the bolt, extended end-plate behavior, moment-rotation relation, and beam and column strains. Some or all of these characteristics are used by many Standards; therefore, it is essential to predict the global behavior of column-beam connections by their geometrical and mechanical properties. The experimental test results are compared with two theoretical (equal distribution and linear distribution) approaches in order to assess the capabilities and accuracy of the theoretical models. A simple model of the joint is established and the essential parameters to predict its strength and deformational behavior are determined. The equal distribution method reasonably determined the tension forces in the upper two bolts while the linear distribution method underestimated them. The deformation behavior of the tested connections was characterized by separation of the column-flange from the extended end-plate almost down to the level of the upper two bolts of the lower group and below this level the two parts remained in full contact. The neutral axis of the deformed joint is reasonably assumed to pass very close to the line joining the upper two bolts of the lower group. Smooth monotonic moment-rotation relations for the all tested frames were observed.

• 패션비즈니스
• /
• 제11권6호
• /
• pp.125-138
• /
• 2007

The modern fashion contains the religious factors or theories out of numerous cultural traits. Shamanism is a product of the very complicated combination of diversified cultural phenomena and whose traits are depicted as spiritual and artistic forms, reflecting on the materialism culture, social relations, customs, and religious faith. The Shamanism that lies in the life of humans gives much impact on their clothing life up to date, consciously or nonconsciously as well. The Shamanism clothing studied as yet has been focused on the costumes that a Shamanism priest and a shaman, the principal Shamanism performer wears and on the symbolic meaning or formativeness of the traditional shaman clothing that is only confined to certain local regions. The Shamanism in the modern costume influences not only on the traditional clothing unique to shaman but also on the other apparels in a widely extended sense. Nevertheless, the research on the modern costumes related to Shamanism is yet to be progressed. In this context, it is believed that the examination of Shamanism interrelated with a contemporary clothing expression is needed. This work would take a look specifically at how the Shamanism is given in the modern clothing fashion and review the inherent aesthetic characteristics. A fact was driven through this study that the shamanism shown in fashion is not only expressed in the modern style of shaman clothing but also unconsciously absorbed in the fashion on the whole. A finding was also revealed that the geometrical and abstract expression, the implication of animistic components, and the application of inherent shaman's costume on to design in regard to clothing are related to a view point of studying about shamanism. The meaning in each expressive method is focused on the superhumanistic desire of shamanism.

• 한국의류학회지
• /
• 제36권7호
• /
• pp.727-740
• /
• 2012

This study is for the enhancement and utilization of future graphic design for T-shirts and deals with the expression styles and features of T-shirt graphic designs that appear in modern fashion. A literature examination about graphic design and T-shirts was performed for the research method and the analysis followed 378 pieces of graphic design featured in four major international collections for females from 2001S/S to 2011S/S. The research results from the expression type of T-shirt graphic design in the modern fashion are as follows. Expression in graphic figure accounts for the largest portion of 40.8% that includes illustration or cartoon characters, personal figure or part of the physical body, object in daily life or landscape pictures, animals and plants, and others. Expression given in text with typography or logo accounted for 27.5%, expression combined with letter/text, graphics and geometric figures accounted for 24.3%, geometrical expression accounted for 7.4%; most of which are given in print. Characteristics found in modern fashion graphic design are as follows. First, role of sort of public relations marketing was accompanied with utilization of brand logo or symbol. Second, visual play was shown in a sense of humor with diverse graphic figures and playful texts, witty layout with graphic motives, and a free design formation. Third, it denoted a front burner issue delivering the message for various current events or arguments via the way of texts, slogans, and symbolic pictures. Fourth, it depicted artistry through the self-expressive creation of the designer.

• 한국전산구조공학회논문집
• /
• 제29권4호
• /
• pp.309-315
• /
• 2016

최근 치의학 분야에서도 인체에 대한 구조적이고 역학적인 이해를 위하여 유한요소해석 기법이 널리 사용되고 있다. 따라서 본 연구에서는 CT 이미지를 기반으로 하는 유한요소모델링 기법을 제안하고, 실험결과와 비교하여 검증하였다. 또한 제안된 해석기법을 통해 교합 시뮬레이션을 구현하여 정상 I급 교합과 Full-CUSP II급 교합상태의 두개골 모델에 대하여 기하비선형구조해석을 수행하였다. 그 결과, 하악골이 같은 거리만큼 이동할 때 사람의 실제 교합력 범위에서는 두 모델의 교합력에 큰 차이가 없는 것으로 나타났다. 그러나 응력분포를 비교했을 때 정상 I급 교합모델은 치아 및 치조골 전반에 응력이 균등하게 발생하는 반면, Full-CUSP II급 교합모델의 경우 일부 구역에 응력집중 현상이 나타났다. 이는 치아의 부재 및 재배열로 인하여 교합면이 달라지면서 생긴 결과라고 분석된다.

• Structural Engineering and Mechanics
• /
• 제75권6호
• /
• pp.747-769
• /
• 2020

This paper provides a semi-analytical approach to investigate the variations of 3D displacement components, electric potential, stresses, electric displacements and transverse vibration frequencies in laminated piezoelectric composite plates based on the scaled boundary finite element method (SBFEM) and the precise integration algorithm (PIA). The proposed approach can analyze the static and dynamic responses of multilayered piezoelectric plates with any number of laminae, various geometrical shapes, boundary conditions, thickness-to-length ratios and stacking sequences. Only a longitudinal surface of the plate is discretized into 2D elements, which helps to improve the computational efficiency. Comparing with plate theories and other numerical methods, only three displacement components and the electric potential are set as the basic unknown variables and can be represented analytically through the transverse direction. The whole derivation is built upon the three dimensional key equations of elasticity for the piezoelectric materials and no assumptions on the plate kinematics have been taken. By virtue of the equilibrium equations, the constitutive relations and the introduced set of scaled boundary coordinates, three-dimensional governing partial differential equations are converted into the second order ordinary differential matrix equation. Furthermore, aided by the introduced internal nodal force, a first order ordinary differential equation is obtained with its general solution in the form of a matrix exponent. To further improve the accuracy of the matrix exponent in the SBFEM, the PIA is employed to make sure any desired accuracy of the mechanical and electric variables. By virtue of the kinetic energy technique, the global mass matrix of the composite plates constituted by piezoelectric laminae is constructed for the first time based on the SBFEM. Finally, comparisons with the exact solutions and available results are made to confirm the accuracy and effectiveness of the developed methodology. What's more, the effect of boundary conditions, thickness-to-length ratios and stacking sequences of laminae on the distributions of natural frequencies, mechanical and electric fields in laminated piezoelectric composite plates is evaluated.

• Geomechanics and Engineering
• /
• 제6권6호
• /
• pp.517-530
• /
• 2014

Seismic ground response analysis is one of the most important issues in geotechnical earthquake engineering. Conventional seismic site response and free field analysis of layered soils does not consider the effect of surcharge mass which may be present on the top layer. Surcharge mass may develop extra inertial force to the soil and, hence, significantly affect on the results of seismic ground response analysis. Methods of analysis of ground response may also be categorized into time domain and frequency domain concepts. Simplicity in developing analytical relations and accuracy in considering soil dynamic properties dependency to loading frequency are benefits of frequency domain analysis. In this part of the paper, seismic ground response is analyzed using transfer function method for soil layers considering surcharge mass on the top layer. Equation of motion, wave equation, is solved using amended boundary conditions which effectively take the impact of surcharge mass into account. A computer program is developed by MATLAB software based on the solution method developed for wave equation. Layered soils subjected to earthquake loading were numerically studied and solved especially by the computer program developed in this research. Results obtained were compared with those given by DEEP SOIL computer program. Such comparison showed the accuracy of the program developed in this study. Also in this part, the effects of geometrical and mechanical properties of soil layers and especially the impact of surcharge mass on transfer function are investigated using the current approach and the program developed. The efficiency and accuracy of the method developed here is shown through some worked examples and through comparison of the results obtained here with those given by other approaches. Discussions on the results obtained are presented throughout in this part.

• Journal of Astronomy and Space Sciences
• /
• 제30권4호
• /
• pp.255-267
• /
• 2013

In this research, the ground contact opportunity for the fictitious low lunar orbiter is analyzed to prepare for a future Korean lunar orbiter mission. The ground contact opportunity is basically derived from geometrical relations between the typical ground stations at the Earth, the relative positions of the Earth and Moon, and finally, the lunar orbiter itself. Both the cut-off angle and the orbiter's Line of Sight (LOS) conditions (weather orbiter is located at near or far side of the Moon seen from the Earth) are considered to determine the ground contact opportunities. Four KOMPSAT Ground Stations (KGSs) are assumed to be Korea's future Near Earth Networks (NENs) to support lunar missions, and world-wide separated Deep Space Networks (DSNs) are also included during the contact availability analysis. As a result, it is concluded that about 138 times of contact will be made between the orbiter and the Daejeon station during 27.3 days of prediction time span. If these contact times are converted into contact duration, the duration is found to be about 8.55 days, about 31.31% of 27.3 days. It is discovered that selected four KGSs cannot provide continuous tracking of the lunar orbiter, meaning that international collaboration is necessary to track Korea's future lunar orbiter effectively. Possible combinations of world-wide separated DSNs are also suggested to compensate for the lack of contact availability with only four KGSs, as with primary and backup station concepts. The provided algorithm can be easily modified to support any type of orbit around the Moon, and therefore, the presented results could aid further progress in the design field of Korea's lunar orbiter missions.

• 한국정보처리학회논문지
• /
• 제5권8호
• /
• pp.2061-2074
• /
• 1998

패턴 인식의 분야에서 그래프는 복잡한 대상체의 표현 및 인식의 도구로서 많이 사용되지만, 그래프간의 유사성 비교에는 많은 시간이 소요될 뿐아니라 실제 입력되는 영상은 왜곡으로 인해 저장되어 있는 이상적인 영상과 동일함을 기대할 수 없으므로 유사한 정도를 판별하는 기준이 마련되어야만 한다. 이 논문에서는 행렬을 그래프의 표현 수단으로 사용하였다. 행렬은 표현이 간단하며, 정의되어 있는 연산을 통해 순서 배열 및 매칭 과정을 간단히 수행하루 수 있다. 이 때 그래프를 구성하는 노드(node)들을 기하학적 위치에 따라 순서 배열함으로써 그래프를 구성하는 노드들 사이의 대응 관계를 효율적으로 찾을 수 있도록 하였으며, 또한 왜곡으로 인하여 기호를 표현하는 그래프의 노드가 제대로 추출되지 못한 경우는 기호의 구조를 고려하여 보정해 줄 수 있는 분할 과정을 도입하여 해결하였다. 제안한 방법은 악보의 비음표 기호 인식을 통해 실험하였으며, 실험 결과 95% 정도의 인식률을 얻을 수 있었다.