• 에너지공학
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• 제15권1호
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• pp.74-81
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• 2006

이 연구에서는 해석적 계층과정 기법 및 설문조사를 바탕으로 다중기준 평가기준에 따라서 여러 가지 전력생산 시스템들을 종합적으로 비교할 수 있는 비교지표의 평가체계를 개발하였다. 의사결정 문제를 계층구조로 파악하는 해석적 계층과정 기법은 설문조사로 얻어진 주관적 견해를 추출하는 데 아주 용이하다. 여기서, 종합선호도는 판단기준의 가중치와 대안의 평가치가 선형적으로 결합되어 얻어진다. 대표적 전력생산 시스템들은 국내 전력공급의 대부분을 차지하고 있는 전통적인 원자력, 석탄(유연탄), 중유, LNG 발전소, 수력 발전원 등이 선정되었고, 덧붙여 최근에 관심거리인 재생에너지 시스템으로는 우리나라에서 대표적인 풍력, 태양광 발전원 등이 포함되었다. 시범연구의 결과에 따르면, 종합적인 비교지표로 1) 평가기준 간 상대적 중요성을 비교하기 위해 에너지 시스템의 4가지 대-평가기준의 가중치, 11가지 소-평가기준의 가중치, 2) 평가기준별 에너지 시스템의 효용성을 비교하기 위해 7가지 에너지 시스템의 선호평가치, 3)우선순위를 판단하기 위해 종합점수 등이 제시된다.

• 한국정보통신학회논문지
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• 제19권12호
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• pp.2844-2851
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• 2015

다수의 2차원 객체 영상으로부터 3차원 형상을 복원하는 방법은 컴퓨터 비젼 분야에서 널리 연구되고 있다. 복원된 3차원 형상의 정확도 개선을 위해서는 잡음 영향을 줄이거나 영상 프레임 수를 확보하는 것이 무엇보다 중요하다. 그렇지만 특징점 추정 시 잡음은 잠재적으로 내포되고, 관측행렬을 구성하는 영상 프레임 수는 특징점 추적 실패, 장애요소 또는 낮은 해상력 등에 의해 일반적으로 감소하게 된다. 그래서 잠음 환경 하에 손실된 특징점을 보다 정확히 보정하여 사용 가능한 영상 프레임 수를 확보하는 것이 필수적이다. 따라서 우리는 잡음 분포 하에서 기하학적 특성을 이용해 손실 특징점의 오차 거리와 방향을 직접 제어할 수 있는 분석적 접근방법을 제안한다. 제안한 방법의 우수성은 합성과 실제 객체에 대한 실험 결과를 통해서 검증한다.

• Structural Engineering and Mechanics
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• 제68권4호
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• pp.385-398
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• 2018

In the present paper, we offer a new flat shell finite element. It is the result of the combination of a membrane element and a bending element, both based on the strain-based formulation. It is known that $C^{\circ}$ plane membrane elements provide poor deflection and stress for problems where bending is dominant. In addition, they encounter continuity and compliance problems when they connect to C1 class plate elements. The reach of the present work is to surmount these problems when a membrane element is coupled with a thin plate element in order to construct a shell element. The membrane element used is a triangular element with four nodes, three nodes at the vertices of the triangle and the fourth one at its barycenter. Each node has three degrees of freedom, two translations and one rotation around the normal. The coefficients related to the degrees of freedom at the internal node are subsequently removed from the element stiffness matrix by using the static condensation technique. The interpolation functions of strain, displacements and stresses fields are developed from equilibrium conditions. The plate element used for the construction of the present shell element is a triangular four-node thin plate element based on Kirchhoff plate theory, the strain approach, the four fictitious node, the static condensation and the analytic integration. The shell element result of this combination is robust, competitive and efficient.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권3호
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• pp.229-237
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• 2000

According to the functional matrix theory, Delaire proposes that individual occlusal plane was determined by variable effects of teeth, maxilla, mandible, cranium, cranial base and soft tissue matrix including the orofacial musculature. and that there is the ideal occlusal plane determined by the most proper spatial position of maxilla and mandible, functionally and esthetically. This study was designed to find out the relation between Delaire's ideal occlusal plane and muscle activity of masticatory muscles in individuals who have normal maxillo-mandibular relationships. Lateral cephalometric radiographs were taken and his/her individual occlusal plane and ideal occlusal plane were analyzed with Delaire's architectural and structural craniofacial analytic method. For evaluation of muscle activities of masticatory muscles, electromyography of anterior temporal muscle, superficial masseter muscle, and anterior belly of digastric muscle was recorded in fifty Korean normal Angle class I occlusion individuals. According to the average value of ideal occlusal plane, fifty normal Angle class I occlusion individuals were classified into three groups: Ideal occlusal plane group(I group), hyperrotation group(I+ group) and hyporotation group(I- group). The result of this study was as follows: 1. The results of Delaire's architectural and structural craniofacial analysis of lateral cephalography of the fifty Korean normal Angle class I occlusion individuals are that twelve persons(24%) have consistent or parallel with ideal occlusal plane and the average of angular difference was $1.22^{\circ}{\pm}3.69^{\circ}$. 2. There is no significant difference in muscle activities of masticatory muscles during resting(p<0.05), but significant increases of muscle activity of ipsilateral anterior temporal and masseter muscle, contralateral anterior belly of digastric muscle during unilateral chewing and of anterior temporal and masseter muscle during bilateral clenching(p<0.05). 3. To find out the effect of the angular difference between Delaire's ideal occlusal plane and real occlusal plane to muscle activity, muscle activities of masticatory muscles were compared with three groups in each other; I group, I+ group and I- group. The results were no significant differences during resting, unilateral chewing and bilateral clenching.(p>0.05) 4. Although there is no significant differences of masticatory muscle activities among the three groups, the fact that increasing tendency of masseter muscle activity of ideal occlusal plane group(I+) than those of any other groups(I+ and I-) during bilateral clenching was noted. There is only the implication that occlusal plane makes some effects on masticatory muscle activities, espacially that of masseter muscle during bilateral clenching. In conclusion, the hypothesis that occlusal plane is one of the factors which affect the muscle activities of masticatory muscles and that anyone whose occlusal plane consistent with Delaire's ideal occlusal plane has an extraordinary functional advantage in masticatory muscle function cannot be proven with electromyography methods.