능동 화이버 복합재의 모델링 및 적용 연구

하성규,이영우,김영호,Ha, Seong-Gyu,Lee, Yeong-U,Kim, Yeong-Ho 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.8

Effective material properties of active fiber composites with interdigitated electrodes are derived as a function of the fiber volume fraction. For the purpose of applying the rule of mixture, three unit cell models are introduced; each for the deformation and stress continuities in the out of plane and in-plane directions, and the continuity of the electrical displacement in the longitudinal direction. Derived effective material properties are compared with the results by the finite element method; good agreements are observed between them. As an application, the electromechanical behavior of the angle ply laminates with the active fiber layers bonded on the top and bottom surfaces are investigated; the angle of piezoelectric fiber to maximize the twisting curvature is obtained using the present model.

지속 가능한 도시개발

하성규,Ha, Seong-Gyu 에너지절약전문기업협회 2009 esco Vol.56 No.-

지금까지 인류가 창안해 낸 가장 훌륭한 대안적 개발 패러다임은 '지속가능한 개발'이라 할 수 있다. 어젠다21(Agenda 21) 등 국제기구에서 논의되는 지속가능한 개발의 개념은 '미래 세대의 욕구를 충족시킬 수 있는 환경과 여건을 저해하지 않으면서 현 세대의 욕구를 충족시키는 개발'이다. 그리고 이 지속가능한 개발은 세 가지 핵심적 요소를 포함하고 있는바 이는 환경적 가치, 미래 지향성, 그리고 형평성이다. 이와 관련한 지속가능한 도시개발에 대해 알아보자.

공동주택관리의 의미와 중요성

하성규,Ha, Seong-Gyu 한국주거학회 2014 住居 Vol.9 No.2

부분 장골과 장요추 인대를 포함한 요추 천추골의 유한 요소 모델링 및 비선형 해석

하성규,임종완,Ha, S.K.,Lim, J.W. 대한의용생체공학회 2007 의공학회지 Vol.28 No.3

Owing to needs of biomechanical comprehension and analysis to obtain various medical treatment designs which are related with the spine in order to cure and diagnose LBP patients, the FE modeling and nonlinear analysis of lumbosacrum including a partial ilium and iliolumbar ligaments, were carried out. First, we investigated whether the geometrical configuration of vertebrae displayed by DICOM slice files is regular and normal condition. After constructing spinal vertebrae including a partial ilium, a sacrum and five lumbars (from L1 to L5)with anatomical shape reconstructed using softwares such as image modeler and CAD modeler, we added iliolumbar ligaments, lumbar ligaments, discs and facet joints, etc.. And also, we assigned material property and discretized the model using proper finite element types, thus it was completely modeled through the above procedure. For the verification of each segment, average sagittal ROM, average coronal ROM and average transversal ROM under various loading conditions(${\pm}10Nm$), average vertical displacement under compression(400N), ALL(Anterior Longitudinal Ligament) and PLL(Posterior Longitudinal Ligament) force at L12 level, strains of seven ligaments on sagittal plane at L45 level and maximal strain of disc fibers according to various loading conditions at L45 level, etc., they were compared with experimental results. For the verification of multilevel-lumbosacrum spine including partial ilium and iliolumbar ligaments, the cases with and without iliolumbar ligaments were compared with ROM of experiment. The results were obtained from analysis of the verified FE model as follows: I) Iliolumbar ligaments played a stabilizing role as mainly posterior iliolumbar ligaments under flexion and as both posterior and anterior iliolumbar ligaments of one side under lateral bending. 2) The iliolumbar ligaments decreased total ROM of 1-8% in total model according to various motion conditions, which changed facet contact forces of L5S level by approximately 0.8-1.4 times and disc forces of L5S level by approximately 0.8-1.5 times more than casewithout ilioligaments, under various loading conditions. 3) The force of lower discs such as L45 and L5S was bigger than upper discs under flexion, left and right bending and left and right twisting, except extension. 4) It was predicted that strains of posterior ligaments among iliolumbar ligaments would produce the maximum 16% under flexion and the maximum 10% under twisting. 5) It's expected that this present model applies to the development and design of artificial disc, since it was comparatively in agreement with the experimental datum.

복합재료 지능구조물의 제어를 위한 압전소자를 이용한 변형형상예측

하성규,조영수,Ha, Seong-Gyu,Jo, Yeong-Su 대한기계학회 1996 大韓機械學會論文集A Vol.20 No.4

A method is proposed to predict the deformed shape of the structure subjected to the unknown external loads using the signal from the piezoceramic sensors. Such a shape estimation is based on the linear relationship between the deformation of structure and the signal from sensor, which is calculated using finite element method. The deformed shape is, then calculated using the linear matrix and the signals from the piezoceramic sensors attached to the structures. For the purpose, a structural analysis program is developed using a multi-layerd finite element of 8 nodes with 3 displacement and one voltage degrees of freedom at each node. The multiple layers with the different material properties can be layered within the element. The incompatible mode with the element is found to be crucial to catch the bending behavior accurately. The accuracy of the program is, then, verified by being compared with the experimental results performed by Crawley. The proposed shape estimation method is also verified for the different loads and sensor size. It is shown that the results of shape estimation method using the linear matrix well predicts the deflections compared with those of finite element method.

도시재생의 길

하성규,Ha, Seong-Gyu 한국주택협회 2007 주택과 사람들 Vol.205 No.-

금속라이너 - 복합재 적층 압력 용기의 최적설계

하성규,이동건 ( Sung Kyu Ha,Dong Gun Yi ) 한국복합재료학회 1997 Composites research Vol.10 No.1

21世紀를 대비한 持續可能한 地域開發戰略硏究

하성규(Seong-Kyu Ha),김재익(Jae-Ik Kim),전명진(Myung-Jin Jun),문태훈(Tae-Hoon Moon) 한국지방자치학회 1997 韓國地方自治學會報 Vol.9 No.2

헌법과 국제인권규범을 통해서 본 주거권과 "적절한 주거(Adequate housing)" 확보 방안

하성규(Seong Kyu Ha) 한국사회정책학회 2010 한국사회정책 Vol.17 No.1

인간은 누구나 적정한 수준의 삶을 누릴 권리를 가진다. 인간다운 삶의 가장 기본적 조건은 적정한 주거확보이다. 주거권은 이미 세계인권선언에서 선언한바 있다. 주택 및 주거생활에 연관된 권리에 관한 논의로서 국제기구(UN 등)와 인권단체 및 학계에서는 "적절한 주거생활을 누릴 권리" 즉 "주거권" 보장을 위한 노력이 유엔 등 국제기구를 통해 오랜 세월 동안 지속되어왔다. 많은 선진외국에서는 주거권에 대한 다양한 조치들이 취해졌고 이를 보장하기 위한 노력이 결실을 맺고 있다. 아울러 경제적·사회적 및 문화적 권리에 관한 국제규약, 유엔인권위원회 결의(제77호)는 강제퇴거가 명백한 인권침해이며 각국 정부는 강제퇴거(철거)를 방지할 수 있는 제도적 장치 마련을 강력하게 권고 하였다. 우리나라도 적절한 주거생활을 누릴 권리는 헌법 및 주택법등에서 근거를 찾을 수 있다. 그러나 강제철거(퇴거), 안전을 위협받고 주거차별 등이 법적으로 보호받지 못하는 경우가 종종 발생하고 있다. 정부는 주택정책을 수립함에 있어 주거권 보장 및 저렴주택공급을 우선으로 하는 주택프로그램을 사회취약계층을 중심으로 보다 더 체계적 주거안전망이 구축되어야 할 것이다. Everyone shares the right to a decent standard of living. Essential to the achievement of this standard and therefore to the fulfillment of human lie beyond simple survival is access to adequate housing. The right to housing codified as a human right in the Universal Declaration of Human Rights. And The right to housing is included in several international legally-binding documents such as UN-Habitat and UN Housing Rights Programme, Among the most significant of these is UN International Covenant of Economic, Social, and Cultural Rights(Article 11.1). Although most states do not stipulates a clear right to housing, most do have legislation and national programs related to housing. Korea has the constitution and national laws that promote the progressive realization of the right to adequate housing. In Korea legal protection of the right to housing at the national level often involve arbitrary eviction, safety and health regulations, or equal protection issues. The housing policy should be oriented around securing the right to housing and the affordability of housing, particularly for the underprivileged groups.

한국의 공공임대 주택정책과 주택정치

하성규(Ha, Seong-Kyu),배문호(Bae, Mun-Ho) 한국지역개발학회 2004 韓國地域開發學會誌 Vol.16 No.4

The purpose of this paper is to examine a much neglected aspect of the pitics of housing in Korea. The public rental housing picy in Korea is a reflection of political and social state of each administration. The ordinary citizen, interested minority groups, and ’public opinion' are all seen as potentially important political influences sustained by a participatory political culture. Roh, Tae-W 00 administration constructed 190,000 permanent rental housing for the housing poverty group. It can be evaluated that the pennanent public rental housing was a starting point of the Korean social housing program Kim Yeoung-Sam administration was differ from that of Roh’s administration. Kim' s aclrninstration pursued rather liberal approach, which focus on market mechanism, emphasizing the role of private sector. Kim, Dae-Jung administration implemented one million rental housing (Kukmin Ju떠ek) construction plan. This period of time can be referred to as the advancing period of public housing policy. Three governments have a different housing po1icies and paradigms of public rental housing. Korea's public rental housing policies during these three administrations reflect all combination from social-democratic housing programs to those more new liberalism approaches based on the private market.