• Title/Summary/Keyword: active spring

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A study on the Improvement of the Performance of Biodirectional NITINOL Actuator (NITINOL을 이용한 차동식 액츄에이터의 동작성능 향상을 위한 연구)

  • Jung, Sang-Hwa;Kim, Hyun-Wook;Cha, Kyung-Rae;Song, Seok;Shin, Byung-Soo;Lee, Kyung-Hyung
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1577-1580
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    • 2003
  • In the recent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. The dynamic characteristic analysis of SMA is necessary for actuator application and many common researches report the material characteristics of SMA sufficiently. However, the research on dynamic characteristics is very deficient. In this paper, the helical spring are fabricated with NiTi SMA wire of high resistivity. The force, response speed, temperature, and displacement are measured by digital force gauge, infrared thermometer, and laser displacement sensor so that the dynamic characteristics of this SMA is analyzed. Also, bidirectional actuator was fabricated and experimented for its performance.

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Moving Motivation of Senior Cohousing Inhabitants in Scandinavian Countries (스탄디나비아 노인용 코하우징 주민의 이주동기)

  • Choi, Jung-Shin
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2003.11a
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    • pp.307-312
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    • 2003
  • The purpose of this study was to find out the moving motivation of senior cohousing inhabitants in Scandinavian countries, which experienced change of typical nuclear family structure and higher vocational activity rates of women, earlier than East Asian countries. Cohousing schemes were evolved as an alternative housing to reduce housework for working women, and to reduce loneliness of elderly people by promoting active mutual relationship among inhabitants in the community. This paper described why the elderly moved to senior cohousing in Sweden and Denmark. The project was carried out by social survey. 935 postal questionnaires were sent from April to May 2002 to 28 senior cohousing communities throughout Denmark and Sweden. Of those, 536 replies (57.3%) were collected and analyzed by SPSS program. 19 moving motivations were discussed connected with the variables such as characteristics of residents, community-initiative, and dwelling size. As a result ideology of senior cohousing, wanting to be free from housing management and physical attraction of the building could be interpreted as main reasons to make inhabitants move to senior cohousing community. The important variables affecting moving motivation were found out as living situation and community-initiative. This findings could be used for some information to architects, designers and decision makers who intend to develope senior cohousing projects in the near future in Korea as well as Scandinavian countries.

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Survey on Incidence of Exercise Induced Pulmonary Hemorrhage(EIPH) of Thoroughbred Racehorses in Seoul Racecourse (서울경마장 경주마의 운동기인성 페출혈 발생동향 조사)

  • 김병선;황용규;권철재;임영재
    • Journal of Veterinary Clinics
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    • v.15 no.2
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    • pp.417-426
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    • 1998
  • During the 5 years period(93-197) of Seoul racecourse Thoroughbred racing, 2i963 holies took an active part in Seoul Racecourse and 61,181 horses entered the racing.400 horses(305 : 1 time, 76 :2 times, 19 :3 times, total : 514 cases) had bled(EIPH) from their nostils after their races. Incidence of bleeding horses from the 21963 racehorses was 13.5%, and incidence of bleeding cases from the 61,181 horses was 0.84%. The average racing frequence (1.05 times/1 month) of bleeders was more than that(0.8 times/1 month) of total race-horses. There was tendency to higher incidence of bleeding at older in age, female in sex, England/ Ireland horses in origin, higher grade in performances heavier in body weight increased, larger in weight to be carried, mid or longer in racing distance, handicap race, spring in season. Relationship did not exist between bleeding and respiratory disease. These results suggested that frequent entering into the race should be controlled. And body weight regulation with conditioning is recommended far reducing incidence of EIPH. It is supposed to prevent bleeding that decrescent performance horses should not be entering long distance or handicap race.

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Underactuated Finger Mechanism for Body-Powered Partial Prosthesis (신체 힘에 의해 동작되는 부분 의수를 위한 부족구동 손가락 메커니즘)

  • Yoon, Dukchan;Lee, Geon;Choi, Youngjin
    • The Journal of Korea Robotics Society
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    • v.11 no.4
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    • pp.193-204
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    • 2016
  • This paper presents an anthropomorphic finger prosthesis for amputees whose proximal phalanx is mutilated. The finger prosthesis to be proposed is able to make the amputees to perform the natural motion such as flexion/extension as well as self-adaptive grasping motion as if normal human finger does. The mechanism of finger prosthesis with three degrees-of-freedom (DOFs) consists of two five-bar and one four-bar linkages. Two passive components composed of torsional spring and mechanical stopper and only one active joint are employed in order to realize an underactuation. Each passive component is installed into the five-bar linkage. In order to activate the finger prosthesis, it is required for the user to flex and extend the remaining proximal phalanx on the metacarpophalangeal (MCP) joint, not an electric motor. Thus the finger prosthesis conducts not only the natural motion according to his/her intention but also the grasping motion through the deformation of springs by the object for human finger-like behavior. In order to reveal the operation principle of the proposed mechanism, kinematic analysis is performed for the linkage design. Finally both simulations and experiments are conducted in order to reveal the design feasibility of the proposed finger mechanism.

Rehabilitation of Urban Residence and Vision Examination with Inhabitants - The Trial of Workshop Tool for Decision of Inhabitant Opinions (도심주거지 정비를 위한 주민참여와 마을의 미래상 검토 - 주민의사결정을 위한 워크숍 툴의 시도 -)

  • Park, Chung-Shin;Youm, Chirl-Ho;Won, Se-Yong;Kim, Tai-Young
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2008.04a
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    • pp.266-271
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    • 2008
  • Recently, concern about urban residence community will increase from the 1990s in Korea, and the activity is active. In this research, by holding the workshop by participation with inhabitants spontaneous for Seowoon-dong of Cheongju City which is a place of urban residence, a workshop tool which is different in that process is tried, and that validity is evaluated. As a result of there being three, 'The tool of inhabitants opinion expression using figure card', 'PIC tool', and a 'The tool of inhabitants opinion expression using a drawing', as a workshop tool and examining the validity, validity of two, 'The tool of inhabitants opinion expression using figure card' and 'PIC tool', is high. Moreover, if some are complemented also with 'The tool using a drawing', it can use with it. Finally, in a future inhabitants workshop, residents' agreement formation is important and the system maintenance hurries.

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On the Globalization of the Journal of the Korean Meteorological Society (한국기상학회지의 국제화에 대한 방안)

  • Kwon, H. Joe;Lee, Dong-Kyou;Park, Seon Ki;Ahn, Myung-Hwan
    • Atmosphere
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    • v.16 no.2
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    • pp.159-168
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    • 2006
  • Journal of the Korean Meteorological Society (JKMS) is confronted by a huge challenge. Following the long-term plan of the Korean Meteorological Society (KMS), the JKMS has entered a new era in 2006 in the sense that the all papers are published in English. Tremendous efforts are needed to accomplish the original goal of JKMS becoming an internationally recognized journal. A forum was held in this connection with the subject of the vitalization of the JKMS at the Spring Meeting of the Korean Meteorological Society held at Gwangju, 2006. A number of special topics were presented at the forum and active and vigorous discussions followed. Professor Dong-Kyou Lee presented strategies to increase the number of submission to the JKMS. Professor Seon Ki Park gave a presentation on how JKMS can grow into the SCI journal. The Editor-in-Chief of JKMS, professor H. Joe Kwon introduced the on-line review system of JKMS which had launched in 2006. This manuscript is presented on the basis of the presentations and the discussions at the forum for the purpose of finding the way in aiming the direction of the long-term goal of the KMS.

An Experimental Study on Residential Moving and Satisfaction Causes in Ulsan city (울산시 거주자의 주거이동동기와 주거만족에 관한 연구)

  • 김선중;강혜경
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2002.11a
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    • pp.249-254
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    • 2002
  • The purpose of this study is to identify the causes-effects of residential mobility and satisfaction. The research design employes a survey questionnaire for gathering a set of statistically-reasonable number of data among one million population of Ulsan metropolitan city. To make it more concrete, the attentions to be taken are on establishing (1) motives for moving (2) satisfaction factors in living, and (3) a relationship between houses and their environmental characteristics and the degree of satisfactions by them. The results of empirical analyses provide the following major findings: The most significant house-moving motivations were to achieve living-space at an affordable size or as wide as possible and to gain access to a comfortable and convenient environment. Per the residential satisfaction, highly respected factors were having good neighbors and active interactions with them and having good cooling-heating conditions, sunny rooms, and less noise and air pollution. Finally, the relation of house and its environment with the satisfaction indicated the following significant two: The higher the satisfaction, the shorter the duration of living and the history of construction. The less the satisfaction, the smaller the size of house and/or its complex.

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Species Composition and Primary Production of the Benthic Algal Assemblage along a Channel in Salt Marsh, Kyonggi Bay, Korea (조간대 감습지 수로지역의 저생조류의 종조성 및 일차생산)

  • Cho, Kyung Je;Joon Ho Kim
    • The Korean Journal of Ecology
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    • v.11 no.1
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    • pp.1-15
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    • 1988
  • Studies on species compostion, promary production of benthic algal assemblage were carried out along a channel of the salt marsh near Inch'on, Kyonggi Bay, Korea. Possible biological, physical and KDICical factors controlling the aglal assemblage were also examined. The oveall diatoms were encountered one hundred and thirty-seven taxa, of which the dominant species were Paralia sulcata and Cymatosira belgica. These two species accounted for 32.6% relative abundance throughout the study period. Diatom taxa had no clear seasonal pattern in abundance analysis. But at the algal blooming period in spring, euglenoids occurred with a high abundance. The chlorophyll a content of benthic algae showed definite seasonal pattern. The algal biomass of the appeared to influence the spatial fluctuation in the algal biomass of the channel was regulated primarily by water content of sediment. Grazing by zoobenthos apperaed to influence the spatial fluctuation in the algal biomass of the sediment surface. The algal photosynthesis was measured in the laboratory with oxygen method. Photo-synthetic rate was independent of the temperature under the lower irradiance. The gross production from March to November was estimated to be 190g C/m2 at the channel slope. Photosynthetic efficiency was 0.37% on the basis of the photosyntherically active radiation for the study period.

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A Study on the Interactive space of Contemporary City - focused on interactive space of citize - (현대도시에서 나타나는 상호작용 공간에 대한 연구 - 시민과 상호작용하는 공간을 중심으로 -)

  • Koh, Gwi-Han;Kim, Jung-Gon
    • Korean Institute of Interior Design Journal
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    • v.21 no.5
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    • pp.57-64
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    • 2012
  • The ideologie of modern society as per something to phenomenology problem is to show various different looks. The community space is spring from Greek and Roman of community place by agora and forum is make a active communicate to interpersonally. Subject to centrically In the context, this paper is study on the Sustainable development for community space about interactive space. and focusing is Response to human of interact in each other intelligent space. And this paper suggestion is composition method of community space in technology advanced, Interactive interface form for human, sustainable to community space direction elements. First, I'll rearrange the distinctive features of modern society through references of various scholars. This is to understand how interactivity affects the whole society and what is the importance of this interactive wave. Second, I'll analyze several trends of modern community space and figure the change of methodology of design based on the advancement of design technology. This is to understand the interactive relation of the subjects. Third, I'll seek how community space design has changed in modern society and under which process design is made. This is to clarify the fact that the portion of interaction will increase in future design according to the intervention of equipment, which is one of the objects of interaction space.

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Fast and Safe Contact Establishment Strategy for Biped Walking Robot (이족 보행 로봇을 위한 빠르고 안전한 접촉 생성 전략)

  • Lee, Hosang;Jung, Jaesug;Ahn, Junewhee;Park, Jaeheung
    • The Journal of Korea Robotics Society
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    • v.16 no.2
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    • pp.147-154
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    • 2021
  • One of the most challenging issues when robots interact with the environment is to establish contact quickly and avoid high impact force at the same time. The proposed method implements the passive suspension system using the redundancy of the torque-controlled robot. Instead of utilizing the actual mechanical compliance, the distal joints near the end-effector are controlled to act as a virtual spring-damper system with low feedback gains. The proximal joints are precisely controlled to push the mid-link, which is defined as the boundary link between the proximal and distal joints, towards the environment with high feedback gains. Compared to the active compliance methods, the contact force measurements or estimates are not required for contact establishment and the control time delay problems do not occur correspondingly. The proposed method was applied to the landing foot control of the 12-DoF biped robot DYROS-RED in the simulations. In the results, the impact force during landing was significantly reduced at the same collision speed.