• Title/Summary/Keyword: GRASP

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Performance Evaluation of Robotic Physics Engine for Mobile Manipulator Simulation (모바일 매니퓰레이터 시뮬레이션을 위한 로봇 물리 엔진의 성능 평가)

  • Kwanwoo Lee;Junheon Yoon;Suhan Park;Jaeheung Park
    • The Journal of Korea Robotics Society
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    • v.19 no.1
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    • pp.31-38
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    • 2024
  • A mobile manipulator is capable of handling a wide range of workspaces by overcoming the limitations of mobility inherent in existing fixed-base manipulators. To simulate the mobile manipulator, two contact operations should be considered in the physics engines. One of these operations is the grasp stability between the gripper and the object, while the other involves the contact between the wheels of the mobile robot and the ground during driving. However, it is still difficult to choose an appropriate physics engine for simulating these contact operations of the mobile manipulator. In this paper, the performance of physics engines for simulating the mobile manipulator is evaluated. Firstly, the grasp stability of the physics engine is quantitatively evaluated based on the contact force discontinuity. Secondly, when the mobile robot is controlled by open or closed-loop control methods, differences in the path taken by the mobile robot depending on the physics engine are analyzed. To assess the performance of robot simulation, three dynamic simulators-MuJoCo, CoppeliaSim, and IsaacSim-are used along with five physics engines: MuJoCo, Newton, ODE, Bullet, and PhysX.

A Survey on the Visual Characteristics and Preference of Road Landscape of Traditional Gardens in Suzhou, China based on Rockery Ratio - With a Comparison of Consciousness between Korean and Chinese - (중국 전통원림의 치석피도(置石被度)에 따른 원로경관의 시지각적 특성 분석 - 한국인과 중국인 시지각 비교를 중심으로 -)

  • Kim, Dong-Chan;Park, Yool-Jin;Song, Mei-Jie
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.29 no.4
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    • pp.70-77
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    • 2011
  • This study takes road landscape of traditional Chinese Kangnam gardens in Suzhou as the object. It compares the relations and differences between preferences of Korean and Chinese on road landscapes with different rockery ratios, and studies the differences between Korean and Chinese's adjective visual characteristics of road landscape of traditional gardens and impacts of visual characteristics on preference. The following is the research process: Firstly, the theoretical survey of road landscape of traditional Chinese Kangnam gardens is conducted, pictures of the road landscape of gardens in Suzhou are taken, and 15 pictures are selected based on rockery ratio. Secondly, in order to grasp the visual preference and landscape characteristics of road landscape of garden in Suzhou, 15 pictures and 21 pairs of adjectives are adopted for the questionnaire survey. Thirdly, in order to grasp the differences between preferences of Korean and Chinese on road landscape of traditional Chinese Kangnam gardens, thet-test analysis is conducted. In order to grasp the impacts of rockery ratio on preference, and after the classification of landscape pictures based on rockery occupancy, the average analysis, factor analysis of results of questionnaire survey for Korean and Chinese are conducted respectively. In order to grasp the differences of incentives of landscape preference, the incentive analysis of results of questionnaire survey for Korean and Chinese is carried out. In order to grasp the impacts of various factors on the preference, The results are as follows: The results of analysis of differences between Korean and Chinese's preference on road landscape of traditional Chinese Kangnam gardens show that the overall preference of Chinese is higher than that of Korean. The results of the landscape preference analysis show that the ranking order of average value of Korean and Chinese's preference on rockery ratio categories is: medium ratio, very small ratio, small ratio, large ratio, very large ratio. The results of analysis of relations between rockery ratio of traditional Chinese Kangnam gardens and preference show that the preference increases as the rockery ratio decreases, and the rockery ratio variation causes greater impacts on Korean. Results of the analysis of visual characteristics, factors of visual characteristics of Koreans are "aesthetic factor", "comfort factor", "neat(orderly) factor", and "fun factor". The visual characteristics of Chinese has three factors, namely "psychological factor", "comfort factor", and "neat factor".

A study for the standardization of dental hygiene terms (치위생 용어 표준화를 위한 방안 연구)

  • Hwang, Ji-Young;Cho, Min-Jeong;Park, Young-Nam;Lim, Soon-Ryun;Hwang, Soo-Jeong;Oh, Sang-Hwan
    • Journal of Korean society of Dental Hygiene
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    • v.10 no.4
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    • pp.627-633
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    • 2010
  • Objectives : The purpose of this study was to compare and analyse periodontal terminology of 16 dental hygiene textbooks including periodontology, dental prophylaxis for the standardization. Methods : 16 kinds of major publications were classified into the following criteria. - the standardization of translation, orthography, classification Results : 1. There are twelve cases, all told, of words with same origin used as different explanation and interpretation. Mucogingival Junction is most translated as '치은점막 경계' with high percentage of 53.8%, while Probe is translated as '치주낭 측정기' with 41.7% and Acquired Pellicle is translated as '획득피막' with 57.1%. In addition, Stippling is interpreted as '점몰' with high percentage of 70%, and Supine Position is interpreted as '수평자세' or '앙와위' with 33.3%. Yet, Pen Grasp is explained differently in all five books, whereas Modified Pen Grasp is explained as '변형 연필 잡기법' with 57.1%. The rest, Palm Thumb Grasp and Adaptation, have different interpretation in books, requiring unified interpretation of terms. 2. There are two cases of loanwords expressed according to orthography. Implant is expressed as '임플란트'(87.5%) and '임프란트'(12.5%). Scaling is expressed as '스켈링'(40.0%) and '스케일링'(60.0%). 3. There are four cases of same terms classified in a different way. Classification of 'Probing시 압력' and '치주인대섬유군' concurs only 50.0% in six books. '치석제거 시술자의 위치' is classified differently in all six books, while '정상치은 열구 깊이' concurred 45.5% in books. Conclusions : In conclusion, related academic majors and writers should provide cohesive explanation and interpretation of terms for unification of terminology in the field of periodontics as well as higher level of understanding and learning opportunities for students. Furthermore, description of all terms should be reviewed and analyzed comprehensively based on existing classification criteria in order to provide best standard explanation.

Transmission Characteristics on Wire-Driven Links of a Bridge Transported Servo Manipulator for the ACP Equipment Maintenance (사용후핵연료 차세대관리 공정장치 유지보수용 천정이동 서보 매니퓰레이터 와이어 구동부 동작특성)

  • 박병석;진재현;송태길;김성현;윤지섭
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.2 no.3
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    • pp.189-199
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    • 2004
  • A bridge transported servo manipulator (BTSM) system for the advanced spent fuel conditioning process (ACP) has been developed to overcome the limitation of access, which is a drawback of mechanical master-slave manipulators (MSM) for the equipment maintenance. The servo manipulator is composed of a slave manipulator attached to the telescoping tubesets equipped with the overhead bridge installed at a hot cell and a master manipulator installed at an out-of-hot cell. Each manipulator has 7 degrees-of-freedom (DOF): a body rotation, an upper-arm tilt, a lower-arm tilt, a lower-arm rotation, a wrist pan & tilt, and a grasp motion. A wire-driven mechanism for a lower-arm rotation, a wrist pan and tilt, and a grasp motion of the manipulator has been adopted to increase the handling capacity compared to the manipulator weight and decrease the friction. The main disadvantage of the wire-driven mechanism is that if one link is in motion, other links can be affected. In this paper, the transmission characteristics among the wire-driven links have been formulated to overcome this drawback. The unexpected behaviors are confirmed by analyses of transmission characteristics as well as experiments. Also, the experimental results show that the unexpected behaviors are greatly decreased by the proposed compensation equations.

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A Convergence Study on association of Internet Use Time with Perceived Status in Adolescents (청소년 인터넷 사용시간이 청소년 주관적 상태에 미치는 영향에 대한 융합연구)

  • Baek, Seung Hee;Kim, Ji hyun
    • Journal of the Korea Convergence Society
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    • v.9 no.11
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    • pp.153-159
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    • 2018
  • The purpose of this study is to grasp the internet use time that young people use for purposes other than learning purpose, to grasp the perceived status of the youth according to internet use time and to grasp the interrelationships of them. Using the 2016 youth health behavior online survey, the odds ratios and 95% confidence intervals of perceived status according to internet use time were calculated by binary logistic regression analysis. The main results are as follows. In perceived health and perceived oral health the odds ratios of perceived who feel that they are perceived and unhealthy as the time spent using the Internet increased significantly compared to those who did not use the Internet for learning purposes. In the perceived body type, the odds ratio of being overweight increased significantly with longer internet use time. The odds ratios of perceived happiness were 1.19 times (CI = 1.10-1.30) higher than the perceived expectation of unhappiness when using the Internet for over 300 minutes. The use of the internet for a long time other than the purpose of learning may have a negative effect on the health and happiness of the youth, so we think that the recommended time for using the internet is necessary.

A case study of large-scale slope failure in Granite - Andesite contact area (화강암-안산암 접촉부 대규모 사면의 붕괴 사례 연구)

  • 이수곤;양홍석;황의성
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.503-508
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    • 2003
  • In this study, we peformed ahead a field geological investigation, boring investigation for slope stability analysis in large scale slope failure area. But the geological stratum was not clearly grasped, because ground was very disturbed by large scale Granite intrusion. Furthermore, the existing test data was not pertinent to the large scale Granite intrusion site like here. Therefore, various kind of field test were performed to grasp clearly for geological stratum. And the results of back analysis, various kind tests used to slope stability analysis.

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LSI-Updating Application for Internet-based Information Retrieval - LSI Improvement Using QR Decomposition (인터넷기반 정보 검색을 위한 LSI 활용 - QR 분해를 이용한 LSI 향상)

  • 박유진;송만석
    • Proceedings of the IEEK Conference
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    • 2001.06c
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    • pp.47-50
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    • 2001
  • This paper took advantage of SVD (Singular value Decomposition) techniques of LSI(Latent Semantic Indexing) to grasp easily terminology distribution. Existent LSI did to static database, propose that apply to dynamic database in this paper. But, if dynamic applies LSI to database, updating problem happens. Existent updating way is Recomputing method, Folding-in method, SVD-updating method. Proposed QR decomposition method to show performance improvement than existent three methods in this paper.

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A Study on IFGP Model for Solving Multiobjective Quality Management under Fuzzy Condition

  • Cheong, Jong Shik;Pak, Pyong Ki
    • Journal of Korean Society for Quality Management
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    • v.21 no.2
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    • pp.194-214
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    • 1993
  • This paper purports to study on interactive fuzzy goal programming model which leads to the compromise solution which the decision maker satisfies through the interactive approach. We also attempted to calculate local proxy preference function from utility function of sum-of-logarithms in connection with marginal rate of substitution and interactive approach for the purpose of applying weight of multiobjective function. In an attempt to grasp compromise solution from fuzzy efficient solution, we decided to take the interactive method and presented stopping rule for this.

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Filtering Theory (필터링 이론)

  • 송택렬
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.6
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    • pp.413-419
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    • 2003
  • The objective of this paper is to survey and put in perspective the existing methods of dynamic filter development. This includes theories and practices for linear and nonlinear filters, multiple model filters, and data association methods for tracking in multitarget environment. The presentation of this paper is motivated by recent surge of interest in the area of designing feedback control systems with reduced number of sensors, detection and identification of abrupt changes, and multitarget tracking in clutter. It is hoped to be useful in view of the need to take a grasp of existing techniques before using them in practice and developing new techniques.

A study on the Awareness of Employees and Consumers about the Show Window in Apparel Shops (의류매장 쇼윈도에 대한 종사자와 소비자의 의식에 관한 조사 연구)

  • 김현지
    • Journal of the Korean housing association
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    • v.5 no.2
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    • pp.119-127
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    • 1994
  • This study has tried to grasp the awareness of employees in current apparel industry and common consumers about the show window in apparel shops. Interestingly, the employees were more concerned about the necessity of display and lighting than the consumers. However, the current display and lighting systems did not satisfy the consumers' requirements. Although they did not recognize that lighting display was closely related with display, color, and so on, they thought lighting indispensable. In consequnce, they light source and lighting method have to be carefully chosen, and the relationship between color and lighting should be fully considered as well.

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