• Title/Summary/Keyword: Joint Action

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A study on simulation and performance improvement of industrial robot manipulator controller using adaptive model following control method (적응모델추종제어기법에 의한 산업용 로봇 매니퓰레이터 제어기의 성능개선 및 시뮬레이션에 관한 연구)

  • 허남수;한성현;이만형
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.2
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    • pp.463-477
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    • 1991
  • This study proposed a new method to design a robot manipulator control system capable of tracking the trajectories of joint angles in a reasonable accuracy to cover with actual situation of varying payload, uncertain parameters, and time delay. The direct adaptive model following control method has been used to improve existing industrial robot manipulator control system design. The proposed robot manipulator controller is operated by adjusting its gains based on the response of the manipulator in such a way that the manipulator closely matches the reference model trajectories predefined by the designer. The manipulator control system studied has two loops: they are an inner loop on adaptive model following controller to compensate nonlinearity in the manipulator dynamic equation and to decouple the coupling terms and an outer loop of state feedback controller with integral action to guarantee the stability of the adaptive scheme. This adaptation algorithm is based on the hyperstability approach with an improved Lyapunov function. The coupling among joints and the nonlinearity in the dynamic equation are explicitly considered. The designed manipulator controller shows good tracking performance in various cases, load variation, parameter uncertainties. and time delay. Since the proposed adaptive control method requires only a small number of parameters to be estimated, the controller has a relatively simple structure compared to the other adaptive manipulator controllers. Therefore, the method used is expected to be well suited for a high performance robot controller under practical operation environments.

The Effects of Electroacupuncture on SNCV and SEP in Acute Hyperglycemia Rats (전침자극이 초기 고혈당 백서의 감각신경전도속도 및 체성감각유발전위에 미치는 영향)

  • Lim, Young-Eun;Jeong, Jeong-Woo;Kim, Tae-Youl
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.5 no.2
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    • pp.47-59
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    • 2007
  • The purpose of this study were to investigate the effects of electroacupuncture(EA) on sensory nerve function in acute hyperglycemia rats. Male Sprague-Dawley rats weighing 250~270 g(8 weeks of age) were used in this study, and the induced hyperglycemia rats were produced by intraperitoneal injection of streptozotocin(70 mg/kg body weight). Only animals with blood glucose levels of 300 mg/dl or higher were used in this study. Animal were divided into two groups: the control group and EA group (n=7 in each group). For EA, two stainless-steel needles were inserted into Zusanli (ST36) which is located at the anterior tibial muscle and about 10mm below the knee joint. Pulsed current(2 Hz, 0.3 ms) were applied to the inserted needle for 20 mim. We measured glucose level, weigh, sensory nerve conduction and somatosensory evoked potential(5EP) before and after injecting streptozotocin, 2 weeks, 4 weeks. The change of blood glucose on EA group trended to decrease compared with the control group and there were significant differences(p<0.05). The body weight of the EA group trended to be reduced compared with the control group and there were significant differences(p<0.05). The amplitude of sensory nerve action potential on EA group to increase compared with the control group and there were significant differences(p<0.05). There were no significant differences in SEP. These results suggest that EA has beneficial effect on diabetic neuropathy and this effect may be related in part with prevention of hyperglycemia.

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A Joint Wakeup Scheduling and MAC Protocol for Energy Efficient Data Forwarding in Wireless Sensor Networks (무선 센서 네트워크에서 에너지 효율적인 데이터 전송을 위한 스케줄링/ MAC 통합 프로토콜)

  • Cho, Jae-Kyu;Kwon, Tae-Kyoung;Choi, Yang-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.4B
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    • pp.207-214
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    • 2008
  • Under future internet environment, wireless sensor networks will be used in a wide range of applications. A major problem for designing sensor protocol is developing the most energy efficient technique to monitor an area of interest for a long time since sensors have some constraints such as small and a limited energy level. In addition, data latency is often a critical issue since sensory data is transmitted via multi hop fashion and need to be delivered timely for taking an appropriate action. Our motivation for designing a data forwarding protocol is to minimize energy consumption while keeping data latency bound in wireless sensor networks. In this paper, we propose a data forwarding protocol that consists of wakeup scheduling and MAC protocols, the latter of which is designed to achieve load balancing. Simulation results show that the proposed framework provides more energy-efficient delivery than other protocol.

A Study on Characteristics of Ecological Expression in Shigeru Ban's Architecture - Focus on the Paper Tube Architecture of Hanover Expo 2000 Japan Pavillion (시게루 반의 건축에 나타나는 생태적 표현특성에 관한 연구 - 하노버 엑스포 일본관의 종이튜브건축을 중심으로 -)

  • Cho Hyeon-Mi
    • Korean Institute of Interior Design Journal
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    • v.14 no.6 s.53
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    • pp.75-85
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    • 2005
  • The 1990s' characteristics of Ecological architectural design would be choosing the traditional materials of the region's, the creative usage of construction methods, the expressive properties of materiality in spatial forms and so on. The overall organic relationships between human and men-made environments have been sublimated by the expression of poetic qualities of perception in ecological man-made environment. Hannover Expo 2000 did set up an opportunity to exposure the fact that Ecological Architecture will be the major trend in 21st Century's Architecture and its exploration in possible ways will be the most important matter. Japanese Architect Shigeru Ban's Japan Pavilion in this Exposition has shown the meaning of this turning point in Ecological Architectural thinking, which would be recognized as the convincing possibilities for the future architectural practice to the public. Thus this research has the purpose to study the meaning of the constructing action in Shigeru Ban's recent architectural space-making practice with the Paper Tube structural system. The creative foundation of Shigeru Ban's own method to apply paper tube -that is impossible material to pre-estimate- and other materials in the creation of architectural spaces would be searched in this paper. The period to this research will be between 1990s and 2000s, and the subject will be the experimental architecture of Shigeru Ban. The range of this research Is including the process of development in the paper tube architectural structure and joint system. This study would contribute to understand the intrinsic value of Shigeru Ban's Ecological architecture of the paper tube system, in which the relationship between the regional environment and human regaining the ecological abiogenesis.

Nonlinear response of stiffened triceratops under impact and non-impact waves

  • Chandrasekaran, Srinivasan;Nassery, Jamshed
    • Ocean Systems Engineering
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    • v.7 no.3
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    • pp.179-193
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    • 2017
  • Dynamic response analysis of offshore triceratops with stiffened buoyant legs under impact and non-impact waves is presented. Triceratops is relatively new-generation complaint platform being explored in the recent past for its suitability in ultra-deep waters. Buoyant legs support the deck through ball joints, which partially isolate the deck by not transferring rotation from legs to the deck. Buoyant legs are interconnected using equally spaced stiffeners, inducing more integral action in dispersing the encountered wave loads. Two typical nonlinear waves under very high sea state are used to simulate impact and non-impact waves. Parameters of JONSWAP spectrum are chosen to produce waves with high vertical and horizontal asymmetries. Impact waves are simulated by steep, front asymmetric waves while non-impact waves are simulated using Stokes nonlinear irregular waves. Based on the numerical analyses presented, it is seen that the platform experiences both steady state (springing) and transient response (ringing) of high amplitudes. Response of the deck shows significant reduction in rotational degrees-of-freedom due to isolation offered by ball joints. Weak-asymmetric waves, resulting in non-impact waves cause steady state response. Beat phenomenon is noticed in almost all degrees-of-freedom but values in sway, roll and yaw are considerably low as angle of incidence is zero degrees. Impact waves cause response in higher frequencies; bursting nature of pitch response is a clear manifestation of the effect of impact waves on buoyant legs. Non-impact waves cause response similar to that of a beating phenomenon in all active degrees-of-freedom, which otherwise would not be present under normal loading. Power spectral density plots show energy content of response for a wide bandwidth of frequencies, indicating an alarming behaviour apart from being highly nonlinear. Heave, being one of the stiff degrees-of-freedom is triggered under non-impact waves, which resulted in tether tension variation under non-impact waves as well. Reduced deck response aids functional requirements of triceratops even under impact and non-impact waves. Stiffened group of buoyant legs enable a monolithic behaviour, enhancing stiffness in vertical plane.

Inhibitory Effect of a Decoction Combined with Ostericum koreanum Maxim. and Aralia continentalis Kitagawa on Collagen II-induced Arthritis Mice (Type II Collagen으로 유도된 관절염에 대한 강활(羌活), 독활(獨活) 배합약물의 억제 효과)

  • Yoon, Ho-Suk;Lee, Young Cheol;Lee, Jang-Cheon
    • Herbal Formula Science
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    • v.21 no.1
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    • pp.161-176
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    • 2013
  • Objectives : To clarify the anti-arthritic activity of Ostericum koreanum Maxim. (OS) plus Aralia continentalis Kitagawa (AC) in vivo. Methods : All mice were immunized with bovine type II collagen. After a second collagen immunization, mice were treated with OS plus AC once a day for 7 weeks. Oral administration of OS plus AC (200 or 50 mg/kg) significantly suppressed the progression of CIA, which extend is comparable to that of methotrexate (MTX, 0.3 mg/kg), a positive control. The severity of arthritis within the knee joints was evaluated by histological assessment of cartilage destruction and pannus formation. Results : Administration of OS plus AC significantly suppressed the progression of CIA and inhibited the production of TNF-${\alpha}$ and IL-6 in serum. The erosion of cartilage was dramatically reduced in mouse knees after treatment with OS plus AC. In conclusion, our results demonstrates that OS plus AC significantly suppressed the progression of CIA and that this action was characterized by the decreased production of IL-6, IFN-${\gamma}$ and collagen II specific antibody in serum, CD3+CD69+ T cells, MHC class II+/CD11c+ (in DLN), CD11b+Gr-1+ cells (in PBMC), CD11b +Gr-1+ cells, B220+/CD23+ (in paw joint). Conclusions : The the levels of IFN-${\gamma}$ in the culture supernatant of splenocytes stimulated with CD3/CD28 or collagen were dramatically decreased, while those of IL-4 was increased. In the serum of OS and AC-treated mice, the levels of IgM RA factor were decreased.

Design of longitudinal prestress of precast decks in twin-girder continuous composite bridges (2거더 연속강합성 교량의 프리캐스트 바닥판 종방향 프리스트레스 설계)

  • Shim, Chang Su;Kim, Hyun Ho;Ha, Tae Yul;Jeon, Seung Min
    • Journal of Korean Society of Steel Construction
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    • v.18 no.5
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    • pp.633-642
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    • 2006
  • Serviceability design is required to control the cracking at the joint of precast decks with longitudinal prestress in continuous composite bridges. Details of twin-girder bridges are especially complex not only due to their main reinforcements and transverse prestresses for the design of long-span concrete slabs, but also due to the shear pockets for obtaining the composite action. This paper suggests the design guidelines for the magnitude of the effective prestress and for the selection of filling materials and their requirements that would allow for the use of precast decks for twin-girder continuous composite bridges. The necessary initial prestress was also evaluated through long-term behavior analysis. From the analysis, existing design examples were revised and their effectiveness was estimated. When a filling material with a bonding strength higher than the requirement is used in the region of a high negative moment, a uniform configuration of the longitudinal prestressing steels along thewhole span length of continuous composite bridges can be achieved, which would result in the simplification of the details and the reduction of the construction costs.

Theoretical Basis and Application of the Neurac Technique Which Uses the Sling Exercise Therapy (슬링운동치료를 이 용한 Neurac 기법의 이론적 근거와 적용방법)

  • Kim, Suhn-Yeop;Kim, Taek-Yean
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.12 no.2
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    • pp.52-65
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    • 2006
  • Sling exercises therapy can speak as appliable comprehensive exercises therapy technique efficiently in general exercise field for injured worker's rehabilitation process and health improvement patient or athlete, injury or disease that have pain or dysfunction to neuromuscular system using that shake. At 1990 an early stage, because physical therapist and doctors of medical treatment developed country norway of north europe cooperate sling exercises therapy's concept trend spreading worldwide establishing theory newly based on scientific basic be. Musculoskeletal system, old man and young child's nervous system injurer's treatment and exercise and industry worker's rehabilitation process, athlete's rehabilitation etc. several fields introduced in early 2000s to Korea apply. Sling exercises therapy neuromuscular system disease continuous abatement as general concept of active exercise and treatment that use sling exercises equipment by purpose know can. This review article wishes to introduce about neuromuscular activation, "Neurac" technique that can speak as step developed more concept based on application principle etc, of basic sling exercises effort's change by suspension point's change that is concept, stability exercises principle, open kinetic chain exercises and closed kinetic chain exercises. Arranged about Plateau potential's characteristic and working mechanism and Neurac technique's application method that can say as Neurac technique's neuro-physiologic base, and presented treatment method of lumbar part disease and cervical part, shoulder joint part disease to application example. Because plateau potential forward player that induce using Neurac technique in part muscles that act role that keep spine surrounding stability in this article keeps muscle's contraction continuously, between global and local muscles, presented several study findings that can cause affirmative change in insufficient muscle adjustment state such as imbalance of muscles' action order. Expect that case studies that use this Neurac technique here after consist continuously.

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A Study on the Working Clothes for Korea Railroad -Focused on Winter Upper Garment- (한국철도공사 작업복에 관한 연구 (제1보) -동복 상의를 중심으로-)

  • Kim, Ji-Won;Choi, Hei-Sun;Ryou, Heun-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.33 no.2
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    • pp.308-318
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    • 2009
  • The purpose of this study was to develop the functionally improved winter work clothing for the Korean railroad workers. Based on the questionnaires, the sample clothing for the Korean railroad workers was produced. The design, materials, and patterns were modified to increase mobility and comfort of workers. Water-repellent treatment was added to the material in order to decrease the dirt and stains while working. Also the reflective strips were added to chest and back of the upper garment in order to increase visibility and safety of the workers. In terms of the design and pattern underarm of the sleeve and side panel of the bodice were put in together and action pleats at the back were inserted in order to decrease the pullback of the armpit and scapular area and increase mobility of the arm movement. Also the patterns of the elbows areas were modified to increase mobility of joint. The prototype was evaluated an objective assessment and subjective assessment to compare to the existing working uniform. Assessment group was consisted of 5 subject groups and 11 expert groups and evaluated external appearance and adaptability to the movements. According to the results, the prototype was evaluated better than the existing working uniform in appearance and adaptability except height of collar. A field test was conducted to compare the prototype and the existing working uniform. The field tests were performed by 6 workers in the Korean railroad. According to the results, the prototype was improved in terms of adaptability and comfort.

A Study of Proprioceptive Neuromuscular Facilitation Principles (고유수용성 신경근 촉진법 원리에 관한 고찰)

  • Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.5 no.1
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    • pp.109-114
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    • 1993
  • The originator of the proprioceptive neuromuscular facilitation method was Dr. Herman Kabat, a man who received the bachelor of science degree from New York University in 1932. In 1936 he moved to the University of Minnesota where he served as instructor in physiology and also studies medicine. He received his medical doctorate in 1942. When Dr. Karbat meet Sister Kenny suggested that certain change. She does not receptive his ideas. So that he decided to pursure the treatment of patients. Upon the establishment of the Karbat- kaiser Institute to be opened in 1946. Margaret Knott, the first physical therapist to be employed by him and to become his head physical therapist. In 1948 Vallejo center was opened. Dr. Kabat developed the PNF method combined motions to ascertain the effectiveness of maximal resistance and stretch in facilitating the response of a weak distal muscle. He identified mass movement patterns that were spiral and diagonal in character in 1965. Margaret Knott presented lecture at tile APTA Annual Conference in Las Vegas. The title was In the groove. On December 18, 1978 she passed away at her home in Vallejo. Marie-Louise Mangold is director of the Kaiser Foundation Rehabilitation Center now. She is the Vice President of International Proprioceptive Neuromuscular facilitation Association. About 20 physical therapist working teaching and study at KFRC in Vallejo. PNF neuromuscular mechanism becomes integrated and efficient without awareness of individual muscle action, reflex and a multitude of other neurophysiological reactions. The principles of PNF are visual consideration, verbal consideration, and proprioceptive input consideration with tactile stimulation, joint receptors, appropriate facilitation, stretch reflex normal timing, irradiation, pattern of movement.

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