• Title/Summary/Keyword: Joint Action

Search Result 276, Processing Time 0.026 seconds

Dynamic behaviors of viscous damper on concrete archaized building with lintel-column joint

  • Xue, Jianyang;Dong, Jinshuang;Sui, Yan
    • Earthquakes and Structures
    • /
    • v.13 no.4
    • /
    • pp.409-419
    • /
    • 2017
  • In order to analyze the vibration control effect of viscous damper in the concrete archaized buildings with lintel-column joints under seismic action, 3 specimens were tested under dynamic excitation. Two specimens with viscous damper were defined as the controlled component and one specimen without viscous damper was specified as the non-controlled component. The loading process and failure patterns were obtained from the test results. The failure characteristics, skeleton curves and mechanical behavior such as the load-displacement hysteretic loops, load carrying capacity, degradation of strength and rigidity, ductility and energy dissipation of the joints were analyzed. The results indicate that the load-bearing capacity of the controlled component is significantly higher than that of the non-controlled component. The former component has an average increase of 27.4% in yield load and 22.4% in ultimate load, respectively. Meanwhile, the performance of displacement ductility and the ability of energy dissipation for the controlled component are superior to those of the non-controlled component as well. Compared with non-controlled component, equivalent viscous damping coefficients are improved by 27.3%-30.8%, the average increase is 29.0% at ultimate load for controlled component. All these results reflect that the seismic performance of the controlled component is significantly better than that of the non-controlled component. These researches are helpful for practical application of viscous damper in the concrete archaizing buildings with lintel-column joints.

Singularity Avoidance Path Planning on Cooperative Task of Dual Manipulator Using DDPG Algorithm (DDPG 알고리즘을 이용한 양팔 매니퓰레이터의 협동작업 경로상의 특이점 회피 경로 계획)

  • Lee, Jonghak;Kim, Kyeongsoo;Kim, Yunjae;Lee, Jangmyung
    • The Journal of Korea Robotics Society
    • /
    • v.16 no.2
    • /
    • pp.137-146
    • /
    • 2021
  • When controlling manipulator, degree of freedom is lost in singularity so specific joint velocity does not propagate to the end effector. In addition, control problem occurs because jacobian inverse matrix can not be calculated. To avoid singularity, we apply Deep Deterministic Policy Gradient(DDPG), algorithm of reinforcement learning that rewards behavior according to actions then determines high-reward actions in simulation. DDPG uses off-policy that uses 𝝐-greedy policy for selecting action of current time step and greed policy for the next step. In the simulation, learning is given by negative reward when moving near singulairty, and positive reward when moving away from the singularity and moving to target point. The reward equation consists of distance to target point and singularity, manipulability, and arrival flag. Dual arm manipulators hold long rod at the same time and conduct experiments to avoid singularity by simulated path. In the learning process, if object to be avoided is set as a space rather than point, it is expected that avoidance of obstacles will be possible in future research.

Prediction of Type 2 Diabetes Remission after Bariatric or Metabolic Surgery

  • Park, Ji Yeon
    • Journal of Obesity & Metabolic Syndrome
    • /
    • v.27 no.4
    • /
    • pp.213-222
    • /
    • 2018
  • Bariatric surgery has evolved from a surgical measure for treating morbid obesity to an epochal remedy for treating metabolic syndrome as a whole, which is represented by type 2 diabetes mellitus. Numerous clinical trials have advocated bariatric or metabolic surgery over nonsurgical interventions because of markedly superior metabolic outcomes in morbidly obese patients who satisfy traditional criteria for bariatric surgery (body mass index [BMI] >$35kg/m^2$) and in less obese or simply overweight patients. Nevertheless, not all diabetes patients achieve the most desirable outcomes; i.e., diabetes remission after metabolic surgery. Thus, candidates for metabolic surgery should be carefully selected based on comprehensive preoperative assessments of the risk-benefit ratio. Predictors for diabetes remission after metabolic surgery may be classified into two groups based on mechanism of action. The first is indices for preserved pancreatic beta-cell function, including younger age, shorter duration of diabetes, and higher C-peptide level. The second is the potential for an insulin resistance reduction, including higher baseline BMI and visceral fat area. Several prediction models for diabetes remission have been suggested by merging these two to guide the joint decision-making process between clinicians and patients. Three such models, DiaRem, ABCD, and individualized metabolic surgery scores, provide an intuitive scoring system and have been validated in an independent external cohort and can be utilized in routine clinical practice. These prediction models need further validation in various ethnicities to ensure universal applicability.

Scientific exploration on physiological basis of Svedana Karma (Sudation): A clinical application of heat stress.

  • Yadav, Saurabh;Verma, Vandana;Abhinav, Abhinav
    • CELLMED
    • /
    • v.9 no.3
    • /
    • pp.4.1-4.8
    • /
    • 2019
  • Now researchers have focused attention on exploring the mechanism of acute responses of heat stress given in heat therapy that ultimately promotes the long term health benefits. Heat therapy is not a new idea rather it was practiced since thousands years back in the form of hot bath, sauna bath, steam room. Similarly in Ayurveda there is very comprehensive description of heat therapy in the form of Svedan karma (Sudation therapy). Svedan is a process to induce sweating artificially in a patient who had already undergone Snehan. Svedan is applied for purification of body, as well as in management of various disorders originated due to vitiation of Vata, Kapha Dosha, Meda Dhatu and musculoskeletal disorders. It produces various beneficial effects by augmenting the Agni like clears the channels, liquefies the deposited Dosha, regulates Vata Dosha, helps in removal and pacification of Dosha, augments metabolism (Agni Deepan), increases appetite, flexibility in body parts, softness and shining of skin, removes coldness, stiffness, drowsiness, improves joint motility. However, Svedana karma is vastly used by Ayurveda Physicians in treatment of various disorders but the mechanisms of beneficial effects produced by Svedan Karma are yet not completely explored on scientific basis. In this article, we will discuss and try to establish a possible mechanism of action of Svedana karma in relation to heat stress, mitochondrial adaptation, heat shock protein (HSP) and glucocorticoids as these are secreted under stressful conditions.

Analysis of the Phillips Curve: An Assessment of Turkey

  • NAR, Mehmet
    • The Journal of Asian Finance, Economics and Business
    • /
    • v.8 no.2
    • /
    • pp.65-75
    • /
    • 2021
  • This study analyzes the validity of the Phillips curve with regards to Turkey. The existence and direction of the causality relationship (reason-outcome relationship) between unemployment and inflation is investigated using inflation and unemployment data for the period 1980-2019. Unit root tests were utilized to evaluate the stationarity of the series. In line with the Zivot-Andrews unit root test, which was developed in response to the criticism of the failure of studies that presented macro-variables like inflation to consider traditional unit root tests, in this research, the Engle-Granger cointegration test was implemented to check whether the series could perform a joint action, and, finally, the Granger causality relationship was explored. According to the results of the analysis, over the relevant period there was a single directional causality relationship from inflation toward unemployment in Turkey. The importance of this relationship at the 10% significance level indicates the existence of many different factors that affect inflation and unemployment. Given the existence of a cointegration and causality relationship between inflation and unemployment, it can be said that, in Turkey, the Phillips curve is valid for the period 1980-2019 and that an increase of 1% in inflation will reduce the unemployment rate by 0.028%.

Articulatory robotics (조음 로보틱스)

  • Nam, Hosung
    • Phonetics and Speech Sciences
    • /
    • v.13 no.2
    • /
    • pp.1-7
    • /
    • 2021
  • Speech is a spatiotemporally coordinated structure of constriction actions at discrete articulators such as lips, tongue tip, tongue body, velum, and glottis. Like other human movements (e.g., reaching), each action as a linguistic task is completed by a synergy of involved basic elements (e.g., bone, muscle, neural system). This paper discusses how speech tasks are dynamically related to joints as one of the basic elements in terms of robotics of speech production. Further this introduction of robotics to speech sciences will hopefully deepen our understanding of how speech is produced and provide a solid foundation to developing a physical talking machine.

The mechanism of action of pulsed radiofrequency in reducing pain: a narrative review

  • Park, Donghwi;Chang, Min Cheol
    • Journal of Yeungnam Medical Science
    • /
    • v.39 no.3
    • /
    • pp.200-205
    • /
    • 2022
  • Pain from nervous or musculoskeletal disorders is one of the most common complaints in clinical practice. Corticosteroids have a high pain-reducing effect, and their injection is generally used to control various types of pain. However, they have various adverse effects including flushing, hyperglycemia, allergic reactions, menstrual changes, immunosuppression, and adrenal suppression. Pulsed radiofrequency (PRF) is known to have a pain-reducing effect similar to that of corticosteroid injection, with nearly no major side effects. Therefore, it has been widely used to treat various types of pain, such as neuropathic, joint, discogenic, and muscle pain. In the current review, we outlined the pain-reducing mechanisms of PRF by reviewing previous studies. When PRF was first introduced, it was supposed to reduce pain by long-term depression of pain signaling from the peripheral nerve to the central nervous system. In addition, deactivation of microglia at the level of the spinal dorsal horn, reduction of proinflammatory cytokines, increased endogenous opioid precursor messenger ribonucleic acid, enhancement of noradrenergic and serotonergic descending pain inhibitory pathways, suppression of excitation of C-afferent fibers, and microscopic damage of nociceptive C- and A-delta fibers have been found to contribute to pain reduction after PRF application. However, the pain-reducing mechanism of PRF has not been clearly and definitely elucidated. Further studies are warranted to clarify the pain-reducing mechanism of PRF.

Design Considerations and Pull-Out Behavior of Mechanical Anchor of Reinforcement (철근 기계적 정착장치의 설계 고려사항과 인발특성)

  • 천성철;김대영
    • Journal of the Korea Concrete Institute
    • /
    • v.13 no.6
    • /
    • pp.593-601
    • /
    • 2001
  • In RC structure, sufficient anchorage of reinforcement is necessary for the member to produce the full strength. Generally, conventional standard hook is used for the reinforcement's anchorage. However, the use of standard hook results in steel congestion, making fabrication and construction difficult. Mechanical anchor offers a potential solution to these problems and may also ease fabrication, construction and concrete placement. In this paper, the required characteristics and the design considerations of mechanical anchor were studied. Also, the mechanical anchor was designed according to the requirements. To investigate the pull-out behavior and properness of mechanical anchorage, pull-out tests were performed. The parameters of tests were embedment length, diameter of reinforcement, concrete compressive strength, and spacing of reinforcements. The strengths of mechanical anchor were consistent with the predictions by CCD method. The slip between mechanical anchor and concrete could be controlled under 0.2mm. Therefore, the mechanical anchor with adequate embedment could be used for reinforcement's anchorage. However, it was observed that the strength of mechanical anchors with short spacing of reinforcements was greatly reduced. To apply the mechanical anchor in practice (e.g. anchorage of the beams reinforcements in beam-column joint), other effects that affect the mechanical anchor mechanism, such as confinement effect of adjacent member from frame action or effects of shear reinforcement, should be considered.

A Comic Facial Expression Method for Intelligent Avatar Communications in the Internet Cyberspace (인터넷 가상공간에서 지적 아바타 통신을 위한 코믹한 얼굴 표정의 생성법)

  • 이용후;김상운;청목유직
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.40 no.1
    • /
    • pp.59-73
    • /
    • 2003
  • As a means of overcoming the linguistic barrier between different languages in the Internet, a new sign-language communication system with CG animation techniques has been developed and proposed. In the system, the joint angles of the arms and the hands corresponding to the gesture as a non-verbal communication tool have been considered. The emotional expression, however, could as play also an important role in communicating each other. Especially, a comic expression is more efficient than real facial expression, and the movements of the cheeks and the jaws are more important AU's than those of the eyebrow, eye, mouth etc. Therefore, in this paper, we designed a 3D emotion editor using 2D model, and we extract AU's (called as PAU, here) which play a principal function in expressing emotions. We also proposed a method of generating the universal emotional expression with Avatar models which have different vertex structures. Here, we employed a method of dynamically adjusting the AU movements according to emotional intensities. The proposed system is implemented with Visual C++ and Open Inventor on windows platforms. Experimental results show a possibility that the system could be used as a non-verbal communication means to overcome the linguistic barrier.

Study of emoticon as an emotional sign under the digital communication environment (디지털 커뮤니케이션 환경에서 감성기호로서 이모티콘에 관한 연구)

  • 조규명;김경숙
    • Archives of design research
    • /
    • v.17 no.1
    • /
    • pp.319-328
    • /
    • 2004
  • The communication environment made by digital technologies has made it possible to exchange information and deliver messages fast and easily among people of various classes in virtual space beyond time and space. Net-generation, who is accustomed to this virtual space, couldn't be satisfied with the linear text-oriented language any more, and began to make signs by use of computers in order to differentiate itself from others and to express its desires. Among the signs, emoticon created by joint of popular culture and digital communication centering around young generation is a new visual sign and emotional sign that can deliver a sender's feelings contained in a message. This paper has studied social phenomena, their relationships with emoticon and background of its creation through documentary review of media development, changes in the communication environment and popular culture. Furthermore, it has analyzed the meaningful action and roles of emoticon as a sign in terms of semiotics and also, studied a possibility of using emoticon as a new emotional sign. The study results say that emoticon can play the roles of a non-linguistic sign just like general signs that make mutual exchange through meaningful action, and also that it can be used to effectively deliver messages not only in virtual space, but also in advertising, posters, magazines and CI. However, emoticon is better at emotional expressions yet than other textual signs or visual signs, but in order to position itself as a universal and popular sign, emotional expressions should be clear, any difference in understanding messages should be removed, and message delivery should be more efficient.

  • PDF