• Title/Summary/Keyword: Dynamic Contact

Search Result 1,165, Processing Time 0.023 seconds

Interfacial and Durability Evaluation of Jute and Hemp Fiber/Polypropylene Composites Using Micromechanical Test and Acoustic Emission (미세역학적시험법과 음향방출을 이용한 Jute 및 Hemp 섬유/폴리프로필렌 복합재료의 내구성 및 계면 평가)

  • Kim, Pyung-Gee;Jang, Jung-Hoon;Kim, Sung-Ju;Hwang, Byung-Sun;Park, Joung-Man
    • Composites Research
    • /
    • v.20 no.3
    • /
    • pp.55-62
    • /
    • 2007
  • Interfacial evaluation and durability of Jute and Hemp fibers/polypropylene (PP) composites were investigated. Moisture content of various treated conditions were measured by thermogravimetic analyzer (TGA). After boiling water test, mechanical properties and IFSS between Jute, Hemp fibers and PP matrix decreased. On the other hand, work of adhesion increased due to swelled fibril by water. Surface energies of Jute and Hemp fibers before and after boiling water test were obtained using dynamic contact angle measurement. IFSS was not always consistent with thermodynamic work of adhesion. In boiling water case, since Jute and Hemp fibers could be swelled by water, surface area and moisture infiltration space increased. Environmental effect on microfailure modes of Jute or Hemp fibers and Jute or Hemp fibers/PP composites were obtained by observing via optical microscope and by monitoring acoustic emission (AE) events and their AE parameters. After boiling water test, unlike Hemp fiber, microfailure process of Jute fiber could occur due to low tensile strength by swelled fibril. In addition, AE events occurred more and AE amplitude and energy became lower than those of before boiling water test.

The Building Plan of Online ADR Model related to the International Commercial Transaction Dispute Resolution (국제상거래 분쟁해결을 위한 온라인 ADR 모델 구축방안)

  • Kim Sun-Kwang;Kim Jong-Rack;Hong Sung-Kyu
    • Journal of Arbitration Studies
    • /
    • v.15 no.2
    • /
    • pp.3-35
    • /
    • 2005
  • The meaning of Online ADR lies in the prompt and economical resolution of disputes by applying the information/communication element (Internet) to existing ADR. However, if the promptness and economical efficiency are overemphasized, the fairness and appropriateness of dispute resolution may be compromised and consequently Online ADR will be belittled and criticized as second-class trials. In addition, as communication is mostly made using texts in Online ADR it is difficult to investigate cases and to create atmosphere and induce dynamic feelings, which are possible in the process of dispute resolution through face-to-face contact. Despite such difficulties, Online ADR is expanding its area not only in online but also in offline due to its advantages such as promptness, low expenses and improved resolution methods, and is expected to develop rapidly as the electronic government decided to adopt it in the future. Accordingly, the following points must be focused on for the continuous First, in the legal and institutional aspects for the development of Online ADR, it is necessary to establish a framework law on ADR. A framework law on ADR comprehending existing mediation and arbitration should be established and it must include contents of Online ADR, which utilizes electronic communication means. However, it is too early to establish a separate law for Online ADR because Online ADR must develop based on the theoretical system of ADR. Second, although Online ADR is expanding rapidly, it may take time to be settled as a tool of dispute resolution. As discussed earlier, additionally, if the amount of money in dispute is large or the dispute is complicated, Online ADR may have a negative effect on the resolution of the dispute. Thus, it is necessary to apply Online ADR to trifle cases or domestic cases in the early stage, accumulating experiences and correcting errors. Moreover, in order to settle numerous disputes effectively, Online ADR cases should be analyzed systematically and cases should be classified by type so that similar disputes may be settled automatically. What is more, these requirements should reflected in developing Online ADR system. Third, the application of Online ADR is being expanded to consumer disputes, domain name disputes, commercial disputes, legal disputes, etc., millions of cases are settled through Online ADR, and 115 Online ADR sites are in operation throughout the world. Thus Online ADR requires not temporary but continuous attention, and mediators and arbitrators participating in Online ADR should be more intensively educated on negotiation and information technologies. In particular, government-led research projects should be promoted to establish Online ADR model and these projects should be supported by comprehensive researches on mediation, arbitration and Online ADR. Fourth, what is most important in the continuous development and expansion of Online ADR is to secure confidence in Online ADR and advertise Online ADR to users. For this, incentives and rewards should be given to specialists such as lawyers when they participate in Online ADR as mediators and arbitrators in order to improve their expertise. What is more, from the early stage, the government and public institutions should have initiative in promoting Online ADR so that parties involved in disputes recognize the substantial contribution of Online ADR to dispute resolution. Lastly, dispute resolution through Online ADR is performed by organizations such as Korea Institute for Electronic Commerce and Korea Consumer Protection Board and partially by Korean Commercial Arbitration Board. Online ADR is expected to expand its area to commercial disputes in offline in the future. In response to this, Korean Commercial Arbitration Board, which is an organization for commercial dispute resolution, needs to be restructured.

  • PDF

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014 (설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.27 no.7
    • /
    • pp.380-394
    • /
    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

The Practice of 'Liberated-ness': An Education Model for Protestant Spiritual Practice (개신교 '자유케 됨'의 영성에 기초한 기독교 영성교육 모형: '자유케 됨'의 실천)

  • Hwang, In-Hae
    • Journal of Christian Education in Korea
    • /
    • v.68
    • /
    • pp.375-415
    • /
    • 2021
  • Although the interest in Christian education of spirituality has increased recently, the practice of the education of spirituality in the Korean Church has been fragmented in the contents and methods without any clear educational purpose of the Protestant tradition. This requires a creative study to seek out the contents and method best suited to realizing the educational purpose of the Protestant tradition, through a rigorous academic methodology. This study proposes just such a creative model for the education of spirituality with an educational purpose based on the core ethos of the Protestant spirituality, integrating the long tradition of spiritual practices of Christianity. First, I survey the teachings on 'the life of faith' of the main leaders of the Protestant church, including Martin Luther, John Calvin, and John Wesley. Through this process, I reveal 'liberated-ness' to be the common purpose of the Protestant leaders, and the core of the practices for that purpose are 'the means of grace,' which has a different meaning from that of the Roman Catholic tradition. I construct the meaning of 'liberated-ness' in a dynamic manner, which begins with the 'liberating will' of God, and is followed by the 'self-giving will' of the believer as the response to the 'grace' of the 'liberating will.' The contact point of these two 'wills' is what I call 'the living membrane of faith.' As a creative synthesis of the above discussions, I propose a model of 'the practice of liberated-ness' for an education in spiritual practice. The purpose of this education is for the learner to become a person who continuously experiences ever-increasing 'liberated-ness' through continuous personal 'encounters' with God, and to become ever more faithful in carrying out practices for the 'liberated-ness' of her or his neighbors. The relationship between the teacher and the learner is that of personal 'encounter' as put forth by Sherrill, and also incorporates elements of 'co-authorship' as conceptualized by Kim. I transform and rename major practices of spiritual discipline according to a principle of 'liberated-ness' based on the Protestant tradition, and these comprise the main content of my spirituality education model. They include: 'lectio divina of encounter,' 'prayer facing the Lord,' 'service in liberation,' 'reflection of liberated-ness,' and 'mutual spiritual direction.' The teaching and learning process draws on Dykstra's methods of coaching and mentoring. The key environment is that of a 'sacramental community' as defined by Moore. Evaluation can be performed only by the learner her/himself. The significance of this model is that it creatively inherits and succeeds the tradition of Christian spiritual discipline from the early church onwards by transforming it through a Protestant spirituality of 'liberated-ness.'

Dynamic response of segment lining due to train-induced vibration (세그먼트 라이닝의 열차 진동하중에 대한 동적 응답특성)

  • Gyeong-Ju Yi;Ki-Il Song
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.25 no.4
    • /
    • pp.305-330
    • /
    • 2023
  • Unlike NATM tunnels, Shield TBM tunnels have split linings. Therefore, the stress distribution of the lining is different even if the lining is under the same load. Representative methods for analyzing the stress generated in lining in Shield TBM tunnels include Non-joint Mode that does not consider connections and a 2-ring beam-spring model that considers ring-to-ring joints and segment connections. This study is an analysis method by Break-joint Mode. However, we do not consider the structural role of segment lining connections. The effectiveness of the modeling is verified by analyzing behavioral characteristics against vibration loads by modeling with segment connection interfaces to which vertical stiffness and shear stiffness, which are friction components, are applied. Unlike the Non-joint mode, where the greatest stress occurs on the crown for static loads such as earth pressure, the stress distribution caused by contact between segment lining and friction stiffness produced the smallest stress in the crown key segment where segment connections were concentrated. The stress distribution was clearly distinguished based on segment connections. The results of static analysis by earth pressure, etc., produced up to seven times the stress generated in Non-joint mode compared to the stress generated by Break-joint Mode. This result is consistent with the stress distribution pattern of the 2-ring beam-spring model. However, as for the stress value for the train vibration load, the stress of Break-joint Mode was greater than that of Non-joint mode. This is a different result from the static mechanics concept that a segment ring consisting of a combination of short members is integrated in the circumferential direction, resulting in a smaller stress than Non-joint mode with a relatively longer member length.