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Dynamics Modeling of Plate Treated with Active Constrained Layer Damping (능동 구속층 감쇠 처리된 판의 동적 모델링)

  • Park, C.H.;Kim, W.C.
    • Journal of Power System Engineering
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    • v.1 no.1
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    • pp.124-143
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    • 1997
  • 본 논문은 능동 구속층 감쇠(active constrained layer damping) 처리된 관의 동적 모델링과 정식화를 제시한다. 판의 운동방정식은 Hamilton정리를 이용하여 전개된 판, piezoelectric film 및 점탄성층의 운동방정식을 조합하므로서 유도된다. 이 운동방정식은 외부인가전압의 영향하에서 적층판의 해석적 모델을 제공할 뿐만이 아니라, 판 구조내에서 진동에너지를 감소시킬 수 있는 전단층의 효과에 대한 변위관계식을 나타낸다. 그리고 운동방정식에 대응하는 경계조건도 유도되었다. 또한 판과 능동구속층감쇠계의 동특성을 설명하기 위한 유한요소모델이 유도되었다. 이 모델의 타당성을 실온조건에서 실험적으로 입증하였다. 개발된 이론 및 실험적인 결과들은 판과 능동구속층 감쇠계가 구조진동의 감쇠를 위한 매우 유효한 수단으로 사용될 수 있음을 나타내었다.

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미국과 캐나다의 수의학 교육현황

  • Talbot Richard B.
    • Journal of the korean veterinary medical association
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    • v.29 no.3
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    • pp.155-159
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    • 1993
  • 나는 미국과 캐나다에서의 수의과교육의 현황을 밝혀보려고 노력했다. 이 미국대륙에서 비교적 역사가 ?음에도 우리 교육기관은 과학적, 임상적 측면에서의 개발에 많은 발전을 이룩했다. 그리고 우리 교육기관들이 우리의 직업을 건전하게 유지하고, 우리의 업무를 이행함으로써 우리를 후원하고 있는 사회의 요구와 마주할 때 당면하게 되는 세 가지 문제점을 상술하려는 시도를 했다. 내가 미국과 캐나다의 수의과대학에 국한된 언급을 하면서도 어떤 점들은 세계 여러 나라에도 적용되리라고 생각한다. 특히 마지막으로 내가 하는 말은 더욱 그러하리라. 지난 50년간에 세계적으로 이룩된 수의과 교육의 탁월한 진보는 계속되리라고 나는 확신한다. 우리가 현재 가지고 있는 것은 물론 완벽하지는 않지만 이제까지 있어 온 것중에서는 최선의 것이며 솔직히 상당히 좋은 것이기도 하다. 우리가 우리 자신을 전문의라고 부를 수 있는 특권을 계속 지니려면 그것을 개선하려는 노력을 계속해야만 한다.

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Collaborative Planning Model for Brownfield Regeneration (브라운필드 재생을 위한 협력적 계획 모델 연구)

  • Kim, Eujin Julia;Miller, Patrick
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.3
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    • pp.92-100
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    • 2015
  • Unlike most other planning processes, brownfield planning generally requires a high level of technical and legal expertise due to potential site contamination. To successfully engage in inclusionary decision making, an adaptive collaboration strategy for brownfield planning is therefore critical. This study examines how a communicative planning approach can be used to overcome the challenge of enabling experts from different fields to work alongside lay people from the local community to achieve a properly balanced collaboration in brownfield planning. After identifying appropriate indicators for collaboration through a literature review of established communicative planning theory, these indicators are applied to the brownfield planning process, highlighting critical points of collaboration such as site prioritization, assessment, remediation, and redevelopment throughout. The results suggest the critical need for an adaptive model focusing on three aspects: 1. Facilitation of a balanced dialogue between the experts with social, cultural, and design-based knowledge and the ones with scientific and engineering-based knowledge, 2. Preparation of an appropriate tool for risk communication with the lay people, 3. Development of decision support system for the integration of expert-oriented technical data and public opinion-oriented subjective data.

Periodic Characteristics and Implications of Programs and Policies for Brownfield Management in the U.S.A. (미국 브라운필드 관리 프로그램과 정책의 시기별 특성과 함의)

  • Kim, Eujin Julia;Miller, Patrick
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.1
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    • pp.96-107
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    • 2015
  • Brownfield sites are beginning to be considered as potentially useful areas for landscape design and planning, with post-industrial areas such as water treatment facilities and military training bases being converted into useful landscapes such as parks and recreation areas. These redevelopments bring broad benefits through revitalizing communities and increasing property values, thus, increasing the demand for comprehensive management and planning policies. This study examines changes in U.S. brownfield policies and programs and, identifies their periodic characteristics over the thirty years since the Superfund program was introduced in 1980. A descriptive and interpretive approach was utilized, focusing specifically on a time sequential analysis of the data gathered from the overview of the Environmental Protection Agency's web-based documents and related literature. The primary changes in and characteristics of programs and policies were analyzed and divided into three periods : environmental protection, remediation and reuse, and comprehensive planning. Four major features were identified: relaxation and readjustment of regulation, diversification of support programs, a mix of top-down and bottom-up approaches, and database system building. The study examines how common brownfield problems such as site identification difficulties and assessment and remediation cost have been dealt with in the regulatory context and has implications for future policies and programs for effective brownfield planning and management in Korea.

An Empirical Study for Performance Evaluation of Web Personalization Assistant Systems (웹 기반 개인화 보조시스템 성능 평가를 위한 실험적 연구)

  • Kim, Ki-Bum;Kim, Seon-Ho;Weon, Sung-Hyun
    • The Journal of Society for e-Business Studies
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    • v.9 no.3
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    • pp.155-167
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    • 2004
  • At this time, the two main techniques for achieving web personalization assistant systems generally concern direct manipulation and software agents. While both direct manipulation and software agents are intended for permitting user to complete tasks rapidly, efficiently, and easily, their methodologies are different. The central debate involving these web personalization techniques originates from the amount of control that each allows to, or holds back from, the users. Direct manipulation can provide users with comprehensibel, predictable and controllable user interfaces that give them a feeling of accomplishnent and responsibility. On the other hand, the intelligent software components, the agents, can assist users with artificial intelligence by monitoring or retrieving personal histories or behaviors. In this empirical study, two web personalization assistant systems are evaluated. One of them, WebPersonalizer, is an agent based user personalization tool; the other, AntWorld, is a collaborative recommendation tool which provides direct manipulation interfaces. Through this empirical study, we have focused on two different paradigms as web personalization assistant systems : direct manipulation and software agents. Each approach has its own advantages and disadvantages. We also provide the experimental result that is worth referring for developers of electronic commerce system and suggest the methodologies for conveniently retrieving necessary information based on their personal needs.

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An Analysis of Observation and Measurement Standards in Foreign National Science Curriculums (외국 과학교육과정의 관찰과 측정 기준 분석)

  • Lee, Bong-Woo;Kim, Hee-Kyong
    • Journal of Korean Elementary Science Education
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    • v.26 no.1
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    • pp.87-96
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    • 2007
  • The purpose of this study was to examine the features of the standards of observation and measurement in foreign national science curriculums. For the purpose of this study, we analyzed the science standards of the USA (National Science Education Standards, the Science Standards of the State of California, Massachusetts, Colorado, Nebraska, Virginia and Florida), the United Kingdom (England), Singapore, Canada (the State of Alberta), Australia (the State of Victoria) and New Zealand. The results of the study indicated that foreign national science curriculums put an emphasis on accurate and systematical observation, usage of the five senses, usage of observation tools, and an understanding of observation. Regarding the 'measurement' factors, foreign national science curriculums emphasized systematic and accurate measurement. Measurement targets and tools were presented for each grade. The usage of appropriate units was also included in the foreign national curriculums which we examined.

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INTRACEREBROVENTRICULARLY ADMINISTERED PHENYLALANINE AND TYROSINE: EFFECTS ON FEEDING BEHAVIOUR AND NOREPINEPHRINE CONCENTRATIONS OF SPECIFIC BRAIN SITES IN THE CHICKEN

  • Choi, Y.-H.;Furuse, M.;Okumura, J.;Shimoyama, Y.;Sugahara, K.;Denbow, D.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.9 no.3
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    • pp.255-259
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    • 1996
  • A study was carried out to investigate the action of central L-pheylalanine (Phe) and L-tyrosine (Tyr) on food intake of the chicken. In the first trial, Phe ($200{\mu}g/10{\mu}l$) or saline was acutely administered into the right lateral ventricle (i.c.v.) of chickens (5 birds per each group). Birds (4 birds per each group) were administered with the i.c.v. Tyr ($200{\mu}g/10{\mu}l$) or saline in the second trial. The brains of the birds were removed for catecholamine assy 30 min postadministration. Catecholamine concentrations were measured at specific sites of the brain (LH: lateral hypothalamus, PVN: paraventricular nucleus, and VMH: ventromedial hypothalamus). No significant effect of amino acids on the concentration of norepinephrine of brain sites investigated was detected. Food intake and rectal body temperature were also monitored for 6 h after central administrations of Phe, Tyr or saline (5 birds per each group). Both Phe and Tyr, up to $1mg/10{\mu}l$, failed to modulate food intake or rectal body temperature.

The role of extensional rheology in polymer processing

  • Baird, Donald G.
    • Korea-Australia Rheology Journal
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    • v.11 no.4
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    • pp.305-311
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    • 1999
  • The shear behavior of polymers obtained by means of devices such as capillary and cone-and-plate rheo-meters is commonly used to assess their processing performance and as a characterization tool. However, the number of instances when two polymers have the same shear properties but perform differently during certain types of processing operations (e.g. film blowing and sheet extrusion) indicate that shear properties alone may not be sufficient to characterize polymeric fluids. We begin by defining the kinematics of shear-free or extensional flow and the associated material functions. The extensional and shear behavior of three different types of polyethylene (PE) are then compared to illustrate the points that one cannot ascertain the extensional properties of polymer melts from their shear properties and, furthermore, there may not be a simple relation between properties obtained from one type of extensional flow and those of another type. The kinematics of most processing flows are extensional rather than shear in nature, and , hence, the performance of polymers during processes such as fiber spinning, film casting, film blowing, thermoforming, blow molding, and even extrusion is more readily accounted for through extensional viscosity measurements. Methods for carrying out extensional flow measurements are then reviewed including approximate methods. To illustrate the sensitivity of extensional viscosity measurements to subtle changes in the molecular architecture of PEs, results are presented for samples with a narrow molecular weight distribution but with varying numbers of long chain branches. Finally, constitutive equations which allow one to separate shear and extensional flow behavior are discussed as any attempts to simulate the subtle processing differences between two polymers will require constitutive equations of this nature.

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Nutrient Recycling : The North American Experience - Review -

  • Fontenot, J.P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.4
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    • pp.642-650
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    • 1999
  • Options available for utilization of animal wastes include sources of plant nutrients, feed ingredients for farm animals, substrate for methane generation, and substrate for microbial and insect protein synthesis. The wastes have the most economic value for use as animal feed. Performance of animals fed diets containing animal wastes is similar to that of animals fed conventional diets. Processing of animal wastes to be used as animal feed is necessary for destruction of pathogens, improvement of handling and storage characteristics, and maintenance or enhancement of palatability. Feeding of animal waste has not adversely affected the quality and taste of animal products. In the USA copper toxicity has been reported in sheep fed high-copper poultry litter, but this is not a serious problem with cattle. Potential pathogenic microorganisms in animal wastes are destroyed by processing such as heat treatment, ensiling and deep stacking. Incidents of botulism, caused by Clostridium botulinum, have been reported in cattle in some countries, and this problem was caused by the presence of poultry carcasses in litter. This problem has not occurred in the USA. With appropriate withdrawal, heavy metal, pesticide or medicinal drug accumulation in edible tissues of animals fed animal wastes is not a problem. Feeding of animal wastes is regulated by individual states in the USA. The practice is regulated in Canada, also. With good management, animal wastes can be used safely as animal feed.

Visual Attention Model Based on Particle Filter

  • Liu, Long;Wei, Wei;Li, Xianli;Pan, Yafeng;Song, Houbing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.8
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    • pp.3791-3805
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    • 2016
  • The visual attention mechanism includes 2 attention models, the bottom-up (B-U) and the top-down (T-D), the physiology of which have not yet been accurately described. In this paper, the visual attention mechanism is regarded as a Bayesian fusion process, and a visual attention model based on particle filter is proposed. Under certain particular assumed conditions, a calculation formula of Bayesian posterior probability is deduced. The visual attention fusion process based on the particle filter is realized through importance sampling, particle weight updating, and resampling, and visual attention is finally determined by the particle distribution state. The test results of multigroup images show that the calculation result of this model has better subjective and objective effects than that of other models.