• Title/Summary/Keyword: Gravity system

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Analyses of Patterns of Spins with Insole Foot-Pressure Distribution during a Figure Skating (Flying Sit Spin과 Flying Camel Spin 시 규정자세에 따른 족저압력패턴의 연구)

  • Yoo, Kyoung-Seok
    • Korean Journal of Applied Biomechanics
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    • v.18 no.1
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    • pp.159-168
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    • 2008
  • The purpose of this study was to analyze the variables of plantar pressure distribution, the COG between Flying Sit Spin(FSS) and Flying Camel Spin(FCS) during a Figure Skating. In order to investigate the two types of spin mechanism in the Korea national of elite women Figure skaters(N=4), this study investigated the phase time, CA(contact area), MF(maximum force) Mean Force, and PP(peak pressure) Mean Force. The data was collected using PEDAR Mobile System which is the pressure distribution measuring devices. The obtained conclusions were as follow: During the two types of spins(FSS and FCS), the FCS is higher than the FSS on the MF(20%BW), PP(20%BW) variables during P4 phase, but the FSS is larger than the FCS in the CA, MF, and PP during P1, P2, P3 phase. Consequently, depend on the COP and the COG locations about the vertical ground reaction vector, the FCS comparatively excelled control of speed feedback than the FSS in the P4 phase.

A Study on the Ergonomic features and Their Improvements in Pen Design (필기구 디자인의 인간공학적 제요소와 개선에 관한 연구)

  • 이재환
    • Archives of design research
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    • v.13 no.3
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    • pp.253-260
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    • 2000
  • Writing instruments or pens have many features not commonly found in other products in terms of their structure and characteristics of use. That is, different pens are usually composed of almost identical parts and/or structure. The fact they work always grabbed in hands considered, the ergonomic design of pens is essential. Reports indicate consumers evaluate pens in writing comfort above all other factors when they select pens. Among various factors related to writing comfort, it shouldspecifically be the ergonomic improvements that design can effectively contribute to. Studies on the pen-grabbing comfort or on approaches based on the understanding of human-work relationships generally lack when compared with fashion-conscious aesthetic approaches to pen design. This paper, therefore, aims to reestablish the ergonomic design criteria including the necessities of specifications required to provide indispensable data for the pen design processes. Consequently, it should produce basic set of information for systematic approach to pen design and development, which is commonly called'concurrent engineering'. Also a cost-effective solution for product diversification strategy could be attributed to a modular system database based on the result of this attempt.

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A STUDY ON THE APPLICATION OF THE COMPREHENSIVE LAND USE/TRANSPORTATION MODELS IN SEOUL CAPITAL REGION (서울수도권에 있어서의 토지이용 및 교통 통합모델 응용에 관한연구)

  • 윤정섭
    • Spatial Information Research
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    • v.2 no.1
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    • pp.3-14
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    • 1994
  • The external diseconomy has been accelerated by the megaspatial structure of metropolis such as Seoul Capital Region(below SCR), Korea in which the more than 10 million populations inhabit. The main course for It could be elaborated by the overconcentration of the urban and regional function of various kinds. The study is performed to analyze quantitatively the status quo of the region as described above and proceed into forecasting the future population trend, the land use at location for the increment of regional population and to set the location of new towns in Seoul Capital Region System projected by the methods in computer algorithm of descriptive models such as the simple and multiple regress ion analysis models, the gravity model and the facility location on a plane model analysis. The goal and object ive of the metropolitan planning are to decentralize the regional growth management to the optimum degree, which will not hinder the economic growth of the region, but the result of the study is that we can not discourage the functional concentration of Seoul Capital Region and, we have to provide the region with the appropriate new towns.

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A Study on the Estimation of the Ride Quality of a Large-Sized Truck Using a Computer Model (컴퓨터 모델을 이용한 대형트럭의 승차성능 평가에 관한 연구)

  • Mun, Il-Dong;O, Jae-Yun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.12
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    • pp.2048-2055
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    • 2001
  • This paper develops a computational model for estimating the ride quality of a cabover type large-sized truck in a double wheel bumpy ride test. The computational model is developed using ADAMS. To verify the developed model, an actual vehicle double wheel bumpy ride test is performed. In the test, the vehicle maintains a straight course with a constant velocity such that the front two wheels are passed the bump at the same time. The bump has the height of 60mm, and the width of 550mm. In the test, four velocities are used. They are 10kph, 20kph, 30kph and 40kph. Since the large-sized truck's center of gravity location is high, and its weight is heavy, it is a quite severe test condition to perform the test with more than 30kph velocity. In the test, vertical accelerations on the floor of the cab are measured. The measured accelerations are compared to the simulation results. From the comparison, it is shown that the developed model can predict not only the measured acceleration's tendency but also peak accelerations quite well. In this paper, the validated model is utilized to compare the ride quality between a vehicle with a multi-leaf spring and a vehicle with a tapered leaf spring in the front suspension system in a double bumpy ride test.

Stability of fishing vessel according to the LED luring lamp installation (LED집어등 설치에 따른 연안 채낚기 어선의 복원성능)

  • Jeong, Seong-Jae;An, Heui-Chun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.4
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    • pp.623-632
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    • 2014
  • In this study, the stability of fishing vessels get some change in accordance with the installation of LED luring lamp in comparison with metal halide luring lamp were investigated. Inclining test for 9.77 ton class of squid jigging and hair-tail angling vessel was performed in order to make a stability evaluation. A performance analysis of the target vessels to the stability on the basis of KST-SHIP program was evaluated. The results were as follows in this study. The stability of the fishing vessel by a metal halide such as LED and the like according to the result obtained by the inclining test is a slightly present difference, and the stability is not affected. The fishing vessel with LED lamp installed satisfies all the stability criteria specified in law and IMO rule. Compared to the metal halide LED lamp the increase of the height of the center of gravity and the initial transverse metacenter was caused. Due to the LED installation, the somewhat wider wind area of the waterline, which appears as a result, does not lead to an actual increase in rolling period. But then it is necessary to be designed on that the LED lamp shape reduces wind pressure area. Because of LED lamp installation, the GM value of vessels is increasing faster rolling cycle so causes a decrease in the sense that the crew is aboard.

Anaerobic Biotreatment of Animal Manure - A review of current knowledge and direction for future research -

  • Hong, Jihyung
    • Journal of Animal Environmental Science
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    • v.11 no.2
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    • pp.97-102
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    • 2005
  • Anaerobic decomposition is one of the most common processes in nature and has been extensively used in waste and wastewater treatment for several centuries. New applications and system modifications continue to be adapted making the process either more effective, less expensive, or suited to the particular waste in question and the operation to which it is to be applied. Animal manure is a highly biodegradable organic material and will naturally undergo anaerobic fermentation, resulting in release of noxious odors, such as in manure storage pits. Depending on the presence or absence of oxygen in the manure, biological treatment process may be either aerobic or anaerobic. Under anaerobic conditions, bacteria carry on fermentative metabolisms to break down the complex organic substances into simpler organic acids and then convert them to ultimately formed methane and carbon dioxide. Anaerobic biological systems for animal manure treatment include anaerobic lagoons and anaerobic digesters. Methane and carbon dioxide are the principal end products of controlled anaerobic digestion. These two gases are collectively called biogas. The biogas contains $60\~70\%$ methane and can be used directly as a fuel for heating or electrical power generation. Trace amounts of ammonia and hydrogen sulfide ($100\~300\;ppm$) are always present in the biogas stream. Anaerobic lagoons have found widespread application in the treatment of animal manure because of their low initial costs, ease of operation and convenience of loading by gravity flow from the animal buildings. The main disadvantage is the release of odors from the open surfaces of the lagoons, especially during the spring warm-up or if the lagoons are overloaded. However, if the lagoons are covered and gases are collected, the odor problems can be solved and the methane collected can be used as a fuel. Anaerobic digesters are air-tight, enclosed vessels and are used to digest manure in a well-controlled environment, thus resulting in higher digestion rates and smaller space requirements than anaerobic lagoons. Anaerobic digesters are usually heated and mixed to maximize treatment efficiency and biogas production. The objective of this work was to review a current anaerobic biological treatment of animal manure for effective new technologies in the future.

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Evaluation of Airflow Control Capability of Natural Ventilators with Various Dampers (자연환기 벤틸레이터의 댐퍼 형태별 환기량 조절능력 평가)

  • Kim, Tae-Hyeong;Ha, Hyun-Chul;Park, Seung-Chul
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.16 no.4
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    • pp.364-374
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    • 2006
  • Natural ventilation technique could be the substitute for or the complement to the local exhaust ventilation system in the sense of protecting work environment. Moreover, it has many strong points ; almost no mechanical parts, no energy use and no noise. If applied appropriately, it could have the very high ventilation rate and save a lot of energy expense. But, it depends on the outdoor environment, especially temperature and wind speed/direction. Predicting the capacity of natural ventilation is not an easy job because it comes from both buoyancy and wind effect. Another problem is too much flow through the ventilator especially in winter time due to too much difference between indoor and outdoor temperature. Thus some ventilators in industries are sealed by door or plastic sheet, resulting in bad work environment. Various types of dampers are used to control the flow rate through ventilators. The capabilities of flow control by damper has not been estimated. In addition, it was not tested whether the damper could obstruct the flow through ventilator when fully opened. To answer these questions, 4 types of dampers were tested by using computational fluid dynamics. 10 different configurations includes no damper, full open and half open. Flow rates were estimated and airflow fields were analysed to clarify the before-mentioned questions. The dual type damper was the best choice for controling the capability of ventilator. In addition, the upward grill type damper was the best for not obstructing the air flow when fully opened.

Punching Shear Strength of CFT Column to RC Flat Plate Connections Reinforced with Shearhead (전단머리 보강 CFT기둥-RC 무량판 접합부의 펀칭전단강도)

  • Kim, Jin-Won;Lee, Cheol-Ho
    • Journal of Korean Society of Steel Construction
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    • v.24 no.4
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    • pp.423-433
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    • 2012
  • This paper summarizes full-scale gravity-load test results on CFT column-to-RC flat plate connections reinforced with shearhead. CFT construction has many structural and constructional advantages over conventional steel and RC column construction and is gaining wide acceptance. Meanwhile the use of RC flat plate system in the basement and residential floors of tall buildings is often mandatory to reduce story height and enable rapid construction in domestic practice. Combining CFT column and flat plate floor is expected to result in further rapid construction. However, the issues related to connecting CFT column to RC flat plate have not been fully addressed yet. Several promising connecting schemes by using steel shearhead were proposed and tested in this study. Test results showed that the proposed connection can exhibit the punching shear strength higher than RC flat plate counterparts. An empirical formula that can reasonably predicts the punching shear strength of the proposed connection was also proposed.

Design and Development of the Simulated Die casting Process by using Rapid Prototyping (쾌속조형을 이용한 다이 캐스팅 제품의 시작 공정 설계 및 제작)

  • Kim, Ki-Don;Yang, Dong-Yol;Jeong, Jun-Ho;Park, Tae-Kwon
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.7
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    • pp.167-173
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    • 2001
  • The simulated die-casting process in which the traditional plaster casting process is combined with Rapid Prototyping technology is being used to produce AI, Mg, and Zn die-casting prototypes. Unlike in the die-casting process, molten metal in the conventional plaster casting process is fed via a gravity pour into a mold and the mold does not cool as quickly as a die-casting mold. The plaster castings have much larger and grosser grain structure as compared with the normal die-castings and the thin walls of the plaster mold cavity may not be completely filled. Because of lower mechanical properties induced by the large grain structure and incomplete filling, the conventional plaster casting process is not suitable for the trial die-casting process to obtain quality prototypes. In this work, an enhanced trial die-casting process has been developed in which molten metal in the plaster mold cavity is vibrated and pressurized simultaneously. Patterns for the casting are made by Rapid Prototyping technologies and then plaster molds, which have a runner system, are made using these patterns. Pressurized vibration to imparted molten metal has made grain structure of castings much finer and improved fluidity of the molten enough to obtain complete filling at thin walls which may not be filled in the conventional plaster casting process..

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A Study on the Expressional characteristics of Geometrical Design in the Deconstructive and Experimental Architects (해체 및 실험적 건축가들의 기하학적 디자인 표현 특성에 관한 연구)

  • 황태주
    • Korean Institute of Interior Design Journal
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    • no.11
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    • pp.57-63
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    • 1997
  • In the early 20'c, scientific thoughts make a change the absolute and separate concept of space-time into relative concept of continual entity; a kind of ideal world. It suggests that the meaning of geometry as absolute truth with which has endowed human beings would changed to a relative meaning of accumulation in intellectual work on 'nature'. This cognitive changes appeared into absolute arts in 20'c like Cubism, Superematism or Constructivism. De Stijl movement which had recepted the relative concepts like Einstein's 'theory of relativity' as a developed thought from Newton-Cartesian cognition on the world. Abstration would be adequate method for expressing the dynamics and interrelationship between forms and for giving values to indivisual elements in a compositiov. This method had appeared Modern architectural form, as a common framework. The expression characteristics of geometrical design in Deconstructive and Experimental architecture were summerized in four features through the results of the analysis. First, the relation of architectural element and intertextuality is expressed in discontinuation of context and refusal of functional building. Second, the concept of trace expresses as connection of place, decomposing of excavation of trace, trace of axis, trace of fragments. Third, anti-gravity expression is there to express of open cubic, to outgrow of rectangular system, to outgrow of volume, to separate of ground connectiov. Fourth, the complex composition of abstracted geometric form is these to abstracted geometry about indefinite shape, to layer through the overlap and collage, to de-meaning and amusement of form through the pursuit of uncertainty, to indeterminate of formal meaning through operation and composition of similar form cause to the diverse of meaning.

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