• Title/Summary/Keyword: Load Reducing

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Experimental Study of Driving Load Conditions for the Wheel Bearing Hub Unit of Passenger Car (승용차용 Wheel Bearing Hub Unit 설계를 위한 주행 하중조건의 실험적 연구)

  • 김기훈;유영면;임종순
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.2
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    • pp.166-173
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    • 2002
  • The wheel bearing hub unit is developed type of wheel bearing unified with the hub parts. It has advantage of reducing the weight and the number of components. And, it also improves uniformity of manufacturing quality, In order to design the wheel bearing hub units, many techniques are used such as load analysis, structure analysis and bearing characteristics analysis and so forth. These techniques need highly accurate load conditions founded on service conditions. In this study, to design the wheel bearing hub units used widespread in passenger cars, the service load was measured through driving tests on the public roads and in the special events. The public roads are classified into highway, intercity road, rural road, urban road, and unpaved road so as to know what the characteristics of the road loads are. The results of the tests showed that the wheel force was relative to the lateral acceleration, and also could be calculated from the lateral acceleration. The lateral acceleration was measured from 0.0G to 0.6G in general driving on the public roads, with different distributions in each road type. In special events, the maximum lateral acceleration was measured from 0.8G to 1.3G.

Girder distribution factors for steel bridges subjected to permit truck or super load

  • Tabsh, Sami W.;Mitchell, Muna M.
    • Structural Engineering and Mechanics
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    • v.60 no.2
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    • pp.237-249
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    • 2016
  • There are constraints on truck weight, axle configurations and size imposed by departments of transportation around the globe due to structural capacity limitations of highway pavements and bridges. In spite of that, freight movers demand some vehicles that surpass the maximum size and legal weight limits to use the transportation network. Oversized trucks serve the purpose of spreading the load on the bridge; thus, reducing the load effect on the superstructure. For such vehicles, often a quick structural analysis of the existing bridges along the traveled route is needed to ensure that the structural capacity is not exceeded. For a wide vehicle having wheel gage larger than the standard 1830 mm, the girder distribution factors in the design specifications cannot be directly used to estimate the live load in the supporting girders. In this study, a simple approach that is based on finite element analysis is developed by modifying the AASHTO LRFD's girder distribution factors for slab-on-steel-girder bridges to overcome this problem. The proposed factors allow for determining the oversized vehicle bending moment and shear force effect in the individual girders as a function of the gage width characteristics. Findings of the study showed that the relationship between the girder distribution factor and gage width is more nonlinear in shear than in flexure. The proposed factors yield reasonable results compared with the finite element analysis with adequate level of conservatism.

Method for Maximal Utilization of Idle Links for Fast Load Balancing (신속한 부하균등화를 위한 휴지링크의 최대 활용방법)

  • Im, Hwa-Gyeong;Jang, Ju-Uk;Kim, Seong-Cheon
    • Journal of KIISE:Computer Systems and Theory
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    • v.28 no.12
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    • pp.632-641
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    • 2001
  • In this paper, we introduce new methods for hiding computation overheads involved in load redistributing for parallel computer of hypercube, mesh and tree topologies. The basic idea is either coalescing some phases of load redistributing to overlap the transfer on different links or dividing each phase into steps to pipeline the transfer of load unit by unit for maximum utilization of links. They proved effective in making links busy transmitting load as soon as possible, hence reducing the computation overheads involved in balancing. Proposed techniques experimented on hypercube, mesh or tree topologies reduce communication overheads by 20% to 50% compared with known methods.

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A Comparative Study on the Costs of Structural Materials Based on Different Types of Soil Load on Artificial Ground (인공지반에서 토양하중에 따른 건축구조물 골조원가의 비교연구)

  • 김도경;황지환
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.6
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    • pp.72-81
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    • 2002
  • The purpose of this study is to determine the impact of the soil load for artificial ground on a building's structural expenses. Three types of soil - 100% soil, soil mixed with 50% perlite, and 100% artificial soil - were used for this study. A one story concrete steel building specific to each soil load was designed, and then, the cost of steel and concrete used for the design was estimated. As the result of this study, the structural expenses in the case of 5:5 mixed soil can be reduced about 17% compare with 100% soil. Using artificial soil, the structural expenses can be cut about 32% compare to 100% soil and about 12% less when 5:5 mixed soil is used. However, considering total expense which includes the structural expense and soil expense, the expense of 5:5 mixed soil have an increase 25% compared with 100% soil. In the artificial soil, the total expense is 45% more expensive than 100% soil and 17% higher when 5:5 mixed soil is used because of the high unit price of artificial soil. This study expected substantial savings in structural cost as the soil-load was lightened. But, savings were significantly reduced because the unit price of the artificial soil is much more expensive than the price of the natural one. Therefore, further research on methods of reducing the unit price of the artificial soil should be conducted in order to extend green space on to artificial ground.

The study of self excited type brushless charging generator, it has generated region (발전영역을 갖은 자동형 brushless 충전발전기에 관한 연구)

  • Byung In Oh
    • 전기의세계
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    • v.18 no.4
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    • pp.7-15
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    • 1969
  • In this method the condenser excite winding has the phase angle of 90 electrical degree, with the load winding in stator. The condenser excite wing is connected with the condenser while the load winding is with the full rectifer. Direct and quardrature axis components of rotating field winding are composed, of balanced two phase winding, and each one of them is connected with half wave rectifiers. Initically, small amount of lead current can be induced at the condenser excite winding by residual magnetism of rotor. The induced lead current forces the rotating field winding to be excited by synchronous alternating magnetic field. The speed electromotive force, there for, induced in rotating field winding shall electro magnetize the rotating field pole by rotating half wave rectifiers. In the case of the charging generator directly coupled with engines at the operation of wide range speed, the generated region, such as vehicles, aircraft, ships etc, is occured. In conclusion, we can take the advantage of, omitting of voltage regurator and current limiter for charging load and reducing the consumption of fuel using the generated region which can be devided in to Impossible generated region, Generated region, and suspension generated region.

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Preform Effect on the Plastic Deformation Behavior of Workpieces in Equal Channel Angular Pressing (Equal Channel Angular Pressing 가공 중 소성 변형에 미치는 재료의 초기 형상 효과)

  • Yoon, Seung-Chae;Seo, Min-Hong;Kim, Hyoung-Seop
    • Transactions of Materials Processing
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    • v.15 no.5 s.86
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    • pp.382-386
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    • 2006
  • Preform design is an effective means of achieving the homogeneous deformation of workpiece materials and decreased load in metal forming. However, this approach has not been applied to equal channel angula. pressing (ECAP). In this paper, plastic deformation behavior of workpieces having four different preform shapes during ECAP was investigated using finite element analyses. The results indicated that a preform design of the workpiece head has a beneficial effect on homogeneous deformation, reducing the maximum pressing load at the initial stage and eliminating folding defects at strain concentration points.

Revised NIOSH lifting equation의 현장 적용

  • 기도형;정민근;임종호
    • Proceedings of the ESK Conference
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    • 1995.04a
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    • pp.106-110
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    • 1995
  • A local manufacturing companyin which low back pain(LBP) complaints were frequently reported was selected, and regularly perfomed lifting tasks were investigated using questionnaires and the 1991 NIOSH lifting guide. Among several processes of manufacture in the company, three processes-forming, heating and packing-were studied, where most of tasks were perfomed through manual materials handling (MMH). Questionnaire surveys showed that anthropometric data such as stature, weight and someatotype did not affect and weight of load influenced significantly the incidence of LBP, and workers who expwrienced LBP was older than the inexperienced. In addition, safety education conducted at the company was found to be ineffective in preventing LBP injuries. Lifting indexes(LI) was ranged from 0.86 to 17.0 with an average of 4.49, which revealed that tasks performing in the selected factory were in danger of LBP, and should be ertonomically redesigned. The critical factor reducing LI was found to be the horizontal component in all three processes, and most of weight of load was heavier than load constant(23kg) of the 1991 NIOSH lifting equation in heating process and packing.

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A Multi Router Support Mechanism in 6LowPAN (6LowPAN 에서 멀티 라우터 지원 방법)

  • Jung, Seuk;Lim, Chae-Seong;Jung, Won-Do;Yoo, Seung-Wha;Roh, Byeong-Hee;Kim, Ki-Hyung
    • 한국정보통신설비학회:학술대회논문집
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    • 2007.08a
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    • pp.279-282
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    • 2007
  • Typically a wireless sensor network consists of a number of nodes that sense surrounding environment and collaboratively work to process and route the sensing data to a sink or gateway node. We propose an architecture with support of multiple routers in IPv6-based Low-power Wireless Personal Area Network (6LoWPAN). Our architecture provides traffic load balancing and increases network lifetime as well as self-healing mechanism so that in case of a router failure the network still can remain operational. Each router sends its own Router Advertisement message to nodes and all the nodes receiving the messages can select which router is the best router with the minimum hop-count and link information. We have implemented the architecture and assert our architecture helps in traffic load balancing and reducing data transmission delay for 6LoWPAN.

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Characteristics Analysis of Capacitor and Reactor for Harmonic Filter (고조파 필터용 커패시터와 리액터의 특성 해석)

  • Kim, Jong-Gyeum;Park, Young-Jeen;Lee, Eun-Woong
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.1
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    • pp.1-8
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    • 2009
  • Recently, application of non-linear load is gradually increased. Non-linear load produces harmonic components of current during the energy conversion transition. Passive filter is used for reducing of harmonics in the user power systems. This filter, which is composed of capacitor and reactor, frequently get out of order by electrical stress. There are voltage and current increase when capacitor and reactor are applied in the user's filter systems. If increased voltage and current is above stipulated values, they have severely an influences on the life of capacitor and reactor. This paper describes that the voltage and current of capacitor used for filter is within the limits of allowable values, but reactor is beyond the limits and reveals spike voltage. Therefore this phenomenon brings about premature fault of reactor and capacitor.

A Study on the Characteristic of Capacitor by Voltage and Current Harmonics (전압 및 전류 고조파에 의한 커패시터 동작 특성)

  • Kim, Jong-Gyeum;Park, Young-Jeen;Lee, Dong-Ju;Lee, Eun-Woong
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.3
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    • pp.257-262
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    • 2009
  • Capacitor is basically used for the power-factor compensation and sometimes as the passive filter to reduce harmonics of nonlinear load. Since the impedance of capacitor is inversely proportional to the frequency. The harmonic current may result in the problems of voltage distortion and resonance. Capacitor has easily fall under by two harmonic components, a nonlinear load and a distorted utility voltage. The amplified harmonic current and voltage may damage power capacitor. Hence the pre-investigation of harmonic is needed before designing and application the power factor for reducing fault rate. In this paper, we analyzed that voltage and current with harmonics components act on the capacitor under the resonance condition. we concluded that both voltage and current harmonics have an bad effect on the capacitor and current harmonics is a bitter rather than effect by voltage harmonics.