• 한국자동차공학회논문집
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• 제8권6호
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• pp.220-229
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• 2000

In the brake systems a proportioning valve which reduces the brake pressure at each wheel cylinder for anti-locking of rear wheels is closely related with the safety of vehicles. But, it is impossible for a present proportioning valve to exactly control brake pressure because mechanically it is an open loop control system. So, in this paper we describe a electronic brake pressure distribution system using a fuzzy controller in order to exactly control brake pressure using a close loop control system. The object of electronic brake pressure distribution system is to change an cut-in pressure and an valve slop of proportioning valve in order to obtain better good performance of brake system than with mechanical system.

• 복합신소재구조학회 논문집
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• 제5권3호
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• pp.23-31
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• 2014

Recently, sewer-pipe constructions replacing deteriorated pipes are currently underway in the downtown area. To resolve many problems in the conventional method of open-cut construction, lining-board system using light-weight GFRP panels is developed. The pultruded GFRP panels can be successfully used for the developed lining-board system as temporary decks and retaining walls in virtue of light weight, high strength and high durability. In this paper, the structural safety and serviceability of the lining-board system are examined through FE analyses and experiments. Further more, a field application of the lining-board system is presented. The field application shows that quality and environment of construction can be significantly improved.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.445-450
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• 2000

In this paper, a numerical method is proposed for cam synthesis. kinematics of closed loop system with cam and follower is presented using relative coordinates. The system is transformed into an open loop system by cutting fictitiously higher-pair contact of cam and follower and envelope constraint equations are derived. Follower constraint equations are derived from the motion of the follower ends. The joint variables and follower profile parameters are calculated from the envelope constraint equations and follower constraint equations by using the Newton - Raphson iterative method. Algorithms for cam synthesis are presented and simulations are done to verify the effectiveness of the proposed method.

• 한국지열·수열에너지학회논문집
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• 제14권1호
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• pp.16-21
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• 2018

This work aims to develop a platform to investigate the effect of operation schedules on the building energy consumption and to derive a simulation model based optimal start and stop daily strategy. An open-source building energy simulation tool DOE2 is used for the engine, and the developed simulation model is validated using ASHRAE guideline 14. The effect of late-start/early-stop operation of HVAC system on the daily building energy consumption was analyzed using the developed simulation model. It was found that about 10% of energy consumption cut was possible using the control strategy for an hour of advance of the stop operation, and about 3% per an hour of delay of the start operation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1990년도 PROCEEDINGS OF THE FIRST KOREA-JAPAN JOINT GEOTECHNICAL SEMINAR ON EXCAVATION and TUNNELING IN URBAN AREAS
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• pp.97-110
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• 1990

This paper presents a case history of a deep open cut excavation of Nakagawa section for Futuoka Subway construction which adopted observational mettled against boiling failure and completed with success by modifying construction based upon field monitoring. One of the difficult conditions for the excavation was sandy layer with high water pressure which was anticipated boiling failure. The boiling was generally considered as one of the difficult phenomena to work with the observational method because of its unpredictable catastrophic nature. Laboratory experiments showed the existence of the prefailure movements of the ground and the possibility of the application of the observational method against the boiling failure. Construction step was planned to be modified, if necessary, based upon field monitoring and was completed with success.

• 건설안전기술
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• 통권50호
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• pp.84-96
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• 2009

Road is typically constructed along ridge area of mountain because of topographical and economic reasons. Therefore, road may face lots of open cut slope which can easily cause rock falling. This study evaluates the structural safety of newly developed falling rock protection system which has a roof deck plate. The structural performance under self-weight, snow load and load from failing rock was investigated using a finite element numerical analysis method. From the analysis results, the H-beam space was limited not to exceed 2.2m. The deck plate was also safe under the examined loading condition. A hinge and connection in the system were investigated through detailed modelling and analysis. The results showed that the hinge was safe enough and that the connection should strengthened with appropriate stiffeners.

• 호남수학학술지
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• 제35권1호
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• pp.37-49
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• 2013

Consider a non-degenerate open convex cone C with vertex the origin in the $n$2-dimensional Euclidean space $E^n$. We study volume properties of strictly convex hypersurfaces in the cone C. As a result, for example, if the volume of the region of an elliptic cone C cut off by the tangent hyperplane P of M at $p$ is independent of the point $p{\in}M$, then it is shown that the hypersurface M is part of an elliptic hyperboloid.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.253-257
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• 1996

A basic assumption in the current design and analysis of reinforced concrete(RC) box structures, which are constructed by the open cut and fill method, is that the displacements and forces are uniform in the longitudinal direction of the structure. The solution may be therefore obtatined from the analysis of a unit wide strip along longitudinal axis. This strip is said to be in a plane strain condition, meaning that the out of plane deformations are vanished. The current design of box structure is carried out by the result of planar frame model for the sake of simplicity. The purpose of this study is to show more rational design method of box culverts considering a rigid zone of corner joints. The current analysis of box structures will be compared with the plane strain analysis as well as 3-d shell model. Reinforcement quantity is also determined to resist the tensile force in corner joints of box structures using strut-tie model which has been developed through the elastic analysis.

• 한국안전학회지
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• 제24권3호
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• pp.47-53
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• 2009

Road is typically constructed along ridge area of mountain because of topographical and economic reasons. Therefore, road may face lots of open cut slope which can easily cause rock falling. This study evaluates the structural safety of newly developed falling rock protection system which has a roof deck plate. The structural performance under self-weight, snow load and load from falling rock was investigated using a finite element numerical analysis method. From the analysis results, the H-beam space was limited not to exceed 2.2m. The deck plate was also safe under the examined loading condition. A hinge and connection in the system were investigated through detailed numerical modelling and analysis. The results showed that the hinge was safe enough and that the connection should strengthened with appropriate stiffeners.

• Journal of Mechanical Science and Technology
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• 제15권1호
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• pp.66-80
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• 2001

In brake systems, a proportioning valve(P. V), which reduces the brake line pressure on each wheel cylinder for the anti-locking of rear wheels, is closely related to the safety of vehicles. However, it is impossible for current P. V. s to completely control brake line pressure because, mechanically, it is an open loop control system. In this paper we describe an electronic brake force distribution system using a direct adaptive fuzzy controller in order to completely control brake line pressure using a closed loop control system. The objective of the electronic brake force distribution system is to change the cut-in-pressure and the valve slop of the P. V in order to obtain better performance of the brake system than with mechanical systems.