• Title/Summary/Keyword: Multi-step process

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FEM Analysis for Optimization of Hot Forging Process of Piston Crown (피스톤크라운의 열간단조공정 최적화를 위한 유한요소해석)

  • Min, K.Y.;Lim, S.J.;Choi, H.J.;Choi, S.O.;Park, Y.B.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.98-101
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    • 2009
  • Piston crown to the hot forge a unified nature of the product has a shape with multi-level step forging process, so if you are not a mechanical process that can be a significant loss is material. Therefore, minor in terms of material technology; continue to improve the collection rate should be. The Piston crown and the manufacturing of products such as marine diesel engines, reducing costs and to improve mechanical properties of the method are being forged. Piston crown molding hot forging process the large volume forging products handling because of the size of the size of the hard plastic material flow process for improving the design and actual field experience through advanced plastic technology, and it is important to interpret the results and for many experimental plastic The accumulation of results is very important.

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Development of Thermal Imprint System for Net-Shape Manufacturing of Multi-layer Ceramic Structure (세라믹 정형 가공을 위한 성형기 개발)

  • Park, C.K.;Rhim, S.H.;Hong, J.P.;Lee, J.K.;Yoon, S.M.;Ko, J.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.10a
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    • pp.401-404
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    • 2008
  • In the present investigation, a high precision thermal imprint system for micro ceramic products was developed and the net-shape manufacturing of multi-layer ceramic reflector for LED (Light Emitting Diode) was conducted with a precision metal die. Workpiece used in the present investigation were the multi-layer laminated ceramic sheets with pre-punched holes. The cavity with arbitrary angle was formed on the circular and rectangular holes of the ceramic sheets. During the imprinting process, the ambient temperature of the imprint system was kept over the transition temperature of the ceramic sheet and then rapidly cooled. The results in this paper show that the present method can be successfully applied to the fabrication of very small size hole array for ceramic reflector in a one step operation.

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Make-or-buy Decision Model Using Fuzzy-AHP Method for School Foodservice System

  • Hwang, Heung-Suk;Ko, Wen-Hwa
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2007.11a
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    • pp.121-129
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    • 2007
  • Recently a multi-attribute structure analysis method is one of the evident areas of important points in the decision support system analysis. This research developed an internet/intranet-based solution builder for a three-step decision support system using fuzzy-AHP in the view of 1) brainstorming far the idea generation, 2) fuzzy-AHP (fuzzy analytic hierarchy process) as a multi-attribute structured analysis method and 3) aggregation logic model to integrate the results of individual analysis. We applied this decision support system to the make-or-buy decision problem for school foodservice system considering the multi-attributes in the decision making. A computer program is developed and demonstrated it internet/intranet-based decision problem. It was known that this solution builder provides decision makers a good tool for mate-of-buy group decision making.

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Development of Virtual Prototype for Multi-Purpose Lathe Slide System (다기능 복합가공기 이송시스템의 가상시제품 개발)

  • 정상화;차경래;김상석
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.556-556
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    • 2000
  • In the multi-purpose lathe, the design of tilting turret slide system has an important and critical role to enhance the accuracy of the machining process. Tilting turret unit is traveled by 3-axis slide systems. There is a need to design this part very carefully. In this research, the 3-axis slide system with tilting turret unit is researched with two approaches; The first is that 3-axis slide system is modeled and simulated using ADAMS software. The dynamic behavior of this system is visualized by data graphs and dynamic animations. The second is that the slide system is analyzed with the aspect of stress distribution. The slide system is modeled and displayed by PATRAN and analyzed by NASTRAN. The analysis of strain and stress distribution in the each node is prompted and visualized in the computer. The first step of virtual prototype which makes it possible to design economically and effectively is developed.

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Development of Metal Substrate with Multi-Stage Nano-Hole Array for Low Temperature Solid Oxide Fuel Cell (저온 고체산화물연료전지 구현을 위한 다층 나노기공성 금속기판의 제조)

  • Kang, Sangkyun;Park, Yong-Il
    • Journal of the Korean Ceramic Society
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    • v.42 no.12 s.283
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    • pp.865-871
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    • 2005
  • Submicron thick solid electrolyte membrane is essential to the implementation of low temperature solid oxide fuel cell, and, therefore, development of new electrode structures is necessary for the submicron thick solid electrolyte deposition while providing functions as current collector and fuel transport channel. In this research, a nickel membrane with multi-stage nano hole array has been produced via modified two step replication process. The obtained membrane has practical size of 12mm diameter and $50{\mu}m$ thickness. The multi-stage nature provides 20nm pores on one side and 200nm on the other side. The 20nm side provides catalyst layer and $30\~40\%$ planar porosity was measured. The successful deposition of submicron thick yttria stabilized zirconia membrane on the substrate shows the possibility of achieving a low temperature solid oxide fuel cell.

Dynamic Analysis of Carbon-fiber-reinforced Plastic for Different Multi-layered Fabric Structure (적층 직물 구조에 따른 탄소강화플라스틱 소재 동적 특성 분석)

  • Kim, Chan-Jung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.4
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    • pp.375-382
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    • 2016
  • The mechanical property of a carbon-fiber-reinforced plastic (CFRP) is subjected to two elements, carbon fiber and polymer resin, in a first step and the selection of multi-layered structure is second one. Many combination of fabric layers, i.e. plainweave, twillweave, can be derived for candidates of test specimen used for a basic mechanical components so that a reliable identification of dynamic nature of possible multi-layered structures are essential during the development of CFRP based component system. In this paper, three kinds of multi-layered structure specimens were prepared and the dynamic characteristics of service specimens were conducted through classical modal test process with impact hammer. In addition, the design sensitivity analysis based on transmissibility function was applied for the measured response data so that the response sensitivity for each resonance frequency were compared for three CFRP test specimens. Finally, the evaluation of CFRP specimen over different multi-layered fabric structures are commented from the experimental consequences.

Night-time Vehicle Detection Based On Multi-class SVM (다중-클래스 SVM 기반 야간 차량 검출)

  • Lim, Hyojin;Lee, Heeyong;Park, Ju H.;Jung, Ho-Youl
    • IEMEK Journal of Embedded Systems and Applications
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    • v.10 no.5
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    • pp.325-333
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    • 2015
  • Vision based night-time vehicle detection has been an emerging research field in various advanced driver assistance systems(ADAS) and automotive vehicle as well as automatic head-lamp control. In this paper, we propose night-time vehicle detection method based on multi-class support vector machine(SVM) that consists of thresholding, labeling, feature extraction, and multi-class SVM. Vehicle light candidate blobs are extracted by local mean based thresholding following by labeling process. Seven geometric and stochastic features are extracted from each candidate through the feature extraction step. Each candidate blob is classified into vehicle light or not by multi-class SVM. Four different multi-class SVM including one-against-all(OAA), one-against-one(OAO), top-down tree structured and bottom-up tree structured SVM classifiers are implemented and evaluated in terms of vehicle detection performances. Through the simulations tested on road video sequences, we prove that top-down tree structured and bottom-up tree structured SVM have relatively better performances than the others.

Computation of the Shortest Distance of Container Yard Tractor for Multi-Cycle System (다중 사이클 시스템을 위한 실시간 위치 기반 컨테이너 야드 트랙터 최단거리 계산)

  • Kim, Han-Soo;Park, Man-Gon
    • Journal of Korea Multimedia Society
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    • v.13 no.1
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    • pp.17-29
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    • 2010
  • A container terminal productivity is maximized by a minimized time for processing containers. So, we have been elevated the container terminal productivity through an improvement of computing system, but there are a limitation because of problems for transportation management and method. A Y/T(Yard Tractor), which is a representative transportation, is able to do only one process, loading or unloading, at one time. So if the Y/T can do loading and unloading step by step at a same time, the processing time would be shortened. In this paper, we proposed an effective operating process of Y/T(Yard Tractor) Multi-Cycle System by applying RTLS(Real Time Location System) to Y/T(Yard Tractor) in order to improve the process of loading and unloading at the container terminal. For this, we described Multi-Cycle System. This system consists of a real time location of Y/T based on RTLS, an indicating of Y/T location in real time with GIS technology, and an algorithm(Dijkstra's algorithm) of the shortest distance. And we used the system in container terminal process and could improve the container terminal productivity. As the result of simulation for the proposed system in this paper, we could verify that 9% of driving distance was reduced compared with the existing rate and 19% of driving distance was reduced compared with the maximum rate. Consequently, we could find out the container performance is maximized.

Stepwise Ni-silicide Process for Parasitic Resistance Reduction for Silicon/metal Contact Junction

  • Choi, Hoon;Cho, Il-Whan;Hong, Sang-Jeen
    • Transactions on Electrical and Electronic Materials
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    • v.9 no.4
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    • pp.137-142
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    • 2008
  • The parasitic resistance is studied to silicon/metal contact junction for improving device performance and to lower contact/serial resistance silicide in natural sequence. In this paper constructs the stepwise Ni silicide process for parasitic resistance reduction for silicon/metal contact junction. We have investigated multi-step Ni silicide on SiGe substrate with stepwise annealing method as an alternative to compose more thermally reliable Ni silicide layer. Stepwise annealing for silicide formation is exposed to heating environment with $5^{\circ}C/sec$ for 10 seconds and a dwelling for both 10 and 30 seconds, and ramping-up and the dwelling was repeated until the final annealing temperature of $700\;^{\circ}C$ is achieved. Finally a direct comparison for single step and stepwise annealing process is obtained for 20 nm nickel silicide through stepwise annealing is $5.64\;{\Omega}/square$ at $600\;^{\circ}C$, and it is 42 % lower than that of as nickel sputtered. The proposed stepwise annealing for Ni silicidation can provide the least amount of NiSi at the interface of nickel silicide and silicon, and it provides lower resistance, higher thermal-stability, and superior morphology than other thermal treatment.

A Job Scheduling Scheme based on Analytic Hierarchy Process in Cloud Computing (클라우드 컴퓨팅에서 Analytic hierarchy process를 활용한 작업 스케줄링 기법)

  • Kim, Jeong-Won
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.8
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    • pp.9-15
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    • 2013
  • As the resources of cloud computing are essentially heterogeneous and jobs have various characteristics, resource allocation to jobs is one of important problems. We define this issue as a multi-criteria decision-making problem. This paper proposes a priority-based job scheduling algorithm based on analytic hierarchy process (AHP). On the first step, jobs are classified based on their preferences. On the second step, response time, system utilization, and load becomes decision criteria based on the AHP algorithm. Jobs are allocated to adequate resources through their priorities that are calculated by the AHP algorithm. Through analysis and experiment of the proposed algorithm, we are to confirm that the scheme can schedule jobs as well as utilize its resource efficiently.