• Title/Summary/Keyword: Bottom-Up

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Research on High-Efficiency Machining through Bottom-up Machining using CAD/CAM System (CAD/CAM시스템을 이용한 상향식 가공에 의한 고효율가공에 관한 연구)

  • Jeong, Dae Hoon;Han, Kyu-Taek
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.11
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    • pp.89-95
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    • 2019
  • In this research, the effect of roughing on tool load through bottom-up machining is investigated through actual machining. Generally, through the use of high-speed machining technology, machining methods, such as general roughing, operate by deepening the cutting depth for as long as the tool is able to withstand it, giving a slower feed rate, less cutting depth, and faster feed. However, when the cutting depth is deep, there is a problem in that the stepped shape of the cutting area is increased (e.g., by the shaking of the tool or the chipping load). However, if the cutting is performed less, the cutting time becomes relatively long. To compensate for these drawbacks and extend the service life of the tool, economic efficiency needs to be secured.

Exploring Control in Bottom-Up Information System Development Projects to Improve Software Development Performance

  • Cho, Donghwan
    • International Journal of Contents
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    • v.15 no.2
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    • pp.38-43
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    • 2019
  • Recently, bottom-up information systems (BUIS), developed according to the requirements of individual user departments, have become popular. However, effective management of BUIS projects is not enough, with many organizations having experienced integration challenges with such individual projects. BUIS projects are relatively small and limited in scope, as opposed to the large, complex systems developed through traditional top-down information system development projects. Due to these differences in characteristics, the control modes as well as the aspects to improve development performance in each type of project are also different. Therefore, it is difficult to apply the results of prior research on control in system development projects to improve BUIS project performance. The purpose of this study is to derive a new theory of control to improve BUIS project performance. The results contribute to the improvement of firm performance through effective control of BUIS projects in modern enterprises.

Effect of an Obstacle on the Bottom Surface of a Circular Cylinder on the Spin-up Flow (원통 용기 바닥의 장애물이 스핀업 유동에 미치는 영향)

  • Choi, Yoon-Hwan;Moon, Jong-Choon;Suh, Yong-Kweon
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.676-681
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    • 2001
  • In this paper, the spin-up from rest to a state of solid-body rotation in a circular container with a slender rectangular obstacle on the bottom wall is analysed experimentally. We use a PIV method for the evolution of the free-surface flow. Laboratory experiments have been carried out for a variety of the obstacle height h(0, 5, 10 [mm]) and the liquid depth H(25, 50, 75, 100 [mm]). It was found that the spin-up time is crucially dependent on the obstacle height T. In the case of T=10[mm] the spin-up time is considerably shorter then the other cases.

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A Study on a Recombination Method for the Bottom-up Construction of Spatial Information Products (재조합을 위한 Bottom-up 공간정보제품 제작 방법)

  • Choi, Jae-Yeon;Kim, Eun-Hyung
    • Journal of Cadastre & Land InformatiX
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    • v.47 no.2
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    • pp.185-199
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    • 2017
  • This study is on a recombination method for the construction of spatial information products which demands are unpredictably various. The present production method of digital maps is not flexible enough for their reusability because it is not object-oriented but top-down. Each spatial object needs to have particular attributes to be recombined. The demand changes the production method through the reclassification of data and changing the properties. In a user perspective, the bottom-up method can produce on-demand spatial information products including existing digital maps. The method is derived from case studies and theoretical reviews and compared with the existing production method. In the method spatial information products are reclassified by their geometry objects such as point, line, and polygon, with basic attributes, and other related domain attributes. The geometry objects and domain attributes are connected by adding new attributes for their later relationship and management, which make the recombination possible. To prove its usability of the method it is tested for current and future user demands including the national base map, thematic maps and the future spatial information products.

Bycatch Reduction by Experimental Shaking Codend Attached with Canvas in a Bottom Trawl

  • Kim, Yonghae
    • Fisheries and Aquatic Sciences
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    • v.18 no.3
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    • pp.325-332
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    • 2015
  • An active stimulating method for juvenile fishes to drive escaping from mesh of the codend was examined by shaking canvas in the bottom trawl followed by shrimp beam trawl. Field fishing trials by a bottom trawl were carried out between the Geomoondo and Jejudo in west of South sea, Korea by conver-net methods to examine the effect on the reduction of juvenile fish as a discard catch by generating a shaking movement of the codend using two pieces of asymmetrical semi-circular canvas. The mean period of the shaking motion with the round canvas was 10-15 s, and the range of amplitude as a vertical depth change was up to 0.4-0.6 m when towing speed 3.4-4.3 k't as estimated by peak event analysis. The escape rate of juvenile fish in conver-net by total juvenile bycatch (codend and cover-net) in 14 trials increased from 20% in a steady codend to 34% using a shaking codend in the bottom trawl, while the marketing catch or total bycatch was similar between steady and shaking cod ends. There was no difference in the body size of the fish and species composition between the steady and shaking cod ends. Above results demonstrate a new method for bycatch reduction actually up to 18% using an active stimulating device, although further experiments are needed to increase an effective shaking motion of the codend in amplitude and period for more bycatch reduction.

Development of Bottom-up model for Residential Energy Consumption by Use (생활행위 분류에 의한 가정부문 용도별 에너지소비 분석모형 개발)

  • Lim, Ki Choo
    • Journal of Energy Engineering
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    • v.22 no.1
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    • pp.38-43
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    • 2013
  • There was a dire need to compile data about energy consumption data by use to analyze residential energy consumption patterns relating to changes in lifestyles, or changes in life behavior. Accordingly, bottom-up model for residential energy consumption by residential use was developed by life behavior classification in an attempt to analyze energy consumption. This paper multiplied each appliance's running times by each appliance by life behavior and built a residential bottoms-up model to figure out the energy consumption of each household. The uses by life behavior were broken down into lighting, heating, cooling, entertainment, obtaining information, hygiene, and cooking.

EFFICIENT MARKER EXTRACTION ALGORITHM FOR INITIAL SEGMENTATION IN A BOTTOM-UP IMAGE SEGMENTATION SCHEME (상향식 영상분할 구조에서의 초기 영상분할을 위한 효율적인 마커 추출 알고리즘)

  • 박현상;나종범
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.895-898
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    • 1998
  • In this paper, we propose an efficient marker extraction algorithm for initial image segmentation in a bottom-up segmentation scheme. The proposed algorithm generates dense markers in visually complex areas and coarse markers in visually uniform areas. which conforms to the human perceptual system. Experimental results show that the proposed method achieves better subjective quality for fine initial image segmentation.

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집속이온빔(Focused Ion Beam)을 이용한 3차원 나노가공

  • 박철우;이종항
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.05a
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    • pp.11-11
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    • 2004
  • 나노기술은 크게 2가지 접근방법을 가진다. 하나는 위에서 아래로(Top-Down)라는 관점으로 벌크물질로부터 이온빔 등을 이용해 이를 작게 잘라가는 방식이며, 다른 하나는 아래에서 위로(Bottom-Up) 방식으로 재질을 구성하는 분자를 재구성해 원하는 물성 및 특성을 가지도록 만드는 방법이다. 이 두 가지 접근 방법은 원하는 결과를 얻기 위해 상호 보완적으로 사용되기도 한다. Top-Down방식의 대표적인 기기로는 접속이온빔 장치(FIB, Focused Ion Beam)를 등 수 있으며, Bottom-Up방식의 대표적인 기기로는 SPM(Scanning Probe Microscope)을 들 수 있다.(중략)

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Analysis of the Behaviors of Continuous parts in Continuous PSC Girders Bridges (PSC 연속 거더교의 연속화부 거동에 관한 해석적 연구)

  • 구민서;김훈희;정영도
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.404-411
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    • 2002
  • The PSC 2-span-continuous-bridge by Up-Down Method on construction process is used for this research. It is measured the strain of lower-steel-plate at continuous section on the active range of negative moment at the stage of introducing compressive stress to bottom-plate and compared with results of structural analysis. On the basis of these results, it is confirmed the introduced compressive stress tか bottom-plate. The object of this research is presenting the degree of continuity at the stage of lifting up process.

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The Basic Concepts Classification as a Bottom-Up Strategy for the Semantic Web

  • Szostak, Rick
    • International Journal of Knowledge Content Development & Technology
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    • v.4 no.1
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    • pp.39-51
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    • 2014
  • The paper proposes that the Basic Concepts Classification (BCC) could serve as the controlled vocabulary for the Semantic Web. The BCC uses a synthetic approach among classes of things, relators, and properties. These are precisely the sort of concepts required by RDF triples. The BCC also addresses some of the syntactic needs of the Semantic Web. Others could be added to the BCC in a bottom-up process that carefully evaluates the costs, benefits, and best format for each rule considered.