• 제목/요약/키워드: min-cut

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최대 수용량-기반 최소절단 알고리즘 (Maximum Capacity-based Minimum Cut Algorithm)

  • 이상운
    • 한국컴퓨터정보학회논문지
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    • 제16권5호
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    • pp.153-162
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    • 2011
  • 최소 절단 문제는 공급처 S에서와 수요처 T로의 흐름 용량이 최소가 되는 지점들을 절단하는 문제이다. 망의 병목지점을 찾는 방법은 대부분 유동망을 계산하여 최소 절단값을 찾는 유동-기반 알고리즘이 적용되고 있다. 이 알고리즘은 최소절단은 제시하지 않는 단점이 있다. 본 논문은 유동망을 구하지 않고 망으로부터 직접 최대 수용량을 가진 정점을 인접한 S 또는 T로 병합하는 방법으로 최소 절단값을 찾는 간단한 알고리즘이다. 13개의 한정된 그래프에 적용한 결과 제안된 알고리즘은 간단하면서도 정확하게 최소 절단 값 $_{\min}c$(S, T)을 찾을 수 있었다.

소형 앵글 스핀들 공구의 절삭성능에 관한 연구 (Cutting Performance of a Developed Small-angle Spindle Tool)

  • 김진수;김용조
    • 한국기계가공학회지
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    • 제15권2호
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    • pp.111-117
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    • 2016
  • The cutting performance of a developed small-angle spindle tool was investigated with Al6061 using a TiAlN coated high-speed steel end mill. Up-cut and down-cut processes in a milling machine were carried out at the range of 1000-4000 rpm for spindle speed and 50-300 mm/min for feed rate. As a result, the highest cutting force in the Fx direction was obtained from the up-cut process when the spindle speed was 1000 rpm and the feed rate was 100 mm/min. In the Fy direction, the highest cutting force appeared in the up-cut process at a feed rate of 250 mm/min at the same spindle speed. Conversely, the lowest cutting force came out in the up-cut process at a spindle speed of 4000 rpm and a feed rate of 50 mm/min. As for surface finish, the finest surface roughness was obtained as Ra 0.7642 um at a spindle speed of 4000 rpm and a feed rate of 50 mm/min. Consequently, given the cutting performance of the developed small-angle spindle tool, we conclude that its use in industrial practice is feasible.

Thermal-Aware Floorplanning with Min-cut Die Partition for 3D ICs

  • Jang, Cheoljon;Chong, Jong-Wha
    • ETRI Journal
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    • 제36권4호
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    • pp.635-642
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    • 2014
  • Three-dimensional integrated circuits (3D ICs) implement heterogeneous systems in the same platform by stacking several planar chips vertically with through-silicon via (TSV) technology. 3D ICs have some advantages, including shorter interconnect lengths, higher integration density, and improved performance. Thermal-aware design would enhance the reliability and performance of the interconnects and devices. In this paper, we propose thermal-aware floorplanning with min-cut die partitioning for 3D ICs. The proposed min-cut die partition methodology minimizes the number of connections between partitions based on the min-cut theorem and minimizes the number of TSVs by considering a complementary set from the set of connections between two partitions when assigning the partitions to dies. Also, thermal-aware floorplanning methodology ensures a more even power distribution in the dies and reduces the peak temperature of the chip. The simulation results show that the proposed methodologies reduced the number of TSVs and the peak temperature effectively while also reducing the run-time.

Assessing the Adequacy of Superficial Temporal Artery Blood Flow in Korean Patients Undergoing STA-MCA Anastomosis

  • Jin Eun; Ik Seong Park
    • Journal of Korean Neurosurgical Society
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    • 제67권2호
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    • pp.158-165
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    • 2024
  • Objective : Superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis is conducted for flow augmentation. In this study, we measured the STA cut flow of a Korean population and evaluated the relationship between STA cut flow and long-term patency of the bypass. Methods : A retrospective study was conducted. Intraoperative measurement of STA flow was conducted using a microvascular flow meter on patients who underwent STA-MCA. After cutting the distal end, the STA flow rate was measured with no resistance and recorded. After finishing anastomosis, STA flow was measured and recorded. The cut flow index was calculated by dividing post anastomosis flow by cut flow in intracranial atherosclerotic stenosis patients. Results : The median STA cut flow was 35.0 mL/min and the post anastomosis flow was 24.0 mL/min. The cut flow of STA decreased with aging (p=0.027) and increased with diameter (p=0.004). The cut flow showed no correlation with history of hypertension or diabetes mellitus (p=0.713 and p=0.786), but did correlate a positively with history of hyperlipidemia (p=0.004). There were no statistical differences in cut flow, STA diameter, and post anastomosis flow between the frontal and parietal branches (p=0.081, p=0.853, and p=0.990, respectively). Conclusion : The median STA cut flow of a Korean population was 35 mL/min. Upon reviewing previous articles, it appears that there are differences in the STA cut flow between Western and Asian patients.

최소절단 문제의 자유계약 알고리즘 (A Free Agent Algorithm for Min-Cut Problem)

  • 이상운
    • 한국인터넷방송통신학회논문지
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    • 제19권4호
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    • pp.27-33
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    • 2019
  • 공급지(s)에서 수요지(t)로 흐르는 복잡한 망에서 망의 최대 흐름을 결정하는 최소절단 면을 찾는 최소절단 문제는 난제로 알려져 있다. 이에 대해 증대경로 알고리즘은 증대경로를 갖는 단일 경로로 분할하여 병목 지점(간선)을 찾는 방식을 채택하고 있으나 최소절단면을 추가적으로 결정해야만 한다. 본 논문에서는 프로스포츠계에서 적용되고 있는 자유계약제 방식을 적용하여, 정점 수 n에 대해 수행 복잡도가 O(n)인 휴리스틱 탐욕 알고리즘을 제안한다. 자유계약 방식은 $v{\in}V{\backslash}\{s,t\}$정점들 중에서 $N_G(S),N_G(T)$정점들을 자유계약 선수라고 가정하고, 이 선수들의 연봉이 보다 상승하는 팀으로 이적하는 방식을 적용하였다. 제안된 알고리즘을 다양한 망 형태에 적용한 결과, 모든 망에서 최소절단 치 뿐 아니라 망에 존재하는 모든 최소절단 들을 찾을 수 있음을 보였다.

하이브리드 로켓 추진장치 연소 열원을 이용한 절단기초실험 (A cutting Experiments the materials by using heat source of the Hybrid Propulsion System Combustion)

  • 유덕근;김수종;김진곤;구자예;문희장;이보영;길성만;오재영;국태승
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.344-349
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    • 2003
  • The purpose of this study is to ascertain the ability of New type cutter using Hybrid Rocket Propulsion System to cut normal carbon steel and also compound metal like stainless steel which cannot be cut by regular oxygen-acetylene cutter. To compare cutting performance, Two different types of experiment with oxygen-acetylene and Hybrid Combustion cutters were performed. As a result, Hybrid Combustion cutter is used to cut both carbon steel and stainless steel with cutting speed of 400mm/min(carbon steel) and 250mm/min(stainless steel). Otherwise, oxygen-acetylene cutter can be used to cut only carbon steel with cutting speed of 500 $^{\sim}$ 700mm/min. The possibility of Hybrid Combustion cutter as a cutting machine was confirmed.

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파인 세라믹 ($Al_2O_3$)의 被削性에 관한 硏究 (A Study on the Machinability of Fine Ceramics (($Al_2O_3$)))

  • 김성겸;이용성
    • 대한기계학회논문집
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    • 제13권4호
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    • pp.604-610
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    • 1989
  • 본 연구는 알루미나계 세라믹의 소결 다이아몬드 공구로 절삭시의 칩의 형태 와 절삭저항을 관찰하였다. 절삭 양식은 건식과 습식으로 하고, 여러 가지 적삭조건 에 따른 flank 마멸의 진행과정, 가공면의 표면거칠기에 미치는 영향 및 가공면의 크랙 상태를 조사형 현미경으로 확대 검출하여 가공상태를 정밀하게 조사, 측정하였 다.

신선편이 근채류에 대한 소비자 인식도 조사 (Survey on Consumers' Perception of Fresh-cut Root Vegetables)

  • 장민선;김지강;김건희
    • 한국식품조리과학회지
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    • 제26권5호
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    • pp.649-654
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    • 2010
  • This study investigated the recognition of and preference for consumer root vegetables for the improvement of fresh-cut root vegetable quality. The questionnaires consisted of questions on general preference, purchasing locations and quality factors. Answers to 286 questionnaires were analyzed both descriptively and quantitatively using SPSS for Windows (Version 14.0). The principal results were as follows: 37% of the respondents preferred potatoes to other root vegetables; 52% purchased at wholemarket. Most consumers preferred fresh-cut root vegetables; 56% were un-satisfied with fresh-cut vegetables quality as high quality agents. The most considered factor in purchasing fresh-cut root vegetables was shape/appearance.

연삭가공특성에 미치는 연삭입자 최대물림깊이의 영향 (Effects of the maximum grit depth of cut on grinding characteristics)

  • 허인호
    • 한국생산제조학회지
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    • 제8권5호
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    • pp.63-69
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    • 1999
  • In tis study the effects of the maximum grit depth of cut on the grinding characteristics were investigated. They are AE signals produced during grinding processes have been studied to find out the appropriate AE parameters for assessing grinding processes. SM45C steel has been ground under the conditions yielding removal rate of workpiece 100, 200,300, and 400m{{{{ {m }^{3 } }}}}/min which was achieved by altering workpiece velocity(v) and apparent depth of cut(Z). According to the experimental result the value of surface roughness increases but grinding power energy rate of AE signal(AErmas2) and specific grinding energy consumed decrease as increasing the maximum grit depth of cut.

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