• Title/Summary/Keyword: Branch-and-cut

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A Study on Minimum Cost Expansion Planning of Power System by Branch and Bound Method (분지한정법에 의한 전력계통의 최소비용에 관한 연구)

  • 송길영;최재석
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.33 no.1
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    • pp.9-16
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    • 1984
  • This paper describes the minimum cost expansion planning which is based on the economical aspect under the various conditions on the power system expansion planning. It presents not only linear cost characteristics analysis but also stepwise cost characteristics analysis which satisfies practical condition in the power system. The latter analysis must be handled by integer programming (IP), because the relation between the cost and the capacity has stepwise characteristics. In order to proceed the latter analysis, the solving procedure is illustrated in detais by using branch and bound method which includes the network flow theory and maximum flow-minimum cut theorem.

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Relation Between the Growth Habitat and the Leaf Quality of Cultivated Mulberry Plants (뽕나무의 생육특성과 엽질과의 관계)

  • 김준호
    • Journal of Plant Biology
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    • v.17 no.3
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    • pp.118-126
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    • 1974
  • Mulberry plants cultivated in mid-Korea were studied on the growth habitat, canopy type, productive structure and vertical light intensity in relation to the quality of mulberry leaves for sericulture. The growth in length of new branch of summer cut mulberry in spring was vigorous on the uppermost of old shoot. Numbers of leaves on a branch were barely 4 leaves on lower than 20th branch from base, but those were 13 leaves on higher than 24th branch. Area of leaves completely expanded was broad on high branch, but narrow on low one. The form of canopy, the type of productive structure and the vertical light distribution depend upon varieties of cultivated mulberry plants were classified according to characteristic of each variety in two groups, respectively; globular and columnar form in canopy, broad leaves and narrow leaves types in productive structure, and seriously obstructured the light and fairly transmitted the light into lower leaf stratum invertical light distribution. Out of varieties of mulberry investigated, Suwon No. 4 and Rosang were belong to the former characters, but Illchiroe and Kaeryangsubun were to the latters. The values of leaf dry matter index and dry matter production produced by leaves were increased in direct proportion to the height of leaf stratum; the leaf dry matter index of the uppermost leaf was twice as much that of the lowest, and the dry matter production by the highest leaf was 17 times compared with that by the lowest leaf. It is assumed that the meagre leaves occurred in the lower leaf stratum of Suwon No. 4 and Rosang were caused to diminished the dry matter index and dry matter production in the under leaves of plant, which were affected by receiving the weak light.

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Pre-Hospital and In-Hospital Management of an Abdominal Impalement Injury Caused by a Tree Branch

  • Ahn, So Ra;Lee, Joo Hyun;Kim, Keun Young;Park, Chan Yong
    • Journal of Trauma and Injury
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    • v.34 no.4
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    • pp.288-293
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    • 2021
  • In South Korea, most patients who visit trauma centers with abdominal injuries have blunt trauma, and penetrating injuries are relatively rare. In extremely rare cases, some patients are admitted with a long object penetrating their abdomen, and these injuries are referred to as abdominal impalement injuries. Most cases of impalement injuries lead to fatal bleeding, and patients often die at the scene of the accident. However, patients who survive until reaching the hospital can have a good prognosis with optimal treatment. A 68-year-old female patient was admitted to the trauma center with a 4-cm-thick tree branch impaling her abdomen. The patient was transported by a medical helicopter and had stable vital signs at admission. The branch sticking out of the abdomen was quite long; thus, we carefully cut the branch with an electric saw to perform computed tomography (CT). CT revealed no signs of major blood vessel injury, but intestinal perforation was observed. During laparotomy, the tree branch was removed after confirming that there were no vascular injuries, and enterostomy was performed because of extensive intestinal injury. After treating other injuries, the patient was discharged without any complications except colostomy. Abdominal impalement injuries are treated using various approaches depending on the injury mechanism and injured region. However, the most important consideration is that the impaled object should not be removed during transportation and resuscitation. Instead, it should only be removed after checking for injuries to blood vessels during laparotomy in an environment where injury control is possible.

A Wavelength Path Accommodation Method in Wavelength Routed WDM Network (파장 라우팅 WDM망에서의 파장 경로 설정 방식)

  • 김병재;박진식;신기수
    • Proceedings of the Korean Information Science Society Conference
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    • 1998.10a
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    • pp.636-638
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    • 1998
  • WDM망을 구성하는데 있어서 광학적 파장은 가장 중요한 자원의 하나이다. 그러나 주어진 통신 요구를 모두 수용하면서 동시에 최소한의 파장만을 사용하는 WDM망의 설계 문제는 이미 NP-complete 계열의 문제인 것으로 밝혀졌으며 많은 휴리스틱 알고리즘들이 제안되었다. 본 논문에서는 임의의 물리적 망 위상(topology)과 완전 연결(full connection)형태의 통신 요구가 주어질 경우, 요구되는 파장 경로(Wavelength Path, lightpath)를 확립하기 위한 방법으로써 각 노드 사이의 최단 거리 경로를 기반으로 하여 탐색 공간을 만들고 구성된 탐색 공간 내에서 Branch-and-bound 탐색방식을 수행하는 파장 경로 설정 알고리즘을 제안한다. Branch-and-bound탐색방식은 초기에 좋은 bound조건을 가질 경우 주어진 시간 안에 보다 넓은 탐색 공간을 검색할 수 있으므로 최초의 탐색에서 가능한 좋은 성능의 파장 경로 설정을 발견할 수 있어야한다. 시뮬레이션 실험을 통하여 최초의 탐색에서 발견한 파장 경로 설정과 구성된 탐색 공간내의 최적해를 얻고, cut-set를이용하여 요구 파장 개수의 하위 한계값을 계산한후, 이를 상호 비교하여 제안된 알고리즘의 성능을 평가한다.

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Reproductive Structures of Pachymeniopsis elliptica (Holmes) Yamada (Rhodophyta, Grateloupiaceae) (홍조 도박(Pachymeniopsis elliptica (Holmes) Yamada)의 생식기 구조)

  • 이해복
    • Journal of Plant Biology
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    • v.27 no.4
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    • pp.233-239
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    • 1984
  • Reproductives structures of Pachymeniopsis elliptica (Holmes) Yamade (Rhodophyta, Grateloupiaceae) are investigated. In female gametophyte the carpogonial branch and auxiliary cell are produced in separate accessory branch system, the primary ampullar filament originated from mid-cortical layer. After fertilization, auxiliary cell joined with connecting filament becomes a fusion cell by fusing with several neighboring ampullar cells. The fusion cell produces a gonimoblast initial. It divides into gonimoblast cells, which later convert to carposporangia. In male gametophyte superficial cortical cells of vegetative filament produce two spermatangial mother cells which cut off up to three spermatangia respectively. Tetrasporangial initials are formed from the 6th to 12th cells of the cortical layer in tetrasporophyte, and divided cruciately to form tetrasporangium. Some of the sporangia are, however, divided zonately.

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A Computer Method for the Dynamic Analysis of a System of Rigid Bodies in Plane Motion

  • Attia, Hazem-Ali
    • Journal of Mechanical Science and Technology
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    • v.18 no.2
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    • pp.193-202
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    • 2004
  • This paper presents a computer method for the dynamic analysis of a system of rigid bodies in plane motion. The formulation rests upon the idea of replacing a rigid body by a dynamically equivalent constrained system of particles. Newton's second law is applied to study the motion of the resulting system of particles without introducing any rotational coordinates. A velocity transformation is used to transform the equations of motion to a reduced set. For an open-chain, this process automatically eliminates all of the non-working constraint forces and leads to an efficient integration of the equations of motion. For a closed-chain, suitable joints should be cut and few cut-joints constraint equations should be included. An example of a closed-chain is used to demonstrate the generality and efficiency of the proposed method.

Approach to BMI Problems Using Evolution Strategy

  • Chung, Tae-Jin;Chung, Chan-Soo
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.224-224
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    • 2000
  • Biaffine Matrix Inequalities(BIs) are known to give more general and flexible frameworks in control designs than Linear Matrix Inequalities(LMIs). However, BMIs are nonconvex constraints and very difficult to solve. In this paper, BMI problems are solved using Evolution Strategy(ES). Numerous BMI problems are solved to verify performances of ES solver for BMI problems and compared with those of Genetic Algorithms and Branch-and-Cut algorithm.

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Cover Inequalities for the Robust Knapsack Problem

  • Park, Kyung-Chul
    • Management Science and Financial Engineering
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    • v.14 no.1
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    • pp.91-96
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    • 2008
  • Robust knapsack problem appears when dealing with data uncertainty on the knapsack constraint. This note presents a generalization of the cover inequality for the problem with its lifting procedure. Specifically, we show that the lifting can be done in a polynomial time as in the usual knapsack problem. The results can serve as a building block in devising an efficient branch-and-cut algorithm for the general robust (0, 1) IP problem.

The Usefulness of Cephalic Vein Cut-Down for Totally Implantable Central Venous Port in Children (소아에서 완전 이식형 중심정맥포트를 위한 두정맥 절개술의 유용성)

  • Jung, Kyu-Whan;Moon, Suk-Bae;Jung, Sung-Eun;Lee, Seong-Cheol;Park, Kwi-Won
    • Advances in pediatric surgery
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    • v.14 no.1
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    • pp.67-74
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    • 2008
  • The usefulness of totally implantable central venous port for long-term intravenous infusion is widely accepted in children. Usually the catheters are placed through the internal or external jugular vein. In case of jugular vein cut-down, two separate incisions are needed for catheter and port respectively. Patients also feel uncomfortable as the catheter run through the neck. However these disadvantages can be overcome by using the cephalic vein (CV). We reviewed our experiences on CV cut-down for totally implantable central venous port in children. From January 2002 to December 2006, 201 patients (M:F=127:74) underwent 218 central venous port insertions. Mean age at operation was 5.9 years (2 months - 19 years). Indications included chemotherapy (N=167), long-term intravenous antibiotics infusion (N=36), and total parenteral nutrition (N=15). CV was selected preferentially. The incision includes the deltopectoral triangle laterally, and both the CV cut-down and port insertion were achieved with a single incision. The number of insertion through external, internal jugular vein, and CV was 77, 66 and 75, respectively. The median age, height and body weight were higher in CV cut-down group. The youngest age for CV cut-down was 8 months, the shortest height was 69 cm and the smallest body weight was 5.9 kg. Of 118 trials of CV cut-down, cut-down was successful in 75 cases (63.6 %). CV was absent in 10 cases(8.4 %) and CV was sacrificed after catheter tip malposition in 10 cases (8.4 %). There was only one complication, in which the catheter was inserted into the minute branch of subclavian artery. The CV cut-down method for totally implantable central venous port was safe and feasible in selected groups of patients in children. In addition, preservation of jugular vein and a more favorable cosmetic effect are other benefits of CV cut-down.

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Optimum Irrigation Point to Produce High Quality Cut Flowers of Gypsophila paniculata 'Bristol Fairy' (브리스톨 훼어리 안개초 고품질 절화 생산을 위한 적정 관수 개시점)

  • Cheong, Dong Chun;Jeong, Jong Seong;Park, Hak Bong
    • Horticultural Science & Technology
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    • v.19 no.4
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    • pp.579-584
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    • 2001
  • This experiment was conducted to investigate the effect of soil moisture content on cut flower quality of Gypsophila paniculata L. 'Bristol Fairy' in spring and autumn cultivations. The soil moisture potential (SMP) set point for irrigation was either -3.2 or -10.0kPa in the vegetative growth stage, and -10.0, -31.6, or -79.4kPa after the budding stage. When soil moisture reached at each set SMP point, 10 mm water was drip-irrigated. Tendency of flowering was earlier as SMP set point was lower in both vegetative growth and after budding stages. No other flower characteristics were found among other treatments. In both spring and autumn cultivations, as SMP set point was lower, the low primary branch length and upper internode length were decreased, the stem firmness was increased, and curvature of cut flower stem was decreased. Especially, in autumn, the higher the SMP set point, the higher the low primary branch than the apex, thus the paniculate inflorescence was deeply destroyed. Yield in spring cultivation was not significantly different among treatments, while that in autumn cultivation increased as the lower the SMP value. It is thought that optimal imgation points during vegetative growth and after budding stages to produce high quality cut flowers are -10.0 and -79.4kPa, respectively.

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