• Title/Summary/Keyword: global best

Search Result 706, Processing Time 0.029 seconds

Design and Performance Analysis of a Parallel Optimal Branch-and-Bound Algorithm for MIN-based Multiprocessors (MIN-based 다중 처리 시스템을 위한 효율적인 병렬 Branch-and-Bound 알고리즘 설계 및 성능 분석)

  • Yang, Myung-Kook
    • Journal of IKEEE
    • /
    • v.1 no.1 s.1
    • /
    • pp.31-46
    • /
    • 1997
  • In this paper, a parallel Optimal Best-First search Branch-and-Bound(B&B) algorithm(pobs) is designed and evaluated for MIN-based multiprocessor systems. The proposed algorithm decomposes a problem into G subproblems, where each subproblem is processed on a group of P processors. Each processor group uses tile sub-Global Best-First search technique to find a local solution. The local solutions are broadcasted through the network to compute the global solution. This broadcast provides not only the comparison of G local solutions but also the load balancing among the processor groups. A performance analysis is then conducted to estimate the speed-up of the proposed parallel B&B algorithm. The analytical model is developed based on the probabilistic properties of the B&B algorithm. It considers both the computation time and communication overheads to evaluate the realistic performance of the algorithm under the parallel processing environment. In order to validate the proposed evaluation model, the simulation of the parallel B&B algorithm on a MIN-based system is carried out at the same time. The results from both analysis and simulation match closely. It is also shown that the proposed Optimal Best-First search B&B algorithm performs better than other reported schemes with its various advantageous features such as: less subproblem evaluations, prefer load balancing, and limited scope of remote communication.

  • PDF

Beam and Diffuse to Global Solar Irradiation Correlation Coefficients for Daejeon (대전지역 직달 및 산란과 전일사 상관계수)

  • Lee, Kwan-Ho;Song, Doo-Sam
    • Journal of the Korean Solar Energy Society
    • /
    • v.39 no.4
    • /
    • pp.11-24
    • /
    • 2019
  • The total solar irradiation on horizontal surfaces is separated into the beam and diffuses components. Although horizontal global irradiance is a commonly measured parameter for many sites, horizontal diffuse irradiance is not so readily obtainable. For such sites that measure global irradiation alone, a simple but reasonably accurate method is required to estimate diffuse irradiance from its global counterpart. This study investigates the applicability of correlation coefficients models correlating hourly diffuse and beam fraction and hourly clearness index in Daejeon. The three diffuse to global correlation coefficients models (Orgill and Holland model, CIBSE Guide J model, and Erbs et al. model) are selected and the three modified beam to global correlation coefficients models are generated. MBE, RMSE, r-squared of Daejeon and Daejeon boundary site-fitted models are compared with the case of original coefficients. The comparison result shows that the beam and diffuse to global solar irradiation correlation coefficients models with boundary site-fitted coefficients are best suitable for Daejeon. Further researches will be conducted to find the boundary site-fitting method using measured data of other cities and correlation coefficients models using solar altitude, cloud cover, and sunshine duration.

A Study on the Development of ERP

  • Lee, Soowook
    • International Journal of Internet, Broadcasting and Communication
    • /
    • v.8 no.3
    • /
    • pp.58-62
    • /
    • 2016
  • Due to the rapidly changing global business environment and global management environment, companies must actively act for competitiveness. By examining the development process of Enterprise Resource Planning (ERP), there is a chance to optimize the organization and find measures to improve the company competitiveness. It seems examining task process, and studying the influence of ERP introduction to management performance by considering whether the excessive maintenance cost or repetitive investment toward ERP is quiet significant. The companies which instituted ERP uses "business process model" provided by "Best Practice" compare own task to choose much efficient method. This allows simultaneous realization of ERP institution and Business Reengineering (BR).

The Comparison of Pulled and Pushed-SOFM in Single String for Global Path Planning of Mobile Robot (이동로봇의 전역경로계획을 위한 단경로 String에서 당기기와 밀어내기 SOFM을 이용한 방법의 비교)

  • Cha, Young-Youp
    • Proceedings of the KSME Conference
    • /
    • 2008.11a
    • /
    • pp.900-901
    • /
    • 2008
  • In this research uses a predetermined initial weight vectors of 1-dimensional string, gives the systematic input vector whose position best matches obstacles, and trains the weight vectors such that neurons within the activity bubble are moved toward or reverse the input vector. According to simulation results one can conclude that the modified neural network is useful tool for the global path planning problem of a mobile robot.

  • PDF

Global Flood Alert System (GFAS)

  • Umeda, Kazuo
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2006.05a
    • /
    • pp.28-35
    • /
    • 2006
  • Global Flood Alert System (GFAS) is an attempt to make the best use of satellite rainfall data in flood forecasting. The project of GFAS is promoted both by Ministry of Land, Infrastructure and Transport-Japan (MLIT) and Japan Aerospace Exploration Agency (JAXA), under which Infrastructure Development Institute-Japan (IDI) has been working on the development of Internet-based information system and just launched trial run of GFAS in April 2006 on International Flood Network (IFNet) website. The function of GFAS is to connect space agencies and hydrological services/river authorities in charge of flood forecasting and warning by providing global rainfall information in maps, text data e-mails and so on which is produced from binary global rainfall data downloaded from National Aeronautics and Space Administration (NASA) website. Although the effectiveness of satellite rainfall data in flood forecasting and warning has yet to be verified, satellite rainfall is expected to play an important role to strengthen existing flood forecasting systems by diversifying hydrological data source.

  • PDF

An Effective Ant Colony System Optimization for Symmetric Traveling Salesman Problem (Symmetric Traveling Salesman Problem을 해결하기 위해 Ant Colony System에서의 효과적인 최적화 방법에 관한 연구)

  • Jung, Tae-Ung;Lee, Sung-Gwan;Jung, Tae-Chung
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2000.10a
    • /
    • pp.321-324
    • /
    • 2000
  • 조합 최적화 문제인 Traveling Salesman problems(TSP)을 Genetic Algorithm(GA)[3]과 Local Search Heuristic Algorithm[8]을 이용하여 접근하는 것은 최적해를 구하기 위해 널리 알려진 방법이다. 본 논문에서는 TSP문제를 해결하기 위한 또 다른 접근법으로, 다수의 Ant들이 Tour들을 찾는 ACS(Ant Colony System) Algorithms[4][6][7]을 소개하고, ACS에서 Global Optima를 찾는 과정에서, 이미 이루어져 있는 Ant들의 Tour결과들을 서로 비교한다. Global Updating Rule에 의해 Global Best Tour 에 속해 있는 각 Ant Tour의 edge들을 update하는 ACS Algorithm에, 각 루프마다 Ant Tour들을 우성과 열성 인자들로 구분하고, 각각의 우성과 열성 인자들에 대해서 Global Updating Rule에 기반한 가중치를 적용(Weight Updating Rule)하므로서 기존의 ACS Algorithm보다 효율적으로 최적 해를 찾아내는 방법에 대해서 논하고자 한다.

  • PDF

Transient global amnesia associated with multiple lesions in the corpus callosum and hippocampus

  • Kim, Jin-Ah;Min, Young Gi;Koo, Dae Lim
    • Annals of Clinical Neurophysiology
    • /
    • v.21 no.2
    • /
    • pp.102-104
    • /
    • 2019
  • Transient global amnesia is a syndrome of temporary loss of short-term memory and is not accompanied by any other neurological deficit. Diffusion-weighted imaging is useful to improve the diagnostic accuracy of transient global amnesia. We report a 68-year-old woman with multiple lesions on diffusion-weighted imaging in the right corpus callosum and left hippocampus. To the best of our knowledge, this is the first case of a diffusion-weighted imaging lesion in the body portion of the corpus callosum.

Damping-off of Deltoid Synurus Caused by Rhizoctonia solani AG-1 (IB)

  • Kim, Wan-Gyu;Lee, Gyo-Bin;Shim, Hong-Sik;Cho, Weon-Dae
    • The Korean Journal of Mycology
    • /
    • v.49 no.2
    • /
    • pp.249-251
    • /
    • 2021
  • Damping-off symptoms were frequently observed in young deltoid synurus (Synurus deltoides) plants grown in a farmer's vinyl greenhouse located in Hwacheon, Gangwon Province, Korea, during a disease survey in July 2019. The incidence of diseased plants in the vinyl greenhouse investigated was 5-30%. Five isolates of Rhizoctonia sp. were obtained from the diseased plants and identified as Rhizoctonia solani AG-1 (IB), based on morphological and cultural characteristics and anastomosis test results. Three isolates of R. solani AG-1 (IB) were tested for pathogenicity on deltoid synurus using artificial inoculation. All the tested isolates induced damping-off symptoms in the inoculated plants. The symptoms were similar to those observed in plants from the farmer's vinyl greenhouse. To our best knowledge, this is the first report of R. solani AG-1 (IB) causing damping-off in deltoid synurus.

A Dynamic Processor Allocation Strategy for Mesh-Connected Multicomputers

  • Kim, Geunmo;Hyunsoo Yoon
    • Journal of Electrical Engineering and information Science
    • /
    • v.1 no.1
    • /
    • pp.129-139
    • /
    • 1996
  • The processor allocation problem in mesh multicamputers is to recognize and locate a free submesh that can accommodate a request for a submesh of a specified size. An efficient submesh allocation strategy is required for achieving high performance on mesh multicomputers. In this paper, we propose a new best-fit submesh allocation strategy for mesh multicomputers. The proposed strategy maintains and uses a free submesh list to get global information for free submeshes. For an allocation request the proposed strategy tries to allocate a best-fit submesh which causes the least amount of potential processor fragmentation so as to preserve the large free submeshes as many as possible for later requests. For this purpose, we introduce a novel function for quantifying the degree of potential fragmentation of submeshes. The proposed strategy has the complete submesh recognition capability. Extensive simulation is carried out t compare the proposed strategy with the previous strategies and experimental results indicate that the proposed strategy exhibits the best performance along with about 10% to 30% average improvement over the best previous strategy.

  • PDF

Ethical Considerations in the Healthcare Field: A Focus on Global Health

  • SHIN, Dong-Jin
    • Journal of Research and Publication Ethics
    • /
    • v.2 no.1
    • /
    • pp.13-18
    • /
    • 2021
  • Purpose: This paper aimed to examine the ethical considerations that are the basis for many functions in the healthcare field. The key ethical values in global health, as well as future considerations imperative to this area, were observed. Research design, data and methodology: The current study utilized the past literature studies that were examined in the field of global health. An overview of the role of ethics in the healthcare field, as well as important considerations that needed to be taken into account in order to provide advancements in this area, were investigated. Results: Ethics are an important set of principles that guides humankind into the right conduct or action to better society and each other. Ethical values are one of the pinnacle points for any healthcare provider, as healthcare is not only considered from the aspect of patient health and well-being, but also in its role of keeping ethical guidelines to achieve the best possible care for a patient. Conclusions: A comprehensive understanding of healthcare is needed in order to tackle next generational challenges in global health. These ethical considerations will inevitably play a significant role in harnessing the patient-healthcare professional relationships as well as care for the shortening of a global disparity on healthcare.