• Title/Summary/Keyword: dynamic resource allocation

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A Study of Mobile Ad-hoc Network Protocols for Ultra Narrowband Video Streaming over Tactical Combat Radio Networks (초협대역 영상전송 전투무선망을 위한 Mobile Ad-hoc Network 프로토콜 연구)

  • Seo, Myunghwan;Kim, Kihun;Ko, Yun-Soo;Kim, Kyungwoo;Kim, Donghyun;Choi, Jeung Won
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.4
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    • pp.371-380
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    • 2020
  • Video is principal information that facilitates commander's immediate command decision. Due to fading characteristics of radio link, however, it is difficult to stably transmit video in a multi-hop wireless environment. In this paper, we propose a MANET structure composed of a link adaptive routing protocol and a TDMA MAC protocol to stably transmit video traffic in a ultra-narrowband video streaming network. The routing protocol can adapt to link state change and select a stable route. The TDMA protocol enables collision-free video transmission to a destination using multi-hop dynamic resource allocation. As a result of simulation, the proposed MANET structure shows better video transmission performance than proposed MANET structure without link quality adaption, AODV with CSMA/CA, and OLSR with CSMA/CA structures.

A Dynamic Transmission Rate Allocation Algorithm for Multiplexing Delay-sensitive VBR-coded Streams (VBR로 부호화된 지연 민감 서비스의 다중화를 위한 동적인 전송률 할당 알고리즘)

  • 김진수;유국열;이문노
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.7B
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    • pp.628-637
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    • 2003
  • This paper describes a novel multiplexing scheme for delay-sensitive multiple VBR-coded bit streams in live multimedia service offered to high-speed networks. The primary goal of multiplexing in this paper is to keep delay limits of each bit streams and to enhance network resource utilization when they no multiplexed and transmitted over network. For this aim, this paper presents a dynamical control scheme which does not cause violation of any delay constraints to each bit steam. The scheme is based on the assumption that recent behavior of the each bit scream has high correlation with near-term future behavior. Such property is used to make as flat as possible by both temporal averaging on a stream-by-stream and spatial averaging is introduced when multiple VBR-coded bit streams are multiplexed. The effectiveness of the scheme is evaluated by several simulation using an MPEG-coded video trace of Star_wars and it is shown that the proposed scheme can effectively reduce the feat rate md coefficient of variation of the multiplexed transmission rate.

Design and Implementation of User-Oriented Virtual Dedicate Network System Based on Software-Defined Wide Area Network (SD-WAN 기반의 사용자 중심 가상 전용 네트워크 시스템 설계 및 구현)

  • Kim, Yong-hwan;Kim, Dongkyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.9
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    • pp.1081-1094
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    • 2016
  • KREONET is a principal national R&E network running by KISTI in Korea. It uniquely provides production research network services for around 200 non-profit research and educational organizations, based on hybrid (IP and non-IP) network infrastructure. However, KREONET is limited to meet various needs of new network services for advanced Science & Technology (S&T) users because its infrastructure is inherently derived form classical hardware-based, fixed and closed environments. So, KREONET-S is designed to provide advanced S&T services to catch up with time-to-research and time-to-collaboration. In this paper, we present a system architecture of KREONET-S based on network infrastructure that consists of data and control planes separately. Furthermore, we propose and describe VDN service which is capable of building a virtual dedicate & bandwidth-guaranteed network for S&T group dynamically. we implement VDN application on KREONET-S and then perform performance analysis for proving that KREONET-S system and VDN application can be a good solutions to cope with new network paradigms for various advanced S&T applications and users.

A Case Study of Drug Repositioning Simulation based on Distributed Supercomputing Technology (분산 슈퍼컴퓨팅 기술에 기반한 신약재창출 시뮬레이션 사례 연구)

  • Kim, Jik-Soo;Rho, Seungwoo;Lee, Minho;Kim, Seoyoung;Kim, Sangwan;Hwang, Soonwook
    • Journal of KIISE
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    • v.42 no.1
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    • pp.15-22
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    • 2015
  • In this paper, we present a case study for a drug repositioning simulation based on distributed supercomputing technology that requires highly efficient processing of large-scale computations. Drug repositioning is the application of known drugs and compounds to new indications (i.e., new diseases), and this process requires efficient processing of a large number of docking tasks with relatively short per-task execution times. This mechanism shows the main characteristics of a Many-Task Computing (MTC) application, and as a representative case of MTC applications, we have applied a drug repositioning simulation in our HTCaaS system which can leverage distributed supercomputing infrastructure, and show that efficient task dispatching, dynamic resource allocation and load balancing, reliability, and seamless integration of multiple computing resources are crucial to support these challenging scientific applications.

On an Enhanced Model of System Readiness Level by Incorporating Safety for the Development of Live Fire Test Systems (실사격 시험시스템의 효율적인 개발을 위해 안전도 반영을 통해 개선된 시스템 성숙도 모델에 관한 연구)

  • Ye, Sung Hyuck;Lee, Jae-Chon
    • Journal of the Korea Safety Management & Science
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    • v.17 no.3
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    • pp.195-204
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    • 2015
  • The live fire test has been playing a critical role in evaluating the goals-to-meet of the weapon systems which utilize the power of explosives. As such, the successful development of the test systems therein is quite important. The test systems development covers that of ranges and facilities including system-level key components such as mission control, instrumentation or observation, safety control, electric power, launch pad, and so on. In addition, proper operational guidelines are needed with well-trained test and operation personnel. The emerging weapon systems to be deployed in future battle field would thus have to be more precise and dynamic, smarter, thereby requiring more elaboration. Furthermore, the safety consideration is becoming more serious due to the ever-increasing power of explosives. In such a situation, development of live fire test systems seems to be challenging. The objective of the paper is on how to incorporate the safety and other requirements in the development. To achieve the goal, an architectural approach is adopted by utilizing both the system components relationship and safety requirement when advanced instrumentation technology needs to be developed and deteriorated components of the range are replaced. As an evaluation method, it is studied how the level of maturity of the test systems development can be assessed particularly with the safety requirement considered. Based on the concepts of both systems engineering and SoS (System-of-Systems) engineering process, an enhanced model for the system readiness level is proposed by incorporating safety. The maturity model proposed would be helpful in assessing the maturity of safety-critical systems development whereas the costing model would provide a guide on how the reasonable test resource allocation plan can be made, which is based on the live fire test scenario of future complex weapon systems such as SoS.

Operational Process and Success Factors of Corporate Venture in a Chinese Company: A Case Study of Haier (중국기업의 사내벤처 운영과정과 성공요인: 하이얼(Haier) 중심으로)

  • Yu-Rou Hou;Yuan-Jing Jin;Moon-Gu Huh
    • Asia-Pacific Journal of Business
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    • v.14 no.4
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    • pp.87-113
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    • 2023
  • Purpose - Focusing on Haier, a successful corporate venture in China, we analyse the operating mechanism and success factors of corporate venture, and reveal the necessary factors for the successful implementation of corporate venture. Design/methodology/approach - This study is a single case study centred on Haier, a successful corporate venture in China. Findings - The operational process of Haier's corporate venture includes six key aspects: project selection, team building, resource allocation and support, project implementation, risk control measures, performance evaluation and rewards. In terms of success factors, the support of top management with leadership capability of value creation and sharing is very important for the success of corporate venture. Secondly, a multi reward mechanism can be introduced to motivate employees and improve performance. Thirdly, it is important to integrate corporate culture into the operating mechanism of an corporate venture. Fourthly, flexible operations that break down rigid organisational boundaries and transform the organisation into a more open platform for entrepreneurship can increase the likelihood of success. Finally, empowering employees with operational discretion can also have a positive impact on the success of an Corporate Venture. Research implications or Originality - This study contributes to theory and practice by analysing the success conditions of corporate venture, providing new understanding and drawing new perspectives, especially from the experience of Haier. The results suggest strategies and flexibility for successfully pursuing corporate venture, and provide important experience for international companies to help them gain competitive advantage in global competition. It also helps corporate leaders to promote new directions and innovations and improve their strategies to respond to dynamic environments.

Compact Field Remapping for Dynamically Allocated Structures (동적으로 할당된 구조체를 위한 압축된 필드 재배치)

  • Kim, Jeong-Eun;Han, Hwan-Soo
    • Journal of KIISE:Software and Applications
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    • v.32 no.10
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    • pp.1003-1012
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    • 2005
  • The most significant difference of embedded systems from general purpose systems is that embedded systems are allowed to use only limited resources including battery and memory. Especially, the number of applications increases which deal with multimedia data. In those systems with high data computations, the delay of memory access is one of the major bottlenecks hurting the system performance. As a result, many researchers have investigated various techniques to reduce the memory access cost. Most programs generally have locality in memory references. Temporal locality of references means that a resource accessed at one point will be used again in the near future. Spatial locality of references is that likelihood of using a resource gets higher if resources near it were just accessed. The latest embedded processors usually adapt cache memory to exploit these two types of localities. Processors access faster cache memory than off-chip memory, reducing the latency. In this paper we will propose the enhanced dynamic allocation technique for structure-type data in order to eliminate unused memory space and to reduce both the cache miss rate and the application execution time. The proposed approach aggregates fields from multiple records dynamically allocated and consecutively remaps them on the memory space. Experiments on Olden benchmarks show $13.9\%$ L1 cache miss rate drop and $15.9\%$ L2 cache miss drop on average, compared to the previously proposed techniques. We also find execution time reduced by $10.9\%$ on average, compared to the previous work.

Development of Intelligent ATP System Using Genetic Algorithm (유전 알고리듬을 적용한 지능형 ATP 시스템 개발)

  • Kim, Tai-Young
    • Journal of Intelligence and Information Systems
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    • v.16 no.4
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    • pp.131-145
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    • 2010
  • The framework for making a coordinated decision for large-scale facilities has become an important issue in supply chain(SC) management research. The competitive business environment requires companies to continuously search for the ways to achieve high efficiency and lower operational costs. In the areas of production/distribution planning, many researchers and practitioners have developedand evaluated the deterministic models to coordinate important and interrelated logistic decisions such as capacity management, inventory allocation, and vehicle routing. They initially have investigated the various process of SC separately and later become more interested in such problems encompassing the whole SC system. The accurate quotation of ATP(Available-To-Promise) plays a very important role in enhancing customer satisfaction and fill rate maximization. The complexity for intelligent manufacturing system, which includes all the linkages among procurement, production, and distribution, makes the accurate quotation of ATP be a quite difficult job. In addition to, many researchers assumed ATP model with integer time. However, in industry practices, integer times are very rare and the model developed using integer times is therefore approximating the real system. Various alternative models for an ATP system with time lags have been developed and evaluated. In most cases, these models have assumed that the time lags are integer multiples of a unit time grid. However, integer time lags are very rare in practices, and therefore models developed using integer time lags only approximate real systems. The differences occurring by this approximation frequently result in significant accuracy degradations. To introduce the ATP model with time lags, we first introduce the dynamic production function. Hackman and Leachman's dynamic production function in initiated research directly related to the topic of this paper. They propose a modeling framework for a system with non-integer time lags and show how to apply the framework to a variety of systems including continues time series, manufacturing resource planning and critical path method. Their formulation requires no additional variables or constraints and is capable of representing real world systems more accurately. Previously, to cope with non-integer time lags, they usually model a concerned system either by rounding lags to the nearest integers or by subdividing the time grid to make the lags become integer multiples of the grid. But each approach has a critical weakness: the first approach underestimates, potentially leading to infeasibilities or overestimates lead times, potentially resulting in excessive work-inprocesses. The second approach drastically inflates the problem size. We consider an optimized ATP system with non-integer time lag in supply chain management. We focus on a worldwide headquarter, distribution centers, and manufacturing facilities are globally networked. We develop a mixed integer programming(MIP) model for ATP process, which has the definition of required data flow. The illustrative ATP module shows the proposed system is largely affected inSCM. The system we are concerned is composed of a multiple production facility with multiple products, multiple distribution centers and multiple customers. For the system, we consider an ATP scheduling and capacity allocationproblem. In this study, we proposed the model for the ATP system in SCM using the dynamic production function considering the non-integer time lags. The model is developed under the framework suitable for the non-integer lags and, therefore, is more accurate than the models we usually encounter. We developed intelligent ATP System for this model using genetic algorithm. We focus on a capacitated production planning and capacity allocation problem, develop a mixed integer programming model, and propose an efficient heuristic procedure using an evolutionary system to solve it efficiently. This method makes it possible for the population to reach the approximate solution easily. Moreover, we designed and utilized a representation scheme that allows the proposed models to represent real variables. The proposed regeneration procedures, which evaluate each infeasible chromosome, makes the solutions converge to the optimum quickly.

Effects of weather change, human disturbance and interspecific competition on life-history and migration of wintering Red-crowned cranes (기후변화와 인간의 방해 및 종간경쟁이 두루미 월동생태와 이동에 미치는 영향)

  • Hong, Mi-Jin;Lee, Who-Seung;Yoo, Jeong-Chil
    • Korean Journal of Environment and Ecology
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    • v.29 no.5
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    • pp.681-692
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    • 2015
  • It is well documented that physiological and nutritional condition of wintering birds is strongly related to migration success to breeding sites, and also breeding success. However, how abiotic factors during winter affect the migration and breeding successes still remains unclear. Thus, this study developed a dynamic-state-dependent model for wintering life-history to identify the potential impact on the life-history, success to breeding site and breeding success of wintering birds, which are related to temperature fluctuation, interspecific competition and human disturbance at the wintering sites. To find the best-fit-model, we referred to the existing research data on wintering ecology of Red-crowned cranes (Grus japonensis) in Cheolwon, Korea, which is well documented as a long-term wintering study. Our model predicted that the higher temperature fluctuation and a higher rate of human disturbance are negatively related to migration success to breeding sites and their fitness, ultimately breeding success via changing of proportion in resource allocation (for e. g., lower energy compensation or higher level of stress accumulation). Particularly, the rate of body mass compensation after arrival at wintering sites may be accelerated when there are less temperature fluctuations and a lower rate of human disturbance. In addition, the rate of interspecific competition sharing the wintering foraging sites is negatively related to the rate of body mass compensation. Consequently, we discussed the conservation strategies of wintering birds based on the outcomes of the model.

Empirical Assessment of International Entry Strategy for Large Construction Companies (주요 전략지수별로 살펴 본 국내 대형건설업체의 해외건설 진출전략 효과에 대한 실증적 연구)

  • Jung, Woo-Yong;Han, Seung-Heon;Jang, Woo-Sik;Koo, Bon-Sang
    • Korean Journal of Construction Engineering and Management
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    • v.11 no.1
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    • pp.59-69
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    • 2010
  • Although international construction market gradually takes a important position among the export industries, the previous studies about international construction entry strategy have just focussed on trend investigation or suggestion for revitalization. Moreover, in order to prepare the market uncertainty such as world financial crisis and to plan the long term strategy, specific strategy studies based on corporate level are required. Therefore, this study estimates the nine strategic index and four financial index of 31 companies that performed 1920 international projects from 1993 to 2007 and evaluate the performance as three periods by multi-regression analysis. Also, this study analyze dynamic correlation between these index and the performance considering times. this study verifies that market diversification, product diversification, localization and decrease of debt to asset ratio make a good effect on the international order as long term strategy and shows that collaborated entry with domestic corporations, alliance entry with host country's company, alliance entry with third country's company, portion of labor cost and portion of management expense differently make a influence on the performance as times. these results will be helpful for the construction companies to plan the international entry strategy reasonably and specifically.