• Title/Summary/Keyword: task scheduling

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A hybrid genetic algorithm for the optimal transporter management plan in a shipyard

  • Jun-Ho Park;Yung-Keun Kwon
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.12
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    • pp.49-56
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    • 2023
  • In this study, we propose a genetic algorithm (GA) to optimize the allocation and operation order of transporters. The solution in the GA is represented by a set of lists each of which the operation order of the corresponding transporter. In addition, it was implemented in the form of a hybrid genetic algorithm combining effective local search operations for performance improvement. The local search reduces the number of operating transporters by moving blocks from a transporter with a low workload into that with a high workload. To evaluate the effectiveness of the proposed algorithm, it was compared with Multi-Start and a pure genetic algorithm through a simulation environment similar in scale to an actual shipyard. For the largest problem, compared to them, the number of transporters was reduced by 40% and 34%, and the total task time was reduced by 27% and 17%, respectively.

Collaborative Inference for Deep Neural Networks in Edge Environments

  • Meizhao Liu;Yingcheng Gu;Sen Dong;Liu Wei;Kai Liu;Yuting Yan;Yu Song;Huanyu Cheng;Lei Tang;Sheng Zhang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.7
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    • pp.1749-1773
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    • 2024
  • Recent advances in deep neural networks (DNNs) have greatly improved the accuracy and universality of various intelligent applications, at the expense of increasing model size and computational demand. Since the resources of end devices are often too limited to deploy a complete DNN model, offloading DNN inference tasks to cloud servers is a common approach to meet this gap. However, due to the limited bandwidth of WAN and the long distance between end devices and cloud servers, this approach may lead to significant data transmission latency. Therefore, device-edge collaborative inference has emerged as a promising paradigm to accelerate the execution of DNN inference tasks where DNN models are partitioned to be sequentially executed in both end devices and edge servers. Nevertheless, collaborative inference in heterogeneous edge environments with multiple edge servers, end devices and DNN tasks has been overlooked in previous research. To fill this gap, we investigate the optimization problem of collaborative inference in a heterogeneous system and propose a scheme CIS, i.e., collaborative inference scheme, which jointly combines DNN partition, task offloading and scheduling to reduce the average weighted inference latency. CIS decomposes the problem into three parts to achieve the optimal average weighted inference latency. In addition, we build a prototype that implements CIS and conducts extensive experiments to demonstrate the scheme's effectiveness and efficiency. Experiments show that CIS reduces 29% to 71% on the average weighted inference latency compared to the other four existing schemes.

Development of One-to-One Shortest Path Algorithm Based on Link Flow Speeds on Urban Networks (도시부 가로망에서의 링크 통행속도 기반 One-to-One 최단시간 경로탐색 알고리즘 개발)

  • Kim, Taehyeong;Kim, Taehyung;Park, Bum-Jin;Kim, Hyoungsoo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.5
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    • pp.38-45
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    • 2012
  • Finding shortest paths on time dependent networks is an important task for scheduling and routing plan and real-time navigation system in ITS. In this research, one-to-one time dependent shortest path algorithms based on link flow speeds on urban networks are proposed. For this work, first we select three general shortest path algorithms such as Graph growth algorithm with two queues, Dijkstra's algorithm with approximate buckets and Dijkstra's algorithm with double buckets. These algorithms were developed to compute shortest distance paths from one node to all nodes in a network and have proven to be fast and efficient algorithms in real networks. These algorithms are extended to compute a time dependent shortest path from an origin node to a destination node in real urban networks. Three extended algorithms are implemented on a data set from real urban networks to test and evaluate three algorithms. A data set consists of 4 urban street networks for Anaheim, CA, Baltimore, MD, Chicago, IL, and Philadelphia, PA. Based on the computational results, among the three algorithms for TDSP, the extended Dijkstra's algorithm with double buckets is recommended to solve one-to-one time dependent shortest path for urban street networks.

Using the METHONTOLOGY Approach to a Graduation Screen Ontology Development: An Experiential Investigation of the METHONTOLOGY Framework

  • Park, Jin-Soo;Sung, Ki-Moon;Moon, Se-Won
    • Asia pacific journal of information systems
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    • v.20 no.2
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    • pp.125-155
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    • 2010
  • Ontologies have been adopted in various business and scientific communities as a key component of the Semantic Web. Despite the increasing importance of ontologies, ontology developers still perceive construction tasks as a challenge. A clearly defined and well-structured methodology can reduce the time required to develop an ontology and increase the probability of success of a project. However, no reliable knowledge-engineering methodology for ontology development currently exists; every methodology has been tailored toward the development of a particular ontology. In this study, we developed a Graduation Screen Ontology (GSO). The graduation screen domain was chosen for the several reasons. First, the graduation screen process is a complicated task requiring a complex reasoning process. Second, GSO may be reused for other universities because the graduation screen process is similar for most universities. Finally, GSO can be built within a given period because the size of the selected domain is reasonable. No standard ontology development methodology exists; thus, one of the existing ontology development methodologies had to be chosen. The most important considerations for selecting the ontology development methodology of GSO included whether it can be applied to a new domain; whether it covers a broader set of development tasks; and whether it gives sufficient explanation of each development task. We evaluated various ontology development methodologies based on the evaluation framework proposed by G$\acute{o}$mez-P$\acute{e}$rez et al. We concluded that METHONTOLOGY was the most applicable to the building of GSO for this study. METHONTOLOGY was derived from the experience of developing Chemical Ontology at the Polytechnic University of Madrid by Fern$\acute{a}$ndez-L$\acute{o}$pez et al. and is regarded as the most mature ontology development methodology. METHONTOLOGY describes a very detailed approach for building an ontology under a centralized development environment at the conceptual level. This methodology consists of three broad processes, with each process containing specific sub-processes: management (scheduling, control, and quality assurance); development (specification, conceptualization, formalization, implementation, and maintenance); and support process (knowledge acquisition, evaluation, documentation, configuration management, and integration). An ontology development language and ontology development tool for GSO construction also had to be selected. We adopted OWL-DL as the ontology development language. OWL was selected because of its computational quality of consistency in checking and classification, which is crucial in developing coherent and useful ontological models for very complex domains. In addition, Protege-OWL was chosen for an ontology development tool because it is supported by METHONTOLOGY and is widely used because of its platform-independent characteristics. Based on the GSO development experience of the researchers, some issues relating to the METHONTOLOGY, OWL-DL, and Prot$\acute{e}$g$\acute{e}$-OWL were identified. We focused on presenting drawbacks of METHONTOLOGY and discussing how each weakness could be addressed. First, METHONTOLOGY insists that domain experts who do not have ontology construction experience can easily build ontologies. However, it is still difficult for these domain experts to develop a sophisticated ontology, especially if they have insufficient background knowledge related to the ontology. Second, METHONTOLOGY does not include a development stage called the "feasibility study." This pre-development stage helps developers ensure not only that a planned ontology is necessary and sufficiently valuable to begin an ontology building project, but also to determine whether the project will be successful. Third, METHONTOLOGY excludes an explanation on the use and integration of existing ontologies. If an additional stage for considering reuse is introduced, developers might share benefits of reuse. Fourth, METHONTOLOGY fails to address the importance of collaboration. This methodology needs to explain the allocation of specific tasks to different developer groups, and how to combine these tasks once specific given jobs are completed. Fifth, METHONTOLOGY fails to suggest the methods and techniques applied in the conceptualization stage sufficiently. Introducing methods of concept extraction from multiple informal sources or methods of identifying relations may enhance the quality of ontologies. Sixth, METHONTOLOGY does not provide an evaluation process to confirm whether WebODE perfectly transforms a conceptual ontology into a formal ontology. It also does not guarantee whether the outcomes of the conceptualization stage are completely reflected in the implementation stage. Seventh, METHONTOLOGY needs to add criteria for user evaluation of the actual use of the constructed ontology under user environments. Eighth, although METHONTOLOGY allows continual knowledge acquisition while working on the ontology development process, consistent updates can be difficult for developers. Ninth, METHONTOLOGY demands that developers complete various documents during the conceptualization stage; thus, it can be considered a heavy methodology. Adopting an agile methodology will result in reinforcing active communication among developers and reducing the burden of documentation completion. Finally, this study concludes with contributions and practical implications. No previous research has addressed issues related to METHONTOLOGY from empirical experiences; this study is an initial attempt. In addition, several lessons learned from the development experience are discussed. This study also affords some insights for ontology methodology researchers who want to design a more advanced ontology development methodology.

A Study of Competency for R&D Engineer on Semiconductor Company (반도체 기술 R&D 연구인력의 역량연구 -H사 기업부설연구소를 중심으로)

  • Yun, Hye-Lim;Yoon, Gwan-Sik;Jeon, Hwa-Ick
    • 대한공업교육학회지
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    • v.38 no.2
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    • pp.267-286
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    • 2013
  • Recently, the advanced company has been sparing no efforts in improving necessary core knowledge and technology to achieve outstanding work performance. In this rapidly changing knowledge-based society, the company has confronted the task of creating a high value-added knowledge. The role of R&D workforce that corresponds to the characteristic and role of knowledge worker is getting more significant. As the life cycle of technical knowledge and skill shortens, in every industry, the technical knowledge and skill have become essential elements for successful business. It is difficult to improve competitiveness of the company without enhancing the competency of individual and organization. As the competency development which is a part of human resource management in the company is being spread now, it is required to focus on the research of determining necessary competency and to analyze the competency of a core organization in the research institute. 'H' is the semiconductor manufacturing company which has a affiliated research institute with its own R&D engineers. Based on focus group interview and job analysis data, vision and necessary competency were confirmed. And to confirm whether the required competency by job is different or not, analysis was performed by dividing members into workers who are in charge of circuit design and design before process development and who are in the process actualization and process development. Also, this research included members' importance awareness of the determined competency. The interview and job analysis were integrated and analyzed after arranging by groups and contents and the analyzed results were resorted after comparative analysis with a competency dictionary of Spencer & Spencer and competency models which are developed from the advanced research. Derived main competencies are: challenge, responsibility, and prediction/responsiveness, planning a new business, achievement -oriented, training, cooperation, self-development, analytic thinking, scheduling, motivation, communication, commercialization of technology, information gathering, professionalism on the job, and professionalism outside of work. The highly required competency for both jobs was 'Professionalism'. 'Attitude', 'Performance Management', 'Teamwork' for workers in charge of circuit design and 'Challenge', 'Training', 'Professionalism on the job' and 'Communication' were recognized to be required competency for those who are in charge of process actualization and process development. With above results, this research has determined the necessary competency that the 'H' company's affiliated research institute needs and found the difference of required competency by job. Also, it has suggested more enthusiastic education methods or various kinds of education by confirming the importance awareness of competency and individual's level of awareness about the competency.