• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2006년도 추계학술대회 학술발표 논문집 제16권 제2호
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• pp.289-292
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• 2006

In this paper, a wireless control network based on IEEE 802.15.4 MAC protocol is proposed. The superframe of IEEE 802.15.4 is applied to the proposed wireless control network. The transmission and bandwidth management method are proposed for efficient transmission in the superframe. By these methods, the proposed wireless control network protocol is able to transmit three types of data (periodic data, sporadic data, and non real-time message), and guarantee real-time transmission within deadline.

• 한국가정과학회지
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• 제8권4호
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• pp.37-56
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• 2005

With the recently increasing need for more theoretical approach on family resources aiming healthy family in the society, this study is to emphasize how important time, a personal resource, means for a healthy family and to seek how effectively time can be managed by referring to some documents. The followings are to be suggested in order for anyone to be able to apply by oneself to achieve a healthy family. First, time should be planned minute by minute. Second, prioritization should be done. Third, deadline should be made. Fourth, day planner and keeping a journal on it are recommended.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.2045-2050
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• 2008

The Autonomous station control system by applying the concepts of autonomous decentralized system is a system which can solve the problems of the current central control system. The Autonomous station control system tester developed in order to test for Autonomous station control system. The main function of tester is a time-deadline test, a schedule broadcast test, a route control test and a version-up test, etc. In the paper, we build the reliability of the Autonomous station control system by testing the Autonomous station control system tester. Also, the test enable the on-line test without the system interruption and verify the function of the Autonomous station control system developed by applying the concepts of Autonomous decentralized system to the current Central control system.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2019년도 제60차 하계학술대회논문집 27권2호
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• pp.7-8
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• 2019

In this paper, we applied the migration technique to real-time tasks that have relatively low criticality but still important to be dropped by the mixed-criticality scheduling algorithms. The proposed drop and migrate algorithm analyzes the schedulability by calculating CPU utilization and response time of using task migration. We provide analysis to guarantee the deadline of LO-tasks, by transforming the response time equation specified with migration time. The transformed response time equation was able to analyze the migration schedulability. This algorithm can be used with various mixed-criticality schedulers as a supplementary method. We expect this algorithm will be used for scheduling LO-tasks such as communication task that requires safety guarantee especially in platooning and autonomous driving by utilizing the advantages of multiple node connectivities.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권3호
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• pp.861-876
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• 2022

Cryptoassets such as Bitcoin and Ethereum are widely traded around the world. Cryptocurrencies are also transferred between investors. Cryptocurrency has become a new and attractive means of remittance. Thus, blockchain-based smart contracts also attract attention when central banks design digital currencies. However, it has been discovered that a significant amount of cryptoassets on blockchain are lost or stranded for a variety of reasons, including the loss of the private key or the owner's death. To address this issue, we propose a method for recoverable transactions that would replace the traditional transaction by allowing cryptoassets to be sent to a backup account address after a deadline has passed. We provide the computational workload required for our method by analyzing the prototype. The method proposed in this paper can be considered as a good model for digital currency design, including central bank digital currency (CBDC).

• International Journal of Internet, Broadcasting and Communication
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• 제14권4호
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• pp.80-87
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• 2022

Lack of sufficient battery capacity is one of the most important challenges impeding the development of wireless sensor networks (WSNs). Recent innovations in the areas of wireless energy transfer and rechargeable batteries have made it possible to advance WSNs. Therefore, in this article, we propose an energy-efficient charging of sensors in a WSN scenario. First, we have formulated the problem as an integer linear programming (ILP) problem. Then a utility function-based greedy algorithm named UGreedy/UF1 is proposed for solving the problem. Finally, the performance of UGreedy/UF1 is analyzed along with other baseline algorithms: UGreedy/UF2, 2-opt TSP, and Greedy TSP. The simulation results show that UGreedy/UF1 performs better than others both in terms of the deadline missing ratio of sensors and the total energy consumption of UAVs.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2010년도 추계학술발표대회
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• pp.996-999
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• 2010

Business transactional process is usually long running computation which requests services from multiple enterprises. Web Services Transaction specification (WS-TX) defines a protocol, WS-BusinessActivity which is specifically designed for such lengthy interaction and maintains overall consistency through compensation. However timely web services transaction is prone to compensate due to tasks' missing deadline. Therefore, this paper proposes a reservation-based protocol which is used to select providers who can provide resources promptly and deselect ones who may fail. And this selection happens during resource reservation phase and before real commitment. In this way, we achieve the goal of minimizing transactions' compensation. Finally, we design the framework architecture for the proposed protocol that is extended from WS-BusinessActivity.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2009년도 춘계학술발표대회
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• pp.670-673
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• 2009

TinyOS는 현재 가장 널리 사용되는 센서 노드용 운영체제이지만, 태스크의 실시간성을 지원하지 않는다는 단점이 있다. 이에 TinyOS에 실시간성을 부여하기 위한 다양한 연구가 진행되었다. 그러나 이들 연구는 TinyOS의 사용자 태스크에 대한 실시간성만을 고려하여, TinyOS 플랫폼이 제공하는 태스크가 포함된 실제의 센서 노드 작업에 대해서는 실시간성을 만족시키지 못한다는 문제점이 있다. 따라서 본 논문에서는 TinyOS에서 센서 노드 작업의 실시간성을 지원하는 새로운 스케줄링 기법을 제안하고자 한다. 이를 위해 기존 연구의 스케줄링 기법을 센서 노드 작업에 적용했을 때 나타나는 작업 중첩 현상과 우선순위 조정 현상을 분석하고, 이를 효율적으로 해결하는 비선점형 EDF(Earliest Deadline First) 작업 스케줄링 기법을 구현하였다. 그리고 제안한 스케줄링 기법은 TinyOS의 이벤트 기반 비선점형 속성을 유지하여 제한된 하드웨어 자원을 가지는 센서 노드에 적합하다는 것을 확인하였다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2022년도 춘계학술발표대회
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• pp.56-59
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• 2022

최근 인터넷 기반 서비스에서 사용되는 데이터가 개인화 및 맞춤화가 됨에 따라 사용자의 상황이나 요구사항에 따라 실시간 AI 추론 및 데이터 분석과 같이 데이터를 서비스 요청 즉시 처리해야 하는 실시간 서비스에 대한 요구사항이 증가하고 있다. 하지만, 기존 컨테이너 관리 시스템은 컨테이너의 데드라인 할당 및 관리 기능이 제공되지 않으며, 컨테이너 관리 시스템에서 GPU(Graphic Processing Unit) 작업의 실행과 같은 작업 상태를 알 수 없다. 본 논문에서는 컨테이너에서 실행되는 GPU 작업의 실시간 처리를 지원하기 위해 컨테이너에서 실행되는 GPU 작업의 시작 및 종료 상태의 추적과 데드라인 할당 기법을 위한 실시간 처리 정보 관리 기법을 제안한다.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.158-160
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• 2015

Efficient scheduling and resource management are the key factor to reduce construction project budget (e.g., labor cost, equipment cost, material cost, etc.). Resource-based line of balance (LOB) technique has been used to complement the limitations of existing time-driven scheduling techniques (e.g., critical-path method). Optimizing construction alternatives contributes to cost savings while honoring the project deadline. However, existing LOB scheduling is lack of identifying optimal resource combination. This study presents a method which identifies the optimal construction alternatives, hence achieving resource minimization in a repetitive construction by using genetic algorithm (GA). The method provides efficient planning tool that enhances the usability of the system.