• 전자통신동향분석
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• 제36권6호
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• pp.13-24
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• 2021

Industrial networks has been developing various technologies from fieldbus technology to industrial Ethernet and time-sensitive networking. The industry expects that the 5G mobile network will solve the diverse and highly specific industrial site requirements. Accordingly, 3GPP has been developing standard functions to provide ultra-high reliability, ultra-high speed, ultra-connection, and ultra-low latency services, and 3GPP Rel-16 began developing ultra-low latency and ultra-high reliability communication functions for 5G mobile networks to support vertical industries. In this paper, we show the related standardization trends and requirements to apply industrial IoT service scenarios to 5G mobile networks, and in particular, we introduce 5G system features and extended 5G system architecture to provide time sensitive communication and time synchronization services.

• 제어로봇시스템학회논문지
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• 제16권2호
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• pp.194-201
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• 2010

This paper discuss a performance evaluation of the synchronization algorithm for hybrid networks in industrial environments. The proposed algorithms minimizes synchronization errors which were caused from channel, Propagation, and frequency delays. The modified RBS and offset synchronization methods can be operated by adjustment parameters. The differential BP (Back-off Period) adjustment can synchronize the local time of each node with master node's time in hybrid networks. For the performance analysis, the data transmission time between the wired and wireless devices are investigated. The experimental results show the performance evaluations in terms of the polling service time and an average end-to-end delay.

• Journal of Communications and Networks
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• 제15권1호
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• pp.87-101
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• 2013

In industrial applications, sensor networks have to satisfy specified time requirements of exchanged messages. IEEE 802.15.4 defines the communication protocol of the physical and medium access control layers for wireless sensor networks, which support real-time transmission through guaranteed time slots (GTSs). In order to improve the performance of IEEE 802.15.4 in industrial applications, this paper proposes a new traffic scheduling algorithm for GTS. This algorithm concentrates on time-critical industrial periodic messages and determines the values of network and node parameters for GTS. It guarantees real-time requirements of periodic messages for industrial automation systems up to the order of tens to hundreds of milliseconds depending on the traffic condition of the network system. A series of simulation results are obtained to examine the validity of the scheduling algorithm proposed in this study. The simulation results show that this scheduling algorithm not only guarantees real-time requirements for periodic message but also improves the scalability, bandwidth utilization, and energy efficiency of the network with a slight modification of the existing IEEE 802.15.4 protocol.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권10호
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• pp.2509-2528
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• 2012

Time division multiple access (TDMA) is a widely used media access control (MAC) technique that can provide collision-free and reliable communications, save energy and bound the delay of packets. In TDMA, energy saving is usually achieved by switching the nodes' radio off when such nodes are not engaged. However, the frequent switching of the radio's state not only wastes energy, but also increases end-to-end delay. To achieve high energy efficiency and low delay, as well as to further minimize the number of time slots, a multi-objective TDMA scheduling problem for industrial wireless mesh networks is presented. A hybrid algorithm that combines genetic algorithm (GA) and simulated annealing (SA) algorithm is then proposed to solve the TDMA scheduling problem effectively. A number of critical techniques are also adopted to reduce energy consumption and to shorten end-to-end delay further. Simulation results with different kinds of networks demonstrate that the proposed algorithm outperforms traditional scheduling algorithms in terms of addressing the problems of energy consumption and end-to-end delay, thus satisfying the demands of industrial wireless mesh networks.

• 대한지리학회지
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• 제40권1호
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• pp.78-95
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• 2005

호남 장수지역 경제활동의 산업연계와 혁신네트워크에 대해 분석함으로써 지식정보화 시대의 이상적인 고령사회에 대비한 새로운 지역발전 방향을 모색하고자 하였다. 이를 위해 한국 장수지역 중의 하나인 전라북도의 순창군과 전라남도의 담양군, 곡성군, 구례군 등의 대표적 제조업체를 중심으로 심층 인터뷰를 실시하였다. 연구 결과, 산업 연계에 있어 원료구입과 노동력이용은 해당 군에서 많이 이루어지고 있고, 제조업과 농업 및 관광업간 연계와 인터넷을 이용한 통신판매가 활성화되고 있었다. 그리고 혁신네트워크에 있어서는 지식정보화시대에 가상혁신클러스터의 형성 가능성을 확인할 수 있었다. 따라서 농촌지역 발전을 위해서는 지식기반경제의 지역혁신체계 개념을 이용해 지역의 자원 및 전통지식과 밀접한 혁신네트워크 구축이 필요하다.

• 산업경영시스템학회지
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• 제32권2호
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• pp.132-139
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• 2009

Yield is a very important measure that can expresses simply for productivity and performance of company. So, yield is used widely in many industries nowadays. With the development of the information technology and online based real-time process monitoring technology, many industries operate the production lines that are developed into automation system. In these production lines, the product structures are very complexity and variety. So, there are many multi-variate processes that need to be monitored with many quality characteristics and associated process variables at the same time. These situations have made it possible to obtain super-large manufacturing process data sets. However, there are many difficulties with finding the cause of process variation or useful information in the high capacity database. In order to solve this problem, neural networks technique is a favorite technique that predicts the yield of process for process control. This paper uses a neural networks technique for improvement and maintenance of yield in manufacturing process. The purpose of this paper is to model the prediction of a sub process that has much effect to improve yields in total manufacturing process and the prediction of adjustment values of this sub process. These informations feedback into the process and the process is adjusted. Also, we show that the proposed model is useful to the manufacturing process through the case study.

• 한국지역지리학회지
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• 제10권4호
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• pp.787-799
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• 2004

본 연구는 대도시 산업 지역사회 존립기반 연구의 일환으로 대구시 북성로 공구상가를 사례로 기업간 거래 네트워크의 실태를 분석하였다. 이 지역은 영세소규모의 공구 판매업체 집적지로 이들 업체가 거래 관계를 맺고 있는 주요 업체들을 주로 북성로 및 인접지역에 분포하는 전형적인 도심형 산업지역사회를 구성하고 있다. 북성로 총구상가가 산업지역사회로서 존립할 수 있었던 가장 중요한 기반은 상가내 제품 수급상의 장기적인 거래 네트워크였다. 지역 업체들은 거래 관계에 있어 순수한 시장 메커니즘에 의존하기 보다는 사회자본에 기초한 기업간 네트워크 관계에 더 의존하고 있었다. 기업간 거래 네트워크를 맺게 되는 이유는 무리한 주문의 경우에도 거래가 가능하였다는 점과 외상거래가 가능한 점이였다. 이러한 기업간 거래 네트워크의 기능 및 역할에 있어서는 업체 상호간에 기술이전과 학습이 가장 중요하며, 장기간의 거래 네트워크를 유지함에 있어서는 공간적 접근성보다는 관계적 접근성이 오히려 중요한 의미를 가진다.

• 한국산업보건학회지
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• 제10권2호
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• pp.1-17
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• 2000

We investigated dissatisfaction of elements of local exhaust system, needs for local exhaust system, and information networks for local exhaust system from June 1998 to September 1999 using the questionnaire structured. It contained questions concerning general characteristics of factory and local exhaust system, troubles and dissatisfaction of elements of local exhaust system, and information networks for local exhaust system. The collected data were analyzed by descriptive statistics analysis. Information networks for local exhaust system were analyzed by multidimensional scaling using path distance of network analysis and by graph analysis using Krackplot. Among complaints of local exhaust system, that of duct has show the highest percentage of complaint. In the information network for local exhaust system, Seoul is positioned in the center of network with mediating role.

• 대한산업공학회지
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• 제31권3호
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• pp.201-209
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• 2005

Empty moves are necessary when there are imbalances among transportation demands from source locations to destination locations and the transportation demands require empty equipment that must be supplied to source locations. When the amount of the inflow exceeds that of the outflow or the amount of the outflow exceeds that of the inflow, repositioning empty equipment is necessary. Examples of the empty equipment are containers, chassis, and pallets. This paper addresses how to estimate the empty moves on several typical transportation networks. Types of transportation networks considered are chain, tree, cycle, tree of cycles, and hybrid networks. Simple procedures are suggested for determining the optimal empty flows. Numerical examples are provided to illustrate procedures in this paper.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제9권2호
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• pp.83-89
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• 2005

In this paper a new algorithm of learning and evolving artificial neural networks using gene expression programming (GEP) is presented. Compared with other traditional algorithms, this new algorithm has more advantages in self-learning and self-organizing, and can find optimal solutions of artificial neural networks more efficiently and elegantly. Simulation experiments show that the algorithm of evolving weights or thresholds can easily find the perfect architecture of artificial neural networks, and obviously improves previous traditional evolving methods of artificial neural networks because the GEP algorithm imitates the evolution of the natural neural system of biology according to genotype schemes of biology to crossover and mutate the genes or chromosomes to generate the next generation, and the optimal architecture of artificial neural networks with evolved weights or thresholds is finally achieved.