• Journal of Communications and Networks
• /
• 제10권2호
• /
• pp.204-212
• /
• 2008

We study the routing problem in all-wireless networks based on cooperative transmissions. We model the minimum-energy cooperative path (MECP) problem and prove that this problem is NP-complete. We hence design an approximation algorithm called cooperative shortest path (CSP) algorithm that uses Dijkstra's algorithm as the basic building block and utilizes cooperative transmissions in the relaxation procedure. Compared with traditional non-cooperative shortest path algorithms, the CSP algorithm can achieve a higher energy saving and better balanced energy consumption among network nodes, especially when the network is in large scale. The nice features lead to a unique, scalable routing scheme that changes the high network density from the curse of congestion to the blessing of cooperative transmissions.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제12권1호
• /
• pp.135-158
• /
• 2018

High-Speed vehicles can be considered as multiple mobile nodes that move together in a large-scale mobile network. High-speed makes the time allowed for a mobile node to complete a handover procedure shorter and more frequently. Hence, several protocols are used to manage the mobility of mobile nodes such as Network Mobility (NEMO). However, there are still some problems such as high handover latency and packet loss. So efficient handover management is needed to meet Quality of Service (QoS) requirements for real-time applications. This paper utilizes the cross-layer seamless handover technique for network mobility presented in cellular networks. It extends this technique to propose QoS-aware NEMO protocol which considers QoS requirements for real-time applications. A novel analytical framework is developed to compare the performance of the proposed protocol with basic NEMO using cost functions for realistic city mobility model. The numerical results show that QoS-aware NEMO protocol improves the performance in terms of handover latency, packet delivery cost, location update cost, and total cost.

• Journal of Biosystems Engineering
• /
• 제30권6호통권113호
• /
• pp.360-365
• /
• 2005

Precision agriculture attempts to improve cropping efficiency by variable application of crop treatments such as fertilizers and pesticides, within field on a point-by-point basis. Therefore, a more complete understanding of the relationships between yield and soil properties is of critical importance in precision agriculture. In this study, the functional relationships between measured soil properties and rice yield were investigated. A supervised back-propagation neural network model was employed to relate soil chemical properties and rice yields on a point-by point basis, within individual site-years. As a results, a positive correlation was found between practical yields and predicted yields in 1999, 2000, 2001, and 2002 are 0.916, 0.879, 0.800 and 0.789, respectively. The results showed that significant overfitting for yields with only the soil chemical properties occurred so that more of environmental factors, such as climatological data, variety, cultivation method etc., would be required to predict the yield more accurately.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제50권1호
• /
• pp.30-36
• /
• 2001

This paper introduces a new indirect rotor position estimation algorithm for the SRM sensorless control, based on the magnetizing curves of aligned and unaligned rotor positions. Through the basic test method, the complete SRM magnetizing characterization is first constructed using a neural network training, and then used to estimate the rotor position. And also, the optimal phase is selected by the phase selector. In order to verify this approach, the proposed rotor position estimation algorithm using a neural network learning data is investigated. The experimental results show that the proposed control algorithm can be effectively applied to SRM sensorless control.

• International Journal of Control, Automation, and Systems
• /
• 제4권5호
• /
• pp.567-574
• /
• 2006

This paper presents the hardware implementation of a neural network controller for a nonlinear system with a micro-controller unit (MCU) and a field programmable gate array (FPGA) chip. As an on-line learning algorithm of a neural network, the reference compensation technique has been implemented on an MCU, while PID controllers with other functions such as counters and PWM generators are implemented on an FPGA chip. Interface between an MCU and a field programmable gate array (FPGA) chip has been developed to complete hardware implementation of a neural controller. The developed neural control hardware has been tested for balancing the inverted pendulum while controlling a desired trajectory of a cart as a nonlinear system.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2002년도 추계종합학술대회
• /
• pp.518-521
• /
• 2002

본 논문에서는 GMDSS 시행이후 우리나라 선박들의 해난사고는 점차적으로 다소 줄어가고 있으나, 자체해난사고는 오히려 증가하고 있는데 그 원인은 GMDSS제도에 의하여 관리되지 않는 비 협약 소형선박들의 사고는 오히려 증가하고 있다. 해난사고가 가장 많이 발생하는 5톤미만의 소형선박들을 위한 현실적이고 합리적인 해양종합 통신시스템을 구축하고자 하는데 연구에 목적이 있다.

• 한국지능시스템학회논문지
• /
• 제12권3호
• /
• pp.261-268
• /
• 2002

This paper represents that auto tunings of membership functions and weights in the fuzzy neural networks are effectively performed by immune algorithm. A number of hybrid methods in fuzzy-neural networks are considered in the context of tuning of learning method, a general view is provided that they are the special cases of either the membership functions or the gain modification in the neural networks by genetic algorithms. On the other hand, since the immune network system possesses a self organizing and distributed memory, it is thus adaptive to its external environment and allows a PDP (parallel distributed processing) network to complete patterns against the environmental situation. Also, it can provide optimal solution. Simulation results reveal that immune algorithms are effective approaches to search for optimal or near optimal fuzzy rules and weights.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2014년도 추계학술발표대회
• /
• pp.173-174
• /
• 2014

Handover is constantly a challenging issue in wireless networks. Most of the existing solutions are host-based, which are implemented on the wireless terminals and leave the decision making to the terminals. This paper studies the problem of network-based handover in the wireless networks with the constraints of low latency as well as low computational time. To address this problem, we employ the software-defined network (SDN) architecture to facilitate handover. According to the operational model of the SDN, we define a workflow for all involved network entities, and then design a framework implementing the workflow as a complete handover system. The proposed framework aims to establish a channel conveying the mobility-related information of devices and the context information of their vicinity from the switches/access routers to the controllers. Based on collected information, the controller can optimally execute the handover.

• 농촌지도와개발
• /
• 제30권4호
• /
• pp.199-212
• /
• 2023

Recently, despite the active interest and research on biochar, there is a lack of research on the acceptance intention of farmers, who are technology adopters. Accordingly, the purpose of this study was to conduct a survey of 168 farmers and structurally analyze the factors affecting farmers' intention to accept biochar. The analysis results are as follows. First, promotion conditions and network effects have a positive influence on farmers' intention to accept biochar. Second, the mediating variable, network effect, has a complete mediating effect between performance expectations, social influence, and acceptance intention. This suggests that organizations need to be utilized to spread biochar because network effects increase the explanatory power of acceptance intention.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2013년도 춘계학술대회
• /
• pp.213-216
• /
• 2013

인터넷의 발달과 유무선 네트워크 인프라 기술의 발전으로 빅테이터 및 개인정보보의 활용이 많아지고 있다. 하지만 개인정보보호법의 시행에도 불구하고, 개인정보 유출로 인한 침해사고가 발생하고 있다. 개인정보 유출은 개인의 사생활피해와 금융피해로 연관된다. 따라서 개인정보의 탐색 및 검출과정에서 개인정보의 패턴을 분석하여 추출하는 연구와 불필요한 개인정보의 완전삭제에 관한 연구가 필요하다. 본 연구에서는 개인정보보호에 대한 패턴추출 연구와 완전삭제 방법을 연구하여 개인정보의 패턴추출 및 완전삭제 실험을 하였다.