• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권1호
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• pp.341-360
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• 2012

The network topology for a wide area sensor network has to support connectivity and a prolonged lifetime for the many applications used within it. The concepts of structure and group in sociology are similar to the concept of cluster in wireless sensor networks. The clustering method is one of the preferred ways to produce a topology for reduced electrical energy consumption. We herein propose a cluster topology method based on sociological structures and concepts. The proposed sociological clustering topology (SOCT) is a method that forms a network in two phases. The first phase, which from a sociological perspective is similar to forming a state within a nation, involves using nodes with large transmission capacity to set up the global area for the cluster. The second phase, which is similar to forming a city inside the state, involves using nodes with small transmission capacity to create regional clusters inside the global cluster to provide connectivity within the network. The experimental results show that the proposed method outperforms other methods in terms of energy efficiency and network lifetime.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.777-780
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• 2014

센서 네트워크 기술이 각광을 받으면서 다양한 종류의 센서 노드로 구성된 센서 네트워크에 대한 연구가 활발히 진행되고 있다. 센서 네트워크 어플리케이션들의 주요 트래픽 패턴은 몇몇의 센서 노드들로부터 싱크 노드로 패킷을 전송하는 타입의 단일 방향성 데이터 수집형태로 구성되어있으며 소스 노드, 중간 노드, 싱크 노드에 이르기 까지 각각 자신의 상위 노드를 곧 바로 깨움으로써 지연의 감소와 에너지 효율성을 이끌어냈다. 본 논문에서는 저 전력 센서 네트워크에서사용중인 다양한 프로토콜들을 분석하여 가장 효율적인 프로토콜을 네트워크 시뮬레이션을 통해 비교 분석하여 실질적 적용 가능성을 제시 하였다.

• International Journal of Internet, Broadcasting and Communication
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• 제10권1호
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• pp.11-15
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• 2018

The application of Wireless Sensor Networks requires a wise utilization of limited energy resources. Therefore, a wide range of routing protocols with a motivation to prolong the lifetime of a network has been proposed in recent years. Hierarchical clustering based protocols have become an object of a large number of studies that aim to efficiently utilize the limited energy of network components. In this paper, the effect of mismatch in parameter estimation is discussed to evaluate the robustness of a distanced based algorithm called distributed clustering protocol in homogeneous and heterogeneous environment. For quantitative analysis, performance simulations for this protocol are carried out in terms of the network lifetime which is the main criteria of efficiency for the energy limited system.

• 한국태양에너지학회 논문집
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• 제28권6호
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• pp.58-63
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• 2008

It is essential to investigate the structure and the main characteristic of Home USN (Ubiquitous Sensor Network) technologies in built ubiquitous environment while designing bio-sensors. For this study, Thermistor elements and Thermopile black body have been selected to implement ubiquitous technologies for bio-sensors and wireless network such as WiBro has been used to transfer sensing data to the BSN (Bio-Sensor Network) gateway. It is certain that efficiency of ubiquitous space design is improved if main components of each specific sensor network are analyzed precisely in digital way and corresponding communication modules are prepared accordingly. Ubiquitous technology, in conclusion, has to be applied not only with systematical mechanism or electronic setting but in human-centered atmosphere as well, keeping with deep consideration for bio-housing service factors in eco-friendly surrounding.

• International Journal of Computer Science & Network Security
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• 제22권1호
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• pp.255-261
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• 2022

Routing Protocol for Low-Power and Lossy Networks (RPLs) in Internet of Things (IoT) is currently one of the most popular wireless technologies for sensor communication. RPLs are typically designed for specialized applications, such as monitoring or tracking, in either indoor or outdoor conditions, where battery capacity is a major concern. Several routing techniques have been proposed in recent years to address this issue. Nevertheless, the expansion of the network lifetime in consideration of the sensors' capacities remains an outstanding question. In this research, aANN-CUCKOO based optimization technique is applied to obtain a more efficient and dependable energy efficient solution in IOT-RPL. The proposed method uses time constraints to minimise the distance between source and sink with the objective of a low-cost path. By considering the mobility of the nodes, the technique outperformed with an efficiency of 98% compared with other methods. MATLAB software is used to simulate the proposed model.

• 전기학회논문지P
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• 제55권3호
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• pp.133-140
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• 2006

This paper is proposed an efficiency optimization control algorithm for a synchronous reluctance motor(SynRM) which minimizes the copper and iron losses. Also, this paper presents a speed estimated control scheme of SynRM using artificial neural network(ANN). There exists a variety of combinations of d and q-axis current which provide a specific motor torque. The objective of the efficiency optimization controller is to seek a combination of d and q-axis current components, which provides minimum losses at a certain operating point in steady state. It is shown that the current components which directly govern the torque production have been very well regulated by the efficiency optimization control scheme. The proposed algorithm allows the electromagnetic losses in variable speed and torque drives to be reduced while keeping good torque control dynamics. The control performance of ANN is evaluated by analysis for various operating conditions. Analysis results are presented to show the validity of the proposed algorithm.

• 디지털산업정보학회논문지
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• 제16권1호
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• pp.33-39
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• 2020

A smart grid is a next-generation power grid that can improve energy efficiency by applying information and communication technology to the general power grid. The smart grid makes it possible to exchange information about electricity production and consumption between electricity providers and consumers in real-time. Advanced metering infrastructure (AMI) is the core technology of the smart grid. The AMI provides two-way communication by installing a modem in an existing digital meter and typically include smart meters, data collection units, and meter data management systems. Because the AMI requires data collection units to control multiple smart meters, it is essential to ensure network availability under heavy network loads. If the load on the work done by the data collection unit is high, it is necessary to allocation new data collection units to ensure availability and improve energy efficiency. In this paper, we discuss the allocation scheme of data collection units for the energy efficiency of the AMI.

• 한국항해항만학회지
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• 제36권7호
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• pp.535-544
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• 2012

In order to improve the overall ASEAN maritime transport network, each port's efficiency is regarded as a crucial factor that should be calculated periodically. This study evaluated the relative efficiency of container port operations of 32 ports belonging to 9 ASEAN nations using Data Envelopment Analysis (DEA). It found that 2 out of 32 ports in 2010 were measured as efficient ports. This study yielded two major findings. Firstly, the ports assessed as inefficient need to benchmark similar ports in size and structure from the ports that are assessed as efficient to improve their efficiency. Secondly, these results could be used to determine potential candidates and country for an international port development co-operation programme with Korea to improve the performance of the entire ASEAN port network by developing the infrastructures of ill-equipped ports.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권3호
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• pp.819-837
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• 2014

Data centers, which implement cloud service, have been faced up with quick growth of energy consumption and low efficiency of energy. 60GHz wireless communication technology, as a new option to data centers, can provide feasible approach to alleviate the problems. Aiming at energy optimization in 60GHz wireless data centers (WDCs), we investigate virtualization technology to assign virtual resources to minimum number of servers, and turn off other servers or adjust them to the state of low power. By comprehensive analysis of wireless data centers, we model virtual network and physical network in WDCs firstly, and propose Virtual Resource Mapping Packing Algorithm (VRMPA) to solve energy management problems. According to VRMPA, we adopt packing algorithm and sort physical resource only once, which improves efficiency of virtual resource allocation. Simulation results show that, under the condition of guaranteeing network load, VPMPA algorithm can achieve better virtual request acceptance rate and higher utilization rate of energy consumption.

• Journal of information and communication convergence engineering
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• 제19권3호
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• pp.136-141
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• 2021

Research on wireless sensor networks has focused on the monitoring and characterization of large-scale physical environments and the tracking of various environmental or physical conditions, such as temperature, pressure, and wind speed. We propose a stochastic mobility model that can be applied to a MANET (Mobile Ad-hoc NETwork). environment, and apply this mobility model to a newly proposed clustering-based routing protocol. To verify its stability and durability, we compared the proposed stochastic mobility model with a random model in terms of energy efficiency. The FND (First Node Dead) was measured and compared to verify the performance of the newly designed protocol. In this paper, we describe the proposed mobility model, quantify the changes to the mobile environment, and detail the selection of cluster heads and clusters formed using a fuzzy inference system. After the clusters are configured, the collected data are sent to a base station. Studies on clustering-based routing protocols and stochastic mobility models for MANET applications have shown that these strategies improve the energy efficiency of a network.