• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권6호
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• pp.1133-1151
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• 2010

Energy balanced consumption routing is based on assumption that the nodes consume energy both in transmitting and receiving. Lopsided energy consumption is an intrinsic problem in low-cost sensor networks characterized by multihop routing and in many traffic overhead pattern networks, and this irregular energy dissipation can significantly reduce network lifetime. In this paper, we study the problem of maximizing network lifetime through balancing energy consumption for uniformly deployed low-cost sensor networks. We formulate the energy consumption balancing problem as an optimal balancing data transmitting problem by combining the ideas of corona cluster based network division and optimized transmitting state routing strategy together with data transmission. We propose a localized cluster based routing scheme that guarantees balanced energy consumption among clusters within each corona. We develop a new energy cluster based routing protocol called "OECR". We design an offline centralized algorithm with time complexity O (log n) (n is the number of clusters) to solve the transmitting data distribution problem aimed at energy balancing consumption among nodes in different cluster. An approach for computing the optimal number of clusters to maximize the network lifetime is also presented. Based on the mathematical model, an optimized energy cluster routing (OECR) is designed and the solution for extending OEDR to low-cost sensor networks is also presented. Simulation results demonstrate that the proposed routing scheme significantly outperforms conventional energy routing schemes in terms of network lifetime.

• Nutritional Sciences
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• 제2권2호
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• pp.102-106
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• 1999

Changes in nutritional and health status brought on by a two-year balanced diet were assessed with anthropometric measurements as well as hematological and lipid profiles in 56 healthy young men. Recommended dietary allowances (RDA) were adjusted with estimated daily weighted activity factor. The weighted resting energy expenditure factor of the subjects was 2.37 $\pm$ 0.05. Compared with RDA, all nutrient intakes were adequate and 56% of energy was supplied by carbohydrates, 18% by protein and 26% by fat. The vitamin and mineral intakes except vitamin B-2 were higher (26.46-129.88%) than RDA. Vitamin B-2 intake was 92.15 \ulcorner 14.16% of RDA. There was no seasonal variation on nutrient intakes. Height was increased and systolic blood pressure was decreased by balanced diet for two years. Body weight, diastolic blood pressure and body mass index (BMI) were unchanged. The level of hemoglobin and hematocrit was not changed, the level of plasma protein was decreased and the level of plasma total cholesterol and albumin was increased. These results suggest that a balanced diet can increase height and complement health status achieved through vigorous exercise, even in adults, and that the level of Korean RDA for energy is adequate to maintain existing body weight.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제4권12호
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• pp.409-414
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• 2015

제한된 에너지 자원으로 동작하는 무선 센서 네트워크에서는 에너지 소비를 최소화하여 통신하는 방법이 중요한 연구 주제이다. 클러스터 헤드를 가진 구분되는 클러스터 안에 센서 노드를 그룹으로 묶는 클러스터링은 에너지 절약에 가장 효과적인 기술로 알려져 있다. 그러나 클러스터 기반 무선 센서 네트워크에서 클러스터 헤드나 게이트웨이는 수집된 정보를 싱크로 보내는 역할 등을 수행하기 때문에 더 많은 에너지를 소비하게 된다. 부적절한 클러스터의 구성은 게이트웨이에 오버로드를 가중시켜 전체 네트워크의 성능을 저하시킨다. 본 논문에서는 에너지 효율을 높이고 네트워크 수명을 향상시키기 위하여 새로운 부하 균형 클러스터링 모델을 제시하고 이를 분기한정 알고리즘과 다중시작 지역탐색 알고리즘을 설계하여 기존에 제시된 부하 균형 클러스터링 모델과 비교한 후 성능 측정 실험 후 결과를 제시한다.

• Journal of Information Processing Systems
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• 제16권1호
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• pp.83-95
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• 2020

Because sensor nodes have limited resources in wireless sensor networks, data aggregation can efficiently reduce communication overhead and extend the network lifetime. Although many existing methods are particularly useful for data aggregation applications, they incur unbalanced communication cost and waste lots of sensors' energy. In this paper, we propose a privacy-preserving, energy-saving data aggregation scheme (EBPP). Our method can efficiently reduce the communication cost and provide privacy preservation to protect useful information. Meanwhile, the balanced energy of the nodes can extend the network lifetime in our scheme. Through many simulation experiments, we use several performance criteria to evaluate the method. According to the simulation and analysis results, this method can more effectively balance energy dissipation and provide privacy preservation compared to the existing schemes.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 봄 학술발표논문집 Vol.30 No.1 (C)
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• pp.403-405
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• 2003

Ad Hoc 네트워크에서 Threshold-Tuning을 통한 노드들간의 균형적인 에너지 소모를 위한 알고리즘 (BECT : A Balanced Energy Consumption Algorithm by Threshold-Tuning)을 제안한다. BECT는 노드간 에너지 균형을 맞추어 네트워크의 수명 (Network Lifetime)을 연장한다. 제안한 알고리즘은 DSR (Dynamic Source Routing) 프로토콜을 기반으로 구현하였으며, GloMoSim 2.0을 이용하여 실험을 하였다. 실험 결과 BECT가 실험 토폴로지에 따라 DSR의 에너지 균형을 17-31% 향상시키며, 데이터 전송율이나 제어 패킷 비율에 있어서도 향상된 성능을 보여준다.

• 대한기계학회논문집
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• 제16권12호
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• pp.2368-2375
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• 1992

본 연구에서는 축대칭 유동장치를 구성하여 열선 풍속계를 이용, 중심축에 따 른 난류쇠퇴양식을 살펴보고 동시에 난류에너지천이에 대한 세밀한 분석을 통하여 각 각 상류유동전개부, 수축부 및 자유분사류로 연속되는 3개의 유동 구조속에서 어떻게 천이해 갈 것인가를 측정하여 축대칭 유동의 난류구조 변천에 대한 기초 실험자료로 제시하고저 한다.

• 한국통신학회논문지
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• 제31권11A호
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• pp.1120-1129
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• 2006

무선 ad-hoc 네트워크 환경에서 이동 호스트의 배터리 수명을 최대화하는 것은 시스템의 수명과 성능을 향상시키므로 매우 중요하다. 이동 호스트들은 라우팅 역할을 수행하므로 네트워크의 구조와 이동 호스트들의 위치에 따라 이동 호스트들의 에너지 소비의 차이가 발생된다. 본 논문에서 각 이동 호스트는 에너지 트리를 유지하며, 메시지 트리 패킷을 이용하여 이웃 이동 호스트들의 에너지의 양을 주기적으로 파악한다. 이동 호스트는 패킷을 전송하기 위한 라우팅 경로를 설정할 때 에너지 트리와 너비우선 탐색을 이용하여 에너지 소비가 가장 적절한 경로를 선택한다. 제안기법은 무선 ad-hoc 네트워크 환경에서 각 이동 호스트의 에너지의 양이 균등하게 사용됨으로써 제한된 배터리 용량을 가진 이동 호스트들이 최대한 오랫동안 동작하므로 시스템의 수명과 성능을 향상시킨다.

• 한국멀티미디어학회논문지
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• 제19권5호
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• pp.910-917
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• 2016

Sensors have limited resources in sensor networks, so efficient use of energy is important. Representative clustering methods, LEACH, LEACHC, TEEN generally use direct transmission methods from cluster headers to the sink node to pass collected data. However, the communication distance of the sensor nodes at low cost and at low power is not long, it requires a data transfer through the multi-hop to transmit data to the sink node. In the existing cluster-based sensor network studies, cluster process and route selection process are performed separately in order to configure the routing path to the sink node. In this paper, in order to use the energy of the sensor nodes that have limited resources efficiently, a cluster-based multi-hop routing protocol which merges the clustering process and routing process is proposed. And the proposed method complements the problem of uneven cluster creation that may occur in probabilistic cluster methods and increases the energy efficiency of whole sensor nodes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권4호
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• pp.1237-1255
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• 2014

In wireless sensor networks (WSNs), hierarchical clustering is an efficient approach for lower energy consumption and extended network lifetime. In cluster-based multi-hop communications, a cluster head (CH) closer to the sink is loaded heavier than those CHs farther away from the sink. In order to balance the energy consumption among CHs, we development a novel cluster-based routing protocol for corona-structured wireless sensor networks. Based on the relaying traffic of each CH conveys, adequate radius for each corona can be determined through nearly balanced energy depletion analysis, which leads to balanced energy consumption among CHs. Simulation results demonstrate that our clustering approach effectively improves the network lifetime, residual energy and reduces the number of CH rotations in comparison with the MLCRA protocols.

• 한국지하수토양환경학회지:지하수토양환경
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• 제21권3호
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• pp.64-81
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• 2016

To analyze the influence of various groundwater flow rates (specific discharge) on BHE system with balanced and unbalanced energy loads under assuming same initial temperature (15℃) of ground and groundwater, numerical modeling using FEFLOW was used for this study. When groundwater flow is increased from 1 × 10⁻⁷ to 4 × 10⁻⁷m/s under balanced energy load, the performance of BHE system is improved about 26.7% in summer and 22.7% at winter time in a single BHE case as well as about 12.0~18.6% in summer and 7.6~8.7% in winter time depending on the number of boreholes in the grid, their array type, and bore hole separation in multiple BHE system case. In other words, the performance of BHE system is improved due to lower avT in summer and higher avT in winter time when groundwater flow becomes larger. On the contrary it is decreased owing to higher avT in summer and lower avT in winter time when the numbers of BHEs in an array are increased, Geothermal plume created at down-gradient area by groundwater flow is relatively small in balanced load condition while quite large in unbalanced load condition. Groundwater flow enhances in general the thermal efficiency by transferring heat away from the BHEs. Therefore it is highly required to obtain and to use adequate informations on hydrogeologic characterristics (K, S, hydraulic gradient, seasonal variation of groundwater temperature and water level) along with integrating groundwater flow and also hydrogeothermal properties (thermal conductivity, seasonal variation of ground temperatures etc.) of the relevant area for achieving the optimal design of BHE system.