• 전자공학회논문지CI
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• 제45권6호
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• pp.45-51
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• 2008

유시티를 비롯하여 여러 시범사업에서 나타나듯이 유비쿼터스 네트워크상에서 제공되는 서비스가 다양해질수록 안정적인 데이터 전송은 필수적인 요건이 되었다. 이렇듯 신뢰성은 서비스에서 요구하는 그 외의 서비스 품질상의 요구사항들에 앞서서 해결되어야 하는 가장 기본적인 사항이 되었다. 또한 유비쿼터스 센서 네트워크에서 가장 중요시 생각하는 저전력 통신의 근간을 지키기 위해서도 효율적이며 안정적인 데이터 전송은 기본적으로 필요한 사안이 되었는데 근본적으로 효율적이고 안정적인 데이터의 전달이 에너지 절감에도 도움이 되기 때문이다. 이에 본 논문에서는 유비궈터스 센서 네트워크에서의 데이터 전송 방법에 따른 효율성과 안정성을 성능 분석을 통해서 비교해 보고자 한다.

• 보건교육건강증진학회지
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• 제29권5호
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• pp.27-36
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• 2012

Objectives: Developing efficient health messages is important for improving health behaviors at a societal level. This study attempts to test a few variables that could constitute the elements for measuring readability of health message. The number of subject-verb relationships in a sentence, placement of jargon, i.e., explication before or after each jargon, and the number of less familiar Chinese characters were manipulated to hypothetically differentiate readability. Methods: In a $2{\times}2$ mixed factorial experiment, 152 college students read two health messages regarding side effect of health functional food and energy drink. The participants' perceived readability was asked, and eight questions were developed to measure the participants' recognition of the health information. Results: Those who read messages manipulated to have high readability rated the message significantly higher than those who read messages with low readability. Also, the former answered the questions more correctly than the latter, implying the association between readability and knowledge acquisition regarding health. Conclusions: Readability is suggested as a factor determining the effect of health messages in affecting the public's health risk perception and relevant behaviors. Further studies to sophisticate the measurement itself and to examine the effect of actual public messages with different readabilities are suggested.

• Smart Structures and Systems
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• 제14권1호
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• pp.1-16
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• 2014

In this work, we address the so-called sensor reachback problem for Wireless Sensor Networks, which consists in collecting the measurements acquired by a large number of sensor nodes into a sink node which has major computational and power capabilities. Focused on applications such as Structural Health Monitoring, we propose a cooperative communication protocol that exploits the spatio-temporal correlations of the sensor measurements in order to save energy when transmitting the information to the sink node in a non-stationary environment. In addition to cooperative communications, the protocol is based on two well-studied adaptive filtering techniques, Least Mean Squares and Recursive Least Squares, which trade off computational complexity and reduction in the number of transmissions to the sink node. Finally, experiments with real acceleration measurements, obtained from the Canton Tower in China, are included to show the effectiveness of the proposed method.

• Journal of Information Processing Systems
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• 제16권5호
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• pp.1113-1128
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• 2020

Ad hoc networks play an important role in mobile communications, and the performance of nodes has a significant impact on the choice of communication links. To ensure efficient and secure data forwarding and delivery, an intelligent routing protocol (IAODV) based on learning method is constructed. Five attributes of node energy, rate, credit value, computing power and transmission distance are taken as the basis of segmentation. By learning the selected samples and calculating the information gain of each attribute, the decision tree of routing node is constructed, and the rules of routing node selection are determined. IAODV algorithm realizes the adaptive evaluation and classification of network nodes, so as to determine the optimal transmission path from the source node to the destination node. The simulation results verify the feasibility, effectiveness and security of IAODV.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.752-754
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• 2016

전력은 전체 에너지 대비 점유율이 지속적으로 증가하고 있으며, 이에 따른 효율적 수요 관리 및 부가 가치 창출을 위한 방안으로 원격 검침 시스템이 도입되었다. 하지만 원격 검침 시스템을 사용하면, 사이버 공격 및 해킹과 같이 다양한 외부 공격으로 위험이 존재한다. 이를 미리 예방하거나 좀 더 안전하게 이용될 수 있는 방안 모색이 시급하다고 사료된다. 이 논문에서는 원격검침 시스템의 현 보안 인증 기술의 연구 동향 및 이슈를 짚어보고자 한다.

• ETRI Journal
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• 제30권4호
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• pp.516-525
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• 2008

This paper proposes a compact, energy-efficient, and smart gas sensor platform technology for ubiquitous sensor network (USN) applications. The compact design of the platform is realized by employing silicon-on-insulator (SOI) technology. The sensing element is fully integrated with SOI CMOS circuits for signal processing and communication. Also, the micro-hotplate operates at high temperatures with extremely low power consumption, which is important for USN applications. ZnO nanowires are synthesized onto the micro-hotplate by a simple hydrothermal process and are patterned by a lift-off to form the gas sensor. The sensor was operated at $200^{\circ}C$ and showed a good response to 100 ppb $NO_2$ gas.

• Journal of Electrical Engineering and Technology
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• 제2권1호
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• pp.42-49
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• 2007

For electricity markets to function in a truly competitive and efficient manner, it is not enough to focus solely on improving the efficiencies of power supply. To recognize price-responsive load as a reliability resource, the customer must be provided with price signals and an instrument to respond to these signals, preferably automatically. This paper attempts to develop the Windows-based load management system in competitive electricity markets, allowing the user to monitor the current energy consumption or billing information, to analyze the historical data, and to implement the consumption strategy for cost savings with nine possible scenarios adopted. Finally, this modeling framework will serve as a template containing the basic concepts that any load management system should address.

• 한국군사과학기술학회지
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• 제13권5호
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• pp.875-885
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• 2010

Recently, the role of Ubiquitous Sensor Network(USN) has been considered to be essential for supporting the near future Network Centric Warfare(NCW) and Tactical Information Communication Network(TICN). In this paper, we explore a set of data storage methods(external storage, local storage and data storage) and query processing methods in WSN. In particular, we focus on analyzing a novel data structure for supporting the local storage method, named the partial ordered tree(POT). The main idea behind POT is that sensor readings are usually correlated with the physical spatial domain. With the help of POT, only a small portion of sensor nodes participate in query processing tasks, and thus network lifetime is greatly increased. Through a series of simulation experiments, we demonstrate that the POT based local storage method clearly outperforms the existing data storage methods in terms of the energy-efficiency, which directly affects the network lifetime, for processing exact match queries, range queries and top-k queries.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권10호
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• pp.3810-3830
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• 2015

In this paper, we investigate the differential game theoretic approach for distributed dynamic cooperative power control in cognitive radio ad hoc networks (CRANETs). First, a payoff function is defined by taking into consideration the tradeoff between the stock of accumulated power interference to the primary networks and the dynamic regulation of the transmit power of secondary users (SUs). Specifically, the payoff function not only reflects the tradeoff between the requirement for quickly finding the stable available spectrum opportunities and the need for better channel conditions, but also reveals the impact of the differentiated types of data traffic on the demand of transmission quality. Then the dynamic power control problem is modeled as a differential game model. Moreover, we convert the differential game model into a dynamic programming problem to obtain a set of optimal strategies of SUs under the condition of the grand coalition. A distributed dynamic cooperative power control algorithm is developed to dynamically adjust the transmit power of SUs under grand coalition. Finally, numerical results are presented to demonstrate the effectiveness of the proposed algorithm for efficient power control in CRANETs.

• 한국정보통신학회논문지
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• 제11권9호
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• pp.1679-1686
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• 2007

클러스터링은 ad hoc네트워크에서 확장성 개선과 네트워크 수명 연장뿐만 아니라 클러스터 내 멤버 관리기능과 링크용량을 개선해주는 토폴로지 제어 기법이다. 본 논문에서는 단말의 이동성과 네트워크의 이종성을 고려하여 multi-radio무선 메쉬 네트워크를 위한 클러스터링 알고리즘을 설계하였다. 수학적 분석을 통하여 제안 알고리즘은 시간 t내에 종료되며, 메시지 제어 처리를 위한 복잡도는 각 노드 당 O(1)임을 알 수 있었다. 이는 본 제안 알고리즘을 적용함으로써 무선 메쉬 네트워크의 안정성, 연결성, 확장성과 에너지 효율성이 향상됨을 알 수 있었다.