• Title/Summary/Keyword: sensor databases

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A Hybrid In-network Join Strategy using Bloom Filter in Sensor Network (센서 네트워크에서 블룸 필터를 이용한 하이브리드 인-네트워크 조인 기법)

  • Song, Im-Young;Kim, Kyung-Chang
    • Journal of KIISE:Databases
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    • v.37 no.3
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    • pp.165-170
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    • 2010
  • This paper proposes an in-network join strategy SBJ(Semi & Bloom Join), an efficient join strategy for sensor networks, that minimizes communication cost. SBJ is a hybrid join strategy that can reduce energy consumption by using a bloom filter to reduce the size of data that needs to be sent or received in sensor network. The key to reducing the communication cost in SBJ is to eliminate data not involved in the join result in the early stages of join processing. Through simulation, the paper shows that compared to other join strategies in sensor network, SBJ join strategy is more efficient in reducing the communication cost resulting in a significant reduction in battery consumption.

Energy-efficient query processing based on partial attribute values in wireless sensor networks (무선 센서 네트워크에서 부분 속성값을 활용한 에너지 효율적인 질의처리)

  • Kim, Sung-Suk;Kim, Hyong-Soon;Yang, Sun-Ok
    • Journal of KIISE:Databases
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    • v.37 no.3
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    • pp.137-145
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    • 2010
  • Wireless sensors play important roles in various areas as ubiquitous computing is generalized. Depending on applications properties, each sensor can be equipped with limited computing power in addition to general function of gathering environment-related information. One of main issues in this environment is to improve energy-efficiency in sensor nodes. In this paper, we devise a new attribute-query processing algorithm. Each sensor has to maintain partial information locally about attributes values gathered at its all descendent nodes. As the volume is higher, however, the maintenance cost also increases. And the update cost also has to be considered in the proposed algorithm. Thus, some bits, AVB(Attribute-Value Bits), are delivered instead of the value itself, where each bit represents a bound of attribute. Thus, the partial information can decrease the number of exchanged messages with a little cost during query processing. Through simulation works, the proposed algorithm is analyzed from several points of view.

Energy-Efficient Routing for Data Collection in Sensor Networks (센서 네트워크에서의 데이타 수집을 위한 라우팅 기법)

  • Song, In-Chul;Roh, Yo-Han;Hyun, Dong-Joon;Kim, Myoung-Ho
    • Journal of KIISE:Databases
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    • v.33 no.2
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    • pp.188-200
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    • 2006
  • Once a continuous query, which is commonly used in sensor networks, is issued, the query is executed many times with a certain interval and the results of those query executions are collected to the base station. Since this comes many communication messages continuously, it is important to reduce communication cost for collecting data to the base station. In sensor networks, in-network processing reduces the number of message transmissions by partially aggregating results of an aggregate query in intermediate nodes, or merging the results in one message, resulting in reduction of communication cost. In this paper, we propose a routing tree for sensor nodes that qualify the given query predicate, called the query specific routing tree(QSRT). The idea of the QSRT is to maximize in-network processing opportunity. A QSRT is created seperately for each query during dissemination of the query. It is constructed in such a way that during the collection of query results partial aggregation and packet merging of intermediate results can be fully utilized. Our experimental results show that our proposed method can reduce message transmissions more than 18% compared to the existing one.

Performance Analysis of Siding Window based Stream High Utility Pattern Mining Methods (슬라이딩 윈도우 기반의 스트림 하이 유틸리티 패턴 마이닝 기법 성능분석)

  • Ryang, Heungmo;Yun, Unil
    • Journal of Internet Computing and Services
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    • v.17 no.6
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    • pp.53-59
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    • 2016
  • Recently, huge stream data have been generated in real time from various applications such as wireless sensor networks, Internet of Things services, and social network services. For this reason, to develop an efficient method have become one of significant issues in order to discover useful information from such data by processing and analyzing them and employing the information for better decision making. Since stream data are generated continuously and rapidly, there is a need to deal with them through the minimum access. In addition, an appropriate method is required to analyze stream data in resource limited environments where fast processing with low power consumption is necessary. To address this issue, the sliding window model has been proposed and researched. Meanwhile, one of data mining techniques for finding meaningful information from huge data, pattern mining extracts such information in pattern forms. Frequency-based traditional pattern mining can process only binary databases and treats items in the databases with the same importance. As a result, frequent pattern mining has a disadvantage that cannot reflect characteristics of real databases although it has played an essential role in the data mining field. From this aspect, high utility pattern mining has suggested for discovering more meaningful information from non-binary databases with the consideration of the characteristics and relative importance of items. General high utility pattern mining methods for static databases, however, are not suitable for handling stream data. To address this issue, sliding window based high utility pattern mining has been proposed for finding significant information from stream data in resource limited environments by considering their characteristics and processing them efficiently. In this paper, we conduct various experiments with datasets for performance evaluation of sliding window based high utility pattern mining algorithms and analyze experimental results, through which we study their characteristics and direction of improvement.

Energy Efficient Query Processing based on Multiple Query Optimization in Wireless Sensor Networks (무선 센서 네트워크에서 다중 질의 최적화 기법을 이용한 에너지 효율적인 질의 처리 기법)

  • Lee, Yu-Won;Chung, Eun-Ho;Haam, Deok-Min;Lee, Chung-Ho;Lee, Yong-Jun;Lee, Ki-Yong;Kim, Myoung-Ho
    • Journal of KIISE:Databases
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    • v.36 no.1
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    • pp.8-21
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    • 2009
  • A wireless sensor network is a computer network which consists of spatially distributed devices, called sensor nodes. In wireless sensor networks, energy efficiency is a key issue since sensor nodes must resides upon limited energy. To retrieve sensor information without dealing with the network issues, a sensor network is treated as conceptual database on which query can be requested. When multiple queries are requested for processing in a wireless sensor network, energy consumption can be significantly reduced if common partial results among similar queries can be effectively shared. In this paper, we propose an energy efficient multi-query processing technique based on the coverage relationship between multiple queries. When a new query is requested, our proposed technique derives an equivalent query from queries running at the moment, if it is derivable. Our technique first computes the set of running queries that may derive a partial result of the new query and then test if this set covers all the result of the new query attribute-wise and tuple-wise. If the result of the new query can be derived from the results of executing queries, the new query derives its result at the base station instead of being executed in the sensor network.

Query Processing using Partial Indexs based on Hierarchy in Sensor Networks (센서 네트워크에서 계층기반 부분 인덱스를 이용한 질의처리)

  • Kim, Sung-Suk;Yang, Sun-Ok
    • Journal of KIISE:Databases
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    • v.35 no.3
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    • pp.208-217
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    • 2008
  • Sensors have a function to gather environment-related information operating by small-size battery in sensor networks. The issue related with energy is still an important in spite of the recent advancements in micro-electro-mechanical-system(MEMS) related techology. Generally it is assumed that replacement or rechargement of battery power in sensor is not feasible and a message send operation may spend at least 1000 times battery than a local operation. Thus, there have been several kinds of research efforts to lessen the number of unnecessary messages by maintaining the information of the other neighboring(or all) sensors. In this paper, we propose an index structure based on parent-children relationship to the purpose. Namely, parent node gathers the set of location information and MBA per child. It's named PH and may allow to process the range query with higher accurate and small size information. Through extensive experiments, we show that our index structure has better energy consumption.

Scoring Method of Fingerprint Image Quality using Classified Block-level Characteristics (블록 레벨의 분류 특성을 이용한 지문 영상의 품질 측정 방법)

  • Moon, Ji-Hyun;Kim, Hak-Il
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.17 no.2
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    • pp.29-40
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    • 2007
  • The purpose of this research is to propose a method for scoring the quality of a fingerprint image using the local information derived from the fingerprint image. In previous works for the quality measuring, most of the quality scores are related to the performance of a matching algorithm, and this makes the quality result more subjective. The quality score of a fingerprint image proposed in this work is sensor-independent, source-independent and matcher-independent one, and this concept of fingerprint sample quality results in effective improvement of the system performance. In this research, a new definition of fingerprint image quality and a new method for measuring the quality are proposed. For the experiments, several sub-databases from FVCs are used and the proposed method showed reasonable results for the test database. The proposed method can be used in various systems for the numerous purposes since the quality scores generated by the proposed method are based on the idea that the quality of fingerprint should be sensor-independent, source-independent and matcher-independent.

Automation of a Teleoperated Microassembly Desktop Station Supervised by Virtual Reality

  • Antoine Ferreira;Fontaine, Jean-Guy;Shigeoki Hirai
    • Transactions on Control, Automation and Systems Engineering
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    • v.4 no.1
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    • pp.23-31
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    • 2002
  • We proposed a concept of a desktop micro device factory for visually servoed teleoperated microassembly assisted by a virtual reality (VR) interface. It is composed of two micromanipulators equipped with micro tools operating under a light microscope. First a manipulator, control method for the micro object to follow a planned trajectory in pushing operation is proposed undo. vision based-position control. Then, we present the cooperation control strategy of the micro handling operation under vision-based force control integrating a sensor fusion framework approach. A guiding-system based on virtual micro-world exactly reconstructed from the CAD-CAM databases of the real environment being considered is presented for the imprecisely calibrated micro world. Finally, some experimental results of microassembly tasks performed on millimeter-sized components are provided.

Design and Implementation of a Framework for Context-Aware Preference Queries

  • Roocks, Patrick;Endres, Markus;Huhn, Alfons;KieBling, Werner;Mandl, Stefan
    • Journal of Computing Science and Engineering
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    • v.6 no.4
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    • pp.243-256
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    • 2012
  • In this paper we present a framework for a novel kind of context-aware preference query composition whereby queries for the Preference SQL system are created. We choose a commercial e-business platform for outdoor activities as a use case and develop a context model for this domain within our framework. The suggested model considers explicit user input, domain-specific knowledge, contextual knowledge and location-based sensor data in a comprehensive approach. Aside from the theoretical background of preferences, the optimization of preference queries and our novel generator based model we give special attention to the aspects of the implementation and the practical experiences. We provide a sketch of the implementation and summarize our user studies which have been done in a joint project with an industrial partner.

The Scheme of Facilities Management based on the Zigbee (지그비를 이용한 시설물 관리 기법)

  • Kim, Dong-Hyun;Cho, Dae-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.11
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    • pp.2361-2366
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    • 2009
  • Usually, it is possible for human administrator to control the facilities manually or automatically using sensors in order to manage the fixed electricity facilities. However, it is difficult to collect the status data of those facilities in the central management system. In this paper, we propose the electricity facility management system to collect the status of facilities using the Zigbee networks. the proposed system exploits the various types of sensors, such as motion, heat, optical, etc, to measure the states of the facilities.