• 한국인터넷방송통신학회논문지
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• 제17권1호
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• pp.139-144
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• 2017

최근 GeoSensor 활용이 증가함에 따라 공간 센서 데이터와 같은 2차원 데이타를 효율적으로 처리하기 위한 질의 처리 시스템이 활발히 연구되고 있다. 하지만 기존 질의 처리 시스템들은 시공간 센서 데이터와 같은 다차원 데이타를 처리하기 위한 데이타 타입과 연산자를 지원하지 않기 때문에 이와 같은 다차원 데이터를 처리하기에 미흡하다. 따라서, 본 논문은 이러한 센서 네트워크에서 다차원 데이타를 효율적으로 처리하기 위하여 질의 처리 시스템을 개발하였다. 마지막으로 본 논문은 시나리오를 통해 본 시스템의 효용성을 검증하고, 수행시간 및 메모리 사용량 등의 성능평가를 통해 기존 시스템들보다 성능이 우수함을 입증하였다.

• 조명전기설비학회논문지
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• 제29권1호
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• pp.113-120
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• 2015

Network type distributed control system uses a communication line which is named the BUS to exchange a data among the sub-systems. Usually, on the bus, only one data must be exited at one time, so the control algorithm to prevent collision or to manage a priority of data is important. Including CAN Protocol, many kind of FieldBus which are used for distributed control system, prevent data collision by controlling transmission time. But, a system which have to make a control signal or get a data from a sensor at fixed time will be met a problem when it is composed by using a network type distributed control structure. In this paper, some of these cases will be discussed and solutions be proposed for preventing a data collision. Also, using Arago Disk System which have a structure for inner loop control, the validity of the proposed methods will be verified.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.165-168
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• 2005

The objects, which can be personal digital assistants, electronic rings, doors or even clothes, offer embedded chips with computation facilities and are generally called artifacts. I later realized that this was not so the real problem is actually authentication. Recent results indicate scalability problems for flat ad hoc networks. Sensor network achieves function that handle surrounding information perception through sensor and sensed information to network that is consisted of sensor nodes of large number. Research about new access control techniques and height administration techniques need authentication information persons' certification assurance level classification in sensor network environment which become necessary different view base with authentication information at node for application of AAA technology in USN environment that must do authentication process using information that is collected from various sensor mountings. So, get base authentication information in sensor type and present weight grant model by security strength about authentication information through information who draw. In this paper collected information of sensor nodes model who give weight drawing security reinforcement as authentication information by purpose present be going to. and Must be able to can grasp special quality of each sensor appliances in various side and use this and decide authentication assurance level for value estimation as authentication information elements. Therefore, do to define item that can evaluate Authentication information elements thus and give simple authentication assurance level value accordingly because applying weight. Present model who give authentication assurance level value and weight for quotation according to security strength.

• 센서학회지
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• 제15권4호
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• pp.291-296
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• 2006

We focus on the solutions to prevent fatal risk to patient's life caused by transfusing blood which is wrong type or has exceeded norm temperature. Also, this study gives priority to the verification of medical safety of using blood, of which management is applied advanced sensor tag technology adopted RFID(Radio Frequency Identification) temperature sensor and USN(Ubiquitous Sensor Network) for temperature management of blood. Therefore, this study can contribute to protect of health of patients who take blood transfusion through construction of basis of new process of blood management.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.433-435
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• 2007

Geographic wireless sensor networks use position information for Greedy routing. Greedy routing works well in dense network where as in sparse network it may fail and require the use of recovery algorithms. Recovery algorithms help the packet to get out of the communication void. However, these algorithms are generally costlier for resource constrained position based wireless sensor type networks. In the present work, we propose a Void Avoidance Algorithm (VAA); a novel idea based on virtual distance upgrading that allows wireless sensor nodes to remove all stuck nodes by transforming the routing graph and forward packet using greedy routing only without recovery algorithm. In VAA, the stuck node upgrades distance unless it finds next hop node which is closer to the destination than itself. VAA guarantees the packet delivery if there is a topologically valid path exists. NS-2 is used to evaluate the performance and correctness of VAA and compared the performance with GPSR. Simulation results show that our proposed algorithm achieves higher delivery ratio, lower energy consumption and efficient path.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.831-832
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• 2006

In this paper, we introduce a canonical framework of the large-scaled web-based sensor gateway and practically implement it as the environment monitoring system. The system consists of a central management server, up to 250 local embedded subsystems and up to 250 sensor or actuator nodes for each subsystem. The node information is gathered periodically through a well-defined protocol on the sensor network and converted to the web contents and the SNMP MIB objects according to its data type. The MIB objects are well-defined and include system, network, sensor, actuator and alarm specific data classes. Because there is an increasing trend that a large number of sites are willing to adapt unmanned sensing and control, the developed system will play a key role to efficiently manage a large scale sensor networked system such as environment monitoring systems or countermeasure systems against disaster and calamities.

• 반도체디스플레이기술학회지
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• 제22권2호
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• pp.64-71
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• 2023

If an impedance mismatch occurs between the source and load in a Radio Frequency transmission system, reflected power is generated. This results in incomplete power transmission and the generation of Reflected Power, which returns to the Radio Frequency generator. To minimize this Reflected Power, Impedance matching is performed. Fast and efficient Impedance matching, along with converging reflected power towards zero, is advantageous for achieving desired plasma characteristics in semiconductor processes. This paper explores Impedance matching by adjusting the Vacuum Variable Capacitor of an L-type Matching Module based on the trends observed in the voltage of the Phase Sensor and Electromotive Force voltage. After assessing the impedance matching characteristics, the findings are described.

• 전자공학회논문지
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• 제53권4호
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• pp.20-26
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• 2016

무선 수동형 센서 망은 RF 소스가 센서 노드에게 에너지를 공급하여 적어도 이론적으로 배터리 없이 영원히 동작할 수 있는 망이다. 그러나 기술이 성숙하지 못하여 무선 수동형 센서 망은 아직 센서 노드에서 에너지의 희소성, 에너지 수신과 data 전송의 동시불가성, data 전송의 비효율성 등 많은 어려움을 안고 있다. 본 논문에서는 이러한 현실적 제약을 고려하여 여러 센서 노드가 하나의 싱크 노드에게 packet을 전달하기 위한 기본적인 MAC 방식을 제안한다. 수신한 에너지로 캐패시터를 충전하는 충전 구간과 싱크 노드와 통신하는 활동 구간이 번갈아 반복되는 시간 구조에 기초하여 제안하는 MAC 방식은 활동 구간 동안 slotted ALOHA를 따라 싱크 노드에게 패?을 전달한다. 일반적으로 경합형 방식은 throughput이 상대적으로 낮은 경향을 보인다. 따라서 모의 실험 방법을 이용하여 제안하는 MAC 방식의 throughput 성능을 다각도로 평가한다. 모의 실험 결과로부터 활동 구간의 길이를 적절히 설정하여 망 전체 throughput 성능을 높일 수 있음을 확인할 수 있다.

• Smart Structures and Systems
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• 제14권1호
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• pp.55-70
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• 2014

The paper presents a multi-objective optimization strategy for a multi-type sensor placement for Structural Health Monitoring (SHM) of long span bridges. The problem is formulated for simultaneous placement of strain sensors and accelerometers (heterogeneous network) based on application demands for SHM system. Modal Identification (MI) and Accurate Mode Shape Expansion (AMSE) were chosen as the application demands for SHM. The optimization problem is solved through the use of integer Genetic Algorithm (GA) to maximize a common metric to ensure adequate MI and AMSE. The performance of the joint optimization problem solved by GA is compared with other established methods for homogenous sensor placement. The results indicate that the use of a multi-type sensor system can improve the quality of SHM. It has also been demonstrated that use of GA improves the overall quality of the sensor placement compared to other methods for optimization of sensor placement.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.560-562
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• 1999

The SOFM neural network as the recognizant algorithm of 3-D underwater object with ultrasonic sensor had the recognizant rate of 100%.