• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1996년도 추계학술대회 학술발표 논문집
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• pp.123-128
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• 1996

In this paper, a fuzzy controller is proposed for the operation of stoker-type refuse incinerator with many kinds of uncertain factors. To build the exact mathematical model is very difficult because of the variation of physical/chemical properties of refuse as a fuel and the complexity of the combusiton process. The fuzzy controller consists of fuzzy sensor, fuzzy decision maker and tracking part. The rules based on the professional operators empirical knowledge are made for the control of the boiler evaporation rate, emission gas and refuse throughput. For the performance measure of the proposed fuzzy controller, the model of the incinerator is constructed and the simulation results are given.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제5권3호
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• pp.268-273
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• 2005

We propose the specialized product-line development methodology for developing the embedded system of an MSDFS (Multi Sensor Data Fusion System : called MSDFS). The product-line methodology provides a simultaneous design between software and hardware, high level reusability. However this is insufficient in requirement analysis stage due to be focused on software architecture, detailed design and code. Thus we apply the business model based on IDEF0 technique to traditional methodology. In this paper, we describe the processes of developing Core-Asset, which are requirement analysis, feature modeling, validation. The proposed model gives the efficient result for eliciting features, and ensures the high level reusability of modules performing on embedded system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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• pp.3554-3570
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• 2021

With the rapid development of the Chinese water project, the safety monitoring of dams is urgently needed. Many drawbacks exist in dams, such as high monitoring costs, a limited equipment service life, long-term monitoring difficulties. MEMS sensors have the advantages of low cost, high precision, easy installation, and simplicity, so they have broad application prospects in engineering measurements. This paper designs intelligent monitoring based on the collaborative measurement of dual MEMS sensors. The system first determines the endpoint coordinates of the sensor array by the coordinate transformation relationship in the monitoring system and then obtains the dam settlement according to the endpoint coordinates. Next, this paper proposes a dual-MEMS sensor collaborative measurement algorithm that builds a mathematical model of the dual-sensor measurement. The monitoring system realizes mutual compensation between sensor measurement data by calculating the motion constraint matrix between the two sensors. Compared with the single-sensor measurement, the dual-sensor measurement algorithm is more accurate and can improve the reliability of long-term monitoring data. Finally, the experimental results show that the dam subsidence monitoring system proposed in this paper fully meets the engineering monitoring accuracy needs, and the dual-sensor collaborative measurement system is more stable than the single-sensor monitoring system.

• 한국정보과학회논문지:시스템및이론
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• 제34권12호
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• pp.630-640
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• 2007

센서 네트워크의 응용 범위가 점차 넓어지면서 군사 분야나 방사능 감지와 같이 실시간성을 요구하는 응용분야가 생겨나게 되었다. 하지만 기존의 센서 운영체제 연구는 효율적인 자원 활용에 초점을 두고 연구가 진행되었기 때문에 실시간성을 만족시켜 주기 어려운 구조를 가지고 있다. 본 논문에서는 정시성을 보장하는 실시간 분산 객체 TMO 모델을 센서 네트워크의 제한된 자원 환경에 알맞도록 경량화 시킨 ${\mu}TMO$ 모델을 제안한다. ${\mu}TMO$ 모델을 이용한 실시간 센서 네트워크 운영체제를 개발하기 위하여 한국전자통신연구원에서 개발한 센서 노드용 운영체제인 Nano-Q+를 이용하였다. Nano-Q+의 타이머 모듈을 높은 해상도를 가질 수 있도록 수정하였으며, EDF(Earliest-Deadline-First)기반의 실시간 스케줄러에 CST(Context Switch Threshold)와 PAS(Power Aware Scheduling) 기법을 적용하여 센서 노드에 적합한 실시간 스케줄러로 변경하였다. ${\mu}TMO$ 모델을 지원하기 위해 채널 기반의 통신 수단인 ITC-Channel을 새롭게 구현하였으며, 주기적인 스레드를 관리하는 WTMT(Watchdog TMO Management Task) 모듈을 구현하여 SpM 스레드를 주기에 맞게 실행할 수 있도록 하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.276-279
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• 2005

This paper presents a novel cylindrical capacitive sensor (CCS) for both radial and axial motion measurements. Although the new CCS has almost the same geometric configuration as the conventional CCS, the unused axial area of the CCS is utilized to measure the axial motion of the rotor, which can affords more compact design and reduction of the system complexity. First, a theoretical model of the proposed CCS is derived. Based on the derived theoretical model, compensation methods to decouple the radial and axial motion measurements are proposed. In addition, error analysis is performed and a design rule is proposed to guarantee the same accuracy in measuring both radial and axial motions. Finally, a test rig and electronics for the proposed CCS are built and the effectiveness of the proposed CCS is verified with experiments and simulations.

• International Journal of Precision Engineering and Manufacturing
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• 제8권2호
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• pp.20-25
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• 2007

This paper describes a second-generation dual sine-grid surface encoder for 2-D position measurements. The surface encoder consisted of a 2-D grid with a 2-D sinusoidal pattern on its surface, and a 2-D angle sensor that detected the 2-D profile of the surface grid The 2-D angle sensor design of previously developed first-generation surface encoders was based on geometric optics. To improve the resolution of the surface encoder, we fabricated a 2-D sine-grid with a pitch of $10{\mu}m$. We also established a new optical model for the second-generation surface encoder that utilizes diffraction and interference to generate its measured values. The 2-D sine-grid was fabricated on a workpiece by an ultra precision lathe with the assistance of a fast tool servo. We then performed a UV-casting process to imprint the sine-grid on a transparent plastic film and constructed an experimental setup to realize the second-generation surface encoder. We conducted tests that demonstrated the feasibility of the proposed surface encoder model.

• 한국인터넷방송통신학회논문지
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• 제9권2호
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• pp.51-57
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• 2009

유비쿼터스 센서 네트워크(USN)는 센서 노드들이 자유롭게 이동하며 망을 구성하고, 시스템에 접속하여 통신하는 환경을 말하며, 고정 망이 필요 없으므로 접근이 어려운 지역이나 전장 또는 재난 구조를 위한 응용을 위해 임의로 배치될 수 있다. 무선 센서 망 프로토콜은 자가 구성 능력을 가지며, 노드들의 이동성으로 인해 네트워크 회선 단절을 유발하기 쉬우므로 토폴로지 변경에 유연하게 적응하면서 동시에 센서 노드들이 서로 협력하며 동작하는 기법이 요구된다. 본 논문에서는 이러한 환경에서의 효율적인 토폴로지 구성과 데이터 전송을 보장하고자 노드 이동성으로 인한 망 단절에 경로 재설정을 위한 망 재구성 없이 유연한 클러스터 기반 결함허용 라우팅 프로토콜을 설계하고, 분석적 모델을 통하여 그 성능을 평가한다.

• 한국정밀공학회지
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• 제18권8호
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• pp.40-47
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• 2001

Optical measurement methods make it possible to detect object displacements with high resolution and noncontact measurements. Also, they are very robust against EMI noises and have long operation range. An optical triangulation sensor is one of widely used displacement measurement sensors for its sub-micron resolution, fast response, simple structure, and low cost. However. there are several errors caused by inclinations of a surface. speckle effects, power fluctuations of light sources, and noises of detectors. In this paper, in order to minimize error effects, we performed error analysis and proposed a new structure. Then, we setup a new modeling method and verify it through simulations and experiments. Based on the new model. we propose a new sensor structure and establish design criteria. Finally, we design a signal processing system to overcome a resolution-limited problem of light detectors. The resolution of the proposed system is 0.2${\mu}{\textrm}{m}$ in 5mm operating range.

• Journal of Biosystems Engineering
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• 제38권1호
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• pp.25-32
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• 2013

Purpose: The objective of this study is to develop a data middleware for u-IT convergence in agricultural environment monitoring, which can support non-standard data interfaces and solve the compatibility problems of heterogenous sensor networks. Methods: Six factors with three different interfaces were chosen as target data among the environmental monitoring factors for crop cultivation. PostgresSQL and PostGIS were used for database and the data middleware was implemented by Python programming language. Based on hierarchical model design and key-value type table design, the data middleware was developed. For evaluation, 2,000 records of each data access interface were prepared. Results: Their execution times of File I/O interface, SQL interface and HTTP interface were 0.00951 s/record, 0.01967 s/record and 0.0401 s/record respectively. And there was no data loss. Conclusions: The data middleware integrated three heterogenous sensor networks with different data access interfaces.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.767-770
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• 2009

본 논문에서는 자동화설비에서 가장 많이 사용되는 부품인 센서와 Cylinder를 기준으로 두 가지 Model을 기준으로 "고장허용 시스템 구축"에 관한 연구를 진행하였다. Free Flow Conveyor상에서 Sensor의 고장발생 시 Virtual Sensor Mode로 전환되어 정상동작 하는 것을 Simulation을 통해 구현을 하였으며, Cylinder의 내압을 이용하여 Cylinder의 동작 시 부하에 따른 Analog data변화를 확인함으로써 고장허용 시스템을 다양하게 적용할 수 있는 토대를 마련하였다. 이러한 방법은 Cylinder의 수명예상은 물론 Grease 주입예상시기와 Cylinder의 불량유무판단 등 개발자의 능력에 따라 여러 가지 응용이 가능할 것이라 생각된다.