• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.683-684
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• 2012

본 논문에서는 스쿨존에서 센서 기반의 관제 시스템 구성에 대해 고려하였다. 본 논문을 통하여 센서 및 네트워크 구성, 학생 모니터링 시스템에 대한 구조를 고려한다.

• Current Optics and Photonics
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• 제4권4호
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• pp.293-301
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• 2020

In this paper we propose and theoretically analyze a monolithic multiparametric sensor consisting of a superstructure of surface-relief waveguide Bragg gratings (WBGs), a micro-machined diaphragm, and a cantilever beam. Diaphragms of two different configurations, namely circular and square, are designed and analyzed separately for pressure measurement. The square diaphragm is then selected for further study, since it shows relatively higher sensitivity compared to the circular one, as it incurs more induced stress when any pressure is applied. The cantilever beam with a proof mass is designed to enhance the sensitivity for acceleration measurement. A unique mathematical method using coupled-mode theory and the transfer-matrix method is developed to design and analyze the shift in the Bragg wavelength of the superstructure configuration of the gratings, due to simultaneously applied pressure and acceleration. The effect of temperature on the wavelength shift is compensated by introducing another Bragg grating in the superstructure configuration. The measured sensitivities for pressure and acceleration are found to be 0.21 pm/Pa and 6.49 nm/g respectively.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.184-189
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• 2000

Two types of fiber-optic sensors, EFPI(extrinsic Fabry-Perot interferometer) and FBG(fiber Bragg grating), have been investigated for measurement of thermal strain and temperature. The EFPI sensor is only for measurement of thermal strain and the FBG sensor is for simultaneous measurement of thermal strain and temperature. FBG temperature sensor was developed to measure strain-independent temperature. This sensor configuration consists of a single-fiber Bragg grating and capillary tube which makes it isolated from external strain. This sensor can then be used to compensate for the temperature cross sensitivity of a FBG strain sensor. These sensors are demonstrated by embedding them into a graphite/epoxy composite plate and by attaching them on aluminum rod and unsymmetric graphitelepoxy composite plate. All the tests were conducted in a thermal chamber with the temperature range $20-100^{\circ}C$. Results of strain measurements by fiber-optic sensors are compared with that from conventional resistive foil gauge attached on the surface.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1807-1810
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• 2002

This paper presents a technique for avoid- ing indefiniteness in Maximum Likelihood (ML) criteria for Direction-of-Arrival (DOA) finding using a sensor ar- ray with arbitrary configuration. The ML criterion has singular points in the solution space where the criterion becomes indefinite. Solutions fly iterative techniques for ML bearing estimation may oscillate because of numerical instability which occurs due to the indefiniteness, when bearings more than one approach to the identical value. The oscillation makes the condition for terminating iterations complex. This paper proposes a technique for avoiding the indefiniteness in ML criteria.

• 한국정보통신학회논문지
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• 제15권4호
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• pp.993-999
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• 2011

무선 센서노드들은 초기에 대량으로 랜덤하게 배치되어 스스로 클러스터를 구성하고, 각 클러스터 헤드 노드를 선출하여 정상적인 통신이 이루어져야 한다. 이러한 일련의 작업을 무선 센서노드 설치시 관리자가 직접적으로 관여할 수 없기 때문에 자가 구성 라우팅 기능이 가능하여야 한다. 논문에서 제안하는 통신영역을 고려한 클러스터 헤드 노드 선출 알고리즘은 계층구조를 형성하는 무선센서 네트워크 환경에서 적용되며, 베이스 스테이션의 통신 영역을 계산하여 클러스터 헤드 노드를 선정하고 클러스터를 구성한다.

• 제어로봇시스템학회논문지
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• 제6권5호
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• pp.396-403
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• 2000

A thermal imaging system is implemented for the measurement and the analysis of the thermal distribution of the target objects. The main part of the system is a thermal camera in which a focal plane array typed sensor is introduced. The sensor detects the mid-range infrared spectrum of target objects and then it outputs a generic video signal which should be processed to form a frame thermal image. Here, a digital signal processor(DSP) is applied for the high speed processing of the sensor signals. The DSP controls analog-to-digital converter, performs correction algorithms and outputs the frame thermal data to frame buffers. With the frame buffers can be generated a NTSC signal and transferred the frame data to personal computer(PC) for the analysis and a monitoring of the thermal scenes. By performing the signal processing functions in the DSP the overall system achieves a simple configuration. Several experimental results indicate the performance of the overall system.

• 조명전기설비학회논문지
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• 제27권1호
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• pp.92-98
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• 2013

In this paper, Completely beyond the existing conventional Guard Light management system, introduced the 447Mhz band wireless sensor network Guard Light to manage efficiently the shape of the new system is proposed. In addition, about wireless sensor network technology, control server technology, application layer protocol technology etc which is core technology for the proposed system configuration, it was verified by the design and experiment. Especially studying wireless Guard Light System(about 1,700 node configuration) commercially installed in the Daegu area as a results of the study, I would like to prove the effectiveness of the study.

• 전기학회논문지
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• 제58권4호
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• pp.795-800
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• 2009

Surface plasmon resonance (SPR) has been widely used for biological and chemical sensing applications. The present study investigates numerically the optical characteristics for the single Au film and bimetallic Ag/Au film SPR configurations by using the multiple beam interference matrix (MBIM) method. We use the prism coupling method, especially Kretschmann configuration for excitation of surface plasmon wave (SPW). The estimated results of reflectance, phase shift and magnetic field intensity enhancement factor are provided for finding out the optimum configuration with high sensitivity for SPR measurement. As a result, the optimum thicknesses are found to be 52 nm for a single Au film and 5 nm to 36 nm for bimetallic Ag-Au film. From the comparison of full width half maximum (FWHM) values for reflectance, phase shift, and enhancement of magnetic field intensity, it is concluded that the highest sensitivity can be obtained when using the phase shift for SPR sensor.

• 대한기계학회논문집B
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• 제36권12호
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• pp.1177-1183
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• 2012

본 연구의 목적은 형상계수와 태양추적장치를 이용하여 헬리오스타트에서 흡수기로 복사열전달이 최대화 될 수 있는 시스템을 개발하는 것이다. 헬리오스타트에서 타워 상단에 위치한 흡수기로의 열전달은 대부분 복사에 의해 일어나기 때문에, 복사 열전달에서 사용되는 형상계수를 헬리오스타트 제어에 이용하였다. 태양 추적 및 태양 위치 계산은 CdS 센서와 시뮬링크 프로그램을 이용하였다. 시뮬링크 프로그램을 이용하여 실시간으로 헬리오스타트, 흡수기, 태양 사이의 형상계수가 최대화되는 알고리즘을 적용함으로서, 헬리오스타트에서 흡수기로의 복사 열전달이 최대화 될 수 있도록 하였다. 또한 다양한 조건에 따른 헬리오스타트 제어에 필요한 각을 시뮬레이션 함으로서 각 조건에 필요한 각을 도출할 수 있었다.

• 전기학회논문지P
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• 제57권3호
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• pp.270-274
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• 2008

The microwave sensor in which the sensitivity was excellent and a structure is simple was developed and it manufactured. And the sensing range that uses the developed product was confirmed. When the developed microwave sensor was set up in the ceiling of a building, we confirmed that the amplitude of the sensitive area increased as the tilting angle was enlarged. The sensitive area became a greatest in case the tilting angle was 65 degree. According to the height of a ceiling, because the sensing range is determined, in case of using in the building in which the height of a ceiling is enough secured it is determined to secure the more wide sensitive area. Moreover, the configuration of the circuit having the simple structure makes the miniaturization of a product, and the light weight possible. It is considered to have the price competitive power which it reduces the manufacturing cost, is sufficient.