• 한국정보통신학회논문지
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• 제24권4호
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• pp.553-559
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• 2020

우리나라에서 단일품목으로 가장 큰 수출품인 마른 김은 현재 우리나라의 시장 사정상 대량생산에 중점을 둔 상황이다. 이는 자연스럽게 마른 김의 품질하락으로 이어졌다. 따라서 본 논문에서는 마른 김 생산 시에 기존에 사용자의 경험에 의존하여 김 혼합 비율을 맞추는 방식을 포토센서(IR sensor)를 이용한 보다 효율적으로 조절하는 방식을 제안하였다. 또한 광원을 발생시키는 IR LED Lamp와 농도를 검출하는 포토센서 등을 통하여 얻어진 1차 영상정보들을 바탕으로 실시간으로 김 혼합물 농도를 판단할 수 있는 임베디드 측정 시스템을 개발하였다. 이 방식에서는 정밀한 데이터를 실시간으로 수집 저장함으로써 매년 겨울마다 반복되는 작업 환경에서 이전 연도의 데이터를 확인하여 보다 손쉽게 대처할 수 있게 한다.

• 전기학회논문지
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• 제65권11호
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• pp.1907-1912
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• 2016

In fact, in order to obtain good performances and low torque ripple, a high-resolution sensor is needed, which is costly and usually needs a special construction for the machine. So researchers are becoming aware of their cost and are exploring the possibility of cost reduction. Information of rotor position is necessary to drive Linear Switched Reluctance Motor(LSRM). Therefore, linear optical encoder is used to detect a mover position. Normally, since the price of encoder, which is used for linear motor is relatively higher than the one used for rotory motor and the cost of additional equipment increases with the length of motor. This is not always appropriate, considering economical efficiency in case of using the linear optical encoder. As a results, LSRM has a great part for the total cost. Therefore, in this paper, we propose LSRM position detecting modeling with reflective type photo-sensor. Additionally, we have investigated the possibility of the reduced position sensor for LSRM drives with advanced control technique. To certify the overall characteristics of the proposed method, a simulation using PSIM software has been carried out and the informative results are displayed.

• 전기학회논문지
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• 제60권5호
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• pp.1049-1054
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• 2011

Color is discerned due to the reflectance of object and its hue is determined by the Ratio of RGB spectrum. The aim of this study is to evaluate the Color information using by the optical system in terms of convenience and simplicity. Firstly, the differential Ratio of RGB is evaluated by photodiode Sensor which achieves a high efficiency with quick tranducer output. To extract the information of RGB Ratio, light emitting diode is built in Color sensing system with photodiode. Our proposed method is very economical, simple, and convenient. Our results can be applied to confirm the accurate information of Color in the research environments and commercial purposes. Thus RGB information can be determined subjectively and thus, the inherent characteristic of Color will be revealed precisely and its related features can be resolved in a real time mode.

• 반도체디스플레이기술학회지
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• 제13권2호
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• pp.45-52
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• 2014

This paper proposes an efficient photo retrieval system that automatically indexes for searching of relevant images, using a combination of geo-coded information, direction/location of image capture device and content-based visual features. A photo image is labeled with its GPS (Global Positioning System) coordinates and direction of the camera view at the moment of capture, and the label leads to generate a geo-spatial index with three core elements of latitude, longitude and viewing direction. Then, content-based visual features are extracted and combined with the geo-spatial information, for indexing and retrieving the photo images. For user's querying process, the proposed method adopts two steps as a progressive approach, filtering the relevant subset prior to use a content-based ranking function. To evaluate the performance of the proposed scheme, we assess the simulation performance in terms of average precision and F-score, using a natural photo collection. Comparing the proposed approach to retrieve using only visual features, an improvement of 20.8% was observed. The experimental results show that the proposed method exhibited a significant enhancement of around 7.2% in retrieval effectiveness, compared to previous work. These results reveal that a combination of context and content analysis is markedly more efficient and meaningful that using only visual feature for image search.

• International Journal of Aeronautical and Space Sciences
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• 제17권1호
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• pp.37-44
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• 2016

Optical fiber temperature sensing systems have incomparable advantages over traditional electrical-cable-based monitoring systems. However, the fiber optic interrogators and sensors have often been rejected as a temperature monitoring technology in real-world industrial applications because of high cost and over-specification. This study proposes a multiplexed fiber optic temperature monitoring sensor system using an economical Optical Time-Domain Reflectometer (OTDR) and Hard-Polymer-Clad Fiber (HPCF). HPCF is a special optical fiber in which a hard polymer cladding made of fluoroacrylate acts as a protective coating for an inner silica core. An OTDR is an optical loss measurement system that provides optical loss and event distance measurement in real time. A temperature sensor array with the five sensor nodes at 10-m interval was economically and quickly made by locally stripping HPCF clad through photo-thermal and photo-chemical processes using a continuous/pulse hybrid-mode laser. The exposed cores created backscattering signals in the OTDR attenuation trace. It was demonstrated that the backscattering peaks were independently sensitive to temperature variation. Since the 1.5-mm-long exposed core showed a 5-m-wide backscattering peak, the OTDR with a spatial resolution of 40 mm allows for making a sensor node at every 5 m for independent multiplexing. The performance of the sensor node included an operating range of up to $120^{\circ}C$, a resolution of $0.59^{\circ}C$, and a temperature sensitivity of $-0.00967dB/^{\circ}C$. Temperature monitoring errors in the environment tests stood at $0.76^{\circ}C$ and $0.36^{\circ}C$ under the temperature variation of the unstrapped fiber region and the vibration of the sensor node. The small sensitivities to the environment and the economic feasibility of the highly multiplexed HPCF temperature monitoring sensor system will be important advantages for use as system-integrated temperature sensors.

• 대한화학회지
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• 제64권2호
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• pp.74-78
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• 2020

산성 영역에서 작동하는 고감도 형광 pH 센서막을 제조하기 위하여 실란화된 유리 표면 상에 push-pull 공액 염료(DCMP)를 공유결합에 의해 고정화하였다. DCMP 유도체(DCMA), 2-hydroxyethyl methacrylate (HEMA)및 triethylene glycol dimethacrylate의 혼합물을 광개시 공중합하여 pH 감응성 형광센서막을 제조하였다. 분광학적 측정 결과, pH 2.0-5.0 사이에서 pH가 증가함에 따라 센서막의 흡광도가 증가하였으며, 같은 pH 범위에서 pH 증가에 따라 센서막의 형광 세기도 약 50배 정도 증가하였다. 산성 조건에서 pH 변화에 대한 센서막의 감응은 가역적이고 재현성이 우수하였다. 또한 센서막은 20-50초 사이의 비교적 짧은 감응 시간과 여러 금속이온 존재에서 수소 이온에 대해 높은 선택성을 나타내었다.

• Journal of information and communication convergence engineering
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• 제7권3호
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• pp.281-285
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• 2009

Mobile robot has various sensors for describing the external world. The ultrasonic sensor widely applied to the most mobile robot to detect the obstacle and environment owing to low cost, its easy to use. However, ultrasonic sensor has major problems: the uncertainty information of sensor, false readings caused by specular reflection, multi path effect, low angular resolution and sensitivity to changes in temperature and humidity. This paper describes a sensor system for map building of mobile robot. It was made of low cost PSD (Position Sensitive Detector) sensor array and high speed RISC MPU. PSD sensor is cost effective and light weighting but its output signal has many noises. We propose heuristic S/W filter to effectively remove these noises. The developed map building sensor system was equipped on a mobile robot and was compared with ultrasonic sensor through field test.

• 제어로봇시스템학회논문지
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• 제11권9호
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• pp.810-815
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• 2005

As the pharmaceutical industry grows and becomes more competitive, the need of automation increases to establish effective mass production and to maintain consistent quality control. Accurate counting and packing of medicinal pills is one of the most essential processes that the automation can benefit. In conventional automated counting and packing processes, the performance of counting process varies with the size, the shape and the dispersion degree of pills. In this research, the authors developed a new pill-counting algorithm based on carefully analyzed characteristics of the pill-drop behavior. Also a new scheme for the packing of an exact number of pills has been implemented. A pill counting and packing machine with the new pill-counting algorithm and the new packing scheme has been constructed and put in an actual production line. To achieve precise and quick sensing of pills dropping at a high speed from the preceding processors, the machine uses non-contact photo sensors. Experimental results from the actual process using the machine are included to verify the effectiveness of the proposed algorithm and the machine.

• 전자공학회논문지 IE
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• 제46권4호
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• pp.8-15
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• 2009

본 논문은 CMOS 이미지센서 SPICE 회로 해석을 위한 포토다이오드 및 픽셀 모델링을 나타내었다. 소자 시뮬레이터인 메디치(Medici)를 이용하여 입사광의 세기에 따른 광전류 특성을 확보하고 SPICE 시뮬레이션에서 활용하기 위한 SPICE용 포토 다이오드 모델을 개발하였다. 그리고 그 결과를 검증하기 위하여 포토다이오드와 NMOS로 구성된 시험용 회로구조에 대한 메디치(Medici)의 mixed mode 시뮬레이션 결과와 SPICE 시뮬레이션 결과를 비교하였다.

• 센서학회지
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• 제17권1호
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• pp.41-52
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• 2008

In this paper, a circuit analysis of the complementary CMOS active pixel and readout circuit is carried out. Complementary pixel structure which is different from conventional 3TR APS structure is consist of photo diode, reset PMOS, several NMOSs and PMOSs sets for complementary signals. Photo diode is modelled with Medici device program. HSPICE was used to analyze the variation of the signal feature depending on light intensity using $0.5{\mu}M$ standard CMOS process. Simulation results show that the output signal range is from 0.8 V to 4.5 V. This signal range increased 135 % output dynamic range compared to conventional 3TR pixel in the condition of 5 V power supply.