• Smart Structures and Systems
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• 제5권4호
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• pp.483-494
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• 2009

Damage detection has been proven to be a challenging task in structural health monitoring (SHM) due to the fact that damage cannot be measured. The difficulty associated with damage detection is related to electing a feature that is sensitive to damage occurrence and evolution. This difficulty increases as the damage size decreases limiting the ability to detect damage occurrence at the micron and submicron length scale. Damage detection at this length scale is of interest for sensitive structures such as aircrafts and nuclear facilities. In this paper a new photonic sensor based on photonic crystal (PhC) technology that can be synthesized at the nanoscale is introduced. PhCs are synthetic materials that are capable of controlling light propagation by creating a photonic bandgap where light is forbidden to propagate. The interesting feature of PhC is that its photonic signature is strongly tied to its microstructure periodicity. This study demonstrates that when a PhC sensor adhered to polymer substrate experiences micron or submicron damage, it will experience changes in its microstructural periodicity thereby creating a photonic signature that can be related to damage severity. This concept is validated here using a three-dimensional integrated numerical simulation.

• 한국환경농학회지
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• 제29권1호
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• pp.72-76
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• 2010

본 연구에서는 탄소 유기물과 CoPh를 혼합하여 농약 잔류량을 측정 할 수 있는 바이오센서를 구현 하였다. 작동 전극은 탄소유기물과 CoPh를 섞어 사용하였고 비율은 CoPh를 7%로 제작하였다. CoPh가 7%인 경우 저농도 thiocholine 농도에서도 민감하게 반응하였다. 대표적인 농약인 카보후란에 대하여 센서의 감도 한계는 약$0.5{\mu}g/L$ 수준이며, 농약 농도에 따른 전극의 출력이 선형적인 결과를 얻었다. 또한 EPN 및 클로로피리포스 농약에 대하여 실험 한 결과 카보후란과 같이 농도에 따라 효과적으로 반응하는 것을 확인하였다. 이러한 센서는 현재 농약 잔류량 측정에 사용되는 비색법과 비교하여도 감도 및 선형성 면에서 뒤떨어지지 않으며, 간이 농약 잔류량 측정기 센서로 사용가능성이 있다.

• 센서학회지
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• 제6권2호
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• pp.131-136
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• 1997

The ISFET(ion sensitive field effect transistor), a semiconductor ion sensor, has many advantages over conventional ion sensors. Various single-sensor type ISFET pH-meters have been developed. However, they could not be applied in fields because their performances are directly affected by the sensor condition. With only one sensor, the system could be easily damaged from environmental factors, and reliability of it is decreased. Therefore, a 4-channel PH-meter system is proposed to improve the reliability of ISFET pH-meter. It has 4 ISFETS as ion sensor, and a software which contains a new calibration and measurement algorithm appropriate to the system. The reliability of the system was proved by measuring hydrogen ion concentration in the pH standard solutions and buffer solutions.

• 대한전자공학회논문지
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• 제26권6호
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• pp.48-56
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• 1989

밀착형 1차원 영상감지소자로서 팩시밀리에 사용될 광도전막을 사일랜듸 글로방전 분해법으로 제작하였다. 우선 rf전력, 사일랜유량, 분위기 가스압, $H_2/SiH_4$비 및 기판온도의 증착조건에 따른 단층광전도막의 전기적 및 광학적특성을 조사하였다. 이 단층구조 영상감지막은 광전감도 0.85와 100lux 조도하에서 $I_{ph}/I_d=100$을 나타내었다. 그러나 이러한 단층박막은 양 전극으로 부터의 캐리어주입으로 인해 큰 암전류도 0.2nA 이하를 나타내었다. 또한 다층막은 단층막에 비해 단파장 가시광영역이 보상되어 팩시밀리용 1차원 영상감지소자에 사용될 만한 결과를 나타내었다.

• 디지털산업정보학회논문지
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• 제7권1호
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• pp.1-9
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• 2011

In this paper, Wireless sensor network technology applied to various greenhouse agro-industry items such as horticulture and local specialty etc., we was constructed automatic control system for optimum growth environment by measuring growth status and environmental change. existing monitoring systems of greenhouse gather information about growth environment depends on the temperature. but in this system, Can be efficient collection and control of information to construct wireless sensor network by growth measurement sensor and environment monitoring sensor inside of the greenhouse. The system is consists of sensor manager for information processing, an environment database that stores information collected from sensors, the GUI of show the greenhouse status, it gather soil and environment information to soil and environment(including weather) sensors, growth measurement sensor. In addition to support that soil information service shows the temperature, moisture, EC, ph of soil to user through the interaction of obtained data and Complex Growth Environment information service for quality and productivity can prevention and response by growth disease or disaster of greenhouse agro-industry items how temperature, humidity, illumination acquiring informationin greenhouse(strawberry, ginseng). To verify the executability of the system, constructing the complex growth environment measurement system using wireless sensor network in greenhouse and we confirmed that it is can provide our optimized growth environment information.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.64-64
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• 2009

As the advanced packaging technology developing, Copper electro-plating processing has be wildly utilized in the semiconductor interconnect technique. Chemical solution monitoring methods, including PH and gravity measurement exist in industry, but economical and practical real-time monitoring has not been achieved yet. Red-green-blue (RGB) color sensor can successfully monitor the condition of $CuSO_4$ solution during electric copper plating process. Comparing the intensity variations of the RGB data and optical spectroscopy data, strong correlation between two in-situ sensors have shown.

• 전자공학회논문지A
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• 제28A권11호
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• pp.894-901
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• 1991

Contact-type linear image sensors have been fabricated by means of RF glow discharge decomposition method of silane and hydrogen mixtures. The dependences of the electrical and optical properties of these sensor on thickness, RF power, substrate temperature and ambient gas pressure have been investigated. the ITO/i-a-Si:H/Al structure film shows photosensitivity of 0.85 and photocurrent to dark current ratio ($I_{ph}/I_{d}$) of 150 at 5V bias voltage under 200${\mu}W/cm^[2}$ red light intensity. Under 200${\mu}W/cm^[2}$ green light intensity, the ratio is 100. In order to investigate photocarrier transport mechanism and to obtain ${\mu}{\gamma}$ product we have measured the I-V characteristics of these sensors favricated with several different deposition parameters under various light sources. The linear inage sensor for document reading has been operated under reverse bias condition with green light source, resulting in ${\mu}{\gamma}$ product of about 1.5$[\times}10^{-9}cm^{2}$/V.

• 한국전기전자재료학회논문지
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• 제25권7호
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• pp.516-520
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• 2012

In this paper, we have theoretically analyzed and designed a dielectric multi-layer sensor with a SPR (surface plasmon resonance) using analytical calculation and FDTD (finite difference time-domain) methods. The proposed structure is composed of periodic layer and thin metal film. It has many advantages. One of that is a high sensitivity of the SPR. Another is a high Q-factor of the characteristics in the PhC (photonic crystals) micro-cavity structure. The incident light has double resonance characteristics, because the filtered light by PhC structure, dielectric multi-layer, is met the thin metal film for SPR effect. We have also observed the change of resonance characteristics according to the variation of effective index on the metal film.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.849-852
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• 2013

최근 발효식품이 건강식으로 대두되면서 발효식품에 대한 사람들의 관심이 증가되고 있다. 발효식품의 맛, 건강 기능성 및 저장성 등에 영향을 주는 요소들은 발효 재료, 온도, 습도 pH 등이 있으며, 숙성도를 나타내는 지표는 여러 가지가 있으며 그 중에서 pH 변화에 대한 모델 식은 아직 정립이 되지 않았다. 또한 식품 관리자나 소비자 입장에서는 발효 식품에 대한 숙성도 및 품질 상태를 알 수 있다면 발효 식품의 신뢰성이 높아지고 소비성도 높아질 것이다. 그러므로 본 논문에서는 발효 식품의 pH를 측정하여 회귀방정식을 이용하여 모델식을 구하여 발효 식품의 숙성도를 구하는데 플랫폼을 제공한다. 제안된 모델 식의 유용성을 확인하기 위해서 대표적인 발효식품 중 하나인 김치와 막걸리를 사용한 실험을 실시하였다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.99.1-100
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• 2003

E. intermedium Blocontrol activity of a P. chlororaphis rhizobacteium O6, depends to the synthesis of extracellular secondary metabolites and exoenzymes, thought to antagonize the pathogenicity of a variety of phytopathogenic fungi. The production of secondary metabolites and exoenzymes in O6, depends essentially on the GacS-mediated signal transduction pathway, which activates largely unknown signal transduction pathway. To exploit the GacS-mediated signal transdcution pathway involved in activation of ph genes that are necessary for biosynthesis of phenazine from P. chlororaphis O6, we cloned and sequenced the phz operon, rpoS gene encoding stationary specific sigma factor, ppx gene encoding polyphosphatase, and lon gene encoding ion protease. Expression of each gene in wild type and GacS mutant were analyzed by RT-PCR. Transcripts from rpoS, phzI enconing acylhomoserine lactone (AHL) synthase, and ph structural genes in the GacS mutant were reduced in each of these growth phases compared to the wild type. The GacS or Lon mutant was found to be deficient in the production of phenzines, exoenzymes, and the acylhomoserine lactone. These mutants were not complemented by ph operon and addition of exogenous AHL. These results indicate that the GacS global regulatory systems controls phenazine production at multiple levels. Future research will focus to identifying the GacS-mediated regulatory cascade involving in production of phenazine in P. chlororaphis.