• Title/Summary/Keyword: In-situ measurement

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USING MODIS DATA TO ESTIMATE THE SURFACE HEAT FLUXES OVER TAIWAN'S CHIAYI PLAIN

  • Ho, Han-Chieh;Liou, Yuei-An;Wang, Chuan-Sheng
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.317-319
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    • 2008
  • Traditionally, it is measured by using basin or empirical formula with meteorology data, while it does not represent the evaportransporation over a regional area. With the advent of improved remote sensing technology, it becomes feasible to assess the ET over a regional scale. Firstly, the IMAGINE ATCOR atmospheric module is used to preprocess for the MODIS imagery. Then MODIS satellite images which have been corrected by radiation and geometry in conjunction with the in-situ surface meteorological measurement are used to estimate the surface heat fluxes such as soil heat flux, sensible heat flux, and latent heat flux. In addition, the correlation coefficient between the derived latent heat and the in-situ measurement is found to be over 0.76. In the future, we will continue to monitor the surface heat fluxes of paddy rice field in Chiayi area.

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A Study on the Behavior Prediction of Underground Structures by Back Analysis (역해석에 의한 지하구조체의 거동예측에 관한 연구)

  • 장정범;김문겸
    • Tunnel and Underground Space
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    • v.8 no.2
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    • pp.139-145
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    • 1998
  • The reliable estimation of the system parameters and the accurate prediction of the system behavior are important to design underground structures safely and economically. Especially, the elastic modulus and the in-situ stresses are very important parameters in predicting the behavior of the underground structure. Therefore, the back analysis using the field measurement data is developed to determine accurately the elastic modulus and the in-situ stresses of the underground structural system in this study. A back analysis using the combined finite and boundary element is developed. It can consider the far field boundary condition and is efficient in computation. In this study, a back analysis is performed to predict behaviors of underground structures for the real construction site. The comparison between the results of the back analysis with field measurement data and the obtained material properties from the field test shows good agreement for the real construction site.

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Analysis of Growth Mechanism of Al Thin Film by in-situ Surface Reflectance Measurement During MOCVD Process (MOCVD에 의한 Al 박막 증착 중의 표면 반사도 측정을 통한 박막 성장 메커니즘 분석)

  • Kim, Kisoo;Seo, Moon Kyu
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.2
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    • pp.104-108
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    • 2015
  • Al thin films were deposited on TiN/Si(100) via metal-organic chemical vapor deposition using N-methylpyrrolidine alane as a precursor. Characterization of the deposited films were investigated with SEM, XRD, ${\alpha}$-step, AFM, 4-point probe. The early stage of Al thin film deposition was analyzed by in-situ surface reflectance measurement with laser and photometer apparatus. The surface reflectance were changed greatly during the initial 30~40 seconds. There were two increases and two decreases in the surface reflectance, thus the sequence of Al films were deposited at 8 significant points of the surface reflectance change. Surface topograph and cross-sectional view of each film were analyzed with SEM. Al films were grown in the complex mechanism of Volmer-Weber and Stranski-Krastanov process.

Chemical reaction at Cu/polyimide interface (Cu/polyimide 계면에서의 화학반응)

  • 이연승
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.3
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    • pp.494-503
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    • 1997
  • We investigated the initial stages of formation of the Cu/polyimide interface using another two methods by X-ray photoelectron spectroscopy. : One, in-situ measurement with increasing of Cu deposition thickness onto polyimide(PI), the other, measurement with decreasing of Cu thickness of Cu/pI film by $Ar^+$ ion etching. From these results, we find that the chemical reactions exist in Cu/PI interface. However, the measured chemical reactions were different according to experimental method.

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A Preliminary Research on Optical In-Situ Monitoring of RF Plasma Induced Ion Current Using Optical Plasma Monitoring System (OPMS)

  • Kim, Hye-Jeong;Lee, Jun-Yong;Chun, Sang-Hyun;Hong, Sang-Jeen
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.523-523
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    • 2012
  • As the wafer geometric requirements continuously complicated and minutes in tens of nanometers, the expectation of real-time add-on sensors for in-situ plasma process monitoring is rapidly increasing. Various industry applications, utilizing plasma impedance monitor (PIM) and optical emission spectroscopy (OES), on etch end point detection, etch chemistry investigation, health monitoring, fault detection and classification, and advanced process control are good examples. However, process monitoring in semiconductor manufacturing industry requires non-invasiveness. The hypothesis behind the optical monitoring of plasma induced ion current is for the monitoring of plasma induced charging damage in non-invasive optical way. In plasma dielectric via etching, the bombardment of reactive ions on exposed conductor patterns may induce electrical current. Induced electrical charge can further flow down to device level, and accumulated charges in the consecutive plasma processes during back-end metallization can create plasma induced charging damage to shift the threshold voltage of device. As a preliminary research for the hypothesis, we performed two phases experiment to measure the plasma induced current in etch environmental condition. We fabricated electrical test circuits to convert induced current to flickering frequency of LED output, and the flickering frequency was measured by high speed optical plasma monitoring system (OPMS) in 10 kHz. Current-frequency calibration was done in offline by applying stepwise current increase while LED flickering was measured. Once the performance of the test circuits was evaluated, a metal pad for collecting ion bombardment during plasma etch condition was placed inside etch chamber, and the LED output frequency was measured in real-time. It was successful to acquire high speed optical emission data acquisition in 10 kHz. Offline measurement with the test circuitry was satisfactory, and we are continuously investigating the potential of real-time in-situ plasma induce current measurement via OPMS.

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In Situ Gamma-ray Spectrometry Using an LaBr3(Ce) Scintillation Detector

  • Ji, Young-Yong;Lim, Taehyung;Lee, Wanno
    • Journal of Radiation Protection and Research
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    • v.43 no.3
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    • pp.85-96
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    • 2018
  • Background: A variety of inorganic scintillators have been developed and improved for use in radiation detection and measurement, and in situ gamma-ray spectrometry in the environment remains an important area in nuclear safety. In order to verify the feasibility of promising scintillators in an actual environment, a performance test is necessary to identify gamma-ray peaks and calculate the radioactivity from their net count rates in peaks. Materials and Methods: Among commercially available scintillators, $LaBr_3(Ce)$ scintillators have so far shown the highest energy resolution when detecting and identifying gamma-rays. However, the intrinsic background of this scintillator type affects efficient application to the environment with a relatively low count rate. An algorithm to subtract the intrinsic background was consequently developed, and the in situ calibration factor at 1 m above ground level was calculated from Monte Carlo simulation in order to determine the radioactivity from the measured net count rate. Results and Discussion: The radioactivity of six natural radionuclides in the environment was evaluated from in situ gamma-ray spectrometry using an $LaBr_3(Ce)$ detector. The results were then compared with those of a portable high purity Ge (HPGe) detector with in situ object counting system (ISOCS) software at the same sites. In addition, the radioactive cesium in the ground of Jeju Island, South Korea, was determined with the same assumption of the source distribution between measurements using two detectors. Conclusion: Good agreement between both detectors was achieved in the in situ gamma-ray spectrometry of natural as well as artificial radionuclides in the ground. This means that an $LaBr_3(Ce)$ detector can produce reliable and stable results of radioactivity in the ground from the measured energy spectrum of incident gamma-rays at 1 m above the ground.

Study on Characteristics of In-situ Rock Stress State in Mountainous Region by Hydraulic Fracturing Method (수압파쇄시험에 의한 산악지역에서의 현지 암반 초기응력 측정 및 분포특성 연구)

  • Bae, Seong-ho;Jeon, Seok-won;Choi, yong-kun;Kim, Hak-soo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.4 no.1
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    • pp.57-70
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    • 2002
  • Since early in the 90's, the need for construction of underground rock structures such as long and large section traffic tunnel, energy storage cavern, industrial facility, etc. has been largely increased because the Korean territory is not wide and about 65 % of the land consists of mountainous region. The initial rock stress measurement has been widely conducted to provide the quantitative information on the stress state of engineering site at the design stage of underground rock structures. Among the diverse methods developed for measuring rock stress, hydraulic fracturing test is most popularly used because it is applicable at pre-construction stage and has no limit in testing depth. In this paper, the characteristics of initial rock stress state in mountainous region were studied on the basis of the in-situ hydraulic fracturing stress measurement results from the 60 test boreholes in various parts of Korea.

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In situ photoemission and inverse photoemission studies on the interfacial electronic structures of organic materials (In situ 광전자분광/역광전자분광 분석을 이용한 유기물 계면의 전자구조 연구)

  • Yi, Yeonjin
    • Vacuum Magazine
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    • v.2 no.2
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    • pp.4-11
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    • 2015
  • During last two decades, remarkable progresses have been made in organic electronic devices, such as organic light-emitting device, organic photovoltaic and many other applied devices. Many of these progress are attributed to the multilayered/heterojunction device architectures, which could be achieved from the control of "interfacial energetics". In that sense, the interfacial electronic structures in organic electronic devices have a decisive role in device performance. However, the prediction of the interfacial electronic structures from each separate material is not trivial. Many complex phenomena occur at the interface and these can be only understood from thorough measurements on interfacial electronic structures in situ. Photoemission and inverse photoemission spectroscopy have been known as the most proper measurement tools to analyze these interfacial electronic structures. In this review, the basic principles of (inverse) photoemission spectroscopy and typical measurement results on organic/inorganic interfaces are introduced.

The study of in-situ measurement method for wall thermal performance diagnosis of existing apartment (기존 공동 주택의 벽체 열성능 현장 측정법에 관한 연구)

  • Kim, Seohoon;Kim, Jonghun;Yoo, Seunghwan;Jeong, Hakgeun;Song, Kyoodong
    • KIEAE Journal
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    • v.16 no.4
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    • pp.71-77
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    • 2016
  • Purpose : The energy saving in a residential building (apartment) sector is known as one of the effective solution of energy reduction. In South Korea, the government has recently reinforced regulations associated with the energy performance of buildings. However, there is a lack of research on the methods for the energy performance diagnosis that is used to analyze the wall thermal performance of the existing apartments. Because a reliable diagnosis is necessary to save the building energy, this study analyzed wall thermal performance of an existing apartment in Seoul. Method : This paper applied two methods for analysis of the thermal insulation performance; HFM(Heat Flow Meter) method and ASTR(Air-Surface Temperature Ratio) method. The HFM method is suggested by ISO9869-1 code to measure the thermal performance. The ASTR method is proposed by this study for the simplified In-situ measurement and it uses three temperature data (interior wall surface, interior and exterior air) and the overall heat transfer coefficient. This study conducted the experiment of an existing apartment in Seoul using these methods and analyzed the results. Furthermore, the energy simulation tool of the building was used to suggest retrofit of the building based on the results of measurements. Result : The error rate of HFM method and ASTR method was analyzed in about 17 to 20%. As the results of comparison between the initial design values of the wall and the measured values, the 26% degradation of insulation thermal performance was measured. Lastly, the energy simulation tool of the building shows 10.8% energy savings in accordance with the construction of suggested retrofit.