• Title/Summary/Keyword: K-SPM

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Use of Beam Transmissometer as an Indirect Measure of Suspended Sediment Concentration in the Estuarine Environment: Application and Problems (강하구에서의 부유물질농도 결정을 위한 광전도측정기의 이용 및 문제점)

  • KIM Seok-Yun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.6
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    • pp.771-781
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    • 1994
  • Monthly measurements made at 15 stations along the axis of the upper Neuse River estuary show a highly variable degree of correlation between concentration of suspended particulate material (SPM) and attenuation coefficient (c) of light as measured by transmissometer. Coefficients of determination along transect lines ranged from $0.12{\sim}0.93$ and calibration slopes ranged from $0.50{\sim}5.63$. When examined on a station-by-station basis, coefficients of determination ranged from $0.21{\sim}0.96$ and calibration slopes ranged from $1.04{\sim}4.94$. Surface calibrations made at individual stations over the full 13-month period were the most consistent of all observations and were considerably better than calibrations made using all of the stations on a given day. Organic content, which can dominate the suspended sediment load during some months, does not appear to explain the variations in reliability of the calibrations. However, an abundance of large aggregates with time-varying size and shape distributions may be partly responsible for variations in optical properties of the sediments, and thus may confound the relationship between SPM and c in the Neuse River estuary Time-varying calibrations to account for non-negligible changes in optical properties may not suffice in complex estuarine environments where the in situ particle dynamics are poorly understood. However, the best use of Beam Transmissometer will continue to be for applications such as detecting water-column events or for use in situations where wide error bars in establishing SPM concentrations are acceptable.

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Microstructure Evolution and Properties of Silicides Prepared by dc-sputtering (스퍼터링으로 제조된 니켈실리사이드의 미세구조 및 물성 연구)

  • An, Yeong-Suk;Song, O-Seong;Lee, Jin-U
    • Korean Journal of Materials Research
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    • v.10 no.9
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    • pp.601-606
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    • 2000
  • Nickel mono-silicide(NiSi) shows no increase of resistivity as the line width decreases below 0.15$\mu\textrm{m}$. Furthermore, thin silicide can be made easily and restrain the redistribution of dopants, because NiSi in created through the reaction of one nickel atom and one silicon atom. Therefore, we investigated the deposition condition of Ni films, heat treatment condition and basic properties of NiSi films which are expected to be employed for sub-0.15$\mu\textrm{m}$ class devices. The nickel silicide film was deposited on the Si wafer by using a dc-magnetron sputter, then annealed at the temperature range of $150~1000^{\circ}C$. Surface roughness of each specimen was measured by using a SPM (scanning probe microscope). Microstructure and qualitative composition analysis were executed by a TEM-EDS(transmission electron microscope-energy dispersive x-ray spectroscope). Electrical properties of the materials at each annealing temperature were measured by a four-point probe. As the results of our study, we may conclude that; 1. SPM can be employed as a non-destructive process to monitor NiSi/NiSi$_2$ transformation. 2. For annealing temperature over $800^{\circ}C$, oxygen pressure $Po_2$ should be kept below $1.5{\times}10^{-11}torr$ to avoid oxidation of residual Ni. 3. NiSi to $NiSi_2$ transformation temperature in our study was $700^{\circ}C$ from the four-point probe measurement.

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Compensation of Distorted WDM signals due to Cross Phase Modulation Effects using Mid-Span Spectral Inversion (상호 위상 변조에 의해 왜곡된 WDM 신호의 Mid-Span Spectral Inversion을 이용한 보상)

  • Lee, Seong-Real
    • Journal of Advanced Navigation Technology
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    • v.7 no.2
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    • pp.128-134
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    • 2003
  • In this paper, we investigated the degree of compensation for WDM channel signal distortion due to chromatic dispersion, self phase modulation (SPM) and cross phase modulation (XPM) as a function of transmission length using mid-span spectral inversion (MSSI) compensation method. The considered system is $3{\times}40$ Gbps intensity modulation direct detection (IM/DD) WDM transmission system. This system has highly nonlinear dispersion shifted fiber (HNL-DSF) as a nonlinear medium in optical phase conjugator (OPC). We confirmed that the transmission length is more increased by applying MSSI to distorted signal due to chromatic dispersion, SPM and XPM as dispersion coefficient of fiber becomes higher. And the compensation degree of distorted WDM channels due to chromatic dispersion, SPM and XPM becomes better stable as dispersion coefficient of fiber becomes higher.

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Safety Assessment of Potential Lactic Acid Bacteria Bifidobacterium longum SPM1205 Isolated from Healthy Koreans

  • Choi Sung Sook;Kang Byung Yong;Chung Myung Jun;Kim Soo Dong;Park So Hee;Kim Jung Soo;Kang Chin Yang;Ha Nam Joo
    • Journal of Microbiology
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    • v.43 no.6
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    • pp.493-498
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    • 2005
  • The safety assessment of Bifidobacterium longum SPM1205 isolated from healthy Koreans and this strain's inhibitory effects on fecal harmful enzymes of intestinal microflora were investigated. The overall safety of this strain was investigated during a feeding trial. Groups of SD rats were orally administered a test strain or commercial reference strain B. longum $1\times10^9\;CFU/kg$ body weight/day for four weeks. Throughout this time, their feed intake, water intake and live body weight were monitored. Fecal samples were periodically collected to test harmful enzyme activities of intestinal microflora. At the end of the four-week observation period, samples of blood, liver, spleen, kidney, and gut tissues were collected to determine for hematological parameters and histological differences. The results obtained in this experiment demonstrated that four weeks of consumption of this Bifidobacterium strain had no adverse effects on rat's general health status, blood biochemical parameters or histology. Therefore, it is likely to be safe for human use. Fecal harmful enzymes such as $\beta-glucosidase,\;\beta-glucuronidase$, tryptophanase and urease, were effectively inhibited during the administration of the B. longum SPM1205. These results suggested that this B. longum SPM 1205 could be used for humans as a probiotic strain.

A Novel IGBT inverter module for low-power drive applications (소용량 전동기 구동용 새로운 IGBT 인버터 모듈)

  • Kim M. K.;Jang K. Y.;Choo B. H.;Lee J. B.;Suh B. S.;Kim T. H.
    • Proceedings of the KIPE Conference
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    • 2002.07a
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    • pp.158-162
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    • 2002
  • This paper presents a novel 3-phase IGBT module called the SPM (Smart Power Module). This is a new design developed to provide a very compact, low cost, high performance and reliable motor drive system. Several distinct design concepts were used to achieve the highly integrated functionality in a new cost-effective small package. An overall description to the SPM is given and actual application issues such as electrical characteristics, circuit configurations, thermal performance and power ratings are discussed

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Voxel-based Morphometry (VBM) Based Assessment of Gray Matter Loss in Medial Temporal Lobe Epilepsy: Comparison with FDG PET (화소기반 형태분석 방법을 이용한 내측측두엽 간질환자의 회백질 부피/농도 감소평가; FDG PET과의 비교)

  • Kang, Hye-Jin;Lee, Ho-Young;Lee, Jae-Sung;Kang, Eun-Joo;Lee, Sang-Gun;Chang, Kee-Hyun;Lee, Dong-Soo
    • The Korean Journal of Nuclear Medicine
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    • v.38 no.1
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    • pp.30-40
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    • 2004
  • Purpose: The aims of this study were to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphometry (VBM) analysis for lateralizing epileptogenic zones in medial temporal lobe epilepsy (mTLE). The findings were compared with fluorodeoxyglucose positron omission tomography (FDG PET). Materials and Methods: MR T1-weighted images of 12 left mTLE and 11 right mTLE patients were compared with those of 37 normal controls. Images were transformed to standard MNI space and averaged in order to create study-specific brain template. Each image was normalized to this local template and brain tissues were segmented. Modulation VBM analysis was performed in order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was peformed using statistical parametric mapping software (SPM99). FDG PET images were compared with those of 22 normal controls using SPM. Results: Gray matter volume was significantly reduced in the left amygdala and hippocampus in left mTLE. In addition, volume of cerebellum, anterior cingulate, and fusiform gyrus in both sides and left insula was reduced. In right mTLE, volume was reduced significantly in right hippocampus. In contrast, FDG uptake was decreased in broad areas of left or right temporal lobes in left TLE and right TLE, respectively. Conclusions: Gray matter loss was found in the ipsilateral hippocampus by modulation VBM analysis in medial temporal lobe epilepsy. This VBM analysis might be useful in lateralizing the epileptogenic zones in medial temporal lobe epilepsy, while SPM analysis of FDG PET disclosed hypometabolic epileptogenic zones.

The efficacy of Quantitative Analysis of Basal/Acetazolamide SPECT Using SPM and Statistical Probabilistic Brain Atlas in Patients with Internal Carotid Artery Stenosis (뇌혈관 협착 환자에서 SPM과 확률뇌지도를 이용한 기저/아세타졸아미드 SPECT의 정량적 분석법의 유용성)

  • Lee, Ho-Young;Lee, Dong-Soo;Paeng, Jin-Chul;Oh, Chang-Wan;Cho, Maeng-Jae;Chung, June-Key;Lee, Myung-Chul
    • The Korean Journal of Nuclear Medicine
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    • v.36 no.6
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    • pp.357-367
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    • 2002
  • Purpose: While cerebral blood flow and cerebrovascular reserve could be evaluated with basal/acetazolamide Tc-99m-HMPAO SPECT in cerebrovascular disease, objective quantification is necessary to assess the efficacy of the revascularization. In this study we adopted the SPM method to quantify basal cerebral blood flow and cerebrovascular reserve on basal/acetazolamide SPECT in assessment of the patients who underwent bypass surgery for linternal carotid artery (ICA) stenosis. Materials and Methods: Twelve patients ($51{\pm}15$ years) with ICA stenosis were enrolled. Tc-99m-HMPAO basal/acetazolamide perfusion SPECT was peformed before and after bypass surgery. After spatia1 and count normalization to cerebellum, basal cerebral blood flow and cerebrovascular reserve were compared with 21 age-matched normal controls and postoperative changes of regional blood flow and reserve were assessed by Statistical Parametric Mapping method. Mean pixel values of each brain region were calculated using probabilistic anatomical map of lobes. Perfusion reserve was defined as the % changes after acetazolamide over basal counts. Results: Preoperative cerebral blood flow and cerebrovascular reserve were significantly decreased in involved ICA territory, comparing with normal control (p<0.05). Postoperative improvement of cerebral blood flow and cerebrovascular reserve was observed in grafted ICA territories, but cerebrovasculr reserve remained with significant difference with normal control. Improvement of the cerebrovascular reserve was most prominent in the superior temporal and the angular gyrus, nearest to the anastomosis sites. Conclusion: Using SPM quantification method on hasal/acetazolamide Tc-99m-HMPAO SPECT, the cerebral blood flow and cerebrovascular reserve could be assessed before revascularization and so could the efficacy of the bypass surgery.