• Title/Summary/Keyword: normalization method

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Development of a Climate Change Vulnerability Index on the Health Care Sector (기후변화 건강 취약성 평가지표 개발)

  • Shin, Hosung;Lee, Suehyung
    • Journal of Environmental Policy
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    • v.13 no.1
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    • pp.69-93
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    • 2014
  • The aim of this research was to develop a climate change vulnerability index at the district level (Si, Gun, Gu) with respect to the health care sector in Korea. The climate change vulnerability index was esimated based on the four major causes of climate-related illnesses : vector, flood, heat waves, and air pollution/allergies. The vulnerability assessment framework consists of six layers, all of which are based on the IPCC vulnerability concepts (exposure, sensitivity, and adaptive capacity) and the pathway of direct and indirect impacts of climate change modulators on health. We collected proxy variables based on the conceptual framework of climate change vulnerability. Data were standardized using the min-max normalization method. We applied the analytic hierarchy process (AHP) weight and aggregated the variables using the non-compensatory multi-criteria approach. To verify the index, sensitivity analysis was conducted by using another aggregation method (geometric transformation method, which was applied to the index of multiple deprivation in the UK) and weight, calculated by the Budget Allocation method. The results showed that it would be possible to identify the vulnerable areas by applying the developed climate change vulnerability assessment index. The climate change vulnerability index could then be used as a valuable tool in setting climate change adaptation policies in the health care sector.

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Long Term Follow Up of Interferon-alpha Treatment in Children with Chronic Hepatitis B (만성 B형간염 환아에 대한 Interferon-alpha 치료결과의 장기 추적관찰)

  • Baek, Seoung-Yon;Eom, Ji-Hyun;Chung, Ki-Sup
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.6 no.2
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    • pp.140-151
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    • 2003
  • Purpose: We tried to evaluate the long term efficacy and positive predictive factors of interferon-alpha treatment in children with chronic hepatitis B. Methods: The study population included 113 children who received interferon therapy between May 1982 and July 2002 (20 years) for chronic hepatitis B in Department of Pediatrics, Yonsei University College of Medicine. Male to female ratio was 2.3 : 1 and the mean age at diagnosis was $11.1{\pm}4.1$ years old. Response to treatment was defined as normalization of alanine aminotransferase (ALT), disappearance of HBeAg and HBV-DNA Eighty two children responded while 32 did not. Interferon-alpha was given intramuscularly for 6 months at a dosage of $3{\times}10^6$ unit, 3 times weekly. In relapsed cases, lamivudine or interferon retreatment was done. Results: Seroconversion rate was 77.0% in terms of HBeAg, 74.3% in terms of HBV-DNA, and 80.5% in terms of ALT normalization after treatment. Seroconversion rate of both HBeAg and HBV-DNA was 72.6%. Analyzed by life table method, the effect of the treatment had been maintained over 10 years after cessation of therapy. Pre-treatment ALT level was the only significant positive predictive factor of response. Eleven cases (13.4%) relapsed, and 2 out of 3 showed response when treated with lamivudine and 1 out of 3 with interferon retreatment. Conclusion: Interferon-alpha showed significant efficacy in the treatment of chronic hepatitis B in our study. Further studies about the effect of interferon therapy on complications of hepatitis such as hepatocarcinoma, cirrhosis are warranted.

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Wavelet Transform-based Face Detection for Real-time Applications (실시간 응용을 위한 웨이블릿 변환 기반의 얼굴 검출)

  • 송해진;고병철;변혜란
    • Journal of KIISE:Software and Applications
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    • v.30 no.9
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    • pp.829-842
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    • 2003
  • In this Paper, we propose the new face detection and tracking method based on template matching for real-time applications such as, teleconference, telecommunication, front stage of surveillance system using face recognition, and video-phone applications. Since the main purpose of paper is to track a face regardless of various environments, we use template-based face tracking method. To generate robust face templates, we apply wavelet transform to the average face image and extract three types of wavelet template from transformed low-resolution average face. However template matching is generally sensitive to the change of illumination conditions, we apply Min-max normalization with histogram equalization according to the variation of intensity. Tracking method is also applied to reduce the computation time and predict precise face candidate region. Finally, facial components are also detected and from the relative distance of two eyes, we estimate the size of facial ellipse.

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.

Development of Measuring Technique for Milk Composition by Using Visible-Near Infrared Spectroscopy (가시광선-근적외선 분광법을 이용한 유성분 측정 기술 개발)

  • Choi, Chang-Hyun;Yun, Hyun-Woong;Kim, Yong-Joo
    • Food Science and Preservation
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    • v.19 no.1
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    • pp.95-103
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    • 2012
  • The objective of this study was to develop models for the predict of the milk properties (fat, protein, SNF, lactose, MUN) of unhomogenized milk using the visible and near-infrared (NIR) spectroscopic technique. A total of 180 milk samples were collected from dairy farms. To determine optimal measurement temperature, the temperatures of the milk samples were kept at three levels ($5^{\circ}C$, $20^{\circ}C$, and $40^{\circ}C$). A spectrophotometer was used to measure the reflectance spectra of the milk samples. Multilinear-regression (MLR) models with stepwise method were developed for the selection of the optimal wavelength. The preprocessing methods were used to minimize the spectroscopic noise, and the partial-least-square (PLS) models were developed to prediction of the milk properties of the unhomogenized milk. The PLS results showed that there was a good correlation between the predicted and measured milk properties of the samples at $40^{\circ}C$ and at 400~2,500 nm. The optimal-wavelength range of fat and protein were 1,600~1,800 nm, and normalization improved the prediction performance. The SNF and lactose were optimized at 1,600~1,900 nm, and the MUN at 600~800 nm. The best preprocessing method for SNF, lactose, and MUN turned out to be smoothing, MSC, and second derivative. The Correlation coefficients between the predicted and measured fat, protein, SNF, lactose, and MUN were 0.98, 0.90, 0.82, 0.75, and 0.61, respectively. The study results indicate that the models can be used to assess milk quality.

Detection Characteristics of Gamma-Irradiated Korean Medicinal Herbs by Using PSL, TL, and ESR (PSL, TL 및 ESR 분석에 의한 감마선 조사 한약재의 검지 특성)

  • Yang, Hee-Sun;Park, Yong-Dae;Jin, Chang-Hyun;Choi, Dae-Seong;Chung, Hyung-Wook;Byun, Myung-Woo;Jeong, Il-Yun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.11
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    • pp.1529-1533
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    • 2008
  • The detection characteristics of gamma-irradiated ($0{\sim}10.0\;kGy$) medicinal herbs (Platycodon grandiflorum, Acanthopanax chiisanensis) were investigated by photostimulated luminescence (PSL), thermoluminescence (TL), and electron spin resonance (ESR). The results of the PSL, a first screening method in comparison with the TL, showed photon counts greater than 5,000 counts/60 s (positive) in the irradiated samples, while the non-irradiated samples yielded photon counts less than 700 counts/60 s (negative). The TL was also applied for the detection method of irradiated medicinal herbs and showed that the non-irradiated sample revealed a glow curve with a low intensity, while the irradiated samples showed a higher intensity. These results were normalized by re-irradiating the mineral grains with a irradiation dose of 1.0 kGy, and a second glow curve was recorded. The ratio of the intensity of the first glow curve ($TL_1$) to that after the normalization dose ($TL_2$) was determined and compared with the recommended threshold values. TL ratio ($TL_1/TL_2$) was below 0.007 for the non-irradiated sample and higher than 0.1 for all irradiated samples (above 1.0 kGy). ESR spectroscopy revealed specific signals (6.065 mT) derived from free radicals in cellulose containing irradiated medicinal herbs. The P. grandiflorum showed clearer signals than A. chiisanensis. From the results of our studies, the PSL, TL, and ESR determinations were found to be suitable for the detection of irradiated medicinal herbs such as P. grandiflorum and A. chiisanensis.

Principal component analysis in C[11]-PIB imaging (주성분분석을 이용한 C[11]-PIB imaging 영상분석)

  • Kim, Nambeom;Shin, Gwi Soon;Ahn, Sung Min
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.1
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    • pp.12-16
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    • 2015
  • Purpose Principal component analysis (PCA) is a method often used in the neuroimagre analysis as a multivariate analysis technique for describing the structure of high dimensional correlation as the structure of lower dimensional space. PCA is a statistical procedure that uses an orthogonal transformation to convert a set of observations of correlated variables into a set of values of linearly independent variables called principal components. In this study, in order to investigate the usefulness of PCA in the brain PET image analysis, we tried to analyze C[11]-PIB PET image as a representative case. Materials and Methods Nineteen subjects were included in this study (normal = 9, AD/MCI = 10). For C[11]-PIB, PET scan were acquired for 20 min starting 40 min after intravenous injection of 9.6 MBq/kg C[11]-PIB. All emission recordings were acquired with the Biograph 6 Hi-Rez (Siemens-CTI, Knoxville, TN) in three-dimensional acquisition mode. Transmission map for attenuation-correction was acquired using the CT emission scans (130 kVp, 240 mA). Standardized uptake values (SUVs) of C[11]-PIB calculated from PET/CT. In normal subjects, 3T MRI T1-weighted images were obtained to create a C[11]-PIB template. Spatial normalization and smoothing were conducted as a pre-processing for PCA using SPM8 and PCA was conducted using Matlab2012b. Results Through the PCA, we obtained linearly uncorrelated independent principal component images. Principal component images obtained through the PCA can simplify the variation of whole C[11]-PIB images into several principal components including the variation of neocortex and white matter and the variation of deep brain structure such as pons. Conclusion PCA is useful to analyze and extract the main pattern of C[11]-PIB image. PCA, as a method of multivariate analysis, might be useful for pattern recognition of neuroimages such as FDG-PET or fMRI as well as C[11]-PIB image.

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Treatment of Pyogenic Arthritis of the Knee Using Drainage Tube Insertion in the Posterior Compartment through the Posterior Transeptal Portal after an Arthroscopic Synovectomy (관절경적 활액막 절제술 후 후격막 삽입구를 통한 배액관의 후방 거치를 이용한 무릎의 화농성 관절염 치료)

  • Kim, Tae Ho;Yu, Chang Eon;Shin, Chung Shik
    • Journal of the Korean Orthopaedic Association
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    • v.54 no.3
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    • pp.269-275
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    • 2019
  • Purpose: This study analyzed the treatment effects of drain insertion in the posteromedial portal after an arthroscopic synovectomy and posterior septum resection for pyogenic arthritis. Materials and Methods: From June 2005 to December 2016, 56 cases (55 patients, 1 case of bilateral knee) were diagnosed with pyogenic arthritis and arthroscopic treatment was performed. Fourteen patients (25.0%) were identified with causative organisms. The average follow-up period was 12.3 months, and the mean age was 67.8 years old. Twenty-four cases were males and 31 cases were females. Kellgrene-Lawrence grade (K-L grade) I was 6 patients, II was 20 patients, III was 11 patients, and IV was 18 patients. Surgery was performed through six portal. The posterior septum was removed and a drainage tube was inserted from the posterior medial side to the posterior side of the joint. The Lysholm score was used after surgery for a functional evaluation. The K-L grade at the time of admission and at the last follow-up were compared for a radiological evaluation. Results: The mean normalization period of the C-reactive protein was 59.8 days (6-164 days). Intravenous antibiotics were used for an average of 37.1 days. The results of the functional evaluation revealed a mean Lysholm score of 64.5 (30-98) in a total of 56 cases. Two reoperations was performed, but the treatment was completed with same method in all patients. The K-L grade was similar at the time of surgery and at the last follow-up (p>0.05). Conclusion: The method of drain insertion in the posteromedial portal after arthroscopic synovectomy and posterior septum resection for pyogenic arthritis is an effective technique that can obtain satisfactory results by inducing proper exudate discharge.

Analysis of Q Values on the Crust of the Kimcheon and Mokpo Regions, South Korea (남한 김천.목포 일대 지각의 Q 값 분석)

  • Do, Ji-Young;Lee, Yoon-Joong;Kyung, Jai-Bok
    • Journal of the Korean earth science society
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    • v.27 no.4
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    • pp.475-485
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    • 2006
  • The physical properties of the central and southwestern crust of South Korea were estimated by comparing values of ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ in the Kimcheon and Mokpo areas. In order to get ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ values, seismic data were collected from two stations of the KIGAM network (KMC and MUN) and four stations of the KMA network (CPN, KUC, MOP, and WAN). An extended coda-normalization method was applied to these data. Estimates of ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ show variations depending on frequency. As frequencies vary from 3 Hz to 24 Hz, the estimates decrease from $(1.4{\pm}3.9){\times}10^{-3}\;to\;(2.3{\pm}3.5){\times}10^{-4}\;for\;{Q_P}^{-1}\;and\;(1.8{\pm}1.3){\times}10^{-3}\;to\;(1.9{\pm}1.5){\times}10^{-4}\;for\;{Q_S}^{-1}$ in central South Korea, and $(5.9{\pm}4.8){\times}10^{-3}\;to\;(2.2{\pm}3.8){\times}10^{-4}\;for\;{Q_P}^{-1}\;and\;(0.5{\pm}2.8){\times}10^{-3}\;to\;(1.8{\pm}1.6){\times}10^{-4}\;for\;{Q_S}^{-1}$ in southwestern South Korea. According that a frequency-dependent power law is applied to the data, the best fits of ${Q_P}^{-1}\;and\;{Q_S}^{-1}\;are\;0.003f^{-0.49}\;and\;0.005f^{-1.03}$ in central South Korea, and $0.026f^{-1.47}$ and $0.001f^{-0.49}$ in southwestern South Korea, respectively. These values almost correspond to those of seismically stable regions although ${Q_P}^{-1}$ values of southwestern South Korea are a little high due to lack of data used.

Quantification of Brain Images Using Korean Standard Templates and Structural and Cytoarchitectonic Probabilistic Maps (한국인 뇌 표준판과 해부학적 및 세포구축학적 확률뇌지도를 이용한 뇌영상 정량화)

  • Lee, Jae-Sung;Lee, Dong-Soo;Kim, Yu-Kyeong;Kim, Jin-Su;Lee, Jong-Min;Koo, Bang-Bon;Kim, Jae-Jin;Kwon, Jun-Soo;Yoo, Tae-Woo;Chang, Ki-Hyun;Kim, Sun-I.;Kang, Hye-Jin;Kang, Eun-Joo
    • The Korean Journal of Nuclear Medicine
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    • v.38 no.3
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    • pp.241-252
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    • 2004
  • Purpose: Population based structural and functional maps of the brain provide effective tools for the analysis and interpretation of complex and individually variable brain data. Brain MRI and PET standard templates and statistical probabilistic maps based on image data of Korean normal volunteers have been developed and probabilistic maps based on cytoarchitectonic data have been introduced. A quantification method using these data was developed for the objective assessment of regional intensity in the brain images. Materials and Methods: Age, gender and ethnic specific anatomical and functional brain templates based on MR and PET images of Korean normal volunteers were developed. Korean structural probabilistic maps for 89 brain regions and cytoarchitectonic probabilistic maps for 13 Brodmann areas were transformed onto the standard templates. Brain FDG PET and SPGR MR images of normal volunteers were spatially normalized onto the template of each modality and gender. Regional uptake of radiotracers in PET and gray matter concentration in MR images were then quantified by averaging (or summing) regional intensities weighted using the probabilistic maps of brain regions. Regionally specific effects of aging on glucose metabolism in cingulate cortex were also examined. Results: Quantification program could generate quantification results for single spatially normalized images per 20 seconds. Glucose metabolism change in cingulate gyrus was regionally specific: ratios of glucose metabolism in the rostral anterior cingulate vs. posterior cingulate and the caudal anterior cingulate vs. posterior cingulate were significantly decreased as the age increased. 'Rostral anterior'/'posterior' was decreased by 3.1% per decade of age ($P<10^{-11}$, r=0.81) and 'caudal anterior'/'posterior' was decreased by 1.7% ($P<10^{-8}$, r=0.72). Conclusion: Ethnic specific standard templates and probabilistic maps and quantification program developed in this study will be useful for the analysis of brain image of Korean people since the difference in shape of the hemispheres and the sulcal pattern of brain relative to age, gender, races, and diseases cannot be fully overcome by the nonlinear spatial normalization techniques.