• Title/Summary/Keyword: sensitivity study

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Studies on the Anodic Oxidation Behavior of Methanol and L-Ascorbic Acid by Using Glassy Carbon Electrodes Modified with Inorganic-Metal Polymeric Films (무기 금속 고분자 막을 도포시킨 유리질 탄소전극을 이용한 메탄올과 L-ascorbic acid의 양극 산화 거동에 관한 연구)

  • Yoo, Kwang-Sik;Woo, Sang-Beom
    • Analytical Science and Technology
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    • v.11 no.5
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    • pp.347-352
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    • 1998
  • A study was carried out on the elelctrochemical characteristics of chemically modified electrodes (CMEs) by cyclic voltammetry. Fabrication of CMEs was made by coating with mixed valence (mv) inorganic-metal polymeric films on the glassy carbon electrode surface by potential cycling. Anodic oxidation behavior of methanol and L-ascorbic acid was studied by using CMEs working electrode. Deposition of films such as mv ruthenium oxo/ruthenium cyanide film (mv Ru-O/CN-Ru), mv ruthenium oxo/ferrocyanide film (mv Ru-O/$Fe(CN)_6$), and mv ruthenium oxo/ruthenium cyanide/Rhodium film (mv Ru-O/CN-Ru/Rh) was obtained to coat by scan rate of 50 mV/sec within the specified potential range (-0.5V ~ +1.2V). Film thickness was controlled by the repeat of the potential cycling. Anodic oxidation behavior of methanol was as follow. Calibration graph by using mv Ru-O/CN-Ru film showed linearly from 10 mM to 80 mM MeOH with slope factor of $-7.552{\mu}A/cm^2$. Although slope factor by using mv Ru-O/$Fe(CN)_6$ film was $-5.13{\mu}A/cm^2$, yet linear range of calibration graph could be extended from 10 mM to 100 mM MeOH. Anodic oxidation behavior of L-ascorbic acid was studied by mv Ru-O/CN-Ru film on the glassy carbon electrode and the glassy carbon electrode with Rh film, Glassy carbon electrode modified with Ru polymeric film was showed better sensitivity than the Rh-glassy carbon modified electrode (mv Ru-O/CN-Ru/Rh). Calibration graph was linear from 0.1 mM to 5 mM L-ascorbic acid by using glassy carbon electrode modified with Ru polymeric film. Solpe factor and relative coefficient are $-84.78{\mu}A/mM$ and 0.998, respectively.

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Development of an Eating Habit Checklist for Screening Elementary School Children at High Risk of Energy Overintake (초등학생의 에너지 과잉섭취 위험 진단을 위한 식습관평가표 개발)

  • Yon, Mi-Yong;Hyun, Tai-Sun
    • Journal of Nutrition and Health
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    • v.41 no.5
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    • pp.414-427
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    • 2008
  • The purpose of the study was to develop an eating habit checklist for screening elementary school children at high risk of energy overintake. Dietary habits, food intake, anthropometric data were collected from 142 children (80 boys and 62 girls) in the 4th to 6th grades of elementary schools. Energy intake, fat intake, and percentage of Estimated Energy Requirement (%EER) were used as indices to detect the risk of energy overintake of the children. Pearson correlation coefficients were calculated between dietary habit scores and energy overintake indices in order to select questions included in the checklist. TV watching during the meal, meal speed, meal amount, overintake frequency, eatingout frequency, snack frequency, frequency of eating Ramyun or fast foods showed significant correlations with energy overintake indices. Stepwise regression analysis was performed to give each item a different weight by prediction strength. To determine the cut-off point of the test score, sensitivity, specificity, and positive predictive values were calculated. The 7-item checklist with test results from 0 to 13 points was developed, and those with equal or higher than 5 points were diagnosed as a risk group of energy overintake. Among our subjects 13.4% was diagnosed as the risk group. Mean energy intake of the subjects in the risk group and the normal group were 2,650 kcal and 1,640 kcal, respectively. However, there were no significant differences of Index of Nutritional Quality (INQ) of the other nutrients except eating fiber between the risk group and the normal group. This checklist will provide a useful screening tool to identify children at high risk of energy overintake.

Correlations between Neurologic and Psychiatric Symptoms in Acute Stroke Patients (급성기 뇌졸중 환자에서 신경 및 정신 증상간 상호관계)

  • Kang, Hee-Ju;Bae, Kyung-Yeol;Kim, Sung-Wan;Kim, Jae-Min;Shin, Il-Seon;Park, Man-Seok;Cho, Ki-Hyun;Yoon, Jin-Sang
    • Korean Journal of Psychosomatic Medicine
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    • v.20 no.2
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    • pp.98-104
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    • 2012
  • Objectives : This study aimed to investigate the correlations between neurological and psychiatric symptoms at two weeks after stroke. Methods : For 412 stroke patients, stroke severity was evaluated by the National Institutes of Health Stroke Scale(NIHSS), disability by the Barthel Index(BI) and modified Rankin Scale(mRS), cognitive function by the Korean Mini-Mental State Examination(K-MMSE), and muscle power by grip strength. Psychiatric symptoms were assessed by Symptom check list-90-Revision(SCL-90-R), consisted of nine symptom domains : Somatization, Obsessive-compulsive, Interpersonal sensitivity, Depression, Anxiety, Hostility, Phobic anxiety, Paranoid ideation, Psychoticism, and Additional items. The correlations between the neurological and psychiatric symptoms were investigated at the time of admission and before discharge(i.e. before and after treatment). Results : At the time of admission, NIHSS score was associated with scores on Phobic anxiety and Additional items ; and scores on BI and mRS were associated with Depression, Phobic anxiety and Additional items. At the time of discharge, NIHSS score was associated with scores on Somatization, Depression, Phobic anxiety, and Additional items ; scores on BI and mRS were associated with scores on Depression, Phobic anxiety and Additional items ; MMSE score was associated with Obsessive-compulsive, Depression, Phobic anxiety, and Additional items ; and grip strength was associated with Somatization, Depression, Anxiety and Additional items. Conclusions : More severe neurological symptoms were associated with higher psychiatric morbidity particularly in depression, phobic anxiety, sleep and appetite disturbance at acute stage of stroke. More intensive psychiatric care and intervention are needed for the high risk group.

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Relationship between △FVC(% fall in FVC at the PC20 Dose of Methacholine) and Serum Eosinophil Cationic Protein(ECP) in 6-8 Year Old Children with Asthma (6-8세 천식 환아에서 △FVC(메타콜린 PC20에서의 강제폐활량의 감소율)와 혈청 호산구 양이온 단백의 관계)

  • Suh, Dong In;Yu, Jinho;Yoo Young;Kim, Do Kyun;Kang, Hee;Koh, Young Yull
    • Clinical and Experimental Pediatrics
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    • v.48 no.10
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    • pp.1126-1131
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    • 2005
  • Purpose : Bronchial hyperresponsiveness(BHR) is considered a hallmark of asthma. Increased levels of eosinophil cationic protein(ECP) have been identified in serum of asthma patients. Several studies have examined the relationship between serum ECP and bronchial responsiveness, expressed as methacholine $PC_{20}$ in asthmatic patients, with conflicting results. The aims of this study were to examine the relationship between serum ECP and ${\Delta}FVC$, another index of bronchial responsiveness, which reflects increased maximal airway response. Methods : Six to 8-year-old children with asthma(n=109) underwent methacholine bronchoprovocation testing. The $PC_{20}$ dose of methacholine and ${\Delta}FVC$ were calculated for each individual from the methacholine dose response curves. Serum ECP levels and blood total eosinophil counts were also measured. Results : Serum ECP correlated with ${\Delta}FVC$(r=0.217, P=0.023), as well as $PC_{20}$(r=-0.208, P=0.030). However, blood eosinophil counts failed to show any correlations with ${\Delta}FVC$(r=0.085, P=0.378) or $PC_{20}$(r=-0.148, P=0.125). ${\Delta}FVC$ did not correlate with $PC_{20}$(r=-0.079, P=0.417). Conclusion : Blood eosinophil activation is associated with both components of BHR including increased sensitivity and increased maximal response in 6-8 year old children with asthma.

Usefulness of serum procalcitonin test for the diagnosis of upper urinary tract infection in children (소아 상부 요로감염의 진단을 위한 혈청 procalcitonin 검사의 유용성)

  • Kim, Dong Wook;Chung, Ju Young;Koo, Ja Wook;Kim, Sang Woo;Han, Tae Hee
    • Clinical and Experimental Pediatrics
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    • v.49 no.1
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    • pp.87-92
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    • 2006
  • Purpose : It is difficult to make a distinction between lower urinary tract infection(UTI) and acute pyelonephritis(APN) during the acute phase of febrile UTI due to nonspecific clinical symptoms and laboratory findings, especially among young children. We measured the serum procalcitonin(PCT) in children with UTI to distinguish between acute pyelonephritis and lower UTI, and to determine the accuracy of PCT measurement compared with other inflammatory markers. Methods : Serum samples were taken from children who admitted with unexplained fever or were suspected of having UTI. 51 children(mean $12.2{\pm}11.4$ months) were enrolled in this study. Leukocyte counts, erythrocyte sedimentation rates(ESR) and C-reactive protein(CRP) were also measured. Renal parenchymal involvement was assessed by $^{99m}Tc$ DMSA scintigraphy in the first 7 days after admission. PCT was measured by immunoluminometric assay. Results : PCT values were significantly correlated with the presence of renal defects in children with UTI(n=16)($5.06{\pm}12.97{\mu}g/L$, P<0.05). However, PCT values were not significantly different between children with UTI without renal damage(n=18) and children without UTI(n=17). Using a cutoff of $0.5{\mu}g/L$ for PCT and 20 mm/hr for ESR, 20 mg/L for CRP, sensitivity and specificity in distinguishing between UTI with and without renal involvement were 81.3 percent and 88.9 percent for PCT 87.5 percent and 72.2 percent for ESR, and 87.5 percent and 55.6 percent for CRP, respectively. Positive and negative predictive values were 86.7 percent and 84.2 percent for PCT and 60.9 percent and 81.8 percent for CRP, respectively. Conclusion : In febrile UTI, PCT values were more specific than CRP, ESR and leukocyte count for the identification of patients who might develop renal defects.

The Etiologic Diseases and Diagnostic Usefulness of Color Doppler Ultrasonography in Children with Chronic Coughs (소아 만성 기침의 원인 질환과 컬러 도플러 초음파 검사의 진단적 유용성)

  • Park, Sun Young;Lee, Joon Sung
    • Clinical and Experimental Pediatrics
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    • v.45 no.4
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    • pp.489-497
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    • 2002
  • Purpose : The objectives of this study were to investigate the causes of chronic cough and to establish the appropriate diagnostic approach to chronic cough in children. Methods : One hundred and thirty two cases of chronic cough were prospectively evaluated. They visitors to pediatric chronic cough clinics at Kang-nam saint Mary's Hospital of Catholic University from August 2000 to July 2001 for 12 months. Careful history taking by questionnaire, physical examination, radiologic studies of chest and sinus, hematologic and immunologic studies, allergic skin tests, and methacholine challenge tests were performed. Color doppler(CD) ultrasonography were performed and compared with simultaneous 24 Hr. esophageal pH monitoring to diagnose gastroesophageal reflux disease(GERD). Results : Age distributions were demonstrated that nine in infants, 82 in early childhood, 38 in late childhood, and three in adolescence. Common causes of chronic cough were bronchial asthma in 40 cases, chronic sinusitis in 22 cases, GERD in seven cases, bronchial asthma combined with sinusitis in 28 cases, bronchial asthma combined with GERD in 14 cases, psychogenic cough in two. cases, foreign body in one case, chronic bronchitis in one case, and bronchiolitis in one case. Comparing with 24 Hr. pH monitoring, sensitivity, specificity, positive predictive value and negative predictive values of CD ultrasonography were 88%, 69%, 85 %, and 73% respectively. Conclusion : The most common causes of chronic cough in children were bronchial asthma, sinusitis and GERD in order. We suggest that CD ultrasonography can be used as a good, convenient screening method for patients with suspected GERD in outpatient settings.

Comparison of Acute Toxicity of Molinate on Two Aquatic Insects, Chironomus riparius and Cloeon dipterum in Different Larval Stages (2종의 수서곤충 Chironomus riparius와 Cloeon dipterum의 유충 성장단계별 molinate 급성독성 비교)

  • Kim, Byung-Seok;Park, Yoen-Ki;Hong, Soon-Sung;Yang, Yu-Jung;Park, Kyung-Hun;Joeng, Mi-Hye;Kim, Se-Ri;Park, Kyeong-Hun;Yeh, Wan-Hae;Kim, Doo-Ho;Hong, Moo-Ki;Ahn, Young-Joon;Shin, Jin-Sup
    • The Korean Journal of Pesticide Science
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    • v.13 no.4
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    • pp.256-261
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    • 2009
  • Molinate (S-ethyl hexahydro-1H-azepine-1-carbothioate), a selective, preemergence thiocarbamate herbicide used for grass weed control in rice fields, is being most widely used in Korea. This study was conducted to assess the comparative toxicity of molinate on two aquatic insects, Chironomus riparius and Cloeon dipterum in four larval stages. First-instar larvae of C. riparius appeared to be the most sensitive to acute exposure of molinate with a 48-h $EC_{50}$ of 7.8 mg/L, followed by third instar (48-h $EC_{50}\;=\;22.9\;mg/L$), second instar (48-h $EC_{50}\;=\;25.0\;mg/L$) and fourth instar (48-h $EC_{50}$ > 50 mg/L) larvae. Also, the sensitivity of the larvae of C. dipterum was presented as the same manner of the larvae of C. riparius. The youngest group of larvae of C. riparius appeared to be the most sensitive to molinate, with 96-h $EC_{50}$ values ranged from 14.3 to 24.1 mg/L. The authors assume that the young instar lavae of aquatic insects, Chironomus riparius and Cloeon dipterum are more sensitive to molinate. Also, the authors propose that Mayfly, Cloeon dipterum is well suited as a bioassay organism because it is one of the most vulnerable aquatic insects inhabiting agricultural ecosystem in Korea.

The Effect of Mean Brightness and Contrast of Digital Image on Detection of Watermark Noise (워터 마크 잡음 탐지에 미치는 디지털 영상의 밝기와 대비의 효과)

  • Kham Keetaek;Moon Ho-Seok;Yoo Hun-Woo;Chung Chan-Sup
    • Korean Journal of Cognitive Science
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    • v.16 no.4
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    • pp.305-322
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    • 2005
  • Watermarking is a widely employed method tn protecting copyright of a digital image, the owner's unique image is embedded into the original image. Strengthened level of watermark insertion would help enhance its resilience in the process of extraction even from various distortions of transformation on the image size or resolution. However, its level, at the same time, should be moderated enough not to reach human visibility. Finding a balance between these two is crucial in watermarking. For the algorithm for watermarking, the predefined strength of a watermark, computed from the physical difference between the original and embedded images, is applied to all images uniformal. The mean brightness or contrast of the surrounding images, other than the absolute brightness of an object, could affect human sensitivity for object detection. In the present study, we examined whether the detectability for watermark noise might be attired by image statistics: mean brightness and contrast of the image. As the first step to examine their effect, we made rune fundamental images with varied brightness and control of the original image. For each fundamental image, detectability for watermark noise was measured. The results showed that the strength ot watermark node for detection increased as tile brightness and contrast of the fundamental image were increased. We have fitted the data to a regression line which can be used to estimate the strength of watermark of a given image with a certain brightness and contrast. Although we need to take other required factors into consideration in directly applying this formula to actual watermarking algorithm, an adaptive watermarking algorithm could be built on this formula with image statistics, such as brightness and contrast.

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Development of an Eating Habit Checklist for Screening Elementary School Children at Risk of Inadequate Micronutrient Intake (초등학생의 미량영양소 섭취부족 위험 진단을 위한 간이 식습관평가표 개발)

  • Yon, Mi-Yong;Hyun, Tai-Sun
    • Journal of Nutrition and Health
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    • v.42 no.1
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    • pp.38-47
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    • 2009
  • The purpose of the study was to develop an eating habit checklist for screening elementary school children at risk of inadequate micronutrient intake. Eating habits, food intake, and anthropometric data were collected from 142 children (80 boys and 62 girls) in the $4^{th}$ to $6^{th}$ grades of elementary schools. Percentage of Recommended Intakes (RI) and Mean Adequacy Ratio (MAR) of six micronutrients; vitamin A, riboflavin, vitamin C, calcium, iron, zinc, and the number of nutrients the children consumed below EAR among the six nutrients were used as indices to detect the risk of inadequate micronutrient intake. Pearson correlation coefficients were calculated between eating habit scores and inadequate micronutrient intake indices in order to select questions included in the checklist. Meal frequency, enough time for breakfast, regularity of dinner, appetite, eating frequencies of Kimchi, milk, fruits and beans showed significant correlations with indices of inadequate micronutrient intake. Stepwise regression analysis was performed to give each item a different weight by prediction strength. To determine the cut-off point of the test score, sensitivity, specificity, and positive predictive values were calculated. The 8-item checklist with test results from 0 to 12 points was developed, and those with equal or higher than 6 points were diagnosed as high-risk group of inadequate micronutrient intake, and those with 4 or 5 points were diagnosed as moderate-risk group. Among our subjects 14.1% was diagnosed as high-risk group, and 30.3% as moderate-risk group. The proportions of the subjects who consumed below EAR of all micronutrients but vitamin C were highest in the high-risk group, and there were significant differences in the proportions of the subjects with intake below EAR of all micronutrients except vitamin B6 among the three groups. This checklist will provide a useful screening tool to identify children at risk of inadequate micronutrient intake.

Numerical Simulation of the Formation of Oxygen Deficient Water-masses in Jinhae Bay (진해만의 빈산소 수괴 형성에 관한 수치실험)

  • CHOI Woo-Jeung;PARK Chung-Kill;LEE Suk-Mo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.4
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    • pp.413-433
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    • 1994
  • Jinhae Bay once was a productive area of fisheries. It is, however, now notorious for its red tides; and oxygen deficient water-masses extensively develop at present in summer. Therefore the shellfish production of the bay has been decreasing and mass mortality often occurs. Under these circumstances, the three-dimensional numerical hydrodynamic and the material cycle models, which were developed by the Institute for Resources and Environment of Japan, were applied to analyze the processes affecting the oxygen depletion and also to evaluate the environment capacity for the reception of pollutant loads without dissolved oxygen depletion. In field surveys, oxygen deficient water-masses were formed with concentrations of below 2.0mg/l at the bottom layer in Masan Bay and the western part of Jinhae Bay during the summer. Current directions, computed by the $M_2$ constituent, were mainly toward the western part of Jinhae Bay during flood flows and in opposite directions during ebb flows. Tidal currents velocities during the ebb tide were stronger than that of the flood tide. The comparision between the simulated and observed tidal ellipses showed fairly good agreement. The residual currents, which were obtained by averaging the simulated tidal currents over 1 tidal cycle, showed the presence of counterclockwise eddies in the central part of Jinhae Bay. Density driven currents were generated southward at surface and northward at the bottom in Masan Bay and Jindong Bay, where the fresh water of rivers entered. The material cycle model was calibrated with the data surveyed in the field of the study area from June to July, 1992. The calibrated results are in fairly good agreement with measured values within relative error of $28\%$. The simulated dissolved oxygen distributions of bottom layer were relatively high with the concentration of $6.0{\sim}8.0mg/l$ at the boundaries, but an oxygen deficient water-masses were formed within the concentration of 2.0mg/l at the inner part of Masan Bay and the western part of Jinhae Bay. The results of sensitivity analyses showed that sediment oxygen demand(SOD) was one of the most important influence on the formation of oxygen depletion. Therefore, to control the oxygen deficient water-masses and to conserve the coastal environment, it is an effective method to reduce the SOD by improving the polluted sediment. As the results of simulations, in Masan Bay, oxygen deficient water-masses recovered to 5.0mg/l when the $50\%$ reduction in input COD loads from Masan basin and $70\%$ reduction in SOD was conducted. In the western part of Jinhae Bay, oxygen deficient water-masses recovered to 5.0mg/l when the $95\%$ reduction in SOD and $90\%$ reduction in culturing ground fecal loads was conducted.

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