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A Study on Serum Lipid Levels of Elderly People in Wando Area -Based on Dietary Behaviors- (완도지역 중·장년층의 혈중지질 수준에 관한 연구 -식행동을 중심으로-)

  • Kim, Eun-Ju;Cha, Bok-Kyeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.9
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    • pp.1148-1160
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    • 2007
  • This study was performed to document the association between eating behaviors and major risk factors for cardiovascular diseases. Those who stated that they ate a daily breakfast for male and female were 88.6% and 96.0%, $1{\sim}2$ times a week were 9.1% and 2.0%, $3{\sim}4$ times a week were 2.3% and 2.0%, respectively. Those who stated that they were overeating of $0{\sim}1$ time a week for man and female were 80.7% and 89.9%, overeating of $2{\sim}3$ times a week were 19.3% and 10.1%, respectively. Those who said that they were regular of meal time for man and female were 38.6%, and 37.4%, sometimes irregular of meal time were 14.8% and 19.2%, irregular of meal time were 46.6% and 43.4%, respectively. Those who said that they were light of eating volume for man and female were 20.5% and 25.3%, moderate of eating volume were 69.3% and 61.6%, heavy of eating volume were 10.2% and 13.1%, respectively. Those who said that they were very fast of eating speed for man and female were 15.9% and 8.1%, fast of eating speed were 51.1% and 34.3%, moderate of eating speed were 4.5% and 20.2%, slow of eating speed were 17.0% and 14.1%, and very slow of eating speed were 11.4% and 23.2%, respectively. Higher frequency of breakfast a week resulted in higher serum total cholesterol and blood sugar for the daily eating group for both genders with women having high LDL-cholesterol and HDL-cholesterol. Both group had high HDL-cholesterol and low blood sugar with less number of overeating, with men having low triglyceride and LDL-cholesterol. With regular meal, both group had low triglyceride, total-cholesterol, atherogenic index, and blood sugar with women having low LDL-cholesterol. For both groups, the triglyceride, total-cholesterol, LDL-cholesterol, atherogenic index, and blood sugar had higher figures for overeating, with men having low HDL-cholesterol and women having high HDL-cholesterol. This study revealed that less number of overeating, regular mealtime, and less volume of food intake are effective in preventing and treating for the cardiovascular diseases.

A Study of Students' Knowledge Level of Dental Health Care (초중등학생의 구강보건관리에 대한 인식도 조사)

  • Kim, Kyo-Woong;Nam, Chul-Hyun
    • Journal of the Korean Society of School Health
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    • v.13 no.2
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    • pp.295-317
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    • 2000
  • This study was conducted to prevent oral disease of primary school, middle school, and high school students, providing basic data for the development of oral health education programs. Data were collected from 898 primary school, middle school, and high school students from March 2, 1999 to May 31, 1999. The results of this study are summarized as follows; 1) The subjects of this study were primary school students(32.6%), middle school students(33.0%), and high school students(34.4%). Boy students were slightly more prevalent than girl students. That is, primary school boys were 56.3%, middle school boys were 53.2%, and high school boys were 52.6%. 2) According to the self-judgement of oral health, primary school students were better than middle/high school students and boy students were better than girl students, 63.5% of primary school students and 57.8% of middle/high school students brushed their teeth once or twice a day. 3) 76.3% of middle/high school students and 63.5% of primary school students experienced dental caries. Girl students were higher than boy students in experiencing dental caries, 35.9% of primary school students and 27.6% of middle/high school students experienced periodontal disease. 4) 22.9% of primary school students and 7.9% of middle/high school students received oral examinations periodically. Girl students showed a higher rate than boy students in primary school, while boy students showed a higher rate than girl students in middle/high school. 5) Explaining to the reasons for reluctant visits to dental hospitals and clinics, 'no time to go' was highest(22.9% of primary school students; 27.4% of middle/high school students) and the rate of 'feeling scared' was second highest. Middle/high school students were more reluctant to visit dental hospitals and clinics than primary school students. In case of problematic symptoms in the mouth, the rate of 'feeling painful or cold in teeth when eating cold or hot foods' was highest, 71.3% of primary school students was concerned about oral health, while 68.6% of middle/high school students was concerned about it. 6) In gathering to the sources of information on oral health, the rate of medical institutions was highest(30.0%) in primary school students, while the rate of family members or persons around them was highest in middle/high school students. 7) 54.9% of primary school students received oral health education, while 13.1% of middle/high school students received it. Only 4.7% of middle school and high school girls received it. In relation to dental health education, the rate of 'possibility of prevention of oral caries or disease of the gum' was highest. 79.5% of primary school students and 80.3% of middle school students answered that they would attend oral health education. 8) 60.4% of primary school students and 60.2% of middle/high school students think the purpose of oral health is to prevent dental caries and disease of the gums. In preventing dental caries, 78.8% of primary school students and 71.8% of middle school students thought that periodical oral examination was effective, 88.4% of primary school students and 88.8% of middle/high school thought that brushing one's teeth was effective and 64.1% of primary school students and 50.7% of middle school students thought that the use of toothpaste containing fluoride was effective. In preventing periodontal disease, 91.1% of primary school students and 90.2% of middle/high school students thought that brushing one's teeth was effective, while 72.4% of primary school students and 70.3% of middle/high school students thought that teeth cleaning was effective. 9) 16.0% of middle school students and 12.7% of high school students thought that their oral health condition was healthy. According to individual experiences in dental treatment, the rate of experience of middle school students was higher than that of high school students, 12.7% of middle school students received oral examinations periodically, while only 3.3% of high school students did so. 10) In cases of 'having no problematic symptoms in the mouth' and 'concerns about oral health', the rate of middle school students was higher than that of high school students. In gathering obtaining information on oral health, the rate of obtaining it through broadcast media including TV, Radio, etc. was highest in middle school students, while the rate of obtaining it through family members or persons around them was highest in high school students. 11) 81.7% of middle school students have not received oral health education. In case of girl students, 97.3% have not received it in high school students. 85.6% of middle school students and 151.2% of high school students think that oral health education is necessary. 12) According to the knowledge level of oral health, the point of high school students($26.33{\pm}2.33$) was similar to the point of high school students($26.23{\pm}2.30$). It appeared that the point of primary school students was highest($26.35{\pm}2.50$) The more concerned about oral health the students were the higher the knowledge level of oral health was. In conclusion, the middle/high school students' knowledge level of oral health was lower than primary school students. The rate of middle/high School students' experience in oral health education was too low. Therefore, it is necessary to intensify oral health education for middle/high school students. Especially, the necessity of oral health education to girl students is strongly recommended. Developing an oral health education program for primary school, middle school, and high school students, related public authority and organizations, teachers; and dentists must actively make efforts together in order to maintain healthy teeth through having students prevent dental caries and periodontal disease.

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Methacholine Responsiveness of Bronchial and Extrathoracic Airway in Patients with Chronic Cough (만성 기침 환자에서 기관지와 흉곽외 기도의 Methacholine 유발검사의 의의)

  • Shim, Jae-Jeong;Kim, Je-Hyeong;Lee, Sung-Yong;Kwan, Young-Hwan;Lee, So-Ra;Lee,, Sang-Yeub;Lee, Sang-Hwa;Suh, Jung-Kyung;Cho, Jae-Youn;In, Kwang-Ho;Yoo, Se-Hwa;Kang, Kyung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.44 no.4
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    • pp.853-860
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    • 1997
  • Background : Chronic cough, defined as a cough persisting for three weeks or longer, is a common symptom for which outpatient care is sought. The most common etiologies of chronic cough are postnasal drip, asthma, and gastroesophageal reflux. Methacholine challenge is a useful diagnostic study in the evaulation of chronic cough, particularly useful in chronic cough patients with asthmatic symptom. Patients with chronic cough may have dysfunction of bronchial and extrathoracic airways. To evaluate if dysfunction of the bronchial and extrathoracic airways causes chronic cough, we assessed bronchial (BHR) and extrathoracic airway (EAHR) responsiveness to inhaled methacholine in patients with chronic cough. Method : 111 patients with chronic cough were enrolled in our study. Enrolled patients had no recorded diagnosis of asthma, bronchopulmonary disease, hypertension, heart disease or systemic disease and no current treatment with bronchodilator or corticosteroid. Enrolled patients consisted of 46 patients with cough alone, 24 patients with wheeze, 22 patients with dyspnea, 19 patients with wheeze and dyspnea. The inhaled methacholine concentrations causing a 20% fall in forced expiratory volume in 1s($PC_{20}FEV_1$) and 25% fall in maximal mid-inspiratory flow ($PC_{25}MIF_{50}$) were used as bronchial and extra thoracic hyperresponsiveness. Results : There were four response patterns to methacholine challenge study : BHR in 27 patients, EAHR in 16 patients, combined BHR and EAHR in 8 patients, and no hyperresponsiveness in 60 patients. In patients with cough alone, there were BHR in 3 patients, EAHR in 9 patients, and combined BHR and EAHR in 2 patients. In patients with wheeze and/or dyspnea, there were BHR in 24 patients, EAHR in 7 patients, and BHR and EAHR in 6 patients. Compared with patients with wheeze and/or dyspnea, patients with cough alone had more common EAHR than BHR. In patients with wheeze and/or dyspnea, BHR was more common than EAHR. Conclusion : These results show that among patients with hyperresponsiveness to methacholine, those with dyspnea and/or wheezing had mainly bronchial hyperresponsiveness, whereas those with chronic cough alone had mainly extrathoracic airway hyperresponsiveness.

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Tc-99m ECD Brain SPECT in MELAS Syndrome and Mitochondrial Myopathy: Comparison with MR findings (MELAS 증후군과 미토콘드리아 근육병에서의 Tc-99m ECD 뇌단일 광전자방출 전산화단층촬영 소견: 자기공명영상과의 비교)

  • Park, Sang-Joon;Ryu, Young-Hoon;Jeon, Tae-Joo;Kim, Jai-Keun;Nam, Ji-Eun;Yoon, Pyeong-Ho;Yoon, Choon-Sik;Lee, Jong-Doo
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.6
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    • pp.490-496
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    • 1998
  • Purpose: We evaluated brain perfusion SPECT findings of MELAS syndrome and mitochondrial myopathy in correlation with MR imaging in search of specific imaging features. Materials and Methods: Subjects were five patients (four females and one male; age range, 1 to 25 year) who presented with repeated stroke-like episodes, seizures or developmental delay or asymptomatic but had elevated lactic acid in CSF and serum. Conventional non-contrast MR imaging and Tc-99m-ethyl cysteinate dimer (ECD) brain perfusion SPECT were Performed and imaging features were analyzed. Results: MRI demonstrated increased T2 signal intensities in the affected areas of gray and white matters mainly in the parietal (4/5) and occipital lobes (4/5) and in the basal ganglia (1/5), which were not restricted to a specific vascular territory. SPECT demonstrated decreased perfusion in the corresponding regions of MRI lesions. In addition, there were perfusion defects in parietal (1 patient), temporal (2), and frontal (1) lobes and basal ganglia (1) and thalami (2). In a patient with mitochondrial myopathy who had normal MRI, decreased perfusion was noted in left parietal area and bilateral thalami. Conclusion: Tc-99m ECD SPECT imaging in patients with MELAS syndrome and mitochondrial myopathy showed hypoperfusion of parieto-occipital cortex, basal ganglia, thalamus and temporal cortex, which were not restricted to a specific vascular territory. There were no specific imaging features on SPECT. The significance of abnormal perfusion on SPECT without corresponding MR abnormalities needs to be evaluated further in larger number of patients.

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SNR and ADC Changes at Increasing b Values among Patients with Lumbar Vertebral Compression Fracture on 1.5T MR Diffusion Weighted Images (1.5T MR 기기를 이용한 확산강조영상에서 b Value의 증가에 따른 요추압박골절 환자의 신호대 잡음비와 현성 확산 계수의 변화)

  • Cho, Jae-Hwan;Park, Cheol-Soo;Lee, Sun-Yeob;Kim, Bo-Hui
    • Progress in Medical Physics
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    • v.21 no.1
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    • pp.52-59
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    • 2010
  • To examine among patients with vertebral compression fracture the extent to which signal-to-noise ratio (SNR) and Apparent Diffusion Coefficient (ADC) values at the lumbar vertebral compression fracture site vary on diffusion-weighted MR images according to varying b values on the 1.5T MR device. Diffusion-weighted MR images of 30 patients with compression fracture due to chronic osteoporosis who underwent vertebral MRI from Jan. 2008 to Nov. 2009 were respectively obtained using a 1.5-T MR scanner with the b values increased from 400, 600, 800, 1,000 to $1,200\;s/mm^2$. For diffusion-weighted MR images with different b values, the signal-to-noise ratio (SNR) was assessed at three sites: the site of compression fracture of the lumbar vertebral body at L1 to L5, and both the upper and lower discs of the said fracture site, while for ADC map images with different b values, the SNR and ADC were respectively assessed at those three sites. As a quantitative analysis, diffusion-weighted MR images and ADC map images with b value of $400\;s/mm^2$ (the base b values) were respectively compared with the corresponding images with each different b value. As far as qualitative analysis is concerned, for both diffusion-weighted MR and ADC map images with b value of $400\;s/mm^2$, the extent to which signal intensity values obtained at the site of compression fracture of the lumbar vertebral body at L1 to L5 vary according to the increasing b values were examined. The quantitative analysis found that for both diffusion-weighted MR and ADC map images, as the b values increased, the SNR were relatively lowered at all the three sites, compared to the base b value. Also, it was found that as the b values increased, ADC valueswere relatively lowered at all the three sites on ADC map images. On the other hand, the qualitative analysis found that as the b values increased to more than $400\;s/mm^2$, the signal intensity gradually decreased at all the sites, while at the levels of more than $1,000\;s/mm^2$, severe image noises appeared at all of the three sites. In addition, higher signal intensity was found at the site of compression fracture of the lumbar vertebral body than at the discs. Findings showed that with the b value being increased, both the signal-to-noise ratio (SNR) and Apparent Diffusion Coefficient (ADC) values gradually decreased at all the sites of the lumbar vertebral compression fracture and both the upper and lower discs of the fracture site, suggesting that there is a possibility of a wider range of applications to assessment of various vertebral pathologies by utilizing multi b values in the diffusion-weighted MRI examination.

Clinical Characteristics of Arthrogryposis, Renal Tubular Dysfunction, Cholestasis(ARC) Syndrome in Korea (ARC(Arthrogryposis, Renal Tubular Dysfunction, Cholestasis) 증후군의 발병양상에 관한 연구)

  • Lee Soon Min;Kim Ji Hong;Lee Jae Seung;Han Suk Joo
    • Childhood Kidney Diseases
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    • v.9 no.2
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    • pp.222-230
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    • 2005
  • Purpose : ARC syndrome refers to an association of arthrogryposis, renal tubular dysfunction, and cholestasis. The VPS33B gene was recently identified as the causative gene. So far, 41 cases of ARC syndrome have been reported worldwide, and it has rarely been reported in Korea. This study was conducted to report the clinical findings of seven ARC syndrome cases in Korean children, focusing especially on renal tubular dysfunction. Methods : The hospital records of 7 cases diagnosed as ARC syndrome at Severance Hospital between Mar. 1995 and Aug. 2005 were reviewed and analyzed. Results : Of the 7 cases, 4 were boys and 3 were girls. Six patients(85$\%$) were born with normal birth weight at term, and one was born at preterm. All cases presented with cholestasis and severe jaundice. According to the type of arthrogryposis described by Brown et al, type 3 and 4 were found in 2 patients and type,6, 7, and the undistributed type in one patient respectively. Other associated clinical findings were as follows : failure to thrive in 6(85$\%$), lax skin in 5(71$\%$), and gray platelet syndrome in 4(57$\%$). Urine analysis revealed 6 cases(85$\%$) with proteinuria, 3(43$\%$) with hematuria, 5(71$\%$) with glycosuria, 2(29$\%$) with phosphaturia and 2(29$\%$) with calciuria. Serum electrolytes showed 4 cases(57$\%$) with hyponatremia, 3(43$\%$) with hypokalemia, and 1(14$\%$) with creatinine elevation. Renal tubular dysfunctions were diagnosed as renal tubular acidosis in 6 cases(85$\%$), nephrogenic diabetes insipidus in 2(29$\%$), and Fanconi syndrome in 2(29$\%$). During the follow-up period, 2(29$\%$) had no treatment, 5(85$\%$) had continuous supplementation to correct the electrolyte imbalance and acidosis, and 1(14$\%$) had dialysis. Only one patient had a family history of ARE syndrome in a sibling. Four cases(57$\%$) were diagnosed at the mean age of 8.2 months, and one case was lost during follow-up. Ages of the survived 2 cases were 13 and 25 months, respectively. Conclusion : The rare disease of ARC syndrome Is associated with severe renal dysfunction. However, this study revealed that the renal manifestation of ARC syndrome in Korean children is relatively mild and survival rate is higher than that of previous studies. Contrary to previous reports, this study showed that familial cases are rare and sporadic occurence is possible in Korea. Thus, the diagnosis of this syndrome requires a careful evaluation of the venal function in cases of congenital arthrogryposis, and a mandatory genetic counseling of affected family for prevention of familial occurance. (J Korean Soc Pediatr Nephrol 2005;9:222-230)

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A student on the Nursing Needs and Satisfaction of Primipara During the Early Postpartum Period (산욕기 초산모의 간호요구와 만족도에 관한 연구)

  • Chun, Young-Ja
    • Women's Health Nursing
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    • v.3 no.1
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    • pp.5-27
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    • 1997
  • This study was carried out to identify the difference between nursing needs and levels of satisfaction of primiparae during the early postpartum period. The goal of the study was to obtain data needed to develope maternal education programs and to improve the nursing quality for primipara. The subjects were 111 primiparae who had normal delivery at 2 general hospitals in the Seoul area. The data was gathered using an 81 items questionnaire which was developed by the researcher from Nov. 30, 1995 to Feb. 5, 1996. Results found are as follows : 1. The characteristics of subjects : The majority of subjects were aged 26-30yrs(60.4%), high school graduated(49.5%), jobless(52.3%), had no religion(49.5%), no antenatal(74.5%), and postnatal education on self and infant care(55.9%). A large proportion of primiparae intended to feed breast milk(49.5%) but in fact only 7.2% fed breast milk while in the hospital. Many subjects perceived that they had reasonable self confidence about self care(46.8%), and infant care(36%). 2. The level of nursing needs of overall nursing care was relatively high(Mn 3.98) but the level of satisfaction was of average level(Mn 3.09). Therefore, difference between the level of nursing needs and satisfaction was significant(p=0.0001). 3. The nursing needs by category of nursing care the highest need was on the education of infant care(4.29), the lowest was on physical care(3.80). The level of satisfaction was higher on environmental care(3.40) and physical care(3.32). But the category that showed the lowest satisfaction was education of infant care(2.67). Hence, difference of categories between the level of nursing needs and satisfaction was significant(p=0.0001). 4. Among items of physical care, observation of primiparas' conditions(4.21), accurate medication and treatment(4.18), care of breast engorgement(4.07) and control of postpartal hemorrage(4.01) showed high nursing needs. On the other hand, only the level of satisfaction was higher on accurate medication and treatment(3.82). The rest of items revealed only average level of satisfactions. Difference of items between the level of nursing needs and satisfaction was significant(p=0.0001) except items of dietary care. 5. Among items of psychological care, 8 items of nursing needs were high(3.72-4.29), expecially detailed explanation on which mothers want to know(4.29), treatment and nursing care they receive(4.23), kind and faithful care(4.22), early contacts with their baby(4.20), and adequate draping during the care and treatment(4.18). Among items of psychological care higher satisfactions were shown on items of kind and faithful care(3.80), personal treatment(3.70), and detailed explanation to mothers, but the least satisfied items was early contact with baby(2.13). Difference between the level of nursing needs and satisfaction was significant(p=0.0001). 6. Among items of environmental care, the highest level of need and satisfaction was on the items of neat bedding and pajamas(3.54). The difference was significant (p=0.0001). 7. Among the items of educational needs on self care, all of 22 items revealed higher educational needs(3.50-4.33) but the levels of satisfaction varied with a range of 2.63-3.42. Among the items the satisfactions were high on items of breast care including massages(3.42), perineal care(3.36) and expression of breast milk(3.32). Less satisfied items were drugs not be taken by breast milk feeder(2.63), maintenance of breast figure(2.76) and postpartum exercise(2.80) and so on. The difference was significant(p=0.0001). maintain 8. Among the items of educational needs on infant care, 19 items revealed higher educational needs(3.28-4.54). And the highest need were on the 3 items of normal growth and development of infant, safety and emergency care, symptoms of sick(4.45) and the meaning of crying of the baby(4.52). The level of satisfaction among items of education of infant care ranged from 2.47 to 3.16. Most satisfied items were buriping(3.16), bathing(3.11) and diapering(3.09). The items of which the mother's needs were high revealed the lowest satisfaction level. The difference was significant (p=0.0001). 9. Relationship between nursing needs and levels of satisfaction among primiparae of different characteristics were as follows : 1) Nursing needs of physical and psychological areas were significantly different among different age levels but no relationship was found on other categories regardless of the level of satisfaction. 2) With regard to different levels of education, some relationship was found in nursing needs of psychological area(p=0.007), educational needs on infant care(p=0.04) and environmental care(p=0.01). Also, the difference of satisfaction level was significant. 3) Working mothers had higher nursing needs and were more satisfied on items of physical care(p=0.05), education on self care and infant care. Difference were significant between nursing needs and level of satisfaction. 4) With regards to different religion a moderate relation was found between nursing needs of environmental care infant care education but no relationship was found on levels of satisfaction. 5) With regards to antenatal education, the mothers who have had no antenatal education revealed higher nursing needs on physical care but those who had antenatal education were more satisfied with education on self care and infant care. The difference was significant. (p=0.0001). 6) With regards to postpartum education, the mothers who have had some sort of postpartum education revealed higher nursing needs on physical and self care. And they were more satisfied with nursing of every category except infant care than mothers who had not any postpartum education. Differences was significant between the nursing needs and levels of satisfaction.(p=0.0001). 7) With regards to breast feeding experience during the hospitalization, those who had no experience of breast feeding revealed higher nursing needs on physical care in contrast to breast feeders, who had higher educational needs on infant care. And breast feeder were more satisfied with all categories. Differences was significant(p=0.0001). 8) With regards to perception of self confidence on self care and infant care, no relationship was found on nursing needs and level of satisfaction in every category of nursing.

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Performance Improvement on Short Volatility Strategy with Asymmetric Spillover Effect and SVM (비대칭적 전이효과와 SVM을 이용한 변동성 매도전략의 수익성 개선)

  • Kim, Sun Woong
    • Journal of Intelligence and Information Systems
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    • v.26 no.1
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    • pp.119-133
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    • 2020
  • Fama asserted that in an efficient market, we can't make a trading rule that consistently outperforms the average stock market returns. This study aims to suggest a machine learning algorithm to improve the trading performance of an intraday short volatility strategy applying asymmetric volatility spillover effect, and analyze its trading performance improvement. Generally stock market volatility has a negative relation with stock market return and the Korean stock market volatility is influenced by the US stock market volatility. This volatility spillover effect is asymmetric. The asymmetric volatility spillover effect refers to the phenomenon that the US stock market volatility up and down differently influence the next day's volatility of the Korean stock market. We collected the S&P 500 index, VIX, KOSPI 200 index, and V-KOSPI 200 from 2008 to 2018. We found the negative relation between the S&P 500 and VIX, and the KOSPI 200 and V-KOSPI 200. We also documented the strong volatility spillover effect from the VIX to the V-KOSPI 200. Interestingly, the asymmetric volatility spillover was also found. Whereas the VIX up is fully reflected in the opening volatility of the V-KOSPI 200, the VIX down influences partially in the opening volatility and its influence lasts to the Korean market close. If the stock market is efficient, there is no reason why there exists the asymmetric volatility spillover effect. It is a counter example of the efficient market hypothesis. To utilize this type of anomalous volatility spillover pattern, we analyzed the intraday volatility selling strategy. This strategy sells short the Korean volatility market in the morning after the US stock market volatility closes down and takes no position in the volatility market after the VIX closes up. It produced profit every year between 2008 and 2018 and the percent profitable is 68%. The trading performance showed the higher average annual return of 129% relative to the benchmark average annual return of 33%. The maximum draw down, MDD, is -41%, which is lower than that of benchmark -101%. The Sharpe ratio 0.32 of SVS strategy is much greater than the Sharpe ratio 0.08 of the Benchmark strategy. The Sharpe ratio simultaneously considers return and risk and is calculated as return divided by risk. Therefore, high Sharpe ratio means high performance when comparing different strategies with different risk and return structure. Real world trading gives rise to the trading costs including brokerage cost and slippage cost. When the trading cost is considered, the performance difference between 76% and -10% average annual returns becomes clear. To improve the performance of the suggested volatility trading strategy, we used the well-known SVM algorithm. Input variables include the VIX close to close return at day t-1, the VIX open to close return at day t-1, the VK open return at day t, and output is the up and down classification of the VK open to close return at day t. The training period is from 2008 to 2014 and the testing period is from 2015 to 2018. The kernel functions are linear function, radial basis function, and polynomial function. We suggested the modified-short volatility strategy that sells the VK in the morning when the SVM output is Down and takes no position when the SVM output is Up. The trading performance was remarkably improved. The 5-year testing period trading results of the m-SVS strategy showed very high profit and low risk relative to the benchmark SVS strategy. The annual return of the m-SVS strategy is 123% and it is higher than that of SVS strategy. The risk factor, MDD, was also significantly improved from -41% to -29%.

The Factors Influencing the Systemic Action of Dimethoate (O.O-dimethyl-S-(N-methylcarbamoylmethyl) phosphorodithioate) to the Rice Seeds and Phytotoxic Effects (수도종자에의 Dimethoate 침투력 및 발아저해에 관여하는 요인에 관한 연구)

  • Choi Seung Yoon
    • Korean journal of applied entomology
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    • v.9 no.2
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    • pp.57-74
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    • 1970
  • These experiments were conducted to investigate the :actors influencing the systemic action of Dimethoate (O,O-dimethyl-S-(N-methylcarhamoylmethyl) photphorodithioate) to rice seeds and the phytotoxic effects on the seed germination. Dimethoate $(Roxion^{(R)})$ $40\%$ emulsion was used. The varieties tested were Jinheung. Nongkwang,Suwon #82, Norm #6, Paltal, Shirogane, Suseong, Pungkwang, Shin #2, Fujisaka #5, Kwanok, and Jaekeun. The permeated Dimethoate was extracted from the treated seeds by chloroform and quantities were determined by Spectrophotometer. The phytotoxicity was evaluated from the effects on the germination of the treated seeds which were kept in an incubator. The oxygen consumption was measured by Warburg Manometer at $30^{\circ}C$ for 60 minutes. Indices of KOH disintegration of seeds and chemical composition of the seeds were also determined. The results obtained were as followings; 1) The amount of permeated Dimethoate in the seeds showed remarkable differences with varieties. The amount of Dimethoate per 100 grains was greater as in the ascending order of Suseong, Kwanok, Nongkwang, Jinheung, Paltal, Fujisaka #5, Suwon #82, Norm #6, Shirogane, Shin #2, Pungkwang and Jaekeun. 2) It was observed that the total amount of Dimethoate in the seeds(mg./100 grains) were greater among the varieties with large grain than those with small grains, while reverse cases were true in the amount of Dimethoate in a gramme of seeds, probably because of the greater surface areas In a small grains for a gramme weight. 3) There was no significant correlation between the permeated amount of Dimethoate and amount of absorbed water by the seeds when the seeds were treated with $0.1\%$ Dimethoate for 24 and 48 hours. 4) The permeability of Dimethoate to seeds significantly increased in the prolonged soaking periods, higher concentration, and higher temperature. 5) When the seeds were treated with $0.1\%$ Dimethoate for 24 and 48 hours at $15^{\circ},\;20^{\circ},\; 20^{\circ},\; and \;30^{\circ}C$, the permeated amount of Dimethoate were increased at higher temperature. It seems to be that the more active penetration of Dimethoate was involved at the higher temperature. 6) The phytotoxic effects of Dinethoate on the seed germination varied with the varieties. An descending order of varietal tolerance of seeds was as followings: Jinheung, Fujisaka #5, Suwon #82, Paltal, Nongkwang, Jaekeun, Shin #2, Kwanok, Shirogane, Pungkwang, Suseong, and Norm #6. 7) There was a positive correlation between the amount of Dimethoate permeated into the seeds (mg./gram. of seeds) and phytotoxicity of seeds. 8) The Phytotoxic effects of Dimethoate showed close correlation with the degree of KOH disintegration of seeds, average germination periods, and oxygen respiration of seeds. 9) It was observed that higher protein contents of the seeds decreased the phytotoxic effects of Dimethoate. 10) Relatively high negative correlation between the degree of KOH disintegration of seeds and crude protein content of the seeds was observed. 11) The average germination period was delayed for about 2 days when the seeds were treated with $0.2\%$ Dimethoate for 24 hours at $30^{\circ}C$. 12) The oxygen consumption of the seeds treated with $0.2\%$ Dimethoate for 24 hours at $30^{\circ}C$ was greatly decreased when compared with that of the normal seeds. 13) The amount of oxygen consumption of the seeds (in 24 hours after 24 hours water soaking) was negatively correlated with the average germination periods of the seeds.

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Lung Uptake of $^{99m}Tc-sestamibi$ during Routine Gated Exercise SPECT Imaging : Comparison with Left Ventricular Ejection Fraction and Severity of Perfusion Defect (일상적인 운동 부하 게이트 심근 관류 SPECT에서 $^{99m}Tc-sestamibi$ 폐섭취 : 좌심실 구혈률과 관류 결손 정도와의 비교)

  • Jeong, Shin-Young;Lee, Jae-Tae;Bae, Jin-Ho;Ahn, Byeong-Cheol;Lee, Kyu-Bo
    • The Korean Journal of Nuclear Medicine
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    • v.37 no.2
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    • pp.83-93
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    • 2003
  • Background: Lung-to-heart uptake ratio (LHR) in $^{201}Tl-chloride$ myocardial perfusion scan is believed to be a reliable marker for left ventricular (LV) dysfunction, but the clinical value of LHR is controversial for $^{99m}Tc-MIBI$ imaging. Furthermore, most of results suggesting lung uptake of $^{99m}Tc-MIBI$ as a potential marker for LV dysfunction used immediate post-stress images, instead of routine images acquired 1 hour after tracer injection. The goal of our study was to investigate whether LHR evaluated with routine gated $^{99m}Tc-MIBI$ imaging can reflect the degree of perfusion defect or left ventricular performance. Subjects and Methods: 241 patients underwent exercise $^{99m}Tc-MIBI$ myocardial SPECT were classified into normal myocardial perfusion (NP, n=135) and abnormal myocardial perfusion (AP, n=106) group according to the presence of perfusion defect. LHR was calculated from anterior projection image taken at 1-hour after injection. Two legions of interest (ROIs) were placed on left lung above LV and on myocardium showing the highest radioactivity. Subjects were classified by left ventricular ejection fraction (LVEF), as Gr-I: >50%, Gr-II: 36-50%, Gr-III: <36% and by summed stress score (SSS), as Gr-A: <4, Gr-B: 4-8, Gr-C: 9-13, Gr-D: >13, LHR was compared among these groups. Results: In NP group(n=135), LHR, were higher in men than women ($men:\;0.311{\pm}0.03,\;women:\;0.296{\pm}0.03,\;p<0.05$). Significant difference, in LHR were found between NP and AP groups both for men and women ($men:\;0.311{\pm}0.03\;vs\;.\;0.331{\pm}0.06,\;women:\;0.296{\pm}0.03\;vs.\;0.321{\pm}0.07.\;p<0.05$). There were weak negative correlation between LHR and LVEF (r=-0.342, p<0.05) and weak positive correlation between LHR and SSS (r=0.478, p<0.05) in men, but not in women (LVEF: r=-0.279, p=0.100, SSS: r=0.276, p=0.103). Increased LHR was defined when for more than mean + 2SD value ($men{\geq}0.38,\;women{\geq}0.37$) of the LHR of the subject with normal perfusion. Increased LHR were observed more frequently in subjects with lower LVEF (Gr-I: 11.1%, Gr-II: 27.0%, Gr-III: 35.4%, p<0.05) and higher SSS(Gr-A: 14.0%, Gr-B: 5.7%, Gr-C: 18.2%, Gr-D: 40.7%, p<0.05). Conclusions: LHRs obtained from routine $^{99m}Tc-MIBI$ gated SPECT images were weakly correlated with LVEF and perfusion defect. Although significant overlaps were observed between normal and abnormal perfusion group, LHRs could be used as an indirect marker of severe perfusion defect or reduced left ventricular function.