• Journal of Nutrition and Health
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• 제30권3호
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• pp.349-359
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• 1997

This study was designed to study sources of variability(subjects, day by day, season, day of week, sequence, number of repeated days, compliance etc.) in multiple 24-hour dietary recall method. Dietary intakes of college women in Seoul were obtained using 24-hour dietary recalls, consecutive 7 days, 4 times for 1 year. The result of this study shows that 1) the reproducibility of multiple 24-hour recalls is low(intraclass correlation coefficient<0.3), 2) the intraindividual variations of all nutrients are more than 80%, 3) the major components of variation are interindividual vriability and intraindividual variability(within person variability and methodologic error). There were small but statistically significant season and compliance effects. 4) the ratio within-person varation to between-person variation for absolute and transformed nutrient intakes except some nutrients such as vitamin A, vitamin C, energy from protein and fat etc, was less than 1.7 the minimum numbers of days needed in 24-hour dietary recalls to estimate usual intake for this group were 1 to 21 days. And the numbers of days needed to get the usual intake of an individual varied among individuals and within individuals for different nutrients, ranged from 1 days for log carbohydrate(% energy) to 470 days for Na. 6) There were greater than 0.7 correlation coefficients between the average nutrient intakes of 12 days and intakes of 28 days. Therefore, it was desirable to take the 24-hour recall more than 12 times, repeating 3 days every season.

• Journal of Nutrition and Health
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• 제33권8호
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• pp.882-889
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• 2000

This study was conducted to examine contribution of specific foods to absolute intake and between-person variation in nutrients consumed by 2037 adults living in Korean rural area using one day 24-hour recall method. To measure contribution of food to absolute nutrient intake, all foods consumed were ranked by percentages calculated as the sum of the nutrient intake contributed by a given food divided by the total nutrient intake from al categories. To assess between-person variability in nutrient intake, stepwise multiple regression analysis was used with total nutrient intake from al foods as the dependent variable and the nutrient amount from each of all foods as independent variables. The kind and the number of foods necessary to account for the variation in nutrient intake among persons varied significantly depending on the nutrient. The nutrients contributing more than 80% of total intake with a few number of food items were ${\beta}$-carotene(ll), vitamin C(15) and vitamin A(16). Foods sometimes overlooked as important sources were found in some instances to be quantitatively important to population intake. Even though rice and Korean cabbage kimchi do not contain much nutrients in quantity, they made a major contribution to most nutrient intake of subjects because of large serving size and high frequency of intake. The food items and contributing order for between person variance was different from those of absolute intake. A large fraction of the variability of nutrient intake in this population was explained by a small number of foods. Fewer foods were required to explain a given proportion of the between-person variance in intake than to account for the same proportion of the popylation\`s total intake. These data may be useful in the development of dietary assessment instrument and in nutrition education. (Korean J Nutrition 33(8) : 882-889, 2000)

• 한국컴퓨터정보학회논문지
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• 제22권6호
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• pp.87-93
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• 2017

In this paper, we design a small low power single channel ECG(Electrocardiogram) system of Chest Belt type with fiber-type electrodes to measure emotional state change of game addict. HRV(Heart Rate Variability) is analyzed through heart rate signal measurement and the psychological stress state is judged by using it. And it verifies its effectiveness through prototype. First, we design HR measurement module through low power MCU(Micro Controller Unit) and implement prototype level measurement system. The results showed that the difference between the addiction group and the general group was confirmed and that the system was effective. The result of this study can be used for health management such as reduction of stress of the user through music and breathing that lowers the stress by detecting the stress state of the general person or the chronic ill person.

• Journal of Nutrition and Health
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• 제25권2호
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• pp.179-186
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• 1992

식품영양학을 전공하는 18~21세의 여대생 57명을 대상으로 1990년 5월 14일~5월 21일까지 연속 7일간의 식품섭취량을 기록에 의하여 조사한 후 1일 평균 영양소섭취량을 구한 결과는 다음과 같았다. 1) 식이조사를 하루 또는 이틀 동안 실시했을 때의 섭취량과 7일간 조사시의 조사일수에 따른 평균 섭취량 간에는 유의한 차이를 볼 수 없었다. 주중과 주말의 섬취량비교에서 비타민 A를 제외하고는 유의한 차이를 보이지 않있다. 2) 영양소 섭취량의 개인내변이계수는 0.27~0.93으로 나타났으며, 영양소군별로 볼때 비타민군의 변이가 가장 컸으며, 무기질군이 중간 정도, 대량 열양소군이 가장 낮았다. 개인간 변이계수는 0.16~0.50으로 역시 에너지나 당류가 가장 낮았으며 비타민C와A가 가장 높았다. 모든 영양소에서 개인내 변이계수가 개인간 변이계수보다 컸으므로 개인간 변이에 대한 개인내변이의 비는 2.15로 나타났다. 전체적으로 볼 때 대체로 개인내 변이가 낮은 영양소들(에너지, 당류, 단백질, 지방)이 개인변이도 낮게 나타난 반면 개인내변이가 높았던 영양소(비타민 C와A)들이 개인간 변이도 높게 나타났으므로 그둘간의 비는 영양소별로 큰차이를 보이지 않았다. 3) 7일 조사시의 섭취량과 실제 섭취량과의 상관계수는 영양소별로 큰차이를 보이지 않았으며, 에너지, 단백질, 당류, 비타민 A등이 0.84~0.85로 높았고, 비타민 B$_1$이 0.74, 칼슘이 0.78로 낮았다. 상관관계수 0.9가 되기 위한 최소한의 필요조사일수는 에너지, 당류, 단백질, 비타민A 등이 11~13일로 비슷했고, 칼슘이 20일로 가장 길었다.TEX>$33.37$\mu\textrm{g}$/m\ell로$ 분석되었다. 모유의 평균 망간 함량은 초유와 이행유에서 각각 $0.024$\mu\textrm{g}$/m\ell,$ 성숙유에서 $0.014$\mu\textrm{g}$/m\ell,$ 믈리브덴의 평균 농도는 각각 $0.035$\mu\textrm{g}$/m\ell,$ $0.044$\mu\textrm{g}$/m\ell$ 그리고 $0.044$\mu\textrm{g}$/m\ell이었고$ 니켈 함량은 초유에서 $0.062$\mu\textrm{g}$/m\ell이행유에서$ $0.022$\mu\textrm{g}$/m\ell,$ 성숙유에서 $0.017$\mu\textrm{g}$/m\ell이었다.$ 수유기간에 따른 모유내 무기질과 미량원소 함량의 감소가 영아의 성장발달과 어떻해 관련 되는가에 관한 연구와 함께 유선조직에서 유즙으로의 무기질과 미량원소의 분비기전에 관한 생리학적 연구가 병행되어야 하겠으며, 본 연구결과가 앞으로 우수한 조제분유나 기타 영아식 개발에 활용되고, preterm milk의 무기질 성분을 비교하는데 이용될 수 있기를 희망한다.Willumsen, 1980)에 의하여 개발된 ME2(Maximum Entropy Matrix Estimation)기법에서 반복식

• Nutrition Research and Practice
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• 제13권4호
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• pp.323-332
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• 2019

BACKGROUND/OBJECTIVES: The aim of this study was to analyze specific foods influencing absolute nutrient intake and between-person variations of nutrient intake among Korean preschoolers. SUBJECTS/METHODS: This study included 2,766 participants aged 1-5 years in the 2009-2013 Korea National Health and Nutrition Examination Surveys. Dietary data were obtained from a 24-h dietary recall method. Major food sources of absolute nutrient intake were evaluated based on percent contribution of each food. To assess the contribution of specific foods to between-person variations in nutrient intake, stepwise multiple regressions were performed and cumulative $R^2$ was used. RESULTS: White rice and milk were main food sources of energy, protein, carbohydrate, phosphorus, iron, potassium, thiamin, riboflavin, and niacin. The percentage of fat contributed by milk was 21.3% which was the highest, followed by pork, soybean oil, and egg. White rice accounted for 25% and 40% of total variability in total energy and carbohydrate intakes, respectively. About 39% of variation in calcium intake was explained by milk while 40% of variation in phosphorous intake was explained by cheese. The top 10 foods contributing to between-person variations in nutrient intakes were similar with food items that mainly contributed to absolute nutrient intakes. The number of foods explaining 90% of absolute amounts of nutrient intakes varied from 28 for vitamin A to 80 for iron. CONCLUSIONS: This study identified specific foods that contributed to absolute nutrient intakes and between-person variations in nutrient intakes among Korean preschoolers. Our findings can be used to develop dietary assessment tools and establish food-based dietary guidelines for young children.

• Nutrition Research and Practice
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• 제17권4호
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• pp.747-761
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• 2023

BACKGROUND/OBJECTIVES: In Korea, studies of diet in elementary school children are hindered by the need for a comprehensive dietary assessment tool. Thus, the aim of this study was to develop a semi-quantitative food frequency questionnaire (FFQ) for Korean elementary school children. SUBJECTS/METHODS: The 24-h recall data for 1,624 subjects aged 6-11 yrs from the seventh Korea National Health and Nutrition Examination Survey were used to extract the items included in the questionnaire. The FFQ items were developed by selecting major dishes based on the results of nutritional contribution and between-person variability for energy and 14 nutrients (carbohydrate, protein, fat, crude fiber, calcium, phosphorous, iron, sodium, potassium, vitamin A, thiamin, riboflavin, niacin, and vitamin C). We selected the major dishes with over 90% of the total contribution to each nutrient and with over 90% of the accumulated R² for each nutrient. Among the 452 dishes, we selected 248 dishes contributing more than 1% of the total consumption. RESULTS: Finally, the FFQ included 107 items combined from 248 dishes based on nutrient profile and recipe. The FFQ items accounted for an average of 88.6% of the energy, 14 nutrient intakes, and 91.4% of the between-person variability. Quantities of dietary intake were assessed by 9 categories of frequency and 3 categories of portion size. Percentages of coverage for energy, protein, fat, carbohydrate, and calcium were 90.2%, 87.8%, 89.9%, 90.8%, and 88.7%, respectively. CONCLUSIONS: We developed a dish-based, semi-quantitative FFQ comprising 107 items for Korean elementary school children aged 6 to 11. Further studies are needed to evaluate the reproducibility and validity of this FFQ for elementary school children.

• Journal of Community Nutrition
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• 제5권2호
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• pp.72-82
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• 2003

We here outlined our study on the variations in intake of nutrients based on four season 7 consecutive day weighed diet records (WDRs) from 80 Japanese female dietitians in 1996 - 1997. Furthermore, we reviewed Japanese, Korean and international articles investigating variability in consumption of foods as well as nutrients. The relative contributions of variation for all nutrients by person were greater than those by day, week and season. Within individual variances were greater than that between individual variances, being generally observed in Korea and in the world. The ratios of within- vs. between-individual variations ranged from 1.3-26.9 in our study, the ratios being greatest in Korean, followed by Japanese and western people. Based on within individual coefficients of variation, minimal days necessary for estimating nutrient consumption per person within 10％ (20％) of the true mean with 95％ confidence intervals were estimated. They ranged from 10-35 (3-9) days for energy and major nutrients and 15-640(4-160) days for micro-nutrients. Two Japanese studies reported that the ratios for foods were as a whole greater than those for nutrients, except for cereals, rice and milk. (J community Nutrition 5(2) : 72-82,2003).

• 융합신호처리학회논문지
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• 제1권1호
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• pp.15-22
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• 2000

선형 자귀회귀(AR) 모델을 근거로한 심박변동의 파워 스펙트럼 해석은 비침습적으로 자율신경의 반응을 정량화 하는데 폭넓게 사용된다. 본 연구는 짧은 데이터 저장(2분 미만)의 심전도와 맥파 신호의 심박변동에 대한 파워스펙트럼밀도을 추정한다 심박변동의 시계열은 정상인을 대상으로 검출한 심전도와 맥파신호의 특징점 사이의 시간간격(RRI, PPI)으로부터 구하였다. 발생된 시계열은 다항식 보간법에 의해 AR모델에 적합하게 새로운 시계열로 재구성하였다 AR모델에 의한 파워스펙트럼 밀도는 Burg 알고리즘을 사용하여 계산하였다 AR 모델을 적용한 단 구간의 심전도와 맥파의 심박변동에 대한 파워스펙트럼밀도는 저주파수와 고주파수 영역에서 매끄러운 스펙트럼 파워를 나타내고 있다. 또한 통일한 피험자의 심전도와 맥파의 파워스펙트럼밀도를 비교한 결과 유사한 모양을 나타내었다.

• 동의신경정신과학회지
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• 제15권1호
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• pp.197-209
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• 2004

Objectives : The purpose of this case-control research was to investigate the effects of acupuncture stimulation on autonomic nervous system for patients with HRV and to find out relationship with anti-stress effects. Methods : The study group consists of 24 patients with self-recognition of stress as the case group, and 20 normal person as the control group by similar age. We measured HRV of case and control groups before acupuncture stimulation, prick acupuncture in Hegu(LI4), Taichong(Liv3), Shenme(H7), Neiguan(P6), Zusanli(S36). After treating for 20 minutes, measurement values of HRV and PSV were compared for pre-acupuncture and post-acupuncture. Results : 1. LF norm, HF norm, LF/HF between the case and control groups were significant different in HRV before acupuncture stimulation in the 1st experiment. 2. HRT, SDNN, SDSD, LF norm, HF norm, and LF/HF of the case group were significant different in HRV after acupuncture stimulation in the 1st experiment. HRT of the case group was significantly different in HRV after acupuncture stimulation in the 1st experiment. 3. LF norm, HF norm, LF/HF of the case group were significant different between the 1st and 2nd experiment in HRV before acupuncture stimulation. 4. LF norm, HF norm, and LF/HF were significant different between the 1st and 2nd experiment in HRV of patients whose symptoms improved. But HRV of patients whose symptoms unimproved didn't show significant difference. Conclusion : The results suggest that acupuncture stimulation is associated with changed activity in the sympathetic and parasympathetic nervous system. Measurement values of HRV is suitable to estimate the activity of automatic nervous system.

• 한국운동역학회지
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• 제23권1호
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• pp.77-83
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• 2013

The purpose of this study was to compare kinematic variables and stiffnesses of ankle joints between normal person and transfemoral amputee gait in order to develop or fit prosthetic leg. Twenty subjects (ten normal persons and ten transfemoral amputees) participated in this experiment, and walked three trials at a self-selected pace. The gait motions were captured with Vicon system and variables were calculated with Visual-3D. The velocity, stride length, stride width, cycle time, double limb support time and right swing time of gaits were statistically significant. Because coefficients of variability of normal persons on velocity, double limb support time and swing time were greater than transfemoral amputees, normal persons controlled these gait variables effectively. The stiffnesses of ankle joints were not statistically significant, but patterns of stiffnesses of ankle joints during three rockers were absolutely different. The negative correlations between stiffnesses of ankle joints and cycle time and swing time were presented. These differences suggest that developing and fitting prosthetic leg were demanded. Further studies should develop fitting program and simulator of prosthetic leg.