• 전기전자학회논문지
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• 제22권4호
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• pp.1025-1030
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• 2018

제안하는 4차 델타-시그마 변조기는 1개의 연산증폭기를 시분할 기법을 이용하여 4차 델타시그마 변조기를 구현한 구조를 이용하여 설계하였다. KT/C 잡음의 영향을 줄이기 위하여 첫 번째와 두 번째로 재사용하는 적분기의 적분 커패시터 사이즈를 크게 설계하였으며, 세 번째와 네 번째로 재사용하는 적분기의 적분 커패시터 사이즈는 작게 설계하였다. 다른 커패시터 용량을 한 개의 연산증폭기가 로드하기 때문에 안정도 문제를 해결하기 위하여 연산증폭기 단을 가변 하는 방법을 이용하였다. 전력을 절감하기 위하여, 1단으로 연산증폭기가 동작할 때 사용되고 있지 않는 2단을 구성하고 있는 CS증폭기와, 그 출력단에 붙어있는 연속모드 공통모드피드백회로 의 전류원을 차단하는 방법을 이용함으로써, 아이디어 적용전과 비교하였을 때, 15%의 전력 절감 효과를 얻었다. 제안한 변조기는 TSMC 0.18um CMOS N-well 1 poly 6 metal 공정을 이용하여 제작되었으며, 1.8V의 공급전압에서 305.55uW의 전력을 소모하였다. 256kHz의 샘플링 주파수, OSR 128, 1.024MHz의 클럭주파수, 250Hz 의 입력 싸인 파형을 공급하였을 때, 최대 SNDR은 66.3dB, 유효비트수는 10.6bits, DR은 83dB로 측정되었다. Fom(Walden)은 98.4pJ/step, Fom(Schreier)는 142.8dB 로 측정되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권12호
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• pp.1756-1760
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• 2016

Estimation of feed intake (FI) for individual animals within a pen is needed in situations where more than one animal share a feeder during feeding trials. A partitioning method (PM) was previously published as a model to estimate the individual FI (IFI). Briefly, the IFI of a pig within the pen was calculated by partitioning IFI into IFI for maintenance ($IFI_m$) and IFI for growth. In the PM, $IFI_m$ is determined based on the metabolic body weight (BW), which is calculated using the coefficient of 106 and exponent of 0.75. Two simulation studies were conducted to test the hypothesis that the use of different coefficients and exponents for metabolic BW to calculate $IFI_m$ improves the accuracy of the estimates of IFI for pigs, and that PM is applied to pigs fed in group-housing systems. The accuracy of prediction represented by difference between actual and estimated IFI was compared using PM, ratio (RM), or averaging method (AM). In simulation studies 1 and 2, the PM estimated IFI better than the AM and RM during most of the periods (p<0.05). The use of 0.60 as the exponent and the coefficient of 197 to calculate metabolic BW did not improve the accuracy of the IFI estimates in both simulation studies 1 and 2. The results imply that the use of $197kcal{\times}kg\;BW^{0.60}$ as metabolizable energy for maintenance in PM does not improve the accuracy of IFI estimations compared with the use of $106kcal{\times}kg\;BW^{0.75}$ and that the PM estimates the IFI of pigs with greater accuracy compared with the averaging or ratio methods in group-housing systems.

• 대한지역사회영양학회지
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• 제19권2호
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• pp.187-197
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• 2014

Objectives: This study was carried out to determine nutritional status of elderly patients in a long-term care hospital according to meal type and eating ability. Methods: Subjects were 47 female patients aged over 65 ($79.3{\pm}7.1$ years) who resided in a long-term care hospital in Seoul. Thirty seven patients who ate diet orally were grouped according to meal type (27 general diet and 10 soft diet) and eating ability (26 eating by oneself and 11 eaten with help) and 10 were on tube feeding. Nutritional status was determined by food consumption and mid-arm circumference. Results: The mean adequacy ratios (MARs) of 12 nutrients (protein, calcium, phosphorus, zinc, vitamin A, vitamin $B_1$, vitamin $B_2$, vitamin $B_6$, niacin, folic acid, vitamin C) were 0.687 for general diet, 0.565 for soft diet, 0.680 for eating by oneself and 0.677 for eaten with help, which were significantly lower than 0.982 for tube feeding (p < 0.05 or p < 0.01). The patients on tube feeding had significantly lower % arm circumference compared to those who ate general diet (84.0% vs. 95.4%, respectively, p < 0.05). Nutrients intakes, nutrient adequacy ratio (NAR) and index of nutritional quality (INQ) were not different between meal types as well as eating ability. The most insufficiently consumed nutrients by the patients on diet were folic acid, vitamin $B_2$, and calcium (NAR 0.334~0.453, 0.515~ 0.539, and 0.516~0.533, respectively). Conclusions: The results suggested that regardless of meal type or eating ability, the subjects who were on diets in this study might have inadequate intake of folic acid as well as vitamin $B_2$, and calcium, which need to be reflected on menu planning. The measurement of mid-arm circumference presented more risk of malnutrition of patients on tube feeding than those on diets, despite apparently better nutrient consumption.

• 한국물환경학회지
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• 제18권4호
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• pp.379-386
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• 2002

In this study, estimation model for iron compound originated from upflow, anaerobic fixed bed reactor, which treats sewage domestic wastewater, was developed. The estimation model was formulated by a mathematical expression which was based on the mass balance. Below the HRT of 60 minute, sulfide concentration combining with iron $FeS_2$ is the highest because the maximum sulfate consumption rate $V_{maxS}$ and half-saturation constant of sulfate $K_{mS}$ exert an important effect on the estimation model as temperature was increased. But increment of $FeS_2$ concentration is weakened above the HRT of 60 minutes and represent the lowest value at the HRT of 108 minutes. It implies that liquid phase distribution ratio of sulfide ${\alpha}r$ becomes lower as temperature was increased. While phosphorus concentration combining with iron $Fe_3(PO_4)_3$ is increased as HRT and temperature are increased, which is affected by phosphorus removal rate constant $k_p$. As the result of estimating the iron concentrations of corrosion by the model, the concentration of iron corrosion is higher than any other at the HRT of 108 minute and $20^{\circ}C$. The predicted values were compared with measured ones at different HRT(13.5, 27, 54, 108 min) and temperature(20, 25, $30^{\circ}C$). The experimental data could be fitted with the simulated curves. Therefore, the mathematical expression could be applicable to design full-scale wastewater treatment plants.

• 한국식품영양과학회지
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• 제38권10호
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• pp.1353-1361
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• 2009

본 연구는 서울지역에 거주하는 건강한 성인 남녀(남자 29명, 여자 10명) 39명을 대상으로 trans 지방산 3.75 g을 각각 첨가한 찹쌀보리빵과 밀빵의 섭취가 혈중 지방산 조성과 지질 수준에 미치는 효과를 확인하기 위하여 실시하였다. 시험군은 밀빵 군(19명)과 찹쌀보리빵 군(20명)의 2군으로 분류하였으며 장기(6주) 임상시험으로 시행하였다. 밀빵 군은 밀가루 80 g에 trans 지방산 3.75 g을 첨가한 밀빵을, 찹쌀 보리빵 군은 $\beta$-glucan 5%를 함유한 찹쌀보리가루 40 g과 밀가루 40 g에 trans 지방산 3.75 g 첨가하여 찹쌀보리빵을 조제하여 제공하였다. 찹쌀보리빵을 섭취한 군에서는 섭취기간이 증가할수록 C18:3c,n-9 지방산을 제외한 지방산들의 농도가 낮아졌으며 특히 섭취 6주경과 후에서는 C16:0, C18:1t, C18:1c, C18:2t와 C18:2c의 농도는 밀빵을 섭취한 군에 비해 유의적으로 낮은 수준을 보였다. 밀빵을 섭취한 군에서 섭취기간이 증가할수록 C18:1t, C18:2c, C18:2t의 농도는 증가하는 것으로 나타난 반면 C18:0, C18:1c, C18:3c,n-9과 C18:3c,n-3의 농도는 감소하였고 C16:0와 C18:2c의 농도는 증가 후 일정수준을 유지하여 6주경과 후에서는 섭취 전보다 현저하게 높은 수준을 보였다. P/M/S 비를 보면 섭취4주까지 두 군 모두에서 다가불포화지방산의 비가 증가한 반면 섭취 6주경과 후에서는 다소 감소하는 경향을 보였으며, 단일불포화지방산의 비는 찹쌀보리빵 군에서는 감소하는 추세이나 밀빵 군에서는 증가하는 경향을 보였다. 또한 혈중 trans 지방산을 비롯한 포화지방산 농도가 낮은 수준이었으며 또한 찹쌀보리빵의 섭취는 밀빵의 섭취에 비해 총 콜레스테롤 농도와 TG/HDL-C의 비를 감소시켰다. 이러한 결과는 찹쌀보리에 함유된 $\beta$-glucan이 trans 지방의 체내 흡수율을 저하시키거나 흡수속도를 느리게 하기 때문으로 사료된다. 따라서 이상의 결과에서 가공식품으로부터 공급되는 trans 지방의 체내 농도를 저하시키고 혈장 총 콜레스테롤 농도를 개선시키기 위해서는 밀가루 보다는 찹쌀보리를 활용한 형태로 섭취하는 것이 바람직하다고 하겠다.

• 한국가금학회지
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• 제29권1호
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• pp.25-35
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• 2002

조기제한사양의 강도(정도)와 시기 및 기간이 육계의 보상성장과 사료효율 및 복강지방 축적에 미치는 영향을 구명하기 위해 2개의 실험을 실시하였는데, 실험 1에서는 7일령된 무감별 육계 240수를 4처리 3반복에 반복당 20수씩 공시하여 7일령에서부터 49일령까지 실시하였다. 대조구(C)는 7일령부터 49일령까지 전기간 육계 전기사료와 후기사료를 자유채식을 시켰으며, 시험구(T1,T2 및 T3)들은 각각 1일 0.75 kcal ME/9B $W^{0.67}$로 7일령부터 9일령까지 3일간, 1.50 kcal ME/gB $W^{0.67}$로 7일령부터 11일령까지 5일간 및 2.25 kcal ME/gB\$^{0.67}$로 7일령부터 13일령까지 7일간 육계전기사료를 제한급여하였다. 실험 2는 4일령된 무감별 육계 420수를 7처리 3반복, 반복당 20수씩 공시하여 4일령에서부터 49일령까지 실시하였는데 대조구(C)는 4일령부터 49일령까지 전기간 육계 전기사료와 후기사료를 자유채식을 시켰으며, 시험구(T1~T6)들은 모두 1일 0.75kcal ME/gB $W^{0.67}$로 4,7일 및 10일령에 3일간 또는 5일간육계전기사료를 제한급여하였으며, 제한사양이 끝난 시험구들은 전기사료 및 후기사료를 자유채식시켰다. 실험 1에서 제한사양기간을 포함한 21일령가지의 증체량은 대조구에 비해 시험구들이 유의적으로 적었으나(P<0.05), 22일령부터 49일령까지의 증체량은 대조구에 비해 시험구들이 유의적으로 높았으며(P<0.05), 전기간인 7일령부터 49일령까지의 증체량과 49일령 체중은 처리간에 유의적 차이가 없었다. 제한사양후부터 21일령까지의 사료섭취량은 T1구를 제외한 나머지 시험구에서는 대조구와 유의적인 차이를 보이지 않았으며, 22~47일령의 사료섭취량은 처리간에 유의적인 차이가 없었으나, 전기간 섭취량은 대조구에 비해 시험구들이 유의적으로 적게 섭취하였다 (P<0.05). 제한사양기간을 포함한 7일령부터 21일령까지의 사료요구율은 T1구만 유의적으로 낮았으며(P<0.05), 22일령부터 49일령가지의 사료요구율과 전기간동안의 사료요구율은 대조구에 비해서 시험구들이 유의적으로 낮았다(P<0.05) , 복강내지방함량 및 전기간 폐사율은 처리간에 유의적 차이가 없었다.

• Journal of Preventive Medicine and Public Health
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• 제30권1호
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• pp.103-128
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• 1997

The object of this study is to evaluate the possibility of chemical-induced liver disorder among workers exposed to various chemicals and to classify the the liver function abnormalities by causes and to analyse the risk factors for each liver disorders. A cross-sectional study including questionnaire survey, physical examination, laboratory tests and ultrasonography of liver was conducted on 1,126 workers, 459 workers in a coal chemical plant(company A) and 667 workers in an insulation material manufacturing factory(company B). An industrial hygienist reviewed the chemicals used in both companies and evaluated the work environments to classify the workers by chemical exposure semiquantitatively. The results are as follows: 1. Of 459 workers in company A, 83 workers(18.1%) are classified as nonexposed, group 163(35,5%) as short-term exposure group, 155(33.8%) as intermediately exposed group and 58(12.6%) as long-term exposed group bared on the mean daily exposure to hepatotoxic chemicals evaluated by an industrial hygienist. Of 667 workers in company B, 484(72.6%) workers were classified as nonexposed and 183(35.5%) as exposed group. 2. Workers with SGOT level higher than 40 IU/l were (10.0%) in company A and 77(11.5%) in company 3, and those with SGPT level higher than 35 IU/l were 118(25.7%) in company A and 198(29.7%) in company B. The differences were not significant between companies and between exposure groups(p>0.05). Workers with $\gamma-GT$ level higher than 62 IU/l were 29(6.3%) in company A and 77(11.5%) in company B (p<0.01). The difference between exposure groups was not significant(p>0.05) within companies. Workers with liver function abnormalities(defined as SGOT higher than 40 IU/l or SGPT higher than 35 IU/l) were 338(30.0%) among 1,126 workers. Of 338 workers with live. function abnormalities 139(12.3%) had fatty liver by ultrasonography, 79(7.0%) had alcoholic liver(defined as workers with liver function abnormalities with weekly alcohol consumption greater than 280 g for more than 5 years), 54(4.8%) had hepatitis B, 12(1.1%) had hepatitis C and the other 114(33.7%) was not otherwise classified. Prevalences of alcoholic liver and fatty liver were significantly lower in company A(prevalence ratio 0.24 for alcoholic liver, p<0.001, prevalence ratio 0.76 for fatty liver, p<0.05) but prevalences of liver disorders between exposure groups within companies were not significant(p>0.05). 3. Summary prevalence ratios(SPR) of live. function abnormalities, fatty live. and other liver disorders, adjusted by age and company were not significantly higher in exposed group in any chemicals(p>0.05) but in some chemicals, SPRs were significantly lower. 4. On simple analysis of risk factors for liver function abnormalities, prevalence odds ratio(POR) of those with age between 30 and 39 was 1.54(p<0.01) and those with age ever 40 was 1.51(p<0.01). POR of those with histories of liver disorders and general anesthesia was 1.77(p<0.001) and 4.02 for those with overweight and 6.23 for those with obesity, defined by body mass index(p<0.001). 5. On logistic regression analysis, risk factors of liver function abnormality were fatty liver(POR 2.92 for grade 1, 12.15 for grade 2), presence of hepatitis B surface antigen(POR 3.62) and obesity(POR 5.38 for overweight and 16.52 for obesity). Presence of hepatitis B surface antigen(POR 0.18) was the only preventive facto. of fatty live. Company(POR 0.30) and obesity(POR 2.49 for overweight, 4.52 for obesity) were related to the alcoholic live. Obesity(POR 2.94 for overweight) was the only significant risk factor of hepatitis B and there was no significant risk factor for liver function abnormality not otherwise classified. It is concluded that the evidence of liver disorder related with chemical exposure is not evident in these factories. It is also postulated that fatty liver and alcoholic liver is most common causes of liver function abnormalities among workers and effort for weight control and improvement of life style should be done.

• 대한지역사회영양학회지
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• 제12권3호
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• pp.259-271
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• 2007

The purpose of this study was to investigate the dietary habits and daily intake of nutrients in college students. This survey was conducted using a self-administered questionaire. The average heights and weights were 173.5 cm and 72.3 kg of male students and 161.8 cm and 57.2 kg of female students. The average of BMI was $24.2kg/m^2$ of male and $21.9kg/m^2$ of female, and the value of male students was higher than the value of female students. The response to the daily meals was 54.6% for '$2{\sim}3$ times/week'. The regularity of mealtime was 41.7% for irregular and the frequency eating after nine was 45.7% for '5-6 times/week', respectively. The repast was 72.2% for 'overeating and little eating' and was a significant difference of male and female students (p<0.05). The eating rate was higher '$10{\sim}20min$'. As for breakfast food eaten, skipping breakfast was 23.6% for 'no/week' and female students were higher than male students (p<0.05). The frequency of snacks was 36.0% for 'nothing' of males students and 34.8% for '3-4 times/week' of female students (p<0.05). The type of snack was a significant difference of males and females students (p<0.01), and was the highest 75.0% for carbonated drinks of males and 37.5% for snacks of females. The eating due to stress solution was a significant difference of male and female students (p<0.01), and was the highest 23.0% for 'frequency' of males and 44.7% for 'sometime' of females. As for food intake of male and female students, the meat intake was 66.7% for 'everything of male and female students. The fish intake was 68.1 % for '1-2times/week'. The milk, milk products, eggs and beans were each 40.3%, 58.3%, 56.9%, 47.2% for '1-2 times/week' (p<0.05). The fat intake was 55.6% for '$1{\sim}2$ times/week'. The average consumption of energy was 58% of male and 67% of female of estimated energy requirement (EER). Their mean ratio of carbohydrate: protein: fat was 57 : 15 : 28 of all subjects. The mean intakes of vitamin C and folic acid were 70% and 51% of males and 62% and 52% of females of recommended intake (RI). The mean intakes of Ca, P, Fe and Na were 71%, 140%, 146% of males and 72%, 122%, 76% of female of RI and 273% of males and 233% of females of adequate intake (AI). Therefore, nutritional education is necessary for college students to establish physicall and mentall optimal health conditions though nutritional intervention.

• 한국식품영양과학회지
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• 제32권3호
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• pp.450-457
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• 2003

본 연구는 SD계 흰쥐를대상으로 전분을 식이 무게의 50%로 주면서 일반 옥수수전분을 고아밀로오스 옥수수전분으로 대치시 켜 RS양을 증가시켰을 때, 지방대사와 면역능력에 미치는 영향을 살펴보는 것을 목적으로 하였다. 식이섭취량이나 식이 효율에는 유의적인 차이가 없었으나 최종 체중은 대조군에 비해 HA100군에서 감소하는 경향이었다. 맹장무게와 하루 변배설량은 식이내 HAS량이 증가할수록 유의적으로 증가하였다. 맹장내용물의 pH는 식이 내 HAS량이 증가할수록 유의적으로 감소하였다. 혈장 내 총 지방, 중성지방, 총 콜레스테롤량은 HAS섭취가 증가하면 감소하였으나 HDL-콜레스테롤량과 간내 총 지방, 중성 지방, 콜레스테롤량은 HAS섭취에 의한 영향을 받지 않았다. 변을 통한 총 콜레스테롤의 배설량은 HA50군에서 대조군에 비해 유의적으로 증가하였다. 면역 기관인 흉선과 비장의 무게와 혈장의 Ig G와 $C_3$농도는 식이에 의해 영향을 받지 않았다. 비장세포의 증식 능력을 보았을 때 PHA에 의한 자극에는 식이의 영향이 없었으나 저용량의 Con A로 자극하였을 때 HA25, HA50에서 증식이 유의적으로 낮았고, 배양액 내 PGE$_2$의 생산량이 증가하는 경향을 보였다. 이를 종합해보면, HAS의 섭취는 체중감소의 효과가 있는 것으로 보이며, 맹장의 무게를 증가시키고, 맹장 내 pH를 낮추고, 혈액내 지방성분을 감소시키는 것으로 나타났다.

• Journal of Nutrition and Health
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• 제49권4호
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• pp.247-257
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• 2016

본 연구에서 2013~2014 국민건강영양조사 중 정량적 식품섭취빈도조사로 분석된 라면의 섭취 빈도 및 섭취량에 근거하여, 성인 남녀의 라면 섭취 실태 및 라면 섭취 정도에 따른 영양소 섭취 상태, 대사적 지표를 비교하고 이들과의 관련성을 분석하였으며, 그 결과는 다음과 같다. 우리나라 성인에서 라면의 섭취 빈도는 주당 1.2회 (남성 1.4회, 여성 0.9회)였으며, 섭취량은 주당 1.2개 (남성 1.5개, 여성 0.8개)로 나타났다. 주당 1개 이상의 라면을 섭취하는 군 (라면 고섭취군)과 미만으로 섭취하는 군 (라면 저섭취군)으로 분류하여 분석시, 라면 고섭취군의 경우 라면 저섭취군에 비해 연령은 유의적으로 낮았고, 허리둘레, 혈중 중성지방, 총 콜레스테롤 및 HDL-콜레스테롤 수준이 유의적으로 높았다. 또한 영양소 섭취에서 라면 고섭취군은 라면 저섭취군에 비해 총 열량 및 지방, 나트륨 및 비타민 $B_2$의 섭취 밀도는 유의적으로 높은 반면, 탄수화물, 인, 철, 칼륨, 비타민 A, 비타민 $B_1$, 나이아신 및 비타민 C의 섭취 밀도는 유의적으로 낮은 결과를 보였다. 또한 전체 대상자에서 교란인자의 보정 후 라면 섭취가 가장 높은 Q4군은 라면 섭취 정도가 가장 낮은 Q1군에 비해 고혈당의 odds ratio가 1.4 (95% CI: 1.1~1.8)였으며 (p for trend = 0.003), 여성에서는 라면 섭취 정도가 가장 높은 Q4군에서 Q1군에 비해 복부비만의 위험률이 60% (95% CI: 1.2~2.2) 높은 것으로 나타났다 (p for trend = 0.03). 이와 같은 결과는 라면의 섭취가 상대적으로 높은 우리나라에서 라면의 질적, 양적 섭취와 대사적 위험성을 의미하는 지표와의 관련성을 제안할 수 있는 근거자료가 될 수 있으며, 향후 라면 섭취가 건강상태에 미치는 영향에 관한 영양교육시 활용할 수 있는 기초자료가 될 수 있을 것으로 생각된다.