• 분석과학
• /
• 제26권1호
• /
• pp.51-60
• /
• 2013

본 연구는 c-$C_nF_{2n}$ (n=8, 9)과 $C_{10}F_{18}$ (perfluorodecalin)의 가능한 분자구조를 여러 이론 수준에서 최적화 하였으며, 각 화합물의 가장 안정한 분자구조 (global minimum)를 확인하고 전자 친화도를 계산하여 구조적 특성에 따른 전자 친화도와의 상호 연관성을 고찰하였다. 보다 정확한 전자 친화도를 계산하기 위하여 진동주파수를 계산하여 영점 진동 에너지를 보정하였으며, IR 스펙트럼을 예측하였다. 전자 친화도는 c-$C_8F_{16}$의 경우 ortho 위치에 두 개의 $-CF_3$ 치환기가 붙어있는 구조에 대하여 영점 진동 에너지를 보정한 MP2 이론 수준에서 1.18 eV로 계산되었으며, c-$C_9F_{18}$의 경우 하나의 $-CF_3$와 하나의 $-C_2F_5$ 치환기가 인접하여 붙어있는 구조에 대하여 1.37 eV로, 그리고 $C_{10}F_{18}$인 perfluorodecalin의 경우 1.38 eV로 예측되었다.

• KIEAE Journal
• /
• 제13권6호
• /
• pp.121-128
• /
• 2013

This study attempted to explore the MC design methods of modular construction using discontinuous double module grids and further, the design methods of walls. Modular construction is generally characterized with multiple units called modules with a module dimension of 3M(300mm) appearing in the form of double grids. The discontinuous double grids including correction values and gap values occurs inevitably in the modular construction where units are joined horizontally. Therefore, it is desirable to carry out the MC design taking into account these discontinuous double grids. In this study, the MC design was applied to the plane of wooden houses in modular construction, going through a process of setting the size of pillars and inside dimensions, of determining the dimension of discontinuous double grids that occur during the assembly of units, and of setting the dimension of outer walls in conjunction with the derived dimensions. The dimension of outer walls was applied differently depending on the range of regional use by analyzing the energy performance with the materials used. Consequently, the materials and components of factory-produced buildings can be used directly without processing, and the suitability of the outer wall design can be pre-determined by previewing the calculation of the cross-sectional configuration and heat transmission coefficients of outer walls in modular construction, allowing to be used as a decision-making tool of design.

• Nuclear Engineering and Technology
• /
• 제6권4호
• /
• pp.219-230
• /
• 1974

강한 방향성이 있는 다결정에 의한 중성자회절강도에 대한 재래의 공식을 결정의 반사율에 관한 Kunitomi 의식을 사용하여 수정하였다. 시료내의 grain 에서 회절이 일어나는 정화한 위치가 회절강도의 Maxwell곡선의 소각부분에 관한 이론치와 계산치를 비교함으로써 발견된다는 사실과 위의 회절강도 공식을 사용하여 금속내의 Preferred orientation을 백색중성자를 가지고 조사한 수 있는 방법을 고안하였다. 결정 내에서 일어나는 중성자비 다중반사와 흡수에 대해서 교정하여 원자로의 중성자 스펙트럼을 측정함으로써 열중성자의 확실성있는 파장이 1.025$\pm$0.001$\AA$임을 알았다. 대부분 cube-on-face 방향을 갖인 씰리콘 강철을 본 연구방법으로 조사차였는바 grain들이 압연방향에서 5도 이내에 배열되어 있다는 사실을 발견하였다. 커다란 결정에 적합한 이론들이 강한 방향성이 있는 다결정 물체에도 적응될 수 있음을 알게 되었다.

• 한국식품영양과학회지
• /
• 제28권5호
• /
• pp.1172-1179
• /
• 1999

The purpose of this study was to determine eating behaviors and nutrient intakes of 256 third grade primary school children(134:boys, 122:girls) in Kwangju. There were no significant differences in the heights, weights, physical circumferences measurements between the boys and girls, but the skinfold thickness measurements were significantly different. Most nutrient intakes were higher than the Rec ommended Dietary Allowances but the intake of energy, calcium, and vitamin E were lower than the RDA. The intakes of calcium, niacin, and vitamin E of the girls were significantly lower than those of the boys. With regard to meal volume, 13.6% of the subjects has been 'much'. With regard to meal speed, 24.6% of the subjects has been 'fast'. The study also found that 50% of the subjects skipped breakfast, 67.6% of the subjects had irregular meal times, 64.6% of the subjects ate snacks after dinner and 85.9% of the subjects ate snacks. These results show that the nutrient intake of children was related to snack eating more than regular meals. With regard to dietary behavior and nutrient intakes, meal volume, meal speed, skipping breakfast, eating snacks and eating snacks after dinner were major influences. But regularity of meal time was not influence on nutrient intakes. These results suggest that children's eating behaviors are in needs of correction. This reasserts the importance of nutrition education to children through teachers, parents and dietitians. The findings of this study should be applied to nutrition education to ensure better physical fitness of children.

• 대한핵의학회지
• /
• 제3권1호
• /
• pp.33-39
• /
• 1969

The conventional triolen absorption test has its defect in that the stool collection was cumbersome, time and energy-wasting. In the present study, the triolen absorption test was carried out using double tracer technique with $^{125}I-triolen\;and\;^{51}Cr_2O_3$ to determine if it can overcome the defect of the conventional method also with satisfactory results. Following were the results: 1. The clinical significance of this double tracer method was essentially the same with that previously done by radioactive. triolen alone. With the fractional fecal samples, the equation, y=0.626x+2.010 was substantiated, hence, this method appears to be clinically valuable if the appropriate correction is applied. With the mixed fecal samples, the equation y=0.642x+1.468 was substantiated (p<0.005) which appears to be also clinically valuable. When these two data were compared, the equation y=0.975x+0.090 (P<0.05) was substantiated, hence, $x{\fallingdotseq}y$. 2. The normal ranges of the fecal triolen excretion rate in this double tracer method were $3.46{\pm}1.69%$, namely, less than 6.9%. 3. The samplings were done from the first to third defecation in cases of clinically normal, and from the first to second defecation in cases of diarrhea or malabsorption. 4. The intestinal malabsorption of triolen was not observed in whom the triolen absorption was supposed to be clinically normal, however. a good number of suspicious malabsorptive cases showed the normal values.

• KIEAE Journal
• /
• 제15권5호
• /
• pp.107-112
• /
• 2015

Purpose: This study desires to investigate an effect of indoor temperature, humidity, and illuminance targeting a planting system of double-skin facade and cavity space adjacent to the outside within a certain period of winter. Through this, the study suggests a basic material about an energy conservation effect of double window system using planting to reduce heating load of a building in winter, so desires to contribute to indoor thermal comfort effect and illuminance correction study of double window and indoor plant. Method: Considering effects such as day and night climatic elements and air conditions in winter, illuminance measurement was conducted through a double-skin facade of space, a subject of the measurement, on the basis of practical residence time of a resident, and this study analyzed characteristics of indoor illuminance about this. The study measured and compared a change of insolation, dry-bulb temperature, and relative humidity at each indoor-outdoor measuring point, so measured and compared characteristics of an indoor temperature effect by elements of double-skin facade and indoor plant. Result: Through this study, the researcher could determine that indoor plant within double window in winter not only blocks solar radiation but also photosynthesizes, so is somewhat disadvantageous to winter thermal comfort reducing heating load. In addition, solar radiation going through interior plays a role to bring down somewhat high humidity to about 50% of reasonable humidity, so plays a direct role of maintenance of comfortable indoor space. Although there are effects such as blocking of solar radiation and temperature reduction, this has a positive influence on humidity control and proper illuminance distribution. The researcher could determine that illuminance, temperature, and humidity by solar radiation penetration for the whole measuring time play a role to supplement indoor environment mutually.

• 대한지역사회영양학회지
• /
• 제23권1호
• /
• pp.38-47
• /
• 2018

Purpose: The aim of this study was to analyze the association between sodium excretion and obesity for healthy adults in the Gwangju area. Methods: The participants included 80 healthy adults aged 19 to 69 years in Gwangju. The dietary intake and sodium excretion were obtained using the 24-hour recall method and 24 hour urine collection. The participants were classified into two groups according to the amount of urinary sodium excretion: (${\leq}141.75mmol/dL$, > 141.75 mmol/dL). Results: After adjusting for sex, age, smoking history, and income, the high excretion of sodium group was significantly higher for weight, body mass index, body fat mass, percent body fat, visceral fat area (VFA), waist circumference, hip circumference, and WHR. The energy and nutrients intake were significant after adjusting for sex, age, smoking history, and income. The LSE group had a significantly higher fat intake and Na/K intake ratio. The HSE group had significantly higher fiber intake, and K intake. As the amount of urinary sodium excretion increased, the risk of obesity before correction was 3.57 (95% CI: 1.13-11.25) times greater, and the risk of obesity of T3 increased significantly by 3.33 times (95% CI: 1.05-10.59). After correcting for sex and age, the obesity risk of T2 increased significantly by 4.23 times (95% CI: 1.11-16.06), and after correcting for sex, age, smoking history, and income, the obesity risk of T2 increased significantly by 6.81 times (95% CI: 1.44-32.19) the risk of obesity. Conclusions: An association exists between sodium excretion and obesity in Korean adults. In this study, the high excretion of sodium group was obese and the risk of obesity was higher than the low excretion of sodium group.

• 터널과지하공간
• /
• 제25권6호
• /
• pp.527-533
• /
• 2015

본 연구에서는 고정익 무인항공기(드론, SenseFly eBee)를 이용하여 국내 대규모 석회석 노천광산에 대한 지형측량을 수행하였다. 비행고도 300 m, 비행속도 12 m/s 조건으로 약 30분간 자동모드 비행을 수행한 결과 현장에서 총 288장의 항공사진을 촬영할 수 있었다. 특이점 추출이 불가능한 37장의 항공사진을 제외한 251장의 항공사진 자료들을 보정하고, 정합한 결과 7 cm 해상도의 정사영상과 수치표면모델 자료를 생성할 수 있었다. 4곳의 지상기준점에 대하여 고정밀 위성측정시스템를 이용하여 측정한 위치 좌표와 고정익 무인항공기 사진측량시스템을 이용하여 추출한 위치 좌표를 비교한 결과 평균 제곱근 오차가 15 cm 내외로 분석되었다. 고정익 무인항공기는 회전익 무인항공기에 비해 상대적으로 비행시간이 길어 넓은 영역의 신속한 지형측량이 가능하므로 대규모 노천광산 현장에서 효과적으로 활용될 수 있을 것이다.

• 공업화학
• /
• 제23권1호
• /
• pp.35-41
• /
• 2012

본 논문에서는 바이오연료 제품 품질 분석의 저가격화와 시간단축, 그리고 궁극적으로 바이오연료 생산 공정의 모니터링 실시간화를 해결하기 위해 적외선 분광분석과 화학계량학(Chemometrics)을 융합한 on-line 분광 모니터링 시스템을 제안하고자 한다. 화학계량학 중 부분최소자승법을 사용하여 적외선 spectrum과 성분 농도 간의 정량분석을 실시하였다. 몇 가지 전처리법과 변수 중요도척도를 이용하여 모델링한 결과 spectrum의 보정, 노이즈 감소, 검량선의 유지보수 등의 측면에서 Savitzky-Golay 전처리가 가장 우수함을 보였다. 본 연구의 결과를 통해 실시간 품질 측정뿐만 아니라 하나의 분광분석 장치로 여러 성분들의 동시 측정이 가능함을 확인함으로써 비용의 절감도 예상된다. 뿐만 아니라 결정계수 $R^2$이 0.99 이상으로 실험실분석의 대체도 가능하다.

• 대한의용생체공학회:의공학회지
• /
• 제37권3호
• /
• pp.112-118
• /
• 2016

The neck pain is fairly common occurance. Forward head posture and text neck are poor postures which may be related with neck pain but the evidence is not enough. We developed the wearable sensor which can assess the head & neck posture in daily life. Microprocessor, Bluetooth low energy, and 3-axis accelerometer, rechargeable battery and vibratior for reminding are used to implement the wearable sensor. Real-time algorithm to parameterize the posture for one epoch is implemented which classifies the posture in the epoch into three classed; dynamic, static_good posture, and static_poor posture. Also the algorithm makes reminding to its wearer to give them the prolonged poor posture is detected. The mean error of measurement was 1.2 degree. The correlation coefficient between neck angle and craniovertebral angle was 0.9 or higher in all cases. With the pilot study on text neck syndrome was also quatified. Average of neck angle were 74.3 degree during the listening in the classroom and 57.8 degree during the smartphoning. Using the wearable sensor suggested, the poor postures of forward head posture and neck neck can be detected in real-time which can remind the wearer according to his/her setting.