• Nutritional Sciences
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• 제5권2호
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• pp.84-90
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• 2002

The purpose of this study was to investigate the effects of dietary behavior on the nutritional status of university students in Korea. A dietary intake survey of 603 university students (223 males and 380 females) was conducted using a 24-hour recall method. The resulting data on dietary behavior and nutrient intakes were analyzed by the SAS program package. The main results were as follows : 1) Most of the subjects were in their twenties and no obese cases were found. 2) Dietary intake data showed that, except for vitamin C in the female students, the average daily intakes of most nutrients did lot meet the Korean Recommended Dietary Allowances (RDA). The study also showed that most of the subjects, especially the female students, were concerned about having satisfactory physical appearances. Fat provided 25% of the daily energy intake, and this level was higher than the 20% recommended by the Korean Dietary Guidelines. In the female students, the iron intake from animal foods was lower than that from plant foods. 3) Male students were not very serious about healthy eating. However, the female group, who obtained a high score in dietary behavior, consumed more vegetables and had higher intakes of energy, protein, Ca, p, vitamin A, and vitamin C than the male group, even though they did not meet the Korean RDA in most nutrients. Energy intake from fats, as a percent of total energy intake, was lower than in the group of females who obtained higher stores in dietary behavior than the other groups. To sum up, the university students surveyed in this study were found to have the typical dietary behavior of young adults, such as frequent eating out and snacking. Female students were extremely conscious of their body images this can exert an important direct influence on their dietary intakes and health status. It is very important for university students to develop healthy lifestyles and desirable dietary behaviors, to best enable them to continue to lead a healthy lift: in their later years.

• 한국재료학회지
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• 제17권3호
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• pp.152-159
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• 2007

When the electronics are tested with thermal shock for Pb-free solder joint reliability, there are temperature conditions with use environment but number of cycles for test don't clearly exist. To obtain the long term reliability data, electronic companies have spent the cost and times. Therefore this studies show the test method and number of thermal shock cycles for evaluating the solder joint reliability of electronic components and also research bonding strength variation with formation and growth of intermetallic compounds (IMC). SMD (surface mount device) 3216 chip resistor and 44 pin QFP (quad flat package) was utilized for experiments and each components were soldered with Sn-40Pb and Sn-3.0 Ag-0.5 Cu solder on the FR-4 PCB(printed circuit board) using by reflow soldering process. To reliability evaluation, thermal shock test was conducted between $-40^{\circ}C\;and\;+125^{\circ}C$ for 2,000 cycles, 10 minute dwell time, respectively. Also we analyzed the IMCs of solder joint using by SEM and EDX. To compare with bonding strength, resistor and QFP were tested shear strength and $45^{\circ}$ lead pull strength, respectively. From these results, optimized number of cycles was proposed with variation of bonding strength under thermal shock.

• 폴리머
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• 제24권6호
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• pp.837-844
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• 2000

본 연구에서는 반도체 봉지제로 사용되는 상용 EMC중 가속제의 함량이 다른 두 종류의 프리프레그에 대하여 그 경화거동을 등온 및 승온조건에서 시차 주사 역량계, 점도계 및 유전율 측정계를 이용하여 분석하였다. 경화반응 속도변수는 Kamal의 자동촉매 반응식을 이용하여 m+n을 2로 가정한 후 Ryan Dutta의 방법에 따라 계산에 의한 경화반응 속도의 예측 치와 실제 실험 데이터가 10$0^{\circ}C$를 제외한 나머지 온도에서는 잘 일치하는 경향을 나타내었다. 경화과정 중 겔화와 유리화와 같은 상 전이를 관찰하였으며 각각의 등온 경화온도에서 경화시간에 따른 유리전이 온도 ($T_{g}$ )를 측정하여 경화온도와 유리전이 온도가 같아지는 유리화점을 구할 수 있었고 절대온도와의 사이에 Arrhenius관계가 성립함을 확인하였다. 또한 평판형 전극을 이용한 DEA는 EMC의 경화 과정을 동정하는데 효과적으로 이용될 수 있음을 알 수 있었다. 같은 종류의 수지 시스템에서는 TTT diagram상에서 $_{gel}$$T_{g}$ 가속제의 농도에 상관없이 일정한 온도에서 나타남을 확인하였다.

• Journal of Preventive Medicine and Public Health
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• 제33권1호
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• pp.69-75
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• 2000

Objectives : This study was conducted to evaluate the risk factors associated with cardiovascular disease. Methods : By the questionnaire, the informations of education level, monthly income, alcohol consumption and smoking habit were obtained. Height, weight and blood Pressure(BP) were measured by a trained nurse. The level of lasting blood sugar(FBS), total cholesterol, hight-density lipoprotein(HDL) cholesterol and triglyceride were tested by enzyne method about a group of 2888 males and 1696 females ages ever 20 who had never taken the medication for hypertension. Statistical analysis, ANOVA, stepwise multiple regression, correlation analysis were peformed using SAS package program. Results : There were significant differences among age groups in systolic and diastolic blood pressure, body mass index(BMI), FBS, triglyceride and cholesterol except HDL-cholesterol. The risk factors associated with systolic and diastolic BP significantly in male were BMI, age, alcohol intake, but in female BMI, age. Smoking habit had a significant negative correlation with BP in both sex. In the group of mild hypertension ($\geq140\;mmHg\;or\geq90\;mmHg$ defined by JNC-VI) and hypertension ($\geq160\;mmHg\;or\;\geq95\;mmHg$ defined by WHO), the percent of diabetes $(FBS\geq140\;mg/dl)$, hypercholesterolemia $(\geq240mg/dl)$, and hypertriglyceridemia $(\geq200\;mg/dl)$ were significantly higher compared with normal group in male and female. BMI, and alcohol consumption had a positive correlation with FBS, total cholesterol and triglyceride. Smoking had a positive correlation with cholesterol and triglyceride but negative correlation with HDL-cholesterol in male. The educational attainment had a negative correlation with BMI, FBS, total cholesterol and triglyceride in female. Conclusions : This study suggested that drinking, smoking, and BMI and lower educational level were associated with hypertension, hyperlipidemia and diabetes, but further evaluation was needed by prospective intervention study.

• 패션비즈니스
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• 제12권2호
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• pp.134-152
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• 2008

Functional, aesthetic and symbolic working uniforms in the industrial complex are demanded by employees and employers. The purpose of this research was to find out the actual wearing condition and preference of the working uniform design in the industrial complex. The research selected 7 enterprise subjects located in the Changwon National Industrial Complex and adopted a questionnaire method. 912 workers categorized into 4 work groups according to their work posts replied in total. The data and the degrees of satisfaction/preference of the working uniforms were analysed into descriptive statistics and F-tests by using the SPSS S/W package. The results were as follows: First, the style of the working uniform was the standard two-piece style. Second, the degree of the satisfaction with the entrepreneurial image implied to the working uniform was 2.83 throughout the 5-scale evaluation. In addition, the degree of the satisfaction with the working uniform colors was in between 2.94 and 2.96. Third, unsatisfied parts of the upper and lower uniform garments were: sleeve > pocket > collar; and waist belt loop > hip pocket > hem line respectively. Fourth, beige was the most preferred color for the working uniform top and bottom both. The most preferred color images were the calm and safety and the bright and light in order. Especially, the demand on the safety factors and soil proof colors of the outside field workers was much higher than the clerical workers. Fifth, the blouson type jacket with shirts collar or soutien roll collar was more preferred to than the casual style; and the straight formal pants were more preferred to than the casual/sweat sports pants styles. Sixth, inner pockets to keep the mobile phone and pens were required for upper garment details specially by manufacture workers. Increase of the waist belt loop numbers was required by all work groups.

• 수산해양기술연구
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• 제49권1호
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• pp.58-66
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• 2013

Most of steam power plant in Korea are heating the feed water system to prevent freezing water flowing in the pipe in winter time. The heating system is operated whenever the ambient temperature around the power plant area below 5 degree Centigrade. But this kind of heat supplying system cause a lot of energy consuming. If we think about the method that the temperature of the each pipe is controled by attaching the temperature measuring sensor like RTD sensor and heat is supplied only when the outer surface temperature of the pipe is under 5 degree Centigrade, then we can save a plenty of energy. In this study, the computer program package for simulation is used to compare the energy consumption load of both systems. Energy saving rate is calculated for the location of Youngweol area using the data of weather station in winter season, especially the January' severe weather data is analyzed for comparison. Various convection heat transfer coefficients for the ambient air and the flowing water inside the pipe was used for the accurate calculation. And also the various initial flowing water temperature was used for the system. Steady state analysis is done previously to approximate the result before the simulation. The result shows that the temperature control system using RTD sensor represents the high energy saving effect which is more than 90% of energy saving rate. Even in the severe January weather condition, the energy saving rate is almost 60%.

• 대한방사선기술학회지:방사선기술과학
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• 제33권1호
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• pp.45-50
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• 2010

본 연구는 T2고속스핀에코 3.0T 자기공명영상에서 지방조직 소거기법인 SPAIR와 STIR기법의 임상적 유용성에 관한 비교연구를 시행하였다. SPAIR와 STIR 프로토콜을 사용하여 뇌의 축방향 영상(20개), 요추의 시상단면영상(20개), 고관절의 관상단면영상(17개), 무릎관절의 축방향 영상(25개)을 획득하였다. 검사부위별로 지방억제기법의 지방소거능력과 화질을 파악하기위해 지방조직의 신호강도와 불균일성을 측정하였다. 지방조직에서 불균일치는 측정된 지방 신호의 평균치(mean)에 대한 표준편차(SD)로서 그 산출은 SD/mean으로 계산하였다. 수집된 자료는 SPSS(Statistical Package for the Social Science) WIN 13.0 프로그램을 이용하여 분석한 결과 다음과 같은 결론을 얻었다. 첫째, 뇌 검사는 SPAIR가 STIR보다 지방억제능력과 화질면에서 우수한 결과를 나타냈으며, 둘째, 요추, 고관절, 무릎관절 검사는 지방의 신호억제능력은 STIR가 우수하고, 화질면에서는 SPAIR가 우수한 결과를 나타냈다.

• 한국강구조학회 논문집
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• 제22권3호
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• pp.241-251
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• 2010

본 논문에서는 등분포 하중을 받는 등방성 환형 섹터판의 지배방정식에 대한 새로운 해석적 해가 3차원 극좌표계에서 개발된다. 4차의 편미분방정식 형태를 가지는 지배방정식은 레비 타입 시리즈 해에 대한 가정과 그 후속적인 수학적 처리를 통해 4차의 상미분방정식으로 전환된다. 전환된 상미분방정식의 특성방정식에 대한 실수 영역 및 복소수 영역의 해를 해석적으로 구한 후 제차 및 비제차 방정식의 각 해의 조합으로 최종적인 지배방정식의 해가 완성된다. 개발된 해의 수렴성 및 정확성을 보여주기 위해 다양한 경계조건 및 내부 중심 각도를 가지는 판에 대한 예제 해석을 수행하였고 그 결과를 다른 해석적 연구결과와 비교하였다. 또한 개발된 해의 정확성을 확인하기 위하여 유한요소 프로그램인 ABAQUS를 이용한 탄성해석을 추가로 수행하여 그 결과를 비교하였다. 제안된 해로부터 결정된 환형 섹터판의 변위 및 모멘트 값은 여타의 해석적 및 수치적 접근방법으로 구한 값들과 비교해 본 결과 매우 높은 수준에서 일치하고 있음이 확인되었다.

• 한국연초학회지
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• 제20권2호
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• pp.191-197
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• 1998

Discriminant analysis using near infrared spectra derived from Korean Flue-cured(KF) and American Flue-cured(AF), and also Korean Burley(KB) and American Burley(AB) tobacco was done to classify flue-cured and burley tobacco as either grown in Korea or grown in the USA. Samples were scanned in the wavelength of 400 ～ 2500 nm by near infrared analyzer(NIRSystem Co., model 6500). The discrimination equations for flue-cured and burley tobacco were developed using partial least square 2 method in Infrasoft International NIRS 3 software package. KF samples used for the development of the discrimination equations were higher contents of total sugar, crude ash and chlorine, and higher value of leaf density and brightness, but lower contents of nicotine, total nitrogen and ether extracts, and higher value of redness than those of AF samples. KB samples were higher contents of nicotine, crude ash and chlorine, but lower contents of ether extracts and value of brightness than those of AB samples. On 3 dimensional graph drawn with 3 principal component scores calculated with 3 principal component from KF and KB sample spectra, KF sample spectra were significantly different from AF, and also KB sample spectra were significantly different from AB. The discrimination equations of flue-cured and burley were developed with 3 principal component, respectively. The discrimination equations for flue-cured and burley had a standard error of 0.03 and 0.04, and a R2 of 0.88 and 0.84, respectively. The tobacco samples used for the development of discrimination equation were perfectly classified as KF and AF by flue-cured discrimination equation, and also perfectly classified KB and AB by burley discrimination equation, respectively. The correct classification rates of KF and AF samples not used for the development of discrimination equations were 9S % (828 out of 869 samples) and 98 % (98 out of 100 samples) by flue-cured discrimination equations, and KB and AB samples were 94%(345 out of 368 samples) and 100%(42 out of 42 samples) by burley discrimination equations, respectively.

• Computers and Concrete
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• 제25권1호
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• pp.67-73
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• 2020

Traditionally used analytical approach to predict the fatigue failure of reinforced concrete (RC) structure is generally conservative and has certain limitations. The nonlinear finite element method (FEM) offers less expensive solution for fatigue analysis with sufficient accuracy. However, the conventional implicit dynamic analysis is very expensive for high level computation. Whereas, an explicit dynamic analysis approach offers a computationally operative modelling to predict true responses of a structural element under periodic loading and might be perfectly matched to accomplish long life fatigue computations. Hence, this study simulates the fatigue behaviour of RC beams with finite element (FE) assemblage presenting a simplified explicit dynamic numerical solution to show computer aided fatigue behaviour of RC beam. A commercial FEM package, ABAQUS has been chosen for this complex modelling. The concrete has been modelled as a 8-node solid element providing competent compression hardening and tension stiffening. The steel reinforcements are simulated as two-node truss elements comprising elasto-plastic stress-strain behaviour. All the possible nonlinearities are duly incorporated. Time domain analysis has been adopted through an automatic Newmark-β time incremental technique. The program consists of twelve RC beams to visualize the real behaviour during fatigue process and to obtain the reliability of the study. Both the numerical and experimental results indicate a redistribution of stresses along the time and damage accumulation of beam which severely affect the serviceability and ultimate capacity of RC beam. The output of the FEM analysis demonstrates good match with the experimental consequences which affirm the efficacy of the computer aided model. The controlled fatigue damage evolution at service fatigue load limits makes the FE model an efficient tool in predicting high cycle fatigue behaviour of RC structures.