• 한국식품저장유통학회지
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• 제30권5호
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• pp.743-757
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• 2023

The formulation of a novel functional fresh apple juice enriched with dietary prebiotic fiber (inulin or polydextrose), ginger extract (GE), and cardamom essential oil (CEO) was carried out based on a combined D-optimal design. In the first stage, sensory evaluation was performed to screen and select the optimum sample for further experiments. The sensory evaluation showed that the sample containing inulin 0.25 g/100 g GE and 0.03 g/100 g CEO had the highest organoleptic score. In the second stage, various chemical experiments, including pH, acidity, formalin index, total phenol, flavonoids, antioxidant capacity, and vitamin C content, were evaluated on the selected enriched apple juices. The addition of GE and CEO caused changes in nutritional characteristics, including antioxidant capacity, total phenol, flavonoids, vitamin C, and IC50, from 35 g/100 g, 350 mg GAE/g, 17 mg/L, 370 mg/kg, and 1,800 mg/kg to 45 g/100 g, 460 mg GAE/g, 21 mg/L, 420 mg/kg, and 1,200 mg/kg respectively. The steady shear flow and dynamic oscillatory shear rheological tests were also performed on the screened samples, and results showed that the addition of dietary fiber in apple juices increased the apparent viscosity, storage modulus, loss modulus, and complex viscosity. In general, adding plant extracts and processed essential oil to apple juice increased the nutritional-nutraceutical value and sensory attributes of apple juice.

• 한국군사과학기술학회지
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• 제27권1호
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• pp.43-50
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• 2024

Large planar military antenna boasts a range of electrical components, including TRA(Transmit-Receive Assembly), signal processors, etc. which engage in computations and calculations. These processes generate a significant amount of heat, leading to unforeseen consequences for the equipment. To mitigate these adverse effects, it's imperative to implement a cooling system that can effectively reduce heat-related issues. Given the antenna's intricate nature and the multitude of components it houses, a two-step estimation process is necessary. The first step involves a comprehensive model calculation to determine the total flow characteristics, while the second step entails a thermal analysis of individual TRA set. In this study, we depicted an antenna set using simplified 3D models of its components, considering their material and thermal properties. The sequential analysis process facilitated the calculation of branched flow rates, providing insights into the individual TRA. This approach also allowed us to design a cooling system for the TRA set, assessing its thermal stability in high-temperature environments. To ensure the optimal performance of TRA, breaking down the analysis into stages based on the cooling system's structure can assist operators in predicting numerical results more effectively.

• 한국방재학회 논문집
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• 제8권5호
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• pp.137-145
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• 2008

이 연구는 계획규모를 초과하는 홍수량으로 인하여 예상되는 하천범람피해를 경감하기 위한 지하방수로 계획에서의 적정 위치선정 및 규모를 결정하기 위한 기초분석기술에 대한 것으로서, 1998년과 2001년에 집중호우로 일부제방의 범람 및 붕괴에 의해 막대한 손실이 발생한 중랑천을 대상으로 하였다. 지하방수로의 유입부 위치는 200년 빈도홍수에 취약한 서울시경계, 당현천 합류부, 월계 1교, 묵동천 합류부의 4곳을 후보지로 선정하였고, 유출부는 국공유지로서 사용이 가능한 중랑천하구부와 한강의 반포대교 우안부을 선정하였다. 유입부의 월류고별 횡월류량을 산정하고 홍수저감효과를 분석하였다. 검토결과, 유입부의 위치는 당현천 합류부가 적정한 것으로 판단되었는바, 이곳에 지하방수로 유입부를 설치하였을 때 홍수저감효과가 가장 큰 것으로 나타났다. 지하방수로의 적정규모검토를 위해 방류구 운영규칙을 단순저류, 일정률, 일정량, 일정률+일정량의 혼합방류의 4가지 방식을 기본으로 하는, 총 8가지 경우를 적용하여 비교 분석하였다. 200년 규모의 홍수에 대응하는 지하방수로의 적정규모를 검토한 결과 방수로의 크기는 단순저류(Rule D)일때 가장 큰 규모인 직경 12 m로 분석되었고, 일정률 방류(Rule E)에서는50%방류에서 직경 9 m, 일정량 방류(Rule F)에서는 직경 8 m, 일정량 + 일정률 방류(Rule G)의 경우는 직경 7 m로 각각 산정하였다. 이 연구에서 제시한 검토과정은 하천제방의 범람으로 연안의 침수피해가 막대할 것으로 예상되는 경우에 EAP 차원에서의 방수로 건설 계획에 유용할 것으로 판단된다. 또한, 중랑천 방수로를 건기시에는 서울시와 의정부지역을 연결하는 지하 도로로 활용하는 방안을 함께 고려함으로써 방수로의 활용성을 크게 증대시킬 수 있을 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권8호
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• pp.1172-1180
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• 2013

Two experiments were conducted to determine the standardized ileal digestible (SID) lysine (Lys) requirement and the ideal SID threonine (Thr) to Lys ratio for finishing barrows. In Exp. 1, 120 barrows with an average body weight of $72.8{\pm}3.6$ kg were allotted to one of six dietary treatments in a randomized complete block design conducted for 35 d. Each diet was fed to five pens of pigs containing four barrows. A normal crude protein (CP) diet providing 15.3% CP and 0.71% SID Lys and five low CP diets providing 12% CP with SID Lys concentrations of 0.51, 0.61, 0.71, 0.81 and 0.91% were formulated. Increasing the SID Lys content of the diet resulted in an increase in weight gain (linear effect p = 0.04 and quadratic effect p = 0.08) and an improvement in feed conversion ratio (FCR) (linear effect p = 0.02 and quadratic effect p = 0.02). For weight gain and FCR, the estimated SID Lys requirement of finishing barrows were 0.71 and 0.71% (linear broken-line analysis), 0.79 and 0.78% (quadratic analysis), respectively. Exp. 2 was a 26 d dose-response study using SID Thr to Lys ratios of 0.56, 0.61, 0.67, 0.72 and 0.77. A total of 138 barrows weighing $72.5{\pm}4.4$ kg were randomly allotted to receive one of the five diets. All diets were formulated to contain 0.61% SID Lys (10.5% CP), which is slightly lower than the pig's requirement. Weight gain was quadratically (p = 0.03) affected by SID Thr to Lys ratio while FCR was linearly improved (p = 0.02). The SID Thr to Lys ratios for maximal weight gain and minimal FCR and serum urea nitrogen (SUN) were 0.67, 0.71 and 0.64 using a linear broken-line model and 0.68, 0.78 and 0.70 using a quadratic model, respectively. Based on the estimates obtained from the broken-line and quadratic analysis, we concluded that the dietary SID Lys requirement for both maximum weight gain and minimum FCR was 0.75%, and an optimum SID Thr to Lys ratio was 0.68 to maximize weight gain, 0.75 to optimize FCR and 0.67 to minimize SUN for finishing barrows.

• Asian-Australasian Journal of Animal Sciences
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• 제20권11호
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• pp.1705-1712
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• 2007

The effect of different tropical feed sources on rumen ecology, cellulolytic bacteria, feed intake and digestibility of beef cattle was investigated. Four fistulated, castrated male crossbred cattle were randomly allocated to a $4{\times}4$ Latin square design. The treatments were: T1) urea-treated (5%) rice straw (UTS); T2) cassava hay (CH); T3) fresh cassava foliage (FCF); T4) UTS:FCF (1:1 dry matter basis). Animals were fed concentrates at 0.3% of body weight on a DM basis and their respective diets on an ad libitum basis. The experimental period was 21 days. The results revealed that the use of UTS, CH, FCF and UTS:FCF as roughage sources could provide effective fiber and maintain an optimal range of ruminal pH and $NH_3-N$. Total viable and cellulolytic bacterial populations were enhanced (p<0.05) with UTS as the roughage source. Animals fed FCF had a higher rumen propionate production (p<0.05) with a lower cellulolytic bacteria count. Moreover, three predominant cellulolytic bacteria species, namely Fibrobacter succinogenes, Ruminococcus albus and Ruminococcus flavefaciens, were found in all treatment groups. Roughage intake and total DM intake were highest with UTS (2.2 and 2.5% BW, respectively) as the roughage source (p<0.05). Nutrient intake in terms of organic matter intake (OMI) was similar in UTS, CH and UTS:FCF treatments (8.0, 6.8 and 8.7 kg/d, respectively), while crude protein intake (CPI) was enhanced in CH, FCF and UTS:FCF as compared to the UTS treatment (p<0.05). Digestion coefficients of DM and organic matter (OM) were similar among treatments, while the CP digestion coefficients were similar in CH, FCF and UTS:FCF treatments, but were higher (p<0.05) in CH than in UTS. CP and ADF digestible intakes (kg/d) were highest (p<0.05) on the CH and UTS treatments, respectively. It was also observed that feeding FCF as a full-feed resulted in ataxia as well as frequent urination; therefore, FCF should only be fed fresh as part of the feed or be fed wilted. Hence, combined use of FCF and UTS as well as CH and FCF were recommended.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2004년도 추계학술발표회 발표논문집
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• pp.99-100
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• 2004

AMBIDEXTER-NEC의 천이노심은 $^{Nat}Th$과 $^{Nat}U$의 주입만으로 전 출력의 Break-even 노심에 도달하기위한 중간 단계이다. 선행연구에서 수행한 전 출력노심인 평형노심의 핵종수밀도에 도달하기 위해서 평형노심에서의 기저물질, 잠재핵분열성물질, 핵분열물질의 수밀도를 각 SEU-기반, Pu-기반, ADS-기반에서 그대로 유지하여 초기노심을 구성하였다. 또 각 시나리오에 대해 최대첨두출력과 원자로의 안전성을 고려해 Excess Reactivity를 5mk 내에서 초기노심을 결정하였다. 각 노심은 주 핵분열성물질 $^{235}U$, $^{239}Pu$ 및 $^{233}U$의 핵반응단면적 특성에 따라 평균 전환율이 각각 0.95, 0.83 및 1 .21 로서 핵연료물질의 적절한 선택만으로도 전환로, 연소로 및 증식로로 설계할 수 있음을 보여준다. 이러한 $Th/^{233}U$, U/Pu 핵연료주기를 사용하는 AMBIDEXTER-NEC 용융염핵연료 원자로의 초기노심에서 시작한 천이노심은 평형노심에장전할 충분한 $^{233}U$ 양을 확보해야 하므로 천이노심의 목표는 평형노심 $^{233}U$의 요구량에 최소한의 기간에 가장 적은 외부주입을 통해 도달하는 것이다. 천이노심에서 임계가 유지되는 AMBIDEXTER-NEC 원자로시스템의 3군 핵종변환 코드인 HELIOS-SQUID-AMBIBURN 체제를 개발하였고 그림 1.에 나타내었다. 이 알고리즘은 각 초기노심 중원소의 미시단면적, 중원소를 제외한 원소들의 거시단면적, 임계도를 만족하는 중성자속 및 외부주입율을 계산하여 SQUID 및 AMBIBURN 입력자료를 제공한다. 또한 일정시간 중원소의 핵종농도, 외부주입율과 중성자속이 일정하다는 가정 하 에 반복수행 하고 SEU-기반과 Pu-기반의 경우에는 각각 핵변환을 거쳐 재순환되는 $^{233}U$ 및 $^{239}Pu$의 양을 바로 주입하는 최대재순환 경우와 평형노심 요구 장전량에 이를 때까지 시설 내 저장하는 최소재순환 경우로 상황을 모사하였다. 그림 2 는 각 시나리오별 초기노심에서부터 200FPD까지 단위 용융염 체적당 $^{233}U$의 수밀도 시간변화를 나타낸 것이다. 그림을 보면 50일 이후부터는 수밀도의 변화가 일정한 기울기를 보이고 있고 재처리공정에서 $^{233}Pa$를 분리하는 최소재순환의 경우에는 최대재순환보다 2-3%정도에 지나지않아 그림에서 나타내지않았다. SEU-기반 및 Pu-기반에서 $^{233}U$의 증가율이 각각 2.54E+13, 2.81E+13 #/cc/d 로 Pu 기반이 조금 더 큰 증가율을 나타내고 있지만 평형노심 농도 1.04E+20 #/cc/d 에 도달하기 위해서는 두 경우 모두 매우 긴 시간이 걸릴 것을 예상할 수 있다. 요컨대 250MWth AMBIDEXTER-NEC가 평형노심을 이루기 위해 필요로 하는 $^{233}U$을 생산하는데 제안한 SEU-기반, Pu-기반 시나리오는 천이노심주기기간이 전형적인 원자로 수명 3-40년 보다 매우 큰 것으로 나타났다. 따라서 장전될 $^{233}U$의 확보를 위한 최적옵션은 초기노심부터 ADS와 같은 외부생산시설로부터 전량을 공급 받아 운전하는 것이라 판단된다.

• 한국터널지하공간학회 논문집
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• 제16권6호
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• pp.585-597
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• 2014

본 연구에서는 받음각이 $45^{\circ}$인 경우에 대해 사각이 $0^{\circ}$와 $6^{\circ}$이고 S/d비가 1.3~12사이인 시험조건에 대해 슬림 코니컬커터를 사용하여 선형절삭시험동안 발생하는 커터작용력을 측정하였다. 각 시험조건에서 커터작용력인 연직력, 절삭력, 구동력을 측정하였고 그 측정결과의 평균값을 사용하여 분석을 실시하였다. 커터관입깊이가 깊어질수록 비에너지가 감소하였고 커터관입깊이에 따른 커터작용력의 변화는 사각이 $6^{\circ}$인 경우가 작게 나타났다. 이와 같은 결과로부터 사각이 $6^{\circ}$인 경우가 $0^{\circ}$인 경우에 비해 장비설계측면에서 효과적인 것으로 판단된다. 또한 $F_c/F_n$은 사각이 $6^{\circ}$일 때가 $0^{\circ}$인 경우에 비해 작게 나타났다. 그러나 사각이 있을 경우 구동력의 증가가 나타날 수 있으므로 이에 대한 고려가 필요하다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권1호
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• pp.126-142
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• 2016

This paper presents a wide-frequency-range, low-power transceiver with an automatic impedance-matching calibration for TV-white-space (TVWS) application. The wide-range automatic impedance matching calibration (AIMC) is proposed for the Drive Amplifier (DA) and LNA. The optimal $S_{22}$ and $S_{11}$ matching capacitances are selected in the DA and LNA, respectively. Also, the Single Pole Double Throw (SPDT) switch is integrated to share the antenna and matching network between the transmitter and receiver, thereby minimizing the systemic cost. An N-path filter is proposed to reject the large interferers in the TVWS frequency band. The current-driven mixer with a 25% duty LO generator is designed to achieve the high-gain and low-noise figures; also, the frequency synthesizer is designed to generate the wide-range LO signals, and it is used to implement the FSK modulation with a programmable loop bandwidth for multi-rate communication. The TVWS transceiver is implemented in $0.13{\mu}m$, 1-poly, 6-metal CMOS technology. The die area of the transceiver is $4mm{\times}3mm$. The power consumption levels of the transmitter and receiver are 64.35 mW and 39.8 mW, respectively, when the output-power level of the transmitter is +10 dBm at a supply voltage of 3.3 V. The phase noise of the PLL output at Band 2 is -128.3 dBc/Hz with a 1 MHz offset.

• 한국보건간호학회지
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• 제16권2호
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• pp.239-253
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• 2002

Health care for women regularly focuses on the reproductive system to the exclusion of other health needs. The lack of research focusing on women's common health issues is a major problem to the enhanced optimal level of women's health. Health care providers have to recognize biological and social differences between men and women. This study was conducted to identify the baseline data and their correlation of health perception, health behavior, and health status of adult women for developing nursing intervention. The study was a descriptive correlational design. A convenient sampling method was used for collecting data from 103 adult women, over 18 years of age, during the period from Sep 1 to Nov 30, 2001. The study's subjects were interviewed using a structured questionnaire. The instruments for this study were the health perception scale modified by Lee(1985) based on the tool developed by Ware(1977) and Jenkins (1966), and the health behavior scale by Ko, Kumja(1987). Health status was measured by the short form Cornell Medical Index(CMI) modified by Nam, Hochang(1965). The data were analyzed SPSS PC+, by frequency, mean, t-test, ANOVA, and Pearson correlation coefficients. Also, the Duncan test was utilized for a post hoc test of ANOVA. The results of this study are as follows: 1. The mean score for health perception was 3.02(S.D=0.39) on a 5 point scale. 2. The mean score for health behavior was 3.08(S.D=0.43) on a 5 point scale. 3. The mean score for health status was 18.54 on 58 items. The mean score for physical symptoms of a subscale of health status was 11.30 on 36 items and the mean score for psychological symptoms was 7.37 on 22 items. 4. The relationship of sociodemographic variables to health perception. health behavior, and health status of women.: 1) There were significant differences in the scores of health perception by disease experience(t=-3.37, p=0.00). 2) There were significant differences in the scores of health behavior by age(F=10.52, p=0.00), height(F=4.73, p=0.01), marital status(t=-5.56, p=0.00), educational background(t=2.90, p=0.00), and drinking or non-drinking(t=2.17, p=0.03). 3) There were significant differences in the scores of health status by educational background(t=2.28, p=0.02) and disease experience(t=2.61, p=0.01). 5. Health perception showed significant positive correlation with health behavior(r=0.39, p=0.00). Health perception showed significant negative correlation with health status(r=-0.44, p=0.00), that is, the more women perceived health, the less she complained about unhealthy symptoms. Health behavior had no significant correlation with health status but showed a positive correlation with psychological symptoms of a subscale of health status(r=-0.19, p=0.05). Many of the leading causes of disease are preventable through changes in health perception and behavior. The need to increase individual awareness of relationships among health perception, health behavior, and health status and to enhance knowledge regarding the long-term effects of positive health behaviors, is an important nursing strategy for women's health promotion.

• 대한기계학회논문집B
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• 제35권12호
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• pp.1285-1292
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• 2011

본 연구에서는 전자식 팽창밸브를 적용한 반도체 공정용 칠러에 관한 실험적 연구를 통해 시스템 특성을 파악하였다. 또한 온도 변화에 따른 신속한 대응을 할 수 있도록 온도상승 및 하강실험, 부하변화에 따른 온도영역별 제어정밀도 실험을 함으로써 각 제어 방식에 따른 운전 특성을 파악하였다. 온도상승 시 소비전력은 8.9 kW로 측정되었으며 CH1이 37.5분, CH2가 39.5분이 소요되었으며, 온도하강에는 총 26.5분이 소요되었다. 부분부하가 적용되는 경우 전부하가 적용되는 경우에 비해 제어정밀도의 변화폭이 큰 것으로 나타났으며 스텝모터 구동방식을 적용한 CH2의 제어정밀도가 상대적으로 우수한 것으로 나타났다. 냉각수를 이용한 냉각사이클 영역에서 소비전력은 1.8 kW로 냉동사이클을 적용한 방식에 비해 절반가량으로 감소된 것으로 나타났다. 본 연구는 실험결과를 바탕으로 반도체 공정용 칠러의 최적제어방안을 제시하였다.