• 한국농공학회논문집
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• 제62권2호
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• pp.63-73
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• 2020

Drought is considered as a devastating hazard that causes serious agricultural, ecological and socio-economic impacts worldwide. Fundamentally, the drought can be defined as temporarily different levels of inadequate precipitation, soil moisture, and water supply relative to the long-term average conditions. From no unified definition of droughts, droughts have been divided into different severity level, i.e., moderate drought, severe drought, extreme drought and exceptional drought. The drought severity classification defined the ranges for each indicator for each dryness level. Because the ranges of the various indicators often don't coincide, the final drought category tends to be based on what the majority of the indicators show and on local observations. Evaporative Stress Index (ESI), a satellite-based drought index using the ratio of potential and actual evaporation, is being used as a index of the droughts occurring rapidly in a short period of time from studies showing a more sensitive and fast response to drought compared to Standardized Precipitation Index (SPI), and Palmer Drought Severity Index (PDSI). However, ESI is difficult to provide an objective drought assessment because it does not have clear drought severity classification criteria. In this study, U.S. Drought Monitor (USDM), the standard for drought determination used in the United States, was applied to ESI, and the Percentile method was used to classify drought categories by severity. Regarding the actual 2017 drought event in South Korea, we compare the spatial distribution of drought area and understand the USDM-based ESI by comparing the results of Standardized Groundwater level Index (SGI) and drought impact information. These results demonstrated that the USDM-based ESI could be an effective tool to provide objective drought conditions to inform management decisions for drought policy.

• 대한산업공학회지
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• 제41권2호
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• pp.121-127
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• 2015

A reduction of motor performance due to brain disorders can be screened by evaluating force tracking capabilities (FTCs). Existing studies have examined FTCs mainly using simple sinusoidal waves, of which repeated profiles have a critical limitation due to a learning effect in force tracking. The present study examined the effects of personal factors (age and gender) and sinusoidal wave factors (central force and complexity) on FTCs of healthy adults using composite sinusoidal wave profiles (CSWPs). FTCs were measured using Finger $Touch^{TM}$ for 30 seconds and quantified in terms of time within the target range (TWR, accuracy measure) and relative RMSE (RRMSE, variability measure). A total of 90 healthy adults in 20s to 70s with the equal gender ratio participated in the experiment consisting of combinations of 2 central force levels (6 N and 10 N) and 2 complexity levels (approximate entropy, ApEn = 0.03 and 0.06) of CSWPs. Significantly decreased FTCs (lower TWR and higher RRMSE) were found in aged adults, females, the low central force, and the high complexity. The detailed FTC decrements include a 43% reduced TWR and a 85% increased RRMSE of older adults in 70s as compared to those in 20s, a 17% reduced TWR and a 17% increased RRMSE of female as compared to those of male, a 30% reduced TWR and a 108% increased RRMSE at central force = 6N when compared to those at central force = 10N, and a 19% reduced TWR and a 30% increased RRMSE at ApEn = 0.06 as compared to those at ApEn = 0.03. The characteristics of FTCs for CSWPs can be of use in establishing an assessment protocol of motor performance for screening brain disorders.

• 한국식품과학회지
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• 제49권1호
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• pp.1-7
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• 2017

본 연구에서는 국내산 특수용도 쌀품종 내 전분의 분자 및 결정 구조적 특성과 소화 특성을 분석하고 상관성을 살펴봄으로써 향후 쌀가공식품들을 개발하는 기초자료로 활용하고자 하였다. 백진주1호 전분은 다른 쌀품종에 비하여 아밀로스 함량, 아밀로펙틴의 분자량, A 사슬 (DP 6-12), 페이스팅 온도, 치반점도, SDS 함량은 유의적으로 낮았으며 아밀로펙틴의 B1 사슬(DP 13-24), 상대적 결정성, 호화온도($T_o$, $T_p$, $T_c$), 호화 엔탈피(${\Delta}H$), 최고점도, 강하점도, RDS 함량이 유의적으로 높은 결과를 나타냈다. 소화율과 구조 및 이화학적 특성 간의 상관성을 분석한 결과 RDS 및 SDS는 아밀로스 함량, 결정성, 호화 온도와 높은 상관성을 보였으며 이는 쌀전분의 구조적 특성과 이화학적 특성의 차이가 전분의 소화율에 영향을 미친 것으로 생각된다. 국내에서 생산된 4가지 특수용도 쌀품종의 전분 분자 및 결정 구조적 특성, 이화학적 특성, 및 소화율 특성이 다르게 나타났으며 이러한 결과는 특수용도 쌀품종을 활용한 가공제품개발에 기초자료로 활용될 것으로 기대된다.

• 한국터널지하공간학회 논문집
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• 제19권3호
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• pp.355-373
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• 2017

도심지에서의 터널굴착은 상부구조물과의 상호거동에 대한 이해가 필수적이다. 도심지에 사용중인 대부분의 구조물은 말뚝기초로 상부의 하중을 지지하고 있어, 터널 굴착 시 반드시 영향을 받는다. 따라서 본 연구에서는 실내모형시험을 통해 기존의 군말뚝 기초 하부 터널굴착에 따른 축력 분포와 지반의 거동을 분석하였다. 말뚝 기초는 2, 3 열 말뚝으로 가정되었으며, 말뚝 선단부와 터널 천단부의 이격거리는 터널직경에 대한 일반화를 위해 터널 직경(D) 대비 0.5D, 1.0D 그리고 1.5D로 고려되었다. 지반은 약 30%의 상대밀도(Dr)를 가지는 느슨한 사질토로 형성되었으며, 말뚝의 축력 분포를 측정하기 위해 말뚝에 변형률게이지(strain gauge)를 부착하였다. 또한, 이격거리에 따른 군말뚝의 침하와 인접지반의 침하를 변위센서(linear variable differential transformer; LVDT)와 다이얼게이지(dial gauge)를 통해 측정였으며, 터널굴착에 따른 지중의 변형을 근거리사진계측기법(close range photogrammetric technique)을 통해 측정하였다. 수치 해석을 통해 실내모형시험 및 근거리사진계측 결과와 비교 분석하였다. 본 연구에서는 체적손실율(volume loss; $V_L$) 개념을 이용하여 터널굴착을 모사하였으며, 1.5%로 적용되었다. 연구결과, 이격거리가 멀어질수록 말뚝의 축력감소는 작게 나타났으며, 침하량은 모두 유사한 경향을 나타내었다. 특히, 말뚝 선단부와 터널 천단부의 이격거리가 0.5D에서 1.0D로 증가할 때 축력과 침하량의 가장 큰 감소율이 가장 큰 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권3호
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• pp.390-395
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• 2002

Two experiments were conducted to study the performance and carcass characteristics of Hanwoo (Korean native beef cattle) steers (Experiment 1) and the nutrient digestibility of sheep (Experiment 2) when the animals fed diets containing four levels of dried wormwood (Artemisia sp.). For both experiments the animals were given a basal diet consisting of rice straw and concentrate mixed at 3:7 ratio (on DM basis). In Experiment 1, the treatments were designed as a completely randomized design with two feeding periods. Steers were allotted in one of four dietary treatments, which were designed to progressively substitute dried wormwood for 0, 3, 5 and 10% of the rice straw in the basal diet. Bodyweight gain and average daily gain (ADG) of Hanwoo steers fed diets containing the 5 and 10% wormwood inclusion were greater (p<0.05) than the 3% wormwood-feeding group. Total and daily intakes of roughage and concentrate were not altered by all levels of dried wormwood inclusion. However, the 10% dried wormwood inclusion led to increased total feed intake (p<0.05) compared with that of the 0 and 3% of dried wormwood inclusion. Carcass weight, carcass yield and backfat thickness were not altered by dried wormwood inclusion. The highest level of dried wormwood inclusion resulted in significantly increased (p<0.05) loin-eye area compared with the 0 and 5% levels of dried wormwood inclusion. Experiment 2 was designed by a $4{\times}4$ Latin square with four periods. Sheep were allocated in one of four dietary treatments as same as in Experiment 1. Digestibilities of DM and TDN were significantly increased (p<0.05) in sheep fed the diet containing all three levels of dried wormwood inclusion compared with the control treatment. Digestibilities of CP and crude fiber in the 5% dried wormwood inclusion highly increased (p<0.05) up to 8.2 and 5.5% respectively relative to the control treatment. The palatability was significantly improved (p<0.05) by the 5% dried wormwood inclusion compared with the control treatment. It is concluded that feeding diets containing dried wormwood substituted for equal weights of rice straw at 5 and 10% levels would be anticipated to provide better quality roughage for beef cattle production and higher income for beef cattle producers.

• Asian-Australasian Journal of Animal Sciences
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• 제21권10호
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• pp.1395-1403
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• 2008

The objective of the present study was to estimate genetic parameters for economic traits in Markhoz goats. Data collected from 1993 to 2006 by the Markhoz goat Performance Testing Station in Sanandaj, Iran, were analyzed. The traits recorded as body weight performance at birth (BW), weaning (WW), six month (6MW), nine month (9MW), yearling (YW) and yearling fleece weight (YFW) were investigated. Least square analyses were used for estimation of environmental effects. Genetic parameters were estimated with single and multi trait analysis using restricted maximum likelihood (REML) procedures, under animal models. By ignoring or including maternal additive genetic effects and maternal permanent environmental effects, five different models were fitted for each trait. The effects of sex, type of birth, age of dam and year of birth on the all body weights were significant (p<0.01), but had no effects on YFW except year of birth. Age of kids had significant influences on WW and 6MW (p<0.01). A log likelihood ratio test was carried out for choosing the most suitable model for each trait. Total heritability estimates for YFW and growth traits varied from 0.16 for YFW and WW to 0.41 for YW. For all traits, maternal heritability was lower than direct heritability, ranging from 0.06 for BW to 0.01 for 6MW and 9MW. The magnitude of $c^2$ was more substantial for BW than the others, and relative importance was reduced from 0.12 for BW to 0.04 for 9MW. The direct additive genetic correlations estimates were positive and varied from 0.21 between BW-YW to 0.96 between WW-6MW. Direct additive genetic correlations between YFW and body weight traits were positive and ranged from 0.14 between BW-YFW to 0.67 between 6MW-YFW. For all traits, the corresponding estimates for phenotypic correlation were positive and lower than genetic correlations. The maternal additive genetic correlations between various traits were varied and ranged from -0.19 between 9MW-YFW to 0.96 between 6MW-9MW. The estimates of the maternal permanent environmental correlations between various traits were positive and ranged from 0.33 between WW-YFW to 0.93 between WW-6MW. Also, the environmental correlations between various traits ranged from 0.01 between BW-YFW and WW-YFW to 0.70 between 9MW-YW. Estimates of genetic parameters for various traits in this study confirm that selection should be applied on WW for genetic improvement in Markhoz goats.

• Asian-Australasian Journal of Animal Sciences
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• 제28권7호
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• pp.1006-1013
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• 2015

Heat-stress remains a costly issue for animal production, especially for poultry as they lack sweat glands, and alleviating heat-stress is necessary for ensuring animal production in hot environment. A high ${\gamma}$-aminobutyric acid (GABA)-producer Lactobacillus strain was used to investigate the effect of dietary GABA-producer on laying performance and egg quality in heat-stressed Hy-line brown hens. Hy-Line brown hens (n = 1,164) at 280 days of age were randomly divided into 4 groups based on the amount of freeze-dried GABA-producer added to the basal diet as follows: i) 0 mg/kg, ii) 25 mg/kg, iii) 50 mg/kg, and iv) 100 mg/kg. All hens were subjected to heat-stress treatment through maintaining the temperature and the relative humidity at $28.83{\pm}3.85^{\circ}C$ and 37% to 53.9%, respectively. During the experiment, laying rate, egg weight and feed intake of hens were recorded daily. At the 30th and 60th day after the start of the experiment, biochemical parameters, enzyme activity and immune activity in serum were measured. Egg production, average egg weight, average daily feed intake, feed conversion ratio and percentage of speckled egg, soft shell egg and misshaped egg were significantly improved (p<0.05) by the increasing supplementation of the dietary GABA-producer. Shape index, eggshell thickness, strength and weight were increased linearly with increasing GABA-producer supplementation. The level of calcium, phosphorus, glucose, total protein and albumin in serum of the hens fed GABA-producing strain supplemented diet was significantly higher (p<0.05) than that of the hens fed the basal diet, whereas cholesterol level was decreased. Compared with the basal diet, GABA-producer strain supplementation increased serum level of glutathione peroxidase (p = 0.009) and superoxide dismutase. In conclusion, GABA-producer played an important role in alleviating heat-stress, the isolated GABA-producer strain might be a potential natural and safe probiotic to use to improve laying performance and egg quality in heat-stressed hens.

• 한국지역지리학회지
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• 제10권2호
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• pp.466-478
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• 2004

사회과 지역학습은 교육과정의 지역화에 부응하고 사회과의 축소판이자 영역 통합의 실험장이라는 점에서 중요한 교육적 의미를 갖는다. 우리나라의 사회과 지역학습은 초등사회과를 중심으로 발전해 왔으나, 현재 보급된 지역교과서는 전국적으로 획일적인 목차구성을 보이는 소극적 의미의 지역화에 머물고 있다. 본 연구에서는 중등학교의 지역학습이 초등사회과의 지역학습과 연계된다는 측면에서, 특히 교사-학생이 주도하는 보다 적극적 의미의 지역화를 지향해야 한다고 주장한다. 이를 위해 지역적 적합화를 위한 이론적 과정을 검토한 후, 서로 다른 지역적 성격을 가진 두 지역을 사례로 하여 지역적 적합화 과정을 비교, 검토하였다. 그리하여, 각 지역의 경관과 지역관련 담론, 생태 환경 특성이 스트랜드의 지역별 비중 조절에 고려되어야 한다는 점과, 이것을 바탕으로 주제 추출의 지역적 적합화 및 내용조직이 진행되어야 한다는 점을 보여주었다. 이러한 이론적 배경을 근거로 이 글의 후반부에서는 지역적으로 차별화된 주제 및 내용조직의 실제를 제시하였다.

• Journal of Animal Science and Technology
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• 제44권1호
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• pp.75-86
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• 2002

반추동물에서 적당한 조사료의 공급은 젖소의 정상적인 반추 기능을 위해서 반드시 필요하다. 본 연구는 사료 작물 종류별, 볏집 및 곡류의 가공 상태를 달리하여 제조한 TMFF에 대하여 일반 성분, RFV 및 면양의 반추위 성상 변화를 조사하기 위하여 실시하였다. 청예 작물인 옥수수, 목초, 호밀, 유채, 알팔파와 귀리를 주구로 하고 곡류 가공 수준을 무가공 (대조구), 거칠게 분쇄 (7～14mm mesh 이상), 일반 분쇄 (7mm 이하)를 세구로 하여 조제한 각각의 TMFF에 대한 일반 성분을 조사하였다. 또한 Fistula가 부착된 면양 8두를 이용한 반추위 성상과 기호성에 미치는 영향을 조사하였다. 유채 TMFF는 상대적 사료가 (RFV)와 일당 사료 섭취량, A/P 비율에 있어서 다른 처리구보다 높은 경향을 나타내었다. 옥수수 TMFF를 급여한 면양의 반추위 VFA 함량은 90.9 mmol%로서 다른 처리구 보다 높았으며, 또한 사료의 pH도 3.82로서 가장 낮은 경향을 보였다. 그러나 TMFF에 있어서 휘발성 지방산 각각에 대한 차이는 찾을 수 없었다. 결론적으로 곡류 가공 방법에 따른 효과는 나타나지 않았지만 상대적 사료가와 기호성, 건물 손실율만을 고려하여 우수성을 판단할 때 유채, 옥수수, 알팔파, 목초, 귀리, 호밀 TMFF의 순서로 나타났다.

• Advances in nano research
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• 제8권4호
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• pp.323-333
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• 2020

In recent years, there has been an upsurge for the usage of buckling restrained braces (BRB) rather than ordinary braces, as they have evidently performed better. If the overall brace buckling is ignored, BRBs are proven to have higher energy absorption capacity and flexibility. This article aims to deliberate an economically efficient yet adequate type of all-steel BRB, comprised of the main components as in traditional ones, such as : (1) a steel core that holds all axial forces and (2) a steel restrainer tube that hinders buckling to occurr in the core; there is a more practical detailing in the BRB system due to the elimination of a filling mortar. An investigation has been conducted for the proposed rectangular-tube core BRB and it is hysteric behavioral results have been compared to previous researches conducted on a structure containing a similar plate core profile that has the same cross-sectional area in its core. A loss of strength is known to occur in the BRB when the limiting condition of local buckling is not satisfied, thus causing instability. This typically occurs when the thickness of the restrainer tube's wall is smaller than the cross-sectional area of the core plate or its width. In this study, a parametric investigation for BRBs with different formations has been performed to verify the effect of the design parameters such as different core section profiles, restraining member width to thickness ratio and relative cross-sectional area of the core to restrainer, on buckling load evaluation. The proposed BRB investigation results have also been presented and compared to past BRB researches with a plate profile as the core section, and the advantages and disadvantages of this configuration have been discussed, and it is concluded that BRBs with tubular core section exhibit a better seismic performance than the ones with a plate core profile.