• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.137-137
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• 2021

In this study we aimed to enhance streamflow prediction skill of a land-surface hydrological model, WRF-Hydro, over one of the snow dominated catchments lies in Himalayan mountainous range, Astore. To assess the response of the Himalayan river flows to climate change is complex due to multiple contributors: precipitation, snow, and glacier melt. WRF-Hydro model with default glacier module lacks generating streamflow in summer period but recently developed WRF-Hydro-CROCUS model overcomes this issue by melting snow/ice from the glaciers. We showed that by implementing WRF-Hydro-CROCUS model over Astore the results were significantly improved in comparison to WRF-Hydro with default glacier module. To constraint the model with the observed streamflow we chose 17 sensitive parameters of WRF-Hydro, which include groundwater parameters, surface runoff parameters, channel parameters, soil parameters, vegetation parameters and snowmelt parameters. We used Dynamically Dimensioned Search (DDS) method to calibrate the daily streamflow with the Nash-Sutcliffe efficiency (NSE) being greater than 0.7 both in calibration (2009-2010) and validation (2011-2013) period. Based on the number of iterations per parameter, we found that the parameters related to channel and runoff process are most sensitive to streamflow. The attempts to address the responses of the streamflows to climate change are still very weak and vague especially northwest Himalayan Part of Pakistan and this study is one of a few successful applications of process-based land-surface hydrologic model over this mountainous region of UIB that can be utilized to have an in-depth understanding of hydrological responses of climate change.

• Animal Bioscience
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• 제37권7호
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• pp.1196-1203
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• 2024

Objective: A study was conducted to quantify the performance differences of the near-infrared spectroscopy (NIRS) calibration models developed with different degrees of hay sample preparations. Methods: A total of 227 imported alfalfa (Medicago sativa L.) and another 360 imported timothy (Phleum pratense L.) hay samples were used to develop calibration models for nutrient value parameters such as moisture, neutral detergent fiber, acid detergent fiber, crude protein, and in vitro dry matter digestibility. Spectral data of hay samples prepared by milling into 1-mm particle size or unground were separately regressed against the wet chemistry results of the abovementioned parameters. Results: The performance of the developed NIRS calibration models was evaluated based on R², standard error, and ratio percentage deviation (RPD). The models developed with ground hay were more robust and accurate than those with unground hay based on calibration model performance indexes such as R² (coefficient of determination), standard error, and RPD. Although the R² of calibration models was mainly greater than 0.90 across the feed value indexes, the R² of cross-validations was much lower. The R² of cross-validation varies depending on feed value indexes, which ranged from 0.61 to 0.81 in alfalfa, and from 0.62 to 0.95 in timothy. Estimation of feed values in imported hay can be achievable by the calibrated NIRS. However, the NIRS calibration models must be improved by including a broader range of imported hay samples in the modeling. Conclusion: Although the analysis accuracy of NIRS was substantially higher when calibration models were developed with ground samples, less sample preparation will be more advantageous for achieving rapid delivery of hay sample analysis results. Therefore, further research warrants investigating the level of sample preparations compromising analysis accuracy by NIRS.

• 한국지반환경공학회 논문집
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• 제13권2호
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• pp.19-26
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• 2012

본 연구에서는 연약지반 중 선행하중재하 공법을 적용한 6개 지역과 연직배수 공법을 적용한 6개 지역을 대상으로 압밀침하 특성을 비교하였다. Asaoka방법, 쌍곡선방법, Hoshino방법의 장래 예측 침하량 기법을 이용하여 압밀침하량을 예측하고, 실제 계측 침하량과 비교하였으며, 종합적으로 Asaoka방법에 의해 예측된 장래침하량이 쌍곡선방법이나 Hoshino방법에 비해 예측 정확도가 높게 평가되었다. 연직배수공법을 적용한 지역에서는 Asaoka방법이 침하량 예측 정확도가 다른 방법에 비해 높게 평가된다고 알려진 것과는 다르게 세 방법 모두 비슷한 정확도를 나타내었다. 또한 연구대상지역의 지반개량 전후의 확인조사를 통해 N치의 변화, 토층의 물리적, 역학적 특성을 조사하였으며, 개량 후 물성치는 개선되고, 침하량 크기와 관계되는 역학적 특성들은 개선되었다. 또한, 토질의 강도는 증가한 것을 확인하였으며, 침하량과 관계되는 물성치의 변화가 큰 것으로 나타났다.

• 지질공학
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• 제19권1호
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• pp.89-98
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• 2009

암반내의 핵석의 존재는 불안전한 요소로 작용하고 있으며 특히, 절개사면의 경우 노출이 되지 않더라도 핵석이 풍화정도의 차이에 따라 사면의 불연속면 증가 또는 강도 감소가 되며 사면의 낙석이나 붕괴등 사면 거동의 중요한 요소로 작용한다. 연구대상 사면은 20여년전 절개가 완료되어 일부분 사면보강을 완료하였으나 적은 강우에도 잦은 낙석이 발생하여 항구적인 안정대책이 시급한 실정이었다 탄성파탐사와 사면지질조사 견과를 비교 분석하여 핵석의 분포특성 및 규모를 파악할 수 있었다. 또한 주변 암반사면에서 DIPS 프로그램을 이용한 평시투영을 실시하여 주변 풍화토 사면에서의 핵석 분포특성 및 규모 파악에 대하여 검토하였다.

• 한국작물학회지
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• 제54권4호
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• pp.427-432
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• 2009

Seashore Paspalum (Paspalum vaginatum Swartz) is a warm season grass and indigenous to tropical and subtropical regions of coastal areas worldwide. The species is used as feed for cattle and horses and has been very successful for golf courses worldwide. One of the most outstanding characteristics of seashore paspalum is its tolerance to saline soils compared to other warm season turfgrasses. The development of new seashore paspalum cultivars with improved traits could be facilitated through the application of biotechnological strategies. The purpose of this study was to product for herbicide resistant seashore paspalum using Arobacterium-mediated transformation and this study is the first report on transformation and herbicideresistant transgenic plants in seashore paspalum. Embryogenic calli were induced from the seeded variety of pseashore paspalum. Embryogenic calli were transformed with Agrobacterium tumefaciens strain EHA105 carrying the binary vector pCAMBIA3301 with two genes encoding gusA and bar. Transformed calli and plants were selected on medium containing 3 mg/l PPT. PCR detected the presence of the gusA and bar gene, indicating both genes are integrated into the genome of seashore paspalum. A chlorophenol red assay was used to confirm that the bar gene was expressed. By application of herbicide BASTA, the herbicide resistance in the transgenic seashore paspalum plants was confirmed.

• 한국작물학회지
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• 제44권3호
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• pp.225-229
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• 1999

Unstable seedling stand establishment of wet direct seeding culture of rice is one of the major elements preventing the extension of its culture area. In order to develop methods of seedling stand improvement in direct seeded rice on flooded surfaces, three field experiments were conducted on silty loam soil using a cultivar 'Donjinbyeo' for three years, mainly focusing on water management after seeding and seed soaking with plant growth regulators (PGRs). Under the condition of shallow flooding after seeding, seedling stand rate increased and floating seedling rate decreased in both early and normal season seeding compared to deep flooding. With earlier draining time after seeding, there was a tendency towards preferential growth of the seminal root, increase of seedling stand and decrease of the floating seedling rate. Therefore the highest seedling numbers per unit area and the lowest floating seedling numbers were found upon drainage at 1 day after seeding (DAS), while a contrary tendency was shown upon conventional drainage at 7 DAS. Seed soaking with PGRs such as Metalaxyl or mixing of Metalaxyl with gibberellic acid (GA$_3$) significantly increased the seedling stand. In addition the effects of PGR treatment on seedling stand and the early growth of plants were greater under flooded conditions than under drained conditions after seeding, although draining of water after seeding improved the seedling establishment rate more when compared with the PGR treatment. These results suggest that draining management after seeding or maintaining of shallow flooding for a week is the most effective method to improve the seedling stand rate in wet direct seeding.

• 한국식품영양학회지
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• 제10권3호
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• pp.295-301
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• 1997

토양으로부터 분리한 120 여종의 집락 중 응집제를 생산하는 집락을 선발하고 가장 응집력이 우수한 K-67 균주를 최종 선발하여 Agrobacterium sp. KF-67로 동정하고 실험균주로 사용하였다. 응집제 생산시 최적 배지성분을 조사하기 위하여 응집활성을 kaolin과 활성탄 현탁액에서 응딥활성을 측정하였다. 최적 배지성분과 농도는 탄소원과 무기질소원은 glucose와 NH4NO3 각각 2%와 0.1%, 유기질소원은 yeast extract와 peptone 각 0.01%, 무기염으로 CaCO3을 0.04%를 첨가하였을 때 응집활성이 가장 우수하였다. 배지 중 0.03% NaCl 첨가로 약 19%의 응집활성을 향상시킬 수 있었다. 이상과 같은 결과로 볼 때 Agrobacterium sp.에 의한 응집제 생산시 최적배지의 성분 조성과 함량은 2% glucose, 0.1% NH4NO3, 0.01% yeast extract, 0.01% peptone, 0.04% CaCO3, 0.03% NaCl이었고, 이때 기초배지에 비해 약 76.1%의 응집활성력이 증가하여 응집제 생산에 효과적인 배지성분 조건으로 조사되었다.

• Applied Biological Chemistry
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• 제43권1호
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• pp.34-38
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• 2000

과채류에 대한 키토산 유기농업의 효과를 알아보기 위한 시도의 일환으로 배추의 생장 및 배추 중의 ${\gamma}-aminobutyric$ acid(GABA) 함량에 미치는 키토산비료의 시비효과를 조사하였다. 육묘상태에서 대조구에는 물을, 실험구에는 3% 키토산액을 500배 희석하여 2일에 1회 처리하였고, 본 밭에 정식후 대조구에는 물을, 실험구에는 동일한 키토산 희석액을 7일 1회 간격으로 엽면시비 하였다. 키토산비료의 시비는 물 처리구에 비하여 육묘상태에서 배추묘의 잎 길이를 증가시켰고, 어린묘 중의 GABA함량도 증진시켰다. 키토산비료의 시비는 본밭 토양의 물리화학적 특성을 크게 변화 시키지 않으면서 본밭에서의 배추의 평균 둘레 및 무게를 대조구에 비하여 증가시켰으며, GABA 함량도 증진시키는 것으로 조사되었다. 이들 결과들은 키토산비료의 시비가 배추의 생산량과 품질을 일부 향상시킬 수 있음을 제안해 주는 것이다.

• 한국농공학회논문집
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• 제60권1호
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• pp.11-20
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• 2018

This study is to calibrate the SWAT (Soil and Water Assessment Tool) water quality of SS (Suspended Solid), T-P (Total Phosphorus), and T-N (Total Nitrogen) by focusing on 2014~2015 drought periods and identify the important parameters. For Gongdo watershed ($366.5km^2$), the SWAT was calibrated for 2 cases of 2002~2006 normal year focusing calibration and 2014~2015 drought focusing calibration respectively. The parameters of N_UPDIS (Nitrogen uptake distribution parameter) and CMN (Rate factor for humus mineralization of active organic nutrients) played important roles for T-N calibration during drought periods. The SWAT SS, T-N, and T-P average $R^2$ (Coefficient of determination) results by focusing on 2014~2015 drought periods calibration showed 0.71, 0.65 and 0.62 while 2002~2006 normal year focusing calibration showed 0.63, 0.58 and 0.50 respectively. Also SWAT SS, T-N, and T-P model efficiency NSE (Nash-Sutcliffe efficiency) results by focusing on drought period (2014~2015) calibrated showed 0.76, 0.77, 0.87 respectively. Even though the SS, T-P parameters were unchanged during the calibration, the SS and T-P results were improved by the hydrological parameters (SCS-CN, SOL_K, SLSOIL) during the drought periods. The SWAT water quality calibration needs to be considered for the movement of SS and nutrients transport especially focusing on the drought characteristics.

• 한국지반공학회논문집
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• 제19권3호
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• pp.23-31
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• 2003

지난 반세기 동안 검측공 탄성파시험은 시험 장비 및 그 배치에 따라 크로스홀, 다운홀, 서스펜션로깅과 같은 시험으로 발전하였다. 이런 현장시험은 장비와 시험기법이 꾸준히 개선되어 지반 및 지진공학 분야의 부지특성규명에 매우 값진 기술이 되었다. 그러나 이 기술은, 공학적 의의와 중요성에도 불구하고, 표준관입 시험처럼 실무에 보편적으로 적용되지 못하고 있다. 그 이유는 장비가 복잡 정교할 뿐만 아니라, 사용하기 어렵고 비싸기 때문이다. 이 연구에서는 경제적이고 실용적인 지반의 동적물성치 계측 기술 개발을 목표로 하여 인홀 시험법을 연구하였다. 이 연구에서 개발한 인홀장비 시작품은 NX 크기의 검측공에 사용하고 맨손으로 다룰 정도로 작고 가볍다. 이 장비의 발진장치는 여러 현장에서 크로스홀시험을 통하여 그 성능을 검증하였고 꾸준히 개선되고 있다. 세 현장에서 인홀시험을 수행하고 그 결과를 크로스홀시험 결과와 비교하여 타당성을 검증하였다.