• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.344-347
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• 2012

The basic strength of the MgO catalyst was enhanced by impregnating it with KF to synthesize a highly active catalyst for the bio-diesel production. To increase basicity, KF impregnated on synthesized MgO in laboratory. The synthesized catalyst was characterized using $N_2$ adsorption-desorption, X-Ray diffraction, X-Ray fluorescence, and $CO_2$ temperature programmed desorption analyses. Bio-diesel was produced from soybean and methanol and its fatty acid methyl ester content was measured to evaluate the activity of the catalyst. The catalyst impregnated with 30 wt% KF exhibited the highest activity, which was attributed to its abundant intermediate base site.

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.95-102
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• 2005

This paper introduces the LAE(Liquid Apogee Engine) and station acquisition fuel budget estimation method for the COMS(Communication, Ocean and Meteorological Satellite) of Korea which is planned to be launched in 2008. And the estimation results are also presented. A statistical approach, more specifically, the Monte-Carlo method was employed to have the estimation include the effect of the launch vehicle GTO injection accuracies. A case study was conducted for several potential launch vehicles to compare the fuel requirements.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1746-1750
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• 2006

다양한 목적의 장기유출분석에 많이 적용되고 있는 4단 Tank 모형의 증발산관련 입력자료는 증발접시자료를 이용하거나 또는 장기간의 유량과 강수량의 차이로 정의되는 월별 손실량을 계산한 결과를 사용하고 있다. 증발접시자료는 자료 구득문제와 신뢰성 문제 등으로 인해 적용사례가 적고 통상 인근 관측지점의 손실량을 계산하고 이를 전이하여 적용하고 있다. 그러나 이러한 일증발산량 산정방법은 장기적인 유량 자료를 보유한 인근 관측지점이 있어야 적용할 수 있다는 점과 관측지점의 자료 신뢰성에 따라 유출결과에 큰 영향을 미칠수 있는 한계가 있다. 따라서 본 연구에서는 이러한 문제점을 개선하기 위하여 Hamon 방법과 Jensen-Haise 방법 및 FAO Penman-Monteith 방법을 검토하여 Tank 모형 계산에 필요한 실제증발산량을 산정할 수 있는 방안에 대해 모색하였다. 분석결과 유역별 실제손실량은 지형적인 영향을 받는 것으로 분석되었으며, 이를 통해 잠재증발산량을 실제증발산량으로 보정하는 월별보정계수를 지형인자로부터 추정하는 방법을 제안하였다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.491-494
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• 1996

주문이 매 시점마다 있는 것이 아니라 간헐적인, 즉 어느 시점에는 주문이 있고(ON) 다른시점에는 주문이 없는(OFF) 패턴에서 미래의 주문량에 대한 예측을 고려한다. 다음 시점의 예측량은 우선 주문이 있을 것인가에 대한 판단과 주문이 있다면 어느정도가 예상되는가 하는 문제의 두 가지 측면을 모두 고려해야 한다. 기존의 예측모델은 주문량 자체에 대한 고려가 일반적이며 주문시기에 대한 고려는 전무한 상태이기 때문에 이와 같은 주문패턴을 반영시키는데는 어려움이 따른다고 볼 수 있다. 본 논문에서는 이러한 주문패턴을 마코브 체인으로 모델링하고, 이러한 형태의 상태전이확률(state transition probaility) 추정식이 각각 독립적인 오목함수 (concave function)로 구성되어 있음을 보인다. 또한 확률적으로 표현되는 미래의 주문상태들에 대한 패턴을 확정시키는 알고리듬과 주문량 추정에 있어서 과거의 주문패턴을 반영시키는 모델을 제시한다.

• Horticultural Science & Technology
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• v.18 no.5
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• pp.594-598
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• 2000

This study was carried out to investigate the tissue-specific expression of ${\beta}$-glucuronidase (gus) gene driven by endosperm-specific promoter (Z4 promoter) in the transgenic tobacco and to find out inheritance pattern of transgene to the next generation. Tobacco (Nicotiana tabaccum cv. Havana SR1) was transformed with Agrobacterium tumerfaciens LBA4404 harboring BV3 construct containing gus gene driven by Z4 promoter and a kanamycin resistant gene. Seven hundred bp PCR products, indicating the presence of npt II gene, were found in the all eight transformants by PCR analysis using nptII primers. To study the expression pattern of the two different kind of promoters, leaf disks of the Z4pro-gus-transformed plants and 35Spro-gus-transformed plants were analyzed histochemically for gus activity. As a result, leaf disks of Z4pro-gus-transformed plants showed very weak and partial positive gus activity. In contrast, leaf disks of 35Spro-gus-transformed plants showed relatively strong positive gus activity. To investigate the expressed position of Z4 promoter, seeds from Z4pro-gus-transformed plants and 35Spro-gus-transformed plants were analyzed histochemically for gus activity. Z4pro-gus-transformed seeds showed positive gus activity restricted to the endosperm. However, the blue-colored product in 35Spro-gus-transformed seeds was observed in all the area including endosperm. Kanamycin resistance assay showed that transgenes were stably inherited to next generation in all lines.

• Journal of Nutrition and Health
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• v.53 no.4
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• pp.369-380
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• 2020

Purpose: It has been previously reported that breast tumor incidence, growth, and metastasis are stimulated by high-fat diet but reduced by caloric restriction. However, few studies have elucidated the effects of dietary change from a high-fat diet after breast cancer initiation. Therefore, in this study, we attempted to provide practical assistance to breast cancer prevention and management by investigating the effects of dietary change from a high-fat diet to normal diet on breast cancer growth and metastasis. Methods: The experimental animals were divided into 2 groups (high-fat diet control [HFC] group and diet restriction [DR] group) and consumed a high-fat diet for 8 weeks. 4T1 cells were transplanted into subcutaneous fat or tail vein to measure the growth and metastasis of breast cancer. The HFC and DR groups continuously ingested either high-fat diet or AIG-93G diet for 5 weeks or 3 weeks, respectively. Cell proliferation and apoptosis markers from tumor tissues were analyzed by Western blot analysis. The data were analyzed using the SPSS 25.0 package program. Results: The results show that the DR group significantly reduced breast tumor initiation, growth, and tumor tissue weight compared to the HFC group. The DR group suppressed tumor growth by decreasing proliferation and inducing apoptosis through down-regulation of Bcl-xL and up-regulation of caspase-3 activity. Furthermore, the DR group significantly reduced numbers of metastasized tumors in lung tissues. Conclusion: These results suggest that dietary change from a high-fat diet to normal diet decreased breast growth by reducing cell proliferation and inducing apoptosis and metastasis. Taken together, these results indicate that dietary change to a low-fat and balanced diet might suppress breast tumor growth and metastasis even after tumor diagnosis.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.2
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• pp.35-46
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• 2008

Soil moisture is one of the important components in hydrological processes and also controls the subsurface flow mechanism at a hillslope scale. In this study, time series of soil moisture were measured at a hillslope located in Gwangneung National Arboretum, Korea using a multiplex Time Domain Reflectometry(TDR) system measuring soil moisture with bi-hour interval. The Box-Jenkins transfer function and noise model was used to estimate spatial distributions of soil moisture histories between May and September, 2007. Rainfall was used as an input parameter and soil moisture at 10 cm depth was used as an output parameter in the model. The modeling process consisted of a series of procedures(e.g., data pretreatment, model identification, parameter estimation, and diagnostic checking of selected models), and the relationship between soil moisture and rainfall was assessed. The results indicated that the patterns of soil moisture at different locations and slopes along the hillslope were similar with those of rainfall during the measurment period. However, the spatial distribution of soil moisture was not associated with the slope of the monitored location. This implies that the variability of the soil moisture was determined more by rainfall than by the slope of the site. Due to the influence of vegetation activity on soil moisture flow in spring, the soil moisture prediction in spring showed higher variability and complexity than that in early autumn did. This indicates that vegetation activity is an important factor explaining the patterns of soil moisture for an upland forested hillslope.

• Korean Journal of Breeding Science
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• v.42 no.5
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• pp.540-546
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• 2010

This study was conducted to understand the role of soybean pathogenesis-related 10 (GmPR10) gene in salt tolerance and to develop salt-tolerant rice using GmPR10 cDNA. GmPR10 transgene was expressed constitutively in the shoot and root of the $T_1$ transgenic rice plants. Interestingly, however, the levels of the transgene expression were increased temporally up to over four- to five-fold in the shoot and root by 125 mM NaCl treatment, peaking at six hours after the treatment and decreasing thereafter. Electrolyte leakage of leaf cells under 125 mM NaCl treatment was lower in all the transgenic lines than in the control variety, Dongjin-byeo. Ability of seedlings to recover from 125 mM NaCl treatment for two weeks was higher in the transgenic plants than in the control plants. These results demonstrated that GmPR10 had function to increase cell integrity and promote growth under the saline stress imposed by NaCl. The transgenic line GmPR10-3 which showed highest ability to recover from the saline stress could be used as a potential source for salt tolerance in rice breeding programs.

• Journal of Korea Water Resources Association
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• v.54 no.7
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• pp.523-534
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• 2021

Meteorological drought originates from a precipitation deficiency and propagates to agricultural and hydrological droughts through the hydrological cycle. Comparing with the meteorological drought, agricultural and hydrological droughts have more direct impacts on human society. Thus, understanding how meteorological drought evolves to agricultural and hydrological droughts is necessary for efficient drought preparedness and response. In this study, meteorological and hydrological droughts were defined based on the observed precipitation and the synthesized streamflow by the land surface model. The Bayesian network model was applied for probabilistic analysis of the propagation relationship between meteorological and hydrological droughts. The copula function was used to estimate the joint probability in the Bayesian network. The results indicated that the propagation probabilities from the moderate and extreme meteorological droughts were ranged from 0.41 to 0.63 and from 0.83 to 0.98, respectively. In addition, the propagation probabilities were highest in autumn (0.71 ~ 0.89) and lowest in winter (0.41 ~ 0.62). The propagation probability increases as the meteorological drought evolved from summer to autumn, and the severe hydrological drought could be prevented by appropriate mitigation during that time.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.275-282
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• 2020

As pesticide safety was extended to agricultural environments and Positive List System was carried out, Pesticide safety management in soils has become even more important. To improve pesticide safety in soils needs the degradation technology of the residues in soils and reduce plant uptake of pesticides. In this study, biochars and quicklime as the degradation methods of pesticides (azoxystrboin, procymidone and tricyclazole) were used to identify the reduction effects. The experimental methods were putting biochars and quicklimes (0, 0.5, 1.0, 2.0% per 15 cm soil weight) in soils and analyzing the pesticide residues at 0, 10, 20, 35, 50 day. To identify the reduction effects of uptake from soil to korean cabbages (roots, leave, stems) by biochar treatment, the residues in samples were analyzed. As a results, azoxystrobin (36-96%), procymidone (40-117%) and tricyclazole (26-83%) were reduced in soils when treated with 2.0% quicklime (p<0.05). There were no reduction effect in soils when treated with 1.0% or less biochar. However, the amounts of residues translocated to roots (0.11-1.62 mg/kg), leave (0.05-0.29 mg/kg), stems (0.06-0.1 mg/kg) were reduced treated with 2.0% biochar treatments. The biochar and quicklime can be applicable to agricultural field to improve pesticide safety in soils.