• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.506-513
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• 1992

Several experiments were conducted to classify the variablity of field emergence rate among the major soybean(Glycine max. (L) Merril) cultivars. The results obtained are summerized as follows. The speed of emergence is highly correlated with diameter of hypocotyl. As increasing the seed depth, emergence percentage of small seed is higher than that of large seed, and emergence of large seed at seeding depth 5cm is higher than that of small seed, at seeding depth 7cm. Emergence percentage in clay, clay : sand :(1 : 1), sand : vermiculite(1 : 1), clay : (1 : 1), sand, vermiculite are 65, 80, 84, 89, 90 and 91%, respectively. As the soil water potential was decreasing from-0.1 to-0.5 bar, emergence percentage is increasing. The highest emergence percentage was shown at -0.5 bar, and the lowest emergence percentage at -0.7 bar.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.1
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• pp.89-96
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• 2013

Combustion pressures were measured to study combustion stability for an oxygen rich preburner by both of static and dynamic pressure sensors. The resolutions of each static and dynamic pressure sensor are the 1,000 Hz and 25,600 Hz, respectively. The nominal combustion pressure of the preburner was 200 bar but 80 bar was used at the several initial tests for the safety reason. Two stage ignition was applied to reduce the ignition impact for every tests including the tests with 200 bar combustion pressure. The tests lasted for 10 sec. max. and a little fluctuations of pressure was observed during the main mode. The measured pressures were studied by FFT analysis and no noticeable frequency coupling was found. Thus the preburner can be regarded as stable and it can be utilized for further study on staged combustion cycle liquid rocket engine.

• Journal of Welding and Joining
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• v.3 no.1
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• pp.22-31
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• 1985

Hot straining embrittlement is one of the most important factors which cause the brittle fracture initiation even in the service temperature in the case of mild steel and high tensile steel. Therefore it is necessary to analyze thoroughly the hot straining embrittlement occurred in weld HAZ of the structural steels. The behaviors of plastic deformation and fracture toughness at the notch tip of the hot strained weld HAZ in structural steels (SB 41 KS, SA 588-Grade A ASTM) have been studied by the recrystallization technique and crack opening displacement (COD) test method. The obtained results are summarized as follows; 1. The plastic zone is formed at the notch tip of weld HAZ owing to nomotonic and cyclic hot stran, and the maximum plastic strain increases with the accumulated hot straining amounts. 2. The distribution of the effective strain at the plastic deformed zone in HAZ can be determined as follows; (.epsilon. over bar $_{p}$ )$_{\chi}$=.epsilon. over bar $_{cr}$ ( $R_{/chi}$/.chi.)$^{m}$ where, .epsilon. over bar $_{cr}$ : (SB 41; .epsilon. over bar $_{cr}$ = 0.2, SA 588; .epsilon. over bar $_{cr}$ = 0.1) 3. The embrittlement of weld HAZ in SB 41 and SA 588 is influenced by hot strain, and the degree of embrittlement becomes deeper with hot straining amounts. 4. The embrittlement of weld HAZ of SB 41 is not influenced by the hot straining amounts until .epsilon. over bar $_{max}$ = 0.36, $R_{\chi}$ = 0.065mm, however the embrittlement of structure in SA 588 is considerably influenced even by a small quantity of the hot straining amounts.s.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.2
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• pp.165-175
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• 1995

To determine the effect of soil moisture stress on growth of barley and grain quality, a pot experiment was carried out for two barley varieties(Olbori and Chogangbori) by using large plastic pot(52cm in diameter and 55cm in depth) filled with sandy loam soil under rain-controlled open green house. By means of measuring soil water potential with micro tensiometer and gypsum block installed at 10cm in soil depth, soil moisture was controlled by sub-irrigation at several irigation points such as -0.05bar, -0.2bar, -0.5bar, -1.0bar, -5.0bar and -10.0bar in soil water potential. The lower soil water potential was controlled, the shorter length of stem and internode became, and the more narrow stem diameter was. Leaf area was significantly decreased when soil water potential was controlled lower than -0.5bar, although chlorophyll content of flag and first leaves was not changed so much. Weight of grain and ear was significantly decreased when soil water potential was lower than -5.0bar and the highest grain yield was obtaind in a plot where soil water potential was controlled at -0.2bar. However, the most efficient water use of Olbori and Chogangbori was obtained at -0.5bar and -1.0bar in water potentials, respectively. Crude protain content, maximum viscosity, consistency and ${\beta}$-glucan content of barley flour increased as soil water potential significantly decreased, especially below -5.0bar, but gelatination temperature decreased as soil water potential decreased.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.467-473
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• 2018

R-Bar(Overhead Rigid Conductor system) is being developed for the high-speed in Europe because it has an advantage of cross section area reduction of tunnel compared with OCS (Overhead Catenary Line). Because there are lots of underground sections and mountains in korea, it is necessary to develop the R-Bar for a high-speed line. In this study, a method on speed-up of transition section between OCS and R-Bar is proposed. The commercial program, DAFUL, is used to predict a dynamic characteristics between Overhead Line and pantograph. The program is evaluated according to EN 50318 which is the European Norm for evaluation of the program. Using the evaluated modeling and method, a method for the max. speed of 250 km/h of transition section is proposed.

• Journal of Welding and Joining
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• v.2 no.1
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• pp.41-48
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• 1984

Recrystallization technique was applied to analyze plastic strain at the notch tip of coarse grain HAZ in mild steel (SB 41) and high strength steel (SA 588). The notch tip of specimen was deformed by three point bending. Accumulated displacement (Crack Opening Displacement ${delta}t$) by the monotonic and cyclic loading under room temperature and hot strain embrittlement temperature ($250^{\circ}C$) was 0~1.0mm. Recrystallization heat treatment conditions were $650^{circ}C{ imes}3hr$ for SB 41 and $700^{circ}C{ imes}3hr$ for SA 588. The experimental results obtained were as follows ; 1) Distribution of the effective plastic strain at plastic zone was appeared by the function of crack opening displacement, and plastic zone or the effective plastic strain increased with crack opening displacement. 2) Plastic strain at notch tip of HAZ due to accumulated hot strain calculated as follows. .epsilon. over bar $_{p}$ = .epsilon. over bar $_{cr}$ (x/ $R_{x}$ ) $^{m}$ (m=0.25) 3) Work hardending ratio of notch tip for hot strain was linearly increased with .epsilon. over bar $_{max}$ and dependent upon the material types.s.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.57-60
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• 2020

순위다중패턴매칭문제는 길이가 n인 텍스트 T와 패턴들의 집합 P' = {P₁,P₂…,P_k}가 주어졌을 때, P'에 속하는 패턴들과 상대적인 순위가 일치하는 T의 모든 부분문자열들의 위치를 찾는 문제이다. P'에서 가장 짧은 패턴의 길이가 m, 가장 긴 패턴의 길이를 $\bar{m}$, 모든 패턴들의 길이의 합을 M, q개의 연속된 문자들을 q-그램이라 할 때, 기존에 텍스트의 핑거프린트를 이용하여 순위다중패턴매칭문제를 $O(q!+nqlogq+Mlog\bar{m}+nM)$ 시간에 해결하는 알고리즘이 제시되었다. 본 논문에서는 텍스트의 핑거프린트를 활용하여 O(max(q!,M,n))개의 스레드를 이용하여 순위다중패턴매칭문제를 평균적으로 $O(\bar{m}+qlogq+n/q!)$ 시간에 해결하는 병렬 구현 방법을 제시한다. 실험 결과, n = 1,000,000, k = 1,000, m = 5, q = 3일 때, 본 논문에서 제시하는 병렬 구현 방법은 기존의 순차 알고리즘보다 약 19.8배 빠르게 수행되었다.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.278-286
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• 2021

Efficient in vitro regeneration system is essential for the successful crop breeding of soybean (Glycine max (L.) Merr.) using the new biotechnology. The genotype of donor plants strongly influences the establishment of tissue culture system. Therefore, the screening of genotypes with excellent tissue culture ability is very important for soybean genetic improvement. In this study, we report the tissue culture efficiency of 21 soybean cultivars belong to Korean soybean core-collection and two foreign cultivars (Jack and Maverick). The Kwangan, Anpyeong and Seonam are share close genetic relationship in 21 cultivars and these three cultivars were observed the high frequency of germination and regeneration. Furthermore, the high tissue culture abilities were also observed in the Williams 82 used in reference genome sequencing and the two foreign cultivars. The transformation of pBAtc:tRNA with bar gene was performed by Agrobacterium tumefaciens in the cultivars with high tissue culture ability. Transformation of the bar gene was identified by PCR analysis in Kwangan, Pungwon, Seonam, and Maverick. Our results provide useful information for the breeding of various soybean cultivars by plant biotechnology such as, genome editing.

• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.350-355
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• 1995

UV spectrophotometric investigation has been carried out on the system of charge-transfer (CT) complex with iodine and tetramethyltin in carbon tetrachloride solvent. The transient CT absorption spectrum can be observed in ${\lambda}_{max}=270nm$ and the subsequent disappearance of CT absorption spectrum was accompained by the cleavage of tetramethyltin with iodine (iododestannylation). From there, the rate constants for the iododestannylation were determined at 10, 20 and $35^{\circ}C$ up to 1200 bar and the reaction rates were increased with increasing temperature and pressure. From these rate constants, the values of the activation parameters (${\Delta}V^{\neq},\;{\Delta}{\beta}^{\neq},\;{\Delta}H^{\neq}\;and\;{\Delta}S^{\neq}$) were obtained and from these values discussed in terms of solvent structure variation of transition state and mechanism. From these results, it was found that the reaction is followed with $S_F2$ mechanism and weakened $S_F2$ mechanism nature by increasing pressure.

• Journal of Plant Biotechnology
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• v.31 no.4
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• pp.255-259
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• 2004

Agrobacterium tumefaciens-mediated cotyledonary node transformation was used to produce transgenic soybean. Cotyledonary node explants of three cultivars and one genotype were co-cultivated with strains Agrobacterium (LBA4404, GV3101, EHA101, C58) containing the binary vectors (pCAMBIA3301 and pPTN289) carrying with CaMV 35S promoter-GUS gene as reporter gene and NOS promoter-bar gene conferring resistance to glufosinate (herbicide Basta) as selectable marker. There was a significant difference in the transformation frequency depend on bacteria strain. The EHA101 strain of the bacterial strains employed gave the maximum efficiency (3.6%). One hundred-six lines transformed showed the resistance in glufosinate. Histochemical GUS assay showed that at least 11 plants transformed with the GUS gene were positive response. The soybean transformants were obtained from the Thorne (5 plants), 1049 (5 plants) and Bakun (1 plant), respectively. Southern blot analysis and leaf painting assay revealed that the GUS and bar gene segregated and expressed in their progeny.