• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.21-28
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• 2000

A new fourty six 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)-N-phenylpro- pionamide derivatives were synthesized and the herbicidal activities against rice plant and barnyard grass with pre-emergence in down land were measured. The structure activity relationships (SAR) between the activities and physicochemical parameters of the substituted(X) N-phenyl group in substrates were analyzed and discussed by Free- Wilson and Hansch method from the basis on the former study (Sung. et. al., 1999). The conditions of selective herbicide activity both the barnyard grass and rice plant are shown that the optimal hydrophobicity, $({\pi})_{opt.}=1.34$ and electron donating with field effect (F<0) of meta and ortho, para-substituted mono or disubstituent on the N-phenyl ring were found to contribute significantly. The herbicidal activities against barnyard grass are roughly the same as the results in up land whereas damage to rice plant in down land more increase than that of up land. Degradation products in water are 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)propionic acid ((A)) (obs. pKa=4.35 & obs. logP=4.77) and 6-chloro-2-benzoxazolone (B) (obs. pKa=8.40 & obs. logP=2.90). These results were supposing that the hydrolysis product of substrates, (A) is comparatively absorbed in rice plant but not in barnyard grass. And it is assumed from the SAR equations that the 2,6-dimethyl-4-methoxymethyl group substituent ($pI_{50}=5.41$, 3g/ha) is selected as the most highest herbicidal activity against barnyard grass in green house.

• Applied Biological Chemistry
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• v.30 no.3
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• pp.227-233
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• 1987

Some derivatives of 3-(benzothiazol-2-yl)-1-methyl urea were synthesized by reaction of methyl isocyanate with 2-aminobenzothiazole derivatives prepared by thiocyanation of various substituted anilines. The compounds synthesized were identified by IR, NMR and mass spectra as 3-(5-methyl benzothiazol-2-yl)-1-methyl urea, 3-(5,6-dimethyl benzothiazol-2-yl)-1-methyl urea, 3-(6-ethyl benzothiazol-2-yl)-1-methyl urea, 3-(6-methoxy benzothiazol-2-yl)-1-methyl urea, 3-(6-chloro benzothiazol-2-yl)-1-methyl urea, and 3-(5, 6-dichloro benzothiazol-2-yl)-1-methyl urea. These compounds were subjected to the test for pre-emergence herbicidal activity in the pots with wettable powder formulation. All of these compounds showed pre-emergence herbicidal activity on the grasses (Digitaria adscendens HENR and Setaria viridis P. BEAUV) and broad-leaf weeds (Portulaca oleraces L. and Chenopodium album L.) at the dosage of 800g a.i. per 10a. Of the 6 compounds, 3-(6-ethyl benzothiazol-2-yl)-1-methyl urea showed the highest herbicidal effect on both the grasses and broad-leaf weeds. Even at the rate of 50g a.i. per 10a, this compound inhibited the growth of grasses, selectively.

• The Korean Journal of Pesticide Science
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• v.10 no.1
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• pp.7-14
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• 2006

Three-dimensional quantitative structure-activity relationships (3D-QSARs) on the herbicidal activities against in-vitro pre-emergence rice plant (Oryza sativa L.) and barnyard grass (Echinochloa crus-galli) by new 5-benzofuryl-2-[1-(alkoxyimino)alkyl]-3-hydroxycyclohex-2-en-1-one derivatives were studied quantitatively using comparative molecular similarity indices analysis (CoMSIA) methodology. The optimized CoMSIA model(A5: $r^2_{cv.}=0.569$ & $r^2_{ncv.}=0.941$) for rice plant exhibited a good correlation with steric (31.6%) and hydrophobic (39.7%) factors of the substrate molecules, and the model (B4: $r^2_{cv.}=0.569$ & $r^2_{ncv.}=0.941$) for barnyardgrass exhibited a good correlation with electrostatic (46.7%) and H-bond acceptor field (30.8%), respectively. The predicted $R_1=SF_5,\;R_2=R_3=R_4=H(P1)$ substituent (Rice plant: $pI_{50}=4.84$ & Barnyardgrass: $pI_{50}=7.21$, ${\Delta}pI_{50}=2.37$) by the model (B4) not only exhibited to the highest herbicidal activity against barnyardgrass, but also exhibited to the highest selecticity between two plants.

• Korean Journal of Weed Science
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• v.15 no.1
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• pp.13-18
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• 1995

This experiment was carried out to investigate occurrence ecology and control of soil-flakes in flood-direct seeded rice field. The occurrence of soil-flakes were inhibited in blue light of 450nm wave length and promoted in red light of 660nm wave length. The diatoms of Pinnularia spp. largely occurred in low fertilizer level and which much more increased when nitrogen was mixed with thinly soil depth. The diatoms of Pinnularia spp. were effectively controlled by carbamate and triazine herbicides when treated in pre-emergence of soil-flakes. Beside, triazine herbicides, simetryne, dimethametryn, prometryne 5g ai/10a showed high control effect in pre and post-emergence of soil-flakes. Expecially, In water-direct seeded rice pyrazosulfuron-methyl molinate simetryne 5.37% GR and dimepiperate bensulfuron dimethametryn 7.643% GR showed high control effect on the soil-flakes when treated at 10 days after seeding and didn't showed rice injury.

• Weed & Turfgrass Science
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• v.5 no.2
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• pp.82-87
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• 2016

Herbicide options for weed control in sorghum is very limited, hence there is a need for exploring potential herbicides. Sorghum herbicide tolerance field trails were conducted at two locations, Yaechoun, Gyeongsangbuk-do, and Miryang, Gyeongsangnam-do, in 2013. Tolerance of sorghum was evaluated following the pre-emergence application of methabenzthiazuron 70% (WP), simazine 50% (WP), oxadiargyl 1.7% (EC), and dimethenamid-P 5% + pendimethalin 20% (EC) at the standard rate 157.5 g, 75 g, 5.1 g, and 75 g a.i. $10a^{-1}$, respectively. As well as double the standard rate. On a phytotoxicity scale of 0 to 9, methabenzthiazuron (WP) induced injury to sorghum up to level 1 at the standard rate and to 3 at double the rate, but did not significantly affect the yield any statistical difference from the untreated. Simazine (WP) induced phytotoxicity up to levels 2 and 4 at single and double rates, respectively. Simazine (WP) did not significantly affect yield: however, the values were numerically lower than those in the methabenzthiazuron (WP) treatment. Oxidiargyl (EC) and dimethenamid + pendimethalin (EC) induced no or slight phytotoxicity; however they failed to provide effective weed control at the standard rate (32 and 68% control, respectively). Out of the tested, methabenzthiazuron (WP) was found to have potential for use in sorghum whereas the other herbicides caused unacceptable levels of injury.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.103-110
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• 2008

To develop the third generation herbicidal cyclic imide (Cyl) derivatives, the new 1-(4-chloro-2-fluoro-5-propargyloxyphenyl)-3-thiourea derivatives were synthesized and measured their herbicidal activities ($pI_{50}$) in vivo (preemergence) against rice plant (Orysa Sativa) and barnyard grass (Echinochlor crus-galli). The synthetic yields (%) of aryl derivatives (21-40) in general was higher than that of alkyl derivatives (1-20). In case of alkyl derivatives, the synthetic yield depended on the structural forms of alkyl amine groups. From the results of correlation analysis between herbicidal activities and substituents, the compound 8 and 24 showed the highest herbicidal activity against the shoot and root of barnyard grass. Especially, the compounds 11 and 6 showed the selective herbicidal activities between rice plant and barnyard grass.

• Journal of Korea Multimedia Society
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• v.23 no.5
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• pp.650-657
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• 2020

The rapid growth of internet users and faster network speed are driving the new ICT services. ICT Technology has improved our way of thinking and style of life, but it has created security problems such as malware, ransomware, and so on. Therefore, we should research against the increase of malware and the emergence of malicious code. For this, it is necessary to accurately and quickly detect and classify malware family. In this paper, we analyzed and classified visualization technology, which is a preprocessing technology used for deep learning-based malware classification. The first method is to convert each byte into one pixel of the image to produce a grayscale image. The second method is to convert 2bytes of the binary to create a pair of coordinates. The third method is the method using LSH. We proposed improving the technique of using the entire existing malicious code file for visualization, extracting only the areas where important information is expected to exist and then visualizing it. As a result of experimenting in the method we proposed, it shows that selecting and visualizing important information and then classifying it, rather than containing all the information in malicious code, can produce better learning results.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.1
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• pp.1-9
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• 1990

This experiment was carried out to understand the effect of pre-sowing seed treatment by GA$_3$ and IAA on flowering and characteristics of yield component in peanuts. Peanut seed was treated by soaking in 10, 50, 100ppm of GA$_3$ solution, and 50, 100, 200ppm of IAA solution. Treatments of GA$_3$ and IAA resulted 7-5 days earlier emergence and 11-17days shorter of the flowering date compared with the untreated control. By soaking treatments with IAA in 100ppm and GA$_3$ in 100ppm, accumulated flowers were increased at early growing stage of 30 days after flowering compared with untreated control. By soaking treatments with IAA in 100ppm and GA$_3$ in 100ppm, main stem length, branch length and internode of main stem showed to flourish at investigation from early growing stage to 3 days before harvesting.

• Architectural research
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• v.21 no.2
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• pp.49-57
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• 2019

Risk assessment during pre-construction phase is important due to the uncertainty of the risks that may exist in projects. Risk checklist is a method to systematically classify and organize the risks that have been experienced in the past, and to identify the risk factors that may be present in the future projects. In addition, risk value assessment based on checklists plays a key role in risk management, and various risk assessment researches have been conducted to carry out this systematically. However, previous approaches have limitations in common, this is because risk values are evaluated individually in risk checklists, which ignore interdependencies among risk factors and neglect the emergence of co-occurrence of risks. Hence, when multiple risk factors cooccur, they cannot be far off from the conventional method of summing the total risk value to establish the risk response strategy. Most of risk factors are interdependent and may have multiple effects if occurred than expected. In particular, specific cause can be overlapped if multiple risks co-occur, and this may result in overestimation of the risk response for the future project. Thus, the objective of this research is to propose a model to help decision makers to quantify the risk value reflecting the interdependency during the identification phase using existing risk checklist that is currently being practiced in actual construction projects. The proposed model will provide the guideline to support the prediction and identification of the interdependency of risks in practice. In addition, the better understanding and prediction of the exceeding risk response by co-occurring risks during the risk identification phase for decision makers.

• Mycobiology
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• v.32 no.1
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• pp.35-41
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• 2004

A total of 374 Pythium isolates were isolated and identified from the rhizosphere soils of maize plants grown in 100 different agricultural fields in nine provinces at El-Minia Governorate, Egypt. Five Pythium spp. of P. deliense, P. graminicola, P. irregulare, P. oligandrum and P. splendens were obtained P. deliense and P. oligandrum were predominant in all of the locations with 48.1% and 41.4% of total counts, respectively. P. graminicola, P. irregulare and P. splendens were not isolated in 4, 2 and 4 provinces out of 9 provinces with 5.3%, 3.5%, and 1.6% of isolation percentage from total counts, respectively. Number of Pythium isolates in each were 34, 31, 34, 33, 34, 96, 37, 37 and 38 out of 374, for locations of El-Edwa, Maghagha, Beni-Mazar, Matai, Samalout, El-Minia city, Abou-Querquas, Mallawi and Der Mawas, respectively. Pre- and post-emergence pathogenicity tests indicated that only P. deliense was highly pathogenic to germinating grains and seedlings of maize whereas P. oligandrum was non-pathogenic.