• Korean journal of applied entomology
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• v.24 no.4 s.65
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• pp.231-238
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• 1986

Molecular orbital theoretical study on the stability of conformations and chemical reactivity of 0,0-diethylphenylphosphate derivatives were carried out by EHT and CNDO/2 molecular orbital calculation method. The results shown that the dipole moment(${\mu}$) and total energies of the ${\theta}=90^{\circ}$ conformer were ${\mu}=3.185D\;&\;E_t=-162.6479(au)$ and also that of the ${\theta}=0^{\circ}$ conformer were ${\mu}=5.596D\;&\;E_t=-162.4013(au)$, respectively. Therefore, the values of ${\mu}\;&\;E_t$ of the ${\theta}=90^{\circ}$ conformer were much smaller than that of the ${\theta}=0^{\circ}$ conformer. The form with angle of rotation ${\theta}=90^{\circ}$ of phenyl ring was shown to be most stable and this was interpreted in terms of electrostatic and steric effect. 0,0-diethylphenylphosphate derivatives are predicted to increase both charge and orbital controlled $SN_2$ reactivity of the electron withdrawing substituent reduces the HOMO & LUMO energy, while the electron withdrawing substituent due to increase in positive charge of phosphorus atom of phosphate molecule.

• The Korean Journal of Zoology
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• v.32 no.2
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• pp.120-133
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• 1989

The paraidehyde-fuchsin(PAE)-positive neurosecretory cells in the brains of wax moth Galleria mellonella have been morphologically examined at the six different metamorphic stages. During the metamorphosis, neurosecretory cells in the brain can be found in the five unclei of pars intercerebralis, lateral region of protocerebrum, optic lobe, deutocrebrum and tritocerebrum. The five nuelel include one to seven neurosecretory cells. On the bases of cell sizes and histochemical specificities of neurosercretion within cells, all the PAF-positive neurosercretory cells included in the six different metamorphic brains can be recognized as four species of neurosecretory cells as follows; (1) large (about 25 $\mu$m), neurosecretion-parcked cell (type I neurosecretory cell), (2) large, granule-dispersed cell (type II neurosecretury cell), (3) small (about 15 $\mu$m), neurosecretion-packed cell (type III neurosecretory cell), and (4) small, granule-dispersed cell (type IV neurose-cretory cell). The three tb seven medial neurosecretory cells are included in the pars intercerebralis of the six different metamorphic brains. With the increase of days from the late larva to the adult the type I cells of medial neurosecretory cells gradually decrease in number, but the respective three type II neurosecretory cells appear in the five different metamorphic brains except in pupa 2 day before the emeregnce of the adult which has only one type II. The one to five lateral neurosecretory cells are observed in the lateral region of protocerebrum from thepupa just after pupation to the adult. The type IV neurosecretory cells are the most in number of lateral neurosecretory cells. The one type Ineurosecretory cells are included near the optic lobe of only the 4-day-old pupa. the one deutocerebral neurosecretory cell, type II, appears only in the adult. The tritocerebrum includes both three neurosecretory cells in the late larva and one neuresecretory cell in the adult. In the late larva the two tritocerebral neurosecretory cells are type Ill neurosecretory cell and the one is type IV. The remaining one tritocerebral neurosecretory cell is type IV.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.2
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• pp.121-128
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• 2009

A field study was conducted from 2007 to 2008 at Department Rice and Winter Cereal Crop, NICS, RDA, to evaluate the effects of harvest time and cultivar on forage yield and quality. Four whole crop barley cultivars ('Youngyang', 'Wooho', 'Yuyeon' and 'Dami') were selected and harvested on five separate growth stages (heading, and intervals of 1, 2, 3 and 4 weeks after heading) in split plot design with three replications. Results from this experiment indicated significant differences due to harvest time and cultivar in dry matter yield and total digestible nutrients (TDN) yield for forage. The interaction between harvest time and cultivar was not significant. The TDN yield trends were increasing with later harvest time due to higher dry matter yield and TDN content. This experiment provides some interesting results with respects to optimum harvest time, feed value and ultimately yield for the different whole crop barley cultivars.

• Journal of Korean Home Economics Education Association
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• v.20 no.4
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• pp.59-75
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• 2008

This study is designed to support the development and the teaching of revised curriculum of 2007 "Technology & Home Economics" by investigating the actual condition and the necessity of education for elderly housing education. Questionnaire survey was conducted with 488 high school students in Gyeongnam in 2008. The data analyzed by descriptive statistics, t-test, One-way ANOVA, Duncan's multiple range test by using SPSS 14 program. The results showed that most of the students were dissatisfied with their middle school education of elderly housing due to the lack of interesting and practical contents. Thus, various teaching-learning methods where student can experience and experiment is needed. Also, the students demanded more of factors of elderly housing, spacing plan, elderly welfare service and less of three-generation housing and senior housing in their elderly housing education. The needs of education contents differed among students depending on variables such as sex, graduated middle school, household income, dwelling space and length of residential years. Therefore, revised 2007 curriculum of "Technology & Home Economics" should include required contents in related chapters. Because there are significant differences among textbooks about elderly housing, further attention needs to be paid to the new textbooks in order to include education contents evenly. At the same time, teachers should organize their teaching contents considering the divergence of variables. The effect of elderly housing education will be maximized if the revised curriculum consists of more experimental activities such as elderly simulation in the local community.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.373-380
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• 2017

Operational errors caused by human factors, which is the major cause of marine accidents, include lack of knowledge, misunderstanding knowledge, and inadequate procedures. Recently, the type of propulsion mounted on KCG cutters has been diversified. In particular, the water jet propulsion unit, which was mainly installed in small boats, have been gradually expanded to medium and large size Coast Guard cutters, reaching 50% of the total. Axes types are divided into 2 to 4, and the bucket types are divided into Double Reverse Bucket(DRB) and Single Reverse Bucket(SRB); in these, the backward and steering control methods are completely different. Diversification of these operating systems can increase factors causing human error by the ships' operators. However, there is a lack of research on the maneuvering methods, considering the inherent active characteristics of each type of water jet. In this paper, we analyze the sideway method suitable for the condition of Coast Guard Exclusive wharf without assistance, based on the astern performance of each type. Then, a ship handling simulator was used for the experiment; they compared and verified through interviews of captains.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.3
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• pp.45-57
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• 2016

This study was focused on the northernmost limit of the distribution changing of Daphniphyllum macropodum and studied characteristic of plant communities of natural monument No. 91 in Najangsan national park, Korea. The results of this study were as follows : 1. The highest importance percentage(I.P.) value at tree layer in Quercus. mongolica community was Q. mongolica, 37.8%. But the highest value of mean importance percentage(M.I.P.) was D. macropodum, 32.8%. 2. The highest I.P. value at tree layer in Carpinus laxiflora community was C. laxiflora, 47.4%. The highest M.I.P. value was C. laxiflora, 28.8% and M.I.P. value of D. macropodum was 24.0%. 3. The highest I.P. value at tree layer in D. macropodum community was D. macropodum, 55.6%. C. laxiflora and Q. mogolica I.P. value was 14.8% and 6.8%, respectively. The highest M.I.P. value was D. macropodum, 47.9%. Sapium japonicum and C. laxiflora M.I.P. value was 11.4% and 10.7%, respectively. 4. The highest I.P. value at tree layer in Quercus variabilis community was C. laxiflora, 20.8%. Q. variabilis and Acer pseudosieboldianum I.P. value was 15.3% and 12.5%, respectively. The highest M.I.P. value was D. macropodum, 21.5%. It needs to the continuous monitoring of vegetation and importance percentage change in tree layer and subtree layer of D. macropodum. The researching results of D. macropodum distribution, the distribution range of D. macropodum showed expanded more than range of Lim and Oh' result(1999). In other words, it was distributed low density level between Najangsa temple and Byeokryeonam, and distributed in upper Keumsun waterfall and Wonjeok upper valley. D. macropodum was appeared on hiking trails around from Wonjeokam to Bulchulbong. Especially, it was found in this study that D. macropodum was distributed on Seoraebong's north which placed outside area of Naejangsa region. In this study, it was considered that distribution range of D. macropodum was expanded. Also, it is expected to be used as a result of the field study of changing distribution study of broad leaved evergreen forest due to global warming.

• Research in Plant Disease
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• v.14 no.1
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• pp.71-75
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• 2008

An isolate of Peanut stunt virus (PSV), named as Tr-PSV, was isolated from white clover (Trifolium repens L) showing mosaic symptom. Tr-PSV systemically infected all plants tested in the Nicotiana spp. and induced local lesions on inoculated leaves of Chenopodium amaranticolor. However, Tr-PSV induced typical mosaic symptoms as ER-PSV on Vigna unguiculata 5 to 6 days after inoculation, while Fny-CMV used as a control virus of Cucumovirus produced local lesions on inoculated leaves. In dsRNA analysis, Tr-PSV consisted of four dsRNAs, but satellite RNA was not detected. The cDNA of coat protein gene of Tr-PSV was amplified by RT-PCR using a Cucumovirus-specific single pair primers that designed to amplify a DNA fragment of approximately 950 bp. By restriction mapping analysis using RFLP of the RT-PCR products and by serological properties of gel diffusion test, Tr-PSV belongs to a typical member of PSV subgroup I. This is the first report on the occurrence of PSV in white clover in Korea.

• Fire Science and Engineering
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• v.24 no.1
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• pp.90-94
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• 2010

In this study it is intended to review the moving characteristics of smoke by performing visualization simulation for the calculation of the optimal smoke exhaust air volume in case a fire occurs in tunnels where transverse ventilation is applied, and to obtain basic data necessary for the design of smoke exhaust systems by deriving optimal smoke exhaust operational conditions under various conditions. As a result of this study, if it was assumed 0 critical velocity in the tunnel, the smoke exhaust air volume was limited within 250 meter in the road-tunnel disaster prevention indicator and the exhaust efficiency was from 55.1% to 95.8% in the result of this study. If the wind velocity is in the tunnel, the exhaust rate intends to increase rapidly and the exhaust efficiency is decreased. In addition, if the wind velocity is increased, the exhaust rate should be increased in compared with the generation rate of smoke in maximum 1.8 or 1.04 times. In this study, when the wind velocity is in the tunnel, the limited exhaust rate is $84m^3/s{\cdot}250m$. And if it was assumed 1.75 m/s critical velocity in the tunnel, the exhaust rate would be defined $393m^3/s{\cdot}250m$($Q_E$ = 80 + 5Ar).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.576-584
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• 2017

Traffic demand prediction result is a primary factor for decision making such as the traffic planning and operation. The existing traffic demand prediction 4-step model only covers the trip between the origin and the destination, and not the demand followed by the accessibility improvement, due to the characteristic of this model. Therefore, the purpose of this research is to improve the limitations of the existing model by developing the inter-city trip generation and trip distribution model with more accessibility. After calculating of the trip generation and trip distribution model with more accessibility, the sign of the accessibility coefficient was positive. Commuting was the most insensitive indicator, affected by external factors among the other trip purposes. The leisure trip was the most sensitive, affected by the trip fee. According to the result of comparison with each of estimated model and observational data, it was certain that the reliability and assumption of the model have been improved by discovering the reduced weighted average error rate, Root Mean Square Error (RMSE) and total error through the model with more accessibility compared with the existing one.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.117-124
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• 2019

Military Vehicles of the Korean army had been developed before 2004 and used manual transmissions. Manual transmissions contain a clutch system regulating the force from engine to transmission. In this study, a 2.5-ton military vehicle's clutch system was investigated. The existing clutch system had the characteristics that need to adjust the clearance between the clutch cover and release bearing. Improper clearance led to early wear of the clutch disk and failure of the clutch cover. To solve these problems, an improved clutch system was suggested and tested. The improved clutch system contains auto adjustment of the clearance and an enhanced clutch disk. To verify the improved clutch systems, 2 stage tests were conducted: an accelerated life test of the clutch system, and a driving test by trainee of driving more than 3,000km. As a result, the problems caused by the improper clearance adjustment were solved and this design was verified.