• Korean Journal of Weed Science
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• v.11 no.1
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• pp.32-49
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• 1991

Residual period and carry-over effect of some herbicides were determined using a bioassay method in five winter crops (chinese cabbage, radish, spinach, onion and garlic). The effects were measured at regular time intervals after applling different rates of the herbicides. There were no great differences in residual period and carry-over injury between the soils and kinds of crops used. However, the residual period varied with the herbicides studied and the carry-over injury was rate of the herbicide application, sampling depth of soil, and kind and seeding date of the test plant. When the residual herbicides were applied, the carry-over injury could be minimized by selecting tolerant crops, delaying seeding of the crops after application of the herbicides, and regulating the cultivation depth. Herbicides which showed no residual effect by the end of the cropping period (200-240 days for winter crops) and no carry-over effect were alachlor, trifluralin, ethalfluralin and prometryn. When pendimethalin, metolachlor, linuron and methabenthiazuron were applied at the recommended rate or less, there was no carry-over injury at harvesting time. With doubling the recommended rate, however, the carry-over effect was found in sensitive crops. Napropamide applied in winter crops at rate of 150-300g a.i./10a brought about carry-over injury for such Gramineae as Italian ryegrass, direct-seeded rice and barley, whereas the injury was not found in lowland-transplanted rice, Cruciferae, Cucurbitaceae and Solanaceae. Long residual herbicide nitralin applied at the rate of 75g a.i./10a caused the carry-over injury for Italian ryegrass, direct-seeded rice, baley and lowland-transplanted rice at 275 days in winter crops. In addition, a slight injury occurred in sesame, perilla and spinach, However, there was no injury for Cruciferae, Cucurbitaceae and Solanaceae.

• Journal of the Korea Concrete Institute
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• v.19 no.5
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• pp.613-621
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• 2007

Due to the increasing significance of durability, much researches on carbonation, one of the major deterioration phenomena are carried out. However, conventional researches based on fully hardened concrete are focused on prediction of carbonation depth and they sometimes cause errors. In contrast with steel members, behaviors in early-aged concrete such as porosity and hydrates (calcium hydroxide) are very important and may be changed under carbonation process. Because transportation of deteriorating factors is mainly dependent on porosity and saturation, it is desirable to consider these changes in behaviors in early-aged concrete under carbonation for reasonable analysis of durability in long term exposure or combined deterioration. As for porosity, unless the decrease in $CO_2$ diffusion due to change in porosity is considered, the results from the prediction is overestimated. The carbonation depth and characteristics of pore water are mainly determined by amount of calcium hydroxide, and bound chloride content in carbonated concrete is also affected. So Analysis based on test for hydration and porosity is recently carried out for evaluation of carbonation characteristics. In this study, changes in porosity and hydrate $(Ca(OH)_2)$ under carbonation process are performed through the tests. Mercury Intrusion Porosimetry (MIP) for changed porosity, Thermogravimetric Analysis (TGA) for amount of $(Ca(OH)_2)$ are carried out respectively and analysis technique for porosity and hydrates under carbonation is developed utilizing modeling for behavior in early-aged concrete such as multi component hydration heat model (MCHHM) and micro pore structure formation model (MPSFM). The results from developed technique is in reasonable agreement with experimental data, respectively and they are evaluated to be used for analysis of chloride behavior in carbonated concrete.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.12 s.159
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• pp.1690-1696
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• 2006

The purpose of this study is to provide the basic data useful in designing apparel patterns for aged abdominal obese women. The body measurements of 318 women were taken at random, whose ages were over 60 and fields of action were colleges, sports centers, or business sites in Seoul and the neighboring districts. A total of 33 features in the upper body and lower body were used fer the anthropometric measurement and analysis using anthropometry. The collected measurement data were processed statistically using the SPSS 12.0 program for technical statistical analysis, t-test, frequency analysis, correlation analysis. The results of the study are as follows. 1. Subjects were classified into two groups as a result of analysis for measurement data. It was revealed that 251(about 79 percent) women of total subjects(n=318) have a characteristic of abdominal obese body type and elderly women of these group usually had big abdomen rather than hip. The criteria of abdominal obesity based on waist-hip ratio, WHR(=0.85). 2. Aged abdominal obese women have shown much larger size in most body measurements except items of some vertical length, such as bust ponit-bust point, font interscye, back interscye with circumference and depth of armscye, bust, waist, abdomen and hip while showing no difference in height, biacrominal breadth, hip width, neck shoulder point to breast point, crotch length. 3. Vervaeck index(=100.1) and Rohrer index(=1.7) indicated that the abdominal obese women were fat in overall body. And aspect ratio of waist(=0.86), abdomen(=0.92) and hip(=0.75) also appeared high that the shape of cross sections in those regions was similar to a figure of circle 4. In view of the correlation coefficient between hip circumference and the rest measurement items, and between hip circumference inclusively of the abdomen protrusion and the rest measurement items, there were found some differences for each group. In case of Group (abdominal obese group), the former is smaller than the other. 5. In case of Abdominal obese women, hip circumference inclusively of the abdomen protrusion is more mutually related to the rest items related to make apparel pattern as waist circumference, depth of armscye and so on than what hip circumference is. This result indicated which must be considered hip circumference inclusively of the abdomen protrusion to make apparel patterns for abdominal obese women unlike women of common body types.

• 대한공업교육학회지
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• v.39 no.2
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• pp.101-121
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• 2014

The study aims to develop the NCS based vocational curriculum model for the practical and creative human resources. For effectiveness of the study, the study consists of literature studies of both domestic and international, contents analysis, case study, expert(9samples) consultation and review, and in-depth-interview of the three advisory members. The validity of the developed model is analyzed through mean, standard deviation and contents validity ratio(CVR). The main results of the model development in our study are as follow. First, our NCS based vocational curriculum model for the practical and creative human resources is developed with the analyses of NCS development manuals, training standard utilization and training curriculum organization manuals, NCS learning module development manual and case studies, NCS research report, NCS based curriculum pilot development resources directed toward the high schools and vocational school as well as the domestic and international literature study on career training model like NCS. Second, based on the findings of our analysis in combination with the findings from the consultations with the expert and advisory committee, total 19 sub-factors of each step and domain are extracted. The sub-factors of domain in step 1 are the competency unit, definition of competency unit, competency unit element, performance criteria, range of variable, guide of assessment, key competency; in step 2, they are subject title, subject objectives, chapter title, chapter objectives, pedagogical methods, assessment methods and basic job competence; and in step 2, they are NCS based subject matrix table, NCS based subject profile, NCS based job training curriculum table, NCS based subjects organization flowchart, NCS based job training operation plan. Third, the final model including step 3 NCS based subject profile are developed in association with the linked organizational sub-factors of step 1 and step 2. Forth, the validity tests for the final model by the step and domain yield the mean 4.67, CVR value 1.00, indicating the superior validity. Also, the means of each sub-factors are all over 4.33 with the CVR value 1.00, indicating the high validity as well. The means of the associated organizations within the model are also over 4.33 with the CVR value of 1.00. Standard deviations are all .50 or lower which are small. Fifth, based on the validity test results and the in-depth-interview of the expert and advisory committee, the model is adjusted complemented to establish final model of the NCS based vocational curriculum for the practical and creative human resources.

• Atmosphere
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• v.23 no.1
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• pp.85-92
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• 2013

We estimate atmospheric radiative heating effect of aerosols, based on AErosol RObotic NETwork (AERONET) and lidar observations and radiative transfer calculations. The column radiation model (CRM) is modified to ingest the AERONET measured variables (aerosol optical depth, single scattering albedo, and asymmetric parameter) and subsequently calculate the optical parameters at the 19 bands from the data obtained at four wavelengths. The aerosol radiative forcing at the surface and the top of the atmosphere, and atmospheric absorption on pollution (April 15, 2001) and dust (April 17~18, 2001) days are 3~4 times greater than those on clear-sky days (April 14 and 16, 2001). The atmospheric radiative heating rate (${\Delta}H$) and heating rate by aerosols (${\Delta}H_{aerosol}$) are estimated to be about $3\;K\;day^{-1}$ and $1{\sim}3\;K\;day^{-1}$ for pollution and dust aerosol layers. The sensitivity test showed that a 10% uncertainty in the single scattering albedo results in 30% uncertainties in aerosol radiative forcing at the surface and at the top of the atmosphere and 60% uncertainties in atmospheric forcing, thereby translated to about 35% uncertainties in ${\Delta}H$. This result suggests that atmospheric radiative heating is largely determined by the amount of light-absorbing aerosols.

• Journal of the Korean Geosynthetics Society
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• v.17 no.2
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• pp.41-49
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• 2018

The purpose of this study is to fabricate a full scale road embankment using lightweight air foamed soil as a soil material on soft ground and to investigate its material characteristics and behavior in order to promote dredged soil utilization and minimize ground improvement. As a result of the laboratory test of the onsite mixed samples, the total unit weight of the specimens decreased almost linearly until curing 28 days. In particular, the total unit weight after 28 days of curing was reduced to about 81% of the slurry state before curing, which will be useful in the formulation of similar native soil materials in the future. The unconfined compressive strength began to decrease with the 14th day of curing as shown in the previous study. When the cement content is increased, the strength decreases sharply at a small strain change after the occurrence of the maximum compressive strength, and the maximum strength is exhibited in a range of a smaller axial strain than normal range. The settlement at the surface layer of the ground due to the lightweight embankment was about 1 / 2.75 of the soil embankment and was in agreement with the unit weight ratio (1 / 2.7) of the embankment materials. This indicates the cause and effect of the settlement due to the difference in self weight of the embankments. Also, the difference in settlement between soil and lightweight embankment increased with increasing depth. This shows that the difference in the point at which the settlement is terminated is clear. The ground horizontal displacement under the lightweight embankment was about 15~20% smaller than that of the soil embankment and the depth of occurrence was also 4.5~5.0m shallower in the lightweight embankment.

• Korean journal of applied entomology
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• v.38 no.1
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• pp.47-52
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• 1999

Effects of organic matter content in soil on activity. vertical migration. and persistence of two nernaticides. carbofuran and ethoprophos. to root-knot nematode, Mrloitlog!~iei ~lcognita.w ere investigated. As the organic matter content increased. activity of the nernaticides tended to be reduced. Both nematicides exhibited control values of more than 80'k' to M. iix.o,yilit~iln 0-2 cm depth soil layer from the surface. regi~rdless of organic matter content in soil. In 2-4 cm depth soil layer. however. the control value of the neniaticides varied with the organic niatter content in soil. The control value of carbofuran in the soil layer was ranged from I0 to 30'2,. depending on the soil organic niatter content. In contrast. ethoprophos had no control value against M. i/ic.o,ytlitcr in the \oil layer, except that the nematicide had a control value of 30% when the organic matter content was 0.4%. Furthermore. ethoprophos had no effect on controlling M. i/ic.o,gtiitrr in soil layer of below 4cm. whereas control values of carbofuran were approximately from 5 to 20% in all test soils having different organic matter contents. These results indicate that carbofuran has more vertical migration effect than ethoprophos. Persistence of the two neniaticides was also decreased with increasing soil organic matter content. Half life of carbofuran was 2-3 weeks in soil containing 0.4% organic matter, whereas it was found to be I week in soils containning 0.8 ant1 1.6% of organic matter. On the other hand. activity of ethoprophos was reduced to half in 3-3 weeks and in 2-3 weeks in soil containing 0.4 and 0.8%, and 1.6%) of organic matter, respectively. However, no activity of the both nernaticides was found in soil containing 3.2% of organic matter.

• Journal of the Korean Society of School Health
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• v.4 no.2
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• pp.193-215
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• 1991

This study is aimed at providing basic information applicable to setting up the education programs and strategies to prevent smoking among high school students by analysing smoking behavior and influencing factors. The samples consisted of 814 students, 557 parents and 362 teachers selected randomly from 8 high schools, one from each school district in Seoul. Date Analyses were made through Chi-Square test, Factor Analysis, One Way ANOVA, Multiple Regression, Correlation. SPSS/$PC^+$program was utilized. Smoking behavior (continuous smoking, re-smoking, ex-smoking, never smoking, daily smoking, occasional smoking) were used as dependent variables. Influencing factors (male students, habits, attitudes and knowledge toward smoking, home life, school life, juvenile delinquency, friendship, demographic parent's and teacher's recognition toward male students smoking) were used as in dependent variables. The major findings of the study are as follows : 1. The total smoking rate occupies 41.1% whereas the continuous smoking rate stands at 19.2%, re-smoking rate 9.5%, ex-smoking rate 12.4% and never smoking rate 58.9%. 2. The total smoking rate among high school students is significantly correlated with their monthly expenditures and type of school (p<0.001). The continuous smoking rate also shows the same tendency. As the length of butt get shorter, the current smoking rate increase. The duration of smoking is in proportion to its continuity. The major motive of smoking is curiousity whereas that re-smoking is to follow friend's behavior. The study shows that peer pressure is the most powerful factor influencing smoking behavior of students. Friends and fellow students encourage to pick up smoking and resume smoking even alter one stops smoking. 3. The correlationship between favorable attitudes toward smoking and the current smoking rate and its continuity is statistically significant(p<0.05, p<0.01, p<0.001). 4. The stability and harmony of family life and the current smoking rate show negative correlationship. The daily smoking amount of father is in proportion to the continuity of students' smoking. When parents are in favor of smoking, it is more likely that the experimental smoking rate increase the smoking rate increases, and vice versa. The more acceptable attitudes toward smoking among siblings is also one of the factors to increase the smoking rate and continuity (p<0.001). The more lenient the attitudes of parents toward their children's association with smoking friends, the higher the smoking rate. When students have difficulties in adjusting to school life, it is more likely that the current smoking rate and continuity increase. 5. The continuity of smoking and friendship are significantly correlated (p<0.05, p<0.01, p<0.001). 6. The continuity of smoking and juvenile delinquency are significantly correlated (p<0.001). 7. The difference in attitudes and smoking reasons of parents and students is significantly correlated to different smoking behavior (p<0.01, p<0.001). While smoking knowledge does not significantly influence their smoking behavior, it is noted that in the case of teachers, smoking reason (p<0.05), attitudes (p<0.001) and knowledge (p<0.05) strongly influence their smoking behavior. 8. There is a significantly correlation among the smoking reasons, attitudes and knowledge between students and parents(p<0.001). As for the correlationship between regularity and smoking amount and other influencing factors, the daily smoking amount is in proportion to depth of inhalation and duration of smoking, negative attitudes of parents unstability of family, dissatisfaction of family members, juvenile delinquency, strong smoking reasons and positive attitudes towards smoking. 9. In the case of daily smokers depth of inhalation is significantly correlated to the duration of smoking, juvenile delinquency, acceptability of parents, dissatisfaction of family members and smoking reasons. The duration of smoking motives is significantly correlated to juvenile delinquency, high acceptability of parents, strong smoking motive and positive attitudes toward smoking. 10. It is noted that 40% of parents and 30% of teachers do not recognize the significant correlationship between and the relative influencing factors mentioned above.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.5
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• pp.42-59
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• 2017

To investigate rooting and community forming ability, sod strips of Gramineae such as Miscanthus sacchariflorus (Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg., and Arundinella hirta(Thunb.) Tanaka were planted horizontally at a width of 10~15cm in October 2010 on the bank slope of Kwangju Stream in Korea. Seeds of each species were sown in April 2010 in plastic seedbeds(60cm length ${\times}$ 30cm width ${\times}$ 5cm depth) filled with 4cm of garden soil and grew until October 2010 to form rectangular sod, which then was cut into multiple strips(20cm length ${\times}$ 6cm width ${\times}$ 4cm root depth). Weeds growing on the experiment sites were removed twice a year until those four species had formed a community by 2013. Weeds were not eradicated during 2014 and 2015 to observe whether the community formation can be maintained without weed removal. t-tests on stem numbers and heights in May, July, and September were conducted between 2013 and 2014, and between 2014 and 2015. Stem numbers and heights of the four species in 2014 were significantly decreased(p<0.001) compared with those in 2013 due to weed damage to their growth in 2014. Stem numbers and heights of Miscanthus sacchariflorus(Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg. in 2015 were similar to those in 2014(p>0.05). Stem numbers and heights of Arundinella hirta(Thunb.) Tanaka in 2015, however, were significantly reduced compared with those in 2014(p<0.001) due to weed impact on its growth. After three years of weed removal, a community of each species was formed. Miscanthus sacchariflorus(Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg. were able to establish communities without any further weed removal. Arundinella hirta(Thunb.) Tanaka, however, was not able to maintain its community due to considerable damage to its growth caused by weeds even after three years of weed removal. Miscanthus sacchariflorus(Maxim.) Benth., Miscanthus sinensis var. purpurascens(Andersson) Rendle, Imperata cylindrica var. koenigii(Retz.) Pilg. are more suitable to sod strip plantings on stream bank slopes in terms of the maintenance of community formation without weed eradication. t-test on stem numbers and heights each September during the five year experiment period between sod strip planting and potted plants of the four species were conducted. Stem numbers of strip sod plantings were significantly higher(p<0.001) than those of potted one. Heights of strip sod plantings, however, were significantly lower(p<0.05) than those of the potted samples. Therefore, strip sod planting is more advantageous regarding bank slope erosion protection due to the higher number of stems.

• The Journal of Korean Society for Radiation Therapy
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• v.15 no.1
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• pp.1-9
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• 2003

I. Purpose The multileaf collimator(MLC) has many advantages, but use of the MLC increased effective penumbra and isodose undulation in dose distribution compared with that of an alloy block. In this work, we introduced the HD-270 MLC, which can improve the above disadvantages of MLC, and reported its feasibility study. II. Method and Materials The HD-270 MLC is a technique which combines the use of the existing Siemens multileaf collimator(3D MLC) with patient translation perpendicular to the leaf plane. The technique produces a smoothed isodose distribution with the reduced isodose undulation and effective penumbra. To assess the efficacy of the HD-270 technique and determine the appropriate resolution, a polygonal shaped MLC field was made to produce field edge angles from 0 degree to 75 degree with a step of 15 degree. Each HD-270 group was generated according to the allowed resolution, i. e., 5, 3, and 2mm. The experiment was carried out on Primus, a Siemens linear accelerator configured with HD-270 MLC. The total 60 MU of 6 MV photon beam was delivered to X-Omat film(Kodak, USA) at a SAD of 100 cm and 1.5 cm depth in solid water phantom. Exposed films were scanned by Lumiscan75(LUMISYS) and analyzed using RIT113 software(Radiological Imaging Technology Inc., USA). To test the mechanical accuracy of table movement, the transverse, longitudinal, and vertical positions were controlled by a consol with ${\pm}5\;mm,\;{\pm}4\;mm,\;{\pm}3\;mm,\;and\;{\pm}2\;mm$ steps, and then measured using a dial gauge with an accuracy of 0.001 inch. During the experiments, the table loaded with about 50Kg human phantom to simulate the real treatment situation. III. Results The effective penumbra and isodose undulation became larger with increase the resolution and field edge angle. The accuracy of the table movement on each direction is good within the ${\pm}1\;mm$. IV. Conclusion Clinical use of the MLC can be increased by using of the HD-270 MLC which complements to the disadvantages of the MLC.