• KOREAN JOURNAL OF CROP SCIENCE
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• v.11
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• pp.81-97
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• 1972

Experiments and investigations were done basically and practically for the purpose of labor saving in paddy rice cultivation especially on Homizil i.e. hoeing and herbicide, 1969. 8 concrete tanks were established on the open base of Keon Kuk University for comparison of percolation, dissolved oxygen and yield test of rice in the paddy plot of tank. The dimension of the bottom of each tank is square meter. Each of the 4 of the 8 tanks is 21cm in height and each of the remaining 4 tanks is 36cm. Each tank has a system that comprises 2 sets of tubes, each of which has 20 holes of 5mm in diameter scattered every side and is covered with nylon cloth taking water in the tank. One set consists of 4 P.V.C tubes. The first set is situated 8cm below the top of the tank and the second set is located at bottom layer inside the tank. The 4 tubes of each set are combined together and led to the glass tube which protects from inside to outside. And this inside-outside glass tube is connected to the small rubber tube. Also a glass tube is set 4cm below the top of the tank. Paddy loam was filled on sand in each of the tanks in the soil depth of either 15cm or 30cm. The depth of sand was 5cm in the soil depth of 15cm and 10cm in the soil depth of 30cm. (Fig. 1, 2 and 3). The paddy rice was grown in the tank. The percolation of water, the dissolved oxygen and the yield of rice were observed in the tank. And the dissolved oxygen was detected by Winkler method. A sandy paddy field of heavy percolation was selected at the field of the National Agricultural Material Inspection Center in Seoul. It was divided into 9 plots. These plots were given 3 treatments: (A) not hoeing, (B) hoeing one time and (C) hoeing two times. These treatments were replicated 3 times along the latin square design. The paddy rice was grown and sprayed with Stam F-34 in the all plots for the purpose of killing weeds before hoeing. The two types of paddy of field i.e. one for normal percolation and the other for ill drainage were selected at Iri Crop Experiment Station, Jeonla-Bukdo. Each field was divided into 24 plots for 8 treatments. They are: (A) not hoeing; (B) hoeing one time; (C) hoeing two times; (D) not hoeing but treating with herbicide, Pamcon; (E) hoeing one time and weeding two times also treating with herbicide, Pamcon; (F) hoeing two times and weeding one time a], o treating with herbicide, Pamcon; (G) hoeing two times and weeding two times also treating with herbicide, Pamcon, ; (H) usual manner. The labor hours and expenses needed for weeding in the paddy by hoeing were investigated in a farmer at Suwon and the price of herbicide and the yield of rice were taken out at Iri, Jeonla-Bukdo. The results obtained from the above experiments and investigations are as follows: 1. The relationship between percolation and dissolved oxygen shows that a very small amount of oxygen is detected in the soil water under 2cm below surface of earth in the paddy even when percolation is over 4.0cm per 24 hours (Tab. 1). 2. The relationship between percolation and yield of rice shows that the yield of rice increases in the percolation of 0cm and 1.5cm per 24 hours and decreases in the percolation of 2.5cm and 3.4cm in the plot of the 15cm ploughing depth and increases in the percolation of 1.4cm and 3.0cm and decreases in the percolation of 0cm and 4.0cm in the plot of 30cm ploughing depth (Tab. 1 and Fig. 5). 3. The yield of paddy weeded with Stam F-34 in the sandy field of heavy percolation in Seoul was 3.02 tons in the plot of not hoeing, 2.99 tons in hoeing one time and 3.05 tons in hoeing two times per hectare (Tab. 5). 4.1). 4. 1) The yield of rice per 10 ares in the field of normal percolation at Iri was 338kg in not hoeing, 379kg in hoeing one time, 383kg in hoeing two times, 413kg in spraying herbicide, Pamcon, and not hoeing, 433kg in spraying herbicide, Pamcon, and hoeing one time and weeding two times, 399kg in spraying herbicide, Pamcon, and hoeing two times and weeding one time, 420kg in spraying herbicide, Pamcon, and hoeing two times and weeding two times and 418kg in usual manner (Tab. 6-1). 2) The yield of rice per 10 ares in the field of ill drainage at Iri was 323kg in not hoeing, 363kg in hoeing one time, 342kg in hoeing two times, 388kg in spraying herbicide, Pamcon, and not hoeing, 425kg in spraying herbicide, Pamcon, and hoeing one time and weeding two times, 427kg in spraying herbicide, Pamcon, and hoeing two times and weeding one time, 449kg in spraying herbicide, Pamcon, and hoeing two times and weeding two times and 412kg in usual manner (Tab. 6-2). 5. 1) The labor hours for weeding by hoeing was 37.1 hours but 53.5 hours if hours for meal, smoking and so on are included, and the expenses including labor cost needed for weeding by hoeing in the paddy rice was 2, 346 Won per 10 ares at Suwon (Tab. 7). 2) The labor hours for weeding by spraying herbicide with hand sprayer in the paddy rice was about 5 hours per 10 ares at Suwon and the expenses for weeding by spraying herbicide in the paddy rice was 750 Won but 1130 Won if the loss by decrement of rice in the paddy field of ill drainage per 10 ares is calculated in estimation at Iri (Tab. 8). From these observations and investigations it is known that using of some kinds of herbicides Saves labor and expenses of weeding, almost without giving damages to the rice itself, in the field of normal or heavy percolation comparing usual manner of hoeing.

• Korean Journal of Weed Science
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• v.12 no.4
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• pp.317-334
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• 1992

Weed flora and floristic composition were reviewed in lowland rice field and upland crop area. For lowland rice field weed flora was not much changed since 1971. About 29 weed species belonged to 18 families were occurred. However, floristic composition of dominant weed species has greatly changed mainly due to introduction of herbicides. The predominant weed species in 1971 when herbicide was not used were Rotala indica, Eleocharis acicularis, Monochoria vaginalis, Echinochloa crus-galli, while these for in 1991 were Eleocharis kuroguwai, Sagittaria pygmaea, S. trifolia, Echinochloa crus-galli and M, vaginalis, respectively. In 1981 weed survey, E. crus-galli was no longer troblesome weed. However, this species became important again thereafter by introduction of herbicide mixtures with pyrazolate, bensulfuron-methyl or pyrazosulfuronethyl. For upland crop area, 216 weed species belonged to 46 families were recorded. One hundred and sixtyfive of these were grown in winter crop area while 189 weed species occurred in summer crop area, respectively. Among these, 138 weed species were grown in both crop seasons. In general, summer crops had less number of weed species compared to winter crops. Even though the dominant weed species varied by crop the most common weeds were Chenopodium album, Alopecunrs aqualis, Stellaria alsine and S, media for winter crops and Digitaria sanguinalis, Portulaca oleracea, Chenopodium album and Acalypha australis for summer crops, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.119-126
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• 2011

High-speed railway raises global interests with the growing concerns on the green development and the green energy. However, since most of the infrastructure investment of Korea was focused on the highway projects for last forty years, the investment on the railway has been limited around 40~50% of that of the highway projects. In addition, due to the world economy crisis and unsatisfactory support of existing policy for the private investment project, the private investment is given a small deal of weight on the social overhead capital investment. Meanwhile, despite the world high-speed railway market is growing rapidly and the Korean contractors have won the international construction contracts over 70 billion USD, past records of railway projects are very rare. Therefore, it is required to develop strategies for encouraging private investment in the domestic market to achieve efficient high-speed railway development and for advancing into foreign high-speed railway market. This study carried out data collection and market analysis for both domestic and foreign market respectively. Through a structured questionnaire survey and expert interviews, contractors' perceptions on the high-speed railway market and needs for the government support are collected. Summary of strategies drawn from this study are as follows: 1) carrying out BTL high-speed railway projects and revising related policies; 2) upwarding incentive level for the private pre-investment projects considering the contractors' credit rating; 3) carrying out Honam-Jeju submarine railway project; 4) establishing a efficient consortium model for foreign market; 5) improving the capacity of the Korea Railway Association that support Korean contractors' foreign advancement; and 6) expand the budget for Global Infra-fund.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.115-123
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• 1990

The purpose of this study was to examine the uses of coal ash as a type of construction material. The methods of examination were chemical anlysis, soil laboratory test and the soil vibration test. Materials used were coal ash obtained as a by-product from 5 thermal power plants in Yongdong, Yongwol, Sochon(anthracite coal) and in Samchonpo and Honam (bituminous coal). Over 70% of the coal ash consisted of silica and alumina. The fly ash grain size showed a uniform distribution from fine-sand to silt, and that of the bottom ash showed from sand to gravel. The specific gravity and density of the coal ash were low. The long term strength increased gradually due to the self-setting property resulting from pozzolanic activity. The shear strength was higher than that of general soil. Cohesion and optimum moisture content of anthracite coal ash were higher than bituminous coal ash, whereas the maximum dry density was higher in bituminous coal ash. The coal ash dynamic Young's modulous curve range was similar to that of general soil. Of the results from the soil vibration test by car-running, the size relative acceleration level in the ash pond was higher than that of natural ground, but the damping ratio was lower than that of natural ground near the ash pond. The coal ash has more advantageous engineering properties than general soil with particles of the same size. For example, the California Bearing Ratio of the bottom ash at both Yongdong and Yongwol was 77~137%. Therefore we expect that if further study is done, coal ash can be used as a construction material when reclaiming seashore, construction embankments, road construction, making right-weight aggregate, or as a general construction material.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.279-288
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• 2011

To suggest the weed management technique for environment friendly rice cultivation, we investigated occurrence patterns of weeds, the actual condition of weed management, and rice yield at the environment friendly agricultural complex located in Honam and Chungnam regions. The practical performance of weed management was relatively satisfactory in decreasing order of agricultural technique with golden-apple-snail (GAS) > agricultural technique with duck (Duck) > agricultural technique with rice bran (RB) > agricultural technique with soft-shelled turtle (ST). In the rice fields employed by agricultural technique with GAS, the dominant weeds were Echinochloa crus-galli, Ludwigia prostrata, Monochoria vaginalis, Sagittaria trifolia, and Aneilema keisak. However, E. crus-galli, M. vaginalis, L. prostrata, Aeschynomene indica and Bidens frondosa were found as dominant weeds at the fields using the Duck and E. crus-galli, M. vaginalis, L. prostrata, Polyganum hydropiper and Eleocharis kuroguwai at the fields using RB. In comparison of rice yield ($5.2\;MT\;ha^{-1}$) obtained from the conventional cultivation using herbicides, about 93% was reached by Duck, about 91% by GAS, about 92% by RB, and about 78% by ST. When rice qualities obtained from environment friendly rice cultivation were compared with those from the conventional cultivation, the producing rates of perfect kernel, immature kernel, immature opaque kernel, cracked rice, and damaged kernel were lower in the former cultivation, whereas contents of protein, amylose, and fatty acid were similar in the two cultivation methods. The problems found in the environment friendly agriculture were poor plowing and harrowing, carless irrigation management, and geological poor condition as cultivation area with cold water. These have caused severe infestation of weeds, frequent incident of disease and insect pest, and rice lodging. This resulted in reduction of rice yield as high as about 32 to 79% as compared with the conventional cultivation using herbicides.

• Journal of Korea Entertainment Industry Association
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• v.14 no.4
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• pp.321-331
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• 2020

This study was conducted to investigate communication competence, clinical competence and experience of handover which influence self-efficacy of handover among nursing students. The study design was a descriptive survey. A total of 255 students were recruited from nursing departments in G-city. Structured questionnaire was self-administrated from June to September, 2019. The collected data were analyzed using t-test, ANOVA, Pearson's coefficient and stepwise multiple regression. As results of the study, communication competence 57.3, clinical competence 69.8 and self-efficacy of handover was 33.8. Self-efficacy of handover had significant differences in gender(F=4.60, p<.001), age(F=16.72, p<.001), grade(t=-6.39, p<.001), satisfaction of clinical practice(F=3.68, p=.027), education experience about handover(t=26.44, p<.001), experience of handover(t=4.84, p<.001), fear of handover(F=16.97, p<.001), and handover importance of patient's safety(F=6.42, p=.002). Self-efficacy of handover had significant positive correlations with communication competence(r=.249, p<.001) and clinical competence(r=.426, p<.001). In multiple regression analysis, fear of handover(β=-.294, p<.001), clinical competence(β=.252, p<.001), grade(β=.191, p=.001), experience of handover(β=.185, p<.001), gender(β=.150, p=.003), and education experience about handover(β=.126, p=.017) were significant factors of self-efficacy of handover explaining 40.0%(F=29.26, p<.001) of the variables. In conclusion, to enhance self-efficacy of handover for nursing students, it is necessary to develop educational program for increasing experiences of handover, education experience about handover, and clinical competence.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.429-437
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• 2020

This study is aimed at exploring the current state, necessity and activation of curriculum related to image making program in domestic colleges. To achieve this, an empirical survey was carried out to college students to provide basic data for the development of image making education program in the college curriculum as a measure to guide job interviews with them and improve interpersonal skills of employees-to-be. To achieve this, a survey was carried out to 400 college students in Gwangju and Jeonnam areas. The analysis was conducted to verify the collected data using SPSS v. 21.0 through the process of data coding and data cleaning. The results are as follows. First, the necessity of image making program curriculum showed that they needed the image making program in the college curriculum, the image making program curriculum to get a job and manage an image of employees-to-be after graduation, and other people's help to figure out the images objectively. Second, the educational importance of image making program showed that attitude (behavior) was the highest, followed by manners & greeting, look, speech, relationship, clothes, hairstyle, and makeup. In terms of the important educational factors of image making program, look was the highest, followed by makeup, hairstyle, attitude (behavior), relationship, speech, clothes, and manners & greeting, which look was the most important. Third, the educational influence of image making program showed that the influence on employment was the highest, followed by the influence on relationship, and the influence on life. Fourth, the educational activation of image making program showed that the appropriate educational time for image making program they want was from the second year. Education hours they want were once a week for one semester. And the curriculum they want was liberal arts or an optional course of liberal arts. In terms of image making program-related curriculum contents, manner & greeting was the highest, followed by makeup & coordination, job fair, education to acquire a skill qualification, and training for domestic companies, which their biggest wish was manner & greeting. And image making program leaders they want were major professors. In terms of image making program-related education, speech or voice was the highest, followed by education to analyze communication, education to analyze and practice matching hairstyles and makeup, Education on corporate interviews, and education on walking or posture correction, which their biggest wish was speech or voice and education to analyze communication.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.599-608
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• 2020

This study aims to investigate the performance and satisfaction of occupational therapists at the Dementia Relief Center for health care of the elderly in local communities, and to provide basic data necessary for role establishment by checking occupational therapists' tasks according to the priority. The subjects of this study were occupational therapists in dementia care centers in the Honam area and Gwangju Metropolitan City, who were surveyed via mail and e-mail. The survey had a total of 54 items covering the general characteristics of the therapists and current state of the centers (n=8), performance and satisfaction with the service areas and task content of the centers (n=45), and tasks that were considered important (one short-answer question). It was found that occupational therapists at the Dementia Relief Center were mainly carrying out the "Dementia Prevention Management Projects", which provided the programs for the patients, and they showed the highest satisfaction. Although the 'MMSE-DS' is occupational therapists' own area with high performance and satisfaction, it was not assigned to the occupational therapists at the Dementia Relief Center, indicating that the role was insufficient. The tasks related "administrative works and strengthening community capacities" showed low performance and satisfaction, but they are essential for the operation of the Dementia Relief Center and the management of the patients, so the plans to increase the occupational therapists' performance should be established. The categories of projects that occupational therapists consider important were also consistent with those they had to perform. It means the occupational therapists at the Dementia Relief Center recognized their unique roles. In this context, to establish the role of occupational therapist at the Dementia Relief Center, it is necessary to amend the operating guidelines based on the performance, satisfaction, and priorities of the projects, and to develop the curriculums and programs that can improve the tasks with insufficient performance and low satisfaction.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.1
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• pp.1-13
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• 2011

The aim of this study was to evaluate shear bond strength of pressed reinforced composite resin ($TESCERA^{TM}$ ATL) veneering to zirconia with various surface treatments. Forty sintered zirconia specimens and forty pockmarked zirconia specimens were fabricated. All the materials were categorized as Group 1 (Control : porcelain veneering on zirconia surface), Group 2 ( $TESCERA^{TM}$ ATL dentine veneering after bonding agent application on zirconia surface), Group 3 ($TESCERA^{TM}$ ATL dentine veneering on pockmarked zirconia surface), Group 4 ($TESCERA^{TM}$ ATL dentine veneering after bonding agent application on pockmarked zirconia surface), Group 5 (Thermocycling on Group 1), Group 6 (Thermocycling on Group 2), Group 7 (Thermocycling on Group 3), and Group 8 (Thermocycling on Group 4). SBS(Shear bond strength) of 8 groups was determined with an Instron Universal Testing Machine. Also fractured surface of specimens were observed with a scanning electron microscope. There were no significant differences in the initial SBS between Group 1(control group), Group 3, and Group 4. (p>0.05) Group 2 presented the lowest SBS values. There was a no significant difference between just as 24hour water storage and simulated aging on pockmarked zirconia groups. (p>0.05) A formation of pockmarked irregularities on zirconia surface as mechanically pitted surface was reliable method for establishing a stronger bond between $TESCERA^{TM}$ ATL and zirconia-based material.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.3
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• pp.181-188
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• 2007

Objective of this research was to identify by-product composting impacts on paddy soil properties and rice yield. Research was conducted in Iksan (soil was identified as a Jeonbug series) located in Honam plain area from 2001 to 2004. Composts, such as cow manure sawdust compost(CMSC), Chicken manure sawdust compost(ChMSC) and Pig manure sawdust compost(PMSC) were treated in the reseach plots for every, 2, and 3 year term. Some physical properties, such as, soil hardness, and bulk density tended to decrease with application of compost and decreased in order of CMSC, ChMSC, and PMSC, while surface soil depth and porosity were increased in order of CMSC, PMSC, and ChMSC. Some chemical soil properties, such as organic matter, available phosphorus, available silicate, and exchangeable cations were increased with application of compost and every year application plots. Nitrogen uptake was higher in order of CMSC, ChMSC, SF, and PMSC. Nitrogen use efficiency was higher in order of CMSC, ChMSC, SF, and PMSC. Rice yields was increased in all application plot of CMSC, in every other year application plot ChMSC and PMSC compared with SF($5.07Mg\;ha^{-1}$). Also average rice yield on years were increased in all application plot of CMSC and in every other year application plot ChMSC, while decreased in all application plot of PMSC compared with SF($5.27Mg\;ha^{-1}$). Head rice ratio and perfect grain ratio on hulled rice was high in all application plot of PMSC and in every year, in every other year app lication plot of ChMSC while its lowered percentage of 10~13 caused by application of CMSC compared with SF.