• Korean Journal of Agricultural Science
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• v.5 no.2
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• pp.149-157
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• 1978

This study was carried out to obtain basic data for the type selection of furrow openers for the no-tillage soybean planter trailed by the two-wheel tractor from the standpoint of minimum draft and good performance of furrowing. For this study, two models of furrow opener, hoe and disc type, were tested on the artificial soil stuffed in the moving soil bin. The results obtained were as follows. In the case of disc furrow opener, the drafts were measured according to various diameters of discs under the condition of disc angle $8^{\circ}$ and $16^{\circ}$, working depth 3cm and 6cm, working speed 2.75cm/sec. Minimum draft appeared when the diameter of disc was about 28cm and the drafts increased as the diameter of discs became larger or smaller than this diameter. Specific draft showed almost same tendencies as above but showed the minimum when the diameter was about 30cm. For the purpose of controlling the seeding depth, the relationships between draft and working depths, 3cm and 6cm, were tested. The variations of draft concerning the various working depths showed linear changes and were affected in higher degree by depths than other factors. There were general tendencies at both working depths, 3cm and 6cm, that total draft showed the minimum with the disc diameter of about 28cm and specific draft showed it with the disc diameter of about 30cm regardless of disc angle and working speed. For the purpose of controlling the working width and speed, the relationships among drafts, disc angle and working speed were investigated and there were general tendencies that the draft increased as the angle and speed were increased and the draft was affected more by speed than by angle. To compare the hoe-type with disc-type opener, the specific drafts of hoe openers were compared with those of disc opener of $16^{\circ}$ angle and 30cm diameter. The specific draft of disc-type opener with the diameter of 30cm was $0.35{\sim}0.5kg/cm^2$, while $0.71{\sim}1.02kg/cm^2$ in the case of hoe type with the lift angle of $20^{\circ}$ which is 2 times as much as that of disc type in average value. And the furrows opened by disc openers were cleaner than those opened by hoe openers.

• Korean Journal of Agricultural Science
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• v.6 no.2
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• pp.166-184
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• 1979

In order to prevent the water loss in the irrigation canal constructed on the sandy gravel layer or on the other highly permeable ground layer, lining has been practiced. Many studies have been done so far on the lining method to prevent the water loss in the irrigation canal and recently studies on the lining with plastic film or polyethylene film were also reported. However, the plastic film or polyethylene film has low strength and is liable to break, and water loss from pin hole caused by contacting with sand or gravel is highly predicted. This study was then conducted to find proper lining and buring method in canal construction of polypropylene mat after coated with vinyl, as one way to overcome the shortcoming frequently observed when plastic or usual polyehtylene film were used. Eventhough rather longer periods of experiments are needed to attain reliable and accurate results on the variation of durability, the durability of asphalt coated area, or on the damage due to freeze after burial or exposure of polypropylene mat, the experiemental results obtained during one year of period are summarized as follows: 1. The curvature at the area between canal bottom and side slope had increased stability and saved consruction cost. The relationship among the variation of curvature, the reduction of polypropylene mat and the reduced amount of soil cutting at each side slope was presented in Fig. 7 through 9. 2. The depth of covering material to protect polypropylene mat was desired to be over 30cm, considering the water depth, side slope, canal cleaning practices, traffic, or back pressure of irrigation period. 3. In order to increase the canal stability and to prevent slope erosion, sandy soil was required, to be placed under ground, and coarse gravel should cover the surface area of canal. 4. The studies on the stability of side slope in the canal should consider the passive area on the bottom and the slope should be about 1 to 2, considering the slope stability, allowable velocity and tractive force. 5. When compared with earth lining, the lining with polypropylene mat coated with vinyl was responsible to save 28% and 37% of canal lining cost, when the soil carrying distances were 500 and 700m. respectively. 6. The water interception was almost completely attained when the polypropylene mat coated with vinyl was used for lining. But further studies were assumed to be necessary for the use of asphalt since the strength of polypropylene mat connected with asphalt will vary with duration.

• Journal of Gastric Cancer
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• v.6 no.3
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• pp.146-153
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• 2006

Purpose: Gastrointestinal stromal tumorsm (GISTs) are the most common mesenchymal tumors that arise anywhere in the tubular GI tract. The prognosis for GSTIs is important because f GISTs may metastasiwx in the liver or the abdominal cavity in an early stage. For the reason we examined the tumor size, the mitotic number, ki 67, p53, and c-kit mutation as independent prognostic factor for GISTs. Materials and Methods: A retrospective study was conducted in 76 patients who had been re-evaluated for confirmation of diagnosis between Jan 1998 and Dec. 2001. at Catholic University of medicine. Results: There were significant difference between the turner size, mitotic indices, ki 67, c-kit mutations and the 5-years survival rates. Tumor size (${\geq}5\;cm$) and mitotic index (${\geq}5/50\;HPF$) were statistically related to a significantly poor prognosis (P=0.017 and P=0.042, respectively). c-kit mutations in exon 11 were found in 7 cases c-kit mutation was observed more frequently in high risk patients, and there was a significant difference between c-kit mutation and survival (P=0.037). Elevated ki 67 was noted in 34 out of the 76 cases. High risk patients showed elevated ki67 index more frequently and there was significant relation with the survival rate (P=0.0417). Conclusion: We think that tumor size, mitotic index, Ki 67 and c-kit mutation are as independent prognostic factors for GISTs, but more research is needed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.3 no.1
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• pp.28-30
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• 1978

Communication actions as a social band or Human community stick (fast) to human being ceaselessly w without stopping everywhere. All of comm. actions can be kept up and developed by the education of its own. Comm. actions have to include a character of social process, and so for it the social science should t to be some essential part of it. Therefore, Comm. education have to be schemed for achieving with a point of view of synthetical s science including technical and social factor. However, recentry Comm. education be suffered to lose of itowns essential attribute and individual i independence becausing to reduce social weight recklessly in their education It is a prindiple that Comm. science is an integrate science being composed of human, social and t technical subdepartments and so comm. education have to obey for Comm. constuctional theory, i international and social claim. Originally in Korea a educational idea and genealogy forming by the comm. scientific theory has I inherited on orthodoxy. But in 1961, communication college that is only the orthodox model of Comm. education, was f forced to close by some reckless policy and then the national administration for the Comm. education h have been weakened, and so recently it’s education became to degenerate as out of genealogy or n nonsystem alike some scattering Family. On the other side, today comm. science make to it’s modern scientific factor and to keep its l integrate level, therefore, all of educational provisions and administration for the telecomm. should t to be supplement to be fit for their plural chatacters. Comm. education have to occupy an individual educational system through the comm. theory, and t then it can be coexisted with neighbour scientific field equally and can include, connect coordinate o or effect its inference in each subfactor organically. Finally, educational system for telecommunication should to be requested as preeedence that i independent field including pluralism must be formed and sufficient autonomy be guarenteed, and s so Comm. education must be to restored its orthodox genealogy and be recovered individual system a and seIfrestraint field, and then it can be accomplished its own duty for nation and society.

• Korean Journal of Biological Psychiatry
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• v.13 no.2
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• pp.70-81
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• 2006

Objective : The purpose of this study was to investigate the differences of the cognitive performance, emotional and behavioral problems among the attention-deficit/hyperactivity disorder(ADHD) groups that show the difference between visual and auditory attention. Method : Using 'ADHD Diagnostic System(ADS)', visual attention and auditory attention of 98 children diagnosed as ADHD were measured. According to the omission and commission error of ADS, they were divided into three groups ; 1) the group whose each visual omission and commission error scores were higher than each auditory omission and commission error scores(VV group), 2) the group whose each auditory omission and commission error scores were higher than each visual omission and commission error scores(AA group), 3) the group that was the rest of VV and AA group(M group). And the results of both the subscales of Korean Educational Development Institute-Wechsler Intelligence Scale for Children(KEDI-WISC) and the subscales of Korean Child Behavior Checklist(K-CBCL) among three groups were compared. Finally, the correlation between the visual omission, visual commission, auditory omission, auditory commission error and the results of KEDI-WISC, K-CBCL were investigated. Results : The results were as follows ; 1) In 98 ADHD children, the number of VV group(N=56) was higher than that of AA (N=10) and M group (N=32). 2) All mean scores of the subscales of KEDI-WISC of VV group were higher than those of M and AA group. The score of verbal IQ(p=.039) of VV group was significantly higher than that of AA group and the scores of block design(p=.015), Kaufman's factor 2(p=.045), performance IQ(p=.004) were significantly higher than those of M group. The score of full IQ(p=.004) were significantly higher than that of M and AA group. 3) The mean scores of all K-CBCL subscales of VV group were higher than those of M and AA group, except the score of Somatic complaint subscale. The score of Social subscale(p=.041) of VV group was significantly higher than that of AA group. The score of Withdrawn subscale(p=.021) of AA group was significantly higher than that of VV group. 4) There were no significant correlation between the scores of visual omission/commission error and those of each subscale of KEDI-WISC. But, there were many significant correlations between the scores of auditory omission/commission error and those of each subscale of KEDI-WISC. 5) There were significant correlation between the score of the visual omission error and that of Thought problem subscale(r=.205, p=.043) of K-CBCL. There were significant correlation between the scores of the auditory omission error and those of Social subscale(r=-.319, p=.001), Social problems subscale(r=.206, p=.042), Thought problem subscale(r=.235, p=.021). Finally, there were significant correlation between the scores of auditory commission error and those of Social subscale(r=-.241, p=.017), Thought problem subscale(r=.235, p=.020). Conclusion : The ADHD children whose auditory attention ability were higher than visual attention ability had relatively better cognitive performance and less emotional/behavioral problems than the others. The more comprehensive experiment will be needed about the cognitive performance, emotion and behavior problems of the ADHD children showing the difference between visual and auditory attention.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.285-301
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• 2020

Looking at the problem of aging in the nation from a demographic perspective, it is not a problem of the overall population, but of the structure of the population. It is the baby boomer and post-baby boomers, the largest population in the country. Baby boomers were born between 1955 and 1963, and currently have a population of 7001,333, which is 13.6 percent (as of 2015). The Post-Baby Boomer generation was born between 1964 and 1974, with a total population of 9,567,171, accounting for 18.8 percent of the total population. In particular, baby boomers and post-baby boomers (32.4% of the total population) have begun to retire or will retire soon. The average life expectancy continues to increase due to the development of medical technology, and the falling birth rate of newborns and the declining population of the production population are darkening the domestic economy. In a policy proposal aimed at easing the nation's falling economic growth rate, women's participation rate is as high as Sweden and men's efforts to increase it as high as Japan's, while the elderly rate is desirable to maintain Korea's high level. This is because the expansion of the elderly generation's participation in economic activities could ease a sharp drop in economic growth and reduce the burden of supporting the elderly population. The study, based on this social problem awareness and problem solving plan, looks at the relationship between career orientation and satisfaction in start-up education based on the diverse career base of active seniors, and also suggests the importance of customized start-up education on the diversity of active seniors by clarifying the relationship between them, and suggests the desirable direction of senior start-up policy design, funding, and start-up education. Based on the theoretical background, the concept of five factors was defined: active senior, career-oriented, satisfaction level of start-up education, willingness to start a business, and the concept definition of an active senior, which is particularly key to the baby boomers in their 50s and 60s, is generally regarded as a source of consumption or welfare benefits, but in this study, the concept of active start-up is reflected in the domestic start-up market by young people in their 40s, 50s and 60s. As a result of a hypothesis test. Hypothesis 1 and Hypothesis 5: Career orientation has been verified to affect the willingness to start a business and the behavior of preparation for a start-up. Hypothesis 3: The willingness to start a business has been verified as having an effect between startup preparation actions. Hypothesis 4: The satisfaction level of start-up education has been verified to affect start-up preparation behavior. However, hypothesis 2: The satisfaction level of education for start-ups does not affect the willingness to start a business. Such results can be inferred that satisfaction in start-up education does not have a direct effect on the will to start a business and increases the will to start a business through the influence of personal career orientation.

• Journal of Preventive Medicine and Public Health
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• v.18 no.1
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• pp.99-112
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• 1985

It was measured to check the state of health education by the survey of the items related to the health with the first grade of students in middle school who mastered elementary courses. Totally 50 questions, which were selected from Standard and Dong-A reference books, were given to teachers and have got answered by the students who were totally 959(491 from urban areas and 468 from rural areas). It's done just after they entered middle school for a month, from April 10 to may 10, 1984. There were totally 782 items of health in all subjects of all grades. In contents, the most cases were about mental and emotional health(17.7%), exercise and rest (15.1%), environmental health, health life, personal health care, nutrition and foods, social health and organization, physiology and anatomy, statistics of public health population problem, disease and care, food sanitation, school health, parasitic and communicable disease control, eugenics and heredity(0.4%), etc were followed. In subjects, Korean language had 44.7% of mental and emotional health in 114 cases, arithmetics 46.4% of statistics of public health in 26, sociology, 23.1% of environmental health in 118, natural science, 60.1% of physiology and anatomy in 30, ethics, 40.3% of mental and emotional health in 176, music, 21.8% of mental and emotional health and accidents in 23, art, 42.9% of exercise and rest in 28, physical education, 38.6% of exercise and rest in 201, practical course, 36.2% of nutrition and foods in 61, and there was nothing but only one case in Korean history. Subjects in total cases of health informing items are below: Physical education 25.8, ethics 22.5%, sociology 15.1%, Korean language 14.6%, practical course 7.8%, natural science 3.8%, art 3.6%, arithmetics 3.3%, music 2.9%, Korean history 0.6%. Grades in total cases of health informing items are belows: the sixth grade 29.1%, the fourth grade 21.2%, the fifth grade 18.9%, the third grade 11.6%, the first grade 11.5%, the second grade 7.7%. The sections related to health matters were average 35.4%. According to the grades, the fourth and the sixth grade were 38.2% each other, the highest, and the second grade was 29.3%, the lowest. All scetions in physical education included them. The acceptability to the knowledge for health was belows: 56.3% in urban students and 53.9% in rural students. There was some difference in acceptability between two parties (p<0.005).

• Journal of Preventive Medicine and Public Health
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• v.24 no.3 s.35
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• pp.428-440
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• 1991

This study was conducted to estimate the prevalence rate of cervical cancer and to investigate its risk factors. 5,417 asymptomatic married women were screened from March, 1984 to December, 1990 in Taegu city. Of 5,417 examinees, 3,817 (70.46%) were normal, 1,542 (28.7%) showed inflammatory change, 51 (0.94%) were dysplasia and 7 (0.13%) were carcinoma in situ or invasive carcinomas. The prevalence of abnormal finding (dysplasia, carcinoma in situ or invasive carcinoma) was 1,070 per 100,000 population. The prevalence of dysplasia was 940 per 100,000 and that of carcinoma in situ or invasive carcinoma was 130 per 100,000. Age-adjusted prevalence rate for abnormal finding adjusted with standard population of Taegu city was estimated to be 850 per 100,000. The prevalence of cervical cancer was significantly increased with age (P<0.05). The prevalence of cervical cancer was significantly decreased with age at marriage and educational level (P<0.05). The history of induced abortion and the number of pregnancies were significantly associated with the prevalence of cervical cancer (p<0.05), whereas, the number of parity was not. Age at marriage was significantly associated with the prevalence of cervical cancer after stratification by age (p<0.05). However, the level of education, parity, induced abortion, number of pregnancies were not significant. Inflammation and human papiloma virus infection were associated with cervical cancer with odds ratio of 13.48 (95% confidence interval $7.80{\sim}23.40$) and 474.29 (95% confidence interval $196.80{\sim}1143.10$), respectively. In conclusion, for early detection of cervical cancer it should be recommended to perform mass cytological screening. In particular, regular and periodic cytologic screening, starting at age 25, for cervical cancer should be recommended for those women who have frequent cervical inflammation and for those women married before age of 20.

• Korean Journal of Ecology and Environment
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• v.36 no.1 s.102
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• pp.21-28
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• 2003

Community composition and functional feeding groups of aquatic insects according to stream order were investigated from the Gapyeong Creek, a typical mid-sized Korean stream in Gyeonggi -do, Korea, in April 2000. For field investigations, the main watercourse and three major tributaries of the stream that belong to stream order ll to Vll were divided into reaches (ca. $1{\sim}4$ km in distance). Aquatic insects were sampled from one or two sites each reach (total 30 sites) using a Surber sampler ($50{\times}50$cm, mesh 0.75 mm). As a result of the quantitative samplings(two Surber samplings at riffle and pool/run per site; total $2{\times}30$=60 Surber samplings) and additional qualitative samplings, a total of 164 species of aquatic insects in 103 genera, 54 families, and 8 orders were collected from the stream. Those aquatic insects were composed of Trichoptera (56spp.: 34.1%), Ephemeroptera (43 spp.: 26.2%), Diptera (25spp.: 15.2%), Plecoptera (23 spp.: 14.0%), Coleoptera (6 spp.: 3.7%), Odonata (6 spp.:3.7%), Hemiptera (3 spp.: 1.8%), and Megaloptera (2 spp.: 1.2%); EPT-group (122 spp.:74.4%) or EPT-group plus Diptera (147 spp.: 89.6%) occupied most of the aquatic insect community; relatively larger number of species occurred in the mid-stream reaches (order III-Vl). The quantitative samplings throughout the study sites yielded a total of 26,286 individuals of aquatic insects ($136{\sim}2522$ inds./0.5 $m^2$, mean 906.4inds./0.5 $m^2$) that belongs to Ephemeroptera (11,994 inds.: 45.6%), Diptera (8730 inds.:33.2%), Trichoptera (4123 inds.: 15.7%), Plecoptera (1213 inds.: 4.6%), Coleoptera (204 inds.: 0.8%), Odonata (13 inds.: 0.05%), Megaloptera (5 inds.: 0.02%), and Hemiptera (4inds.: inds.: 0.02%); average number of individuals of aquatic insects increased as the stream order increased: average numbers of individuals of Bllecoptera and Trichoptera decreased and increased, respectively, as the stream order increased. Tolerant species such as Chironomidae spp., Uracanthella rufa and Hydropsychidae spp. were particularly abundant in the down stream reaches (order Vll) . Species diversity indices (H`) and dominance indices (Dl) were relatively higher and lower, respectively, in the mid-stream reaches (order $IV{\sim}VI$). Shredders occupied the smallest partand collector-gatherers were most abundant among the functional feeding groups(FFGs); collector-filterers considerably increased in the down stream reaches (orders Vl and VII); scrappers were relatively evenly distributed throughout the stream reaches: predators were relatively more abundant in the uppermost stream reaches(order ll) . Overall, the characteristics of aquatic insect comminity and FFGs in the Gapyeong Creek are largely similar to those in the normal streams of temperate deciduous forest in the northern hemisphere that is explained by the river confineum concept.

• Korean Journal of Agricultural Science
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• v.15 no.2
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• pp.143-152
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• 1988

This study was conducted to obtain basic data which affected engine performance of the power tiller being widely used in the rural area. Among the various factors affected engine performance, only flywheel weight was considered as the major factor in this study. Fuel consumption ratio, motoring loss, torque, vibration and mechanical efficiency of the engine tested were measured and analyzed on the four levels of flywheel weight (32.2, 29.7, 26.4, 24.2 kg). The results obtained were as follows: 1. The maximum output of 6 and 7.5 kW engine was 7.43 kW and 7.85 kW respectively. When flywheel weight was reduced from 32.2 kg to 24.2 kg, output power of the engine was increased 0.27 kW in 6 kW engine and increased 0.39 kW in 7.5 kW engine. 2. The fuel consumption ratio was decreased from 300.8 to 296.8 g/kW-hr in 6 kW engine and decreased from 313.6 to 312.8 g/kW-hr in 7.5 kW engine when the flywheel weight was reduced from 32.2 kg to 24.2 kg. 3. The mechanical efficiencies of the engine was increased from 76.1 to 76.8% in 6 kW engine and increased from 76.7 to 77.0% in 7.5 kW engine when the flywheel weight was reduced from 32.2 kg to 24.2 kg. 4. When the flywheel weight was reduced from 32.2 kg to 24.2 kg, a tendency of a little decrease of vibration at X- and Z-axis in 6 kW engine and of a little increase of vibration at Y-axis in 6 kW engine and all directions in 7.5 kW engine was observed. 5. Motoring losses was decreased from 2.33 to l.76 kW in 6 kW engine and decreased from 2.46 to 1.84 kW in 7.5 kW engine when the flywheel weight was reduced from 32.2 kg to 24.2 kg. From the above results and the flywheel weight calculated theoretically, it was recommendable that the flywheel weight should be reduced about 7 kg in 6 kW engine and about 10 kg in 7.5 kW engine, respectively.