• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.79-87
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• 2010

Research was initiated to investigate the early establishment characteristics and germination patterns of perennial ryegrass (PR, Lolium perenne L.). Eight cultivars of PR were evaluated in the study. Experiment was conducted under a room temperature condition of $6^{\circ}C$ to $23^{\circ}C$ (natural conditions). Daily and cumulative germination patterns were measured and analyzed on a daily basis. Significant differences were observed in germination pattern, days to the first germination, days to 50% germination, days to 75% germination, and germination percentage with different environments and cultivars. Germination percentage was variable with cultivars at the end of study. It was 66.25 to 93.50% under natural conditions. There were considerable variations in the early germination characteristics and germination pattern among the entries according to different conditions. The first germination was initiated between 3 and 5 DAS (days after seeding) under ISTA (International Seed Testing Association) conditions. But it started between 6 and 8 DAS under natural conditions, being 2 to 4 days later as compared with that under ISTA conditions. It was 8 to 12 DAS that reached to days to the 50% germination, which was 2 to 5 days after the first germination. Days to the 75% germination were 10.08 to 13.70 DAS under natural conditions, being 2.07 to 5.70 days slower as compared with ISTA conditions. 'Pennant II' was the fastest cultivar. But the slowest was 'Catalina II' that was 3.62 days later than 'Pennant II' under natural conditions. Considering days to the first germination, days to 75% germination, and germination pattern etc, 'Pennant II' and 'Brightstar II' were regarded as excellent cultivars under both conditions. From this study, information on differences in germination characteristics and patterns would be usefully applied for golf course design and construction, when established with PR.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.3
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• pp.543-560
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• 2018

With the increased development in downtown underground space facilities that vertically cross under a railway at a shallow depth, the demand for non-open cut method is increasing. However, most construction sites still adopt the pipe roof method, where medium and large diameter steel pipes are pressed in to form a roof, enabling excavation of the inside space. Among the many factors that influence the loosening region and loads that occur while pressing in steel pipes, the size of the pipe has the largest impact, and this factor may correspond to the magnitude of load applied to the underground structure inside the steel pipe roof. The super equilibrium method (SEM) has been developed to minimize ground disturbance and loosening load, and uses small diameter pipes of approximately 114 mm instead of conventional medium and large diameter pipes. This small diameter steel pipe is called an SEM pile. After SEM piles are pressed in and the grouting reinforcement is constructed, a crossing structure is pressed in by using a hydraulic jack without ground subsidence or heaving. The SEM pile, which plays the role of timbering, is a fore-poling pile of approximately 5 m length that prevents ground collapse and supports surface load during excavation of toe part. The loosening region should be adequately calculated to estimate the spacing and construction length of the piles and stiffness of members. In this paper, we conducted a comparative analysis of calculations of loosening load that occurs during the press-in of SEM pile to obtain an optimal design of SEM. We analyzed the influence of factors in main theoretical and empirical formulas applied for calculating loosening regions, and carried out FEM analysis to see an appropriate loosening load to the SEM pile. In order to estimate the soil loosening caused by actual SEM-pile indentation and excavation, a steel pipe indentation reduction model test was conducted. Soil subsidence and soil loosening were investigated quantitatively according to soil/steel pipe (H/D).

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.5
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• pp.63-72
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• 2012

In contemporary times, "environmental designers" need to consider both exterior and interior aspects because of the growing trend in dissolution between exterior and interior spaces. To quantify "spatial sense" which serves as the standard for environmental design, this study has asked 63 subjects to evaluate 15 interior and 14 exterior spaces. The "spaciousness (small-large)", "openness(closed-open)", "warmness(warm-cold)", "brightness(bright-dark)", "softness(soft-hard)", "spatial intimacy" and "frequency of visit" were adopted as variables of spatial sense. Through the analysis of these variables, this study could gain the difference between spatial sense for exterior and interior environments, quantify the spatial sense that physically and psychologically appropriates to human beings. The result of this study can be summarized as follows: Twice the amount of spaciousness was observed between the interior and exterior spaces. And the standard on intimate space is established with W/H ratio of 5.71 and high Window/Wall Area ratio in the interior and an area of 3,800m2 and a W/H ratio of 5.57 in exterior. The difference between the spatial sense in the interior and exterior space is mostly dependent on the psychological sense. The increase of physical size caused by the interior space to be perceived as cold, dark and hard psychologically, but exterior space to be perceived as warm, bright and soft. Psychological senses, especially softness, affect spatial intimacy to the greatest extent among the given variables. As the psychological senses for interior spaces were largely independent from the given space's size and perceptive senses, the size of the interior space, which exhibited spatial intimacy, could not be deduced. In comparison to this, due to the high dependency between the psychological senses for exterior spaces and the given space's size and perceptive senses. The study also showed that interior and exterior spaces have relatively different spatial sense and physical standards. Such research results are predicted to provide applicable standards for environmental designers for exterior and interior spaces in the future.

• Journal of Korean Academy of Nursing Administration
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• v.3 no.1
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• pp.119-133
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• 1997

Continuing shift service of clinical nurses can be not only the cause of occupational dissatisfaction by being connected with the change of circadian rhythm and the burden of duties to be applicable to such changes. But also of inviting the lowering of nursing quality by being affected to the resignation of the nurses as the threat to the health of the nurses. This study has selected 500 nurses at random under non-probability sampling who have been serving by shift in 7 general hospitals which have over 400 sickbeds for the purpose of cross-sectional survey design from Sep. 7 through 20, 1996. Standardized modification of the CMI has been used which was designed for Koreans with Cornell Medical Index developed by Broadman and his fellow workers as the study device. The structure of the device was composed of 35 questions on physical appeal(Chronbach's ${\alpha}=8507$) and 22 questions of mental appeal(Cronbach's ${\alpha}=.8166$ totalling 57 questions. The collected data has been computerrized by using SPSS. General character, present symptom, perceived symptom and others are sought by practical number and percentage, and the health condition comparison followed by general characters was conducted by t-test and ANOVA. The post test was by Duncan's test by the level of p<.05. 1) The items of the answer that they have the physical symptom presently by 50% or over of the nurses were as "Do you often have spells of severe dizziness", "Are your eyes often red or inflamed", "Does press or pain in the head often make like miserable", "Are your ankles often badly swollen", "Do pains in the back make it hard for you to keep up with your work". 2) The items of the answer by over 50% of the nurses as the mental symptom at present were "do you fell bad when criticized?", "Do you get angry when everything is against your will?", "do you get angry when ordered to do this and that?", "do you feel uneasy by such a trifle thing?", "do you tremble or are you freightened by sudden sound?". The mental and physical symptoms which have appeared presently in connection with the shift service have been agreed with each other. But the physical condition has been worse than the mental one. 3) In the physical health conditions followed by demosociological character, there were the significant differences by sex, religion and place of residence(p<.05), and in the mental health conditions, there were the significant differences by age, marital status, residence place and the required time for attending hospital(p<.05). 4) There was significant difference by the degree of satisfaction about the duty in both the physical and mental health conditions. In short, the higher the degree of duty satisfaction, the better the health conditions. 5) There were the significant difference according to the times of night duty and whether they take the drug or not or the kinds of the drugs in the physical health conditions related with the characters of night shift. Mental health conditions in the night shift case showed significant differences according to their taking drug or not or the kinds of the drugs(p<.05). I can confirm that the nurses have been affected continuously by the shift service mentally and physically. The maintenance of the physical and mental health of the nurses and its promotion are very important problem to guarantee the quality nursing in the performance of the nursing service continuously and effectively, so the hospital should make every effort to improve the duty conditions by finding out the causes affecting to their health. In the nursing management viewpoint, I think that elevating the satisfaction degree about the duty would be a great help to the promotion of physical and mental health conditions. But what is most important is that the nurses themselves should take care of themselves in maintaining the good conditions in their service in the hospital.

• Journal of Korean Home Economics Education Association
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• v.21 no.2
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• pp.23-43
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• 2009

This study examined the relativity between school uniform behavior(especially attitude toward school uniform, school uniform satisfaction, school uniform alteration) and attitude toward appearance in the adolescence. From November to December in 2007, 898 middle school and high school students from four schools in Jeollabuk-do Province were analyzed and the influence of relevant variables was understood to gather basic information about the fashion life in the adolescence. This study used SPSS 11.5 for Windows Program to conduct frequency analysis, factor analysis, reliability analysis, ${\chi}^2$-test, t-test, One-way ANOVA, Duncan's multiple comparison test, and Pearson's correlation. The following summarizes the findings of this study: The results of analysing the factors to the response attitude toward uniforms and attitude toward appearance and clothing attitude emerged four dimensions(fashion, symbolism, cleanliness, alternation), three dimensions(needs value conformity toward appearance). In attitude toward uniform, female students were more actively altering their uniforms than male students and middle school students were more sensitive to trends than high school students. However, high school students were more aware of the cleanliness and alteration of uniforms. Overall, most students were not very satisfied with their uniforms (design, color, texture). When students' attitude toward appearance and demographical characteristics were examined, it was found that female students were more aware of desire, value, and conformity in appearances than male students. By age, it was found that high school students were more aware than middle school students. Also, students receiving KRW 30,000 or more for monthly allowance were more aware than others who receive a lower amount between KRW 10,000 and KRW 20,000. Therefore, most students(62.1%) have experiences in altering uniforms. Especially, more female students and more high school students had such experiences. Uniform alteration is more related to attitude to appearance. In other words, students who choose to alter their uniforms are highly aware of desire, value, and conformity toward appearance. Students who are satisfied with all factors regarding attitude toward uniform, except for alteration, did not alter their uniforms that much. In addition, when the relativity between students' attitude toward appearance with uniform was considered, students that are not very satisfied with their uniforms were more aware of desire, value, and conformity toward appearance. In conclusion, it was found that students' attitude toward appearance and school uniform behavior are closely related and their interests in appearance lead to alteration of uniforms, the clothing in which they spend most time of the day. From now on, students' opinions shall be considered when selecting or designing school uniforms.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.4
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• pp.90-103
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• 2012

The aim of this study is to be able to understand the problems within the urban agriculture policy promoted by the Government and local autonomous entity base on the comparison of the consciousness of the urban agriculture between urban farmers and public officials and to inquire into the further revitalization scheme in the end. For this purpose, this study drew implications through studying latest trend and the legislation of domestic and foreign urban agriculture and then conducted a questionnaire survey of urban farmers and public officials. Because of this research, the revitalization schemes of urban agriculture are as follows: First, it's necessary to secure the usable arable land, such as the green roof, community garden, as well as urban agriculture park, etc. Second, it is necessary to establish the urban agriculture relations act suited for the actual circumstances of our country and to back up the legislation at an institutional, technological level in terms of a nation in order to secure the durability of urban agriculture. Third, it is advisable to make a proposal about the problems in time of activities for cultivation by forming a network between urban farmers and public officials and to prepare the plan for the active exchange of farming technologies. Fourth, it's necessary to activate the community gardens by supplying the education through cultivation method & its management method, and a variety of urban-agriculture-participation programs. Fifth, it is necessary to set up the specialized and practical education through an institute for landscape architecture. Sixth, it is necessary to induce the spontaneous participation in urban agriculture from urban farmers accompanied by the activities for promotion that are worth arousing urban farmers' interest. Lastly, it is also necessary to establish a legal basis of urban agricultural parks and facilities as well as to promote a search for multilateral policies and their practice so that the further urban agriculture can be stably continued within city boundaries.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.71-84
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• 2003

The metallic shell of soil-steel structures are so weak in bending moment that it should sustain the applied load by the interaction of the backfill soil around the structures. The shell can be subjected to excessive bending moment during side backfilling or under live-load when the soil cover is less than the minimum value. The current design code specifies the allowable deformation and Duncan(1979) and McGrath et al.(2001) suggested the strength analysis methods to limit the moments by the plastic capacity of the shell. However, the allowable deformation is an empirically determined value and the strength analysis methods are based on the results of FE analysis, hence the experimental verification is necessary. In this study, the full-scale tests were conducted on the high-profile arch to investigate its behaviors during backfilling and under static live-loads. Based on the measurements, the allowable deformation of the tested structure could be estimated to be 1.45% of rise, which is smaller than the specified allowable deformation. The comparison between the measurements and the results of two strength analyses indicate that Duncan underestimates the earth-load moment and overestimates the live-load moment, while McGrath et al. predicts both values close to the actual values. However, as the predicted factors of safeties using two methods coincide with the actual factor of safety, it can be concluded that both methods can predict the structural stability under live-loads adequately when the cover is less than the minimum.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.362-371
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• 2004

It is essential to have adequate knowledge of the timing of root resorption of deciduous teeth for diagnosis and treatment planning in pediatric and orthodontic dentistry. Dental development is also influenced by hereditary characteristics, environmental factors, race, sex, endocrine reaction, nutrition, socioeconomic condition and secular factor. The aims of the present study were to determine the mean age of root resorption of deciduous teeth in contemporary Korean children and to compare the mean age of root resorption time of deciduous teeth between early 1990s and early 2000s. The study population was made up of Korean children attending the pediatric dentistry ward of Kyungpook National University Hospital. One thousand thirty seven children's panoramic radiograph (girls: 528 persons, boys: 509 persons) in $1990{\sim}1992$ and one thousand sixty five children's panoramic radiograph (girls: 394 persons, boys: 671 persons) in $2001{\sim}2003$ were examined. This study utilized a cross-sectional design. Due to the problems of imaging in the maxillary region and the mandibular incisor region, the mandibular deciduous canine, the mandibular deciduous first molar and the mandibular deciduous second molar were chosen for examination. The results were as follows. 1. There is a tendency for the teeth to resort earlier in the early 2000s group than the in early 1990s group. At the Res c stage, the difference of the mean age was 0.4 years. 2. At the Res c stage, the order of difference of the mean age from smaller to larger for the girls was the mandibular deciduous canine, the mandibular first deciduous molar, and the mandibular second deciduous molar. On the other hand, for the boys, the order was the mandibular second deciduous molar, the mandibular first deciduous molar, and the mandibular deciduous canine. The difference was larger with aging in girls and smaller with aging in boys. 3. There is a tendency for the teeth to resort earlier in girls in both the early 1990s group and the early 2000s group. The difference of the mean age between girls and boys was 0.3 year. 4. The commencement of root resorption of the mandibular deciduous canine was slower than that of the mandibular first deciduous molar. However, the completion of root resorption of the mandibular deciduous canine is faster than that of the mandibular first deciduous molar. The total elapsed time of root resorption from commencement to completion was shortest in the mandibular deciduous canine. 5. For each of the teeth in the early 1990s and the early 2000s groups, the speed of root resorption was in the later stage faster than in the earlier stage. In order to know about the exact timing of root resorption of deciduous teeth, periodic and longitudinal studies preferably covering the entire period of growth, is required.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.5
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• pp.29-43
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• 2016

The Lean Startup, a methodology for minimizing failure rate of startups, has been receiving attention since its publication in 2011. Although it has been receiving enormous attention as an effective methodology of startups' growth and the emergence of unicorn companies, it is undeniable that the theoretical research and cases on this topic have not been fully accumulated in Korea. Progress of management theory has been made when combining the theory and case studies. In this paper, we thus excavated the 'Cardoc' case, which has applied the lean startup concept to the entire process of service and customer development from the inception of its product design. The following are the findings of the case. First, for the successful application of lean startup, it is essential that all team members to understand the lean startup concept and are willing to apply it thoroughly to the business management. Second, the prompt launching of MVP(Minimum Viable Product) is more important than table discussion. Third, it is crucial to select the appropriate key metrics and analytic tools for effective learning. Fourth, startup must scale up promptly as soon as it verifies the product-market fit through the BML(Build-Measure-Learn) iteration cycle. Fifth, all new business expansion should be lean. Cardoc is currently testing new MVPs in order to move onto the next scale-up process with huge investments in newly added segments. This study is meaningful in that it elaborates the representative case of a Korean startup that has applied the lean startup strategy under the circumstance of insufficient discussion of Korean startup cases in comparison with growing attention both in concept development and case accumulation abroad. We hope that this paper can be a stepping stone for future relevant research on the implementation of lean startup methodology in Korea.

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.39-53
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• 2007

Generally, fractured medium can be described with some key parameters, such as hydraulic conductivities or random field of hydraulic conductivities (continuum model), spatial and statistical distribution of permeable fractures (discrete fracture network model). Investigating the practical applicability of the well-known conceptual models for the description of groundwater flow in fractured media, various types of hydraulic tests were applied to studies on the highly fractured media in Geumsan, Korea. Results from single-hole packer test show that the horizontal hydraulic conductivities in the permeable media are between $7.67{\times}10^{-10}{\sim}3.16{\times}10^{-6}$ m/sec, with $7.70{\times}10^{-7}$ m/sec arithmetic mean and $2.16{\times}10^{-7}$ m/sec geometric mean. Total number of test interval is 110 at 8 holes. The number of completely impermeable interval is 9, and the low permeable interval - below $1.0{\times}10^{-8}$ m/sec is 14. In other words, most of test intervals are permeable. The vertical distribution of hydraulic conductivities shows apparently the good correlation with the results of flowmeter test. But the results from the cross-hole test show some different features. The results from the cross-hole test are highly related to the connectivity and/or the binary properties of fractured media; permeable and impermeable. From the viewpoint of the connection, the application of the general stochastic approach with a single continuum model may not be appropriate even in the moderately or highly permeable fractured medium. Then, further studies on the investigation method and the analysis procedures should be required for the reasonable and practical design of the conceptual model, with which the binary properties, including permeable/impermeable features, can be described.