• Korean Journal of Animal Reproduction
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• v.23 no.2
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• pp.165-174
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• 1999

Boar semen can be frozen successfully. However, there is a large variability in the extent of damage boar semen samples experiences during cryopreservation. This experiment was undertaken to find out factors that affect a post-thaw viability of boar spermatozoa. For this purpose, cryodiluents(BF5, LEY, Soejima and M-Soejima), cryoprotectants(glycerol. ethylene glycol, and propylene glycol), pre-freezing method(dryice-pellet, dryice-straw and L$N_2$vapour-st-raw) and total time required for freezing(2. 5, and 7 h) were compared as a factors. To investigate quality of semen during freezing process, motility(%), normal apical ridges(%, NAR), and proportion of living sperm(%) by flow cytometic analysis were assessed after collection, cooled, pre-frozen and post-thawing. Post-thaw motility of semen diluted with M-Soejima was 52.0%, respectively. When heparin, caffeine or heparin＋caffeine was added to 2nd cryodiluent of M-Soejima during freezing process, the highest motility after thawing was shown at the addition of caffeine (2mM), with 61.7$\pm$2.9% of motility. M-Soejima with heparin or caffeine was significantly higher than that of controI(p＜0.05). The result using glycerol(Gly), ethylene glycol(EG), propylene glycol(PG), and their mixture (Gly＋EG and Gly＋PG) as cryoprotectants, the highest motility was shown at the mixture treatment with Gly plus PG. However, the highest proportion of live spermatozoa was shown at Gly＋EG, there was no significantly difference among treatments(p＞0.05). When semen was pre-frozen with three manners(dryice-pellet, dryice-straw, and L$N_2$ vapor-straw), motility(%) of post-thaw spermatozoa was the highest in the L$N_2$ vapor-straw pre-freezing method of M-Soejima cryodiluent with 57.5% of motility, For a simple, economical and timesaving approach to freezing boar semen, total time required for freezing were 2, 5, and 7 hours, post-thaw motility were 43.8, 45.0 and 38.8%, NAR were 19.5, 22.7 and 28.5%, and viability were 20.8, 19.9 and 22.1%, respectively. This data suggests that boar semen diluted with M-Soejima cryodiluent contained caffeine, using mixture of glycerol and propylene glycol or ethylene glycol as cryoprotectants, frozen with 2 hours, can be taken better motility, NAR, and proportion of live spermatozoa.

• Journal of The Korean Association For Science Education
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• v.22 no.1
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• pp.190-203
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• 2002

The purpose of this study is to test content validity of a portfolio assessment and to analyse the information which can be obtained from student portfolios. The content validity of the portfolio was tested against the objectives of each lesson and the emphasis of curriculum. The information was identified from the analysis of student portfolios. Students' portfolios from a fourth grade class in Pyeungteak, Kyeungki-do were used for analysis. The portfolios included students' evidence of learning on (I) Strata, Unit 2 'Strata and Fossil,' and (3) Change of Object by Heat, Unit 4 'Heat and Change of Object'. Fourth-grade science textbooks were also analyzed to understand the base level information for portfolio analysis. Two science education specialists and ten elementary teachers majored in science education took part in this analysis. The results of the analysis showed $70{\sim}100%$ of agreement between the objectives of lesson and portfolio forms. Over 90% of agreement is reached between portfolio forms and the emphasis of the curriculum. Student portfolios revealed much information on comprehension, observation, will to study, and process of learning. They also revealed some information on drawing conclusion, communication. self-direction, progress of learning, self-concept, interaction, and process of learning. As a whole, the information in students' portfolios is similar with that dealt in science textbooks. However, students' portfolios have more information on anticipation, will to study, self-direction, and interaction. On the contrary, science textbook deals more with information on observation, planning inquiry, than students' portfolios. The portfolio assessment examined has very sound content validity. The results also show that much more and various information which can not be obtained from pencil and paper test could be obtained from student portfolios. The use of information, obtained from student portfolios will make it possible understand students' learning. their strength and weakness, hence improve student' science learning.

• Journal of Dairy Science and Biotechnology
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• v.14 no.1
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• pp.57-69
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• 1996

This study was desiged to carry out an observation study on the cognitive level of health benefitis of fermented milk and subsequntly, on prevention of gastrointestinal diseases for the consumers in Korea. Data used in this study were collected from two different source ; 1) 987 university students living in Seoul, were selected randomly and interviwed induvidual from May 25 to September 30 1994, to investigate the awareness status as a consomer of fermented milk, and 2) health benefits of fermented milk with respect to prevention gastric intestinal diseases such as typhoid fever, paratyphoid fever and bacillary dysentery in Korea with the raw data from the Yearbook of Health and Social Statistics by Ministry of Health and Social Affairs (1976${\sim}$1995) and Ministry of Agriculture, Forestry & Fisheries (1976${\sim}$1995), Republic of Korea. The results of this study were as follows : The effects of femented milk on health appeared to be attributed to taking care of an environment of the gastrointestinal tract regarding diarrhea, constipation and digestion, with showing 75.1% of male and 71.1% of female of university students in Seoul answered positively, The correlation coefficients of statistics between amounts of consumption per capita of fermented milk and incidence rates of gastrointestinal diseases during the period from 1975 to 1994 in the whole country was r = -0.308 (p<0.05). those of Seoul a major comsuming area of fermented milk in the country and Kangwon province, a minor consuming area were r = -0.704 (p<0.01) and r = +0.262 (n.s.), respectively. In conclusion, the results obtained in this study suggest that fermented milk exert its effect on gastrointestinal tract. Furthermore, the results warrant a futher study in the field of preventive medicine and health science with respect to efficacy of fermented milk consumption.

• Korean Security Journal
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• no.10
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• pp.53-77
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• 2005

This thesis analyzes the effectiveness of master's transformational and transactional leadership on organizational commitment as well as job satisfaction of private security, scrutinizes the difference in master's leadership according to social-demographic group. The sum of this thesis is as follows. To begin with, analyzed the difference of leadership style according to social-demographic characteristics of private security, it showed that monthly income is over 2.5 million won as well as people over 30 years old have higher transformational leadership than the others. That is, the older people's age is and the more someone gains his living, the higher he esteems and trusts his master who has charisma, personal concern and shows intellectual stimulus. And examined thoroughly the difference of organizational commitment as well as job satisfaction in accordance with social-demographic characteristics of private security, people who are 20-25 years old, are college graduates and employees who have worked for 2-3 years do well calculational commitment. It means that the younger he is and the lower academic background is, the higher calculational commitment is by the profit and loss which affects them. Secondly, inquired into consequence of leadership style on job satisfaction. Leadership of intellectual stimulus has negative effect on job satisfaction, whereas it has positive effect on conditional compensation. Exactly, if the master exhibits leadership that stimulate to improve an initiative, it reduces the job satisfaction. On the contrary, for the reason that his master indicates leadership that accompanies conditional compensation, job satisfaction tends to increase. Finally, judged from the effects of leadership style on organizational commitment, the charisma, the lower factor of transformational leadership affects to emotional commitment positively and then, it shows that employees tend to become attached to the organization and have a sense of oneness with it, if their master is able to show charismatic leadership. In conclusion, the private security companies pursue employees whose school career and payment is lower because of incidence in labor expense related with the profit and loss. Owing to it, employees are not satisfied with their job much. And also there is the change in increasing rate of job satisfaction according to business performance of the conditional compensation, i.e. a consideration, a promotion, etc., and the calculational commitment. Therefore, the university should try to focus on the researches for cultivate more professional manpower for business, the companies must try to make better deal, offer welfare for their employees to develop of the private security industry, to rise the job satisfaction of private security. And then, investigation to find private security's own level ought to be done by organic industry-academic cooperation of university and industries.

• Land and Housing Review
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• v.8 no.1
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• pp.1-11
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• 2017

The government has been constructing and supplying public rental housing to ordinary people in order to stabilize housing since 1989. However, the public rental houses initially supplied to ordinary people are at high risk for safety accidents due to the deterioration of the facilities. Therefore, this study is aimed to propose a solution to solve the life safety hazards of the old rental housing complex as a follow-up study of Analysis of Accident Patterns and Hazard Factor for Life Safety in Rental Housing Complex. Types of life safety accidents that occur in public rental housing complexes are sliding, falling, crash, falling objects, breakage, fire accidents, traffic accidents and criminal accidents. The types of safety accidents that occur in rental housing complexes analyzed in this study are sliding, crashes, falling objects, and fire accidents. Although the incidence of safety accidents such as falling, breakage, traffic accidents and crime accidents in public rental housing complexes is low, these types are likely to cause safety accidents. The method of this study utilized interviews and seminar results, and it suggested ways to solve the life safety hazards in rental housing complexes. Interviews were conducted with residents and managers of rental housing complexes. Seminars were conducted twice with experts in construction, maintenance, asset management, housing welfare and safety. Through interviews and seminars, this study categorizes the life safety hazards that occur in rental housing complexes by types of accidents and suggests ways to resolve them as follows. (1) sliding ; use of flooring materials with high friction coefficient, installation of safety devices such as safety handles, implementation of maintenance, safety inspections and safety education, etc. (2) falling ; supplementation of safety facilities, Improvement of the design method of the falling parts, Safety education, etc. (3) crash ; increase the effective width of the elevator door, increase the effective width of the lamp, improve the lamp type (U type ${\rightarrow}$ I type), etc. (4) falling objects and breakage ; design of furniture considering the usability of residents, replacement of old facilities, enhancement of safety consciousness of residents, safety education, etc. (5) fire accidents ; installation of fire safety equipment, improvement by emergency evacuation, safety inspection and safety education, etc. (6) traffic accidents ; securing parking spaces, installing safety facilities, conducting safety education, etc. (7) criminal accidents; improvement of CCTV pixels, installation of street lights, removal of blind spots in the complex, securing of security, etc. The roles of suppliers, administrators and users of public rental housing proposed in this study are summarized as follows. Suppliers of rental housing should take into consideration the risk factors that may arise not only in the design and construction but also in the maintenance phase and should consider the possibility of easily repairing old facilities considering the life cycle of rental housing. Next, Administrators of rental housing should consider the safety of the users of the rental housing, conduct safety checks from time to time, and immediately remove any hazardous elements within the apartment complex. Finally, the users of the rental housing needs to form a sense of ownership of all the facilities in the rental housing complex, and efforts should be made not to cause safety accidents caused by the user's carelessness. The results of this study can provide the necessary information to enable residents of rental housing complexes to live a safe and comfortable residential life. It is also expected that this information will be used to reduce the incidence of safety accidents in rental housing complexes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.146-153
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• 2010

The objectives of this study were to explore food-related lifestyle segments of the older consumers, to identify its socio-demographic characteristics, and to investigate the differences in variables regarding health beliefs. A survey was conducted of adults 55 years of age and older living in Seoul, South Korea from March 28 to April 10, 2007. Out of the 500 distributed questionnaires, 361 were retained for final analysis: a response rate of 72.2%. As a result of cluster analysis, five consumer segments were identified; health-managing group, diet-unconcerned group, convenience-oriented group, taste-oriented group, unpracticed group. Significant differences were found among the five segments in terms of socio-demographic characteristics and variables regarding health beliefs (i.e., perceived self-efficacy, perceived barriers, perceived benefits). In the health-managing group and taste-oriented group, mean scores of perceived self-efficacy (p<0.001) and perceived benefits (p<0.001) were significantly higher than other groups. However, in the diet-unconcerned group and convenience-oriented group, the mean scores of perceived barriers (p<0.01) were significantly high. This study shows that foodservice operators targeting the older consumers should consider characteristics of each segment to develop a customized program.

• Journal of the Korean earth science society
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• v.33 no.7
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• pp.627-636
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• 2012

In the Obongri-Goseong area of Gangwondo, South Korea, there are six densely distributed volcanic edifices i.e., Duibaejae, Oeumsan, Galmibong, 249 m height, 166 m height, and 102 m height, and two other volcanic edifices including Goseongsan and Unbongsan volcanic edifice that are separately located from a distance. A previously undiscovered 249m volcanic edifice in Obongri was found in this investigation, and the six volcanic edifices distributed in Obongri will be referred to as the Obongri volcanic edifice group. Volcanic edifices in this area were interpreted by other researchers as being volcanic plug, plug dome, and cylindrical volcanic pipe type edifices. The aim of this study is to investigate the aspect of volcanic activity in the Obongri-Goseong area and the formation of volcanic edifices by examining of the shape of volcanic edifices, stratigraphy, and characterization of volcanic products. All the volcanic edifices in the area are composed of basaltic rocks on the Mesozoic granite basement, and the prevalence of the dome shape increased towards the upper part of the mountain. Three volcanic edifices (Duibaejae, 166 m height, 102 m height) include intercalated pyroclastic deposits between the basaltic rocks and the basement. The pyroclastic deposit in the Duibaejae volcanic edifice is composed of quartz, feldspar, granite fragments originated from the basement, and scoria fragments originated from the volcanic eruption. In addition to angular olivine, plagioclase, and pyroxene xenocrysts, all the basaltic rocks contained mantle xenolith, gabbroic xenolith originated from the lower crust, and granitic xenolith originated from the basement. This fact indicates that magma rapidly rose to the surface and that the volcanic activity was explosive. It is also interpreted that, as the basaltic magma became highly viscous due to the large amount of xenocrysts, the erupted magma formed a dome structure on the surface. The original dome structure was then severely eroded out leaving a plug dome formation on the basement.

• Journal of Mushroom
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• v.14 no.4
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• pp.202-206
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• 2016

Oyster mushrooms are widely cultivated and consumed in Korea. P. ostreatus 'Suhan(ASI 2504)' is an ideal cultivar for mushroom farmers due to its dark pileus and thick stipe; however, as it is very sensitive to environmental conditions, an alternative cultivar is required. To develop a new cultivar, parental strains 'Suhan(ASI 2504)' and 'ASI 0665 (Heuktari)' were selected from various collected strains according to morphological characteristics. P. ostreatus 'Soltari' was developed by DiMon crossing between the dikaryotic strain 'Suhan' and the monokaryotic strain derived from 'Heuktari'. Thirty-eight of the 100 crossed strains were selected following analysis of mitochondrial genetic characteristics, and 'Soltari' was ultimately selected by continuous cultivation tests. The mitochondrial DNA profile of 'Soltari' was found to be the same as that of 'Heuktari, and a nuclear DNA profile of 'Soltari' was similar as those of the parental strains, 'Suhan' and 'Heuktari.' 'Soltari' mycelium grows adequately in moderate to high temperatures of $12-20^{\circ}C$, although its optimum temperature was found to be $30^{\circ}C$. Fruiting body production per 1.1-L cultivation bottle was approximately 158.8 g. Its stipe length and thickness were comparable to those of diameter and thickness were somewhat lower (42.72 vs. 51.33 mm and 18.18 vs. 22.46 mm, respectively). 'Soltari' was found to be more resistant to high $CO_2$ atmosphere than 'Suhan', and the color of the pileus of 'Soltari' was dark gray at high temperature. Therefore, it is suggested that this new cultivar 'Soltari' is a good alternative cultivar and will contribute to energy saving in oyster mushroom farms.

• Geotechnical Engineering
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• v.12 no.4
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• pp.157-178
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• 1996

Current design methods for reinforced earth structures take no account of the magnitude of the strains induced in the tensile members as these are invariably manufactured from high modulus materials, such as steel, where straits are unlikely to be significant. With fabrics, however, large strains may frequently be induced and it is important to determine these to enable the stability of the structure to be assessed. In the present paper internal design method of analysis relating to the use of fabric reinforcements in reinforced earth structures for both stress and strain considerations is presented. For the internal stability analysis against rupture and pullout of the fabric reinforcements, a strain compatibility analysis procedure that considers the effects of reinforcement stiffness, relative movement between the soil and reinforcements, and compaction-induced stresses as studied by Ehrlich 8l Mitchell is used. I Bowever, the soil-reinforcement interaction is modeled by relating nonlinear elastic soil behavior to nonlinear response of the reinforcement. The soil constitutive model used is a modified vertsion of the hyperbolic soil model and compaction stress model proposed by Duncan et at., and iterative step-loading approach is used to take nonlinear soil behavior into consideration. The effects of seepage pressures are also dealt with in the proposed method of analy For purposes of assessing the strain behavior oi the fabric reinforcements, nonlinear model of hyperbolic form describing the load-extension relation of fabrics is employed. A procedure for specifying the strength characteristics of paraweb polyester fibre multicord, needle punched non-woven geotHxtile and knitted polyester geogrid is also described which may provide a more convenient procedure for incorporating the fablic properties into the prediction of fabric deformations. An attempt to define improvement in bond-linkage at the interconnecting nodes of the fabric reinforced earth stracture due to the confining stress is further made. The proposed method of analysis has been applied to estimate the maximum tensions, deformations and strains of the fabric reinforcements. The results are then compared with those of finite element analysis and experimental tests, and show in general good agreements indicating the effectiveness of the proposed method of analysis. Analytical parametric studies are also carried out to investigate the effects of relative soil-fabric reinforcement stiffness, locked-in stresses, compaction load and seepage pressures on the magnitude and variation of the fabric deformations.

• Journal of The Korean Association For Science Education
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• v.34 no.7
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• pp.677-691
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• 2014

Understanding of the nature of science (NOS) has been a consistent topic as one of the most important goals in science education for the past several decades. Even though there is a variety of research related with the NOS conducted in science education, few researches has been conducted for the conception of scientists regards to the nature of science (Bayir et al., 2014; Taylor et al., 2008; Wong & Hudson, 2008). Recently, researchers in science education turned their attention to identifying views of scientists about the nature of science since they recognized the importance of participation of scientists in science education (Southerland et al., 2003; Taylor et al., 2008). This study was conducted to examine the Korean scientists' views of the nature of science. Through the use of semi-structured questionnaire and in-depth interview the views of 35 scientists who belong to the Korean-American Scientists and Engineers Association (KSEA) regards to the nature of science were explored. Findings show that while the scientists have more informed views with respect to the tentativeness of scientific knowledge, cultural and social influence embedded in science, the limitation of science, and the collaboration of science with others, the scientists have more na${\ddot{i}}$ve views about the distinction between laws and theories, the existence of a universal scientific method, and the importance of imagination and creativity. As such, it can be assumed that the scientists cannot conceptualize their notion in a philosophical sense even though they are engaged in scientific work in reality (Bayir et al., 2014).