• Journal of Korean Society of Environmental Engineers
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• 제31권11호
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• pp.997-1006
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• 2009

Organic removal efficiency and methane production rate, a feasibility of power generation from biogas, and the optimum conditions for membrane operation were evaluated for the pilot scale (5 tons/day) two-phase anaerobic digestion coupled with ultra filtration (TPADUF) system fed with garbage leachate. The TPADUF system is consisted of a thermophilic acidogenic reactor, a mesophilic methanogenic reactor, and an UF membrane. When garbage leachate with 150 g/L of TCOD was fed to the TPADUF up to organic loading rate (OLR) of 11.1 g COD/L/d, the effluent TCOD was lower than 6 g/L and the average removal efficiencies of TCOD and SCOD were higher than 95%. The methane composition of the gas was 65%, and the methane yield was 39 $m^3/m^3$ garbage leachatefed, 260 $m^3$/tons $COD_{added}$, or 270 $m^3$/tons $COD_{removed}$, even there was some gas leak. The power production per consumed gas was 0.96 kWh/$m^3$ gas or 1.49 kWh/$m^3$ methane. This lower power production efficiency mainly due to the small capacity of gas engine (15 kW class). The membrane was operated at the average flux of 10 L/$m^2$/hr. When the flux decreased, washing with water and chemical (NaOCl) was conducted to restore the flux. In the TPADUF system, optimum pH could be maintained without alkali addition by recycling the membrane concentrate or mixed liquor of the methanogenic digester to the acidogenic reactor. Also, partial production of methane in the acidogenic reactor had a positive effect on lowering the OLR of the methanogenic reactor.

• Clinical and Experimental Pediatrics
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• 제46권12호
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• pp.1186-1193
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• 2003

Purpose : Fragile sites are points on chromosomes which tend to break non-randomly when exposed to specific chemical agents or conditions of tissue culture. The chromosomal break induced by the antineoplastic drug, 1-${\beta}$-D-arabinofuranosyl-cytosine(Ara-c), was investigated to study the laboratory conditions in which the incidence of chromosomal break could be enhanced. Besides, the fragile sites induced by Ara-C were investigated and compared to the already known locations of the specific chromosomal alterations observed in specific neoplasms. Methods : T-lymphocytes from theree normal males and three females were cultured for 48 hours. Cells from each individual were exposed to the Ara-C for an additional 24 hours. After the caffeine was added during the last six hours culture, the metaphase chromosomes were prepared following the conventional method. A site was considered fragile if it was found to break two or more per 100 chromosomal breaks in more than four of six individuals tested. Results : Ara-C induced 252.1 chromosomal breaks per 100 mitotic cells and this result was significantly higher than that of the control, which induced 25.2 breaks(P<0.05). The incidence of the chromosomal break by Ara-C was higher, if cultured in the MEM-FA, which has no folic acid, than in the RPMI 1640 which contains enough folic acid(P<0.05). The most common break site by Ara-C was 3p14.2(FRA3B). There were 20 fragile sites induced by Ara-C. Among these 20 fragile sites, seven coincided with the locations of the mapped oncogenes, JUN, SKI, REL, N-MYC, FHIT, MET, ETS-1, and FOS. Conclusion : S phase specific chemotherapeutic agent, Ara-C, induced the expression of the chromosomal fragile sites effectively using the T-lymphocyte in vitro. Some of the fragile sites by Ara-C highly coincided with the oncogenes and neoplasm specific chromosome breakpoints. In this regard, the fragile sites reported here could provide the unknown neoplasm related chromosomal alternation points.

• Journal of the Korean Institute of Landscape Architecture
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• 제37권1호
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• pp.78-86
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• 2009

Recently, there seems to besome problems in the urban visual landscape as a result of continuous economic growth and industrial development. At the same time, the public has begun to be aware of the importance of visual resources, and the necessity for visual landscape conservation and improvement. Therefore, the development of evaluative indicators for systematic visual landscape planning and design is urgent. The purpose ofthis study is to discover evaluative models and indicators for the diagnosis of urban visual landscapes. This study included the selection of 18 physical indicators(statistical data) by literature reviews, adoption of field and questionnaire surveys at 12 autonomous districts in Seoul and surrounding major mountain valleys and river streams(i.e. Mt. Nam and Han-River). The content of the questionnaire is scenic beauty. Moreover, the linear regression analysis between the scenic beauty mean scores and the physical indicator scores figure out the scenic beauty prediction model. As this study suggests, the most important indicators in urban visual landscapes are 'Greens', 'Park' and 'the number of apartment buildings(higher than 20 stories).' Based on the results, greens and parks should be priority elements to considerin urban landscape planning and design. Moreover, since the number of apartment buildings that are higher than 20 stories has a negative correlation with the scenic beauty score, it can be used as basic data for landscape planning. For the scenic beauty prediction models and evaluative indicators suggest a direction of urban management, each indicator becomes basic data for visual landscape planning and design. In following studies, if physical indicators and case studies are added, the scenic beauty prediction models and evaluative indicators could be more synthetic and systematic. Moreover, the development of physical indicators in three dimensions(3D)(i.e. results from visual district analysis, view surface analysis) could be expected to obtain more general and varied results.

• Journal of the Korea Concrete Institute
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• 제25권3호
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• pp.321-329
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• 2013

Recently, the medium-low level radioactive waste from nuclear power plant must be transported from temporary storage to the final repository. Medium-low level radioactive waste, which is composed mainly of the liquid ion exchange resin, has been consolidated with cementitious material in the plastic or iron container. Since cementitious material is brittle, it would generate cracks by impact load during transportation, signifying leakage of radioactive ray. In order to design the safety transporting equipment, there is a need to check the compressive strength of the current waste. However, because it is impossible to measure strength by direct method due to leakage of radioactive ray, we will estimate the strength indirectly by the dynamic modulus of elasticity. Therefore, it must be identified the relationship between of strength and dynamic modulus of elasticity. According to the waste acceptance criteria, the compressive strength of cement based solid is defined as more than 3.44 MPa (500 psi). Compressive strength of the present solid is likely to be significantly higher than this baseline because of continuous hydration of cement during long period. On this background, we have tried to produce the specimens of the 28 day's compressive strength of 3 to 30 MPa having the same material composition as the solid product for the medium-low level radioactive waste, and analyze the relationship between the strength and the dynamic modulus of elasticity. By controling the addition rates of AE agent, we made the mixture containing the ion exchange resin and showing the target compressive strength (3~30 MPa). The dynamic modulus of elasticity of this mixtures is 4.1~10.2 GPa, about 20 GPa lower in the equivalent compressive strength level than that of ordinary concrete, and increasing the discrepancy according to increase strength. The compressive strength and the dynamic modulus of elasticity show the liner relationship.

• Journal of dental hygiene science
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• 제14권1호
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• pp.43-50
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• 2014

The purpose of this study was to examine the influence of internal marketing activities on motivating dental hygienists in dental hospital in an effort to be of use for setting strategies geared toward boosting the productivity of dental hygienists. The findings of the study were as follows: Concerning internal marketing activities by general characteristics, the dental hygienists who received 4-year college or higher education received more education than the college graduates ($p{\leq}0.001$). As for the leave system, the dental hygienists who worked in general hospitals (p=0.011) and sited in Chungcheongnam-do ($p{\leq}0.001$) replied more leaves were provided. In terms of welfare benefits, there were significant differences in those regards according to the type of hospital (p=0.029) and service area ($p{\leq}0.001$). As to the reward system, their responses about this system were similar to their responses about education & training, leaves and welfare benefits. The motivating factors consisted of 6 motivation factors and 10 hygiene factors. The motivation factors included an opportunities to develop ability and appropriate training to their work. The hygiene factors involved implement of policies and procedures, work environments, relationship with colleagues. Regarding awareness of the motivation factors by general characteristics, there were differences in that aspect according to age (p=0.043), and their awareness of the hygiene factors was different according to service area (p=0.038). As a result of analyzing which factors affected motivating, the leave system (p=0.038) and communication (p=0.001) that belonged to the internal marketing activities were identified as the influential motivation factors. In terms of the hygiene factors, age and service area were influential among the general characteristics (p=0.047, p=0.045). Above findings of the study suggest that it will be possible for dental institutions to ensure successful management by conducting internal marketing activities tailored to the characteristics of their organizational members and by motivating dental hygienists especially through communication.

• Korean Security Journal
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• 제19호
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• pp.225-244
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• 2009

Electronic security system is composed mainly of electronic-information-communication device, so system technology, configuration and management of the electronic security system could be affected by the change of information-communication environment. This study is to propose the future prospect on the development of technique for electronic security system through the analysis of the trend and the actual condition on the development of technique. This study is based on literature study and interview with user and provider of electronic security system, also survey was carried out by system provider and members of security integration company to come up with more practical result. Hybrid DVR technology that has multi-function such as motion detection, target tracking and image identification is expected to be developed. And 'Embedded IP camera' technology that internet server and image identification software are built in. Those technologies could change the configuration and management of CCTV system. Fingerprint identification technology and face identification technology are continually developed to get more reliability, but continual development of surveillance and three-dimension identification technology for more efficient face identification system is needed. As radio identification and tracking function of RFID is appreciated as very useful for access control system, hardware and software of RFID technology is expected to be developed, but government's support for market revitalization is necessary. Behavior pattern identification sensor technology is expected to be developed and could replace passive infrared sensor that cause system error, giving security guard firm confidence for response. The principle of behavior pattern identification is similar to image identification, so those two technology could be integrated with tracking technology and radio identification technology of RFID for total monitoring system. For more efficient electronic security system, middle-ware's role is very important to integrate the technology of electronic security system, this could make possible of installing the integrated security system.

• Korean Journal of Soil Science and Fertilizer
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• 제25권3호
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• pp.249-254
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• 1992

This research was conducted to investigate the effects of fly ash applications on growth and yield parameters of corn (Zea mays L.), and soil chemical properties. Corn height at silking stage, and height and dry matter ratio at harvesting stage were enhanced by applications of fly ashes derived from bituminous coal and anthracite, respectively. Effects of fly ash treatment on growth parameters of corn were varied with kinds and levels of fly ash application and growth periods, but relatively small without revealing a major negative effect as compared to the control. Yield of corn was increased by applying fly ash of anthracite origin, but other yield components were not influenced negatively by fly ash treatment. Soil total carbon contents, cation exchange capacity, and phosphorus contents of soils sampled after harvest of corn were significantly increased by fly ash treatment, although there were slightly different effects according to kinds and levels of fly ash application. Exchangeable cations of soils were varied within an experimental error range. Phosphorus taken up by corn was enhanced by treating fly ash of the bituminous coal to the soil and there were a positive correlation between phosphorus uptake and soil Phosphorus level. Cation uptake by corn was changed a little, but no significant reduction was observed in cation uptake due to fly ash treatment. It seems to be difficult to figure out the mechanism of fly ash effects on growth and nutrient uptake by corn with one year field experiment, however treatment of fly ash enhanced some parameters of growth and yield, and nutrient uptake by corn without revealing any major negative effects. To determine the value of fly ash as a fertilizer source, continuous researches under various soil and crop conditions were considered to be necessary.

• Journal of agricultural medicine and community health
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• 제35권2호
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• pp.177-192
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• 2010

Objectives: This study was conducted to examine the educational needs of elderly hypertensive or diabetes patients and educators for the education program development of cardiocerebrovascular high-risk group in community. Methods: This study was conducted with 60 hypertensive or diabetes patients aged 65 years or above (cardiocerebrovascular high-risk group) who had registered KHyDDI(Korea Hypertension Diabetes Daegu Initiative) Project and attended Hypertension Diabetes Intervention Center Program, and with 44 educators in the center between June and August, 2009. Data were collected using questionnaires including general characteristics, educational objectives, curriculum, contents, and methods. Results: The major findings of this study were as follows: In education methods, cardiocerebrovascular high-risk group and educators both preferred small-grouped(5-9 persons) or individual education, 30min-1 hour, 50%-50% of theory-practice ratio, 3 months of education. In education contents, both groups needed all the suggested contents. Five categories would be suggested for the development of education program. The first category was that there was no significant difference between cardiocerebrovascular high-risk group's needs and knowledge. The second was category of low knowledge level in cardiocerebrovascular high-risk group's knowledge. The repeated education would be necessary for this category. The third was category with large standard deviation in cardiocerebrovascular high-risk group's knowledge. Individual education would be necessary for this category. The fourth category was that there was significant difference between cardiocerebrovascular high-risk group's knowledge and knowledge assessed by educators. The improvement of educator's education skill would be necessary for this category. The fifth category was that there was significant difference between cardiocerebrovascular high-risk group and educator's needs. Conclusions: Small group or individualized and staged education reflecting above cardiocerebrovascular high risk group and educators' needs should be developed for more effective education to prevent and manage the cardiocerebrovascular disease.

• Journal of Korean Home Economics Education Association
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• 제26권3호
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• pp.35-52
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• 2014

This study analyzed the 12 different technology home economics textbooks I, II for middle school students and the content systems of the textbooks by 7 instructional strategies in Reigeluth's elaboration theory. The units analyzed were 'Clothing and self-expression' and 'Eco-friendly clothing life and recycling by reform'. The purpose of this study was to provide basic information for the development of textbooks and teaching materials by analyzing current textbooks. Researchers analyzed the textbooks individually using pre-developed analysis frame using Reigeluth's elaboration theory. The results of the study were as follows. The conceptual elaboration process was used in the unit of 'Clothing and self-expression' of all the textbooks used in this study, and procedural elaboration process was mostly used in the unit of 'Eco-friendly clothing life and recycling by reform'. The strategies of advance learning ability were presented mostly in the forms of 'Learning Objective', 'Thought Opening', 'Key terms' in either unit and sub unit. The strategies of summarizer were presented as 'Unit Summary', 'Cleanup' and 'Assessment'. The strategies of synthesizer were used in all the textbooks as the 'Exploration' to increase the students interest through the promotion of the learning content in a variety of activities and projects. The cognitive activator strategies were shown in all of the textbooks using mostly 'Figure,' and others such as 'Table,' 'Diagram', and 'Explanation of Terms'. The strategies of learner control were used to guide the supplement and deepen the learning by various forms. However the analogy strategies were hardly used in units of textbooks analyzed in this study. As a result, the technology home economics textbooks I, II for middle school students applied the Reigeluth's elaboration theory, except the analogy strategies. It is recommended to utilize th analogy strategies and various activities to enhance the students' understanding and participation.

• 대한공업교육학회지
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• 제42권1호
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• pp.30-52
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• 2017

The purpose of this study is to investigate the duties of teachers working at secondary level technical vocational education institutes, and analyze job importance, difficulty and frequency of performance perceived by teachers. For deducing the duties of teachers working at secondary level technical vocational education institutes, they were theoretically devised by reviewing related legislations & regulations and domestic & overseas literatures. The devised duties were reviewed by 16 current teachers and 3 education experts to be revised and supplemented to complete the job model. Based on this, development of research tool was finalized, and questionnaires were used as the research tool. The results of this study are as follow. First, the job categories of teachers working at secondary level technical vocational education institutes consisted of 7 categories that are subject instruction, student instruction, class management, curriculum organization & administration, school affairs & administrative duties, PR & field practical training and expertise enhancement. Based on the CFA, they consisted of 46 sub-factors in 10 categories with 3 categories of lesson preparation & planning, lesson administration and academic evaluation for subject instruction, and 2 categories of extracurricular student guidance and school life guidance for student instruction, and class management, curriculum organization & administration, school affairs & administrative duties, PR & field practical training and expertise enhancement. Second, job importance perceived by teachers working at secondary level technical vocational education institutes was found to be high overall with 4.10, while above average in difficulty with 3.45 and average in frequency of performance with 3.12 (1-3 times a month). As for categories with high job importance, they were found to be in the order of academic evaluation (4.32), lesson preparation & planning (4.28), expertise enhancement (4.27), lesson administration (4.26), school life guidance (4.25), class management (4.17) and PR & field practical training (4.12). In regards to categories with high job difficulty, they were found to be in the order of PR & field practical training (4.07), curriculum organization & administration (3.73), expertise enhancement (3.55), school life guidance (3.48), academic evaluation (3.35) and extracurricular student guidance (3.22). As for categories with high frequency of job performance, they were found to be in the order of class management (3.88), lesson administration (3.77), school life guidance (3.52), school affairs & administrative duties (3.40) and lesson preparation & planning (3.17).