• Journal of Environmental Science International
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• v.23 no.4
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• pp.681-695
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• 2014

In a pilot-scale dyeing wastewater treatment using two-type fluidizing media, each thickness of biofilm was 15 and 30 ${\mu}m$, respectively. The numbers of protozoa inhabited in small-size (PEMT A) and big-size (PEMT B) media were $7.5{\times}10^4$ and $1.25{\times}10^5$ cells/ml, respectively, and dominant species were Entosiphon sulcatus var sulcatus in PEMT A and Chlamydomonas reinhardtii in PEMT B, respectively. Flask experiments using the two media revealed that the percentages of color removal were 25.8% in PEMT A and 27.1% in PEMT B after 72-h cultivation, indicating the necessity of bioaugmentation. Experiments for bioaugmentation effect on color removal were carried out in the pilot-scale treatment for 75 d by three-step operation under the control of wastewater loading rate and microbial input rate. Dye degradation occurred mainly in the second reaction tank, and the attachment of augmented dye-degrading microorganisms to media took at least 35 d. Final value of chromaticity in effluent was 227, meeting the required standard. Therefore bioaugmentation onto media was good for color treatment. In summary, thickness of biofilm formed on the media depended upon the size of media, resulting in different ecosystem inside the media. Hence, this affected microbial community and color treatment further. Accordingly, the reduction of operation cost is expected by efficient color-treatment process using bioaugmented media.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.80-91
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• 2001

The purpose of this research is to provide a basic knowledge to open up for undeveloped park in process of the park policy establishment by setting up the priority of park development and valuation factor, valuation index as well as building a basic material to undeveloped neighborhood park in Daegu Metropolitan City. Thirteen urban neighborhood parks(1,841,663$m^2$) in the Daegu Metropolitan City were selected for this study. Analyzing and reviewing the previous research and literature review were conducted, and the evaluation index and analysis criteria were constructed to decide the development priority of parks. The results of this research are as follows; 1) Following to the result of the expert questionnaire test in order to estimate weight of valuation factors. It had a high score in available population, and estimated amount of the gross compensation, unpurchased land rate. On the other hand park rate of autonomous district, altitude, rate of population increase in autonomous district and a low score. 2) Generally, most f the plain type parks had a high score in the Sea level, land using pattern, an estimated amount of the gross compensation, but hill type parks had a high score the rate of green covered, park area for one person of administration building. 3) Daebong, Soosung, Dosan, 2.28 youth, Kyungnam parks were selected high priority. Soochang, Donsibong, Janggi, Dongin parks were selected middle priority. Bokhyun, Galsan, Manchon, Gusoosan parks, which were selected low priority. This research for undeveloped park is a basic research step to open up. Three many difficult things in shortage of the basic material for building valuation factor and measuring of the method measurement. The application of weight which make a decision importance among the valuation factor should have ore reasonable study and more scientific research from now because there still remains a lot of shortage of positive materials in there.

• School Mathematics
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• v.16 no.4
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• pp.727-743
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• 2014

The concepts of sample and sampling are central to the statistical thinking and foundations of the statistical literacy, so we need to be emphasized their importance in the statistics education. However, many researches which dealt with samples only analyze textbooks or students' responses. In this study, the concept of sample is addressed by a historical consideration which is one aspect of the didactical analysis. Moreover, developing concept of sample is analyzed from the preceding studies about the statistical literacy, considering the sample representativeness and the sampling variability. The results say that the historical process of developing the concept of sample can be divided into three step: understanding the sample representativeness; appearing the sample variance; recognizing the sampling variability. Above all, it is important to aware and control the sampling variability, but many related researches might not consider sample variability. Therefore, it implies that the awareness and control of sampling variability are needed to reflect to the teaching-learing of sample for developing the students' statistical literacy.

• Journal of Microbiology and Biotechnology
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• v.7 no.2
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• pp.144-150
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• 1997

We developed a simple and efficient method to prepare a Pseudomonas vaccine of outer membrane (OM) proteins free from lipopolysaccharide (LPS). A three step purification process including extraction, ultrafiltration and ultracentrifugation effectively removed LPS from the OM protein fraction. Approximately 2 mg of the OM proteins was obtained from 1 g of wet cell. LPS contaminant in the vaccine preparation was less than 0.003% (w/w) of protein and protease activity was not detectable. To achieve a wide range of protection, OM proteins prepared from four attenuated P. aeruginosa strains were mixed in equal amounts and used as a vaccine, which elicited in rabbits a high titer of antibody reactive to all of the seven Fisher types. The antisera from the immunized rabbit had a strong reactivity to vaccine proteins larger than 25 kDa. In a burned mouse infection model, immunization with the vaccine significantly enhanced bacterial clearance in the Pseudomonas infected skin. The vaccination also provided mice an excellent protection against Pseudomonas infection (11, 16). Data on antigenicity, mutagenicity, acute, subacute toxicity and pharmacological tests confirmed the safety of the vaccine (1, 3, 10, 12, 17). These data demonstrate that this method can be applied to manufacture a bacterial vaccine of OM proteins with safety and prophylactic efficacy at a practical low cost.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.262-270
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• 2007

Of the twelve lytic bacteriophages recovered from five different fermenting cucumber tanks that were inoculated with Pediococcus sp. LA0281, a lytic phage, ${\phi}ps05$, was characterized in the present study. The plaques were mostly clear and round-shaped on the lawn of starter strain, indicating lytic phage. Overall appearance indicated that it belongs to the Siphoviridae family or Bradley's group B1, with a small isometric head and a flexible noncontractile tail with swollen base plate. The average size was found to be 51.2 nm in head diameter and 11.6 nm wide ${\times}$ 129.6 nm long for the tail. The single-step growth kinetics curve showed that the eclipse and the latent period were 29 min and 34 min, respectively, and an average burst size was calculated to be 12 particles per infective center. The optimum proliferating temperature ($35^{\circ}C$) was slightly lower than that of cell growth ($35\;to\;40^{\circ}C$). The structural proteins revealed by SDS-PAGE consisted of one main protein of 33 kDa and three minor proteins of 85, 58, and 52 kDa. The phage genome was a linear double-stranded DNA without cohesive ends. Based on the single and double digestion patterns obtained by EcoRI, HindIII, and SalI, the physical map was constructed. The overall size of the phage genome was estimated to be 24.1 kb. The present report describes the presence of a lytic phage active against a commercial starter culture Pediococcus sp. LA0281 in cucumber fermentation, and a preliminary study characterizes the phage on bacterial successions in the process of starter-added cucumber fermentation.

• Journal of The Korean Society of Agricultural Engineers
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• v.60 no.5
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• pp.17-27
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• 2018

The objective of this study is to identify the priority area where the nonpoint source pollution (NPS) management is required and to set up the load reduction goals for the identified priority area. In this study, the load duration curve (LDC) was first developed using the flow and water quality data observed at 286 monitoring stations. Based on the developed LDC, the priority area for the NPS pollution management was determined using a three-step method. The 24 watersheds were finally identified as the priority areas for the NPS pollution management. The water quality parameters of concern in the priority areas were the total phosphorus or chemical oxygen demand. The load reduction goals, which were calculated as the percent reduction from current loading levels needed to meet target water quality, ranged from 67.9% to 97.2% during high flows and from 40.3% to 69.5% during moist conditions, respectively. The results from this study will help to identify critical watersheds for NPS program planning purposes. In addition, the process used in this study can be effectively applied to identify the pollutant of concern as well as the load reduction target.

• Land and Housing Review
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• v.8 no.3
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• pp.113-121
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• 2017

Wirye New Town is constructed as a new complex city with three municipalities. Infrastructure must be managed by administrative districts, but integrated management is also needed when considering the planned identity and efficient management and operation aspects of a new town. The purpose of this study is to establish why the integrated management of infrastructure is needed, to form a consensus of stakeholders and to set priorities of integrated management considering characteristics of each facility. This thesis analyzes the order of priorities for integrated management of the infrastructures in Wirye New Town. The study includes an analytic hierarchy process (AHP) survey that asked 95 local city officials and experts in city planning about important values to consider, such as efficiency, equity, and identity, for the integrated management of infrastructures in Wirye New Town. Another survey requested these same people to identify the priorities for integrated management in terms of different infrastructure types. The results are as follows. Those who were surveyed considered efficiency(0.442) to be the most important value for integrated management. Equity was deemed to be the next most important(0.369), followed by identity(0.190). The second step in the AHP survey revealed that "efficiency of management governance" (0.202) was considered to be the most important, then "equity of infrastructure quality among the sub-regions" (0.155), and finally "efficiency for improvement of quality and quantity of services" (0.133). The results of the survey about the priority for integrated management among infrastructure types and AHP shows that 'specialized facilities', 'Space facilities located in more than two municipalities', and 'linear facilities located in more than two municipalities.' are important.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.362-365
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• 2005

Currently Chemical Mechanical Planarization (CMP) has become an essential step in the overall semiconductor wafer fabrication technology. Especially the CMP pad conditioner, one of the diamond tools, is required to have strong diamond retention. Strong cohesion between diamond grits and metal matrix prevents macro scratch on the wafer. If diamond retention is weak, the diamond will be pulled out of metal matrix. The pulled diamond grits are causative of macro scratch on wafer during CMP process. Firstly, some results will be reported of cohesion between diamond grits and metal matrix on the diamond tools prepared by three different manufacturing methods. A measuring instrument with sharp cemented carbide connected with a push-pull gauge was manufactured to measure the cohesion between diamond grits and metal matrix. The retention force of brazed diamond tool was stronger than the others. The retention force was also increased in proportion to the contact area of diamond grits and metal matrix. The brazed diamond tool has a strong chemical combination of the interlayer composed of chrome in metal matrix and carbon which enhance the interfacial cohesion strength between diamond grits and metal matrix. Secondly, we measured real-time data of the coefficient of friction and the pad wear rate by using CMP tester (CETR, CP-4). CMP pad conditioner samples were manufactured by brazed, electro-plated and sintered methods. The coefficient of friction and the pad wear rate were shown differently according to the arranged diamond patterns. Consequently, the coefficient of friction is increased according as the space between diamonds is increased or the concentration of diamonds is decreased. The pad wear rate is increased according as the degree of diamond protrusion is increased.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.45-52
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• 2008

In order to investigate the initiation and propagation processes of a spherical detonation wave induced by direct initiation, numerical simulations were carried out using two-dimensional compressible Euler equations with an axisymmetric assumption and a one-step reaction model based on Arrhenius kinetics with various levels of ignition energy. By varying the amount of ignition energy, three typical initiation behaviors, which were subcritical, supercritical and critical regimes, were observed. Then, the ignition energy of more than $137.5{\times}10^6$ in non-dimensional value was required for initiating a spherical detonation wave, and the minimum ignition energy(i.e., critical energy) was less than that of the one-dimensional simulation reported by a previous numerical work. When the ignition energy was less than the critical energy, the blast wave generated from an ignition source continued to attenuate due to the separation of the blast wave and a reaction front. Therefore, detonation was not initiated in the subcrtical regime. When the ignition energy was more than the minimum initiation energy, the blast wave developed into a multiheaded detonation wave propagating spherically at CJ velocity, and then a cellular pattern radiated regularly out from the ignition center in the supercritical regime. The influence on ignition energy was observed in the cell width near the ignition center, but the cell width on the fully developed detonation remained constant during the expanding of detonation wave due to the consecutive formation of new triple points, regardless of ignition energy. When the ignition energy was equal to the critical energy, the decoupling of the blast wave and a reaction front appeared, as occurred in the subcrtical regime. After that, the detonation bubble induced by the local explosion behind the blast wave expanded and developed into the multiheaded detonation wave in the critical regime. Although few triple points were observed in the vicinity of the ignition core, the regularly located cellular pattern was generated after the onset of the multiheaded detonation. Then, the average cell width on the fully developed detonation was almost to that in the supercritical regime. These numerical results qualitatively agreed with previous experimental works regarding the initiation and propagation processes.

• Journal of the Korean Chemical Society
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• v.63 no.2
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• pp.123-133
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• 2019

The purpose of this study was to investigate the effect of responsive teaching method for pre-service teachers in Chemistry Education Department of H University. We designed three steps for the discussions: foregrounding the substance of learners' ideas, recognizing the disciplinary connections within learners' ideas, taking up and pursing the substance of thinking. In the step of foregrounding the substance of learners' ideas, we analyzed the questionnaires conducted by the 20 pre-service teachers to understand the nature of their ideas about evaporation and boiling. Among them, five pre-service teachers were selected to recognize the disciplinary connections within learners' ideas. Through these steps, the pre-service teachers have grasped the nature of their thinking about evaporation and boiling, and have experienced the process of modifying or expanding the frames of thought by the disciplinary connections within learners' ideas. In addition, the pre-service teachers directly perceived the effect of the responsive teaching method by experiencing dynamic changes of their conceptions.