• 한국환경과학회지
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• 제23권4호
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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.

• 한국조경학회지
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• 제29권1호
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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.

• 대한수학교육학회지:학교수학
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• 제16권4호
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• pp.727-743
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• 2014

표본(sample)과 표집(sampling)은 통계적 사고의 핵심이며 통계적 소양의 기초로서 통계교육에서 매우 강조되어야 하는 개념이다. 그러나 표본에 관한 선행연구에서는 대개 교과서 분석과 학생의 반응 분석 등에 그치고 있다. 이에 본고에서는 표본 개념에 대한 교수학적 분석의 한 측면으로서 역사적 분석을 시행하였다. 특히, 통계적 소양의 관점에서 이루어진 선행연구를 토대로, 표본 개념을 이해하기 위한 두 핵심요소인 표본대표성과 표집변이성에 기반을 두고 표본 개념의 역사적 발달을 분석하였다. 연구 결과, 표본 개념의 역사적 발달 과정은 표본대표성(sample representativeness)의 이해, 표본 변이(sample variance)의 등장, 표집변이성(sampling variability)의 인식으로 분류할 수 있으며, 특히 표집변이성을 인식하고 이를 제어하는 과정의 중요성을 확인 할 수 있었다. 그러나 표본 개념의 이해 수준에 대한 기존의 선행연구에는 표집변이성 개념이 잘 반영되지 않고 있다. 이를 토대로, 표본 개념의 교수학습에서 표집변이성을 강조해야 하며, 통계적 소양의 함양을 위해 표집변이성의 인식과 해결의 과정을 포함해야 한다는 시사점을 도출하였다.

• Journal of Microbiology and Biotechnology
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• 제7권2호
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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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• 제17권2호
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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.

• 한국농공학회논문집
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• 제60권5호
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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.

• 토지주택연구
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• 제8권3호
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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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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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.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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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.

• 대한화학회지
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• 제63권2호
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• pp.123-133
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• 2019

이 연구에서는 H대학교 화학교육과 예비교사들을 대상으로 반응적 교수법의 효과를 알아보고자 하였다. 이를 위하여 토론을 학습자 생각의 본질 존중하기, 학습자 생각에서 학문적 연결 관계 인식하기, 학습자 생각의 본질 확장하기의 3단계로 구성하였다. 학습자 생각의 본질 존중하기 단계에서는 예비교사 20명을 대상으로 실시한 설문지를 분석하여 증발과 끓음에 관련된 예비교사들의 생각의 본질을 파악하였다. 이 중에서 5명의 예비교사를 선발하여 자신의 생각과 학문적 연결 관계를 인식하도록 하였다. 이러한 단계를 통해 예비교사들은 증발과 끓음에 대한 자신들의 생각의 본질을 파악하였으며, 이러한 생각의 본질을 학문적으로 연결하여 사고의 프레임을 수정하거나 확장하는 과정을 경험하였다. 또한 예비교사 스스로 자신의 개념이 역동적인 변화하는 과정을 직접 체험함으로써 반응적 교수법의 효과를 인식하였다.