• Title/Summary/Keyword: Building materials

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Analysis on the Status of the Pilot Project to Spread Hands-on Robots in Elementary After-School (초등 방과후학교 교구로봇 시범사업 현황 분석)

  • Kim, Deok-Gwan;Ryuh, Young-Sun;Han, Jeong-Hye
    • Journal of The Korean Association of Information Education
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    • v.14 no.1
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    • pp.79-87
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    • 2010
  • To support the expansion of diversity for schooling and make a plan for systematic robot education Ministry of Knowledge Economy did Pilot Project of Hands-on Robot at 68 Elementary Schools after building up the supporting system for teachers to practically use robots such as training course with Hands-on Robot. According to this, this paper will be shown about the analysis results of preliminary data about next expansion project of Hands-on Robot through analyzing the current status of Pilot Project of Hands-on Robot at Elementary After-School. For this, status of offered lesson and usage of teaching aids and materials, the number of regular/part-time teachers, students' satisfaction and so on at schools which are listed for the Pilot Project. The results show that at most of elementary schools students' creativity and interests about robots was increased and they tried to take the classes actively with high concentration. In spite of these positives, improvement needs for textbooks were also ascertained, therefore proper textbooks for student and teaching aids to bring on variable activities of students shall be based on additionally for the success.

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Preparation of Nanostructures Using Layer-by-Layer Assembly and Applications (층상자기조립법을 이용한 나노구조체의 제조와 응용)

  • Cho, Jin-Han
    • Journal of the Korean Vacuum Society
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    • v.19 no.2
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    • pp.81-90
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    • 2010
  • We introduce a novel and versatile approach for preparing self-assembled nanoporous multilayered films with antireflective properties. Protonated polystyrene-block-poly (4-vinylpyrine) (PS-b-P4VP) and anionic polystyrene-block-poly (acrylic acid) (PS-b-PAA) block copolymer micelles (BCM) were used as building blocks for the layer-by-layer assembly of BCM multilayer films. BCM film growth is governed by electrostatic and hydrogen-bonding interactions between the oppositely BCMs. Both film porosity and film thickness are dependent upon the charge density of the micelles, with the porosity of the film controlled by the solution pH and the molecular weight (Mw) of the constituents. PS7K-b-P4VP28K/PS2K-b-PAA8K films prepared at pH 4 (for PS7K-b-P4VP28K) and pH 6 (for PS2K-b-PAA8K) are highly nanoporous and antireflective. In contrast, PS7K-b-P4VP28K/PS2K-b-PAA8K films assembled at pH 4/4 show a relatively dense surface morphology due to the decreased charge density of PS2K-b-PAA8K. Films formed from BCMs with increased PS block and decreased hydrophilic block (P4VP or PAA) size (e.g., PS36K-b-P4VP12K/PS16K-b-PAA4K at pH 4/4) were also nanoporous. Furthermore, we demonstrate that the nanostructured electrochemical sensors based on patterning methods show the electrochemical activities. Anionic poly(styrene sulfonate) (PSS) layers were selectively and uniformly deposited onto the catalase (CAT)-coated surface using the micro-contact printing method. The pH-induced charge reversal of catalase can provide the selective deposition of consecutive PE multilayers onto patterned PSS layers by causing the electrostatic repulsion between next PE layer and catalase. Based on this patterning method, the hybrid patterned multilayers composed of platinum nanoparticles (PtNP) and catalase were prepared and then their electrochemical properties were investigated from sensing $H_2O_2$ and NO gas. This study was based on the papers reported by our group. (J. Am. Chem. Soc. 128, 9935 (2006); Adv. Mater. 19, 4364 (2007); Electro. Mater. Lett. 3, 163 (2007)).

Isolation of Acinetobacter calcoaceticus BP-2 Capable of Degradation of Bisphenol A (Bisphenol A 분해균주 Acinetobacter calcoaceticus BP-2의 분리 및 bisphenol A 분해 특성)

  • Kwon, Gi-Seok;Kim, Dong-Geol;Lee, Jung-Bok;Shin, Kee-Sun;Kum, Eun-Joo;Sohn, Ho-Yong
    • Journal of Life Science
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    • v.16 no.7 s.80
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    • pp.1158-1163
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    • 2006
  • Bisphenol A (BPA), 2,2-bis(4-hydroxyphenyl) propane, has been widely used as a monomer for production of epoxy resins and polycarbonate plastics, and final products of BPA include adhesives, protective coatings, paints, optical lens, building materials, compact disks and other electrical parts. Since BPA is a toxic chemical to elicit acute cell cytotoxicity and chronic endocrine disrupting activity, the degradation of BPA has been focused during last decades. To overcome the problem of photo-, and chemical-degradation of BPA, in this study, a bacterium that is able to biodegrade BPA, was isolated. The bacterium, isolated froln the soil of plastic factory, was identified as Acinetobacter calcoaceticus (strain BP-2) based on physiological and 16S rDNA sequencing analysis. A. calcoaceticus BP-2 was able to grow in the presence of $1140{\mu}g\;ml^{-1}$ BPA. Biodegradation experiments showed that BP-2 mineralized BPA via 4-hydroxybenzoic acid and 4-hydroxyacetophenone, and average degradation rate was $53.3{\mu}g\;ml^{-1}\;day^{-1}$ under optimal conditions (pH 7 and $30^{\circ}C$). In high density resting cell $(3.5g-dcw.1^{-1})$ experiments, the maximal degradation rate was increased to $89.7{\mu}g\;ml^{-1}\;h^{-1}$. Our results suggest that BP-2 has high potential as a catalyst for practical BPA bioremediation.

Evaluation of Ground Thermal Conductivity by Performing In-Situ Thermal Response test (TRT) and CFD Back-Analysis (현장 열응답 시험(TRT)과 CFD 역해석을 통한 지반의 열전도도 평가)

  • Park, Moonseo;Lee, Chulho;Park, Sangwoo;Sohn, Byonghu;Choi, Hangseok
    • Journal of the Korean Geotechnical Society
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    • v.28 no.12
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    • pp.5-15
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    • 2012
  • In this study, a series of CFD (Computational Fluid Dynamics) numerical analyses were performed in order to evaluate the thermal performance of six full-scale closed-loop vertical ground heat exchangers constructed in a test bed located in Wonju. The circulation HDPE pipe, borehole and surrounding ground formation were modeled using FLUENT, a finite-volume method (FVM) program, for analyzing the heat transfer process of the system. Two user-defined functions (UDFs) accounting for the difference in the temperatures of the circulating inflow and outflow fluid and the variation of the surrounding ground temperature with depth were adopted in the FLUENT model. The relevant thermal properties of materials measured in laboratory were used in the numerical analyses to compare the thermal efficiency of various types of the heat exchangers installed in the test bed. The simulation results provide a verification for the in-situ thermal response test (TRT) data. The CFD numerical back-analysis with the ground thermal conductivity of 4 W/mK yielded better agreement with the in-situ thermal response tests than with the ground thermal conductivity of 3 W/mK.

A Study of Potential Buyers' Consciousness of Single-Family Housing in Ulsan (단독주택에 대한 울산시 거주자의 주의식 연구)

  • Kim, Ji-Suk;Yang, Se-Hwa
    • Journal of Families and Better Life
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    • v.28 no.6
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    • pp.35-46
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    • 2010
  • The purpose of the study was to identify the potential buyers' consciousness of single-family housing to provide useful data to help future single-family housing supplies in Ulsan. The study selected residents in Ulsan, who were over twenty and had an interest in living in a single-family housing. A survey was conducted from September 11, 2008 to September 25, 2008. The sample consisted of 364 persons who are currently live in Ulsan metropolitan area. The results are as following. About two thirds of the sample had the desire to live in a single-family housing. Moving into a single-family housing had financial preparation as the greatest issue. When moving into a single-family housing, the convenience of the residential district was the greatest consideration, whether or not it is a green environment, pollution level, etc. The potential buyers valued environment-friendly features and also had a very strong desire to own their own house. Many of them wanted to design and build their own single-family housing within a budget of 100-200 million KRW. In terms of the location, there was a higher preference for the riverside or lakeside rural areas outside the city. In terms of size, the preference was less than $330m^2$, which includes $99-132m^2$ for residential. When considering a single-family housing the direction was the most important feature, along with eco-friendly and safer materials and equipments. When building the single-family housing the potential buyers considered the community spaces first with a preference for having three bedrooms and two bathrooms. For the exterior, they wanted a unique shape of roof and there were high preferences for brown and beige colors. In terms of housing complexes, the potential buyers preferred individual unit types over complexes. If they preferred housing complexes, they wanted the cluster form complex with about 10-30 units. The complex also required a park-like setting with a guard system, which shows that convenience and safety were the most important features. In terms of complex management, they considered environmental management as the most important feature. The potential buyers were willing to pay belw 200,000 KRW, which showed their desire to minimize financial burdens.

A Study of the Plan for Library Operation and Curation Provision as a Community Memory Preservation Center (공동체 기억보존센터로서의 도서관 운영 및 큐레이션 제공 방안 연구)

  • Kwak, Woojung;Noh, Younghee
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.31 no.2
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    • pp.53-70
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    • 2020
  • This study was intended to present the need for building the library as a hub of the community memory preservation which provides the collection, sharing, and curation services of the locality specific historical and local data based on the policy task, namely supporting the collection, preservation, and management system of the community's life memory. To this end, the current status of data collection, management, and operation of institutions serving regional-based materials such as cultural centers and regional archives was grasped, and the cases and status of curation services in libraries were investigated and analyzed. The discussion proposed via the results of the study are as follows. First, to the culture center, external demand has been increased from the aspect of social education including festivals, cultural and art event, cultural and art educational business, art activities business of local residents and managerial business is to be carried out, which makes it difficult for the culture center to manage its businesses. Accordingly, it is necessary to collect and preserve regional various data at the pubic libraries playing various roles including provision of informative services, cultural programs and information sharing places to local residents and provision of services to vulnerable social group. As the existing libraries have a plan to collect data systematically, it is considered that those libraries will smoothly operate the data management through cooperation with existing culture centers and various cultural organizations. Second, it appears that a plan will be needed to set up all the data including the ones owned by libraries, local administrative agencies, individuals and other competent agencies in online database so that they are easily available to the public and always available in the libraries because there are a lot of data which cannot be moved to other place and it is actually difficult to concentrate and set up all the data to those libraries.

Development of a Decision Making Model for Construction Management in LNG Plant Construction - Focused on Construction Stage - (LNG 공사의 건설사업관리 의사결정지원모델 개발 - 시공단계 중심 -)

  • Park, Hwan Pyo;Han, Jae Goo;Chin, Kyung Ho
    • Korean Journal of Construction Engineering and Management
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    • v.15 no.3
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    • pp.47-57
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    • 2014
  • LNG plant projects tend to be implemented in overseas owing to its characteristics, so their project management scheme is somewhat different from those of general projects. Value chain in a LNG plant project includes exploration/production of gases, physical liquefaction/chemical conversion processes, transportation and storage. Key factors in the chain include liquefaction process (including ultra-low temperature liquefaction) to convert natural gas into liquid materials or fuel, and Front End Engineering Design (FEED) package, as well as Engineering, Procurement and Construction (EPC) technology comprising control, operation and construction. Success of a complex LNG plant project implemented in overseas depends on decision-making process in project management. Accordingly, to develop a decision-making model in of plant construction, the study extracted none factors in project management by EPC stage and assessed importance of each factor. The result showed that items in both project management and project risk management are important. Especially, the study developed a decision-making model in the construction stage of a LNG plant project based on the project management factors and importance assessment. The developed decision-making model would lay groundwork in building a decision-making system in construction stage of project management.

A Study on the Change of Landscape in Korean Rural Village - From Chosun Dyansty to Olympic Games(1988) - (농촌(農村) 향토(鄕土)마을 경관(景觀)의 변화(變化) - 조선 말기부터 올림픽개최 전(1988)까지 -)

  • Lee, Shi-Young;Jang, Min;Shim, Joon-Young;Heo, Jun
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.4
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    • pp.112-119
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    • 2010
  • This study aims at interpreting Korean Rural Landscape by applying the analytical tool thus developed to the lifestyles of ordinary people found in their permanent dwellings both before and after Korea first opened its door to the world in 1896. By so doing, this study hopes to contribute to building a framework with which to understand the tradition of ordinary people by exploring the uniqueness and basic characteristics of Korean Rural Landscape. This study relies primarily on field studies and publications including, without limitation, the televised documentaries, as well as newspapers and scholastic writings and relating to, the agrarian and residential landscapes changed over time. In the Vernacular world, the present does not passively inherit the past. Rather, it is re-born each time, reflecting the society and history of the period. It does not change, but is shaped by the necessities of the period. This may be the reason why there are different Korean Rural Landscapes over a rather short period of time. For instance, the pre-modern Korean Rural Landscape tends to be shaped almost entirely by the nature, while the intention of people begins to find much more expressions in the modern Korean Rural Landscape. As the commodities become more readily available to people thanks to industrialization, such ready availability has brought about changes in the materials used in, as well as functions of, Rural Landscape.

Reconsideration of Teaching Addition and Subtraction of Fractions with Different Denominators: Focused on Quantitative Reasoning with Unit and Recursive Partitioning (이분모분수의 덧셈과 뺄셈 교육 재고 - 단위 추론 및 재귀적 분할을 중심으로 -)

  • Lee, Jiyoung;Pang, JeongSuk
    • School Mathematics
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    • v.18 no.3
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    • pp.625-645
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    • 2016
  • This study clarified the big ideas related to teaching addition and subtraction of fractions with different denominators based on quantitative reasoning with unit and recursive partitioning. An analysis of this study urged us to re-consider the content related to the addition and subtraction of fraction. As such, this study analyzed textbooks and teachers' manuals developed from the fourth national mathematics curriculum to the most recent 2009 curriculum. In addition and subtraction of fractions with different denominators, it must be emphasized the followings: three-levels unit structure, fixed whole unit, necessity of common measure and recursive partitioning. An analysis of this study showed that textbooks and teachers' manuals dealt with the fact of maintaining a fixed whole unit only as being implicit. The textbooks described the reason why we need to create a common denominator in connection with the addition of similar fractions. The textbooks displayed a common denominator numerically rather than using a recursive partitioning method. Given this, it is difficult for students to connect the models and algorithms. Building on these results, this study is expected to suggest specific implications which may be taken into account in developing new instructional materials in process.

An Experimental Study on Fundamental Properties of a Sprayable Waterproofing Membrane (뿜칠 방수 멤브레인 시작품의 기초 물성평가)

  • Chang, Soo-Ho;Kang, Tae-Ho;Choi, Soon-Wook;Lee, Chulho;Hwang, Gwi-Sung;Choi, Myung-Sik
    • Tunnel and Underground Space
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    • v.26 no.3
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    • pp.220-234
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    • 2016
  • Sprayable waterproofing membrane has been considered as a substitute for a sheet waterproofing membrane in a variety of underground excavation works. However, fundamental properties of sprayble waterproofing membrane have not been fully given yet. In this study, a new two-component sprayable waterproofing membrane prototype was developed. In addition, its physico-mechanical properties were measured and compared with those of two kinds of thin spray-on liners where constitutive materials and construction methods are very close to each other. From direct tensile tests, the sprayable waterproofing membrane with elongations at break between 250% and 300% showed much higher ductility than TSLs. However, the sprayable waterproofing membrane had a limitation as a support member since its bond strength and loading capacity was lower than those of TSLs. From three-dimensional X-ray CT images, the porosity of the sprayable waterproofing membrane was estimated to be 26.13%. However, most of pores which might have been generated during membrane curing were not observed to be interconnected but isolated.