• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.75-80
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• 2001

This paper investigates the flexural behavior of reinforced concrete beams strengthened with externally bonded fiber reinforced plastic (FRP) sheets is investigated in this work. FRP is attractive for strengthening the RC beams due to its good tensile strength, low weight, resistance to corrosion, and easy applicability. A simple and direct analytical procedure for evaluating the ultimate flexural capacity of FRP strengthened reinforced concrete (SRC) beams is presented using the equilibrium equations and compatibility of strains. Upper and lower limits of FRP sheet area to ensure the ductile behavior are established. A parametric study is conducted to investigate the effects of design variables such as sheet area, sheet stiffness and strength, concrete compression strength, and steel reinforcement ratio. The analytical procedure is compared with results of experimental data available in the literature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.334-337
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• 1996

Si anisotropic etching is a key technology for micromachining. The main advantages of tetramethyl ammonium hydroxide (TMAH)-based solution are their full compatibility with IC process. In this work the anisotropic etching of single crystal Si in a TMAH (($CH_3$)$_4$NOH) based solution was studied. The influence of the addition of IPA to TMAH solution on their etching characteristics was also presented. The crystal planes bounding the etch front and their etch rates were determined as a function of temperature, crystal orientation, and etchant concentration. The etch rates of (100) oriented Si crystal planes decreased linearly with increasing the IPA concentration, The etched (100) planes were covered by Pyramidal-shaped hillocks below 15 wt.%, but very smooth surfaces were obtained above 20 wt.%. The addition of IPA to TMAH solution leads to smoother surfaces of sidewalls etched planes.

• Composites Research
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• v.26 no.3
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• pp.165-169
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• 2013

This work presents the tensile properties and water uptake behavior of plasma treated abaca fibers reinforced epoxy composites. The composites were prepared by vacuum assisted resin transfer molding. The effects of treatment on tensile properties and sorption characteristics of abaca fiber composites in distilled water and salt solution at room temperature were investigated. The tensile strength of the composites increased with plasma treatment. With plasma treatment, an improvement of 92.9% was obtained in 2.5 min exposure time in plasma. This is attributed to high fiber-matrix compatibility. Less improvement on tensile properties of hybrid treatment of sodium hydroxide and plasma was obtained. However, both treatments reduced overall water uptake in distilled water and salt solution. Hydrophilicity of the fibers decreased upon plasma and sodium hydroxide treatment, which decreases water uptake.

• Journal of Information Processing Systems
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• v.17 no.6
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• pp.1035-1043
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• 2021

An Internet of Things (IOT) sensor network is an effective solution for monitoring environmental conditions. However, IOT sensor networks generate massive data such that the abilities of massive data storage, processing, and query become technical challenges. To solve the problem, a Hadoop cloud platform is proposed. Using the time and workload genetic algorithm (TWLGA), the data processing platform enables the work of one node to be shared with other nodes, which not only raises efficiency of one single node but also provides the compatibility support to reduce the possible risk of software and hardware. In this experiment, a Hadoop cluster platform with TWLGA scheduling algorithm is developed, and the performance of the platform is tested. The results show that the Hadoop cloud platform is suitable for big data processing requirements of IOT sensor networks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.2005-2014
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• 2009

There are several methods to fabricate Polymer Dispersed Liquid Crystal(PDLC) films. One of them, so-called Nematic Curvilinear Aligned Phase(NCAP) film, is based on emulsion technology. To produce NCAP systems various water soluble polymers, such as partially hydrolyzed polyvinylalcohol(PVA) and polyvinyl pyrrolidone(PVP), which can form stable emulsion of liquid crystal(LC) without any stabilizers were used. In this work, we studied the dependence of emulsion stability on nature and composition of copolymers composed of water-soluble and water-insoluble moiety. We found that interfacial surface tension depends on the composition of comonomer, the copolymer concentration in the water, and the nature of hydrophobic chain. The Acrylamide -styrene(AA-ST) copolymer showed the lowest interfacial surface tension among the tested copolymers at the same concentration. Since the interfacial surface tension decreases with increasing the compatibility of copolymer with LC phase the AA-ST copolymer has the best compatibility with LC molecules. It is believed that molecules adsorbing easily on the surface of LC droplets allows the LC emulsion system to be more stable.

• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1456-1463
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• 2017

In recent times, IaaS (Infrastructure as a Services) have been rapidly evolving to allow developers to easily and efficiently access work in the server and network areas for development of a web of App based on cloud computing. In this study, we developed the collaborative image editing tool App based on Cloud-computing, by adopting AWS of representative company that develops IaaS. First, it is crucial to understand various situation conditions for representative infrastructure services: AWS, Azure and Google (GCP). This may have the effect of reducing manpower and development time, but as each company has different policy and technical support, we need a new study every time the environment changes of infrastructure services. We tried to develop a hybrid-App so that users with various devices can collaborate work each other by utilizing the infrastructure service AWS through the process of developing the image editing authoring tool based on the cloud computing. The future studies should continue about compatibility issues and support issues in order to minimize the problems of overseas infrastructure services, but we think that domestic cloud computing policies and developments should be urgently considered.

• Journal of the Korea Society of Computer and Information
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• v.3 no.2
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• pp.29-35
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• 1998

In this paper, the proposed audio/video control device for multiple user in the multimedia platform is changed for the better a disadvantage that must get one computer per participant to process a floor mode needed for interactive collaboration in the multimedia based distance education. It also proposed simulator of co-work environment that included multimedia data. This developed to proceed a multimedia distance education efficiently and sharing a computer among multiple users. Therefore, this is resulting in a reduction the cost needed to build a multimedia distance education system as well as totally simplified the organization of system. It also offers compatibility and generality, interfacing with the printer port of standard PC supporting the bi-direction mode.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.421-424
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• 2000

Cartilage injuries are frequent nowadays. The previous surgical treatment of cartilage defect was limited. Another approach in the treatment of cartilage injuries is the use of reconstitute cartilage consisting of chondrocytes cultured in suitable biodegradable scaffolds. Current studies have demonstrated the compatibility of chondrocytes with different biomaterials and the chondrogenesis in various types of porous scaffolds. The cell ingrowth into the porous scaffolds is modulated by initial cell loading efficiency. Therefore, well-interconnected pore structure and even pore distribution of the scaffolds are essential for efficient cell seeding. According to our previous work, well-interconnected macroporous scaffolds can be prepared by gas-foaming/salt-leaching method using ammonium bicarbonate salt as porogen additives. In this work, primary chondrocytes were cultured in PLGA 65/35 scaffolds fabricated by using our method. Cells seeded in the scaffolds showed well distribution by agitated seeding method. Histochemical staining of proteoglycans present in the scaffolds was used to visualize the chondrocyte ingrowth in the scaffolds. At 3 weeks, the population of chondrocytes was increased for the most part of the scaffolds, and extra cellular matrix (ECM) secretion was increased as culture periods progressed.

• Korean Journal of Computational Design and Engineering
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• v.21 no.2
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• pp.130-142
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• 2016

BIM library, as a systematic collection of BIM objects where the building information is stored, is a vital factor to construct the BIM based work environment. However, construction business is faced the problems relating BIM library such as the absence of the standard for establishing BIM library, the discontinuity of BIM library's compatibility and the lack of practice applicable BIM library. These problems cause the decreasing work efficiency and the recreating BIM model, by delivering inefficient information required in each stage and application field. The purpose of this study is to suggest the integrated management system for property information of BIM library in order to minimize the reworking and to manage information of each stage and application field when exchanging and sharing information. To achieve this, the BIM information classification, the criteria of property requirements for information exchange in BIM application field and the BIM library management system are developed. This study could contributes to ensuring the reliability and accuracy of results of BIM based analysis and to enhancing the speed of business process with sharing and exchanging building information utilizing a single BIM model.

• Journal of Information Technology Services
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• v.14 no.2
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• pp.289-314
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• 2015

Recently, Most of the companies and government offices are under consideration about the adoption of cloud office service to actualize the smart work policies. Comparing with traditional office software, a cloud office service have the advantage of the method of payment and coming over the physical limitations. Many cloud office service users tend to adopt an official evaluated the service without doubt. However after deciding to adopt cloud office service, many users are faced with a variety of problems and difficulties practically. In this study, researchers carried out interview about those problems and difficulties after adopting a cloud office service. Consequently, there are several problems and difficulties such as compatibility, document security, document lost and maladjusted to the new graphic user interface between traditional office software and a cloud office service. A cloud office service have still several advantages not only a competitive price but also ubiquitous attributes. Thus, researchers need to study about what kinds of reason variables can solve those problems and difficulties. In existing research, DeLone & McLean have suggested information system success model. They use three independent variables which are system quality, information quality, service quality. Parameters are user satisfaction, intention to use and use. Lastly, dependent variables are net benefits. However in this study, we need to change the scope of measurement. In other words, we have to replace parameters with dependent variables. Simply, user satisfaction, intention to use and use is going to be dependent variables. There are several reasons why we need changing variables. First, we aim at giving a some suggestions to a cloud service providers which independent variables do not work to satisfy for the users. Second, we need to find out how to maximize cloud office service user's satisfaction and intention to use. Third, we should firstly know that relationship between independent variables and dependent variables. Finally, those research results give for the cloud office service provider to solve the cloud office service adopting problems and difficulties.