• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.779-784
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• 2002

Porous concrete with a great deal of continuous porosity enables to contain water and to pass air freely through firmly hardened material, and allow necessary nutrients to reach roots of vegetation. Therefore, this paper deals with the voluntary properties and efficiency for planting of plant porous concrete. The results of experiment showed that void volumes were 17% to 31%, and compressive strength ranged between 80kgf/cm$^2$ and 180kgf/cm$^2$ when the ratio of the paste to aggregate was 0.3-0.5 When the aggregate size are 20-30mm, the paste to aggregate ratio is 0.3, and the length of Paranial Ryegress came up as 32cm. Ut supra the efficiency of planting goes through Paranial Ryegrass in result the length of plant are in compliance with void volume and aggregate size.

• Journal of Information Processing Systems
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• v.6 no.2
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• pp.219-234
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• 2010

Gaming is an old humans' habit. Games help in logical development and encourage learning of theoretical and practical concepts. Besides they offer entertainment and challenge. The advent of the personal computer changed this tradition. Every year new challenges arise in a digital format, which lead the young and adults to spend hours in front of a computer or TV screen in an attempt to overcome hurdles and reach an objective. Quality, sophistication, and constant innovation are attained through complex computer software that almost has an obligation to improve as each new title is released, due to this game development becomes a challenge. Considering that a game title is software and thus faces the same restrictions of business applications, this article intends to analyze, under the optics of reuse, if game development resorts to reuse, and where and how this happens.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.329-341
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• 2008

Knowledge management has garnered attention due to its role of maintaining competitive advantage. Creating and sharing knowledge is an essential part of managing knowledge. However, the best knowledge is underutilized because employees tend to seek knowledge through their informal networks, not reach out to other sources for obtaining the best knowledge. Prior studies on informal networks pointed out a negative influence of heavy reliance on learning through informal networks but they paid little attention to a structure of informal networks and its impacts on diffusion of knowledge. The aim of our study is to show impacts of informal network on knowledge management by employing a network structure and investigating diffusion of knowledge within it. Our study found out that performance of learning becomes lower in a highly clustered network. Creating random links such as serendipitous learning can improve performance of knowledge management. When employees rely on a knowledge management system, creating random links is not necessary. Costs of adopting knowledge affect performance of knowledge management.

• Journal of the Korean Chemical Society
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• v.43 no.6
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• pp.621-627
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• 1999

A new predictive scheme to calculate hydrocarbon enthalpies of formation from ab initio total energy calculations is described. The method improves a previous computation procedure (based on the total number of atoms) through the inclusion of bond parameters. Present results are good enough and the average absolute errors in the computed values of enthalpies of formation are lower than the experimental uncertainties. Some possible extensions are pointed out in order to reach definitive conclusions about the proposed methodology.

• International Journal of Human Ecology
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• v.9 no.1
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• pp.63-69
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• 2008

Character education is an opportunity for students to develop character through teaching values in schools. In the past, students have been taught values at home but contemporary society has strongly encouraged the public schools to provide time for children to learn values because society is facing a crisis of human values that affects the behavior of individuals. According to research findings, the primary benefit of character education is to develop the intellectual, personal, and social aspects of students. However, there are some problems concerning how to teach values and how to evaluate student outcomes in public schools. This article explores the current character education in the U. S. through a review of the literature in order to reach a better understanding of how character education might be included in the Family and Consumer Sciences Education curriculum.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.4
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• pp.71-77
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• 2001

In this paper, stress wave propagation characteristics of MR(Magneto-rheological) inserts are experimentally investigated. Generally, stress waves of structures such as warships or submarines are induced by shock waves from underwater explosion. Their fatal effects on the shipboard equipments or structures damage the performance of warships. But, such a problem can be solved by controlling the stress waves propagating through structures by means of MR inserts. MR insert consists of two aluminum layers and MR fluid filled in between. Two piezoceramic disks are embedded on the host plate as a transmitter and a receiver of stress waves. Pulse waves are generated by the transmitter and they reach to the receiver through the MR insert. Permanent magnet and magnetic coil are used to produce magnetic field at the MR insert. In the presence of magnetic field, MR particles are arranged in chains parallel to the magnetic field such that the transmitted stress waves are reduced. Attenuation of stress waves is experimentally investigated.

• Advances in biomechanics and applications
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• v.1 no.4
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• pp.227-237
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• 2014

The in vitro construction of osteo-articular large implants combining biomaterials and cells is of great interest since these tissues have limited regeneration capability. But the development of such organoids is particularly challenging, especially in the later time of the culture, when the extracellular matrix has almost filled the initial porous network. The fluid flow needed to efficiently perfuse the sample can then not be achieved using only the hydraulic driving force. In this paper, we investigate the interest of using an electric field to promote mass transport through the scaffold at the late stage of the culture. Based on the resolution of the electrokinetics equations, this study provides an estimation of the necessary electric driving force to reach a sufficient oxygen perfusion through the sample, thus analyzing the feasibility of this concept. The possible consequences of such electric fields on cellular activities are then discussed.

• CDE review
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• v.4 no.2
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• pp.30-35
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• 1998

Recently, many enterprises wish to preoccupy competitive positions in the market by motivating themselves towards CALS(Commerce At Light Speed) and try hard to achieve system implementation with the use of new concept-based backbone systems such as ERP(Enterprise Resource Planning) or PDM(Product Data Management). However, unfortunately there is an inevitable discrepancy during implementation period between package vendors and customers due to lack of clear methodology and misunderstanding about system. In some cases, consensus on partially verified system design invokes customers'continuous change demands and often it tends to result in unnecessary project delays. PDM application system implementation project of the company L has been studied here to solve these sorts of problems. The major yields of this work are achievement of a willing approval from customers and rapid system design under a time-limited and conceptually defined project scope and finally, through fully verified system design, we were able to reach successful system implementation.

• Proceedings of the Korea Crystallographic Association Conference
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• 2002.11a
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• pp.53-53
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• 2002

Alkali-soluble random copolymer (ASR) was used as a functional resin in the emulsion polymerization of styrene to prepare structured nanoparticles. The calorimetric technique was applied to study the kinetics of emulsion polymerization of styrene using ASR and conventional ionic emulsifier, sodium dodecyl benzene sulfonate (SDBS). ASR could form aggregates like micelles and the solubilization ability of the aggregates was dependent on the neutralization degree of ASR. The rate of polymerization in ASR system was lower than that in SDBS system. This result can be explained by the creation of a hairy ASR layer around the particle surface, which decreases the diffusion rate of free radicals through this region. Although a decrease in particle size was observed, the rate of polymerization decreased with increasing ASR concentration. The higher the concentration of ASR is, the thicker and denser ASR layer may be, and the more difficult it would therefore be for radicals to reach the particle through this layer of ASR. The rate of polymerization decreased with increasing the neutralization degree of ASR. The aggregates with high neutralization of ASR are less efficient in solubilizing the monomer and capturing initiator radicals than that of the lower neutralization degree, which leads to decrease in rate of polymerization.

• Korean Educational Research Journal
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• v.37 no.1
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• pp.33-45
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• 2016

We propose a research for detection of the fluoride ion using borane compounds. Based on the Lewis acid-base reaction, we discussed the fundamental of sensing for fluoride ion. One of the important aspects in the chemistry of organoboranes is their behaviors as Lewis acids, which is a result of the vacant $2p_{\pi}$ orbital on the tricoordinate boron center. The electronic interaction between boron atoms and ${\pi}$-orbitals of donor molecules, constructed from the carbon 2p orbitals, is generally strong. Boron atoms can reach the desired octet configuration either through ${\pi}$-overlap with a suitable X or through formation of Lewis acid-Lewis base complexes.