• Computers and Concrete
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• v.25 no.2
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• pp.111-118
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• 2020

The construction field must always explore sustainable ways of using its raw materials. Studying the environmental impact generated by reinforced concrete raw materials during their production and transportation can contribute to reducing this impact. This paper initially presents the carbon dioxide emissions from reinforced concrete raw materials, quantified per kilo of raw material and per cubic meter of concrete with different characteristic strengths, for southern Brazil. Subsequently, reinforced concrete elements were optimized to minimize their environmental impact and cost. It was observed that lower values of carbon dioxide emissions and cost savings are generated for less resistant concrete when the structural element is a beam, and that reductions in the cross section dimensions of the beams, sized based on the use of higher strength concrete, may not compensate for the increased environmental impact and costs. For the columns, the behavior differed, presenting lower values of carbon dioxide emissions and costs for higher concrete strengths. The proposed methodology, as well as the results obtained, can be used to support structural projects that have less impact on the environment.

• International Journal of Reliability and Applications
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• v.14 no.2
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• pp.97-105
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• 2013

A stress-strength model is formulated for a multi-component system consisting of k identical components. The k components of the system with random strengths ($X_1$, $X_2$, ${\ldots}$, $X_k$) are subjected to one of the r random stresses ($X_{k+1}$, $X_{k+2}$, ${\ldots}$, $X_{k+r}$). The estimation of system reliability based on maximum likelihood estimates (MLEs) and Bayes estimators in k component system are obtained when the system is either parallel or series with the assumption that strengths and stresses follow exponential distribution. A simulation study is conducted to compare MLE and Bayes estimator through the mean squared errors of the estimators.

• Journal of the Korea Society of Computer and Information
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• v.21 no.6
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• pp.55-62
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• 2016

In this paper, we present indoor positioning technologies using the wireless signal categorizing them into triangulation based, fingerprinting based, and cell ID based technologies. We describe several representative techniques for each of them emphasizing their strengths and weaknesses. We define important performance issues for indoor positioning technologies and analyze recent technologies according to the performance issues. We believe that this paper provide wise view and necessary information for recent indoor positioning technologies using wireless signals.

• Journal of Technologic Dentistry
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• v.32 no.3
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• pp.195-207
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• 2010

Purpose: The purpose of this study was to observe the microstructural changes of surface in the specimens, performing the shear bond strength testing. The currently most used non-precious alloys are nickel-chromium based alloys with or without beryllium. However, their biocompatibility has been questioned concerning possible damages to the health of the patient and professionals involved in the fabrication of prosthesis caused by long exposure to Ni and Be. An option to nickel-chromium alloys is the cobalt-chromium alloy, an alternative that does not sacrifice the physical properties of the metal porcelain systems. Studies in the animals substantially show that the cobalt-chromium alloys are relatively well tolerated, being therefore more biocompatible than the nickel-chromium alloys. Methods: Non-addition Be to nickel-chromium based alloy(Bellabond plus) and cobalt-chromium alloy which has been widely used(Wirobond C) fused with ZEO light porcelain classified control group and cobalt-chromium alloy which is developing alloy of Alphadent company in Korea(Alphadent alloy) fused with ZEO light porcelain classified experimental group. The specimens of $4mm{\times}4mm{\times}0.5mm$ were prepared as-cast and as-opaque to cast body to analyze the mechanical characteristic change, the microstructure of alloy surface. The phase change was used to observe through XRD analysis and OM/SEM was used to observe the surface of specimens as-cast and as-opaque to cast body. Chemical formation of their elements was measured with EDS. Then hardness was measured with Micro Vicker's hardness tester. Shear bond strength test thirty specimens of $10mm{\times}10mm{\times}2mm$ was prepared, veneered, 3mm high and 3mm in diameter, over the alloy specimens. The shear bond strength test was performed in a universal testing machine(UTM) with a cross head speed of 0.5mm/min. Ultimate shear bond strength data were analyzed with one-way ANOVA and the Scheffe's test (P<0.05). Within the limits of this study, the following conclusions were drawn: The X-ray diffraction analysis results for the as-cast and as-opaque specimens showed that the major relative intensity of Bellabond plus alloy were changed smaller than Wirobond C and Alphadent Co-Cr based alloys. Results: Microstructural analysis results for the opaque specimens showed all the alloys increased carbides and precipitation(PPT). Alphadent Co-Cr based alloy showed the carbides of lamellar type. The Vickers hardness results for the opaque specimens showed Wirobond C and Alphadent Co-Cr based alloys were increaser than before ascast, but Bellabond plus alloy relatively decreased. The mean shear bond strengths (MPa) were: 33.11 for Wirobond C/ZEO light; 25.00 for Alphadent Co-Cr alloy/ZEO light; 18.02 for Bellabond plus/ZEO light. Conclusion: The mean shear bond strengths for Co-Cr and Ni-Cr based alloy were significantly different. But the all groups showed metal-metal oxide modes in shear bond strengths test at the interface.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.2
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• pp.124-131
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• 2012

This paper provides prediction of ultimate longitudinal strengths of hull girder of a VLCC considering probabilistic damage extents due to collision and grounding accidents based on IMO Guideline(2003). The probability density functions of damage extents are expressed as a function of nondimensional damage variables. The accumulated probability levels of 10%, 30%, 50%, and 70% are taken into account for the damage extent estimation. The ultimate strengths have been calculated using in-house software UMADS (Ultimate Moment Analysis of Damaged Ships) which is based on the progressive collapse method. Damage indices are provided for all heeling angles due to any possible flooding of compartments from $0^{\circ}$ to $180^{\circ}$ which represent from sagging to hogging conditions, respectively. The analysis results reveal that minimum damage indices show different values according to heeling angles and damage levels.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.419-422
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• 2003

To improve the recognition accuracy of a developed artificial odor discrimination system for three mixture fragrance recognition, Fuzzy Similarity based Self-Organized Network inspired by Immune Algorithm (F-SONIA) is proposed. Minimum, average, and maximum values of fragrance data acquisitions are used to form triangular fuzzy numbers. Then the fuzzy similarity treasure is used to define the relationship between fragrance inputs and connection strengths of hidden units. The fuzzy similarity is defined as the maximum value of the intersection region between triangular fuzzy set of input vectors and the connection strengths of hidden units. In experiments, performances of the proposed method is compared with the conventional Self-Organized Network inspired by Immune Algorithm (SONIA), and the Fuzzy Learning Vector Quantization (FLVQ). Experiments show that F-SONIA improves recognition accuracy of SONIA by 3-9％. Comparing to the previously developed artificial odor discrimination system that used FLVQ as pattern classifier, the recognition accuracy is increased by 14-25％.

• Journal of Distribution Science
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• v.10 no.8
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• pp.15-23
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• 2012

This study is an attempt to explore the nature and characteristics of strategic impact of green strategy by environmental capital, corporate reputation, and technology strengths on the firm's performance across countries. The main question addressed in this paper relates to how corporate sustainability, corporate reputation, technology strength, and capabilities influence the firm's economic performance with respect to diverse dimensions of performance measures including sustained growth through the leading firms across countries in the United States, Canada, Europe, and Asia-Pacific countries. Particularly, this study attempts to empirically explore the directions and magnitudes of the operational links between new emerging strategic core competencies (e.g., sustainability green strategy by environmental focus for more sustainable path, corporate reputation by corporate social responsibility and image enhancement, and technology strengths to develop a new product and market) and the firm's economic performance with respect to diverse dimensions of performance such as accounting (ROE and EOA) - and market-based performance (Market value and Tobin's q). Considering all possible limitations that might exist with regard to selected samples and methods, this study demonstrates that environmental sustainability, corporate reputation, technological capabilities and competencies through R&D intensity and patent are most likely to be significantly associated with most market-based performance measures, but the strategic significance of other variables such as capital intensity, leverage, and administrative cost efficiency on performance tends to be different depending on which performance measure is used across different countries with diverse economic and business contexts.

• 한국정보교육학회:학술대회논문집
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• 2011.01a
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• pp.153-158
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• 2011

The idea that the mobile phone could be used in the education field recently comes from it's strengths. They have mobility, on-the-spot-study, portablity, immediacy and they are easy to connect to educational information. The application which I developed in this study is using Google-Map API and is based on GPS. It can share the information about the area where user is located like text data and pictures of geography, culture, and historical remains. This application makes the best use of the mobile phone's strengths. It's more effective and we can expect that users could manage resources of learning and do self-directed study in spite of being outside of the classroom or after regular classtime.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1283-1290
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• 2005

A thixotropic grout has been newly developed for the use of back-filling a tail void in the shield tunnel and filling up ground voids. The grout developed in the study is a mixture of colloidal silica, cement and some functional additives. Its engineering characteristics was investigated by measuring a viscosity and unconfined compressive strengths. The optimum mixing proportion for an effective thixotropic grout was proposed through several repeated laboratory tests. The various physical properties such as thixotropy, unconfined compressive strengths, and durability of the thixotropic grout and the gels produced from the grout were compared with those of the well-known waterglass grout such as L.W.. The thixotropic grout developed in the study exhibited an excellent performance for back-filling of tail voids, based on experimental results compared to the existing waterglass grout.

• Fashion & Textile Research Journal
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• v.17 no.6
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• pp.895-906
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• 2015

Seoul Fashion Week aims to be the world’s fifth Fashion Week from the year after 2000. This has involved significant labour and investment, not all of which has been successful. This study analyses the strengths and weaknesses of SFW based on the London Fashion Week as a successful model. By identifying its obvious and less obvious characteristics, this analysis aims to diagnose SFW’s current status in order to upgrade the event at an international level. Key factors are organisational body, designers, visitors, sponsors, schedule, venue, main events and supportive events. The following points have emerged from the research: the success of Seoul Fashion Week was based on the combination of separate collections, an appropriate fashion show venue, and the active role of new designers. The problems were: lack of an independent organisation, non-professional staff, lack of diverse visitors, exclusive governmental funding, late timing, excessive distance from the main European and American fashion markets, lack of sustainability of the main events, a limited variety of supportive events, the absence of online promotion and, last but not least, no distinctive features. The study concludes that Seoul Fashion Week has great potential with its fast growth and young designers. This should be complemented with an independent organisation and effective administration and strategy.