• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.25 no.6
• /
• pp.471-478
• /
• 2016

This paper describes a method to design a lightweight modular bridge for a railway infrastructure system. A lightweight design was achieved using the material selection method. Aluminum extrusions and honeycomb sandwich composites were selected as the best materials to reduce the weight of the upper structure of a conventional modular bridge made of carbon-steel material. The structural integrity of the lightweight modular bridge was evaluated under vertical and wind loads. The twisting and bending natural frequencies were also evaluated to investigate its dynamic characteristics. The results showed that the structural integrity and natural frequencies of the lightweight modular bridge, made of aluminum extrusion and sandwich composites, satisfied the design requirements. Moreover, it was found that the weight of the conventional modular bridge made of carbon steel could be reduced by a maximum of 47% using lightweight materials.

• The Korean Journal of Health Service Management
• /
• v.3 no.2
• /
• pp.55-64
• /
• 2009

The purpose of this study was to examine the use of skincare & obesity clinics, customer satisfaction with franchise and non-franchise skincare & obesity clinics and customer selection criteria in the region of Busan in a bid to suggest some of the right directions for marketing strategies for the inauguration of skincare & obesity clinics. The subjects in this study were 240 users of 16 different skincare & obesity clinics selected from Busan. Out of the clinics, four franchise clinics and four non-franchise clinics were selected from the major commercial districts, and four franchise clinics and four non-franchise clinics were selected from the residential areas. Concerning the influence of three leading factors on customer satisfaction, all the service price, material service and human service had a significant impact on customer satisfaction in the franchise model for the commercial districts. In the case of the franchise clinics in the residential areas, only service price exerted a significant influence on customer satisfaction. In terms of the non-franchise model for the commercial districts, customer satisfaction was under the significant influence of human service and material service, and that was significantly affected by human service and service price in the non-franchise model for the residential areas.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.35 no.2
• /
• pp.58-64
• /
• 2003

Because of its tendency of making strong Hoc on the fiber surface with fines, Meogujaengi has not been valued as a material of Hanji. As an attempt to manufacture high value-added products using the material made from Jumchihanji, this study performed morphological classification and chemical component analysis and selection of pulping of Meogujaengi method. As a result, it can be concluded as follows, 1. Meogujaengi is assumed to be a local variety of Broussonetia karinoki and its outward appearance is distinguished from Broussonetia kazinoki. 2. The bast fiber of Meogujaengi is longer and thinner than that of Broussonetia papyrifera or Broussonetia kazinoki. However, because of the coarse linear of fiber tissue, there are many clusters. 3. The cluster phenomenon of Meogujaengi is nothing to do with its chemical components. Although the contents of its chemical components are different from those of Broussonetia kazinoki, no component was found that obstructs pulping. 4. The pretreatment for suppressing the occurrence of clusters of Meogujaengi was effective, and it was necessary to do secondary beating using hollander beater after beating mixed with PAM using knife beater.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.58 no.2
• /
• pp.73-82
• /
• 2016

This study is about development of personal disaster shelters for minimization of the casualties caused by the landslide and steep slope collapse. The objectives of present research is the selection of disaster evacuation facilities utilizing FRP (Fiber Reinforced Plastic) material. For the proper assessment of FRP member, several layers by strength test and the three-dimensional numerical analysis of these FRR member was carried out. As a result, the personal disaster evacuation facility utilizing FRP materials, was found to be of a material that is able to protect the weak person at the time of the collapse of the landslides and steep slopes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.2
• /
• pp.135-141
• /
• 2007

The conduction-cooled HTS SMES is operated in cryogenic and high vacuum condition. Thus, Insulation design at cryogenic temperature and high vacuum is a key and an important element that should be established to accomplish miniaturization that is a big advantage of HTS SMES. However, the behaviors of insulators for cryogenic conditions in vacuum are virtually unknown. Therefore, we need active research and development of insulation concerning application of the conduction-cooled HTS SMES. Therefore, in this study, we experimented about insulation characteristic high vacuum and cryogenic similar to driving condition of SMES system. Also, investigated about insulation characteristic of suitable some materials to insulator for conduction-cooled HTS SMES. As this results, we possessed basis data for insulation materials selection and insulation design for development of 600 kJ class conduction-cooled HTS SMES.

• Hwankyungkyoyuk
• /
• v.19 no.3
• /
• pp.165-182
• /
• 2006

Demands for developing diverse teaching methods and materials which can lead to active participation of students in classes have been emerged for environmental education in secondary schools. In order for more effective environmental education, a variety of programs in the mass media including public broadcasting have been used. Advantages associated with the broadcasted TV programs include compensation of temporal and spatial limits embedded with the printing media, improvement of studying efficiency, and provision of diverse studying opportunities, leading to the promotion of the awareness of environmental issues. In this study, 256 environmental issues related TV programs being aired via major public broadcasting companies such as EBS, KBS, MBC and SBS between years of 2003 and 2004 were analyzed. During the present research, selection of the programs was made based on the weight of the environmental issues in independent programs being aired for at least 10 minutes. A survey as a primary means was carried out for the utilization of the audio-visual educational materials in order to provide a new method employing the TV programs which were related to the environmental issues during the instruction in secondary schools.

• Journal of Welding and Joining
• /
• v.29 no.4
• /
• pp.41-47
• /
• 2011

GMA welding process is a production process to improve productivity for the provision of higher welding quality of material. These includes numerous process variables that could affect welding quality, productivity and cost savings. Recently, the welding part of construction equipment had frequent failure of major components in the welding part of each subsidiary material due to shock which is very poor according to the welding part. Therefore, the implementation of sound welding procedure is the most decisive factor for the reliability of construction machinery. The data generated through experiments conducted in this study has validated its effectiveness for the optimization of bead geometry and process variables is presented. The criteria to control the process parameters, to achieve a good bead geometry. This study has developed mathematical models and algorithms to predict or control the bead geometry in GMA fillet welding process.

• Elastomers and Composites
• /
• v.51 no.4
• /
• pp.308-316
• /
• 2016

The rubber materials are widely used in automobile industry due to their capability of a large amount of elastic deformation under a force. Current trend of design process requires prediction of functional properties of parts at early stage. The behavior of rubber material can be modeled using strain energy density function. In this study, five different strain energy density functions - Neo-Hookean model, Reduced Polynomial $2^{nd}$ model, Ogden $3^{rd}$ model, Arruda Boyce model and Van der Waals model - were used to estimate the behavior of carbon black added natural rubber under uniaxial load. Two kinds of tests - uniaxial tension test and biaxial tension test - were performed and used to correlate the coefficients of the strain energy density function. Numerical simulations were carried out using finite element analysis and compared with experimental results. Simulation revealed that Ogden $3^{rd}$ model predicted the behavior of carbon added natural rubber under uniaxial load regardless of experimental data selection for coefficient correlation. However, Reduced Polynomial $2^{nd}$, Ogden $3^{rd}$, and Van der Waals with uniaxial tension test and biaxial tension test data selected for coefficient correlation showed close estimation of behavior of biaxial tension test. Reduced Polynomial $2^{nd}$ model predicted the behavior of biaxial tension test most closely.

• Journal of Environmental Science International
• /
• v.23 no.10
• /
• pp.1745-1753
• /
• 2014

Sediment microbial fuel cell (SMFC), equipped with Zn, Al, Cu, Fe or graphite felt (GF) anode and marine sediment, was performed. Graphite felt was used as a common cathode. SMFC was single chambered and did not use any redox mediator. The aim of this work was to find efficient anodic material. Oxidation reduction potential (ORP), cell voltage, current density, power density, pH and chemical oxygen demand (COD) were measured for SMFC's performance.. The order of maximum power density was $913mWm^{-2}$ for Zn, $646mWm^{-2}$ for Fe, $387.8mWm^{-2}$ for Cu, $266mWm^{-2}$ for Al, and $127mWm^{-2}$ for graphite felt (GF). The current density over voltage was found to be strongly correlated with metal electrodes, but the graphite felt electrode, in which relatively weaker electricity was observed because of its bio-oriented mechanism. Metal corrosion reactions and/or a complicated microbial electron transfer mechanism acting around the anodic compartment may facilitate to generate electricity. We presume that more sophisticated selection of anodic material can lead to better performance in SMFC.

• Journal of the Korean Electrochemical Society
• /
• v.6 no.3
• /
• pp.183-186
• /
• 2003

In a PEM fuel cell electrode, backing layer has tremendous impact on electrode performance. The backing layer provides structural support for the porous electrode, distributes the reactants to the other layers and acts as a current collector. It has major influence on the water management in a PEM fuel cell. Selection of suitable backing layer material for the fabrication of electrode is thus very important to achieve high performance. In this paper we have compared the performance of PEM fuel cell electrodes fabricated using carbon paper EC-TPI-060T, carbon cloth EC-CCI-060T, (ElectroChem Inc.USA) and Carbon cloth from Textron, USA (CPW 003 grade). Mass transport problem was observed under non-pressurized condition, at high current densities, in the caie of EC-CC1-060T carbon cloth electrode (at $50^{\circ}C$), due to its higher thickness. The performance of carbon paper electrode was higher than EC-CCI-060T carbon cloth electrode. The performance of Textron carbon cloth was comparable to EC-TPI -060T carbon paper.