• Transactions of Materials Processing
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• v.20 no.4
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• pp.273-278
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• 2011

Employing the TRIZ problem solving technique, a hybrid-type center plate for the molten carbonate fuel cell(MCFC) was developed for the purpose of improving gas sealing and maintenance. The manufacturing method of the hybrid-type center plate was divided into a trimming operation and a two-step bending process. In the latter, a modified punch shape was used to reduce springback. Using finite element(FE) simulations, bending stresses in the thickness and the in-plane directions were computed and the bending conditions were optimized. The optimized results of the two-step bending process were used as a basis for the design of the trimming process of the hybrid-type center plate. Finally, the external manifold-type center plate and the hybrid-type center plate were fabricated using a die set that accounts for the optimized conditions. It was found that the numerical simulation results were in good agreement with the experiments.

• Transactions of The Korea Fluid Power Systems Society
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• v.6 no.2
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• pp.1-6
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• 2009

The APU(Auxiliary Power Unit) needs a set of complex pipeline for the fuel supply system where some of the main valves controlling the flow rate consist of the servo valve worked with a torque motor. The input electric current produces an induced magnetic field almost perpendicular to the background magnetic filed generated by fixed permanent magnets. The induced torque deforms the tubular bushing, and directly rotates an armature, which can open and close the valve. In this study, we start from a basic analytic model using a simple electro-magneto-statics, and expand our model to the three-dimensional one computationally applying a commercial code named COMSOL. The result is compared with each other, and reasonable numerical data are obtained for the dynamic behavior and multi-physics system.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.2
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• pp.145-151
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• 2015

In this paper, we proposed the fabrication methodology of orthotic device using 3D Computer-Aided Design programme and 3D printing technology based on images acquired from 3D scanner. We set the process and methodology of its fabrication method and confirmed whether it is available for clinical by fabricating four kinds of orthotic device for a patient with cerebral palsy. 3D printing technology method was indicated quantitatively and qualitatively about duration, tensile strength stronger comparing with conventional method, and we could propose that the 3D printing technology for the orthosis could be the proper method to mediate and compensate with reported problems related to orthosis.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.4
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• pp.611-621
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• 1995

The objectives of this study are to find out and to analyze the heat transmission characteristics of the conventional and prefabricated Ondol systems. To compare the thermal characteristics of these Ondol, a real sized Ondol model is set in a chamber. Hot water whose temperature is varied from $45^{\circ}C$ to $60^{\circ}C$ with $5^{\circ}C$ interval is supplied to each Ondol system. At that time the temperature distribution of floor surface, the amount of supplied heat, the heat radiation aspect and the heat loss from the floor to the underground are measured and analyzed simultaneously. As a result, even if the supplied hot water temperature to the prefabricated Ondol panel is lower by about $5^{\circ}C$ than that of the conventional Ondol panel, the net radiant effect is same. Heat radiation efficiency of the prefabricated Ondol panel is over 5% better than that of the conventional Ondol panel. It takes 12 hours for the conventional Ondol and 45 minutes for the prefabricated Ondol, respectively to reach steady state.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.4 no.1
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• pp.23-28
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• 2010

Case of patients with weakness in cardiopulmonary system, other ambulatory function is normal, but oxygen supply function is problem. So they need reduce energy consumption for gait by assistance system. In this study, we designed and developed walking assistant device which helps flexion and extension of hip joint for cardiopulmonary patients. There are two motors, each at the left and right side of pelvis, providing torque to the hip joint. The target angle of the flexion and extension in the hip joint is set according to the normal gait. As a result, reduction of energy consumption was 14.8% by gait assistive device.

• Journal of the Korea Fashion and Costume Design Association
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• v.16 no.2
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• pp.71-80
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• 2014

The purpose of this study was to investigate consumer evaluation on visual sensibility of stripe pattern shirts for separation coloration. The experimental materials developed for this study were a set of clothing stimuli and response scales. The clothing stimuli were 27 color pictures, in which separation color(white: W, gray: G, black: B), separation width(small: S, medium: M, large: L), and combination color(magenta and yellow: MY, magenta and cyan: MC, yellow and cyan: YC) were manipulated. The subjects of this research were female in their 20s to 30s living in Seoul, Gwangju, Daegu, Busan, and Changwon. The investigation was carried out at December 2013. The data were analyzed by using SPSS program. Analysis methods were factor analysis, ANOVA, and Duncan-test. Results of this study were as follow.; The factors of visual sensibility according to separation color, separation width, and combination color consisted of four dimensions of attractiveness, appeal, individuality freshness, and grace. Separation color showed an independent effect on appeal and individuality freshness. Combination color showed an independent effect on individuality freshness. Interaction effects of separation color and separation width on appeal were found. Interaction effects of separation color and combination color on individuality freshness and grace were found. The study results are highly expected to be used as useful sources in a fashion product.

• Nuclear Engineering and Technology
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• v.50 no.5
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• pp.690-697
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• 2018

Criticality alarm systems (CASs) are mandatory in nuclear plants for prompt alarm in the event of any criticality incident. False criticality alarms are not desirable as they create a panic environment for radiation workers. The present article describes the design enhancement of the CAS at each stage and provides maximum availability, preventing false criticality alarms. The failure mode and effect analysis are carried out on each element of a CAS. Based on the analysis, additional hardware circuits are developed for early fault detection. Two different methods are developed, one method for channel loop functionality test and another method for dose alarm test using electronic transient pulse. The design enhancement made for the external systems that are integrated with a CAS includes the power supply, criticality evacuation hooter circuit, radiation data acquisition system along with selection of different soft alarm set points, and centralized electronic test facility. The CAS incorporating all improvements are assembled, installed, tested, and validated along with rigorous surveillance procedures in a nuclear plant for a period of 18,000 h.

• The Korean Journal of Food & Health Convergence
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• v.4 no.3
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• pp.22-31
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• 2018

In this present work, the amounts of toxic elements were determined in the soft tissues of mollusks (Mytilus galloprovincialis and Rapana venosa) collected from Igneada shores of the Black Sea where suggested as Marine Protection Area (MPA). M. galloprovincialis accumulated the highest amounts of Cd in winter, while the highest amounts of Cd and Hg were detected in R. venosa in winter and autumn. The concentrations of toxic elements found in the soft tissues of mollusks varied for Cd: 0.07-0.14, Hg: 0.03-0.44 and Pb: 0.09-0.21 mg/g dry wt. The estimated levels of all non-essential metals in the present work were lower than the limits permitted by European Community Regulation (EU) and the Turkish Food Codex (TFC). The estimated weekly intakes (EWI) and daily intakes (EDI) of all the through consumption of these seafood by Turkish people in the Igneada coasts of the Black Sea were quite below the permissible tolerable weekly/daily intakes for 70 kg person (PTWI / PTDI) set by FAO/WHO. As results, it can be concluded that no hazard effects on people health would be raised at present from the consumption of these mollusks' species.

• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.410-416
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• 1995

The proton transfer energies of gas phase glycine and alanine and those of hydrated glycine and alanine were calculated both with Hartree-Fock and $M{\Phi}ller-Plesset$ ab initio molecular orbital (MO) calculations with 6-31G** basis set. The transition states of the proton transfer of gas phase glycine was also investigated. For zwitterions, both for glycine and alanine, the water bound to -NH3+ site stabilize the complex more compared with the water bound to -CO2-. The proton transfer energy, ΔEpt, of glycine, alanine, mono-hydrated glycine, mono-hydrated alanine, di-hydrated glycine and di-hydrated alanine were obtained as 30.78 (MP2: 22.57), 31.43, 23.99 (MP2: 17.00), 24.98, 22.87, and 25.63 kcal/mol, respectively. The activation energy for proton transfer from neutral (Nt) glycine to zwitterion (Zw) glycine, Ea, was obtained as 16.13 kcal/mol and that for reverse process, Ear, was obtained as 0.85 kcal/mol. Since the transition state of the proton transfer of gas phase glycine locate near the glycine zwitterion on the potential energy surface and the shape of the potential well of the zwitterion is shallow, the zwitterion easily changed to neutral glycine through the proton transfer.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1995.11a
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• pp.11-30
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• 1995

The ignition characteristics of a reactive solid with rough surface by constant heat flux were studied. The geometry of surface was represented by a set of identical protrusions having a shape of wedge based on the block of reactive solid. Several regimes of ignition were found, depending on the ratio of the protrusion length and the depth of the heated layer, formed in course of ignition process: 1) when the substance is ignited as the massive block, and the effect of roughness is not pronounced; 2) when ignited are the individual protrusions; and 3) in the intermediate region between the first two. Critical ignition conditions: ignition time and ignition criterion, are determined for the three regimes. The results are compared with the results for the one-dimensional ignition of the semi-infinite body. It is shown, that the effect of geometry on ignition results in the considerable reduction of ignition delay, and the amount of energy required for the successful ignition is less compared to the one- dimensional case.