• Fashion & Textile Research Journal
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• v.19 no.2
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• pp.221-229
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• 2017

This study researched the needs of smart fashion items using energy harvesting for outdoor wearers and surveyed the application areas and design preferences for energy-harvesting systems based on outdoor activities. A total of 217 subjects were surveyed. Subjects who had at least 3 years of experience in outdoor activities were selected in order to increase the reliability of the research results. The survey investigated lifestyles based on outdoor activities, outdoor clothing and electronic equipment usage, purchase style, utilization plan, and design preference for energy-harvesting clothing and supplies. The results showed that 62.7% of the respondents had experience in outdoor activities for more than five years. 96.3% of the subjects carried electronic equipment, and 179 participants(82.5%) experienced discomfort due to battery consumption/dead batteries during outdoor activities. 78.4% were interested in smat fashion items using energy-harvesting technology, and the energy-conversion technology that was useful for outdoor activities was "kinetic energy"(74.7%). Participants showed a high preference for a detachable type(30.9%) and a city type(69.1%) that can be worn in outdoor activities as well as in general life. The preferred location of the electric power-charging device was the "Hem area of top garment"(35.9%), and the reason for this selection was that it was easy to operate and did not interfere with movement. The data from this paper can be used as a basis for product planning and product design for energy-harvesting apparel designers and supply developers for outdoor clothing.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.6
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• pp.28-44
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• 2020

In this paper, the scavenging process of various transfer ports was evaluated to improve the performance of a small two-stroke engine for unmanned aerial vehicles. Three-dimensional computational fluid dynamics simulations were performed to four transfer ports for the evaluation, and a three-phase scavenging model was developed and applied to the simulation results for the quantitative comparison of scavenging performance. the short-circuit of fresh charge was restrained and an in-cylinder turbulent kinetic energy was enhanced by changing the transfer port. Also, a difference in the scavenging for each port were confirmed by applying the three-phase model to the simulation results.

• Advances in Computational Design
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• v.8 no.4
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• pp.309-325
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• 2023

An innovative inertial reactive armor is being developed through a multi-discipline project. Unlike the well-known explosive or non-explosive reactive armour that uses high-energy explosives or bulging effect, the proposed inertial reactive armour uses active disc elements that is set to rotate rapidly upon impact to effectively deflect and disrupt shaped charges and kinetic energy penetrators. The effectiveness of the proposed armour highly depends on the tangential velocity of the impact point on the rotating disc. However,for a single layer armour with an array of high-speed rotating discs, the tangential velocity is relatively low near the center of the disc and is not available between the gap of the discs. Therefore, it is necessary to configure the armor with double layers to increase the tangential velocity at the point of impact. This paper explores a multi-objective geometry design optimization for the double-layered armor using Nelder-Mead optimization algorithm and integration tools of the python programming language. The optimization objectives include maximizing both average tangential velocity and high tangential velocity areas and minimizing low tangential velocity area. The design parameters include the relative position (translation and rotation) of the disc element between two armor layers. The optimized design results in a significant increase of the average tangential velocity (38%), increase of the high tangential velocity area (71.3%), and decrease of the low tangential velocity area (86.2%) as comparing to the single layer armor.

• Journal of computational fluids engineering
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• v.13 no.4
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• pp.50-57
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• 2008

The prediction of hydrate pellet decomposition characteristics is required to design the regasification process of GTS (gas to solid) technology, which is considered as an economic alternative for LNG technology to transport natural gas produced from small and stranded gas wells. Mathematical model based on the conservation principles, the phase equilibrium relation, equation of gas state and phase change kinetics was set up and numerical solution procedure employing volume averaged fixed grid formulation and extended enthalpy method are implemented. Initially, porous methane hydrate pellet is at uniform temperature and pressure within hydrate stable region. The pressure starts to decrease with a fixed rate down to the final pressure and is kept constant afterwards while the bounding surface of pellet is heated by convection. The predicted convective heat and mass transfer accompanied by the decomposed gas flow through hydrate/ice solid matrix is reported focused on the comparison of spherical and cylindrical pellets having the same effective radius.

• 전기의세계
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• v.25 no.5
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• pp.79-87
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• 1976

This paper is to investigate the A.C generation of MHD engine, converting directly the kinetic energy of conductive gas in high temperature to electric power by the effect of magnetic field. It is known that there are at least two kinds of method in A.C MHD power generation; one, by sending stationary plasma flow in an alternating or rotating magnetic field and the other, by transmission of pulse type plasma flow in uniform and constant magnetic field, former method is adopted here. In order to raise the total efficiency of close cycle in combination with nuclear power and MHD genertaion, an argon plasma jet is utilized as heat source, which is not mixed with the seed material, and the design data are obtained for A.C MHD generation in small capacity, but induced voltage and power output have the maximum values, 15 voltages and 7.5W respectively due to plasma flow with low conductivity and weak magnetic field.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.512-515
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• 2005

The Korean peninsula has a number of coastal sites where the rhythmic rising and lowering of water surface due to tides result in strong tidal current. The kinetic energy of these currents can be efficiently exploited by using tidal current turbines. The pilot tidal current power plant is to be constructed at the Uldolmok between Chindo and Haenam. Extensive coastal engineer ing research works have been carried out. This paper describes some observation results of field campaign, design of the supporting structure of a pilot plant of 1,000kW and a future tidal current power plant and so on.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.514-517
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• 2008

Water gas shift(WGS) is an important step in fuel process for fuel cells, and improperness of commercial WGS catalysts for use in fuel cell systems has prompted numerous researches on noble metal catalysts. A selected noble metal catalyst for water gas shift reaction(WGS) was prepared with various metal loadings. The prepared catalysts were tested under two feeding conditions. At moderate residence time, carbon monoxide conversion was much higher on the noble metal catalysts as compared to commercial high-temperature shift catalyst. Effects of metal loading were examined by activity tests at short residence time. Higher metal loading effected higher reaction rate. The kinetic data was fitted to simple reaction equations and effectiveness factor was estimated. The results suggest the necessity of a structural design for the highly active noble metal catalysts.

• Journal of the Korean Graphic Arts Communication Society
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• v.6 no.1
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• pp.59-66
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• 1988

One of the rising problems in the field of environmental engineering is the eutrophic phenomenon which appears in the closed water basin. This study is the elimination orthophosphate by adsorption, which is indispensible nutritive element for eutrophication Ziriconium(IV) oxide hydrate-activatedcarbon complex. which has excellent adsorptivity for orthophosphate and can easily be reused after desorption process has been made and used as adsorbents. The main purpose of this study is to obtain intraparticle diffusivity which is basic data for the design of adsorption operation the experimental results were as follows. 1. Optimum condition which gave maxinum adsorption of orthophosphate was ph5 2. Equilibrium adsorption showed good consistency with Freundlich type. q=10.80C1/2.08 3. Pore diffusivity and surface diffusivity obtained the kinetic experiment of batch adsorption were respectivity 5.38 and 2.06 ($\textrm{cm}^2$/sec)

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.1
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• pp.123-129
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• 2007

A 2-step process for the safe destruction of chemical wafare agents(agent hydrolysis followed by supercritical water oxidation) was studied to obtain kinetic data for the pilot plant design. This process is simple to operate by using commercial equipments and could be applied as an alternative technology to incineration. Sarin(GB) and sulfur mustard(HD) were hydrolysed in sodium hydroxide and water respectively and their hydrolysates and OPA, which is binary agent for GB were oxidized in a continuous flow supercritical water oxidation system. Destruction efficiencies of the materials were above 99.99% in supercritical water.

• Journal of Environmental Science International
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• v.7 no.6
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• pp.773-782
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• 1998

The adsorption experiment of phenol(Ph) from aqueous solution on granular activated carbon was studied in order to design the fixed-bed adsorption column. The experimental data were analyzed by unsteady-state, one-dimensional heterogeneous model. Finite element method(FEM) was applied to analyze the sensitivity of parameter and to predict the fixed-bed adsorption column performance on operation variable changes. The prediction model showed similar effect to mass transfer and intraparticle diffusion coefficient changes suggesting that both parameter present mass transfer rate limits for GAC-phenol system. The Freundlich constants had a greater effect than kinetic parameters for the performance of fixed-bed adsorption column. FEM solution facilitated prediction of concentration history in solution and within adsorbent particle.