• 한국가구학회지
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• 제27권2호
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• pp.80-90
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• 2016

The idea of Sustainable, first mentioned in "Our Future (Bruntdland)" from the United Nations report released in 1987 has been highly affect design disciplines in developed countries in 21st century. It relocated industrial society and structure's attentions to nature and recourse conservation and reuse. Designed and manufactured products eventually disposed and it leads to waste of resources as well as creates environmental issues. Unfortunately, vast majority of designers starts designing without anticipation of this matter and produce more believing this leads to more sales. However shorter life of a product will create bigger increase of resource consumption and waste than, importance of re-usage and recycle will eventually increase. In modern furniture industry metal and plastics are frequently used beside wood that material has been diverse than in past. However, there are lack of plans and regulations of re-usage of those material due to difficulties of separating each different materials and collecting due to it's size. This study would like to look into recycling rate, methods and usage of three major materials (wood, metal, plastic) that is typically used in current furniture industries. Furthermore, see the potential of sustainable furniture by analyzing furniture practices made by each different recycled material from old furniture and what designers should consider to achieve feasibility of sustainable furniture.

• 한국전기전자재료학회논문지
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• 제34권6호
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• pp.393-400
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• 2021

As the recent climate problems are getting worse year after year, the demands for clean energy materials have highly increased in modern society. However, the candidate material classes for clean energy expand rapidly and the outcomes are too complex to be interpreted at laboratory scale (e.g., multicomponent materials). In order to overcome these issues, the first-principles calculations are becoming attractive in the field of material science. The calculations can be performed rapidly using virtual environments without physical limitations in a vast candidate pool, and theory can address the origin of activity through the calculations of electronic structure of materials, even if the structure of material is too complex. Therefore, in terms of the latest trends, we report academic progress related to the first-principles calculations for design of efficient electrocatalysts. The basic background for theory and specific research examples are reported together with the perspective on the design of novel materials using first-principles calculations.

• Elastomers and Composites
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• 제57권4호
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• pp.197-204
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• 2022

Recently, the demand has increased for protective clothing materials capable of shielding the wearer from bullets, fragment bullets, knives, and swords. It is therefore necessary to develop light and soft protective clothing materials with excellent wearability and mobility. To this end, research is being conducted on hybrid design methods for various highly functional materials, such as carbon nanotube (CNT) sheets, which are well known for their low weight and excellent strength. In this study, a hybrid protective material using CNT sheets was developed and its performance was evaluated. The material design incorporated a bonding method that used a binder for interlayer combination between the CNT sheets. Four types of binders were selected according to their characteristics and impregnated within CNT sheets, followed by further combination with aramid fabric to produce the hybrid protective material. After applying the binder, the tensile strength increased significantly, especially with the phenoxy binder, which has rigid characteristics. However, as the molecular weight of the phenoxy binder increased, the adhesive force and strength decreased. On the other hand, when a 25% lightweight-design and high-molecular-weight phenoxy binder were applied, the backface signature (BFS) decreased by 6.2 mm. When the CNT sheet was placed in the middle of the aramid fabric, the BFS was the lowest. In a stab resistance test, the penetration depth was the largest when the CNT sheet was in the middle layer. As the binder was applied, the stab resistance improvement against the P1 blade was most effective.

• 한국소음진동공학회논문집
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• 제23권4호
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• pp.332-337
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• 2013

This paper presents a subsequent research work on the roller design of IRB(isolation roller bearing) seismic isolation device presented in Part 1 by focusing on heat treatment. The hardness and friction factor are very important factors of material and after-treatment process selection. Normally, roller bearing consists of roller and retainer. The roller gets high pressure constantly, while the retainer gets tensile and compressive stress. Therefore, sensitive material selection and heat treatment of each part is quite important. In this experimental evaluation, carbon steel, chrome special steel and others are employed and their characteristics after heat treatment are identified. Each material is prepared by refining high frequency heat treatment. The friction factor and static load capacity of manufactured material are experimentally identified and destructive test of material is processed. Optimal material and heat treatment conditions for IRB roller bearing are determined based on experiment results.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.562-566
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• 2004

Thermal shock is a physical phenomenon that occurs in the condition of the exposure of a rapidly large temperature and pressure change of in the quenching condition of material. The rocket nozzle is exposed to high temperature combustion gas, it may have failure and erosion deformation. So, it is important to select a suitable material having excellent thermal shock properties and evaluate these materials in rocket design. In this study, the temperature gradient and crack initiation of rocket nozzle material is investigated using by FEM under thermal shock condition. This is very important information in the design process of thermal structure.

• Design & Manufacturing
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• 제6권2호
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• pp.42-47
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• 2012

The paper deals with an analysis of an extrusion process with a divided material flow in a combined radial - backward extrusion. We have discussed the influences of tool geometry such as punch nose angle, relative gap height, die corner radius on material flow and surface expansion into can and flange region. To analyse the process, numerical simulations by the FEM and experiment by physical modeling using Al alloy as a model material have been performed. Based on the results, the influence of fixed parameters on the distribution of divided material flow and surface expansion are obtained.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.385-388
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• 2001

The cutting performance of a machine depends on the ability of the design of the acoustic horn to facilitate an increase in tool-tip vibration, allowing a significant amount of material to be removed. In this paper, three kinds of acoustic horns were designed and FEM was used to estimate displacement magnifications of horn tips. An optimization procedure for the profile has been followed to obtain maximum magnification, for higher rate of material removal and safe working stresses for the horn material.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.501-507
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• 1997

Composite material has very excellent mechanical properties including tensile stress and specific strength. Especially impact loads may be expected in many of the engineering applications of it. The suitability of composite material for such applications is determined not only by the usual paramenters, but its impactor energy-absorbing properties. Composite material under impact load has poor mechanical behavior and so needs tailoring its structure. Genetic algorithms(GA) is probabilistic optimization technique by principle of natural genetics and natural selection and neural networks(NN) is useful for prediction operation on the basis of learned data. Therefore, This study presents optimization techniques on the basis of genetic algorithms and neural networks to minimum stiffness design of laminated composite material.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.321-324
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• 1998

Pixel-Design Array Simulation Tool(PDAST) was used to profoundly the gate signal distortion and pixel changing capability, which are the most critical limiting factors for high-quality TFT-LCDs. Since PDAST can simulate the gate, data and pixel voltages of a certain pixel on TFT array at any time and at any location on an array, the effect of the resistivity of gate line material on the pixel operations can be effectively analyzed. The gate signal delay, pixel charging ratio, level-shift of the pixel voltage were simulated with varying the resis5tivity of the gate line material. The information obtained from this study could be utilized to design the larger area and finer image quality panel.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.2047-2052
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• 2004

Inconel-600 alloy has been used as steam generator tube material for current pressurized water reactors (PWRs). The long-term operation of steam generators showed that the use of this material induced localized corrosion damages and increased tube wear of steam generator. To protect these problems, steam generator tube material is being changed to Inconel-690 alloy. Based on the current trend, we have chosen Inconel 690 as the Advanced Power Reactor 1400 (APR1400) steam generator(SG) tube material and performed the design optimization of preventive measure against tube fretting wear for the APR1400 steam generator. In this paper, we examined the technical consideration in this modification : the selection of material, wear characteristics, effect of the Egg-crate Flow Distribution Plate installation, and effect analysis of vertical strip installation.