• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.708-712
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• 2007

Restriking is a shaping method added to the processed products to get higher precision and accuracy in the press die process. This method is frequently used in bending works and drawing works. The purpose of this research is to develop a design for rectangular drawing die punch and die block form which enables drawing formation and restriking in one set.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1526-1527
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• 2007

This paper presents the design, fabrication and experimental results of an electromagnetic microvalve for drug delivery systems. The microvalve consists of two silicon substrates with a silicone rubber diaphragm and a flow channel, a PDMS layer, and an electromagnetic actuator. Each substrate is fabricated by using the silicon wet etch, SU-8 mold process and $O_2$ plasma bonding.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.649-655
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• 2019

Fracture behaviors of SCM435 high strength bolt have been studied including macroscopic and microscopic fracture observation, Energy Dispersive X-ray Spectroscopy, Vickers hardness test and applied stress evaluation. cracks (ratchet marks) were generated by the repetitive loads acting on the bolts, initial stress of bolt and the stress concentration. The applied stress was found to be slightly higher than the fatigue limit of the material. The initial stress of bolt must be removed, and the mold temperature during the process must be maintained by room temperature. Bolts are recommended to be peened to improve fatigue limit.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.10
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• pp.16-23
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• 2020

Vehicle seats provide a comfortable ride for passengers by properly absorbing vibrations and shocks transmitted during driving. Vibration analyses on three models with different shapes were carried with the same material properties and constraint conditions. By varying the height of the seat-back, models 1, 2, and 3 were designed according to the inclined angle of the seat-back frame. Models 1, 2, and 3 were modeled with relatively simple designs using CATIA. The areas touching the buttocks of passengers show the most deformation. This work shows that seat durability and stability can vary depending on the shape of the seat design.

• Design & Manufacturing
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• v.16 no.1
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• pp.15-20
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• 2022

This paper is about elimination the situation in which gas sensor data becomes inaccurate due to temperature control when a semiconductor gas sensor is driven. Recently, interest in semiconductor gas sensors is high because semiconductor sensors can be driven with small and low power. Although semiconductor-type gas sensors have various advantages, there is a problem that they must operate at high temperatures. First temperature control was configured to adjust the temperature value of the heater mounted on the gas sensor. At that time, in controlling the heater temperature, gas sensor data are fluctuated despite supplying same gas concentration according to the temperature controlled. To resolve this problem, gas and temperature are extracted as a data. And then, a relation function is constructed between gas and temperature data. At this time, it is included low pass filter to get the stable data. In this paper, we can find optimal gain and parameters between gas and temperature data by using genetic algorithm.

• Polymer(Korea)
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• v.36 no.6
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• pp.677-684
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• 2012

Injection molding process is a popular polymer processing involving plasticizing and enforcing the material flow into the mold. A polymer material shrinks according to temperature variations during the shaping process, and subsequently molding shrinkage developed. Developed deflections or warpages after molding process in part are caused by residual stress relaxation contained in the part. Adding inorganic materials or fibers such as glass and carbon to control shrinkage and enhance warpage resistance are common. In this study, warpages according to part design have been investigated through experiment. Warpages for molding conditions and mold designs such as gate locations were measured. Warpages along flow direction and perpendicular to the flow direction were also measured. Warpages near gate and far from gate were compared. Glass fiber reinforced crystalline polymers, PP and PA66 have been used in this experiment. Glass fiber reinforced crystalline polymers showed large warpage compared with glass reinforced amorphous polymers. Warpages in crystalline polymers were less influenced by molding conditions compared with amorphous polymers, however warpages of crystalline polymers significantly depend on part design.

• Archives of design research
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• v.16 no.2
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• pp.197-208
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• 2003

A recent trend for product development requires that product design firms participate in every process in cooperations with clients. So, this study proposed an advanced practical management process for product design according to the new trend Because existing processes explain summary steps just including market research, design, engineering, manufacturing., to support the recent trend, an extended process which explains every steps should be prepared. Design development precesses include initial meeting, contact, kick-off meeting, market research, idea sketch, rendering, design drawing, design mock-up, design manual, engineering drawing, ES mock up, mold, manufacturing, and patent. To manage these whole design processes, designers should have abundant knowledge about them. This process has three merits: 1) understanding the whole processes, 2)the unity between design and manufactures, 3)collecting accurate information by market research, 4)elevating design quality. So, designers are able to manage whole product development processes. This practical management process proposes an advanced structure for product design development, and can be accepted for various product design development environments.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.4
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• pp.335-343
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• 2012

As a matter of fact, it has been not allowed to modify the shape of a vehicle body skeleton since the technical definition for the structure was fixed and the corresponding molds were developed. By the way, if it is available to apply an alternative to reinforce the skeleton without changing its mold, it must be much flexible to improve the performance qualities relevant to not only NVH(noise, vibration and harshness) but also crash and durability. Recently, a solution of so-called composite body becomes available for the need. We present a design method to insert the composite body inside a vehicle body skeleton in order to improve a structure-borne noise at the idle condition. The algorithms, topology optimization and design sensitivity analysis, are applied to mainly search the sensitive structural sections in the body skeleton and to extract the target stiffness of the sections. Inserting the composite bodies into the sensitive portions, it is predicted to achieve the countermeasures which can compromize the design availability in terms of the idle noise and weight. According to the validation result with test vehicles, the concerned noise transfer function is reduced and the idle booming noise is resultantly improved.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.4
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• pp.7-13
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• 2010

Linear motors are efficient mechanism that offers high speed and positioning accuracy. By eliminating mechanical transmission mechanisms, much higher speeds and greater acceleration can be achieved without backlash or excessive friction. However, an important disadvantage of linear motor system is its high power loss and heating up of motor and neighboring machine components on operation. Therefore, it is necessary to design moving table with high stiffness, high efficiency and light weight construction. This paper presents the development of moving table using composite material. In order to develop light weight construction of moving table, finite element analysis is performed to find best moving table construction and composite stacking sequence. NASTRAN and MINITAB were used as the optimizer. A prototype for the moving table using composite material was created.

• Journal of the Korea Furniture Society
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• v.25 no.1
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• pp.1-10
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• 2014

The First bentwood chairs in the world, called "winsor chairs" were made by British craftsman in the 17th century. Since then, from the start of NO.14 using solid bentwood by 19th-century German Michael Thonet, furniture making techniques such as Bent knee, Y-leg, X-leg- were developed based on Llaminated bentwood made by Alvar Aalto of Finland in the 20th century. In the 20th century Charles Eames of the United States studied Molded plywood, using plywood to produce a variety of furniture and during the 17~20 century a variety of Bentwood were developed. Coming into the 21st century, American Matthias Pliessnig and Phil Seaton worked with past Bentwood designs, developing Bentwood further by adapting Bentwood's know-how and IT technology. Science and technology evolved and Reholz of Germany developed technology which can mold three-dimensional wood using a new matarial called 3D-veneer, In the past only plastic or metal could be moulded 3 dimensional but now beautiful wood grain patterns can be molded by utilizing this technology. Also this is comparable with the past two-dimensional molding technology. In this Sustainable Design techniauses era, Bentwood fused with IT technology has great potential as a high-tech and eco-friendly techniche.