• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2003년도 The Korea-Japan Plastics Processing Joint Seminar
• /
• pp.41-47
• /
• 2003

This study is an attempt to understand the birefringence and stress development in an injection molded disk. A computer code was developed to simulate all three stages of the injection molding process - filling, packing and cooling by finite element method. The constitutive equation used here was compressible Leonov model. The PVT relationship was assumed to follow the Tait equation. The flow-induced birefringence was related to the calculated flow stresses through the linear stress-optical law. The predicted birefringence was in good agreement with the experimental results.

• Korea-Australia Rheology Journal
• /
• 제15권4호
• /
• pp.159-166
• /
• 2003

This study is an attempt to understand the birefringence and stress development in an injection molded disk. A computer code was developed to simulate all three stages of the injection molding process filling, packing and cooling by finite element method. The constitutive equation used here was compressible Leonov model. The PVT relationship was assumed to follow the Tait equation. The flow-induced birefringence was related to the calculated flow stresses through the linear stress-optical law. The predicted birefringence was in good agreement with the experimental results.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.1510-1515
• /
• 2004

Aggregability of red blood cells (RBCs) was determined by a laser backscattering light analysis in a microfluidic channel. Available techniques for RBC aggregation often adopt a rotational Couette-flow using bob-and-cup system for disaggregating RBCs, which causes the system to be complex and expensive. A disposable microfluidic channel and vibration generating mechanism were used in the proposed new detection system for RBC aggregation. Prior to measurement, RBC aggregates in a blood sample were completely disaggregated by applying vibration-induced shear. With the present apparatus, the aggregation indexes of RBCs can be easily measured with small quantities of blood sample. The measurements with the present aggregometer were compared with those of LORCA and showed a strong correlation between them. The aggregability of the defibrinogenated blood RBCs is markedly lower than that of the normal RBCs. The noble feature of this design is the vibration-induced disaggregation mechanism, which enables to incorporate disposable element that holds the blood sample.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1993년도 추계학술대회 논문집
• /
• pp.273-278
• /
• 1993

Conventional measurement methods for non-destructive testing(NDT) in nuclear power plants other industrial plants have been performed as the methods of contact with objects to be inspect, but those methods have been taken relatively much time to be inspected. Holographic interferometry which is a non-contact optical measurement method using a coherent light can overcome these demerit, and also has an advantage that the quantitative measurement of small deformation for large areas can be accomplished at a time with high precision. In this paper the comparisons of the experimental results from holographic interferometry with those form the finite element method(FEM) and the analytical solutions of elastic equation are discussed.

• International Journal of Precision Engineering and Manufacturing
• /
• 제8권1호
• /
• pp.66-72
• /
• 2007

A computer code was developed to simulate the filling stage of an injection/compression molding process using a finite element method. The constitutive equation was the compressible Leonov model and the PVT relationship was assumed to follow the Tait equation. The flow-induced birefringence was related to the calculated flow stresses through the linear stress-optical law. Simulations of a disk under different processing conditions, including variations of the compression stroke and compression speed, were performed to determine their effects on the flow-induced birefringence. Simulated pressure traces were also compared to those obtained in conventional injection molding and with experimental data from the literature.

• 한국정밀공학회지
• /
• 제20권1호
• /
• pp.79-84
• /
• 2003

A light guide panel is an element of the LCD backlight module that is often used for the display of compact electronic devices. In this study, a laser marking system is proposed to fabricate light guide panel, which can replace other manufacturing methods such as silk printing, stamping, or v-cutting methods. The objective of this research is to evaluate the process parameters of the laser marking system. Light guide patterns were marked with a 50W $CO_2$ laser (CW) to understand the effects of average power and scanning speed on the geometry and quality of groove pattern. The width of the fabricated grooves increases with increasing laser power and decreasing scan speed. In order to analyze surface characteristics and optical properties (luminance, uniformity), SEM photography and BM7 (luminance measuring system) were used. As a result, the optimal conditions of the process parameters were determined.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.401-404
• /
• 2004

The electron beam machining provides very high resolution up to nanometer scale, hence the E-beam writing technology is rapidly growing in MEMS and nano-engineering areas. In the optical column of the e-beam writer, there are several lenses condensing and focusing electron beams from electron gun with fringing magnetic fields. To achieve small spot size as 1-2 nm for higher power of electron beam, magnetic lenses should be designed considering their magnetic field distribution. In this paper, the magnetic field at two condenser lenses and object lens are calculated with finite element method and discussed its performances.

• 조명전기설비학회논문지
• /
• 제28권9호
• /
• pp.28-34
• /
• 2014

A claw pole stepping motor is widely used in various fields such as a compact optical disk drive, computer peripherals, digital cameras, office automation(OA), handheld mobile devices, because it has the suitable structure for compact motor. However 3D analysis is essential for design of Claw pole stepping motor because of axial flux path. Thus, in general, it takes a lot of time in the design of Claw pole motor. In this paper, magnetic equivalent circuit considering axial flux was proposed to reduce design time of Claw pole motor and we has designed by using the magnetic equivalent circuit. In addition, in oder to verify the study, design model was verified by 3D FEM simulation and experiment.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1992년도 하계학술대회 논문집 B
• /
• pp.1250-1254
• /
• 1992

This paper describes the designed and fabricated thermal imaging system with the SPRITE(Signal PRocessing in The Element) detector, operating in the 3-12 micron band. This system consists of an afocal telescope, a scan unit containing the SPRITE detector, an electronic processor unit and a cooler. The optical scan system utilizing rotating polygon and oscillating mirror, is 2-dimensional serial/parallel scan type using five elements of the detector. And the electronic processor unit performs digital scan conversion to reform the parallel data stream into serial analog data compatable with conventional RS-170 video. The scan field of view is 40 ${\times}$ 26.7 and the MRTD(Minium Resolvable Temperature Difference) is 0.6 K at 7.5 cycles/mm. The acquired thermal image indicates that this system has a satisfactory performance.

• 한국실내디자인학회:학술대회논문집
• /
• 한국실내디자인학회 2006년도 추계학술발표대회 논문집
• /
• pp.151-155
• /
• 2006

The objective of commercial space design is not only to sell goods but also provide customer experience so called 'Experience marketing'. Therefore, companies are in search for various methods to give special customer experience and interior design is being considered as an important tool. For example, providing catharsis through commercial interior design, or bringing In the concept of hands-on exhibition into sales area relate to affirmative images of specific products or brands. Graphics in various methods has now become important interior design medium of expression. Therefore the study investigates graphical methods that appear in interior space such as objet, frame, optical illusion, moire and information transmission. It also analyzes their applications and roles in commercial spaces as major element in establishing spatial identity.