• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1391-1394
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• 2007

In order for Hypoid gear development. Gears are required to sustain heavy loads or on applications where the gear box is made or a material with a different coefficient of thermal expansion form that or the gears and shafts, it is desirable to make a deflection and contact check under load. The deflection test is performed in the actual gear mounting using completely processed gear. This test should cover the full operating range of gear loads from no load to peak load. Under peak load the contact pattern should extend to the tooth boundaries without showing a concentration of the contact pattern at any point on the tooth surface.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.42-46
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• 1993

This paper presents development of a pratical tool deflection compensation system in order to reduce the machining error by the tool deflection in the end-milling process. The system is a tool adapter which includes 2-axis force sensor for detecting tool deflection and 2-axis tool tilting device for adjusting tool position through computer interface in on-line process. In experiments, it is revealed that the force sensor applying parallel plate principle and strain gauge is proper to obtain dynamic process signal, and the tilting device using stepping motor and cam drive mechanism is suitable to have necessary action. By the system and control algorithm, it is possible to get precise machining surface profile without excessive machining error and overcut generated due to increased cutting force in more productive machining condition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.88-89
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• 2014

In dynamic force microscopy, the cantilever oscillates at a resonant frequency, and the tip deflection is measured at this frequency. The cantilever deflection is, however, highly nonlinear, and the surface properties can be embedded in the deflection at the frequencies other than the original resonant frequency of the cantilever. Multifrequency atomic force microscopy includes the excitation and detection of the deflection in two or more frequencies which are higher harmonics or eigenmodes. This can overcome the limitations of conventional atomic force microscope. We reviewed the multifrequency atomic force microscopy and its applications in many fields.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.31-35
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• 2000

A cantilever deflection measurement system for AFM(atomic force microscope) was constructed by the laser deflection method using LEP type PSD. Design process including sensitivity analysis was presented and the performance of the system was demonstrated by several experiments using a sample specimen with 50nm-step on the surface. The measured displacement-amplification-factor showed good agreement with the expected one with about 8% deviation. The step height measurement data were compared to what were acquired by commercial AFM, and the result showed that there were about 5nm-deviation between the two data. These results satisfies our expectation in the stage of system design.

• Steel and Composite Structures
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• v.4 no.1
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• pp.9-21
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• 2004

The present study aims at the reliability analysis of steel towers against the limit state of deflection. For this purpose tip deflection of the tower has been obtained after carrying out the dynamic analysis of the tower using modal method. This tip deflection is employed for subsequent reliability analysis. A limit state function based on serviceability criterion of deflection is derived in terms of random variables. A complete procedure of reliability computation is then presented. To study the influence of various random variables on tower reliability, sensitivity analysis has been carried out. Design points, important for probabilistic design of towers, are also located on the failure surface. Some parametric studies have also been included to obtain the results of academic and field interest.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.1141-1146
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• 2003

We have developed the three-dimensional simulation tool for the design of deflection yoke. This tool consists of a modeler, a solver and a post-processor. The modeler easily makes models of Deflection Yoke (DY) and ferrite core (Circle, RAC and RTC) by the parameters and supports several element types (line, surface and quadrilateral). The solver calculates charge density and magnetic field of DY by boundary element method (BEM). We can simply evaluate misconvergence, distortion and inductance of DY in the post-processor, so we apply this simulation tool to 32" rectangular deflection yoke. We can conveniently implement the efficient development of DY in the future.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.4 s.148
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• pp.422-430
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• 2006

The horn and movable parts around the gap of the conventional semi-spade rudder are visualized by high speed CCD camera with the frame rate of 4000 fps (frame per second) to study the unsteady cavity pattern on the rudder surface and gap. In addition, the pressure measurements are conducted on the rudder surface and inside the gap to find out the characteristics of the flow behavior. The rudder without propeller wake is tested at the range of $1.0{\leq}{\sigma}_v\;1.6$ and at the rudder deflection angle of $-8{\leq}{\theta}{\leq}10^{\circ}$. The time resolved cavity images are captured and show strong cavitation around the rudder gap in all deflection angles. As the deflection angle gets larger, the flow separated from the horn surface increases the strength of cavitation. The accelerated flow along the horn decreases its pressure and the separated flow from the horn increases the pressure abruptly. The pressure distribution inside the gap reveals the flow moving from the pressure to suction side. In the negative deflection angle, the turning area on the movable part initiates the flow separation and cavitation on it.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.356-359
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• 2005

Ionic-polymer-metal-composite(IPMC), one of new actuation materials of electroactive polymers plated with noble metallic electrodes is known for the fast bending upon electric field. The IPMC strip bends towards anode under electrical field. It has many merits of low driving voltage, quick responsiveness, high durability, possibility of miniaturizability. In this paper, we studied for developing the large deflection of IPMC according several fabricating parameters. We measured the large deflection by the different process of sandpaper and sandblasting in surface treatment, the initial compositing process and the surface electroding process, and the different counter ions in ion exchanging process. In fundamental, the displacement of IPMC strip depends on voltage magnitude and applied signal frequency and its maximum deformation is observed at a critical frequency, resonant frequency.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.125-128
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• 1997

They use a Ball End-mill in order to manufacturing sculptured surface when making metal mold, mold, cars and aircraft. In the work of a Ball End-mill case, customers do not often satisfied with manufacturing precision. Eventually, they have to re-work for the purpose of meeting manufacturing precision. There are resulted in lots of loss, whereby, in terms of both time and costs. The reasons of tolerance reducing manufacturing precision are thermal strain, the surface is damaged because of increasing cutting force and tool wear, tool deflection etc.. We focus on, however, manufacturing precision caused due to deflection of tool.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.6
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• pp.804-812
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• 2003

This paper introduces optical methods for in-situ measurement of surface temperature and pressure transient in thermal processes having nanosecond time scales. In the temperature measurement, a p -Si thin film whose refractive index is calibrated as a function of temperature is embedded beneath the sample surface and the photothermal reflectance is monitored for estimating the surface temperature. The pressure transients are measured using the photoacoustic optical deflection method. The experimental technique is used to analyze the nanosecond laser induced vaporization process that is central to numerous engineering and bio-medical applications. Based on the experimental results, discussions are made on the experimental technique and the physical mechanisms of laser-driven explosive vaporization phenomena.