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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Precision Engineering
Journal Basic Information
Journal DOI :
Korean Society of Precision Engineering
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Volume & Issues
Volume 24, Issue 12 - Dec 2007
Volume 24, Issue 11 - Nov 2007
Volume 24, Issue 10 - Oct 2007
Volume 24, Issue 9 - Sep 2007
Volume 24, Issue 8 - Aug 2007
Volume 24, Issue 7 - Jul 2007
Volume 24, Issue 6 - Jun 2007
Volume 24, Issue 5 - May 2007
Volume 24, Issue 4 - Apr 2007
Volume 24, Issue 3 - Mar 2007
Volume 24, Issue 2 - Feb 2007
Volume 24, Issue 1 - Jan 2007
Selecting the target year
Introduction to the Measurements and Standards in Physical Properties of a Human Body
Song, Han-Wook ; Kim, Yong-Gyoo ; Kim, Min-Seok ; Woo, Sam-Yong ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 7~11
Development of Standard and Improvement of Reliability in Blood Pressure Measurement
Woo, Sam-Yong ; Lee, Sung-Jun ; Song, Han-Wook ; Kim, Jong-Ho ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 12~16
Tonometry and its Standards
Kim, Min-Seok ; Woo, Sam-Yong ; Lee, Sung-Jun ; Park, Yon-Kyu ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 17~22
Preliminary Study for Simultaneous Measurement of Blood Flow Velocity and Viscosity
Chun, Se-Jong ; Paik, Jong-Seung ; Choi, Yong-Moon ; Choi, Hae-Man ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 23~31
Development of Standard and Improvement of Reliability in Body Temperature Measurement
Park, Chul-Woung ; Park, Seung-Nam ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 32~36
Research on Standards for Exposure Parameters of Medical Ultrasound
Kim, Yong-Tae ; Jung, Sung-Soo ; Jho, Moon-Jae ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 37~43
Development of a Technique to Prevent Bolt Looseness and to Decrease in Quantity for the Plate Type Heat Exchanger Used in Large Craft
Kim, Ho-Yoon ; Bae, Won-Byong ; Jang, Young-Jun ; Han, Seung-Moo ; Kim, Chul ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 44~51
There are many methods to assemble various parts of a product, and one of them is the bolting system widely used in a industrial field due to the merits; easiness to obtain strong tightening force, simplicity of assemble or disassemble in order to repair, substitution or cleaning, and so on. But this bolting system needs attachments not to let a bolt loose and they are an important factor to cost a great deal. In this study, some equations are suggested and FE analyses are carried out to verify the cause of the bolt looseness occurring in the tightening process. And because the number of bolts in the bolting system has been decided by empirical know-how of designers in the field, safety rate in the plate type heat exchanger is often too high. Therefore the equations to decrease in quantity are suggested in consideration of the relationship between a critical shearing force acting on the screw and a normal force acting on the cooling plate by the working fluid.
A Study on the Injection Rate Observer of the Piezo-actuated and Solenoid-operated Injectors for CRDI Diesel Engines
Sa, Jong-Seong ; Chung, Nam-Hoon ; SunWoo, Myoung-Ho ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 52~59
Fuel injection system greatly affects the performance of a direct injection diesel engine. A common rail injection system was introduced to satisfy the stringent emission standards, low fuel consumption, and low noise in recent years. The performance of a common-rail fuel injection system is strongly influenced by the injector characteristics. The common rail injector has evolved in order to improve its injection performance. The piezo-actuated injector is more suitable for common rail injection system due to its fast response and is expected to replace current solenoid-operated injector. In this study, nonlinear mathematical models are proposed for the solenoid-operated and the piezo-actuated injectors for control applications. Based on these models, the injection rate, which is one of the most important factors for the injection characteristics, is estimated using sliding mode observer. The simulation results and the experimental data show that the proposed sliding mode observers can effectively estimate the injection timing and the injection rate for both common-rail injectors.
Development of a Signal Conditioning Circuit for Capacitive Displacement Sensors and Performance Evaluation
Kim, Jong-Ahn ; Kim, Jae-Wan ; Eom, Tae-Bong ; Kang, Chu-Shik ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 60~67
A signal conditioning circuit for capacitive displacement sensors was developed using a high frequency modulation/demodulation method, and its performance was evaluated. Since capacitive displacement sensors can achieve high resolution and linearity, they have been widely used as precision sensors within the range of several hundred micrometers. However, they inherently have a limitation in low frequency range and some nonlinearity characteristics and so a specially designed signal conditioning circuit is needed to handle these properties. The developed signal processing circuit consists of three parts: linearization, modulation/demodulation, and nonlinearity compensation. Each part was constructed discretely using several IC chips and passive elements. An evaluation system for precision displacement sensors was developed using a laser interferometer, a precision stage, and a PID position controller. The signal processing circuit was tested using the evaluation system in the respect of resolution, repeatability, linearity, and so on. From the experimental results, we know that a highly linear voltage output can be obtained successfully, which is proportional to displacement and the nonlinearity of output is less than 0.02% of full range. However, in the future, further investigation is required to reduce noise level and phase delay due to a low-pass filter. The evaluation system also can be applied effectively to calibration and evaluation of precision sensors and stages.
Measurements of Two-dimensional Gratings Using a Metrological Atomic Force Microscope and Uncertainty Evaluation
Kim, Jong-Ahn ; Kim, Jae-Wan ; Kang, Chu-Shik ; Eom, Tae-Bong ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 68~75
The pitch and orthogonality of two-dimensional (2D) gratings have been measured by using a metrological atomic force microscope (MAFM) and measurement uncertainty has been analyzed. Gratings are typical standard artifacts for the calibration of precision microscopes. Since the magnification and orthogonality in two perpendicular axes of microscopes can be calibrated simultaneously using 2D gratings, it is important to certify the pitch and orthogonality of 2D gratings accurately for nano-metrology using precision microscopes. In the measurement of 2D gratings, the MAFM can be used effectively for its nanometric resolution and uncertainty, but a new measurement scheme was required to overcome some limitations of current MAFM such as nonnegligible thermal drift and slow scan speed. Two kinds of 2D gratings, each with the nominal pitch of 300 nm and 1000 nm, were measured using line scans for the pitch measurement of each direction. The expanded uncertainties (k = 2) of measured pitch values were less than 0.2 nm and 0.4 nm for each specimen, and those of measured orthogonality were less than 0.09 degree and 0.05 degree respectively. The experimental results measured using the MAFM and optical diffractometer were coincident with each other within the expanded uncertainty of the MAFM. As a future work, we also proposed another scheme for the measurements of 2D gratings to increase the accuracy of calculated peak positions.
Development of a High-Resolution Encoder System Using Dual Optical Encoders
Lee, Se-Han ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 76~85
An optical rotary encoder is easy to implement for automatic control applications. In particular, the output of the encoder has a digital form pulse, which is also easy to be connected to a popular digital controller. By using the encoder, there are various angular velocity detecting methods, M-, T-, and M/T-method. Each of them has a property of its own. They have common limitation that the angular velocity detection period is strongly subject to the destination velocity magnitude in case of ultimate low range. They have ultimate long detection period or cannot even detect angular velocity at near zero velocity. This paper proposes a dual encoder system with two encoders of normal resolution. The dual encoder system is able to keep detection period moderately at near zero velocity and even detects zero velocity within nominal period. It is useful for detecting velocity in case of changing rotational direction at which there occurs zero velocity. In this paper, various experimental results are shown for the dual encoder system validity.
Structure Development of Systematic Conceptual Design Process for Designing Engineering Systems
Park, Yong-Taek ; Kuk, Kum-Hoan ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 86~94
The design process must be planned carefully and executed systematically in order to support designers who are faced with many engineering design problems. In particular, conceptual design stage is very important than other stages such as detailed design or manufacturing stage on designing engineering systems. When designers are faced contradictory situation in task, conceptual design usually requires inventive thinking which depends on their creativity. And in order to develop good concepts, it is necessary to resolve contradictory situations during conceptual design. This paper presents a structure of systematic conceptual design process for designing engineering systems. And we developed the automatic feeding screw device using the proposed design process structure.
A Study on Design and Analysis for Magnetic Lenses of a Scanning Electron Microscope using Finite Element Method
Park, Keun ; Jung, Hyun-Woo ; Park, Man-Jin ; Kim, Dong-Hwan ; Jang, Dong-Young ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 95~102
The scanning electron microscope (SEM) is one of the most popular instruments available for the measurement and analysis of the micro/nano structures. It is equipped with an electron optical system that consists of an electron beam source, magnetic lenses, apertures, deflection coils, and a detector. The magnetic lenses playa role in refracting electron beams to obtain a focused spot using the magnetic field driven by an electric current from a coil. A SEM column usually contains two condenser lenses and an objective lens. The condenser lenses generate a magnetic field that forces the electron beams to form crossovers at desired locations. The objective lens then focuses the electron beams on the specimen. The present work concerns finite element analysis for the electron magnetic lenses so as to analyze their magnetic characteristics. To improve the performance of the magnetic lenses, the effect of the excitation current and pole-piece design on the amount of resulting magnetic fields and their peak locations are analyzed through the finite element analysis.
Design of Pad Type Air-Bearing for LCD Inspection
Oh, Hyun-Seong ; Lee, Sang-Min ; Park, Jeong-Woo ; Kim, Yong-Woo ; Lee, Deug-Woo ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 103~109
LCD (Liquid Crystal Display) is widely used electronic product. It needs too many processes such as PECVD (Plasma Enhanced Vapor Deposition), Sputtering, Photo-lithography, Dry etch. Each process is important but inspection process is more important because most companies emphasis on the six sigma. Recently, LCD inspection system is composed with inlet, inspector, outlet air pads. LCD is inspected on air pad which is shooting air from air hole. This paper studies on pad design of air bearing for LCD inspection to minimize LCD fluctuation. This design is able to reduce fluctuation and then satisfies CCD inspectional range. Also inspection pad needs to adequate stable area.
Variation of Impact Characteristics of ISB Panels with a Pyramidal Inner Structure According to Joining Technologies
Ahn, Dong-Gyu ; Moon, Gyung-Jae ; Jung, Chang-Gyun ; Yang, Dong-Yol ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 110~118
ISB (Inner structured and bonded) panel with a pyramidal inner structure is actively developing to reduce the weight and to improve the crashworthiness of the material. The objective of this paper is to investigate into the variation of impact characteristics of ISB panels with a pyramidal inner structure according to joining types between skin sheets and inner structures. Several drop impact tests have been performed. In order to examine the impact characteristics at a drawing condition, drawing type of experimental set-up has been proposed. From the results of the experiments, the influence of joining types between skin sheets and the inner structures on the characteristics of the deformation, the energy absorption and the failure has been quantitatively examined. In addition, it has been shown that maximum load decreased and the maximum displacement increases as the joining type changes from the bonding to the welding. The results of the observation of the specimen have been shown that major wrinkles form in the minor crimping direction irrespective of the joining types. Through the comparison of the experimental results for bonding and welding specimens, it has been shown that the absorption energy of the bonded specimen is nearly 1.3-1.5 times of the welded specimen at the same displacement.
Computer Simulation for Residual Life Expectancy of a Container Crane Boom Structure
Kim, Sang-Yeol ; Bae, Hyung-Sub ; Lee, Yuk-Hyung ; Park, Myeong-Kwan ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 119~129
The residual life expectancy of the container crane which has been operated more or less 39 years is examined carefully, especially on the boom structure. The basic load and load combination need to be considered for to analyse the boom structure. Various parts of container crane are modeled for to analyse stress, the deflection and the fatigue. Analysis results show that the boom is stable in the stress and deflection but the boom vertical member is over the fatigue life. The rail support beam and boom bottom chord are approximately near the fatigue life. Analysis results show that the residual life of rail support beam and the boom bottom chord would be 2.2 years and 6.8 years, respectively.
Development of Ultrasound Diagnostic System for Functional Gastrointestinal Disorders using Finite Difference Method
Park, Won-Pil ; Woo, Dae-Gon ; Ko, Chang-Yong ; Lee, Qyoun-Jung ; Lee, Yong-Heum ; Choi, Seo-Hyoung ; Shin, Tae-Min ; Kim, Han-Sung ; Lim, Do-Hyung ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 130~139
The disaster from functional gastrointestinal disorders (FGID) has detrimental impact on the quality of life of the affected population. There are, however, rare diagnostic methods for FGID. Our research group identified recently that the gastrointestinal tract well of the patients with FGID became more rigid than that of healthy people when palpating the abdominal regions overlaying the gastrointestinal tract. The objective of the current study is, therefore, to identify feasibility of a diagnostic system for FGID based on ultrasound technique, which can quantify the characteristics above. Two-dimensional finite difference (FD) models (one normal and two rigid models) were developed to analyze the reflective characteristic (displacement) on each soft-tissue layer responded after application of ultrasound signals. Based on the results from FD analysis, the ultrasound system for diagnosis of the FGID was developed and clinically tested via application of it to 40 human subjects with/without FGID who were assigned to Normal and Patient Groups. The results from FD analysis showed that the maximum displacement amplitude in the rigid models (0.12 and 0.16) at the interface between the fat and muscle layers was explicitly less than that in the normal model (0.29). The results from actual specimens showed that the maximum amplitude of the ultrasound reflective signal in the rigid models
at the interface between the fat and muscle layers was explicitly higher than that in the normal model
. Clinical tests using our customized ultrasound system showed that the maximum amplitudes of the ultrasound reflective signals near to the gastrointestinal tract well for the patient group
were generally higher than those in normal group
. These findings suggest that our customized ultrasound system using the ultrasound reflective signal may be helpful to the diagnosis of the FGID.
Medical Image Registration Methods for Intra-Cavity Surgical Robots
An, Jae-Bum ; Lee, Sang-Yoon ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 140~147
As the use of robots in surgeries becomes more frequent, the registration of medical devices based on images becomes more important. This paper presents two numerical algorithms for the registration of cross-sectional medical images such as CT (Computerized Tomography) or MRI (Magnetic Resonance Imaging) by using the geometrical information from helix or line fiducials. Both registration algorithms are designed to be used for a surgical robot that works inside a cavity of human body. This paper also reports details about the fiducial pattern that includes four helices and one line. The algorithms and the fiducial pattern were tested in various computer-simulated situations, and the results showed excellent overall registration accuracy.
Offsetting of Triangular Net using Distance Fields
Yoo, Dong-Jin ;
Journal of the Korean Society for Precision Engineering, volume 24, issue 9, 2007, Pages 148~157
A new method which uses distance fields scheme and marching cube algorithm is proposed in order to get an accurate offset model of arbitrary shapes composed of triangular net. In the method, the space bounding the triangular net is divided into smaller cells. For the efficient calculation of distance fields, valid cells which will generate a portion of offset model are selected previously by the suggested detection algorithm. These valid cells are divided again into much smaller voxels which assure required accuracy. At each voxel distance fields are created by calculating the minimum distances between corner points of voxels and triangular net. After generating the whole distance fields, the offset surface were constructed by using the conventional marching cube algorithm together with mesh smoothing scheme. The effectiveness and validity of this new offset method was demonstrated by performing numerical experiments for the various types of triangular net.