• Journal of Institute of Control, Robotics and Systems
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• v.9 no.10
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• pp.774-781
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• 2003

The important factors that cause position error in X-Y robot are inertial force, frictions and spring distortion in screw or coupling. We have to estimate these factors precisely to correct position errors, Which is very difficult. In this paper, we makes systems to inspect metal stencil which is used to print solder paste on pads of SMD of PCB with low precision X-Y robot and vision system. To correct position error that is caused by low precision X-Y robot, we defines position error vector that is formed with position of objects that exist in reference and camera image. We apply MHT(Modified Hough Transformation) for the aim of determining the dominant position error vector. We modify reference image using extracted dominant position error vector and obtain reference image that is the same with camera image. Effectiveness and performance of this method are verified by simulation and experiment.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.2
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• pp.79-83
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• 2001

A verification of multi-spindles drilling NC data is presented. The drilling of multi-spindles can offer productivity over three times as fast as that of single spindle. The most important things in machining tube sheet are precision of hole position and machining time. The drilling of multi-spindles has difficulties in controlling many motors to drive spindles and assign a correspondent number to each spindles. Multi-spindles drilling has different codes from CNC milling ; many subroutines, assignment of spindle, and so on. The conventional method, which inspects the NC code of the drilling, is to drill holes on a thin plate or tube sheet previously. The method results in low productivity because it consumed long machining time and welding for correction. This paper describes details of multi-spindles NC code and operation of multi-spindles drilling machine. A verification software of the multi-spindles drilling NC code is developed on the details.

• Journal of Astronomy and Space Sciences
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• v.19 no.2
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• pp.163-172
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• 2002

This article investigates the problem of data preprocessing for the precision orbit determination (POD) of low earth orbit satellite using GPS .aw data. Several data preprocessing algorithms have been developed to edit the GPS data automatically such that outlier deletion, cycle slip identification and correction, and time tag error correction. The GPS data are precisely edited for the accuracy of POD. Some methods of data preprocessing are restricted to the rate of the collections of the pseudorange and carrier phase measurements. This study considers the preprocessing efficiency varied with the rate, the quality of receiver and the altitude of the satellite's orbit. We also propose the proper methods in accordance with the rate for single frequency and dual frequency receivers.

• Proceedings of the KSRS Conference
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• v.2
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• pp.756-759
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• 2006

The ocean tide loading (OTL) is an important factor for the GPS positioning, especially in the height direction. The shorter of the distance to the ocean, the larger of the error by the OTL. The influence will be changed when we measure in different place and the order of magnitude is from few centimeters to ten centimeters. In this study, more than ten kinds of the OTL models were collected and applied on the GPS static relative positioning in Taiwan. The GPS observations including five stations were obtained from Nov. 9, 2004 to Feb. 23, 2005 and we used the Bernese GPS software to execute the data processing. In this period, the average amplitudes of the 3-D coordinates are as follows: N is 0.4 cm, E is 0.7 cm, h is 1.8 cm at Kinmen station; N is 0.7 cm, E is 1.3 cm, h is 2.3 cm at Lanyu station; N is 0.5 cm, E is 0.7 cm, h is 2.0 cm at Matsu station; N is 0.6 cm, E is 0.6 cm, h is 2.0 cm at Penghu station and N is 0.5 cm, E is 1.2 cm, h is 1.7 cm at Hsinchu station. Moreover, we will analyze the advantage and disadvantage of every kind of the OTL models in different environments to offer some information to the GPS users and enhance the precision of the GPS positioning.

• Journal of Advanced Navigation Technology
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• v.22 no.2
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• pp.64-69
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• 2018

Automatic test equipment for field maintenance of aircraft mounted equipment is effective for integrated design when operating a small number of aircraft for special purposes. The integrated automatic test equipment identifies commonly used interfaces and is used for branching or generating routes for each unit under test specific inspection. High-precision signals such as RTD, TC, and analog voltage can cause measurement errors due to conduction resistance during signal branching and connection when generating branches and paths. The measurement error caused by the resistance of the wire leads to a lot of restrictions in designing the equipment to be inspected. In this paper, we propose a method of calibrating highly accurate signals of an integrated automatic inspection equipment that minimizes measurement errors of analog voltage and high - precision signals.

• Journal of Korean Physical Therapy Science
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• v.30 no.3
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• pp.49-58
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• 2023

Background: This study aims to examine the useful- ness of the portable spirometer "The Spirokit" as a clinical diagnostic device through technology introduction, precision test, and correction. Design: Technical note Methods: "The Spirokit" was developed using a propeller-type flow rate and flow rate measurement method using infrared and light detection sensors. The level of agreement between the Pulmonary Waveform Generator and the measured values was checked to determine the precision of "The Spirokit", and the correction equation was included using the Pulmonary Waveform Generator software to correct the error range. The analysis was requested using the ATS 24/26 waveform recognized by the Ministry of Food and Drug Safety and the American Thoracic Society for the values of Forced Voluntary Capacity (FVC), Forced Expiratory Volume in 1second (FEV1), and Peak Expiratory Flow (PEF), which are used as major indicators for pulmonary function tests. All tests were repeated five times to derive an average value, and FVC and FEV1 presented accuracy and PEF presented accuracy as the result values. Results: FVC and FEV1 of 'The Spirokit' developed in this study showed accuracy within ± 3% of the error level in the ATS 24 waveform. The PEF value of 'The Spirokit' showed accuracy within the error level ± 12% of the ATS 26 waveform. Conclusion: Through the results of this study, the precision of 'The Spirokit' as a clinical diagnosis device was identified, and it was confirmed that it can be used as a portable pulmonary function test that can replace a spirometer.

• Korean Journal of Remote Sensing
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• v.33 no.5_1
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• pp.495-506
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• 2017

This study was carried out to effectively perform relative color correction for high-resolution aerial ortho image. For this study, relative geometrical error between adjacent images was analyzed. The block sum method is proposed to reduce the relative geometrical error. We used the regression coefficients determined based on the block sum size to perform the color correction. As a result, it was confirmed that the relative color correction was visually performed well. Quantitative analysis was performed through histogram similarity analysis. It is proved that block sum method is useful for relative color correction. Particularly, the block sum size was very important to correct color based on the amount of relative geometrical error.

• Journal of the Korean Solar Energy Society
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• v.30 no.5
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• pp.25-31
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• 2010

A Precision Spectral Pyranometer (PSP) is mainly used as a reference to calibrate other pyranometers due to its high accuracy and sensitivity in response to the spectrum wavelength range of 0.285 ${\mu}$ to 2.8 ${\mu}$, while the sensitivity of photovoltaic-type Li-Cor pyranometer is limited within a certain spectral range from 0.4 ${\mu}$ to 1.1 ${\mu}$. In this study, two Eppley PSPs($PSP_1$ and $PSP_2$) were first compared to the calibrated Eppley PSPs from National Renewable Energy Laboratory (NREL), resulting in two linear correction factors based on the comparison between the logger output (V) from the test PSP and the solar radiation (W/m2) from the NREL PSP. The Li-Cor pyranometer used in this study was then corrected based on the comparison of measured solar radiation ($W/m^2$) from the corrected $PSP_1$ and the Li-Cor pyranometer. In addition, instrument scale corrections were also performed for the PSPs and the Li-Cor from the transmitter to the data logger. From the comparisons, a linear correction factor (1.0214) with R=0.9998 was developed for the scale correction between$PSP_1$ and $PSP_2$, while the Li-Cor pyranometer has a scale(1.0597) and offset (32.046) with R=0.9998 against$PSP_1$. As a result, it was identified that there were good agreements within ${\pm}$ 10 W/ $m^2$ between Eppley $PSP_1$ vs. $PSP_2$ solar radiation and within ${\pm}$ 20 W/$m^2$ between$PSP_1$ vs Li-Cor solar radiation after the empirical scale corrections developed in this study.

• Journal of the Korea Society of Computer and Information
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• v.17 no.10
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• pp.25-33
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• 2012

In this paper, we propose a rule-based model to correct errors in a speech recognition result in the mobile device environment. The proposed model considers the mobile device environment with limited resources such as processing time and memory, as follows. In order to minimize the error correction processing time, the proposed model removes some processing steps such as morphological analysis and the composition and decomposition of syllable. Also, the proposed model utilizes the longest match rule selection method to generate one error correction candidate per point, assumed that an error occurs. For the purpose of deploying memory resource, the proposed model uses neither the Eojeol dictionary nor the morphological analyzer, and stores a combined rule list without any classification. Considering the modification and maintenance of the proposed model, the error correction rules are automatically extracted from a training corpus. Experimental results show that the proposed model improves 5.27% on the precision and 5.60% on the recall based on Eojoel unit for the speech recognition result.

• Journal of Adhesion and Interface
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• v.5 no.2
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• pp.14-26
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• 2004

For reliable determination of mechanical characteristics of adhesively bonded joints used e.g. as input data for computer-aided design of complex components, the thick-adherend tensile-shear test according to ISO 11003-2 is the most important material testing method. Although the total displacement of the joint is measured across the polymer layer directly in the overlap zone in order to minimize the influence of the stepped adherends, the substrate deformation must be taken into account within the framework of the evaluation of the shear modulus and the maximum shear strain, at least when high-strength adhesives are applied. In the standard ISO 11003-2 version of 1993, it was prescribed to perform the substrate deformation correction by means of testing a one-piece reference specimen. The authors, however, pointed to the excessive demands on the measuring accuracy of the extensometers connected with this technique in industrial practice and alternatively proposed a numerical deformation analysis of a dummy specimen. This idea of a mathematical correction was included in the revised ISO 11003-2 version of 2001 but in the simplified form of an analytical method based on Hooke's law of elasticity for small strains. In the present work, it is shown that both calculation techniques yield considerably discordant results. As experimental assessment would require high-precision distance determination (e.g. laser extensometer), finite element analyses of the deformation behavior of the bonded joint are performed in order to estimate the accuracy of the obtained substrate deformation corrections. These simulations reveal that the numerical correction technique based on the finite element deformation modeling of the reference specimen leads to considerably more realistic results.