• Structural Engineering and Mechanics
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• v.57 no.1
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• pp.21-43
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• 2016

A conditional probability based approach known as Particle Filter Method (PFM) is a powerful tool for system parameter identification. In this paper, PFM has been applied to identify the vehicle parameters based on response statistics of the bridge. The flexibility of vehicle model has been considered in the formulation of bridge-vehicle interaction dynamics. The random unevenness of bridge has been idealized as non homogeneous random process in space. The simulated response has been contaminated with artificial noise to reflect the field condition. The performance of the identification system has been examined for various measurement location, vehicle velocity, bridge surface roughness factor, noise level and assumption of prior probability density. Identified vehicle parameters are found reasonably accurate and reconstructed interactive force time history with identified parameters closely matches with the simulated results. The study also reveals that crude assumption of prior probability density function does not end up with an incorrect estimate of parameters except requiring longer time for the iterative process to converge.

• Journal of radiological science and technology
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• v.36 no.1
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• pp.19-24
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• 2013

The measurement of Korea people's Radial-terminal region were frequently measure of the left hand of Radial-terminal region due to the most Korean's are right-handed and it occasionally showed incorrect results. Therefore, in this study, we accessed a correlation with error of measurement and reduced the measurement error invalid. We reviewed 50 adults patients, from March 2012 for a certain period of time, visited the orthopedic center for the neutral position of forearm of plain radiography and measured the left side of the distal radial-terminal region containing the terminal region of the right distal radius. Then we have compared and analysed both T-score. As a result, the lower value of left wrist were 45 out of 75 which is approximately 60% of left wrist group while the lower value of right wrist were 30 out of 75 which is approximately 40% of right wrist group.

• Journal of Korea Water Resources Association
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• v.37 no.5
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• pp.375-386
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• 2004

A water shortage is one of the most important factors for development and management of water resources. For reliable water shortage measurement in a stream, Korea Water Resources Corporation(KOWACO) founded five foot Parshall flume at Yong-dam experimental watershed in 2000. The Parshall flume has a specially designed shape to facilitate flow measurements by eliminating sediment deposition problem that could lead to an incorrect measurement. In this study, computational fluid dynamics(CFD) model was used to analyze flow behavior of Parshall Flume under free discharge of five headwater level cases. The flow rates computed by CFD model are compared with those by ISO's formula, USBR's formula and stage-discharge rating curves. Flow rates computed by ISO's and USBR's formula are mostly same, but flow rate by CFD model is larger than empirical value by 9% and flow rate by stage-discharge rating curves is less than empirical value by 16%.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.11 s.158
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• pp.1507-1518
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• 2006

The middle-aged body differs from the youthful body and has its own body type due to the considerable difference in body structure by age. However, most ready-made clothes for middle-aged women are designed according to the youthful body types. They are looking for the better fitness of the ready-made clothes. Thus clothing fitness is strongly required for a middle-aged women. The purpose of this study is to analyze the basic characteristics of middle-aged women's body types and to compare the real somatotype and cognitive somatotype. The subjects are 238 middle-aged women between 35 and 49 years old living in Daegu. Data are collected through anthropometric measurement and questionnaire on somatotype from September to October 2004. The results are as follows: 1. Using factor analysis, cluster analysis is carried out and the subjects of this research are classified into 4 groups. 2. Middle-aged women usually are not satisfied with their body. Particularly, they show the lowest satisfaction measurement about their abdominal girth, weight, and overall body-shape in total 16 categories. 3. As a result of body cathexis for each part, women are usually not satisfied with their body parts for themselves, regardless of real somatotype. 4. As I divide middle-aged women's somatotype by Rohrer index into the groups of three body-types, then examine real somatotype and cognitive somatotype, I get the following result : The slimmer their bodies are, the more satisfied middle-aged women we. Besides, 40.3% of middle-aged women have an incorrect and distorted understanding of their somatotype. 5. As a result of this research for ideal state of body-size, the women shows their Ideal sizes as follow: 160.55cm for ideal height, 88.73cm for ideal bust girth, 71.14cm for ideal waist girth, 90.03cm for ideal hip girth, and 53kg for ideal weight.

• Journal of Radiation Protection and Research
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• v.41 no.2
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• pp.93-99
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• 2016

Background: Industrial X-ray CT system is normally applied to non-destructive testing (NDT) for industrial product made from metal. Furthermore there are some special CT systems, which have an ability to inspect nuclear fuel assemblies or rocket motors, using high power and high energy (more than 6 MeV) pulsed X-ray source. In these case, pulsed X-ray are produced by the electron linear accelerator, and a huge number of photons with a wide energy spectrum are produced within a very short period. Consequently, it is difficult to measure the X-ray energy spectrum for such accelerator-based X-ray sources using simple spectrometry. Due to this difficulty, unexpected images and artifacts which lead to incorrect density information and dimensions of specimens cannot be avoided in CT images. For getting highly precise CT images, it is important to know the precise energy spectrum of emitted X-rays. Materials and Methods: In order to realize it we investigated a new approach utilizing the Bayesian estimation method combined with an attenuation curve measurement using step shaped attenuation material. This method was validated by precise measurement of energy spectrum from a 1 MeV electron accelerator. In this study, to extend the applicable X-ray energy range we tried to measure energy spectra of X-ray sources from 6 and 9 MeV linear accelerators by using the recently developed method. Results and Discussion: In this study, an attenuation curves are measured by using a step-shaped attenuation materials of aluminum and steel individually, and the each X-ray spectrum is reconstructed from the measured attenuation curve by the spectrum type Bayesian estimation method. Conclusion: The obtained result shows good agreement with simulated spectra, and the presently developed technique is adaptable for high energy X-ray source more than 6 MeV.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.4
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• pp.325-332
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• 2022

Determination of VLBI IVP (Very Long Baseline Interferometry Invariant Point) position with high accuracy is required to compute local tie vectors between the space geodetic techniques. In general, reflective targets are attached on VLBI antenna and slant distances, horizontal and vertical angles are measured from the pillars. Then, adjustment computation is performed by using the mathematical model which connects measurements and unknown parameters. This indicates that the accuracy of the estimated solutions is affected by the accuracy of the measurements. One of issues in local tie surveying, however, is that the reflective targets are not in favorable condition, that is, the reflective sheet target cannot be perfectly aligned to the instrument perpendicularly. Deviation from the line of sight of an instrument may cause different type of measurement errors. This inherent limitation may lead to incorrect stochastic modeling for the measurements in adjustment computation procedures. In this study, error characteristics by measurement types and pillars are analyzed, respectively. The analysis on the studentized residuals is performed after adjustment computation. The normality of the residuals is tested and then equal variance test between the measurement types are performed. The results show that there are differences in variance according to the measurement types. Differences in variance between distances and angle measurements are observed when F-test is performed for the measurements from each pillar. Therefore, more detailed stochastic modeling is required for optimal solutions, especially in local tie survey.

• Journal of Mechanical Science and Technology
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• v.17 no.10
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• pp.1411-1422
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• 2003

The detection of free spaces between obstacles in a scene is a prerequisite for navigation of a mobile robot. Especially for stereo vision-based navigation, the problem of correspondence between two images is well known to be of crucial importance. This paper describes multi-range approach of area-based stereo matching for grid mapping and visual navigation in uncertain environment. Camera calibration parameters are optimized by evolutionary algorithm for successful stereo matching. To obtain reliable disparity information from both images, stereo images are to be decomposed into three pairs of images with different resolution based on measurement of disparities. The advantage of multi-range approach is that we can get more reliable disparity in each defined range because disparities from high resolution image are used for farther object a while disparities from low resolution images are used for close objects. The reliable disparity map is combined through post-processing for rejecting incorrect disparity information from each disparity map. The real distance from a disparity image is converted into an occupancy grid representation of a mobile robot. We have investigated the possibility of multi-range approach for the detection of obstacles and visual mapping through various experiments.

• Journal of the Korean Society of Physical Medicine
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• v.2 no.1
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• pp.65-72
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• 2007

Purpose : The purpose of this study is a research on the evaluation about shoulder joint function. Methods : It's based on the reference books. Result : Shoulder joint has the biggest ROM in human body, and it is a joint that stability and mobility are required at the same time sport art. Especially, function of shoulder joint than other what item players of more important overhead item correct diagnosis and evaluation for shoulder joint injury require. Measurement equipment for shoulder joint is helping a lot of incorrect diagnosis and analysis about shoulder joint function of overhead players through a lot of developments. Conclusion : I think a lot of helps torture in motor ability elevation of players and player protection as analysis by special quality in item of overhead players.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.5
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• pp.992-999
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• 2009

The pulse transit time(PTT), which is determined by measuring the electrocardiogram(ECG) and pulse wave, gives comprehensive information about the cardiovascular system. However, a little movement of body and/or inaccurate pressure applied to skin during the measurement of pulse wave leads to acquire incorrect results. To overcome such problem, we developed an integrated sensor system which makes it possible to measure ECG, pressure pulse wave(PPW) and photoplethysmograph(PPG) at the same time. Futhermore, we implemented a new metal electrode which enables to continuously measure ECG. We verified that both integrated sensor system and new electrode provide useful effect.

• Journal of Industrial Technology
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• v.22 no.B
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• pp.89-93
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• 2002

When testing products before shipment to the customer, quality characteristics are measured to decide whether or not their values are between the specification limits. Unfortunately, this testing procedure can lead to incorrect decisions because of gauge error. That is, good products can erroneously be qualified as bad, and bad products as good, and this has consequences for producer's and consumer's risk. In cases of such as this, the compressed gauge limit can be used to achieve the desired product quality level dictated by the manufacturer or the customer. A compressed gauge limit is a limit set by the manufacturer on a test gauge that is tighter than the specification limit established by the customer. The compressed gauge limits should be set at levels to achieve the defect levels desired by the customer and simultaneously minimize the loss of good product that is rejected due to errors in the gauges. In this article, the models for determining the defect levels and the losses obtained by adding compressed gauge limits will be developed. A response surface model approach is utilized which allows an optimal operating condition to be generated relatively easily.