• The Journal of the Acoustical Society of Korea
• /
• v.17 no.1E
• /
• pp.30-35
• /
• 1998

Given a noisy sampled at equispaced points with white noise, we consider problems where the signal to be recovered is known to be positive; for example, images, chemical spectra or other measurements of intensities. Shrinking noisy wavelet coefficients via thresholding offers very attractive alternatives to existing methods of recovering signals from noisy data. In this paper, we propose a method of recovering the original signal from a corrupted noisy signal, guaranteeing the recovered signal positive. We first obtain wavelet coefficients by thresholding, and use a nonlinear optimization to find the denoised signal which must be positive. Numerical examples are used to illustrate the performance of the proposed algorithm.

• 제어로봇시스템학회:학술대회논문집
• /
• 2002.10a
• /
• pp.63.5-63
• /
• 2002

In this paper, we are concerned with a maneuver detection algorithm which uses the 'lost' measurements down-sampled for computation load saving when a target is in quiescent motion. In general applications of estimation, measurements are available at a relatively high rate, while the estimation processing equipment can only operate at a lower sampling rate. Furthermore, when a target is in nearly quiescent motion, the update of the tracking filter need not to be implemented with maxim urn process power of the filter since the states of the target vary relatively slowly. This does not give serious degradation on the estimation performance. We consider the maneuver detection problem at the case...

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2006.05a
• /
• pp.272-277
• /
• 2006

High speed electric trains have nonlinear loads including converters and inverters for the contol synchronous motors. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. Direct application of the harmonic assessment to the snapshot measurements would result in ambiguous conclusions depending on which instant is sampled. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. This paper provides an in depth analysis on harmonics field measurement of the high speed electric train loads, harmonics assessment by the international harmonic standards IEC 61000-3-6 and IEEE std. 519-1992, and harmonics simulation using EDSA program for the case study.

• Journal of Fashion Business
• /
• v.5 no.4
• /
• pp.144-157
• /
• 2001

The purpose of this study was to research on breast shape and size to suggest a brassiere sizing chart for elderly women. For this purpose 90 elderly women aged between 55 and 69 were sampled at random to review their breast types by age group, and thereby, suggest the basic measurements and production ratio of each brassiere size in reference to KS K 0070: 1999. The collected measurement data were processed statistically using the SPSS PC/WIN program for technical statistical analysis. The results of this study can be summarized as follows; 1. Analysis of Breast Measurements To find out difference among age groups, the 90 subjects were grouped into three(Group 1 ; aged 55 to 59, Group 2 ; aged 60 to 64, Group 3 ; aged 65 to 69). The results of the comparative analysis of anthropometric data from three groups show that getting older;- Various length measurements related to the drooping degree of breast were increased. It was found that the older group in their 65-69's had more drooping breasts than their 55-59's or 60-64's counterparts. Such findings suggests that older women's drooping can be corrected by a brassiere which serves to support the breasts. 2. Suggestions on a Brassiere Sizing For the basic measurements of brassiere parts for the elderly women, the correlation between underchest circumferences and cup sizes were analyzed. 3% or higher occurrences among the whole sample elderly women were included in the brassiere sizes. thus, the under-chest measurements were set at four intervals from 75 to 95, while the cup measurements were determined also at four intervals from "AAA" to "B" sizes. The resultant 6 sizes excluding the least frequent occurrences covered 73.2% of the sample elderly women actual breast sizes. As a consequence of reviewing the production ratio of each brassiere size for the women, it was found that the brassiere size of highest production ratio was "85A" (17.4%), followed by 80A (14.5%), 85AA 90A (10.1%) and 75A (8.7%) in their order.

• Journal of Fashion Business
• /
• v.6 no.5
• /
• pp.87-95
• /
• 2002

The purpose of this study is to survey toddlers' apparel brands in Korea for operation of pattern work rooms, pattern sizes and uses of bodies and measurements, and thereby, provide for some basic data useful to development of toddlers' apparel prototypes and production of bodies. For this study, 13 domestic brands were surveyed. The results of this study can be summarized as follows; As a result of surveying the pattern work rooms, it was found that 53.8% of the sample brands employed a director of pattern work room, while 38.5% of them did not employed any pattern director. 7.7% of the sample brands employed two pattern directors. Such findings suggests that pattern works for toddlers' apparels are neither specialized nor differentiated as for adults' apparels, and therefore, that apparel production is not efficient. In view of the body profiles, only six brands possessed some or other bodies produced in Japan. The average breast size of No. 3 body was found 51.7cm, waist 48.4cm and hip size was 53.7cm. According to National Standard Body Size Survey Report, average breast size of three-year-old toddlers is 51.2cm, The average waist size is 49.5cm, and the hip size is 52.6cm. All in all, our toddlers' sizes are slightly different from Japanese toddlers', and so, it is deemed necessary to produce the bodies for our toddlers' apparels. As a consequence of surveying the measurements used for pattern production, it was found that five brands of the sample brands were using some or other 'body measurements', and another five brands were body measurements and apparel ones in parallel. All the brands sampled were found using some or other 'apparel measurements'.

• Safety and Health at Work
• /
• v.15 no.1
• /
• pp.42-52
• /
• 2024

Background: The lack of headforms that accurately reflect the head characteristics of Koreans and the demographic composition of the Korean population can lead to inadequate FFR testing and reduced effectiveness of FFRs. Method: Direct measurements of 5,110 individuals and 3D measurements of 2,044 individuals, aged between 9 and 69 years, were sampled from the data pool of Size Korea surveys based on the age and gender ratios of the Korean resident demographics. Seven head dimensions were selected based on the ISO 16976-2, availability of Size Korea measurements, and their relevance to the fit performance of FFRs. A principal component analysis (PCA) was performed using the direct measurements to extract the main factors explaining the head characteristics and then the main factors were standardized and remapped to 3D measurements, creating five size categories representing Korean head shapes. Lastly, representative 3D headforms were constructed by averaging five head shapes for each size category. Results: The study identified two main factors explaining Korean head characteristics by the PCA procedure specified in ISO 16976-2 and developed five representative headforms reflecting the anthropometric features of Korean heads: medium, small, large, short & wide, and long & narrow. Conclusion: This study developed representative headforms tailored to the Korean population for conducting total inward leakage (TIL) tests on filtering facepiece respirators (FFRs). The representative headforms can be used for TIL testing by employing robotic headforms to enhance the performance of FFRs for the Korean target population.

• Journal of Korean Society of Water and Wastewater
• /
• v.19 no.5
• /
• pp.582-594
• /
• 2005

The under-registration of water meters of 20mm to 50mm in diameter, installed in Seoul city, was estimated by random sample method. The sample sites and sampled meters were selected for the measurements of flow rates and accuracy tests, respectively. The measurement of flow rates was conducted for 20mm to 50mm meters for about 20 days per site using flow meters and data loggers. The under-registration of 20mm, 25mm, 32mm, 40mm, and 50mm meters was observed as 3.96%, 1.10%, 2.47%, 4.04%, and 1.04%, respectively. The under-registration might be increased more or less as malfunction and failure of the sampled meters was not considered. In this study the under-registration of 20mm, 25mm, 32mm, 40mm, and 50mm meters was accurately estimated on the basis of the investigation data. The estimation of under-registration of water meters, one of the basic figures in water industry, contributed to accurate calculation of leakage, water supply and consumption, and strategic planning to reduce the unaccounted-for water.

• Smart Structures and Systems
• /
• v.16 no.2
• /
• pp.295-328
• /
• 2015

In recent years the monitoring of structural behavior through acquisition of vibrational data has become common practice. In addition, recent advances in sensor development have made the collection of diverse dynamic information feasible. Other than the commonly collected acceleration information, Global Position System (GPS) receivers and non-contact, optical techniques have also allowed for the synchronous collection of highly accurate displacement data. The fusion of this heterogeneous information is crucial for the successful monitoring and control of structural systems especially when aiming at real-time estimation. This task is not a straightforward one as measurements are inevitably corrupted with some percentage of noise, often leading to imprecise estimation. Quite commonly, the presence of noise in acceleration signals results in drifting estimates of displacement states, as a result of numerical integration. In this study, a new approach based on a time domain identification method, namely the Unscented Kalman Filter (UKF), is proposed for correcting the "drift effect" in displacement or rotation estimates in an online manner, i.e., on the fly as data is attained. The method relies on the introduction of artificial white noise (WN) observations into the filter equations, which is shown to achieve an online correction of the drift issue, thus yielding highly accurate motion data. The proposed approach is demonstrated for two cases; firstly, the illustrative example of a single degree of freedom linear oscillator is examined, where availability of acceleration measurements is exclusively assumed. Secondly, a field inspired implementation is presented for the torsional identification of a tall tower structure, where acceleration measurements are obtained at a high sampling rate and non-collocated GPS displacement measurements are assumed available at a lower sampling rate. A multi-rate Kalman Filter is incorporated into the analysis in order to successfully fuse data sampled at different rates.

• Speech Sciences
• /
• v.15 no.4
• /
• pp.107-119
• /
• 2008

This paper intends to investigate the correlation of 12 MDVP measurements with age, sex and body-size of sampled healthy patients. In order to extract pitch and 12 MDVP parameters efficiently and display the correlation of each parameter easily, we developed the speech analysis program using C/C++ and MFC development tool. The sample group consists of 205 males and 343 females with ages 9-81. We collected vowel voices /a/ and 8 body-size measurements from them. Body-size values were taken at 8 different torso positions of each person. We analyzed the matched voice samples and body-size measurements by the developed speech analysis program and SPSS program. The result shows that a typical characteristic age-F0 pattern that F0 of male subjects are rapidly decreased after mutational period and have stable state with age and that of female subjects are slowly changed by overall age. In MDVP, age-STD in males, age-sPPQ in females relationships are especially similar to the age-F0 relationship. In case of male group, sPPQ(0.316%), Jitt(0.04%), Shim(0.25%), APQ(0.28%) variables are increased with age after mutational period. And Jitt(0.042%), sPPQ(0.219%) of females group are increased with age too. In cases of height, weight and BMI there exists a weak correlation with MDVP, which shows a correlation coefficient below 0.25 about male and female groups. The survey of correlation relationship between 8 body-size measurements and MDVP shows a insignificant statistical result by only just having the correlation coefficient maximum in M8-8 and F0(-0.394%) for males and M8-6,7(-0.368%, -0.364%) for females.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.8
• /
• pp.1525-1532
• /
• 2008

An instrument was developed for the simultaneous determination of gas- and aerosol-phase nitrous acid (HONO). Gaseous HONO (HONO(g)) was sampled by a diffusion scrubber and particulate nitrite ($NO_2\;^-$(p)) was collected by a particle growth chamber. The collected samples were analyzed in time-sharing manner, based on the peroxynitrite-induced luminol chemiluminescence. The automated system was found to be sensitive with 13 pptv of detection limit, fast with 4 min. of sampling frequency, and simple and affordable to construct and operate. The system was optimized by adjusting the experimental parameters. The system was applied to the field measurement of gas- and particle-phase HONO during the springtime of 2004 in Gwangju, South Korea. HONO(g) concentrations varied diurnally from 200 pptv around 3 P.M. to 800 pptv at 5 A.M. The variation of $NO_2\;^-$(p) was not significant with the maximum of 240 pptv at 11 P.M. and the minimum of 170 pptv at 4 P.M., not displaying distinct characteristics.