• Journal of IKEEE
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• v.2 no.2 s.3
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• pp.278-284
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• 1998

This paper describes a l0b CMOS A/D converter (ADC) for HDTV applications. The proposed ADC adopts a typical multi-step pipelined architecture. The proposed circuit design techniques are as fo1lows: A selective channel-length adjustment technique for a bias circuit minimizes the mismatch of the bias current due to the short channel effect by supply voltage variations. A power reduction technique for a high-speed two-stage operational amplifier decreases the power consumption of amplifiers with wide bandwidths by turning on and off bias currents in the suggested sequence. A typical capacitor scaling technique optimizes the chip area and power dissipation of the ADC. The proposed ADC is designed and fabricated in s 0.8 um double-poly double-metal n-well CMOS technology. The measured differential and integral nonlinearities of the prototype ADC show less than ${\pm}0.6LSB\;and\;{\pm}2.0LSB$, respectively. The typical ADC power consumption is 119 mW at 3 V with a 40 MHz sampling rate, and 320 mW at 5 V with a 50 MHz sampling rate.

• Science of Emotion and Sensibility
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• v.12 no.1
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• pp.45-54
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• 2009

Categorization in a vital means for dealing with the multitudes of entities in the world surrounding people. Among others, the perceptual and the evaluative similarities factors strongly affect categorization. The conventional SD-type procedure are insufficient in this regard, since it requires an individual subject to make isolated judgments about each stimulus to identify categorization in terms of a group tendency. It disregards the individual categorization in which the similarities are of great importance. Thus in this study the phased emotional evaluation method is suggested based on the intuitive categorization of stimuli and on the similarity judgement of representative/ non-representative case in each category. To verify the effectiveness of the suggested evaluation method the scanned jewelry images are selected as test stimuli for emotional evaluation experiment. As a result of the evaluation experiment, the conventional SD-type procedure is complemented by the emotional evaluation method in phases of the task of intuitive categorization, the selection of the representative images and the setup of the evaluation score of the representative images to internally supplied anchors of evaluating non-representative images.

• Geophysics and Geophysical Exploration
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• v.1 no.3
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• pp.183-187
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• 1998

Seismic waveform estimation is based on the assumption that the seismic trace tying a well is one dimensional convolution of the propagating seismic waveform and the reflectivity series derived from well logs (sonic and density). With this assumption, the waveform embedded in a seismic trace can be estimated using a Wiener match filter. In this paper, I experimented a preprocessing procedure that applies both on the seismic trace and on the reflectivity series. The procedure is based on the assumption that the travel time can be estimated better from the seismic trace and that the instantaneous reflectivity values can be measured better on the well log. Thus the procedure is, 1) start-time adjustment and dynamic differential stretches are applied on the sonic log, and 2) seismic amplitudes are balanced such that the low frequency part of the seismic are matched to that of the reflectivities derived from well logs.

• Journal of Korean Medical Science
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• v.33 no.48
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• pp.312.1-312.10
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• 2018

Background: Obesity is related to several comorbidities and mortality, but its relationship with acute kidney injury (AKI) and long-term mortality remain undetermined in patients undergoing coronary artery bypass grafting. Methods: Data from 3,018 patients (age ${\geq}18$ years) who underwent coronary artery bypass graft surgery from two tertiary referral centers were retrospectively reviewed between 2004 and 2015. Obesity was defined using the body mass index, according to the World Health Organization's recommendation. The odds and hazard ratios in post-surgical, AKI, and all-cause mortality were calculated after adjustment for multiple covariates. Patients were followed for $90{\pm}40.9$ months (maximum: 13 years). Results: Among the cohort, 37.4%, 2.4%, 21.1%, 35.1%, and 4.0% of patients were classified as normal weight, underweight, overweight-at-risk, obese I, and obese II, respectively. Post-surgical AKI developed in 799 patients (26.5%). Patients in the obese groups (overweight-at-risk to obese II) had a higher risk of AKI than did those in the normal-weight group. During the follow-up period, 787 patients (26.1%) died. Underweight patients had a higher risk of mortality than did normal-weight patients, whereas overweight-at-risk, obese I, and obese II patients showed better survival rates. Conclusion: After coronary artery bypass graft surgery, obese patients encountered a high risk of AKI, and underweight patients exhibited a low chance of survival. Awareness of both obese and underweight statuses should be raised in these patients.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.2
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• pp.97-104
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• 2005

A simple but efficient grid generation technique by using the modified compressible form of stream function has been formulated. Transformation of a physical plane to a streamline plane, the Von Mises Transformation, has been widely used to solve the differential equations governing flow phenomena, however, limitation arises in low velocity region of boundary layer, mixing layer and wake region where the relatively large grid spacing is inevitable. Modified Von Mises Transformation with simple mathematical adjustment for the stream function is suggested and applied to solve the confined coaxial turbulent jet mixing with simple $\kappa-\epsilon$ turbulence model. Comparison with several experimental data of axial mean velocity, turbulent kinetic energy, and Reynolds shear stress distribution shows quite good agreement in the mixing layer except in the centerline where the turbulent kinetic energy distributions were somewhat under estimated. This formulation is strongly suggested to be utilized specially for free turbulent mixing layers in axisymmetric flow conditions such as the investigation of mixing behavior, jet noise production and reduction for Turbofan engines.

• Korean Journal of Remote Sensing
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• v.35 no.1
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• pp.29-37
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• 2019

Synthetic Aperture Radar (SAR) observations are powerful tools to monitor surface's displacement very accurately, induced by earthquake, volcano, ground subsidence, glacier movement, etc. Especially, radar interferometry (InSAR) which utilizes phase information related to distance from sensor to target, can generate displacement map in line-of-sight direction with accuracy of a few cm or mm. Due to decorrelation effect, however, degradation of coherence in the InSAR application often prohibit from construction of differential interferogram. Offset tracking method is an alternative approach to make a two-dimensional displacement map using intensity information instead of the phase. However, there is limitation in that the offset tracking requires very intensive computation power and time. In this paper, efficiency of parallel computing has been investigated using high performance computer for estimation of glacier velocity. Two TanDEM-X SAR observations which were acquired on September 15, 2013 and September 26, 2013 over the Narsap Sermia in Southwestern Greenland were collected. Atotal of 56 of 2.4 GHz Intel Xeon processors(28 physical processors with hyperthreading) by operating with linux environment were utilized. The Gamma software was used for application of offset tracking by adjustment of the number of processors for the OpenMP parallel computing. The processing times of the offset tracking at the 256 by 256 pixels of window patch size at single and 56 cores are; 26,344 sec and 2,055 sec, respectively. It is impressive that the processing time could be reduced significantly about thirteen times (12.81) at the 56 cores usage. However, the parallel computing using all the processors prevent other background operations or functions. Except the offset tracking processing, optimum number of processors need to be evaluated for computing efficiency.

• Korean Journal of Social Welfare Studies
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• v.40 no.1
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• pp.139-161
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• 2009

The purpose of this study was to investigate the paths of the related variables that exert an influence upon the increase in mild and serious delinquencies of part-time work adolescents. Based on differential association theory, social control theory and power resource theory, the research model was composed and analyzed through structural equation model. Data came from survey which was done by fifteen high schools located in Seoul, and 201 questionnaire of returned were used for analysis. The results were congruent with theoretical expectations. The relationship between work hour per week and delinquency was mediated by delinquent propensity of fellow workers, amount of spending money and school adjustment. In conclusion, various theoretical and practical implications for social work practice focusing on the part time work students were discussed. Enforcement of regulation and revision of current law and various ways for helping and supervising working students in school, family and working places are needed.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.12
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• pp.1696-1702
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• 2015

The objective of this study was to compare the effects of body weight growth adjustment methods on genetic parameters of body growth and tissue among three pig breeds. Data collected on 101,820 Landrace, 281,411 Yorkshire, and 78,068 Duroc pigs, born in Korean swine breeder farms since 2000, were analyzed. Records included body weights on test day and amplitude (A)-mode ultrasound carcass measures of backfat thickness (BF), eye muscle area (EMA), and retail cut percentage (RCP). Days to 90 kg body weight (DAYS90), through an adjustment of the age based on the body weight at the test day, were obtained. Ultrasound measures were also pre-adjusted (ABF, EMA, AEMA, ARCP) based on their test day measures. The (co)variance components were obtained with 3 multi-trait animal models using the REMLF90 software package. Model I included DAYS90 and ultrasound traits, whereas model II and III accounted DAYS90 and pre-adjusted ultrasound traits. Fixed factors were sex (sex) and contemporary groups (herd-year-month of birth) for all traits among the models. Additionally, model I and II considered a linear covariate of final weight on the ultrasound measure traits. Heritability ($h^2$) estimates for DAYS90, BF, EMA, and RCP ranged from 0.36 to 0.42, 0.34 to 0.43, 0.20 to 0.22, and 0.39 to 0.45, respectively, among the models. The $h^2$ estimates of DAYS90 from model II and III were also somewhat similar. The $h^2$ for ABF, AEMA, and ARCP were 0.35 to 0.44, 0.20 to 0.25, and 0.41 to 0.46, respectively. Our heritability estimates varied mostly among the breeds. The genetic correlations ($r_G$) were moderately negative between DAYS90 and BF (-0.29 to -0.38), and between DAYS90 and EMA (-0.16 to -0.26). BF had strong $r_G$ with RCP (-0.87 to -0.93). Moderately positive $r_G$ existed between DAYS90 and RCP (0.20 to 0.28) and between EMA and RCP (0.35 to 0.44) among the breeds. For DAYS90, model II and III, its correlations with ABF, AEMA, and ARCP were mostly low or negligible except the $r_G$ between DAYS90 and AEMA from model III (0.27 to 0.30). The $r_G$ between AEMA and ABF and between AEMA and ARCP were moderate but with negative and positive signs, respectively; also reflected influence of pre-adjustments. However, the $r_G$ between BF and RCP remained non-influential to trait pre-adjustments or covariable fits. Therefore, we conclude that ultrasound measures taken at a body weight of about 90 kg as the test final should be adjusted for body weight growth. Our adjustment formulas, particularly those for BF and EMA, should be revised further to accommodate the added variation due to different performance testing endpoints with regard to differential growth in body composition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5820-5825
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• 2014

The aim of this study was to verify the suitability or unsuitability of Korean body types by measuring the opening force criteria of an air pressurized access door to a smoke control zone. The opening force criteria were verified by comparing the NFSC 501A, NFPA 92A and BS-EN 12101-6 based on the body standards information from the Korean Agency for Technology and Standards. When measuring the opening forces, the posture of the body should be standing upright and pushing an access door with the right hand, which is a criterion for designing doors. As a result of analyzing the actual measurement results, the pushing force of men and women in their 30's was the maximum value and the forces in those in their 60's was the minimum value. In addition, the deviations in the pushing forces varied considerably. As a result of comparing the NFSC 501A, the men showed lower values than the criteria in every gender and age variable except for the 20's, 30's and 50's variable. A comparison of the criteria of NFPA 92A showed that the mean of the measured values from every gender and age was also lower than the criteria. In addition, when comparing the criteria of BS-EN 12101-6, it was found that the men in every age variable were higher than the criteria. On the other hand, the women in every age variable were lower than the criteria. Therefore, considering the Korean body type against the Western body type, it was decided that the opening force of an access door to a smoke control area to make a downward adjustment should be 110 N in the local criteria. Furthermore, the criteria should consider the characteristics of buildings and users because an optional application of the international standard is not necessarily suitable for local situations.

• Korea journal of population studies
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• v.31 no.2
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• pp.101-132
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• 2008

This paper discusses transformation of the US population census since 1990 and its future prospects by mentioning the 2000 census experience and the 2010 census plans. First, it examines the recommendations written for the 2000 census by the Committee on National Statistics, National Research Council, such as introduction of statistical estimation, response rate improvement, long form improvement, adjustment in differential undercount by race/ethnicity, alternative census methods, collection of small-area statistics in non-census years, and census frame enhancement, and describes how the US Supreme Court decision of 1998 led the Census Bureau to fail in conducting the US version of One Number Census which uses statistical estimation by matching actual enumerations from the Census main survey and post-enumeration survey. Second, it examines one key element of the 2010 U. S. census, say, the separation of long form from short form and describes the main features of American Community Survey, a rolling census which replaces long-form component of the traditional US "Decennial Census" Another element is MAF/TIGER Enhancement Program which aims to improve enumeration accuracy in the traditional short-form census and help the Census Bureau introduce a mobile computer system as part of high-tech census operation. In this paper, it is pointed out that the separation of long form from short form is not an accidental one which results from the US Supreme Court decision, but the Census Bureau at this time in 2008 worries about the accuracy of enumeration because it has failed to develop a mobile computer system and will have to canvass 115 million households by paper and pencil by hiring 600 thousand temporary census workers.