• Bulletin of the Korean Space Science Society
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• 1993.04a
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• pp.16-16
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• 1993

The Cosmic Mach number M is the ratio of the bulk flow velocity of the galaxrvelocity field on some scale R to the unall scale velocity dispersion within refcions of scale R. Because M is the ratio of two velocities, it is inn-dimansionat and the Here, independent of the amplitude of the power specHim and of the biasplnmeter in the linear theory. We have measured the Mach rnlmber for two observational samples: a spiral galaxy sample(AHM) of Aaronson and hiscoBlaborators with absolute distances measured by the infrared Ttillr-Fisher relatioa and an elliptical galaxy sample(EGALS) of Faber or 0, with distances determined by the relation. The effective depths distances of galaxies from the Local Group of these samples are 1639 km/s and 2862 e/s, respectivelr. The Machnumbers from these observed peculiar velocity Selds He fund as M=0.95 for AHMand M=0.59 for EGALS. We comPBre these calculated Mach numbers with thosefrom meck surweys drawn fuom three cosnulogical medels: the stand8rd biased nh=0.5 CDM modet an open CDM rrudel with gh=0.2, and a medd with thepower-law power specelm P(k)-k-1 and n=1. The Mach rnlmber test can give robust constraints on these cosmelogical nudels whose power spectra have very different shapes at large scales.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.3
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• pp.7-13
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• 2004

In this paper, machine cell formation problem is discussed. To reflect precisely actual manufacturing situations such as routing sequences, production quantities, and machining (or operation) characteristics, a new network presentation (or the problem is proposed. It is formulated as a simple 0-1 quadratic programming model with linear constraints. Then, the model is converted into a 0-1 integer programming model using a variable transformation technique. Lastly, some computational results are presented.

• Journal of the Korean Home Economics Association
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• v.42 no.12 s.202
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• pp.231-251
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• 2004

The purpose of this study us to determine the adolescents' leisure activity pattern, leisure constraints and leisure satisfaction and to identify the relevant variables. The subjects were middle and high school students. The data was collected by using the questionnaire and the final 741 cases were analyzed by SPSS Win 10.0 program. The major findings were as follows: 1. The adolescents' leisure activity hours were 2.27hours/day(weekday), 4.20hours/day(Saturday) and 5.35hours/day(Sunday). On weekdays, female students spent more time for leisure activity than male students. The most frequent activities were watching TV and playing computer. 2. The adolescents' leisure constraints were social-economic, psychological and situational. The degree of the adolescents' situational constraint was the highest. 3. The adolescents' leisure satisfactions were leisure use, leisure condition and leisure meaning. The adolescents' degree of leisure meaning satisfaction was relatively high. 4. The major related variable influencing the leisure satisfaction were psychological constraint, situational constraint and gender.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.309-313
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• 2015

If the present universe is slightly open then pre-inflation curvature would appear as a cosmic dark-flow component of the CMB dipole moment. We summarize current cosmological constraints on this cosmic dark flow and analyze the possible constraints on parameters characterizing the pre-inflating universe in an inflation model with a present-day very slightly open ${\Lambda}CDM$ cosmology. We employ an analytic model to show that for a broad class of inflation-generating effective potentials, the simple requirement that the observed dipole moment represents the pre-inflation curvature as it enters the horizon allows one to set upper and lower limits on the magnitude and wavelength scale of pre-inflation fluctuations in the inflaton field and the curvature parameter of the pre-inflation universe, as a function of the fraction of the total initial energy density in the inflaton field. We estimate that if the current CMB dipole is a universal dark flow (or if it is near the upper limit set by the Planck Collaboration) then the present constraints on ${\Lambda}CDM$ cosmological parameters imply rather small curvature ${\Omega}_k{\sim}0.1$ for the pre-inflating universe for a broad range of the fraction of the total energy in the inflaton field at the onset of inflation. Such small pre-inflation curvature might be indicative of open-inflation models in which there are two epochs of inflation.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.459-468
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• 2011

This study was to analyze the relationship of leisure constraint, boredom and satisfaction among the private security agents. To attain the goal of this study, the employee of private security organization located in Seoul, 2011 year were sampled 400 peoples by purposive sampling method. The result of reliability check up was here below; over Cronbach's ${\alpha}$=.587. To analyze materials, reliability analysis, factor analysis, T test and F test, multiple regression analysis and path analysis were used as statistic analysis techniques. The conclusion are here below. First, leisure constraints, boredom and satisfaction have a difference in demographic and socio-economic characteristics. Second, leisure constraints influence on the leisure boredom. Third, leisure constraints influence on the leisure satisfaction. Fourth, leisure constraints influence directly, indirectly on leisure boredom and satisfaction. Leisure boredom is very important variable connecting leisure constraints and satisfaction.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.6
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• pp.755-760
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• 2010

In general, Lagrangian method for discrete optimization is a kind of technique to easily manage constraints. It is traditionally used for finding upper bounds in the branch-and-bound method. In this paper, we propose a new Lagrangian search method for the 0-1 knapsack problem with multiple constraints. A novel feature of the proposed method different from existing Lagrangian approaches is that it can find high-quality lower bounds, i.e., feasible solutions, efficiently based on a new property of Lagrangian vector. We show the performance improvement of the proposed Lagrangian method over existing ones through experiments on well-known large scale benchmark data.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.242-251
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• 2015

The purpose of this study was to explore leisure constraints and the strategies to overcome leisure constraints of career women, and to examine the difference in leisure constraints and leisure constraints negotiation strategies between married and unmarried career women. In Seoul, a total of 440 career women selected using the cluster quota sampling method participated in the current study. Finally, 433 responded data with the exception of 7 unreliable surveys were employed for the analyses such as frequency, exploratory factor, reliability analysis, and t-test. Main findings were as follows; First, six factors including interpersonal, intrapersonal, time, expense and information, environmental, and physical constraints were extracted for career women. Environment and time commonly constrained their participation in leisure activities the most. Second, five factors including skill acquisition, finding alternative activity, control intensity, finding partners, and financial and time management strategies were extracted for them. Third, there were the differences in time and physical constraints between two groups and married career women's constraints were higher than singles. Finally, there was the difference in skill acquisition strategy and married career women's it was higher than the other group.

• The Journal of the Acoustical Society of Korea
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• v.40 no.5
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• pp.503-514
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• 2021

Reverberation in speech signals tends to significantly degrade the performance of the Blind Source Separation (BSS) system. Especially in online systems, the performance degradation becomes severe. Methods based on joint diagonalizability constraints have been recently developed to tackle the problem. To improve the quality of separated speech, in this paper, we add the proposed de-reverberation method to the online BSS algorithm based on the constraints in reverberant environments. Through experiments on the WSJCAM0 corpus, the proposed method was compared with the existing online BSS algorithm. The performance evaluation by the Signal-to-Distortion Ratio and the Perceptual Evaluation of Speech Quality demonstrated that SDR improved from 1.23 dB to 3.76 dB and PESQ improved from 1.15 to 2.12 on average.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.6 s.261
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• pp.686-693
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• 2007

To perceive body movement, the nervous system uses multi-sensory cues such as vision, vestibular signals, and somatosensation. Among the multi-sensory modality, the previous researchers reported that the lower limb somatosensation plays an important role on maintaining postural balance. In this study, we examined the contribution of somatosensory cues to linear motion perception by measuring the detection threshold of the direction of linear motion with and without lower limb somatosensory constraints. Six healthy male volunteers participated in randomly ordered 33 single sinusoidal acceleration trials with the stimulus at 0.25Hz with peak magnitude ranged from 0 to 8mG. After each stimulus, subjects reported their perceived direction of motion by button press. Results showed that the reduced lower limb somatosensation significantly increased perception threshold. Without constraints, mean threshold was $0.82{\pm}0.23mG$, while it was $1.23{\pm}0.35mG$ with reduced lower limb somatosensation. The results suggest that without visual cues, perception of the movement direction strongly depends on the lower limb somatosensory information.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.192-198
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• 2016

The distributions of (or constraints for) amplitude and phase around C-points, including Lemon, Mon-Star and Star, are studied. A Cartesian coordinate system with origin at the C-point is established. Four curves, where the azimuthal angles of polarization ellipses are 0°, 45°, 90°, and 135° respectively, are used to determine the distributions. Discussions of these constraints illustrate why Mon-Star is rarer than Lemon or Star in experiments. The transformation relationships between these three polarization singularities (PSs) are also discussed. We construct suitable functions for amplitude and phase according to their constraints, and simulate several PSs of particular shapes. With the development of modulation techniques for amplitude and phase, it is clear that this work is helpful for generating arbitrarily shaped C-points in experiments.