• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1129-1134
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• 2006

Mass estimation was derived as functions of acceleration magnitude and primary frequency. The conventional method of mass estimation used frequency data directly in the frequency domain. The signals that can be obtained sensor contained noise as well as impact signal. Therefore, how well we can detect the frequency data in noise directly determines the quality of mass estimation. To find exact frequency data, we used time-frequency analysis. The time frequency method are expected to be more useful than the conventional frequency domain analyses for the mass estimation problem on a plate type structure. Also it has been concluded that the smoothed WVD can give more reliable means than the other methodologies for the mass estimation in a noisy environment.

• 한국소음진동공학회논문집
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• 제16권8호
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• pp.872-878
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• 2006

Mass estimation was derived as functions of acceleration magnitude and primary frequency. The conventional method of mass estimation used frequency data directly in the frequency domain. The signals that can be obtained sensor contained noise as well as impact signal. Therefore, how well we can detect the frequency data in noise directly determines the quality of mass estimation. To find exact frequency data, we used time-frequency analysis. The time-frequency methods are expected to be more useful than the conventional frequency domain analyses for the mass estimation problem on a plate type structure. Also it has been concluded that the smoothed WVD can give more reliable means than the other methodologies for the mass estimation in a noisy environment.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.238-238
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• 2010

This paper describes the design and analysis of vibration driven energy harvester for low frequency. The maximum output powers at load were $124.2{\sim}132.2\;{\mu}W$ with magnets during 3 mm input displacement at 6 Hz resonant frequency of system.

• 소음진동
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• 제10권1호
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• pp.168-173
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• 2000

This paper deals with the theoretical study on the effect of the viscosity of an adjacent viscous fluid on the characteristics of the torsional vibration of a rod with fixed-free boundary conditions. Expressions for the natural frequency and damping factor have been obtained as functions of the viscosity of the fluid by exact and asymptotic analyses. The results provide quantitative information of the natural frequency reduction and damping rate affected by the fluid viscosity.

• 복식
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• 제67권3호
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• pp.47-65
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• 2017

The purpose of this study was to divide respondents by consumption values, and to examine the differences in their cosmetic purchase behavior. Cosmetic purchase behavior consisted of variables such as purchase frequency, purchase amount, place of purchase, purchase reason, reason for using cosmetics, purchase propensity, degree of using information source, and selection criteria. A survey was conducted with 308 women between the ages 20 and 29 from December 5th to 10th 2016. Data collected from the respondents through an Internet survey were analyzed using descriptive statistics, factor analyses, cluster analysis, analyses of variance and chi-square tests. Four consumption value dimensions emerged that were termed emotional, differentiated individuality-pursuing, functional and social value. The respondents were classified into three groups(emotional consumer group, functional consumer group, active consumer group) by cluster analysis using four dimensions of consumption value. The results of the analyses of variance and chi-square tests showed significant differences in purchase frequency, place of purchase, purchase reason, reason for using cosmetics, degree of using information source and selection criteria among groups classified by consumption value. However, there were no differences in purchase amount and purchase propensity among them.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2005년도 학술발표회 논문집
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• pp.277-283
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• 2005

Inelastic model of Second Jindo Bridge is investigated to perform nonlinear dynamic analyses with various earthquake ground motions. The modal analysis is performed to obtain dynamic characteristics of the bridge and verify the model. It proves that the model has an appropriate dynamic characteristic and its natural frequency is relatively low. Four ground motions are chosen for time history dynamic analyses; El Centro, Kobe, Taft, and Mexico earthquake. Each ground motion multiplied by specified factors to investigate damages of the structure. The analyses prove that responses of the bridge depend on the duration time and the frequency characteristics of ground motion, not only peak acceleration. Static push-over analysis of steel pylon shows that the dynamic analysis over-estimates the seismic behavior of steel pylon definitely. Nonlinear spring hinge model is suggest to improve the shortage of the inelastic model could not deliberate local buckling damage. According to the time history analysis of nonlinear spring hinge model, it is proved that the inelastic beam element analysis overestimate the seismic capacity of steel pylon unquestionably with a large amount of errors.

• Archives of Pharmacal Research
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• 제29권12호
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• pp.1132-1139
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• 2006

Single nucleotide polymorph isms (SNPs) in the MDR1 gene that are responsible for drug efflux can cause toxicity. Therefore, this study determined the SNPs of the Korean MDR1 gene, and analyzed the haplotypes and a linkage disequilibrium (LD) of the SNPs determined. The frequency of 9 SNPs from the MDR1 gene was determined by PCR-RFLP analyses of 100 to 500 healthy individuals. The frequcies of the SNPs were C3435T (47.7%), G2677T (37.6%), G2677A (4.4%), T1236C (21.7%), T129C (8%), A2956G (2.5%), T307C (1.5%), A41aG (9.2%), C145G (0%), and G4030C (0%). Analyses of the haplotype structure and an estimation of the LD of the combined polymorph isms demonstrated that the frequency of the 1236T-2677G-3435T haplotype is much higher in Koreans (14.1%) than in Chinese and western black Africans and the C3435T SNP in Koreans appears to have LD with T129C in Koreans for the first time. These results provide insight into the genetic variation of MDR1 in Koreans, and demonstrated the possibility of a new LD in this gene.

• 한국해양공학회지
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• 제30권6호
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• pp.440-450
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• 2016

The capsizing and consequent sinking of a coastal car ferry was recently reported, with numerous human casualties. The primary cause was determined to be a sudden turn with improperly stowed and secured cargo. Part I of this study introduces how long term acceleration components are determined from seakeeping analyses. A carferry with a displacement of 1,633 tonf was selected as the target vessel. Sea data that included the significant wave heights and periods were collected at four observation buoys, some of which were far away from two main voyage routes: Incheon-Jeju and Pusan-Jeju. Frequency response analyses were performed to obtain the linearized radiation force coefficients, hydrostatic stiffnesses, and wave excitation forces. Time response analyses were sequentially performed to produce the motion-induced acceleration processes. The probabilistic distributions of the acceleration components were determined using a peak and valley counting method. Long term extreme acceleration components were proposed as a final result.

• Geomechanics and Engineering
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• 제29권1호
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• pp.53-63
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• 2022

Simplified analytical solutions are developed for the dynamic analyses of an axially loaded pile foundation embedded in a transverse-isotropic, fluid-filled, poro-visco-elastic soil with rigid substratum. The pile is modeled as a viscoelastic Rayleigh-Love rod, while the surrounding soil is regarded as a transversely isotropic, liquid-saturated, viscoelastic, porous medium of which the mechanical behavior is represented by the Boer's poroelastic media model and the fractional derivative model. Upon the separation of variables, the frequency-domain responses for the impedance function of the pile top, and the vertical displacement and the axial force along the pile shaft are gained. Then by virtue of the convolution theorem and the inverse Fourier transform, the time-domain velocity response of the pile head is derived. The presented solutions are validated, compared to the existing solution, the finite element model (FEM) results, and the field test data. Parametric analyses are made to show the effect of the soil anisotropy and the excitation frequency on the pile-soil dynamic responses.

• 환경영향평가
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• 제13권1호
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• pp.1-8
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• 2004

A wide spectrum of risk assessments including qualitative and quantitative approaches and the analyses of its consequence were performed for an environmentally sensitive object such as incineration facility. To find out the major risk concerns, HAZOP(Hazard and Operability) were performed. Then, the frequency of hazardous gas release scenarios was calculated. Finally consequence analyses were performed for the gas release scenarios. On the basis of analyses through evaluation, a more innovative way for making a better control system or the enhancement of operation procedure was given. The results from these analyses would act as a substantial benefits for the incineration facility operator, and giving some measured information for the neighbors and the people involved.