• Transactions of the Society of Information Storage Systems
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• v.2 no.2
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• pp.111-116
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• 2006

The purpose of this paper is to study the effects of the flexibility of HDD base plates on spindle vibration via theoretical predictions and experimental measurements. The flexibility of the base plate can significantly affect HDD spindle vibration. This is the most prominent feature in 2.5 inch HDD. Nevertheless, theoretical analysis of the spindle vibration often neglects the flexibility of the non-rotating part including spindle, base plate, and top cover. Our theoretical model developed in University of Washington can include the flexibilities of spindle and base plate. As a result, our theoretical prediction generally agrees well with our experimental measurements in vibration analysis. Moreover, because of its small form factor, industrial practice is to use flanged disks instead of regular disks in vibration testing of prototypes. Our experimental measurements indicate that flanged disks and regular disks have very different behavior when the frequency is above 1 KHz.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.176-179
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• 2005

A case-study in classroom acoustics was conducted and the effects of two types(system air conditioner and packaged air conditioner) of air conditioner were investigated. Acoustical measurements were made in two different classrooms. Each classroom has different acoustics showing sound quality of air conditioner. Mental concentration test was conducted to evaluate the effects of air conditioner noise with different sound presure level(dBA). Speech intelligibility test was also planed with adopting Korean phonetic balanced words.

• Journal of the Korean Statistical Society
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• v.31 no.1
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• pp.93-107
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• 2002

Random effects generalised linear models are useful for analysing clustered count data in which responses are usually correlated. We propose a Bayesian approach to parameter estimation and variable selection in random effects generalised linear models for count data. A simple Gibbs sampling algorithm for parameter estimation is presented and a simple and efficient variable selection is done by using the Gibbs outputs. An illustrative example is provided.

• Journal of the korean Society of Automotive Engineers
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• v.13 no.1
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• pp.66-74
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• 1991

A multidimensional numerical simulation of turbulent combustion in a constant volume bomb is implemented to clarify the effects of swirl on combustion. This simulation includes the ICED-ALE numerical technique, the skew-upwind differencing scheme, the modified .Kappa.-.epsilon. turbulence model, and the combustion model of the Arrhenius type and the turbulence-mixing-control type. The calculations of the turbulent combustion with swirl are carried out. It shows that the results agree with the measurements allowably. Therefore, the effects of swirl on turbulent combustion are examined through the parametric study of swirl.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.3 no.1
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• pp.41-56
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• 1999

Since UV-B radiation measuring networks have not been established, numerical models which calculate the flux from other readily available meteorological measurements may play an important role. That is, such a problem can be solved by using parameterization models such as two stream approximation, the delta-Eddington method, doubling method, and discrete ordinate method. However, most UV-B radiative transfer models have not been validated with measurements, because such models are not intended as practical computational schemes for providing surface estimates of UV-B radiation. The main concern so far has been to demonstrate model sensitivity for cloudless skies. In particular, few have been concerned with real cloud information. Clouds and aerosols have generally been incorporated as constituents of particular atmospheric layers with specified optical depths and scattering properties. The parameterization model presented here is a combination of a detailed radiative transfer algorithm for a coludless sky radiative process and a more approximate scheme to handle cloud effects. The model input data requires a daily measurement of the total ozone amount plus a daily record of the amount and type of cloud in the atmosphere. Measurements for an examination of the models at the Department of Atmospheric Sciences, Pusan National University have been takenfrom February, 1995. These models can be used to calculate present and future fluxes where measurements have not been taken, and construct climatologies for the period before ozone depletion began.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.1-6
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• 2001

Additive and dominance genetic variances were estimated for purebred Landrace selected with line breeding from 1989 to 1995 at Miyazaki Livestock Experiment Station, Kawaminami Branch. Ten body measurements, two reproductive traits and fifteen carcass traits were analyzed with single-trait mixed model analysis. The estimates of narrow-sense heritabilities by additive model were in the range of 0.07 to 0.46 for body measurements, 0.05 to 0.14 for reproductive traits, and 0.05 to 0.68 for carcass traits. The additive model tended to slightly overestimate the narrow-sense heritabilities as compared to the additive and dominance model. The proportion of the dominance variance to total genetic variance ranged from 0.11 to 0.91 for body measurements, 0.00 to 0.65 for reproductive traits, and 0.00 to 0.86 for carcass traits. Large differences among traits were found in the ratio of dominance to total genetic variance. These results suggested that dominance effect would affect the expression of all ten body measurements, one reproductive trait, and nine carcass traits. It is justified to consider the dominance effects in genetic evaluation of the selected lines for those traits.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.582-589
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• 2006

Shear wane velocity is important property for grasping the dynamic characteristics of material. It is has been used in various fields such as non-destructive testings of structures, seismic analysis of geotechnical structures and maintenance of concrete structure, and etc. Usually, shear wave velocities of rock cores and concrete cylinders are determined by free-free resonance tests, Shear wave measurement in free-free resonance tests is not straightforward, as compared with rod wave and flexural wane measurements. In This study, a new technique using resonance features of flexural and shear waves were proposed in which the nodal points for the fundamental mode of flexural waves were employed to generate and measure the shear waves with the flexural waves minimized. The real measurements for aluminum cylinders proved validity and reliability of the proposed algorithm. In addition to the proposed algorithm, the effects of material properties on elastic-wave velocities in resonance measurements were also studied. In summary, a new framework of the resonance measurements for shear-wave velocity determination was established, based on the results of this thesis.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1125-1128
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• 2002

Tantalum pentoxide (Ta$_2$O$\sub$5/) is a candidate for use in metal-insulator-metal diode in switching devices for active-matrix liquid-crystal displays. The MIM diode with very low threshold voltage and perfect symmetry was fabricated. High quality Ta$_2$O$\sub$5/ thin films were obtained by using an anodizing method. Rutherford backscattering spectroscopy, transmission electron microscope observations, auger electron spectroscopy, ellipsometry measurements, and electrical measurements, such as current - voltage(I-V) measurements were performed to investigate Ta$_2$O$\sub$5/ films and their reliability and indicated that the obtained TaOx thin films were reliable Ta$_2$O$\sub$5/ films for the applications. Furthermore, in this paper, we discuss the effects of top-electrode metals and annealing conditions. The conduction mechanism of the leakage current and the symmetry characteristics related to the Schottky emission and Poole-Frankel effect are also discussed using the results of electrical measurements and conduction barrier theory.

• Structural Engineering and Mechanics
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• v.38 no.6
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• pp.715-732
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• 2011

A novel structural damage detection method with a new damage index has been recently proposed by the authors based on the statistical moments of dynamic responses of shear building structures subject to white noise ground motion. The statistical moment-based damage detection (SMBDD) method is theoretically extended in this paper with general application. The generalized SMBDD method is more versatile and can identify damage locations and damage severities of many types of building structures under various external excitations. In particular, the incomplete measurements can be considered by the proposed method without mode shape expansion or model reduction. Various damage scenarios of two general forms of building structures with incomplete measurements are investigated in consideration of different excitations. The effects of measurement noise are also investigated. The damage locations and damage severities are correctly identified even when a high noise level of 15% and incomplete measurements are considered. The effectiveness and versatility of the generalized SMBDD method are demonstrated.

• Wind and Structures
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• v.4 no.3
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• pp.247-260
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• 2001

In the last three decades several comprehensive field measurement programs have produced significant insight into the wind effects on low-rise structures. The most notable and well published of these efforts are measurements being collected at the Wind Engineering Field Laboratory (WERFL) at Texas Tech University, measurements on low-rise structures in Silsoe, England and measurements on groups of low-rise structures collected in Aylesbury, England. Complementary to these efforts, an additional full-scale field investigation program has recently collected meteorological, pressure, strain and displacement data on a low-rise structure in Southern Shores, North Carolina. To date over seventy-five hundred data sets have been collected at the Southern Shores site in a variety meteorological conditions up to and including hurricane-force winds. This paper provides details of the system, its development, and preliminary assessment of its performance. A description of the field site, the instrumented structure, and the instrumentation system is provided. In addition, an example of the data collected during three hurricanes is presented. The primary goal of this paper is to provide the reader with the necessary technical details to appropriately interpret data from this experiment, which will be presented in future publications currently under development.