• Analytical Science and Technology
• /
• v.8 no.4
• /
• pp.707-714
• /
• 1995

Two types of regularization method (singular system and HMP approaches) for generating depth-concentration profiles from angle-resolved XPS data were evaluated. Both approaches showed qualitatively similar results although they employed different numerical algorithms. The application of the regularization method to simulated data demonstrates its excellent utility for the complex depth profile system. It includes the stable restoration of the depth-concentration profiles from the data with considerable random error and the self choice of smoothing parameter that is imperative for the successful application of the regularization method. The self choice of smoothing parameter is based on generalized cross-validation method which lets the data themselves choose the optimal value of the parameter.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.13 no.3
• /
• pp.34-42
• /
• 2005

The objectives of the study are to present simple physical and mathematical models of liquid fuel in the tank of an aerospace vehicle such launch vehicle or missile and to investigate its dynamic stability for a parameter space. In this paper, liquid in the container is modeled as multi-mass system subject to parametric excitations, and a stability diagram for determination of stable-unstable regions of the motion is obtained by using an analytical method. Also, computer simulations are conducted at various parameter points to verify the analytical results, and time histories of motion are compared to explain the effect of variation of parameters of the system.

• New Physics: Sae Mulli
• /
• v.68 no.12
• /
• pp.1331-1337
• /
• 2018

We present a three-parameter phase shift model whose form is the same as that of Coulombmodified Glauber model obtained from Gaussian nuclear densities. This model is applied to the $^6Li+^{12}C$ and the $^6Li+^{28}Si$ elastic scatterings at $E_{lab}=318MeV$. The calculated differential cross sections provide quite a satisfactory account of the experimental data. The diffractive oscillatory structures observed at forward angles can be explained as being due to the strong interference between the near-side and the far-side scattering amplitudes. The optical potentials for two systems are predicted by using the method of inversion. The calculated inversion potentials are found to be in fairly good agreements with the results determined from the optical model analysis in the surface regions around the strong absorption radius. We also investigate the effects of parameters in the three-parameter phase shift model on the elastic scattering cross sections.

• Bulletin of the Korean Chemical Society
• /
• v.17 no.8
• /
• pp.707-712
• /
• 1996

Growth and changes of electronically conducting polypyrrole (PPy) in the form of thin films polymerized on metal electrodes were investigated by electrochemical and in situ three-parameter ellipsometry methods at the wavelength of 632.8 nm. Although the optical equations produced multiple sets of solution, it was possible to determine a unique set of thickness and the optical constants of a film by auxiliary measurements and/or physical reasoning. The changes in the thickness and the optical properties of the polymers during polymerization and electrochemical oxidation/reduction was successfully followed by the three-parameter ellipsometric technique. The optical properties of the polymers continuously changed as the film grew. The imaginary part of the refractive index of polypyrrole seemed to be dominantly determined by the existence of an absorption band around the visible range.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.1117-1126
• /
• 1993

Physical parameters in the forward direction of the tractor , which mainly affects the vibration characteristics of the tractor dynamic model, were able to be identified in a short time by using the Gauss-Newton method with extremum searching based on the data obtained from a forced vibration experiment. It was clarified that a period for the updating of the parameter estimates method has effects on the convergence accuracy of identification for the spring constant in the forward direction of the tractor.

• Structural Engineering and Mechanics
• /
• v.90 no.5
• /
• pp.459-466
• /
• 2024

Eringen's nonlocal thermoelasticity theory is used to study wave propagations in a rotating two-temperature thermoelastic half-space with temperature-dependent properties. Using suitable non-dimensional variables, the harmonic wave analysis is used to convert the partial differential equations to ordinary differential equations solving the problem. The modulus of elasticity is given as a linear function of the reference temperature. MATLAB software is used for numerical calculations. Comparisons are carried out with the results in the context of the dual-phase lag model for different values of rotation, a nonlocal parameter, an inclined load, and an empirical material constant. The distributions of physical fields showed that the nonlocal parameter, rotation, and inclined load have great effects. When a nonlocal thermoelastic media is swapped out for a thermoelastic one, this approach still holds true.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.8 no.3
• /
• pp.57-70
• /
• 2008

This paper introduces a new paradigm of physical layer security through channel coding for wireless networks. The well known spread spectrum based physical layer security in wireless network is applicable when code division multiple access (CDMA) is used as wireless air link interface. In our proposal, we incorporate the proposed security protocol within channel coding as channel coding is an essential part of all kind of wireless communications. Channel coding has a built-in security in the sense of encoding and decoding algorithm. Decoding of a particular codeword is possible only when the encoding procedure is exactly known. This point is the key of our proposed security protocol. The common parameter that required for both encoder and decoder is generally a generator matrix. We proposed a random selection of generators according to a security key to ensure the secrecy of the networks against unauthorized access. Therefore, the conventional channel coding technique is used as a security controller of the network along with its error correcting purpose.

• The Journal of Korean Physical Therapy
• /
• v.25 no.6
• /
• pp.399-404
• /
• 2013

Purpose: To investigate the effects of initiation side on gait symmetry in the chronic stroke patients. Methods: Twenty one patients with independent gait after stroke were divided into the paretic-leg gait initiation group (PLI) and the nonparetic-leg gait initiation group (NPLI). The symmetry ratio (SR) was calculated from of the spatiotemoral and kinematic parameter which measured by 3D motion analysis. Results: In the spatiotemporal variables, SR-step length and SR-velocity was significantly different between groups (p<0.05). In the kinematic variables, SR-TOAA and SR-SwPAA of the hip joint was significantly different between groups (p<0.05). Conclusion: We suggest that the initiating leg may influence on the gait symmetry of stroke patient These results will be a helpful reference in hemiplegic gait training or intervention.

• The Bulletin of The Korean Astronomical Society
• /
• v.38 no.2
• /
• pp.35.2-35.2
• /
• 2013

I will present a new approach to constrain galaxy physical parameters from the combined interpretation of stellar and nebular emission in wide ranges of observations. This approach relies on a comprehensive library of synthetic spectra, assembled using state-of-the-art models of star formation and chemical enrichment histories, stellar population synthesis, nebular emission and attenuation by dust. We focus on the constraints set by 5-band photometry and low- and medium-resolution spectroscopy at optical rest wavelengths on a few physical parameters characterizing the stars and interstellar medium. Since these parameters cannot be known a priori for any galaxy sample, we assess the accuracy to which they can be retrieved by simulating 'pseudo-observations' using models with known parameters. We find that the combined analysis of stellar and nebular emission in low-resolution (50A FWHM) galaxy spectra provides valuable constraints on all physical parameters. The approach can be extended to the analysis of any type of observation and during this talk i will present some applications to observed galaxies up to redshift 1.5.

• KIEAE Journal
• /
• v.8 no.1
• /
• pp.31-36
• /
• 2008

For the comfortable housing life, comfortable and pleasant urban environment should be created for the people living in house and in city. There are lots of environmental conditions in city affecting house and life. Also most of all the noise pollution have been become major factor that makes people's life uncomfortable. Recently soundscape researches have been performed to create comfortable urban environment and various studies on the evaluation of urban environmental sounds are now undergoing. This study aimed to analyse the subjective characteristics through the subjective evaluation to the sounds measured with physical parameters and eventually to find out alternative evaluation method for urban environmental sounds. Adjectives applied to previous studies were used for the subjective evaluation and sound sources recorded in specific places were presented with picture at the same time. As a result, new physical parameters such as Lmax, Unbiased Annoyance, G, N and EmT have a feasibility to evaluation of urban environment sounds in terms of acoustic comfort.