• Nuclear Engineering and Technology
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• v.54 no.2
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• pp.462-468
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• 2022

The selection and effective utilization of peak-fitting software for conventional gamma-ray spectrum analysis is significant for accurate determination of the mass fraction of elements, particularly in complex peak regions. Majority of the peak-fitting programs can derive similar peak characteristics for singlet peaks, but very few programs can deconvolute multi-peaks in a complex region. The deconvolution of multi-peaks requires special peak-fitting functions, such as left and right-skew distributions. In the this study, 843.76 keV (²⁷Mg) peak area from the complex region (840 keV-850 keV) determined and compared using four different peak-fitting programs, namely, GammaVision, Genie2000, HyperLab, and HyperGam. The 843.76 keV peak interfered with 841.63 keV (^152mEu) and 846.81 keV (⁵⁶Mn). The total Mg concentration was determined through k₀-instrumental neutron activation analysis by applying the isotopic interference correction factor ²⁷Al(n,p)²⁷Mg through the simultaneous determination of Al concentration. HyperLab and HyperGam peak-fitting programs reported consistent peak areas, and resultant concentrations agreed with the certified values of matrix-certified reference materials.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.10a
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• pp.180-186
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• 1996

Using carbon steel or ceramic as a shaft material of monolithic and slited insert ring clamped on it. The fitting strengths of the sgrink fitted assemblies measured from room temperature to 30$0^{\circ}C$ and following conclusions were obtained as results of this investigation. 1) The fitting condition under which the shrink fitted assemble was stronger than that using simple fit in high temperature. 2) When both material of the 30mm-diameter shaft and 55mm-diameter boss are SM45C the clamping torque is increased 2.7times as the interference increases 3 times from 20${\mu}{\textrm}{m}$ at the contact length of 6mm monolithic fit. 3) When only the material of boss is changed to STS 304 the clamping torque is increased at the rate of 37.3N.m per 1mm increase of the contact length at the interference of 50${\mu}{\textrm}{m}$ monolithic fit.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.91-94
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• 2012

Arrayed waveguide grating (AWG) phase errors are normally assessed from the Fourier transform of the interference intensity data in the frequency domain method. However it is possible to identify the phases directly from the intensity data if one adopts a trial-and-error method. Since the functional form of the intensity profile is known, the intensities can be calculated theoretically by assuming arbitrary phase errors. Then we decide the phases that give the best fit to the experimental data. We verified this method by a simulation. We calculated the intensities for an artificial AWG which is given arbitrary phases and amplitudes. Then we extracted the phases and amplitudes from the intensity data by using our trial-and-error method. The extracted values are in good agreement with the originally given values. This approach yields better results than the analysis using Fourier transforms.

• Current Optics and Photonics
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• v.7 no.5
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• pp.518-528
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• 2023

As an effective means of remotely detecting the spectral information of the object, the spectral calibration for the Savart polarization interference imaging spectrometer (SPIIS) is a basis and prerequisite of information quantification, and its experimental calibration scheme is firstly proposed in this paper. In order to evaluate the accuracy of the spectral information acquisition, the linear interpolation, cubic spline interpolation, and piecewise cubic interpolation algorithms are adopted, and the precision of the quadratic polynomial fitting is the highest, whose fitting error is better than 5.8642 nm in the wavelength range of [500 nm, 820 nm]. Besides, the inversed value of the spectral resolution for the monochromatic light is greater than the theoretical value, and the deviation between them becomes larger with the wavelength increasing, which is mainly caused by the structural design of the SPIIS, together with the rationality of the spectral restoration algorithm and the selection of the maximum optical path difference (OPD). This work demonstrates that the SPIIS has achieved high performance assuring the feasibility of its practical use in various fields.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.205-215
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• 2015

Common mode (CM) conducted interference are predicted and compared with experiments in a motor drive system of Electric vehicles in this study. The prediction model considers each part as an equivalent circuit model which is represented by lumped parameters and proposes the parameter extraction method. For the modeling of the inverter, a concentrated and equivalent method is used to process synthetically the CM interference source and the stray capacitance. For the parameter extraction in the power line model, a computation method that combines analytical method and finite element method is used. The modeling of the motor is based on measured date of the impedance and vector fitting technique. It is shown that the parasitic currents and interference voltage in the system can be simulated in the different parts of the prediction model in the conducted frequency range (150 kHz-30 MHz). Experiments have successfully confirmed that the approach is effective.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.219-223
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• 2005

In this work, a hybrid composite proceeding bearing (HCJB) composed of carbon/phenolic laminated composite bush and steel housing was designed for marine vessels because the composite proceeding bearing reduces the possibility of the seizure problem between the proceeding and bearing. The two components of bearing were assembled by interference fit joining method and a series of durability tests were conducted using the laboratory bench with the lubricants of SAE 30 oil, water, and sea water. That the HCJB was found reliable under the interference fitting loads and environmental temperature change.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.57-59
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• 2003

Shrink fitting is often used to constrain a conventional mechanical fasteners and fastening methods with temperature difference. Localized heating of the mating surface provides temporary expansion and allows slip fit assembly. The resulting interference fit exhibits exceptional strength without surface deformation at ambient temperatures. We studied an analysing method to find out a deformation of motor axis as variation of constrained method with shrink fitting.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.25-29
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• 2004

Corona on polymer materials causes deterioration by the combined action of the discharge striking the surface and the action of certain chemical compounds that are formed by the discharges. In the design and manufacture of polymer insulators must be sufficiently large to avoid corona discharges, otherwise a shielding or corona ring (grading ring) needs to be installed on the insulator. To conduct this purpose, many researchers have investigated end-fitting of polymer insulator by voltage distribution simulation and electrical test. Grading rings are used to improve the performance of the insulator in multiple ways. They can reduce corona and associated audible noise and radio influence and television interference. The factors determining the uses of a grading ring are line voltage, geometry and dimensions of end fittings, geometry and dimensions of line hardware, and environmental conditions. In this paper, electrical property of polymer insulator with end-fitting design have been investigated by electrical field analysis, various end-fitting design, tracking wheel test, corona inception voltage and extinction voltage. Electrical field analysis is conducted by FEM program and various end-fitting is designed through this result. Designed end-fittings are manufactured and their performance is conducted by electrical performance test.

• Transactions of Materials Processing
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• v.17 no.6
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• pp.407-411
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• 2008

A brake system in automobile is one of the important parts that directly affect the safety of passengers. Particularly, disk brake module is applied to almost all kinds of automobile brake system due to its remarkable braking power and braking distance. In the disk brake module of an automobile, the bolt for tire wheel is assembled to the disk brake hub by interference fit(bolt pressing process). The process induces small deformation whose range is within tens of ${\mu}m$ and this deformation may cause the runout badness of the whole disk brake module, and even braking problems such as judder or squeal phenomena which makes the loss of braking efficiency. In this study, bolt pressing fit into hub was simulated by $ANSYS^{TM}$, a commercial structure analysis program. Also, the aspect and the cause of hub displacement were analyzed and the solution for decreasing runout of hub was proposed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.6C
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• pp.551-559
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• 2005

Estimation of unknown signal parameters with sensor array measurements has been investigated quite extensively. Also, there has been in recent years an explosive increase in the number of mobile users in wireless cellular systems, thus contributing to growing levels of multi-user interference. To overcome this problem, application of adaptive antenna array techniques to further increase the channel capacity has been discussed. In this paper, a new model of locally scattered signals in the vicinity of mobiles is proposed by defining the mean steering vector and is manipulated mathematically for several distributions. Under this model an estimation method of the angle of arrival(AOA) is investigated based on a weighted subspace fitting(WSF) technique. Statistical analysis and simulations are also considered.