• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.5 s.248
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• pp.528-532
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• 2006

In the aerospace industry, Cold expansion has been used the most important method that is retarded of crack initiation from fastener hole surface. Cold expansion method(CEM) is that a oversized tapered mandrel goes through the hole in order to develop a compressive residual stress as the passing of the mandrel around the hole. Therefore, because of characteristic of mandrel inserting, Residual Stress Distributions (RSD) are differently generated form Entry, Mid and Exit position of the plate. Also, it is respected that RSD are changed as distances between holes. In this paper, It is performed a FE analysis of RSD by CEM and it is respectively shown RSD in the Entry, Mid and Exit position. It is compared residual stress results form the cold expansion in these two cases: the concurrent CEM and the sequential CEM. From this research, it has been found that compressive residual stress of Entry position is lower than other positions. Also, the concurrent CE of adjacent holes leads to much higher compressive residual stress than the sequential CE. In addition, in the sequential CE case, a compressive RSD of 1 step's hole around is lower than compressive RSD of 2 step's hole around.

• Bulletin of the Korean Mathematical Society
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• v.38 no.1
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• pp.137-142
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• 2001

In this paper, we initiate the study of some annihilator conditions on polynomials which were used by Kaplansky [4] to abstract algebras of bounded linear operators on a Hilbert spaces with Baer condition. On the other hand, p.p. rings were introduced by A. Hattori [3] to study the torsion theory. The purpose of this paper is to introduce near-rings with Baer condition and near-rings with p.p. condition which are somewhat different from the ring case, and to extend a results of Armendarz [1] to polynomial near-rings with Baer condition in somewhat different way of Birkenmeier and Huang [2].

• Analytical Science and Technology
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• v.25 no.4
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• pp.223-229
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• 2012

Analytical signal from ICP was compensated by the light scattering of sample aerosols. Reference scattering signal was generated by a He-Ne or diode laser, monitored for the amount of aerosol producing and used for the compensation of analytical signals. The result showed that significant improvement in precision could be achieved for the short-term signal (within 1 minute) from 3.4% to 0.9% RSD in signal and 14.9% to 4.2% for the long-term (10 minutes) for Be, Pb and Co. This method is very useful not only for the pulse type but for continuous type signals especially when a nebulizer is unstable. To improve long-term precision, higher stability is required in the scattering cell and detector as well as the reduction of noise from the line between a nebulizer and plasma.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.11
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• pp.5436-5458
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• 2017

Automatic Video Surveillance System (AVSS) has become important to computer vision researchers as crime has increased in the twenty-first century. As a new branch of AVSS, baggage detection has a wide area of security applications. Some of them are, detecting baggage in baggage restricted super shop, detecting unclaimed baggage in public space etc. However, in this paper, a detection & classification framework of baggage is proposed. Initially, background subtraction is performed instead of sliding window approach to speed up the system and HSI model is used to deal with different illumination conditions. Then, a model is introduced to overcome shadow effect. Then, occlusion of objects is detected using proposed mirroring algorithm to track individual objects. Extraction of rotational signal descriptor (SP-RSD-HOG) with support plane from Region of Interest (ROI) add rotation invariance nature in HOG. Finally, dynamic human body parameter setting approach enables the system to detect & classify single or multiple pieces of carried baggage even if some portions of human are absent. In baggage detection, a strong classifier is generated by boosting similarity measure based multi layer Support Vector Machine (SVM)s into HOG based SVM. This boosting technique has been used to deal with various texture patterns of baggage. Experimental results have discovered the system satisfactorily accurate and faster comparative to other alternatives.

• Analytical Science and Technology
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• v.31 no.6
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• pp.240-246
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• 2018

The present study analyzed standard samples of three types of aluminum matrix certified reference materials (CRM) using GD-MS. Calibration curves were constructed for 13 elements (Mg, Si, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Sn, and Pb), with the slope representing the relative sensitivity factor (RSF). The x- and y-axes of the calibration curve represented ion beam ratio (IBR) and the authenticated value of the standard sample, respectively. In order to evaluate precision and linearity of the calibration curve, RSD and the coefficient of determination were calculated. Curve RSD for every element reflected high precision (within 10 %). For most elements, the coefficient of determination was ${\geq}0.99$, indicating excellent linearity. However, vanadium, nickel, and gallium curves exhibited relatively low linearity (0.90~0.95), likely due to their narrow concentration ranges. Standard RSF was calculated using the slope of the curve generated for three types of CRM. Despite vanadium, nickel, and gallium exhibiting low coefficients of determination, their standard RSF resembled that of the three types of CRM. Therefore, the RSF method may be used for element quantitation. Standard iron matrix samples were analyzed to verify the applicability of the aluminum matrix standard RSF, as well as to calculate the RSD-estimated error of the measured value relative to the actual standard value. Six elements (Al, Si, V, Cr, Mn, and Ni) exhibited an RSD of approximately 30 %, while the RSD of Cu was 77 %. In general, Cu isotopes are subject to interference: $^{63}Cu$ to $^{54}Fe^{2+}-^{36}Ar$ and $^{65}Cu$ to $^{56}Fe-Al^{3+}$ interference. Thus, the influence of these impurities may have contributed to the high RSD value observed for Cu. To reliably identify copper, the resolution should be set at ${\geq}8000$. However, high resolutions are inappropriate for analyzing trace elements, as it lowers ion permeability. In conclusion, quantitation of even relatively low amounts of six elements (Al, Si, V, Cr, Mn, and Ni) is possible using this method.

• Journal of the Korean Society of Radiology
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• v.10 no.8
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• pp.597-602
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• 2016

Recent clinical field utilizes the aluminium filter in order to reduce the low-energy photons. However, the usage of the filter can cause adverse effect on the image quality because of the scattered dose that is generated by X-ray hardening phenomenon. Further, usage of filter with improper thickness can be a reason of dose creep phenomenon where unnecessary exposure is generated towards the patient. In this study, the author evaluated the RMS and the RSD analysis in order to have a quantitative evaluation for the effect of forward scattering dose by the filter on the image. as a result of the study, the FSR and the RSD was increased together with the increasing of thickness of the filter. In this study the RSD means the standard deviation of the mean value is relatively size. It can be understood that the signal-to-noise ratio decreases when the average value is taken as a signal and the standard deviation is judged as a noise. The signal-to-noise ratio can understanding as index of resolution at image. Based on these findings, it was quantitatively verified that there is a correlation of the image quality with the FSR by using an additional filter. The results, a 2.5 mmAl which is as recommended by NCRP in the tube voltage of 70 kVp or more showed the 14.6% on the RSD when the filter was not in used. these results are considered able to be utilized as basic data for the study about the filter to improve the quality of the image.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.4
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• pp.339-349
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• 1995

The purpose on this study is to optimize the chromatographic determination method of trace aldehydes in ambient air. Carbonyl compounds in urban air were trapped at $C_{18}$ DNPH-coated cartridges, and generated hydrazone derivatives were separated by HPLC and detected by UV-vis spectroscopic detector at 360nm. Formaldehyde and acetaldehyde compounds could be isolated from urban(Seoul) air with more than 95% collection efficiency. The analytical detection limits for formaldehyde and acetaldehyde are 0.06pp $b_{v}$, 0.08pp $b_{v}$ for 108 L air samples, respectively. The precision of this method are 3 .sim. 4%(RSD) for mutiple injection of hydrazone standards. Separation of seven dinitrophenylhydrazones could be achieved in appoximately 20 minutes operation time using $C_{18}$ column with apprepriate eluent. The method was applied to the analysis of aldehydes and ketone in Seoul ambient air. The 24-h ambient levels of formaldehyde, acetaldehyde reached up to 6 .sim. 14 and 3 .sim. 8ppbv, respectively. The daily average concentration ratio were 0.60 for acetaldehyde/formaldehyde.yde.

• Analytical Science and Technology
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• v.28 no.2
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• pp.79-85
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• 2015

A preliminary experiment was performed to develop a fast, convenient, and economical semi-quantitative method of analyzing amphetamine-like amines from images of derivatives. These were generated from the reaction (in situ, co-spot) of three amphetamine-like compounds with three derivatization reagents on a TLC plate. The attempt was made to optimize the reaction conditions for an efficient derivatization reaction, and TLC images taken by a digital camera were analyzed using two types of image analysis program (CP Atlas 2.0 and ImageJ) for repeatability (RSD, %) and linearity (R²). Then, their results were compared. For efficient derivatization, the reaction conditions needed to be modified. The results of image analysis of each of the samples at two different concentrations (0.5 mg/mL and 0.01 mg/mL) showed that the RSD values for reaction repeatability were in the range of 0.69-5.50%. From the calibration curves between the area of the derivative and the concentration of amines, the R² values (R² > 0.9906) for good linear correlation were found to be high, in a concentration range of 0.1-0.005 mg/mL of amines. In addition, the two programs demonstrated little difference in the analysis of repeatability and linearity of the derivatization, so that the current method has the potential to be used for the semi-quantitative analysis of amines.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.1
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• pp.24-31
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• 1994

Hourly variation of gaseous nitrous acid( HNO$_2$) concentration in Seoul air was monitored from Jan. 11 to SeP. 12, Nitrous acid concentration was determined by DS/IC over nine months of observation, HNO$_2$ range from 0.04 ppb to 5.5 ppb. Gor-tex tube as gaseous HNO$_2$generator in this study is thought to be more convenient and reproducible device than previous generator. As a result of NaOH instead of Na$_2$ CO$_3$/NaHCO$_3$ solution as the IC eluent, we could obtain more stable baseline. The concentration of the NaOH eluent was 15 mM . The limit of detection(3$\sigma$) of the liquid- Phase and gas phase nitrous acid of this method are 1.1ng/$m\ell$ , 0.04 n $\ell$ / $\ell$, respectively. The precisions evaluated by 10 replicate analysis of standard solution and standard gas generated are $\pm$1.59, $\pm$2. 89% RSD, respectively. Due to the lack of standard material for air, direct assessment of the accuracy was not possible. This study was applied to the analysis of Seoul ambient air and their results are reported herein.

• Carbon letters
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• v.8 no.3
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• pp.191-198
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• 2007

Recent studies have revealed the poisonous nature of aluminum(III) species to aquatic and terrestrial organisms. Therefore, this investigation aims to develop batch adsorption experiments in the laboratory, aiming to the removal of aluminum(III) from aqueous solutions onto powdered activated carbon (PAC). The latter (which is an effective and inexpensive sorbent) was prepared from olive stones generated as plant wastes and modified with an aqueous modifying oxidizing agent, viz. $HNO_3$. The main parameters (i.e. initial solution pH, sorbent and $Al^{3+}$ ions concentrations, stirring times and temperature) influencing the sorption process were examined. The results obtained revealed that the sorption of $Al^{3+}$ ions onto PAC is endothermic in nature and follows first-order kinetics. The adsorption data were well described by the Langmuir, Freundlich and Dubinin-Radushkevich (D-R) adsorption models over the concentration range studied. Under the optimum experimental conditions employed, the removal of ca. 100% $Al^{3+}$ ions in the concentration range $1.35-2.75\;mg{\cdot}l^{-1}$ was attained. Moreover, the procedure was successfully applied to the recovery of aluminum spiked to some environmental water samples with an RSD (%), does not exceed 1.22%.