• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.25 no.4
• /
• pp.1-7
• /
• 2002

Statistical process control is used widely as an effective tool to solve the quality problems in practice fields. All the control charts used in statistical process control are parametric methods, suppose that the process distributes normal and observations are independent. But these assumptions, practically, are often violated if the test of normality of the observations is rejected and/or the serial correlation is existed within observed data. Thus, in this study, to screening process, the Combined Shewhart - CUSUM quality control chart is described and evaluated that used bootstrap method. In this scheme the CUSUM chart will quickly detect small shifts form the goal while the addition of Shewhart limits increases the speed of detecting large shifts. Therefor, the CSC control chart is detected both small and large shifts in process, and the simulation results for its performance are exhibited. The bootstrap CSC control chart proposed in this paper is superior to the standard method for both normal and skewed distribution, and brings in terms of ARL to the same result.

• CELLMED
• /
• v.6 no.1
• /
• pp.3.1-3.4
• /
• 2016

Consumption of herbal products from the medicinal plants contaminated with heavy metals can cause serious consequences on human health. This is a major concern for traditional and herbal medicine. The present study was carried out to analyze and quantify the levels of six potentially toxic heavy metals namely arsenic, lead, cadmium, mercury, chromium and nickel in ten important Indian medicinal herbs. The air dried raw herbs were processed by microwave assisted wet digestion and analyzed by using atomic absorption spectrophotometer equipped with graphite tube atomizer. Except the chromium content in three plants, all the levels of six heavy metals analyzed were found to be quite below the permissible limits in all the ten raw medicinal herbs analyzed. The present work implies that, regular and systematic screening of raw medicinal herbs is necessary to check the levels of the heavy metal contaminants before using them for consumption or preparation of herbal formulations so that the possible contamination cannot cumulate up to the finished products.

• Journal of Korean Society for Atmospheric Environment
• /
• v.18 no.6
• /
• pp.475-485
• /
• 2002

An analytical method was investigated for the meaiiurement of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) concentrations in air samples. Procedures required for column chromatographic clean up. silicagel (stage I) and gel permeation chromatography (stage II), were discussed. Identification and quantification of PCBs and OCPs were performed using a combination of gas chromatography/mass spectrometry/ selected ion monitoring. Recovery tests calculated from six samples are 68∼137% for PCBs and 58∼130% for OCPs except for endrin aldehyde. Instrumental detection limits determined for the PCBs and OCPs varied from 0.05 to 0.18 pg/m3 and from 0.71 to 16.82 pg/㎥, respectively. The method has been applied to the analysis of air samples collected at Ansung city, Kyonggi province, Korea. This method may serve as a screening protocol for the simultaneous determination of PCBs and OCPs in air.

• Architectural research
• /
• v.24 no.2
• /
• pp.53-61
• /
• 2022

Irregularities in the structure are crucial factors in screening structural vulnerability under extreme loadings. Numerical analyses were carried out considering wind and seismic loadings for four structures with discrete irregularity: continuous and discontinuous beams with varied story levels, and L-shaped irregular buildings. Structural responses such as maximum displacements, bending moments, axial forces, torsions, and story drifts are evaluated as per the criteria and limits defined by ACI 318. The outcomes indicate that the frame system with beam discontinuity on the upper half of the height exhibits the best structural performance. The results also indicate that the asymmetrical design of the L-shaped model makes it more susceptible to damage when subjected to strong lateral loading conditions.

• Journal of Soil and Groundwater Environment
• /
• v.14 no.2
• /
• pp.45-53
• /
• 2009

A quick and simple detection method of explosive compounds in environmental matrix (soil and water) can provide a screening step which reduces the number of unnecessary samples and the cost of expensive laboratory analysis at a site investigation. A commercially available EXPRAY$^{(R)}$Explosives Field Detection Kit (EXPRAY) was used to determine the minimum detection concentration and to test the possibility of semi-quantitative analysis of 14 explosive compounds using standard solutions. The results showed that EXPRAY could detect 5 explosive compounds, TNT, RDX, HMX, Tetryl, and TNB, out of 14 US EPA designated explosives. The minimum detection limit of the nitramine explosives was 14 ng/$^2$ for HMX and RDX. EXPRAY was more sensitive to nitroaromatics than the nitramines and the minimum detection limits per unit area (mm$^2$) for Tetryl, TNB, and TNT, were 3 ng, 3 ng, and 0.3 ng, respectively. The semi-quantification of 5 explosive compounds in an order ofmagnitude could be achieved by the intensity of developed color only when EXPRAY was applied on the standard solutions under controlled laboratory conditions. With contaminated soil samples, however, only the presence and type of explosive compounds was identified. Therefore, EXPRAY is an economic and sensitive method that can be used in a screening step for the identification of explosives in the field samples.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.10 no.3 s.49
• /
• pp.125-134
• /
• 2006

Conventional methods for the assessment of liquefaction potential were primary for severe earthquake regions $(M{\geq}7.5)$ such as North America and Japan. In Korea, an earthquake related research has started in 1997, but most contents in the guidelines were still quoted from literature reviews of North America and Japan, which are located in strong earthquake region. Those are not proper in a moderate earthquake regions including Korea. Also the equivalent uniform stress concept (Seed & Idriss, 1971) using regular sinusoidal loading which is used, in a conventional method for the assessment of liquefaction potential, can't reflect correctly the dynamic characteristics of real irregular earthquake motions. In this study, cyclic triaxial tests using irregular earthquake motions are performed with different earthquake magnitudes, relative densities, and fines contents. Assessment of liquefaction potential in moderate earthquake regions is discussed based on various laboratory test results. From the results, screening limits in seismic design were re-investigated and proposed using normalized maximum stress ratios under real irregular earthquake motions. Also from the tests using constant wedge loading and incremental wedge loading, the characteristics of liquefaction resistance of saturated sand under irregular ground motions are investigated.

• Korean Journal of Veterinary Service
• /
• v.32 no.3
• /
• pp.281-286
• /
• 2009

Fluoroquinolones in muscle and egg were separated by liquid extraction and determined. The analysis was carried out using following conditions; C18 column ($150{\times}4.6mm$, $5{\mu}m$), mobile phase composed of D.W. (containing 0.4% triethylamine and phosphoric acid) : methanol : acetonitrile (780:100:120, v/v/v), quarternary pump at a flow rate of 0.9ml/min and $20{\mu}l$ of injection volume, fluorescence detector with EX 278nm/Em 456nm. The calibration range of seven fluoroquinolones showed linearity ($r^2{\geq}0.999$) at concentration range of $0.025{\sim}0.8{\mu}g/ml$. The recoveries in fortified muscle and egg represented more than 81.3%. The detection limits for ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin, saraloxacin and orbifloxacin were 3.1, 2.5, 3.6, 1.7, 0.9, 2.5 and $2.1{\mu}g/kg$, respectively. We also monitored fluoroquinolones residue in the sample (chicken muscle 182, cattle muscle 140, pig muscle 139, egg 212) using EEC-plate (E. coli ATCC 11303) screening and HPLC confirmation methods. The screening test results, fluoroquinolones, antibacterial substances were all negative.

• Korean Journal of Veterinary Service
• /
• v.28 no.3
• /
• pp.203-213
• /
• 2005

Oxytetracycline, tetracycline, chlortetracycline and doxycycline in honey were separated by solid phase extraction (SPE) and determined with high performance liquid chromatography (HPLC) with UV/Visible detector. Analysis was carried out using following conditions: XTerra $C_8$ column $(3.9\times150mm\;i.d. 5{\mu}m)$, mobile phase composed of 0.01M oxalic acid : methanol : acetonitrile (820 : 80 : 100, v/v/v), isocratic pump at a flow rate of 0.9 ml/min. and $50{\mu}l$ of injection volume, UV/Visible detector with wavelength of 360nm. The calibration curves of four tetracyclines showed linearity $(\gamma^2>0.999)$ at concentration range of $100\~1,000 ng/ml$. The recoveries in fortified honey represented more than $70\%$ with low coefficient of variation $(<10\%)$ for concentration range of four tetracyclines. The detection limits for oxytetracycline, tetracycline, chlortetracycline and doxycycline were 13.8, 14.6, 26.2 and 24.9ng/g in acacia honey. respectively. We also monitored tetracyclines residue in domestic honey [n : 38, acacia (20), wild flower (18) ] and foreign honey [n=22, legally distributed (13), illegally distributed (9)] using modified Charm II screening and HPLC confirmation methods. Seven of the 60 samples $(11.7\%)$ were suspect positive using modified Charm II screening test. Chlortetracycline residue was found in one foreign honey (illegally distributed) tested at concentrations of 0.22 ppm. Conclusively, for more effective control of tetracyclines used in beekeeping should be further survey for residues in honey and also national guidelines (maximum residue limit : MRL) and methods should be obligatory.

• Biomedical Science Letters
• /
• v.26 no.3
• /
• pp.149-156
• /
• 2020

We developed a simple and rapid method for detecting vancomycin resistance genes, such as vanA and vanB, using loop-mediated isothermal amplification (LAMP). To identify not only vancomycin resistance genes, but also the genus Enterococcus, primers were designed for vanA, vanB, and 16S rRNA. Screening for vancomycin susceptibility in Enterococcus was performed using Etest (bioMérieux Inc). The results of the LAMP assay were compared to those of real-time RT-PCR. The optimal conditions for the LAMP assay were 65℃ for 60 min. The detection limits of the LAMP assay for vanA, and vanB were 2 × 10² copies/reaction. Compared to RT-PCR, the sensitivities and specificities of LAMP for 16S rRNA, vanA, and vanB were 100/100%, 100/100%, and 100/100%, respectively. The vanA genotype-vanB phenotype accounted for 57.5% (46/80) of the vancomycin-resistant Enterococci samples collected from 2016 to 2019. In conclusion, the LAMP assay developed in this study showed high sensitivity and specificity for vancomycin-resistant genes. Moreover, due to the simplicity and rapidity of the LAMP assay, its use can be very useful in clinical microbiology laboratories.

• Korean Journal of Veterinary Service
• /
• v.31 no.1
• /
• pp.129-135
• /
• 2008

A total of 3,943 samples (beef 698, pork 2,178 and chicken 1,067)were collected from slaughter houses in Daegu from January to December 2006 for analysis of antimicrobial residues. The results were also comparatively analyzed with those carried out from 16 veterinary service laboratories nationwide as a part of national residue program in 2006. The samples from 11 farms (cattle 2, pig 9) were found to exceed the legal limit. Among them 5 were classified as tetracyclines, 3 as $\beta$-lactams, 2 as sulfonamides and 1 as quinolone. Nationally a total of 222 farms (241 cases) were found to violate the residual limits, of which 47.3% were detected by screening test, followed by surveillance (38.3%). Failure to observe withholding periods of antimicrobial drugs after treatment was the most significant cause of the non-compliance.