• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.8
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• pp.963-969
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• 2020

Cities in the region have a problem in that they cannot accurately monitor small areas because the number of air pollution is differently observed depending on variables such as population, season, traffic volume, and industrial complexes. In order to solve this problem, in this paper, comparative analysis was performed on small areas where representative air pollutants SO2, PM10, NO2, CO, and O3, which adversely affect the human body, are observed through coefficient of determination. In addition, based on Bonferroni's multiple comparative analysis, the air pollution level by period is shown. The map for the monitoring system was linked with the coordinates of each small city to visualize air pollutants for small cities based on the analysis data. Through this, it is possible to provide the user with a monitoring system of air pollutants for the region more precisely, and to prevent them from accidents that may occur due to air pollution in everyday life.

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.3
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• pp.8-13
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• 2006

It is very important for the manufacturers to predict the life of hydraulic system components according to the results of life tests. Since it takes too much time to test the hydraulic system components until failure, the no-failure test method is applied for the life test of them. If the shape parameter of Weibull distribution, the number of samples, the confidence level, and the assurance life are given, the no-failure test times of hydraulic system components can be calculated by given equation. Here, the procedures to obtain the no-failure test times of the hydraulic system components such as hydraulic motors and pumps, hydraulic cylinders, hydraulic valves, hydraulic accumulators, hydraulic hoses, and hydraulic filters are described briefly.

• Bulletin of the Korean Chemical Society
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• v.23 no.2
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• pp.179-183
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• 2002

Resonance-enhanced multiphoton ionization with time-of-flight product imaging of the $N(^2D)$ atoms has been used to study the $N_2O$ photodissociation at 118.2 nm and the two-photon dissociation at 268.9 nm. These imaging experiments allowed the determination of the total kinetic energy distribution of the $NO(X^2{\prod})$ and $N(^2D_{5/2})$ products. The $NO(X^2{\prod})$ fragments resulting from the photodissociation processes are produced in highly vibrationally excited states. The two-photon photodissociation process yields a broad $NO(X^2{\prod})$ vibrational energy distribution, while the 118.2 nm dissociation appears to produce a vibrational distribution sharply peaked at $NO(X^2{\prod},\;{\nu}=14)$.

• Food Science and Biotechnology
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• v.14 no.4
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• pp.466-469
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• 2005

Chinese cabbage (Brassica campestris L. Pekinensis) is Brassica vegetable that contains high amounts of glucosinolates. Glucosinolates and their breakdown products are thought to contribute to health promotion by preventing some cancers. Chinese cabbage is the most commonly consumed vegetable in Asian countries including Korea. In this study, qualitative and quantitative analyses of 3-butenyl glucosinolate (Gluconapin) from different cultivars and different parts of the cabbage were performed. Gluconapin of Chinese cabbage was extracted by hot ethanol ($80^{\circ}C$), isolated by an anion exchange column and identified by GC/MS and LC/MS. The levels of glucosinolates in Chinese cabbage varied according to the different parts, cultivars, and blanching time. In general, the concentrations of 3-butenyl isothiocyanate (ITC) were higher in the leaf than in the midribs parts. The cultivar 'Bulam no. 3' had a much greater content of 3-butenyl ITC than the cultivar 'Garak no. 1,' and the levels of butenyl ITC were highest after two weeks of storage. Blanching treatment decreased the concentration of 3-butenyl ITC. The ITC concentration varied extensively among different crops of the same species, and according to the different parts on the cabbage, the storage duration and the boiling time.

• Imaging Science in Dentistry
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• v.44 no.3
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• pp.199-205
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• 2014

Purpose: This study aimed to investigate the effect of changing the kilovoltage peak (kVp) on the radiographic assessment of dental caries. Materials and Methods: Seventy-five extracted posterior teeth with proximal caries or apparently sound proximal surfaces were radiographed with conventional E-speed films and a photostimulable phosphor system using 60 kVp and 70 kVp for the caries assessment. The images were evaluated by three oral radiologists and compared with the results of the stereomicroscope analysis. Results: No statistically significant difference was found between 60 kVp and 70 kVp for the caries detection, determination of caries extension into dentin, and caries severity in either the conventional or the digital images. Good to very good inter-observer and intra-observer agreements were found for both kilovoltage values on the conventional and digital images. Conclusion: Changing the kilovoltage between 60 kVp and 70 kVp had no obvious effect on the detection of proximal caries or determination of its extension or severity.

• Carbon letters
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• v.26
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• pp.43-50
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• 2018

In this research, a novel and efficient quinoline thioacetamide functionalized magnetic graphene oxide composite ($GO@Fe_3O_4@QTA$) was synthesized and utilized for dispersive magnetic solid phase preconcentration of Cd(II) and Ni(II) ions in urine and various food samples. A number of diverse methods were employed for characterization of the new nanosorbent. The design of experiments approach and response surface methodology were applied to monitor and find the parameters that affect the extraction performance. After sorption and elution steps, the concentrations of target analytes were measured by employing FAAS. The highest extraction performance was achieved under the following experimental conditions: pH, 5.8; sorption time, 6.0 min; $GO@Fe_3O_4@QTA$ amount, 17 mg; 2.4 mL $1.1mol\;L^{-l}$ $HNO_3$ solution as the eluent and elution time, 13.0 min. The detection limit is 0.02 and $0.2ng\;mL^{-1}$ for Cd(II), and Ni(II) ions, respectively. The accuracy of the new method was investigated by analyzing two certified reference materials (sea food mix, Seronorm LOT NO 2525 urine powder). The interfering study revealed that there are no interferences from commonly occurring ions on the extractability of target ions. Finally, the new method was satisfactorily employed for rapid extraction and determination of target ions in urine and various food samples.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.3
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• pp.185-195
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• 2002

Purpose This article describes the historic and clinical aspects of the determination of the vertical dimension of occlusion and the synoptic procedure of the determination of the vertical dimension of occlusion in complete denture. The determining procedure of the susceptible vertical dimension of occlusion is one of the most important steps in construction of complete denture and prosthodontic treatment. It is considered essential for the improvement and the recovery of facial esthetics and stomatognathic functions. Results Several methods have been suggested for measurement of the vertical dimension of occlusion in the construction of complete denture and the prosthodontic rehabilitation. These range from pre-extraction records to the use of physiologic rest position, swallowing, phonetics, esthetics and facial proportion, etc. But, there is no universally accepted or completely accurate method. There seems to be no significant advantages of one technique other than those of cost, time and equipment requirements, and seems to be in controversial in determining the vertical dimension. Conclusion The vertical dimension of occlusion should be determined and reinspected carefully by dentist for a successful prosthesis with several methods. The more investigations are necessary for more objective and scientific techniques in determining the vertical dimension of occlusion.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.68-74
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• 2005

Glycerol triacetate(triacetin) is the currently used common plasticizer in the making filters from cellulose acetate tow. For the mono acetate filter, the determination of triacetin contents is already established by CORESTA recommended method (No. 59). But unfortunately, the analytical method of triacetin in the activated carbon filter have not reported so far. In this study, it was established the analytical method of carbon filter's triacetin contents at various extraction conditions, bath ratio and internal standard materials. The confidential level appeared above $95\%$ when the extraction time, ISTD material and bath ratio was 3 hours, tripropionin and below 500 mg activated carbon / 50 $m\ell$ ethanol, respectively. Also, in the distribution of triacetin with filter materials in activated carbon filters, the triacetin amount was the most contained in activated carbon. Therefore, this method can be applied to the determination of triacetin contents in the activated carbon filter.

• English Language & Literature Teaching
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• v.17 no.2
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• pp.93-114
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• 2011

The aim of this study is twofold. First, this study aimed to explore how Korean university students' English learning motivation is related to their English listening proficiency and study time. Second, it attempted to interpret the English learning motivation linking the two different motivation theories: self-determination theory and L2 motivational self system. The constructs of the students' L2 learning motivation were investigated with the data obtained through the questionnaire from 122 sophomore students. A factor analysis was conducted to extract the major factors of motivation. As a result, 6 factors were extracted: Intrinsic Pleasure, Identified Value Regulation, Intrinsic Accomplishment, Introjected Regulation, External Regulation, and Identified Regulation. The Interrelatedness among the assessment results on the L2 listening proficiency (pre and post test), listening study time, and motivation factors was measured by correlation coefficients. The statistical results indicated that pre-test scores were significantly related to Identified Regulation and Identified Value Regulation toward English learning, and post-test results had significant correlation with Intrinsic Accomplishment and Identified Regulation. However, no motivation subtypes showed statistical association with the students' listening study time. The results were attempted to be interpreted both under L2 motivational self system and self-determination framework to better illuminate the motivation theory with more explanatory power.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.11
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• pp.1563-1571
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• 2003

This paper is the second part of several companion papers which compare the method of Air-fuel ratio(AFR) determination. In the previous paper, Eltinge chart was applied to the arbitrary fuel composition and the charts for gasoline, diesel, methanol, M85, liquefied petroleum gas(LPG), natural gas(NG), propane and butane were illustrated. In Eltinge chart, however, unburned hydrocarbon (UHC) is not used for determination of AFR. For improving accuracy, Eltinge suggested UHC compensation after the AFR reading in the chart. This compensation reduced the difference between real and reading value. In the compensation, however, the correction of oxygen and carbon dioxide is uncertain and there might be a mistake in conversion of UHC reading value. Therefore, the error is overestimated comparing with Spindt one which is most widely used. In addition, there is no comparison of the value with other useful methods. In this paper, the compensation of unburned HC was performed in Eltinge chart and the compensated value was compared with Spindts formula over wide range of AFR. The objects of investigating fuel are gasoline, methanol, NG and LPG. The result shows that Eltinge and Spindt method is flawlessly compatible and the difference between the two methods is under 0.3% in a λrange from 0.9 to 1.7. The method fur debugging instrumentation error is also presented.