• 대한수학회보
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• 제48권3호
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• pp.455-468
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• 2011

We introduce the notion of refinement rings, and generalize some comparability properties of regular rings to the setting of refinement rings.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권3호
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• pp.1-9
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• 2012

According to the agreement on WTO/TBT, we are under the situation to adopt international standard (ISO standard) as a national standard if it exists. However, in case of environmental area, it is a domestic legal obligation to use Korean environmental standard method(KESM) for analyzing various contaminants. Therefore it is necessary to assess the comparability between KEM and ISO standard prior to apply ISO standard to soil conservation law in Korea. The main purpose of this study is to assess the comparability of both methods for analyzing heavy metals in soil. We looked over various aspects like pre-treatment, calibration curve range, detection wavelength, soil organic matter content and so on. Apparently, the procedure of both methods is almost same. However in details, both methods are different in stationary time before aqua-regia extraction using reflux system, calibration curve range for Cu, Pb, Ni and measuring wavelength for Pb. According to the results of comparison test, the results were significantly different when the different calibration range was used. In case that all the extracts independent of methods were reanalyzed with the same calibration range of each method, both methods showed statistically same results. Other conditions like different stationary time, measuring wavelength of AAS and soil organic matter content did not have any influence on the analytical result. Therefore, we suggest to extend the calibration curve range to 0~8 mg/L which is used in KS I ISO standard(Korean standard related with environment which is translation version of ISO standard without any technical change). In case of $Cr^{6+}$, the results showed no significant differences between two methods even though the pretreatment, instrumentation and other analysis conditions were different. In addition to UV/Visble spectrometry of KESM for soil contamination, we suggest to adopt ion chromatography of ISO 15192(US EPA method 7199) for analyzing $Cr^{6+}$ with the consideration of laboratory work efficiency.

• 가정과삶의질연구
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• 제27권3호
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• pp.213-224
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• 2009

This research aims to analyze and compare the objective and subjective evaluation criteria for home appliances. In addition, this research examined the correlation between those evaluation criteria. Furthermore, consumers are divided by the level of the differences between those criteria; consumer groups whose subjective evaluation level for the quality of home appliances is greater than objective evaluation level, consumer groups whose subjective evaluation level is almost the same, and consumer groups whose subjective evaluation level for the quality of home appliances is lower than objective evaluation level, and this study investigated the differences those three groups by the socio-demographic characteristics and consumers' behavior in the stage of purchase. Results of this research could be summarized as follows. First of all, there were statistically significant between the level of the objective and subjective evaluation in the quality of home appliances. Second, when consumers purchased the expensive home appliance, imported-brand home appliance, home appliances in department store, the level of subjective evaluation level for the quality of home appliances is higher than objective evaluation level. Third, the level of satisfaction for the price, quality, AS, overall satisfaction, and the level of willingness to repurchase were higher in consumer groups whose subjective evaluation level was higher than objective evaluation level.

• 농업과학연구
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• 제44권1호
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• pp.86-94
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• 2017

In Korea, chemical analysis of animal feed is done through authorized feed analysis laboratories (AFALs). Analysis results among the AFALs need to be similar or within acceptable variations; however, there is no experimental evidence of their comparability. We aimed to determine the level of variation of feed chemical analysis results from different AFALs. For this, we requested analysis of four kinds of feed (corn, soybean meal, corn gluten feed, and ryegrass) to eight AFALs and the Cumberland Valley Analytical Services (CVAS) which is an internationally well-recognized feed analysis laboratory. The AFALs spent more time on analysis than did CVAS. Fiber analysis results varied significantly among laboratories. However, moisture, CP, and ash content values showed almost no variation. At least one AFAL obtained results with significant differences from CVAS for all tested values. These differences can be explained by the followings: 1) the standard methods for feed analysis (SMFA) established for AFALs are not detailed enough to control the analytical variations among different laboratories and 2) guidelines are insufficient for the quality control of analysis results in Korea. Failure to accurately identify the nutritional components of the feed could mean failure to provide adequate nutrients to the animals. Therefore, efforts to reduce the differences among AFALs, such as revising SMFA and publishing guidelines on quality control of feed analysis results, are important.