• Journal of Educational Research in Mathematics
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• v.20 no.3
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• pp.241-254
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• 2010

Under the consideration of Chinese math education tradition and new educational orientation, we compared and analyzed Korea and China's lower-grade elementary school textbooks. The result was that Chinese textbook puts much emphases on practice, skill and repetition, presents condensed contents, provides various learning contents simultaneously, rich humorous expressions, and a lot of implicit representations. From these results, we presented some implications for our mathematics education, future textbook writing, and the follow-up studies.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.15 no.1
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• pp.1-3
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• 1979

The sand-eel, Ammodytes personatus GIRARD, "Kka-na-ri" is an important commercial fish inhabiting the coastal waters of Korea. The numbers of vertebrae (except urostyle) waR statistically analysezed based on the samples collected at three major fishing localitie" Jumunjin (East Sea), Geoje Island (southern coast) and Baegryeong Island (Yellow Sea) from May 1978 to June 1979. It was found that there was a very distinct difference in the numbers of vertebrae in the samples.rae in the samples.

• Food Science and Biotechnology
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• v.16 no.3
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• pp.337-342
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• 2007

Conventional methods for pathogen detection and identification are labor-intensive and take days to complete. Biosensors have shown great potential for the rapid detection of foodborne pathogens. Fiber-optic biosensors have been used to rapidly detect pathogens because they can be very sensitive and are simple to operate. However, many fiber-optic biosensors rely on manual sensor handling and the sandwich assay, which require more effort and are less sensitive. To increase the simplicity of operation and detection sensitivity, a binding inhibition assay method for detecting Listeria monocytogenes in food samples was developed using an automated, fiber-optic-based immunosensor: RAPTOR (Research International, Monroe, WA, USA). For the assay, fiber-optic biosensors were developed by the immobilization of Listeria antibodies on polystyrene fiber waveguides through a biotin-avidin reaction. Developed fiber-optic biosensors were incorporated into the RAPTOR to evaluate the detection of L. monocytogenes in frankfurter samples. The binding inhibition method combined with RAPTOR was sensitive enough to detect L. monocytogenes ($5.4{\times}10^7\;CFU/mL$) in a frankfurter sample.

• Korean Journal of Microbiology
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• v.30 no.3
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• pp.187-192
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• 1992

The spatial and temporal distribution of petroleum-degrading bacteria(PDB) was studied at six sampling sites in Kyeonggi Bay of the Yellow Sea fiom March 1990 to October 1991. In addition, petroleum-degrading potcntial of natural ~iiai-ineb acterial population was studied at different culturc contlitions. During the period o f stutly. thc heterotrophic bacterial number and PDB number were n1e;rsured in the range of 7 000-108.400 CFU/nil. 0-2.800 MPN1100 mi. respectively. The spatial tlistribution of PDB wa\ highly affected by presence of petroleum hydrocarbon. In laboratory cxperirncnt. petrolcu~n biodegradation wac enhanced hy addition of yeast cxtracl. cell free cxtr:~ct. anti rnixctl culture of PI)B.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.4
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• pp.87-92
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• 2013

In this study, we carried out the turning of plastic mold steel(STAVAX) with whisker reinforced ceramic tool(WA1) and analyzed ANOVA(Analysis of Variance) test. Multi-regression analysis was performed to find influential factors to surface roughness and to derive regression equation. Results are follows: From ANOVA test and confidence interval analysis of surface roughness, We found that influential factors to surface roughness was feed rate, cutting speed and depth of cut in order. From multi-regression analysis, we derived regression equation of STAVAX. it's coefficient of determination($R^2$) was 0.945 and It means that regression equation is significant. From experimental verification, we confirmed that surface roughness was predictable by regression equation. Compared with former research, we confirmed that increase of feed rate is the main cause of the growing of surface roughness and cutting force.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.4
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• pp.100-110
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• 1995

This paper aims at reviewing the possibility of application over normal or abnormal, detection used by AE, and the characteristics of grinding processes. In this study, when WA-vitri-fied ' resinoid bond grinding wheels:36 kinds of grinding wheel and grinding depth were tuned at the surface grinding, the zone of AE signal generation is theoretically modelled and reviewed by grinding processes. The variation of grinding resistance( F$n^{9}$ $F_{t}$) and AE signal is detected in-process by the use of AE measuring system. The tests are carried out in accordance with grain size and grade of grinding wheels, and work-pieces-STD11 and STD61. According to the experiment's results, the following can be expected;as grinding time passes by, the relation of grinding depth and quantity of AE signal, observing on AE signal and grinding burn suggest the characteristics of grinding processes and evalution on the possibility of control of grinding machine, and monitoring abnormal conditions.e, and monitoring abnormal conditions.

• Microbiology and Biotechnology Letters
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• v.28 no.1
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• pp.45-51
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• 2000

Photobacterium phosphoreum was used for the study of bioluminescence response to toxic substances including phenol, As2O3, SoO2, and CrO3 in view of developing monitoring system. measurement of inhibition of bioluminescence in P. phosphoreum has been proposed as a sensitive and raped procedure to monitor toxic substances. The concentration of toxic substance causing 50% light reduction(EC50) in bioluminescence intensity was determined with free and immobilized P. phosphoreum, The minimum inhibitory concentrations (MICs) for bioluminescence emission were found to be 400ppm for As2O3, 800ppm for phenol, 60ppm for SeO2 and 60ppm for CrO3 , respectively. The linear correlation between Gamma value and the concentration of toxic substances was obtained and EC50 wa calculated from the linear correlation. The free cells were shown to be more sensitive to toxic substances than cells immobilized on Sr-alginate and Ca-alginate. However, the linear regression curves were derived from the Sr-alginate immobilized cells indicating the immobilization method in s useful tool for monitoring of toxic substances under the more stable condition of bioluminescence.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.812-816
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• 2007

To overcome the problem of ginseng's earthy smell in the manufacture of ginseng wine, we used dried ginseng powder that was extrusion-cooked at $125-168^{\circ}C$ in the wine making process. By using a ginseng powder that was extrusion-cooked at higher temperatures, fermentation by Maillard reaction products (MRPs) was delayed, and the acidic pH that results from extrusion cooking was improved. At $15^{\circ}C$ with glucose instead of sucrose, an addition of 0.5%(w/v) diammonium phosphate (DAP) to the $125^{\circ}C$ extrusion-cooked ginseng powder reduced the primary fermentation time to 11 days versus 33 days without DAP. In the absence of DAP, by increasing the fermentation temperature from 15 to $30^{\circ}C$, increasing the starter yeast inoculate from 0.02 to 1 %, and by increasing the amount of ginseng extrudate from 1 to 2%, fermentation time was effectively reduced more than 10-fold. The results of this study may provide information for the alcohol fermentation of materials containing MRPs as well as for poor nitrogen sources.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.251-258
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• 2001

In Gram(+) bacteria and organelles in higher eukarotes, $Gln-tRNA^{Gln}$ utilized for protein biosynthesis is formed by a tRNA-dependent amino acid transformation using mischarged $Gln-tRNA^{Gln}$ as the intermediate. In this study, the gatCAB gene encoding $Gln-tRNA^{Gln}$ amidotransferase (Glu-AdT) of Staphylococcus aureus was cloned and its nucleotide sequence wa determined. The S. aureus gatCAB gene was organized in an operon structure consisting of three open reading frames (gatC, gatA, and gatB), similar to that of Bacillus subtilis. The gene sequences for the A and B subunits of$Gln-tRNA^{Gln}$ amidotransferase showed significant homology (77 and 87% homology with amino acid sequence) with the gatA and gatB genes of B. subtilis, yet the C subunit (gatC) showed a relatively lowe homology with the B. subtilis gatC gene and other orthologues. The cloned S. aureus <$Gln-tRNA^{Gln}$ amidotransferase gene was highly expressed in Escherichia coli, and the resulting crude enzyme could convert misacylated <$Gln-tRNA^{Gln}$ into $Gln-tRNA^{Gln}$ in vitro.

• Smart Structures and Systems
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• v.1 no.1
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• pp.47-61
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• 2005

A ring-shaped lead zirconate titanate (PZT) piezoceramic sensor has been integrated with the Langevin-type piezoceramic driver of an ultrasonic wire-bonding transducer to form a smart transducer for in-situ measurement of three essential bonding parameters: namely, impact force, ultrasonic amplitude and bond time. This sensor has an inner diameter, an outer diameter and a thickness of 12.7 mm, 5.1 mm and 0.6 mm, respectively. It has a specifically designed electrode pattern on the two major surfaces perpendicular to its thickness along which polarization is induced. The process-test results have indicated that the sensor not only is sensitive to excessive impact forces exerted on the devices to be bonded but also can track changes in the ultrasonic amplitude proficiently during bonding. Good correlation between the sensor outputs and the bond quality has been established. This smart transducer has good potential to be used in automatic process-control systems for ultrasonic wire bonding.