• Korean Journal of Microbiology
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• v.23 no.2
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• pp.115-121
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• 1985

Five representative virulent phages (J1, TK93, K1, PD5, and CP1) and one temperate phage (.phi.1043) of Lactobacillus casei were compared to each other by analyzing the agarose gel electrophoretic patterns of restriction enzyme-digested phage DNAs. Nucleic acids of all the tested phages were double stranded DNA. DNAs of J1, TK93, K1, and ${\phi}$ 1043 phages had a size of about 42kb, but the size of PD5 and CP1 DNAs was avout 140kb. J1, TK93, K1, PD5, CP1, and ${\phi}$ 1043 DNAs were digested to 13, 13, 11, 14, 14, and 12 fragments by EcoR1, respectively, and showed its characteristec restriction patterns. Cohesive ends were present in J1, TK93, and ${\phi}$ 1043, but were absent in K1, PD5, and CP1. Restriction maps of J1 and TK93 DNAs showed nearly complete homology and their evolutionary relationship based upon the restriction analysis was discussed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.1
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• pp.131-137
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• 1986

Cutting oil cools the chip and a tool as well as lubricates the chip-tool interface, the flank and machined surface. Rehbinder effect has been known as a phenomenon, the reduction of mechanical strength, when the metal is exposed to a polar organic environment or the surface of metal is coated with some polar organic substances. About the cause of Rehbinder effect there have been many different ideas by Rehbinder, Shaw, Barlow, Sakida and etc. In this report, the efect of polar organic substance( $C_{6}$ $H_{5}$C $H_{3}$+ $C_{6}$ $H_{4}$(C $H_{3}$)$_{2}$+ $C_{4}$ $H_{9}$OH+ $C_{6}$ $H_{12}$ $O_{2}$) (magic ink) upon the mechanism of chip formation on the orthogonal cutting of copper and mechanical properties of the work material are experimentally discussed with various rake angles. As expected no lubrication action could be noticed, but the shear angle increased and the cutting force and shear strain on the shear plane decreased, therefore the work material must be embrittled under polar organic substance.substance.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.3
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• pp.283-298
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• 2008

The purpose of this study was to evaluate mechanical fit of fixture- abutment-screw interface in the internal connection implant systems. In this study, each two randomly selected internal implant fixture- abutment assemblys from Certain, Xive, Replace, Ankylos, SS II. were used. The implants were perpendicularly mounted in liquid unsaturated polyester by use of dental surveyor. Each abutment was connected to the implant with recommended torque value using a torque controller. All samples were cross-sectioned with grinder-polisher unit after embeded in liquid unsaturated polyester, and then fixture-abutment-screw interfaces of all samples by using optical microscope and scanning electron microscope were analyzed. Conclusively, although a little variation in machining accuracy and consistency was noted in the samples, important features of all internal connection systems were the deep, internal fixture-abutment connections which provides intimate contact with the implant walls to resist micromovement, resulting in a strong stable interface.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.436-440
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• 1987

Pullulanase gene (pul) of Klebsiella pneumoniae NFB-320 which was cloned previously in Escherichia coli with plasmid pBR322. The gene was analyzed with various restriction enzymes. The cloned gene was contained within n 10 kb BamHI DNA fragment. We constructed the restriction map of the hybrid plasmid pYKL451. The optimum temperatures for pullulanases produced in E. coli (pYKL451) and K. pneumoniae NFB-320 were almost the same, 50-55 $^{\circ}C$. The optimum pHs for the reaction of the enzymes produced by E. coli (pYKL451) and K. pneumoniae NFB-320 was 6.0. Both enzyme preparations were stable under the range of pH 5.0 to 10.0 when those were kept at 40 $^{\circ}C$ for 90 min and were stable until 40 $^{\circ}C$ when allowed to stand for 1hr at various temperatures.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.6
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• pp.481-486
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• 2011

The evaluation of supercooled water droplet impingement characteristics of full-scale aircraft components in wind tunnels under icing conditions has been severely limited by the relative size of the component and the test facility. The concept of truncated airfoil sections has been suggested in order to extend the operational range of icing tunnels. With proper deflection of the small trailing-edge flap on the truncated airfoil the local pressure distribution may remain very close to that of the full-scale airfoil. In this study the shape of a truncated flapped airfoil is investigated for various deflection angles. To validate the truncated flapped airfoils, air flow and collection efficiency over the truncated airfoil are compared with the results of the full-scale airfoil obtained from the state-of-the-art icing simulation code.

• The Korean Journal of Applied Statistics
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• v.33 no.1
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• pp.61-74
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• 2020

Interval-valued data, one type of symbolic data, are observed in the form of intervals rather than single values. Each interval-valued observation has an internal variation. Principal component analysis reduces the dimension of data by maximizing the variance of data. Therefore, the principal component analysis of the interval-valued data should account for the variance between observations as well as the variation within the observed intervals. In this paper, three principal component analysis methods for interval-valued data are summarized. In addition, a new method using a truncated normal distribution has been proposed instead of a uniform distribution in the conventional quantile method, because we believe think there is more information near the center point of the interval. Each method is compared using simulations and the relevant data set from the OECD. In the case of the quantile method, we draw a scatter plot of the principal component, and then identify the position and distribution of the quantiles by the arrow line representation method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1270-1277
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• 2003

The extrusion conditions of the soymilk residue and corn grits mixtures were optimized. The experiment was designed according to the D-optimal design of response surface methodology (RSM), which shows 18 experimental points including 4 replicates for three independent variables (screw speed, water content and die temperature). The responses variables such as bending force, expansion ratio, bulk density, water solubility index (WSI), water absorption index (WAI), and color values (L＊, a＊, b＊) were evaluated using response surface analysis. Expansion ratio and WSI decreased with increasing water content, whereas bulk density tended to increase with increasing water content. While greater screw speeds enhanced WSI and yellowness, higher moisture contents decreased the expansion ratio and WSI value. However, die temperature did not influence upon the response variables. The optimum extrusion conditions by numerical and graphical methods were similar: the screw speed, water content, and die temperature were 250 rpm, 22.43% and l28.16$^{\circ}C$ by the numerical method; 250 rpm, 22.43%, and 128.02$^{\circ}C$ by graphical method.

• Journal of Convergence for Information Technology
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• v.10 no.11
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• pp.148-155
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• 2020

The purpose of the study was to test the reliability and validity of the Korean version of Pittsburgh Sleep Quality Index (PSQI-K) and to examine the cutoff point of the PSQI-K for screening insomnia among young adults. The subjective quality and patterns of sleep in 64 participants were measured using PSQI-K and Fitbit Charge 3^TM. The properties of the instrument were analyzed using Cronbach's alpha coefficient for the internal consistency reliability, factor analysis for the construct validity, and Spearman's rho correlation coefficient for the correlation between the PSQI-K total scores and Fitbit tracker scores. The Cronbach's alpha coefficient of the PSQI-K was 0.69. The Spearman's rho correlation coefficient between the PSQI-K and Fitbit tracker was higher than 0.67. A cutoff point of ≥6.0 had a sensitivity of 0.93 and a specificity of 0.84. In conclusion, the PSQI-K is a reliable and valid instrument to evaluate sleep disturbance in Korean young adults.

• Survey Research
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• v.12 no.2
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• pp.1-26
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• 2011

Mortality for oldest-old age (aged 80 or over) in Korea has never been studied mainly due to lack of data leaving its quality aside. The rapid aging recently occurring in Korea, which no other country has never experienced, must introduce a drastic change in the structure of future population pyramid, requring a careful investigation on mortality level, pattern, and trend for the oldest-old age in Korea. For mortality trend, we need to extend the past mortality data, which has provided only an open-ended age interval 80 or 85 years and over, to age-specific mortality up to 115 years old. A prerequisite for such an extension is constructing a Korean standard mortality by which one can figure out the mortality level and pattern of the oldest-old age. A Korean standard mortality is proposed by applying one relational model and eleven functions from which we select best models for each sex in terms of three measures of fits and three consistencies of mortality. Then we extend the mortality of the open-ended age intervals by providing a method to avoid the longitudinal consistency of mortality.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.95-100
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• 2009

This study was conducted to develop an imaging processing system of inoculation processing of a lily callus. The image processing system was composed of a camera, a image processing board, and etc. And the illuminance always decided by setting up 55W/3 wavelength lamp respectively on all aspects and the side was maintained by the lighting part. The image characteristic was examined according to each frame of RGB,therefore the culture vessel was able to be separated with B frame. The required time was 2.2 seconds in one cycle from the image acquisition to obtaining the result. The recognition rate of the container was 100%, and the result of image processing showed that the recognition success rate of lily callus was 93%.