• The Journal of the Acoustical Society of Korea
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• v.16 no.3E
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• pp.7-13
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• 1997

This paper addresses traffic prediction issues on MPEG. A new adaptive traffic prediction scheme is proposed using MPEG picture characteristic that picture traffic depends on the coding mode of that picture, that is, I, P, and B mode. Our prediction scheme, which is based n picture decomposition (PD) and the cross-correlation of the different types of pictures, has better performance in predicting bursty MPEG traffic than that of the first-order autoregressive (AR) prediction scheme. Our simulation results show that the performance is further improved about 15% by utilizing the cross-correlations between pictures.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.3
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• pp.468-482
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• 1998

Since the concept of osseointegration was introduced by Branemark of Sweden, dental implants have been used for various dental prosthetic treatments. The survival rate of dental implant is likely to be closely related to the total biomechanical role of each component of implant system. The use of interchangeable component is very attractive for dental practitioners because such an approach would save treatment cost, flexibility of prosthetic treatment options as well as conveniences. Therefore, the use of interchangeable implant system has been increasing without scientific assessment of safety and efficacy of various interchangeable implant system. The purpose of this study, therefore, were to compare the geometric characteristic of four interchangeable dental implant screws and the loosening torque of these screws. Four types of dental implant screws tested in this study were Nobelpharma, 3i, Impla-med, Restore. Four screws each of the test specimens were subjected for scanning electron microscopic examinations under the same condition and a 35x magnified standard SEM picture was objected from each test specimen using JSM-5200 scanning microscope. From each of the SEM pictures, eight parameters. i.e., diameter of screw head. screw length, thread pitch, major diameter. neck diameter, neck length, crest width and root width were determined using a caliper. The measurement for each parameters were then corrected for their magnification factor. The loosening torque were also determined by using a torque gauge. All of the measurements were statistically analyzed by ANOVA test and multiple range test. Statistical significance was set in advance at the probability level of less than 0.05. All analyses were done with SPSS software for the personal computer. The conclusion obtained from this studies were summarized as the following; 1. No statistically significances were noted in the thread pitch. and crest width in the four screws, and in the case of major diameter, the Impla-med screw was significantly smaller than the other three screws (p<0.05). Therefore, four implant bolts could be physically inserted in a abutment nuts. 2. The diameter of screw head was decreased in the order of Restore, 3i, Nobelpharma, Impla-med screws and the length of screws were decreased in the order of 3i, Restore, Nobelpharma and Impla-med. The diameter of neck was decreased in the order of Impla-med, Restore. Nobelpharma, 3i screws. The differences of each of these parameters were statistically significant (p<0.05). The width of root of screws were decreased in the order of Nobelpharma, Impla-med, Restore and 3i. The differences among Nobelpharma and Impla-med. Restore and 3i were statistically significant (p<0.05). 3. When the screws were loosening 1, 3, 4 and 5 times, the loosening torque for Impla-med and 3i screws were significantly higher than that of Nobelpharma or Restore screws (p<0.05). However, when statistically smaller than that of 3i, Restore or Nobelpharma screws(p<0.05).

• Food Science and Preservation
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• v.10 no.3
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• pp.302-307
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• 2003

In the present study, we investigated the quality characteristic of old pumpkin extract treated with enzymes. As a results, all the groups treated with pectinase were better in quality characteristic than control group and the group treated with 0.15％(w/w) pectinase was specially great. All the groups treated with simultaneous pectinase and cellulase were higher in the extraction rate than the groups treated with pectinase or cellulase. The experimental groups were divided into non-treated control(I) and three treatment groups(II- IV) for optimum condition of enzyme treatment. The II and IV groups were treated with 0.15％(w/w) pectinase and 0.15％(w/w) cellulase, respectively, and the ill group was treated with both 0.15％(w/w) petinase and 0.05％(w/w) cellulase. Yield for old pumpkin extract of the III group (86.94％) was higher than that of other groups, but there were no significant difference among the groups in soluble solide content and pH of the extract. Reducing sugar and total sugar contents in the ill group were 2.81％ and 4.60％, respectively. Total carotene content in the II group (5.36 mg％) was higher than other groups. Old pumpkin extracts in all the groups showed nitrite-scavenging ability to pH 1.2, 3.0 and 4.0. Total free amino acid content in the III group (176.7 mg％) was higher than other groups. Citrulline contents in the II and III groups were detected 1.66 and 1.41 mg％, respectively but the contents in other groups were not detected.

• Journal of the Korean Institute of Telematics and Electronics
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• v.11 no.1
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• pp.8-14
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• 1974

Investigation of the electrical properties of GaAs after the heat treatment at various As vapor pressure have been carried out. Hall coefficient mesurments were utilized to study the cause of the effect on the electrical properties, of GaAa by the heat treatment. Various defects possibly created by the heat treatment were discussed. Also, p-n GaAs diodes were fabricated and the I-V characteristic curves were presented.

• Journal of Technologic Dentistry
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• v.35 no.3
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• pp.243-257
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• 2013

Purpose: This study aims to analyze the factors affecting the dropout intentions of the dental technology students of a college. Methods: The subject of this study was 76 freshmen and 74 sophomores of dental technician major in an anonymous college. Results from the questionnaire called K-vision diagnosis program were computed by means of t-test, One-Way ANOVA, and correlation analysis. Results: 1. Total points of the drop out intention came to 782.14 points. Of the five categories concerned with the drop out intention, complain in college satisfaction(50.12points) was the highest and department satisfaction(47.51points) was the lowest. Of 16 subcategories, complaining in administrative supporting system proved the highest as 50.80 points and Inquiry to Professor the lowest(45.56 points). 2. Among the general characteristic gender (p<. 01), student group (p<.01), and credit (p<.05) made a meaningful statistical difference; no statistical significance was found in grade, admission, and dwellings. 3. Of the five categories, statistical significance was shown as follows; Department satisfaction (p<.01), College satisfaction (p<.05) under gender, Department satisfaction (p<.05) in grade, Academic integration (p<.01), Department satisfaction (p<.01) in credit. No statistical meaning was found in admission and dwellings. 4. Statistical significance was found under 16 subcategories as follows: Career identification(p<.01), Academic support system(p<.01), Social activity II(p<.05) in gender area, Inquiry to professor(p<.01), Learning(p<.05), Understanding learning I(p<.05) in grade area, Learning(p<.001), Career identification(p<.001), Understanding learning I(p<.01), Understanding learning II(p<.01), Inquiry to professor (p<.01), Learning ability (p<.05), Occupation (p<.05), Social Activity II(p<.05), Administrative support system (p<.05) in student group area, Credit (p<.001), Career identification (p<.01), Understanding learning I(p<.05) in credit area; admission and dwellings was statistically meaningless. 5. Of the 5 categories academic integration (r=.766) was most relevant to the dropout intention of the subjects and followed by department satisfaction (r=.735), college satisfaction (r=.554), service acceptability (r=.373), and statistical significance was shown as p<.01. Conclusion: Considering the results of this study, we are in a pressing need for the introduction of policies and programmes aiming at preventing the dropout rates of the dental technician majors at college. In tandem with this, qualitative and viable human resource management of the dental technicians should be implemented.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.7
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• pp.85-93
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• 2020

In peer-to-peer (P2P) loan markets, as most lenders are unskilled and inexperienced ordinary individuals, it is important to know the characteristics of borrowers that significantly impact their repayment performance. This study investigates the effects and importance of borrowers' past repayment performance track record within the platform to identify its predictive power. To this end, I analyze the detailed loan repayment data from two leading P2P lending platforms in Korea using a Cox proportional hazard, multiple linear regression, and logit models. Furthermore, the predictive power of the factors proxied by borrowers' track records are evaluated through the receiver operating characteristic (ROC) curves. As a result, it is found that the borrowers' past track record within the platform have the most important impact on the repayment performance of their current loans. In addition, this study also reveals that the borrowers' track record is much more predictive of their repayment performance than any other factor. The findings of this study emphasize that individual lenders must take into account the quality of borrowers' past transaction history when making a funding decision, and that platform operators should actively share the borrowers' past records within the markets with lenders.

• Economic and Environmental Geology
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• v.26 no.4
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• pp.507-518
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• 1993

Paleomagnetic investigations have been carried out on the Tertiary sedimentary formations (Yeonil Group) in Pohang basin, southeastern Korea. A total of 215 samples were collected from 26 sites. Progressive thermal demagnetization indicates that many samples have unstable magnetization and do not reveal a characteristic direction. However, some samples from the lower and upper Duho Formation show a characteristic direction $D/I=7.8^{\circ}/48.3^{\circ}$ (${\alpha}_{95}=3.7^{\circ}$, k=174.1). Stepwise thermal demagnetization data show that some samples from the Hagjeon and middle Duho Formations reveal great-circle distributions moving from the present to a reversed direction of geomagnetic field. The mean of intersection points of the great-circles is nearly antipodal to the characteristic normal direction of the lower and upper Duho Formation. We infer that the Hagjeon Formation was formed during the reversed polarity chron C5B (16.2~14.7 Ma) and the Duho Formation 14.7~11.6 Ma based on our results and previous paleontologic and age dating data. Paleomagnetic direction for the Middle Miocene of Korea, analysed from the combined results of stable endpoints and great circles, is $D/I=8.7^{\circ}/53.9^{\circ}$ (${\alpha}_{95}=4.2^{\circ}$, k=74.8), and the corresponding paleopole is Lat./Long.=$82.7^{\circ}/230.2^{\circ}$ (${\delta}p=2.8^{\circ}$, ${\delta}m=5.9^{\circ}$). On the basis of this, we interpret that the opening of the East sea (Japan sea) or the synchronous clockwise rotation of the Southwest Japan exerted no structural influence on the Yeonil Group in the Middle Miocene.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.61-68
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• 2023

This study analyzed and compared the physicochemical characteristics of topsoil and subsoil of Grade 1 soil from an igneous rock area on the ecological and nature map. The water content and pH of the collected soil samples were measured, and X-ray fluorescence and X-ray diffraction analyses were performed. The results showed that the water content of the topsoil was higher than that of the subsoil, and its pH was more acidic than that of the subsoil. According to the X-ray fluorescence analysis results, sample I9 was closest to kaolinite, while sample I7 was most distant from kaolinite. All other samples were located between samples I7 and I9. The X-ray diffraction analysis showed that the average content of clay minerals was higher in the topsoil than in the subsoil. The most notable clay minerals produced included illite, vermiculite, kaolinite, chlorite, and gibbsite. The results of this study will be used as a basic data for topsoil restoration to convert subsoil into topsoil.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.265-268
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• 2005

This paper deals with the optimal design of a permanent magnet linear synchronous motor (PMLSM) with the analysis of prototype PMLSM. In the PMLSM, thrust ripple is one of the causes disturbing high-precision position control. Therefore, Response surface methodology (RSM), one of the optimization methods, is applied to obtain the shape decreasing thrust ripple of the prototype PMLSM. In the end, characteristic analysis of the PMLSM is performed by space harmonic method for shortening of a computation time, and final results is verified by finite element analysis.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.11a
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• pp.188-190
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• 2001

We carried out to measure the variations of potential with current density polymers. The results were particularly examined to identify the influences on corrosion potential and corrosion rate of various factors including temperature and pH. The Tafel slope for anodic dissolution was determined by the polarization effect depending on these conditions. The optimum conditions were established for each case. The second anodic current density peak and maximum passive current density were designated as the relative corrosion sensitivity($I_{r}I_{f}$). The mass transfer coefficient value (${\alpha}$) was determined with the Tafel slope for anodic dissolution based on the polarization effect with optimum conditions.