• Economic and Environmental Geology
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• v.25 no.3
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• pp.275-282
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• 1992

Mineral chemistry and stable isotope compositions of sericites from the Sangdong mine in the Kimhae area, Kyungsangnamdo, were studied. The Sangdong sericite deposit occurs in rhyolitic tuff of late Cretaceous age and considers to have been fonned by the hydrothennal alteration. The sericites are classified as $2M_1$ polytype and are characterized by less celadonite substitution indicating muscovite-phengite series. Their compositions are very close to that of the ideal muscovite but net layer charge ranges 1.71~1.91 which is less than 2 per formula unit of ideal muscovite. Predominant interlayer cation is K and K/(K+Na) ratio ranges 0.91 and 0.93. ${\delta}^{18}O$ values of sericites and quartz separated from the ore range 7.70~9.07 and 8.20~10.87‰, respectively. The formation temperature of sericite can be estimated as $315{\sim}340^{\circ}C$( based on ${\delta}^{18}O$ value of sericite and ${\delta}D$ value of of Cretaceous meteoric water. Their formation temperature discrepancy between coexisting sericite and quartz indicates that they are in isotopically inequilibrium. Two types of quartz, coarse grained phenocrysts and micrcrystalline aggregates are observed and the former must have been formed during volcanic eruption and remained isotopically unexchanged during hydrothermal alteration period. ${\delta}^{14}S$ values of pyrites range 1.9~4.5‰ which is within a range of volcanogenic sulfur, indicating magmatic source.

• KSBB Journal
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• v.13 no.6
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• pp.693-699
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• 1998

The relationship between bioluminescence of immobilized Photobacterium phosphoreum and toxic substances was investigated to monitor toxic substances in aqueous solution. The sodium alginate was used as an immobilization matrix. A bioluminescence intensity was maximum when OD660 for cell concentration were between 1.0 and 1.2 and the biolumescence was stable at the pH range of between 6.0 and 8.0. The optimum concentration of alginate for immobilization was found to be 5.0%(w/v) in which dilution was carried out with 2.5%(w/v) NaCl solution that is an optimum environmental condition for the growth of P. phosphoreum. The bioluminescence intensity responded against the toxic substances was proportional to the concentration and a regression curve were established with linearity by using specific bioluminescence reduction rate and Gamma values. It was also found that the response was very rapid and sensitive. The response with such rapidity and sensitivity is a very important factor for the real time monitoring. The immobilized cells showed higher sensitive response to the toxic substances than free cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.1
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• pp.27-35
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• 2006

Purpose: This study was performed to investigate the expression of the transforming growth factor (TGF)-1, in a rat calvarium defect model using particulate dentin and/or plaster of Paris, and correlate the bone regeneration process with the histologic events. Materials and Methods: Thirty-two Sprague-Dawley rats were divided into 4 groups of 8 animals each. A 1.0 cm-sized calvarial defects were made and the defect was filled with different graft materials as follows : Group A, the defects were filled with a mixture of particulate dentin and plaster of Paris with a 2:1 ratio; Group B, the defects were filled with plaster of Paris only; Group C, defects were filled with particulate dentin only; Group D, untreated control group. The animals were sacrificed by 1, 2, 4, 8 weeks after implantation. Excised wound tissues were processed for histology, immunohistochemistry and RT-PCR for the analysis of TGF-1 expression. Results: Gene expression of TGF-1 was detected for all experimental groups. The highest gene expression was observed in the specimen taken at the first week after implantation in Group A. According to the histologic and immunohistochemical studies, TGF-1 positive osteoblast-like cells were found in the early stage of healing after the implantation of particulate dentin and plaster of Paris. Conclusion: These findings suggest that TGF-1 may be related to new bone formation at the early healing process after the implantation of particulate dentin and plaster of Paris.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.99-107
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• 1984

The auther studied clinically and. radiologically 48 cases which had been diagnosed as TMJ ankylosis in SNUDH (1974-1984). The purpose of this study is to analyse clinical features of TMJ ankylosis and to evaluate the effect of TMJ ankylosis on the growth of the mandible. The obtained results were as follows: 1. Total 48 cases of TMJ ankylosis patients consist of 23 males and 25 females. 65 percent of all cases of TMJ ankylosis occurred in patients between 1 and 10 years of age. The awerage age at the onset of ankylosis was 11.7 and average duration at the time of examination was 11.7 years. 2. Unilateral akylosis (81.3%) was more frequent than bilateral ankylosis (18.7%). 3. Traum a (57.9%) and infection (21.2%) were main etiology. 4. Inability to open the mouth (78.3%) and facial asymmetry (17.4%) were main chief complaints. 5. Mandibular morphology through radiographic features. (a) In TMJ ankylosis patients the ramus length of the ankylosed side was shorter than that of the non-ankylosed side. Comparing with the centrol group, ramus length of the each side was shorter than normal value. (b) The partial body length of the ankylosed side was longer than that of the non-ankylosed side. Comparing with the control group, partial body length of the each side was longer than normal value. Partial body length was related with antegonial notch depth. (c) Ratio of upper and lower ramus length at the level of mandibular foramen was smaller in ankylosed side than in non-ankylosed side. (d) Antegonial notch depth and ramus posterior contour depth were deeper in ankylosed side than in non-ankylosed side and those of both sides were deeper than normal value. (e) Gonial angle in ankylosed side was larger than in non-ankylosed side and that in both sides was smaller than normal value.

• The Korean Journal of Ceramics
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• v.6 no.3
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• pp.291-295
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• 2000

The pyroelectric property of $Pb_{0.9}La$_{0.1}TiO_3$ceramics in a range of 1.3-4.1$\mu\textrm{m}$, fabricated by conventional solid sintering, was investigated as a function of poling field. The pyroelectric of the 4.1$\mu\textrm{m}$ of $Pb_{0.9}La$_{0.1}TiO_3$ceramics is higher than that of the 1.3$\mu\textrm{m}$ and 1.7$\mu\textrm{m}$ of $Pb_{0.9}La$_{0.1}TiO_3$ceramics at a low poling field and the pyroelectric coefficient is 25nC/$\textrm{cm}^2$K at a 4kV/mm poling field in every grain size. In order to explain this phenomenon, the intrinsic and extrinsic effects in view of the definition of the pyroelectric coefficient are introduced. The intrinsic and extrinsic effects on the pyroelectric property were investigated by measuring the tetragonal ratio and the $I_{002}$ with temperature with high temperature X-ray diffractometer. The change of spontaneous polarization and the $90^{\circ}$domain wall motion with temperature in the 1.3$\mu\textrm{m}$ and 4.2$\mu\textrm{m}$ of $Pb_{0.9}La$_{0.1}TiO_3$ceramics have no effects on the pyroelectric coefficient. In our study, it can be seen that the pyroelectric coefficient is related to the quantity of $180^{\circ}$domain switching after poling treatment.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.216-218
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• 2001

The transformer role is very important in power system operation and control; also its price is very expensive. Therefore many kinds of the efforts for transformer protection have been executed. So for as, current differential relay(87) has been mainly used for transformer protection. But current differential relaying method has several troubles as followings. Differential current can be occurred by transformers inrush current between winding1 and winding2 of transformer when transformer is initially energized. Also harmonic restrained element used in current differential relaying method is one of the causes of relays mal-operation because recently harmonics in power system gradually increase by power switching devices(SVC, FACTS, DSC, etc). Therefore many kinds of effort have been executed to solve the trouble of current differential relay and one of them is method using ratio of increment of flux linkages(RIFL) of the primary and secondary windings. This paper introduces a novel protective relay for power transformers using RIFL of the primary and secondary windings. Novel protective relay successfully discriminates between transformer internal faults and normal operation conditions including inrush and this paper includes real time test results using RTDS(Real Time Digital Simulator) for novel protective relay. A novel protective relay was designed using the TMS320C32 digital signal processor and consisted of DSP module. A/D converter module, DI/DO module, MMI interface module and LCD display module and developed by Xelpower co., Ltd.

• Korean Journal of Materials Research
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• v.17 no.4
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• pp.203-206
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• 2007

Effects of doping rare earth elements on Ln site of $Ln_{0.7}Ca_{0.3}MnO_3$ (Ln = N d, Sm and La) were examined from structure, magnetic and electrical properties. Size of a-axis increased as following order of La < Nd < Sm, whereas c-axis was not much changed. Curie temperatures of 170 K for $Nd_{0.7}Ca_{0.3}MnO_3$, 110 K for $Sm_{0.7}Ca_{0.3}MnO_3$ and 250 K for $La_{0.7}Ca_{0.3}MnO_3$ were obtained. This result coincides with change of Mn-O bond length causing by a-axis lattice constant. The highest magnetroresistance ratios were 22% at 77 K for $Sm_{0.7}Ca_{0.3}MnO_3$, 32% at 110 K for $Nd_{0.7}Ca_{0.3}MnO_3$, and 33% at 180 K for $La_{0.7}Ca_{0.3}MnO_3$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.569-573
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• 2001

A pectic substance from citron peel was extracted with different methods to establish the optimum extraction conditions. The extraction yields of pectin with HCl, citrate and tartrate (concentration : 0.1 N, extraction ratio : 1 : 20) were 17.9%, 15.6% and 11.4%, respectively. Six times of 65% ethanol washing step was followed after first ethanol precipitation of acid extract for pure pectin. The degree of esterification (DE) of pectins was in the range of 43.0~47.6% and intrinsic viscosity was in the range of 0.94~2.63 (η$_{sp}$ /C (dL/g)). The sugar compositions such as rhamnose, xylose, glucuronic acid, galacturonic acid, galactose and glucose were little different in three kinds of pectins except for the content of arabinose.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.10-20
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• 2017

The proportion of software in the automotive industry is steadily increasing due to the rapid technological development of automobile E/E parts. Because the automotive E/E technology is now on the basis of intelligent automobile and advanced safety automobile technology. The purpose of this study is to investigate the effect of organizational capability (organizational resource capability and management capability), process capability (process capability, customer Requirement management capability), performance dimension (motivation, participation level). In this study, we conducted questionnaires and statistical analysis on engineers (members of the Korea Advanced Automotive Technology Association) who perform research and development activities in the R&D organization of the automotive E/E part in South Korea. ANOVA is applied for the verification of the difference in performance measured by organizational capability, process maturity, and motivation participation level according to company characteristics (level of processing : supply chain configuration, annual sales, total SW development ratio). According to the results of this study, in order to improve the performance of ASPICE or ISO 26262-related consulting project, a different consulting approach strategy considering the characteristics of organization and personnel is needed. In summary, the analysis results for the three main treatment levels are as follows. The difference in organizational capacity, process capability and performance was found to be statistically significant according to supply chain configuration and annual sales, but it was found that the difference of response according to the proportion of total SW was not significant.

• International Journal of Concrete Structures and Materials
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• v.11 no.1
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• pp.135-149
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• 2017

The prediction of the actual ultimate capacity of confined concrete columns requires partial confinement utilization under eccentric loading. This is attributed to the reduction in compression zone compared to columns under pure axial compression. Modern codes and standards are introducing the need to perform extreme event analysis under static loads. There has been a number of studies that focused on the analysis and testing of concentric columns. On the other hand, the augmentation of compressive strength due to partial confinement has not been treated before. The higher eccentricity causes smaller confined concrete region in compression yielding smaller increase in strength of concrete. Accordingly, the ultimate eccentric confined strength is gradually reduced from the fully confined value $f_{cc}$ (at zero eccentricity) to the unconfined value $f^{\prime}_c$ (at infinite eccentricity) as a function of the ratio of compression area to total area of each eccentricity. This approach is used to implement an adaptive Mander model for analyzing eccentrically loaded columns. Generalization of the 3D moment of area approach is implemented based on proportional loading, fiber model and the secant stiffness approach, in an incremental-iterative numerical procedure to achieve the equilibrium path of $P-{\varepsilon}$ and $M-{\varphi}$ response up to failure. This numerical analysis is adapted to assess the confining effect in rectangular columns confined with conventional lateral steel. This analysis is validated against experimental data found in the literature showing good correlation to the partial confinement model while rendering the full confinement treatment unsafe.