• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.989-996
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• 2007

In this study, abiotic transformation of 1-naphthol(1-NP) via oxidative-coupling reaction and its reaction products were investigated in the presence of Mn oxides. The reaction products were characterized for their relative polarity using solvent extraction experiment and reverse-phase HPLC, and for structure using CCMS and LC/MS, and for absorption characteristics using UV-Vis spectrometry. The reaction products present in aqueous phase were more polar than parent naphthol and comprised of 1,4-naphthoquinon(1,4-NPQ) and oligomers such as dimers and trimers. Hydrophilic component present in water phase after solvent$(CH_2Cl_2)$ extractions was identified as naphthol polymerized products having molecular weight(m/z) ranging from 400 to 2,000, and showed similar UV-Vis. absorption characteristics to that of foil fulvic acid. Transformation of 1,4-NPQ, which is non-reactive to Mn oxide, to the polymerized products via cross-coupling reaction in the presence of 1-NP was also verified. In this experimental conditions(20.5 mg/L, 1-NP, 2.5 g/L $MnO_2$, pH 5), the transformation of 1-NP into the oligomers and polymerized products were about 83% of initial 1-NP concentrations, and more than 30% of the reaction products was estimated to be water insoluble fractions, not extracted by $H_2O$ methanol. Results from this study suggest that Mn oxide-mediated treatment of naphthol contaminated soils can achieve risk reduction through the formation of oligomers md polymer precipitation.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.12 no.1
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• pp.25-50
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• 2001

Using Fourier transformation and wavelet analysis, we compared the auditory event-related potentials of the patients with attention deficit-hyperactivity disorders(abbr. ADHD, 13 boys) and normal control children(8 boys). Amplitudes of the event-related potentials which were calculated via Fourier transformation were compared between the groups and between conditions(non-target versus target) in each group. To the non-target stimuli, the patients with ADHD showed significantly greater amplitudes across almost all of the electrode sites and frequencies. To the target stimuli, the incidents which ADHD patients showed much higher amplitudes than normal controls significantly decreased, while those of the reverse results increased significantly. These results were consistent with the comparison results about negative difference wave(abbr. Nd wave) using Fourier transformation. In summary, it was proved that non-target stimulus which should be ignored elicited more robust electrical response from the patients with ADHD than normal children, but the target stimulus which reguired active processing did much less electrical activity in the patients. For the patients, they showed much inhibited electrical response to the target stimuli in some electrodes and frequency ranges. Normal children were more strongly stimulated by the target stimuli in almost all electrodes and frequency ranges than the patients, but less in prefrontal leads and frontal leads. Wavelet analysis results proved that early responses(0-300msec) to the nontarget stimuli of the patients were significantly greater than the normal controls in prefrontal, anterior frontal, some parts of temporal, and occipital lobes and that late response(300-370msec) were significantly lesser than normal children in parietal and central electrodes. Target stimuli elicited significantly higher electrical activity in both group than non-target stimuli did. Prefrontal and frontal lobes showed stronger responses in the patients than normal children irrespective of stimulus condition, but parietal and temporal lobes did higher activities in normal children than the patients only to the target stimuli. In conclusion, the patients with ADHD showed much greater responses to the stimuli which should be ignored, but failed to activated the necessary processes to the target stimuli. Also, we found that the frequency-dimension analysis and wavelet analysis were useful for the signal processing such as event related potentials.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.156-161
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• 2002

Two different cDNA clones for superoxide dismutase (SOD) were isolated from an weedy rice variety (Oryza sativa, cv. Bhutan14Ad) and were introduced into a cultivated rice variety (Oryza sativa, cv. Nakdong) in order to develop the environmental stress-resistant rice plants. Sequence analysis of the cloned cDNAS indicated that the deduced amino acid sequence of SOD-A is 88.4% identical to that of SOD-B. Furthermore, the nucleotide sequence of SOD-A is 99.3% identical to that of a Cu/Zn SOD gene of Oryza sativa (GenBank accession No. L36320). The nueleotide sequence of SOD-B was identical to that of the previously published SOD gene (Accession No. D01000). A cultivated rice variety, Nakdong-byeo, was transformed with chimeric SOD genes containing a actin promoter of rice and pin2 terminator using a particle bombardment technique. Transformed calli were selected on an selection medium containing phosphinothricin (PPT). Transgenic rice plants were regenerated from the PPT-resistant calli. PCR analysis with genomic DNAs from transgenic plants revealed that transgenes are introduced into rice genome.

• 대한공업교육학회지
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• v.31 no.2
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• pp.155-176
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• 2006

The purpose of this study was to explore the strategies for applying TRIZ to technology education. This study was carried out through literature review on contradiction, 40 principles, 76 standard solutions, multi screen method, effects, the law of technology evolution, and ARIZ, and questionnaire survey to investigate the validity. Through this study the strategies for applying TRIZ to technology education were proposed and the validity was identified. Only the '40 Principles' was appropriate to technology education of elementary and middle school. The results of this study were as follows; In elementary school technology education, segmentation, extraction, local quality, asymmetry, consolidation, universality, counterweight, do it in reverse, mediator, self service, dispose, flexible membranes or thin films, changing the color, homogeneity, rejecting and regenerating parts, and composite materials were suitable. And in middle school technology education, segmentation, extraction, local quality, asymmetry, consolidation, universality, counterweight, prior counteraction, prior action, cushion in advance, do it in reverse, dynamicity, partial or excessive action, continuity of useful action, convert harm into benefit, mediator, self service, dispose, flexible membranes or thin films, changing the color, homogeneity, rejecting and regenerating parts, transformation of properties, phase transition, thermal expansion, and composite materials were suitable.

• The KIPS Transactions:PartD
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• v.12D no.7 s.103
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• pp.947-956
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• 2005

Software(S/W) reengineering is one of the effective technologies to produce a business worth and en and the S/W ROI continuously. In spite of, S/W reengineering has been recognized a cost-consumptive works with inefficient productivity. In fact we have used to transform to confusion system with destructive system architecture by extending and updating legacy system in a temporary expedients. Moreover it is impossible to provide the time-market products for coping with rapid changeable system environment and meeting to complicated customer's requirements. Therefore, we need a systematic reengineering methodology to fulfill the changeable environment, as appearance of new IT techniques, various alteration of business information model, and increment of business logic. Legacy systems can be utilized as the core property in business organization through reengineering methodology. In this paper, we target to establish the reengineering process, proposed MaRMI-RE consisting of initial Planning phase, reverse engineering and component transformation phase. To describe the MaRMI-RE, we presented the concrete tasks and techniques and artifacts per individual phase in process, and the case study is showed briefly.

• Journal of the Korean Ceramic Society
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• v.40 no.10
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• pp.991-997
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• 2003

The effect of A1$_4$C$_3$ additive on the thermoelectric properties of SiC ceramics were studied. Porous SiC ceramics with 47∼59% relative density were fabricated by sintering the pressed $\alpha$-SiC powder compacts with A1$_4$C$_3$at 2100∼220$0^{\circ}C$ for 3 h in Ar atmosphere. Crystalline phases of the sintered bodies were identified by powder X-Ray Diffraction (XRD) and their microstructures were observed with a Scanning Electron Microscope (SEM). In the case of A1$_4$C$_3$ addition, the phase transformation of 6H-SiC to 4H-SiC could be observed during sintering. The Seebeck coefficient and electrical conductivity were measured at 550∼95$0^{\circ}C$ in Ar atmosphere. In the case of undoped specimens, the Seebeck coefficients were positive (p-type semiconducting) possibly due to a dominant effect of the acceptor impurities (Al, Fe) contained in the starting powder and electrical conductivity increased as increasing sintering temperature. Electrical conductivity of A1$_4$C$_3$doped specimen is larger than that of undoped specimen under the same condition, which might be due to the reverse phase transformation and increasing of carrier density. And the Seebeck coefficient of A1$_4$C$_3$ doped specimen is also larger than that of undoped specimen. The density of specimen, the amount of addition and sintering atmosphere had significant effects on the thermoelectric property.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.1
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• pp.47-52
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• 2018

In this study, a collimator composed of multi-dielectric structures is designed using the phase field design method, a kind of topology optimization methods. It is also purposed to improve the mechanical-structural performance of a collimator by replacing previously used air regions with another dielectric material. Polypropylene and paraffin are selected as the dielectric materials for the design process taking manufacturability into account. The design objective is formulated by integrating the intensity of the electromagnetic field in the pre-determined target area to realize the collimating performance. The model for accurate numerical analysis was derived from the final result obtained from the design process through the simple cut-off method and it shows the improved performance of 105% compared with the free space wave propagation. For the designed model, the possibility of reverse transformation, the mechanical durability evaluation under the compression load, and the electromagnetic performance in the X-band range were also evaluated.

• Journal of Periodontal and Implant Science
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• v.40 no.1
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• pp.39-44
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• 2010

Purpose: Bone tissues for clinical application can be improved by studies on osteoblast differentiation. Runx2 is known to be an important transcription factor for osteoblast differentiation. However, bone morphogenetic protein (BMP)-2 treatment to stimulate Runx2 is not sufficient to acquire enough bone formation in osteoblasts. Therefore, it is necessary to find other regulatory factors which can improve the transcriptional activity of Runx2. The erythroblast transformation-specific (ETS) transcription factor family is reported to be involved in various aspects of cellular proliferation and differentiation. Methods: We have noticed that the promoters of osteoblast differentiation markers such as alkaline phosphatase (Alp), osteopontin (Opn), and osteocalcin (Oc) contain Ets binding sequences which are also close to Runx2 binding elements. Luciferase assays were performed to measure the promoter activities of these osteoblast differentiation markers after the transfection of Runx2, myeloid Elf-1-like factor (MEF), and Runxs+MEF. Reverse-transcription polymerase chain reaction was also done to check the mRNA levels of Opn after Runx2 and MEF transfection into rat osteoblast (ROS) cells. Results: We have found that MEF, an Ets transcription factor, increased the transcriptional activities of Alp, Opn, and Oc. The addition of Runx2 resulted in the 2- to 6-fold increase of the activities. This means that these two transcription factors have a synergistic effect on the osteoblast differentiation markers. Furthermore, early introduction of these two Runx2 and MEF factors significantly elevated the expression of the Opn mRNA levels in ROS cells. We also showed that Runx2 and MEF proteins physically interact with each other. Conclusions: Runx2 interacts with MEF proteins and binds to the promoters of the osteoblast markers such as Opn nearby MEF to increase its transcriptional activity. Our results also imply that osteoblast differentiation and bone formation can be increased by activating MEF to elicit the synergistic effect of Runx2 and MEF.

• Animal Systematics, Evolution and Diversity
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• v.18 no.2
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• pp.233-244
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• 2002

As one of the serial studies on the taxonomy of Conthocamptus mirabilis species group in South Korea, C. semicirculus Kikuchi, widely distributed in the southern part of the Far East, and C. coreensis n. sp. from the middle west of South Korea are recorded. Intraspecific variability of some important characters like outer caudal setae and the spinous process of male leg 3 exopod was examined in Korean population of C. semicirculus. Canthocamptus coreensis n. sp. possesses the plesiomorphic characters of the round and narrow hyaline membrane of anal operculum and lacking the sexual reverse transformation in female caudal rami, while it also evolves the apomorphic ones of the modified outer apical setae of male leg 4 exopod and the spinous process of male leg 3 exopod. A key to the five species of the species group known from Korea is prepared.

• 한국가스학회:학술대회논문집
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• 1997.09a
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• pp.45-52
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• 1997

The objective of this study is, with concept of fitness-for-purpose, to evaluate the fracture toughness in X-grooved weld HAZ(heat-affected zone) of QLT(quenching, lamellarizing and tempering)-processed $9\%$ Ni steel, qualitatively and quantitatively, and analyze the relation with the change of microstructure. In general, CTOD test is widely used to determine the fracture toughness of steel weldments. But several problem of accuracy has been brought up. Therefore, in this study, modified CTOD test was used for X-grooved weld HAZ for $9\%$ Ni steel. Additionally, microstructure of HAZ is observed and analyzed by OM, SEM and XRD. From the resulty, HAZ toughness of QLT-$9\%$ Ni steel decreased as the evaluated region approaches the fusion line. The decreased toughness was partly caused by reduction of the retained austenite content, resulted from decreased nucleation site of the retained austenite content, resulted from decreased nucleasion site for reverse transformation due to the increasing fraction of coarse grained region. On the other hand, unexpectedly, the increasing fraction of ductile weld did not increase the HAZ toughness. Therefore, in this X-grooved weld HAZ, the primary factor affecting fracture toughness was the fraction of coarse grained region, i.e., the weakest region.