• Composites Research
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• v.26 no.4
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• pp.254-258
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• 2013

Polypropylene films reinforced with multi-walled carbon nanotubes and exfoliated graphite nanoplatelets were fabricated by extrusion, and the effects of filler type and take-up speed on the mechanical properties and microstructure of composite films were investigated. Differential scanning calorimetry revealed that the addition of carbon nanomaterials resulted in increased degree of crystallinity. However, increasing the take-up speed reduced the degree of crystallinity, which indicates that tension-induced orientations of polymer chains and carbon nanomaterials and the loss of degree of crystallinity due to rapid cooling at high take-up speeds act as competing mechanisms. These observations were in good agreement with tensile properties, which are governed by the degree of crystallinity, where the C-grade exfoliated graphite nanoplatelet with a surface area of $750m^2/g$ showed the greatest reinforcing effect among all types of carbon nanomaterials used. Scanning electron microscopy was employed to observe the carbon nanomaterial dispersion and orientation, respectively.

• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.87-94
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• 2018

This study investigated the feasibility of the lytic, tailed Bacillus cereus-specific phage for use in a ferromagnetoelastic (FME) biosensor as a novel recognition element. The phage was immobilized at various concentrations through either direct adsorption or a combination of 11-mercapto-1-undecanoic acid (11-MUA) and [N-(3-dimethylaminopropyl)-N'-carbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS)]. The effects of time and temperature on its lytic properties were investigated through the exposure of B. cereus (4 and 8 logCFU/ml) to the phage (8 logPFU/ml) for various incubation periods at $22^{\circ}C$ and at various temperatures for 30 and 60 min. As the phage concentration increased, both immobilization methods also significantly increased the phage density (p < 0.05). SEM images confirmed that the phage density on the FME platform corresponded to the increased phage concentration. As the combination of 11-MUA and EDC/NHS enhanced the phage density and orientation by up to 4.3-fold, it was selected for use. When various incubation was conducted, no significant differences were observed in the survival rate of B. cereus within 30 min, which was in contrast to the significant decreases observed at 45 and 60 min (p < 0.05). In addition, temperature exerted no significant effects on the survival rate across the entire temperature range. This study demonstrated the feasibility of the lytic, tailed B. cereus-specific phage as a novel recognition element for use in an FME biosensor. Thus, the phage could be placed on the surface of foods for at least 30 min without any significant loss of B. cereus, as a result of the inherent lytic activity of the B. cereus-specific phage as a novel recognition element.

• Journal of the Korean Society for Heat Treatment
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• v.31 no.6
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• pp.269-274
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• 2018

Grain-oriented electrical steel sheets are mainly used as core materials for transformers and motors. They should have excellent magnetic properties such as low core loss, high magnetic flux density and high permeability. In order to improve the magnetic properties of the electrical steel sheet, it is important to form Goss oriented grains with a very strong {110}<001> orientation. Recently, efforts have been made to develop Goss grains by controlling processes such as hot rolling, cold rolling, and primary and secondary recrystallization. In this study, the sheets containing 3.2 and 3.4wt.% Si were used, which were rolled with 1 and 10 passes with total thickness reduction of 89%. Heating was carried out for primary recrystallization with different heating rates of $25^{\circ}C/s$ and $24^{\circ}C/min$ until $720^{\circ}C$. The behavior of Goss-, {411}<148>-, and {111}<112>-oriented grains were analyzed using X-ray diffraction(XRD) and electron back-scatter diffraction(EBSD) analysis. The area fraction of Goss-oriented grains increased with the number of rolling passes during cold rolling; however, after the primary recrystallization, the area fraction of the Goss grains was higher and exact Goss grains were found in the specimens subjected to rapid heating after one rolling pass.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.189-192
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• 2001

We have investigated the effects of abiotic and biotic stresses on leaf senescence using transgenic tobacco plants, in which cellular contents of polyamines were increased by introducing the genes of polyamine and ethylene biosynthesis in sense or antisense orientation. These transgenic plants showed accumulations of polyamines at higher levels than were found in wild-type. Stress-induced senescence was attenuated in transgenic plants cpmpared with wild-type plants, in terms of total chlorphyll loss and phenotypic changes after oxidative stress of hydrogen peroxide($H_2O_2$), high salinity, acid stress (pH3.0), ABA and fungal pathogen(phytophothora parasitica pv.Nicotianae). Transcripts for antioxidant enzyme, glutathionine-S-transferase and catalase, were also more abundant in transgenic plants than wild-type plants. These result suggested that higher expression of those genes caused a broad-spectrum resistance to abiotic stress/biotic stress. These phenomena indicate that polyamines may play an important role in contributing to the antioxidant defense function in plants. Our findings suggest that facilitate the improvement of stress tolerance of crop plants.

• Korean Journal of Materials Research
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• v.11 no.11
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• pp.960-964
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• 2001

$Bi_{3.99}Ti_{2.97}V_{0.03}O_{12}$ (BTV) thin films with 3 mol% vanadium doping were Prepared on $Pt/Ti/SiO_2/Si$ substrate by sol-gel method. X-ray diffraction analysis indicated that single-phase layered perovskite were obtained and preferred orientation was not observed. Under the annealing temperature at $600^{\circ}C$, the surface morphology of the BTV thin films had fine-rounded particles and then changed plate-like at $650^{\circ}C$ and $700^{\circ}C$. The remanent polarization $(2P_r)$ and coercive field $(2E_c)$ of $700^{\circ}C$ annealed BTV thin film were 25 $\mu$C/cm$^2$ and 116 kV/cm, respectively. In addition, BTV thin film showed little polarization fatigue during $10_9$ switching cycles. These improved ferroelectric properties were attributed to the increased rattling space and reduced oxygen vacancies by substitution $Ti^{4+}$ ion (68 pm) with smaller $V^{5+}$ ion (59 pm). The dielectric constant and loss were measured 130 and 0.03 at 10 kHz, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.3
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• pp.288-296
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• 1992

This paper describes an improved 2D QPS(quadrature polar separable) filter design and its applications to texture processing. The filter kernel pair consists of the product of a radial weighting function based on the finite PSS (prolate spheroidal sequences) and an exponential at tenuation function for the orientational angle. It is quadrature and polar separable in the frequency domain. It is near optimal in the energy loss because we let the orientational angle function approximate the radial weighting function. The filter frequency characteristics is easy to control as it depends only upon the design specifications such as the bandwidth, the directional angle, the attenuation constant, and the shift constant of the central frequency. Some applications of the filter in texture processing, such as the generation of the texture image, the estimation of orientation angles, and the segmentations for the synthetic texture image, are considered. The result shows that the filter with the wide bandwidth can be used for the generation of discrimination of the strong orientational textures and the segmentation results are good.

• Archives of Plastic Surgery
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• v.33 no.6
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• pp.711-714
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• 2006

Purpose: Contralateral reduction mammaplasty at the time of breast reconstruction using autogenous tissue gives aesthetically improved results in the patients with mammary hypertrophy or ptosis. It also reduces required flap size for reconstruction and permits discarding zones of poor perfusion, decreasing flap size-related problems such as partial flap loss or fat necrosis. Considering the high rate of bilaterality of breast cancer, it also provides a good opportunity for exploration and occult cancer diagnosis in such high risk group patients. Methods: We retrospectively reviewed 45 consecutive patients who underwent simultaneous breast reconstruction and contralateral reduction mammaplasty was performed about surgical technique, pathologic diagnosis, and subsequent treatment. Results: Three occult breast cancers were found in 45 patients(6.7%); one was microinvasive, and the other two were invasive carcinomas and their mean diameter was 1.2 cm. One patient underwent subsequent breast conserving mastectomy, adjuvant radiation and chemotherapy. The others underwent only radiation and hormone therapy. They were followed up for 10 to 42 months without evidence of recurrence or metastasis. Conclusion: Occult breast cancer diagnosed in reduction mammaplasty specimen will lead to good prognosis due to its early detection. Treatment options depend on pathologic finding, stage, marginal status, and the timing of diagnosis. We recommend adequate markings for orientation and margins, excision with sufficient margin, and confirmation by frozen biopsy for suspected lesions.

• Korean Institute of Interior Design Journal
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• v.23 no.3
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• pp.39-47
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• 2014

This study was initiated by the fact that modern architecture caused the loss of placeness by seeing place with wrong interpretation and method and provided people with a phenonenon of separation between the depth of experience and honesty. As a solution for such problems, this study intended to suggest a direction through an analysis on the works of Geoffrey Bawa who was recognized as 'a genius of place' and the investigation on the place characteristics of his representative work 'Lunuganga'. Its process was as follows; First, this study explored the characteristics of the place, Sri Lanka, which was the background of his architectures, to see its impact on his life and architecture. Second, based on his representative works of each period and the contents that he mentioned in literature, the general characteristics appearing in his architectures were identified. Third, through an analysis on the work, Lunuganga, the place characteristics appearing in his architectures were investigated. Through such process, it could be recognized that Geoffrey Bawa's architectures reveal the place characteristics as nature, place characteristic as journey and stay, and place characteristic as sense. In this study, it could be verified that place was integrated and applied to Geoffrey Bawa's architectures through the above characteristics and the spaceness was manifested. Through this, this study intended to suggest an orientation for the above problems.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.592-599
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• 2004

Talus topography is that weathered rock clasts were accumulated dropping in steep slope to action of gravity. Rock fall talus is formed by the accumulation of rock debris falling as individual particles from a cliff. If the collapse is produced in talus slope. it will be possible the loss of manpower and country. Despite correct access about talus is required, domestic research was scientific access about talus short because of short resolution of aerophoto and difficulties of research about huge talus. In this Study, Our research team analgize the wetness index using the geomorphogical data. Lineament through wetness index is simillar with distribution of the talus. And, the aim of the present study is to review and compare fabric data derived from rock fall talus about orientation, distribution and morphology. These deposits tend to have approximately equal amounts of clasts oriented parallel and perpendicular to the dip direction of the slope. And, platy- shaped clasts dominate the proximal and intermediate parts of the talus, wheres blocky-shaped clasts is more common in the distal part. we carry out Rock Fall Simulation. And, We install criteria of the rockfall protective barrier using talus and geomorphological characteristics.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.5
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• pp.434-444
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• 1991

An improved 2-D quadrature polar separable (QPS) filter and its applications to texture processing are discussed in thie paper. The frequency response of the filter consists of two independent parts. The first is a radial weighting function based on the prolate spheridal sequence(PSS). The second is the same orientational function of the angle as in the Knutsson filter. The new filter is suboptimal in the energy loss because we let the polar angle function approximate the radial weighting function as in the 2-D Cartesian filter composed of two PSS's. It is easy to control as it depends only upon the design specification of the bandwidth, the drectional agnle, and the central freqneucy. Also the filter is circularly more symmetric in the frequency domain than the Knutsson filter. In order to estimate the orientation and the frequency component of loca textures in the frequency domain, some applications of the new filter, such as the generation of synthetic textures, the estimation of texture orientations, and texture segementations, are discussed.