• 열처리공학회지
• /
• 제16권1호
• /
• pp.10-15
• /
• 2003

In Nb, V and Ti added steels, carbo-nitrides are formed due to their strong interaction with C and N. The formation of carbo-nitrides has an important role to control the microstructure as well as mechanical properties by grain size refinement and precipitation hardening. However, the quantitative analysis of distribution of precipitates and the effect of precipitates on the phase transformation and mechanical properties are still far from satisfactory. In this study, the quantitative analysis of precipitates in austenite was investigated using the fact that the formation of precipitates in Nb, V and Ti added steels accelerates austenite/ferrite transformation. The formation of precipitates was controlled by adjusting holding temperature and time in austenite region, transformed Volume fractions were measured by dilatometer during slow cooling, Iso-precipitation kinetics were determined by comparing 5% and 50% volumes transformed at various conditions respectively. The result was compared with the calculated.

• The Plant Pathology Journal
• /
• 제21권1호
• /
• pp.13-20
• /
• 2005

Chlorella viruses are large icosahedral, plaque-forming, dsDNA viruses that infect certain unicellular, chlorellalike green algae. The genomic DNA of over 300 kb contains many useful genes and promoters. Over 40 chlorella viruses have been isolated from fresh water in Korea since 1998. The viruses were amplified initially in chlorella strain NC64A, and pure isolates were obtained by repeated plaque isolation. SDS-PAGE analysis revealed similar but distinct protein patterns, both among the group of purified viruses and in comparison with the prototype chlorella virus PBCV-1. Digestions of the 330- to 350-kb genomic DNAs with 10 restriction enzymes revealed different restriction fragment patterns among the isolates. The tRNA-coding regions of 8 chlorella viruses were cloned and sequenced. These viruses contain 14-16 tRNA genes within a 1.2- to 2-kb region, except for the SS-1 isolate, which has a 1039-bp spacer in a cluster of 11 tRNA genes. Promoter regions of several early genes were isolated and their activities were analyzed in transformed chlorella. Some promoters showed stronger activity than commonly used CaMV 35S promoter and chlorella transformation vectors for heterologous protein are beings constructed using these promoters.

• 한국세라믹학회지
• /
• 제37권4호
• /
• pp.359-367
• /
• 2000

Particulate composites of Al2O3/SiC, Al2O3/ZrO2 and Al2O3/ZrO2/SiC have been fabricated to investigate their R-curve behaviors and toughening mechanisms. Al2O3 containing 30 vol% SiC particles of 3${\mu}{\textrm}{m}$ showed rising R-curve behavior owing to the strong crack bridging by SiC particles. The fracture toughness reached 9.1 MPa {{{{ SQRT {m} }} at the crack length of 1000${\mu}{\textrm}{m}$. On the other hand, ZrO2-toughened Al2O3 had a high flat R-curve since it rose steeply in the short crack region due to the well known transformation toughening. For Al2O3/ZrO2/SiC composites, the R-curve behavior was similar to that of Al2O3/SiC but with slightly higher toughness. The SiC particles in this composite decreased the amount of transformable tetragonal phase to reduce the effect of transformation toughening by 50%. It was also found that the fracture toughness of this composite with two different toughening mechanisms was markedly lower than that estimated by the simple addition of two contributions.

• 열처리공학회지
• /
• 제16권4호
• /
• pp.205-210
• /
• 2003

Various types of high strength steel sheets were usually used for improving the automobile safety and fuel efficiency by reducing the vehicle weight. The present study aimed to develop the TRIP (transformation induced plasticity) aided high-strength low carbon steel sheets by using a reverse transformation process. The 0.1C-4~8Mn steels were reverse-transformed by slow heating to intercritical temperature region and then furnace cooled to the room temperature. Granular type retained austenite was observed in 4Mn steel and lath type retained austenite was also observed in 6~8Mn steel. The results show that the 6Mn steel under reverse transformed at $625^{\circ}C$ for 6 hrs has maximum elongation up to 39%. The optimum strength-elongation combination was 3,888 ($kg/mm^2{\times}%$) when the 8Mn steel was reverse transformed at $625^{\circ}C$ for 12 h.

• 대한건축학회논문집:계획계
• /
• 제34권4호
• /
• pp.133-140
• /
• 2018

This study is change of the street space of the port city of Yokohama and the transformation process of the canal. modern port city Yokohama is a region that was responsible for the development of East-West maritime transport routes in Japan in the 17th century and the inland transportation through fishing villages and ports. it has also grown rapidly as a regional port and new port. In particular, through the revitalization of trade between foreign settlements and Japanese residents in the port area, the existing fishing area became a modern port city space. Yokohama went through the following process and grew into a modern port city. The construction of the port harbor and the maintenance of existing logistics functions, the formation of the central horizontal axis through maintenance of the fishing village, the construction of the logistics movement route to the inland area through the construction of the canal, the expansion of the horizon for fire prevention and fire restoration, The formation of a new settlement space according to the movement, the transformation of the existing religious axis by the combination of the elaboration and the introduction of modern transportation, and the spatial connection between the inland cities.

• Journal of Microbiology
• /
• 제44권5호
• /
• pp.515-522
• /
• 2006

A cDNA library of Ganoderma lucidum has been constructed using a Zap Express cloning vector. A glyceraldehyde-3-phosphate dehydrogenase gene (gpd) was isolated from this library by hybridization of the recombinant phage clones with a gpd-specific gene probe generated by PCR. By comparison of the cDNA and the genomic DNA sequences, it was found that the complete nucleotide sequence encodes a putative polypeptide chain of 338 amino acids interrupted by 6 introns. The predicted amino acid sequence of this gene shows a high degree of sequence similarity to the GPD proteins from yeast and filamentous fungi. The promoter region contains a CT-rich stretch, two CAAT boxes, and a consensus TATA box. The possibility of using the gpd promoter in the construction of new transformation vectors is discussed.

• Journal of Plant Biotechnology
• /
• 제7권4호
• /
• pp.225-231
• /
• 2005

Five day old cotyledon explants of Cucumber (Cucumis sativus L) cv Poinsett 76 were cocultivated with two Agrobacterium strains (EHA105 and LBA 4404) each carrying GUS as the reporter gene and npt-II as the selection marker gene in the T-DNA region of the vector. Transformed shoots were selected at 150 mg/L kanamycin. A two day cocultivation coupled with $20\;{\mu}M$ acetosyringone increased the frequency (8.2 and 15.4 shoots) of GUS expression in the shoots of transformed plant. Among the two Agrobacterium strains, EHA 105 performed better than LBA 4404 in bringing two-fold increase in transformation efficiency (14%) than LBA 4404 (7.4%). PCR analysis was done to confirm the integration of T-DNA into cucumber genome.

• 제어로봇시스템학회논문지
• /
• 제9권11호
• /
• pp.937-942
• /
• 2003

We present a self-localization method for mobile robots using vertical line features of indoor environment. When a 2D map including feature points and color information is given, a mobile robot moves to the destination, and acquires images from the surroundings having vertical line edges by one camera. From the image, vertical line edges are detected, and pattern vectors meaning averaged color values of the left and right regions of the each line are computed by using the properties of the line and a region growing method. The pattern vectors are matched with the feature points of the map by comparing the color information and the geometrical relationship. From the perspective transformation and rigid transformation of the corresponded points, nonlinear equations are derived. Localization is carried out from solving the equations by using Newton's method. Experimental results show that the proposed method using mono view is simple and applicable to indoor environment.

• 한국실내디자인학회논문집
• /
• 제19권2호
• /
• pp.33-41
• /
• 2010

This study aims to analyze the typological characteristics of Alvar Aalto's library design. The unique characteristics of Aalto's architecture are the result of accommodating Modern architecture with regional qualities of Finland. Besides this, Aalto's typological approach in design made his color. The library might be the best example for understanding his design approach in that he showed 3 main features of type; wholeness, self-control and transformation. He established architectural types in his 30s through Viipuri public library and developed so-called fan type library plan. Aalto's library type is not a simple copy of exterior and interior form. It acts as a principle of configuration of his library architecture and applied to the building. Therefore, Aalto's library architecture can be recognized as the results of typological design approach in that it shows the transformation of type in according to factors including site, size, region and cultural tradition. In conclusion, Aalto's libraries reveal the typological characteristics in the field of building layout, dynamic space and the effective use of light.

• 전자공학회논문지B
• /
• 제33B권4호
• /
• pp.124-130
• /
• 1996

A compensation method of color error resulting from dynamic range transformation of color image is propsoed. The color error is measured using the CIE L a b uniform color space, and the color image is compensated to minimize it. The color error is significant in the dark region of image, which is caused by the lunimance scaling factor is relatively large in that case. In the proposed method, we weight the luminance scaling factor corresponding to luminnce to minimize the error. Because the weighting factor depends on luminace distribution of image, a decisio method of weighting factor using histogram is also proposed.