• Carbon letters
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• v.3 no.3
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• pp.127-132
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• 2002

Unidirectional polymer composites were prepared using high-strength carbon fibers as reinforcement and phenolic resin as matrix precursor with keeping fiber volume fraction at 30, 40, 50 and 60% respectively. These composites were carbonized at $1000^{\circ}C$ and graphitised at $2600^{\circ}C$ in the inert atmosphere. The carbonized and graphitised composites were characterized for mechanical properties as well as microstructure. Microscopic studies were carried out of the polished surface of carbonized and graphitised composites after etching by chromic acid, to understand the effect of fiber volume fraction on oxidation at fiber-matrix interface. It is found that the flexural strength in polymer composites increases with fiber volume fraction and so does for the carbonised composites. However, the trend was found to be reversed in graphitised composites. In all the carbonized composites anisotropic region has been observed at fiber-matrix interface which transforms into columnar type microstructure upon graphitisation. The extension of strong and weak columnar type microstructure is function of fiber volume fraction. SEM microscopy of the etched surface of the sample reveal that composites containing 40% fiber volume has minimum oxidation at the interface, revealing a strong interfacial bonding.

• Journal of Microbiology and Biotechnology
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• v.6 no.6
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• pp.445-450
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• 1996

Gelatinase A is a member of the matrix metalloproteinases that play an important role in cancer invasion and metastasis. In the course of screening gelatinase A inhibitors from microbial sources, a fungal strain PT-262 showed a strong inhibitory activity. The strain was identified as Chaunopycnis alba on the basis of its morphological characteristics. The inhibitor was isolated from acetone extract of mycelial cake by sequential chromatographies on MCI-gel, Sephadex LH-20, and a reverse-phase HPLC column. The purified inhibitor was identified as pyridoxatin by its physico-chemical properties and spectroscopic analysis. Pyridoxatin is not a peptide analog and has cyclic hydroxamic acid moiety. It inhibited activated gelatinase A with an $IC_{50}$ value of 15.2 ${\mu}M$ using fluorescent synthetic peptide. It also had a strong cytotoxicity against human cancer cell lines in vitro. Furthermore, this compound inhibited DNA synthesis with an $IC_{50}$ value of 2.92 ${\mu}M$ in PC-3 prostate cancer cells by [$^3H$]thymidine incorporation assay.

• Korean Institute of Interior Design Journal
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• v.18 no.6
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• pp.202-210
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• 2009

This research was undertaken to prove the relationship between street mall activation and architectural plan design. The research methodology was established based on the analysis of data of two existing street malls in Korea (Western Dome & LaFesta) and theoretical studies of outdoor space design. The findings from this study are the following: First, building blocks with segments in every 50m or so are ideal for detailed communication between visitors and building contents. Second, the ratio of width of main corridor and building height should be less than 1 to provide intimate feel and keep visitors' attention concentrated in the facility. Third, store unit should have more storefronts to be exposed more to passers-by and lead more pedestrian traffic. Fourth, shape of store unit would rather be wide and shallow, instead of narrow and deep, to have more exposure to the central corridor. Fifth, the building block of the busiest(most expensive) area that is usually at the main entrance area of street mall should be flexible to fit more smaller units to maximize the profitability. Sixth, the main entrance of store should face the main pedestrian corridor to induce the influx of visitors. Lastly seventh, anchor tenant that has strong name recognition is usually located on basement or higher level to induce pedestrian traffic into the mall, key tenants that are strong and familiar brand names should be located at the corner of building block with spacing to attract visitors, provide even distribution of traffic, and support wayfinding, and local tenant should be located at small units along the central corridor or remainder spaces occurred from building core layout.

• Structural Engineering and Mechanics
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• v.15 no.3
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• pp.285-297
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• 2003

Complementing recent advances made in the field of structural health monitoring and damage detection, the concept of a wireless sensing network with distributed computational power is proposed. The fundamental building block of the proposed sensing network is a wireless sensing unit capable of acquiring measurement data, interrogating the data and transmitting the data in real time. The computational core of a prototype wireless sensing unit can potentially be utilized for execution of embedded engineering analyses such as damage detection and system identification. To illustrate the computational capabilities of the proposed wireless sensing unit, the fast Fourier transform and auto-regressive time-series modeling are locally executed by the unit. Fast Fourier transforms and auto-regressive models are two important techniques that have been previously used for the identification of damage in structural systems. Their embedment illustrates the computational capabilities of the prototype wireless sensing unit and suggests strong potential for unit installation in automated structural health monitoring systems.

• MALSORI
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• no.35_36
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• pp.101-119
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• 1998

By analyses of lullabies, nursery rhymes, Christmas carols, and pop songs, the relevances of beat, syllable and note are set up as follows. (1) The relevance of beat to syllable a. A stressed syllable can occupy a strong beat. b. A monosyllabic word carrying a strong beat must have the syllabic structure of a strong syllable. (2) The note duration a. The duration of a note carrying a strong beat tends to be as long as or longer than that of a note carrying a weak beat. b. The note connected with the last position of phonological unit tends to be longer than that of other position without regard to the syllabic structure.

• Communications of the Korean Mathematical Society
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• v.37 no.2
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• pp.445-454
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• 2022

Using the concept of the strong differential subordination introduced in [2], we find conditions on the functions θ, 𝜑, G, F such that the first order strong subordination θ(p(z)) + $\frac{G(\xi)}{\xi}$zp'(z)𝜑(p(z)) ≺≺ θ(q(z)) + F(z)q'(z)𝜑(q(z), implies p(z) ≺ q(z), where p(z), q(z) are analytic functions in the open unit disk 𝔻 with p(0) = q(0). Corollaries and examples of the main results are also considered, some of which extend and improve the results obtained in [1].

• Bulletin of the Korean Mathematical Society
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• v.50 no.1
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• pp.125-134
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• 2013

An element in a ring R is strongly clean provided that it is the sum of an idempotent and a unit that commutate. In this note, several necessary and sufficient conditions under which a $2{\times}2$ matrix over an integral domain is strongly clean are given. These show that strong cleanness over integral domains can be characterized by quadratic and Diophantine equations.

• CDE review
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• v.21 no.2
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• pp.50-60
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• 2015

Corresponding to the high consumption rate of the selfie stick for cell phone camera, the design of the product is becoming diverse. However, relatively low cost selfie stick models are not strong enough to stand the weight of the cell phone. This results into a bending of the stick or the accidental fall of the cell phone by the failure of the holding unit. As a solution to the problem, design of selfie stick that is structurally strong enough to stand the weight of the cell phone with the minimum weight for the portability is proposed in this paper.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.344-346
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• 2002

The pneumatic/nydraulic brake system is recently apply to the AGT system such merit as installation is convenient and brake force is strong or than pneumatic brake system. The pneumatic/ hydraulic brake system consist of brake operating unit, electronic control unit, air compressor and pneumatic/hydraulic tranducer. The components of it are controlled and designed to perform the function of brake system. Therefore, This paper design and the pnuematic/hydraulic brake system and propose the derection of development for AGT system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.1
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• pp.42-47
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• 2016

Adjacent housing units suffer inevitable thermal losses if an unheated unit exists in an apartment building. Thermal loss of the units adjoining the unheated apartment can be neglected because the contact area is small and insulators are located in the walls. When insulators are not included in the slab between the upper and lower units, 70% of the heat supplied by an Ondol system may be used in the original unit, but 30% is transferred to the unit on the lower floor. Another 30% can be obtained from the ceiling if the upper floor housing unit is heated. This strong thermal connection is a characteristic of Ondol heating in apartment buildings. When there is an unheated unit, the lower floor unit uses 42.3% more heating energy if there is no insulation and 19.5% if a 35 mm insulator is used as in the current guidelines. Therefore, much thicker insulation should be applied to weaken the thermal connection.