• Electrical & Electronic Materials
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• v.5 no.2
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• pp.224-236
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• 1992

본 논문에서는 내부전극을 갖는 마이카-에폭시 복합시료의 계면정합상태에 따른 계면층에서의 절연파괴특성에 대해 조사 연구하였다. 실험결과, 계면은 이상수지층으로 작용되며 마이카는 계면결합제와의 화학적반응 및 흡착에 의해 친수성이 적어짐을 확인하였고 또한 계면의 정합상태는 계면결합제의 수용액 농도에 의해 좌우되었다. 계면정합이 불량하면 인가전압의 상승에 따라 부분방전량의 증가 및 발생빈도의 직선적인 증가 특성이 보이며 계면정합이 양호한 경우는 방전량이 포화되는 시점에서 발생빈도는 지수함수적으로 증가되었다.

• Applied Microscopy
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• v.20 no.2
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• pp.57-70
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• 1990

Characterization and electron microscopic visualization of the plasmid and the gene expression of Escherichia coli were carried out. Transcriptional units of active structural genes were observed after lysis of Escherichia coli cells. The ribosomes attached to the E. coli genome on mRNA molecule as polyribosomes. From this gradient of polyribosome length, we estimated location of mRNA synthesis initiation site. In this experiment, a granule is ofen present which may correspond to a RNA polymerase at the promoter site. pOX1, pOX7, pOX7A, $pOX7{\Delta}1$, pSTP36, pSTP21, pBR322, and pJH12 were visualized by way of electron microscope, and their estimated sizes were determined to be $5.70{\pm}0.08{\mu}m,\;2.15{\pm}0.10{\mu}m,\;2.14{\pm}0.12{\mu}m,\;7.39{\pm}0.08{\mu}m,\;4.03{\pm}0.04{\mu}m,\;1.50{\pm}0.03{\mu}m\;and\;1.25{\pm}0.09{\mu}m$ respectively. One micrometer of measured length corresponded to about 3.0 Kb. Mica-press adsorption method that allows selectivs visualization of the plasmid DNA released in situ from the bacterial cell is rapid and useful for visualization of plasmids. The released plasmid DNA was adsorbed preferently on mica in a divalent cation-free solution. Miller chromatin-spreading method was useful to observe the plasmid and transcripts. BAC method and cytochrome C monolayer were useful to observe the plasmid DNA. Our ability to visualize ultrastructural aspects of the expression of E. coli has given us a unique tool with which to study the regulation the level of an individual gene.

• Economic and Environmental Geology
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• v.22 no.4
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• pp.355-370
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• 1989

Igneous rocks of study area consist of Pre-Cambrian orthogneiss, Devonian granite, Triassic foliated granites and Jurassic granites distributed along the southeast margin of Ogcheon Geosynclinal belt(SE-zone), and irregular shaped granitic stocks in the central part of the belt(C-zone). Anorthosite and gaabbro are also present in southern part of the SE-zone in the belt and intruded into gneiss complex of Ryongnam massif. Distribuition of foliated granites shows three linear arrangements which are composed of hornblende-biotite foliated granodiorite, porphyritic foliated granodiorite, biotite foliated granodiorite, leuco foliated granite and two mica foliated granite. Foliated granites generated by dextral strike slip movement at deep level. Jurassic granites composed of several rock facies are considered to be formed by differentiation of magma during Daebo Orogeny. A general trend of the chemical composition of these igneous rocks in study area suggests that most of them corresponding to calc-alkaline rock series was affected under orogeny and I-type granite except for two mica foliated granite. In chondrite normalised REE pattern of these igneous rocks, LREE shows more variable range and strong (-)Eu anomaly than HREE. Geochronological episodes of igneous activity from early Proterozoic to Cretaceous in SE-zone of Ogcheon Geosynclinal belt are two more Pre-Cambrian Orogeny, Devonian Orogeny(Variscan), Songrim Disturbance, Daebo Orogeny and Bulkuksa Disturbance.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.11
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• pp.572-580
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• 2007

Wireless sensor networks are sensing, computing and communication infrastructures that allow us to monitor, instrument, observe, and respond to phenomena in the harsh environment. Generally, the wireless sensor networks are composed of many deployed sensor nodes that were designed to be very cost-efficient in terms of production cost. For example, UC Berkeley's MICA motes have only 8-bit CPU, 4KB RAM, and 128KB FLASH memory space. Therefore, sensor operating systems that run on the sensor nodes should be able to operate efficiently in terms of the resource management. In this paper, we present a dynamic threads stack management scheme for space-constrained and multi-threaded sensor operating systems. In this scheme, the necessary stack space of each function is measured on compile-time. Then, the information is used to dynamically allocate and release each function's stack space on run-time. It was implemented in Nano-Qplus sensor operating system. Our experimental results show that the proposed scheme outperforms the existing fixed-size stack allocation mechanism.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1510-1518
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• 2006

As a promising technology that enables ubiquitous computing and leads IT(information Technology) industries of next generation, the exciting new field of sensor networks is attracting so much attention and considered to be the one of the hottest research topics these days. From now on, all the each node, forming a network, and even the sensor network itself will interact with the generic network and evolve dynamically according to the change of environment with the perpetual creation and extinction. In this paper, we purpose the dynamic address interworking scheme for interactive networking between sensor network and Internet(IPv6). Proposed scheme is enable to interworking dynamically between sensor network address scheme based on Zigbee and Internet address scheme based on IP. Additionally, we implement the proposed address interworking scheme using Berkeley TinyOS, mica motes, and IP protocol. And, we verify the proposed scheme by the interconnection experimental between wireless sensor networks and Internet based on IPv4/IPv6.

• Economic and Environmental Geology
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• v.16 no.2
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• pp.111-123
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• 1983

The studied area is situated in tho southern part of the Ogcheon fold belt, where the "Ogcheon Group" is widespread with Jurassic and Cretaceous intrusions. The regional stratigraphy may be divided into three formations, the lower pebble bearing phyllitic, the middle dark grey phyllitic, and the upper black phyllitic formations. For the purposes of the present study, the area has been partitioned to three structural subareas based on major fold axes and fault line. The main subjects of the research have been discussed from two different points, multiple deformation and minor-micro fold styles. The former is analyzed by pebble elongation, folding and lineation in a pebbly formation as well as schistosity, crenulation cleavage and crenulated lineation in the phyllitic formation. The later describes the characteristic features of fold style in each formation and structural subarea. Although minor fold axes within broad pelitic rocks usually tend to trend northeast and to plunge northward, most of these were probably formed by two stages, first a similar fold phase and second a kink fold phase. Measured structural elements indicate that crenulation cleavage in phyllite formed parallel to fold axes of folded pebble followed a NE phase of first deformation and a fold axes of pebbles diagonal to bedding of phyllite are represented by a NW phase of a second deformation. Microscopically, quartz and mica grains form a micro fold enabling one to establish tectonic levels which occur in different deformation modes in each stratigraphic sequence. Microtextures such as crenulation cleavage, kink band, aggregate band of mica and pressure shadows of porphyroblast of quartz related to qarnet and staurolite may suggest the time relation of crystallization and tectonism. The result of this study may conform that three deformation phase, NE first phase-NE second phase-NW phase, occurred in the area.

• Economic and Environmental Geology
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• v.23 no.1
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• pp.87-104
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• 1990

Foliated granites between Damyang and Jinan are subdivided into Daegang foliated granite, Foliated hornblende biotite granodiorite, Sunchang foliated granodiorite, Foliated two mica granite and Samori foliated granite by mineral and texture. From EPMA data of the foliated granites following results are achieved. Composition of plagioclase are correspond to andesine, oligoclase and albite in Foliated hornblende biotite granodiorite, Sunchang foliated granodiorite and other foliated granites, respectively. And amphiboles are calcic hornblende in Foliated hornblende biotite granodiorite, and riebeckite in Daegang foliated granite. In differentiation index(D. I.) and Larsen index(L. I.), Daegang foliated granite, Foliated two mica granite and Samori foliated granite which belong to granite are 83.12-95.54 and 25.86-29.05 and Foliated hornblende biotite granodiorite and Sunchang foliated granodiorite of diorite to granodiorite are 54.99-78.54(D. I.) and 6.48-21.01(L. I.). Harker and AMF diagrams plotted from foliated granites show that the granites are product of calc alkali rock series orignated from co-magma. Characteristic foliation of foliated granites fromed by ductile deformation at deep zone of dextral strike slip fault. Foliated granites are considered as a series of differentiated product of Triassic Igneous activity of Songrim disturbance. According to REE, (La/Lu) and Eu/Sm, Foliated hornblende biotite granodiorite and Sunchang foliated granodiorite are correspond to granodiorite, and other foliated granites are monzo-and syeno-granite. Foliated granites having 0.20-0.01 of Em/Sm ratio are plutons emplaced by the tectonic setting in continents and continental margin.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9B
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• pp.832-844
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• 2008

Distributed localization algorithms are necessary for large-scale wireless sensor network applications. In this paper, we introduce an efficient node distribution based localization algorithm that emphasizes simple refinement and low system load for low-cost and low-rate wireless sensors. Each node adaptively chooses neighbor nodes for sensors, update its position estimate by minimizing a local cost function and then passes this update to the neighbor nodes. The update process considers a distribution of nodes for large-scale networks which have same density in a unit area for optimizing the system performance. Neighbor nodes are selected within a range which provides the smallest received signal strength error based on the real experiments. MATLAB simulation showed that the proposed algorithm is more accurate than trilateration and les complex than multidimensional scaling. The implementation on MicaZ using TinyOS-2.x confirmed the practicality of the proposed algorithm.

• Journal of the Korean Vacuum Society
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• v.15 no.4
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• pp.367-373
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• 2006

We have observed a large increase in the magnetoresistance (MR) of Bi thin films, which were subjected to a post-annealing procedure at $268^{\circ}C$C, $3^{\circ}C$ below the Bi melting point. We have achieved an increase in the MR by 260-fold and 1200-fold at 5 K and 5 T after post-annealing, as compared with 190 and 620 for an as-deposited Bi film on PbTe/CdTe(111) and on mica, respectively. The large MR increase by post-annealing might be due to the improvement of crystallinity according to the x-ray analysis. However, post-annealing over a certain amount time showed the reduction in MR values.

• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.271-283
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• 1988

A Fourier transform infrared spectrophotometric method was described for the determination of quartz, mica(sericite) and feldspar(potassium feldspar) in respirable dust in Taebaek area. The results were as follows; 1) The concentration of minerals were determined from the intensity of absorption peak of quartz at $799cm^{-1}$, sericite at $539cm^{-1}$, and potassium feldspar at $648cm^{-1}$ respectively. 2) The precision(C. V. %) for the quartz determination was $7.70{\pm}2.68%$ from 10 to $200{\mu}g$ of quartz. 3) The precision for the sericite determination was $16.34{\pm}6.82%$ from 30 to $500{\mu}g$ of serictite. 4) The precision for the potassium feldspar determination was $5.28{\pm}1.74%$ from 30 to $500{\mu}g$ of potassium feldspar. 5) The concentration of respirable dust in Taebaek area was $4.90{\pm}3.29mg/m^3$ (0.4-93.7%), percent quartz was $1.80{\pm}4.14%$ (0.01-20.56%), percent sericite was $11.37{\pm}6.43%$ (0.00-29.69%), percent potassium feldspar was 8.15% (n=7, 3.41-19.70%). 6) The difference of respirable coal dust, quartz, and sericite concentrations in drilling, coal cutting, hauling and seperating was significant respectively (p<0.05).