• Journal of Sensor Science and Technology
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• 제9권5호
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• pp.365-372
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• 2000

In this study, a multichannel taste sensor using the evanescent field absorption in fiber optic was developed, and evaluated its characteristics for several basic taste substances. This sensor is based on the change of evanescent field absorption at the surface of optical fiber core layer. The sensor device was made of a plastic-clad-silica fiber (3M Co., FP-400-UHT, core diameter $400\;{\mu}m$) and a middle portion of cladding layer was removed and the surface of stripped fiber core was dip-coated with a sensing membrane. And then, it was determined the difference of evanescent field absorption into the sensing membrane, according to various taste substances and its concentrations variance. The sensing membranes were prepared with six kinds of dyes, were known as potential sensitive dye together with silicone polymer the same refractive index of cladding. Each output patterns were obtained from the sensor devices could be distinguished not only five kinds of basic taste substances such as sweetness, saltiness, sourness, bitterness and umami, but also various mixed taste substances.

• The Journal of the Petrological Society of Korea
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• 제24권2호
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• pp.91-105
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• 2015

Jungtaesan and Galpyeongji intrusions in the northeastern Cheongsong occur as laccolith and stock which intrude Gasongdong Formation and Dogyedong Formation, respectively. Cheongsong dike swarm, intruding the Dogyedong Formation, is closely associated with this stock. The dike swarm is more radial to focus into Galpyeongji and its outline is oval. The dikes of the dike swarm are only rhyolite dikes with flow banded, spherulitic and rare stony structures, and represents a single intrusive phase of magma. It can be interpretated that orientation of the dikes is controlled by stress states. Therefore, the dikes display a radial pattern through occupying vertical joints that have been generally attributed to radial fractures formed during doming of the sedimentary rocks by the intrusion of the Galpyeongji stock. The dike pattern could sufficiently account for dike injections into these joints.

• The Journal of the Acoustical Society of Korea
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• 제20권4호
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• pp.48-53
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• 2001

In this paper, selectively attentive learning method has been proposed to improve the learning speed of multilayer Perceptron based on the error backpropagation algorithm. Three attention criterions are introduced to effectively determine which set of input patterns is or which portion of network is attended to for effective learning. Such criterions are based on the mean square error function of the output layer and class-selective relevance of the hidden nodes. The acceleration of learning time is achieved by lowering the computational cost per iteration. Effectiveness of the proposed method is demonstrated in a speaker adaptation task of isolated word recognition system. The experimental results show that the proposed selective attention technique can reduce the learning time more than 60% in an average sense.

• Korean Journal of Environment and Ecology
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• 제8권2호
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• pp.167-176
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• 1995

Autumn visitors to Chuwangsan National Park was more than summer's. About 89% of total visitors used main trail but approximately 35% visited to the Third Falls. The entire width, bare width, maximum depth and slope of trail as the trail condition surveyed at the total of 103 points were significantly greater on the more heavily-used trail. Trail conditons of rock-exposed, root-exposed, deepening points as the deterioration types of trail were significantly different from those of non-deteriorated points. According to the topographic position of trail, severe difference of dominant trees in the edge vegetation was found and Lespedeza maximowiczii, Rhododendron yedoense and Fraxinus sieboldana were dominant in shrub layer of trail edge vegetation. The crown coverage, number of species and individuals of shrub layer in edge vegetation were generally higher than those in the other national parks with more heavily-used trail.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.174-174
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• 1999

Pt(001)의 깨끗한 표면은 재배열된 (5x20) 또는 (nxn) 구조를 갖는다. 이러한 재배열된 구조는 소？의 가스를 흡착에 대해서도 (1x1)구조로 다시 재배열되는 재배열인 쉽게 풀리는 준안정적 재배열 구조를 갖는 표면이다. Pt(100) 표면 위에 Ni과 같은 금속을 흡착시키는 경우도 동일하게 표면의 장력을 해소시켜 (1x1) 표면을 만든다. Pt와 Ni과 같은 덩어리 상태에서 Pt와 Ni가 질서있게 교차되어 배열되는 합금이 쉽게 이루어지는 물질들로 잘 알려져 있고, 이 합금은 Pt나 Ni와 동일한 규칙적인 fcc 구조를 갖는다. 따라서 Pt(100) 표면 위에 Ni를 흡착시키는 것은 Nm/Cu(100)과 같은 표면합금이나 Mn/Ag(1000에서 보이는 2층으로 된 표면 합금과 같은 표면 근방에 국한된 질서있는 표면 합금의 가능성이 있다. 또한 Ni/Pt(100)은 Ni과 Pt가 3대 1의 비로 조합될 때 나타나는 Ni3Pt의 층별구조인 표면에 Ni가 채워져 있고, 다음 층에 Ni와 Pt가 50%씩 질서 있게 섞여 있는 형태의 구조 즉 표면 밑 합금이 나타날 수 있는 가능성이 있는 물질계라는 점에서 관심을 갖게 한다. 본 연구는 LEED를 이용하여 Ni/Pt(100) 박막의 층별구조를 확인하고자 한다. PtNi 합금은 ATA(average t-matirx approximation)을 이용한 LEED 분석이 잘 적용되는 물질계로 알려져 있고, 본 연구는 ATA를 적용한 LEED I/V 분석을 통하여 Ni가 성장된 Pt(100) 표면의층별 농도비와 층별 구조를 구하고자 한다. 실험은 기본 압력이 3x10-11torr인 챔버에서 이루어졌으며, 증착시 압력은 5x10 torr이고, 증착은 열증발 방법을 이용하였다. Ni가 증착됨에 따라 (nxn) 재배열 표면에 기인한 extra spot들의 세기는 점차 감소하고 특정 증착량 이상에서부터 이 (nxn)의 spot들이 사라지고 깨끗한 (1x1) 패턴이 나타난다. 계속되는 증착량의 증가에 대해서도 이 (1x1) 형태는 유지되며, 표면의 질서에 따르는 c(2x20 패턴은 보이지 않았다. (1x1) LEED spot를 보임에도 불구하고 덩어리 절단 형태의 구조를 기반으로 한 LEED I/V 분석으로는 잘 맞출수 없었다. 이것은 Ni가 일정 이상 흡착된 경우 그 구조가 덩어리 절단 형태의 fcc(100) 구조와 벗어난 구조를 가지는 것으로 보인다.

• Journal of Korean Society of Steel Construction
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• 제20권6호
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• pp.751-759
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• 2008

In this study, the effect of an unsteady flow field around a body of aerostatic/aerodynamic forces were investigated using rectangular cylinders (B/D = 2, 3, 4, 5). Proper orthogonal decomposition (POD) was introduced to the analysis of the fluctuating pressure field that was measured on the stationary/oscillatory B/D=4 rectangular cylinder, and the characteristics of the proper functions with flow patterns were identified. In addition, the physical decoupling and interactions in the different co-existing flow patterns were investigated through POD. The comparison with the identified proper function associated with a particular flow pattern revealed that the Karman vortex is almost not affected by the separation bubble, but that the Karman vortex considerably interferes in the development of the separation bubble around the trailing edge. It can be considered that the Karman vortex induces the increment of the curvature of the substantial separated flow.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제36권12호
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• pp.1563-1568
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• 2012

Printed electronics is a technology used for forming electronic circuits or devices, and it is used in the manufacture of many products such as RFID tags, solar cells, and flexible display panels with a much lower cost than in the case of semiconductor process technology. Web-guide-type printing such as roll-to-roll printing is a method used to produce printed electronic devices in a large volume. To commercialize such products, highly precise alignment between printed layers is required. In this study, a highly precise alignment system is proposed, and some experimental results are compared with those obtained using a laser surface vibrometer to illustrate the reliability of the proposed system. The robustness of the proposed system to web deformation is also considered experimentally.

• Journal of the Korean Magnetics Society
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• 제9권6호
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• pp.301-305
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• 1999

NiFe(60$\AA$)/Co(5$\AA$)/Cu(60$\AA$)/Co(30$\AA$) spin valve thin films were patterned into magnetoresistive random access memory (MRAM) cells by a conventional optical lithography process and their output and switching properties were characterized with respect to the cell size and geometry. When 1 mA of constant sense current was applied to the cells, a few or a few tens of mV of output voltage was measured within about 30 Oe of external magnetic field, which is an adequate output property for the commercializing of competitive MRAM devices. In order to resolve the problem of increase in the switching thresholds of magnetic layers with the downsizing of MRAM cells, a new approach using the controlled shape anisotropy was suggested and interpreted by a simple calculation of anisotropy energies of magnetic layers consisting of the cells. This concept gave a reduced switching threshold in NiFe(60$\AA$)/Co(5$\AA$) layer consisting of the patterned cells from about 15 Oe to 5 Oe and it was thought that this concept would be much helpful for the realization of competitive MRAM devices.

• Journal of the Korean earth science society
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• 제33권6호
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• pp.534-543
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• 2012

The relationship between tectonic uplift and geophysical analysis of gravity anomalies and the in-situ stress fields in the Otway Ranges, SE Australia is addressed in this study to understand the nature and possible mechanism for the neotectonic movements. The uplift axis of the ranges is coincident with the regional Bouguer gravity highs whereas thick Tertiary sedimentary successions are highly correlated with the gravity lows along the basin rift geometry. This result suggests that the gravity highs are separated by the thick Tertiary sedimentary successions. Regional structural trends associated with faults and foldings of the deformed surfaces are consistent with the prevailing NW-SE $S_{Hmax}$ trend in this part of the continent. The anomalously positive correlation between topography and Bouguer gravity fields suggests possibly a lithospheric flexural deformation mode at a long wavelength (order of $10^2$ kms) in the region. It also suggests that the reactivation of pre-existing lithospheric structures driven by plate boundary forces plays a key role in this mode.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제28권6A호
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• pp.414-424
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• 2003

In this paper, a multiple U-shaped slot antenna for 5.25㎓~5.35㎓ is designed, fabricated, and measured. The prototype consists of U-slot and two invert U-slot. To obtain enough bandwidth, the foam layer is inserted between ground plane and substrate. Important parameters in the design are U-slot length, width, position, airgap length, and feed point. From these parameters optimized, a multiple U-shaped slot antenna is fabricated and measured. The measured results of the antenna are compared with its simulated results. The resonant frequency of the fabricated multiple U-shaped slot antenna is 5.25㎓ the bandwidth for approximately 7.4%(VSWR<1.5) and the gain is 2.9~5.3dBi. The experimental far-field patterns are stable across the pass band. The 3dB bandwidth in H-Plane and I-Plane are 62$^{\circ}$ and 50$^{\circ}$, respectively.