• 한국항행학회논문지
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• 제15권4호
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• pp.616-625
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• 2011

본 연구에서는 지형을 Rendering 기법의 대표적인 방법인 Geometry Clipmaps와 ROAM 2.0을 분석하여 Rendering 연산에 소요되는 연산을 CPU가 아닌 GPU에 중점을 두어 보다 빠르고 넓은 가시화 영역을 보장하는 확장된 Geometry Clipmaps 알고리즘을 제안한다. 확장된 알고리즘은 LOD(Level of Detail)을 통한 각 레벨의 Mesh 구성 방법, 레벨간의 연결망 Mesh 구성 방법, VFC(View Frustum Culling)을 사용하여 Rendering을 최적화 할 수 있는 Mesh Block화 방안 그리고 최대 1m 해상도를 갖는 고해상도 영상 Mapping 방안 등을 포함하고 있다.

• Ocean Science Journal
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• 제40권3호
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• pp.127-143
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• 2005

The taxonomic sufficiency approach has been proposed as a surrogate for the typical analysis of species-abundance data, especially in conditions involving prominent pollution gradients. Here, we evaluate the use of taxonomic sufficiency with infralittoral macrobenthic data derived from samples taken in a moderate polluted subtropical environment in southeastern Brazil, analysing five taxonomic levels and including two functional levels throughout polychaete feeding guilds and trophic groups. The data were collected seasonally at nine stations and studied for two abundance data series (0.5 and 1.0 mm sieve mesh-size). The results showed a similar ordination pattern between the two sieve mesh-size, but with the 0.5 mm sieve data a different pattern was observed during austral summer. A slight loss of information was detected using genus, family, polychaete species and their feeding guilds as taxonomic/functional units. These results together with those of the cost! benefit ratio, suggested that the family level seemed to be sufficient to detect the impact caused by moderate pollution in this shallow-water, subtropical environment. In additional, through the use of feeding guilds, similar patterns are obtained. Correlation analysis showed that chlorophyll a, total organic matter, zinc, and chromium sediment content were the variables that best explained the biological pattern observed and not always the best correlation coefficient occurring at the species level. The feeding guild approach seems to be useful and generates interpretable results similar to those obtained with the species level of the whole macroinfauna. The results showed an important cost reduction in the sample processing, suggesting that it is possible to adopt a coarser taxonomic level monitoring program even in species-rich communities.

• 한국통신학회논문지
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• 제36권6C호
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• pp.349-354
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• 2011

수동형(passive) 밀리미터파(millimeter wave) 영상은 의복 등에 은닉된 물체의 탐지가 가능하며 악천후의 상황에서도 감쇄도(attenuation)가 낮아 식별이 가능한 영상을 획득할 수 있다. 그러나 영상 시스템의 공간 해상도(spatial resolution)가 낮고 수신신호가 미약하여 잡음의 영향이 크고 시스템의 온도 분해능(temperature resolution)에 따라 영상의 질이 달라진다. 본 논문에서는 수동형 밀리미터파 영상과 일반 카메라부터 획득되는 영상의 정합(registration)과 은닉된 물체의 시각화를 위한 영상 융합(fusion)을 연구한다. 영상의 정합은 추출된 몸체 경계 간의 상호상관도를 최대로 하는 어파인 변환(affine transform)으로 수행되며 융합은 영상 분해를 위한 이산 웨이블릿 변환(discrete wavelet transform), 융합 법칙(fusion rule), 영상을 복원하기 위한 역 이산 웨이블릿 변환의 3단계로 구성된다. 실험에서는 수동형 밀리미터파 영상 시스템에 의해 칼, 도끼, 화장품, 그리고 휴대폰과 같은 또는 비금속의 다양한 물체가 탐지됨을 보인다. 또한 정합과 융합된 영상의 결과로부터 가시 영상으로부터 얻은 얼굴과 의복 등의 대상자의 신원정보와 밀리미터파 영상으로부터 획득한 은닉된 물체의 정보를 동시에 시각화할 수 있음을 보인다.

• 응용통계연구
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• 제7권2호
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• pp.201-211
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• 1994

다구찌에 의해서 개발된 파라미터 설계법에서는 교호작용효과를 무시하고 직교배열을 이용하여 실험을 분석하는 것이 일반적인 방법으로 사용되고 있다. 본 논문에서는 직교배열과 거의 유사한 통계적 성질을 가지면서 최소의 실험횟수로 2인자 교호작용까지 분석할 수 있는 실험계획을 제시하고, 이러한 계획법에 의해 파라미터 설계법을 분석하고 유의적인 2인자 교호작용까지 검출하는 방법을 제시하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.137-137
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• 2013

The most stable adsorption structures and their corresponding energies of 4-pyridone, 4-hydroxypyridine, 2-pyridone and 2-hydroxypyridine have been investigated by Density Functional Theory (DFT) calculation method and high-resolution photoemission spectroscopy (HRPES). We confirmed that between the two reaction centers of 4- and 2-pyridone, only O atom of carbonyl functional group can act as a Lewis base and thus, O dative bonding structure is the most stable. On the other hand, we clarified that both the two reaction centers (the cyclic N atom and the O atom of hydroxyl functional group) of 4- and 2-hydroxypyridine (tautomers of 4- and 2-pyridone) can successfully function as a Lewis base. Through the interpretation of the N 1s and O 1s core level spectra obtained using HRPES, we could confirm the electronic structures and bonding configurations of these molecules with a coverage dependence on the Ge(100) surface.

• Current Optics and Photonics
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• 제5권6호
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• pp.711-720
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• 2021

A novel optical hybrid device that doubles the multilevel demodulation resolution by adding the optical interferometer with a waveguide crossover is proposed, theoretically analyzed and experimentally verified. We report two types of all-passive phase control schemes that will be referred to as a phase compensation scheme and a phase optimization scheme. We also apply the proposed phase control schemes to a 45° optical hybrid consisting of two parallel 90° optical hybrids together with the proposed phase control scheme for demodulating 8-level differential phase shift keying optical signals. Octagonal phase response with low wavelength sensitive excess loss of <0.8 dB over 31-nm-wide spectral range will be demonstrated in the InP-based material platform.

• Agricultural and Biosystems Engineering
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• 제5권1호
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• pp.10-20
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• 2004

Precision agriculture aims to minimize costs and environmental damage caused by agriculture and to maximize crop yield and profitability, based on information collected at within-field locations. In this process, quantification of soil physical properties, including soil strength, would be useful. To quantify and manage variability in soil strength, there is need for a strength sensor that can take measurements continuously while traveling across the field. In this paper, preliminary analyses were conducted using two datasets available with current technology, (1) cone penetrometer readings collected at different compaction levels and for different soil textures and (2) tillage draft (TD) collected from an entire field. The objective was to provide information useful for design of an on-the-go soil strength profile sensor and for interpretation of sensor test results. Analysis of cone index (CI) profiles led to the selection of a 0.5-m design sensing depth, 10-MPa maximum expected soil strength, and 0.1-MPa sensing resolution. Compaction level, depth, texture, and water content of the soil all affected CI. The effects of these interacting factors on data obtained with the soil strength sensor should be investigated through experiments. Spatial analyses of CI and TD indicated that the on-the-go soil strength sensor should acquire high spatial-resolution, high-frequency ($\ge$ 4 Hz) measurements to capture within-field spatial variability.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 춘계학술대회 논문집
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• pp.113-119
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• 2007

This article deals mainly with two objectives viz, 1) the potentiality of very high-resolution(VHR) multi-spectral and pan chromatic QuickBird satellite data in resources mapping over moderate resolution satellite data (IRS LISS III) and 2) the advantages of using object oriented classification method of eCognition software in land use and land cover analysis over the ISODATA classification method. These VHR data offers widely acceptable metric characteristics for cartographic updating and increase our ability to map land use in geometric detail and improve accuracy of local scale investigations. This study has been carried out in the Sukkalampatti mini-watershed, which is situated in the Eastern Ghats of Tamil Nadu, India. The eCognition object oriented classification method succeeded in most cases to achieve a high percentage of right land cover class assignment and it showed better results than the ISODATA pixel based one, as far as the discrimination of land cover classes and boundary depiction is concerned.

• 전자공학회논문지B
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• 제28B권7호
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• pp.566-577
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• 1991

In this paper, the method of image segmentation based on a pyramid of reduced resolution versions of the input input image is persented. In a pyramid structure, two regions (a given pixel and its mother pixels) are compared by the proposed inverse-mother-son variance ratio (IMSVR) method for the detection of an optinal object pixel and are determined whether they are similar enough to be viewed as one region or disparate to be viewed as ditinct regions By the proposed method, an l`timal object pixel has been setectedat some level, it is necessary to retrieve its boundary precisely. Moving down the pyramid to levels of higher resolution is requires. In this paper, the top-sown pyramid traversing algorithm for an image segmentation using a pyrmid structure is presented. Using the computer simulation, the results by the proposed statistical method and object traversing method are investigated for the binary image and the real image at the results of computer simulation, the proposed method of image segmentation based on a pyramid structure seem to have useful properties and deserve consideration as a possible alternative to existing methods of omage segmentation. The computation for the proposed method is required 0 (log n), for an TEX>$n{\times}n$ input image.

• 한국생산제조학회지
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• 제20권6호
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• pp.756-760
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• 2011

This paper proposed an alignment stage driven by piezo actuators for alignment process of a contact-type lithography. Among contact-type lithography processes, an UV-curable nanoimprint process is an unique process to be able to align patterns on upper and lower layers. An alignment stage of the UV-curable nanoimprint process requires nano-level resolution as well as high stiffness to overcome friction force due to contact moving. In this paper, the alignment stage consists of a compliant mechanism using flexure hinges, piezo actuators for high force generation, and capacitive sensors for high-resolution measurement. The compliant mechanism is implemented by four prismatic-prismatic compliant chains for two degree-of-freedom translations. The compliant mechanism is composed of flexure hinges with high stiffness, and it is directly actuated by the piezo actuators which increases the stiffness of the mechanism, also. The performance of the ultra-precision stage is demonstrated by experiments.