• Title/Summary/Keyword: light elements

검색결과 838건 처리시간 0.259초

섭동 현상을 갖는 광 방향성 결합기의 응답 특성의 해석 (An Analysis of characteristic response for Optical Directional Coupler with Perturbation Phenomenon)

  • 김선엽;박형근
    • 한국정보통신학회논문지
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    • 제10권2호
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    • pp.353-359
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    • 2006
  • 광통신시스템들에서 사용되는 많은 통신용 소자들의 특성은 방향성 결합기(directional coupler)의 구조에 따라 영향을 받게 된다. 본 논문에서는 방향성 결합기 구조에 섭동현상을 일으킬 수 있는 도파로 구조를 포함시켜 그 특성에 대해 연구를 수행하였고, 또한 도파로 구조를 변화시켰을 때, 얻어지는 특성에 대해 시뮬레이션을 수행하였다. 결과로써, 섭동현상을 일으키는 도파로 구조를 첨가한 방향성 결합기가 광 필터로 동작함을 확인 할 수 있었고, 또한 도파로 구조의 듀티 비를 조절하여 보다 우수한 광 필터로 동작함을 확인할 수 있었다. 시뮬레이션 결과, 도파로 구조의 듀티 비가 $50\%$인 경우보다 듀티 비가 변화하는 경우가 -l8dB정도의 우수한 응답특성을 갖게 됨을 확인 할 수 있었다.

현대 건축공간에 나타나는 데페이즈망 특성에 관한 연구 - 르네 마그리트를 중심으로 - (A Study on the de'paysment characteristics in modern architecture - In light of Rene Magritte -)

  • 장한솔;허범팔
    • 한국실내디자인학회논문집
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    • 제18권6호
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    • pp.96-103
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    • 2009
  • Man has an unconscious desire to free oneself from everyday selves and a strong intellectual desire to see and analyze things in a different perspective. This provided a momentum for architectural design that has long been confined to its limits of modernism of being rational and objective. The ever-changing society that we live in filled with various attempts and pluralistic characteristics shows a complex set of attributes that can hardly be defined by a single term. As society moves towards an uncertain and volatile state, the boundary between literature, philosophy and art has dimmed out and converged. Such tendencies have been observable in recent establishments in architecture in the form of introducing external elements and create an alien and farfetched architectural space. Using the 'depaysement' defamiliarization method expressing irrationality and randomness, it is applied in various aspects, sharing the counter-rational structure and features of such architectural space. Hence, it is the purpose of this study to delve into the unique characteristics of depaysement through Magritte's work which reflects the unique pictorial world built under the influence of surrealism, and discover the $D\acute{e}paysement$ tendencies in modern architectural space. It is apparent in Modern architecture that, owing to the development in digital technology, it is showing process changes in design and an interfacial $D\acute{e}paysement$ effect in cyberspace, an interlace of reality and the virtual world. In this study, the focus of analysis was architectural properties such as the program, figure/spatial, material and the objective side, but due to mutual text properties, it is bound to be an overlapping analysis.

Hyperspectral Remote Sensing for Agriculture in Support of GIS Data

  • Zhang, Bing;Zhang, Xia;Liu, Liangyun;Miyazaki, Sanae;Kosaka, Naoko;Ren, Fuhu
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1397-1399
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    • 2003
  • When and Where, What kind of agricultural products will be produced and provided for the market? It is a commercial requirement, and also an academic questions to remote sensing technology. Crop physiology analysis and growth monitoring are important elements for precision agriculture management. Remote sensing technology supplies us more selections and available spaces in this dynamic change study by producing images of different spatial, spectral and temporal resolutions. Especially, the hyperspectral remote sensing should do play a key role in crop growth investigation at national, regional and global scales. In the past five years, Chinese academy of sciences and Japan NTT-DATA have made great efforts to establish a prototype information service system to dynamically survey the vegetable planting situation in Nagano area of Japan mainly based on remote sensing data. For such concern, a flexible and light-duty flight system and some practical data processing system and some necessary background information should be rationally made together. In addition, some studies are also important, such as quick pre-processing for hyperspectral data, Multi-temporal vegetation index analysis, hyperspectral image classification in support of GIS data, etc. In this paper, several spectral data analysis models and a designed airborne platform are provided and discussed here.

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$CIEL^*a^*b^*$ 색 공간에서 적응적 컬러 샘플링을 이용한 Mobile Phone 카메라용 자동화이트 밸런스 알고리즘 (Novel Auto White Balance Algorithm Using Adaptive Color Sampling Based on $CIEL^*a^*b^*$ color space for Mobile Phone Camera)

  • 김경린;손경수;하주영;김상준;강봉순
    • 한국정보통신학회논문지
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    • 제12권8호
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    • pp.1356-1362
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    • 2008
  • 본 논문에서는 카메라가 가지는 대표적인 기능중의 하나인 자동 화이트 밸런스에 대한 알고리즘을 제안한다. 화이트 밸런스는 흰색의 물체나 물건 고유의 색이 아닌 부분들을 제거하는 과정이다. 화이트 밸런스를 수행하기 위해 사람의 눈에 의해 느끼는 시각차와 색차의 표현이 동일한 $CIEL^*a^*b^*$ 색 공간에서 영상의 분포를 분석하여 흰색 물체의 색 변화 정도를 추정한다. 이를 기준 백색 추정이라 한다. 정확한 추정을 위하여 환경에 의해 변화되었다고 추정되는 부분에 대해 그룹화 한다. 그룹화 된 영상 정보를 통해 영상의 특성을 파악하여 기준 그룹을 정하여 기준 그룹까지의 누적 픽셀들을 선택하는 컬러 샘플링하여 기준 백색을 추정한다. 또한 영상 보정을 위한 컬러 이득은 영상의 포화(Saturation)를 고려하여 얻어진다. 이를 통한 제안된 자동 화이트 밸런스 알고리즘은 뛰어난 영상 보정 기능을 가진다.

엠마누엘 무니에의 '인격(personne)'의 세 가지 존재론적인 특성 (The three Ontological Characteristics of the Person with Emmanuel Mounier)

  • 이명곤
    • 철학연구
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    • 제137권
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    • pp.249-276
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    • 2016
  • 엠마누엘 무니에의 '인격에 대한 사유'는 인간적인 삶에 있어서 가장 본질적이고도 중요한 문제를 다루고 있는데, 본 연구에서는 그의 사상에서 '인격의 특성'이 무엇인지를 크게 3가지 차원에서 고찰하고 있다. 첫째 인격이란 '진정한 그 자신', 한 개인의 자아를 형성하고 있는 내면적이고 정신적인 존재라는 차원에서 '비-규정적'이고 '환원 불가능한 특성'을 가진 것이며, 인격이 가진 유일성 그 자체로부터, 그리고 자기 세계를 지니고 있는 존재자의 '최고의 완성'이라는 의미에서의 '개별성'을 지닌 것으로 파악하고 있다. 둘째, 이러한 인격의 '개별성'은 인격의 차원에서 소통이 불가능한 '존재론적인 고독'을 지니고 있지만, 또한 자기 세계를 형성하는 제 요소들을 '소통'과 '관계성'을 통해서 취하는 것으로, 본질적으로 '실존적인 열림'을 가지고 끊임없이 '관계성' 중에 있는 '역설적인 것'으로 파악된다. 마지막으로 '인격'은 끊임없이 새로운 자아를 창조하는 '역동적'인 것으로 나타나고 있는데, 이러한 인격의 역동성은 자기 동일성을 보존하고자 함과 동시에 '인류애'에 기초한 '사회의 인격화'를 지향하는 것으로 나타나고 있다. 이러한 그의 사유는 현대사회의 비참에 빛을 줄 수 있는 새로운 '휴머니즘'의 한 유형이 될 수 있다.

Alanine and serine functionalized magnetic nano-based particles for sorption of Nd(III) and Yb(III)

  • Galhoum, Ahmed A.;Mahfouz, Mohammad G.;Atia, Asem A.;Gomaa, Nabawia A.;Abdel-Rehem, Sayed T.;Vincent, Thierry;Guibal, Eric
    • Advances in environmental research
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    • 제5권1호
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    • pp.1-18
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    • 2016
  • Magnetic nano-based sorbents have been synthesized for the recovery of two rare earth elements (REE: Nd(III) and Yb(III)). The magnetic nano-based particles are synthesized by a one-pot hydrothermal procedure involving co-precipitation under thermal conditions of Fe(III) and Fe(II) salts in the presence of chitosan. The composite magnetic/chitosan material is crosslinked with epichlorohydrin and modified by grafting alanine and serine amine-acids. These materials are tested for the binding of Nd(III) (light REE) and Yb(III) (heavy REE) through the study of pH effect, sorption isotherms, uptake kinetics, metal desorption and sorbent recycling. Sorption isotherms are well fitted by the Langmuir equation: the maximum sorption capacities range between 9 and 18 mg REE $g^{-1}$ (at pH 5). The sorption mechanism is endothermic (positive value of ${\Delta}H^{\circ}$) and contributes to increase the randomness of the system (positive value of ${\Delta}S^{\circ}$). The fast uptake kinetics can be described by the pseudo-second order rate equation: the equilibrium is reached within 4 hours of contact. The sub-micron size of sorbent particles strongly reduces the contribution of resistance to intraparticle diffusion in the control of uptake kinetics. Metal desorption using acidified thiourea solutions allows maintaining sorption efficiency for at least four successive cycles with limited loss in sorption capacity.

Discrimination of Ginseng Habitat by Using Instrumental Analysis Techniques

  • Sohn H. J.;Lee S. K.;Cho B. G.;Kim S. J.;Lee N. Y.;Choi D. S.;Jeong M. S.;Bae H. R.;Yang J. W.
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 2002년도 학술대회지
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    • pp.238-252
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    • 2002
  • In order to screen out indicators for the discrimination of ginseng habitat, some physical and chemical characteristics of Korean red ginsengs (94 kinds) and Chinese red ginsengs (50 kinds) were analyzed by using a rheometer, an electronic nose system, a combined technique of solid phase micro-extraction (SPME) and gas chromatograph equipped with an electron capture detector (GC/ECD), an X-ray fluorescence spectrometer (XRF), an inductively coupled plasma mass spectrometer (ICP/MS), a near infrared spectrometer (NIRs) and high performance liquid chromatography equipped with evaporative light scattering detector (HPLC/ELSD). The results are summarized as follows: (i) The rhizome strengths of Korean red ginsengs were significantly higher than those of Chinese red ginsengs. (ii) The electronic nose patterns of Korean red ginsengs were significantly different from those of Chinese red ginsengs. (iii) Some unidentified peaks were detected not in the headspace of Korean red ginsengs but in the headspace of Chinese red ginsengs when the headspace volatiles prepared by the SPME technique were analyzed by GC/ECD. (iv) Either the content ratios of K to Ca or Mn to Fe were significantly different between Korean red ginsengs and Chinese red ginsengs. (v) The reflectance ratios of NIRs wavenumbers such as $904\;cm^{-1}\;to\;1088\;cm^{-1}$ for Korean red ginsengs were significantly different from those for Chinese red ginsengs. (vi) The content ratios of ginsenoside-Rg to ginsenoside-Re of Korean red ginsengs were significantly higher than those of Chinese red ginsengs. These results indicate that the rhizome strength, the electronic nose pattern, the occurrence of ECD-sensitive headspace volatile components, the content ratios of K to Ca and Mn to Fe, the NIRs pattern and the content ratio of ginsenoside-Rg to -Re may be indicators for the discrimination of ginseng habitat.

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Calibration-free real-time organic film thickness monitoring technique by reflected X-Ray fluorescence and compton scattering measurement

  • Park, Junghwan;Choi, Yong Suk;Kim, Junhyuck;Lee, Jeongmook;Kim, Tae Jun;Youn, Young-Sang;Lim, Sang Ho;Kim, Jong-Yun
    • Nuclear Engineering and Technology
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    • 제53권4호
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    • pp.1297-1303
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    • 2021
  • Most thickness measurement techniques using X-ray radiation are unsuitable in field processes involving fast-moving organic films. Herein, we propose a Compton scattering X-ray radiation method, which probes the light elements in organic materials, and a new simple, non-destructive, and non-contact calibration-free real-time film thickness measurement technique by setting up a bench-top X-ray thickness measurement system simulating a field process dealing with thin flexible organic films. The use of X-ray fluorescence and Compton scattering X-ray radiation reflectance signals from films in close contact with a roller produced accurate thickness measurements. In a high-thickness range, the contribution of X-ray fluorescence is negligible, whereas that of Compton scattering is negligible in a low-thickness range. X-ray fluorescence and Compton scattering show good correlations with the organic film thickness (R2 = 0.997 and 0.999 for X-ray fluorescence and Compton scattering, respectively, in the thickness range 0-0.5 mm). Although the sensitivity of X-ray fluorescence is approximately 4.6 times higher than that of Compton scattering, Compton scattering signals are useful for thick films (e.g., thicker than ca. 1-5 mm under our present experiment conditions). Thus, successful calibration-free thickness monitoring is possible for fast-moving films, as demonstrated in our experiments.

Actual Situation Analysis of Walking Environment in Chongqing, China - Case Studies of First Experimental Elementary School and Zaozilanya Elementary School -

  • Hong, Shi;Suh, JooHwan
    • 휴양 및 경관연구
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    • 제12권4호
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    • pp.1-10
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    • 2018
  • This study is about the investigation of the walking environment of the First Experimental Elementary School in Shapingba District of Chongqing City and the Zaozilanya Elementary School in Yuzhong District and the analysis of the pedestrian's consciousness. The improvement plan is obtained by comparing and analyzing the walking environment around the school. The survey results are as follows. According to the survey results of the walking environment around the school, the sidewalks of the two schools are relatively narrow, and there are more pedestrians crossing the road. There is a phenomenon of parking in both schools. The phenomenon of parking in Zaozilanya Elementary School is even more serious. In investigating the most important elements of the school's pedestrian environment, the setting of the signpost, the setting of the crosswalk and signal lights, the setting of the fence, the setting of the vehicle's deceleration facilities, and the control of the school gate are all necessary. Therefore, in order to create a safe and comfortable improvement plan for the surrounding environment of the school, first of all, in the improvement of the facilities around the school, the setting of the fence, the setting of the speed bump, the improvement of the crosswalk and the signal light. Second, in terms of restrictions, the scope of protection around the school needs to be expanded, and restrictions on parking and restrictions on vehicle traffic need to be implemented. Third, in terms of education and publicity, it is not only necessary to provide safety guidance for students to go to school, but also to provide drivers with driving safety education and publicity.

클러스터를 이용한 고성능 RC4 암호화 하드웨어 설계 (The Design of a High-Performance RC4 Cipher Hardware using Clusters)

  • 이규희
    • 한국정보통신학회논문지
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    • 제23권7호
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    • pp.875-880
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    • 2019
  • RC4 스트림 암호화는 내부 구현이 간단하고 빠르게 암호화 할 수 있는 초경량 암호화 알고리즘으로 IEEE 802.11의 WEP와 IEEE 802.11i의 TKIP 등에 널리 이용되고 있다. RC4는 IoT 등의 제한적 자원을 갖는 시스템들에도 사용되지만 성능상 제약이 있다. RC4 암호화는 S-배열과 K-배열의 초기화 및 랜덤화를 수행하는 KSA(Key Scheduling Algorithm)와 랜덤화된 S-배열을 이용하여 암호문을 생성하는 PRGA(Pseudo-Random Generation Algorithm)의 두 단계로 구성된다. 본 논문에서는 KSA에서 발생하는 초기화 지연시간을 줄이기 위해, 랜덤화 과정에 초기화를 삽입하여 함께 처리한다. KSA의 랜덤화에서 교환(swap) 작업과 PRGA의 암호문 생성은 클러스터를 이용하여 매 클록마다 두 개의 교환 및 암호문이 생성되도록 하였다. 제안된 RC4 암호화 하드웨어 구조는 초기화 지연시간이 발생하지 않으며, 랜덤화와 키 스트림 생성율에서 다른 연구들과 비교하여 약 2배에서 6배의 성능이 향상되었다.