• Title/Summary/Keyword: Far field pattern

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Defect Inspection of Extreme Ultra-Violet Lithography Mask (극자외선 리소그래피용 마스크의 결함 검출)

  • Yi Moon-Suk
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.8 s.350
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    • pp.1-5
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    • 2006
  • At-wavelength inspection system of extreme Ultra-violet lithography was developed and the inspection results were compared with the optical mask inspection system by cross correlation experiments. In at-wavelength EUV mask inspection system, a raster scan of focused euv light is used to illuminate euv light to mask blank and specularly and non-specularly reflected euv light are detected by photo diode and microchannel plate. The cross correlation results between at-wavelength inspection tool and optical inspection tool shows strong correlation. Far-field scattering fringe pattern from programmed phase and opqque defect, which were detected by phosphor plate and CCD camera shows that distinct diffraction fringes were observed with fringe spacing dependent on the defect size.

Rejection Study of Mearest Meighbor Classifier for Diagnosis of Rotating Machine Fault (회전기계 고장 진단을 위한 최근접 이웃 분류기의 기각 전략)

  • 최영일;박광호;기창두
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.81-84
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    • 2000
  • Rotating machine is used extensively and plays important roles in the industrial field. Therefore when rotating machine get out of order, it is necessary to know reasons then deal with the troubles immediately. So many studies far diagnosis of rotating machine are being done. However by this time most of study has an interest in gaining a high recognition But without considering error $rate^{(1)(2)(3)}$ , it is not desirable enough to apply h the actual application system. If the manager of system receives the result misjudging the condition of rotating machine and takes measures, we would lose heavily. So in order to play the creditable diagnosis, we must consider error rate. T h ~ t is. it must be able to reject the result of misjudgment. This study uses nearest neighbor classifier for diagnosis of rotating $machine^{(4)(8)}$ And the Smith's rejection $method^{(1)}$ used to recognize handwritten charter is done. Consequently creditable diagnosis of rotating machine is proposed.

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The Level of EC Utilization and its Impact on Firm Performance in SMEs

  • Jun, Byoung-Ho
    • Journal of Information Technology Applications and Management
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    • v.15 no.3
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    • pp.127-152
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    • 2008
  • This study sought to explore how SMEs are utilizing EC. Drawing on existing research on IT and EC related field, this study presented the framework of EC utilization level and analyzed its affecting factors in the point of organizational perspectives; strategy and competency. The impact of EC utilization on firm performance was also examined by employing BSC. Structural equation model was applied to test the relationships among the theoretical constructs with data from 171 SMEs. The results showed that the rate of EC utilization in SMEs is growing quite rapidly. However, manufacturing related firms still remain at a lower level compared to service related firms. As for the two affecting factors of EC utilization level, it was found that the level of EC utilization appeared to be driven not by strategy but by competency. This result implicates that EC utilization in SMEs doesn't reach to strategic purpose yet, while it is dependent on firm's competency. As far as the impact of EC utilization on firm performance, the study showed that the level of EC utilization has significant relationship with all perspectives performance indicators of BSC. This study can provide the managers with current EC utilization pattern and the guidelines as to where to put the efforts in the EC utilization and how to get an effective EC utilization strategy in the future.

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A Pattern of Multimodal Transport Liability and its Adaptation on Practice (복합운송인(複合運送人)의 책임(責任) 한계(限界)에 대한 형태별(形態別) 분류(分類)와 실무상(實務上) 적용(適用))

  • Kim, Joong-Kwan
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.13
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    • pp.257-281
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    • 2000
  • The world economy is becoming increasingly globalized. The globalization has resulted in far reaching agreements to deepen trade liberalization and enlarge its scope to cover new areas in addition to strengthening its supporting institutional base. Economic growth has developed international trade which has accelerated the development of international carriage of goods in 21st century. The international trade is basically founded on the contract of international sale of goods and backed up by the contract of international carriage of goods and the insurance on the goods carried. It is essential to incorporate each other sections for the efficient development of international trade. As a result of rapid expansion of international carriage of goods, rationalization of transport was required, which has brought about the International Multimodal Transport System through containerization. The approach to liability system will be a right way to solve the insurance problems for the development and enlargement of world trade volume. International multimodal transport system has affected international trade a lot, especially the field of insurance a grate deal. This paper is to analyze contents of liability system on Multimodal Transport with in the UN Convention on International Multimodal Transport of goods.

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Super-Resolution Optical Fluctuation Imaging Using Speckle Illumination

  • Kim, Min-Kwan;Park, Chung-Hyun;Park, YongKeun;Cho, Yong-Hoon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.403.1-403.1
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    • 2014
  • In conventional far-field microscopy, two objects separated closer than approximately half of an emission wavelength cannot be resolved, because of the fundamental limitation known as Abbe's diffraction limit. During the last decade, several super-resolution methods have been developed to overcome the diffraction limit in optical imaging. Among them, super-resolution optical fluctuation imaging (SOFI) developed by Dertinger et al [1], employs the statistical analysis of temporal fluorescence fluctuations induced by blinking phenomena in fluorophores. SOFI is a simple and versatile method for super-resolution imaging. However, due to the uncontrollable blinking of fluorophores, there are some limitations to using SOFI for several applications, including the limitations of available blinking fluorophores for SOFI, a requirement of using a high-speed camera, and a low signal-to-noise ratio. To solve these limitations, we present a new approach combining SOFI with speckle pattern illumination to create illumination-induced optical fluctuation instead of blinking fluctuation of fluorophore.. This technique effectively overcome the limitations of the conventional SOFI since illumination-induced optical fluctuation is possible to control unlike blinking phenomena of fluorophore. And we present the sub-diffraction resolution image using SOFI with speckle illumination.

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Acoustic Scattering from Circular Cylinder by Periodic Sources (주기적인 음원에 의한 원형 실린더의 음향 산란)

  • Lee, Duck-Joo;Kim, Yong-Seok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.1 s.118
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    • pp.41-47
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    • 2007
  • Scattering fields of two dimensional acoustic waves by a circular cylinder are investigated. The present numerical approach for the acoustic scattering problem has difficulties of numerical robustness, long-time stability and suitability of far-field boundary treatments. The time-dependent periodic acoustic source is used to analyze Interference patterns between incident waves and waves reflected by the cylinder. Characteristic boundary algorithms coupled with 4th order Modified-Flux-Approach ENO(essentially non-oscillatory) schemes are employed in generalized coordinates to examine the effect of the wane frequency on the interference patterns. Non-reflecting boundary conditions, which is crustal for accurate computations of aeroacoustic problems, are used not to contaminate scattering fields by reflected waves at the outer boundary. Computed scattering fields show the circumferential acoustic modes generated by interacting between acoustic sources and scattered waves. At a lower frequency, the wave passes almost straight through the cylinder without Interacting with circular cylinder. Simulation results are presented and compared with the analytic solution. Computed RMS-pressure distribution on the cylinder wall is good agreement with exact solution.

Angular Division Multiplexing for Multichannel Optical Fiber Communication Systems (광섬유 다중통신 시스템을 위한 각도분할 방식)

  • 허선종;김성일;박한규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.8 no.4
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    • pp.164-171
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    • 1983
  • In this paper, angular division multiplexing of the optical multiplexing technique for transmitting several channels using a relatively short step-index fiber is described. Mode coupling and the output power distributionin the fiber for the plane wave excitations is calculated and the crosstalk level determination of the system is proposed. In the presence of the mode coupling, the pulse width in terms of the fiber's length and input condition is calculated in the slab waveguide and the fiber. For the input angles (

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Anisotropic Whispering Gallery Modes Formed in Various Transformation Cavities (다양한 변환 공진기에 형성되는 비등방성 속삭임의 회랑 모드)

  • Kim, Inbo;Choi, Muhan
    • Korean Journal of Optics and Photonics
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    • v.29 no.3
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    • pp.104-109
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    • 2018
  • We explain the basic principle of transformation optics, and introduce several design techniques for transformation cavities that can maintain the characteristics of whispering gallery modes (WGMs) even if the cavity is strongly deformed from a circular shape. As a method of obtaining various transformation cavities under a specific conformal mapping, we suggest a method of parallel movement of the initial cavity domain, and a method of rotating the ellipse as a cavity domain. The internal wave pattern and the far-field output characteristics of several designed resonant modes are numerically calculated. From these results, it is confirmed that a variety of GRIN resonators are possible for a given conformal coordinate transformation.

Analysis of EM Penetration Problems in Complex Structures Using Finite-Difference Time-Domain Method (FDTD 방법을 이용한 복잡한 구조물에서의 전자파 침투 특성 해석)

  • 김병남;채찬병;박성욱;이형수
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.1
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    • pp.68-75
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    • 2000
  • In this paper, we analyzed the radiation patterns of a monopole antenna mounted on cylinder and EM penetration problems in the complex structures by using FDTD method associated with 3-D PML absorbing boundary condition. In order to validate the proposed FDTD code, the radiation patterns of monopole antenna mounted on cylinders were compared with the exact Carter's solutions. As a results, the predicted radiation pattern exhibited excellent agreement with exact solution. And the FDTD code is applied to analyze the EM penetration problems in complex structures, Blackhawk helicopter. As the plane wave is excited, a significant amount of energy penetrates the helicopter structure, and it is dependent on aperture/airframe interface.

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Analysis of the Radiation Pattern of a Microstrip Array Antenna on a Non-Planar Surface by using FOURIER TRANSFORM (FOURIER TRANSFORM을 이용한 비평면형 마이크로스트립 어레이 안테나의 복사패턴 해석)

  • 고광태;구연건
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.15 no.9
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    • pp.785-795
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    • 1990
  • For the far field radiation pattern of a microstrip array antenna which is conformed to a cylindrical surface and forms an arc array, an approximate analysis method using FOURIER TRANSFORM is presented. In this method, the conformal array antenna is projected on the effective aperture plane and assumed to be an aperiodic array with nonlinear phase tilt. The effective aperture plane includes four end-points of each arc on the cylindrical surface. When the effective aperture ratio which is normalized to the planar type is from 1.0 to 0.9, it is confirmed that this approximate method is valid. To the array on the effective aperture plane, it is assumed that the phase tilt is due to the distance between aperture plne and curvature surface. Specially, when the radius of arc is more than 5 times to its length, the FOURIER TRANSFORM METHOD could be used with only varying scale factors. The results of calculating by approximate method are good agreement with the results of COORDINATE TRANSFORM METHOD and experimentally measured value in the range of -40dB. And, the difference of half power angle is less than 5 degrees when the effective aperture ratio moer than 0.9.

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