• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.1
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• pp.78-89
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• 1999

In this paper, to improve bandwidth amplitude fluctuation for the broadband signal in indoor propagation environment, we measured and analyzed broadband signal using a vertically polarized, horizontally polarized and circularly polarized antenna, conducting by frequency sweeping method in NLOS (Non-Line-of-Sight) environment. And, to investigate the optimum condition for the improvement of broadband propagation characteristics we also examined the effects of both human motions and transmission antenna height in the NLOS environment. As a result, in the case of NLOS environment, it was found that the amplitude deviation characteristics in frequency bandwidth can be improved by polarization diversity reception. Especially, we found that it is the best effective one to make polarization diversity reception branches, which install the circularly polarized antenna at transmitting end and install the polarized diversity branches received vertical or/and horizontal polarized wave at receiving end. The affection of a human motions is not so much in LOS and NLOS environment, but it can lead to the cause of burst error in indoor digital radio communications as the fade of signal strength become more deeper. And also, when raise the transmitting antenna up to the ceiling, the LOS and NLOS environment could be coexisted. In this case, it can be also inferred that frequency bandwidth amplitude deviation must be fundamentally improved by using polarization diversity reception technique to make the possibility of high transmission rate.

• Carbon letters
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• v.17 no.1
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• pp.79-84
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• 2016

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.364-368
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• 2000

In this paper, we present the design and fabrication of a new circularly polarized circular patch antenna. The antenna is realized using a plastic foam sheet, a Teflon substrate and a metal-coated film. The radiating element is a circular patch proximity-fed by a wide microstrip line. Two thins slots are introduced on the circular patch to obtain a circular polarized radiation. The antenna is optimized using a commercial software. The antenna has 18% impedance bandwidth, 4% axial-ratio band width and 9.12dBi gain.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.8
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• pp.39-46
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• 1995

A complete form of physical optics solution to the E-polarized diffraction by a composite of conducting and dielectric wedges is obtained by sum ov geometrical optics solution and edge-diffracted field. The diffraction coefficients of the edge-diffracted field are expressed in series of cotangent functions. The electric field patterns of the physical optics solution are plotted in figures.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.1-7
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• 1997

The physical optical solution to the E-polarized diffraction by a composite wedge consisting of perfect conductor and lossless dielectric cannot sayisfy not only the boundary conditions at the wedge interfaces but also the edge condition at the wedge tip. Its diffraction coefficients are extended outside the composite wedge to become the exact solution to the perfectly conducting wedge as its relative dielectric constant increases to infinite or decreases to 1. It is assured that the extended diffraction coefficients approach zero in the arificially complementary region of the composite wedge.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.8-14
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• 1997

The phusical optics approximation to an E-polarized diffraction by a composite wedge provides its diffraction coefficients in terms of finite series of cotangent functions. In this paper, its diffraction coefficients inside the dielectric part are extended to become the exact solution to the perfectly conducting wedge as its relative dielectric constant increases to infinite or decreases to 1. It is assured that the extended diffraction coefficients satisfy the boundary condition at th econducting interface and become zero in the artificially complementary region of the composite wedge.

• Journal of the Korean Mathematical Society
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• v.49 no.1
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• pp.1-16
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• 2012

In the present paper we describe a class of Gorenstein, finite and at morphism ${\varrho}$: $X{\rightarrow}Y$ of degree 6 of algebraic varieties, called Anglo-American covers. We prove a general Bertini theorem for them and we give some evidence that the cover ${\varrho}$: $A{\rightarrow}\mathbb{P}_k^2$ associated general (1, 3)-polarized abelian surface is Anglo-American.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.207-208
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• 2003

일반적으로 결정성 고분자에 공정에 있어서 배향 및 결정화 거동은 두 가지 중요한 공정 프로세스로써 고분자의 모폴로지 및 결정구조형성에 매우 큰 영향을 미치며 최종적으로 고분자의 거시적인 물성에 영향을 준다. 고분자 물질의 물리적 특성을 정확하게 이해하여 최적의 물성을 나타내는 내부 구조를 제시하기 위하여서는 고분자 물질의 배양분석에 있어서 분자의 2차원적 배향 상태뿐만 아니라 전체적인 3차원 배향 상태에 관한 정보가 필수적이다. (중략)

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.60-61
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• 2003

We proposed an optical encryption system using circular polarization based on interferometer. The phase modulated input image, represented as orthogonal linearly polarized states respectively, is encrypted into circularly polarized states using polarization modulated masks. In the decryption we use the inverse matrix of polarization modulation mask and can recover the original polarization states.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1005-1009
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• 2009

An invisible code is one of the useful technologies for a computer interaction. In this paper, we propose a method to display invisible codes using LCD panels and to detect a polarized symbol image with a conventional CCD camera.