• 한국정밀공학회지
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• 제23권5호
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• pp.103-110
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• 2006

Automatic optical alignment modules are a key technology in optical communication system. However, the optic component assembly depends highly on manual or semi-automated alignment process. In this paper, a novel alignment mechanism with minimum degree-of-freedom has been designed and theoretical models are derived from geometric optical characteristics on collimators, optical filters and optical ray alignment. The automatic alignment control algorithm has been newly developed based on the mechanism and models, and then we make fast, precise and reliable alignment through the algorithm. The reliability of developed modules has been verified with various simulations and performance evaluations.

• International Journal of Aeronautical and Space Sciences
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• 제2권1호
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• pp.44-54
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• 2001

This paper describes the antenna alignment method of the tracking antenna system for LEO satellite. The purpose of the antenna alignment is to reduce the angular error due to the structural alignment and the monopulse null point alignment error. The angular error of 3 axis tracking system is the key performance parameter that should be minimized to accurately track satellite movement. The angular error is analyzed via a simulation and boresight measurement. The simulation is done with formulas to be derived from vector concept for 3-axis movement. The formulas of the structural alignment are verified by comparing the formula result with the field measurement. Also, the angular error due to monopulse null shift is obtained via boresight measurement. Based on the analyzed and measured results, the antenna alignment was performed and was verified via tracking test of operating LEO satellite.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권3호
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• pp.956-970
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• 2015

In this paper, we study the design of network coding for the generalized transmit scheme in multiple input multiple output Y channel, where K users wish to exchange specified and shared information with each other within two slots. Signal space alignment at each user and the relay is carefully constructed to ensure that the signals from the same user pair are grouped together. The cross-pair interference can be canceled during both multiple accessing channel phase and broadcasting channel phase. The proposed signal processing scheme achieves the degrees of freedom of ${\eta}(K)=K^2$ with fewer user antennas.

• 한국컴퓨터정보학회논문지
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• 제10권5호
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• pp.1-10
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• 2005

다중 서열 정렬(multiple sequence alignment, MSA)은 단백질과 핵산 서열들의 분석에 필요한 가장 중요한 도구이다. 생물학적인 서열들은 그들 사이의 유사성과 차이점을 보여주기 위하여 각각의 서열들을 수직적으로 정렬한다. 본 논문에서는 클러스터링 분기를 이용하여 두 그룹의 서열들 사이에서 정렬을 수행하는 효율적인 그룹 정렬 방법을 제안하였다. 제안한 알고리즘(Multiple Sequence Alignment using Clustering Divergence : CDMS)은 하향식 발견 방법인 트리 형태의 병합을 위해 클러스터링 방법으로 구축하였다. 클러스터링 방법은 가장 긴 거리를 가지는 서열을 두 개의 클러스터로 나눌 수 있다는 것에 기초하였다. 제안한 새로운 서열 정렬 알고리즘은 기존의 Clustal W알고리즘 보다 질적 향상과 처리 시간 단축 O($n^{3} L^{2}$)이 기대된다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.112-114
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• 2009

Charge injection at electrode-organic interfaces is key to the performance, lifetime and stability of organic electronic devices. The link between fundamental material properties and the energy-level alignment at electrode-organic interfaces will be discussed. In addition the impact of the injection barrier height-a parameterization of the energylevel alignment-on device characteristics will also be discussed.

• 한국정보통신학회논문지
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• 제6권1호
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• pp.99-102
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• 2002

다결정 실리콘층 아래의, 게이트 산화막이라고 불리는 높은 온도에서 형성된 산화막에서 핀홀이 관찰되었으며 그 메카니즘이 분석되었다. 다결정 실리콘층 아래의 산화막은 다른 다결정 실리콘층의 플라즈마 에칭 과정 동안에 파괴되어진다. 두 개의 다결정 실리콘층은 CVD증착에 의해 만들어진 0.8$\mu\textrm{m}$의 두꺼운 산화막에 의해 분리되어 있다. 파괴된 산화막들이 아크가 발생한 부분을 중심으로 흩어져 있으며 아크가 발생한 부분에서 생성된 극도로 강한 전계가 게이트 산화막을 파괴 시켰다고 가정된다. 아크가 발생한 부분은 Alignment key에서 관찰되었고 그리고 이것이 발견된 웨이퍼는 낮은 수율을 보여주었다. 아크가 발생한 부분이 칩의 내부가 아니더라도 게이트 산화막의 파괴에 의해 칩이 정상적으로 동작하지 않았다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.644-647
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• 2004

Optical add/drop multiplexers (OADMs), one of the new network elements, will play a key role enabling greater connectivity and flexibility in the dense wavelength-division multiplexing (DWDM) networks. The importance of OADMs is that they allow the optical network to be local transmitting/extraction on a wavelength-by-wavelength basis to optimize traffic, efficient network utilization, network growth, and to enhance network flexibility. Also, the automatic assembly system of micro optical filters and fibers is a key technology in the development of optical modules with high functionality. Recently, one of remarkable tends in the development of optical communication industry is the miniaturization and integration of products. In this research, we have developed a system capable of automatic alignment of a film filter and a lensed fiber in order to improve the speed and losses in the optical fiber to filter alignment of optical modules. Using the developed automatic alignment system and silicon optical benches, we have fabricated the micro OADM and measured the insertion loss and aging effect.

• 말소리와 음성과학
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• 제3권2호
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• pp.37-52
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• 2011

This study investigates patterns of the alignment of the accentual peaks in bisyllabic words of the CVNCV, CVNV, and CVNNV structures in North Kyungsang Korean. Based on the tonal alignment, patterns of the F0 pitch excursion are discussed relative to one another. Issues are addressed concerning how the tonal targets are aligned, and how the tonal specifications of nasals in postvocalic, intervocalic, and prevocalic environments are supplied in the LH, HL, and HH classes. Tonal specification of nasals in various environments is accounted for by extension of the L target, displacement of the pitch peak, and interpolation between two tonal targets, depending on the tonal class. The results in this study provide preliminary evidence that the categorical alignment of the tonal targets is implemented by simply checking the presence or absence of a nasal before or after the nucleus vowel on the segmental string, without reference to the constituency of the nasal in the syllable structure. However, the prosodic structure has a key role to play in explaining speaker-dependent variations in the tonal alignment. Sensitivity to tautosyllabicity has an effect on the shape of the F0 contour, and disparity in the patterns of the pitch excursion is represented as a function of syllable structure correlated with segmental composition of the nasal.

• 한국통신학회논문지
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• 제37B권10호
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• pp.947-955
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• 2012

본 논문에서는 셀룰러 네트워크상의 간섭정렬을 위한 송수신벡터를 구하는 반복 알고리즘들을 제안한다. 기존의 간섭채널상의 간섭정렬을 위해 고안된 반복 알고리즘을 셀룰러 네트워크에 적용하는 것이 물론 가능하지만, 높은 합용량을 달성하려면 큰 반복횟수가 필요하다. 본 논문에서 제안된 알고리즘의 핵심은 상향링크의 송신벡터 그리고 하향링크의 수신벡터를 갱신할 때 셀내간섭을 고려하지 않는다는 점이다. 모의실험은 간섭정렬을 위해 다중안테나와 단일 반송파가 사용되었을 때, 제안된 알고리즘이 기존의 알고리즘보다 주어진 반복횟수에서 월등히 높은 합용량을 달성함을 보인다. 또한 제안된 알고리즘이 간섭정렬을 위해 단일 안테나와 다중 부반송파가 사용되었을 때도 기존 간섭정렬 알고리즘보다 성능이 우수함을 보인다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.451-454
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• 2002

The fiber optic communication technology is considered as a key solution for the future communication. However the assembly of the fiber optic components highly depends on manual or semi-automated alignment process. And the light search algorithm is recognized an important factor to reduce the manufacturing process time. Therefore this paper investigates optimal search algorithm for the automatic alignment of fiber optic components. The experiments show the effectiveness of Hill Climbing Search, Adaptive Hill Climbing Search and Steepest Search algorithms, in a view of process time.