• Korean Journal of Optics and Photonics
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• v.30 no.6
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• pp.230-236
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• 2019

We propose and demonstrate a searching and autoalignment method for indoor optical wireless communication, using a cost-effective retroreflective sheet and a microelectromechanical system (MEMS) mirror. We use an extremum-seeking method for a single axis and beam steering with a MEMS mirror to maintain a line of sight (LOS) with the optical link. This autoalignment method shows a receiver sensitivity of -31.87 dBm for a bit rate of 2.5 Gb/s over a 7 m communication link.

• Korean Journal of Optics and Photonics
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• v.22 no.1
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• pp.30-34
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• 2011

A novel alignment method that can be used for aligning the collimating mirror employed in a monochromator is described. In most of the spectrometer industry, the alignment of optical components such as a focusing mirror, a grating and a collimating mirror has been performed manually so far. In this paper, we use a matchedfilter based image correlation technique for measuring the accurate image position which is used for aligning the collimating mirror. The experimental results show that with the proposed scheme automatic alignment can be completed within 10 seconds.

• Annual Conference on Human and Language Technology
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• 2012.10a
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• pp.163-168
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• 2012

문서 또는 문장 단위의 정렬이 통계적 기계 번역에 활발히 이용되고 있다. 문장 정렬은 통계 기반의 기계 번역에서 가장 중요한 작업으로 정렬의 정확도와 속도는 기계 번역 시스템의 성능을 좌우할 수 있다. 문장 정렬을 수행 할 때 대용량의 문서입력이 있을 경우 처리 속도가 상당히 늦어지는 문제를 지적하고 그 문제를 해결하는 두 가지 방법을 제안한다. 문서의 구조적 특성을 이용하여 문서의 경계정보를 추출하거나 또는 단어 출현 빈도의 따른 경계 추출방법을 이용하여 문제를 해결한다. 상기의 방법이 정렬 속도 저하 개선에 비교적 효과가 있고 그에 따른 성능 저하가 없음을 실험을 통하여 확인하였다.

• Korean Journal of Cognitive Science
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• v.17 no.4
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• pp.323-336
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• 2006

In this paper, we present a pilot system that can extract paraphrases from a parallel corpus using to-training method. Paraphrases are useful for the applications that should rreate a varied ind fluent text, such as machine translation, question-answering system, and multidocument summarization system. One of the difficulties in extracting paraphrases is to find a rich source from which we can extract paraphrases. The bible is one of the good sources fur extracting paraphrases as it has several Korean versions in which every sentence can be easily aligned by the chapter and the verse. We ran extract not only the lexical-level paraphrases but also the phrasal-level paraphrases from the parallel corpus which consists of the bibles using co-training method.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.16-17
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• 2000

무선광통신기술은 케이블의 신설 또는 재 설치가 어려운 구간이나 보안성이 요구되는 무선전송 구간에 많이 사용된다. 또한 기존의 무선주파수와 상호간섭이 적으며, 구현이 간편하여 실내의 짧은 광 전송구간과 빌딩간의 고속광전송에 그 이용이 점점 증가하고 있다$^{(1-5)}$ . LOS(Line of sight)방식의 광연결에서는 광원으로부터의 출력빔의 방향과 광검출기의 위치가 잘 정렬되어야 한다. 광원으로부터 광검출기 사이의 신호전송매체가 자유공간이므로 외부의 기계적 진동에 의하여 광원의 위치가 미소하게 변경되는 경우, 출력광의 진행방향이 광검출기의 위치에 일치하지 않아 수신부에서 검출되는 신호는 매우 약해질 수 있다. 본 논문에서는 이러한 경우에 효과적으로 사용할 수 있는 자동정렬형 광검출구조를 개발하였다. 자동정렬형 광검출기의 구조도는 그림[1]과 같다. (중략)

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.2
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• pp.128-132
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• 2005

• KIPS Transactions on Software and Data Engineering
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• v.2 no.6
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• pp.433-442
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• 2013

A set of bilingual terms is one of the most important factors in building language-related applications such as a machine translation system and a cross-lingual information system. In this paper, we introduce a new approach that automatically extracts candidates of English-Korean bilingual terms by using a bilingual parallel corpus and a basic English-Korean lexicon. This approach can be useful even though the size of the parallel corpus is small. A sentence alignment is achieved first for the document-level parallel corpus. We can align words between a pair of aligned sentences by referencing a basic bilingual lexicon. For unaligned words between a pair of aligned sentences, several assumptions are applied in order to align bilingual term candidates of two languages. A location of a sentence, a relation between words, and linguistic information between two languages are examples of the assumptions. An experimental result shows approximately 71.7% accuracy for the English-Korean bilingual term candidates which are automatically extracted from 1,000 bilingual parallel corpus.

• Journal of the Korean Society for information Management
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• v.26 no.4
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• pp.319-336
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• 2009

Semantic web technology is the evolution of current World Wide Web including a machine-understandable knowledge database, ontology, it may be enable machine and people to work together. However, problems arise when we try to communicate with different data, which are annotated by different ontologies created by different people with different concepts. Thus, to communicate between ontologies, it needs to align between heterogeneous ontologies. When it is aligned between concept nodes of heterogeneous ontologies, one of main problems is a misalignment situation caused by false negative of automatic ontology mapping. So, in this paper, we present a new method to minimize the false negative error in the process of aligning concept nodes of different ontology.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.116-124
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• 2002

The planning of part feeder and other manufacturing automation equipments is almost always underestimated. Planning ahead for those crucial pitfalls can permit steps to take to minimize heir impacts, especially if the problems can be discovered in the planning phase, not on the shop floor. Planning process is an engineering process, namely a series of trade-offs. The effective trade-offs in the shortest amount of time can be possible with the help of a computer-aided ngineering (CAE) technique. The main parts of CAE fur part feeder are database system of fabricated workpiece parts, part feeders, part feeder components. In this study, a planning process of part feeder is presented. Especially, a systematic analysis of workpiece parts and part feeders is performed for the design of databases of CAE system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.5
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• pp.822-829
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• 2000

In this paper, we introduce a differential detector that automatically aligns itself to the signal beam in order to prevent the voltage variation that may result from minute misalignment of the light source. In this system, a photodiode-array recognizes the central point of the signal beam, and drives motors that correspond to the x and y axes. The photodiode-array aligns itself to the central point of the signal beam, and eliminates the optical noise effect with differential detectioin method. It is very useful in wireless optical interconnections.