• BMB Reports
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• 제44권1호
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• pp.1-10
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• 2011

Inter-cellular communication via diffusible small molecules is a defining character not only of multicellular forms of life but also of single-celled organisms. A large number of bacterial genes are regulated by the change of chemical milieu mediated by the local population density of its own species or others. The cell density-dependent "autoinducer" molecules regulate the expression of those genes involved in genetic competence, biofilm formation and persistence, virulence, sporulation, bioluminescence, antibiotic production, and many others. Recent innovations in recombinant DNA technology and micro-/nano-fluidics systems render the genetic circuitry responsible for cell-to-cell communication feasible to and malleable via synthetic biological approaches. Here we review the current understanding of the molecular biology of bacterial intercellular communication and the novel experimental protocols and platforms used to investigate this phenomenon. A particular emphasis is given to the genetic regulatory circuits that provide the standard building blocks which constitute the syntax of the biochemical communication network. Thus, this review gives focus to the engineering principles necessary for rewiring bacterial chemo-communication for various applications, ranging from population-level gene expression control to the study of host-pathogen interactions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권1호
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• pp.277-290
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• 2019

The demand for indoor positioning is increasing day by day. However, the widely used positioning methods today cannot satisfy the requirements of the indoor environment in terms of the positioning accuracy and deployment cost. In the existing research domain, the localization algorithm based on three-dimensional space is less accurate, and its robustness is not high. Visible light communication technology (VLC) combines lighting and positioning to reduce the cost of equipment deployment and improve the positioning accuracy. Further, it has become a popular research topic for telecommunication and positioning in the indoor environment. This paper proposes a surface centroid TOA localization algorithm based on the VLC system. The algorithm uses the multiple solutions estimated by the trilateration method to form the intersecting planes of the spheres. Then, it centers the centroid of the surface area as the position of the unknown node. Simulation results show that compared with the traditional TOA positioning algorithm, the average positioning error of the surface centroid TOA algorithm is reduced by 0.3243 cm and the positioning accuracy is improved by 45%. Therefore, the proposed algorithm has better positioning accuracy than the traditional TOA positioning algorithm, and has certain application value.

• 우주기술과 응용
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• 제4권2호
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• pp.87-104
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• 2024

큐브위성은 저비용, 짧은 개발 기간, 임무 지향적 성능 고도화, 군집 및 편대 비행을 통한 다양한 임무 수행이 가능하여 지구관측, 우주탐사, 우주 과학기술 검증 등 다양한 분야에서 활용성이 높다. 최근 큐브위성의 활용성이 높아지고 응용 분야가 확대됨에 따라 대용량 데이터의 고속 전송에 대한 요구가 전례 없이 증가하고 있는 추세이다. 레이저 기반 자유공간 광통신 기술은 기존 전파통신 방식 대비 고속으로 대용량 데이터 전송이 가능하고, 비면허대역 스펙트럼 사용, 저비용, 저전력, 높은 보안 특성 및 소형 통신 플랫폼의 활용 가능성 등 다양한 장점이 있어 큐브위성 임무 지원을 위한 고성능 통신 수단으로 적합하다. 본 논문에서는 큐브위성 기반 우주 레이저 통신 핵심 구성요소 및 특징을 살펴보고, 최근 연구동향, 대표 기술개발 사례 그리고 실증 결과와 함께 향후 개발 계획 등에 대해 살펴보고자 한다.

• 반도체디스플레이기술학회지
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• 제11권2호
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• pp.7-11
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• 2012

SiNx films have been wildly used as anti-reflection coatings and passivation for crystalline silicon solar cells. In this study, the SiNx films were deposited by using high frequency (13.56MHz) PECVD and optical & passivation properties were investigated. The RF power was changed in a certain range for the film deposition. Then, the refractive index, etch rate, minority carrier lifetime and cell efficiency were measured to study the properties of the film respectively. The optimal deposition conditions for application to crystalline silicon solar cells were proposed as results of the study. Finally, the best cell efficiency of 16.98% was obtained from the solar cell with the SiNx films deposited by RF power of 550W.

• 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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• 한국정보과학회언어공학연구회 2013년도 제25회 한글 및 한국어 정보처리 학술대회
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• pp.82-85
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• 2013

개체명 인식기에 대한 연구에서 개체명 사전은 필수적으로 필요하다. 그러나 공개된 개체명 사전은 거의 없기 때문에, 본 논문에서는 디비피디아의 데이터로부터 개체명을 효과적으로 추출하여 자동으로 구축할 수 있는 방법을 제안한다. 제안 방법은 엔트리의 '이름'과 '분류' 정보를 사용한다. 엔트리의 '이름'은 개체명으로 사용하고, 엔트리의 '분류'는 각 개체명 클래스와의 상호정보량을 계산하여 엔트리와 개체명 클래스 사이의 점수를 계산한다. 이렇게 계산된 점수를 이용하여 개체명과 개체명 클래스를 매핑한다. 그 결과 76.7%의 평균 정확률을 보였다.

• 반도체디스플레이기술학회지
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• 제14권3호
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• pp.23-26
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• 2015

A seam carving based micro-crack detection method is proposed which aims at detecting the micro-crack regions in heterogeneously textured surface of polycrystalline solar cells. By calculating the seam which is a connected path of low energy pixels in the image, the micro-crack regions can be detected. Experimental results show that the proposed seam carving based micro-crack detection method has superior efficiency in detecting the micro-crack without background noise pixels and the algorithm's computation time is less than the conventional algorithm.

• International Journal of Knowledge Content Development & Technology
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• 제12권3호
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• pp.19-29
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• 2022

The new age is characterised by information communication technology, where computers, laptops, mobile gadgets such as palmtops, tablets, mobile phones and the internet have made their way to every sphere of life from our domestic environments such a homes, small retail shops, banks to large industries and the world at large. Over time, so many questions about the ethical use of Information and Communication Technology (ICT) have emerged on who has access to what technology and the use of it and like every other technological invention. This paper will look at the morality involved in making use of ICT to promote ethical use of data or information in a virtual environment. ICT also possesses both positive and negative impacts; the questions that these impacts raise are what this piece attempts to answer, providing global scrutiny to these ethical issues, situations and questions; and providing recommendations in line with global best practices.

• International Journal of Knowledge Content Development & Technology
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• 제14권2호
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• pp.7-27
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• 2024

This study examines the use of electronic databases (e-databases) by faculty members of the Ghana Communication Technology University (GCTU). The study used a descriptive research method. Copies of the questionnaire were used for the data collection. Due to the manageable population, no sampling method was used in this study. The Statistical Package for the Social Sciences (IBM-SPSS 21.0) was used for data analysis. The results showed that most faculty members were aware of the availability of databases in the library. Additionally, the findings established that Emerald, as well as Taylor and Francis, were ranked highly in terms of availability and accessibility. The study identified problems such as difficulty in downloading information as well as poor internet connectivity. Based on the results, the study recommended that library management should address all the challenges that users encounter as soon as possible.

• 한국철도학회논문집
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• 제19권4호
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• pp.456-467
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• 2016

차량무선통신(WAVE)은 고속이동환경에서 차량간 통신(V2V), 차량과 인프라간 통신(V2I)을 가능하게 하고 안전 및 편의 서비스를 제공하는 무선통신기술로써 지능형 교통시스템(ITS)에 적용을 위한 연구가 진행되고 있다. 본 논문에서는 WAVE 통신기술을 철도분야에 적용하기 위하여, 철도시험선에 WAVE 통신 기반의 시험용 무선통신시스템을 구축하고 현차시험을 수행하여 철도전용 통합무선망(LTE-R)의 통신성능 요구사항 충족 여부를 검토하였다. 시험 결과, 최대전송거리는 730m, 평균전송지연은 최대 5.69ms, 단절시간은 최대 1.36s로서 목표 요구사항을 충족하였으며, Throughput 및 영상데이터 전송, VoIP 데이터 전송, 채널 스위칭 시험도 성공적으로 수행되었다. 이상의 시험결과로 부터, WAVE 통신 기술이 철도분야에 적용 가능하다는 것을 확인하였으며, 차-지상간의 안정적인 무선통신시스템 구축을 가능하게 할 것으로 기대된다.

• 조명전기설비학회논문지
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• 제27권10호
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• pp.1-8
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• 2013

Wireless Visible Light Communication is the technology that enables communication using LED illumination Infrastructure instead of existing illumination such as incandescent lamp or fluorescent light. Because VLC uses light for communication, it has no problem of frequency permission and is harmless to human body. It is also possible to check the communication through eye. So VLC can be used as a supplement to the Radio Frequency communication, Infrared in indoor environment. So far, researchers on the LED Visible light communication have focused on the increasing transmission speed, transmission distance, modulation method. However, there is few research of main factors that influence on system performance. System performance has been mainly predicted through simulation. In this paper, I recognized that these factors such as outside light noise, obstacle, LED panel position or emitted angle have a great impact on wireless communication system. So I experimented VLC system by changing distance and position to discover location suitable for BER regulation.