• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.202-202
• /
• 2012

유연성 투명 전도막은 현대 전자산업의 발전에 있어 필수적인 부품소재로서, 가시광선의 투과율이 80% 이상이고 면저항이 $100{\Omega}/sq.$ 전후이며 휘거나 접히고 나아가 두루마리의 형태로도 응용이 가능한 소재를 일컫는다. 이러한 유연성 투명 전도막은 차세대 정보디스플레이 산업 및 유비쿼터스 사회의 중심이 되는 유연성 디스플레이, 터치패널, 발광다이오드, 태양전지 등 매우 다양한 분야에 응용이 기대된다. 이러한 이유로 고 신뢰성 유연성 투명 전도막 개발기술은 차세대 산업에 있어서의 핵심기술로 인식되고 있다. 현재로서는 인듐 주석 산화물(indium tin oxide; ITO) 및 전도성 유기고분자를 사용하여 투명 전도막을 제조하고 있으나, ITO 박막의 경우 인듐 자원의 고갈로 인한 가격상승 및 기판과의 낮은 접착력, 열팽창계수의 차이로 인한 공정상의 문제, 산화물 특유의 취성으로 인한 유연소자로서의 내구성 저하 등의 문제가 제기되고 있다. 전도성 유기고분자의 경우는 낮은 전기전도도와 기계적강도, 유기용매 처리 등의 문제점이 지적되고 있다. 따라서 높은 전기전도도와 투광도 뿐만 아니라 유연성을 지니는 재료의 개발이 요구되고 있는 실정이다. 최근 이러한 재료로서 그래핀(graphene)과 탄소나노튜브(carbon nanotube; CNT)를 중심으로 하는 탄소나노재료가 주목받고 있으며 많은 연구가 활발히 진행되고 있다. 본 연구에서는 열화학기상증착법(thermal vapor deposition; TCVD)으로 합성된 그래핀 및 CNT를 이용하여 탄소나노재료 복합체 기반의 유연성 투명 전도막을 제작하고 그 특성을 평가하였다. 그래핀과 CNT합성을 위한 기판으로는 각각 300 nm 두께의 니켈과 1 nm 철이 증착된 실리콘 웨이퍼를 이용하였으며, 원료가스로는 메탄(CH4)과 아세틸렌(C2H2)등의 탄화수소가스를 이용하였다. 그래핀의 경우 원료가스의 유량, 합성온도, 냉각속도를 변경하여 대면적으로 두께균일도가 높은 그래핀을 합성하였으며, CNT의 경우 합성시간을 변수로 길이 제어합성을 도모하였다. 합성된 그래핀은 식각공정을, CNT는 스프레이 증착공정을 통해 고분자 기판(polyethylene terephthalate; PET) 위에 순차적으로 전사 및 증착하여 탄소나노재료 복합체 기반의 유연성 투명 전도막을 제작하였다. 제작된 탄소나노재료 복합체 기반의 유연성 투명 전도막은 물리적 과부하를 받았을 때 발생할 수 있는 유연성 투명 전도막의 구조적결함에 기인하는 전도성 저하를 보상하는 특징이 있어, 그래핀과 탄소나노튜브 각각으로 제조된 유연성 투명 전도막보다 물리적인 하중이 반복적으로 인가되었을 때 내구성이 향상되는 효과가 있다. 40% 스트레인을 반복적으로 인가하였을 때 그래핀 투명 전도막은 20 사이클 이후에 면저항이 $1-2{\Omega}/sq.$에서 $15{\Omega}/sq.$ 이상으로 급증한 반면 그래핀-CNT 복합체 투명 전도막은 30사이클까지 $1-2{\Omega}/sq.$ 정도의 면저항을 유지하였다.

• Journal of Broadcast Engineering
• /
• v.15 no.4
• /
• pp.498-512
• /
• 2010

Intra coding is an indispensable coding tool since it can provide random accessibility as well as error resiliency. However, it is the problem that intra coding has relatively low coding efficiency compared with inter coding in the area of video coding. Even though H.264/AVC has significantly improved the intra coding performance compared with previous video standards, H.264/AVC encoder complexity is significantly increased, which is not suitable for low bit rate interactive services. In this paper, a Voting-based Intra Mode Bit Skip (V-IMBS) scheme is proposed to improve coding efficiency as well as to reduce encoding time complexity using decoder-side prediction. In case that the decoder can determine the same prediction mode as what is chosen by the encoder, the encoder does not send that intra prediction mode; otherwise, the conventional H.264/AVC intra coding is performed. Simulation results reveal a performance increase up to 4.44% overall rate savings and 0.24 dB in peak signal-to-noise ratio while the frame encoding speed of proposed method is about 42.8% better than that of H.264/AVC.

• Journal of Broadcast Engineering
• /
• v.22 no.3
• /
• pp.295-312
• /
• 2017

Digital video content is the most information-intensive and high-value content. Therefore, it is necessary to protect the intellectual property rights of these contents, and this paper also proposes a watermarking method of digital image for this purpose. The proposed method uses the frequency characteristics of 2-Dimensional Discrete Wavelet Transform (2D-DWT) for digital images and digital watermark on global data without using local or specific data of the image for watermark embedding. The method to insert digital watermark data uses a simple Quantization Index Modulation (QIM) and a multiple watermarking method that inserts the same watermark data in multiple. When extracting a watermark, multiple watermarks are extracted and the final watermark data is determined by a simple statistical method. This method is an empirical method for experimentally determining the parameters in the watermark embedding process. The proposed method performs experiments on various images against various attacks and shows the superiority of the proposed method by comparing the performance with the representative existing methods.

• Journal of The Korean Association For Science Education
• /
• v.25 no.2
• /
• pp.122-132
• /
• 2005

Graphing abilities are critical to understand and convey information in science. And then, to what extent are secondary students in science courses able to understand line graphs? To find clues about the students' interpretation processes of the information in science-related line graphs, this study has the following research question: Is there a difference between the levels of complexity of good and poor readers as they use the thinking aloud method for studying cognitive processes? The present study was designed to provide evidence for the hypothesis that good line graph readers use a specific graph interpretation process when reading and interpreting line graphs. With the aid of the thinking aloud method we gained deeper insight into the interpretation processes of good and poor graph readers while verifying verbal statements with respect to line graphs. The high performing students tend to read much more information and more trend-related information than the low performing students. We support the assumption of differential line graph schema existing in the high performing students in conjunction with general graph schema. Also, high performing students tend to think aloud much more metacognitively than low performing students. High performing students think aloud a larger quantity of information from line graphs than low performing students, and more trend-related sentences than value-related sentences from line graphs. The differences of interpretation processes revealed between good and poor graph readers while reading and interpreting line graphs have implications for instructional practice as well as for test development and validation. Teaching students to read and interpret graphs flexibly and skillfully is a particular challenge to anyone seriously concerned with good education for students who live in an technological society.

• Journal of Convergence for Information Technology
• /
• v.10 no.2
• /
• pp.39-48
• /
• 2020

Many studies have been conducted to analyze factors that affect customer satisfaction, and service quality improvement in the parcel delivery industry. Most of these studies have a limited number of respondents using methods such as surveys and interviews. Therefore, this study aims to supplement the shortcomings of previous studies, by searching and analyzing the common major topics related to the complaints pointed out by consumers and suppliers in the parcel delivery service with cases of consumer counseling, and articles that reflect the complaints of workers in the industry. In addition, by analyzing the trend of these topics, we attempted to discover new topics and suggest implications. In conclusion, topics such as delay/lost/wrong deliveries as well as the fierce competition in the parcel delivery industry, turned out to be central aspects. As a result of the topic trend analysis, talks with international couriers have recently increased, and many conflicts related to apartment parcel delivery have been dealt with. The topics presented in this study are mainly focused on the contents of previous studies, but we expect that new and valuable topics can be derived by adding other data and analysis methods, such as internal counseling and academic literature.

• Korean Journal of Plant Taxonomy
• /
• v.41 no.4
• /
• pp.299-314
• /
• 2011

The choice of molecular markers is the first step when selecting experimental plans in the field of population genetics. The popular molecular markers in population genetic studies are mainly allozyme, RAPD, RFLP, AFLP, microsatellite, SNP and ISSR. Among these, microsatellites are frequently found in nuclear, chloroplast and mitochondrial genome, showing a high level of polymorphism and nuclear microsatellites are codominant. Thus, it is a favorable molecular marker for population structure analyses and genetic diversity studies. Microsatellites are composed of tandem repeated 1~6 base pair nucleotide motifs and can be easily amplified by PCR reactions using locus specific primers. Because microsatellites have low cross-species transferability, however, they are only applicable between phylogenetically close species. In wild plants, the lack of genomic information and the high development cost of the microsatellite obstruct the wider use of microsatellites in plant population genetics research. In this review, we introduce the basis for microsatellite markers, the development process, and analytical methods as well as evolutionary models and their applications. In addition, possible genotyping errors which lead to erroneous conclusions are discussed.

• Korean Journal of Construction Engineering and Management
• /
• v.14 no.2
• /
• pp.184-193
• /
• 2013

Procurement System for Korean construction industry has mainly been controlled by the complicated regulatory system which has been recognized as unflexible and remotely separated from the global standard. This has been identified by many Korean construction experts as one of the main reasons that hamper the Korean construction industry becoming the global leader. One commonly discussed regulatory system is the compulsory multiple contracting system that has been enforced for a long time. According to the Korean governmental contracting law 68-3, all construction projects cannot be divided into separate contracting packages with a few exceptions. Exceptions stated in the law include construction activities related electrical, Information communication, fire-fighting, and cultural assets which all are governed by the separate laws/acts controlled by the different governmental bodies. This research is to closely investigate multiple prime contracting system that has been compulsory in Korean construction industry and to provide policy recommendations to these restrictions. Although, there has been a long history of this compulsory contracting system, this study attempted to provide objective analysis on current status of the system as well as global standard on the issue. This study suggests main considerations when considering different contracting system such as rights of owners, flexibilities of regulatory systems, and efficiencies of conducting a construction project. It is envisioned that recommendations from this study, if accepted by the regulatory bodies, would improve the Korean construction contraction system by making it more compatible with global standard. Moreover, these would help making the Korean industry more effective in terms of regulatory restrictions.

• Spatial Information Research
• /
• v.12 no.2
• /
• pp.181-191
• /
• 2004

Nowadays, GPS-photogrammetry can be applied to the basemap production, a land register and NGIS. And from now on, as the increase of GPS receiver rate, the study on the interpolation methods considering the exact movement of an aircraft at photoflight and the study on the supplement of GPS defect by INS are required continuously. GPS-Photogrammetry, which are based on the direct measurement of the projection centers and attitude at the moment of camera exposure time through loading the GPS receiver in aircraft. This photogrammetric methods can of for us to acquire the exterior orientation parameters with only minimum ground control points, even the ground control process could be completely skipped. Consequently, we can drastically reduce the time and cost far the mapping process. In this thesis, two test flights were conducted in area to evaluate the performance of accuracy and efficiency through the analysis of results between the two photogrammetric methods, that is, traditional photograrammetry, GPS-Photogrammetry. Test results shows that a large variety of advantages of GPS-Photogrammetry against traditional photogrammetry is to be verified. Especially, the number of ground control points for the exterior orientation could be saved more than 70～80%, and the cost far map production 30～50%, respectively. In addition, it was convinced that the large reduction of control points has not any effect on the block accuracy.

• Journal of Korea Port Economic Association
• /
• v.27 no.2
• /
• pp.333-354
• /
• 2011

After the terrorist attack of 9/11 on the USA, the security concern to global trade has been raised. In particular, the USA has actively promoted a series of initiatives and rules such as CSI, 24 hour rule, C-TPAT, and so on in the area of logistics activities, which aimed to better protect the country against the potential terrorist threats. While implementing such schemes called as a multi-layed logistics security strategy, a large number of countries trading with USA are facing with the issues of additional time and costs for inspecting cargos in their logistics facilities. As a result, most countries all over the world have sought a way to minimize the impacts from such strategy. The Korea also is preparing the several security programs operated by various ministries, which are aiming to not only improve the efficiency of trade flows but also to ensure supply chain security. However, many companies are expressing the inefficiency of operating such programs. Thus, this paper analyzed several global supply chain security programs currently adopted by international organizations(ISO, WCO, and IMO) and major countries(USA, EU, and Singapore) and suggested a guideline for developing the national logistics security system.

• The Journal of the Convergence on Culture Technology
• /
• v.6 no.1
• /
• pp.335-341
• /
• 2020

As life, once immersed in labor, changes with values and lifestyles, individuals consume or participate in culture and arts for learning, meeting of intellectual needs, pleasure, and exchange. As culture and art spaces have increased in recent times, these spaces have been transformed into places to create, view and exchange culture and art, and to consume cultural goods. Culture and art spaces have created and developed new genres and technologies that give viewers the opportunity to communicate and participate, allowing them to understand and accumulate works of media. A media façade thus gives a preference to places for visitors by giving an impression over a short period of time in culture and art spaces that are not areas for exhibitions and performances, and providing an opportunity to more easily approach and understand works and culture and art spaces. A media façade is a type of medium that imparts aesthetics and information by installing LED lighting on the exterior wall of a building for the realization of media functions. In order to analyze the effect of the media façade on preferences for culture and art spaces, a research model was established with media façade characteristics as independent variables and preferences for culture and art spaces as dependent variables. As a result, media façade design and media features influenced satisfaction, while the media characteristics of the media façade influenced recommendation and revisiting, suggesting that many changes will take place in culture and art spaces.