• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.355-361
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• 2006

In large scale environments like airport, museum, large warehouse and department store, autonomous mobile robots will play an important role in security and surveillance tasks. Robotic security guards will give the surveyed information of large scale environments and communicate with human operator with that kind of data such as if there is an object or not and a window is open. Both for visualization of information and as human machine interface for remote control, a 3D model can give much more useful information than the typical 2D maps used in many robotic applications today. It is easier to understandable and makes user feel like being in a location of robot so that user could interact with robot more naturally in a remote circumstance and see structures such as windows and doors that cannot be seen in a 2D model. In this paper we present our simple and easy to use method to obtain a 3D textured model. For expression of reality, we need to integrate the 3D models and real scenes. Most of other cases of 3D modeling method consist of two data acquisition devices. One for getting a 3D model and another for obtaining realistic textures. In this case, the former device would be 2D laser range-finder and the latter device would be common camera. Our algorithm consists of building a measurement-based 2D metric map which is acquired by laser range-finder, texture acquisition/stitching and texture-mapping to corresponding 3D model. The algorithm is implemented with laser sensor for obtaining 2D/3D metric map and two cameras for gathering texture. Our geometric 3D model consists of planes that model the floor and walls. The geometry of the planes is extracted from the 2D metric map data. Textures for the floor and walls are generated from the images captured by two 1394 cameras which have wide Field of View angle. Image stitching and image cutting process is used to generate textured images for corresponding with a 3D model. The algorithm is applied to 2 cases which are corridor and space that has the four wall like room of building. The generated 3D map model of indoor environment is shown with VRML format and can be viewed in a web browser with a VRML plug-in. The proposed algorithm can be applied to 3D model-based remote surveillance system through WWW.

• Smart Structures and Systems
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• v.25 no.5
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• pp.631-641
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• 2020

To meet the urgent requirements of safety surveillance from civil engineering management authorities, this study proposes a refined and efficient approach to generate full-field high-resolution panorama of construction sites using camera-amounted UAV (Unmanned Aerial Vehicle). GPS (Global Position System) information extraction for pre-registration, feature points filtering for efficient registration and optimal seaming line seeking for fusion are performed in sequence to form the full-field panorama generation framework. Advantages of the proposed method are as follows. First, GPS information can sort images for pre-registration, avoiding inefficient repeated pairwise calculations and matching. Second, the feature points are filtered according to the characteristics of the construction site images to reduce the amount of calculation. The proposed framework is validated on a road construction site and results demonstrate that it can generate an accurate and high-quality full-site panorama for the safety supervision in a much efficient manner.

• Advanced Composite Materials
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• v.16 no.2
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• pp.95-113
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• 2007

Experimental investigations of interlaminar mechanical properties for carbon fiber reinforced plastic (CFRP) laminates were carried out using aramid fiber ($Kevlar^{(R)}$-29 1000d) and carbon fiber (TR40-1K 612d, Mitsubishi Rayon) stitching. Various carbon fiber (CF) stitch densities were used to prepare a number of CF stitched CFRP laminates for double cantilever beam (DCB) tests. An insert tongue-type loading fixture, developed by the Japan Aerospace Exploration Agency (formerly the National Aerospace Laboratory of Japan), was also employed in the DCB test. Interlaminar tension tests were carried out under an out-of-plane directional loading using a single CF stitch thread in the CFRP laminates. The DCB test results clarified that the relationship between the volume fractions of the CF stitch thread ($V_{ft}$) and mode I critical energy release rate ($G_{Ic}$) showed a mostly linear function with a higher gradient than that of the $Kevlar^{(R)}$ stitched CFRP laminates. The CF stitched CFRP tension test results indicated that the consumption energy per unit area ($E_i$) was larger than that of $Kevlar^{(R)}$ stitched CFRP laminates.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.609-612
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• 2002

In this paper, a 12-bit 100-MHz CMOS current steering digital-to-analog converter is designed. In the D/A converter, a driver circuit using a dynamic latch is implemented to obtain low glitch and thermometer decoder is used for low DNL errors, guaranteed monotonicity, reduced stitching noise. And a threshold voltage-compensated current source. The D/A converter is designed with 0.35-$\mu m$ CMOS technology at 3.3 V power supply and simulated with HSPICE. The maximum power dissipation of the designed DAC is 143 mW.

• Advanced Composite Materials
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• v.16 no.2
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• pp.135-149
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• 2007

In the automobile industry, structural health monitoring of fiber reinforced polymer composite parts is a widespread need for maintenance before breakdown of the functional elements or a complete vehicle. High performance sensors are generally used in many of the structural health monitoring operations. Within this study, a carbon fiber sewing thread has been used as a low cost laminate failure sensing element. The experimentation plan was set up according to the electrical conductance and flexibility of carbon fiber threads, advantages of preforming operations, and sewing mechanisms. The influence of the single thread damages by changing the electrical resistance and monitoring the impact location by using carbon thread sensors has been performed. Innovative utilization of relatively cost-effective carbon threads for monitoring the delamination of metallic inserts from the basic composite laminate structure is a highlighting feature of this study.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.06a
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• pp.229-230
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• 2019

실사 기반의 VR (Virtual Reality) 영상을 생성하기 위해서는 카메라 리그 (rig) 설계 기술, 스티칭(stitching) 기술, 3 차원 공간 정보 추정 기술 등 여러 기술이 필요하다. 이러한 기술에 대한 연구를 진행하려면 카메라 위치, 피사체 거리, 조명 정도 등 다양한 요소를 고려한 수 많은 실험을 수행해야 하는데, 실사 조건에서 이를 직접 수행하려면 상당한 시간과 노력이 소요된다. 따라서 원하는 실험 조건을 쉽게 구성할 수 있는 컴퓨터 그래픽스 (CG: Computer Graphics) 환경 상에서 먼저 실험을 진행한 이후 실사로 확장하는 것이 더욱 효율적인 접근법이 될 것이다. 본 논문에서는 VR 영상의 생성에 요구되는 다양한 기술을 연구할 때 활용할 수 있는 CG 기반의 툴을 소개하고자 한다.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.43-49
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• 2019

Nowadays, one-person media broadcasting has become popular, and with the progress of this popularity, multimedia techniques which can support such broadcasting are also becoming more and more advanced. One of the most emerging multimedia technique used in this field is the virtual reality technology which sets the one-person media broadcasting environment as a virtual reality environment. However, as such an environment requires instruments of high cost, it is not easy for normal individuals to constitute such environments. Therefore, in this paper we propose how to construct virtual reality-like panoramas with a multiple of smartphones. For this purpose, we designed a special rig which can hold firmly 8 smartphone cameras which have overlapping view of the environment such that panorama stitching becomes possible. To reduce the computation cost, we precomputed the homography matrices, and used 1-D pointer structures to store the computed coordinate values.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.4 s.107
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• pp.33-40
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• 2004

A white light interferometery (WLI) method for investigating surface microstructure was introduced. Brief description of the principle of this method was provided. The surface structure of various samples, for example, a liner board paper, a pigment coated paper, a intaglio printed paper and a polymer laminated paper were tested and characterized with the WLI method. The data showed the WLI method provided very detailed information about surface topography, which were little affected by the surface condition such as color, opacity, roughness, etc. The data stitching mode of the WLI method could provide high spatial resolution over a large field-of-view, which made it possible to obtain the statistically valid results. Fast and high repeatability also made this method a promising way for investigating the surface micro-structure of paper products and prints.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.4
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• pp.124-130
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• 2008

Automatic layout decomposition techniques have been developed for double patterning technology (DPT). As CMOS manufacturing process scales down to 45nm and below, lithography resolution needs to be improved. DPT has been proposed to enhance the limitation of conventional lithography, by decomposing the layout design into two masks to relax the minimum spacing requirement. However, it is not always possible to decompose a layout into two masks. We have developed new automatic stitching techniques to resolve this problem. Experimental results show that the suggested techniques are promising in decomposing layouts for DPT.

• Advances in aircraft and spacecraft science
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• v.6 no.2
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• pp.105-116
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• 2019

An alternative to the multilayered preforming is to use structures reinforced through-the-thickness in order to manufacture thicker and more complex pieces. Stitching technology is developed to bind dry reinforcements together or to strengthen composites in thickness performance by inserting structural yarns. Tufting process represents the simplest one-sided sewing technology and it is specifically designed for dry preform/liquid composite molding process route. Currently, the tufting technology is getting more and more interest due to its simplest and efficient process where it involves the insertion of binder threads via a single needle through the fabric. This technique of reinforcement through-the-thickness requires only one access to the preform which makes it suitable for three-dimensional structures and complex shaped textile composites. This paper aims to improve the understanding of the mechanical performance of tufted structures. An experimental study was developed, which included tensile and bending behaviours of tufted and un-tufted preforms, in order to evaluate the effect of tufting on the mechanical performance of dry preforms. The influence of the process parameters (tufting density, loop length, tufting yarns${\ldots}$) on the mechanical performance ofthe final structure is also highlighted.