• Composites Research
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• v.29 no.3
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• pp.104-110
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• 2016

This paper reports a novel method for simultaneous exfoliation of graphene and dispersion of carbon nanotube by using intercalation method. In common, graphene flake and carbon nanotubes can be produced through individual exfoliation or debundling process, but the process require significant amount of time. Here, potassium sodium tartrate was thermally intercalated into graphite and carbon nanotube bundle for simultaneous exfoliation and dispersion of graphene and carbon nanotubes. We confirmed expansion of interlayer distance via XRD, and also found that oxidation level of the exfoliated materials were significantly low (below 8.3 at%). The produced materials are fabricated in to conductive composite film via vacuum filtration and spray deposition to show enhancement of conductive properties.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.5
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• pp.387-395
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• 2009

The establishment of security architecture is essential because security vulnerabilities occur such as user's unjustifiable connection for the opened gateway and access to resources without permission in OSGi service platform environment. In this paper, it proposes a authentication technique for an Automatic user authentication which is used the Symmetric Key and the Service bundle authentication to consider the constraints of the hardware in the OSGi service platform environment. Typically, the type of entering a password is used for the user authentication mechanism however OSGi platform environment studies not entering the password but using MAC address and encrypted identifier of the automatic user authentication mechanism because the devices are limited in their input. In this paper, the Symmetric Key is used for bundle authentication mechanism. Therefore operation becomes quick and secure authentication process has been successfully completed by using the time data and a ticket which contains a license. Based on these two different authentication mechanisms, it could eliminate the constraints of resources and improve the convenience of users and administrators. Also it shows an effect from omitting the waiting time to enter a password and reducing operations which need for authentication in the OSGi service platform environment.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.1
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• pp.75-82
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• 1991

The objective of this paper is to investigate the optimal Robust estimation and scale estimator that could be used to treat the gross errors in a self calibrating bundle adjustment. In order to test the variability in performance of the different weighting schemes in accurately detecting gross error, five robust estimation methods and three types of scale estimators were used. And also, two difference control point patterns(high density control, sparse density control) and three types of gross errors(4$\sigma o$, 20$\sigma o$, 50$\sigma o$) were used for comparison analysis. As a result, Anscombe's robust estimation produced the best results in accuracy among the robust estimation methods considered. when considering the scale estimator about control point patterns, It can be seen that Type II scale estimator provided the best accuracy in high density control pattern. On the other hand, In the case of sparse density control pattern, Type III scale estimator showed the best results in accuracy. Therefore it is expected to apply to robustified bundle adjustment using the optimal scale estimator which can be used for eliminating the gross error in precise structure analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.4
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• pp.139-146
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• 1987

The 3-dimensional deformation measurement by the terrestrial photogrammetry is consist of 3-dimensional coordinates computation, displaced point detection and deformation estimation of object targets. In this study, at the first step of deformation analysis, the variation of the variance-covariance matrix for the exterior orientation elements was analyzed by the increment of the ground control points and the photos in the Bundle adjustment. And then, to give the constraints for improving accuracy of ground control points, the concept of Free-Network adjustment was applied to Bundle adjustment. As a result, we knew that it was desired in the accuracy and the economy, the observation time when the numbers of ground control point and photo were respectively 6 points and 3 photos. In addition, in the case of applying the concept of Free Network adjustment in Bundle adjutment, it was desirable that the space distance for the constraints is distributed outside.

• Journal of Cadastre & Land InformatiX
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• v.51 no.2
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• pp.185-198
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• 2021

Researches using UAVs are being actively conducted in the field of quickly constructing 3D spatial information in small areas. In this study, without using ground control points, a stereo camera was mounted on a UAV to collect images and quickly construct three-dimensional positions through image matching, bundle adjustment, and the determination of a scale factor. Through the experiment, when bundle adjustment was performed using stereo constraints, the root mean square error was 1.475m, and when absolute orientation was performed in consideration of a scale, it was found to be 0.029m. Through this, it was found that when using the data processing method of a UAV equipped with a stereo camera proposed in this study, high-accuracy 3D spatial information can be constructed without using ground control points.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.4
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• pp.572-580
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• 2021

In order to reduce transmission delay and increase reliability in networks, mainly high-performance and high-power network equipment is used to guarantee network quality. In this paper, we propose an optimization algorithm to minimize the energy consumed when transmitting traffic in networks with a bundle link composed of multiple physical cables. The proposed optimization algorithm is a meta-heuristic method, which uses tabu search algorithm. In addition, it is designed to minimize transmission energy by minimizing the cables on the paths of the source and destination nodes for each traffic. In the proposed optimization algorithm, performance evaluation was performed in terms of the number of cables used in the transmission and the link utilization for all traffic on networks, and the performance evaluation result confirmed the superior performance than the previously proposed method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.541-548
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• 2021

Recently, multispectral cameras are being actively utilized in various application fields such as agriculture, forest management, coastal environment monitoring, and so on, particularly onboard UAV's. Resultant multispectral images are typically georeferenced primarily based on the onboard GPS (Global Positioning System) and IMU (Inertial Measurement Unit)or accurate positional information of the pixels, or could be integrated with ground control points that are directly measured on the ground. However, due to the high cost of establishing GCP's prior to the georeferencing or for inaccessible areas, it is often required to derive the positions without such reference information. This study aims to provide a means to improve the georeferencing performance of a multispectral camera images without involving such ground reference points, but instead with the simultaneously onboard high resolution RGB camera. The exterior orientation parameters of the drone camera are first estimated through the bundle adjustment, and compared with the reference values derived with the GCP's. The results showed that the incorporation of the images from a high resolution RGB camera greatly improved both the exterior orientation estimation and the georeferencing of the multispectral camera. Additionally, an evaluation performed on the direction estimation from a ground point to the sensor showed that inclusion of RGB images can reduce the angle errors more by one order.

• 월간 기계설비
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• no.5 s.190
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• pp.86-91
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• 2006

현장 환경관리조직 설치 의무화/전문건설업계 유동성 개선/건설현장에 부실벌점 주의보/하도급 위반 중복처벌 못한다/공사 견적능력을 높여라/해외플랜트 수주 1분기 63억달러/초중고 74교 14건으로 번들링/조달청,공사계약팀 시설총괄팀으로 개명

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.1
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• pp.74-80
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• 2010

We implemented an application system which is able to verify visitor identification for remote bundle control based on OSGi and web camera control using embedded linux system. This system are designed open Oscar framework by porting java on the embedded linux system and implemented web camera system in local area networks. Also This system can verify information of visitor from receiving the data of RFID reader and designed the wireless internet system in home. Basically, in this paper we expect that home network system development and the period of application service development are reduced with integrated service provision based on OSGi.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.121-127
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• 2015

In this paper, we propose S/W framework for health care robot based on OSGI middleware. Most healthcare robot developed independently. Therefore most module duplicately developed. However It's not efficient. In this paper we propose S/W framework for healthcare robot that can provide common module for health care robot and can apply heterogeneous robot. By using this S/W framework, we can enhance reusability of s/w module and can provide flexible and efficient development environment.