• Structural Engineering and Mechanics
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• v.50 no.3
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• pp.365-382
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• 2014

In this article, the force method and Charged System Search (CSS) algorithm are used for the analysis and optimal design of truss structures. The CSS algorithm is employed as the optimization tool and the force method is utilized for analysis. In this paper in addition to member's cross sections, redundant forces, geometry and topology variables are considered as the optimization variables. Minimum complementary energy principle is used directly to analyze the structure. In the presented method, redundant forces are calculated by the CSS in order to minimize the energy function. Combination of the CSS and force method leads to an efficient algorithm in comparison to some of the optimization algorithms.

• Korean Journal of Computational Design and Engineering
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• v.1 no.1
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• pp.45-55
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• 1996

This paper presents a new approach to non-parametric modeling of cutter swept surface (CSS) for cutting simulation. Instead of explicitly modeling cutter swept volumes, silhouette curves of the cutter surface are utilized in computing the z-value of the CSS at a grid point on the x,y-plane. The non-parametric evaluation of the CSS constitutes the integral part of 3-axis cutting simulation. The proposed method is more efficient than the existing ones in the case of conventional cutters (i.e., ball-end mills and flat-end mills), and more importantly, it enables the non-parametric modeling of the CSS for the round-end mills which was not possible with the existing methods.

• The Journal of Korea Robotics Society
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• v.7 no.1
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• pp.45-56
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• 2012

This paper proposes how to improve the performance of CSS-based indoor localization system. CSS based localization utilizes signal flight time between anchors and tag to estimate distance. From the distances, the 3-dimensional position is calculated through trilateration. However the error in distance caused from multi-path effect transfers to the position error especially in indoor environment. This paper handles a problem of reducing error in raw distance information. And, we propose the new localization method by pattern matching instead of the conventional localization method based on trilateration that is affected heavily on multi-path error. The pattern matching method estimates the position by using the fact that the measured data of near positions possesses a high similarity. In order to gain better performance of localization, we use EKF(Extended Kalman Filter) to fuse the result of CSS based localization and robot model.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.731-734
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• 2007

본 연구는 구조광 기반의 깊이 에지를 이용하여 조명의 변화와 복잡한 배경에 상관없이 손 제스처의 외곽선 영상을 안정적으로 획득하였고, 제스처 영상을 표현하기 위하여 Curvature Scale Space(CSS) map을 이용하였다. 기존의 CSS map은 외곽선 영상의 깊은 굴곡과 완만한 굴곡을 잘 구분하지 못하는 문제점이 있었으나, 본 연구에서는 이러한 문제점을 분석하고, 이를 개선하기 위해서 각도 좌표를 이용한 CSS map 생성 방법을 제안하였다. 실험을 통해서 제안한 방법이 기존의 CSS map보다 우수한 인식 성능이 있음을 보였다.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.319-320
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• 2008

In this paper, we propose a new frequency offset estimation algorithm for DBO-CSS which is a standard for wireless personal area network (WPAN). In DBO-CSS, there can be several integer multiples of $2{\pi}$ in the phase rotation caused by the frequency offset because of the long time difference between the samples of differential relation and the high permissible frequency offset of the crystal oscillators between the transmitter and the receiver. In this paper, we propose an estimation algorithm by using the relationships of each sub-chirp signals to find the integer part without phase ambiguity.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.321-322
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• 2008

CSS(Chirp Spread Spectrum) technology adopt SDS-TWR algorithms of TOA(Time of Arrival) using velocity of specific medium and ToF(Time of Flight) to measure a distance, but this method always has a regular error on distance regardless of a real distance, as a result, in far distance, it decrease a error on distance relatively, but in near distance, it increase a error on distance relatively. in this paper, we propose and test new method measuring a distance more precisely in near distance using CSS and RSSI

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.6
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• pp.1133-1146
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• 2011

Cognitive radio (CR) is considered one of the most promising next-generation communication systems; it has the ability to sense and make use of vacant channels that are unused by licensed users. Reliable detection of the licensed users' signals is an essential element for a CR network. Cooperative spectrum sensing (CSS) is able to offer better sensing performance as compared to individual sensing. The presence of malicious users who falsify sensing data can severely degrade the sensing performance of the CSS scheme. In this paper, we investigate a secure CSS scheme, based on the Kullback-Leibler Divergence (KL-divergence) theory, in order to identify malicious users and mitigate their harmful effect on the sensing performance of CSS in a CR network. The simulation results prove the effectiveness of the proposed scheme.

• Journal of Information Technology Applications and Management
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• v.13 no.4
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• pp.109-120
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• 2006

Enterprise Content Integration (ECI)is an IT strategy that improves enterprise' competitive advantages by integrating enterprise wide information and content into a unified view, which in turn supports efficient and effective decision making. Content Syndication Systems (CSS) is a solution that implements the ECI strategy. In semi-conductor industries, it is usual that enterprise content is scattered over tens of legacy systems. Therefore, engineers in semi-conductor companies spend a few hours to locate required engineering information on a daily basis as part of their jobs. In this paper, we develop an enterprise CSS system that integrates enterprise wide contents into a unified view that is suitable for semi-conductor industries. For this research, we first define enterprise CSS, then identify their systems requirements. Then we propose an architecture supporting the identified requirements, and present the implemented prototype. One of the most important requirements is the individualized subscription rule setting for engineering information. For this purpose, we developed methods to represent the information properties and subscription rules.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.05a
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• pp.274-282
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• 2005

Customer retention is one of the major issued in life insurance industry, in which competition is increasingly fierce. There are many things to do to retain customers. One of those things is to be continuously in touch with all customers. The objective of this study is to design the contact scheduling system(CSS) to support the planers who must touch the customers without having subjective information. Support-planers suffer from lack of information which can be used to intimately touch. CSS that is developed in this study generates contact schedule to touch customers by taking into account existing contact history. CSS has a two stage process. In the first stage, it segments customers according to his or her demographics and contract status data. Then it finds typical pattern and pattern is combined to business rules for each segment. We expert that CSS would support support-planers to make uncontacted customers' experience positive.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.119-126
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• 2011

In this paper, we expect that the IEEE 802.15.4a, which is based on CSS, will be used a lot without getting help from other systems or sensors and will make it possible to measure the distance between radio chips in sensor network field, where the location information of the standard have to be based upon. But, the error rate will be high, so we will correct the location of the tag, which will be received by anchor. The technology of location correction we offer is reducing the error rate through calculating the distance from Compensation Tag, and after that, unite the Toa method with the Fingerprint method and adapt them to location correction technology, calculate the location's estimate, and finally abstract the best suited location estimate for Compensation Tag. At last, we offer developing systems as indoor systems of CSS, which pursue the location between nodes, and a thesis about indoor systems and making their accuracy higher.