• ETRI Journal
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• v.34 no.6
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• pp.858-868
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• 2012

In this paper, stochastic models for the cross-correlation of multiple channels are established based on measurement data collected using a wideband multiple-input multiple-output relay Band Exploration and Channel Sounder system at 3.7 GHz. We propose models for the cross-correlation characteristics of large-scale parameters (LSPs) between two links, that is, the base station and mobile station (MS) link and the relay station and MS link. The LSPs include shadow fading, Rician K-factor, delay spread, angle spread of arrival, and angle spread of departure. Furthermore, models are established for the cross-correlation of the small-scale fading in the impulse responses of two links. The statistics of these model parameters are investigated as functions of geometrical features of the multilink. They are extracted from a large amount of cross-correlation observations, which are obtained in three measurement sites along more than one hundred measurement routes. These models can be used together with the standard single-link channel models for the generation of correlated components, for example, path clusters, in two separate channels.

• Smart Structures and Systems
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• v.23 no.6
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• pp.669-682
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• 2019

Vibration mitigation of cables or hangers is one of the crucial problems for cable supported bridges. Previous research focused on the behaviors of cable with dampers or crossties, which could help engineering community apply these mitigation devices more efficiently. However, less studies are available for hybrid applied cross-ties and dampers, especially lack of both analytical and experimental verifications. This paper studied damping and frequency of two parallel identical cables with a connection cross-tie and an attached damper. The characteristic equation of system was derived based on transfer matrix method. The complex characteristic equation was numerically solved to find the solutions. Effects of non-dimensional spring stiffness and location on the maximum cable damping, the corresponding optimum damper constant and the corresponding frequency of lower vibration mode were further addressed. System with twin small-scale cables with a cross-link and a viscous damper were tested. The damping and frequency from the test were very close to the analytical ones. The two branches of solutions: in-phase modes and the out-of-phase modes, were identified; and the two branches of solutions were different for damping and frequency behaviors.

• ETRI Journal
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• v.30 no.5
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• pp.663-673
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• 2008

The multi-scenario topology of multi-channel hybrid ubiquitous sensor networks (USNs) is studied and a novel link auto-diversity cross-layer cooperative scheduling scheme is proposed in this paper. The proposed scheme integrates the attributes of the new performance evaluation link auto-diversity air-time metric and the topology space in the given multi-scenario. The proposed scheme is compared with other schemes, and its superiority is demonstrated through simulations. The simulation results show that relative energy consumption, link reception probability, and end-to-end blocking probability are improved. The addressing ratio of success with unchanged parameters and external information can be increased. The network can tolerate more hops to support reliable transportation when the proposed scheme is implemented. Moreover, the scheme can make the network stable. Therefore, the proposed scheme can enhance the average rate performance of the hybrid USN and stabilize the outage probability.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.447-450
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• 2002

Recently polymeric insulators and arresters are being used for outdoor high voltage applications. Polymeric insulators for transmission line have significant advantages over porcelain and glass insulators, especially for ultra-high voltage(UHV) transmission lines. Their advantages are light weight, vandalism resistance and hydrophobicity. Polymeric insulator kind are a relatively new technology, but their expected life is still unknown. In this paper, the material property for polymeric insulating material such as silicone rubber and EPBM is investigated by cross-link time and the relation between tracking resistance and W resistance is analyzed by IEC 60587 and W aging experiment.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.05a
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• pp.67-72
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• 2005

The bonding structure of organic materials such as fluorinated amorphous carbon films was classified into two types due to the chemical shifts. The electrical properties of fluorinated amorphous carbon films also showed very different effect of two types notwithstanding a very little difference. Fluorinated amorphous carbon films with the cross-link breakage structure existed large leakage current resulting from effect of the electron tunneling. Increasing the cation due to the electron-deficient group increased the barrier height of the films with the cross-link amorphous structure, therefore the electric characteristic of the final materials with low dielectric constant was also improved. The lowest dielectric constant is 2.3 at the sample with the cross-link amorphous structure.

• Archives of Pharmacal Research
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• v.20 no.6
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• pp.550-554
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• 1997

Chlorambucil is known to alkylate primarily N7 of guanine and N3 of adenine to induce DNA monofunctional adducts and interstrand cross-links (ISC). We have investigated the sequence specificity for DNA ISC induced by chlorambucil using duplex oligomers containing a defined cross-linkable sequences $ 5^{I}-A*TT, 5^{I}-G*TTor5^{I}-G*CC$ under bar which asterisk indicates the potential cross-linking site and underlined base indicates the potential cross-linking site on the opposite strand. An analysis of 20% denaturing polyacrylamide gel electrophoresis showed that chlorambucil was albe to induce DNA ISC in the duplex oligomers containing a sequence $5^I-GCC$. The formation of DNA ISC was not observed in the duplex oligomers containing sequences $5^I-ATT$. or $5^I-GTT$. These results indicate that chlorambucil induces guanine-guanine DNA ISC but not guanine-adenine or adenine-adenine DNA ISC. In addition, we have tested the ability of chlorambucil to induce DNA ISC within $5^I-GNNC$ or $5^I-GNNC$sequences using duplex oligomers containing the sequence$5^I-G^4G^3G^2^C$. The result of DNA strand cleavage assay showed that DNA ISC was formed at the $5^I-GGC$ sequence (an 1,3 cross-link, $G^1-G^3$) but not at $5^I-GGGC$ (an 1,4 cross-link, $G^1-G^4$) or $5^I-GC$ sequence (an 1,2 cross-link, $G^1-G^2$).

• Journal of Korea Multimedia Society
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• v.18 no.2
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• pp.168-177
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• 2015

To increase the overall utility and decrease the link delay and power consumption, a joint optimal cross-layer design of congestion control at the transport layer, link delay at the data link layer and power allocation at the physical layer for mobile ad hoc networks is considered in this paper. As opposed to previous work, the rate outage probability in this work is based on exactly closed-form; therefore, the proposed method can guarantee the globally optimal solutions to the underlying problem. The non-convex formulated problem is transformed into a convex one, which is solved by exploiting the duality technique. Finally, simulation results verify that our proposal achieves considerable benefits over the existing method.

• The KIPS Transactions:PartC
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• v.10C no.7
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• pp.923-928
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• 2003

This paper proposes a bottleneck link bandwidth measurement algorithm for reducing packet transmission delay within the grid network. There are two methods for measuring bottleneck link bandwidth：Packet Pair algorithm and Paced Probes algorithm. They measure bottleneck link bandwidth using the difference in arrival times of two paced probe packets of the same size traveling from the same source to destination. In addition, they reduce the influences of cross traffic by pacer packet. But there are some problems on these algorithms：it's not possible to know where bottleneck link occurred because they only focus on measuring the smallest link bandwidth along the path without considering bandwidth of every link on the path. So hop-by-hop based bottleneck link bandwidth measurement algorithm can be used for reducing packet transmission delay on grid network. Timestamp option was used on the paced probe packet for the link level measurement of bottleneck bandwidth. And the reducing of packet transmission delay was simulated by the solving a bottleneck link. The algorithm suggested in this paper can contribute to data transmission ensuring FTP and realtime QoS by detecting bandwidth and the location where bottleneck link occurred.

• The Korean Journal of Applied Statistics
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• v.14 no.1
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• pp.25-37
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• 2001

The marginal model is proposed for the analysis of data which have c(2: 3) categories in the 3 x 3 cross-over trials with three periods and three treatments. This model could be used for the counterpart of the Kenward-Jones' joint probability one and should be the generalization of Balagtas et ai's univariate marginal logits one, which analyze the treatment effects in the 3 x 3 cross-over trials with binary response variables[Kenward and Jones(1991), Balagtas et al(1995)]. The model equations for the marginal probability are constructed by the three types of link functions. The methods would be given for making of the link function matrices and model ones, and the estimation of parameters shall be discussed. The proposed model is applied to the analysis of Kenward and Jones' data.

• Journal of the Optical Society of Korea
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• v.11 no.4
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• pp.158-161
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• 2007

We proposed a novel linearization technique for a DFB LD in the RoF link. The proposed scheme is based on the cross gain modulation(XGM) effect of a reflective semiconductor optical amplifier(RSOA) with light injection. We experimentally demonstrated and evaluated the enhanced CIR performance using the proposed linearization scheme.