• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.3
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• pp.328-338
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• 2021

A study on common modular design based on open standards to reduce the life cycle cost of ground weapon system is underway. Since the ground weapon system includes major mission equipment such as fire control system, it is essential to apply the concept of fault tolerance through automatic reconfiguration and blocking unspecified equipment through connectivity control. However, it is difficult to generalize due to the difference in operating characteristics for each system. In this paper, we propose a plug-and-play framework, which includes plug-and-play architecture and mechanism. The proposed method can be used in common by the application of each component as it is divided into a common service layer. In addition, the proposed connectivity control and autonomous reconfiguration method facilitates reflection of operating characteristics for each system. We constructed a verification environment that can simulate ground weapon systems and components, and verified that the proposed framework works through scenario-based functional tests.

• Journal of Astronomy and Space Sciences
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• v.36 no.4
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• pp.235-248
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• 2019

This paper suggests a relative orbit control strategy for the CubeSat Astronomy by NASA and Yonsei using Virtual Telescope Alignment eXperiment (CANYVAL-X) mission whose main goal is to demonstrate an essential technique, which is an arrangement among two satellites and a specific celestial object, referred to as inertial alignment, for a next-generation virtual space telescope. The inertial alignment system is a relative orbit control system and has requirements for the relative state. Through the proposed orbit control strategy, consisting of separation, proximity keeping, and reconfiguration, the requirements will be satisfied. The separation direction of the two CubeSats with respect to the orbital plane is decided to provide advantageous initial condition to the orbit controller. Proximity keeping is accomplished by differential atmospheric drag control (DADC), which generates acceleration by changing the spacecraft's effective cross section via attitude control rather than consuming propellant. Reconfiguration is performed to meet the requirements after proximity keeping. Numerical simulations show that the requirements can be satisfied by the relative orbit control strategy. Furthermore, through numerical simulations, it is demonstrated that the inertial alignment can be achieved. A beacon signal had been received for several months after the launch; however, we have lost the signal at present.

• Journal of the Korea Society of Computer and Information
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• v.6 no.2
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• pp.108-115
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• 2001

SDH-based SHR networks are the reconfiguration process in case of failure and APS protocol used. In this study, addresses the maximum allowed recovery time in two fiber bidirectional networks. We analyse the APS protocol and derive the Processing time domains of each n order to cope with the maximum reconfiguration time of 50㎳, as specified in the ITU-T standard. We finally analyze the interleaved failures. One is the signal degrade then the signal failure, the other is the signal failure then the signal failure. Any case analysis is carried out. reconfiguration time can be guaranteed.

• ETRI Journal
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• v.36 no.2
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• pp.214-223
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• 2014

A fully-integrated penta-band reconfigurable power amplifier (PA) is developed for handset Tx applications. The output structure of the proposed PA is composed of the fixed output matching network, power and frequency reconfigurable networks, and post-PA distribution switches. In this work, a new reconfiguration technique is proposed for a specific band requiring power and frequency reconfiguration simultaneously. The design parameters for the proposed reconfiguration are newly derived and applied to the PA. To reduce the module size, the switches of reconfigurable output networks and post-PA switches are integrated into a single IC using a $0.18{\mu}m$ silicon-on-insulator CMOS process, and a compact size of $5mm{\times}5mm$ is thus achieved. The fabricated W-CDMA PA module shows adjacent channel leakage ratios better than -39 dBc up to the rated linear power and power-added efficiencies of higher than around 38% at the maximum linear output power over all the bands. Efficiency degradation is limited to 2.5% to 3% compared to the single-band reference PA.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.103-109
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• 2013

Mobile ad hoc networks (MANETs) are infrastructure-less and stand-alone wireless networks with dynamic topologies. To support user's safety in MANETs, fundamental and various security services should be supported. Especially in mobile commercial market, one of the major concerns regarding security is user privacy. Recently, researches about security system to protect user privacy in cluster-based MANETs have been introduced. This paper propose a cluster reconfiguration protocol under anonymous cluster-based MANETs to enhance the network stability. The improved anonymous cluster-based MANETs can recover the network structure against abnormal states of clutserheads.

• The Journal of the Korea Contents Association
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• v.6 no.9
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• pp.9-18
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• 2006

We completed a new cluster system based on WDM by proposing a virtual topology reconfiguration schemes. The key idea of the proposed scheme is to construct a set with the longest chains of requests of connecting nodes which need to be assigned a wavelength. All the sets have no common factor, that is, there is no duplicated link among the requests of connecting. After making the set satisfying this condition, we could assign a wavelength to per corresponding set. We could reconfigure a virtual topology with this scheme collectively. we compared our scheme to existing approaches by the OWns simulation tool. As the results, we gained improved performances, reducing 10% of blocking rate and improving 30% of ADM utilization in terms of the blocking probability and the ADM utilization.

• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.321-327
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• 2013

As the market of express delivery services expands rapidly, delivery service companies are exposed to severe competition. As a result of the surplus of delivery companies, they are struggling with remaining competitive at a reasonable price with appropriate level of customer satisfaction. To cope with competition pressures, a strategic alliance is suggested as an effective solution to the challenges faced by small and medium enterprises (SMEs) in express delivery services. Therefore, this study suggests a combined optimization and simulation approach to the reconfiguration of an express delivery service network for strategic alliance with respect to strategy partnership of closing/keeping service centers among companies involved and adjustments of their cutoff times. An illustrative numerical example is presented to demonstrate the practicality and efficiency of the approach.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.160-168
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• 2008

We completed a new cluster system based on WDM by proposing virtual topology reconfiguration schemes. The key idea of the proposed scheme Is to construct a set with the longest chains of requests of connecting nodes which need to be assigned a wavelength. All the sets have no common factor, that is, there is no duplicated link among the requests of connecting. After making the set satisfying this condition, we could assign a wavelength to per corresponding set. We could reconfigure a virtual topology with this scheme collectively. we compared our scheme to existing approaches by the OWns simulation tool. As the results, we gained improved performances, reducing 10% of blocking rate and improving 30% of ADM utilization in terms of the blocking probability and the ADM utilization.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.4
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• pp.318-330
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• 2013

This paper presents a high-linearity low-noise small-size programmable gain amplifier (PGA) based on a new low-noise low-distortion differential amplifier and a proposed reconfiguration technique. The proposed differential amplifier combines an inverter-based differential pair with an adaptive biasing circuit to reduce noise and distortion. The reconfiguration technique saves the chip size by half by utilizing the same differential pair for the input transconductance and load-stage, interchangeably. Fabricated in $0.18-{\mu}m$ CMOS, the proposed PGA shows a dB-linear control range of 21dB in 16 steps from -11 dB to 10 dB with a gain error of less than ${\pm}0.33$ dB, an IIP3 of 7.4~14.5 dBm, a P1dB of -7~1.2 dBm, a noise figure of 13dB, and a 3-dB bandwidth of 270MHz at the maximum gain, respectively. The PGA occupies a chip area of $0.04mm^2$ and consumes only 1.3 mA from the 1.8 V supply.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.6
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• pp.875-882
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• 2010

Nowadays, the global market requires a variety of products and shorter life cycle to fulfill the diverse demands of customers. To survive in the turbulent and competitive markets, automobile assembly companies must design and implement manufacturing systems that respond rapidly to market demands. In this paper, methods for reconfiguring system based on modular concept is proposed using AR(Augmented reality) technologies. First, the relationship matrixes between change drivers and system components are generated to divide existing manufacturing system to each module. And, new change drivers are selected based on required function in new system. Through the modification of relationship matrix, the concept design of new system is proposed and implemented in AR environment. Finally, according to proposed methods and procedure in this paper, the existing cockpit assembly system is reconfigured to spare tire assembly system as a case study. As the use of the modular-based reconfiguration method in AR environment, the time and cost for reconfiguring manufacturing system will be reduced dramatically.