• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.86-89
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• 2009

In this paper, a broadband power line communication modem and network technology to develop tests with actual characteristics of the underground power line communication channel to be interpreted. Length and structure of the underground distribution line due to underground distribution line to the broadband powerline communication channels to measure the amount of attenuation on the signal generator, spectrum analyzer, such as contactless coupler was used to configure the channel measurement system. Demonstration tests in the test line as a single line by selecting the longest high-voltage lines where the two-channel measurement and signal attenuation on the noise level was measured. Measuring results degrade communication performance can be quite sure that was the presence of impulse noise, long lines, the line length was confirmed by the high-frequency attenuation appears.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.367-370
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• 2002

In this paper, we propose a new node architecture LonWorh control Network for home network system environmint using power line communications. Using conventional Lon Work technology is a many disputable points for home network. LonWork network system needs high-cost development equipment. Moreover, conventional Lon Work system can not implement high-grade algorithms and variety application operation. because of the limitation of processing ability in Neuron chip. For that reason, the proposed structure is applicable to low-cost and more complex applications which are impossible in home network using conventional Lonworks structure. The proposed structure is implemented with some hardware and かone software for power line home network. The physical layer and the MAC layer of the LonTalk protocol within ton Work are implemented in hardware, which decreases the development costs communication processor. The upper of link layer of the LonTalk protocol is implemented with software, which decreases the development costs of software and increases the flexibility of tile system and increases the extension of the system. We verified the commercial feasibility of the proposed system through the power line tests with the existing LonWorks network in home network. As a result, it is concluded that the proposed architecture provides increasing flexibility and decreasing cost of the system.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.395-398
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• 2001

Recently, the increasing need for internet and the activation of hiring business of communication line makes the demand for OPGW cable which can construct the optical communication network in the basis of existing overhead power transmission line. Especially, the demand is focused on the high fiber count OPGW due to high capacity transmission. In step with the trend toward high fiber count cable we have developed the Stainless Steel Loose Tube type OPGW within which have 144core firstly in KOREA. This paper describes the cable design and manufacturing process which gives the stable operation in very severe conditions and the long-term reliability test results conducted in according to dominant specification IEEE Std. 1138-1194.

• Journal of information and communication convergence engineering
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• v.13 no.1
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• pp.1-6
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• 2015

In this study, we consider visible light communication in an indoor line-of-sight environment. It has been proved that among the multiple input multiple output (MIMO) techniques, spatial modulation (SM) performs better than repetition coding (RC) and spatial multiplexing (SMP). On the basis of a combination of SM and pulse amplitude modulation (PAM), here, we propose an enhanced SM algorithm to improve the bit error rate. Traditional SM activates only one light-emitting diode (LED) at one time, and the proposed enhanced SM activates two LEDs at one time and reduces the intensity levels of PAM by half. Under the condition of a highly correlated channel, power imbalance is used to improve the algorithm performance. The comparison between the two schemes is implemented at the same signal-to-noise ratio. The simulation results illustrate that the enhanced SM outperforms the traditional SM in both highly correlated and lowly correlated channels. Furthermore, the proposed enhanced SM scheme can increase the transmission rate in most cases.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.481-487
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• 2016

A new two-line based inversion driving method is introduced for low power display-driver ICs. By inserting a timing offset between the chopper stabilization and the alternation of LCD polarity, we can reduce power consumption without noticeable degradation in the display quality. By applying the proposed scheme to 12" LCD applications, we achieved 7.5% and 27% power saving in the display-driver IC with white and black patterns, respectively.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.189-193
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• 2005

In this paper we proposed the remote control system for the door lock by the unified modem with the wireless and the power line modem. We developed the management system program between the door-lock system and the proposed unified modem. The infrared communication system was used between the Door-Lock system and the power line modem. With the unified developed modem and the Door-Lock system, it is possible to control remotely the developed system in the internet service area.

• Journal of Advanced Information Technology and Convergence
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• v.9 no.1
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• pp.25-37
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• 2019

Power-line communication (PLC) has influenced smart grid development. In addition, PLC has also been instrumental in current research on internet-of-things (IoT). Due to the implementation of PLC in smart grid and IoT environments, strides have been made in PLC and its combination with the wireless system to form a hybrid communication system. Also, PLC has evolved from a single-input-single-output (SISO) configuration to multiple-input-multiple-output (MIMO) configuration system, and from a point-to-point communication system to cooperative communication systems. In this work, we extend a MIMO wireless two-way amplify-and-forward (AF) cooperative communication system to a hybrid PLC and wireless (PLC/W) system configuration. We then maximize the weighted sum-rate for the hybrid PLC/W by optimizing the precoders at each node within the hybrid PLC/W system. The sum-rate problem was found to be non-convex, therefore, an iterative algorithm is used to find the optimal precoders that locally maximize the system sum-rate. For our simulation results, we compare our proposed hybrid PLC/W configuration to a PLC only and wireless only configuration at each node. Due to an improvement in system diversity, the hybrid PLC/W configuration outperformed the PLC only and wireless only system configurations in all simulation results presented in this paper.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.720-725
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• 2009

This paper proposes a modified Wilkinson power divider using a zero-degree composit right/left-handed(CRLH) transmission line to obtain a isolation between ports. A zero-degree CRLH transmission line, which has a total electrical length of zero, consists of a RH(Right-Handed) transmission line of a negative phase characteristic and a LH (Left-Handed) transmission line of a positive phase characteristic. To validate a value of zero-degree CRLH transmission line, the electrical lengths of RH and LH transmission line select $-30^{\circ}$ and $+30^{\circ}$ and a 2-way Wilkinson divider designed, we are measured S21 of -3.3dB, S11 of -27.5dB and S23 of -25dB at 1GHz center frequency. These characteristics are same the conventional divider using RH transmission line.

• The Journal of Information Technology
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• v.7 no.3
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• pp.1-10
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• 2004

Considerable efforts has been recently devoted to the determination of accurate channel models for the Power Line environment, both for the indoor and outdoor cases. The common denominator and limitation of the known and previously published models is the particular type of approach followed. In this paper is concerned with a power line channel modeling for the more fast and efficiently power line communication experiment. A capacitor load channel simulator is a essential equipment in the power line modem development for indoor network. We accomplished a channel modelling by the frequency response method about the total 224 capacitor load cases. On the basis of this measurement modeling it is here revealed that the PLC is a more deterministic media that commonly believed.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.848-851
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• 2005

This paper proposes a design of IIR notch filter with modified pole placements. The pole angle is derived from quadratic programming to find the appropriate pole position on the unit circle in z-plane in order to achieve the symmetry of the amplitude response. The simulation results are shown when compared with the conventional design technique. Moreover, it uses the TMS320C31 DSP chip for hardware implementation. Finally, the hardware implementation can be applied to removal of ECG baseline wander and elimination of AC power line interference in ECG signal.