• The Journal of the Acoustical Society of Korea
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• v.8 no.4
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• pp.74-82
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• 1989

In this paper, we have studied on the methodologies of implementation and the performance evaluations about the real-time packetized coding of multi-channel speech signals. Our suggested coding algorithm is very, simple and it has majorly the data handling operations rather than the numerical calculations. And it gives about $40\%$ of compression ratio with less than the conventional codings. Nevertheless, using this algorithm, we can save the memories for the speech signal and we can raise the efficiency of the channel transmission. Especially because of its simplicity of algorithm, we can easily obtain the merits of the multi-channel operations.

• Journal of Information Display
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• v.4 no.4
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• pp.4-7
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• 2003

The world largest 21.3" LTPS LCD has been successfully developed using SLS crystallization technology. Integration of gate circuit, transmission gate and level shifter was successfully performed in a large area display. Uniform and high performance of high quality grains of SLS technology make it possible to realize a uniform large size LTPS TFT-LCD with half the number of data driver IC's that is typically used in a-Si LCD. High aperture ratio of 65 % was achieved using an organic inter insulating method which lead to a high brightness of 500 cd/$cm^2$.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.11
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• pp.25-33
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• 1997

The end-to-end rate-based control mechanism is used for the flow control of the ABR service to allow much more flexibility in ATM switching system. To accommodate the ABR service effciently many algorithms such as EFCI, EPRCA, ERICA, and CAPC2 have been proposed for the switch algorithm. ABR cells and related RM cells are received at the ATM switch fabric transparently without any processing. And then cells received from the traffic source are queued in the ABR buffer of switching system. The ABR buffer usually has some thresholds for easy congestion control signal transmission. Whatever we use, therefore, these can be many ABR traffic control algorithms to implement the ABR transfer capability. The genertion of congestion indicate signal for ABR control algorithms is determined by ABR buffer satus. And ABR buffer status is determined by ABR cells transfer ratio in ATM switch fabrics. In this paper, we presented the functional structures for control of the ABR traffic capability, proposed the readout scheduling, cell slot allocation of output link and the buffer allocation model for effective ABR traffic guranteeing with considering CBR/VBR traffics in ATM switch. Since the proposed readout scheduling scheme can provide more avaliable space to ABR buffer than existing readout scheduling scheme, generation rate of a SEND signal, that is, BCN signal in destination node can be increased for ABR call connection. Therefore, the proposed scheme, in this paper, can be appropriate as algorithm for effective ABR traffic service on output link of ATM switching node.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.8
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• pp.1234-1240
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• 2002

In this paper, we analyze the block error performance of the CDMA system, whose information data are spread spectrum with PN sequences, and the chip signals are modulated with BPSK signal, combining MRC(Maximum Ratio Combine) diversity techniques with repetition transmission, FEC(Forward Error Correction) code in mobile communication channel which is characterized by Nakagami fading. As a results of study, the coding techniques provide more efficient improvement than a diversity techniques, but coding techniques are required the adding bandwidth as many coding rate. Also, when the system is combined MRC diversity techniques with coding techniques, the amount of improvement is dramatically increased.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1402-1405
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• 2006

Using a indium zinc oxide (IZO) alloy target with a ratio of 90:10 in wt%, highly transparent conducting oxide (TCO) thin films are prepared on polyethersulfone (PES) substrates by lowfrequency (LF) magnetron sputtering system. These films have amorphous structures with excellent electrical stability, surface uniformity and high optical transmittance. Experiments were carried out as a function of applied voltage. At optimal deposition conditions, thin films of IZO with a sheet resistance of 29 ohm/sq. and an optical transmission of over 82 % in the visible spectrum range were achieved. The IZO thin films fabricated by this method do not require substrate heating during the film preparation or any additional post-deposition annealing treatment.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1480-1483
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• 2005

Transparent thin composite films (TCFs) were deposited on OLED devices by means of RF sputtering method and their passivation-properties were evaluated by comparing to the e-beam evaporating method. This composite film formed by mixed ratio of MgO (3wt %): $SiO_2$ (1wt %) was developed from pallet as a source of e-beam evaporator to 6-inch size target for sputtering in order to apply for large-sized organic display devices. Water Vapor Transmission Rates (WVTR) of the deposited films were measured as a function of thickness to assess the effectiveness of this film as a passivation layer and it applied to real devices. From this study, we can confirm that the passivation layer formed by TCFs using RF sputtering method sufficiently shows the potentiality of application to passivation layer for organic display devices.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.241-244
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• 2003

The world largest 21.3" LTPS LCD has been successfully developed using SLS crystallization technology. Successful integration of gate circuit, transmission gate and level shifter was performed in a large area uniformly. Uniformity and high performance from high quality grains of SLS technology make it possible to come true a uniform large size LTPS TFT-LCD with half number of data driver IC's used in typical a-Si LCD. High aperture ratio of 65% was obtained using an organic inter insulating method, which lead a high brightness of 500cd/cm2.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8A
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• pp.1126-1132
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• 1999

In this paper, we consider the superposed 16-QAM CDMA system for subband coded (SBC) image transmissions. We divide the SBC image bit into two group according to its significance. First, we investigate the average bit error rate (BER) of the overall system when the significance of bits is ignored. Next, we investigate the optimal signal constellation and processing gain that maximizes the peak signal-to-noise ratio (PSNR) of SBC image, subject to a fixed power and bandwidth constraint. We examine the performance improvement over the conventional equal distane, equal processing gain system, and the equal error protection (EEP) system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1C
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• pp.1-7
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• 2011

Recently, multi-hop relay transmission has drawn much attention owing to its advantage of coverage extension at low power consumption. In this paper, we derive a performance bound of multi-hop communication systems with multiple amplify-and-forward relays when the optimal path is selected. The bound is derived in generalized Nakagami fading channels with different parameters for each hop by applying the geometric mean bound to the path signal-to-noise ratio (SNR) and obtaining the moment generation function of the bound. It is shown that the bound based on the geometric mean is closer to the actual performance of optimal path selection when the fading effect is small.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.783-786
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• 2003

Thin films of vanadium oxide(VOx) have been deposited by r.f. magnetron sputtering from $V_2O_5$ target in gas mixture of argon and oxygen. The oxygen/(oxygen+argon) partial pressure ratio of 0% and 8% is adopted. Crystal structure and optical properties of films sputter-deposited under different oxygen gas pressures and in situ annealed in vacuum at $400^{\circ}C$ for 1h and 4h are characterized through XRD and optical absorption measurements. The films as-deposited are amorphous, but $0%O_2$ films annealed for time longer than 4h and $8%O_2$ films annealed for time longer than 1h are polycrystalline. The optical transmission of the films annealed in vacuum decreases considerably than the as-deposited films and the optical absorption of all the films increases rapidly at wavelength shorter than about 550nm. Indirect and direct optical band gaps were decreased with increasing the annealing time.