• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.327-330
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• 2008

This paper shows an implementation of WLAN-based Audio/Video(A/V) system for multimedia home networks. Proposed WLAN-based A/V system can transmit multimedia data of high quality. The entire system consists of a 16-bit RISC controller, a program ROM, a SRAM, timers, an interrupt controller, a DART, GPIOs, an I2C and the OFDM modem supporting for the IEEE 802.11g standard. The simple MAC functions are implemented by firmware on an embedded 16-bit RISC controller. The OFDM modem supports a complete set of data rates up to 54Mbps. Proposed the system is implemented by an Altera FPGA EP1S60F1020C6 device, a 10-bit 2-ch DAC, a 10-bit 2-ch ADC and RF/IF chips.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.413-420
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• 2006

In this thesis, a RFID baseband system is implemented based on the international standard ISO/IEC 18000-6 Type-B using FPCA, and also anti-collision algorithm is implemented to improve the system performance. We compares the performance of the proposed anti-collision algorithm with that binary tree algorithm and bit-by-bit algorithm, and also validated analytic results using OPNET simulation. The proposed algorithm for Type-B transmission protocol and collision prohibition was designed using ISE7.1i which is a FPGA design-tool of Xilinx and implemented with Spartan2 chip which is a FPGA device.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.3
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• pp.197-212
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• 1990

This paper present a new design concept of a single chip 16-bit data path using the concept of modular design, the whole system is divided into several blocks which can be operated as an independent system itself. Making the internal blocks can act as a subsystem, it is possible to shorten design turn-around time, to be redesigned effectively, and to optimize the system performance. The designed system is data path. The data path is to manipulate 16-bit integer data. It is composed of aritmetic logic unit, register file, barrel shifter and bus circuit. The widths and lengths of gate in the circuit were determined using SPICE2. The results of circuit simulation were in good agreement with expected circuit characteristics.

• Tunnel and Underground Space
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• v.17 no.3 s.68
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• pp.216-224
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• 2007

Blasting, using shock and dynamic energy of explosive, is very effective tunnel excavation method. But it had serious problem which is the blast vibration and over-break. In recent study, pre-cracked excavation method using notch hole reduced blast vibration and over-break in tunnel, so we performed study about developing notch bit system for making notch hole. In order to make notch hole effectively we had perform drilling experiments changing length and height of notch and in order to improve speed and precision of drilling we had developed notch bit system which consists of drilling bit, notch bit, adapter and notch guide.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.2
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• pp.18-26
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• 2009

When channel state information (CSI) is available at the transmitter, the system throughput can be enhanced by adaptive transmissions and opportunistic multiuser scheduling. In this paper, we consider multiple-input multiple-output (MIMO) systems employing bit-interleaved coded orthogonal frequency division multiplexing (BIC-OFDM). We first propose a bit-loading algorithm based on the Levin-Campello algorithm for the BIC-OFDM. Then we will apply this algorithm to the MIMO system with a finite set of constellations, by reassigning residual power on each stream Simulation results show that proposed bit-loading scheme which takes the residual power into account improves the system performance especially at high signal-to-noise ratio (SNR) range.

• Journal of Advanced Navigation Technology
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• v.6 no.3
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• pp.223-230
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• 2002

In this paper, we induced that the noise powers and bit error rate of direct detection receiver taking account of ISI (intersymbol interference) in the 2,000 km optical transmission system. And we evaluated the sensitivity in the vrious bit rate system. We verified that the proposed calculation method is applicable to the exact optical system. And we confirmed that the signal distortion due to both chromatic dispersion and nonlinear effects compensated by using of MSSI (Mid-Span Spectral Inversion) method, and yet the sensitivity of a higher bit rate system is reduced, because of the increase of ISI and then the decrease of the average receiving power, compared with a the lower bit rate system.

• Current Optics and Photonics
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• v.8 no.4
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• pp.345-354
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• 2024

The bit walk-off effect caused by fiber dispersion and carrier reuse in the base station (BS) are two key problems in radio-over-fiber (ROF) systems. In this paper, a novel frequency-octupling ROF system based on the Mach-Zehnder modulator (MZM) is proposed, which can overcome the bit walk-off effect and realize carrier reuse by inserting pilot signals. Theoretical analysis and simulation verification of the system are carried out. Under the condition of a Q factor greater than 6, the optical fiber transmission distance of the upper and lower links is more than 290 km and 80 km, respectively. The influence of the main device parameters of the system on the Q factor is analyzed when they deviate from their designed values. The system designed in this paper can not only effectively overcome the bit walk-off effect, but also solve the problem of downlink performance degradation and the limitation of tunability caused by conventional carrier reuse in ROF. The system can greatly increase the transmission distance and improve the performance of the system and has an important application prospect in ROF.

• Journal of the Korea Society of Computer and Information
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• v.23 no.8
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• pp.75-84
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• 2018

In this research, a bit correction technique of data hiding method in timestamp of MFT entry in NTFS file system is proposed. This method is proposed in two ways, depending on the number of bytes of data to hide. A basic data hiding method using a bit correction technique to solve the problems of the conventional 2-byte technique is proposed. In order to increase the capacity of the data, a 3-byte data hiding method using an extended bit correction technique is proposed. The data hiding method in the timestamps is based on the fact that is not revealed in the Windows explorer window and the command prompt window even if any data is hidden in the timestamp area of less than one second. It is shown that the validity of the proposed method through the experimental two cases of the basic data hiding method by the bit correction method and the 3-byte data hiding method by the extended bit correction method.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.7
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• pp.1-9
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• 1992

In this thesis, the trellis detection scheme is proposed to improve the error performance of the noncoherent detection in the TFM system. Trellis detection takes advantage of the trellis property of TFM-encoded signals. The trellis property is created by giving correlations among adjacent TFM-encoded signals at the transmitter. The performance of the trellis detection scheme is analyzed by means of the Bernoulli trials with the average symbol error probability, and is compared to that of the bit-by-bit detection scheme. As a result,when the SNR is below 20 dB in the Rayleigh fading and AWGN channel, the trellis detection is inferior to the bit-by-bit detections. But when SNR is above 20 dB, the trellis detection is superior to the bit-by-bit detection, and its performance enhancement is better as the SNR increases.

• Journal of Korea Game Society
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• v.19 no.5
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• pp.143-150
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• 2019

Deaf subtitles provide the hearing impaired with visual elements, commentary, and enjoyment of TV programs. Subtitles in game play are a great help to the game play for the hearing impaired as well as the average user. This paper aims at the academic research on the BIT subtitle system BIT, and is intended to help game play and game broadcasting of the hearing impaired.