• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.3 s.357
• /
• pp.43-51
• /
• 2007

OneNAND flash combines the advantages of NAND and NOR flash, and has become an alternative to the former. But the advanced features of OneNAND flash are not utilized effectively in demand paging systems designed for NAND flash. We propose delayed dual buffering, a demand paging system which fully exploits the random-access I/O interface and dual page buffers of OneNAND flash demand paging system. It effectively reduces the time of page transfer from the OneNAND page buffer to the main memory. On average, it achieves and 28.5% reduction in execution time and 4.4% reduction in paging system energy consumption.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.12
• /
• pp.51-60
• /
• 2004

DAB(Digital Audio Broadcasting) is a new media service that can provide CD quality audio, various data service, interactive and high quality mobile communications through popular media such as terrestrial broadcasting, satellite, cable TV, and internet. In this paper, a new EPG(Electronic Program Guide) application model is proposed. The model is based on DAB and combines a DAB receiver and PCs so that it can take advantages of using various multimedia services and plenty of internet contents. The developed EPSD(EPG Provider System on DAB) has Web-based Server/Client structure and povides EPG functionalities to client PCs over internet. Therefore, the DAB receiver can be smaller and cheaper, and can develop abundant data services on internet. It can also provide high quality video services and be expected to become an important component in future home network systems.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.3
• /
• pp.162-170
• /
• 2015

In the bandpass sampling (BPS), the sampling frequency is lower than the frequency of the signal to be sampled. In this method, the baseband spectrum can be directly obtained by the sampling operation. This makes the frequency down converter unnecessary as well as the receiver's circuit simpler. In the second-order BPS system, two sampling devices are used. When aliasing occurs due to the sampling operation, the aliased component can be cancelled by combining the two sampled signals. In this paper, it is presented a design method of the second-order BPS system when multiple interferences are simultaneously aliased to the signal component. The optimum phase of the interpolant filter is searched for maximizing the signal-to-interference ratio, and a practical formula for the suboptimal phase is derived in terms of the power spectrum profile of the BPS input. A computer simulation has been performed for the proposed second-order BPS system, and it has been shown that the signal-to-interference ratio can be increased by considering multiple aliasing.

• The Journal of Society for e-Business Studies
• /
• v.8 no.2
• /
• pp.33-48
• /
• 2003

Wireless Internet, created through the merging of mobile communication with Internet technology, provides the advantage of mobility, but the restrictions of the mobile environment are deterring it from growing into a mass public service. Of the restricting factors of the wireless environment, narrow memory space creates the disadvantage of not being able to manage resources in mobile devices efficiently Because there is a limit to obtaining sufficient memory space from hardware made with consideration of portability, future devices will need to have a platform design with storage area extended from internal storage to external storage space. In this paper, we present a mobile agent that extends the memory space from only the inside of a mobile device to an external server making it possible to use data by on-line Run-time, and can also manage internal files efficiently. We have designed and implemented a RMS(Resources Management System) as a realization. Devices using the proposed RMS will be able to apply extended processes with the 'Mobile Space Extension' and will be benefited with optimal memory space through efficient internal file management.

• Journal of the Korean Institute of Telematics and Electronics C
• /
• v.35C no.9
• /
• pp.11-20
• /
• 1998

High-speed complex-number arithmetic units are essential to baseband signal processing of modern digital communication systems such as channel equalization, timing recovery, modulation and demodulation. In this paper, a new complex-number multiplication algorithm is proposed, which is based on redundant binary (RB) arithmetic combined with radix-4 Booth recoding scheme. The proposed algorithm reduces the number of partial product by one-half as compared with the conventional direct method using real-number multipliers and adders. It also leads to a highly parallel architecture and simplified circuit, resulting in high-speed operation and low power dissipation. To demonstrate the proposed algorithm, a prototype complex-number multiplier-accumulator (CMAC) core with 10-bit operands has been designed using 0.8-$\mu\textrm{m}$ N-Well CMOS technology. The designed CMAC core contains about 18,000 transistors on the area of about 1.60 ${\times}$ 1.93 $\textrm{mm}^2$. The functional and speed test results show that it can operate with 120-MHz clock at V$\sub$DD/=3.3-V, and its power consumption is given to about 63-mW.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.315-315
• /
• 2007

본 논문에서는 DLC (Diamond-like carbon)박막이 가지는 높은 경도, 낮은 마찰계수, 전기적 절연성, 화학적 안정성 등의 특성을 이용하여, 리소그래피를 위한 resist나 hard coating물질로써 응용하기 위해, DLC 박막의 에칭에 관한 연구를 진행하였다. DLC 박막의 합성 과 에칭은 13.56 MHz RF plasma enhanced vapor deposition technique를 통해 이루어졌으며, DLC 박막은 150 W의 RF Power에서 메탄 $(CH_4)$과 수소$(H_2)$ 가스를 이용하여 약 300 nm의 두께로 제작되었으며, DLC박막의 에칭은 RF power의 변화 (50~250 W)와 산소 $(O_2)$가스의 유량변화 (5~25 sccm)에 따라 실시하였다. 에칭 되어진 DLC 박막의 표면 특성들은 AFM (atomic force microscopy)과 contact angle 장치를 사용하여 측정되었고, 측정된 결과로써 DLC 박막은 RF power와 산소 가스의 유량이 높을수록 etching rate는 증가하였고, 박막의 표면은 거칠어졌으며, 결국 DLC 표면에서는 산소에 의한 결합의 증가로 인해 친수성을 나타내었다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.6
• /
• pp.1235-1242
• /
• 2018

When the wind speed changes rapidly, the wind turbine is stopped for the safety of the power system and the mechanical system. At that moment, the wind turbine gearbox is damaged and broken due to the contact load of the gearbox. In addition, the problems such as increasing frictional heat and deteriorate of the brake occur, because the power of the blades is transmitted directly to the brakes. This paper proposes a hybrid magnetic gear shape that solves the problem caused by the contact of the mechanical gear, which is the power transmission device of the wind power generation system, and the power cutoff system. The shape of the hybrid magnetic gearsuitable for the wind power generation system is derived through the torque and loss analysis according to the shape of the hybrid magnetic gear by using the two dimensional finite analysis method.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.12 no.2
• /
• pp.142-149
• /
• 2019

The coils to transmit the electric energy are necessary to charge an electric vehicle wirelessly. There are several types of coils, from basic circular coils to DD-type coils for enhancing the coupling effect between two coils. However, DD-type coils with a good coupling effect between coils have a disadvantage in use because of the structure complexity of the power conversion device of transmitting and receiving side. In this paper, we propose a method to calculate the inductance value and to design the size of the spiral inductor which is convenient to fabricate when the power is transmitted wirelessly by using two coils in free space. Since the bifurcation phenomenon occurs when the XLm value is similar to the load resistance value in the resonator the XLm value was selected to be equal to the minimum load resistance value to minimize this phenomenon, and the inductance value required for the resonator was calculated. In order to realize the calculated inductance value by the spiral inductor, the relationship between the inductance value and the size, the number of turns, the total coil length of a spiral inductor was investigated. In addition, the change of coupling coefficient k according to the horizontal separation of two coils was examined and an appropriate inductor was selected.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.10
• /
• pp.139-147
• /
• 2015

Steady state visual evoked potential (SSVEP) has been actively studied because of its short training time, relatively higher signal-to-noise ratio, and higher information transfer rate. There are two popular analysis methods for SSVEP signals: power spectral density analysis (PSDA) and canonical correlation analysis (CCA). However, the PSDA is known to be vulnerable to noise due to the use of a single channel. Although conventional CCA is more accurate than PSDA, it may not be appropriate for the real-time SSVEP-based BCI system when it has short time window length because it uses sinusoidal signals as references. Therefore, the two methods are not efficient for the real-time BCI system that requires a short TW and a high recognition accuracy. To overcome this limitation of the conventional methods, this paper proposes a frequency recognition method with a combination of CCA and PSDA using the difference between powers of canonical variables obtained from the results of CCA. Experimental results show that the performance of the combination of CCA and PSDA is better than that of CCA for the case of a short TW.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.7
• /
• pp.205-215
• /
• 2013

In digital imaging system, Bayer pattern is widely used and the observed image is degraded by optical blur during image acquisition process. Generally, demosaicing and deblurring process are separately performed in order to convert a blurred Bayer image to a high resolution color image. However, the demosaicing process often generates visible artifacts such as zipper effect and Moire artifacts when performing interpolation across edge direction in Bayer pattern image. These artifacts are emphasized by the deblurring process. In order to solve this problem, this paper proposes a deblurring algorithm combined with edge directional color demosaicing method. The proposed method is consisted of interpolation step and region classification step. Interpolation and deblurring are simultaneously performed according to horizontal and vertical directions, respectively during the interpolation step. In the region classification step, characteristics of local regions are determined at each pixel position and the directionally obtained values are region adaptively fused. Also, the proposed method uses blur model based on wave optics and deblurring filter is calculated by using estimated characteristics of local regions. The simulation results show that the proposed deblurring algorithm prevents the boosting of artifacts and outperforms conventional approaches in both objective and subjective terms.