• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.2 s.332
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• pp.65-72
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• 2005

We can integrate more IP blocks on a silicon die as the development of fabrication technologies and EDA tools. Consequently, we can design complicated SoC architecture including multi-processors. However, most of existing SoC buses have bottleneck in on-chip communication because of shared bus architectures, which result in the performance degradation of systems. In most cases, the performance of a multi-processor system is determined by efficient on-chip communication and the well-balanced distribution of computation rather than the performance of the processors. We propose an efficient SoC Network Architecture(SNA) using crossbar routers which provide a solution to ensure enough communication bandwidth. The SNA can significantly reduce the bottleneck of on-chip communication by providing multi-channels for multi-masters. According to the proposed architecture, we design a model system for the SNA. The proposed architecture has a better efficiency by $40\%$ than the AMBA AHB according to a simulation result.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.1 s.307
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• pp.17-26
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• 2006

The error diffusion method is one of the digital halftoning processes that transforms the continuous-tone image to the binary image and the method has the excellent reproduction ability. However the error diffusion method using the permanent threshold has difficulty in proper binarization, so the method has the periodic pattern and is unpleasant to the eye. In this paper, to reduce defects and to binarize properly, we propose the error diffusion method using the adaptive threshold. Depending on the intensity distribution of the input gray scale image, we decided on the adaptive threshold with the average of the intensities. The error diffusion method with the adaptive threshold has the better performance than the existing method and is evaluated with experiments and comparisons.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.80-87
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• 2006

Recently, the distribution and using of the digital multimedia contents are easy by developing the internet application program and related technology. However, the digital signal is easily duplicated and the duplicates have the same quality compare with original digital signal. To solve this problem, there is the multimedia fingerprint which is studied for the protection of copyright. Fingerprinting scheme is a techniques which supports copyright protection to track redistributors of electronic inform on using cryptographic techniques. Only regular user can know the inserted fingerprint data in fingerprinting schemes differ from a symmetric/asymmetric scheme and the scheme guarantee an anonymous before recontributed data. In this paper, we present a new scheme which is the detection of colluded multimedia fingerprint by neural network. This proposed scheme is consists of the anti-collusion code generation and the neural network for the error correction. Anti-collusion code based on BIBD(Balanced Incomplete Block Design) was made 100% collusion code detection rate about the average linear collusion attack, and the hopfield neural network using (n,k)code designing for the error bits correction confirmed that can correct error within 2bits.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.4
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• pp.25-34
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• 2004

UMTS network, evolved from GSM, includes packet core network that consists of SGSNS and GGSNs. Service providers should consider subscriber mobility, location registration, and subscriber distribution when designing packet core networks and network elements. Since one of the major traffic sources for IMT-2000 will be data which has bursty characteristics, new design guidelines for dimensioning of SGSN and GGSN should be proposed under various constraints of system parameters. In this paper, we first evaluate the performance of signaling traffic for packet call subscribers. After that, we also obtain the impact of bursty data traffic on the SGSN and GGSN by simulation, and suggest new dimensioning guidelines for packet core network of UMTS under various environments.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.5
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• pp.251-258
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• 2004

This paper proposes a method for estimating the illuminant chromaticity using the distributions of the camera responses obtained by a CCD camera in a real-world scene. Illuminant estimation using a highlight method is based on the geometric relation between a body and its surface reflection. In general, the pixels in a highlight region are affected by an illuminant geometric difference, camera quantization errors, and the non-uniformity of the CCD sensor. As such, this leads to inaccurate results if an illuminant is estimated using the pixels of a CCD camera without any preprocessing. Accordingly, to solve this problem the proposed method analyzes the distribution of the CCD camera responses and selects pixels using the Mahalanobis distance in highlight regions. The use of the Mahalanobis distance based on the camera responses enables the adaptive selection of valid pixels among the pixels distributed in the highlight regions. Lines are then determined based on the selected pixels with r-g chromaticity coordinates using a principal component analysis(PCA). Thereafter, the illuminant chromaticity is estimated based on the intersection points of the lines. Experimental results using the proposed method demonstrated a reduced estimation error compared with the conventional method.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.4
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• pp.335-340
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• 2002

In this paper, the stress induced leakage currents of thin silicon oxides is investigated in the ULSI implementation with nano structure transistors. The stress and transient currents associated with the on and off time of applied voltage were used to measure the distribution of high voltage stress induced traps in thin silicon oxide films. The stress and transient currents were due to the charging and discharging of traps generated by high stress voltage in the silicon oxides. The transient current was caused by the tunnel charging and discharging of the stress generated traps nearby two interfaces. The stress induced leakage current will affect data retention in electrically erasable programmable read only memories. The oxide current for the thickness dependence of stress current, transient current, and stress induced leakage currents has been measured in oxides with thicknesses between 113.4${\AA}$ and 814${\AA}$, which have the gate area $10^3cm^2$. The stress induced leakage currents will affect data retention and the stress current, transient current is used to estimate to fundamental limitations on oxide thicknesses.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.11
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• pp.9-17
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• 2000

A sensor array with 10 discrete sensors integrated on a substrate was developed for discriminating the kinds and quantities of explosive gases. The sensor array consisted of 10 oxide semiconductor gas sensors with $SnO_2$ as base material and had broad sensitivity to specific gas. The sensor array was designed with uniform thermal distribution and had also high sensitivity and reproductivity to low gas concentration through nano-sized sensing materials with different additives. By using the sensitivity signal of the sensor array at $400^{\circ}C$, we could reliably discriminate the kinds and quantities of explosive gases like butane, propane and methane under the lower explosion limit through the principal component analysis (PCA) method.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.4
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• pp.103-109
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• 1999

In this paper, we proposed to a new structure of T-shaped fed microstrip slot antenna using 2-layers dielectric material with a directional radiation characteristic. When the slot antenna of bi-directional radiation want to radiate only one direction, the reflector must be set up, but this antenna does'nt need set up reflector. T-shaped microstrip feed line is proposed for a better impedance matching to the microstrip slot antenna in a various range of slot widths. It was also found that the bandwidth of this antenna is proportional to the slot width. It was also found that the radiation resistance of this feed line structure is quite constant and low regardless to the slot width. We also analyzed this antenna by using the FDTD method, and calculating waves and electric field distribution in the time domain. we also are calculated return loss, VSWR, and radiation pattern in the frequency domain by Fourier transforming the time domain results, respectively. From the measured results, bandwidth was 34.8% in the center frequency. These results were in relatively good accordance with the calculated values.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.3
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• pp.24-40
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• 2001

The design and implementation of agents is an essential part of the development of immersive types of tutoring systems using virtual reality. This paper proposes several effective mechanisms for the design and implementation of agents. Unlike existing researches we focus on accommodating diversity of agents' behavior in the proposed mechanisms. First, we define the space object based on the field theory. The introduction of the field theory allows us to approach the space objects in a structural manner rather than by their classification. We can also achieve dynamic genesis and extinction of the space objects, and derivation of overall changes in spatio-temporal situations. Second, we classify the behavior of agents into composite behaviors and primitive actions in order to achieve its dynamic planning. Finally, we distribute the knowledge among agents and their associated objects according to their interrelations. By this distribution, we can handle the otherwise prohibitively large amount of knowledge related to agents' behaviors and construct a dynamic environment. By implementing a situation with agent's navigation across a composite space object, we demonstrate the effectiveness of these schemes presented above.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.5
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• pp.265-270
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• 2016

Objectives: To gain information on anatomical variation in anterolateral thigh (ALT) flaps in a series of clinical cases, with special focus on perforators and pedicles, for potential use in reconstruction of oral and maxillofacial soft tissue defects. Materials and Methods: Eight patients who underwent microvascular reconstructive surgery with ALT free flaps after ablative surgery for oral cancer were included. The number of perforators included in cutaneous flaps, location of perforators (septocutaneous or musculocutaneous), and the course of vascular pedicles were intraoperatively investigated. Results: Four cases with a single perforator and four cases with multiple perforators were included in the ALT flap designed along the line from anterior superior iliac spine to patella. Three cases had perforators running the septum between the vastus lateralis and rectus femoris muscle (septocutaneous type), and five cases had perforators running in the vastus lateralis muscle (musculocutaneous type). Regarding the course of vascular pedicles, five cases were derived from the descending branch of the lateral circumflex femoral artery (type I), and three cases were from the transverse branch (type II). Conclusion: Anatomical variation affecting the distribution of perforators and the course of pedicles might prevent use of an ALT free flap in various reconstruction cases. However, these issues can be overcome with an understanding of anatomical variation and meticulous surgical dissection. ALT free flaps are considered reliable options for reconstruction of soft tissue defects of the oral and maxillofacial area.