• Journal of the Korea Convergence Society
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• v.4 no.3
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• pp.27-33
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• 2013

Conventional bar code has the appearance of line bars and spaces, called as one-dimensional bar code. In contrast, the information in two-dimensional bar code is represented by either a small, rectangular or square with the types of mosaic and Braille. The two-dimensional bar code is much more efficient than one-dimensional bar code because it can allow to store and express large amounts of data in a small space and so far there is also a little information about decoding the Data Matrix in base 256 mode. According to the ISO international standards, there are four kinds of bar code: QR code, Data Matrix, PDF417, and Maxi code. In this paper, among them, we focus on describing the basic concepts of Data Matrix in base 256 mode, how to encode and decode them, and how to organize them in detail. In addition, Data Matrix can be organized efficiently depending on the modes of numeric, alphanumeric characters, and binary system and expecially, we focus on describing how to decode the Data Matrix code by four modes.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.8
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• pp.1-7
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• 1997

In tis paper, w eproposed a modeling for direct-sequence spread communication base band modem in RT-level VHDL and implemented in a one-chip VLSI and tested. The transmitter modulates with DQPSK modulation method and spreads a modulated signal with 32-bit PN code into 1.152MHz. The receiver de-spreads a signal using 32-tap matched filter and recovers with DQPSK demodulation method. The digital frequency synthesizer generates the sine signal and the cosine signal of 2.304MHz with ROM tables in the size of 7$\^$*/256 and 6$\^$*/256, respectively. The implemented VLSI has been verified a BER with 10$\^$-4/ at E$\_$b//N$\_$o/ of 13dB with a SPW fixed design model and fabricated in the 0.8.mu.m KG6423 gate array with a VHDL model.

• ETRI Journal
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• v.34 no.2
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• pp.256-259
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• 2012

The double-base number system has been used in digital signal processing systems for over a decade because of its fast inner product operation and low hardware complexity. This letter proposes an innovative multiplier architecture using hybrid operands. The multiplier can easily be linked to flash analog-to-digital converters or digital systems through a double-base number encoder (DBNE) for realtime signal processing. The design of the DBNE and the multiplier enable faster digital signal processing and require less hardware resources compared to the binary processing method.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.05a
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• pp.256-262
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• 1999

By development of heat resistant alloy, there are much improvement of gas turbine engines. But heat resistant alloy has difficulty of machining. therefore, ECM (Electrochemical Machining) is used for Machining of 3 dimensional curved surface of Ni-base alloy. The purpose of this paper is to investigate ECM parameters that make tile good surface for Ni-base alloy blade. For this purpose, we have been investigated that center line average surface roughness(R$\sub$a/), average R$\sub$a/, Maximum R$\sub$a/ and Standard deviation of R$\sub$a/ for measuring positions is influenced on ECM parameters such as electrolyte types, dwell time, electrolyte pressure and sort of electrolyte for Inconel 718 and Waspaloy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.256-256
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• 2009

This paper presents a proper condition to achieve above 17 % conversion efficiency using PC1D simulator. Crystalline silicon wafer with thickness of $240{\mu}m$ was used as a starting material. Various efficiency influencing parameters such as rear surface recombination velocity and minority carrier diffusion length in the base region, front surface recombination velocity, junction depth and doping concentration in the Emitter layer. Among the investigated variables, we learn that 2nd doping concentration as a key factor to achieve conversion efficiency higher than 17 %.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.3
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• pp.256-266
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• 2012

Cavitating flow simulation is of practical importance for many engineering systems, such as marine propellers, pump impellers, nozzles, torpedoes, etc. The present work has developed the base code to solve the cavitating flows past the axisymmetric bodies with several forebody shapes. The governing equation is the Navier-Stokes equation based on homogeneous mixture model. The momentum is in the mixture phase while the continuity equation is solved in liquid and vapor phase, separately. The solver employs an implicit preconditioning algorithm in curvilinear coordinates. The computations have been carried out for the cylinders with hemispherical, 1-caliber, and 0-caliber forebody and, then, compared with experiments and other numerical results. Fairly good agreements with experiments and numerical results have been achieved. It has been concluded that the present numerical code has successfully accounted for the cavitating flows past axisymmetric bodies. The present code has also shown the capability to simulate ventilated cavitation.

• Journal of Communications and Networks
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• v.14 no.3
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• pp.252-256
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• 2012

We consider resource allocation in femto-cell networks to maximize the throughput while minimizing interference to macro-users nearby. This can be achieved by allocating spectrum resource in a cognitive radio way. The proposed resource allocation is performed in two steps; spectrum sensing and resource scheduling. The femto base station detects idle frequency assignments (FAs) free from the occupation by macro-users and then allocates sub-channels in an idle FA to femto-users, effectively managing the interference problem. Finally, the effectiveness of the proposed scheme is verified by computer simulations.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.247-256
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• 1999

This paper describes the results of analysis, syntheses and Roll Stability of various Di-urea greases. Di-urea greases were synthesized by reaction of 4,4'-Methylenebis(phenyl isocyanate) and various amines, such as cyclohexylamine, octylamine, stearylamine and p-toluidine with base oil at 80-180 $^{\circ}C$. The synthesized di-urea greases were analyzed by FT-R spectroscopy. The Roll Stability of synthesized di-urea greases was evaluated.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.251-256
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• 2005

There is few study which automatically diagnose the fault from ship's monitored signal. The bigger control and monitoring system is, the more important fault diagnosis and maintenance is to reduce damage brought forth by system fault. This paper proposes fault diagnosis system using a correlation analysis algorithm which is able to diagnose and forecast the fault and is composed to fault detection knowledge base and fault diagnosis knowledge base. For this all kinds of ship's engine room monitored data are classified with combustion subsystem, heat exchange subsystem and electric motor and pump subsystem by analyzing ship's operation data. To verifying capability of fault detection, diagnosis and prediction, Fault Management System(FMS) is developed by C++. Simulation experiment by FMS is carried out with population data set made by log book data of 2 months duration from a large full container ship of H shipping company.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.504-506
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• 1993

The Joint Photographic Experts Group (JPEG) standard was proposed by the International Standardization Organization (ISO/SC 29/WG 10) and the CCITT SG VIII as an international standard for digital continuous-tone still image compression. The JPEG standard has been widely accepted in electronic imaging, computer graphics, and multi-media applications, however, due to the lossy character of the JPEG compression its application in the field of medical imaging has been limited. In this paper, the JPEG standard was applied to a series of head sections of magnetic resonance (MR) images (256 gray levels, $256{\times}256$ size) and its performance was investigated. For this purpose, DCT-based sequential mode of the JPEG standard was implemented using the CL550 compression chip and progressive and lossless coding was implemented by software without additional hardware. From the experiment, it appears that the compression ratio of about 10 to 20 was obtained for the MR images without noticeable distortion. It is also noted that the error signal between the reconstructed image by the JPEG and the original image was nearly random noise without causing any special-pattern-related artifact. Although the coding efficiency of the progressive and hierarchical coding is identical to that of the sequential coding in compression ratio and SNR, it has useful features In fast search of patient Image from huge image data base and in remote diagnosis through slow public communication channel.