• Journal of KIISE:Computer Systems and Theory
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• v.35 no.5
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• pp.223-230
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• 2008

Dynamic update of kernel can change kernel functionality and fix bugs in runtime. Dynamic update is important because it leverages availability, reliability and flexibility of kernel. An instruction-granularity update technique has been used for dynamic update. However, it is difficult to apply update technique for a commodity operating system kernel because development and maintenance of update code must be performed with assembly language. To overcome this difficulty, we design the function-granularity dynamic update system which uses high-level language such as C language. The proposed update system makes the development and execution of update convenient by providing the development environment for update code which is same for kernel development. We implement this system for Linux and demonstrate an example of update for EXT3 file system. The update was successfully executed.

• The Journal of the Acoustical Society of Korea
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• v.20 no.7
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• pp.63-68
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• 2001

This paper describes the details of ITU-T SGIS G.729A speech coder implementation using ARM9 Thumb/sup R/ processor core and various techniques used in the optimization process. ITU-T G.729 speech coder is the standard of the toll quality 8 kbit/s speech coding. The input to the speech encoder is assumed to be a 16 bits PCM signal at a sampling rate of 8000 samples per second. G.729A is reduced complexity version of the G.729 coder. This version is bit stream interoperable with the full version. The implemented coder requires 34.8 MIPS for the encoder and 8.1 MIPS for the decoder, 36.5 kBytes of program ROM and 6.3 kBytes of data RAM, respectively. The implemented coder is tested against the set of 9 test vectors provided by ITU-T for bit exact implementation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.2013-2020
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• 2010

This paper presents a study on the modeling for transparent toaster with a cap of folding type. The toaster was modelled to solve problems of customer's unsatisfaction such as heat loss, input of a piece of dirt, unidentified heating state of sliced toaster. Rapid prototyping was followed by the first modeling, and the second modeling was implemented in order to solve the problems of the first modeling such as interference of holder and door, and the third modeling was developed with a cap of folding type through analysis of assembly and simulation. The 3D modeling tool used in this paper was Pro/Engineer 4.0. The modeling was designed to minimize heat loss and structured with transparent outer case. So the toasting procedure will be identified with the naked eye, and the transparent toaster will improve the customer's aesthetic satisfaction.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.2 s.72
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• pp.161-169
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• 2006

The study proposes component models in developing an efficient platform for internet-based structural analysis. Since a structural analysis requires an operation of complicated algorithms, a client-side computation using X-Internet is preferred to a server-side computation to provide a flexible service for multi-users. To compete with the user-friendly interfaces of available commercial analysis programs, a window-based interface using Smart Client was applied. Also, component-based programming was performed with the considerations on reusability and expandability so that active Preparation for future change or modification could be feasible. The components describe the whole system by subdivision and simplification. In the relationship between upper-and lower-level components and also in the relationship between components and objects, a unified interface was used to clearly classify the connection between the libraries. By performing data communication between different types of platforms using XML WebService, a conner-stone of data transfer is proposed for the future integrated CAE. The efficiency of the developed platform has been examined through a sample structural analysis and design on planar truss structures.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.136-144
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• 2003

In this paper, we propose a scheme that can control the loss probability of low priority class bursts by dynamically adjusting the assembly threshold of low priority class. The key ideas is that the loss Probability of the longer burst increases as the load increases, thus reduced low priority class burst length decreases the loss priority at high traffic load. To achieve this aim, we first derive the relation among the loss probability, the assembly threshold, and the traffic load. In this paper we derive the relation by curve fitting on the simulation results. The ingress edge routers periodically or by event-driven receives the proper corresponding assembly threshold information from the core routers. This assembly threshold is calculated from the derived relation so that the required loss probability of the low priority class bursts in the network is satisfied. The simulation results show that the proposed scheme performs well to meet the loss probability target as expected.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.2
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• pp.241-251
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• 2015

In public-key cryptographic system based on finite field arithmetic, it is very important to challenge for implementing high speed operation. In this paper, we focused on 8-bit ATmega128 processor and concentrated on enhancing efficiency of reduction operation which uses irreducible polynomial $f(x)=x^{271}+x^{207}+x^{175}+x^{111}+1$ and $f(x)=x^{193}+x^{145}+x^{129}+x^{113}+1$. We propose optimized reduction algorithms which are designed to reduce repeated memory accesses by calculating final reduced values of Fast reduction. There are 53%, 55% improvement when proposed algorithm is implemented using assembly language, compare to previous Fast reduction algorithm.

• The Journal of Korean Association of Computer Education
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• v.10 no.4
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• pp.113-124
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• 2007

The virtual laboratory is implemented by Java applets and FLASH animations, which provides the learners with improved experimental methods. If the learners have access to the virtual laboratory system through signing up procedure, they can acquire the fundamental concepts and make a virtual experiment on 8051 microcontroller. In addition, we have implemented the remote laboratory for practicing 8051 microcontroller, which can be used to compensate the absence of reality, occurred during virtual laboratory session. Finally, the proposed integration laboratory provides the learners with almost all the same and advantages as a real laboratory environment.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.1
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• pp.113-121
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• 1989

A software interface called CGI-K including device driver routines and graphics primitives for the grphic board "K" was designed, implemented in the Design Automation Laboratory of KAIST and installed on IBM PC/AT, using assembly and C language supported by TMS 34010 grphics processor. Several algorithms generating the graphics primitives such as box, circle, pie chord are proposed. The drawing speed of CGI-K on the graphic board K was found out to be three to ten times faster than that of the EGA for several examples. A 2-D graphics editor called GRIM (graphics input and modification) and a 3-dimensional graphics renderer called IPCHE which can draw 3-D objects were developed as two major application programs running on CGI-K. The graphics primitives supported in GRIM include polygon, box, circle, and ace. The IPCHE receives a 3-D objects data file and displays the 3-D object on the screen with hidden surface removal, shading, and perspective scaling.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.2
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• pp.227-235
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• 2010

This paper introduces the design of a bridge transport system with a telescopic tube for positioning equipment to perform remote handling tasks in a radioactive facility. It consists of an extensible and retractable telescopic tube assembly for z-direction motion, a cabling system for management of power and signal cables, and a trolley system for transverse motion and accommodating servo drives. The working environment for the bridge transport system with the telescopic tube requires strict geometrical constraints, including a short height, short telescopic tube length when retracted, and a long stroke. These constraints were met by solving a nonlinear programming problem involving the optimal dimensions. This paper introduces a cabling system for effective management of cables with changeable lengths to accommodate telescopic motions and a selection guide for servo drives that are sufficient to drive the system.

• The Journal of the Acoustical Society of Korea
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• v.23 no.5
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• pp.420-427
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• 2004

This paper presents real time implementation of 4kbps EHSX (Enhanced Harmonic Stochastic Excitation) speech coder that combines the harmonic vector excitation coding with time-separated transition coding. The harmonic vector excitation coding uses the harmonic excitation coding for voiced frames and used the vector excitation coding with the structure of analysis-by-synthesis for unvoiced frames, respectively. For transition frames mixed with voiced and unvoiced signal, we use the time-separated transition coding. In this paper. we present the optimization methods of implementation speech coder on the EMS320C6701/sup (R)/ DSP. To reduce the complex for real-time implementation. we perform the optimization method in algorithm by replacing the complex sinusoidal synthesis method with IFFT. and we apply fully pipelines hand assembly coding after converting it from floating source to fixed source. To generate a more efficient code. we also make use or the available EMS320C6701/sup (R)/ resources such as Fastest67x library and memory organization.