• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7C
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• pp.735-742
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• 2006

In this paper, we explain the operation scheme and fixed-point design method of DFE (Digital Front End), which performs DC offset compensation, automatic frequency control, and automatic gain control over the input signal to the UE (User Equipment) receiver of IEEE 802.16e OFDMA-TDD system. Then, we analyze the performance of DFE under ITU-R M. 1225 Veh-A 60km/h channel environment. To optimize the fixed-point design of DFE, we reduce the number of bit resulted from calculation without performance degradation, leading to the decreased complexity of the operation in H/W, and design the Loop filter with considering trade-off between the Acquisition time and the Stability.

• Fashion & Textile Research Journal
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• v.11 no.5
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• pp.788-798
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• 2009

This study aims to develop a highly reproducible, optimal frame design algorithm using variations in the curvature of armscye circumference, which will provide the basics for remodeling the 3D human body shape with the concept of reverse design used to develop total contents for the apparel industry. 1. The results of the experiment proved that ratio value was significantly efficient than absolute value of curvature variation to extract feature points in the armscye circumference 2. For the shoulder(1st and 2nd quadrant) and front armhole(3rd quadrant) parts of the armscye circumference, frame remodeling with the positive point of inflection led to the completion of a highly reproducible frame. 3. Similarly, even for the rear armhole part(4th quadrant) in the armscye circumference, it was found that frame remodeling using the positive maximum point of inflection resulted in highly reproducible body shape with the maximum point of inflection situated within the range of split angles $305^{\circ}{\sim}330^{\circ}$, while frame remodeling using simultaneously the two largest points of inflection including maximum point of inflection led to highly reproducible body shape with the maximum point of inflection out of the range $305^{\circ}{\sim}330^{\circ}$. 4. Based upon the optimal frame design algorithm developed in this study, section-specific feature points in the armscye circumference were extracted depending on the rate of curvature variation and remodeling with spline curves was conducted. The results indicate a remarkably high reproducibility(98.6%) and suggest that the algorithm developed in this study is suitable for human body modeling.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.5
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• pp.65-73
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• 2002

In this paper, we propose and verify an implementation method for a single-chip 2048 complex point FFT/IFFT in terms of sequential data processing. For the sequential processing of 2048 complex data, buffers to store the input data are necessary. Therefore, DRAM-like pipelined commutator architecture is used as a buffer. The proposed structure brings about the 60% chip size reduction compared with conventional approach by using this design method. The 16-point FFT is a basic building block of the entire FFT chip, and the 2048-point FFT consists of the cascaded blocks with five stages of radix-4 and one stage of radix-2. Since each stage requires rounding of the resulting bits while maintaining the proper S/N ratio, the convergent block floating point (CBFP) algorithm is used for the effective internal bit rounding and their method contributed to a single chip design of digital audio broadcasting system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.10 s.340
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• pp.55-64
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• 2005

In this paper, we designed floating point units to accelate real-time 3D Graphics for Geometry processing. Designed floating point units support IEEE-754 single precision format and we confirmed 100 MHz performance of floating point add/mul unit, 120 MHz performance of floating point NR inverse division unit, 200 MHz performance of floating point power unit, 120 MHz performance of floating point inverse square root unit at Xilinx-vertex2. Also, using floating point units, designed Geometry processor and confirmed 3D Graphics data processing.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.4
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• pp.251-259
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• 2008

This paper presents the hardware design of a 32bit floating point based processor. The processor can perform nonlinear functions such as sinusoidal functions, exponential functions, and other mathematical functions. Using the Taylor series and Newton - Raphson method, nonlinear functions are approximated. The processor is actually embedded on an FPGA chip and tested. The numerical accuracy of the functions is compared with those computed by the MATLAB and confirmed the performance of the processor.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.4
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• pp.439-444
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• 1986

In this paper the PID-B self-tuner[1] is extended to allow a less abrupt response to set point or plant parameter changes and to control a nonminimum phase plant. The proposed extended PID/ST derived from the direct pole-placement PID/ST is obtained with the Bezout identity as the underlying design method. And its control gains are normalized by the integral control gain. Although the integral control gain is normalized to 1 in our scheme, the so-called "set point and derivative kick" can be avoided sufficiently by normalizing the measurement vector and set point.

• Journal of the Chungcheong Mathematical Society
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• v.18 no.1
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• pp.101-116
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• 2005

Using the iterative method, we derive an controller realization of the bilinear system, which is resulted from the system reformulation. We utilize Banach Fixed Point Theorem to support proposed controller, and the simulation results are also illustrated to verify usefulness of this technique.

• Journal of the Ergonomics Society of Korea
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• v.18 no.2
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• pp.57-69
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• 1999

The primary objective of this research was to suggest the design dimensions of automotive seating package that has an important effect upon seating package design. To conduct the research, a set of manikin dimensions that are representative for Korean was determined by using a statistical scheme. With these dimensions, we generated nine manikins for male and female, respectively. Also, the preferred driving posture was investigated using the experimental setup. To find each joint angle for subjects, a driving monitoring system was developed and a three dimensional motion analysis system was employed. The joint angle for the subject was established and compared with related literature. With the generated manikins and each joint angle, the driving posture was simulated by using SAFEWORK that is a program to generate manikins. The positions and adjustable ranges from the accelerator heel point to the hip point and the steering wheel center point that are important variables in order to design seating package were suggested. Further research is needed to determine the seating package dimensions three dimensionally.

• Journal of computational fluids engineering
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• v.6 no.1
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• pp.14-20
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• 2001

The CFD analysis of the three-dimensional turbulent flow in the impeller and diffuser of an axial flow pump was performed. Not only the design point but also the off-design points were computed. The results were compared with available experimental data in terms of head generated. At the design point, the analysis accurately predicted the experimental head value. In the range of the higher flow rates, the results were also in very good agreement with the experimental data, not only in absolute value but also in term of slope. Although experimental data to be compared were not available in the range of the lower flow rates, the results well described the S-shape performance curve of the axial pump characteristic.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2108-2111
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• 2005

The mission life of a satellite determines the amount of fuel required on-board, while the total mass requirement limits the fuel to be loaded. Hence, for the design of thruster control loop, not only the satellite pointing accuracy but the saving of fuel is to be considered. In this paper, a two-step fuzzy controller is proposed for the thruster control loop to save fuel consumption. This approach combines requirements for pointing control accuracy with minimum fuel consumption into a fuzzy controller design. To demonstrate this approach, we have designed a fuzzy controller for the Sun point Mode of KOMPSAT-2. The performance of this fuzzy controller design is compared with that of PD controller used for KOMPSAT-2.