• The Journal of the Acoustical Society of Korea
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• v.19 no.4
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• pp.37-44
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• 2000

In this paper, we described the real-time implementation effort of MPEG-4 audio HVXC (Harmonic Vector eXcitation Coding) algorithm for very low bitrates, which has target applications from mobile communications to Internet telephony, on current high performance floating point TMS320C6701 DSP. We adopted a hardware structure for real-time operation. In order for software optimization, we used C- and assembly-language level optimizations for time-critical functional codes. Utilizing the internal program memory of the DSP as the program cache, the internal data memory overlap technique and DMA functionality, we could get a goal of realtime operation of HVXC codec both at 2 kbit/s and at 4 kbit/s. For an encoder at 2 kbit/s, the optimization ratio to original code is about 96 %. Finally, we got the subjective quality of MOS 2.45 at 2 kbit/s from an informal quality test.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.10
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• pp.49-54
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• 2007

As digital contents based on 3D graphics are increased, the requirement for low power 3D graphic hardware for mobile devices is increased. We design a transformation engine for mobile 3D graphic processor. We propose a simplified transformation engine for mobile 3D graphic processor. The area of the transformation engine is reduced by merging a mapping transformation unit into a projective transformation unit and by replacing a clipping unit with a selection unit. It consists of a viewing transformation unit a projective transformation unit a divide by w nit, and a selection unit. It can process 32 bit floating point format of the IEEE-754 standard or a reduced 24 bit floating point format. It has a pipelined architecture so that a vertex is processed every 4 cycles except for the initial latency. The RTL code is verified using an FPGA.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.3
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• pp.563-569
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• 2007

As the mobile communication and the semiconductor technology is improved continuously, mobile contents such as the multimedia service and the 2D/3D graphics which require high level graphics are serviced recently. Mobile chips should consume small die area and low power. In this paper, we design a truncated floating-point multiplier that is useful for the 2D/3D vector graphics in mobile devices. The truncated multiplier is based on the radix-4 Booth's encoding algorithm and a truncation algorithm is used to achieve small area and low power. The average percent error of the multiplier is as small as 0.00003% and neglectable for mobile applications. The synthesis result using 0.35um CMOS cell library shows that the number of gates for the truncated multiplier is only 33.8 percent of the conventional radix-4 Booth's multiplier.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.353-361
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• 2018

The purpose of this study is to analyze how Corporate Real Estate Ratio affects Firm's Value for KOSPI Companies and KOSDAQ Companies. The period of analysis is the period of the Financial Crisis (2007-2008), the period immediately after the Financial Crisis (2009-2011), and the period following the introduction of IFRS (2012-2016). The samples of 2761 KOSPI Companies years and 3719 KOSDAQ Companies years are used in this study. The result of Regression Analysis shows that the higher Corporate Real Estate Ratio is, the more negative Firm's Value is. In the comparison of markets, both KOSPI Companies and KOSDAQ Companies had no statistically significant effects during the Financial Crisis. Although KOSDAQ Companies had a greater negative effect on the Firm's Value than KOSPI Companies right after the Financial Crisis, KOSPI Companies have had a greater negative influence on the Firm's Value than KOSDAQ Companies since the introduction of IFRS. Therefore, each corporation should pay more attention to identifying the appropriate amount of their Corporate Real Estate Ratio and should continue to analyze and make decisions on the most efficient use of real estate which is owned by each company. This study shows speciality in dividing into three period, such as the period of the Financial Crisis, the period immediately after the Financial Crisis, and the period following the introduction of IFRS and comparing the degree of influence on the KOSPI Companies and KOSDAQ Companies for the each period. I hope to study the factors that affect the company's real estate policy.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.591-595
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• 2011

In this paper, we design the hardware architecture of the BICM(Bit Interleaved Coded Modulation) module for next generation European broadcast system and implement the BICM module with DSP(Digital Signal Processor) TMS320C6474. Simulation result shows that the BER(Bit Error Rate) performance of the fixed-point BICM module using more than 8 bits is very similar to that of the floating-point BICM module.

• Proceedings of the Korean Society of Computer Information Conference
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• 2012.01a
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• pp.1-4
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• 2012

임베디드 시스템에서 최적화 기술의 성능은 크로스 컴파일러의 성능과 실행상황, 대상 하드웨어의 특징 등에 따라 좌우된다. 본 논문에서는 최적화 기술 중 루프 펼침과 형 변환을 이미지 처리 코드에 적용하여 성능을 측정하였다. 그 결과 기술을 적용하지 않은 성능을 기준으로 55%의 성능향상이 이루어졌다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.1
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• pp.105-113
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• 2000

This paper proposes the optimal design method of PSF(pulse shaping filter) with fixed-point coefficients, often used in digital communication system. Though RCF (Raised Cosine Filter) and Root-Squared RCF have less attenuation in stopband and are designed with floating point coefficients, those are selected by the reason that the design is simple. In this paper, 1 introduce the optimal design method for fixed point PSF including Root Squared type by using mixed integer linear programming. Through some design examples, it is shown that the proposed method better performs in ISI and requires less complexity. The complexity of the proposed filter is reduced to 20% as compared to conventional RCF and Root Squared RCF. For IS-95, that is the standard of CDMA system, the proposed filter reduces ISI up to 75% compared to the standard transmission filter.

• Journal of the Korean Arthroscopy Society
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• v.16 no.1
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• pp.1-8
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• 2012

Purpose: To evaluate clinical and radiologic outcomes of transphyseal anterior cruciate ligament (ACL) reconstruction in patients with open physes who were selected with authors' new operative indications. Materials and Methods: We evaluated 15 patients with open physes who underwent a transtibial ACL reconstruction and were followed up for 4~6 years after surgery. Our operative indications involved 1) choronologic age of ${\geq}$ 16 in male and ${\geq}$ 14 in female, 2) open physes of ${\leq}$ 2 mm width, and 3) Risser sign and Tanner stage of ${\geq}$ 3. Tibialis anterior tendon allograft was used in all patients, and endobutton and bioscrew were used for femoral and tibial fixations, respectively. Functional outcomes were evaluated using Lysholm Knee Scoring scale, Tegner activity scale, and International Knee Documentation Committee (IKDC) 2000 subjective score. Physical examinations to evaluate stability involved Lachman and pivot shift tests. For radiographic results, we evaluated side to side differences of anterior displacement in stress views. In addition, with use of scannograms taken at last follow-up, we examined side to side differences of femorotibial angles, anatomical and mechanical lateral distal femoral angles, mechanical medial proximal tibial angles and leg lengths. Results: The mean Lysholm Knee score was 51(40-61) points preoperatively and 97(94-100) points at last follow up. The mean Tegner activity score was 2.6 points preoperatively and 7.1 points at last follow up. The mean IKDC score was 32.6 points preoperatively and 88.3 points at last follow up. The mean anterior displacement of the tibia was improved from 6.7(${\pm}1.0$) mm to 1.9(${\pm}0.9$) mm. There were no leg length discrepancies over 5 mm and no statistically significant differences in all the radiographic variables representing growth disturbance. Conclusion: This study suggests that patients with open physes who selected by authors' new indication would safely undergo transphyseal ACL reconstruction with successful outcomes.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.3
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• pp.224-231
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• 1984

Having found by means of a tension-shear test an optimal spot welding condition under which the maximum weld strength is to be brought forth, this study made an examination of behavior of fracture concerned with behavior of stress distribution, observed around the nugget periphery of the specimens prepared under the optimal conditions, with one point spot welded mild steel sheets. The resultant findings are as follows: (1)There remarkably exists an optimal spot welding condition to indicate the maximum weld strength, and fracture of the specimens spot welded under that condition occurs outside the nugget boundary. (2)An experiment on the basis of a photoelastic model reveals that the maximum stress is distributed along the center line of the steel plate width but occurs on the region corresponding to heat affected zone of spot welds. (3)Heat affected zone of spot welds consists of coarse grains with considerably low micro Vickers hardness value and of fine grains of high micro Vickers hardness value, and in this unbalanced structure weak region are represented in coarse grain region, where fracture is initiated and continues its propagation.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.173-176
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• 2003

지문은 종생불변성, 만인부동성, 그리고 사용상의 편리함 때문에 신원인증을 위한 생체인식에 많이 사용되고 있다. 최근에는 기하학구조에 기반한 특이점 매칭방식이 제안되어 인식성능이 매우 높고 잡음에 강한 특성이 있으나 매칭 회수가 많아 인식속도가 느린 단점이 있다. 따라서 기존의 방식은 소수의 지문에 대한 1:다 매칭이나 1:1매칭에 주로 사용된다. 본 논문에서는 기존의 문제점들을 개선하기 위하여 생체 면역계의 자기-비자기 인식 능력에 주목하였다. 생체 면역계는 자기-비자기의 구별 능력을 바탕으로 바이러스나병원균 등의 낮선 외부침입자로부터 자신을 보호하고 침입자를 식별, 제거하는 시스템이다. 본 논문에서는 생체 면역계를 이루는 면역세포 중의 하나인 세포독성 T세포의 생성과정에서 자기, 비자기를 구별하기 위한 MHC 인식부를 형성하는 과정에 착안한 빠르고 신뢰성 있는 지문 인식 알고리즘을 제안한다. 제안한 방식은 지문에 존재하는 특이점(minutiae)인식을 통해 1단계로 global 패턴을 생성하고 2단계로 기하학적인 구조를 만들며, 인식시 global 패턴을 인식한 MHC 인식부에 대해서만 2차 local 매칭을 수행함으로써 매칭 속도가 매우 빠르며 지문의 비틀림이나 회전 등에 대하여 강인하게 인식된다.