$\mu$PCM 신호에 대한 Walsh영역에서의 데이타 압축률 고찰

김장복,박규태 한국음향학회 1983 韓國音響學會誌 Vol.2 No.1

고속 Walsh-hadamard 변환방식을 사용하여 근사적으로 조기적인 신호의 μPCM 데이터를 압축 할 수 있음을 확인하였으며 최대 압축율은 기준 SQNR을 30dB로 할 경우 6 이상임을 보였다. 또한 decion level을 변화시킬 때 SQNR 변화를 조사하였으며 시스템 특성에 다라 decion level의 최적화를 얻을 수 있었다. 또한 양자화 레벨을 조정하여 SQNR을 검토한 바 대체로 선형적임을 나타내었다.

한글 숫자음성의 ZCR에 대한 연구

金長福 弘益大學校 1981 弘大論叢 Vol.13 No.-

In this paper, the relation between the ZCR Theory of Statistics and the result of experiments are studied. The method of recognizing korean spoken digits was by using zero crossing rates and energy levels. In the experiments for recognition of the digits, the speech signals are filtered by a LPF and processed by analog circuits. The results were in agreement with statistical ZCR Theory. Therefore it seems valuable for practical use. Ⅰ. 서 론 Ⅱ. 영점교차 밀도와 전력스펙트럼 Ⅲ. 염점교차 검출기 및 실험 Ⅳ. 실험결과 및 고찰 Ⅴ. 결 론 In this paper, the relation between the ZCR Theory of Statistics and the result of experiments are studied. The method of recognizing korean spoken digits was by using zero crossing rates and energy levels. In the experiments for recognition of the digits, the speech signals are filtered by a LPF and processed by analog circuits. The results were in agreement with statistical ZCR Theory. Therefore it seems valuable for practical use.

EPON의 동적대역폭할당을 위한 ONU와 OLT 설계

김장복,이순화,이종호 한국통신학회 2003 韓國通信學會論文誌 Vol.28 No.11B

FWHT에 의한 디지틀신호의 비화 방법

김장복,Kim, Jang-Bok 한국음향학회 1987 韓國音響學會誌 Vol.6 No.1

ISDN에 응용될 수 있는 신호의 비화방식에 대하여 연구되었다. FWHT algorithm을 응용하여, FWHT 계수의 부호를 16자의 password에 의하여 조정함으로써 그 비화성이 $3\times10^{38}$이상 되도록 하였으며 기계어에 의한 module을 최 적합하게 작성함으로써 시스템에의 firmware화가 쉽도록 하였으며 시스템을 최소화 할 수 있도록 하였다. printed data에 대한 computer simulation으로 N=128 일때의 비화 특성을 보였다. Fast Walsh-Hadamard Transform algorithm is discussed for secreting digital signals in ISDN. 16 characters are used for the password to control the coefficients of FWHT. And it gives above $3\times10^{38}$ codes. The FWHT module in presented in machine language. So it is applicable to compact cipher system or firmware system. Computer simulation showed secreting characteristics in printed data for N=128.

디지탈 신호처리를 위한 FFT 알고리즘에 관한 연구

金淳協,金長福 光云大學校 1981 論文集 Vol.10 No.-

The Fast Fourier Transform [FFT] is a computational tool which facilitates signal analysis such as power spectrum analysis and filter simulation by means of digital computers. It is a method for efficiently computing the Discrete Fourier Transform [DFT] of a series of data samples (referred to as a time series). In this paper, we organize a programming package for computing FFT. Once we have considered a program to calculate the FFT, it can efficiently be left to the user to process a digital signal.

μ-Law PCM에 있어서의 Walsh 변환 코팅 특성 ( Coding Characteristics of μ-Law PCM by Walsh Transform )

김장복,박규태 대한전자공학회 1983 대한전자공학회 학술대회 Vol.1983 No.1

WDM망에서의 Label Switching

김장복,김용성 弘益大學校 科學技術硏究所 2000 科學技術硏究論文集 Vol.11 No.-

Because of internet's growth, today's network has a serious bandwidth problem. Today, there are many solution for bandwidth problem. WDM(Wavelength Division Multiplexing) is one of them. In the WDM networks, QoS(Quality of Service) is as important as bandwidth. And today, VoIP and UMS technology makes a lot of delay-sensitive internet traffic. Delay-sensitive internet traffic is growing up, so more QoS is needed. In this paper, we proposed effective solution to assign QoS. This paper proposed a priority algorithm for assign wavelength to each node. If node A has very delay sensitive traffic, it will be assigned wavelength first. This action does before transmission is start. In this paper, It is showed WDM can have QoS supporting ability of itself and no need upper layer's help.

Sequence 영역에서의 디지틀 신호 처리방법에 관한 연구

金長福 弘益大學校 1982 弘大論叢 Vol.14 No.2

This paper studied the effect of companding in coding the PAM signal which was used as reference signal. μ-Law and A-Law companding was applied and compared with PAM, LPCM, and each other. The results from companding signals' SQNR were better about 8-dB than uncompanding signals and in μPCM reported 30-dB up at 1/3 point on the regeneration coefficient rate. Thus we can compress the data-rate in digital signal processing at 3:1.

FWHT용 프로그램 모듈 개발

金長福 弘益大學校 1985 弘大論叢 Vol.17 No.2

This paper presents a program module of fast Walsh-Hadamard Transform(FWHT) on SY6502 processor system. Assembly language is used in this module same as fast Fourier spectrum analyzer program. It is assumed that N=2ⁿ(n=1, 2, 3, …) and N is 256 or less because of fast algorithm application. The memory architecture of the module is presented to be able to call in high-level language program. In program simulation it is verified that the results of double FWHT equal to original patterns. FWHT and inverse FWHT algorithms are the same, so the equality verification proves that FWHT module is perfect. Original patterns are generated by the method of P.R. Risch. A few 10ms are wasted in FWHT module running and this delay time is fairly good for real-time application of speech signal processing. <부록> FWHT 및 SORT Program Module 8B00- D8 CLD 8B7E- D1 EB CMP ($EB),Y 8B01- AO 90 LDY #$90 8B80- D0 5A BNE $8BDC 8B03- 84 07 STY $07 8B82- B1 19 LDA ($19),Y 8B05- 84 09 STY $09 8B84- D1 1B CMP ($1E),Y 8B07- 88 DEY 8B86- 90 2D BCC $8BB5 8B08- 84 1A STY $1C 8B88- D0 06 BNE $8B90 8B0A- 84 1C STY $1C 8B8A- B1 06 LDA ($06),Y 8B0C- 88 DEY 8B8C- D1 08 CMP ($08),Y 8B0D- 84 1E STY $1E 8B8E- 90 25 BCC $8BB5 8B0F- 84 EC STY $EC 8B90- A9 0C LDA #$00 8B11- A0 00 LDY #$00 8B92- 91 1D STA ($1D),Y 8B13- 8C 05 03 STY $0305 8B94- 91 EB STA ($19),Y 8B16- AD 00 03 LDA $0300 8B96- B1 19 LDA ($19),Y 8B19- CB INY 8B98- 48 PHA 8B1A- 4A LSR 8B99- B1 06 LDA ($06),Y 8B1B- D0 FC BNE $8B19 8B9B- 48 PHA 8B1D- 8C 01 03 STY $0301 8B9C- 18 CLC 8B20- EE 05 03 INC $0305 8B9D- 71 08 ADC ($08),Y 8B23- AE 05 03 LDX $0305 8B9F- 91 06 STA ($06),Y 8B26- A9 01 LDA #$01 8BA1- B1 19 LDA ($19),Y 8B28- CA DEX 8BA3- 71 1B ADC ($1B),Y 8B29- F0 04 BEQ $8B2F 8BA5- 91 19 STA ($19),Y 8B2B- 0A ASL 8BA7- 68 PLA 8B2C- 4C 28 8B JMP 8B28 8BA8- 38 SEC 8B2F- 8D 02 03 STA $0302 8BA9- F1 08 SBC ($08),Y 8B32- AD 00 03 LDA $0300 8BAB- 91 08 STA ($08),Y 8B35- AE 05 03 LDX $0305 8BAD- 68 PLA 8B38- CA DEX 8BAE- F1 1B SBC ($1B),Y 8B39- F0 04 BEQ $8B3F 8BB0- 91 1B STA ($1B),Y 8B3B- 4A LSR 8BB2- 4C EE SC JMP $8CEE 8B3C- 4C 38 8B JMP $8B38 8BB5- A9 00 LDA #$00 8B3F- 18 CLC 8BB7- 91 1D STA ($1D),Y 8B40- 69 01 ADC #$01 8BB9- A9 FF LDA #$FF 8B42- 8D 04 03 STA $0304 8BBB- 91 EB STA ($EB),Y 8B45- F0 07 BEQ $8B4E 8BBD- B1 1B LDA ($1B),Y 8B47- 4A LSR 8BBF- 48 PHA 8B48- 8D 03 03 STA $0303 8BC0- B1 08 LDA ($08),Y 8B4B- 4C 53 8B JMP $8B53 8BC2- 48 PHA 8B4E- A9 80 LDA #$80 8BC3- 38 SEC 8B50- 8D 03 03 STA $0303 8BC4- F1 06 SBC ($06),Y 8B53- A2 00 LDX #$00 8BC6- 91 08 STA ($08),Y 8B55- E8 INX 8BC8- B1 1B LDA ($1B),Y 8B56- 8A TXA 8BCA- F1 19 SBC ($19),Y 8B57- 48 PHA 8BCC- 91 1B STA ($1B),Y 8B58- A9 00 LDA 8BCE- 68 PLA 8B5A- 18 CLC 8BCF- 18 CLC 8B5B- CA DEX 8BD0- 71 06 ADC ($06),Y 8B5C- F0 06 BEQ $8B64 8BD2- 91 06 STA ($06),Y 8B5E- 6D 04 03 ADC $0304 8BD4- 68 PLA 8B61- 4C 5B 8B JMP $8B5B 8BD5- 71 19 ADC ($19),Y 8B64- 85 06 STA $06 8BD7- 91 19 STA ($19),Y 8B66- 85 19 STA $19 8BD9- 4C EE 8C JMP $8CEE 8B68- 85 1D STA $1D 8BDC- B1 19 LDA ($19),Y 8B6A- 6D 03 03 ADC $0303 8BDE- D1 1B CMP ($1B),Y 8B6D- 85 08 STA $08 8BE0- 90 2D BCC $8C0F 8B6F- 85 1B STA $1B 8BE2- D0 06 BNE $8BEA 8B71- 85 EB STA $EB 8BE4- B1 06 LDA ($06),Y 8B73- A0 00 LDY #$00 8BE6- D1 08 CMP ($03),Y 8B75- A9 00 LDA #$00 8BE8- 90 25 BCC $8C0F 8B77- D1 1D CMP ($1D), Y 8BEA- A9 00 LDA #$00 8B79- F0 03 BEQ $8B7E 8BEC- 91 1D STA ($1D),Y 8B7B- 4C 36 8C JMP $8C36 8BEE- 91 EB STA ($EB),Y 8BF0- B1 19 LDA ($19),Y 8C5E- F1 1B SEC ($1B),Y 8BF2- 48 PHA 8C60- 91 19 STA ($19),Y 8BF3- B1 06 LDA ($06),Y 8C62- 68 PLA 8BF5- 48 PHA 8C63- 18 CLC 8BF6- 38 SEC 8C64- 71 08 ADC ($08),Y 8BF7- F1 08 SBC ($08),Y 8C66- 91 08 STA ($08),Y 8BF9- 91 06 STA ($06),Y 8C68- 68 PLA 8BFB- B1 19 LDA ($19),Y 8C69- 71 1B ADC ($1B),Y 8BFD- F1 1B SBC ($1B),Y 8C6B- 91 1B STA ($1B),Y 8BFF- 91 19 STA ($19),Y 8C6D- 4C EE 8C JMP $8CEE 8C01- 68 PLA 8C70- A9 00 LDA #$00 8C02- 18 CLC 8C72- 91 1D STA ($1D),Y 8C03- 71 08 ADC 8C74- AP FF LDA #$FF 8C05- 91 08 STA 8C76- 91 EB STA ($EB),Y 8C07- 68 PLA 8C78- B1 1B LDA ($1B),Y 8C08- 71 1B ADC ($1B),Y 8C7A- 48 PHA 8C0A- 91 1B STA ($1B),Y 8C7B- B1 08 LDA ($08),Y 8C0C- 4C EE 8C JMP $8CEE 8C7D- 48 PHA 8C0F- A9 FF LDA #$FF 8C7E- 18 CLC 8C11- 91 1D STA ($1D),Y 8C7F- 71 06 ADC ($06),Y 8C13- A9 00 LDA #$00 8C81- 91 08 STA 8C15- 91 EB STA ($EB),Y 8C83- B1 1B LDA ($1B),Y 8C17- B1 1B LDA ($1B),Y 8C85- 71 19 ADC ($19),Y 8C19- 48 PHA 8C87- 91 1B STA ($1B),Y 8C1A- B1 08 LDA ($08),Y 8C89- 68 PLA 8C1C- 48 PHA 8C8A- 38 SEC 8C1D- 18 CLC 8C8B- F1 06 SBC ($06),Y 8C1E- 71 06 ADC ($06),Y 8C8D- 91 06 STA ($06),Y 8C20- 91 08 STA ($08),Y 8C8F- 68 PLA 8C22- B1 1B LDA ($1B),Y 8C90- F1 19 SEC ($19),Y 8C24- 71 19 ADC ($19),Y 8C92- 91 19 STA ($19),Y 8C26- 91 1B STA ($1B),Y 8C94- 4C EE 8C JMP $8CEE 8C28- 68 PLA 8C97- B1 19 LDA ($19),Y 8C29- 38 SEC 8C99- D1 1B CMP ($1B),Y 8C2A- F1 06 SBC ($06),Y 8C9B- 90 2D BCC $8CCA 8C2C- 91 06 STA ($06),y 8C9D- D0 06 BNE $8CA5 8C2E- 68 PLA 8C9F- B1 06 LDA ($06),Y 8C2F- F1 19 SBC ($19),Y 8CA1- D1 08 CMP ($08),Y 8C31- 91 19 STA ($19),Y 8CA3- 90 25 BCC $8CCA 8C33- 4C EE 8C JMP $8CEE 8CA5- A9 FF LDA #$ff 8C36- A9 00 LDA #$00 8CA7- 91 1D STA ($1D),Y 8C38- D1 EB CMP ($EB),Y 8CA9- 91 EB STA ($EB),Y 8C3A- DO 5B BNE $8C97 8CAB- B1 19 LDA ($19),Y 8C3C- 38 SEC 8CAD- 48 PHA 8C3D- B1 19 LDA ($19),Y 8CAE- B1 06 LDA ($06),Y 8C3F- D1 1B CMP ($1B),Y 8CBO- 48 PHA 8C41- 90 2D BCC $8C70 8CB1- 18 CLC 8C43- DO 06 BNE $8C4B 8CB2- 71 08 ADC ($08),Y 8C45- B1 06 LDA ($06),Y 8CB4- 91 06 STA ($06),Y 8C47- D1 08 CMP ($08),Y 8CB6- B1 19 LDA ($19),Y 8C49- 90 25 BCC $8C70 8CB8- 71 1B ADC ($1B),Y 8C4B- A9 FF LDA #$FF 8CBA- 91 19 STA ($19),Y 8C4D- 91 1D STA ($1D),Y 8CBC- 68 PLA 8C4F- 91 EB STA ($EB),Y 8CBD- 38 SEC 8C51- B1 19 LDA ($19),Y 8CBE- F1 08 SBC ($08),Y 8C53- 48 PHA 8CC0- 91 08 STA ($08),Y 8C54- B1 06 LDA ($06),Y 8CC2- 68 PLA 8C56- 48 PHA 8CC3- F1 1B SBC ($1B),Y 8C57- 38 SEC 8CC5- 91 1B STA ($1B),Y 8C58- F1 08 SBC ($08),Y 8CC7- 4C EE 8C JMP $8CEE 8C5A- 91 06 STA ($06),Y 8CCA- A9 FF LDA #$FF 8C5C- B1 19 LDA ($19),Y 8CCC- 91 1D STA ($1D),Y 8CCE- A9 00 LDA #$00 8D52- 99 00 95 STA $9500,Y 8CD0- 91 EB STA ($EB),Y 8D55- 8A TXA 8CD2- B1 1B LDA ($1B),Y 8D56- 99 00 93 STA $9300,Y 8CD4- 48 PHA 8D59- A9 01 LDA #$01 8CD5- B1 08 LDA ($08),Y 8D5B- 9D 00 94 STA $9400,X 8CD7- 48 PHA 8D5E- 98 TYA 8CD8- 38 SEC 8D5F- 9D 00 92 STA $9200,X 8CD9- F1 06 SBC 8D62- 4C 77 8D JMP $8D77 8CDB- 91 08 STA ($08),Y 8D65- 99 00 95 STA $9500,Y 8CDD- B1 1B LDA ($1B),Y 8D68- BD 00 93 LDA $9300,X 8CDF- F1 19 SBC ($19),Y 8D6B- 99 00 93 STA $9300,Y 8CE1- 91 1B STA ($1B),Y 8D6E- A9 01 LDA #$01 8CE3- 68 PLA 8D70- 9D 00 95 STA $9500,X 8CE4- 18 CLC 8D73- 98 TYA 8CE5- 71 06 ADC ($06),Y 8D74- 9D 00 93 STA $9300,X 8CE7- 91 06 STA ($06),Y 8D77- CC 00 03 CPY $0300 8CE9- 68 PLA 8D7A- 90 A0 BCC $8D1C 8CEA- 71 19 ADC ($19),Y 8D7C- A9 00 LDA #$00 8CEC- 91 19 STA ($19),Y 8D7E- AA TAX 8CEE- C8 INY 8D7F- A8 TAY 8CEF- CC 03 03 CPY $0303 8D80- BD 00 94 LDA $9400,X 8CF2- F0 03 BEQ $8CF7 8D83- F0 07 BEQ $8D8C 8CF4- 4C 75 8B JMP $8B75 8D85- BD 00 92 LDA $9200,X 8CF7- 68 PLA 8D88- AA TAX 8CF8- AA TAX 8D89- 4C 80 8D JMP $8D80 8CF9- EC 02 03 CPX #0302 8D8C- 8A TXA 8CFC- F0 03 BEQ $8D01 8D8D- 99 00 91 STA $9100,Y 8CFE- 4C 55 8B JMP $8B55 8D90- 08 INY 8D01- AD 05 03 LDA $0305 8D91- BD 00 95 LDA $9500,X 8D04- CD 01 03 CMP $0301 8D94- F0 1D BEQ $8DB3 8D07- F0 03 BEQ $8D0C 8D96- 30 07 BMI $8D9F 8D09- 4C 20 8B JMP $8B20 8D98- BD 00 93 LDA $9300,X 8DOC- 60 RTS 8D9B- AA TAX 8DOD- A0 00 LDY #$00 8D9C- 40 80 8D JMP $8D80 8DOF- 98 TYA 8D9F- BD 00 93 LDA $9300,X 8D10- 99 00 94 STA $9400,Y 8DA2- AA TAX 8D13- 99 00 95 STA $9500,Y 8DA3- 4C 8C 8D JMP $8D8C 8D16- 99 00 92 STA $9200,Y 8DA6- B9 00 90 LDA $9000,Y 8D19- 99 00 93 STA $9300,Y 8DA9- DD 00 90 CMP $9000,X 8D1C- C8 INY 8DAC- F0 96 BEQ $8D44 8D1D- A9 00 LDA #$00 8DAE- 90 94 BCC $8D44 8D1F- 99 00 94 STA $9400,Y 8DB0- 4C 36 8D JMP $8D36 8D22- 99 00 95 STA $9500,Y 8D25- 99 00 92 STA $9200,Y 8D28- 99 00 93 STA $9300,Y 8D2B- AA TAX 8D2C- B9 00 8F LDA $8F00,Y 8D2F- DD 00 8F CMP $8F00,X 8D32- 90 10 BCC $8D44 8D34- F0 70 BEQ $8DA6 8D36- BD 00 95 LDA $9500,X 8D39- 30 2A BMI $8D65 8D3B- F0 28 BEQ $8D65 8D3D- BD 00 93 LDA $9300,X 8D40- AA TAX 8D41- 4C 2C 8D JMP $8D2C 8D44- BD 00 94 LDA $9400,X 8D47- F0 07 BEQ $8D50 8D49- BD 00 92 LDA $9200,X 8D4C- AA TAX 8D4D- 4C 2C 8D JMP $8D2C 8D50- A9 FF LDA #$FF

MSM 토폴로지를 갖는 WDM 다중홉망에서의 라우팅 기법의 성능향상에 관한 연구

송재연,김장복 弘益大學校 科學基術硏究所 1999 科學技術硏究論文集 Vol.10 No.2

In this paper, we proposed a cell routing algorihms for ATM services in WDM multihop networks. The proposed routing strategy is for Manhattan Street Network topology the one of WDM logical virtual topologys. In general, routing methods of MSN are Store-and-Forward, Deflection algorithm. S&F method needs a large buffer, thus we chose the deflection scheme. But, this introduces lots of delay in networks, due to additional hops. So, we used the flow control ability of local sources, suggested a new routing algirithm. First, high priority cell of ATM has a highest ranking to output than local output. This is a protection of high priority cell like a one of real-time services. And When aempty slot is only one, local source has a higher ranking than low ATM cell. Finally, If low priority ATM cell experienced lots of deflections, It is outputed instead local source. Simulation results show proposed algorithms have better performance than conventional ones in a point of view of reducing the number of average hops.