• Title/Summary/Keyword: Pseudo Code

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Feature Extraction of Letter Using Pattern Classifier Neural Network (패턴분류 신경회로망을 이용한 문자의 특징 추출)

  • Ryoo Young-Jae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.2
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    • pp.102-106
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    • 2003
  • This paper describes a new pattern classifier neural network to extract the feature from a letter. The proposed pattern classifier is based on relative distance, which is measure between an input datum and the center of cluster group. So, the proposed classifier neural network is called relative neural network(RNN). According to definitions of the distance and the learning rule, the structure of RNN is designed and the pseudo code of the algorithm is described. In feature extraction of letter, RNN, in spite of deletion of learning rate, resulted in the identical performance with those of winner-take-all(WTA), and self-organizing-map(SOM) neural network. Thus, it is shown that RNN is suitable to extract the feature of a letter.

Using nonlinear static procedures for seismic assessment of the 3D irregular SPEAR building

  • Bento, R.;Bhatt, C.;Pinho, R.
    • Earthquakes and Structures
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    • v.1 no.2
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    • pp.177-195
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    • 2010
  • This paper presents an appraisal of four nonlinear static procedures (CSM, N2, MPA and ACSM) employed in seismic assessment of plan-irregular buildings. It uses a three storey reinforced concrete plan-irregular frame building exemplifying typical older constructions of the Mediterranean region in the early 1970s that was tested in full-scale under bi-directional pseudo-dynamic loading condition at JRC, Ispra. The adequacy and efficiency of the simplified analytical modelling assumptions adopted were verified. In addition, the appropriate variants of code-prescribed NSPs (CSM and N2) to be considered for subsequent evaluation were established. Subsequent parametric studies revealed that all such NSPs predicted reasonably well both global and local responses, having the benchmark values been determined through nonlinear dynamic analyses using a suit of seven ground motions applied with four different orientations. The ACSM, however, predicted responses that matched slightly better the median dynamic results.

Robust frame synchronization algorithm in time-varying underwater acoustic communication channel (수중 음향통신에서 채널 시변동성에 강인한 프레임 동기 알고리즘)

  • Ko, Seokjun;Kim, Wan-Jin
    • The Journal of the Acoustical Society of Korea
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    • v.39 no.1
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    • pp.8-15
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    • 2020
  • In this paper, we propose a frame synchronization algorithm for robust to the combined effects of large Doppler fluctuations and extended, time-varying multipath in the underwater acoustic communication. From the algorithm, we can recover a high timing error which is occurred from an acoustic propagation delay and uncertainty of oscillator between transmitter and receiver. In order to verify the performance of the synchronization algorithm, the lake trial results are used. The lake experiments are performed in a Gyeongcheonho located in Mungyeong-si, Gyeongsangbuk-do. We can see that the start position of frame is adjusted after the frame synchronization while the receiver moving.

Design of Clock Synchronization Scheme for Pseudolite (의사위성 시각동기 기법 설계)

  • Lee, Ju Hyun;Hwang, Soyoung;Yu, Dong-Hui;Lee, Sang Jeong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.6
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    • pp.1312-1317
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    • 2013
  • Pseudolite is a contraction of the term "pseudo-satellite", used to refer to something that is not a satellite which performs a function commonly in the domain of satellites. Pseudolite are most often small transceivers that are used to create a local, ground-based GPS alternative. Pseudo-range measurement of pseudolite has around 300m range error, when time synchronization error of $1{\mu}sec$ occurs. Therefore the time synchronization methods play an important part in navigation augmentation using pseudolite. This paper proposes three clock synchronization methods that are installation method of pseudolite station, method using KRISS-UTC and method using PRN code phase difference for pseudolite. The simulation platform structure is presented for evaluating proposed clock synchronization performance.

Rocking behavior of bridge piers with spread footings under cyclic loading and earthquake excitation

  • Hung, Hsiao-Hui;Liu, Kuang-Yen;Chang, Kuo-Chun
    • Earthquakes and Structures
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    • v.7 no.6
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    • pp.1001-1024
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    • 2014
  • The size of spread footings was found to be unnecessarily large from some actual engineering practices constructed in Taiwan, due to the strict design provisions related to footing uplift. According to the earlier design code in Taiwan, the footing uplift involving separation of footing from subsoil was permitted to be only up to one-half of the foundation base area, as the applied moment reaches the value of plastic moment capacity of the column. The reason for this provision was that rocking of spread footings was not a favorable mechanism. However, recent research has indicated that rocking itself may not be detrimental to seismic performance and, in fact, may act as a form of seismic isolation mechanism. In order to clarify the effects of the relative strength between column and foundation on the rocking behavior of a column, six circular reinforced concrete (RC) columns were designed and constructed and a series of rocking experiments were performed. During the tests, columns rested on a rubber pad to allow rocking to take place. Experimental variables included the dimensions of the footings, the strength and ductility capacity of the columns and the intensity of the applied earthquake. Experimental data for the six circular RC columns subjected to quasi-static and pseudo-dynamic loading are presented. Results of each cyclic loading test are compared against the benchmark test with fixed-base conditions. By comparing the experimental responses of the specimens with different design details, a key parameter of rocking behavior related to footing size and column strength is identified. For a properly designed column with the parameter higher than 1, the beneficial effects of rocking in reducing ductility and the strength demand of columns is verified.

Synchronization Scheme Using Phase Offsets of PN Sequences (PN 부호의 위상오프셋을 이용한 동기 방법)

  • Song, Young-Joon;Han, Young-Yearl
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.581-584
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    • 2003
  • It is important to know phase offsets of PN (Pseudo Noise) sequences in spread spectrum communications since the acquisition is equivalent to make a phase offset between a receiving PN sequence and a PN sequence of local PN generator be identical. In this paper, a phase offset enumeration method for PN sequences with error detection, and its application to the synchronization are proposed. The phase offset enumeration far an n-tuple PN sequence and its error detection are performed when one period of the sequence is received. Once the phase offset of the receiving sequence is calculated, we can easily accomplish the synchronization by initializing shift registers of a local PN generator according to the phase offset value. The mean acquisition time of the proposed synchronization method is derived analytically, and we see that the method acquires very fast acquisition in the high SNR (Signal-to- Noise Ratio) environment.

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High Quality Audio Watermarking using Spread Spectrum and Psychoacoustic Model (대역확산과 심리음향 모델을 이용한 고음질 오디오 워터마킹)

  • Noh Jin-Soo;Rhee Kang-Hyeon
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.43 no.5 s.311
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    • pp.48-56
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    • 2006
  • In this paper, we proposed the high quality audio watermarking algorithm using MDCT/IMDCT (Modified DCT/Inverse Modified DCT) with psychoacoustic model. Generally, a digital audio watermark is embedding the frequency domain after frequency transform of the digital audio data but the digital audio quality is affected by watermarking. In our scheme, the digital audio data is spread with PN((Pseudo Noise) code and then audio watermark is embedded in MDCT processing that refers psychoacoustic model. In MDCT processing, according to the shape of filter bank output, the block switching selects a window sequence that has 256, 1,024 or 2,048 points interval for high quality audio. The author confirm that when watermark weight ${\alpha}$ is 2.5 below, the detection ratio of watermark is a satisfied to SDMI's(Secure Digital Music Initiative) recommendation 50% above and SM is $50{\sim}68dB$ range with mainly 4 kind of attacks(Compression, Cropping, FFT and Echo).

Dynamic Bearing Pressure of Inverted T-type Retaining Walls Subjected to Seismic Motion (지진시 동토압을 받는 역 T형 옹벽의 접지압 산정에 관한 연구)

  • Lee, Jin-Sun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.16 no.2
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    • pp.35-45
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    • 2012
  • Pseudo static analysis using the Mononobe-Okabe method and numerical analysis considering a small strain nonlinearity from the soil were performed to determine the bearing pressure changes of the inverted T-type retaining wall subjected to earthquake motions. In many cases, an inverted 'T' type retaining wall of more than 10 m shows bearing capacity failure under earthquake conditions, despite showing sufficient bearing capacity during normal conditions. The most important reason for this is the change of the effective base area during an earthquake. In this paper, the change of the effective base area of an inverted 'T' type wall is analyzed by using finite difference element code (FLAC). In addition, the effect of dynamic bearing capacity coefficients (which has been suggested by several researchers but not adopted in current design codes and procedures) was verified.

A Study on the Implementation of Direct Digital Frequency Synthesizer using the synthesized Clock Counting Method to make the State of randomly Frequency Hopping (주파수 도약용 표본클럭 합성 계수 방식의 직접 디지틀 주파수 합성기 구현에 관한 연구)

  • 장은영;이성수;김원후
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.10
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    • pp.914-924
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    • 1991
  • It has been generally used for PLL(Phase Locked Loop) to be synthesized randomly chosen frequency state, but the PLL locking time was inevitable element. A direct digital synthesizer. Which makes output frequency directly in sine wave by a phase accumulating method, could be leiminate the defect, although a phase distortion in frequency spectrum. In order to improve this disadvantage, the phase accumulating method is reconsidered in the side of he output wave formula expression. A new mechanism is proposed, and it is constructed by a most suitable logic elements. The spectrum of synthesized sine waveform is simulated and compared with a measured value, and it’s the coherence frequency hoppong state with the PN(Pseudo Noise) code sequence is confirmed. In this results, the power levels of phase distortion harmonics are decreased to 10~25dB and bandwidths are increased to 420kHz.

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Performance Improvement of Downlink Real-Time Traffic Transmission Using MIMO-OFDMA Systems Based on Beamforming (Beamforming 기반 MIMO-OFDMA 시스템을 이용한 하향링크 실시간 트래픽 전송 성능 개선)

  • Yang Suck-Chel;Park Dae-Jin;Shin Yo-An
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.3 s.345
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    • pp.1-9
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    • 2006
  • In this paper, we propose a MIMO-OFDMA (Multi Input Multi Output-Orthogonal Frequency Division Multiple Access) system based on beamforming for performance improvement of downlink real-time traffic transmission in harsh channel conditions with low CIR (Carrier-to-Interference Ratio). In the proposed system, we first consider the M-GTA-SBA (Modified-Grouped Transmit Antenna-Simple Bit Allocation) using effective CSI (Channel State Information) calculation procedure based on spatial resource grouping, which is adequate for the combination of MRT (Maximum Ratio Transmission) in the transmitter and MRC (Maximum Ratio Combining) in the receiver. In addition, to reduce feedback information for the beamforming, we also apply QEGT (Quantized Equal Gain Transmission) based on quantization of amplitudes and phases of beam weights. Furthermore, considering multi-user environments, we propose the P-SRA (Proposed-Simple Resource Allocation) algorithm for fair and efficient resource allocation. Simulation results reveal that the proposed MIMO-OFDMA system achieves significant improvement of spectral efficiency in low CRI region as compared to a typical open-loop MIMO-OFDMA system using pseudo-orthogonal space time block code and H-ARQ IR (Hybrid-Automatic Repeat Request Incremental Redundancy).