Earticle

A generalized S transform based on energy normalized windows is presented, which avoids the weighting effect of existing S transform influenced by the time-frequency spectral energy. The transform can reflect the spectral energy distribution of different frequency components while maintaining the excellent time-frequency resolution. While TT transform is a new approach to process non-stationary signal based on S transform, which has differential concentration for different frequency components, and lower frequency components can be suppressed through extracting the TT spectrum’s diagonal elements. However, this method has a deficiency that part of high frequency interference is retained during processing low frequency signal. Therefore, time-frequency filtering based on the generalizing S transform is used to suppress the high frequency interference and TT transform is adopted to suppress the low frequency contents. Finally, this method is used to process seismic data, the result demonstrates the effective of combining energy normalized S transform and TT transform.

This text starts with the short time Fourier transform and continuous wavelet transform to deduce the generalized S-transformation. From the point of generation views, we analyzed a relative relationship between generalized S-transformation and the short time Fourier transform, and the other relative relationship between generalized S transform and continuous wavelet transform. The article gives the definition of “the gene mutation of formula” and “the genetic restructuring of formula”, and introduces the deriving process of the two core concept. Theoretical analyses show that generalized S-transformation inherited the desirable characteristics in short time Fourier transform which use the window function to select suitable signal. Through genome sequencing of specific parameters, generalized S-transformation has a stronger adaptation that the time-frequency window could make real-time adjusting of frequency. Moreover, generalized S-transformation breaks out limitation that the wavelet function has to content the admissible conditions. From the point of gene mutation, we give the definition of “the gene mutation of formula”. Based on the structure form of wavelet functions, we define the generalized S-transformation with a wider domain of definition. Generalized S-transformation inherited the desirable characteristics of the short time Fourier transform and continuous wavelet transform. It has great utility and flexibility in analyzing non-stationary signals.

S-transform is a new time-frequency analysis method, which is deduced from short-time Fourier transform and continue Wavelet transform. It has much better performance than traditional time-frequency method. Therefore, in this paper, the basic principle of is briefly introduced and the relationships between is analyzed by theoretical derivation. According to the simulation experiments, the time-frequency space characteristics of short-time Fourier transform, Wigner-Ville distribution and S-transform are contrasted. As the results shown, the window of S-transform has a progressive frequency dependent resolution. So the S-transform has a great flexibility and utility in the processing of non-stationary signal. Compare with the time-frequency spectrum of three different analysis methods under various noise conditions, it is obvious that S-transform has much better anti-noise performance than that of traditional methods for non-stationary signal processing. Based on the superior time-frequency resolution, the S-transform spectrum can be used to describe the structure of incoming signal effectively.

A new approach to modified S-transform based non-stationary power signal de-noising is presented in this paper. Modified S-transform is employed in de-noising techniques to separate high frequency noise which is prevalent in practical signals like power disturbance signals from the low frequency undistorted signals. In this we have tried to bring out the advantage of the modified S-transform and its application in power signal analysis through various examples. S-transform with modified Gaussian window is found to provide excellent normalized frequency contours of the power signal disturbances suitable for accurate detection, localization and classification. The implementation of the de-noising scheme has been carried out in FPGA using non-stationary power signals.

Power quality (PQ) disturbances recognition is the foundation of power quality analysis and improvement. In order to improve the classification accuracy and efficiency, a new classification approach based on modified Fourier neural networks (FNN) and Hyperbolic S-transform (HST) was designed for PQ disturbances classification. HST has better a time-frequency resolution than S-transform. The features extracted from HST results compose the input vectors of classifier. The DFP emendatory Quasi-Newton method is used to improve the learning ability of FNN and avoid local minimum problem. Three modified FNNs were used to construct a classifier with the structure of decision tree. Six types of disturbances with different noise ratio were simulated to test the classification ability of the new approach. Simulation results show that the new classifier has better classification accuracy than other classifiers based on BP neural networks and Fourier neural networks. The new approach is effective.

The target echo of downward-looking radar can be simulated by a multicomponent Chirp signal with noise, which makes signal detection and parameter estimation a very important processing. Aiming at the problems of error detection caused by the cross-terms in WVD-Hough methods and other modified WVD distribution methods, and low precision due to poor time-frequency concentration in S-Hough transform, this paper proposed a signal detection and parameters estimation algorithm of multicomponent Chirp signals based on generalized S-transform. Firstly calculate the time-frequency distribution of multicomponent Chirp signals by generalized S-transform, then execute Hough transform to the generalized S-transform TFD on the time-frequency plane to implement signal detection and parameter estimation to the multicomponent Chirp signals. The simulation results show that this algorithm has good performance in detection the multicomponent Chirp signals in low SNR case.

본 논문은 16-QAM과 같은 스펙트럼 효율적인 nonconstant modulus 신호 전송에서 채널에서 발생되는 찌 그러짐에 의한 부호간 간섭을 보상하기 위한 SE-MMA (Signed Error-Multiple Modulus Algorithm) 블라인드 적응 등화 알고리즘에서 오차 신호의 비선형성을 이용한 가변 적응 스텝 크기를 적용하여 등화 성능을 개선할 수 있는 VSS_SE-MMA (Varying Step Size_SE-MMA)에 관한 것이다. SE-MMA는 기존 MMA 적응 등화기의 탭 계수 갱 신시 오차 신호의 극성만을 이용하므로서 연산량을 줄이기 위하여 등장하였으나 이로 인한 등화 성능이 열화되는 문제 점이 있다. VSS_SE-MMA에서는 이와 같은 SE-MMA의 문제점을 개선하기 위해 오차 신호를 고려한 스텝의 크기를 변화시켜 적응 등화기의 탭 계수 갱신에 이용하므로서 이의 성능을 시뮬레이션을 통해 확인하였다. 이의 개선된 성능 을 확인하기 위하여 등화기 출력 성상도, 잔류 isi, 최대 찌그러짐과 MSE, 채널의 신호대 잡음비에 따른 SER을 적용 하였으며, 시뮬레이션 결과 VSS_SE-MMA 알고리즘이 SE-MMA보다 수렴 속도에서 거의 비슷하면서도 정상 상태에 서 모든 성능 지수에서 개선됨을 확인하였다.

This paper related with the VSS_SE-MMA (Varying Step Size_Signed Error-MMA) which possible to improving the equalization performance that employing the varying adaptive step size based on the nonlinearities of error signal of SE-MMA (Signed Error-MMA), compensates the intersymbol interference by distortion occurs at the communication channel, in the transmitting the spectral efficient nonconstant modulus signal such as 16-QAM. The SE-MMA appeared to the reducing the computational arithematic operation using the polarity of error signal in the updating the tap coefficient of present MMA adaptive equalizer, but have a problem of equalization performance degradation. The VSS_SE-MMA improves the problem of such SE-MMA, using the varying step size consider the error signal in the update the adaptive equalizer tap coefficient, and its improved performance were confirmed by simulation. For this, the output signal constellation of equalizer, the residual isi and maximum distortion, MSE and SER were applied. As a result of computer simulation, it was confirmed that the VSS_SE-MMA algorithm has nearly same in convergence speed and has more good performance in every performance index at the steady state.

본 연구는 꼬레아 정부의 가장 대표적인 프로젝트인 새로운 경제개발 모델로서의 야차이 지식도시에 대해 다룬다. 2010년부터 에콰도르는 전통적 경제모델인 원자재수출경제를 탈피하여 지식경제로의 전환을 시도하고 있다. 야차이 지식도시 건설 프로젝트를 통하여 국가 경제와 사회 개선을 추구하며, 1차 산품 수출경제를 지식기반의 경제와 사회로 변화시켜 수막 카우사이를 실천하는 것이다. 야차이 프로젝트는 높은 원자재 수출 의존도를 개선하고, 첨단기술산업 클러스터 형성을 통해 고급 일자리의 창출과 국토의 균형개발을 도모하는 프로젝트이다. 에콰도르 정부가 대덕연구단지의 한국형 과학기술단지 개발 정책에서 영감을 얻어 이와 유사한 야차이 지식도시 건설 프로젝트를 개발하였다. 그러나 이 프로젝트가 에콰도르에 알맞은 모델인가에 대한 논란의 여지는 있으며, 이는 한국과 에콰도르는 발전과정에 많은 차이가 있기때문이다. 이 프로젝트는 정치제도와 문화적 차이를 비롯하여 사회조직 형태가 본질적으로 다르다는 것을 감안하여 에콰도르 현실에 맞고 라틴아메리카 지역의 특성이 추진전략에 적절히반영되어야 한다. 에콰도르의 산업발전 정도와 과학기술의 현실을 감안하다면 이 프로젝트가의미 있는 성과를 도출하기 위해서 해결해야 할 과제들이 아직 많이 있다. 지식도시 건설의 성패 여부는 정권교체의 여부와 관계없이 지속적인 정치적 지원과 정부의 재정적 지원에 달려있다. 야차이 프로젝트는 국제시장의 변동에 의존된 원자재수출경제에서 지식경제로 전환하기위한 에콰도르 정부의 과감하고 혁신적인 시도이다.

This article discusses the most emblematic project of the governmentof Correa, Yachay Knowledge City as a new model of economic development. Since 2010 Ecuador has been attempting to transform their traditional economymodel of raw materials exportation to that of knowledge. To achieve this they areconstructing the project Yachay Knowledge City of which proposes to better thesociety and economy, by transforming the extractive economy to an economybased in knowledge with the motive of reaching Good Living. The Yachay Projectproposes to achieve different objectives such as, correcting the highdependency of raw matter exportation; creation of quality employment with thedevelopment of technology and the balanced development of their nationalterritory. Inspired by the development politics from the Science and Researchpark of Daedeok Research complex in Korea, Ecuador’s government decidedto take on a similar project with the erection of Yachay Knowledge City. However,some doubts are present such as the appropriateness of this project due to thegreat differences in process development between Korea and Ecuador. TheProject needs to adapt to Ecuador’s reality and take into account the LatinAmerican region characteristics in their strategies for implementation alsoconsider the differences in the political system, culture, and the social hierarchy. Seeing the current state of Science and industrial development including thetechnological advances in Ecuador, there are still many tasks they must completebefore the project can bear substantial results. The success or failure of theconstruction of Yachay Knowledge City will depend on political backing andgovernmental financing remaining constant no matter the changes ingovernment. Yachay Project is a daring and innovative attempt that Ecuador’sgovernment is using to transform their raw matter export economy, which is always dependent on international pricing to an economy that deals knowledge.

Flashover of power transmission line insulators due to contamination is a major threat to the reliable operation of power system. This paper deals with the analysis of leakage current characteristics of polymeric insulator using S-Transform technique in order to develop a better diagnostic tool to identify the surface condition of outdoor polymeric insulators. In this work, experiments were carried out on 11 kV silicone rubber insulator under AC voltage at different pollution levels. Moving average technique was adopted to find the trend followed by LC peak at different relative humidity conditions. S-Transform was used to find the relationship between energy and frequency content of the leakage current signal with respect to increase in pollution level over a period of time. From the S-Transform time-frequency contour analysis, point of transition to severe arcing due to increase in pollution and its thershold limit were evaluated. Reported results show that the surface condition of insulators could be easily identified from the S-Transform time-frequency analysis of leakage current signals.

Recently, by increasing of devices which are sensitive to power quality, the deterioration of power quality has been accelerated. For this reason, the social and economic losses are increased. So not only correct measurement and evaluation, but also countermeasure for improvement of power quality is surely necessary for both electric power supplier and consumer. In this paper, the discrimination algorithm for events and variation occurred in distribution systems using S-transform is proposed. Firstly, we review for events and variations that occur in distribution system. Next, we simulate events and variations on various conditions using ElectroMagnetic Transient Program(EMTP). For the simulation, the IEEE 13 Node Test Feeder and KEPCO's distribution system is modeled. Finally, for the analysis, a modified wavelet transform known as S-transform is adopted to find out the characteristics of each events and variations.

S-Transform은 어떠한 신호의 변환 후 원 신호의 주파수 및 크기를 모두 알 수 있는 효과적인 방법이다. 따라서, 본 논문에서는 IEEE에서 제시한 전력품질 이벤트의 분류를 기반으로 S-Transform 기반의 전력품질 이벤트의 측정지수를 제안하였다. 제안한 측정지수의 효율성을 검증하기 위하여, ATPDraw를 이용하여 고장 및 비선형 부하를 모의하였다. 그 결과를 이용하여 S-Transform을 수행하여 제안된 측정지수의 효율성을 검증하였다.

Recently, by increasing of devices which are sensitive to power quality, microprocessor and power electronics, the deterioration of power quality is accelerated. Accordingly, various methods for analysis, detection, compensation and countermeasure on power quality are proposed. For this, the study of distinction of various disturbances and fault which is occurred in power system is necessary to prior. Therefore, in this paper, the classification algorithm among steady state and single line to ground fault which is commonly occurred fault is proposed using S-Transform.

One proposes an approach to fractional Fourier's transform, or Fourier's transform of fractional order, which applies to functions which are fractional differentiable but are not necessarily differentiable, in such a manner that they cannot be analyzed by using the so-called Caputo-Djrbashian fractional derivative. Firstly, as a preliminary, one defines fractional sine and cosine functions, therefore one obtains Fourier's series of fractional order. Then one defines the fractional Fourier's transform. The main properties of this fractal transformation are exhibited, the Parseval equation is obtained as well as the fractional Fourier inversion theorem. The prospect of application for this new tool is the spectral density analysis of signals, in signal processing, and the analysis of some partial differential equations of fractional order.

In this paper, we give some sums involving the generalized harmonic numbers H^r_n (σ) and the (q, r)-binomial coefficient $\left({L \atop k}\right)_{q,r}$ by using Euler's transform. For example, for (c, r) ∈ ℤ⁺ × ℝ⁺, $${\sum_{n=0}^{\infty}}{\sum_{k=0}^{n}}\,(-1)^k\,\left({n+r \atop n-k}\right)\frac{c^{n+1}H^{r-1}_k({\sigma})}{(n+1)(1+c)^{n+1}}=-(c+{\frac{1}{{\sigma}}})\,{\ln}\,(1+c{\sigma})+c,$$ and $${\sum_{k=0}^{n}}\left({n \atop k}\right)\left({L \atop k}\right)_{2,r}={\sum_{j=0}^{n}}{\sum_{k=0}^{j}}(-1)^k\left({j-k+2L+r \atop j-k}\right)\left({r \atop n-j}\right)\left({L \atop k}\right)_2,$$ where σ is appropriate parameter, H^r_n (σ) is the generalized hyperharmonic number of order r and $\left({L \atop k}\right)_q$ is the q-binomial coefficient.

Constructed around the activity theoretic view of human being and human learning (Leon’tev, 1981; Engestrom, 1999), this case study documents a high school English teacher’s participation in a six-month intensive teacher education program and how the program has influenced her English learning and instruction. The main interest of the study was to explore how the teacher, as an agent of an activity system, constructed her participation in the program and whether or not and how her program participation rendered transformations in her English learning and teaching practices. Data were collected through the participant’s diaries, interviews, and classroom observations and analyzed following the principles of grounded content analysis (Bogdan & Biklen, 2007). The overall findings disclosed that the participant experienced transformation more as a learner than as a teacher. More in-depth data analysis revealed that these findings were a dialogic interplay between the goals the participant had regarding her program participation, what she mediated during her program participation, and the social and institutional contexts she had been functioning. Lastly, the findings from this study are discussed from an activity theoretic view of teacher learning and thier future implications for teacher education programs.

The classical Hardy Theorem on R states that a function f and its Fourier transform cannot be simultaneously very small; this fact was generalized by Miyachi in terms of L¹ + L^∞ and log⁺-functions. In this paper, we consider the k-Hankel transform, which is a deformation of the Hankel transform by a parameter k > 0 arising from Dunkl's theory. We study Miyachi's theorem for the k-Hankel transform on ℝ^d.

In this paper, differential transform method (DTM) is considered to obtain solution to the generalized Fisher's equation. This method is easy to apply and because of high level of accuracy can be used to solve other linear and nonlinear problems. Furthermore, is capable of reducing the size of computational work. In the present work, the generalization of the two-dimensional transform method that is based on generalized Taylor's formula is applied to solve the generalized Fisher equation and numerical example demonstrates the accuracy of the present method.