• Title/Summary/Keyword: Mixed Network

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A New Approach for Detection of Gear Defects using a Discrete Wavelet Transform and Fast Empirical Mode Decomposition

  • TAYACHI, Hana;GABZILI, Hanen;LACHIRI, Zied
    • International Journal of Computer Science & Network Security
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    • v.22 no.2
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    • pp.123-130
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    • 2022
  • During the past decades, detection of gear defects remains as a major problem, especially when the gears are subject to non-stationary phenomena. The idea of this paper is to mixture a multilevel wavelet transform with a fast EMD decomposition in order to early detect gear defects. The sensitivity of a kurtosis is used as an indicator of gears defect burn. When the gear is damaged, the appearance of a crack on the gear tooth disrupts the signal. This is due to the presence of periodic pulses. Nevertheless, the existence of background noise induced by the random excitation can have an impact on the values of these temporal indicators. The denoising of these signals by multilevel wavelet transform improves the sensitivity of these indicators and increases the reliability of the investigation. Finally, a defect diagnosis result can be obtained after the fast transformation of the EMD. The proposed approach consists in applying a multi-resolution wavelet analysis with variable decomposition levels related to the severity of gear faults, then a fast EMD is used to early detect faults. The proposed mixed methods are evaluated on vibratory signals from the test bench, CETIM. The obtained results have shown the occurrence of a teeth defect on gear on the 5th and 8th day. This result agrees with the report of the appraisal made on this gear system.

Professional Mobility as a Factor of Professional Success of a Modern Specialist in the Conditions of Distance Learning

  • Semchuk, Bohdan;Havryliuk, Svitlana;Karnaukh, Lesia;Balakirieva, Viktoriia;Palshkova, Iryna;Leonova, Veronika;Bida, Olena
    • International Journal of Computer Science & Network Security
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    • v.22 no.8
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    • pp.260-268
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    • 2022
  • The article considers the training, competitiveness of specialists, professional mobility, professionalism and competence of specialists in the context of distance learning. The advantages of distance learning are shown. The characteristic features of distance learning in the preparation of students and in the implementation of these technologies in the educational process of higher educational institutions are determined. Competitiveness, professional mobility, professionalism and competence of a specialist are qualities that determine a person's life and work success. Professional mobility is interpreted as a systemic quality of a specialist's personality, which includes a whole range of knowledge, skills, abilities, personal qualities, value orientations, and so on. The vision of mobility of specialists by foreign scientists is presented. It is noted that the classification of professional mobility presented in the article makes it possible to organize various movements from a single position, to present them as separate manifestations of the general process of professional and pedagogical mobility, to determine which type of mobility ensures the performance of certain social functions. It was found that mobility can be differentiated into differentiated and intergeneration. According to the subject, individual and group mobility are distinguished; according to the direction - internal and external. The classification of employees according to their attitude to mobility is shown, which can be divided into the following groups: actually mobile; potentially mobile; actually stable; potentially stable.

Multimedia Technologies for Teaching Musical Art under Present-day Conditions

  • Svitlana Huralna;Nataliia Demianko;Nataliia Sulaieva;Viktoriia Irkliienko;Tetiana Horokhivska
    • International Journal of Computer Science & Network Security
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    • v.24 no.5
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    • pp.165-171
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    • 2024
  • The processes of society's informatization and digitalization necessitate the widespread use of new pedagogical technologies. Through these technologies, comprehensive disclosure of didactic functions of new methods of educational activity and the realization of the potential and creative potential. The use of information and computer multimedia technologies in teaching music art is especially relevant in the intensification of the development of interactive technologies, the transition to mixed forms of learning, and a period of socio-economic and sociopolitical upheavals. The study aims to substantiate the theoretical and applied principles of the analysis of multimedia technology learning musical art in modern conditions and assess the status and trends in their use in conducting educational activities. The study uses general scientific and unique methods of economic analysis, in particular, analysis and synthesis, analogy and comparison, generalization and systematization, and graphic ways. Regarding the results of the study of multimedia technologies for teaching musical art in current conditions, it was found that they contribute to the development of the seeker's creative, creative, and cognitive activity, have a positive impact on learning material, and diversify the educational process. Multimedia technologies such as presentations, programs for watching a video, listening to audio, music and singing karaoke, electronic encyclopedias, and Internet resources are proven to be the most used in music education. They have several qualitative and quantitative advantages, manifested in the possibilities of audio-visual presentation of educational material and significantly higher information density. It is suggested to strengthen the use of such computer programs as Microsoft Word, Ahead Nero, Finale, Adobe Audition, Sound Forge, and Microsoft PowerPoint for musical art classes.

Development of Forest Road Network Model Using Digital Terrain Model (수치지형(數値地形)모델을 이용(利用)한 임도망(林道網) 배치(配置)모델의 개발(開發))

  • Lee, Jun Woo
    • Journal of Korean Society of Forest Science
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    • v.81 no.4
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    • pp.363-371
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    • 1992
  • This study was aimed at developing a computer model to determine rational road networks in mountainous forests. The computer model is composed of two major subroutines for digital terrain analyses and route selection. The digital terrain model(DTM) provides various information on topographic and vegetative characteristics of forest stands. The DTM also evaluates the effectiveness of road construction based on slope gradients. Using the results of digital terrain analyses, the route selection subroutine, heuristically, determines the optimal road layout satisfying the predefined road densities. The route selection subroutine uses the area-partitioning method in order to fully of roads. This method leads to unbiased road layouts in forest areas. The size of the unit partitiones area can be calculated as a function of the predefined road density. In addition, the user-defined road density of the area-partitioning method provides flexibility in applying the model to real situations. The rational road network can be easily achived for varying road densities, which would be an essential element for network design of forest roads. The optimality conditions are evaluated in conjuction with longitudinal gradients, investment efficiency earthwork quantity or the mixed criteria of these three. The performance of the model was measured and, then, compared with those of conventional ones in terns of average skidding distance, accessibility of stands, development index and circulated road network index. The results of the performance analysis indicate that selection of roading routes for network design using the digital terrain analysis and the area-partitioning method improves performance of the network design medel.

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A preliminary assessment of high-spatial-resolution satellite rainfall estimation from SAR Sentinel-1 over the central region of South Korea (한반도 중부지역에서의 SAR Sentinel-1 위성강우량 추정에 관한 예비평가)

  • Nguyen, Hoang Hai;Jung, Woosung;Lee, Dalgeun;Shin, Daeyun
    • Journal of Korea Water Resources Association
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    • v.55 no.6
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    • pp.393-404
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    • 2022
  • Reliable terrestrial rainfall observations from satellites at finer spatial resolution are essential for urban hydrological and microscale agricultural demands. Although various traditional "top-down" approach-based satellite rainfall products were widely used, they are limited in spatial resolution. This study aims to assess the potential of a novel "bottom-up" approach for rainfall estimation, the parameterized SM2RAIN model, applied to the C-band SAR Sentinel-1 satellite data (SM2RAIN-S1), to generate high-spatial-resolution terrestrial rainfall estimates (0.01° grid/6-day) over Central South Korea. Its performance was evaluated for both spatial and temporal variability using the respective rainfall data from a conventional reanalysis product and rain gauge network for a 1-year period over two different sub-regions in Central South Korea-the mixed forest-dominated, middle sub-region and cropland-dominated, west coast sub-region. Evaluation results indicated that the SM2RAIN-S1 product can capture general rainfall patterns in Central South Korea, and hold potential for high-spatial-resolution rainfall measurement over the local scale with different land covers, while less biased rainfall estimates against rain gauge observations were provided. Moreover, the SM2RAIN-S1 rainfall product was better in mixed forests considering the Pearson's correlation coefficient (R = 0.69), implying the suitability of 6-day SM2RAIN-S1 data in capturing the temporal dynamics of soil moisture and rainfall in mixed forests. However, in terms of RMSE and Bias, better performance was obtained with the SM2RAIN-S1 rainfall product over croplands rather than mixed forests, indicating that larger errors induced by high evapotranspiration losses (especially in mixed forests) need to be included in further improvement of the SM2RAIN.

Partial EBG Structure with DeCap for Ultra-wideband Suppression of Simultaneous Switching Noise in a High-Speed System

  • Kwon, Jong-Hwa;Kwak, Sang-Il;Sim, Dong-Uk;Yook, Jong-Gwan
    • ETRI Journal
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    • v.32 no.2
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    • pp.265-272
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    • 2010
  • To supply a power distribution network with stable power in a high-speed mixed mode system, simultaneous switching noise caused at the multilayer PCB and package structures needs to be sufficiently suppressed. The uni-planar compact electromagnetic bandgap (UC-EBG) structure is well known as a promising solution to suppress the power noise and isolate noise-sensitive analog/RF circuits from a noisy digital circuit. However, a typical UC-EBG structure has several severe problems, such as a limitation in the stop band's lower cutoff frequency and signal quality degradation. To make up for the defects of a conventional EBG structure, a partially located EBG structure with decoupling capacitors is proposed in this paper as a means of both suppressing the power noise propagation and minimizing the effects of the perforated reference plane on the signal quality. The proposed structure is validated and investigated through simulation and measurement in both frequency and time domains.

Spinnability and Rheological Properties of Sols Derived from Si(OC2H5)4 and Zr(O-nC3H7)4 Solutions

  • HAN, SANG-MOK
    • Journal of Industrial Technology
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    • v.20 no.A
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    • pp.29-36
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    • 2000
  • The shape of the polymers in the mixed alkoxide solutions of Si(OC2H5)4 and Zr(n-OC3H7)4 with various water contents (1, 2, 4, and 8 in molar ratio to alkoxide, r) and catalysts was examined by rheological measurements, and its relation with fiber drawing behavior of the solutions was described. It was found that fibers could be drawn in the viscosity range 1~100 P from the acid-catalyzed solutions with lower water contents of the molar ratio H2O/alkoxide, $r{\leq}2$. On the other hand, no fiber could be drawn from the acid-catalyzed solutions including a large amount of water($r{\geq}4$) and the base-catalyzed solutions. The relation between the intrinsic viscosity [${\eta}$] and number average molecular weight ${\bar{M}}n$, namely $[{\eta}]=K{\bar{M}}n{\alpha}$, has shown that the acid-catalyzed spinnable solution (r = 1 and 2) had linear polymers where the exponent a's were about 0.56 and 0.81, whereas non-spinnable solutions (r = 4 and 8) had three dimensional network polymers or spherical particles where the exponent a's were 0.41-0.51 and 0.35.

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Networked Creativity on the Censored Web 2.0: Chinese Users' Twitter-based Activities on the Issue of Internet Censorship

  • Xu, Weiai Wayne;Feng, Miao
    • Journal of Contemporary Eastern Asia
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    • v.14 no.1
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    • pp.23-43
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    • 2015
  • In most of the world, the current trend in information technology is for open data movement that promotes transparency and equal access. An opposite trend is observed in China, which has the world's largest Internet population. The country has implemented sophisticated cyber-infrastructure and practices under the name of The Golden Shield Project (commonly referred to as the Great Firewall) to limit access to popular international web services and to filter traffic containing 'undesirable' political content. Increasingly, tech-savvy Chinese bypass this firewall and use Twitter to share knowledge on censorship circumvention and encryption to collectively troubleshoot firewall evasion methods, and even mobilize actions that border on activism. Using a mixed mythological approach, the current study addresses such networked knowledge sharing among citizens in a restricted web ecosystem. On the theoretical front, this study uses webometric approaches to understand change agents and positive deviant in the diffusion of censorship circumvention technology. On policy-level, the study provides insights for Internet regulators and digital rights groups to help best utilize communication networks of positive deviants to counter Internet control.

OLAP4R: A Top-K Recommendation System for OLAP Sessions

  • Yuan, Youwei;Chen, Weixin;Han, Guangjie;Jia, Gangyong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.6
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    • pp.2963-2978
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    • 2017
  • The Top-K query is currently played a key role in a wide range of road network, decision making and quantitative financial research. In this paper, a Top-K recommendation algorithm is proposed to solve the cold-start problem and a tag generating method is put forward to enhance the semantic understanding of the OLAP session. In addition, a recommendation system for OLAP sessions called "OLAP4R" is designed using collaborative filtering technique aiming at guiding the user to find the ultimate goals by interactive queries. OLAP4R utilizes a mixed system architecture consisting of multiple functional modules, which have a high extension capability to support additional functions. This system structure allows the user to configure multi-dimensional hierarchies and desirable measures to analyze the specific requirement and gives recommendations with forthright responses. Experimental results show that our method has raised 20% recall of the recommendations comparing the traditional collaborative filtering and a visualization tag of the recommended sessions will be provided with modified changes for the user to understand.

Design of the Digital Neuron Processor (디지털 뉴런프로세서의 설계에 관한 연구)

  • Hong, Bong-Wha;Lee, Ho-Sun;Park, Wha-Se
    • 전자공학회논문지 IE
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    • v.44 no.3
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    • pp.12-22
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    • 2007
  • In this paper, we designed of the high speed digital neuron processor in order to digital neural networks. we designed of the MAC(Multiplier and Accumulator) operation unit used residue number system without carry propagation for the high speed operation. and we implemented sigmoid active function which make it difficult to design neuron processor. The Designed circuits are descripted by VHDL and synthesized by Compass tools. we designed of MAC operation unit and sigmoid processing unit are proved that it could run time 19.6 nsec on the simulation and decreased to hardware size about 50%, each order. Designed digital neuron processor can be implementation in parallel distributed processing system with desired real time processing, In this paper.