• 제목/요약/키워드: Mixed Network

검색결과 532건 처리시간 0.022초

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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    • 제22권2호
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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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    • 제22권8호
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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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    • 제24권5호
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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.

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

  • 이준우
    • 한국산림과학회지
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    • 제81권4호
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    • pp.363-371
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    • 1992
  • 본(本) 연구(硏究)는 산지(山地)에서 합리적(合理的)으로 임도망(林道網)을 배치(配置)하는 모델을 개발(開發)할 목적(目的)으로 수행(遂行)되었다. 본(本) 연구(硏究)의 임도망(林道網) 배치(配置)모델은 수치지형해석(數値地形解析)과 노선선정(路線選定)의 두 부분으로 구성되어 있다. 본(本) 모델에서는 수치지형(數値地形) 모델을 통하여 지황(地況) 및 임황(林況)에 대한 정보(情報)를 제공(提供)할 뿐만 아니라 종단구배(縱斷勾配)를 바탕으로 임도개설(林道開設)의 적정성(適正性)을 평가(評價)할 수 있다. 이러한 수치지형해석(數値地形解析)의 결과(結果)를 이용(利用)하여 계획(計劃)된 임도밀도(林道密度)를 만족(滿足)시키는 적정임도망(適正林道網)을 수립하게 된다. 노선선정(路線選定)에서는 임도간격(林道間隔)에 따라 노선(路線)의 선택(選擇) 및 임도배치(林道配置)를 위해 면적분할법(面積分割法)을 적용하였으며, 분할면적(分割面積)의 크기는 임도밀도(林道密度)에 의해 산출(算出)된다. 이 면적분할법(面積分割法)은 임도(林道)가 편재(偏在)되어 배치(配置)되지 않도록 해줄 뿐만 아니라 임도계획(林道計劃) 담당자가 융통성(融通性)있게 임도밀도(林道密度)를 조절(調節)하여 배치계획(配置計劃)을 수립할 수 있다. 즉, 임도망(林道網) 계획(計劃)에 있어서의 필수요소인 임도밀도(林道密度)를 다양하게 적용하여 봄으로써 합리적(合理的)인 임도망(林道網)을 구축할 수 있는 것이다. 또한, 노선선정기준(路線選定基準)은 종단구배(縱斷句配), 투자효과(投資效果), 토공량(土工量) 및 이상의 세가지 기준(基準)의 조합(組合)과 같은 4가지 기준(基準)을 적용(適用)하였다. 임도망(林道網) 배치(配置)모델의 현지(現地) 적용가능성(適用可能性)을 평가(評價)하기 위해 평균집재거리(平均集材距離), 집재가능성(集材可能性), 개발지수(開發指數), 순환로망지수(循環路網指數) 등과 같은 지표(指標)를 사용(使用)하였으며, 임도망(林道網) 계획시(計劃時) 노선(路線)을 선정(選定)함에 있어 수치지형분석(數値地形分析)과 면적분할법(面積分割法)을 이용(利用)하는 것이 효과적(效果的)인 것으로 판단(判斷)된다.

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

  • 능엔 호앙 하이;정우성;이달근;신대윤
    • 한국수자원학회논문집
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    • 제55권6호
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    • pp.393-404
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    • 2022
  • 위성에서 보다 미세한 공간 분해능으로 신뢰할 수 있는 지상 강우 관측은 도시 수문학적 및 미시적 농업 수요에 필수적이다. 전통적으로 "톱다운" 접근 방식 기반 위성 강우 산출물이 널리 사용되고 있지만 공간 분해능에 한계가 있다. 본 연구는 C-밴드 SAR Sentinel-1 위성 데이터(SM2RAIN-S1)에 적용되는 매개 변수화된 SM2RAIN 모델인 강우 추정을 위한 새로운 "상향식" 접근 방식의 가능성을 평가하여 중부지방에 대한 높은 공간 분해능 지상 강우 추정치(0.01° 그리드/6일)를 생성하는 것을 목표로 한다. 그것의 성능은 중부지방 두 개의 다른 하위 지역, 즉 혼합 산림 중심, 중간 하위 지역, 그리고 경작 중심, 서해안 하위 지역의 1년 기간 동안 기존의 재분석 프로덕트와 우량계 네트워크의 각각의 강우 데이터를 사용하여 공간 및 시간적 가변성에 대해 평가되었다. 평가결과에 따르면 SM2RAIN-S1 프로덕트는 중부지방의 일반적인 강우 패턴을 포착할 수 있고, 서로 다른 토지 피복으로 지역 규모에서 공간 분해능 강우량 측정 가능성을 보유할 수 있으며, 강우량 관측치에 대한 편중된 강우량 추정치가 제공되었다. 또한 SM2RAIN-S1 강우량은 피어슨의 상관 계수(R = 0.69)를 고려할 때 혼합림에서 더 우수했으며, 이는 혼합림에서 토양 수분과 강우의 시간 역학을 포착하는 데 6일 SM2RAIN-S1 데이터의 적합성을 암시했다. 그러나, RMSE와 바이어스 측면에서, 혼합림보다는 경작지의 SM2RAIN-S1 강우 생성물에서 더 나은 성능을 얻었으며, 이는 높은 증발증산 손실(특히 혼합림)에 의해 유도된 더 큰 오류를 SM2RAIN의 추가 개선에 포함해야 한다는 것을 나타낸다.

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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    • 제32권2호
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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

  • 한상목
    • 산업기술연구
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    • 제20권A호
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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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    • 제14권1호
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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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    • 제11권6호
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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.

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

  • 홍봉화;이호선;박화세
    • 전자공학회논문지 IE
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    • 제44권3호
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    • pp.12-22
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    • 2007
  • 본 논문에서는 잉여수체계(Residue Number System)를 이용하여 고속의 디지털 신경회로망을 제안하고 이를 구현하기 위한 중요연산부인 고속의 디지털 뉴런프로세서를 설계하였다. 설계된 디지털 뉴런프로세서는 잉여수계를 이용한 MAC 연산기와 혼합계수 변환을 이용한 시그모이드 함수 연산 부로 구성되며, 설계된 회로는 VHDL로 기술하였고 Compass 툴로 합성하였다. 실험결과, 본 논문에서 설계한 디지털 뉴런프로세서는 19.2nsec의 속도를 보였으며, 실수연산기로 설계한 뉴런프로세서에 비하여 약 50%정도 하드웨어 크기를 줄일 수 있었다. 본 논문에서 설계한 뉴런프로세서는 실시간 처리를 요하는 병렬분산처리 시스템에 적용될 수 있을 것으로 기대된다.