http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Fathy, Khairy (검색결과 196 건)
- 무료
- 기관 내 무료
- 유료
-
-
Fathy, I.,Amory-Mazaudier, C.,Fathy, A.,Mahrous, A. M.,Yumoto, K.,Ghamry, E. American Geophysical Union 2014 JOURNAL OF GEOPHYSICAL RESEARCH. SPACE PHYSICS Vol.119 No.5
In this paper we study the planetary magnetic disturbance during the magnetic storm occurring on 5 April 2010 associated with high-speed solar wind stream due to a coronal hole following a coronal mass ejection. We separate the magnetic disturbance associated to the ionospheric disturbance dynamo (Ddyn) from the magnetic disturbance associated to the prompt penetration of magnetospheric electric field (DP2). This event exhibits different responses of ionospheric disturbance dynamo in the different longitude sectors (European-African, Asian, and American). The strongest effect is observed in the European-African sector. The Ddyn disturbance reduces the amplitude of the daytime H component at low latitudes during four consecutive days in agreement with the Blanc and Richmond's model of ionospheric disturbance dynamo. The amplitude of Ddyn decreased with time during the 4days. We discuss its diverse worldwide effects. The observed signature of magnetic disturbance process in specific longitude sector is strongly dependent on which Earth's side faces the magnetic storms (i.e., there is a different response depending on which longitude sector is at noon when the SSC hits). Finally, we determined an average period of 22h for Ddyn using wavelet analysis.
-
A Novel Quasi-Resonant Snubber-Assisted ZCS-PWM DC-DC Converter with High Frequency Link
Fathy, Khairy,Kwon, Soon-Kurl The Korean Institute of Power Electronics 2007 JOURNAL OF POWER ELECTRONICS Vol.7 No.2
In this paper, a novel type of auxiliary switched capacitor assisted edge resonant soft switching PWM resonant DC-DC converter with two simple auxiliary commutation lossless inductor snubbers is presented. The operation principle of this converter is described using the switching mode equivalent circuits. This newly developed multi resonant DC-DC converter can regulate its DC output AC power under a principle of constant frequency edge-resonant soft switching commutation by an asymmetrical PWM duty cycle control scheme. The high frequency power regulation and actual power characteristics of the proposed soft switching PWM resonant DC-DC converter are evaluated and discussed. The operating performances of the newly proposed soft switching inverter are represented based on simulation results from an applications point of view.
-
Fathy, Khairy,Kwon, Soon-Kurl,Nakaoka, Mutsuo The Korean Institute of Power Electronics 2007 JOURNAL OF POWER ELECTRONICS Vol.7 No.3
In this paper, a novel type auxiliary active edge resonant snubber assisted zero current soft switching pulse modulation Single-Ended Push Pull (SEPP) series load resonant inverter using IGBT power modules is proposed for cost effective consumer high-frequency induction heating (IH) appliances. Its operating principle in steady state is described by using each switching mode's equivalent operating circuits. The new multi resonant high-frequency inverter with series load resonance and edge resonance can regulate its high frequency output power under a condition of a constant frequency zero current soft switching (ZCS) commutation principle on the basis of the asymmetrical pulse width modulation (PWM) control scheme. Brand-new consumer IH products using the proposed ZCS-PWM series load resonant SEPP high-frequency inverter using IGBTs is evaluated and discussed as compared with conventional high-frequency inverters on the basis of experimental results. In order to extend ZCS operation ranges under a low power setting PWM as well as to improve efficiency, the high frequency pulse density modulation (PDM) strategy is demonstrated for high frequency multi-resonant inverters. Its practical effectiveness is substantially proved from an application point of view.
-
Fathy, Khairy,Morimoto, Keiki,Suh, Ki-Young,Kwon, Soon-Kurl,Nakaoka, Mutsuo The Korean Institute of Electrical Engineers 2007 Journal of Electrical Engineering & Technology Vol.2 No.1
This paper presents a new circuit topology of active edge resonant snubbers assisted half-bridge soft switching PWM inverter type DC-DC high power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed half-bridge high frequency PWM inverter with a high frequency planar transformer link in addition to input DC busline side power semiconductor switching devices for PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC buslines can achieve ZCS turn-on and ZVS turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, a high switching frequency IGBTs can be actually selected in the frequency range of 60 kHz under the principle of soft switching. The performance evaluations of the experimental setup are illustrated practically. The effectiveness of this new converter topology is proved for such low voltage and large current DC-DC power supplies as DC bus feeding from a practical point of view.
-
Reinforced Connection for Upgrading Strength and Efficiency of Single Angle Tension Members
Fathy Abdelmoniem Abdelfattah,Ali Abdel Hakam Ali abdo 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.2
Single angle tension members are commonly connected by bolting through one leg. Stress concentration and shear lag effects promote the angle failure at the connection region. This angle failure reduces the angle ultimate tensile strength and efficiency of the material. This study proposes a reinforced connection to upgrade the single angle tension strength of the member and its material efficiency. A lug angle was nested into the angle member and bolted to the gusset plate and the angle by the lead bolt in the connection. At some distance, the outstanding legs of the angle and lug angle were bolted. A total of 17 specimens were fabricated and tested until failure. Finite element analysis was performed to model the behavior of the tested specimens and to study the different parameters that may affect the connection's capacity. The proposed reinforced connection increased the tensile strength of the angle and the angle material efficiency by up to 35%. An empirical formula was proposed, and design recommendations are presented.
-
A Novel Quasi-Resonant Snubber Assisted ZCS-PWM Soft-Switching DC-DC Converter
Khairy Fathy,Hyun Woo Lee,Mutsuo Nakaoka 전력전자학회 2006 전력전자학술대회 논문집 Vol.- No.-
In this paper, a novel type of auxiliary switched capacitor assisted edge resonant soft switching PWM resonant DC-DC Converter with two simple auxiliary commutation lossless inductor snubbers. The operation principle of this converter is described using the switching mode equivalent circuits. This newly developed multi resonant DC-DC Converter can regulate its dc output AC power under a principle of constant frequency edge-resonant soft switching commutation by asymmetrical PWM duty cycle control scheme. The high frequency power regulation and actual power characteristics of the proposed soft switching PWM resonant DC-DC Converter are evaluated and discussed. The operating performances of the newly proposed soft switching inverter are represented based on simulation a results from an application point of view.
-
Khairy Fathy,Keiki Morimoto,Ki-Young Suh,Soon-Kurl Kwon,Mutsuo Nakaoka 대한전기학회 2007 Journal of Electrical Engineering & Technology Vol.2 No.1
This paper presents a new circuit topology of active edge resonant snubbers assisted half-bridge soft switching PWM inverter type DC-DC high power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed half-bridge high frequency PWM inverter with a high frequency planar transformer link in addition to input DC busline side power semiconductor switching devices for PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC buslines can achieve ZCS tum-on and ZVS tum-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, a high switching frequency IGBTs can be actually selected in the frequency range of 60 ㎑ under the principle of soft switching. The performance evaluations of the experimental setup are illustrated practically. The effectiveness of this new converter topology is proved for such low voltage and large current DC-DC power supplies as DC bus feeding from a practical point of view.
-
( Alaaeldien Fathy Mohamed Elgabry ) 한국외국어대학교 중동연구소 2014 중동연구 Vol.32 No.3
The paper is an attempt to trace Ahmed Shawqi`s ways of creating preludes and the relation between the prelude and reader-domination in bridging the textual gaps and discussing the communication values of classic texts. The research reviews old critical statements and uses them as a background for integrating the research and its hypotheses. It handles some basic notions of the reception theory such as "ideal reader" , horizon of expectation" and "text asset". It also tackles some of its musical features such as Leonine rhyme, ellipsis, vocative mode, imperative and change of their functional value from heritage to domination. The association of criticism with the recipient is a critical implication which is clearly noticed in the definition of the term rhetoric as "consideration of the context". The research implies the necessity of taking into consideration that researches on the recipient depend on guessing and prediction as a result of the lack of field studies on reader samples. The context gets more complicated with abandoning the exclusive classic features used by classicists to overthrow the recipients` promptness via the most influential formal features they are more likely to admire. To conclude, the paper focuses on some notions such as super reader, horizon of expectation, ideal reader and passive recipient pointing out their impact via a sample of Shawqi`s poetry.
-
Seismic assessment of thin steel plate shear walls with outrigger system
Ebtsam Fathy 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.74 No.2
The seismic performance and failure modes of the dual system of moment resisting frames and thin steel plate shear walls (TSPSWs) without and with one or two outrigger trusses are studied in this paper. These structural systems were utilized to resist vertical and lateral loads of 40-storey buildings. Detailed Finite element models associated with nonlinear time history analyses were used to examine seismic capacity and plastic mechanism of the buildings. The analyses were performed under increased levels of earthquake intensities. The models with one and two outriggers showed good performance during the maximum considered earthquake (MCE), while the stress of TSPSWs in the model without outrigger reached its ultimate value under this earthquake. The best seismic capacity was in favour of the model with two outriggers, where it is found that increasing the number of outriggers not only gives more reduction in lateral displacement but also reduces stress concentration on thin steel plate shear walls at outrigger floors, which caused the early failure of TSPSWs in model with one outrigger.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
