時變媒質 的英文怎麼說
中文拼音 [shíbiànméizhí]
時變媒質
英文
time varying media-
In tranditional ip network, only the “ best effort ” service is provided, but the quality of service can not be guaranteed. though the interserv, deffserv and mpls are presented afterward to guarantee the qos for the ip network. but as a layer network, the realization of the qos function need span different layers ( such as rsvp protocol ) in the ip network, which may result in the function iterance and chaos
多媒體和實時業務的出現要求網路能夠提供足夠的qos保證，在傳統的ip網路中只能提供「盡量傳輸」的服務而不能保證服務質量，后來提出的綜合服務模型（ interserv ）以及區分服務模型（ deffserv ）以及mpls技術保證了ip網路上的服務質量，但由於ip網路是層次結構的網路，因此對qos的支持需要跨層（如rsvp協議） ，這就可能引起功能的重復和混亂，而微通信元系統是無層次結構的網路系統，就克服了這些的問題，變得簡單，效率更高。Some factors that exited in contemporary huizhou block some young people in huizhou from continuing their study after finishing nine - year compulsory education, these factors involved lack of educational funds, the values that men are superior to women and the influence of parents who think " it is no use studying " on their children. through comparison between the traditional and contemporary education, we find some new problems that existed in the present education of huizhou, and this article tries to pose some suggestions to solve these problems. first, strengthen the function of fundamental organizations of rural community, that is, with the aid of non - profit organizations, the community can develop kinds of rural education, and local political and economic organizations should provide support and encouragement in spiritual and material for the development of local education
本文通過傳統與當代徽州教育及教育價值觀念的比較，從經濟、政治方面對其變遷進行社會學的思考，並試圖提出發展當代徽州農村社區教育的對策與建議： 1 、強化農村社區基層組織的功能：藉助社區事業組織開展多種樣式的鄉村教育，同時，社區政治組織、經濟組織應為當代徽州農村社區的教育發展提供物質上和精神上的支持和鼓勵； 2 、通過對崇文重教行為的宣傳，發揮大眾傳播媒介對人們正確價值觀的樹立及活動的導向和暗示作用，以促進當代徽州農村社區教育文化的建構； 3 、發展農村社區職業教育，興辦一些鄉村手工業技術培訓班，為山區的副業就地開辟一條新路，並充分發揮社會教育的作用，使徽州農村教育社會化與農村社會教育化統一併融合起來，實現徽州農村社區教育與社會的良性互動。The conformal microstrip antenna with some unique character has been applied in many fields, especialy on speedy objects. in this paper, an efficient fdtd algorithm is introduced to analyse the microstrip antenna. firstly, the fdtd formula in descartes coordinate system and in cylindrical coordinate system are obtained from the time _ dependent maxwell equations using the yee algorithm in a calculating region where the dielectric parameters are independent of time and space. the choice of the space discretization units and the time discretization interval are discussed which are decided by the accuracy and stability respectively. the shape and setup of the excitation source are discussed too. the excitation source is chosen to be gaussian pulse in shape. secondly, the mur ' s first - order and second - order boundary condition are deduced in cylindrical coordinate system. the methods of transforming radiation fields from near zone to far zone in the frequency domain and in the time domain are presented when fdtd is applied to analyse the characteristics of far zone. finally, three kinds of microstrip antennas are analysed. they are a slot antenna that lies on a plane ground of a microstrip, a slot antenna that lies on a cylindrical ground of a microstrip and a microstrip line _ fed aperture coupled stacked rectangular patch antenna in cylindrical coordinate system
本文從麥克斯韋旋度方程出發，建立了笛卡兒坐標下無源空間中均勻無耗媒質的fdtd基本方程和圓柱坐標下無源空間中均勻無耗媒質的fdtd基本方程，詳細討論了fdtd法計算中時間步長和空間步長的選取原則以及激勵源的類型和設置；推導了mur一階和二階邊界條件在圓柱坐標下的差分格式；給出了在用fdtd法計算天線的遠場輻射特性時必需採用的頻域和時域近場遠場變換技術；最後用fdtd法計算了平面微帶縫隙天線、柱面共形微帶縫隙天線和柱面共形微帶層疊天線的輸入阻抗和遠區輻射場，並分析了天線的一些參數的變化對天線輸入阻抗的影響，得出了一些有用的結論。It takes a quantitative analysis to reveal the direction and intensity of tv violence and simultaneously interprets the meaning of the different indexes form the survey, which provides reliable information about tv violence in china and offers reference for the government policy - making and guidelines for the media development in the right way. what ' s more, it takes a big - scale cross - regional survey, and investigates the regional differences, media contact and the relationship between age, the degree of education and the outlooks of the audience, emphasizing the constraints of the objective reality and the differences of the individuals on the media cultivation effects, which offers a framework for later related research
以量化形式反映電視暴力的指向和強度，同時以質化分析解釋各項指標所蘊含的意義，為了解我國電視暴力狀況提供了非臆想性的可靠資料，為政府有關部門的決策及媒體的良性發展提供參照：進行較大規模的跨地區實證調查，考察了地區差異、媒介接觸及年齡、文化程度等諸多變量與受眾觀念的關系，強調了客觀現實及受眾個體差異對媒介涵化效果的制約，為今後的相關研究提供了可資借鑒的理論框架和操作平臺。At the same time, some new applications ( such as multimedia transmission and multicast etc. ) that are developed recently not only increased the amount of traffics, but also changed the properties of the traffics. so, these applications require new service, which result in the requirement of network improvement
同時，近年來發展起來的一些新應用（如多媒體應用，組播應用等）不僅使傳輸流量增加，更因為這些應用改變了以前的流量性質，因而它們需要全新的服務要求，這也就導致了改變網路的需要。Change in the direction of propagation of radiation determined by change in the velocity of propagation in passing through an optically nonhomogeneous medium, or in passing from one medium to another
當輻射通過光學異性的界面，或從一種媒質進入另一種媒質時，傳播速度的改變而導致的輻射傳播方向的改變。Image compression plays an important role in transmission and storage of multimedia. wavelet has been widely adopted in image compression due to its multiresolution, time / frequency localization, lower time complexity, etc. with the advance of image compression techniques based on wavelet, a variety wavelet coefficient models are presented, such as ezw, spiht and ebcot used in jpeg2000
圖像壓縮在多媒體存儲和傳輸中扮演十分重要的角色，小波變換因具有時域頻域局部性、多分辨等性質在圖像壓縮中正在逐步取代dct變換，並已得到廣泛的應用。Based on the research of videoconference systems of h. 323 protocol over ip networks and the author ' s experiences of implementing h. 323 videoconference systems in remote education area, in this thesis the main factors that affect videoconference quality are analyzed, and a dynamic bit rate allocation model is proposed and partly implemented. this model is designed to dynamically allocate bit rate for multi - media data flow ( including audio data and video data ) in fixed bandwidth network environment. when continuous multi - media packet losses are detected in ip based h. 323 videoconference system, the bit rate of video data is adjusted meanwhile the bit rate of audio data remains unchanged, and the bit rate allocation of multi - media data ( including audio data and video data ) is optimized as a whole effect
本文結合作者在h . 323視頻會議系統應用於遠程教育的經驗，通過對現有的基於ip網路的h . 323協議視頻會議系統的研究，分析了影響視頻會議質量的原因，提出並部分實現了在固定帶寬的網路環境下，基於ip的h . 323視頻會議的多媒體數據包發生丟包、抖動或延時時，保持音頻數據位速率不變，通過對視頻數據的位速率的進行調整，最終實現旨在提高視頻會議語音質量的多媒體數據位速率動態調整的模型。It is quantitative change and split of knowledge, qualitative evolution and communication media change of knowledge, and ways of knowledge increasing that influence the links and framework of the school system at that time
知識的量變和分化、知識性質和媒介的演進、知識增長方式的變動等，都將波及一個時代學校教育制度諸環節及其構架。分享友人