我們編寫的程序由兩個主要方面組成 1 算法的集合就是將指令組織成程序來解決某個特定的問題 2 數據的集合算法在這些數據上操作以提供問題的解決方案 縱觀短暫的計算機發展史這兩個主要方面算法和數據一直保持不變發展演化的 是它們之間的關系就是所謂的程序設計方法programming paradigm 在過程化程序設計方法procedural programming 中一個問題可直接由一組算法來建 立模型例如公共圖書館的資料借閱/登記check out/check in 系統是由一系列過程表現 出來的其中兩個主要的過程是資料的借閱和登記這些數據被獨立存儲起來我們既可以 在某個全局位置上訪問這些數據或者把數據傳遞給過程以便它能夠訪問這些數據Fortran C 和 Pascal 是三種著名的過程語言C++也支持過程化程序設計單獨的過程如check_in() check_out() over_due() fine()等等都被稱為函數第三篇將集中討論C++對過程化程序 設計方法的支持尤其將重點討論函數函數模板和通用算法 在20 世紀70 年代程序設計的焦點從過程化程序設計方法轉移到了抽象數據類型 abstract data type 簡寫為ADT 的程序設計上現在通常稱之為基于對象(object based 的程序設計在基于對象的程序設計方法中我們通過一組數據抽象來建立問題的模型在 C++中我們把這些抽象稱為類class 例如在這種方法下圖書館資料借閱登記系統就 由類的對象實例比如書借閱者還書時間罰款等之間的相互作用表現出來以此表 示出圖書館的抽象概念與每個類相關的算法被稱為該類的公有接口public interface 數 據以私有形式被存儲在每個對象中對數據的訪問應與一般的程序代碼隔離開來CLU Ada 和Modula-2 是三種支持抽象數據類型的程序設計語言第四篇將說明和討論C++對抽象數據 類型程序設計方法的支持 面向對象的程序設計方法通過繼承inheritance 機制和動態綁定dynamic binding 機 制擴展了抽象數據類型繼承機制是對現有實現代碼的重用動態綁定是指對現有的公有接 口的重用以前獨立的類型現在有了類型/子類型的特定關系一本書一盒錄像帶一段錄 音甚至孩子的寵物盡管它們有各自的借閱/登記方式但都可以成為圖書館的收藏資料 共享的公有接口和私有的數據都放在一個抽象類圖書館資料LibraryMaterial 中每個特 殊的圖書館資料類都從LibraryMaterial 抽象類繼承共享的行為它們只需要提供與自身行為相 關的算法和數據Simula Smalltalk 和Java 是三種支持面向對象程序設計方法的著名語言 第五篇將集中討論C++對面向對象程序設計方法的支持 C++是一種支持多種程序設計方法的語言雖然我們主要把它當作面向對象的語言但 實際上它也提供對過程化的和基于對象的程序設計方法的支持這樣做的好處是對每個問題 都能夠提供最合適的解決方案事實上沒有一種程序設計方法能夠
上傳時間： 2019-01-30
上傳用戶：jizhi111
無線電CW通聯 基本Q短語，通聯實例 A: CQCQCQ DE BA4ALC/5 BA4ALC/5 BA4ALC/5 PSE K B:BA4ALC/5 DE BD4IZL BD4IZL K A:BD4IZL DE BA4ALC/5 GM TNX FER CALL DR OM UR RST 559 55N K B:RR BA4ALC/5 DE BD4IZL GM DR OM TNX 55N RPRT UR 599 5NN FB MY NAME IS YU YU QTH JINAN JINAN BA4ALC/5 DE BD4IZL K A: DR YU OM TNX FB RPRT OP JACK JACK QTH NINGBO NINGBO WX HR IS FINE ES WARM TEMP 20C 20C HW? DE BA4ALC/5 K B:R DR JACK OM WX CLOUDY CLOUDY ES TEMP 15C 15C BT RIG FT80C FT80C ANT DIPOLE DP PWR 100WATTS 1TTW BA4ALC/5 DE BD4IZL K A: BD4IZL DE BA4ALC/5 MY RIG IS IC746PRO IC746PRO ES PWR 100W 1OOW BT ANT 2 ELE YAGI 2ELE YAGI 12MH TNX FER NICE QSO QSL VIA BURO HPE CUAGN BD4IZL DE BA4ALC/5 73 73 GL ES GB TU TU SK.. B:TNX FB CW QSO QSL QRZ.COM CUAGN BA4ALC/5 DE BD4IZL 73 DR JACK TU SK.. A:. B:.
上傳時間： 2019-03-05
上傳用戶：shuyinglee
Mobile communication has gained significant importance in today’s society. As of 2010, the number of mobile phone subscribers has surpassed 5 billion [ABI10], and the global annual mobile revenue is soon expected to top $1 trillion [Inf10]. While these numbers appear promising for mobile operators at first sight, the major game-changer that has come up recently is the fact that the market is more and more driven by the demand for mobile data traffic [Cis10].
上傳時間： 2020-05-27
上傳用戶：shancjb
With the advancement of technology and miniaturization of electronic devices, applications of wireless sensor networks (WSNs) can be seen in diverse areas in our lives. In fact, these WSNs have gained a lot of attention from both the research community and industry, making them easily available on the market. An extensive amount of research, easy availability, and cheap cost make them useful in various types of futuristic applications as well.
標簽： Communication Technologies Emerging
上傳時間： 2020-05-27
上傳用戶：shancjb
This book describes how global mobile communication was made. It is written for those who want or need to know how this was achieved e.g.: ? Young professionals who want to build their career on GSM and UMTS and need to understand the basics ? Strategic and technical planners who want to drive the future GSM and UMTS develop- ment ? Strategists who plan to repeat GSM’s success in the fourth generation ? Academics, who want to understand and analyse the development of GSM and UMTS; ? Activists in other large scale international communication projects who want to use experiences gained
標簽： Creation UMTS GSM and The of
上傳時間： 2020-05-27
上傳用戶：shancjb
Having dealt with in-depth analysis of SS#7, GSM and GPRS networks I started to monitor UTRAN interfaces approximately four years ago. Monitoring interfaces means decoding the data captured on the links and analysing how the different data segments and messages are related to each other. In general I wanted to trace all messages belonging to a single call to prove if the network elements and protocol entities involved worked fine or if there had been failures or if any kind of suspicious events had influenced the normal call proceeding or the call’s quality of service. Cases showing normal network behaviour have been documented in Kreher and Ruedebusch (UMTS Signaling. John Wiley & Sons, Ltd, 2005), which provides examples for technical experts investigating call flows and network procedures.
標簽： Performance Measurement Practical Guide UMTS
上傳時間： 2020-06-01
上傳用戶：shancjb
One of the predominant topics in the domain of the emerging Smart Grid can be seen in standardization. With the combination of existing protection and automa- tion technology with upcoming ICT-based solutions, different interoperability is- sues arise when technologies have to be combined in the infrastructure. Standards have proven to be one of the most striking solutions to actually cope with this topic. Since 2008, this topic has gained much attention in various political and technical agendas.
標簽： Standardization Smart Grids in
上傳時間： 2020-06-07
上傳用戶：shancjb
Radio frequency identification (RFID) is a type of automatic identification systems which has gained popularity in recent years for being fast and reliable in keeping track of the individual objects. In RFID systems, contactless object identification is achieved using radio signals without the need for physical contact as the case with other existing identification technologies such as barcodes. Therefore, a huge number of items can be identified in a short amount of time with high reliability and low cost which makes the RFID technology very attractive for a wide range of applications such as supply chain management, e-health, monitoring humans, pets, animals, and many other objects, toll control, and electrical tagging. Furthermore, RFID technology eliminates the human error and reduces the total cost of the products.
上傳時間： 2020-06-08
上傳用戶：shancjb
Research on microwave power amplififiers has gained a growing importance demanded by the many continuously developing applications which require such subsystem performance. A broad set of commercial and strategic systems in fact have their overall performance boosted by the power amplififier, the latter becoming an enabling component wherever its effificiency and output power actually allows functionalities and operating modes previously not possible. This is the case for the many wireless systems and battery-operated systems that form the substrate of everyday life, but also of high-performance satellite and dual-use systems.
上傳時間： 2021-10-30
上傳用戶：得之我幸78
It all started rather innocuously. I walked into Dr GT Murthy’s office one fine day, andchanged my life. “Doc” was then the General Manager, Central R&D, of a very largeelectrical company headquartered in Bombay. In his new state-of-the-art electronics center,he had hand-picked some of India’s best engineers (over a hundred already) ever assembledunder one roof. Luckily, he too was originally a Physicist, and that certainly helped me gainsome empathy. Nowadays he is in retirement, but I will always remember him as athoroughly fair, honest and facts-oriented person, who led by example. There were severalthings I absorbed from him that are very much part of my basic engineering persona today.You can certainly look upon this book as an extension of what Doc started many years agoin India … because that’s what it really is! I certainly wouldn’t be here today if I hadn’t metDoc. And in fact, several of the brash, high-flying managers I’ve met in recent years,desperately need some sort of crash course in technology and human values from Doc!
標簽： 開關電源
上傳時間： 2021-11-23
上傳用戶：
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