About: hamsterdb is a database engine written in ANSI C. It supports a B+Tree index structure, uses memory mapped I/O (if available), supports cursors, and can create in-memory databases. Release focus: Major feature enhancements Changes: This release comes with many changes and new features. It can manage multiple databases in one file. A new flag (HAM_LOCK_EXCLUSIVE) places an exclusive lock on the file. hamsterdb was ported to Windows CE, and the Solution file for Visual Studio 2005 now supports builds for x64. Several minor bugs were fixed, performance was improved, and small API changes occurred. Pre-built libraries for Windows (32-bit and 64-bit) are available for download. Author: cruppstahl
標簽： C. hamsterdb structure database
上傳時間： 2013-12-11
上傳用戶：LouieWu
Traffic sign shape classification based on Support Vector Machines and the FFT of the signature of blobs.pdf
標簽： classification the signature Machines
上傳時間： 2013-12-14
上傳用戶：rishian
隨著光伏發(fā)電系統(tǒng)快速發(fā)展,以及電動汽車充電樁的普及,傳統(tǒng)的剩余電流保護器無法滿足實際需求。介紹了一款B型剩余電流保護器,采用磁調(diào)制剩余電流互感器和零序電流互感器采集剩余電流。根據(jù)GB/T 22794—2017標準要求,可識別1 kHz及以下的正弦交流、帶和不帶直流分量的脈動直流、平滑直流等剩余電流信號。經(jīng)信號調(diào)理電路將電壓信號送到單片機進行采集和判斷。通過試驗測試,該樣機在測試精度和速度上均符合國家標準的相關(guān)要求。The rapid development of photovoltaic power generation systems and the popularity of electric vehicle charging piles make the traditional residual current protective devices unable to meet the actual demand.This paper proposed a type B residual current protective device,which uses the magnetically modulated residual current transformer and the zero sequence current transformer to acquire the residual current.According to the requirements of GB/T 22794—2017,the type B residual current protective device can detect sinusoidal AC residual current of 1kHz and below 1kHz,pulsating DC residual current with and without DC component,smooth DC residual current and so on.The signal processing circuit sends the voltage signal to the MCU for acquisition and judgment.Through experimental tests,the device meets the relevant requirements of national standards in terms of test accuracy and speed.
標簽： 電流保護器
上傳時間： 2022-03-27
上傳用戶：
The Blitz++ project is now being served via SourceForge. To download the Blitz++ library, go to the blitz project web page, at http://sourceforge.net/projects/blitz. More information about supported platforms and C++ compilers is available in this document or on the official Blitz++ home page, at http://oonumerics.org/blitz.
標簽： Blitz SourceForge the download
上傳時間： 2014-01-03
上傳用戶：lo25643
The XML Toolbox converts MATLAB data types (such as double, char, struct, complex, sparse, logical) of any level of nesting to XML format and vice versa. For example, >> project.name = MyProject >> project.id = 1234 >> project.param.a = 3.1415 >> project.param.b = 42 becomes with str=xml_format(project, off ) "<project> <name>MyProject</name> <id>1234</id> <param> <a>3.1415</a> <b>42</b> </param> </project>" On the other hand, if an XML string XStr is given, this can be converted easily to a MATLAB data type or structure V with the command V=xml_parse(XStr).
標簽： converts Toolbox complex logical
上傳時間： 2016-02-12
上傳用戶：a673761058
We analyze, both analytically and numerically, the effectiveness of cloaking an infinite cylinder from observations by electromagnetic waves in three dimensions. We show that, as truncated approximations of the ideal permittivity and permeability tensors tend towards the singular ideal cloaking fields, so that the anisotropy ratio tends to infinity, the D and B fields blow up near the cloaking surface. Since the metamaterials used to implement cloaking are based on effective medium theory, the resulting large variation in D and B will pose a challenge to the suitability of the field averaged characterization of " and 碌. We also consider cloaking with and without the SHS (softand- hard surface) lining, shown in [6] to be theoretically necessary for cloaking in the cylindrical geometry. We demonstrate numerically that cloaking is significantly improved by the SHS lining, with both the far field of the scattered wave significantly reduced and the blow up of D and B prevented.
標簽： effectiveness analytically numerically cloaking
上傳時間： 2017-03-30
上傳用戶：zxc23456789
This material is not only up-to-date, it defines up-to-date. It is truly cutting-edge. As the only book on the subject, Rootkits will be of interest to any Windows security researcher or security programmer. It s detailed, well researched and the technical information is excellent. The level of technical detail, research, and time invested in developing relevant examples is impressive.
標簽： up-to-date only cutting-edge material
上傳時間： 2017-07-09
上傳用戶：comua
All inputs of the C16x family have Schmitt-Trigger input characteristics. These Schmitt-Triggers are intended to always provide proper internal low and high levels, even if anundefined voltage level (between TTL-VIL and TTL-VIH) is externally applied to the pin.The hysteresis of these inputs, however, is very small, and can not be properly used in anapplication to suppress signal noise, and to shape slow rising/falling input transitions.Thus, it must be taken care that rising/falling input signals pass the undefined area of theTTL-specification between VIL and VIH with a sufficient rise/fall time, as generally usualand specified for TTL components (e.g. 74LS series: gates 1V/us, clock inputs 20V/us).The effect of the implemented Schmitt-Trigger is that even if the input signal remains inthe undefined area, well defined low/high levels are generated internally. Note that allinput signals are evaluated at specific sample points (depending on the input and theperipheral function connected to it), at that signal transitions are detected if twoconsecutive samples show different levels. Thus, only the current level of an input signalat these sample points is relevant, that means, the necessary rise/fall times of the inputsignal is only dependant on the sample rate, that is the distance in time between twoconsecutive evaluation time points. If an input signal, for instance, is sampled throughsoftware every 10us, it is irrelevant, which input level would be seen between thesamples. Thus, it would be allowable for the signal to take 10us to pass through theundefined area. Due to the sample rate of 10us, it is assured that only one sample canoccur while the signal is within the undefined area, and no incorrect transition will bedetected. For inputs which are connected to a peripheral function, e.g. capture inputs, thesample rate is determined by the clock cycle of the peripheral unit. In the case of theCAPCOM unit this means a sample rate of 400ns @ 20MHz CPU clock. This requiresinput signals to pass through the undefined area within these 400ns in order to avoidmultiple capture events.For input signals, which do not provide the required rise/fall times, external circuitry mustbe used to shape the signal transitions.In the attached diagram, the effect of the sample rate is shown. The numbers 1 to 5 in thediagram represent possible sample points. Waveform a) shows the result if the inputsignal transition time through the undefined TTL-level area is less than the time distancebetween the sample points (sampling at 1, 2, 3, and 4). Waveform b) can be the result ifthe sampling is performed more than once within the undefined area (sampling at 1, 2, 5,3, and 4).Sample points:1. Evaluation of the signal clearly results in a low level2. Either a low or a high level can be sampled here. If low is sampled, no transition willbe detected. If the sample results in a high level, a transition is detected, and anappropriate action (e.g. capture) might take place.3. Evaluation here clearly results in a high level. If the previous sample 2) had alreadydetected a high, there is no change. If the previous sample 2) showed a low, atransition from low to high is detected now.
上傳時間： 2013-10-23
上傳用戶：copu
基于USB接口的數(shù)據(jù)采集模塊的設(shè)計與實現(xiàn)Design and Implementation of USB-Based Data Acquisition Module路 永 伸(天津科技大學(xué)電子信息與自動化學(xué)院，天津300222)摘要文中給出基于USB接口的數(shù)據(jù)采集模塊的設(shè)計與實現(xiàn)。硬件設(shè)計采用以Adpc831與PDIUSBDI2為主的器件進行硬件設(shè)計，采用Windriver開發(fā)USB驅(qū)動，并用Visual C十十6.0對主機軟件中硬件接口操作部分進行動態(tài)鏈接庫封裝。關(guān)鍵詞USB 數(shù)據(jù)采集Adpc831 PDNSBDI2 Windriver動態(tài)鏈接庫Abstract T hed esigna ndim plementaitono fU SB-BasedD ataA cquisiitonM oduleis g iven.Th ec hips oluitonm ainlyw ithA dpc831a ndP DTUSBD12i sused for hardware design. The USB drive is developed場Wmdriver, and the operation on the hardware interface is packaged into Dynamic Link Libraries場Visual C++6.0. Keywords USB DataA cquisition Adttc831 PDfUSBD12 Windriver0 引言US B總 線 是新一代接口總線，最初推出的目的是為了統(tǒng)一取代PC機的各類外設(shè)接口，迄今經(jīng)歷了1.0,1.1與2.0版本3個標準。在國內(nèi)基于USB總線的相關(guān)設(shè)計與開發(fā)也得到了快速的發(fā)展，很多設(shè)計者從各自的應(yīng)用領(lǐng)域，用不同方案設(shè)計出了相應(yīng)的裝置[1,2]。數(shù)據(jù)采集是工業(yè)控制中一個普遍而重要的環(huán)節(jié)，因此開發(fā)基于USB接口的數(shù)據(jù)采集模塊具有很強的現(xiàn)實應(yīng)用意義。雖然 US B總線標準已經(jīng)發(fā)展到2.0版本，但由于工業(yè)控制現(xiàn)場干擾信號的情況比較復(fù)雜，高速數(shù)據(jù)傳輸?shù)目煽啃圆蝗菀妆槐ＷC，并且很多場合對數(shù)據(jù)采集的實時性要求并不高，開發(fā)2.0標準產(chǎn)品的成本又較1.1標準產(chǎn)品高，所以筆者認為，在工業(yè)控制領(lǐng)域，目前開發(fā)基于USB總線1.1標準實現(xiàn)的數(shù)據(jù)采集模塊的實用意義大于相應(yīng)2.0標準模塊。
標簽： USB 接口 數(shù)據(jù)采集模塊
上傳時間： 2013-10-23
上傳用戶：q3290766
VC技術(shù)內(nèi)幕第五版_English.The 6.0 release of Visual C++ shows Microsoft s continued focus on Internet technologies and COM, which are key components of the new Windows Distributed interNet Application Architecture (DNA). In addition to supporting these platform initiatives, Visual C++ 6.0 also adds an amazing number of productivity-boosting features such as Edit And Continue, IntelliSense, AutoComplete, and code tips. These features take Visual C++ to a new level. We have tried to make sure that this book keeps you up to speed on the latest technologies being introduced into Visual C++.
標簽： Microsoft continued Internet English
上傳時間： 2013-12-08
上傳用戶：lepoke
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