语音识别用户需求说明书user manual
上传时间： 2019-08-26
上传用户：mayifang
以后再也不用担心写爬虫ip被封，不用担心没钱买代理ip的烦恼了 在使用python写爬虫时候，你会遇到所要爬取的网站有反爬取技术比如用同一个IP反复爬取同一个网页，很可能会被封。如何有效的解决这个问题呢？我们可以使用代理ip，来设置代理ip池。 现在教大家一个可获取大量免费有效快速的代理ip方法，我们访问西刺免费代理ip网址 这里面提供了许多代理ip，但是我们尝试过后会发现并不是每一个都是有效的。所以我们现在所要做的就是从里面提供的筛选出有效快速稳定的ip。 以下介绍的免费获取代理ip池的方法： 优点：免费、数量多、有效、速度快 缺点：需要定期筛选 主要思路： 从网址上爬取ip地址并存储 验证ip是否能使用-（随机访问网址判断响应码） 格式化ip地址 代码如下： 1.导入包 import requests from lxml import etree import time 1 2 3 2.获取西刺免费代理ip网址上的代理ip def get_all_proxy(): url = 'http://www.xicidaili.com/nn/1' headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36', } response = requests.get(url, headers=headers) html_ele = etree.HTML(response.text) ip_eles = html_ele.xpath('//table[@id="ip_list"]/tr/td[2]/text()') port_ele = html_ele.xpath('//table[@id="ip_list"]/tr/td[3]/text()') proxy_list = [] for i in range(0,len(ip_eles)): proxy_str = 'http://' + ip_eles[i] + ':' + port_ele[i] proxy_list.append(proxy_str) return proxy_list 1 2 3 4 5 6 7 8 9 10 11 12 13 14 3.验证获取的ip def check_all_proxy(proxy_list): valid_proxy_list = [] for proxy in proxy_list: url = 'http://www.baidu.com/' proxy_dict = { 'http': proxy } try: start_time = time.time() response = requests.get(url, proxies=proxy_dict, timeout=5) if response.status_code == 200: end_time = time.time() print('代理可用：' + proxy) print('耗时:' + str(end_time - start_time)) valid_proxy_list.append(proxy) else: print('代理超时') except: print('代理不可用--------------->'+proxy) return valid_proxy_list 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 4.输出获取ip池 if __name__ == '__main__': proxy_list = get_all_proxy() valid_proxy_list = check_all_proxy(proxy_list) print('--'*30) print(valid_proxy_list) 1 2 3 4 5 技术能力有限欢迎提出意见，保证积极向上不断学习 ———————————————— 版权声明：本文为CSDN博主「彬小二」的原创文章，遵循 CC 4.0 BY-SA 版权协议，转载请附上原文出处链接及本声明。 原文链接：https://blog.csdn.net/qq_39884947/article/details/86609930
上传时间： 2019-11-15
上传用户：fygwz1982
From the transition of analog to digital communication along with seamless mobility and high computing power of small handheld devices, the wireless communications industry has seen tremendous changes leading to the integration of several telecommunication networks, devices and services over last 30 years. The rate of this progress and growth has increased particularly in the past decade because people no longer use their devices and networks for voice only, but demand bundle contents such as data download/streaming, HDTV, HD video , 3D video conferencing with higher efficiency, seamless connectivity, intelligence, reliability and better user experience. Although the challenges facing service providers and telecommunication companies differ by product, region, market size, and their areas of concentration but time to market, efficient utilization of their assets and revenue expansion, have impacted significantly how to manage and conduct their business while maintaining sufficient margin.
标签： Convergence Networks Beyond 4G of
上传时间： 2020-05-26
上传用户：shancjb
Licensed spectrum remains 3GPP operators’ top priority to deliver advanced services and user experience Opportunistic use of unlicensed spectrum is becoming an important complement for operators to meet the growing traffic demand Moving forward 3GPP operators will have two options to offload traffic to unlicensed spectrum: 1. Wi-Fi (via LTE/Wi-Fi interworking) 2. LTE over unlicensed It will then be up to each individual operator to choose which approach to use, which will depend on a number of factors
标签： 3GPP_unlicensed_Dino_Flore 2015 01
上传时间： 2020-05-26
上传用户：shancjb
Device-to-device(D2D) communications are now considered as an integral part of future 5G networks which will enable direct communication between user equipment (UE) without unnecessary routing via the network infrastructure. This architecture will result in higher throughputs than conventional cellular networks, but with the increased potential for co-channel interference induced by randomly located cellular and D2D UEs.
标签： Device-to-Device Communications Analysis of
上传时间： 2020-05-26
上传用户：shancjb
The past decades have witnessed wide demand and applications for wireless commu- nications in the human body area, that is, in the immediate environment around a human body. These demands and applications especially focus on wireless transmis- sion and networking of personal information for user identification, healthcare and medical applications.
标签： communications modeling channel Body area
上传时间： 2020-05-26
上传用户：shancjb
Today’s wireless services have come a long way since the roll out of the conventional voice-centric cellular systems. The demand for wireless access in voice and high rate data multi-media applications has been increasing. New generation wireless communication systems are aimed at accommodating this demand through better resource management and improved transmission technologies.
标签： Radio Cognitive Software Defined
上传时间： 2020-05-26
上传用户：shancjb
Wireless technology has been evolving at a breakneck speed. The total number of cell-phones in use (as of 2011) was over 6 billion for a 7 billion world population [1] constituting 87% of the world population. Additionally, with user convenience be- coming paramount, more and more functions are being implemented wirelessly.
标签： Front-Ends Cognitive Receiver Radio
上传时间： 2020-05-26
上传用户：shancjb
At the time of writing, and to an extent never seen before, there is an expectation that almost any information or service that is available through communication systems in the office or home will be available wherever the user happens to be. This is placing incredible demands on wireless communications and has been the driver for the gen- esis and deployment of three generations of cellular systems in the space of 20 years.
标签： Deploying Wireless Networks
上传时间： 2020-05-27
上传用户：shancjb
Multiuser multiple-input-multiple-output (MU- MIMO) systems are known to be hindered by dimensionality loss due to channel state information (CSI) acquisition overhead. In this paper, we investigate user-scheduling in MU-MIMO systems on account of CSI acquisition overhead, where a base station dynamically acquires user channels to avoid choking the system with CSI overhead.
标签： Acquisition Dynamic Channel
上传时间： 2020-05-27
上传用户：shancjb
