EU and China agree on investment agreement Expected to balance economic relations
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According to the minutes of the online conference, President Emmanuel Macron has announced his intention to visit China in the coming months with German Chancellor Angela Merkel to discuss areas where Europe and China can cooperate, such as health care and the environment.
[Brussels / Paris / Beijing XNUMXth Reuters] – European Union (EU) and China enter the market on the XNUMXth ... → Continue reading
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Video conference(British: Videoconferencing) Is interactiveTelecommunicationstechnologyTo connect two or more remote locations to hold a two-way video and audio conference.GroupwareIs also a kind of. Personal in that it is designed for meetingsVideophoneIs different from.Video conferenceOrVideo conferenceAlso called.
Simple analog video conferencingtv setIt was realized almost simultaneously with the invention of. In this case, the system isCCTVConnect the system with a cable. In the world's first manned space flight,NASAIs a two-way wireless link (UHForVHF) Was used. Television stations usually use video conferencing systems for reporting from remote locations. afterwards,Artificial satelliteThe one using the link by has become popular.
This technology was so expensive thatTelemedicine,Distance learning, It was never used for normal activities such as business meetings (especially the more remote it was).TelTrial of low quality video conferencing system using network (AT&THowever, because the video compression technology at that time was poor, the quality was too low to be generalized. 1970s 1MHzBandwidthAnd 6 Mbps bit rateVideophoneDid not reach widespread use.
1980 eraBecame the digital telephone network (ISDNEtc.) is now available and is the minimum required to transfer compressed video and audio.bit rate(Generally 128 Kbit/s) is now guaranteed. Several video conferencing systems using the ISDN network have become commercially available and have spread worldwide. Video conferencing systems evolved from dedicated devices in the 1990s to ones that used general-purpose hardware and software. AndIP-Based video conferencing emerged, more efficient video compression methods were developed,Personal computerVideo conferencing has become possible. The following have been developed as IP-based video conferencing systems.
- : Cornell University Tim Dorcey et al. (1992)
- IVS: INRIA(1992)
- Netmeeting: Microsoft(1996)
- Yahoo! Messenger: Yahoo!(1998)
- MSN Messenger: Microsoft (1999)
- : A-net (2000)
- Meeting Plaza: NTT Techno Cross(2001)
- Skype: Skype Technologies (2003)
- iChat AV: Apple computer (2003)
The core technology of video conferencing is real-time digital compression of video and audio. Do this compressionhardware,softwareTheCodec(Coder/decoder). The compression ratio is as high as 1:500. Compressed datapacketDivided into units, someComputer networkTransferred over.modemIf you use, you can also use the telephone network,VideophoneCan also be realized.
Other components of the video conferencing system include:
- Video input equipment: Video cameraorWebcam
- Video output device: display,tv set,projector
- Voice input device: microphone
- Audio output device: Included with displayspeakerOr phone
- Data transfer equipment: Telephone network,LAN,インターネット
Video conferencing systems are classified into the following two types depending on the implementation form:
- Dedicated system -A product that packages what you need. On the consoleリ モ コ ンComes with a high quality video camera with. The camera can be moved from side to side (pan), up and down (tilt), and zoom (zoom). For this reason, it is also called a PTZ camera. The console is equipped with all the necessary interfaces, including a control computer and codec. The console has a monitor with an omnidirectional microphone and speakers,projectorConnect. There are several types of dedicated video conferencing systems:
- Large Video Conferencing Systems-Expensive Equipment for Large Meeting Rooms
- Small Video Conferencing Systems-Somewhat cheaper equipment for smaller meeting rooms
- Personal video conferencing system-inexpensive equipment for individuals. The camera and microphone are built into the console.
- Desktop system -A device that enables video conferencing by connecting to a general personal computer. Use by connecting a suitable camera or microphone to a board equipped with a codec and transfer interface. Generally conforms to the H.323 standard. recentlyWeb conferenceOften collectively referred to as a system.
As one of the basic functions of the video conference system,Echo removalThere is. Echo cancellation detects the echo that occurs when the audio output (speaker) audio is picked up by the codec audio input (microphone) again after some time.algorithmIs. Without echo removal, people in the distance will hear your voice come back,reverberationMakes it difficult to hear or howling occurs. Echo cancellation is a processor-intensive process that typically handles repeating voices at subtle intervals.
Multipoint video conferencing
For video conferencing at three or more points, a “multipoint control unit” (MCU) is generally used. This is a device that relays signals from multiple sources. Connect from each point to the MCU or from the MCU to the points scheduled to attend the conference. There are MCUs for IP and ISDN. Also, some MCUs are implemented entirely in software, and some are configured with a combination of hardware and software. The number of connections that the MCU can control varies, and the data transfer capability and available protocols also vary. In addition, there is one that has a function of simultaneously displaying a plurality of points on the screen.
The MCU may be an independent device, but it may also be built into the video conferencing system.
Depending on the system, a multipoint conference can be realized without using an MCU. In that case, the technology called "decentralized multipoint" based on the H.323 standard is used to send data directly from each point to other points. The advantage of this method is that there is no relay point, so the video and audio are of high quality. In addition, it is possible to suddenly hold a multipoint conference without worrying about whether the MCU is available. However, in this case, since the data is directly exchanged with a plurality of points, the network bandwidth must be wide.
Despite the widespread use of devices that can be used for video conferencing, the following two factors have been cited as factors that have hindered the spread of video conferencing as a means of communication..
- eye contact: Eye contact is known to be important in conversation.. I can't see the other person's face on the phone, but I can't see the other person's face in a video conference. To address this problem, research is underway to synthesize images with the correct line of sight in a stereo system..
- Awareness of being seen: The second problem with video conferencing is that cameras are present, and in some cases recorded and remain. If it's just sound, you don't have to worry about its appearance. Earlier studies by Alphonse Chapanis have shown that being conscious of the camera has a negative effect on communication.
While eye contact problems are likely to be solved by technological advances, the problem of "being seen" is the only way people get used to video conferencing.
International Telecommunication Union(ITU) has developed three standards for video conferencing.
- ITU H.320 - ISDNTwo types of video conferencing above: Basic Rate Interface (BRI) and Primary Rate Interface (PRI). T2 orArtificial satelliteAlso used in networks by.
- ITU H.323 -A standard for video communication over Internet Protocol (IP).VoIPAlso applies to
- ITU H.324 -An analog video transfer standard over the public switched telephone network.
Recently, video conferencing over IP has become the most popular. Although there are many H.320 ISDN video conferences in the government and military relations, H.323 IP video conferences have become popular due to price reductions and the spread of broadband. The advantages of H.323 are:Digital subscriber lineThe point is that anyone with a high-speed Internet connection can access it.
Impact on the public
High-speed Internet connection is widely available at a reasonable cost, and technology costs such as video capture are also decreasing. Therefore, anyone can easily hold a video conference by combining a webcam with a personal computer or software codec. Hardware performance continues to improve and prices continue to decline. With the advent of free software, software-enabled video conferencing is now available to anyone.
Impact on healthcare
Video conferencing in real timeTelemedicine(Diagnosis, Interview,Medical imagePlay an important role in applications (such as transfer). With video conferencing systems, patients cannurse,DoctorIt will be possible to contact in case of emergency and to discuss cases with remote experts. Especially if it can be used for diagnostic purposes in remote areas, it will save many lives.microscopeConnectable toDigital camera,UltrasonographyIt is also possible to send patient data by connecting a video conferencing device, etc. to the video conferencing system.
- 20122/20 Nagano Prefectural College of NursingAre professors and private companiesENWAA collaborative project team with etc. jointly developed a medical and welfare system that enables patients to be diagnosed from remote areas and the condition of the care recipient to be seen. It was first released on February 2. With the popular Internet linecomputerUsing the hospital andwelfare facilityIt is a system that connects an ordinary household and an ordinary household to mutually communicate images and sounds. We have succeeded in developing our own technology to compress and send a large amount of data in a shorter time than usual. This has opened a great way for medical treatment and nursing care in remote areas where disasters are inconvenient and during disasters. High cost was a problem in the existing system, but it enabled cost reduction.
Video conferencing enables individuals at remote locations to easily hold a conference. It is possible to hold meetings by saving time and money for travel.VoIPIt becomes possible to have a conference at your own seat in the office by using such technology as the video conference together. Similar technology allows employees to work from homeTeleworkIt is also used for.
TelepresenceThe meeting enhances the sense of presence by displaying the participants of the meeting in real time in real time. This is shocking the concept of business meetings.
Increasingly, video conferencing is being introduced on websites to accelerate business while staying at work. In 2020Emergency declarationso,TeleworkHas been promoted by more than 30% of companies. Video conferencing systems from vendors,free softwareVarious.Some of them have security problems and are concerned about their use in business.Therefore, it is necessary to confirm the vulnerability in advance before using it.
- Remote conference
- Telepresence robot
- New Coronavirus Infection (2019-) -This was the catalyst for the rapid spread.
- ^ Jim Van Meggelen 2005, The problem with video conferencing.
- ^ Vertegaal, "Explaining Effects of Eye Gaze on Mediated Group Conversations: Amount or Synchronization?" ACM Conference on Computer Supported Cooperative Work, 2002.)
- ^ Research on eye contact has been around since the 1990s. For example Teleconferencing Eye Contact Using a Virtual Camera, ACM CHI 1993 is available. Recently, there is research on a system that corrects the line of sight with a single camera. For example in Microsoft GazeMaster System.
- ^ Nagano Daily June 2012, 2
- ^ "Highly secure video conferencing tool for business use Google G Suite Hangouts Meet". 2020/4/25Browse.
- ^ "US Microsoft Corp. Microsoft Teams Remote Work (work from home)". 2020/4/25Browse.
- ^ Impress Corporation (September 2021, 2). “Personally developed video call app "vs5x" supports desktop sharing-v0.1.1 released [Articles you should know under a state of emergency]”(Japanese). Window fence. 2021/2/6Browse.
- ^ "What are the security and vulnerability issues of "Zoom"?Is it okay to use it for web conferencing? | NEC Networks & System Integration Corp.”(Japanese). symphonict.nesic.co.jp (September 2020, 7). 2021/2/6Browse.