• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2022.06a
• /
• pp.1195-1198
• /
• 2022

홀로그램은 빛의 세기와 위상 정보를 모두 기록함으로써 3차원 영상 정보를 기록 및 재현할 수 있는 차세대 영상 시스템이다. 홀로그램은 부동 소수점의 복소 데이터로 실수, 허수 또는 진폭, 위상 신호로 분리되어 압축된다. 본 논문에서는 복소 홀로그램 영상의 표현방식에 따른 압축성능을 비교해보고, 진폭-위상 압축에 대해 압축 친화적인 복소 홀로그램 변환 방식을 제안한다. 이후, 각 표현방식의 압축에서 효율적인 비트량 할당 방법을 제시한다. 본 논문은 제안방식인 QS 진폭-위상 표현이 실수-허수 표현만큼 높은 압축성능을 갖는 것을 확인하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2022.06a
• /
• pp.1187-1190
• /
• 2022

최근 홀로그램(Hologram)을 광학현미경(light microscopy)에 적용하여 시료의 두께를 측정하는 방식의 연구가 활발하게 진행되고 있다. 빛의 간섭패턴(Interference pattern)을 사용하여 시료의 두께를 측정할 수 있는 이유는 시료의 두께에 따라 빛의 위상(phase)이 달라지기 때문이다. 빛의 간섭패턴을 저장하는 홀로그램에서 위상만을 분리한 후 위상을 unwrapping 하면 물체의 두께를 측정할 수 있다. JPEG은 기존의 연구방식인 시료를 통과한 홀로그램 이미지를 직접 압축하는 object 압축방식을 사용한다. 하지만 본 논문에서는 object 압축방식과 달리 홀로그램 이미지를 직접 압축하지 않고 홀로그램 이미지에서 시료의 위상(phase)만을 분리하여 위상 도메인에서 압축하는 방식을 취하였다. 이를 통해 object 압축방식에 비해 위상 도메인 압축방식에서 모든 데이터셋에 대하여 평균적으로 0.0003~0.0142 radian의 성능향상을 이룰 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.620-622
• /
• 2013

Real-time Video communication technology using a Web browser today is on the rise. Video communication system The existing A method of providing an Video communication via a program for a specific server on the service provider, respectively. By using the server of the company that provides an Video communication solutions, were limited by using its own network that you can use to build a separate server for performing Video communication another, using specific software and user groups it was a mechanism for using the Video communication environment. In addition, must be installed separately and ActiveX, plug-in and, use of the service has become possible. Therefore, in this paper, utilizing the real-time Video communication Web-based technology without installing the plug-in, real-time through a Web browser or Active-X of another using a script HTML5 and the Web on the Internet Using HTTP in an environment in the Internet is possible, I've implemented a system capable of Video communication.

• KIPS Transactions on Computer and Communication Systems
• /
• v.8 no.8
• /
• pp.201-208
• /
• 2019

Intra-Body Communication (IBC) is a communication method using the human body as a communication medium. The fact that our human body consists of water and electrolyte allow such communication method could work and have strength in low-power. However, because the IBC directly affects to human body by using it as a medium, there was a lack of research in communication protocols of each communication layer. In this paper, we suggests MAC parameters which affects the performance of communication in human body channel, and propose new MAC protocol. Our results shows that our MAC is suitable for supporting high data rate applications with comparable radio duty cycle performance.

• Journal of Digital Contents Society
• /
• v.15 no.6
• /
• pp.663-673
• /
• 2014

The WBAN technology means a short distance wireless network which provides each device interactive communication by connecting devices inside and outside of body. Standardization on the physical layer, data link layer, network layer and application layer is in progress by IEEE 802.15.6 TG BAN. Wireless body area network is usually configured in energy efficient using sensor and zigbee device due to the power limitation and the characteristics of human body. Wireless sensor network consist of sensor field and sink node. Sensor field are composed a lot of sensor node and sink node collect sensing data. Wireless sensor network has capacity of the self constitution by protocol where placed in large area without fixed position. In this paper, we proposed the efficient addressing scheme for improving the performance of routing algorithm by using ZigBee in WBAN environment. A distributed address allocation scheme used an existing algorithm that has wasted in address space. Therefore proposing x, y and z coordinate axes from divided address space of 16 bit to solve this problems. Each node was reduced not only bitwise but also multi hop using the coordinate axes while routing than Cskip algorithm. I compared the performance between the standard and the proposed mechanism through the numerical analysis. Simulation verified performance about decrease averaging multi hop count that compare proposing algorithm and another. The numerical analysis results show that proposed algorithm reduced the multi hop better than ZigBee distributed address assignment

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.12
• /
• pp.2387-2393
• /
• 2017

The Moon government, launched in May 2017, regards telecommunication service as part of people's welfare and is trying to save telecommunication costs. However, the direction of policy presented is assessed as symptomatic approach. This is largely attributable to the a partial improvement approach from the framework of the present mobile telecommunication industry. However if we restart from an essential point of view, the result is likely to be much better. The nation's mobile communication costs are not adequate because the government's role was not sufficient. There is a problem with the mobile phone supply chain, the subsidy payment mechanism, and the billing system. Addressing these complex issues requires the establishment of an independent system of handset distribution from telecommunication companies, ban on discriminative subsidies payment, and adoption of volume rate system. Telecommunications Business Act that defines the service charges to normalize the market might be somewhat useful, but the normal application of the Fair Trade Act is more important.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.5
• /
• pp.1113-1118
• /
• 2013

Real-time video communication technology of hybrid Web-based using JavaScript and HTML5 today is on the rise. Therefore, in this paper, we have studied the real-time videoo communication technology using a Web browser that supports HTML5. It has been designed and implemented a system based on HTML5 and JavaScript, allowing for video communication of real-time, such as you would using the HTTP/WebSockets and RTC API through the Web servers in the Web browser between different each other, utilizing a Web browser was. It is available in a usable terminal equipment of a Web browser PC or notebook, smart pad, such as a smart phone, which is available without installation, such as a plug-in register or another. In all environments the network is connected, it is available in all terminals use the Web browser is enabled, which will be utilized in the field of video communication in a restricted environment.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.6
• /
• pp.1286-1291
• /
• 2013

Intensive researches on multiuser-based Massive MIMO are performed to increase the spectral efficiency. Although the Massive MIMO scheme based on huge number of antennas inevitably causes hardware and computational complexity in baseband and radio frequency (RF) elements, the problem can be mitigated without serious performance degradation by limiting the number of baseband and RF elements below the number of transmit antennas of base station and opportunistically selecting transmit antennas according to channel states. Accordingly, this paper proposes a simple antenna selection scheme for multiuser-based Massive MIMO systems.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.3
• /
• pp.556-560
• /
• 2013

Recently, solutions to accommodate explosively growing mobile data traffic have attracted intensive attentions since the emergence of high-performance smartphones. Spectrum which can be exploited for mobile communications is very limited. Thus, femto cell is considered as an alternative because it can efficiently offload mobile data traffic from macro cells without using additional spectrum. In this paper, we mathematically analyzed the coverage of femto cell when it is deployed in an area where there exists signals from existing macro base stations. Our numerical results indicate that the coverage of femto cell increases as the total power of femto cell increases or the ratio of power allocated to pilot channel increases. However, it is also shown that the coverage of femto cell is very limited despite its high power when interference signals from macro base stations are strong.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.11
• /
• pp.2405-2410
• /
• 2012

The 4th generation mobile communication system, LTE, does not support an additional core network to provide voice service, and it is merged into a packet network based on all IP. Although Voice service over LTE can be supported by VoIP, it will be provided by the existing 3G networks because of the discontinuity of LTE coverage. However, it is inevitable to adopt VoIP over LTE to provide high quality voice service. In this paper, we investigate the capacity of VoIP over LTE. Our results indicate that spectral efficiency can be significantly improved as channel bandwidth increases in terms of VoLTE capacity. In addition, we can achieve higher VoLTE capacity without decreasing control channel capacity.