A Receiver-Driven Loss Recovery Mechanism for Video Dissemination over Information-Centric VANET

( Longzhe Han ),( Xuecai Bao ),( Wenfeng Wang ),( Xiangsheng Feng ),( Zuhan Liu ),( Wenqun Tan ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.7

Information-Centric Vehicular Ad Hoc Network (IC-VANET) is a promising network architecture for the future intelligent transport system. Video streaming applications over IC-VANET not only enrich infotainment services, but also provide the drivers and pedestrians real-time visual information to make proper decisions. However, due to the characteristics of wireless link and frequent change of the network topology, the packet loss seriously affects the quality of video streaming applications. In this paper, we propose a REceiver-Driven loss reCOvery Mechanism (REDCOM) to enhance video dissemination over IC-VANET. A Markov chain based estimation model is introduced to capture the real-time network condition. Based on the estimation result, the proposed REDCOM recovers the lost packets by requesting additional forward error correction packets. The REDCOM follows the receiver-driven model of IC-VANET and does not require the infrastructure support to efficiently overcome packet losses. Experimental results demonstrate that the proposed REDCOM improves video quality under various network conditions.

Production and characterization of activated carbon derived from brewer’s yeast

Longzhe Cui,Guiping Wu,Tae-seop Jeong,Chan-Hee Won 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.5

Activated carbon (AC) was produced from brewer’s yeast with K2CO3 activation. The effects of K2CO3/yeast ratio and activation temperature on the yield and adsorption properties of the AC were investigated. The results indicate that the optimum conditions were as follows: ratio of K2CO3/yeast=2 and activation temperature 800 oC. The AC produced under the optimum conditions has BET surface area of 1,603 m2/g, pore volume of 1.43 cm2/g and average pore diameter of 3.5 nm. Adsorption of phenol onto the AC was determined by batch test at solution pH of 7. The effects of contact time and initial phenol concentration were investigated. The adsorption process was found to follow pseudosecond-order kinetics. The rate of phenol adsorption onto the AC produced was rapid with the adsorption equilibrium reached within 5 min. The experimental data fitted well with the Langmuir isotherm model. The maximum phenol uptake by the AC was estimated to be 513.5 mg/g.

Deep Learning based Loss Recovery Mechanism for Video Streaming over Mobile Information-Centric Network

( Longzhe Han ),( Taras Maksymyuk ),( Xuecai Bao ),( Jia Zhao ),( Yan Liu ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.9

Mobile Edge Computing (MEC) and Information-Centric Networking (ICN) are essential network architectures for the future Internet. The advantages of MEC and ICN such as computation and storage capabilities at the edge of the network, in-network caching and named-data communication paradigm can greatly improve the quality of video streaming applications. However, the packet loss in wireless network environments still affects the video streaming performance and the existing loss recovery approaches in ICN does not exploit the capabilities of MEC. This paper proposes a Deep Learning based Loss Recovery Mechanism (DL-LRM) for video streaming over MEC based ICN. Different with existing approaches, the Forward Error Correction (FEC) packets are generated at the edge of the network, which dramatically reduces the workload of core network and backhaul. By monitoring network states, our proposed DL-LRM controls the FEC request rate by deep reinforcement learning algorithm. Considering the characteristics of video streaming and MEC, in this paper we develop content caching detection and fast retransmission algorithm to effectively utilize resources of MEC. Experimental results demonstrate that the DL-LRM is able to adaptively adjust and control the FEC request rate and achieve better video quality than the existing approaches.

Adaptive Retransmission Scheme for Video Streaming over Content-Centric Wireless Networks

Longzhe Han,Seung-Seok Kang,Hyogon Kim,In, H. P. IEEE 2013 IEEE COMMUNICATIONS LETTERS Vol.17 No.6

<P>This paper presents an adaptive retransmission scheme to overcome video packet losses in content-centric wireless networks. Because of in-network caching, the round-trip time (RTT) may fluctuate significantly. A new timeout estimation algorithm is proposed to quickly adjust the timeout value. The sequential hypothesis testing methodology is suggested to provide theoretical bounds on the probabilities of false-positive and false-negative detection rates. By considering the reasons for packet losses, the scheme adaptively controls its retransmission window size. Experimental results demonstrate that the proposed scheme efficiently recovers packet losses under various network conditions.</P>

Cross-layer Video Streaming Mechanism over Cognitive Radio Ad hoc Information Centric Networks

( Longzhe Han ),( Nguyen Dinh Han ),( Seung-seok Kang ),( Hoh Peter In ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.11

With the increasing number of the wireless and mobile networks, the way that people use the Internet has changed substantively. Wireless multimedia services, such as wireless video streaming, mobile video game, and mobile voice over IP, will become the main applications of the future wireless Internet. To accommodate the growing volume of wireless data traffic and multimedia services, cognitive radio (CR) and Information-Centric Network (ICN) have been proposed to maximize the utilization of wireless spectrum and improve the network performance. Although CR and ICN have high potential significance for the future wireless Internet, few studies have been conducted on collaborative operations of CR and ICN. Due to the lack of infrastructure support in multi-hop ad hoc CR networks, the problem is more challenging for video streaming services. In this paper, we propose a Cross-layer Video Streaming Mechanism (CLISM) for Cognitive Radio Ad Hoc Information Centric Networks (CRAH-ICNs). The CLISM included two distributed schemes which are designed for the forwarding nodes and receiving nodes in CRAH-ICNs. With the cross-layer approach, the CLISM is able to self-adapt the variation of the link conditions without the central network controller. Experimental results demonstrate that the proposed CLISM efficiently adjust video transmission policy under various network conditions.

An Adaptive FEC Mechanism Using Crosslayer Approach to Enhance Quality of Video Transmission over 802.11 WLANs

( Longzhe Han ),( Sungjun Park ),( Seung-seok Kang ),( Hoh Peter In ) 한국인터넷정보학회 2010 KSII Transactions on Internet and Information Syst Vol.4 No.3

Forward Error Correction (FEC) techniques have been adopted to overcome packet losses and to improve the quality of video delivery. The efficiency of the FEC has been significantly compromised, however, due to the characteristics of the wireless channel such as burst packet loss, channel fluctuation and lack of Quality of Service (QoS) support. We propose herein an Adaptive Cross-layer FEC mechanism (ACFEC) to enhance the quality of video streaming over 802.11 WLANs. Under the conventional approaches, FEC functions are implemented on the application layer, and required feedback information to calculate redundancy rates. Our proposed ACFEC mechanism, however, leverages the functionalities of different network layers. The Automatic Repeat reQuest (ARQ) function on the Media Access Control (MAC) layer can detect packet losses. Through cooperation with the User Datagram Protocol (UDP), the redundancy rates are adaptively controlled based on the packet loss information. The experiment results demonstrate that the ACFEC mechanism is able to adaptively adjust and control the redundancy rates and, thereby, to overcome both of temporary and persistent channel fluctuations. Consequently, the proposed mechanism, under various network conditions, performs better in recovery than the conventional methods, while generating a much less volume of redundant traffic.

中国跨境电子商务征税问题及征管建议

崔?哲(CUI LONGZHE),?宇梁(JIN YULIANG) 동아대학교 법학연구소 2021 國際去來와 法 Vol.- No.35

Since 2014, Chinas cross-border e-commerce has ushered in explosive development, constantly going deep into all aspects of peoples daily life and providing convenience for peoples life. When China sees the contribution of cross-border e-commerce to economic development, it should also pay attention to the tax problems brought by cross-border e-commerce. This problem mainly includes: in cross-border e-commerce transactions, enterprises set up virtual business institutions and places, resulting in unclear judgment standards for tax subjects; In cross-border e-commerce transactions, due to the trend of digitization and virtualization of goods, the qualitative classification standard of enterprise income is not clear, and it is difficult to classify enterprise income qualitatively; And because cross-border e-commerce is a new thing, the original tax management model lags behind. By combining the relevant legal provisions of Chinas enterprise income tax law and the tax collection and administration law, and analyzing the characteristics of Chinas cross-border e-commerce at present, this paper puts forward relevant suggestions on the tax problems of cross-border e-commerce: in view of the unclear judgment standard of tax subject, it is necessary to introduce the concept of real or virtual subject into the enterprise income tax law, Broaden the identification scope of enterprise institutions and places; In view of the unclear qualitative classification standard of enterprise income, it should be judged on the basis of the traditional qualitative classification standard of income, supplemented by the standards of contract type and transaction purpose; In view of the lag of the tax collection management mode, the tax registration system applicable to cross-border e-commerce should be stipulated and improved in the tax collection management law, the tax declaration system should be improved, and the legal liability should be strengthened.

Comparison of catalytic ozonation of phenol by activated carbon and manganese-supported activated carbon prepared from brewing yeast

Guiping Wu,Longzhe Cui,정태섭,원찬희 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.1

Activated carbon (AC) was prepared using brewing yeast as precursor by chemical activation and manganese was supported on activated carbon (Mn/AC) by adsorption-activation method. The characterizations of prepared AC and Mn/AC and their performance as ozonation catalysts was tested. The results indicated that the crystalline phase of supported manganese was MnO. The total BET surface areas of prepared AC and Mn/AC were found to be 1603.0m2/g and 598.9 m2/g, with total pore volumes of 1.43 and 0.49 cm3/g, respectively. The average pore diameters of AC and Mn/AC were found to be 3.5 nm and 3.3 nm. Adsorption capacities of phenol onto the produced AC and Mn/AC were determined by batch test, at 25 oC and pH 7. Langmuir and Freundlich isotherm models were used to fit the isotherm experimental data, and the Langmuir isotherm model fitted these two adsorption systems well. The maximum uptakes of phenol by AC and Mn/AC were estimated to be 513.5 mg/g and 128.2 mg/g. The presence of AC prepared from brewing yeast was advantageous for TOC reduction of phenol solution compared with single ozonation, and the greatest TOC removal efficiency was obtained in the presence of Mn/AC. All ozonation reactions followed the pseudofirst-order kinetics model well, the degradation rate of phenol was enhanced in the presence of catalysts, and the more pronounced degradation rate was achieved in O3/Mn/AC system. The rate constants were determined to be 2.16×10−2min−1 for O3 alone, 5.70×10−2 min−1 for O3/AC and 6.82×10−2 min−1 for O3/Mn/AC.

The Research on Social Influence-based Cache Replacement Policy over Wireless Information-Centric Network

Yunhui Park,Longzhe Han,Geunhyung Lee,Dong-min Seo,Hoh Peter In 보안공학연구지원센터 2012 International Journal of Software Engineering and Vol.6 No.4

An Energy-Efficient Routing Protocol for CCN-based MANETs

Geunhyung Lee,Longzhe Han,Yunhui Park,Jung-Been Lee,Juwon Kim,Hoh Peter In 보안공학연구지원센터 2013 International Journal of Smart Home Vol.7 No.1