Transport Layer

We report the fabrication of polymer light emitting diodes from a cyano-substituted thienylene phenylene vinylene copolymer. Photoluminescence and electroluminescence studies of these devices show a broad emission spectrum which peaks in the near infra-red and extends out to a wavelength of 1000nm. Bilayer structures using poly(p-phenylene vinylene) as a hole transport layer and the cyano-copolymer as the emissive layer showed improved electroluminescence internal quantum efficiency of up to 0.2%..

Considering that current end to end communication services are not adapted for supporting efficiently distributed multimedia application, this paper introduces a new family of generic transport protocols directly instantiated from application layer quality of service requirements. This Generic Transport Protocol (GTP) has been successfully tested for video on demand systems and is one of the major building block of the currently under development GCAP European project. GTP allows one to apply in the transport layer powerful adaptation mechanisms to the network behavior while preserving application requirements and alleviating network bandwidth and buffering needs

Coexistence issues between IEEE 802.11b wireless communication networks and IEEE 802.15.4 wireless sensor networks, operating over the 2.4-GHz industrial, scientific, and medical band, are assessed. In particular, meaningful experiments that are performed through a suitable testbed are presented. Such experiments involve both the physical layer, through measurements of channel power and the SIR, and the network/transport layer, by means of packet loss ratio estimations. Different configurations of the testbed are considered; major characteristics, such as the packet rate, the packet size, the SIR, and the network topology, are varied. The purpose of this paper is to gain helpful information and hints to efficiently face coexistence problems between such networks and optimize their setup in some real-life conditions. Details concerning the testbed, the measurement procedure, and the performed experiments are provided.

In many packet-based communication systems such as TCP/IP-based systems, packets are communicated over a noisy physical layer (a channel), and if a packet cannot be decoded correctly, then the transport layer retransmits it. Of course, retransmissions consume significant resources and their use should be limited. However, decreasing the likelihood of retransmission requires to encode the packets with strong channel codes in the physical layer, which also requires additional channel resources. In this paper, we study the cross-layer tradeoff between coding and packet retransmissions, and optimize over the total channel resource consumption. We show that as the packet length k increases, the redundancy r beyond the k/C channel uses implied by Shannon's channel capacity C is Theta(radickln(k)) extra channel uses. Moreover, as k increases we must use stronger channel codes. We then apply these results to universal coding over a piecewise memoryless channel with transitions between unknown i.i.d. statistics. Our constructive universal algorithm has redundancy r=O(k2/3radicln(k)) using packets of polynomially increasing lengths while accounting for possible packet drops caused by transitions in the statistics.

Providing seamless mobility support is one of the most challenging problems towards the system integration of fourth generation (4G) wireless networks. Because of the transparency to the lower layer characteristics, application-layer mobility management protocol like the Session Initiation Protocol (SIP) has been considered as the right candidate for handling mobility in the heterogeneous 4G wireless networks. SIP is capable of providing support for not only terminal mobility but also for session mobility, personal mobility and service mobility. However, the performance of SIP, operating at the highest layer of the protocol stack, is only as good as the performance of the underlying transport layers in such a heterogeneous environment. In this paper we analyze the handoff performance of SIP in a IP-based 4G network with Universal Mobile Telecommunication System (UMTS) and Wireless LAN (WLAN) access networks. Analytical results show that the handoff to a UMTS access network introduces a minimum delay of 1.4048 s for 128 kbps channel, while for handoff to a WLAN access network the minimum delay is 0.2 ms. In the former case the minimum delay is unacceptable for streaming multimedia traffic and requires the deployment of soft-handoff techniques in order to reduce the handoff delay to a desirable maximum limit of 100 ms.

We report highly efficient red phosphorescent organic light-emitting diodes with a triplet p-i-n single quantum well (QW) structure. This p-i-n single QW structure is realized using p-doped and n-doped wide band-gap hole and electron injection and transporting layers with narrow band-gap host and dopant materials. The maximum current and power efficiencies of 11.1 cd/A and 14.4 lm/W, respectively, are demonstrated by a good carrier confinement effect of QW. Very low driving voltage characteristics of 3.7 ∼ 3.9 V at 1000 cd/m2 are realized by almost no injection barrier with high conductivity configuration in our p-i-n structure.

Global Optimization ) ‫ازدحام‬ ‫کنترل‬ ( congestion control ‫شده‬ ‫توزیع‬ ‫الگوریتم‬ ‫یک‬ ‫عنوان‬ ‫به‬ ‫را‬ ( primal -dual ‫شود‬ ‫می‬ ‫انجام‬ ‫لینکها‬ ‫و‬ ‫منابع‬ ‫توسط‬ ‫که‬ ‫ازدحام‬ ‫کنترل‬ ‫مکانیزم‬ ‫نماییم.‬ ‫می‬ ‫بررسی‬ TCP vegas ‫با‬ ‫را‬ multi link -multi source ‫دهیم.‬ ‫می‬ ‫شرح‬ ‫و‬ ‫عدالت‬ ، ‫تاخیر‬ ‫مهم‬ ‫ویژگیهای‬ ‫شده‬ ‫مطرح‬ ‫مدل‬ loss ‫در‬ TCP Vegas ‫داده‬ ‫نشان‬ ‫کند.‬ ‫می‬ ‫بیان‬ ‫را‬ ‫که‬ ‫شود‬ ‫می‬ vegas ‫اختصاص‬ ‫با‬ ‫باشد،‬ ‫داشته‬ ‫وجود‬ ‫شبکه‬ ‫در‬ ‫کافی‬ ‫میزان‬ ‫به‬ ‫بافرینگ‬ ‫که‬ ‫زمانی‬ ‫است‬ ‫ممکن‬ ‫که‬ ‫کنیم‬ ‫می‬ ‫بررسی‬ ‫ادامه‬ ‫در‬ ‫کند.‬ ‫می‬ ‫پیدا‬ ‫ثبات‬ ، ‫شبکه‬ ‫ظرفیت‬ ‫وزندار‬ ‫عادلنه‬ ‫با‬ ‫که‬ ‫دهد‬ ‫می‬ ‫پیشنهاد‬ ‫و‬ ‫کرده‬ ‫بررسی‬ ‫را‬ ‫آن‬ ‫نتایج‬ ‫و‬ ‫دهد‬ ‫رخ‬ ‫شبکه‬ ‫در‬ ‫ازدحام‬ ‫ایجاد‬ ‫مکانیزم‬ ) ‫صف‬ ‫فعال‬ ‫مدیریت‬ ‫از‬ ‫استفاده‬ REM ‫سازی‬ ‫شبیه‬ ‫نتایج‬ ‫نهایت‬ ‫در‬ ‫کرد.‬ ‫جلوگیری‬ ‫آن‬ ‫از‬ ‫توان‬ ‫می‬ ( ‫ایم.‬ ‫آورده‬ ‫پایان‬ ‫در‬ ‫را‬

... [9] Aruna Balasubramanian, Ratul Mahajan, and Arun Venkataramani. Augmenting mobile 3g using wifi. In Proc. Mobisys. ACM, 2010. [10] Ahmad Rahmati and Lin Zhong. Context-for-wireless: context-sensitive energy-efficient wireless data transfer. In Proc. Mobisys. ...

This paper describes the concept of sensor networks which has been made viable by the convergence of microelectro-mechanical systems technology, wireless communications and digital electronics. First, the sensing tasks and the potential sensor networks applications are explored, and a review of factors influencing the design of sensor networks is provided. Then, the communication architecture for sensor networks is outlined, and the algorithms and protocols developed for each layer in the literature are explored. Open research issues for the realization of sensor networks are also discussed. Ó 2002 Published by Elsevier Science B.V.

The need for reliable data communication performed in critical conditions and the respect of real-time constraints is an open issue in radio-military networks, where fixed and nomadic terminals communicate by means of tactical radio infrastructures. In this perspective the need for real-time constraints plays a fundamental role when the interested applications are remote control, radar traces acquisition and command/control message exchanging. In this paper, the difficulties of data transportation in wireless networks are considered by taking emphasis on the TCP-NewReno implementation that does not guarantee satisfying performance results in such environments. The whole investigation is addressed at designing and validating novel transmission mechanisms to be implemented at the transport layer, directly inherited from standard TCP transmission scheme. TCP-radio and TCP-radio-newRTO proposals are thus discussed and compared with TCP-Westwood+ and TCP-NewReno in order to highlight the necessity for an enhanced transport protocol for data communication performed in radio military environments, where the data transfer is heavily affected by hazardous conditions, such as scattering, shadowing and slow fading.

We propose using the Stream Control Transmission Protocol (SCTP), a recent IETF transport layer protocol, for reliable web transport. Although TCP has traditionally been used, we argue that SCTP better matches the needs of HTTP-based network applications. This position paper discusses SCTP features that address:

The Suzuki-Miyaura coupling between 3,6-dibromo-N-hexylcarbazole and aryl-boronic acids catalyzed by Pd(PPh 3 ) 4 afforded blue emitting molecules, 3,6-diaryl-N-hexylcarbazole: aryl = phenyl (1), p-methoxyphenyl (2), p-cyanophenyl (3), p-acetophenyl (4), pyrenyl (5), biphenyl (6), difluorophenyl (7) and p-nitrophenyl , in good yield. The HOMO level of the carbazole derivative varied between −5.67 and −6.02 eV due to the electron-withdrawing or donating substituent in the aryl group. This is confirmed by the linear correlation of the Hammett parameter of the substituent in the phenyl group with oxidation potential or energy levels. Density functional theory calculation (B3LYP/6-31G*) of carbazole derivatives confirmed the experimentally observed trend. Blue fluorescence quantum yield of these molecules is high (0.19-0.96), except for the nitrophenyl derivative (<0.1). Single layer organic light emitting devices (OLEDs) using spin-coated films of 2-5 showed blue electroluminescence (EL) with a turn-on voltage at ∼6-7 V. The performance of blue EL of molecules 3 and 4 improved dramatically (turn-on at ∼3 V, brightness at ∼1000 cd/m 2 , efficiency at ∼1 cd/A) in a multilayer OLED designed using standard molecules as electron and hole transport layers for efficient and balanced carrier injection.

Transport layer protocols provide for end-to-end communication between two or more hosts. This paper presents a tutorial on transport layer concepts and terminology, and a survey of transport layer services and protocols. The transport layer protocol TCP is used as a reference point, and compared and contrasted with nineteen other protocols designed over the past two decades. The service and protocol features of twelve of the most important protocols are summarized in both text and tables.

Information flow in a telecommunication network is accomplished through the interaction of mechanisms at various design layers with the end goal of supporting the information exchange needs of the applications. In wireless networks in particular, the different layers interact in a nontrivial manner in order to support information transfer. In this text we will present abstract models that capture the cross-layer interaction from the physical to transport layer in wireless network architectures including cellular, ad-hoc and sensor networks as well as hybrid wireless-wireline. The model allows for arbitrary network topologies as well as traffic forwarding modes, including datagrams and virtual circuits. Furthermore the time varying nature of a wireless network, due either to fading channels or to changing connectivity due to mobility, is adequately captured in our model to allow for state dependent network control policies. Quantitative performance measures that capture the quality of service requirements in these systems depending on the supported applications are discussed, including throughput maximization, energy consumption minimization, rate utility function maximization as well as general performance functionals. Cross-layer control algorithms with optimal or suboptimal performance with respect to the above measures are presented and analyzed. A detailed exposition of the related analysis and design techniques is provided.

We report the effects of non-radiative charge recombination interface resulting on high hole mobility and low driving voltage characteristics in organic light-emitting devices. These effects are demonstrated in the following device architecture: hole transporting layer (HTL)/extremely deep LUMO (lowest unoccupied molecular orbital) electron transporting layer (ETL)/HTL. The extremely small gap between the high HOMO (highest occupied molecular orbital) of the HTL and the deep LUMO of the ETL leads to facilitate the hole conduction through charge recombination at the interface. The excellent hole mobility of 4.7 × 10 −1 cm 2 /V s in this device configuration is measured by the space charge limited current method with an electric field of 0.1 MV/cm. We suggest that such a high hole mobility is attributed to the rapid coulombic interaction at the charge recombination interface in addition to the hole and electron mobilities of the individual HTL and ETL, respectively.

Computer networking has become the core centre of computing across many platforms of devices; mobile phones, game consoles, tablets and computers in general. The need to communicate using audio and video has been widely used and is growing. This is often referred to as multimedia networking.
For communication to be complete, multimedia applications or any applications require the services that are provided by the transport layer. The transport layer cannot be by passed. This layer is an interface between the Application layer and the Network layer of the TCP/IP protocol stack. The transport layer has protocols that play a huge role in offering the necessary services for process to process delivery to be successful. The protocols are responsible for the delivery of packets from the source to destination application.

Lapisan transport (transport layer) bertanggung jawab dalam membuat sesi komunikasi sementara antara 2 aplikasi dan saling bertukar data. Lapisan transport menjadi penghubung antara application layer dan layer lain yang berada di bawahnya, bertanggung jawab dalam transmisi jaringan.

This paper describes the concept of sensor networks which has been made viable by the convergence of microelectro-mechanical systems technology, wireless communications and digital electronics. First, the sensing tasks and the potential sensor networks applications are explored, and a review of factors influencing the design of sensor networks is provided. Then, the communication architecture for sensor networks is outlined, and the algorithms and protocols developed for each layer in the literature are explored. Open research issues for the realization of sensor networks are also discussed. Ó 2002 Published by Elsevier Science B.V.

Wireless and satellite networks often have non-negligible packet corruption rates that can significantly degrade TCP performance. This is due to TCP&#39;s assumption that every packet loss is an indication of network congestion (causing TCP to reduce the transmission rate). This problem has re- ceived much attention in the literature. In this paper, we take a broad look at the problem

Rapid advances in transmission technology and networking have resulted in development of hardware implementations of several communication protocols, called protocol controllers. Such controllers have been developed for several standard protocols such as X.25 and LAPD. Controllers for some transport layer protocols are also under development. Several controllers for the IEEE 802 local area networks have been developed. In this paper, these controllers are surveyed and some characteristics for classifying them are given. Some case studies from these controllers are given as illustrations. In addition, two new developments-the Protocol Engine and the Programmable Protocol Engine-are also described. The Protocol Engine, currently under development, will implement a new protocol called XTP which performs the functions of both the network and transport layers. The Programmable Protocol Engine will be able to implement several connection-oriented protocols by changing contents of a programmable RAM.

FPGA-based solutions become more common in embedded systems these days. These systems need to communicate with external world. Considering high-speed and popularity of Ethernet communication, developing a reliable real-time Ethernet component inside FPGA is of special value. To that end, we present a new solution for 100 Mb/s FPGAbased Ethernet communications with timing analysis. The solution deals with "Reduced Media-Independent Interface" in its physical layer. Network protocol is implemented from physical to transport layer which is UDP. For getting used in real-time applications, timing analysis is done. Component based software engineering is used in the design and development process. In order to test the components inside FPGA two different approaches are utilized. Signal measurement in combination with introduced windows based application contributes much in testing and validation phase.

Designing efficient transmission mechanisms for advanced satellite networks is a demanding task, requiring the definition and the implementation of protocols and architectures well suited to this challenging environment. In particular, transport protocols performance over satellite networks is impaired by the characteristics of the satellite radio link, specifically by the long propagation delay and the possible presence of segment losses due to physical channel errors. The level of impact on performance depends upon the link design (type of constellation, link margin, coding and modulation) and operational conditions (link obstructions, terminal mobility, weather conditions, etc.). To address these critical aspects a number of possible solutions have been presented in the literature, ranging from limited modifications of standard protocols (e.g. TCP, transmission control protocol) to completely alternative protocol and network architectures. However, despite the great number of different proposals (or perhaps also because of it), the general framework appears quite fragmented and there is a compelling need of an integration of the research competences and efforts. This is actually the intent of the transport protocols research line within the European SatNEx (Satellite Network of Excellence) project. Stemming from the authors' work on this project, this paper aims to provide the reader with an updated overview of all the possible approaches that can be pursued to overcome the limitations of current transport protocols and architectures, when applied to satellite communications. In the paper the possible solutions are classified in the following categories: optimization of TCP interactions with lower layers, TCP enhancements, performance enhancement proxies (PEP) and delay tolerant networks (DTN). Advantages and disadvantages of the different approaches, as well as their interactions, are investigated and discussed, taking into account performance improvement, complexity, and compliance to the standard semantics. From this analysis, it emerges that DTN architectures could integrate some of the most efficient solutions from the other categories, by inserting them in a new rigorous framework. These innovative architectures therefore may represent a promising solution for solving some of the important problems posed at the transport layer by satellite networks, at least in a medium-tolong-term perspective.

We propose a novel end-to-end architecture for streaming H.264/AVC (advanced video coding) unicast video over the Internet. The proposed video streaming architecture is based primarily on a new transport layer protocol, the stream control transmission protocol (SCTP). We show that the network-friendly specification of H.264/AVC and the novel technical characteristics of SCTP, when coupled together are able to provide a highly adaptive and flexible system for unicast video streaming. With simulation results we prove (1) that our system is capable of maintaining good perceptual quality under various loss conditions and (2) that the proposed system maintains TCP-friendliness.

The standard end-to-end flow control implemented by the TCP protocol is ill-suited when it comes to achieving fair bandwidth allocation among competing TCP flows. Indeed, the lack of feedback from intermediate nodes does not allow a TCP source to regulate its throughput so that it is not sending more than its fair share, thus penalizing other, less aggressive flows. In this paper, we propose a novel scheme that, building on existing work on network-layer stateless fair queueing, extends the approach to the TCP layer. Also, we discuss a possible implementation of both the network-layer and the transport-layer architecture. We test our solution under different traffic scenarios and show that not only is a fair bandwidth allocation achieved, but the overall network utilization for TCP flows is also increased.

Congestion can occur in wireless sensor networks when multiple sensor nodes try to transmit data. The sensor nodes closer to sink are more liable to congestion as they generally carry large upstream traffic. Congestion leads to higher packet loss, increased packet delay, less energy efficiency and poor throughput. Thus, congestion control is an important aspect that should be considered while designing transport layer protocols. In this paper, we first describe the basics of wireless sensor networks and their architecture. Then we elaborate the aspects of congestion control. Then we present various transport layer protocols which provide congestion control and then a comparison of these protocols is given on the basis of various parameters viz. congestion detection, congestion notification, congestion mitigation, hbh/e2e, fairness, energy efficiency, simulation/testbed, network topology, number of sensor nodes, buffer size, packet size, radio transmission range, coverage area, channel bit rate, initial transmission rate, simulation time, energy, fairness, latency, queue size, throughput, source rate, packet drop and fidelity . At the end, we present open research issues in congestion control protocols for wireless sensor networks.

The IEEE Standard 802.11 is one of the most widely adopted mechanisms for WLANs, it provides comprehensive guidelines for their operational smoothness. 802.11 suffered from limited data confidentiality and cumbersome procedure for exchange of security parameters. In response to the security limitations in 802.11, IEEE introduced 802.1x for authentication and key management. The 802.1x is a port based network access control protocol that uses Extensible Authentication Protocol (EAP) at the transport layer. The 802.1x only defines authentication mechanism and does not recommend any appropriate authentication method. Consequently wireless vendors implemented their own 802.1x adaptations such as MD5 (Message Digest 5), TLS (Transport Layer Security), TTLS (Tunneled TLS), PEAP (Protected Extensible Authentication Protocol), LEAP (Lightweight Extensible Authentication Protocol) etc. The paper analyses the performance of 802.1x authentication with respect to different solutions i.e, EAP TLS, PEAP and EAP TTLS. The network performance is gauged with respect to throughput, round time trip (RTT)/response time and packet error in different configurations.

Internet of Things (IoT) can be found everywhere in our life. They find application at homes for control and reporting in emergency clinics and for adjustment reporting in various conditions, counteracting fires and in various other applications. These applications are advantageous in various applications which can be either misfortune of security issues. For securing the various gadgets involved a number of research work has been carried out in various counteractivity measures, thus those issues are identified and then located in order to develop a method for disposing off these problems. For protecting the security of the consumer, the consequences are made to limit. The paper has four sections. First part will present the order of assaults of IoT and following sections tries to concentrate on the design and components for the purpose of verification and also to control. In the last section, various layers are discussed in detail

Organic solar cells require suitable anode surface modifiers in order to selectively collect positive charge carriers and improve device performance. We employ a nickel metal organic ink precursor to fabricate NiO hole transport layers on indium tin oxide anodes. This solution deposited NiO annealed at 250°C and plasma treated, achieves similar OPV device results reported with NiO films from PLD as well as PEDOT:PSS. We demonstrate a tunable work function by post-processing the NiO with an O 2 -plasma surface treatment of varied power and time. We find that plasma treatment is necessary for optimal device performance. Optimal devices utilizing a solution deposited NiO hole transport layer show lower series resistance and increased fill factor when compared to solar cells with PEDOT:PSS.

Our proposed Bandwidth Optimization Control Protocol allows a mobile node to send request and get reply using two different networks simultaneously. Connection supply for mobile nodes is not done by modifying transport layer protocols, but by handling the update of routing table at the Internet layer using bandwidth optimization control protocol messages, options, and processes that ensure the correct delivery of request and reply. The result from our simulation shows that the mobile node is getting higher data rates and efficiently utilizes network resources as compared to using single network.

A blue organic light emitting device (OLED) with improved efficiency and good color purity is reported. The highest occupied molecular orbital (HOMO) level of the hole transport layer (HTL) and that of the emissive layer (EML) differs by 0.3 eV. This energy level mismatch confines the carriers at the HTL/EML interface. Conventional devices have only one HTL/EML interface, with a current efficiency of 2.9 cd/A. Without adding a separate hole blocking layer, incorporating multi-layers of the same HTL and EML increases this efficiency to 5.8 cd/A, with only a small increase in operating voltage yielding increased power efficiency also. But, there are an optimum number of layers, beyond which efficiency loss results. Also, including the multilayer structure simultaneously improves the blue color coordinates. To gain insight into the role of multilayer structures in modifying charge transport and recombination zone a simulator was developed. The simulated results could qualitatively explain the experimental observations.

In this paper we present the Collaborative Computing Frameworks (CCF) as an integration platform for e-learning. The capabilities of the CCF facilitate mixed modes of delivery and the possibility to integrate already existing e-learning platforms. The CCF features allow to form different groups during the learning process. This coupled with peerto-peer communication facilities, promotes the efficient implementation of collaborative technologies as an important component of the Dialogue phase of the learning process. The new Collaborative Computing Transport Layer (CCTL) will allow wireless devices to be experimented with for the purposes of e-learning. It is envisaged that this direction will dramatically widen the possibilities for content delivery.

International conference on AI, Machine Learning in Communications and Networks (AIMLNET 2021) will provide an excellent international forum for sharing knowledge and results in theory, methodology and applications of Artificial Intelligence, Machine Learning impacts on Communications and Networks. The Conference looks for significant contributions to all major fields of the Artificial Intelligence, Machine Learning and networks in theoretical and practical aspects. The aim of the Conference is to provide a platform to the researchers and
practitioners from both academia as well as industry to meet and share cutting-edge development in the field.

A bottom contact/top gate ambipolar “p-i-n” layered light emitting field effect transistor with the active medium inserted between two doped transport layers, is reported. The doping profile results crucial to the capability of emitting light, as well as to the electrical characteristics of the device. In this sense, high output current at relative low applied gate/drain voltage and light emission along the whole large area transistor channel are observed, putting the basis to full integration of organic light emitting field effect transistors in planar complex devices.

In this study, we examine organic light emitting diodes (OLEDs) having Al top electrodes deposited on organic layers by direct-current magnetron sputtering. The OLEDs consisted of electronically doped transport layers and phosphorescent emission layer were characterized by typical current-voltage-luminance measurement. They showed higher leakage currents, decreased forward currents, and corresponding increases of driving voltage after the sputter deposition on the organic layers. The OLEDs exhibited randomly distributed bright spots on the active area, and the bright spots were investigated by scanning electron microscopy/energy-dispersive X-ray spectroscopy. In order to prove the origins of sputter damage, simple organic/Al layer samples were made and investigated by ellipsometry and laser-induced desorption/ionization time-of-flight mass spectrometry. The results are compared with previous works addressing the fundamental phenomena of magnetron sputtering. We conclude that the high leakage current originated from a penetration of sputtered metal atoms into the underlying organic layers, and the decrease of forward current resulted from an interface degradation caused by the radiation of plasma, which reduces charge carrier injection preferentially at the Al/organic layer interface.

We present a detailed analysis and computations of the emitted radiation spectrum for quantum dots (QDs) microcavity light-emitting device, where the total physical thickness of the cavity spacer was kept at 254 nm which corresponds to the wavelength of the mode number (m) = 1 resonant mode of the cavity. Our calculation gives good results for QD diameter only from 1.2 to 6.4 nm. The computations are used to examine how the emitted radiation spectrum can be optimized by varying the position of the light-emitting layer, the type of cathode material, the choice of hole transport layer material, and the thickness of electron transport layer, QD layer, and hole transport layer. These studies showed that the variation of layers geometry and the position of the light-emitting layer will optimize the output intensity and the radiation spectrum and varying the ETL and QD layer thickness will have a more effect on the emitted spectrum than varying HTL thickness. In addition, we have examined the effect of using different quantum dots sizes in emission layer. On the other hand, we have investigated the difference between the electroluminescence (EL) emissions for microcavity device in comparison with the non-cavity device, and we have found that the full width at half maximum (FWHM) of the EL is reduced from 45 nm for the QD non-cavity LED to 30 nm for the output of a resonant microcavity device. Finally, we have investigated the compatibility between our calculation and the experimental results and found a fairly good agreement between them.

Player/Stage has become a de facto standard in the open source robotics community. We describe recent work on restructuring the Player robot device server into a system that more closely aligns with the idea of a robot framework. The general requirements for a robot framework are also discussed. Player 2.0 is a major improvement in two basic areas, simplicity and flexibility. The driver API has been vastly simplified with many more parts of the communication being hidden from the user. The flexibility of the new system is realised in the library division that allows for different transport layers (or no transport at all), and in the new device address structure that allows for inter-server device subscriptions.