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The IEEE 802.3ca Task Force group has recently approved the standardization of the next-generation Ethernet passive optical network (NG-EPON) to satisfy future bandwidth demands. NG-EPON architecture classifies the optical network unit (ONU) transmission to allow simultaneous Wavelength-Agile (WA-PON) transmission, which increases the network capacity (50 Gb/s) and flexibility. The recently launched 5G services and related functional standards, new capabilities, and quality of service (QoS) imposed on the optical transport network. The Peer-to-peer (P2P) based live streaming application is the most popular multimedia application in access networks, i.e., Facebook Live, YouTube Live, Twitch, and other streaming and video conferencing services are increasing, especially in global epidemics which requires a higher QoS. Hence, media-based applications require adequate infrastructure resources to meet customer demands such as high bandwidth, low latency, high quality audiovisual, live streaming, and services. Therefore, this paper proposes an SDN enhanced P2P virtual reality (VR) live video streaming application NG-EPON multicast architecture based on 5G-enabled Tactile Internet (TI) and aims to improve the QoS, QoE and provide flexible services to the end-users. Finally, we proposed an SDN-based TI-dynamic wavelength and bandwidth allocation (SD-TI-DWBA) mechanism. Simulation results show that our proposed architecture can improve the system performance and QoS metrics regarding packet delay, jitter, system throughput, and packet loss.

The inter-cycle sleep design previously proposed as a power-saving scheme for next-generation Ethernet passive optical networks (NG-EPONs) is able to effectively decrease the power consumption of heavy-load traffic. However, with a medium to high traffic load, these networks may still suffer from a high level of power consumption if no enhanced mechanisms are used. It was noted that the optical line terminal (OLT) often fully opens all communication channels at a medium to heavy load. Moreover, the number of opened channels was changed cyclically according to the traffic loading status. Accordingly, optical network units (ONUs) may be frequently allocated to different channels with changing loads. This may lead to inefficient operation and result in significant channel tuning delays. We thus propose a loading-aware time-division multiple access (TDMA) mechanism that allows the OLT to reserve a maximum bandwidth for each ONU when the network experiences heavy-load traffic. The performance results of our simulations reveal that the proposed scheme is able to reduce power consumption for targeted medium to high loads since ONUs under such loads can extend their sleep time because the cycle length is maximized. Moreover, the total delay is maintained at a relatively low level after applying the proposed scheme since the tuning delay is reduced significantly; however, the transmission delay is slightly increased due to the increased cycle length.

Yarı ince kesitlerin kullanımı histolojik ve klinik tanı çalışmalarında önemli bir yere sahiptir. Fakat bu amaçla kullanılan plastik gömme ortamları hidrofobik oldukları için boyaların dokulara girişini sınırlandırmaktadırlar. Bu çalışmada; yarı ince epon kesitlerin boyanmasında daha çok detay sağlamak üzere bilinen epon solventleri ile asetonun karşılaştırılması ve daha önce denenmemiş toluidine blue-eozin ikili boyamasının değerlendirilmesi amaçlanmıştır. Çalışmada sıçan beyin, ince bağırsak ve pankreas doku örneklerine ait epon bloklardan ultramikrotom ile 1µm kalınlığında yarı ince kesitler alındı. Boyama öncesi epon kesitlere boyaların penetrasyonunu kolaylaştırmak amacı ile sodyum hidroksit, periyodik asit ve aseton ile üç ayrı etching uygulandı. Bir grup kesitte epon uzaklaştırılmadı. Toluidine blue ve toluidine blu-eozin ikili boyaması uygulanan kesitler ışık mikroskobunda değerlendirildi. Aseton ile etching sonrası üç dokuya ait toluidine blue boyama sonuçları, alkali ve asit etchingi sonrası boyamalara ve etching uygulanmadan yapılan boyamalara göre çok daha başarılı olarak değerlendirildi. Özellikle pankreasta daha berrak görüntüler sayesinde daha iyi detay sağladığı görüldü. Toluidine blue-eozin boyaması ile beyin ve pankreas dokularında olumlu sonuçlar elde edildi. Eponun uzaklaştırılması amacıyla ilk kez denenen aseton ile başarılı sonuçlar elde edildiği için diğer solventlere alternatif olarak asetonun rutinde kullanılabileceği düşünüldü. Yine ilk kez denenen toluidine blue-eozin ikili boyamasından epon kesitlerin değerlendirilmesinde yararlanılabileceği sonucuna varıldı.

Correlative fluorescent and electron microscopic images of the same section of epoxy (or other polymer)-embedded samples, hereafter referred to as ‘in-resin CLEM’, have been developed to improve the positional accuracy and Z-axis resolution limitations of conventional correlative light and electron microscopy (CLEM). High-pressure freezing and quick-freezing substitution result in in-resin CLEM of acrylic-based resin-embedded cells expressing green fluorescent protein, yellow fluorescent protein, mVenus and mCherry, which are sensitive to osmium tetroxide. The identification of osmium-resistant fluorescent proteins leads to the development of in-resin CLEM of Epon-embedded cells. Using subtraction-based fluorescence microscopy with a photoconvertible fluorescent protein, mEosEM-E, its green fluorescence can be observed in thin sections of Epon-embedded cells, and two-color in-resin CLEM using mEosEM-E and mScarlet-H can be performed. Green fluorescent proteins, CoGFP variant 0 and mWasabi, and far-red fluorescent proteins, mCherry2 and mKate2, are available for in-resin CLEM of Epon-embedded cells using the standard procedure for Epon-embedding with additional incubation. Proximity labeling is applied to in-resin CLEM to overcome the limitations of fluorescent proteins in epoxy resin. These approaches will contribute significantly to the future of CLEM analysis.

For the future high-speed next-generation Ethernet passive optical network (NG-EPON) system, the low-cost system could be kept by adopting low bandwidth devices. To compensate for the signal distortion and improve the performance of high-speed bandwidth limited system, we propose a special feature vector construction to achieve a new equalizer scheme based on support vector machines (SVM) classifier. For the first time, we mathematically analyze the model of the bandwidth-limited optical transmission system and theoretically derive the linear separability of the proposed feature vector formed linear hyperplane in 100-Gb/s NG-EPON system. Furthermore, 4 × 25-Gb/s non-return to zero (NRZ) and 2 × 50-Gb/s four-level pulse amplitude modulation (PAM-4) per wavelength transmission experiments with 10-G class optics system are demonstrated to prove the feasibility of our scheme. The experimental results show that, for 25-Gb/s/λ NRZ transmission, compared to the decision feedback equalizer (DFE) and feed-forward equalizer (FFE), the receiver sensitivity achieved by our scheme can be improved by about 0.5-dB @BER=3.8e-3 with limited training sequence. For the 50-Gb/s/λ PAM-4 case, the SVM-based equalization method improves the receiver sensitivity for about 1-dB.

Histolojide mikroskobik değerlendirme amacıyla alınan doku örnekleri, parafine veya plastik ortamlara gömülür. Plastik yarı ince kesitler, ışık mikroskobu ile elektron mikroskobu arasında bir köprü görevi görür. Bu kesitler parafinden daha ince, ince kesitlerden daha kalındır. Bu sayede ışık mikroskopide yarı ince kesitler, parafine göre daha ileri detay sağlar. Ancak plastik kesitlerin çoğu hidrofobiktir ve birçok boya ile boyanmazlar. Bu çalışmada; parafin ve epon kesitlerde daha çok doku komponentinin ayrımına imkan verecek boyama metotlarının geliştirilmesi amaçlanmıştır. Çalışmada; çeşitli doku örnekleri ikili fiksasyon sonrası Epon ile bloklandı. Aynı dokuların diğer grubu, rutin takip sonrası parafin ile bloklandı. Toluidine blue, hematoksilen, eozin, asit fuksin, metil green ve nötral red boyaları hem tekli, hem ikili kombinasyonlar şeklinde her iki kesit grubunda denendi. Ayrıca elastik, retiküler ve kollajen lifler ile mitokondri boyamaları da çalışıldı. Epon kesitlere boyaların penetrasyonunu kolaylaştırmak amacıyla, üç ayrı etching ajanı (sodyum hidroksit, periyodik asit ve aseton) uygulandı. Sonuçlar ışık mikroskobunda değerlendirildi. Eponun uzaklaştırılmasında aseton en başarılı bulundu. Epon kesitlerde tekli boyamalarda en iyi sonuçlar toluidine blue ile sağlandı. Ayrıca asit fuksin ve metil green de olumlu bulundu. Tekli boyamalar parafin kesitlerde başarılı bulunmadı. Epon kesitlerde ikili boyamalarda; toluidine blue-eozin, toluidine blue-asit fuksin, toluidine blue-metil green ve asit fuksin-toluidine blue kombinasyonlarında başarılı sonuçlar elde edildi. Parafin kesitlerde hematoksilen-eozin ile en iyi sonuçlar alındı. Ayrıca; toluidine blue-eozin ve asit fuksin-metil green kombinasyonlarından da yararlanılabileceği düşünüldü. Parafin ve epon kesitlerde dört özel boyama ile elastik, retiküler ve kollajen lifler ile mitokondri demonstrasyonunda da başarılı sonuçlar elde edildi. Olumlu bulunan boyamaların rutinde kullanılabileceği sonucuna varıldı. Tissue samples received for microscopic evaluation in histology are embedded in paraffin or plastic media. Plastic semithin sections serve as a connection between light and electron microscopies. These sections are thinner than paraffin sections, and thicker than thin sections. This helps semi-thin sections in light microscopy provide more advanced details than paraffin sections do. Most plastic sections are hydrophobic, however, and cannot be stained with many stains. In this study, the aim is to develop staining methods that allow more tissue components to be differantiated in paraffin and epon sections. Various tissue samples were subjected to double fixation and epon blocking in the study. Another group of the same tissues was subjected to routine tissue processing and paraffin blocking. Toluidine blue, hematoxylin, eosin, acid fuchsin, methyl green, and neutral red stains were tested in both section groups as single stains or dual combinations. Elastic, reticular, and collagen fiber stains and mitochondrial stains were tested additionally. Three different etching agents (sodium hydroxide, periodic acid, and acetone) were applied to facilitate the penetration of stains into the epon sections. The results were evaluated under a light microscope. Acetone was found to be the most successful in removing epon. The best results in epon sections with single stains were attained with toluidine blue. Acid fuchsin and methyl green were also found satisfactory. Single stains were not successful in paraffin sections. Among the dual stainings in epon sections, toluidine blue-eosin, toluidine blue-acid fuchsin, toluidine blue-methyl green, and acid fuchsin-toluidine blue combinations yielded successful results. The best results in paraffin sections were obtained with hematoxylin-eosin. Toluidine blue-eosin and acid fuchsin-methyl green combinations were also considered useful. Four special stainings yielded good results in demonstration of elastic, reticular, and collagen fibers and mitochondria in paraffin and epon sections. It was concluded that the stainings that are found successful can be used routinely.

Poly(hexamethylene adipamide), nylon 66, is a popular plastic that requires high surface wettability and strong adhesive bonds for many applications. However, pristine nylon is difficult to bond due to its hydrophobic nature and poor surface wettability. The objective of this work was to modify the physio-chemical surface properties of nylon 66 via a novel atmospheric plasma surface treatment approach using oxygen (O2) or water vapor (H2O) plasma glow. The surface hydrophilicity of the plasma-treated nylon surface was substantially enhanced immediately after either helium (He)/H2O or He/O2 plasma surface treatment. The average water contact angle was reduced from 65 degrees to ~30 degrees after He/H2O plasma and ~40 degrees after He/O2 plasma treatments. The improved hydrophilicity was also evidenced by the increased intensities of the surface oxygen and hydroxyl bonds in the X-ray photoelectron spectra. The interfacial adhesion strength of nylon surfaces before and after plasma treatment was further evaluated by uniaxial tensile tests of nylon single-joint lap shears bonded with three adhesives, i.e., thermoset epoxy resins EPON 825/ JEFFAMINE D-230 and EPON825/JEFFAMINE D-2000, and the thermoelastic polyurethane adhesive Sikaflex 252. The most significant improvements in bond strengths due to plasma treatment were found for lap shears bonded with the EPON 825/JEFFAMINE D-230 epoxy resin; their shear strengths with maximum loads were more than doubled—from 299–451 to 693–1594 N—after plasma treatment and were further enhanced by a factor of four to 895–1857 N after a subsequent silane treatment. In contrast, the bond strength of lap shears bonded with EPON 825/JEFFAMINE D-2000 and Sikaflex was not significantly improved because of the different a, re-affirming the importance of adhesive bulk properties This work presents the preliminary success of effective surface functionalization leading to enhanced interfacial adhesive bonds for nylon 66 via the development of scalable atmospheric plasma surface treatments.

In the last decade, the bit rates achieved on fiber broadband networks have increased multiple times and every new generation of passive optical network (PON) technologies must unlock more of fiber’s potential and must be backward compatible to ensure easy and iterative upgrade of operator’s networks. In this paper we present two novel dynamic wavelength (in the case of multichannel system) and bandwidth allocation models for realization of fully QoS (Quality of Service)-aware single-channel i.e. multichannel Ethernet passive optical network (EPON). The both presented models include a novel approach for inter/intra –ONU (Optical Network Unit) scheduling mechanism as well as advanced support for multimedia and business-related services. Moreover, the single channel system could be upgraded to multichannel system on per-need basis i.e., only nodes with higher traffic demands could be upgraded. The aim of this approach is twofold. On the one side we hope to avoid the implementation of additional, complex algorithms usually related to QoS support in the access segment and on the other side to develop a solution in which new and old EPON technologies are able to coexist. This approach would eliminate the need for complex migrations, complicated and time consuming procedures as well as possible service outages in the access network. We present detailed simulation experiments with the aim of conducting a study of the performances of both presented approaches and validate both of them in the terms of the future application, further service development and implementation in the next generation broadband networks (NGNs).

Owing to the Economic and Environmental concerns, energy-efficient Time and Wavelength Division Multiplexed Ethernet Passive Optical Network (TWDM-EPON) has already emerged as an important research area. TWDM-EPON allows saving energy at the Optical Line Terminal (OLT) along with Optical Network Units (ONUs), where existing protocols to save energy at ONUs of TDM-EPON can be employed. Moreover, a TWDM-EPON network is bound to support traffic with diverse delay bound to fulfil the recent need for supporting a variety of applications. Therefore, in this paper, for the first time to the best of our knowledge, we propose an online scheduling protocol to achieve energy efficiency at the OLT of a TWDM-EPON network that can support traffic with diverse delay bounds. Simulation results depict that the protocol provides a significant reduction in the probability of delay bound violation while maintaining a similar energy efficiency figure when compared with the most energy-efficient existing online protocol for a single traffic type. The performance of the protocol improves when the network is scaled up or the dimension of the network increases, and hence, suitable for both rural and urban scenarios.

Postfixation with osmium tetroxide and Epon embedding are essential for the preservation and visualization of subcellular ultrastructures via electron microscopy. These chemical treatments diminish the fluorescent intensity of most fluorescent proteins in cells, creating a problem for the in-resin correlative light-electron microscopy (CLEM) of Epon-embedded mammalian cultured cells. We found that two green and two far-red fluorescent proteins retain their fluorescence after chemical fixation with glutaraldehyde, osmium tetroxide-staining, dehydration, and polymerization of Epon resins. Consequently, we could observe the fluorescence of fluorescent proteins in ultrathin sections of Epon-embedded cells via fluorescence microscopy, investigate ultrastructures of the cells in the same sections via electron microscopy, and correlate the fluorescent image with the electron microscopic image without chemical or physical distortion of the cells. In other words, referred as "in-resin CLEM" of Epon-embedded samples. This technique also improves the Z-axis resolution of fluorescent images. In this chapter, we introduce the detailed protocol for in-resin CLEM of Epon-embedded mammalian cultured cells using these fluorescent proteins.

This letter deliberates bridging of overall electricity power requirements of the optical network unit (ONU) with the entropy noted through the ONU state transition models considered in ethernet passive optical network (EPON). The entropy depends on the steady state and transition probabilities of data. On the other hand, the power requirements (consumption) of ONUs depend on the steady sate probability of ONUs. The potential relation derived between the entropy and electrical power reveals that they related exponentially but for their logarithmic reliance. Also, the relation is validated through the numerical simulation. The deduced relation has its importance to understand the nuances of one entity given the other.

Biotin ligases have been developed as proximity biotinylation enzymes for analyses of the interactome. However, there has been no report on the application of proximity labeling using biotin ligase for in-resin correlative light-electron microscopy of Epon-embedded cells. In this study, we established a proximity-labeled in-resin CLEM of Epon-embedded cells using miniTurbo, a biotin ligase. Biotinylation by miniTurbo was observed in cells within 10 mins following the addition of biotin to the medium. Using fluorophore-conjugated streptavidin, intracellular biotinylated proteins were labeled after fixation of cells with a mixture of paraformaldehyde and glutaraldehyde. Fluorescence of these proteins was resistant to osmium tetroxide staining and was detected in 100-nm ultrathin sections of Epon-embedded cells. Ultrastructures of organelles including mitochondria and endoplasmic reticulum were preserved well in the same sections. Fluorescence in sections was about 14-fold brighter than that in the sections of Epon-embedded cells expressing mCherry2 and was detectable for 14 days. When mitochondria-localized miniTurbo was expressed in the cells, mitochondria-like fluorescent signals were detected in the ultrathin sections, and ultrastructures of mitochondria were observed as fluorescence-positive structures in the same sections by scanning electron microscopy. These results indicated that in-resin correlative light-electron microscopy of Epon-embedded cells using proximity labeling was achieved.

In the development of ethernet passive optical networks (EPONs), quality of service (QoS) support and fairness per optical network unit (ONU) are crucial issues. However, making an elaborate analysis of the existing prediction-based bandwidth allocation algorithm, light load penalty, low prediction precision are pointed out. We present an improved dynamic bandwidth pre-allocation algorithm (R-DBA), which employs recurrent neural network (RNN) to predict the high-priority service traffic in EPON. And we introduce mixed integer linear programming (MILP) for optimally building DBA algorithm. This algorithm achieves the prediction of the high-priority service traffic by RNN during the waiting time and supports bandwidth pre-allocation, thus ensuring the fairness of the bandwidth allocation.

This study proposes a novel, efficient and cost-effective Passive Optical Network (PON) based next-generation mobile backhaul RAN architecture that enables the redistribution of some of the intelligence currently centralized in the Mobile Packet Core (MPC) platform out into the access nodes of the RAN. Specifically, this work proposes a fully distributed ring-based EPON architecture that enables the support of a converged PON-5G option 3X access networking transport infrastructure to seamlessly backhaul both mobile and wireline multimedia traffic and services.

In the evolution of telecommunication industry towards 5G, Ethernet Passive Optical Networks (EPON) technology, with some unique features such as high capacity, low latency, and minimum cost per bit, positions itself as an interesting option for backhauling solution in the Multi-access Edge Computing (MEC) scenarios. It is expected to see the converged optical-radio nodes play a crucial role in future networks. To maximize the benefits of the 5G EPON networks, besides all other challenges, it is essential to address two main issues, namely softwarization and energy efficiency. To this end, in this paper, initially we introduce a framework to have an open control layer based on SDN (Software-Defined Networks), able to prepare the EPON backhaul to deal with the 5G applications and services. Then we introduce a solution that minimizes the energy consumption of EPON networks without imposing additional packet delay.

In the evolution of telecommunication industry towards 5G, Ethernet Passive Optical Networks (EPON) technology, with some unique features such as high capacity, low latency, and minimum cost per bit, positions itself as an interesting option for backhauling solution in the Multi-access Edge Computing (MEC) scenarios. It is expected to see the converged optical-radio nodes play a crucial role in future networks. To maximize the benefits of the 5G EPON networks, besides all other challenges, it is essential to address two main issues, namely softwarization and energy efficiency. To this end, in this paper, initially we introduce a framework to have an open control layer based on SDN (Software-Defined Networks), able to prepare the EPON backhaul to deal with the 5G applications and services. Then we introduce a solution that minimizes the energy consumption of EPON networks without imposing additional packet delay.

Edge and fog networks call for high speed and energy-efficient networking platforms. Passive Optical Networks (PON) have been identified as a promising candidate for such platforms. In conventional dynamic bandwidth allocation (DBA) schemes for PON, the transmitter of an optical network unit (ONU) remains idle until the completion of upstream transmission of all other ONUs which indicates poor utilization of the transmitter. Scheduling fog services during these free intervals of time would lead to improved transmitter utilization. In this work, we exploit this opportunity and present a DBA protocol and its architecture, for enabling fog services. Our architecture employs a single line card at the ONUs providing considerable savings in terms of cost and energy. The results show that the cost per ONU could be reduced by 87$ and power savings of 5W per ONU could be achieved compared to proposals using separate transceivers at the ONU. The proposed DBA improves the load tolerance by ~300% towards maintaining delay bound of 10 ms and an improvement in throughput by ~20% at high loads when compared to existing philosophies, which is highly desirable for a delay-sensitive fog network. Placing fog node at remote node allows the fog node to operate at higher loads while maintaining delay bound when compared to its placement at OLT.

Integration of Ethernet passive optical network (EPON) and WiMAX technologies is viewed as a great solution for next-generation broadband access networks. In the systems adopting this strategy, weighty bandwidth allocation schemes are fundamental to fulfil the quality of service (QoS) and fairness requirements of different traffic classes. Existing proposals to overcome the bandwidth allocation problem in EPON/WiMAX networks dismiss collaboration between the self-interested EPON and WiMAX service providers (WSPs). This study presents a novel EPON-based semi-dynamic bandwidth allocation (S-DBA) method that shows points of interest in the integration process. In the proposed algorithm depending on the auction process, the optical line terminal runs an auction to adequately post the optical network unit bandwidth that distributes the most elevated bidders based on the measurement of the accessible bandwidth. Simulation results demonstrate massive upgrades compared with fair sharing using dual-service-level agreements, ‘limited service’ interleaved polling with adaptive cycle time methods, bandwidth allocation strategy using Stackelberg game, and bandwidth allocation strategy using coalition game regarding the quality of service parameters such as throughput and time delay. This will be extremely helpful for optical system upgrading and improvement with minimal effort.

As bandwidth requirements of access networks continue to increase rapidly, especially due to the growth of streaming traffic, the need for resolving bandwidth contention among competing users and applications becomes more compelling. The proposed Software-Defined Ethernet Passive Optical Network (EPON) architecture utilizes an application-level feedback from the client side (for video users) to the network through a Software-Defined-Network (SDN) controller to achieve better client-and-service-level differentiation in the downstream direction of an EPON access network Numerical results obtained from simulation experiments demonstrate that the proposed architecture with downstream resource allocation for video streaming applications considerably reduce video stalls and increase video buffer level at the client applications leading to better Quality of Experience (QoE) for users along with better client-and-service-level differentiation.

Super-resolution correlative light and electron microscopy (SR-CLEM) is a powerful approach for imaging specific molecules at the nanoscale in the context of the cellular ultrastructure. Epon epoxy resin embedding offers advantages for SR-CLEM, including ultrastructural preservation and high quality sectioning. However, Epon embedding eliminates fluorescence from most fluorescent proteins. We describe a photocontrollable fluorescent protein, mEosEM, that can survive Epon embedding after osmium tetroxide (OsO4) treatment for improved SR-CLEM.

The surface of nano silica (NS) was modified by [3- (2-Aminoethyl) aminopropyl] trimethoxy silane (KH-792) to increase surface activity. Evaluate the efficiency of grafting [3- (2-Aminoethyl) aminopropyl] trimethoxy silane (KH-792) into NS was characterized by Fourier Transform Infrared Spectrometry (FTIR) and Thermo Gravimetric Analysis (TGA). NS and modified nano silica (m-NS) were dispersed into epoxy resin Epon 1001X75 by mechanical stirring and ultrasonic vibration. Epoxy resin Epon 1001X75 was cured with Epikure 3125 (Epi3125). The structural morphology and dynamic mechanical properties of materials were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Dynamic Mechanical Analysis (DMA). The results showed that NS was modified with the content of 20 wt% KH-792 for the highest denaturation efficiency. With adding the content of 1 wt% NS (NS-1), the mechanical properties of epoxy polymer film Epon 1001X75/Epi3125/NS-1 increased the impact strength from 20kG.cm to 52.5 kG.cm (increased by 162.5%). Adding the content of 2 wt% m-NS (m-NS-2) improved the impact strength of epoxy polymer film Epon 1001X75/Epi3125/m-NS-2 from 20 kG.cm to 55 kG.cm (increased by 175%). The glass transition temperature (Tg) of epoxy polymer composites Epon 1001X75/Epi3125, Epon 1001X75/Epi3125/NS-1, and Epon 1001X75/Epi3125/m-NS-2 gradually increased by 48 °C, 75 °C, and 79 °C. The obtained results showed that m-NS with KH-792 increased the mechanical properties of epoxy polymer film Epon 1001X75/Epi3125.

El presente trabajo parte del diseño de una red GPON y EPON para la empresa CITYCOM.CIA.LTDA para ser implementadas en los sectores de Challuabamba y El Valle de la ciudad de Cuenca, con el propósito de evaluarlas de acuerdo con las métricas de QoS, escalabilidad, velocidad de servicio y gestión de red y poder determinar cuál de estas dos tecnologías tiene mejores prestaciones. This work is based on the design of a GPON and EPON network for the company CITYCOM.CIA.LTDA to be implemented in the Challuabamba and El Valle sectors of the city of Cuenca, with the purpose of evaluating them according to QoS metrics, scalability, speed of service and network management and to be able to determine which of these two technologies has better performance.

Orientadores: Edson Moschim, Felipe Rudge Barbosa Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação Resumo: Neste trabalho apresentamos um estudo atual das plataformas GPON e EPON, mostrando suas principais características técnicas, realizando uma análise comparativa encontrando as vantagens e desvantagens entre as duas tecnologias. Utilizou-se o software livre analisador de protocolos Ethereal, para o estudo experimental de um enlace ponto a ponto Gigabit para diversos testes de tráfego, obtendo a perspectiva desde o modelo OSI do enlace. Também se realizaram estudos econômicos sobre a factibilidade ao momento de desenvolver uma rede óptica passiva, encontrando e apresentando argumentos válidos tanto econômicos como técnicos ao momento de implantar e massificar este tipo de redes em uma região. Abstract: This work presents a study of the current GPON and EPON platforms, showing its main technical characteristics, making a comparative analysis finding the advantages and disadvantages between the two technologies. We used the free software Ethereal, which is an analyzer of protocols for the experimental study of a point to point Gigabit link doing tests for different kinds of traffic to get the perspective from the OSI. We also conducted studies on the economic feasibility of developing a passive optical network, finding and presenting valid economic and technical arguments to deploy and expand this type of networks in a region. Mestrado Eletrônica, Microeletrônica e Optoeletrônica Mestre em Engenharia Elétrica

Orientadores: Nelson Luis Saldanha da Fonseca, Juliana Freitag Borin Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação Resumo: A crescente demanda por acesso banda larga móvel tem motivado a implantação da tecnologia long term evolution (LTE) pelas operadoras de redes móveis (MNOs), permitindo o fornecimento de novos serviços que demandam alta largura de banda e requisitos rigorosos de qualidade de serviço (QoS). Este aumento da demanda de banda passante leva à necessidade de um grande número de estações rádio base e ao aumento na quantidade de tráfego injetado no backhaul da rede móvel (MBH). Para lidar com os elevados custos do MBH, redes ópticas passivas (PONs) podem ser usadas para reduzir os custos do MBH usando sistemas fiber to anywhere (FTTx) já implantado bem como lidar com a crescente demanda por acesso banda larga à Internet por usuários móveis. Além disso, a estação rádio base LTE, também conhecida como evolved NodeB (eNB), pode ser integrada à unidade de rede óptica (ONU) das PONs em um dispositivo único, chamado ONU-eNB. A ONU-eNB compete pela largura de banda com outras ONUs em PONs, o que pode potencialmente prejudicar o fornecimento de QoS aos usuários móveis. Esta dissertação propõe um framework para provisão de QoS em redes móveis LTE que empregam backhaul baseado em redes ópticas passivas Ethernet (EPONs). Propõe também, um escalonador para redes LTE com o objetivo de prover requisitos de QoS e melhorar a vazão total. O framework introduz uma arquitetura funcional para o dispositivo integrado ONU-eNB, um esquema de mapeamento de QoS e um método para permitir que os escalonadores LTE atuais possam levar em conta informações disponíveis da rede de acesso móvel (LTE) bem com informações sobre a rede de backhaul (EPON), a fim de melhorar o desempenho total da rede, especialmente quando o enlace de backhaul está congestionado. Mostra-se como a implementação do framework proposto melhora a utilização da rede e a provisão de QoS em uma rede integrada, mesmo sob variação da carga de tráfego no backhaul e na rede LTE Abstract: The increasing demand for mobile broadband access has motivated mobile network operators (MNOs) to deploy the long term evolution (LTE) technology, which allows the support of new services demanding large amount of bandwidth and strict QoS requirements. The growth of bandwidth demands will increase dramatically the number of base stations and the amount of traffic injected into the mobile backhaul (MBH) network. To cope with the high cost of MBH networks, passive optical networks (PONs) can be employed by using the already deployed fiber to anywhere (FTTx) systems. Moreover, the LTE base station, also known as evolved NodeB (eNB), can be integrated with the optical network unit (ONU) in a single device, called ONU-eNB, which competes for bandwidth with other ONUs in PONs. Such competition for bandwidth can jeopardize the support of mobile users¿ quality of service (QoS) requirements. This dissertation proposes a QoS provisioning framework for LTE mobile networks employing Ethernet PON (EPON)-based backhaul. It also introduces a novel LTE scheduler with the aim of supporting QoS requirements as well as high throughput. The framework includes a functional architecture for the ONU-eNB, a QoS mapping scheme and a method to allow current LTE schedulers to take into account both information available from the mobile access network (LTE) and information from the backhaul network (EPON) in order to improve the overall network performance, specially when the backhaul link is congested. It is shown how the proposed framework can improve network utilization and quality of service provisioning in an integrated network even under variations of traffic load in the backhaul and in the LTE networks Mestrado Ciência da Computação Mestre em Ciência da Computação FAPESP CAPES CNPQ

Next generation passive optical networks provide a large amount of bandwidth but also consumes a lot of power. The ONUs of such networks dominate a major portion of energy consumption. A previous cycle-based energy saving scheme can only apply to those heavy-load ONUs with a bandwidth request size more than 2 times maximum transmission window. Therefore, to enhance the scalability of such an energy saving scheme for accommodating a wider range traffic load, this paper proposes a new process that relaxes the threshold of request size for allowing more ONUs entering inter-cycle sleep mode. It can then schedules ONUs to a designated time slot on next cycle to increase energy saving effect. The simulation results show that the proposed process can actually improve power consumption of targeted ONUs with medium-load traffic effectively.

The next-generation Ethernet passive optical network (NG-EPON) is basically classified into two architectures on the basis of the wavelength sharing by the optical network units (ONUs). The single scheduling domain (SSD) and multi-scheduling domain (MSD) EPON are the two different design architectures for NG-EPON. A vital task in NG-EPON is to design dynamic wavelength bandwidth allocation (DWBA) algorithms that can meet the future demands of the network subscribers. A number of DWBA algorithms have been designed for time and wavelength division multiplex (TWDM) EPON. The existing DWBA algorithms for TWDM-EPON could be used in MSD-EPON by making necessary parametric changes. The design and implementation of new DWBA algorithms for MSD-EPON are still required specifically. In this paper, we have proposed a quality of service (QoS)-based DWBA algorithm for NG-EPON. We have comparatively analyzed our proposed DWBA with the existing algorithms like earlier finished time (EFT), weighted bipartite matching (WBM), and earlier finished time with void filling (EFT-VF). The results show that our proposed DWBA algorithm performs better as compared to EFT, WBM, and EFT-VF on the basis of average packet delay and average completion time for NG-EPON.

Next-generation passive optical networks (PONs) demand power conservation to create a green environment. A reduction in power consumption of the traditional Ethernet passive optical network (EPON) can be achieved by increasing the sleep count in optical network units (ONUs). In this paper, this is accomplished by introducing a first-in-last-out (FILO) polling sequence in the place of a fixed polling sequence to increase the number of ONUs entering sleep mode (sleep count). In a fixed polling sequence, the optical line terminal (OLT) allocates idle time to the ONUs based on the overall load of the ONUs. This leads to a situation that whenever the idle time does not meet the wakeup time threshold of sleep mode, the ONUs are put into doze/active mode, which consumes more power. In the FILO polling sequence, the first polled ONU in the current cycle is made to be polled last in the following cycle. Polling continues in this way, and by this rearrangement, the idle time of delayed poll ONUs increases; hence, it helps to reduce the power consumption. Additionally, a modified load adaptive sequence arrangement (MLASA) method is suggested, where the ONUs are categorized into doze ONUs and sleep ONUs. A numerical simulation of the FILO polling sequence with a vertical cavity surface emitting laser (VCSEL) ONU shows a maximum reduction in power consumption of 15.5 Wand a 20% improvement in energy savings compared with the traditional fixed polling sequence. The MLASA method results in better power consumption with minimum delay than that of the proposed FILO and existing LASA methods.

The increasing use of polymer nanocomposites in armor applications requires an understanding of how these materials behave at strain-rates relevant to ballistic impacts. Of particular interest is the role of the microstructure on the failure of these materials under dynamic tensile loading. In the present study, plate impact experiments were conducted in order to measure the spall strength of a neat epoxy (EPON 828) and an epoxy–carbon nanotube composite. The addition of pristine carbon nanotubes (CNTs) to the epoxy resulted in a composite material with a lower spall strength than the neat epoxy matrix material. Recovered composite fragments were imaged with a scanning electron microscope. Instances of nanotube pull-out were identified on internal fracture surfaces. The lower spall threshold of the epoxy–CNT composite was attributed to the comparatively weak epoxy–CNT interface, which provides potential sites from which spall failure can favorably nucleate.

Recently, the IEEE 802.3 Ethernet Working Group has classified three architectures for the nextgeneration Ethernet passive optical network (NG-EPON). They are called single-scheduling domain (SSD) PON, multi-scheduling domain (MSD) PON, and wavelength-agile (WA) PON, and they differ based on how a group of optical network units (ONUs) share awavelength. Existing dynamic bandwidth and wavelength allocation (DBWA) schemes for conventional EPON can be applied to MSD-PON and SSDPON, but not WA-PON. This is because WA-PON is a new architecture with full flexibility where a flexible number of wavelengths can be assigned to one ONU, and multiple ONUs can transmit at the same time. In this work, we develop a mathematical model and a novel DBWA scheme for transmission scheduling in WA-PON. However, as WA-PON incurs penalties in terms of delay and power consumption when an ONU activates its transmissions on new wavelengths, a trade-off between energy saving and data-transfer latency reduction needs to be carefully addressed when performing transmission scheduling. So, we develop a power-consumption model and modify the proposed DBWA scheme to enhance the energy efficiency ofWA-PON. Finally, we conduct simulation experiments for performance evaluation of the three PON architectures in terms of latency and packet loss ratio.We quantitatively investigate the influence of various parameters, such as the number of ONU transceivers and ONU buffer size, onWA-PON latency and packet loss ratio, and we evaluate the energy efficiency gain of the modified DBWA scheme.

We present different mechanisms for downstream transmissions in the coax segment of Ethernet Passive Optical Network (EPON) Protocol over Coax (EPoC). EPoC is the transparent extension of EPON over a cable operator's Hybrid Fiber-Coax network. For managing and controlling such a hybrid network, a network operator prefers to have a unified scheduling, management, and quality of service environment that includes both the optical and coax portions of the network. In EPoC, this is achieved by extending the EPON Medium Access Control to run over the coax physical layer, to have a centralized end-to-end network control from the cable head-end to the end users premises. In this paper, we focus on the downstream transmissions in EPoC. We study three different framing approaches for downstream coax frames based on how sub-carriers in an orthogonal frequency division multiplexed symbol are modulated. We discuss the merits and demerits of each approach and then compare them based on their control overheads and the maximum average data transmission rates each of them can achieve. We analyze how different parameters such as modulation profile, symbol duration, number of sub-carriers and length of resource blocks affect the data rates and the performance of downstream transmissions. We present simulation results to examine the implications of these factors on packet-level performance, such as delay. The results indicate that dynamic and hybrid framing approaches tend to perform better than static approaches, when traffic and usage pattern are identical to those in real-world scenarios. Finally, we outline the important engineering and research problems in this area which can be topics of future research.

Ultrastructural artifacts regarding collapse and aggregation of cultured cells have been problematic, especially when investigated apoptotic cells. The infiltration process during sample preparation is considered to be the most crucial factor for this problem. This study was conducted using two culture systems: a suspension culture system of human T-lymphocyte Jurkat cells and rabbit mature dendritic cells and a monolayer culture system of human lung macrophages, human breast cancer cells (A-546 cells) and cat bone-invasive gingival cancer cells (sccf3 cells). Fixation was conducted prior to removing or detaching the cells from the culture dishes. Initial infiltration with a 1 : 3 volume ratio of epon resin : propylene oxide was found to be the most crucial step among these cultured cells. The improved epon-resin infiltration method could eliminate the artifacts. Thus, differentiation between artifactual images and true images is highly possible.

The most effective solution to cope with the ever increasing bandwidth demands is by using Ethernet Passive Optical Network (EPON). Thus, there are needs in introducing an EPON subject for Engineering Postgraduate students. However, since networking is a subject that is not easy to visualize, the lack of means to illustrate or convey the EPON network causes an apparent lack of interest amongst engineering students towards the discipline. In order to overcome these problems, a need to develop an educational module for the EPON system is seen. In this paper, an EPON testbed is proposed together with a friendly graphical user interface (GUI) as a tool for the postgraduate engineering subject to better understand the protocol and the bandwidth allocation studies of EPON. The details of the testbed and the preparation stages to make it an educational module are also demonstrated together with results to assist engineering postgraduate students to better understand the subject matters.

Economical and environmental concerns necessitate network engineers to focus on energy-efficient access network design. The optical network units (ONUs) are predominate sources of the energy consumption of Ethernet passive optical network, which motivate us toward designing a novel protocol for saving energy at ONUs. The proposed protocol exploits different low power modes (LPMs) and opts for the suitable one using traffic prediction. This scheme provides a significant improvement of energy-efficiency especially at high load (~40%) over existing ONU-assisted protocols. A better understanding of the performance and a deeper insight into several design aspects can only be addressed through a detailed mathematical analysis. The proposed protocol involves traffic prediction, which infringes the Markovian property. However, some pragmatic assumptions along with a proper selection of observation instances and state descriptions allow us to form a discrete time Markov chain (DTMC) of the proposed algorithm. Thus, the primary objective of this paper is to propose a novel scheme for achieving energy-efficiency at ONUs and mathematically analyze the performance of it with the help of a DTMC. The analysis reveals that the energy-efficiency is more sensitive to the power consumption of doze mode as compared to other LPMs. Further, the effect of sleep-to-wake-up time of all LPMs is minor.