scholarly journals Comparative analysis, design and optimisation of a 48 channel DWDM system using various design parameters

2019 ◽  
Author(s):  
◽  
Jerrin Zachariah Mohan
Keyword(s):  
Comparative Analysis ◽  
Design Parameters ◽  
Communication Link ◽  
Q Factor ◽  
Bit Rate ◽  
Analysis Model ◽  
Transmission Impairments ◽  
Compensation Technique ◽  
Linear Effects ◽  
Dwdm System

In the current era, there is an ever-growing demand for data hungry applications and services that need large amounts of bandwidth to send digital information at very high speeds. In order to meet this challenge for higher bandwidth capacity, Dense Wave Division Multiplexing (DWDM) is used as the strategy to transmit multiple high-bit rate channels at extremely narrow channel spacings over a single fiber core. However, this gives rise to detrimental transmission impairments such as linear effects and non-linear effects. The dissertation minimises the impairments by optimally designing a new DWDM system that produces a detectable and acceptable quality of signal at the receiver. In this dissertation, a comparative analysis is performed on the simulative design of a 48-channel DWDM system that has a 25 Gb/s bit rate and a 100 km transmission distance. The research mitigates the effects of transmission impairments such that an error-free matched communication link is produced for equally spaced (ES) channels of 100 GHz, 50 GHz, 25 GHZ and 12.5 GHz and 6.25 GHz. Various design parameters are used to create the comparative analysis model to optimise the 48 channel DWDM network. The design is simulated using the Optisystem simulation platform and the signal analysis is based on the bit error rate (BER) and quality (Q) factor of the received signal’s eye diagrams. It is established in the desertion that modified networks with matched active components has ES frequency channels that are aligned to each other and has a higher optical signal to noise ratio (OSNR) than mismatched networks. The maximum signal power and OSNR of the 3-erbium doped fiber amplifier (EDFA)-post symmetric compensation technique is always higher than the 1-EDFA post compensation technique for all channel spacings in any type of network. Modified duobinary return to zero (MDRZ) when compared to non-return to zero (NRZ) and return to zero (RZ) has a greater dispersion tolerance, higher fiber non-linearity tolerance and a higher acceptable signal transmission over longer distances with the least amount of errors. The optimised design parameter configurations produce the highest signal performance (highest Q factor > 6 and lowest BER > 10-9) and the highest bandwidth efficiency for the RZ Modulation (at 100 GHz, 50 GHz and 25 GHz channel spacings) and MDRZ Modulation (at 12.5 and 6.25 GHz channel spacing).

Analysis of hybrid integrated-alternate mark inversion (I-AMI) modulation and symmetrical-symmetrical-post (SSP) dispersion compensation technique in single-tone radio over fiber (RoF) system

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Namita Kathpal ◽  
Amit Kumar Garg
Keyword(s):  
Dispersion Compensation ◽  
Chromatic Dispersion ◽  
High Capacity ◽  
Radio Over Fiber ◽  
Q Factor ◽  
Bit Rate ◽  
Eye Diagram ◽  
Single Tone ◽  
Transmission Distance ◽  
Compensation Technique

AbstractThis paper presents the high capacity single-tone Radio over Fiber (RoF) system utilizing advanced modulation technique in conjunction with optimized dispersion compensation scheme to support the high data rate transmission upto 120 Gbps. The proposed system incorporates the Integrated-Alternate Mark Inversion (I-AMI) modulation and Symmetrical-Symmetrical-Post (SSP) compensation technique to enhance the spectral efficiency as well as to reduce the chromatic dispersion effects in long-haul RoF link. The proposed system i.e., I-AMI with SSP has been examined at 60, 80, 100 and 120 Gbps bit rate for various transmission distance. The simulation results obtained in terms of Q-factor, Bit Error Rate (BER) and eye diagram reveal that the proposed system provides wider eye-opening, low BER and high Q-factor as compared to the existing system. The proposed I-AMI with SSP provides the Q-factor of 30.47 whereas the I-AMI with PSP and AMI with SSP provides the Q-factor of 18.77 and 18.40 respectively at 80 Gbps bit rate over a transmission distance of 800 km.

Optimal Offloading Configuration of Spread-Moored FPSOs

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Steven M. Wilkerson ◽  
Satish Nagarajaiah
Keyword(s):  
Environmental Conditions ◽  
Main Tool ◽  
Design Parameters ◽  
Optimization Approach ◽  
Analysis Model ◽  
Simple Analysis ◽  
Formal Approach ◽  
Fine Tune ◽  
Formal Optimization ◽  
Selection Of

As the oil offloading operations of floating production storage and offloading (FPSO) units become more routine, the desire grows to increase the availability for offloading and thus decrease production downtime. Experience with these operations is the main tool available to increase the efficiency of this aspect of deepwater production. However, it is clear that a formal optimization approach can help to fine tune design parameters so that not only is availability increased but the significance of each design parameter can be better understood. The key issue is to define the environmental conditions under which the vessels involved in offloading are able to maintain position. By this, we reduce the notion of availability to a set of operating criteria, which can or cannot be met for a particular set of environmental conditions. The actual operating criteria such as relative vessel heading depend on selection of design parameters, such as the direction and magnitude of external force applied by thrusters or tugs. In the earliest offloading operations, engineering judgment was used to determine the feasibility of offloading at a particular time. For example, if wind and current were not expected to exceed a 1year return period, offloading may be considered safe. This approach can be both conservative and unconservative, depending on the nuances of the particular environmental conditions. This study will propose a formal approach to choosing the design parameters that optimize the availability of a FPSO for offloading. A simple analysis model will be employed so that optimization can be performed quickly using a robust second order method. The proposed analysis model will be compared to model test data to demonstrate its agreement with the more complex system.

scholarly journals A Novel Analytical Modeling of a Loop Heat Pipe Employing Thin-Film Theory: Part II—Experimental Validation

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2403 ◽  
Author(s):  
Eui Guk Jung ◽  
Joon Hong Boo
Keyword(s):  
Steady State ◽  
Heat Pipe ◽  
Film Theory ◽  
Design Parameters ◽  
Working Fluid ◽  
Coolant Temperature ◽  
Loop Heat Pipe ◽  
Analysis Model ◽  
Proposed Model ◽  
Flat Evaporator

Part I of this study introduced a mathematical model capable of predicting the steady-state performance of a loop heat pipe (LHP) with enhanced rationality and accuracy. Additionally, investigation of the effect of design parameters on the LHP thermal performance was also reported in Part I. The objective of Part II is to experimentally verify the utility of the steady-state analytical model proposed in Part I. To this end, an experimental device comprising a flat-evaporator LHP (FLHP) was designed and fabricated. Methanol was used as the working fluid, and stainless steel as the wall and tubing-system material. The capillary structure in the evaporator was made of polypropylene wick of porosity 47%. To provide vapor removal passages, axial grooves with inverted trapezoidal cross-section were machined at the inner wall of the flat evaporator. Both the evaporator and condenser components measure 40 × 50 mm (W × L). The inner diameters of the tubes constituting the liquid- and vapor-transport lines measure 2 mm and 4 mm, respectively, and the lengths of these lines are 0.5 m. The maximum input thermal load was 90 W in the horizontal alignment with a coolant temperature of 10 °C. Validity of the said steady-state analysis model was verified for both the flat and cylindrical evaporator LHP (CLHP) models in the light of experimental results. The observed difference in temperature values between the proposed model and experiment was less than 4% based on the absolute temperature. Correspondingly, a maximum error of 6% was observed with regard to thermal resistance. The proposed model is considered capable of providing more accurate performance prediction of an LHP.

scholarly journals Dimensional Structural Mass Optimization of a Welded I-Profile Bridge Crane Girder

2020 ◽  
Vol 14 (2) ◽  
pp. 186-193
Author(s):  
Nedim Pervan ◽  
Adis J. Muminovic ◽  
Elmedin Mesic ◽  
Mirsad Colic ◽  
Vahidin Hadziabdic
Keyword(s):  
Optimization Model ◽  
Geometrical Model ◽  
Optimization Process ◽  
Design Parameters ◽  
Minimal Amount ◽  
Bridge Crane ◽  
Analysis Model ◽  
Geometrical Constraints ◽  
Minimal Mass ◽  
Structural Mass

This paper presents the methodology for the development of an optimization model for the optimization of the cross-section dimensions of a bridge crane girder designed as a welded I-profile. To carry out this optimization, the CAD/CAE software package CATIA V5 was used. In order to develop an optimization model, a CAD geometrical model and structural analysis model were developed. Optimization was carried out by the iterative method using a simulated hardening algorithm. Additionally, the optimization process is carried out by using the PEO (Product Engineering Optimization) CATIA module that contains tools for setting the optimization criteria, design parameters, constraints, and algorithms. The goal of the optimization is to achieve the minimal mass of the girder, while satisfying all functional and geometrical constraints. As a result of the optimization process, minimal girder dimensions were obtained and due to that, a minimal amount of material can be used for the manufacturing of the girder.

A comparative analysis of embodied carbon in high-rise buildings regarding different design parameters

2017 ◽  
Vol 161 ◽  
pp. 663-675 ◽  
Author(s):  
Vincent J.L. Gan ◽  
C.M. Chan ◽  
K.T. Tse ◽  
Irene M.C. Lo ◽  
Jack C.P. Cheng
Keyword(s):  
Comparative Analysis ◽  
Design Parameters ◽  
High Rise ◽  
Embodied Carbon

Load Analysis of Flexible Ball Bearing in a Harmonic Reducer

2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Ying Xiong ◽  
Yongsheng Zhu ◽  
Ke Yan
Keyword(s):  
Finite Element Method ◽  
Load Distribution ◽  
Ball Bearing ◽  
Design Parameters ◽  
Force Action ◽  
Analysis Model ◽  
Proposed Model ◽  
Action Type ◽  
High Reduction ◽  
Load Analysis

Abstract Harmonic reducers are generally supported by flexible bearings. The elastic deformation of the flexible bearing enables the harmonic reducer to satisfy high reduction ratio performance. By considering the flexible outer ring and noncircular inner ring of the flexible bearing, a universal static analysis model was developed to calculate the ball load distribution of flexible bearings in harmonic reducers. The validity of the proposed model was proved by studying two types of flexible bearings mounted on an elliptical cam and a four-force action-type cam, respectively. Several results validate the use of the model to assess the ball load distribution instead of a more time-consuming finite element method. Influences of design parameters in the flexible bearing on the load distribution were investigated, which makes reference for the optimal design of the flexible bearing.

An Intelligent System for Spur Gear Design and Analysis

2001 ◽  
Author(s):  
El-Sayed Aziz ◽  
C. Chassapis
Keyword(s):  
Finite Element ◽  
Closed Form ◽  
Intelligent System ◽  
Tooth Profile ◽  
Hertzian Contact ◽  
Design Parameters ◽  
Analysis Model ◽  
Closed Form Solutions ◽  
Gear Teeth ◽  
Gear Design

Abstract A methodology for the analysis of load distribution and contact stress on gear teeth, which utilizes a combination of closed form solutions and two-dimensional finite element methods, within a constraint-based knowledge-based environment, is presented. Once the design parameters are specified, the complete process of generating the analysis model, starting from the determination of the coordinates of the tooth profile, the creation of a sector of the mating gear teeth, automatic mesh generation, boundary conditions and loading, is totally automated and transparent to the designer. The effects of non-standard geometry, load sharing on the contact zone, friction and root stresses are easily included in the model. The Finite Element Method (FEM) based results compare favorably with those obtained from closed form solutions (AGMA equations and classical Hertzian contact solution). The advantage of the approach rests in the ability to modify any of the gear design parameters such as diametral pitch, tooth profile modification etc., in an automated manner along with obtaining a better estimation of the risks of failure of the gear design on hand. The procedure may be easily extended to other types of gearing systems.

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