The Impact of Forward Error Correction on Wireless Sensor Network Performance

In networks there are basically two methods to tackle the problem of erroneous packets: Automatic Repeat Requests (ARQ) and Forward Error Correction (FEC). While ARQ means packet retransmissions, FEC uses additional bits to detect and correct distorted data. However, extensive field test of our sensor nodes have shown that FEC can take effect only as long as both sender and receiver are bit-wise synchronized. Otherwise, all following bits are misinterpreted which results in an uncorrectable number of errors. We will thus introduce a new resync scheme which is particularly tailored for many sensor network platforms using UARTs in conjunction with radio transmission. We can show that only using an appropriate resync mechanism exploits the full potential of FEC

TECA : A Topology and Energy Control Algorithm for Sensor Networks

A main challenge in the field of sensor networks is energy efficiency to prolong the sensor's operational lifetime. Due to low-cost hardware, nodes' placement or hardware design, recharging might be impossible. Since most energy is spent for radio communication, many approaches exist that put sensor nodes into sleep mode with the communication radio turned off. In this paper, we propose a new Topology and Energy Control Algorithm called TECA. We will show the performance of TECA by means of extensive simulations compared to two other approaches. In terms of operational lifetime, packet delivery and network connectivity, TECA shows promising results. Unlike many other simulations, we use an appropriate link loss model that was verified in reality. By measuring packet delivery rates, TECA is able to adapt to different environments while still maintaining network connectivity

The Impact of Resync on Wireless Sensor Network Performance

Many of todays sensor nodes exhibit special transmission errors. These errors are due to some common hardware components being used, particularly the so-called UART (serial communication) circuits that interconnects radio transceivers and the CPUs. UARTs generate start-, data- and stop-bits. As long as the state machine at the sender and the receiver is synchronized, even single bit errors can often be corrected by Forward Error Correction (FEC). However, once one or several bits are missed, the state machine at the receiver side will get out of sync so that data bits are misinterpreted as start- or stop-bits and vice versa, rendering the entire remaining communication useless. In this paper, we will devise a periodic resync scheme that enables the receiver to catch up on a data stream even in case of skipped bits. In noisy environments as well as for weak senders, we can improve the overall data throughput significantly

An Energy-Efficient Forwarding Scheme for Wireless Sensor Networks

Energy-efficient forwarding becomes important if resources and battery lifetime are limited such as in Wireless Sensor Networks. Although widely used, simple hop-based forwarding along a path from one node towards a sink can be very inefficient in terms of delivery rate as well as energy efficiency, especially in lossy environments. We will show that just minimizing the expected number of transmissions within the network is not always the most efficient forwarding strategy. Using a realistic link loss model, we derive two new forwarding schemes named Single-Link and Multi-Link Energy-Efficient Forwarding that trade off delivery rate and energy costs best by maximizing energy efficiency. Multi-Link Forwarding further benefits from addressing multiple receivers during packet forwarding, instead of a single one. By mathematical analyses, extensive simulations, and experimental experiments we contrast the performance of our approaches against a comprehensive framework of different forwarding strategies

Development of A Simulink Model To Investigate Fuel Consumption And Efficiency Of A Main Fuel Engine

Marine business is one of the largest businesses in the world. Exports and Imports of human necessities in the majority are using ships. This is because of the ratio between the goods that can be delivered on each trip and the number of trips it can go to fulfill this. This makes the shipping or transport cost-efficient. But the continuous growth of the world population and its standard of living creates an ever-increasing dependency for the world economy on international trade. Therefore a good shipping company will always develop a better way of shipping together with more efficient and optimized voyage planning. To increase the efficiency of shipping, companies try to reduce the cost of almost everything. Therefore, one of the options for improving the efficiency of shipping is by increasing the efficiency of the ship itself. The ship efficiency is not only determined by how fast the ship and how much the ship can load, but also how much fuel does the ship consume for each operation. An investigation of the engine efficiency must be done. The investigation will be done by using an engine model in Simulink to create a similar engine model to the real engine. Then simulate the dynamic process of the engine, which will affect the consumption in general. Therefore the consumption of the engine can be analyzed. The results of this bachelor thesis is an explanation of how to develop the engine model. This includes the explanation of what is the engine efficiency and the engine parameters that affect efficiency, such as engine consumption, engine losses, etc. The model development includes the change in parameters and model structure. Then a simulation is done to compare the results with the measured data. From this process, the model can be considered satisfactory when the results are similar to the measured data

Simulation of Double Walled Pipe Impact to Crude Oil Flow in Subsea Pipeline System

Crude oil contains mixed of hydrocarbons, the most commonly found molecules are alkanes (paraffins), cycloalkanes (naphthenes), aromatic hydrocarbons, or more complicated chemicals. In the process of taking crude oil in subsea pipeline system with depth 1200 meters, the contents of crude oil like sulfur, paraffin, asphalt could deposit in the wall of the pipe because of the different temperature between crude oil and wall of the pipe. The deposition can make blockage to the pipe and cause crude oil flow to be slow or stop. In this bachelor thesis, will be design double walled pipe for Subsea pipeline system with depth 1200 meters and simulation double walled pipe to knowing the impact of double walled pipe to crude oil flow in Subsea with depth 1200 meters. Based on the simulation that has been done, using double walled pipe could stabilize the temperature between crude oil and wall of the pipe. It shows that the average of temperature decrease using double walled pipe is only 0.125 K for 12 meters. So, it could get the conclusion based on the simulation of double walled pipe that the impact to crude oil flow is there’s no blockage in the pipe and the crude oil flow will steady

The Technical and Business Analysis of Using Shore Power Connection in The Port of Hamburg

In port, when the ship is berthing the loading, unloading, and hospitality activity is using auxiliary engine. The combustion of marine fuels is a major contributor to air pollution, the air pollution is released 400 km around the port area. The impacts of the pollution are respiratory, health, and the environment around ports. Study indicates 60.000 of cardiopulmonary mortalities caused by ship air emission. Ship emission represents 3% of global CO2, 15% of global NOx, and 6% of global SOx emission. Because of that Hamburg Port is released the shore power facilities in July 2015 with idea of smart port and use the renewable energy such as wind turbine and solar panel compliance with IEC-ISO-IEEE 8005-1. In this bachelor thesis, the cost and also the condition between shore power and auxiliary engine will be analyzed and compared to find the most economical between shore power facilities and ship’s auxiliary engine. Shore power facilities in Hamburg are provided by SIEMENS with SIHARBOR and use a robot arm by Stemman Technik as the cable management system. The goal of this thesis is developed calculation tool to see the cost comparison and also the emission. And from the calculation tool the shore power is reducing the emission by 100% because of using the renewable energy and become economical than using auxiliary engine, it can save up to €1000. The other benefits  are ship owner can save maintenance of their auxiliary engine and also saved the file. It shows that the shore power is a proven technology to reduce the emission and saved berth cost

Decision Making of Full Speed, Slow Steaming, Extra Slow Steaming and Super Slow Steaming using TOPSIS

Many shipping companies were trying to deliver their cargoes as quickly and reliably as possible. But in the beginning of the latest economic crisis on 2007, the containership fleet is slowing down. Even though world oil prices are now declining, but based on the prediction of World Bank, the price of oil will rise again in 2017. Even some shipping company implements slow steaming method on the operation of their ships. But they do not know whether these methods are effective or not due to any negative effects arising from an implement of slow steaming like increased sailing time so may result in losses to the shippers. This study aims to give suggestions on which ship speed is most optimal for shipping companies by considering technical and operational, financial and also environmental aspect then will be selected one by using Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. While for criteria and sub criteria weighting are calculated by Analytic Hierarchy Process (AHP) method using Expert Choice software. From the TOPSIS method, super slow steaming was chosen to be the first rank

Development of Simulink Model to Investigate Control Structure, Safety, and Stability of a Water Brake System at Main Engine in House 5 Laboratory: Warnemünde

A water brake loads the diesel engine will set desired work points and work curves. So that can find a safe point and control safety. After this, the essential system component will be created the model in block diagram and the block diagram will be simulated with Simulink. This requires a model of combustion machine and its control as well as break system and its control. The valve angle also affects the amount of flow or discharge of water which resides in the brake system. The amount of water flow in the brake system affects the amount of load that will be accepted by the main engine. The model is to be validated with measured data. To define load characteristics for a parallel operating visualization, these load characteristics are to be simulated. The results of the modeling were to know PI controller parameters to control the main engine. In the investigation, then simplify the process of modeling results are displayed in the form of a curve. Where in the curve we can see the performance of the engine and brake system so that the operation of the main engine will get maximum condition within safe limits

Dynamic Information System for Failure Analysis with It’s Application on Ship Main Engine

Ships are often used to move cargo, and their main engines are crucial. Accidents and financial losses might result from the main engine being in poor condition. Before completing maintenance, conducting a failure analysis is necessary. The existing method is static and involves using a list of failure modes from the engine's manufacturing phase. This study proposes a preliminary design of dynamic system prototype that seeks to improve ship engine monitoring of status. It includes features such as a list of failure modes and codes based on ISO 14224:2016, data collection unit worksheet, and dynamic charts for visualizing the results. Two testing iterations were performed on the prototype. First, literature data obtained from the internet was used to generate annual and monthly report charts, confirming the functionality of the prototype. Second, real data from engine failures on the tanker ship were used to ensure logical correlations among failure causative factors. The result from real data testing included Structural Deficiency (STD), External Leakage Fuel (ELF), and Breakdown (BRD) were shown. Based on these results through the prototype simulation, can be taken into consideration for the ship's crew and shipping company management to plan oil monitoring, heating the oil properly, and conduct routine maintenance check as a preventive action to reduce the impact of engine damage in the future due to Engine Breakdown and Structural Defiency