The Usage of Automatic Identification System (AIS) Data for Safety during Navigation

Estimation of safety on navigation by using safety distance formulation of sea transport is possible with by using data from the Automatic Identification System (AIS). Based on AIS data can be calculated the safety distance and actual distance of the target ship and also closest ship Calculation of safety distance and actual distance of the ship using AIS data closer to the real condition because AIS data provide ship data (time and location) as real-time. This study showed that calculation of safety distance is able to cover all speed more than 5 knots. The results show several ships from 295 total numbers of ships through the Strait of Malacca on 15th November 2013, 8.00 pm until 9.00 pm in danger condition but need to refer to the type of the ship also by using the information from the references website. The ships under the Singapore flag contribute the highest values from the total quantity of the marine traffic on 15th November 2013, 8.00 pm until 9.00 pm follow by Panama, Liberia and Marshall Island. The most high-risk time which danger to the marine transportation and shipping traffic in the Strait of Malacca

Feasibility study of wing-in-ground for marine rescue operation

This study aims to investigate performance of current rescue facilities and position based on statistic data of sea accident between 2010 and 2011 in Kepulauan Riau. Current rescue facilities are located at the latitude 0.93105 and longitude 104.44359. Using the statistic data, an optimal recue location and facilities in Kepulauan Riau are determine based on International Maritime Organization (IMO) standard. International Maritime Organization requirement, an emergency, passengers should be able to leave the ship with time 60 minutes. The optimal position and rescue facilities are determined using Great Circle Distance-Spherical Trigonometry and Statistical of Standard Error methods. In this study, simulation code is developed using visual basic 2010 language. Results of simulation show current rescue facility requires a lot of time to reach the accident location which is up to 12.5 hours. In order to meet IMO requirement, this study proposes wing in ground for rescue operation. Using current rescue location, wing in ground also does not meet the IMO standard which is up to 3.04 hours. Additional, this study divides the Kepulauan Riau into two regions of rescue operation. The optimal for rescue facilities of region 1, at the latitude 0.74568 and longitude 104.36256, and based on the distribution of the accidents in Kepulauan Riau 2010-2011, current rescue facility required up to 5.6 hours to reach the accident area, while the wing in ground facilities required up to 1.3 hours. The optimal for rescue facilities of region 2, at the latitude 3.00338 and longitude 107.79373, current rescue facility required up to 5 hours to reach the accident area, while the wing in ground facilities required shorter time that is up to 1.2 hour

Computational fluid dynamics (CFD) mesh independency technique for a propeller characteristics in open water condition

This paper numerically investigated mesh refinement method in order to obtain a mesh independent solution for a marine propeller working in open water condition.Marine propeller blade geometries, especially of LNG carriers, are very complicated and determining the hydrodynamic performance of these propellers using experimental work is very expensive, time consuming and has many difficulties in calibration of marine laboratory facilities. The present research workhas focused on the hydrodynamic propeller coefficients of a LNG carrier Tanaga class such as Kt, Kq and η, with respect to the different advance coefficient (j). Finally, the results of numerical simulation in different mesh density that have been calculated based on RANS (Reynolds Averaged Navier Stocks) equations, were compared with existing experimental results, followed by analysis and discussion sections. As a result the maximum hydrodynamic propeller efficiency occurred when j=0.84

Design and validation of an adaptive Cubesat transmitter system using a Thermal Vacuum Chamber (TVAC)

CubeSat in a low earth orbit primarily uses a UHF transmitter with a fixed RF output power. In this paper, the design of the CubeSat transmitter with adaptive power controlability is presented. The design drive is to optimise the SNR and overcome the variability of the propagation path length due to different ground station elevation angles by adjusting its transmitting power. The TVAC test is conducted to validate the performance of the adaptive function in the transmitter. The TVAC is used to emulate the satellite condition in an outer space environment. Four thermal cycles starting from +60°C to -20°C with less than 10-5Pa pressure condition are employed, which was conducted at the KIT CeNT, Japan. The transmitter was integrated inside the satellite structure as a complete CubeSat system. The output power of the transmitter is tested from 0.5W to 2W based on the proposed satellite adaptive mode. The frequency stability of the transmitter is monitored and complies with an average of 70% below requirement, which is less than 2ppm. The results indicate that the RF output power is adjustable to operate as the proposed CubeSat adaptive transmitter in a thermal vacuum condition, which was first developed in Malaysia

FPGA implementation of multi frequency continuous phase frequency shift keying (MCPFSK) modulation techniques for HF data communication

In HF (High Frequency) data communication systems [1,2], FSK (Frequency Shift Keying) digital modulation is widely used. The simplicity in the implementation is the main reason for its popularity. Since noncoherent detection is possible, additional components such as timing recovery circuits [3] are not necessary as required in PSK (Phase Shift Keying) modulation

EXPERIMENTAL STUDY OF MOTIONS OF TWO FLOATING OFFSHORE STRUCTURES IN WAVES

Drilling is carried out in deeper to deeper waters around the globe to meet growing demands for oil and natural gas, and a number of multi body structures are deployed in various oil fields in the world. Investigation of hydrodynamic interaction of offshore structures is therefore worthwhile. Hydrodynamic interaction between floating offshore structures affects motion and relative motion especially during loading and offloading operations. Hydrodynamic interactions may lead to large motions of floating bodies that would cause damage to moorings and offloading systems and may collide with each other. This research work discusses experimental results of hydrodynamic interaction in surge, heave and pitch motion, relative motion and relative distance between a Tension Leg Platform (TLP) and semi-submersible (Tender Assisted Drilling) in regular waves. The experiment is conducted without tendon because of the depth limitation of the Towing Tank. However, in order to consider the contribution of mooring in linear direction, appropriate stiffness of horizontal springs have been used. The experiment was conducted for a full scale wave height of 3.77 m to 12.49 m for a separation distance of 21.7 m. From the analyses of the experimental and numerical results, it can be concluded that nonlinearity of the wave has an important effect on increasing the motion especially in the natural frequency region. Finally, a number of recommendations have been made for further study

A simple fuzzy logic diagnosis system for control of internal combustion engines

Fuzzy logic (FL) systems are widely established as a technology offering an alternative system to tackle compound and ill defined problems. They can be trained from examples, are fault tolerant in the sense that they are capable to grip noisy and deficient data, are able to deal with non-linear problems, and once trained can perform prediction and generalization at high speed. in this paper a simple fuzzy logic control has been developed which is used for defining engine system faults and control and maintain them in a normal range without use any complicated mathematical equation and any fault sensor

Load characteristics of cold water pipe based on fibreglass-filled HDPE composites

Cold water pipe (CWP) which is used in ocean thermal energy conversion stationary surface platform should be able to keep water at a temperature of ~5°C, with the result that cold water could be used to liquefy ammonia vapor from a turbine generator to generate electricity. CWP has an inner diameter of about 3m to 4m that reach to 500m water depth. CWP on the stationary platform will experience stresses due to current and wave loads and the weight of the pipe itself. This paper will explain the loading that occurs. Seawater currents generate movement of CWP in the horizontal direction which causes the pipe to be subjected to bending stress. Bending loading fluctuates with different wavelengths and angles each time. In addition, seawater currents lead vortex-induced vibration. The properties of pipe material used should be lightweight, flexible and strength that subjected to wave and current loads. HDPE material is suitable for CWP than other polymeric materials. Because of lightweight and flexible. For the strength, it is filled with short fiberglass in order to withstand low temperature and corrosion. The CWP bending due to seawater current causes the structure of the pipe material to experience repetitive tensile and compressive loading. And due to waves occurs axial tensile load. So that the main load on the CWP is the tension and pull loading that occurs repeatedly or fluctuating in sinusoidal shape and the resistance of the CWP will be more accurately known by fatigue testing alternating load

Buckling criteria for subsea pipeline

Oil and gas production in subsea operation continues to the extreme depth. Harsh environment and severe operation of oil and gas transportation due to high pressure and temperature become crucial for pipeline transportation. Consequently, The pipelines will deform to buckle shape which affect to integrity of pipeline. This phenomenon should be considered in design of pipeline to provide reliability of pipeline operation during time life period. The design result of pipelines is according to DNV F 101 whereas the magnitude of pipeline curvature will validate by ANSYS 14 to ensure pipeline reliability

Design and validation of an adaptive CubeSat transmitter system

CubeSat in low earth orbit (LEO) primarily uses an amateur radio-band transmitter with a fixed specification. Nevertheless, the LEO satellite does not have an orbital velocity that equates to one sidereal day. Therefore, the ground station antenna views the satellite at different elevation angles which result in varied propagation path lengths. In this paper, an adaptive transmitter is designed to optimise the LEO satellite communication link and overcome the variability of the propagation path length issue due to different ground station elevation angles. A satellite communication link and operation analyses are performed to identify the relationship between the variation of the elevation angle so as to determine the optimum signal-to-noise ratio (SNR), improve data rate and increase the power efficiency of an adaptive link. Based on the results, a model is developed to control the adaptive configuration. The SNR and power consumption performance of the developed transmitter is compared with commercial transmitters. The results indicate that the transmitter output power is adjustable from 0.5 W to 1 W, and the data rate is selectable between 9600 bps and 19,200 bps. Compared to other CubeSat transmitters, the developed adaptive transmitter demonstrates more than 20% improvement in terms of SNR optimisation, additional throughput and power reduction