Customizing Prosthetic Leg Socket by using Rapid Prototype with Reverse Engineering

The demand of using prosthetic leg keeps on increasing due to unpredictable of certain diseases or physical trauma such as accident and war. Prosthetic devices can help, but making a prosthetic leg can be a long and difficult process. Standard made prosthetic leg come ready-made in various standard sizes, though they are often not as realistic as their custom-made counterparts. Custom-made prosthetic legs are generally more expensive which costing thousands of US dollars, depending on the level of detail. This case study describes implementation of rapid prototyping and reverse engineering technology on customizing the prosthetic leg socket. A negative mold was obtained from the amputee stump with plaster of paris. The positive mold is generated from negative mold and taken to the 3D Renishaw Digitizer machine for reverse engineering. 3D Renishaw Digitizer machine will produce 3D point cloud data from the scanning result. Unigraphics is used to fix, repair and customize the 3D point cloud data into 3D solid modeling and convert into STL file format before send to the Rapid Prototype machine to produce the rapid prototype part. Final rapid prototype part is in wax form, therefore Rapid tooling is needed in order to make the socket of the prosthetic leg more realistic by using the thermoplastic or engineering plastic material. For this FYP project, due to the cost budget of a FYP student is limited the real size of the prosthetic leg socket for this project has been scale down into 80mmX50nunX45mm in order to show the rapid tooling process. The different between the fmal part of the prosthetic leg of the rapid tooling with the rapid prototype is plastic material which can sustain high strength compare with wax. Therefore, a scale down of this project is essential to save material cost of the rapid tooling process

Stories of Cambodian Angkuoch: Documenting a Rare Musical Instrument, its Makers and Players

This piece introduces the endangered Cambodian musical instrument Angkuoch, its makers and players, and a project documenting the making process. It also reflects on ethics of instruments in museum collections

Fish fights over fish rights: Conflicts arising from re-allocation of fishing lots: perceptions from community fisheries in Cambodia

Disputes, Aquaculture, Cambodia,

NAIS: Neural Attentive Item Similarity Model for Recommendation

Item-to-item collaborative filtering (aka. item-based CF) has been long used for building recommender systems in industrial settings, owing to its interpretability and efficiency in real-time personalization. It builds a user's profile as her historically interacted items, recommending new items that are similar to the user's profile. As such, the key to an item-based CF method is in the estimation of item similarities. Early approaches use statistical measures such as cosine similarity and Pearson coefficient to estimate item similarities, which are less accurate since they lack tailored optimization for the recommendation task. In recent years, several works attempt to learn item similarities from data, by expressing the similarity as an underlying model and estimating model parameters by optimizing a recommendation-aware objective function. While extensive efforts have been made to use shallow linear models for learning item similarities, there has been relatively less work exploring nonlinear neural network models for item-based CF. In this work, we propose a neural network model named Neural Attentive Item Similarity model (NAIS) for item-based CF. The key to our design of NAIS is an attention network, which is capable of distinguishing which historical items in a user profile are more important for a prediction. Compared to the state-of-the-art item-based CF method Factored Item Similarity Model (FISM), our NAIS has stronger representation power with only a few additional parameters brought by the attention network. Extensive experiments on two public benchmarks demonstrate the effectiveness of NAIS. This work is the first attempt that designs neural network models for item-based CF, opening up new research possibilities for future developments of neural recommender systems

Development of a novel method in electroless copper plating

Master'sMASTER OF ENGINEERIN

Ultrasonic verification of five wave fronts in unidirectional graphite epoxy composite

The existence of five different waves fronts in a unidirectional graphite fiber reinforced epoxy composite with energy flux propagation at the angle of 60 deg with respect to the fiber direction is verified by measuring their corresponding group and phase velocities of longitudinal and shear waves using the through transmission technique. The experimental and theoretical values of phase velocities show excellent agreement for all three modes of wave propagation. It is also verified that the maximum output voltage amplitude is obtained when the line joining the centers of the transmitting and receiving transducers is parallel to the energy propagation direction defined by the deviation angle

(μ-4-Methyl­benzene­thiol­ato-κ2 S:S)bis­[carbon­yl(η5-cyclo­penta­dien­yl)molybdenum(II)]

The asymmetric unit of the title compound, [Mo2(C5H5)2(C7H7S)2(CO)2], consists of two half-mol­ecules, each molecule lying on a centre of symmetry. The thiol­ate groups function as bridges between the MoII atoms, which adopt a quasi-octa­hedral geometry. In the octa­hedral environment the two ligating S atoms are in a cis arrangement

The theoretical direct-band-gap optical gain of Germanium nanowires

We calculate the electronic structures of Germanium nanowires by taking the effective-mass theory. The electron and hole states at the G-valley are studied via the eight-band k.p theory. For the [111] L-valley, we expand the envelope wave function using Bessel functions to calculate the energies of the electron states for the first time. The results show that the energy dispersion curves of electron states at the L-valley are almost parabolic irrespective of the radius of Germanium nanowires. Based on the electronic structures, the density of states of Germanium nanowires are also obtained, and we find that the conduction band density of states mostly come from the electron states at the L-valley because of the eight equivalent degenerate L points in Germanium. Furthermore, the optical gain spectra of Germanium nanowires are investigated. The calculations show that there are no optical gain along z direction even though the injected carrier density is 4x1019 cm-3 when the doping concentration is zero, and a remarkable optical gain can be obtained when the injected carrier density is close to 1x1020 cm-3, since a large amount of electrons will prefer to occupy the low-energy L-valley. In this case, the negative optical gain will be encountered considering free-carrier absorption loss as the increase of the diameter. We also investigate the optical gain along z direction as functions of the doping concentration and injected carrier density for the doped Germanium nanowires. When taking into account free-carrier absorption loss, the calculated results show that a positive net peak gain is most likely to occur in the heavily doped nanowires with smaller diameters. Our theoretical studies are valuable in providing a guidance for the applications of Germanium nanowires in the field of microelectronics and optoelectronics