Raid elite

This game inspiration are the real-time strategy game and raid in MMORPG. In this game, you need to get familiar with and operate five different characters. There are two bosses you can choose to fight. This game use Unity 2020.3.18f2c2 as game engine. All art is hand drawn. The design goal is making a game with certain depth which requires some effort to win. The design challenge for myself is design some interesting boss fights and accomplish a complete game which has good visual feedback

Towards justifying computer algebra algorithms in Isabelle/HOL

As verification efforts using interactive theorem proving grow, we are in need of certified algorithms in computer algebra to tackle problems over the real numbers. This is important because uncertified procedures can drastically increase the size of the trust base and under- mine the overall confidence established by interactive theorem provers, which usually rely on a small kernel to ensure the soundness of derived results. This thesis describes an ongoing effort using the Isabelle theorem prover to certify the cylindrical algebraic decomposition (CAD) algorithm, which has been widely implemented to solve non-linear problems in various engineering and mathematical fields. Because of the sophistication of this algorithm, people are in doubt of the correctness of its implementation when deploying it to safety-critical verification projects, and such doubts motivate this thesis. In particular, this thesis proposes a library of real algebraic numbers, whose distinguishing features include a modular architecture and a sign determination algorithm requiring only rational arithmetic. With this library, an Isabelle tactic based on univariate CAD has been built in a certificate-based way: external, untrusted code delivers solutions in the form of certificates that are checked within Isabelle. To lay the foundation for the multivariate case, I have formalised various analytical results including Cauchy’s residue theorem and the bivariate case of the projection theorem of CAD. During this process, I have also built a tactic to evaluate winding numbers through Cauchy indices and verified procedures to count complex roots in some domains. The formalisation effort in this thesis can be considered as the first step towards a certified computer algebra system inside a theorem prover, so that various engineering projections and mathematical calculations can be carried out in a high-confidence framework

Numerical Investigation of Laser Absorption by Metal Powder Bed in Selective Laser Sintering Processes

Laser absorption by powder bed in selective laser sintering (SLS) processes remains a critical issue to be fully understood. This issue is important for the appropriate selection of processing parameters in practices as well as an accurate definition of the thermal input in numerical modeling. In this work, a ray tracing model is used to study this issue. In parametric studies, the effects of laser parameters and powder bed structures on the laser absorption are investigated. It is found that a top-hat laser produces a more uniform laser absorption within laser heated spots than a Gaussian laser. The absorption distribution generally does not follow an exponential decay; instead, it gradually increases to a “peak” and then decreases along the laser shooting direction. The absorption near the substrate can be enhanced when the powder bed thickness is reduced, which helps to bind the newly deposited layer with its substrate in SLS processes. Finally, using bimodal powder beds can reduce laser penetration and produce more uniform laser absorption in laser heated spots.Mechanical Engineerin

Realistic Micro-Doppler Database Generation Through Neural Style Transfer Framework

Real-time monitoring of humans can assist professionals in providing healthy living enabling technologies to ensure the health, safety, and well-being of people of all age groups. To enhance the human activity recognition performance, we propose a style-transfer neural framework to generate realistic synthetic micro-Doppler signature dataset. The proposed network extracts environmental effects such as noise, multipath, and occlusions effects directly from the measurement data and transfers these features to the clean simulated signatures generated through our simulator called SimHumaLator. This results in more realistic-looking signatures qualitatively and quantitatively. We use these enhanced signatures to augment our measurement data and observe an improvement in the classification performance by 5% compared to no augmentation case

Selective gas detection using Mn3O4/WO3 composites as a sensing layer

Pure WO3 sensors and Mn3O4/WO3 composite sensors with different Mn concentrations (1 atom %, 3 atom % and 5 atom %) were successfully prepared through a facile hydrothermal method. As gas sensing materials, their sensing performance at different temperatures was systematically investigated for gas detection. The devices displayed different sensing responses toward different gases at specific temperatures. The gas sensing performance of Mn3O4/WO3 composites (especially at 3 atom % Mn) were far improved compared to sensors based on pure WO3, where the improvement is related to the heterojunction formed between the two metal oxides. The sensor based on the Mn3O4/WO3 composite with 3 atom % Mn showed a high selective response to hydrogen sulfide (H2S), ammonia (NH3) and carbon monoxide (CO) at working temperatures of 90 degrees C, 150 degrees C and 210 degrees C, respectively. The demonstrated superior selectivity opens the door for potential applications in gas recognition and detection

Passive Radar for Opportunistic Monitoring in e-Health Applications

This paper proposes a passive Doppler radar as a non-contact sensing method to capture human body movements, recognize respiration, and physical activities in e-Health applications. The system uses existing in-home wireless signal as the source to interpret human activity. This paper shows that passive radar is a novel solution for multiple healthcare applications which complements traditional smart home sensor systems. An innovative two-stage signal processing framework is outlined to enable the multi-purpose monitoring function. The first stage is to obtain premier Doppler information by using the high speed passive radar signal processing. The second stage is the functional signal processing including micro Doppler extraction for breathing detection and support vector machine classifier for physical activity recognition. The experimental results show that the proposed system provides adequate performance for both purposes, and prove that non-contact passive Doppler radar is a complementary technology to meet the challenges of future healthcare applications