571 research outputs found
Understanding and mitigating universal adversarial perturbations for computer vision neural networks
No full textDeep neural networks (DNNs) have become the algorithm of choice for many computer vision applications. They are able to achieve human level performance in many computer vision tasks, and enable the automation and large-scale deployment of applications such as object tracking, autonomous vehicles, and medical imaging. However, DNNs expose software applications to systemic vulnerabilities in the form of Universal Adversarial Perturbations (UAPs): input perturbation attacks that can cause DNNs to make classification errors on large sets of inputs.
Our aim is to improve the robustness of computer vision DNNs to UAPs without sacrificing the models' predictive performance. To this end, we increase our understanding of these vulnerabilities by investigating the visual structures and patterns commonly appearing in UAPs. We demonstrate the efficacy and pervasiveness of UAPs by showing how Procedural Noise patterns can be used to generate efficient zero-knowledge attacks for different computer vision models and tasks at minimal cost to the attacker. We then evaluate the UAP robustness of various shape and texture-biased models, and found that applying them in ensembles provides marginal improvement to robustness.
To mitigate UAP attacks, we develop two novel approaches. First, we propose the Jacobian of DNNs to measure the sensitivity of computer vision DNNs. We derive theoretical bounds and provide empirical evidence that shows how a combination of Jacobian regularisation and ensemble methods allow for increased model robustness against UAPs without degrading the predictive performance of computer vision DNNs. Our results evince a robustness-accuracy trade-off against UAPs that is better than those of models trained in conventional ways. Finally, we design a detection method that analyses the hidden layer activation values to identify a variety of UAP attacks in real-time with low-latency. We show that our work outperforms existing defences under realistic time and computation constraints.Open Acces
Transcutaneous immunization with novel lipid-based adjuvants induces protection against gastric Helicobacter pylori infection
No full textThe development of vaccines to combat pathogens that infect across mucosal surfaces has been a major goal of vaccine research. Successful mucosal vaccination requires the co-administration of adjuvants that can overcome the state of immune tolerance normally associated with mucosal application of proteins. In the case of oral immunization, delivery systems are also required to protect vaccine antigens against destruction by gastric pH and digestive enzymes. Furthermore, adjuvants used for mucosal delivery must be free of neurotoxic effects like those induced by the commonly used experimental mucosal adjuvant cholera toxin. Maintenance of the "cold chain" is also essential for the effectiveness of any vaccine and adjuvants/delivery systems that enhance the stability of a vaccine would offer a significant advantage. Needle-free methods of vaccination that induce protective immunity at multiple mucosal surfaces are also desirable for rapid vaccination of large populations. In the present study we show that transcutaneous immunization (TCI) using Lipid C, a novel lipid-based matrix originally developed for oral immunization, containing soluble Helicobacter sonicate significantly reduces the gastric bacterial burden in mice following gastric challenge with live Helicobacter pylori. Protection is associated with the production of splenic gamma interferon and gastric IgA and was achieved without the co-administration of potent and potentially toxic adjuvants, although protection was further enhanced by inclusion of CpG-ODN and cholera toxin in the lipid delivery system
Singapore : the future project cargo hub of Southeast Asia. Part II : characteristics of project cargo hub/trends in heavy lift shipping
No full textThis report is an explorative study on the desirable characteristics of project cargo hubs and the trends in heavy lift shipping. The author suggests that Singapore, in the heart of Southeast Asia, stands to capitalize on the rapid development of the region if she is able to position itself as a project cargo hub. To explore Singapore’s potential as the project cargo hub of Southeast Asia, there is a need to identify the major project cargo hubs in the world and the desirable characteristics of these hubs. The trends and future of heavy lift shipping were also investigated as market-changing trends may make or break the development of a project cargo hub. Finally, a brief analysis of Singapore’s potential as a project cargo hub was carried out by looking at Singapore’s strengths and constraints as a project cargo hub and how the trends in heavy lift shipping may impact Singapore.Bachelor of Science (Maritime Studies
Finite element analysis of shoulder rotator cuff
No full textThis final year project aims to utilize a previously created three-dimensional (3D) model of the human shoulder Rotator Cuff and its four tendons; Subscapularis, Supraspinatus, Infraspinatus and Teres Minor, for Finite Element Analysis (FEA) to be carried out. The resulting computerized models are to be used to simulate force, stress and strain distribution patterns that the human shoulder joint undergoes in different scenarios. The ultimate aim is to virtually simulate the origination and consequences of muscular tears in the shoulder region, which has become a common problem in the elderly and shoulders that are subjected to repeated or excessive impact during sports.
This project is a continuation from past final year projects, whereby the predecessors had created 3D models of the shoulder tendons from Magnetic Resonance Imaging (MRI) scans. This has provided the author an excellent foundation to build on and start carrying out FEA on the models.
The author made use of ANSYS Workbench software version 11 since it is one of the best tools available within the reach, which is compatible with the existing model. The author then set up a basic methodology on carrying out stress and strain analysis on the shoulder rotator cuff. The 3D models have been converted to Initial Graphics Exchange Specification (IGES) format, which allows the ANSYS software to read them. Material properties and connections between the tendons and the bone have been defined using the ANSYS software.
The author has also inputted different possible parameters such as element type, element size in order to carry out mesh refinements to find out the optimal end results. At the end, the best method, which will be decided after considering its implicated cost factors, will be handed over for further improvisations such as change in direction of forces and utilized for future use. These will be further discussed in detail in the main report.Bachelor of Engineering (Mechanical Engineering
Going from local to global (alliances, mergers & acquisitions)
No full textCo-operative arrangements have been present in the liner shipping industry for over a hundred years. In the modern era, the advent of container shipping facilitated globalisation resulting in competition and demand to be greater than ever. Liner shipping companies are compelled to provide more services in more market areas and with larger capacities. This has led to record levels of consolidation as liner shipping companies become more active in collaborations with fellow players in a bid to meet customers’ demands and gain a competitive edge. The objective of this research project is to investigate how liner companies have grown out of their local origin and expand globally, particularly through alliances and mergers and acquisitions.Bachelor of Science (Maritime Studies
Outlook for the marine container shipping industry part I shipping macroeconomics : the world economy, trade demand and supply implications
No full textThis report is an explorative, forecasted study on the problems and situation faced in the maritime container trade market. The author suggests that the past economic crisis has left too big a dent on the world market such that the world economy has yet to recover fully from the repercussions of the recession. The present mechanism of decision-makings will not function on the current prevailing paradigm: i.e. economies of scale and poor economic situation. To address the globalised economies and the eventual development in world container trade, there is a need to look into the past of the economy, acknowledge the present situation and provide in depth information on countries’ economies that will heavily influence the world economy and the container trade. The world container trade in relation to the economics of demand and supply will also be addressed, after which this paper will round off with an insight of the development of ship financing and a conclusion of the outlook of the marine container shipping industry.Bachelor of Science (Maritime Studies
A study on business development strategies and tactics in the shipping industry to increase customer satisfaction (logistics service providers)
No full textThe paper aims to find out whether organisations from shipping industry consider the use of disruptive technology (e.g. Big Data Analytics) due to the age of digitalisation to improve customer satisfaction. As the scope is in the container shipping industry, the author is focusing on Logistics Service Providers (LSPs) which is one of the major players in the container shipping ecosystem besides Shipping Lines and Port Sector.
Survey questions were customised according to LSPs, together with software providers and shippers to get comprehensive insights. In addition, the option for face to face interview was given to the respondents for further discussion and clarification. Selected excerpts of the interviews were used to substantiate on pointers raised in the discussion section.
The leadership of the organisation plays an important role to ensure its sustainability and distinctiveness not only through cost-cutting measures but with the use of technologies in the age of digitalisation. The consideration on whether the use of technology is considered as disruptive or advanced can be subjective. It will depend on whether the organisation uses it due to market and technology trends. It is also dependable on whether there are concrete thoughts and processes are implemented through close collaboration which can create a difference and resolve the “IT Gap”. The notion on whether the major players in the container shipping ecosystem can collaborate will depend on whether the shipping industry can find and determine what will benefit them in the long run. In addition, it is beneficial to have an influential chain master in the industry that is influential to drive the initiatives or changes that are customer-centric.
Lastly, the blockchain technology has been getting more coverage which sees the feasibility of actual collaboration among the major players of the container shipping ecosystem. Further in-depth research and discussion can be done to find its benefit for the shipping industry.Bachelor of Science (Maritime Studies
Abstract A007: Pancreatic cancer comprises co-existing transcriptional states regulated by distinct master regulator programs
No full textAbstract
Despite extensive efforts, reproducible assessment of pancreatic ductal adenocarcinoma (PDA) heterogeneity and plasticity at the single cell level remains elusive. Systematic, network-based analysis of single cell RNA-seq profiles showed that most PDA tumors comprise three coexisting lineages whose aberrant transcriptional state is mechanistically controlled by distinct regulatory programs. These lineages were characterized by the aberrant activation of either gastrointestinal lineage markers (GLS), transcriptional effectors of morphogen pathways (MOS) and acinar to ductal metaplasia markers (ALS). Each lineage was characterized by cells in two different cell states determined by the differential activation of MEK signaling (M+/M-) and high cellular plasticity. These states were confirmed in multiple cohorts, cell lines, PDX models and harmonized with bulk profile analyses. Master regulators (MRs) of GLS and MOS state were predictive of patient’s survival in bulk profiles. Cross-state plasticity was confirmed by lineage tracing assays, while pooled CRISPR/Cas9 assays confirmed the essentiality of identified MR proteins. Finally, mechanistic MR-mediated cell state control was confirmed by MR expression-mediated reprogramming of MOS cells to a GLS state. Our work provided a mechanistic model of pancreatic cancer heterogeneity and testable hypothesis to target cell state-specific pancreatic cancer dependencies.
Citation Format: Pasquale Laise, Mikko Turunen, Hans Carlo Maurer, Alvaro Curiel Garcia, Ela Elyada, Bernhard Schmierer, Lorenzo Tomassoni, Jeremy Worley, Mariano J. Alvarez, Jordan Kesner, Xiangtian Tan, Somnath Tagore, Ester Calvo Fernandez, Kelly Wong, Alexander L. E. Wang, Sabrina Ge, Alina C. Iuga, Aaron T. Griffin, Winston Wong, Gulam A. Manji, Faiyaz Notta, David A. Tuveson, Kenneth P. P. Olive, Andrea Califano. Pancreatic cancer comprises co-existing transcriptional states regulated by distinct master regulator programs [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A007.</jats:p
- …
