Interprétation d'essais dilatométriques réalisés dans un pilier abandonné par modélisation numérique

International audienceDilatometer tests were carried out in an abandoned pillar of a Lorraine iron basin to characterize the in situ iron ore. Modules of deformability and their variability were determined using the traditional approach. A more comprehensive interpretation, based on numerical modeling and inverse methods, made it possible to estimate the strength properties of the in situ iron ore.Des essais dilatométriques ont été réalisés dans un pilier abandonné du bassin ferrifère lorrain dans le but de caractériser le minerai de fer in situ. Les modules de déformabilité et leur variabilité ont été déterminés par l'approche classique. Une interprétation plus complète, basée sur la modélisation numérique et la méthode inverse, a permis d'estimer les caractéristiques de résistance du minerai de fer in situ

Liquidity in Credit Networks with Constrained Agents

In order to scale transaction rates for deployment across the global web, many cryptocurrencies have deployed so-called "Layer-2" networks of private payment channels. An idealized payment network behaves like a Credit Network, a model for transactions across a network of bilateral trust relationships. Credit Networks capture many aspects of traditional currencies as well as new virtual currencies and payment mechanisms. In the traditional credit network model, if an agent defaults, every other node that trusted it is vulnerable to loss. In a cryptocurrency context, trust is manufactured by capital deposits, and thus there arises a natural tradeoff between network liquidity (i.e. the fraction of transactions that succeed) and the cost of capital deposits. In this paper, we introduce constraints that bound the total amount of loss that the rest of the network can suffer if an agent (or a set of agents) were to default - equivalently, how the network changes if agents can support limited solvency guarantees. We show that these constraints preserve the analytical structure of a credit network. Furthermore, we show that aggregate borrowing constraints greatly simplify the network structure and in the payment network context achieve the optimal tradeoff between liquidity and amount of escrowed capital.Comment: To be published in TheWebConf 202

Remote Oblivious Storage: Making Oblivious RAM Practical

Remote storage of data has become an increasingly attractive and advantageous option, especially due to cloud systems. While encryption protects the data, it does not hide the access pattern to the data. A natural solution is to access remote storage using an Oblivious RAM (ORAM) which provably hides all access patterns. While ORAM is asymptotically efficient, the best existing scheme (Pinkas and Reinman, Crypto'10) still has considerable overhead for a practical implementation: for M stored items, it stores 4 times and sometimes 6 times more items remotely, requires O(log2 M) round trips to storage server per request, and periodically blocks all data requests to shuffle all storage (which is a lengthy process). In this paper, we first define a related notion to ORAM, oblivious storage (OS), which captures more accurately and naturally the security setting of remote storage. Then, we propose a new ORAM/OS construction that solves the practicality issues just outlined: it has a storage constant of ~ 1, achieves O(1) round trips to the storage server per request, and allows requests to happen concurrently with shuffle without jeopardizing security. Our construction consists of a new organization of server memory into a flat main part and a hierarchical shelter, a client-side index for rapidly locating identifiers at the server, a new shelter serving requests concurrent with the shuffle, and a data structure for locating items efficiently in a partially shuffled storage

Simple Opportunistic Encryption

Network traffic encryption is becoming a requirement, not an option. Enabling encryption will be a communal effort so a solution that gives partial benefits until fully deployed is needed. A solution that requires little changes to existing infrastructure will also help as it can be quickly deployed to give immediate shortterm benefits. We argue that tcpcrypt, a TCP option for opportunistic encryption is the path of least-resistance for a solution against large-scale traffic encryption. Tcpcrypt requires no changes to applications, is compatible with existing networks (works with NATs), and just works by default. It is high performance, so it can be deployed on servers without much concern. tcpcrypt attempts to maximize security for any given setting. By default, it will protect against passive eavesdropping, and also allows detecting large scale interception. With authentication, tcpcrypt can provide full security against active attackers and so it is a complete solution both for the short-term and long-term

Delegating Network Security with More Information

Network security is gravitating towards more centralized control. Strong centralization places a heavy burden on the administrator who has to manage complex security policies and be able to adapt to users' requests. To be able to cope, the administrator needs to delegate some control back to end-hosts and users, a capability that is missing in today's networks. Delegation makes administrators less of a bottleneck when policy needs to be modified and allows network administration to follow organizational lines. To enable delegation, we propose ident++ - a simple protocol to request additional information from end-hosts and networks on the path of a flow. ident++ allows users and end-hosts to participate in network security enforcement by providing information that the administrator might not have or rules to be enforced on their behalf. In this paper we describe ident++ and how it provides delegation and enables flexible and powerful policies.United States. Dept. of Homeland Security (Scholarship and Fellowship Program)United States. Dept. of EnergyOak Ridge Institute for Science and Educatio

Apprehending Joule Thieves with Cinder

Energy is the critical limiting resource to mobile computing devices. Correspondingly, an operating system must track, provision, and ration how applications consume energy. The emergence of third-party application stores and marketplaces makes this concern even more pressing. A third-party application must not deny service through excessive, unforeseen energy expenditure, whether accidental or malicious. Previous research has shown promise in tracking energy usage and rationing it to meet device lifetime goals, but such mechanisms and policies are still nascent, especially regarding user interaction. We argue for a new operating system, called Cinder, which builds on top of the HiStar OS. Cinder's energy awareness is based on hierarchical capacitors and task profiles. We introduce and explore these abstractions, paying particular attention to the ways in which policies could be generated and enforced in a dynamic system

Predicting lung cancer recurrence from circulating tumour DNA. Commentary on 'Phylogenetic ctDNA analysis depicts early-stage lung cancer evolution'

No abstract available

PD-1/PD-L1 inhibitor activity in patients with gene-rearrangement positive non-small cell lung cancer-an IMMUNOTARGET case series.

BACKGROUND Prior IMMUNOTARGET registry data had suggested that responses to immune [anti PD(L)1] monotherapy in gene-arranged non-small cell lung cancer (NSCLC) were rare or absent, depending on the specific oncogene. METHODS IMMUNOTARGET sites reporting prior registry data or new individual cases of gene rearranged NSCLC seeming to benefit from immune monotherapy were explored in detail looking to both validate their diagnosis of a functional gene rearrangement and to look for features potentially differentiating them from other such cases associated with low response rates. RESULTS Five cases of NSCLC with a gene rearrangement with reported responses or prolonged stabilization from immune monotherapy were identified in total. All had little or no prior smoking history and had programmed death-ligand 1 (PD-L1) values ranging from zero to 100%. A confirmed rearrangement partner was reported in only 2 of the cases (CD74-ROS1 and KIF5B-RET), however in one of the other three cases [analplastic lymophoma kinase (ALK)], significant benefit from a relevant prior targeted therapy was noted, also consistent with the rearrangement status being correctly assigned. CONCLUSIONS Not all driver oncogene subtypes of NSCLC are equally responsive to immune monotherapy, however even among patients with well-validated gene rearranged NSCLC which has traditionally been considered immune hyporesponsive, objective responses can occur. Additional explorations of the features associated with and underlying the immune hypo-responsiveness of most, but not all, cases of gene-rearranged NSCLC are required