The Use of Internal Rating Models in Managing the Risks Related to the Exposures of Non-banking Financial Institutions

Although there is no express requirement in the regulations of the National Bank of Romania, the design, the implementation and the use of rating systems in the management of risks related to exposures of non-banking financial institutions (NFIs) on the basis of good banking practice, is a valuable and indispensable in the efficient administration of risks, especially in the current crisis. In this framework, this study describes the synthetic process of reviewing the scoring system used by IFN. The mechanism for evaluation of scoring system performance combines the indicators of discrimination power with econometric results of studying the functional relationship between risk variables integrated in the model and the credit status (default/ reimbursement) based on logit model. The empirical analysis provides clear evidences that while the discriminatory power related to qualitative component (reputational scoring) respects the requirements of a good ex-ante identification of non reimbursement cases, the power of discrimination of quantitative scoring is only marginally superior to a random model. The added value of the study is completed by highlighting the importance of technical conditions of financing facility for anticipating events of non reimbursement. At the same time, the study tries to highlight the importance of scientific calibration of such a scoring system to perform effectively in the early detection of cases of default.non-banking financial institutions, credit risk, scoring model, univariate analysis, multivariate analysis, ROC curve, discriminating power

A Hybrid Local Storage Transfer Scheme for Live Migration of I/O Intensive Workloads

International audienceLive migration of virtual machines (VMs) is key feature of virtualization that is extensively leveraged in IaaS cloud environments: it is the basic building block of several important features, such as load balancing, pro-active fault tolerance, power management, online maintenance, etc. While most live migration efforts concentrate on how to transfer the memory from source to destination during the migration process, comparatively little attention has been devoted to the transfer of storage. This problem is gaining increasing importance: due to performance reasons, virtual machines that run large-scale, data-intensive applications tend to rely on local storage, which poses a difficult challenge on live migration: it needs to handle storage transfer in addition to memory transfer. This paper proposes a memory-migration independent approach that addresses this challenge. It relies on a hybrid active push / prioritized prefetch strategy, which makes it highly resilient to rapid changes of disk state exhibited by I/O intensive workloads. At the same time, it is minimally intrusive in order to ensure a maximum of portability with a wide range of hypervisors. Large scale experiments that involve multiple simultaneous migrations of both synthetic benchmarks and a real scientific application show improvements of up to 10x faster migration time, 10x less bandwidth consumption and 8x less performance degradation over state-of-art

BlobCR: Virtual Disk Based Checkpoint-Restart for HPC Applications on IaaS Clouds

International audienceInfrastructure-as-a-Service (IaaS) cloud computing is gaining significant interest in industry and academia as an alternative platform for running HPC applications. Given the need to provide fault tolerance, support for suspend-resume and offline migration, an efficient Checkpoint-Restart mechanism becomes paramount in this context. We propose BlobCR, a dedicated checkpoint repository that is able to take live incremental snapshots of the whole disk attached to the virtual machine (VM) instances. BlobCR aims to minimize the performance overhead of checkpointing by persisting VM disk snapshots asynchronously in the background using a low overhead technique we call selective copy-on-write. It includes support for both application-level and process-level checkpointing, as well as support to roll back file system changes. Experiments at large scale demonstrate the benefits of our proposal both in synthetic settings and for a real-life HPC application

Towards Efficient Live Migration of I/O Intensive Workloads: A Transparent Storage Transfer Proposal

Live migration of virtual machines (VMs) is key feature of virtualization that is extensively leveraged in IaaS cloud environments: it is the basic building block of several important features, such as load balancing, pro-active fault tolerance, power management, online maintenance, etc. While most live migration efforts concentrate on how to transfer the memory from source to destination during the migration process, comparatively little attention has been devoted to the transfer of storage. This problem is gaining increasing importance: due to performance reasons, virtual machines that run I/O intensive workloads tend to rely on local storage, which poses a difficult challenge on live migration: it needs to handle storage transfer in addition to memory transfer. This paper proposes a completely hypervisor-transparent approach that addresses this challenge. It relies on a hybrid active push-prioritized prefetch strategy, which makes it highly resilient to rapid changes of disk state exhibited by I/O intensive workloads. At the same time, transparency ensures a maximum of portability with a wide range of hypervisors. Large scale experiments that involve multiple simultaneous migrations of both synthetic benchmarks and a real scientific application show improvements of up to 10x faster migration time, 5x less bandwidth consumption and 62% less performance degradation over state-of-art

BlobCR: Efficient Checkpoint-Restart for HPC Applications on IaaS Clouds using Virtual Disk Image Snapshots

International audienceInfrastructure-as-a-Service (IaaS) cloud computing is gaining significant interest in industry and academia as an alternative platform for running scientific applications. Given the dynamic nature of IaaS clouds and the long runtime and resource utilization of such applications, an efficient checkpoint-restart mechanism becomes paramount in this context. This paper proposes a solution to the aforementioned challenge that aims at minimizing the storage space performance overhead of checkpoint-restart. We introduce a framework that combines checkpoint-restart protocols at guest level with virtual machine (VM) disk-image multi-snapshotting and multi-deployment at host level in order to efficiently capture and potentially roll back the complete state of the application, including file system modifications. Experiments on the G5K testbed show substantial improvement for MPI applications over existing approaches, both for the case when customized checkpointing is available at application level and the case when it needs to be handled at process level

STUDY ON THE SITUATION OF THE REAL ESTATE MARKET IN THE TOWN OF FLOREȘTI, CLUJ COUNTY

In the context of the development of the real estate market in the metropolitan area of Cluj-Napoca, the paper aims at an analysis of the sale value of the buildings in this area. Thus, in order to carry out the analysis, a residential real estate property located in Floresti, Floresti commune, Cluj County, was studied, being composed of: intravilan land with an area of 600 sqm and Family building with a height regime of P+E, having the following description in the land book: Family construction, with a height regime P+E, built in 2014, with a surface built on the ground of 130 sqm,  developed area of 230 sqm and usable area of 190 sqm. The construction is divided as follows: on the ground floor - vestibule, living room, hallway, G.S., office, 2 storage spaces, kitchen, room, C.T., garage; upstairs - 3 bedrooms, 2 bathrooms, 3 dressing rooms, hallway + staircase. The approach applied to the valuation of this property was: the direct comparison approach (through the market). Following the application of this method and the results according to the valuation report, the estimation of the market value of the property is 227,000 Euro equivalent to 1,118,000 Ron. The amount was taken over as a result of the direct comparison method because the purpose of this valuation is to estimate the value with a view to the sale of the property. At the time of the evaluation (10.05.2021) it is noticed that the zonal supply is quite high, and the demand is also increasing, thus being an active market. &nbsp

BlobSeer: How to Enable Efficient Versioning for Large Object Storage under Heavy Access Concurrency

To accommodate the needs of large-scale distributed P2P systems, scalable data management strategies are required, allowing applications to efficiently cope with continuously growing, highly dis tributed data. This paper addresses the problem of efficiently stor ing and accessing very large binary data objects (blobs). It proposesan efficient versioning scheme allowing a large number of clients to concurrently read, write and append data to huge blobs that are fragmented and distributed at a very large scale. Scalability under heavy concurrency is achieved thanks to an original metadata scheme, based on a distributed segment tree built on top of a Distributed Hash Table (DHT). Our approach has been implemented and experimented within our BlobSeer prototype on the Grid'5000 testbed, using up to 175 nodes