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Virtual Log-Structured Storage for High-Performance Streaming

Ovidiu-Cristian Marcu, Alexandru Costan, Bogdan Nicolae, Gabriel Antonin
2021 2021 IEEE International Conference on Cluster Computing (CLUSTER)  
In the framework of the Ph.D. thesis of Ovidiu Marcu that describes KerA [20] (available Jan. 2019), we preliminarily introduced the virtual log concept for replicating data streams.  ... 
doi:10.1109/cluster48925.2021.00046 fatcat:6spmm5dhfnbjnd25xhkrdj6qxe

Spark Versus Flink: Understanding Performance in Big Data Analytics Frameworks

Ovidiu-Cristian Marcu, Alexandru Costan, Gabriel Antoniu, Maria S. Perez-Hernandez
2016 2016 IEEE International Conference on Cluster Computing (CLUSTER)  
Big Data analytics has recently gained increasing popularity as a tool to process large amounts of data on-demand. Spark and Flink are two Apache-hosted data analytics frameworks that facilitate the development of multi-step data pipelines using directly acyclic graph patterns. Making the most out of these frameworks is challenging because efficient executions strongly rely on complex parameter configurations and on an in-depth understanding of the underlying architectural choices. Although
more » ... nsive research has been devoted to improving and evaluating the performance of such analytics frameworks, most of them benchmark the platforms against Hadoop, as a baseline, a rather unfair comparison considering the fundamentally different design principles. This paper aims to bring some justice in this respect, by directly evaluating the performance of Spark and Flink. Our goal is to identify and explain the impact of the different architectural choices and the parameter configurations on the perceived end-to-end performance. To this end, we develop a methodology for correlating the parameter settings and the operators execution plan with the resource usage. We use this methodology to dissect the performance of Spark and Flink with several representative batch and iterative workloads on up to 100 nodes. Our key finding is that there none of the two framework outperforms the other for all data types, sizes and job patterns. This paper performs a fine characterization of the cases when each framework is superior, and we highlight how this performance correlates to operators, to resource usage and to the specifics of the internal framework design. • We introduce a methodology to understand performance in Big Data analytics frameworks by correlating the operators execution plan with the resource utilization and the parameter configuration.
doi:10.1109/cluster.2016.22 dblp:conf/cluster/MarcuCAP16 fatcat:e6e6aftulved5c3qlj6634b6me

KerA: Scalable Data Ingestion for Stream Processing

Ovidiu-Cristian Marcu, Alexandru Costan, Gabriel Antoniu, Maria Perez-Hernandez, Bogdan Nicolae, Radu Tudoran, Stefano Bortoli
2018 2018 IEEE 38th International Conference on Distributed Computing Systems (ICDCS)  
doi:10.1109/icdcs.2018.00152 dblp:conf/icdcs/MarcuCAPNTB18 fatcat:pphuux34bzar5jxeapv2nwlug4

Retroperitoneal Tumours - Treatment and Prognosis of Tumour Recurrence

Ovidiu Gabriel Bratu, Alexandru Ionut Cherciu, Adrian Bumbu, Sorin Lupu, Dragos Radu Marcu, Florentina Ionita Radu, Maria Manea, Cristian Furau, Camelia Cristina Diaconu, Dan Liviu Dorel Mischianu
2019 Revista de chimie (Bucuresti)  
Retroperitoneal tumors, once considered uncommon, have been reported in the last years in such numbers that they cannot be considered anymore a rare condition. Tumor recurrence following surgical excision is quite common and a tumor that was considered originally as benign in many cases can recur as a malignant tumor. The purpose of this paper is to underline the difficulties in terms of establishing a correct diagnosis and a proper therapeutic protocol when facing a retroperitoneal mass of
more » ... own origin, as well as to present the available data regarding prognosis, treatment options and tumor recurrence. Retroperitoneal tumors can be classified as benign or malignant; solid, cystic or both; single or multiple, and of varied histological types. A high percentage of patients with retroperitoneal tumors are discovered in advanced stages, usually seeking medical help for symptoms related to nearby organ compression/invasion. This pathology requires a prompt and adequate multidisciplinary management, in order to achieve disease control and to reduce the recurrence rate. Complete surgical resection is the potential curative treatment for retroperitoneal tumors and it is best managed in high-volume centers, by a multidisciplinary team. Complete oncological tumor resection and tumor grade remain the most important predictors for local recurrence and disease-specific survival. Further research is required in order to define the role of radiotherapy, as well as to discover new biological therapies that target various molecular pathways involved in retroperitoneal cancers.
doi:10.37358/rc.19.1.6879 fatcat:idqy6i36tnc5falotvrce2vc6q

Towards a unified storage and ingestion architecture for stream processing

Ovidiu-Cristian Marcu, Alexandru Costan, Gabriel Antoniu, Maria S. Perez-Hernandez, Radu Tudoran, Stefano Bortoli, Bogdan Nicolae
2017 2017 IEEE International Conference on Big Data (Big Data)  
Big Data applications are rapidly moving from a batch-oriented execution model to a streaming execution model in order to extract value from the data in real-time. However, processing live data alone is often not enough: in many cases, such applications need to combine the live data with previously archived data to increase the quality of the extracted insights. Current streaming-oriented runtimes and middlewares are not flexible enough to deal with this trend, as they address ingestion
more » ... ion and pre-processing of data streams) and persistent storage (archival of intermediate results) using separate services. This separation often leads to I/O redundancy (e.g., write data twice to disk or transfer data twice over the network) and interference (e.g., I/O bottlenecks when collecting data streams and writing archival data simultaneously). In this position paper, we argue for a unified ingestion and storage architecture for streaming data that addresses the aforementioned challenge. We identify a set of constraints and benefits for such a unified model, while highlighting the important architectural aspects required to implement it in real life. Based on these aspects, we briefly sketch our plan for future work that develops the position defended in this paper.
doi:10.1109/bigdata.2017.8258196 dblp:conf/bigdataconf/MarcuCAPTBN17 fatcat:w5a2fruranfflbwchhfuerqrpm

Hyperkalemia and Cardiovascular Diseases: New Molecules for the Treatment

Camelia Cristina Diaconu, Ana Maria Alexandra Stanescu, Anca Pantea Stoian, Radu Ciprian Tincu, Cristian Cobilinschi, Razvan Ion Florin Dragomirescu, Bogdan Socea, Dan Arsenie Spinu, Dragos Marcu, Laura Ileana Socea, Ovidiu Gabriel Bratu
2018 Revista de Chimie  
Potassium is a key electrolyte for the maintenance of cardiovascular system health, being involved in a broad array of vital physiological processes. Hyperkalemia is a common clinical problem and potentially life-threatening condition predominantly seen in patients with cardiac and kidney disease, especially if receiving treatment with inhibitors of the renin-angiotensin-aldosterone axis. Several studies have demonstrated the short and long-term morbidity and mortality that hyperkalemia induces
more » ... in patients with cardiovascular diseases. Plenty of data is currently emerging on this topic. This paper aims to review the new strategies and molecules for improving the management of hyperkalemia.
doi:10.37358/rc.18.6.6326 fatcat:fandopqs2ffl5odgt3onruazpy

Exploring Shared State in Key-Value Store for Window-Based Multi-pattern Streaming Analytics

Ovidiu-Cristian Marcu, Radu Tudoran, Bogdan Nicolae, Alexandru Costan, Gabriel Antoniu, Maria S. Perez-Hernandez
2017 2017 17th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGRID)  
We are now witnessing an unprecedented growth of data that needs to be processed at always increasing rates in order to extract valuable insights. Big Data streaming analytics tools have been developed to cope with the online dimension of data processing: they enable real-time handling of live data sources by means of stateful aggregations (operators). Current state-of-art frameworks (e.g. Apache Flink [1]) enable each operator to work in isolation by creating data copies, at the expense of
more » ... eased memory utilization. In this paper, we explore the feasibility of deduplication techniques to address the challenge of reducing memory footprint for window-based stream processing without significant impact on performance. We design a deduplication method specifically for windowbased operators that rely on key-value stores to hold a shared state. We experiment with a synthetically generated workload while considering several deduplication scenarios and based on the results, we identify several potential areas of improvement. Our key finding is that more fine-grained interactions between streaming engines and (key-value) stores need to be designed in order to better respond to scenarios that have to overcome memory scarcity.
doi:10.1109/ccgrid.2017.126 dblp:conf/ccgrid/MarcuTNCAP17 fatcat:5oxtilgnibhj5dhp3zb47jhe2a

Research and Science Today Supplement No. 2/2018

Maria MANEA, Dragoş MARCU, Camelia DIACONU, Bogdan SOCEA, Vlad-Dumitru BĂLEANU, Ovidiu BRATU, Raluca GRIGORE, Şerban BERTEŞTEANU, Vlad Denis CONSTANTIN, Lucian IORGA, Radu ANGHEL, Dan MISCHIANU (+16 others)
2018 Research and Science Today  
COJAN Vlad-Dumitru BĂLEANU Vlad Denis CONSTANTIN ➢ Maria MANEA Dragoş MARCU Camelia DIACONU Bogdan SOCEA Mihai DIMITRIU Vlad-Dumitru BĂLEANU Ovidiu BRATU ➢ Simona BOBIC Bogdan SOCEA Camelia  ...  Radu POPESCU Alexandru NICOLAESCU Vlad-Dumitru BĂLEANU Bogdan SOCEA ➢ Bogdan SOCEA Ovidiu BRATU Camelia DIACONU Dragoş MARCU Maria MANEA Raluca GRIGORE Şerban BERTEŞTEANU Tiberiu Stefanita TENEA  ... 
doaj:25735bcf8c634d2eb7b9b05f56e5d3d0 fatcat:xamuqsq6c5g2vnzcdgg5rovzsu

Breast Reconstruction Particularities after Radiotherapy-Case Report

Iulia Marcu, Ovidiu Stefanescu, Cristian Jecan, Laura Raducu, Tiberiu Neagu, Ioan Lascăr, Iulia Marcu
Modern Medicine | 2017   unpublished
Patients undergoing postmastectomy breast reconstruction, with a history of prior radiation therapy, present a particular clinical scenario. This is because of their well-documented higher complication rates, secondary to deleterious effects of irradiation on the soft tissue envelope of the remaining breast. Case presentation: This article presents the case of a breast reconstruction in a 53-year old woman with two subsequent breast reconstruction procedures after being treated with
more » ... and radiotherapy. The fi rst procedure was placing an expander under the mastectomy skin flaps, but it was followed by complications requiring the removal of the expander. One year later the second procedure was performed with latissimus dorsi flap and implant with satisfactory results. But after two years from the latest procedure, the patient turned to our clinic for improvement of the cosmetic outcome. Taking into account the medical and surgical history of the patient and after a complete clinical evaluation, the decision was to perform the right breast reconstruction with contralateral unipedicle musculocu-taneous TRAM flap. Conclusions: The aesthetic results of standard delayed breast reconstruction after radiation therapy in patients with locally advanced breast cancer are satisfactory at best, even in the hands of experienced surgeons. The result quality that can be obtained in a patient with previous radiotherapy is therefore less optimal than the one achieved in a nonirradiated patient.

Table of Contents

2021 2021 16th International Conference on Engineering of Modern Electric Systems (EMES)  
Marcu and Cristian Grava Brain Tumor Classification Using Pretrained Convolutional Neural Networks . . . . . . . . . . . . . 130 Constantin Daniel Mihalas and Mihaela Ruxandra Lascu The Development of  ...  Equipped with Infrared Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 Lich Luu, Ciprian Lupu, Ion Cristian  ... 
doi:10.1109/emes52337.2021.9484100 fatcat:txeikraetjh7boclnnl3232mka

DAS 2020 Index Authors

2020 2020 International Conference on Development and Application Systems (DAS)  
D09 SCHIPOR, Ovidiu-Andrei .....................................................................................  ...  A07 MARCU, Daniela ...........................................................................................................  ... 
doi:10.1109/das49615.2020.9108950 fatcat:lmx44guqcfbf7c5bcnv3zroywm

The Versatility, Plasticity and Esthetic Aspect of Latissimus Dorsi Muscle-Cutaneous Flap in Breast Reconstruction-Case Report

Iulia Marcu, Ovidiu Stefanescu, Cristian Jecan, Tiberiu Neagu, Ioan Lascar, Iulia Marcu
Modern Medicine | 2017   unpublished
The reconstruction of the breast with latissimus dorsi muscle-cutaneous flap and implant continues to be a reliable and easy to perform method, both by the experienced surgeons and also for the beginners. Case presentation: This article describes the case of a 38-year old woman who underwent breast reconstruction after 5 months from the mastectomy. After the clinical and paraclinical evaluation, all reconstruction options were presented to her, with advantages and disadvantages. Following the
more » ... tailed pre-operatory evaluation and observing, as much as possible, the desires of the patient-to have a bigger breast compared to the amputated one and, at the same time, with an as natural as possible aspect, observing the integrity of the abdominal wall and the possibility to hide the scar of the donor area at the back-the surgical team together with the patient decided the reconstruction of the right breast with latissimus dorsi muscle-cutaneous flap and silicone implant (295cc). Even if the specialty literature presents this technique with some disadvantages in the fi nal results and functionality of the ipsilateral shoulder, in this case the latissimus dorsi muscle-cutaneous flap offered a good coverage with satisfactory cosmetic outcome and proper functionality of the shoulder. Conclusions: Through the approach of a standardized protocol and adjusted to the requirements and anatomic possibilities of the patient, the breast reconstruction with LD and implant remains one of the most versatile techniques of reconstruction and which local complications are comparable to the ones in the esthetic mammary augmentation.


2020 2020 IEEE International Conference on Automation, Quality and Testing, Robotics (AQTR)  
WHITLOCK, Raul Cristian MURESAN 343 A1/44 Machine Learning-Assisted Detection of Action Potentials in Extracellular Multi-Unit Recordings Harald BARZAN, Ana-Maria ICHIM, Raul Cristian MURESAN  ...  Alexandra FANCA, Honoriu VALEAN, Liviu MICLEA Session code/ID Paper title Authors Page number R1/60 201 R2/71 Navigation of Outdoor Mobile Robots with Extended Grid Algorithms Cosmin MARCU  ... 
doi:10.1109/aqtr49680.2020.9129960 fatcat:dnwkq3u6fzeqngzgupxcliuvvy

External Reviewers

2018 2018 18th IEEE/ACM International Symposium on Cluster, Cloud and Grid Computing (CCGRID)  
Cristian Marcu, Inria, France x Tatiana Martsinkevich, RIKEN Advanced Institute for Computational Science, Japan x Pierre Matri, Universidad Politécnica de Madrid, Spain x Misbah Mubarak, Argonne National  ...  Tsinghua University, China x Bangtian Liu, Rutgers University, USA x Qingyue Liu, Rice University, USA x Tao Lu, New Jersey Institute of Technology, USA x Huizhang Luo, New Jersey Institute of Technology x Ovidiu  ... 
doi:10.1109/ccgrid.2018.00009 fatcat:z6z2bwtlw5bepbm2m2k7ajktki


Traian Florea
2019 Altarul reîntregirii  
Cathisma, 2014, p. 27. 25 Cristian-Flavius TERINTE, Viața Bisericii conform metaforelor pauline, Oradea, Edit.  ...  Istoricul Ovidiu Drimba spune că "un templu grec era prin definiție «locașul zeului»" 6 .  ... 
doi:10.29302/ar.2019.3.5 fatcat:owgddacj7nd3pic3zfwyeszy24
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