Proceedings of the 19th Panhellenic Conference on Informatics最新文献

Deflation techniques in conjunction with generic factored approximate sparse inverse preconditioning 与一般因子近似稀疏逆预处理相结合的通货紧缩技术

Proceedings of the 19th Panhellenic Conference on Informatics Pub Date : 2015-10-01 DOI: 10.1145/2801948.2801986

B. E. Moutafis, C. Filelis-Papadopoulos, G. Gravvanis

引用次数: 1

On formulating and tackling integrated circuit placement as a scheduling problem 集成电路布置作为调度问题的制定与解决

Proceedings of the 19th Panhellenic Conference on Informatics Pub Date : 2015-10-01 DOI: 10.1145/2801948.2801965

P. Oikonomou, Thanasis Loukopoulos, Antonios N. Dadaliaris, M. Koziri, G. Stamoulis

引用次数: 5

Estimating student dropout in distance higher education using semi-supervised techniques 利用半监督技术估计远程高等教育学生辍学率

Proceedings of the 19th Panhellenic Conference on Informatics Pub Date : 2015-10-01 DOI: 10.1145/2801948.2802013

Georgios Kostopoulos, S. Kotsiantis, P. Pintelas

{"title":"Estimating student dropout in distance higher education using semi-supervised techniques","authors":"Georgios Kostopoulos, S. Kotsiantis, P. Pintelas","doi":"10.1145/2801948.2802013","DOIUrl":"https://doi.org/10.1145/2801948.2802013","url":null,"abstract":"Nowadays, distance higher education has rapidly increased due to advance and integration of information and communications' technology. Students who attend online distance courses have often family obligations and job commitments and are usually in 'high risk' of dropout during their attendance. It is of a highly importance to identify such students, through paying extra attention and support to them could possibly minimize the possibility of student failure or even dropout. The present research intends to study whether semi-supervised techniques could be useful in student dropout prediction in distance higher education. Semi-supervised learning aims to generate reliable predictions using few labeled and many unlabeled data. Labeled data are difficult obtainable quite often, as they require many experts, a lot of human effort and time in experiments. As far as, we are aware in several studies propose and compare supervised methods for students' dropout prediction rates in higher education, but none of them investigates the effectiveness of semi-supervised methods. The results of our experiments reveal that a good predictive accuracy can be achieved using few labeled data in comparison to well known supervised learning algorithms. For that purpose we have developed a web-based tool to estimate if an individual student is going to dropout.","PeriodicalId":305252,"journal":{"name":"Proceedings of the 19th Panhellenic Conference on Informatics","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130632184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 36

Dynamic reduce task adjustment for hadoop workloads 动态减少hadoop工作负载的任务调整

Proceedings of the 19th Panhellenic Conference on Informatics Pub Date : 2015-10-01 DOI: 10.1145/2801948.2801953

Vaggelis Antypas, Nikos Zacheilas, V. Kalogeraki

{"title":"Dynamic reduce task adjustment for hadoop workloads","authors":"Vaggelis Antypas, Nikos Zacheilas, V. Kalogeraki","doi":"10.1145/2801948.2801953","DOIUrl":"https://doi.org/10.1145/2801948.2801953","url":null,"abstract":"In recent years, we observe an increasing demand for systems that are capable of efficiently managing and processing huge amounts of data. Apache's Hadoop, an open-source implementation of Google's MapReduce programming model, has emerged as one of the most popular systems for Big Data processing and is supported by major companies like Facebook, Yahoo! and Amazon. One of the most challenging aspects of executing a Hadoop job, is to configure appropriately the number of reduce tasks. The problem is exacerbated when multiple jobs are executing concurrently competing for the available system resources. Our approach consists of the following components: (i) an algorithm for computing the appropriate number of reduce tasks per job, (ii) the usage of profiler-jobs for gathering information necessary for the reduce task computation and (iii) two different policies for fragmenting the reduce tasks to the available system resources when multiple jobs execute concurrently in the cluster. Our detailed experimental evaluation using traffic monitoring Hadoop jobs on our local cluster, illustrates that our approach is practical and exhibits solid performance.","PeriodicalId":305252,"journal":{"name":"Proceedings of the 19th Panhellenic Conference on Informatics","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128021514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Designing digital artifacts as transient assemblies with different digital materialities 将数字工件设计为具有不同数字材料的瞬态组件

Proceedings of the 19th Panhellenic Conference on Informatics Pub Date : 2015-10-01 DOI: 10.1145/2801948.2801968

D. Akoumianakis, N. Karadimitriou, Dimitrios Kotsalis, Giorgos Ktistakis, C. Michailidis, Efthimios Syntychakis, G. Vellis, N. Vidakis, George Vlachakis

引用次数: 0

Automating data management in heterogeneous systems using polyhedral analysis 使用多面体分析自动化异构系统中的数据管理

Proceedings of the 19th Panhellenic Conference on Informatics Pub Date : 2015-10-01 DOI: 10.1145/2801948.2801957

V. Vassiliadis, C. Antonopoulos, George Zindros

{"title":"Automating data management in heterogeneous systems using polyhedral analysis","authors":"V. Vassiliadis, C. Antonopoulos, George Zindros","doi":"10.1145/2801948.2801957","DOIUrl":"https://doi.org/10.1145/2801948.2801957","url":null,"abstract":"In this paper we introduce a framework which automates the task of data management for OpenCL programs across multiple devices of a heterogeneous system. Our approach uses compile-time analysis, based on the polyhedral model, to associate computations with the data they consume / produce. The results of the analysis are then used by a runtime system which automates the task of data management. Beyond alleviating the programmer from the burden of data management, our framework enables partitioning computations to all computational devices of heterogeneous systems according to the computational power and memory capacity of each device, thus facilitating the exploitation of all computational and memory resources of the system. We evaluate our approach on a system containing a multi-core CPU and 4 GPUs, using a set of OpenCL applications and benchmarks. We find that our framework allows the transparent utilization of all heterogeneous resources with negligible overhead (1.24% on average over hand-mapped to the target system versions of the codes). At the same time, it enables the execution of problem sizes which could not be executed on homogeneous, or less complex heterogeneous systems, due to their high computational and memory requirements.","PeriodicalId":305252,"journal":{"name":"Proceedings of the 19th Panhellenic Conference on Informatics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122249913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Computer assisted gesture recognition for the greek sign language / fingerspelling 计算机辅助手势识别希腊手语/手指拼写

Proceedings of the 19th Panhellenic Conference on Informatics Pub Date : 2015-10-01 DOI: 10.1145/2801948.2802034

Despoina Kotsidou, C. Angelis, Stamatis Dragoumanos, A. Kakarountas

引用次数: 1

A CAD tool for custom magnitude comparators 用于自定义幅度比较器的CAD工具

Proceedings of the 19th Panhellenic Conference on Informatics Pub Date : 2015-10-01 DOI: 10.1145/2801948.2801967

Giannis Petrousov, M. Dasygenis

引用次数: 0

On the use of hard faults to generate test sets 关于使用硬故障生成测试集

Proceedings of the 19th Panhellenic Conference on Informatics Pub Date : 2015-10-01 DOI: 10.1145/2801948.2801951

I. Voyiatzis, C. Efstathiou

引用次数: 0

A fast progressive local learning regression ensemble of generalized regression neural networks 广义回归神经网络的快速渐进局部学习回归集成

Proceedings of the 19th Panhellenic Conference on Informatics Pub Date : 2015-10-01 DOI: 10.1145/2801948.2801962

Y. Kokkinos, K. Margaritis

引用次数: 2