A lot of research and development activities have been referencing to edge and dew computing solutions for IoT applications, but without determining the deep distinction between these two architectural approaches. Furthermore, there is no clear explanation if dew computing is a special case of edge computing or the opposite. In this paper, we analyze the features of post-cloud architectures to build an IoT solution and clarify the main differences between dew and edge computing approaches. Although the provided analysis covers IoT solutions, still the same principles can be applied more generally.

Cloud computing provides computing resources on a subscription basis, targeting infrastructure (hardware), platform (hardware plus system software), and software. Although post-cloud computing models bring the computing closer to the user, they still use the same principles to provide computing resources to the requestor. While building applications, designers face challenges to specify optimal computing resources. Serverless computing is the answer from cloud providers to take care about the availability of computing resources to relieve programmers suggesting to concentrate on programming functions to be executed as a service. Deviceless approach goes even further allowing functions to be executed on nearby devices instead of servers. In this sense, we define infrastructureless computing as the architectural approach where the programming is isolated from specifying the infrastructure requirements, as a general platform of serverless and deviceless computing. Moreover, the generalization of this approach initiates a new computing model where the functions are executed on a lower architectural layer instead of the higher one. For example, an edge server or device, can activate smart devices on the dew computing level and distribute computing to devices (embedded systems) on a lower architectural level. An example may be activating smartphones to perform computing tasks while being charged overnight, or using smart devices installed in cars, while parked in a parking lot. This concept enhances the dew computing architectural model making it a sophisticated platform for future architectural models.

In this paper, we elaborate a new e-Testing platform based on essay questions and a special grading procedure. Our platform enables anonymity during the grading process, equal treatment of all answered questions, grading strategy for each question, easier and faster grading process. The realized user experience analysis shows that the students are satisfied with this new platform, especially that it enables them to more easily understand what they have missed during the provision of answers, and it enables continual learning even after the evaluation. Almost all students that have failed the course also were satisfied of the system. The system is described with its functions, benefits and impact.

Creating an optimal conditions for producing generations of successful Computer scientists and engineers is very demanding. Many aspects have to be taken into consideration. One of the factors is the quality of the Bachelor's education system that actually enables the diplomas in Computer Science and Engineering. However, the students enrolling in the Bachelor's system have to be optimally prepared to follow the curriculum. In this paper we present some of the many factors that influenced the generations of Computer scientists and engineers that have earned their BSc degree in the Faculty of Computer Science and Engineering, and the institutions that preceded this Faculty in the years before 2011. Such factors, investigated in this paper are: the changes in the primary and secondary educational system and the aspects of these systems that influence the informatics knowledge of the pupils on one hand, and on the other hand the evolution of the system of competitions in informatics that sparkles the interest in the talented pupils and enables the most talented and hardworking ones to compete in the international Olympiads in informatics. As a result of improving these two parallel systems, the number of enrolled students in the faculties that teach Computer Science and Engineering has raised. Moreover, some of these pupils have turned into great entrepreneurs and have started their own successful software companies.

Computer science students use data array processing in many courses. To exploit the full power of caches and obtain higher performance, they mostly use the textbook example of sequential access of data arrays. However, a lot of discrepancies occur and the expected performance is not obtained in real life program executions, mostly due to the existence of several cache levels, with various architectures and organizations, different cache sizes and associativity, and cache line width. In addition, Students must be aware of the cache misses categorized as compulsory, capacity and conflict misses. In this paper we present an extension of our EDUCache simulator, which simulates the work of a cache and gives details on data addresses, cache occupancy and other cache parameters. The extension is realized by integrating the cache parameters with GeoGebra, the open source tool whoose primary goal is for teaching and learning mathematics. In our case, we enhance the usage for novel learning and teaching of the hardware-based courses - the Computer architecture and organization, as well as high performance computing. The extension consists of visualizing the performance behavior when a program accesses huge data arrays, analyzing real three level cache based systems, used in almost all today's conventional processors. The possibility to visualize the cache behavior dependent on various cache parameters is the final benefit of this simulator, since the students can understand the cache parameters and their impact on the overall performance. Students can design their own cache with the parameters they like and then execute some arbitrary length data array access to see the performance of the execution.

Coding (programming) is a skill that nowadays is considered as an important asset. Teaching programming is an activity that becomes more and more popular. In the last few years there are great discussions on inclusion of coding in schools. These initiatives impacted the policy makers in Macedonia to include coding as a part of a new compulsory subject for the pupils at the age of 8. In this paper our focus is on the newest change in the Macedonian curriculum - the introduction of the course "Working with computers and basics of programming", which can be shortly named as "Computing" in 2015. Here, we present the proposed and accepted curriculum with emphasis on the topics about computational thinking and programming. Then we discuss the available software and tools suitable for the implementation of the before mentioned topics, and present a newly developed game. At the end we explain the background of the teachers, give the format of the preliminary training of all primary school teachers in the country and present the first impressions of the trainers that conducted the training, and we elaborate the teachers' feedback.

Computer technology changes rapidly, especially in the last decades. IEEE and ACM have developed curriculum recommendations for computer technology in the last 50 years and always add extensions or modify the content to keep the pace with the ongoing changes. Nowadays, five curricula are defined within the Computing Curricula: Computer Science, Computer Engineering, Information Systems, Information Technology and Software Engineering. Although some of them are updated in a period of 4-5 years, there are examples lasting for quite a long time, such as Computing from 2005 and Computer Engineering curricula from 2004. Still, the latest emerging technologies - Cloud computing, Internet of Things, Internet of Everything, Big Data, Machine to Machine and Human to Machine communications and interaction, software-defined everything, smart cities, high performance scaled computing, etc., raise the challenges if these curricula are ready to cover modern trends. Even more, the real question is whether they should be changed, upgraded or give rise to a new curriculum? This paper analyzes the new emerging trends and technologies and how they are covered in the current curricula that are present at our faculty (Computer Science and Computer Engineering). We present how a track of courses and their syllabuses are adapted towards these new emerging technologies, without changing the whole curriculum. There are multiple results of these changes. Students now can choose a track and learn the courses with increased interest; they can see the "whole picture" after finishing all courses of the track; they prepare more complex projects and they are happier with the changes. Finally, several diploma theses emerged that follow the current trends in the computer technology, which prepare the students to be already good engineers on the labor market. We strongly believe that with our new approach, the motivation for learning the hardware-based courses will be returned to the students, which will facilitate the trend of decreasing interest and number of engineering students.

Teaching a hardware-based course for computer science students is a very challenging task. Students need to do a lot of practical work in the laboratory, usually do some practical project, learn theory and finally take the exam. This is a very hard task for the first hardware-based course - Computer architecture and organization (CAO), especially if it is offered in the first year of studies. Many successful examples report introducing some online learning tools, such as distance laboratories or visual simulators, which help students easier to learn the required learning objectives. In this paper, we introduce a brand new approach of reorganizing the curriculum of the course of Discrete Mathematics (DM). This approach transfers the fundamentals of logic design earlier in the DM course. Since both DM and CAO courses are scheduled in parallel, this transfer and reorganization offers necessary background for topics learned in the CAO course. This change prepares the students with relevant content about digital logic part of the CAO course and results with an improvement of 50% of those who had passed the midterm exam compared to the previous years.

Unlike the network TCP/IP's and OSI's layered structure of protocols, which allows the independence of protocols of different layers, as well as defining the upper layer protocols through the protocols of the lower layers, the cloud service layers are tightly dependent on each other.For example, an application of the SaaS layer can neither communicate nor exchange data with another application found on the same layer.The goal of this paper is to overview the cloud interoperability and to analyze it as a service model perspective.Several aspects and categories of cloud interoperability are analyzed in this paper.

The speedup is usually limited by two main laws in high-performance computing, that is, the Amdahl's and Gustafson's laws.However, the speedup sometimes can reach far beyond the limited linear speedup, known as superlinear speedup, which means that the speedup is greater than the number of processors that are used.Although the superlinear speedup is not a new concept and many authors have already reported its existence, most of them reported it as a side effect, without explaining why and how it is happening.In this paper, we analyze several different superlinear speedup types and define a taxonomy for them.Additionally, we present several explanations and cases of superlinearity existence for different types of granular algorithms (tasks), which means that they can be divided into many sub-tasks and scattered to the processors for execution.Apart from frequent explanation that having more cache memory in parallel execution is the main reason, we summarize other different effects that cause the superlinearity, including the superlinear speedup in cloud virtual environment for both vertical and horizontal scaling.

Advanced learning technologies integrate questions as a very relevant function in building e-Testing systems and especially in intelligent tutoring systems. Therefore, a huge challenge is the generation of a necessary and relevant assessment content. The existing efforts to realize open source learning materials and establishment of massive open online courses introduce another challenge for realization of a sophisticated system and appropriate knowledge database with huge number of questions reflecting all relevant knowledge items (learning objectives). In this paper we present the experience in realization of a real e-Testing system by building two variations: the first with standard graphical interface, and the other with an enhanced media interaction supporting interactive images. We present several question generation strategies for conventional approach using multiple-choice questions and also for the system with interactive images. These techniques can be used to develop a large set of questions and assessment content.

This paper presents a new curriculum for the Computer Networks Design course intended as advanced course for computer science students. We have developed an adaptive curriculum, which introduces two CISCO CCNA 3 (LAN Switching) and 4 (WAN Technologies) courses instead of the existing (regular) tutorials and laboratory exercises. The students can choose whether they would like to learn the course by a more practical approach using the CISCO CCNA integration, rather than by a more theoretical approach. The evaluation show much better results for the students that follow the course using the integration of the CISCO practical exercises, rather than those that follow the course regularly only by theoretical approach.

Recently, we have implemented three e-Learning tools in the Computer Architecture and Organization course with more than 800 students, by enabling access to two visual simulators in the laboratory exercises, as well as to an interactive online learning tool. We set a hypothesis that visual simulators will be evaluated by the students as preferred tool for learning in comparison to the online learning tool realized to assess the student knowledge. In this paper, we present the results of a survey to analyze the student satisfaction of introducing these e-learning tools. Our goal was to evaluate the usability and benefits of implemented interactive tools by analyzing anonymous and realistic student feedback. It will give a better understanding about the type of course organization and enable us to make proper decisions about the best learning model suited to the students need and requirements, especially in the case when the course is in the first study year.

Besides the fact that e-Assessment systems can efficiently conduct all paper based tests to evaluate knowledge and skills, they can offer a lot of new features via sophisticated information and communication technologies, including adaptive testing, immediate evaluation, etc. Most of the realised e-Assessment systems use pictures in the realisation of e-Testing, but the pictures are mainly used as supported media enhancement of the multiple choice questions. We introduce a brand new idea to use interactive images, where the user can navigate and zoom the picture and provide answers by clicking on an appropriate graphical object, mark a region, annotate, set an answer/comment on a given position, etc. The application domain of this innovation is huge, including e-Assessment for those sciences, where image analysis is essential, such as analysis of medical images, gathering map selective user's opinion etc. We have developed three new question types based on interactive images that offer these innovations. The impact is not just in enhancement of offered technology, but also on preventing various cheating methods, such as memorising, guessing, etc. These innovations can improve the assessment results, by a more correct evaluation and knowledge assessment.

Nowadays, both wired and wireless computer networks have significant importance. In addition, we are entering the world of big data analysis, where a lot of data is transferred from the sources to given computing centers for further processing. This trend requires changes in the computer science' computer networking curriculum in order to prepare the students with market opportunities and challenges after graduating. The Computer Networks (and / or data communications) course, or the whole knowledge area of networking and communication in general, are supposed to be a core part of computer science and net centric computing. Given the fact that these students prefer to learn software oriented courses, the Universities have to make the course more interesting and sophisticated enough to follow today's trends. In this paper, we present a new adaptive curriculum for the Computer Networks course. The students have the opportunity to choose between a practically or theoretically oriented course. Our intention is to make the most of the learning objectives in the course more practical and thus initiate increased interest of the students. However, the core part of theoretical lectures about low level reliable data communication is obligatory for both approaches.

E-learning is becoming a necessary part of every learning process nowadays, especially when the process involves greater number of students. Different learning activities included in an e-learning enrich the process itself, and improve the learner experience while gaining the knowledge. The new model of on-line collaborative activity for building ontology that we have presented in our previous work is an example of such an activity. It enriches the list of activities, and, at the end, produces ontology for the course domain. Furthermore, we have exposed a complete system that includes the collaborative building of ontology on the domain, as a part of a special course activity, and additionally, uses the produced ontology document as input into our automated system for production of questions for e-testing. Here, we will present the results of the students achieved in the real one-semester experiment conducted at the Faculty of Computer Science and Engineering in Skopje, and the students opinions on the activity. The answers to the questionnaire given to the students at the end of the course give deeper insight on the whole activity and the results can be encouraging for many lecturers to use the proposed activity and the system as a whole.

This paper describes the development of a scalable and elastic e-Assessment solution deployed on the OpenStack open source cloud. The solution activates virtual machine instances with a particular size for each assessment according to the number of students that should be assessed, in order to achieve sustainable performance.

We have recently developed and implemented an E-learning and Benchmarking Platform for the Parallel and Distributed Computing Course. Although this platform reduced the students' problems, we faced an additional problem with the lack of resources expressed in a specific timeframe just before homework deadline. In this paper we propose using a cloud based architecture of an e-Elearning system. It is intended to upgrade the e-Learning and benchmarking platform prototype into a scalable and elastic platform, where the system will send the execution on the virtual machine instance hosted on the cloud node with available resources. Additionally, we propose a strategy for efficient utilisation of cloud resources is proposed.

The main objective of this paper is introducing intelligence in the e-Learning and e-Assessment processes. Therefore, we present an existing adaptive e-Learning and e-Assessment strategies, verify them with machine learning (ML) algorithms, build students Profile and eventually, we present our new model that will be able to estimate the final result of the overall students' work during the semester, taking into account all the learning objectives that the students have passed. Thus, our idea is creating an intelligent agent that will simulate the behavior of a real professor as much as possible.

Cloud architecture has the ability of sharing hardware resources and services among multiple tenants.In this paper we measure the performance for the multi-VM (multiple virtual machines) cloud architecture and compare it with the single-VM architecture.Renting resources on a cloud usually comes with a variety of options, such as use of more and smaller virtual machines or use of less and bigger virtual machines.The objective of this research is to find out which scenario gives better performance for the same price of rented resources.This will be done by comparing the following attributes: Average response time, Pages per second, Average page time, Requests per second, CPU time.We setup a hypothesis that the multi-VM approach would be better, and the best architecture is the one offering the highest number of small virtual machines, predicting that the computational demands will spread to different virtual machines in a balanced manner.The results confirm the hypothesis and lead to a recommendation for an optimal architecture of a cloud based solution for a common transactional web solution.

Abstract—Portability of developed solutions is a huge challenge for both the customers and cloud providers. A typical customer would like to realize a flexible software solution which can be easily deployed on a selected infrastructure or transferred on a cloud environment. Finally, the idea of a software environment independent of a specific cloud provider enables preferable conditions for customers. These portability issues are analyzed for a case study of a custom University Management System- iKnow, used by the University Ss. Cyril and Methodius in Macedonia. This paper presents implementation of a Topology and Orchestration Specification for Cloud Applications (TOSCA) specification to enable a software solution to be deployed on a flexible and portable environment. The motivation to consider the implementation of such a platform is initiated due to the rising number of students that use the iKnow system, reaching the peak during the enrollment periods. A possible solution is to consider the possibility of moving the iKnow system (or its part) to a cloud environment and balance the workload using flexible resources. We conducted research to describe the iKnow system using the TOSCA specification and to enable a rather easy deployment and maintenance. This paper presents the challenges and issues regarding the TOSCA specification while implemented on the iKnow system.

Cloud service providers offer their customers to rent or release hardware resources (CPU, RAM, HDD), which are isolated in virtual machine instances, on demand.Increased load on customer applications or web services require more resources than a physical server can supply, which enforces the cloud provider to implement some load balancing technique in order to scatter the load among several virtual or physical servers.Many load balancers exist, both centralized and distributed, with various techniques.In this paper we present a new solution for a low level load balancer (L3B), working on a network level of OSI model.When a network packet arrives, its header is altered in order to forward to some end-point server.After the server replies, the packet's header is also changed using the previously stored mapping and forwarded to the client.Unfortunately, the results of the experiments showed that this implementation did not provide the expected results, i.e., to achieve linear speedup when more server nodes are added.

SUMMARY The realization of modern processors is based on a multicore architecture with increasing number of cores per processor. Multicore processors are often designed such that some level of the cache hierarchy is shared among cores. Usually, last level cache is shared among several or all cores (e.g., L3 cache) and each core possesses private low level caches (e.g., L1 and L2 caches). Superlinear speedup is possible for matrix multiplication algorithm executed in a shared memory multiprocessor due to the existence of a superlinear region. It is a region where cache requirements for matrix storage of the sequential execution incur more cache misses than in parallel execution. This paper shows theoretically and experimentally that there is a region, where the superlinear speedup can be achieved. We provide a theoretical proof of existence of a superlinear speedup and determine boundaries of the region where it can be achieved. The experiments confirm our theoretical results. Therefore, these results will have impact on future software development and exploitation of parallel hardware on the basis of a shared memory multiprocessor architecture. Copyright © 2013 John Wiley & Sons, Ltd.

In this paper, we analyze the performance of computation intensive and memory demanding web services hosted in different environments with the same amount of resources, but orchestrated differently. A single-VM addresses the environment where all the resources are allocated in one huge virtual machine instance (VMI), while a multi-VM environment uses several smaller VMIs, each allocated with only one CPU core, and the load is balanced among them. We realize series of experiments with different server loads by changing the message size and the number of concurrent messages to analyze the optimal resource allocation to host web services in order to achieve maximum performance from the same resources in the cloud, i.e., for the same price. Despite the hypothesis that the single-VM environment provides better performance than the multi-VM environment, the results show totally opposite for almost all test cases. We achieve maximal relative speedup of 9.83 comparing the multi-VM environment to the single-VM.

Teaching computer architecture requires a lot of effort by the instructor. Introduction of simulators can improve the teaching process and increases student willingness and easier ability to learn the material. There are many visual simulators that cover courses about computer architecture and design. In this paper we present our EDUCache simulator as a supporting tool in the process of understanding the concepts of both computer architecture and computer organization. It focuses on understanding modern multi-layer, multi-cache and multi-core multi-processors. Apart of EDUCache's features to teach the students about the fundamentals of computer architecture and organization, it can be also used for performance engineering of software systems, i.e. the students will also discover the importance of computer architecture which will increase their curiosity for hardware courses in general.

All e-Assessment systems have several challenges, such as accurate evaluation, security and data privacy, performance, scalability etc. In this paper we focus on e-Assessment scalability and performance. We propose a SOA architecture of a cloud hosted e-Assessment system which uses scalability and elasticity in order to achieve sustainable performance. Our solution consists of three subsystems, the first for management, the second for reports, and the third for on-demand activities during the assessments. It reduces the overall costs since it uses minimum resources utilized only during the e-Assessment. Better performance is expected to be achieved since the active subsystem for each assessment works with much smaller data compared to the centralized one.

The evolution of Microsoft Windows from a desktop operating system into a server operating system has brought attention to and concern of some severe security issues. Attacks that exploited buffer overflows started appearing for the services that were used on the new server operating system. Recently, Microsoft decided to implement a protective measure: Data Execution Prevention - DEP in two of their products: Service Pack 2 for Windows XP and Service Pack 1 for Windows 2003. The measure has been implemented as one of the core security mechanisms with the intention to prevent the attackers from breaking into the system i.e., to prevent the execution of code in non-executable memory regions. In this paper we show that the initial implementation of the software for DEP in Windows XP Service Pack 2 is actually not at all secure and that stack overflow attacks against DEP are as effective as attacks against systems that do not have DEP.