The fast growth of Internet traffic, the growing importance of cellular accesses and the escalating competition between content providers and network operators result in a growing interest in improving network performance and user experience. In terms of network transport, different solutions ranging from tuning TCP to installing middleboxes are applied. It turns out, however, that the practical results sometimes are disappointing and we believe that poor testing is one of the reasons for this. Indeed, many cases in the literature limit testing to the simple and rare use case of a single file download, while common and complex use cases like web browsing often are ignored or modelled only by considering smaller files. To facilitate better testing, we present a broader view which includes domain counts, flow counts and different forms of concurrency to better characterise the complexity around web pages, and from which the potential for different optimisation techniques can be estimated. We also derive numerical values of these metrics for a small set of popular web pages and study similarities and differences between pages with the same kind of content (newspapers, e-commerce and video) and between pages designed for the same platform (computer and smartphone).

Active learning is the process where students learn beyond passively listening to an instructor's lecture. In this way students are engaged in their learning activities. It has been accepted that active learning leads to deeper understanding and better learning outcomes.

The term flipped classroom has been widely used to describe a new pedagogical approach in which traditional lecture and homework elements of a course are reversed so that the initial exposure to the learning content takes place outside of the classroom. This approach frees up class time, promotes active learning and engagement in learning and facilitates student-centered learning.

In this study we experimented with flipped classroom approach in the online course Programming in C during the autumn term 2015. The purpose of the experiment was to determine whether flipped classroom can serve as an appropriate method to use in an online course and to find out to what extent flipped classroom can stimulate active learning in an online setting. Based on known concept of flipped classroom approach and literature review, we systematically reviewed YouTube videos and selected 52 video clips to use as companion course materials. We also compiled and produced 212 quiz questions to use as formative assessment. In order to promote interaction among the students, we experimented with peer-review as a part of the laboratory work process. We also provided scheduled online sessions in the form of chat rooms. Short video clips were positively received by the students. Even the peer-review approach was positively received but the students gave up this activity at the end of the course, due to the work load. Flipped classroom has potential to be used in online settings but distinction between "classroom" and "outside classroom" is not always clear.

More work is needed to make this distinction visible and to make the transition between these two learning environments smooth.

As a generalization to cyclic and consta-cyclic codes, quasi-twisted (QT) codes contain many good linear codes. During the last twenty years, a lot of record-breaking codes have been found by computer search for good QT codes. But due to the time complexity, very few QT codes have been reported recently. In this paper, a new iterative, heuristic computer search algorithm is presented, and a lot of new QT codes have been obtained. With these results, a total of 45 entries in the code tables for the best-known codes have been improved. Also, as an example to show the effectiveness of the algorithm, 8 better binary quasi-cyclic codes with dimension 12 and m = 13 than previously best-known results are constructed.

Quasi-twisted (QT) codes are a generalization of quasi-cyclic (QC) codes. Based on consta-cyclic simplex codes, a new explicit construction of a family of 2-generator quasi-twisted (QT) two-weight codes is presented. It is also shown that many codes in the family meet the Griesmer bound and therefore are length-optimal. New distance-optimal binary QC [195, 8, 96], [210, 8, 104] and [240, 8, 120] codes, and good ternary QC [208, 6, 135] and [221, 6, 144] codes are also obtained by the construction.

A code is said two-wight if the non-zero codewords have only two different weights w1 and w2. In this paper, it is generalized that a consta-cyclic code of composite length can be put in the quasi-twisted (QT) form. Based on this result, a new computer method of QT two-weight codes is presented. A large amount of QT two-weight codes are found, and several new codes are also constructed.

As a generalization of cyclic codes, quasi-cyclic (QC) codes contain many good linear codes. But quasi-cyclic codes studied so far are mainly limited to one generator (1-generator) QC codes. In this paper, 2-generator QC codes are studied, and many good 2-generator QC codes are constructed using simplex codes. A computer algorithm is given, and used to find the best possible 2-generator QC codes. Among those 2-generator QC codes constructed, some codes are two-weight codes.

The flipped classroom approach provides implementation of a student-centered learning environment. By changing the traditional classroom lectures and homework elements of a course, it facilitates active learning and higher-order understanding. This paper presents initial experiments on a flipped classroom approach and its application in a programming course. The course results and evaluation show that this approach is rewarding, and why it deserves further investigation.

Further results on the upper bounds for difference tri8nglesets (DTS) are derived from disjoint difference sets and additive sequencesof permutations, whit3 greatly improve the known bounds.

As a generalization of cyclic codes, quasi-cyclic codes contain many good linear codes. Extensive search is made and lots of good quasi-cyclic codes are obtained from irreducible cyclic codes. A new binary [95, 13, 40] code which improves the lower bound on the minimum distance, is also constructed.

An [n, k, d] code is a binary linear code of block length n, dimension k and minimum Hamming distance d. Since the minimum distance determines the error detection or correction capability, it is desired that d is as large as possible for the given block length n and dimension k. One of the most fundamental problems in coding theory is to construct codes with best possible minimum distances. This problem is very difficult in both theory and practice. During the last decades, it has proved that the class of quasi-cyclic (QC) codes contain many such codes. In this paper, augmentation of binary QC codes is studied. A new augmentation algorithm is presented, and 10 new h-generator QC codes that are better than previously known code have been constructed. Furthermore, Construction X has been applied to obtain another 18 new improved binary linear codes.With the standard construction techniques, a total of 124 new binary linear codes that improve the lower bound on the minimum distance have been obtained.

Based on cyclic simplex codes, a new construction of a family of two-weight codes is given. These two-weight codes are in a simple 2-generator quasi-cyclic form. Based on this construction, new optimal binary quasi-cyclic [195, 8, 96], [210, 8, 104] and [240, 8, 120] codes, good QC ternary  [195, 6, 126], [208, 6, 135], [221, 6, 144] codes are thus obtained. It was also shown that some codes that meet the Griesmer bound and thus are optimal. Furthermre, binary  self-complementary codes in a 3-generator quasi-cyclic form,  are also constructed.

New constructions of Steiner systems, majority logic decodable codes, and constant weight codes are presented. Comparisons with known results as well as examples are also given.

As a generalization of cyclic codes, quasi-cyclic (QC) codes contain many good linear codes. But quasi-cyclic codes studied so far are mainly limited to one generator (1-generator) QC codes. In this correspondence, 2-generator and 3-generator QC codes are studied, and many good, new QC codes are constructed from simplex codes. Some new binary QC codes or related codes, that improve the bounds on maximum minimum distance for binary linear codes are constructed. They are 5-generator QC [93 17 34] and [254,23, 102] codes, and related [96, 17, 361, [256, 23,104] codes.

Twelve new binary quasi-cyclic codes, which improve the lower bounds on minimum distances for binary linear codes, are presented, and a Web database on best-known binary quasi-cyclic codes is constructed for public access.

Six new quasi-cyclic codes are presented, which improve thelower bounds on the minimum distance for a binary code. A localexhaustive search is used to find these codes and many other quasi-cycliccodes which attain the lower bounds.

It has been well-known that the class of quasi-cyclic (QC) codes contain many good codes. In thispaper, a method to conduct a computer search for binary 2-generator QC codes is presented, anda large number of good 2-generator QC codes have been obtained. 5 new binary QC codes thatimprove the lower bounds on minimum distance are presented. Furthermore, with new 2-generatorQC codes and Construction X, 2 new improved binary linear codes are obtained. With the standardconstruction techniques, another 16 new binary linear codes that improve the lower bound on theminimum distance have also been obtained.

One central problem in coding theory is to optimize the parameters of a linear code and construct codes with best possible parameters. There are tables of best-known linear codes over nite elds of sizes up to 9. Recently, there has been a growing interest in codes over GF(11), over GF(13) and other elds of size greater than 9. The main purpose of this work is to present new databases of best-known linear codes over the elds GF(11) and GF(13) together with upper bounds on the minimum distances. To nd good linear codes to establish lower bounds on minimum distances, an iterative heuristic computer search algorithm is employed to construct quasi-twisted (QT) codes over these elds with high minimum distances. A large number of new linear codes have been found, improving previously best-known results. Tables of [pm, m] QT codes over the two elds with best-known minimum distances as well as a table of lower and upper bounds on the minimum distances for linear codes of length up to 150 and dimension up to 6 are presented.

Error control codes have been widely used in data communications and storage systems. One centralproblem in coding theory is to optimize the parameters of a linear code and construct codes withbest possible parameters. There are tables of best-known linear codes over finite fields of sizes up to9. Recently, there has been a growing interest in codes over F13 and other fields of size greater than9. The main purpose of this work is to present a database of best-known linear codes over the fieldF13 together with upper bounds on the minimum distances. To find good linear codes to establishlower bounds on minimum distances, an iterative heuristic computer search algorithm is employed toconstruct quasi-twisted (QT) codes over the field F13 with high minimum distances. A large numberof new linear codes have been found, improving previously best-known results. Tables of [pm;m] QTcodes over F13 with best-known minimum distances as well as a table of lower and upper bounds onthe minimum distances for linear codes of length up to 150 and dimension up to 6 are presented.

One fundamental and challenging problem in coding theory is to optimize the parameters [n, k,d] of a linear code over the finite field Fq and construct codes with best possible parameters. There are tables and databases of best-known linear codes over the finite fields of size up to 9 together with upper bounds on the minimum distances. Motivated by recent works on codes over F₁₁, we present a table of best-known linear codes over F₁₁ together with upper bounds on minimum distances. Our table covers the range n ≤ 150 for the length, and 3 ≤ k ≤ 7 for the dimension. To the best of our knowledge, this is the first time such a table is presented in the literature. For the construction of the best-known codes, we employed an iterative heuristic search algorithm to search for new linear codes in the class of quasi-twisted (QT) codes. The search yielded many new codes with better parameters than previously known codes. In many cases, optimal codes are obtained. In addition to presenting a comprehensive table of best-known codes over F₁₁ of dimensions up to 7 with upper bounds on the minimum distances, we also present separate tables for the optimal codes and new QT codes over F₁₁. We hope that this work will be a useful source for further study on codes over F₁₁.

New constructions of regular disjoint distinct difference sets (DDDS) are presented. In particular,multiplicative and additive DDDS are considered.

To build student engagement and belonging early in the education is crucial for retention and student success. Since the COVID-19 outbreak, universities worldwide were forced to seek for alternative and complementary teaching approaches. In Sweden, universities adopted hybrid teaching since the end of the spring in 2020. The traditional face-to-face teaching facilitates immediate, real-time engagement with activities such as discussion and instant interaction between instructors and students and/or among students which encourages active learning, while an online teaching allows the students to watch videos and read requested materials many times, to complete the assignments at their suitable time and place, to enable good discussion and interaction via online forum and messaging. A hybrid approach combines the advantages of both face-to-face and online approaches. Research shows several challenges with online teaching, for examples, students´ engagement [1], communication between student(s) and teacher(s) [2], connection with/within the group, study groups, study buddies [3] as well as social engagement [4]. When a hybrid approach is applied to the First-Year courses due to the COVID-19, these challenges might have even more serious implications on the retention and success. This study explores two successful cases of how active learning, togetherness and engagement can be created among First-Year students. The study is based on two large introductory courses for the first-year students in Computer Science and in Business Administration at Kristianstad University, Sweden. Both programmes provide the Introduction courses for larger number of students (135 respective 195 students). Various methods and tools were used in the course design to engage students and create an active learning [5] environment using the hybrid approach. The results and experience were also presented. We experienced that students had actively participated in the arranged activities and the course passing rate was higher compared with the face-to-face teaching. The course evaluation also showed that the students were satisfied with course contents and various course activities.