Josep M. Basart

On Completely Regular Propelinear Codes

In a previous paper (see [7]) we found that given a distance regular e-latticed graph γ we can associate with it a completely regular code C. We used this in order to solve a conjecture given by Bannai in [1].

Engineering Ethics Beyond Engineers’ Ethics

Engineering ethics is usually focused on engineers’ ethics, engineers acting as individuals. Certainly, these professionals play a central role in the matter, but engineers are not a singularity inside engineering; they exist and operate as a part of a complex network of mutual relationships between many other people, organizations and groups. When engineering ethics and engineers’ ethics are taken as one and the same thing the paradigm of the ethical engineer which prevails is that of the heroic engineer, a certain model of the ideal engineer: someone both quite individualistic and strong enough to deal with all the moral challenges that could arise. We argue that this is not the best approach, at least today in our interrelated world. We have achieved a high degree of independence from nature by means of technology. In exchange for this autonomy we have become increasingly tied up with very complex systems to which we constantly delegate new tasks and powers. Concerns about safety keep growing everywhere due to the fact that now we have a sensitive awareness of the huge amount of power we are both consuming and deploying, thus, new forms of dialogue and consensus have to be incorporated at different levels, in different forums and at different times. Within these democratic channels of participation not just the needs and interests, but also the responsibilities and mutual commitments of all parties should be taken into account.

New ethical challenges for today engineering and technology

New ethical challenges related to feminine values have emerged this century.These demanding ethical values justify the involvement of women in technical fields.Engineering and technical careers will benefit from the added diversity. This paper is about the intersection of three related areas: ethics, gender and the field of engineering. It is important to focus on the attitudes and values woven through this intersection because they become essential for the complete development of the moral life of the engineering profession and of the awareness of the fact that this is a profession made up of both male and female professionals. Thus, specific behaviour coming from the feminine part is necessary in order to contribute to enriching the features of the engineering profile. An approach particularly attached to feminine values, in comparison to the masculine perspective, is a sign of commitment rather than rights, a collective social group rather than the individual and of an ethic based on caring for others rather than the traditional rationalistic arguments. Because of this, the introduction of qualitative diversity within this professional field is an important fact to highlight when women contribute to the engineering community through the enrichment, expansion and transformation of the values and attitudes that are predominant in the people who work and/or study within the area of engineering and technology.

A High Performance Approximate Algorithm for the Steiner Problem in Graphs

A new approximate algorithm (GBA) for the Steiner problem in graphs (SPG) based on an iterative execution of a previous heuristic to the problem (SPH) is presented. GBA looks for a subset of vertices which, used as terminals, can produce a near-optimal solution. In addition, the tree associated to each of these subsets is selected at random. The worst-case time complexity of the algorithm is O(|V|3) and the cost of the solution is guaranteed to be less than twice the optimal. GBA is tested on classical benchmark problems and its performance compares favorably to that of some of the best existing SPG approaches with respect both to solution quality and specially runtime.

An approximation algorithm for the TSP

Abstract We present a new polynomial-time heuristic algorithm for finding a solution to the Travelling Salesman Problem (TSP) for any complete and edge-weighted graph K n , with a set of vertices V and a set of edges E where | V | = n . In a few words, this method is based on the idea of linking the elements of V progressively, one by one, in such a way that the vertex selection which produces fewest disturbances to the other vertices not yet connected, will be selected as the next vertex to join to the subset of already connected vertices. When the cost of the result is compared to the cost of the best circuit, it appears that a good sub-solution is obtained in most of the cases tested. Moreover, comparison tests made between the heuristic introduced and the well-known Quick method, produce a better behaviour, for almost every case, in the first approach.

Covering radius for codes obtained from T(m) triangular graphs

Triangular graphs are a special case of the well-known strongly regular graphs. Taking any spanning tree in a T(m) triangular graph ~14we get a fundamental circuit matrix for it. Using this matrix as a generator matrix we can obtain a single-error-correcting linear code C(T(m)) with parameters: n=(m(m-l)(m-2))/2, k=(m(m-l)(m-3)+2)/2 and d=3. Using the fact that each codeword in C(T(m)) is formed by a combination of simple circuits in T(m), we give a characterization of its codewords which allow us to show that: (i) whatever the value of m be, if we take a hamiltonian path as a spanning tree in T(m), the obtained code C(T(m)) has covering radius ~ equal to [m(m-l)/4] and (ii) fixed m all the C(T(m)) codes are equivalent independently of the chosen spanning tree, so, it is finally proved that given T(m) and any spanning tree in it, C(T(m)) has o=[m(m-l)/4].

Acquiring ethical communicative tools for an online ethics training

Nowadays, one of the most dynamic areas in applied ethics is professional ethics (e.g. in the areas of medicine, business and engineering). In this paper, we will focus on the online teaching of professional ethics to undergraduate engineering students, mainly in the specialty of Information and Communication Technologies (ICT). More specifically, the pedagogical structure for the ethical training of future engineers will be designed, within an online context, based on a set of ethical communicative tools. Besides, our proposal will analyze which technological resources are suitable to develop the appropriate ethical communicative competences required by the engineering students, when confronting moral conflicts in their daily professional exercise.

A solution for the coloured cubes problem

Let C be any set of q cubes in which every face in each one of them has to be coloured using one colour in a set K of q colours. It is asked how to raise, if it is possible, a pile with the q cubes in such a way that every colour will appear once in every one of the four faces of the pile. The case q = 4 was solved long time ago. Now, an answer is presented for the general case by means of an efficient algorithm. This method is based on a particular linear program which always produces integer solutions.

Some upper bounds for minimal trees

Abstract This paper introduces two upper bounds for the length of two kinds of minimal trees. The first upper bound, σ(n) ([((n − 1) π) 1 2 ] + 1 2 )+ 1 2 , is related to the Euclidean Steiner Minimal Tree obtained from any set of n points enclosed i nside a circumference of radius 1. The second upper bound, Φ(n)⩽2(n − 1) k , is related to the Rectilinear Minimal Tree obtained from any set of n = [(k(k+2)+1) 2] points (k=1, 2, 3,…),, enclosed in a square with sides equal to 1. Moreover, we also present the only case where the well-known bound σ(n) = 1 + n is attained for the length of the Rectilinear Steiner Minimal Tree for any set of n = t2 points ,(t=2, 3,…), enclosed in a square with sides equal to 1.