Branch and Bound Algorithm for Multiprocessor Scheduling

The multiprocessor task graph scheduling problem has been extensively studied asacademic optimization problem which occurs in optimizing the execution time of parallelalgorithm with parallel computer. The problem is already being known as one of the NPhardproblems. There are many good approaches made with many optimizing algorithmto find out the optimum solution for this problem with less computational time. One ofthem is branch and bound algorithm.In this paper, we propose a branch and bound algorithm for the multiprocessor schedulingproblem. We investigate the algorithm by comparing two different lower bounds withtheir computational costs and the size of the pruned tree.Several experiments are made with small set of problems and results are compared indifferent sections.

Produktion, skador och grenegenskaper hos 10-årig tall i ett kombinerat förbands- och avkommeförsök : Volume production, damages and branch properties in a 10-year old combined spacing and progeny trial of Scots pine

A Scots pine (Pinus sylvestris) progeny trial was established in 1990, in the southwestern part of Sweden. The offspring was from 30 plus trees. The trial is located on abandoned agricultural land and has a single tree block design with a variation in spacing. The trial has been damaged by voles. At a tree age of ten years, growth, damages and branch properties were estimated. An analysis of variance on height, diameter and stem volume shows significant difference between spacing and progenies as well as interactions between these factors. As indicated by a better annual height increment and fewer and thinner branches at each whorl the densest spacing has the highest potential to produce quality logs.There were also differences between progenies in growth and quality traits. Some progenies combined good growth and branch characters with low mortality, straight stems and few damages. Other progenies had superior volume production.

Solar thermal components adapted to common building standards (SCAS)

Pilot versions of a solar heating/natural gas burner system, of a solar heating/pellet burner system and of a façade/roof integrated polymeric collector have been installed in the summer of 2006 in a number of demonstration houses in Denmark, Sweden and Norway.These three new products have been evaluated by means of measurements of the thermal performance and energy savings of the pilot systems in practice and by means of a commercial evaluation.The conclusion of the evaluations is that the products are attractive for the industry partners METRO THERM A/S, Solentek and SOLARNOR. It is expected that the companies will bring the products into the market in 2007.Further, the results of the project have been presented atinternational and national congresses and seminars for the solar heating branch. The congresses and seminars attracted a lot of interested participants.Furthermore, the project results have been published in international congress papers as well as in national journals in the energy field.Consequently, the Nordic solar heating industry will benefit from the project.

Genetic Control of Residual Variance for Teat Number in Pigs

The genetic improvement in litter size in pigs has been substantial during the last 10-15 years. The number of teats on the sow must increase as well to meet the needs of the piglets, because each piglet needs access to its own teat. We applied a genetic heterogeneity model on teat numberin sows, and estimated medium-high heritability for teat number (0.5), but low heritability for residual variance (0.05), indicating that selection for reduced variance might have very limited effect. A numerically positive correlation (0.8) between additive genetic breeding values for mean and for variance was found, but because of the low heritability for residual variance, the variance will increase very slowly with the mean.

On statistical bounds of heuristic solutions to location problems

Solutions to combinatorial optimization problems, such as problems of locating facilities, frequently rely on heuristics to minimize the objective function. The optimum is sought iteratively and a criterion is needed to decide when the procedure (almost) attains it. Pre-setting the number of iterations dominates in OR applications, which implies that the quality of the solution cannot be ascertained. A small, almost dormant, branch of the literature suggests using statistical principles to estimate the minimum and its bounds as a tool to decide upon stopping and evaluating the quality of the solution. In this paper we examine the functioning of statistical bounds obtained from four different estimators by using simulated annealing on p-median test problems taken from Beasley’s OR-library. We find the Weibull estimator and the 2nd order Jackknife estimator preferable and the requirement of sample size to be about 10 being much less than the current recommendation. However, reliable statistical bounds are found to depend critically on a sample of heuristic solutions of high quality and we give a simple statistic useful for checking the quality. We end the paper with an illustration on using statistical bounds in a problem of locating some 70 distribution centers of the Swedish Post in one Swedish region. 

A stopping rule while searching for optimal solution of facility-location

Solutions to combinatorial optimization, such as p-median problems of locating facilities, frequently rely on heuristics to minimize the objective function. The minimum is sought iteratively and a criterion is needed to decide when the procedure (almost) attains it. However, pre-setting the number of iterations dominates in OR applications, which implies that the quality of the solution cannot be ascertained. A small branch of the literature suggests using statistical principles to estimate the minimum and use the estimate for either stopping or evaluating the quality of the solution. In this paper we use test-problems taken from Baesley's OR-library and apply Simulated Annealing on these p-median problems. We do this for the purpose of comparing suggested methods of minimum estimation and, eventually, provide a recommendation for practioners. An illustration ends the paper being a problem of locating some 70 distribution centers of the Swedish Post in a region.

Confidence in heuristic solutions?

Solutions to combinatorial optimization problems frequently rely on heuristics to minimize an objective function. The optimum is sought iteratively and pre-setting the number of iterations dominates in operations research applications, which implies that the quality of the solution cannot be ascertained. Deterministic bounds offer a mean of ascertaining the quality, but such bounds are available for only a limited number of heuristics and the length of the interval may be difficult to control in an application. A small, almost dormant, branch of the literature suggests using statistical principles to derive statistical bounds for the optimum. We discuss alternative approaches to derive statistical bounds. We also assess their performance by testing them on 40 test p-median problems on facility location, taken from Beasley’s OR-library, for which the optimum is known. We consider three popular heuristics for solving such location problems; simulated annealing, vertex substitution, and Lagrangian relaxation where only the last offers deterministic bounds. Moreover, we illustrate statistical bounds in the location of 71 regional delivery points of the Swedish Post. We find statistical bounds reliable and much more efficient than deterministic bounds provided that the heuristic solutions are sampled close to the optimum. Statistical bounds are also found computationally affordable.

Image processing technique to count the number of logs in a timber truck

This paper summarises the results of using image processing technique to get information about the load of timber trucks before their arrival using digital images or geo tagged images. Once the images are captured and sent to sawmill by drivers from forest, we can predict their arrival time using geo tagged coordinates, count the number of (timber) logs piled up in a truck, identify their type and calculate their diameter. With this information we can schedule and prioritise the inflow and unloading of trucks in the light of production schedules and raw material stocks available at the sawmill yard. It is important to keep all the actors in a supply chain integrated coordinated, so that optimal working routines can be reached in the sawmill yard.   

Att bli, att vara och att ha varit - om ingångar i och utgångar ur Jehovas vittnen i Sverige

Summary To become, to be and to have been: about the  Jehovah’s Witnesses The Watchtower Bible and Tract Society, in the following text referred to as the Jehovah’s Witnesses or “the organisation”, is a worldwide Christian organisation with about 6.7 million members. The organisation has many times, without any success so far, proclaimed Armageddon when they expect Jehovah to return to Earth. They interpret the Bible in their own, often very literal way, and require their members to live according to these interpretations. Among the consequences of this, members are forbidden to vote, to do military service or to receive blood transfusions. Apart from attending the three weekly meetings, members are expected to be active in missionary work, known as “publishing”. If a member fails to do a certain number of hours’ publishing, he or she risks being deprived of active membership status Sweden in general is considered to be a society where the population is not very religious. The formerly state-governed Lutheran church has lost its influence and the vast majority of ordinary Swedes do not visit church on other occasions than weddings, funerals or christenings. Expressing one’s own religious values has become somewhat of a private matter where publicity is seldom appreciated, which is contrary to the practice of the Jehovah’s Witnesses. This is one of the reasons why the Jehovah’s Witnesses are commonly perceived by average Swedes as a “suspicious” religious organisation. The aim and methods of the study This dissertation seeks to describe and investigate the entering and leaving of a highly structured and hierarchical religious community, exemplified in this case by the Jehovah’s Witnesses. What are the thoughts and aspirations of someone who is considering becoming a Jehovah’s Witness? What are the priorities and what experiences seem important when a person is going through such a process? And when this person has finally reached his or her goal of becoming a member, is it the same motivation that makes him or her stay in the organisation for longer periods of time, possibly for the rest of their lives, or does it change during the process of entering, or does this motivation change its character during the transition from entering to being a regular member? Why do some of the members change their attitude to the Jehovah’s Witnesses from rejoicing to bitterness? And how does this process of exit manifest itself? In what way is it different from the process of entry? The respondents in this study were chosen from both active members of the Jehovah’s Witnesses in Sweden and those who have left the organisation for personal reasons. Repeated interviews with ten active members of the organisation have been conducted in the course of the study and compared to equal numbers of former members. The interviews have been semi-structured to deal with questions of how a person has come into contact with the organisation; how they retrospectively experienced the process of entry; the reasons for becoming a member. Questions have also been asked about life in the organisation. The group of “exiters” have also been asked about the experience of leaving, why they wanted to leave, and how this process was started and carried out. In addition to this I have analysed a four-year diary describing the time inside and the process of leaving the organisation. This has given me an extra psychological insight into the inner experience of someone who has gone through the whole process. The analysis has been done by categorising the content of the transcribed interviews. An attempt to outline a model of an entry and exit process has been made, based on ideas and interpretations presented in the interviews. The analysis of the diary has involved thorough reading, resulting in a division of it into four different parts, where each part has been given a certain key-word, signifying the author’s emotional state when writing it. A great deal of the information about the Jehovah’s Witnesses has been collected through discussion boards on the Internet, informal talks with members and ex-members, interviews with representatives of the organisations during visits to its different offices (Bethels), such as St. Petersburg, Russia, and Brooklyn, New York, USA. The context Each organisation evolves in its own context with its own norms, roles and stories that would not survive outside it. With this as a starting point, there is a chapter dedicated to the description of the organisation’s history, structure and activities. It has been stated that the organisation’s treatment of its critical members and the strategies for recruiting new members have evolved over the years of its history. At the beginning there was an openness allowing members to be critical. As the structure of the organisation has become more rigid and formalised, the treatment of internal critics has become much less tolerated and exclusion has become a frequent option. As a rule many new members have been attracted to the organisation when (1) the day of Armageddon has been pronounced to be approaching; (2) the members of the organisation have been persecuted or threatened with persecution; and (3) the organisation has discovered a “new market”. The processes for entering and exiting How the entering processes manifest themselves depends on whether the person has been brought up in the organisation or not. A person converting as an adult has to pass six phases before being considered a Jehovah’s Witness by the organisation. These are:  Contact with the Jehovah’s Witnesses, Studying the bible with members of the organisation, Questioning, Accepting, Being active as publisher (spreading the belief), Being baptised.  For a person brought up in the organisation, the process to full membership is much shorter:   Upbringing in the organisation, Taking a stand on the belief, Being baptised. The exit process contains of seven phases:   Different levels of doubts, Testing of doubts, Turning points, Different kinds of decisions, Different steps in executing the decisions, Floating, a period of emotional and cognitive consideration of membership and its experiences, Realtive neutrality.   The process in and the process out are both slow and are accompanied with anguish and doubts. When a person is going through the process in or out of the organisation he or she experiences criticism. This is when people around the adept question the decision to continue in the process. The result of the criticism depends on where in the process the person is. If he or she is at the beginning of the process, the criticism will probably make the person insecure and the process will slow down or stop. If the criticism is pronounced in a later phase, the process will probably speed up. The norms of the organisation affect the behaviour of the members. There are techniques for inclusion that both bind members to the organisation and shield them off from the surrounding society. Examples of techniques for inclusion are the “work situation” and “closed doors”. The work situation signifies that members who do as the organisation recommends – doing simple work – often end up in the same branch of industry as many other Jehovah’s Witnesses. This often means that the person has other witnesses as workmates. If the person is unemployed or moves to another town it is easy to find a new job through connections in the organisation. Doubts and exclusions can lead to problems since they entail a risk of losing one’s job. This can also result in problems getting a new job. Jehovah’s Witnesses are not supposed to talk to excluded members, which of course mean difficulties working together. “Closed doors” means that members who do as the organisation recommends – not pursuing higher education, not engaging in civil society, working with a manual or in other way simple job, putting much time into the organisation – will, after a long life in the organisation, have problems starting a new life outside the Jehovah’s Witnesses. The language used in the organisation shows the community among the members, thus the language is one of the most important symbols. A special way of thinking is created through the language. It binds members to the organisation and sometimes it can work as a way to get back into the normative world of the organisation. Randall Collins’s (1990, 2004) thoughts about “emotional energy” have enabled an understanding of the solidarity and unity in the organisation. This also gives an understanding of the way the members treat doubting and critical members. The members who want to exit have to open up the binding/screening off. A possible way to do that is through language, to become aware of the effect the language might have. Another way is to search for emotional energy in another situation. During the exit process, shame might be of some importance. When members become aware of the shame they feel, because they perceive they are “acting a belief”, the exit process might accelerate.