Simulation of Sawmill Yard Operations Using Software Agents

Bergkvist insjön AB is a sawmill yard which is capable of producing 350,000 cubic meter of timber every year this requires lot of internal resources. Sawmill operations can be classified as unloading, sorting, storage and production of timber. In the company we have trucks arriving at random they have to be unloaded and sent back at the earliest to avoid queuing up of trucks creating a problem for truck owners. The sawmill yard has to operate with two log stackers that does several tasks including transporting the logs from trucks to measurement station where the logs will be sorted into classes and dropped into pockets from pockets to the sorted timber yard where they are stored and finally from there to sawmill for final processing. The main issue that needs to be answered here is the lining up trucks that are waiting to be unload, creating a problem for both sawmill as well as the truck owners and given huge production volume, it is certain that handling of resources is top priority. A key challenge in handling of resources would be unloading of trucks and finding a way to optimize internal resources.To address this problem i have experimented on different ways of using internal resources, i have designed different cases, in case 1 we have both the log stackers working on sawmill and measurement station. The main objective of having this case is to make sawmill and measurement station to work all the time. Then in case 2, i have divided the work between both the log stackers, one log stacker will be working on sawmill and pocket_control and second log stacker will be working on measurement station and truck. Then in case 3 we have only one log stacker working on all the agents, this case was designed to reduce cost of production, as the experiment cannot be done in real-time due to operational cost, for this purpose simulation is used, preliminary investigation into simulation results suggested that case 2 is the best option has it reduced waiting time of trucks considerably when compared with other cases and it showed 50% increase in optimizing internal resources.

Simulation and optimisation techniques for sawmill yard operation : A literature review

Increasing costs and competitive business strategies are pushing sawmill enterprises to make an effort for optimization of their process management. Organizational decisions mainly concentrate on performance and reduction of operational costs in order to maintain profit margins. Although many efforts have been made, effective utilization of resources, optimal planning and maximum productivity in sawmill are still challenging to sawmill industries. Many researchers proposed the simulation models in combination with optimization techniques to address problems of integrated logistics optimization. The combination of simulation and optimization technique identifies the optimal strategy by simulating all complex behaviours of the system under consideration including objectives and constraints. During the past decade, an enormous number of studies were conducted to simulate operational inefficiencies in order to find optimal solutions. This paper gives a review on recent developments and challenges associated with simulation and optimization techniques. It was believed that the review would provide a perfect ground to the authors in pursuing further work in optimizing sawmill yard operations.

Multi-agent simulation of sawmill yard operations

This paper reports the findings of using multi-agent based simulation model to evaluate the sawmill yard operations within a large privately owned sawmill in Sweden, Bergkvist Insjön AB in the current case. Conventional working routines within sawmill yard threaten the overall efficiency and thereby limit the profit margin of sawmill. Deploying dynamic work routines within the sawmill yard is not readily feasible in real time, so discrete event simulation model has been investigated to be able to report optimal work order depending on the situations. Preliminary investigations indicate that the results achieved by simulation model are promising. It is expected that the results achieved in the current case will support Bergkvist-Insjön AB in making optimal decisions by deploying efficient work order in sawmill yard.

Simulation model using meta heuristic algorithms for achieving optimal arrangement of storage bins in a sawmill yard

Bin planning (arrangements) is a key factor in the timber industry. Improper planning of the storage bins may lead to inefficient transportation of resources, which threaten the overall efficiency and thereby limit the profit margins of sawmills. To address this challenge, a simulation model has been developed. However, as numerous alternatives are available for arranging bins, simulating all possibilities will take an enormous amount of time and it is computationally infeasible. A discrete-event simulation model incorporating meta-heuristic algorithms has therefore been investigated in this study. Preliminary investigations indicate that the results achieved by GA based simulation model are promising and better than the other meta-heuristic algorithm. Further, a sensitivity analysis has been done on the GA based optimal arrangement which contributes to gaining insights and knowledge about the real system that ultimately leads to improved and enhanced efficiency in sawmill yards. It is expected that the results achieved in the work will support timber industries in making optimal decisions with respect to arrangement of storage bins in a sawmill yard.

Vägen till jämställdhet - Kvinnor i styrelserum eller män i förskolan? : En kritisk analys av den svenska jämställdhetsdiskursen

Equality between the sexes has been discussed in Sweden for more than 50 years. In the 60´s and during the 70´s the discourse that dominated the debate was based on the assumption that both men and women needed to liberate themselves from their traditional gender roles. In this approach information and education was perceived as the key to equality. During the 80´s however, power and subordination became the main focal point of concern within this debate, and focus upon changing the patriarchal power structures dominating society were perceived as the principal key for establishing equality between the sexes. Today, the latter discourse still dominates both the scientific and the political perspective upon equality. By examining the debate on equality from two different fields of occupation this paper tries to analyse the fact that the Swedish equality discourse looks very different on male - versus female domination. Although the proportion of male teachers in Swedish preschools is about 3 % and the amount of women serving as public company directors is about 20 %, the current discourse views male dominance within the business sector as problematic, whilst, the dominance of women in the preschool childcare sector as less problematic. In respect of the theory supported by Bourdieu (1999), Hirdman (1990 & 2003) and Foucault (1998 & 2002) this paper advocates that the discourse is biased and simplified and that a perspective that only focuses on areas of male domination sets the wrong priorities. With regards to equality ideals prevalent throughout Norway this paper concludes that the Swedish equality discourse needs a broader and more open approach to assure that Swedish institutions promote equality between men and women in the best possible way.

Färg och missfärgning hos sågad björk : - Variation samt effekter av avverkningstidpunkt, lagring av timmer och torkning av sågad vara

Variation i björkvirkets färg beror på art, läge i träd, ursprung och lagringstid. Vårtbjörk har en mörkare färg än glasbjörk, men livligare struktur och glans. Timmer hugget under tillväxtsäsongen bör sågas färskt eller lagras högst en månad. Vid brädgårdstorkning är god luftcirkulation och skydd för väta och direkt solljus väsentligt. Strövirkets färskhet är av stor betydelse för att undvika fuktfärgning av virket.Variation in birch colours depend on species, position in tree, origin and the storage period. White birch is darker than hairy birch but with a lively structure and shine. During vegetation period timber storage exceeding one month should be avoided. Air circulation, protection from rain and direct sunlight are essential for yard drying. Freshness of stickers used for stacking is important to avoid water marks on wood surface.

- Ni får gärna hoppa på golvet om ni vill hoppa : En studie om pedagogers bemötande av barns egna initativ i förskola och förskoleklass

The purpose of this survey was to discern possible similarities and difference between how teachers in preschool and pre-class respond to children’s own initiative out of a power perspective. The results of this study is collect by observations that we have done in free and planned activity in both preschool and pre-class as well as a few interviews with some of the teachers. The results have shown that teacher’s responses to children’s own initiatives in preschool and pre-class to most part is similar, despite the difference in their commission. The biggest differences are that teachers in preschool prioritize children’s care before allowing the children to pursue their own initiatives, which haven’t emerged from the observations in the pre-class. Another difference is that the teachers in pre-class are more flexible during the planned activities and utilize the children’s own initiatives.

"Amningen känns så skör på ett annat vis" : Hur kvinnor som ammar förskolebarn upplever bemötandet av förskolans pedagoger.

The aim of this study was to visualize in a pluralistic perspective how mothers of breastfed preschool children experience being treated by preschool teachers. Method: Qualitative interviews with 10 mothers and qualitative content analysis. The mothers experienced breastfeeding was surrounded by slience at preschool. The mothers were met with silence, felt vulnerable and did not want to be subject to criticizm. To the best of our knowledge, this is the first investigation on this subject. 

Naturvetenskapliga begrepp i vardagliga samtal : En observationsstudie med fokus på lärande samtal i förskolan

Syftet med studien är att undersöka hur vardagliga situationer kan nyttjas för naturvetenskapligt lärande i förskolan. Den har genomförts med hjälp av observationer av samtal. Det observerade naturvetenskapliga innehållet har genererat en ”lokal teori”, (Grounded Theory), med fokus på använda ord och omnämnda begrepp. Resultatet visar att barnen har en uppfattning om flera naturvetenskapliga begrepp och generellt ett rikt ordförråd för samtal om naturvetenskapliga fenomen. Vissa begrepp har barnen till synes en lägre grad av förståelse för och vissa begrepp är de väl bekanta med men har inget specifikt ord för. Det finns också olika sätt att förklara naturvetenskapliga fakta, vilka inte alltid motsvarar frågeställarens, barnets och/eller pedagogens, förväntningar. De huvud­sakliga slutsatser som har dragits är följande: även om ett barns ordförråd för att beskriva naturvetenskapliga fenomen är rikt ger det inte automatiskt en god begreppsbildning, det informella samtalet är en viktig resurs i barnens lärande samt att det är viktigt att använda rätt förklaringsmodell vid varje tillfälle.

Fotografers och föräldrars attityder kring skönhetsretuschering i skolfotografier : En semistrukturerad intervjustudie

Through semi-structured interviews with 8 school photographers and 10 parents,this study attempted to clarify what photographers and parents of children(aged 1–5) in preschool think of photography business in the current situationprovides retouching children’s school photographs and what they considers tobe acceptable. The result shows that companies do not offer photo retouchingfrequent, but performs this service at the direct request of the customer. Themajority of parents agreed that dirt and food was accepted to be removed fromthe photograph, and that this does not affect the child's self image. The photographersbelieve that one should be very careful when it comes to children andretouching, and that the debate is important.

Vad händer med dialogen? : En studie av dialogisk interaktion mellan pedagog och barn i förskolan

The overall purpose of this study is to gain knowledge about dialogues in the setting of the preschool. The more in-depth purpose is to highlight what happens in dialogues between a teacher and a child when more children join the situation of interaction in which the dialogue is taking place. A further purpose is to attempt to understand what it is that influences change in the dialogue and what significance the actions of the teacher can have for this change. The study is based on several questions that concern interaction in preschools, who it is that initiates an increase in the number of participants in those situations that involve dialogue, and what happens with the dialogue when more children join and what causes the change in the dialogue. The study is based on video observations from a preschool; approximately 10 teachers and 50 children between the ages of one and six took part in the study. The situations that were observed and documented in video format were everyday activities (both indoor and outdoor) that were led at a nominal level by teachers. In total, 40 films were recorded. Film length was between one and 60 minutes. In 32 of the films, there was interaction between a teacher and several children, and 18 of these included dialogues between a teacher and several children. Dialogue is here given a specific significance and refers to the interaction that can be described in terms of presence, listening, reciprocity, and extending. This definition of dialogue derives from a combination of Martin Buber’s philosophy of dialogue and aspects of interaction that earlier research found to be significant for children’s learning. In two of the 18 films that showed dialogue, no other children became part of the situation of interaction; the remaining 16 films were transcribed; and both verbal and non-verbal events were made apparent in the transcriptions. Analyses of the recorded material and of the transcriptions were conducted using analytical terms borrowed from conversation analysis as well as the central term for this study dialogue.  The results demonstrate a complex practice and also demonstrate that dialogues in the sense given in this study take place between children and teachers. Situations of interaction also occur where dialogues take place in which a number of children join. It can be the child joining the situation of interaction who takes the initiative to an increased number of participants; however, it can also be the teacher or the child in the dialogue. The initial address can take place during a moment of transition in the interaction or at the same time as another participant is talking. The dialogue often changes when more children join the situation where the dialogue is taking place. The dialogue can end completely or be interrupted and resume. The results further demonstrate that the dialogue can continue without seemingly being affected by the fact that more children join. This happens when the child joining and the teacher in the dialogue interact in a non-verbal manner at the same time as the teacher is talking with the child in the dialogue. The dialogue can also be continued with more participants. Who takes the initiative, how the initial address occurs, and which content is given focus by the different participants are all factors that seem to affect what happens to the dialogue. How the teacher acts when more children join also appears to be significant in terms of what happens with the dialogue when more children join. In those situations where the teacher begins talking with a number of children about different subjects, the interaction ceases to be dialogic. When the teacher asks the joining child to wait, the dialogue is both interrupted and resumed, and on those occasions when the dialogue continues with more participants, the teacher listens to the joining child and the participants take turns speaking.

Pedagoger i det sociala uppdragets gränstrakter : Att hantera familjerättsliga processer, hot och våld

Pedagogues in the borderland of their social task: dealing with family law proceedings, threats and violence Drawing upon an explorative study of family law proceedings from a school perspective, the aim of this paper is to examine the school staff’s strategies for solving or coping with problematic situations in this context. Gendered conflicts between adults and violence are extreme cases for pedagogues in school and preschool. How do the staff cope with their own and the children’s vulnerability? Based upon interviews with 22 informants, the staff’s strategies are outlined and discussed in relation to organizational and professional circumstances and intersecting social relations of power. An analytical construction of six types of proactive and reactive strategies, ranging from distance keeping to normalization of own exposure, is utilized in the analysis. Findings suggest that the staff’s strategies to handle challenging events in this context vary with the parent’s gender, class position and ethnicity. Further, it is argued that creating a sense of safety and promoting learning among the children may be obstructed by lack of support from the school’s organization, demands on staff to perform customer oriented attitudes towards parents and lack of clarity concerning the limits of the social task. Conflicts between the organization and profession on the one hand and the educational and the social task on the other hand, are thus illuminated. In conclusion, a further aim of this article is to contribute to broader discussions on men’s violence against women and children – in families as well as in workplaces and in the intersection between these two areas.