This dissertation presents four experimental studies (in four papers) with the overall aim to investigate the effects of office noise on cognitive performance and restoration. In the first two papers the focus was on the effects of different sound levels (i.e., the mean level from all sound sources at an office, such as speech, phones, people walking) on performance, fatigue and stress. In the last two papers the focus was on the effects of background speech, as this has previously been shown to be the most disturbing noise source in open-plan offices. Paper I demonstrated decreased word memory performance, increased fatigue and motivational deficits when the background sound level increased by 12 dB, from 39 to 51 dB LAeq. Paper II showed that the sound level effects were more pronounced for individuals with a hearing impairment. Unexpectedly, no effects were found of acute noise exposure on the participant´s stress hormone levels (Paper I and Paper II).Regarding effects of irrelevant speech, Paper III showed that cognitive performance decreased as a function of background speech intelligibility, the higher the intelligibility depicted by the Speech Transmission Index (STI), the worse the performance. The results indicated that the STI-value must be less than 0.50, to avoid a negative influence on performance. Further, both Paper III and IV showed that performance is more impaired by background speech if the focal task requires episodic memory and rehearsal—such as word memory and information search. Interestingly, some tasks were insensitive for speech.The restorative effects of a break were addressed in Paper I and II (i.e., directly after the work sessions in noise). The break period differed in content between the participants. Paper I showed that a break with a nature movie with corresponding sound increased energy ratings compared to just listening to river sounds or office noise. Continued exposure to office noise gave the lowest ratings of motivation after the break. Paper II showed improved arithmetic performance and motivation after the break with a nature movie and decreased performance and motivation after continued noise exposure. For the hearing impaired participants, however, continued noise during the break increased motivation and performance, while the movie did not.Taken together, the current thesis demonstrates that open-plan office noise can have a negative impact on fatigue, motivation and performance. How much performance is impaired varies with the cognitive processes required by the tasks performed and hearing status. Moreover, continued noise exposure during a short break can further decrease motivation and subsequent performance. / <p>Godkänd; 2012; 20120831 (heljah); DISPUTATION Ämne: Teknisk psykologi/Engineering Psychology Opponent: Docent Mats Nilsson, Psykologiska institutionen, Stockholms universitet Ordförande: Professor Håkan Alm, Institutionen för ekonomi, teknik och samhälle, Luleå tekniska universitet Tid: Fredag den 23 november 2012, kl 10.30 Plats: F719J, Luleå tekniska universitet</p>

New societal requirements and functional growth put new demand on future driver information. Simultaneously, new technology and IT capabilities makes it possible to constantly adapt the information given to the driver for different reasons. Therefore, the aim of this thesis was to obtain an improved understanding, strengthen knowledge of the adaptive control of driver information to understand if, for what reason, when and where to use adaptive driver information (ADI). Also some possible new means to support drivers were suggested.The main purpose of driver information is to support the driver in achieving goals such as a safer, more environmentally friendly, more efficient, legal and enjoyable transportation by providing correct information and feedback.ADI can support the driver throughout development of skill and when performing operational, tactical, and strategic level tasks. Also tasks related to setting goals for the driving task and encouraging good driving behaviour can be supported. ADI can, furthermore help drivers to stay within their comfort zone by visualizing risk or certainty, identify and thereafter adapt how a message is communicated to different personalities, maintain the driver’s mental workload within the safe task load area by reducing demand when it is too high, increase mental workload by extra stimulating task during too low a mental demand, and minimize the risk for mismatches between effort and real demand.ADI changes automatically that may cause new and unpredictable issues reducing the purpose of driver information. These may include: mode confusion, function allocation, over and under trust, locus of control issues, skill degeneration and too low/high mental workload. Research has suggested that the most efficient way to reduce these issues is to make the driver and the automation (the agents) get along together and become team players. The team players should share goals, show intention, show limits of performance, state etcetera. However, for cars, a consumer product, in which visual demand is high, an approach can be where information vanishes when agents have become a “team”. This approach may be called “team building”.Research and industrial contributions has been presented. Several examples of how ADI can be carried out have been suggested and some even illustrated. / <p>Godkänd; 2014; 20141006 (stadav); Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Staffan Davidsson Ämne: Teknisk Psykologi/Engineering Psychology Avhandling: Adaptive Driver Information Opponent: Docent Forskningsledare Björn Peters, Statens väg- och transportforskningsinstitut, Linköping Ordförande: Professor Håkan Alm, Institutionen för ekonomi, teknik och samhälle, Luleå Tekniska Universitet Tid: Tisdag 11 november 2014, kl. 10.00 Plats: E243, Luleå tekniska universitet</p>

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<p>Godkänd; 1996; 20080330 (ysko)</p>

En kraftig strukturomvandling pågår inom svensk sågverksindustri. Den har inneburit att produktionen allt mer har förskjutits mot de större sågverken. Historiskt har flera olika faktorer drivit på strukturomvandlingen. Sågverken som producerar mindre än 50 000 kubikmeter per år står idag bara för 30% av den totala produktionen, vilket kan jämföras med 70% på 50-talet. Sågverksstrukturen debatteras återkommande inom branschen. Den övergripande forskningsfrågan för detta arbete är "Hur bör strukturen av produktionsanläggningar utformas inom sågverksindustrin med avseende på antal anläggningar, deras storlek och lokalisering?". Syftet är att utveckla kvantitativa modeller lämpade för analys av hur antalet sågverk, storleken på sågverken samt deras lokalisering påverkar konkurrensförmågan för en grupp av sågverk. Gemensamt för de arbeten som tidigare har analyserat strukturfrågor i sågverksindustrin och som refereras här, är att de behandlar frågor om transportkostnader för olika lokaliseringar var för sig. En teoretisk referensram för arbetet skapas och används senare som stöd för modellutvecklingen. Den teoretiska utgångspunkten för det här arbetet är i första hand totalkostnadssynsättet med trade-off-relationer mellan olika kostnadsfaktorer. Fyra kvantitativa modeller utvecklas, tre plangeometriska och en nätverksmodell. De plangeometriska modellerna har som utgångspunkt den klassiska lokaliseringsteorin. De har en begränsad tillämpbarhet men skapar en förståelse för hur några lokaliseringsfaktorer principiellt påverkar sågverksstrukturen. Nätverksmodellen är däremot direkt tillämpbar på verkliga lokaliseringsfrågeställningar bl a pga att den har en betydligt högre detaljeringsgrad. I den första plangeometriska modellen lokaliseras sågverk i en skog längs en linje genom att minimera totalkostnaden för råvarutransport och sågverksproduktion. I den andra modellen minimeras totalkostnaden för att lokalisera sågverk i hexagonala timmerfångstområden. I den tredje modellen lokaliseras ett sågverk och dess timmerfångstområde i förhållande till ett givet efterfrågecentrum genom maximering av vinsten. Härvid beaktas försäljningsintäkter för sågad vara och flis samt kostnader för råvarutransport, sågverksproduktion och färdigvarutransport. Timmerfångstområdet modelleras som en segmentbeskuren cirkel. Resultaten från beräkningar med de första två modellerna visar att det optimala avståndet mellan sågverken och sågverksstorleken ökar med ökad grad av skalekonomi och minskar med ökad råvarutransportkostnad. Vid ökad timmertillväxt minskar det optimala avståndet mellan sågverken medan sågverksstorleken ökar. Likartade resultat fås med den tredje modellen. Här visas också att sågverkets optimala lokalisering relativt marknaden är beroende av förhållandet mellan kostnaderna för råvaru- och färdigvarutransport samt av såg- och flisutbytena vid sågverken. Höga utbyten och färdigvarutransportkostnader ger en mer marknadsnära lokalisering, medan låga utbyten och höga råvarutransportkostnader ger en mer råvarunära lokalisering... / <p>Godkänd; 1997; 20070418 (ysko)</p>

This thesis addresses the problem of developing and implementing an activity-based system for management of working environment conditions. Through explorative case studies in municipal care of the elderly the prerequisites of motivation, capacity and opportunity were examined. Systems objectives were derived from the Provisions enforced by The Swedish Working Environment Authority. The Provisions emphasize that working environment issues shall be integrated with activity-issues like economy and quality and include routines for risk analysis and action planning. An action research program was initiated including organizational interventions. A specific communication structure of meetings was designed. Simulations of workplace team meetings were accomplished including analysis and management of existing risks. The program was evaluated in the field by means of participant observation and structured interviews. The formative design of evaluation assessed the participants' motivation, capacity and opportunity to perform. The initial evaluation concerned how the participants performed risk analyses according to the action plan. Results showed that the participants operated according to the given meeting structure. Some risk factors were analyzed on numerous occasions, e.g. physical factors, while other risk factors, e.g. harassments were never considered in meeting contexts. The result implies the need of complementary work methods for risk assessment, i.e. professional employee interviews and questionnaires. The subsequent evaluation inquired into the first line managers' mental models using these methods. Results showed that the managers in general acknowledged the characteristics of the methods, i.e. strengths and sources of error. The concluding evaluation examined the working environment planning of the executive board. Results showed that the representatives in general held indistinct perceptions of the systems characteristics. A majority of the executive boards failed to communicate specific strategies for operative management. Some guiding principles for system implementation were suggested on the basis of the empirical results. / <p>Godkänd; 2003; 20070217 (ysko)</p>

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The management concept "supply chain management" was introduced in early 1980s and since then the concept has recieved increasing attention within the fields of logistics. Supply chain management is viewed by many as a highly novel management concept, but comparison with earlier work reveals similarities. The main objective of this study is to examine the concept of supply chain management in order to seek the essence of the concept. A subordinated objective is to give some indication of the degree of novelty of supply chain management. Supply chain management is viewed in this study as a management concept or management theory and a method of five different examinations based on literature studies is developed. Firstly, the "reference network", the references within the examined literature, is established and examined. Secondly, the stated objectives and the stated fundamental beliefs are examined and thirdly, the stated definitions and stated theory relations are examined. These three examinations lay the foundation for the fourth, where the extent to which the different views of supply chain management in the examined literature share a common set of ideas and beliefs is examined. Finally, the extent to which the fundamental beliefs of supply chain management can be distinguished from the ideas and beliefs of its forerunners within logistics is examined. The examination reveal that it is possible to relate the stated objectives of supply chain management to each other in a "hierarchical weave" and that it is also possible to view the concept as constituted by a set of primitive fundamental beliefs. Tentatively, the following set is identified as the primitive fundamental beliefs of supply chain management, coordination and integration along the material flow, win-win relationships and end customer focus. Further, the examinations reveal that few stated definitions exist and that there are only vaguely stated theory relations. The most common stated theory relation is Poster's value chain. Based upon the examinations the conclusion is that supply chain management is a homogenous management concept, where its interpreters share common ideas and beliefs. However, the comparison with the forerunners shows that the ideas and beliefs of supply chain management also can be found in prior works. Accordingly, the degree of novelty is not judged as very high. Although most of the ideas of supply chain management may be found in the work by its forerunners it is concluded that their ideas are more fragmented and less apparent than the ideas of supply chain management. / <p>Godkänd; 1997; 20070418 (ysko)</p>