Journal Staff

The integer factorisation problem (FACT) is a well-known number-theoreticproblem, with many applications in areas such as cryptography. An instanceof a FACT problem (a number n such that n = p × q) can be reduced to aninstance of the conjunctive normal form boolean satisfiability problem (CNF-SAT), a well-known NP-complete problem. Some applications of this is toutilize advances in SAT solving for solving FACT, and for creating difficultCNF-SAT instances.This report compares four different reductions from FACT to CNF-SAT,based on the full adder, array multiplier and Wallace tree multiplier circuits.The comparisons were done by reducing a set of FACT instances to CNF-SATinstances with the different reductions. The resulting CNF-SAT instanceswere then compared with respect to the number of clauses and variables, aswell as the time taken to solve the instances with the SAT solver MiniSat

Digital Winter. Connected vehicles for safer roads

Increased connectivity in cars, means that important information about infrastructure can be instantly transferred from the cars into a cloud. Car manufacturers have provided these systems for decades, but have just recently offered these connected functions to a broader customer base. Sharing data with the road authorities, however, is rare.  Trafikverkets FOI-project Road Status Information wanted to explore the possibilities to gather road friction data from cars in daily traffic to monitor and improve the winter maintenance of the roads.  A new cloud based digital solution from ÅF, in a joint venture with Volvo Cars, will now provide the Swedish Transport Administration of slippery road conditions data. One of the first initiatives in Europe to share data from vehicles in daily traffic with road authorities on a larger scale.&nbsp

The Swedish fuel pellets industry

The production and demand for wood-based fuel pellets has increased considerably both in Sweden and internationally the recent years. Today Sweden is one of the leading nations when it comes to production and use of fuel pellets. Despite the favorable development great challenges wait. The all time high production of saw mill by-products is not enough to satisfy the growing demand for by-products, resulting in increasing raw material prices and competition. Seen in a historic context, the pellet industry has been characterized by fluctuations in supply and demand and uncertainty about how changes in governmental subsidies and the development of competitive substitutes will affect the situation. This study presents a broad overview of the Swedish pellet industry. The study had three purposes; to analyze the business situation for the producers, to examine to what extent product standards and environmental certification instruments were used within the industry, and to make an estimate on future potentials and possibilities for the pellet industry. The study was conducted in the form of a questionnaire survey to the manufacturers of fuel pellets in Sweden and the results are based on answers from 55 % of the producers, accounting for 86 % of the total production capacity. The results indicate a rapidly expanding production capacity and at the same time a strained raw material situation. The production increased with as much as 260 % from 2001 to 2007, and the planned capacity expansion totals 708 000 annual tonnes, or over 40 % of the capacity for 2007. During the same period, the competition for raw materials was getting more intense; one third of the producers experience the raw material situation as the largest threat to the production and the majority of firms have evaluated alternative raw materials in response to the increased competition. Among the alternatives examined are for example roundwood and pulp wood. The majority (47 %) of the production go to small-scale consumers. The greatest part (74 %) of all pellets manufactured are produced according to the Swedish Standard, but among the small-scale producers the use of standardization is low. More than one fifth of the production is certified according to FSC and PEFC (scarcely 300 000 tonnes). The low degree of certification depends in a first instance on the fact that 53 % of the producers do not use environmentally certified raw materials but ultimately on the low demand for environmental certified pellets. Today the pellet industry is very dependent on the demand and supply balance for other forest industry products, a dependence that in a future perspective should be abandoned in favor of alternative and forest industry independent raw materials. To avoid the risks associated with overbuilding capacity, a greater share of the Swedish production should go to the expanding international market.Produktionen av och efterfrågan på träbaserad bränslepellets har ökat mycket kraftigt både i Sverige och internationellt de senaste åren. Sverige är idag en av de ledande nationerna när det gäller produktion och användning av bränslepellets. Trots den gynnsamma utvecklingen väntar stora utmaningar. Sågverkens rekordstora produktion av biprodukter räcker inte för att tillfredsställa den ökande efterfrågan vilket har resulterat i ökade råvarukostnader och konkurrens. Historiskt sett har pelletsindustrin präglats av fluktuationer i tillgång och efterfrågan, osäkerhet beträffande statliga bidrag samt hur utvecklingen hos konkurrerande energislag kan påverka situationen. Den här studien utgör en bred kartläggning av den svenska pelletsindustrin. Studien hade tre övergripande syften; att analysera producenternas affärssituation, att undersöka i vilken omfattning produktstandarder och miljöcertifieringar användes inom industrin samt att bedöma vilken potential och vilka möjligheter som finns för industrin i framtiden. Studien utfördes i form av en enkätstudie till Sveriges producenter av bränslepellets och resultaten är baserade på enkätsvar från 55 % av dessa motsvarande 86 % av den totala produktionskapaciteten. Resultaten visar på en snabbt expanderande produktionskapacitet och samtidigt en ansträngd råvarusituation. Industrins produktion ökade med hela 260 % mellan 2001 och 2007, och den totala planerade kapacitetsutbyggnaden uppgår till 708 000 årston, eller drygt 40 % av kapaciteten år 2007. Under samma period har råvarukonkurrensen hårdnat; en tredjedel av producenterna upplever råvarusituationen som det största hotet mot produktionen och majoriteten av alla företag har undersökt alternativa råvaror som svar på den ökande konkurrensen. Bland de undersökta alternativen ingår bland annat rundved och massaved. Huvuddelen (47 %) av produktionen går till småskaliga användare. Större delen (74 %) av all pellets produceras i enighet med Svensk Standard, men bland de småskaliga producenterna är användandet av standardisering låg. Drygt en femtedel av produktionen certifieras i enighet med FSC och PEFC (knappt 300 000 ton). Den låga certifieringsgraden beror dels på att 53 % av producenterna inte använder miljöcertifierade råvaror och främst på den låga efterfrågan på miljöcertifierad pellets. Pelletsindustrin är idag mycket beroende av utbuds- och efterfrågebalansen på andra skogsindustriprodukter, ett beroende som i ett framtidsperspektiv bör brytas till förmån för alternativa och skogsindustrioberoende råvaror. För att undvika riskerna förknippade med överkapacitet bör en större del av den svenska produktionen avsättas på den expanderande internationella marknaden

A new resorbable device for ligation of blood vessels - A pilot study

<p>Abstract</p> <p>Background</p> <p>During surgery, controlled haemostasis to prevent blood loss is vital for a successful outcome. It can be difficult to ligate vessels located deep in the abdomen. A device that is easy to use and enables secure ligatures could be beneficial. Cable ties made of nylon have been used for ligation but the non-resorbable material caused tissue reactions. The objective of this study was to use a resorbable material to construct a device with a self-locking mechanism and to test its mechanical strength and ligation efficiency.</p> <p>Methods</p> <p>The device was manufactured by injection moulding of polydioxanone, a resorbable polymer used for suture materials. Polydioxanone with inherent viscosities of 1.9 dL/g and 1.3 dL/g were tested. The device consisted of a perforated flexible band which could be pulled through a case with a locking mechanism. After a first version of the device had been tested, some improvements were made. The locking case was downsized, corners were rounded off, the band was made thicker and the mould was redesigned to produce longer devices. Tensile tests were performed with the second version.</p> <p>The first version of the device was used to ligate the ovarian pedicle in a euthanized dog and to test echogenicity of the device with ultrasound. Compression of vessels of the ovarian pedicle was examined by histology. Both versions of the device were tested for haemostasis of and tissue grip on renal arteries in six anaesthetised pigs.</p> <p>Results</p> <p>The tensile strength of the flexible band of the devices with inherent viscosity of 1.9 dL/g was 50.1 ± 5.5 N (range 35.2-62.9 N, <it>n </it>= 11) and the devices with inherent viscosity of 1.3 dL/g had a tensile strength of 39.8 ± 8.1 N (range 18.6-54.2 N, <it>n </it>= 11). Injection moulding of the polymer with lower inherent viscosity resulted in a longer flow distance.</p> <p>Both versions of the device had an effective tissue grip and complete haemostasis of renal arteries was verified. The device attached to the ovarian pedicle could be seen with ultrasound, and vessel compression and occlusion were verified by histology.</p> <p>Conclusions</p> <p>Tests of functionality of the device showed complete haemostasis and good tissue grip. Devices with a band of sufficient length were easily applied and tightened in tissue.</p

Association between polymorphisms in RMI1, TOP3A, and BLM and risk of cancer, a case-control study

BACKGROUND: Mutations altering BLM function are associated with highly elevated cancer susceptibility (Bloom syndrome). Thus, genetic variants of BLM and proteins that form complexes with BLM, such as TOP3A and RMI1, might affect cancer risk as well. METHODS: In this study we have studied 26 tagged single nucleotide polymorphisms (tagSNPs) in RMI1, TOP3A, and BLM and their associations with cancer risk in acute myeloid leukemia/myelodysplatic syndromes (AML/MDS; N = 152), malignant melanoma (N = 170), and bladder cancer (N = 61). Two population-based control groups were used (N = 119 and N = 156). RESULTS: Based on consistency in effect estimates for the three cancer forms and similar allelic frequencies of the variant alleles in the control groups, two SNPs in TOP3A (rs1563634 and rs12945597) and two SNPs in BLM (rs401549 and rs2532105) were selected for analysis in breast cancer cases (N = 200) and a control group recruited from spouses of cancer patients (N = 131). The rs12945597 in TOP3A and rs2532105 in BLM showed increased risk for breast cancer. We then combined all cases (N = 584) and controls (N = 406) respectively and found significantly increased risk for variant carriers of rs1563634 A/G (AG carriers OR = 1.7 [95%CI 1.1-2.6], AA carriers OR = 1.8 [1.2-2.8]), rs12945597 G/A (GA carriers OR = 1.5 [1.1-1.9], AA carriers OR = 1.6 [1.0-2.5]), and rs2532105 C/T (CT+TT carriers OR = 1.8 [1.4-2.5]). Gene-gene interaction analysis suggested an additive effect of carrying more than one risk allele. For the variants of TOP3A, the risk increment was more pronounced for older carriers. CONCLUSION: These results further support a role of low-penetrance genes involved in BLM-associated homologous recombination for cancer risk

Studier av infästningar av takfönster vid vindsinredningar

QC 2011063

Voltage and frequency scaling in an embedded microprocessor; to enable the implementation of dynamic voltage and frequency scheduling for power management

Minimizing power consumption is a critical part of many embedded design projects. The challenge is to limit the power consumption of the system and at the same time provide satisfactory service to the user. With regards to microprocessors, the main way of limiting power consumption during program execution is to adjust the frequency and the voltage at which the processor operates. To enable the implementation of real-time scheduling with support for dynamic voltage and frequency scaling, an exhaustive study of the Freescale i.MX31 embedded microprocessor is performed. Specifically, the power consumption relationship to all relevant frequency and voltage settings is investigated. In addition, to enable frequency and voltage scaling in a real-time environment, a complete timing analysis of proposed voltage and frequency scaling methods is performed and their suitability for use in real-time systems is evaluated. To integrate voltage and frequency scaling capability into OSE RTOS, a software module has been developed for this operating system. The module enables OSE processes to request voltage and frequency changes using a signaling interface. The module has been tested for robustness and its correct operation together with a real-time dynamic voltage frequency scheduler developed at Enea has been verified. Finally, an evaluation of the power consumption of a test program running on the integrated system is performed.Att minimera energiförbrukning ar en mycket viktig del av många utvecklingsprojekt av inbyggda system. Utmaningen består av att minimera systemets energiförbrukning samtidigt som det förväntas leverera en kvalitativ användarupplevelse. Den huvudsakliga metoden som används för att minimera energiförbrukningen en mikroprocessor under programexekvering är att reducera dess klockfrekvens och matningsspänning. För att möjliggöra implementationen av realtidsschemaläggning med stöd for dynamisk justering av processorns spänning och frekvens genomförs en utförlig studie av en Freescale i.MX31- mikroprocessor. Undersökningen fokuserar på relationen mellan energiförbrukning och spannings- och frekvensinställningar. För att möjliggöra frekvens- och spänningsskalning i realtidssammanhang utförs dessutom en tidsanalys av föreslagna spännings- och frekvensjusteringsmetoder och deras lämplighet for användning i realtidssystem utvärderas. För att integrera spännings- och frekvensskalning i OSE RTOS har en mjukvarumodul för operativsystemet utvecklats. Modulen gör det möjligt for OSE-processer att begära spännings- och frekvensändringar genom ett signalinterface. Modulen testas for robusthet och dess korrekta funktion tillsammans med en realtidsschemaläggare med stöd för dynamisk frekvens- och spänningsskalning utvecklad hos Enea verifieras. Slutligen så utvärderas energiförbrukningen av ett testprogram som exekveras av det integrerade systemet

AN ANALYSIS OF A DISTRIBUTED TRACING SYSTEMS EFFECT ON PERFORMANCE Jaeger and OpenTracing API

With micro-services and other service oriented architectures gaining more popularity every day, debugging tools speci\u80cally made for service oriented architectures are also becoming more common. Distributed tracing systems are tools that can be used to debug latency and provide a bett\u8ber understanding about how a systems services communicates with each other among other helpful things. However, this is not a tool without drawbacks. Developers must implement the distributed tracing tools speci\u80ed API into their micro-service system to be able to use these distributed tracing tools. \u91This can have an impact on the microservice system’s performance, but how much of an impact does implementing a distributed tracing tool have on a micro-service system’s performance

Air power : a comparative study between central air power theories and Swedish air doctrine

Att utnyttja flygstridskrafter har sedan tidernas begynnelse varit en effektiv metod att påtvinga motparten sin egen vilja. Sättet man använt flygstridskrafterna på har debatterats under historiens gång. Inom ämnet luftmakt finns det en rad kända och inflytelserika luftmaktsteoretiker som alla har sin idé om hur man bäst utnyttjar flygstridskrafter. Hur ser vår svenska doktrin ut gällande teorier kring luftmakt? Vilka luftmaktsteorier genomsyrar grundtanken bakom hur vi idag vägleder våra luftoperationer? Syftet med uppsatsen är att undersöka vilka generella och centrala luftmaktsteorier som återfinns i den svenska doktrinen. För att kunna svara på mina valda frågeställningar och tillgodose syftet med uppsatsen har jag valt att dela in uppsatsen i två delar. Den första delen är en beskrivande del där jag helt enkelt redogör för vad luftmakt är, presenterar centrala luftmaktsteoretiker och deras teorier samt redogör för vad vår doktrin säger angående luftmakt. Därefter kommer en komparation mellan centrala tankar och teorier kring luftmakt och svensk doktrin för luftoperationer. Resultatet i uppsatsen visar tydliga exempel på att doktrinen återspeglar det bästa hos flera av de centrala luftmaktsteoretikerna. Det centrala i doktrinen är effekttänkandet och utnyttjandet av indirekt metod. Avslutningsvis ser jag en begränsning gällande svensk doktrin och luftmaktsteorier kring strategiska mål och medel nu när Försvarsmakten gått från invasions- till insatsförsvar och därmed minskat på personal och resurser. Frågan är om vi har möjlighet att effektivt verka strategiskt som enskilt land eller om vi är beroende av andra nationer?To use air power has always been an effective way to affect your opponent. The way you use air power has been debated throughout history. There are a number of famous and influential air power theorists who all have their idea of how to best use air power. How does the Swedish air doctrine describe air power? Which airpower theories work as guidelines for our air operations today? The purpose of this paper is to examine general and central air power theories which can be found in the Swedish doctrine. To be able to answer my questions and to achieve the objective of this paper, I have chosen to divide the paper into two parts. The first part is a descriptive part where I simply describe what air power is, present well known air-power theorists and their theories and outline what our doctrine says about air power. The second part is a comparison between the central ideas and theories about air power and the Swedish airdoctrine. The result of this paper shows that the Swedish air doctrine has been influenced by several air-power theorists. Central in the doctrine are effects-based operations and the use of indirect methods. Finally, I see a limitation in the Swedish air doctrine and strategic air power theories now that the Armed Forces have reorganized, which means less personnel and resources. The question is whether we can effectively operate on a strategic level as a single country or if we are dependent on other nations

Implementation and Evaluation of Uncertainty Estimation for Advanced Pharmacokinetic Models in DCE-MRI

The goal of this report is to develop code in Python that implements and evaluates a multivariate linear error propagation for commonly used DCE-MRI models. Two pharmoacokinetic models (PK-models) were tested; modified Kety model and two-compartment exchange model. The analysis compared a Monte carlo simulated signal and a simple analytic model for uncertainty. The purpose of comparing was to have the Monte carlo method and the linear error estimation method reasonably close in terms of estimation of the error of the PK-parameters (parameters are specific for the PK-model). The analysis included an inspection of the resulting plots of the Coefficent of Variation (CV) of the estimation of the PK-parameters, when increasing the ratio of the true value and the added error for each of the input parameters. Generally the CV increased, I.e. the precision decreased, as the noise level increased. For both PK-models, error in injection time of contrast agent were the input parameter with the least tolerance of noise. By comparing the results from both methods, the conclusion is to implement the modified Kety model as the PK-model used in MICE Toolkit (NONPI Medical AB, Umeå, Sweden) and keep the noise to signal level below 15\% in order to obtain precision of the results to less than 33\% error. We have verified the uncertainty estimation method works well for the Modified Kety model but not so well for the two-compartment exchange model. The scope of this study only included two PK-models and one signal model, therefore it would be beneficial to test the linear estimation method used here on other PK-models and signal models to find what models it works well for.Målet med denna rapport är att utveckla kod i Python som implementerar och utvärderar multivariat linjär felpropagering för ofta använda DCE-MRI modeller. Två farmakokinetiska modeller (PK-modeller) testades; den modifierade Kety-modellen och två-utrymme utbytesmodellen. Analysen jämförde en Monte carlo-simulerad signal och en enkel analytisk modell för osäkerhet. Syftet med jämförelsen var att ha Monte carlo-metoden och den linjära feluppskattningsmetoden någorlunda nära när det gäller uppskattning av PK-parametrarnas fel (parametrarna är specifika för PK-modellen). Analysen innebar en inspektion av de resulterande kurvorna för variationskoefficienten (CV) för uppskattningen av PK-parametrarna, när förhållandet mellan det sanna värdet och det pålagda felet för var och en av ingångsparametrarna ökades. Generellt ökade CV:n, det vill säga precisionen minskade när bruset/felet ökade. För båda PK-modellerna var det fel i injektionstid för kontrastmedel den ingångsparameter som hade minst tolerans för brus. Genom att jämföra resultaten från båda metoderna är slutsatsen att använda den modifierade Kety-modellen som PK-modell i MICE Toolkit (NONPI Medical AB, Umeå, Sverige) och hålla brus-till-signal nivån under 15\% för att få precision av resultaten till mindre än 33\% fel. Vi har verifierat att metoden för osäkerhetsuppskattning fungerar bra för den modifierade Kety-modellen men inte så bra för två-utrymme utbytesmodellen. Omfattningen av denna studie inkluderade endast två PK-modeller och en signalmodell, därför skulle det vara fördelaktigt att testa den linjära uppskattningsmetoden som används här på andra PK-modeller och signalmodeller för att hitta vilka modeller den fungerar bra för