Ultrasound, composed of sound waves with frequencies above the human audible range, has become widely used in various technological fields for digital communications. In the past, acoustic and ultrasonic waves were employed in military and commercial un-derwater wireless communication systems due to their superior performance compared to electromagnetic waves. Ultrasound has also emerged as a viable alternative to radio and wired transmission for data transmission through solid bodies like metal plates and pipe walls. Notably, ultrasound offers high-security features as it is nearly undetectable from outside the room, minimizing the risks of wireless interception and attacks like Bluesniping and jamming. In any digital communication system, understanding the propagation channel between the transmitter and receiver is crucial. The ultrasound communication channel comprises three main components: transmitting and receiving transducers and the medium through which the sound propagates. Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier scheme that divides the available spectrum into multiple non-overlapping subcarriers for digital communication. In the context of ultrasound communication, the channel consists of two parts: the combined response of the transducers used as the transmitter and receiver, and the im-pulse response of the propagation medium. When dealing with a thin plate with parallel surfaces, this results in a reverberating channel. The reverberating channel comprises a primary pulse along with echo pulses that possess similar shapes but decaying amplitudes. The amplitude decay occurs due to four prominent factors: power losses in the trans-ducers at each side, transmission losses at the boundaries of the plate and transducer, ultrasound pulse attenuation within the plate, and beam spreading as the ultrasound pulse travels over distance. The reverberations elongate the impulse response of the channel, thus require a long cyclic prefix to prevent data symbols to overlap. However, this limitation restricts the achievable bit rate and energy efficiency of the system. In this thesis, we present a model for the reverberating ultrasound channel suitable for various plate materials. We propose a novel system-level path loss model that accounts for losses at the transducers, transmission losses, material attenuation, and diffraction losses. Based on this model, we calculate a comprehensive link budget that explicitly considers plate thickness. Furthermore, we conduct a quantitative analysis to evaluate the impact of Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI) on the performance of the OFDM system. Through computer simulations, we evaluate the system’s performance and demonstrate that for a metal plate with a thickness of 5 mm, an uncoded data rate of 32 Mbps can be achieved.

Stragglers, which are tasks that operate significantly slower than other tasks in a system, are a big issue in distributed systems. A system can contain relatively few tasks that qualify as stragglers but that have a great impact on the overall system performance. For example, a study of a large data center showed that as few as 3.48 % of the tasks constituting various jobs were stragglers, and that these had a negative performance impact on almost 50 % of all total jobs. The purpose of this study is to utilize distributed tracing to detect stragglers in a service-oriented, distributed system. Distributed tracing is a tool that tracks requests across system boundaries and offers observability into which services a request has interacted with, and in which order. It also measures the duration of each service interaction which could act as a measurement for defining stragglers. Distributed tracing was utilized in this project to track a request in a case-study system constituting four nodes, to find services with straggling behavior. Specifically developed for this project was a program measuring the usage of CPU, memory, disk bandwidth and network bandwidth by a process. This program was used for services with which a request did interact, as well as for other services co-allocated on the same node. The metrics obtained were used as a basis when evaluating the reason for experienced straggling behavior. It was concluded that consuming certain resources together, for example CPU and memory, entailed straggling behavior. It was also shown that making conscious choices regarding how to co-allocate processes with respect to these results could improve a request round-trip time by up to 60 %. However, although time was insufficient to test this theory, it is believed that these results are highly system and application dependent and that the stragglers experienced in this project might not emerge in other systems. Therefore, it is believed that these experiments must be performed on each system of interest to get accurate results for that particular system. Nevertheless, these results demonstrate how severe the performance impact could possibly be due to stragglers caused by resource contention.

This project explores the possibilities for energy cost reduction and revenue generation forindustrial actors in the harbor of Oskarshamn, Sweden. First, a literature review describing theapplicable renewable energy technologies, business models, and electricity markets is included.Then, an optimization problem is formulated to get the optimum sizing and an estimation of theeconomic and environmental gains is solved. Finally, recommendations for the implementation ofan energy system that would achieve these gains are given.

Purpose: The purpose of this research is to induce a deeper and wider understanding of theimplications and the consequences of IoT and how it can affect wholesalers’ and retailers’opportunities to increase the value for their end customer.Design/Methodology/Approach: History and challenges of IoT as well as of the food retailindustry were studied, combined with interviews covering areas such as present challenges andtechnological adoption with 18 professionals from incumbent retailers, wholesalers, disrupters,industry and technical experts. Answers from interviews summarised, categorized and mappedtowards theories on technological transformation and synthesised into future estimations.Findings: The findings regard how IoT can increase the end customer value in the future valuechain of the food retail industry and key limitations and opportunities for its future developmentwithin the sector. The results concern areas such as online shopping and distribution,immigration and travelling, sustainability, stores and offers, technological adoption, internal ITstrategy, sharing of personal and corporate data, standardisation and traceability, customerexpectations and finally change in the customer offer.Practical implications: The study's practical value is related to its utility in explaining andpossibly forecasting the development of IoT applications within different sectors, allowingmanagers to capture value arising from technological changes.Originality/Value: This study offers a model to clarify and explain the impacts and challengesof the IoT within the food retail sector and is generalisable to other sectors and technologies.Paper type: Master thesis

The global supply chain is fundamentally changing to become more complex as the world gets more connected. This causes high pressure on the supply chain to become resilient to a surrounding environment with more risks that affect financial aspects. In order to better understand what measurements and actions that need to be in place when strategizing on inbound supply chain theoretical frameworks needs to be built. To further understand how different risk factors are interlinked within the supply chain, it was decided to make use semi-structured interviews and the methodology called Total Interpretive Structural Modeling (TISM). The method chosen in this work is in accordance with the TISM methodology and is performed as follows: First, an extensive literature and interview process is carried out to identify important risks and how they drive cost. Secondly, utilizing experts knowledge by comparing logical statements against each other to create a hierarchical relationship between risks and cost drivers within the incoming supply chain. Third, Cross-Impact Analysis was utilized to better understand dependency and power and every variable. Finally, a self-explanatory model was developed based on the theoretical relationship between variables. At the same time, a qualitative study was executed. Based on semi-structured interviews with experts in the reas of Logistics & Supply Chain Management. The methodology for analyzing these semi-structured interviews is conducted in accordance with theories on the interpretation of qualitative data: transcribe, encode and index each interview to gain an understanding of the importance of data obtained. This qualitative study is conducted as a check to ensure that the result from the interpretation structure model (TISM) is consistent with reality. All done from a general and conceptual level applicable to the inbound supply chain of a manufacturing organization. The thesis found, by the use of above methodology, that there were 11 different risk factors that directly or indirectly relate to a financial cost driven in the supply chain. The hierarchy of these factors was established through TISM and cross-referenced with the expert opinions within the field of Supply Chain Management and logistics through semistructured interviews. Findings from the thesis conclude that important aspects of an inbound supply chain are (i) the importance of having a conceptual view of the market, strategy and organizational goal; (ii) implement an accurate accounting for materials and products to support transparency; (iii) logistics network and inventory is fairly unimportant in the whole picture; (iv) supplier relations needs to be kept up to standard, even in a seller’s market. / Den globala försörjningskedjan är under förändring mot att bli mer komplex allt eftersom att världen blir allt mer sammankopplad. Detta medför svårigheter då en komplexare omgivning ger med sig fler risker vilket påverkar de finansiella aspekterna i kedjan. För att bättre förstå vilka åtaganden och åtgärder som behövs för att nå en optimal kedja behövs teoretiska ramverk. För att uppnå detta valdes i detta arbete ett tillvägagångssätt och metod benämnt Total Interpretive Structural Modeling (TISM). Tillvägagångssättet är därför i enlighet med TISMmetoden och utförs enligt följande (1) en omfattande litteratur- och intervjuprocess genomförs för att identifiera viktiga risk element i en inåtgående försörjningskedja; (2) användandet av experters kunskap och logiska uttalanden för att skapa ett hierarkiskt förhållande mellan riskelement; (3) Cross-Impact Analysis, för att bättre förstå beroende och drivkraft hos varje riskelement.; (4) slutligen utvecklades en självförklarande modell baserad på den teoretiska relationen mellan de olika riskvariablerna. Parallellt med detta utfördes en kvalitativ studie baserad på halvstrukturerade intervjuer med experter inom Logistik & Supply Chain Management. Metoden för att analysera dessa bygger på teorier om kvalitativa data och dess tolkning: transkribera, kodifiera och indexera varje intervju för att få förståelse av vikten av erhållna data. Den kvalitativa studie utfördes som ett kontrollerande åtagande för att säkerställa att resultatet från TISM metoden var förenligt med verkligheten. Allt arbete gjordes från en generell och konceptuell nivå för att se om kunskapen kunde vara applicerbart på case-företaget. Det här med avseende att optimera tillverkande organisationers inkommande försörjningsflöden. Uppsatsen hittade, med hjälp av ovanstående tillvägagångssätt, att det fanns 11 olika riskfaktorer som direkt eller indirekt hänför sig till en ekonomisk kostnad i försörjningskedjan. Hierarkin för dessa faktorer fastställdes genom TISM och validerades genom expert intervjuer inom ämnet. Resultat från uppsatsen visar att viktiga aspekter för en optimal försörjningskedja var (i) vikten av att ha en konceptuell syn på marknaden, strategin och organisationsmålet; (ii) ha ett kontrollsystem för material och produktspecifika data, för att öka transparensen; (iii) från ett helhetsperspektiv är logistiknätet och lagernivån relativt oväsentlig; (iv) leverantörsrelationer är viktiga att underhålla, även inom säljarens marknad.

A user interface should be intuitive to allow efficient and safe execution of tasks. Helicopter 14 (HKP 14) has operator consoles with an analog user interface, called Programmable Keys (PK), to control a Mission Management System (MMS). The idea of replacing the PK with touch technology has arisen. To understand operators’ working environment, this case study was conducted with inspiration from ethnography. The PK have been studied by reading system manuals and familiarizing with the MMS in Saab’s test rigs and in HKP 14. This study aims to investigate the opportunities and challenges with implementing a touch screen to replace the current PK. Interviews have been conducted with operators and one technician working with HKP 14. To highlight additional perspectives on usage of touch technology, interviews with employees at FMV and Saab were carried out. This study found both benefits and drawbacks with implementing a touch screen in the helicopter. The most common concern was that touch screens lack tactile feedback. This study exemplifies how physical support can be achieved on a touch screen and how a Graphical User Interface (GUI) can be designed with regards to this. / Se filen

In today’s increasingly dynamic business setting innovation is known for being of importance and accomplishing a competitive advantage. The research on innovation has acknowledged the role of knowledge being the foundation of competitive advantage. Many companies imply that knowledge sharing is the reason for the competitive edge. In today’s business world it is gradually turning to become a knowledge environment. This paper addresses the impact of knowledge creation on crowdsourcing in terms of innovation. The objective of this study is to understand the importance of crowdsourcing and knowledge creation within innovation management. Innovation is the outcome from implementing structural knowledge. In this study we will seek to understand and recognize how crowdsourcing can be utilized to enhance the formation of structural knowledge. In our findings we acknowledge that crowdsourcing has a constructive influence on innovation. Knowledge sharing also has an effect on the level of innovation in organizations. The methodology will mainly be based on an interpretivist approach from our literary review. Our research findings from all the literature will primarily be of a qualitative approach. There is also a case study covered in this thesis describing using knowledge management with crowdsourcing as a way to promote innovation.

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<p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

Autonomous driver assistance systems are standard in vehicles. These systems help the driver to prevent an accident by automatically applying brakes on the vehicle. They assist the driver and help to prevent injuries and casualties caused by traffic accidents yearly.  This report shows data about how a vehicles Autonomous Emergency Braking (AEB) system reacts to a road surface with lower friction, for example in winter conditions. To help with the test was a steering robot (SR60 Orbit) and a pedal robot (CBAR 500) used to make the accuracy higher. The target that was used during tests was a Global Vehicle target (GVT). The tests were performed at ArcticFalls proving ground outside Älvsbyn on both asphalt and snow.  The tests show a noticeable difference between the distance it takes the car to stop on asphalt and snow. It emerges from the tests that systems like AEB can’t handle low friction, which is a huge risk for an accident. To prevent the risk of a collision is systems that can measure friction a priority.