Thesis advisor: Steven D. Bruner / Thesis advisor: Larry W. McLaughlin / Nonribosomal peptides are therapeutically important natural products produced through pathways that utilize large multimodular enzymes, termed nonribosomal peptide synthetases (NRPSs). Central to the assembly line methodology, the monomer building blocks and the growing polymer chain are covalently linked to dedicated peptidyl carrier protein domains as phosphopantetheinyl thioesters. Although structures of multidomain NRPS fragments have been solved recently, the active conformation of the carrier domains with their attached phosphopantetheinyl arms has not been determined. Significant conformational changes in carrier domains are likely to occur as the domains shuttle peptidyl phosphopantetheinyl thioesters between the active sites of the partner domains. This thesis focuses on the application of the synthetic isosteric non-hydrolyzable CoA analogs to manipulate carrier domain geometry of NRPS assemblies through. The synthetic conjugates are designed to deliver an inhibitor moiety to a domain of interest. Using this strategy, various complexes have been designed to direct the phosphopantetheinyl arm to active sites of adenylation domains and thioesterase domains in catalytically relevant conformations. The structurally restrained multidomain NRPS assemblies are useful for elucidating the complex structure and mechanism of NRPSs. An X-ray crystal structure of a peptidyl carrier-thioesterase NRPS didomain fragment from enterobactin synthetase has been solved with a phosphopantetheinyl analog which forms a cross-link between the two domains. This structure provides, for the first time, detailed insights into the phosphopantetheinyl arm interaction with an NRPS partner domain, as well as an active confirmation of a mutidomain NRPS in the holo-form. In addition, the hydrolytically stable CoA analogs have been successfully used as probes in the structural and mechanistic study of a CoA-utilizing enzyme DpgC, a unique cofactor-independent dioxygenase involved in vancomycin biosynthesis. / Thesis (PhD) — Boston College, 2009. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

In collaboration with Semcon Karlskrona, a conceptual solution regarding withdrawal of cable from a carousel was developed. The diameter of the cable were 300 mm and its weight were 160 kg/m. By brainstorming, a number of draft was conceived whereof one were chosen by Pugh's concept screening. The solution was an arm supported by a framework construction. The end of the arm is bent to match the minimum bending radius of the cable. The arm is capable to translate sideways by a puck located in runners. These runners are coated by the plastic material Robalon to achieve a good sliding surface. The translation will be made possible by using a wire and a a winch. At the back edge of the arm a hinge were attached, allowing rotation around the supporting pillar. At the centre och the carousel, an axis is located which will be used to fasten the centre pillar against. All of the bars that are used in the construction are hotrolled rectangular hollow sections as these are seen to be advatageuos from a manufacturing perspective. The dimensions of the construction was determined regarding buckling, compression, tension and shear. As were the welded and screwed joints. / I samarbete med Semcon i Karlskrona utvecklades en konceptlösning för upptagning av kabel ur en karusell med två fack. Kabeln ägde en diameter på 300 mm samt en vikt på 160 kg/m. Flertalet konceptförslag togs fram via brainstorming varav ett sållades fram med hjälp av Pughs konceptvalsmatris. Lösningen blev en arm vilken vilar på ett stödfackverk. Armens ände är krökt så att den matchar kabelns bockningsradie. Armen kan translatera i sidled med hjälp av en puck belägen i skenor. Dessa skenor är klädda med Robalonplast för en bra glidyta. Translationen genomförs med hjälp av vinsch och vajer. I armens bakre ände återfinns ett gångjärn vilket möjlig rotation kring stödpelaren. I karusellens centrum finns en centrumaxel vilken den inre stödpelaren är fäst mot. Samtliga de stänger vilka används är varmbearbetade rektangulära konstruktionsrör då dessa anses vara fördelaktiga ur ett tillverkningsperspektiv. Fackverkskonstruktionen dimensionerades gentemot knäckning, tryckning, dragning och skjuvning. Dimensionering gjordes även av de svets-, och skruvförband, vilka fogar samman konstruktionen.

Face Detection has been applied in many fields such as surveillance, human machine interaction, entertainment and health care. Two main reasons for extensive attention on this typical research domain are: 1) a strong need for the face recognition system is obvious due to the widespread use of security, 2) face recognition is more user friendly and faster since it almost requests the users to do nothing. The system is based on ARM Cortex-A8 development board, including transplantation of Linux operating system, the development of drivers, detecting face by using face class Haar feature and Viola-Jones algorithm. In the paper, the face Detection system uses the AdaBoost algorithm to detect human face from the frame captured by the camera. The paper introduces the pros and cons between several popular images processing algorithm. Facial expression recognition system involves face detection and emotion feature interpretation, which consists of offline training and online test part. Active shape model (ASM) for facial feature node detection, optical flow for face tracking, support vector machine (SVM) for classification is applied in this research.

As embedded systems become more connected and more ubiquitous in mission- and safety-critical systems, embedded devices have become a high- value target for hackers and security researchers. Attacks on real-time embedded systems software can put lives in danger and put our critical infrastructure at risk. Despite this, security techniques for embedded systems have not been widely studied. Many existing software security techniques for general purpose computers rely on assumptions that do not hold in the embedded case. This thesis focuses on one such technique, control-flow integrity (CFI), that has been vetted as an effective countermeasure against control-flow hijacking attacks on general purpose computing systems. Without the process isolation and fine-grained memory protections provided by a general purpose computer with a rich operating system, CFI cannot provide any security guarantees. This thesis explores a way to use CFI on ARM Cortex-R devices running minimal real-time operating systems. We provide techniques for protecting runtime structures, isolating processes, and instrumenting compiled ARM binaries with CFI protection.

Current one-handed manual wheelchairs are difficult to propel because one arm can only provide half the power that is ascertained in a two-handed manual wheelchair. A power-assisted hemiplegic (one-sided paralysis) wheelchair was developed that can effectively be propelled with one arm while remaining maneuverable, lightweight, and foldable. An existing manual wheelchair was minimally modified and fitted with powerassisted components that could alternatively be attached to a wide range of manual wheelchairs. The design implements a motor and gear train to power the wheel on the user’s affected side, encoders on both rear wheels to track wheel position, and a heel interface on the footrest to control steering. A controls program was developed that analyzes wheel position and steering to respond to the motion of the hand-driven wheel. Extensive testing was performed to ensure design integrity. Testing results showed that the prototype successfully met and exceeded predetermined design specifications based on industry standard testing procedures. The design has the potential to deliver increased freedom to a considerable consumer base.

<p>Blodtrycksmätning innehåller många olika moment och studiens syfte var att belysa aktuell forskning kring tre faktorer som kan påverka resultatet vid blodtrycksmätning. Faktorerna delades in i kategorierna kläder (med/utan), arm (höger/vänster), och korsade ben eller ej. För att uppnå studiens syfte ställdes tre frågor; Blir det någon skillnad om blodtrycket mäts med eller utan kläder under blodtrycksmanschetten? Spelar det någon roll om blodtrycket mäts i höger eller vänster arm? Hur påverkar korsade ben resultatet vid blodtrycksmätning? Svaren söktes i 12 vetenskapliga artiklar som granskades, analyserades och värderades vetenskapligt. Inom kategorin kläder påvisades inte resultatet någon skillnad i uppmätt blodtryck beroende på om armen var klädd eller ej. Resultatet visade att det fanns viss skillnad i uppmätt blodtryck mellan höger och vänster arm och därför bör blodtrycket mätas i båda. Resultatet visar även att blodtrycket ska mätas med icke korsade ben i knähöjd. En studie visade att blodtrycket inte steg med benen korsade i ankelhöjd. </p>

In this report, a method for exploiting the redundancy of a hand-arm mechanical system for manipulation tasks is illustrated. The basic idea is to try to exploit the different intrinsic capabilities of the arm and hand subsystems. The Jacobian transpose technique is at the core of the method: different behaviors of the two subsystems are obtained by means of constraints in Null(J) generated by non-orthogonal projectors. Comments about the computation of the constraints are reported in the memo, as well as a description of some preliminary experiments on a robotic system at the A.I. Lab., M.I.T.

Blodtrycksmätning innehåller många olika moment och studiens syfte var att belysa aktuell forskning kring tre faktorer som kan påverka resultatet vid blodtrycksmätning. Faktorerna delades in i kategorierna kläder (med/utan), arm (höger/vänster), och korsade ben eller ej. För att uppnå studiens syfte ställdes tre frågor; Blir det någon skillnad om blodtrycket mäts med eller utan kläder under blodtrycksmanschetten? Spelar det någon roll om blodtrycket mäts i höger eller vänster arm? Hur påverkar korsade ben resultatet vid blodtrycksmätning? Svaren söktes i 12 vetenskapliga artiklar som granskades, analyserades och värderades vetenskapligt. Inom kategorin kläder påvisades inte resultatet någon skillnad i uppmätt blodtryck beroende på om armen var klädd eller ej. Resultatet visade att det fanns viss skillnad i uppmätt blodtryck mellan höger och vänster arm och därför bör blodtrycket mätas i båda. Resultatet visar även att blodtrycket ska mätas med icke korsade ben i knähöjd. En studie visade att blodtrycket inte steg med benen korsade i ankelhöjd.

Three experiments compared wrist and arm performance in a cyclical Fitts’ target task. The purpose of Experiment I was to determine if movement kinematics differed for wrist/elbow flexion/extension movements to targets of varying difficulty. Participants were asked to flex/extend a manipulandum in the horizontal plane at the wrist and elbow joint in an attempt to move back and forth between two targets. Online knowledge of effector position was displayed as a visual trace on a projector screen. Target widths were manipulated with amplitude constant (16 degrees) in order to create Indexes of Difficulty of 1.5, 3, 4.5, and 6. Results failed to detect differences in elbow and wrist movements either in terms of movement time, movement accuracy, or kinematic characteristics of the movement. In studies that have reported difference in wrist and arm performance in Fitts’ target tasks, experimenters have typically utilized visual amplification to counterbalance the small resulting wrist movements. The purpose of Experiments II and III was to investigate how changes in task parameters and visual gain play a role in providing a performance advantage for the wrist. In these experiments arm movement amplitude was increased to 32 degrees and wrist amplitude was decreased to 8 degrees. Results found similar overall movement times for arm and wrist movements. However, kinematic analysis of the movement revealed relatively large dwell times for wrist movements at IDs of 4.5 and 6. Removal of dwell time resulted in faster movement times for the wrist compared to arm. The results of these three experiments add to the limited literature examining how different effectors perform a Fitts’ target task. These findings suggest that performance differences in past literature may be due to the visual amplification often used when arm, wrist, and finger movements are studied.

Digital image data requires large compression ratio in applications like internet, communication and audio-visual environment. In this thesis, we realize the MPEG-4 codec standard on the ARM9-based platform and improve the execution performance by efficient implementations of the core operations such as Motion Estimation and DCT. In the assembly codes obtained by directly compiling the C codes, there exists a lot of redundant checking which causes a large amount of execution time waste. We rewrite some of the compiled assembly codes to improve the execution efficiency using a variety of techniques such as loop-unrolling and data-type optimization. We also analyze the experimental results using several benchmark video sequences with different modes.