This thesis considers several instances of abstraction that arose in the design and implementation of the web programming language Links. The first concerns user interfaces, specified using HTML forms. We wish to construct forms from existing form fragments without introducing dependencies on the implementation details of those fragments. Surprisingly, many existing web systems do not support this simple scenario. We present a library which captures the essence of form abstraction, and extend it with more practical facilities, such as validation of the HTML a program produces and of the input a user submits. An important part of our library is a simple semantics, given as the composition of three primitive “idioms”, an interface to computation introduced by McBride and Paterson. In order to justify this approach we present a comparison of idioms with the related notions of monads and arrows, refining the informal claims in the literature. Our library forms part of the Links framework for stateless web interactions. We describe a related aspect of this system, a preprocessor that derives generic instances of functions, which we use to serialise server state between client requests. The abstraction in this case involves the shape of datatypes: the serialisation operation is specified independently of the particular types involved. Our final instance of abstraction involves abstract types. Functional programming languages typically offer one of two styles of abstract type: the abstraction boundary may be drawn using a private data constructor, or using a type signature. We show that there is a pair of semantics-preserving translations between these two styles. In the light of this, we revisit the decision of the Haskell designers to offer the constructor style, and define a library that supports signature-style definitions in Haskell by translation into the constructor style.

No / ...lethal inventions are predicated on our intelligence, the usual story of which involves competition, the accumulated advantages of smartness, and the extinction of the weak. Yet we are the weak, and without technology cannot be strong. So the standard evolutionary tale of us becoming brainier by degrees until we were able to make stuff cannot be true. The alternative, that things came first, evolving us, seems counter-intuitive. But it fits the evidence.

Thesis (D.M.A.)--University of North Texas, 2002. / Accompanied by recitals, recorded Apr. 13, 1992 and Sept. 27, 1993. Includes bibliographical references (p. 37-39) and discography (p. 40).

With the advancement of implementation for a novel traffic control device, the Flashing Yellow Arrow (FYA), agencies across the country have continually sought strategies to improve intersection operations and safety, specifically with respect to the left-turn application. More so, permissive left-turn intervals have been communicated to drivers using several traffic signal indications; however, most frequently these phases are represented through the circular green (CG) ball and more recently, the FYA. Previous research in this area determined that the FYA indication produced the most effective communication of permissive left-turns. Further, this previous research led to the inclusion of the FYA in the 2009 edition of the Manual on Uniform Traffic Control Devices (MUTCD). In recent years, agencies across the country have embraced the implementation of the FYA for permissive left-turns. However, there remains a lack of national guidance on the definition of change and clearance intervals for transitioning between protected and permissive left-turns. Complicating the matter is the connection between traditional signal phasing/design and human factors. Investigation through driver comprehension and real-world operations will allow us to not only evaluate current conditions, but also experimental and future conditions. Recommendations provided from this research will ultimately offer agencies with the strategies for the most effective transition from a protected left-turn to a permissive left-turn phase.

Using silicon based microfabrication and materials, a photonic platform, capable of single bioparticle analysis, has been developed. This platform combines liquid and hollow core waveguides on the micron-scale (5 µm x 12 µm) to isolate femtoliter sized sample volumes. Fluorescence excitation and signals in the visible range are directed into and out of the sample volume at an orthogonal angle to maximize signal-to-noise. In order to guide light in a low-index material antiresonant reflecting optical waveguides (ARROWs) were incorporated into the platform. This thesis reveals the development path of these structures over several device generations including innovations in material, geometries, and fabrication techniques to increase detection sensitivity. As a result of these developments, this photonic platform has shown to successfully detect virus samples and other particles. This thesis also presents a new idea for increasing the signal to noise ratio (SNR) by incorporating Y-splitter devices into the design. Specifically, the 1 x 2 and 1 x 4 splitter structures can be used as orthogonal excitation points to the liquid core waveguide. When fluorescently tagged particles are introduced into the hollow core, these points create an optical signal that is correlated in time and space. The data collected by a photodetector can then be processed by an algorithm to increase SNR. Such advancements have shown to increase the SNR by 175 times.

This thesis presents an analysis of the signal-to-noise ratio in liquid core anti-resonant reflecting optical waveguides (ARROWs) and the application of hydrodynamic focusing to the waveguides. These concepts are presented as a method to improve the detection capabilities of the ARROW platform. The improvements are specifically targeted at achieving single molecule detection (SMD) with the devices. To analyze the SNR of the waveguides a test platform was designed and fabricated. This test platform was then used to examine relationship between the SNR and the location of the excitation region. It was determined that the excitation region should be moved closer to the solid-core. By moving the excitation region closer to the solid-core the distance the signal was required to travel in the hollow-core was reduced. This reduction led to a decrease in optical signal loss and resulted in a more than 2x increase in the SNR. Hydrodynamic focusing in the waveguides was developed as a method to increase the consistency of detection of the devices. In hydrodynamic focusing particles in the sample are forced towards the center of the waveguide with a buffer solution. With the particles focused to the center of the channel the percentage that passed through the excitation region can be increased improving the detection consistency of the device. ARROW chips designed for hydrodynamic focusing were simulated, fabricated, and preliminary testing was performed. Initial results have shown a more than 30% increase in particle focusing.

No description available.

Programming languages traditionally describe computations going one way: a program might compute a hash value from a string, or an encrypted message from a plaintext. However, sometimes it is also of interest to go the other way around: for encryption, we not only want to encrypt messages but also to decrypt them, and to be sure that the decryption correctly reproduces the original message. In an invertible programming language, a single program specifies two directions of a transformation, and the language guarantees that the two correspond as inverses. Invertible languages often require programs to be composed from atomic invertible fragments, a property known as local invertibility. This requirement has connections to applications such as low-energy and quantum computing. However, many invertible algorithms are more naturally expressed as depending unidirectionally on some inputs, e.g., the encryption key—this property is known as partial invertibility. Existing work largely lacks a systematic treatment of partial invertibility, and the connection to the locally invertible paradigm is not yet well-understood. In this thesis, we show that with the right design tradeoff, partial invertibility can be expressed within a locally invertible setting. We present KALPIS, a new functional language supporting expressive partial invertibility, yet maintaining a straightforward locally invertible semantics. This is made formal by a novel arrow combinator language RRARR, with primitives embodying functions, parameterized bijections, and interactions between the two. The formulation is based on recent work on effects in invertible computation, namely the irreversibility effect and the reversible reader. We substantiate the work with a prototype implementation of KALPIS, and demonstrate its utility through a number of nontrivial examples. Further, we give a complete formalization of the two systems, including the operational semantics and type system of KALPIS and a locally invertible interpretation and equational characterization of RRARR. Finally, we give a compositional translation from KALPIS into RRARR, motivating us to call it an arrow metalanguage. Most of the formalization is mechanized using the proof assistant Agda. / Programmeringsspråk beskriver traditionellt beräkningar som går åt ett håll: ett program kan till exempel beräkna ett hash-värde från en sträng eller ett krypterat meddelande från en klartext. Ibland är det dock även av intresse att gå åt andra hållet: vid kryptering vill vi inte bara kryptera meddelanden utan också avkryptera dem, och vara säkra på att avkrypteringen korrekt återskapar det ursprungliga meddelandet. I ett inverterbart programmeringsspråk beskriver ett enskilt program två riktningar av en transformation, och språket garanterar att de två motsvarar varandra som inverser. Inverterbara språk kräver ofta att program konstrueras från enskilt inverterbara komponenter, en egenskap som kallas lokal inverterbarhet. Denna egenskap har kopplingar till tillämpningar som lågenergioch kvantdatorer. Å andra sidan är det ofta naturligt att inverterbara algoritmer beror enkelriktat på vissa indata, till exempel krypteringsnyckeln—något som kallas partiell inverbarhet. Tidigare forskning saknar i stor utsträckning en systematisk behandling av partiell inverterbarhet, och kopplingen till lokal inverterbarhet är ännu inte välförstådd. I denna avhandling visar vi att med rätt designavvägning kan partiell inverterbarhet uttryckas ovanpå en lokalt inverterbar grund. Vi presenterar KALPIS, ett nytt funktionellt språk som stöder uttrycksfull partiell inverterbarhet, samtidigt som det bibehåller en enkel lokalt inverterbar semantik. Detta formaliseras genom ett nytt Arrow-kombinatorspråk RRARR, vars primitiver representerar funktioner, parameteriserade bijektioner och interaktioner mellan de två. Formuleringen baseras på ny forskning om sidoeffekter i inverterbar beräkning, nämligen irreversibilitetseffekten och reversible reader. Vi substantierar arbetet med en prototypimplementation av KALPIS och visar dess användbarhet genom ett antal icketriviala exempel. Dessutom ger vi en komplett formalisering av de två systemen, inklusive operativ semantik och typsystem för KALPIS och en lokalt inverterbar tolkning och ekvationskaraktärisering av RRARR. Slutligen ger vi en kompositionell översättning från KALPIS till RRARR, vilket motiverar oss att kalla det ett Arrow-metaspråk. Det mesta av formaliseringen är mekaniserad med hjälp av bevisassistenten Agda.

In this project I explore visual representation, abstraction, and the interpretation of violence as transformed aesthetic forms. Through drawing and film, I develop a visual language to interpret the subject of war, to allow my audience to experience the dynamics of conflict and to reflect upon the devastating toll that war takes on humanity.

Part importante de l’armement préhistorique pour les périodes récentes (quantitativement et qualitativement), l’archerie représente un objet d’étude riche en développements problématiques. A l’aube de l’introduction progressive de la métallurgie dans les usages techniques, il est intéressant de saisir le ou les processus de transferts mis en œuvre. Transition chronologique (Néolithique/Age du bronze), transition matérielle (types de pièces produites et types de matériaux employés) et transition comportementale sont ainsi envisagées pour parvenir à préciser le statut de cet armement dans les sociétés concernées. En nous basant sur la caractérisation de la panoplie de l’archer, sur l’identification des contextes de fabrication, sur la reconnaissance des champs fonctionnels (utilisations et usagers) et sur l’analyse archéo-balistique des vestiges de traumatismes par flèches dans le cadre de violences interhumaines, il en résulte un ensemble exhaustif qui renouvelle sensiblement la perception de cet armement dans le temps et dans les usages. / For recent prehistory, the archery represents one of the main components of weaponry and, for this reason, it is interesting to examine its impact on societies. At the dawn of the progressive introduction of the metal industry in the technical uses, understanding the process of transfer or implemented is of major interest. Transition time period (Neolithic / Bronze Age), material transition (types of parts produced and types of materials used) and behavioral transition are thus considered for specifying the weapons status in the concerned societies. Here based on the characterization of the archer display, the identification of manufacturing contexts, the recognition of functional fields (uses and users) and the analysis of archaeological remains of ballistic arrow trauma in interpersonal violence contexts, we propose a new recovery of this research field, improving significantly our knowledge and apprehension of these weapons in both time and uses.