Tourist Photographers and the Promotion of Travel: the Polytechnic Touring Association, 1888–1939

The Polytechnic Touring Association (PTA) was a London-based, originally philanthropic turned commercial travel firm whose historical origins coincided with the arrival of the Kodak camera in 1888 – thus, of popular (tourist) photography. This article examines the PTA’s changing relationship with tourist photographers, and how this influenced the company’s understanding of what role photography could play in promoting the tours, in the late nineteenth and early twenty century. This inquiry is advanced on the basis of the observation that, during this time, the PTA’s passage from viewing tourists as citizens to educate, to customers to please, paralleled the move from using photography-based images to mixed media. Such a development was certainly a response to unprecedented market demands; this article argues that it should also be considered in relation to the widening of photographic perceptions engendered by the democratization of the medium, to which the PTA responded, first as educator, then as service provider. In doing so, the article raises several questions about the shifting relationship between “high”, or established, and “low”, or emerging, forms of culture, as mass photography and the mass marketing of tourism developed

The emergence of modern statistics in agricultural science : Analysis of variance, experimental design and the reshaping of research at Rothamsted Experimental Station, 1919–1933

During the twentieth century statistical methods have transformed research in the experimental and social sciences. Qualitative evidence has largely been replaced by quantitative results and the tools of statistical inference have helped foster a new ideal of objectivity in scientific knowledge. The paper will investigate this transformation by considering the genesis of analysis of variance and experimental design, statistical methods nowadays taught in every elementary course of statistics for the experimental and social sciences. These methods were developed by the mathematician and geneticist R. A. Fisher during the 1920s, while he was working at Rothamsted Experimental Station, where agricultural research was in turn reshaped by Fisher’s methods. Analysis of variance and experimental design required new practices and instruments in field and laboratory research, and imposed a redistribution of expertise among statisticians, experimental scientists and the farm staff. On the other hand the use of statistical methods in agricultural science called for a systematization of information management and made computing an activity integral to the experimental research done at Rothamsted, permanently integrating the statisticians’ tools and expertise into the station research programme. Fisher’s statistical methods did not remain confined within agricultural research and by the end of the 1950s they had come to stay in psychology, sociology, education, chemistry, medicine, engineering, economics, quality control, just to mention a few of the disciplines which adopted them

Precision flexible machining cells within a manufacturing system

Robotics Institut

Precision flexible machining cells within a manufacturing system

Robotics Institut

Stereolithographic Injection Molds for Direct Tooling

The use of stereolithographic core and cavity sets in low volume injection molding is experiencing steady growth. The use of plastic instead of metal molds raises several issues in terms ofmold handling, material injection and process cycle requirements. This study focuses on identifying and understanding these issues and optimizing them for low volume direct tooling applications. Some experimental observations are presented using DuPont Somos® epoxy photopolymers and representative mold geometries which identify the critical mold properties that influence mold life and the injection molded part quality.Mechanical Engineerin

Abstract Dynamic Ray Scheduling to Improve Ray Coherence and Bandwidth Utilization

The performance of full-featured ray tracers has historically been limited by the hardware’s floating point computational power. However, next generation multi-threaded multi-core architectures promise to provide sufficient CPU throughput to support real time frame rates. In such systems, limited memory system performance in terms of both on-chip cache and DRAM-to-cache bandwidth is likely to bound overall system performance. This paper presents a novel ray tracing algorithm that both improves cache utilization and reduces DRAM-to-cache bandwidth usage. The key insight is to view ray traversal as a scheduling problem, which allows our algorithm to match ray traversal computations and intersection computations with available system resources. Using a detailed simulator, we show that our algorithm significantly reduces the amount of data brought into the cache in exchange for the small overhead of maintaining the ray schedule. Moreover, our algorithm creates units of work that are more amenable to parallelization than traditional Whitted-style ray tracers. Index Terms: I.3.7 [Computer Graphics]: Ray Tracing—