Darwinism, organizational evolution and survival: key challenges for future research

How do social organizations evolve? How do they adapt to environmental pressures? What resources and capabilities determine their survival within dynamic competition? Charles Darwin’s seminal work The Origin of Species (1859) has provided a significant impact on the development of the management and organization theory literatures on organizational evolution. This article introduces the JMG Special Issue focused on Darwinism, organizational evolution and survival. We discuss key themes in the organizational evolution research that have emerged in recent years. These include the increasing adoption of the co-evolutionary approach, with a particular focus on the definition of appropriate units of analysis, such as routines, and related challenges associated with exploring the relationship between co-evolution, re-use of knowledge, adaptation, and exaptation processes. We then introduce the three articles that we have finally accepted in this Special Issue after an extensive, multi-round, triple blind-review process. We briefly outline how each of these articles contributes to understanding among scholars, practitioners and policy makers of the continuous evolutionary processes within and among social organizations and systems

3D Deformable Hand Models

We are interested in producing a 3D deformable model of the human hand, for use in a tracking application. Statistical methods can be used to build such a model from a set of training examples; however, a key requirement for this is the collection of landmark coordinate data from these training examples. To produce a good model, hundreds of landmarks are required from each example; collecting this data manually is infeasible. We present a method for capturing landmark data which makes use of standard physically-based models. The process is semi-automatic -- key features are located by hand, and a physical model is deformed under the action of various forces to fit the image data. We demonstrate how the technique can be used to build a 3D Point Distribution Model from 3D MRI data, using a Simplex Mesh. 1 Introduction Statistical shape models have already proved useful in many computer vision tasks involving the location and tracking of deformable objects, including our own work on hand..

Evidence-based practice: Tools and techniques.

Evidence-based practice (EBP) requires the conscious, conscientious and explicit application of the best available research evidence, together with professional expertise and patient/customer choice, to work practices. From its origins in clinical medicine, through a broader application to the health services industry, an evidence-based approach to work practices is becoming increasingly influential in all human services. Implementing evidence-based practice is related to the organisational management concepts of Continuous Quality Improvement (CQI), Knowledge Management and the Learning Organisation. For human services professionals finding, critically appraising and applying best evidence requires enhanced information and knowledge management skills. Central to these skills is an understanding of the information ecology, particularly for the multi-disciplinary AOD field. This paper introduces the data-information-knowledge continuum, levels of evidence and the tools and techniques of finding and critically appraising evidence. Examples relevant to the AOD field are provided

Photobook: Content-Based Manipulation of Image Databases

We describe the Photobook system, which is a set of interactive tools for browsing and searching images and image sequences. These query tools differ from those used in standard image databases in that they make direct use of the image content rather than relying on text annotations. Direct search on image content is made possible by use of semantics-preserving image compression, which reduces images to a small set of perceptually-significant coefficients. We describe three types of Photobook descriptions in detail: one that allows search based on appearance, one that uses 2-D shape, and a third that allows search based on textural properties. These image content descriptions can be combined with each other and with textbased descriptions to provide a sophisticated browsing and search capability. In this paper we demonstrate Photobook on databases containing images of people, video keyframes, hand tools, fish, texture swatches, and 3-D medical data

Shoulder joint contact force during lever-propelled wheelchair propulsion

The aim of this study was to obtain quantitative results about shoulder contact force during wheelchair lever propulsion when the gear ratio of the lever propulsion mechanism is changing. The effect of the gear ratio on the shoulder contact force was investigated for few different wheelchair loading. For the experiments we designed a special mechatronic wheelchair simulator that allowed the simulation of different gear ratios ofthe wheelchair lever propulsion mechanism and simulation of different road inclinations. The same simulator was also used for simulation of a hand rim propelled wheelchair. We conducted also a hand rim propulsion experiment and used the results from it for comparison with the lever propulsion data. Four nondisabled male adults with no prior wheeling experience participated in the experiment. In the first tests, a lever propelled wheelchair was simulated with the simulator. The target speed of the wheelchair was set to 2 km/h. For the test the gear ratio was varied from 1.5 to 1/1.5. A load torque was applied to the rear wheels to imitate road inclinations of 0, 2° and 4°.ln the second part of the test, the simulator was structured to simulate a hand rim propelled wheelchair. The participants were asked to keep the same speed (2 km/h) and the simulator was set sequentially to imitate climbing a ramp inclined on 0°,2° and 4°. Kinematic data of the body were collected by a motion capture system. Kinetic data such as hand force and driving torque, were measured by instrumented wheels with incorporated six-axis force sensor. The intersegmental joint forces and moments were calculated from the obtained kinematic and kinetic data via inverse dynamics analysis procedure. Muscle forces were computed from the measured joint moments by using an optimization approach. Shoulder joint contact force, which indicates the joint surface loading, was computed as a synthetic vector of the intersegmental force for shoulder joint acquired from the inverse dynamics analysis and the compressive forces from muscles, tendons, ligaments and cartilages crossing the shoulder joint It was observed that the decrease of the gear ratio causes increased cycle frequency and reduces the shoulder joint contact force. Result showed that the shoulder joint contact force during lever propulsion with a gear ratio 1/1.5 was up to 70% lower than the shoulder joint contact force during handrim propulsion. The results from this study could be used in the design of new lever propulsion mechanisms that reduce the risks of secondary shoulder disorders and increase user's comfort

Segmentation of Biological Volume Datasets Using a Level-Set Framework

This paper presents a framework for extracting surface models from a broad variety of volume datasets. These datasets are produced from standard 3D imaging devices, and are all noisy samplings of complex biological structures with boundaries that have low and often varying contrasts. The level set segmentation method, which is well documented in the literature, creates a new volume from the input data by solving an initial-value partial differential equation (PDE) with user-defined feature-extracting terms. However, level set deformations alone are not sufficient, they must be combined with powerful initialization techniques in order to produce successful segmentations. Our level set segmentation approach consists of defining a set of suitable pre-processing techniques for initialization and selecting/tuning different feature-extracting terms in the level set algorithm. This collection of techniques forms a toolkit that can be applied, under the guidance of a user, to segment a variety of volumetric data.