123 research outputs found
Strategy Workshops and Strategic Change
Despite the attention that strategic change as a topic of research has received, there remain considerable difficulties in conceptualizing the actual sources of strategic change. Strategy workshops represent one obvious and explicit research site since organizations often use such events as a means of effecting or initiating strategic change. This paper examines empirical data from ninety-nine strategy workshops in ten separate organizations to address the research question: Do strategy workshops produce strategic change? The paper concludes that workshops can produce change but that one-off workshops are much less effective than a series of workshops. The data presented indicates that the elapsed duration of the entire series of workshops, the frequency of workshops, the scope and autonomy of the unit concerned, and the seniority of participants have an impact on the success or failure of the venture
Strategy Workshops and Strategic Change
Despite the attention that strategic change as a topic of research has received, there remain considerable difficulties in conceptualizing the actual sources of strategic change. Strategy workshops represent one obvious and explicit research site since organizations often use such events as a means of effecting or initiating strategic change. This paper examines empirical data from ninety-nine strategy workshops in ten separate organizations to address the research question: Do strategy workshops produce strategic change? The paper concludes that workshops can produce change but that one-off workshops are much less effective than a series of workshops. The data presented indicates that the elapsed duration of the entire series of workshops, the frequency of workshops, the scope and autonomy of the unit concerned, and the seniority of participants have an impact on the success or failure of the venture.Co-production of Knowledge; Engaged Scholarship; Strategic Change; Strategy as Practice; Strategy Workshops
Complexity theory
No abstract available
How effective are MPAs in conserving crab stocks? A comparison of fisheries and conservation objectives in three coastal MPAs in Thailand
Mangrove forest ecosystems support aquatic species important to tropical fishing communities, but habitat degradation and over-fishing have caused coastal fishery stocks to decline. Marine Protected Areas (MPAs) are widely promoted as a management option to reverse this situation. Using swimming crabs as indicator species, this paper explores the ecological effectiveness of two community-led MPAs and one co-managed MPA in Ranong and Phang-nga Provinces in southern Thailand. Comparisons were made of two fisheries objectives: catch per unit effort (CPUE); and size frequency distribution of Portunus spp. and Scylla olivacea; and one conservation objective: catch composition on benthic aquatic species, between each managed area and an associated control site to look for effects of management. Eight replicates of each survey were undertaken in each site: four in the wet season, from May to July 2011; and four in the dry season, from February to March 2012. Two of the MPAs, one a no-take zone and one a gear limitation zone, and both managed by local communities, showed a significant increase in CPUE of target species compared with their controls to the benefit of local fishers. There was little evidence of management impact on the composition of benthic aquatic species so community management is not achieving wider conservation in terms of increased biodiversity. The third MPA, a seasonal no-take zone, co-managed by local communities and local government, showed no significant effect on either CPUE of target species, or composition of benthic aquatic species when compared to its control. For size frequency distribution, a higher abundance of all size classes of Portunus pelagicus was observed in all MPAs compared to their control sites. The size distribution of animals suggests that the community-managed MPAs are supporting recruits and contributing to the fisheries by reducing the rates of growth overfishing. To conclude, the two community-led MPAs benefitted fishers but had no effect on marine biodiversity, while the co-managed MPA did not benefit fishers or marine biodiversity. However, all three MPAs showed increase crab abundance in each size class
Stroke saturation on a MEMS deformable mirror for woofer-tweeter adaptive optics
High-contrast imaging of extrasolar planet candidates around a main-sequence
star has recently been realized from the ground using current adaptive optics
(AO) systems. Advancing such observations will be a task for the Gemini Planet
Imager, an upcoming "extreme" AO instrument. High-order "tweeter" and low-order
"woofer" deformable mirrors (DMs) will supply a >90%-Strehl correction, a
specialized coronagraph will suppress the stellar flux, and any planets can
then be imaged in the "dark hole" region. Residual wavefront error scatters
light into the DM-controlled dark hole, making planets difficult to image above
the noise. It is crucial in this regard that the high-density tweeter, a
micro-electrical mechanical systems (MEMS) DM, have sufficient stroke to deform
to the shapes required by atmospheric turbulence. Laboratory experiments were
conducted to determine the rate and circumstance of saturation, i.e. stroke
insufficiency. A 1024-actuator 1.5-um-stroke MEMS device was empirically tested
with software Kolmogorov-turbulence screens of r_0=10-15cm. The MEMS when
solitary suffered saturation ~4% of the time. Simulating a woofer DM with ~5-10
actuators across a 5-m primary mitigated MEMS saturation occurrence to a
fraction of a percent. While no adjacent actuators were saturated at opposing
positions, mid-to-high-spatial-frequency stroke did saturate more frequently
than expected, implying that correlations through the influence functions are
important. Analytical models underpredict the stroke requirements, so empirical
studies are important.Comment: 16 pages, 10 figure
Recommended from our members
Amplitude variations on the Extreme Adaptive Optics testbed
High-contrast adaptive optics systems, such as those needed to image extrasolar planets, are known to require excellent wavefront control and diffraction suppression. At the Laboratory for Adaptive Optics on the Extreme Adaptive Optics testbed, we have already demonstrated wavefront control of better than 1 nm rms within controllable spatial frequencies. Corresponding contrast measurements, however, are limited by amplitude variations, including those introduced by the micro-electrical-mechanical-systems (MEMS) deformable mirror. Results from experimental measurements and wave optic simulations of amplitude variations on the ExAO testbed are presented. We find systematic intensity variations of about 2% rms, and intensity variations with the MEMS to be 6%. Some errors are introduced by phase and amplitude mixing because the MEMS is not conjugate to the pupil, but independent measurements of MEMS reflectivity suggest that some error is introduced by small non-uniformities in the reflectivity
MEMS practice, from the lab to the telescope
Micro-electro-mechanical systems (MEMS) technology can provide for deformable
mirrors (DMs) with excellent performance within a favorable economy of scale.
Large MEMS-based astronomical adaptive optics (AO) systems such as the Gemini
Planet Imager are coming on-line soon. As MEMS DM end-users, we discuss our
decade of practice with the micromirrors, from inspecting and characterizing
devices to evaluating their performance in the lab. We also show MEMS wavefront
correction on-sky with the "Villages" AO system on a 1-m telescope, including
open-loop control and visible-light imaging. Our work demonstrates the maturity
of MEMS technology for astronomical adaptive optics.Comment: 14 pages, 15 figures, Invited Paper, SPIE Photonics West 201
Performance of MEMS-based visible-light adaptive optics at Lick Observatory: Closed- and open-loop control
At the University of California's Lick Observatory, we have implemented an
on-sky testbed for next-generation adaptive optics (AO) technologies. The
Visible-Light Laser Guidestar Experiments instrument (ViLLaGEs) includes
visible-light AO, a micro-electro-mechanical-systems (MEMS) deformable mirror,
and open-loop control of said MEMS on the 1-meter Nickel telescope at Mt.
Hamilton. In this paper we evaluate the performance of ViLLaGEs in open- and
closed-loop control, finding that both control methods give equivalent Strehl
ratios of up to ~ 7% in I-band and similar rejection of temporal power.
Therefore, we find that open-loop control of MEMS on-sky is as effective as
closed-loop control. Furthermore, after operating the system for three years,
we find MEMS technology to function well in the observatory environment. We
construct an error budget for the system, accounting for 130 nm of wavefront
error out of 190 nm error in the science-camera PSFs. We find that the dominant
known term is internal static error, and that the known contributions to the
error budget from open-loop control (MEMS model, position repeatability,
hysteresis, and WFS linearity) are negligible.Comment: 16 pages, 13 figures, to appear in Proc. SPIE 2010 Vol. 7736 Adaptive
Optics Systems II, high-resolution full-color version available at
http://spiedl.org
A comparative analysis of three marine governance systems for implementing the Convention on Biological Diversity (CBD)
Successful implementation of the Convention on Biological Diversity (CBD) requires critical reflection on governance structures especially in the biodiverse tropics where institutional capacity is weak and fragmented. This paper explores three modes of marine governance in Thailand and discusses the challenges each faces when delivering conservation and sustainable development objectives. Focusing on Marine Protected Areas (MPA), the dominant management approaches to biodiversity conservation, centralised, decentralised and shared governance, are scrutinised through a review of the literature and 24 key informant interviews with leading Thai academics, national and regional government officers and NGOs. We find both the centralised, state-managed MPA system and the decentralised, community-based MPA system to have severe limitations, for different reasons, in protecting biodiversity, whereas shared governance, despite being less common, is the best intermediate mode. Shared governance is the most viable option available in Thailand for working towards key CBD targets because: (1) local participation can legitimise much of the relationship with the centralised system and can help embed a decentralised system in natural resources management; (2) the centralised system will still remain in ultimate control, which, whilst not favoured by those who want decentralisation, will satisfy powerful elites, and offer more opportunity to empower local people to take responsibility for conservation targets; and (3) the capacity of both local and national stakeholders can be built to deal with the complexity of the marine environment
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