871 research outputs found
THE RIGHTS GRANTED TO TRADE UNIONS UNDER THE COMPANIES ACT 71 OF 2008
With the entering into force of the Companies Act 71 of 2008 in 2011 a number of rights were granted to trade unions by the act. The Companies Act 71 of 2008 not only grants rights to registered trade unions, as is the case in labour law, but in some cases it grants rights to trade unions representing employees at the workplace. It is argued that rights afforded to trade unions by the act ought to be granted only to trade unions that are registered in terms of the Labour Relations Act 66 of 1995. In addition, it is also argued that the Companies Act 71 of 2008 ought in principle to differentiate between rights that are granted to registered trade unions representing employees at the workplace and rights that are granted to registered majority trade unions, or at the least to sufficiently representative trade unions
Groepsbenadering in die bedryfspsigologie*
Gedurende die ontwikkeling van enige vakwetenskap word gewoonlik aksentverskuiwinge aangetref, en as dit ’n toegepaste vakwetenskap is, wat moet tred hou met die ontwikkelinge in die praktyk, kan sulke aksentverskuiwings geweldig groot wees
Spatial description of leased rural state land inconsistent with the cadastre : its capture and maintenance on an alphanumeric and spatial database.
Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.Leasing of state land under control of the Department of Land Affairs takes place, due to historical reasons, in a manner that is unconformable with the cadastre. The Department (and the State) is obliged to manage its assets efficiently and promote land reform. How can such leases be described spatially, and captured on a land information system? The author argues that it is indeed possible to develop a method, system or convention of spatial description for leased areas unconformable with the cadastre by relating it to the cadastre and capture and maintain data on such areas on a spatially and text-based database. In order to identify relevant best practices, available technology, a review was carried out on methodologies from other countries within the fields of land administration and land information systems, focussing on parcel-based cadastral systems. Fieldwork consisted firstly of interviews with officials and specialists in these fields for more information on the management of leases in the Department and available technology. A full set of active leases (52) from a District Office was acquired for analysis on current spatial descriptions. In a second visit some of these leased areas were surveyed by GPS to construct maps to aid with the development of a convention. Based on this work, the author developed a methodology/convention for indexing and spatial description of unconformable leases, with the current South African cadastre and embedded 21-character land parcel identifier as basis. It was demonstrated that basic technology could be used in the field, supported by an advanced land information system. The value of the convention lies in the fact that it relates the unconformable leases back to the formal cadastre within a land information system Administration of leases will be more effective. Also that it could be applied to other spheres of land reform and non-parcel based geocoding of centroids indicating occupational or communal rights on land
Escapement of the Cape rock lobster (Jasus lalandii ) through the mesh and entrance of commercial traps
Metal-framed traps covered with polyethylene mesh used in the fishery for the South African Cape rock lobster (Jasus lalandii) incidentally capture large numbers of undersize (<75 mm CL) specimens. Air-exposure, handling, and release
procedures affect captured rock lobsters and reduce the productivity of the stock, which is heavily fished.
Optimally, traps should retain legalsize rock lobsters and allow sublegal animals to escape before traps are hauled. Escapement, based on lobster morphometric measurements, through meshes of 62 mm, 75 mm, and 100 mm was investigated theoretically under controlled conditions in an aquarium, and during field trials. SELECT models were used to model
escapement, wherever appropriate. Size-selectivity curves based on the logistic model fitted the aquarium and field data better than asymmetrical Richards curves. The lobster length at 50% retention (L50) on the escapement curve for 100-mm mesh in the aquarium (75.5 mm CL) approximated the minimum legal size (75 mm CL); however estimates of L50 increased to 77.4 mm in field trials where trapentrances
were sealed, and to 82.2 mm where trap-entrances were open.
Therfore, rock lobsters that cannot escape through the mesh of sealed field traps do so through the trap entrance of open traps. By contrast, the wider selection range and lower
L25 of field, compared to aquarium, trials (SR = 8.2 mm vs. 2.6 mm; L25 =73.4 mm vs. 74.1 mm), indicate that small lobsters that should be able to escape from 100-mm mesh
traps do not always do so. Escapement from 62-mm mesh traps with open entrance funnels increased by 40−60% over sealed traps. The findings of this study with a known size
distribution, are related to those of a recent indirect (comparative) study for the same species, and implications for trap surveys, commercial catch rates, and ghost fishing are discussed
The utility of practical theology: mapping the domain, goals, strategies and criteria of practical theological research
Historically practical theology entered the theological encyclopaedia as a discipline of ‘crises’ in the praxis which ministers, congregations and churches experienced in making the Christian tradition relevant in the life of individuals, communities or in society as a whole. Among scholars in practical theology there is a deep consensus that practical theology starts with practical concerns and contributes to practice, but what is the utility of practical theology? This article want to ‘deconstruct’ the consensus that all practical theology is by default practical. If practical theology wants to construct knowledge about the improvement of practice, some strategies are preferable compared to other strategies. The question of utility refers to the methodological criteria of empirical research regarding (a) the object of research or the problem to be solved, (b) the needs of the stakeholders as to the research and its results and, (c) the type of knowledge to be produced. If utility is the target of practical theological research, then the question is which research strategies meet these methodological criteria better than other criteria. Some research strategies are strong on reaching certain goals, but are weak regarding other goals. It is only in the complexity of the type of knowledge, research strategy and methodological criteria that the focus on practice orientation can be decided
MECHANICS OF AMPUTEE JUMPING – JOINT WORK
The purpose of this study was determine if dynamic elastic response (DER) prostheses could absorb energy in the eccentric phase of a vertical jump performed by trans-tibial amputees phase and return this energy in the propulsive phase. Further, given the active nature of the ankle, the study aimed to determine the mechanisms required at the remaining joints to compensate for the pathological ankle. Six amputee (AMP) and 10 able-bodied participants (AB) performed maximal vertical jumps on two force plates which were synchronised with a 9-camera VICON infra red system. The amputees did not jump as high as the AB participants. Only minimal negative work was recorded at the prosthetic ankle in the eccentric phase which resulted in minimal positive work at the ankle in the concentric phase. The intact side produced greater work than the affected side in the concentric phase. The amputees generally adopted a hip strategy to generate positive work. The work recorded at the knee was reduced on the intact and affected side and indicates the prosthesis influences the movement on both sides. To enable amputees to participate in activities which require jumping, prostheses need to be developed and amputees need to be taught how to adjust their biomechanics to store and release energy in the prosthesis
MECHANICS OF AMPUTEE JUMPING – CONSIDERATION FOR LOADING
Amputees must develop compensatory mechanisms to overcome the constraints imposed by a mechanical prosthesis. In completing a bilateral countermovement jump, amputees must accommodate the limited ankle dorsiflexion angle and adapt to the limited plantar-flexor moment that occurs at the prosthetic joint. The aim of this research was to determine the loading on the limbs and the joint kinetics adopted by transtibial amputees in order to achieve a jump. Six amputee (AMP) and 10 able-bodied (AB) participants performed maximal vertical jumps on two force plates while kinematic data was recorded using a 9-camera VICON infrared system. The amputees did not jump as high as the AB participants. The AMPs raised the prosthetic heel from the floor to compensate for the restricted motion at the ankle. Consequently, kinematic symmetry was maintained at the knee and the hip. The knee flexion places the prosthetic shank in a more horizontal position. This is a vulnerable position due to the reduced strength in the knee extensors as a consequence of the amputation. In order to reduce the instability and loading at the knee, the maximum propulsive vGRF on the prosthetic side was reduced and the intact limb assumed a dominant role. Until amputees can take the loading on the prosthetic side, it is not recommended that they participate in jumping
LABCAT: Locally adaptive Bayesian optimization using principal component-aligned trust regions
Bayesian optimization (BO) is a popular method for optimizing expensive
black-box functions. BO has several well-documented shortcomings, including
computational slowdown with longer optimization runs, poor suitability for
non-stationary or ill-conditioned objective functions, and poor convergence
characteristics. Several algorithms have been proposed that incorporate local
strategies, such as trust regions, into BO to mitigate these limitations;
however, none address all of them satisfactorily. To address these
shortcomings, we propose the LABCAT algorithm, which extends trust-region-based
BO by adding principal-component-aligned rotation and an adaptive rescaling
strategy based on the length-scales of a local Gaussian process surrogate model
with automatic relevance determination. Through extensive numerical experiments
using a set of synthetic test functions and the well-known COCO benchmarking
software, we show that the LABCAT algorithm outperforms several
state-of-the-art BO and other black-box optimization algorithms
It often howls more than it chugs: Wind versus ship noise under water in Australia’s maritime regions
Marine soundscapes consist of cumulative contributions by diverse sources of sound grouped into: physical (e.g., wind), biological (e.g., fish), and anthropogenic (e.g., shipping)—each with unique spatial, temporal, and frequency characteristics. In terms of anthropophony, shipping has been found to be the greatest (ubiquitous and continuous) contributor of low-frequency underwater noise in several northern hemisphere soundscapes. Our aim was to develop a model for ship noise in Australian waters, which could be used by industry and government to manage marine zones, their usage, stressors, and potential impacts. We also modelled wind noise under water to provide context to the contribution of ship noise. The models were validated with underwater recordings from 25 sites. As expected, there was good congruence when shipping or wind were the dominant sources. However, there was less agreement when other anthropogenic or biological sources were present (i.e., primarily marine seismic surveying and whales). Off Australia, pristine marine soundscapes (based on the dominance of natural, biological and physical sound) remain, in particular, near offshore reefs and islands. Strong wind noise dominates along the southern Australian coast. Underwater shipping noise dominates only in certain areas, along the eastern seaboard and on the northwest shelf, close to shipping lanes
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