South Africa's domestic intermodal imperative

The original publication is available at http://www.journals.elsevier.com/research-in-transportation-business-and-management/An integrated alternative to road only or rail only transport does not exist in South Africa for domestic freight. This is in spite of the fact that national freight logistics costs are high, road infrastructure is challenged and concern for the environmental impact of road transport is increasing. These factors have renewed interest in intermodal transport solutions, which are the focus of this article. The question is whether a viable domestic intermodal solution can be found through segmenting freight flows and developing a business case based on these segments. The research confirms that this is possible and the segmentation and subsequent business case is presented. The results demonstrate that building three intermodal terminals to connect the three major industrial hubs – Gauteng, Durban and Cape Town – through an intermodal solution could reduce transport costs (including externalities) for the identified 22.9 million tons of intermodal freight flows on the Cape and the Natal corridors by 64% (including externalities).Post-prin

A logistics barometer for South Africa : towards sustainable freight mobility

CITATION: Havenga, J. H., et al. 2016. A logistics barometer for South Africa: towards sustainable freight mobility. Transport and Supply Chain Management, 10(1), a228, doi:10.4102/jtscm.v10i1.228.The original publication is available at http://www.jtscm.co.zaENGLISH SUMMARY : Background: South Africa has a disproportionately high freight transport demand owing to industrial development far from ports, low domestic beneficiation and improper modal use. Historical freight transport policy supported primary economic development, failing to preempt the changing economic structure and the resulting freight transport needs, resulting in excessive transport costs and externalities. Objectives: To share the macroeconomic freight transport challenges revealed by South Africa’s Logistics Barometer, and to identify key interventions to address these. Method: Freight flows are modelled by disaggregating the national input–output model into 83 commodity groupings and 372 geographical areas, culminating in a 30-year forecast at 5-year intervals for three scenarios, followed by distance-decay gravity modelling to determine freight flows. Logistics costs are calculated by relating these flows to the costs of fulfilling associated logistic functions. Results: Long-distance transport remains the largest general freight typology and is, due to inefficient macro logistics design, extremely costly, both in terms of intrinsic and extrinsic costs. Conclusion: South Africa’s freight task will grow 2.5-fold by 2043. Logistics and externality costs are already untenable at current levels. The development of domestic intermodal solutions will support the drive towards sustainable freight mobility.http://www.jtscm.co.za/index.php/jtscm/article/view/228Publisher's versio

On Hilberg's Law and Its Links with Guiraud's Law

Hilberg (1990) supposed that finite-order excess entropy of a random human text is proportional to the square root of the text length. Assuming that Hilberg's hypothesis is true, we derive Guiraud's law, which states that the number of word types in a text is greater than proportional to the square root of the text length. Our derivation is based on some mathematical conjecture in coding theory and on several experiments suggesting that words can be defined approximately as the nonterminals of the shortest context-free grammar for the text. Such operational definition of words can be applied even to texts deprived of spaces, which do not allow for Mandelbrot's ``intermittent silence'' explanation of Zipf's and Guiraud's laws. In contrast to Mandelbrot's, our model assumes some probabilistic long-memory effects in human narration and might be capable of explaining Menzerath's law.Comment: To appear in Journal of Quantitative Linguistic

Container terminal spatial planning : a 2041 paradigm for the Western Cape Province in South Africa

The original publication is available at http://www.jtscm.co.za/index.php/jtscm/article/view/59This paper investigates the suitable location for an intermodal inland container terminal (IICT) in the city of Cape Town. A container market segmentation approach is used to project growth for container volumes over a 30-year period for all origin and destination pairings on a geographical district level in an identified catchment area. The segmentation guides the decision on what type of facility is necessary to fulfil capacity requirements in the catchment area and will be used to determine the maximum space requirements for a future IICT. Alternative sites are ranked from most suitable to least suitable using multi-criteria analysis, and preferred locations are identified. Currently, South Africa’s freight movement is dominated by the road sector. Heavy road congestion is thus prevalent at the Cape Town Container Terminal (CTCT). The paper proposes three possible alternative sites for an IICT that will focus on a hub-and-spoke system of transporting freight

A dynamic network analysis of emergent grammar

For languages to survive as complex cultural systems, they need to be learnable. According to traditional approaches, learning is made possible by constraining the degrees of freedom in advance of experience and by the construction of complex structure during development. This article explores a third contributor to complexity: namely, the extent to which syntactic structure can be an emergent property of how simpler entities – words – interact with one another. The authors found that when naturalistic child directed speech was instantiated in a dynamic network, communities formed around words that were more densely connected with other words than they were with the rest of the network. This process is designed to mirror what we know about distributional patterns in natural language: namely, the network communities represented the syntactic hubs of semi-formulaic slot-and-frame patterns, characteristic of early speech. The network itself was blind to grammatical information and its organization reflected (a) the frequency of using a word and (b) the probabilities of transitioning from one word to another. The authors show that grammatical patterns in the input disassociate by community structure in the emergent network. These communities provide coherent hubs which could be a reliable source of syntactic information for the learner. These initial findings are presented here as proof-of-concept in the hope that other researchers will explore the possibilities and limitations of this approach on a larger scale and with more languages. The implications of a dynamic network approach are discussed for the learnability burden and the development of an adult-like grammar

Jet production in charged current deep inelastic e⁺p scatteringat HERA

The production rates and substructure of jets have been studied in charged current deep inelastic e⁺p scattering for Q² > 200 GeV² with the ZEUS detector at HERA using an integrated luminosity of 110.5 pb⁻¹. Inclusive jet cross sections are presented for jets with transverse energies E_{T}^{jet} > 5 GeV. Measurements of the mean subjet multiplicity, 〈n_{sbj}〉, of the inclusive jet sample are presented. Predictions based on parton-shower Monte Carlo models and next-to-leading-order QCD calculations are compared to the measurements. The value of α_{s} (M_{z}), determined from 〈n_{sbj}〉 at y_{cut} = 10⁻² for jets with 25 < E_{T}^{jet} < 119 GeV, is α_{s} (M_{z}) = 0.1202 ± 0.0052 (stat.)_{-0.0019}^{+0.0060} (syst.)_{-0.0053}^{+0.0065} (th.). The mean subjet multiplicity as a function of Q² is found to be consistent with that measured in NC DIS

Comparing phoneme frequency, age of acquisition, and loss in aphasia:Implications for phonological universals

Phonological complexity may be central to the nature of human language. It may shape the distribution of phonemes and phoneme sequences within languages, but also determine age of acquisition and susceptibility to loss in aphasia. We evaluated this claim using frequency statistics derived from a corpus of phonologically transcribed Italian words (phonitalia, available at phonitalia,org), rankings of phoneme age of acquisition (AoA) and rate of phoneme errors in patients with apraxia of speech (AoS) as an indication of articulatory complexity. These measures were related to cross-linguistically derived markedness rankings. We found strong correspondences. AoA, however, was predicted by both apraxic errors and frequency, suggesting independent contributions of these variables. Our results support the reality of universal principles of complexity. In addition they suggest that these complexity principles have articulatory underpinnings since they modulate the production of patients with AoS, but not the production of patients with more central phonological difficulties

Trapping dust particles in the outer regions of protoplanetary disks

In order to explain grain growth to mm sized particles and their retention in outer regions of protoplanetary disks, as it is observed at sub-mm and mm wavelengths, we investigate if strong inhomogeneities in the gas density profiles can slow down excessive radial drift and can help dust particles to grow. We use coagulation/fragmentation and disk-structure models, to simulate the evolution of dust in a bumpy surface density profile which we mimic with a sinusoidal disturbance. For different values of the amplitude and length scale of the bumps, we investigate the ability of this model to produce and retain large particles on million years time scales. In addition, we introduced a comparison between the pressure inhomogeneities considered in this work and the pressure profiles that come from magnetorotational instability. Using the Common Astronomy Software Applications ALMA simulator, we study if there are observational signatures of these pressure inhomogeneities that can be seen with ALMA. We present the favorable conditions to trap dust particles and the corresponding calculations predicting the spectral slope in the mm-wavelength range, to compare with current observations. Finally we present simulated images using different antenna configurations of ALMA at different frequencies, to show that the ring structures will be detectable at the distances of the Taurus Auriga or Ophiucus star forming regions.Comment: Pages 15, Figures 14. Accepted for publication in Astronomy and Astrophysic