The Locations of Wal-Mart and Kmart Supercenters: Contrasting Corporate Strategies     

Thomas O. Graff 《The Professional geographer》1998,50(1):46-57

Wal-Mart and Kmart, the two largest American discount retailers, have begun to utilize a supercenter retailing format that combines a full-service grocery store with a discount department store. Supercenters are expected to be the major format for future expansion of each of these firms. The purpose of this paper is to analyze the spatial expansion strategies of each firm for the locations of its supercenters. Wal-Mart is quickly expanding its number of supercenters in modest-sized communities clustered around its grocery distribution centers, especially in Southern states. Conversely, most Super Kmart Centers are located inthe suburbs of widely scattered major metropolitan markets, and Kmart has yet to develop a grocery distribution network. Kmart currently has major financial problems that severely restrict the expansion of the Super Kmart Center format.  相似文献   

Image Sources for Informal Settlement Management     

S. O. Mason  & C. S. Fraser 《The Photogrammetric Record》1998,16(92):313-330

Informal settlements are a common feature of developing countries. In South Africa the improvement of living conditions in these settlements and the upgrading to formal housing types are regarded as being of central importance to the nation's development. Effective settlement improvement and upgrading activities, which we here term "management", require adequate spatial data. To date, the acquisition of spatial models of informal settlements has been based on conventional mapping techniques, and mostly on photogrammetry. Data are compiled using analogue or analytical methods. These are manual and hence require both considerable expertise and expensive equipment. Moreover, these methods are uneconomical over the often relatively small, densely populated areas covered by informal settlements and are also too expensive to employ with a regularity required to support such tasks as change detection. Alternative imaging sources and mapping techniques are therefore needed.
In this article we examine the problem of spatial information acquisition for informal settlement management from three perspectives: spatial information requirements, the role which imagery can play in satisfying these spatial information requirements, and effective imaging options. We focus on the potential of high resolution satellite imaging, small format digital aerial imagery and digital multispectral video systems for rapid mapping. We also discuss the example of automated shack extraction from aerial imagery.  相似文献   

IAG Newsletter     

O. B. Andersen 《Journal of Geodesy》1998,72(11):666-671

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IAG Newsletter     

O. B. Andersen 《Journal of Geodesy》1998,72(9):557-560

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Comment and reply regarding Changyou Zhang (1995) A general formula and its inverse formula for gravimetric transformation by use of convolution and deconvolution techniques.     

H. Motao  G. Zheng  O. Yongzhong 《Journal of Geodesy》1998,72(11):663-665

The incorrectness in the derivations of error formula (52) in Zhang's paper is pointed out and the correction is given. Table 3 [list of error formulae of Eqs (5)–(8)] in Zhang's paper is also corrected. Received: 25 February 1998 / Accepted: 30 June 1998  相似文献   

Fossils explained 22: Palaeontology of amber   总被引：1，自引：0，他引：1  

GEORGE O. POINAR  JR 《Geology Today》1998,14(4):154-160

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Sapphirine-bearing granulites and related high-temperature metamorphic rocks from the Higo metamorphic terrane, west-central Kyushu, Japan   总被引：7，自引：0，他引：7  

Y. OSANAI  T. HAMAMOTO  O. MAISHIMA  & H. KAGAMI 《Journal of Metamorphic Geology》1998,16(1):53-66

The Higo metamorphic unit in west-central Kyushu island, southwest Japan is an imbricated crustal section in which a sequence of units with increasing metamorphic grade from high (northern part) to low (southern part) structural levels is exposed. The basal part of the metamorphic sequence representing an original depth of 23–24  km consists mainly of garnet–cordierite–biotite gneiss, garnet–orthopyroxene gneiss, orthopyroxene-bearing amphibolite and orthopyroxene-bearing S-type tonalite. These metamorphic rocks underwent high amphibolite-facies up to granulite facies metamorphism with peak P – T  conditions of 720  MPa, 870  °C. In addition sapphirine-bearing granulites and related high-temperature metamorphic rocks also occur as tectonic blocks in a metamorphosed peridotite intrusion. The sapphirine-bearing granulites and their related high-temperature metamorphic rocks can be subdivided into five types of mineral assemblages reflecting their bulk chemical compositions as follows: (1) sapphirine–corundum–spinel–cordierite (2) corundum–spinel–cordierite (3) garnet–corundum–spinel–cordierite (4) garnet–spinel–gedrite–corundum, and (5) orthopyroxene–spinel–gedrite. These metamorphic rocks are characterized by unusually high Al₂O₃ and low SiO₂ contents, which could represent a restitic nature remaining after partial melting of pelitic granulite under the ultra high-temperature contact metamorphism at the peak metamorphic event of the Higo metamorphic unit. The metamorphic conditions are estimated to be about 800  MPa and above 950  °C which took place at about 250  Ma as a result of the thermal effect of the regional gabbroic rock intrusions.  相似文献   

Surface water quality evaluation in Odukpani, Calabar Flank, south-eastern Nigeria   总被引：1，自引：0，他引：1  

O. E. Offiong  A. E. Edet 《Environmental Geology》1998,36(3-4):343-348

 The present article is the second in a series of baseline water quality evaluation studies in parts of south-eastern Nigeria. Study results indicate that the water samples from the study are generally acidic, soft and fresh in addition to low sodium and salinity hazard. Regression equations indicate a good positive correlation between conductivity and Na, Ca, Mg and SO₄. Ca-SO₄ and Ca-Cl constitute the major facies in the area. Generally the waters in the area are good for most domestic and agricultural purposes. Received: 14 April 1997 · Accepted: 3 February 1998  相似文献   

Extractable and total Fe and Mn contents of three sand dune soils in NW Nigeria     

B.A. Raji  V.O. Chude  I.E. Esu 《Journal of Arid Environments》1998,38(4):585-596

The profile distribution of total, diethylene triamine penta-acetic acid (DTPA)- and 0·1 HCl-extractable Fe and Mn were determined in 12 pedons formed on three contiguous sand dunes in the semi-arid savanna of Nigeria. The total Fe and Mn contents varied from 100 to 3750 and 40 to 11,375 μg g⁻¹, respectively. Values of 0·1 HCl-extractable Fe and Mn varied from 8·0 to 123 and 1·5 to 43·5 μg g⁻¹, respectively. The corresponding values of DTPA-extractable Fe and Mn were 4·5 to 16·0 and 1·0 to 38·8 μg g⁻¹. Total Fe and Mn correlated significantly with clay in nearly all the dunes (p≤ 0·01) but were not significantly correlated with organic matter. The 0·1 HCl-extractable Mn had a positive significant correlation with soil pH (r= 0·58*) in Illela dunes but a negative significant correlation with pH in the Sangiwa dunes (r= −0·75***). The values of extractable Fe and Mn in the sand dune soils are above the critical limits reported in other literature, thus deficiencies of these micronutrients do not pose a problem to crop production in the study area.  相似文献   

Water shortage and associated changes in organic nitrogen betweenPappophorum caespitosum(Gramineae) provenances     

S.O. Trione  J.B. Cavagnaro 《Journal of Arid Environments》1998,38(4):519-528

Three provenances ofPappophorum caespitosum, a forage native grass from the temperate arid region of Argentina, were studied to gain a physiological knowledge of the seasonal organic N status in response to adequate water supply and water stress conditions; and to assess the extent to which variations in the N status between these provenances arise under different water regimes. Plant part samples were analysed for free and bound organic N fractions. Water shortage resulted in a significant depression of plant growth in all provenances. Total N concentration declined along the annual cycle in both water treatments, but it was higher under water stress. The size of the free N pool was very large, suggesting that it may act like an osmoticum. Nitrogen use efficiency increases along the growing period, while the rate of N intake and the specific leaf N content decrease. Variability was found between provenances in most of the physiological and biochemical traits examined under both water regimes.  相似文献