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21.
如今,为了努力满足用户对移动数据日益增长的需求,大部分运营商的网络和频段都在满负荷运行。据相关数据显示,2010年用户每月使用的数据流量已经超过了5GB。由于数据增长的关键驱动因素——smartphone的普及率在全球仍低于20%,运营商预计用户每月使用的数据流量仍将继续增长。因此,如何充分利用自身的频谱资源、开发包括TD-LTE在内的不同技术选择的潜力,就成为运营商极为关注的重要课题。  相似文献   
22.
This article used a data set containing information on 1267 households from Kuwait to investigate the determinants of demand for medical care services by examining households’ out-of-pocket expenses. To deal with the problems associated with households’ health expenditure data, a two-part model (TPM) was estimated. Given Kuwait’s demographic composition, the model was estimated for full sample, nationals only and expatriates only. Prior to estimating the model, tests were conducted to select a transformation that reduces problems associated with heteroscedasticity and non-normality of the errors. In addition, tests were performed to determine if differences in the estimated coefficients across population groups were statistically significant.  相似文献   
23.
The mechanisms used to deliver agricultural beneficial management practices (BMPs) can influence the performance of these policies. Research has suggested that agri‐environmental instruments targeted based on specific economic or environmental characteristics can improve policy performance. Using a case study approach, we evaluate the relative performance of different mechanisms to target subsidized water retention pond BMPs to reduce phosphorus (P) runoff in an agriculture dominated subwatershed within the Lake Winnipeg watershed in southern Manitoba. The water retention pond BMPs were targeted based on estimated establishment costs (cost targeting), total phosphorus removal from surface water (benefit targeting), and pond‐specific benefit–cost ratios. The targeting was simulated using predictions of retention pond‐specific P removal from an adapted hydrology model and site‐specific pond construction and land opportunity costs assembled in a geographic information system database. Targeting of water retention pond BMPs has an impact on the cost effectiveness of the policy delivery with benefit–cost targeting being the most cost‐effective approach. Water retention ponds providing higher P removal at lower cost were smaller in size and on land previously used for the production of lower value crops. Le ciblage économique des pratiques de gestion bénéfiques en agriculture pour remédier au ruissellement du phosphore au Manitoba Les mécanismes utilisés pour livrer des pratiques de gestion bénéfiques (PGB) peuvent influencer la performance de ces politiques. Des études suggèrent que le ciblage d'instruments agroenvironnementaux basé sur des caractéristiques économiques ou environnementales précises peut améliorer la performance des politiques. Au moyen d'études de cas, nous évaluons la performance relative de divers mécanismes pour cibler les PGB des bassins de rétention d'eau subventionnés pour réduire le ruissellement de phosphore (P) dans un sous‐bassin du bassin du Lac Winnipeg au sud du Manitoba. Les PGB du bassin de rétention des eaux ont été ciblées en fonction des coûts estimés d'établissement (ciblage des coûts), de l′élimination totale du phosphore de la surface de l'eau (ciblage des bénéfices), et des ratios avantages‐coûts liés au bassin. Le ciblage fut simulé au moyen de prédictions du taux de suppression de P spécifique à chaque bassin de rétention obtenues à partir d'une adaptation d'un modèle hydrologique et d'une base de données d'un système d'information géographique (SIG) contenant les sites de chaque bassin de rétention et le coût d'opportunité du terrain. Le ciblage des PGB des bassins de rétention d'eau a un impact sur la rentabilité de la mise en ?uvre de politiques, le ciblage coût‐avantages étant l'approche la plus rentable. Les bassins de rétention d'eau ayant le plus haut taux d'élimination de P à moindre coût s'avéraient plus petits et sur des terrains ayant servi, auparavant, à la production de cultures de moindre valeur.  相似文献   
24.
To achieve sustainability in heritage tourism, tourists should be placed at the heart of the management and planning processes. Indicators and standards-based frameworks were developed in the field of outdoor recreation management to manage and measure crowding and other problematic issues in parks and related areas. Using normative theory and visual research methods, this article aims to examine crowding standards of tourists at Petra Archaeological Park, and compare these standards between the types of heritage tourists suggested by a model developed by Bob McKercher. Results showed that tourists’ acceptability levels go down with an increasing number of tourists, and tourists who are highly motivated to visit heritage sites (i.e. purposeful and sightseeing heritage tourists) had the most restrictive acceptable number of tourists at the park. The normative standards formulated in this article provided a guidance to manage crowding at Petra.  相似文献   
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26.
This paper attempts to critically analyze how successful China has been in applying the OECD principles of corporate governance. In doing so, assessment has been made in light of the six core issues of the OECD principles. A satisfactory level of progress has been noted in China’s legal and regulatory framework since the 1990s. New laws, regulations, and rules have been enacted, existing ones have been amended, and all the required institutions have been built accordingly in order to ensure good corporate governance practices in the country. However, there are still bottlenecks in terms of the enforcement of these laws, regulations, and rules mainly due to the various structural limitations in the Chinese administration and judiciary. The paper argues that China should now move forward with an accelerated enforcement agenda in the area of corporate governance in order to make China Inc. more competitive and sustainable.  相似文献   
27.
Energy policy, environmental planning and economic development play a key role in sustainable development. Sustainable development requires suitable and strategic policies satisfying multiple and conflicting objectives. Fuzzy goal programming (FGP) is a well-known approach in multi-criteria decision-making for its practical application. In this article, a FGP approach is proposed to analyse environmental, energy and sustainability goals of India by the year 2030 with reference to the key economic sectors of India. The presented model analyses the improvement opportunities, requirement of efforts and implementation of the sustainable development plans. Numerical illustration is also provided for validation and application of the proposed model.  相似文献   
28.
Accurate assessment of farmers' credit constraint condition is important in order to understand the circumstances under which credit would have its greatest impact. In this study a switching regression model was used to determine the impact of credit on smallholder dairy farms in the East African highlands using farm level data from Ethiopia and Kenya. Farmers were classified as credit constrained or credit non-constrained based on their responses from the farm level surveys. No consistent relationship was found between farmers' credit constraint condition and their borrowing status. Most of the variation in milk output per farm was explained by the number of crossbred milking cows in the dairy herd. As credit is likely to facilitate investment in crossbred dairy cows it will have substantial impacts on smallholder dairy farms especially if it is targeted to credit constrained farms.  相似文献   
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30.
The need of exchange rate forecasting in order to preventing its disruptive movements has engrossed many policy-makers and economists for many years. The determinants of exchange rate have grown manifold making its behavior complex, nonlinear and volatile so that nonlinear models have better performance for its forecasting. In this study the accuracy of ANFIS as the nonlinear model and ARIMA as the linear models for forecasting 2, 4 and 8 days ahead of daily Iran Rial/∈ and Rial/US$ was compared. Using forecast evaluation criteria we found that nonlinear model outperforms linear model in all three horizons.  相似文献   
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