Long-term forecasting of fuel demand at theater entry points

Managing the distribution of fuel in theater requires Army fuel planners to forecast demand at the strategic level to ensure that fuel will be in the right place, at the right time, and in the amounts needed. This work presents a simulation approach to forecasting that accounts for the structure of the supply chain network when aggregating the demand of war fighters across the theater over the forecasting horizon. The resulting empirical distribution of demand at the theater entry point enables planners to identify forecast characteristics that impact their planning process, including the amplitudes and temporal positions of peaks in demand, and the estimated lead time to the point of use. Experimentation indicates that the forecasts are sensitive to the pattern of war fighter demand, the precise structure of the in-theater supply chain network, and the constraints and uncertainty present in the network, all of which are critical planning considerations.     

Forecasting the urban skyline with extreme value theory

The world’s urban population is expected to grow fifty percent by the year 2050 and exceed six billion. The major challenges confronting cities, such as sustainability, safety, and equality, will depend on the infrastructure developed to accommodate the increase. Urban planners have long debated the consequences of vertical expansion—the concentration of residents by constructing tall buildings—over horizontal expansion—the dispersal of residents by extending urban boundaries. Yet relatively little work has predicted the vertical expansion of cities and quantified the likelihood and therefore urgency of these consequences.We regard tall buildings as random exceedances over a threshold and use extreme value theory to forecast the skyscrapers that will dominate the urban skyline in 2050 if present trends continue. We predict forty-one thousand skyscrapers will surpass 150 meters and 40 floors, an increase of eight percent a year, far outpacing the expected urban population growth of two percent a year. The typical tall skyscraper will not be noticeably taller, and the tallest will likely exceed one thousand meters but not one mile. If a mile-high skyscraper is constructed, it will hold fewer occupants than many of the mile-highs currently designed. We predict roughly three-quarters the number of floors of the Mile-High Tower, two-thirds of Next Tokyo’s Sky Mile Tower, and half the floors of Frank Lloyd Wright’s The Illinois—three prominent plans for a mile-high skyscraper. However, the relationship between floor and height will vary considerably across cities.     

中国第三产业的战略地位与发展方向

本文分析了第三产业战略地位的演变历史、趋势和成因;通过回归分析揭示了决定第三产业战略地位的第三产业比重的演变规律;从服务型生产资料、服务消费品、GDP贡献份额、就业贡献份额、第三产业比重增大趋势和资源限制的程度等方面,阐述了第三产业在中国国民经济中的重要战略地位.     

中国产品内贸易发展的国际地位与地理方向特征——基于电子机械类产品的经验研究

对中国电子机械类产品内贸易的实证研究表明,中国仍然处于产品生产的低端环节或价值链的低附加值部分,但已经出现产品生产环节或价值链环节的攀升现象。从贸易地理方向上看,中国电子机械类产品内贸易已经从明显的三角贸易模式逐步转为融入到全球生产网络体系中去,具有明显的全球价值分割的特征。鉴于全球产品内贸易的深入发展,欧美不断引发针对中国的贸易争端是不公正的。     

Are analysts' cash flow forecasts useful?

This study provides evidence that the cost of equity capital decreases with the number of analysts who issue both cash flow and earnings forecasts (cash analysts). The evidence also shows that cash analysts reduce information asymmetry and predict long‐term earnings more accurately than analysts who issue only earnings forecasts. Taken together, these findings suggest that cash analysts provide market participants with high‐quality information and, as a result, firms benefit from cash analyst coverage in the form of a reduced cost of equity capital.     

Position limit for the CSI 300 stock index futures market

The aim of this study was to find the optimal position limit for the Chinese stock index (CSI) 300 futures market. A low position limit helps to prevent price manipulations in the spot market, and thus keeps the magnitude of instantaneous price changes within the tolerance range of policymakers. However, setting a position limit that is too low may also have negative effects on market quality. We propose an artificial limit order market with heterogeneous interacting agents to examine the impact of different levels of position limits on market quality, measured as liquidity, return volatility, efficiency of information dissemination, and trading welfare. The simulation model is based on realistic trading mechanisms, investor structure, and order submission behavior observed in the CSI 300 futures market.Our results show that on the basis of the liquidity status in September 2010, raising the position limit from 100 to 300 could significantly improve market quality and at the same time keep the maximum absolute price change per 5 s below the 2% tolerance level. However, the improvement becomes only marginal if the position limit is further increased beyond 300. Therefore, we believe that raising the position limit to a moderate level can enhance the functionality of the CSI 300 futures market, which should benefit the development of the Chinese financial system.     

A fractional cointegration var analysis of exchange rate dynamics

In their seminal work, Baillie and Bollerslev (1994) carried out an analysis of deviations from the cointegrating relationship of seven important exchange rates. They suggested that the exchange rate series possess long memory and therefore such processes could be well described as fractionally integrated processes. Hence, the influence of shocks to the equilibrium exchange rates may only vanish at very long horizons. In this work we analyze the cointegrating structure of five exchange rates to the US dollar, namely the British pound, the Euro, the Swedish Krona, the Canadian Dollar and the Swiss Franc. The series possess long memory and we show that they can be modeled through fractional integration. In fact, standard cointegration is rejected with the more traditional Johansen CVAR methodology. By using the recently introduced Fractionally Cointegrated VAR by Johansen and Nielsen (2012) we provide a cointegrating relationship taking into account fractional integration.     

煤矿提高块煤率的实践与探索

本文分析介绍了文玉煤矿从原煤运输、煤炭储存、回采工艺、二次筛分等生产过程全方位提高块煤率的途径,并通过实践取得很好效果,显著提高煤矿经济效益。     

What Drives the Historical Formation and Persistent Development of Territorial States?

The importance of the length of state history for understanding variations in income levels and growth rates across countries has received a lot of attention in the recent literature on long‐run comparative development. The literature, however, is silent about its origins. This paper explores the determinants of statehood by considering the potential roles of an early transition to fully‐fledged agricultural production, the adoption of state‐of‐the‐art military innovations, and the opportunity for economic interaction with the regional economic leader. The results demonstrate that only the association between economic interaction and the rise and development of the state is statistically robust.