信息技术在林火探测中的应用

本文在介绍信息技术的基础上。搜集了大量的林火探测方法,分析了人为探测的优缺点以及利用信息技术进行林火探测的必要性。信息技术在林火探测中的应用主要包括4个方面：红外探测、感烟探测、卫星遥感探测和视频图像探测。本文分析了各种信息技术的探火原理以及优缺点,并指出在不同的环境背景下应该选择不同的信息技术进行林火探测．必要的时候可以使用复合型的林火探测方式。一般来说,红外探测和感烟探测比较适合近距离的林火探测．因为红外和烟雾容易受周围环境的影响而有不同程度的削减;对于大面积的森林监测应该采用卫星遥感技术,但由于其覆盖周期长,应用于林火探测上尚有一定距离,在林火灾后评估方面有很好的应用效果;视频图像林火探测是一门新兴的信息技术,虽然有其他方法所不可比拟的优越性,但在应用过程中,其缺点也应受到人们的重视。随着信息技术日新月异的发展,林火探测技术将会越来越科学、准确。     

Strategic interaction between inter vivos gifts and housing acquisition

This paper models the interdependence of parental inter vivos gifts and children’s home purchases when informal care affects decision making. We use data from Japanese households who purchased a detached house in an urban area to test this strategic interaction. Considering both censoring and endogeneity of inter vivos gifts, which are identified by information on formal care, our preferred results demonstrate that inter vivos gifts do not significantly increase the purchase price of housing. Theory suggests that this occurs when informal care tends to be a heavy burden for children. However, subsample analysis of young home buyers indicates that the empirical results are consistent with the literature: children who receive parental gifts tend to purchase a higher-priced dwelling. One potential explanation is that relatively young adult children are less likely to take charge of care obligations, and accordingly, parental gifts are only expected to relax their liquidity constraints. Subsample analysis appears to indicate that the underlying motivation of parental gifts is influenced by the timing of children’s home purchase decisions.     

The interplay between home and host country institutions in an emerging market context: Private equity in Latin America

This study examines how the interplay between home and host country regulatory institutions affects the investment strategy of private equity (PE) firms in an emerging market context. To answer this question, we consider three different mechanisms: (1) the institutional hazard avoidance effect, (2) the institutional escapism effect, and (3) the dysfunctional institutions effect. Contrary to conventional wisdom, we argue that regulatory institutional differences between home and host countries can sometimes have a positive rather than a negative effect on investment likelihood. Our findings show that when a host emerging market has a strong regulatory institutional system relative to other emerging markets, it is more likely that this country will attract PE investments from firms based in home countries with very strong and very weak institutional systems. The empirical analyses, based on a polynomial specification and a dataset covering more than 300 PE firms that made close to 1500 investment transactions in Latin America during 1996–2011, are consistent with our main theoretical arguments.     

瑞士个人产权住宅房屋低拥有率形成机制的深入研究

瑞士作为一个人均收入较高的发达国家,但国民购房的意识却非常淡漠,大部分人宁愿选择以租赁的方式解决居住问题。瑞士人拥有产权房屋的比例在西欧发达国家中所占比例最少,只占所有国民的34%,其中美国为62.5%,法国45%,本文通过对分布在瑞士5个州的1998户居民的抽样调查数据分析来探求该现象的合理解释。通过对众多相关要素的分析来对个人住房拥有率进行剖析,其中,特别对拥有和租赁的相对成本进行了重点研究,因为它与房屋售价、租赁价格与拥有后的使用成本密切相关,在上述影响因素中,产权人的使用成本与所得税政策、预期房屋价格上涨息息相关。本文也综合权衡了按揭贷款现行标准、租赁控制和各种政策对租赁房屋供给量所产生的影响,通过对税收、按揭标准、价格水平等因素进行一系列分析,估算出这些变量对房产拥有率的影响程度。本文得出以下结论:高房价——相对于租金对家庭收入来说是导致瑞士国民拥有住房比例较低的最重要影响因素。     

Home bias and deviations from purchasing power parity

Empirical analysis has produced mixed results in testing for PPP. This note presents a simple model linking home bias towards home-produced tradable goods with deviations from absolute PPP. We show that this bias constitutes a significant determinant of PPP deviations.     

Trade Costs,Trade Balances and Current Accounts: An Application of Gravity to Multilateral Trade

In this paper we test the well-known hypothesis of Obstfeld and Rogoff (NBER Macroeconomics Annual 7777:339–390, 2000) that trade costs are the key to explaining the so-called Feldstein–Horioka puzzle. Our approach has a number of novel features. First, we focus on the interrelationship between trade costs, the trade account and the Feldstein–Horioka puzzle. Second, we use the gravity model to estimate the effect of trade costs on bilateral trade and, third, we show how bilateral trade can be used to draw inferences about desired trade balances and desired intertemporal trade. Our econometric results provide strong support for the Obstfeld and Rogoff hypothesis and we are also able to reconcile our results with the so-called home bias puzzle.

The Lack of International Consumption Risk Sharing: Can Inflation Differentials and Trading Costs Help Explain the Puzzle?

The bulk of evidence on the lack of international risk sharing is based on regressions of idiosyncratic consumption growth on idiosyncratic output growth. This paper argues that the results from such regressions obtained from international data are, however, not directly comparable to those based on regional data: the standard practice of running such regressions on international data fails to account for persistent international differentials in consumer prices, whereas—implicitly—most of the literature based on regional data has accounted for these differences. When risk sharing regressions are set up in conceptually the same way in international and regional data sets, the estimated coefficients are also very similar. To explore this result further, we adapt the variance decomposition of Asdrubali et al. (Q J Econ 111:1081–1110, 1996) to allow for deviations from purchasing power parity across countries. While quantity (income and credit) flows are the dominant channel of risk sharing among regions, relative consumption and output price (internal terms of trade) fluctuations account for the bulk of the deviation from the complete markets outcome in international data. To the extent that persistent differences in consumer prices are an indication of goods market segmentation, our findings provide empirical evidence for the proposition by Obstfeld and Rogoff (NBER Macroeconomics Annual 2000, 2000) that segmented international goods markets rather than asset market incompleteness may account for the (apparent) lack of risk sharing between countries.

How do market conditions impact price-TOM relationship? Evidence from real estate owned (REO) sales

Empirical evidence on the relationship between real estate price and selling time (time-on-market (TOM)) is mixed as to whether the price-TOM relationship is positive or negative. Competing theories also suggest opposite predictions about TOM’s impact on selling price. The article examines the price-TOM relationship against the background of varying market conditions and highlights the impact of these conditions on the relationship. The theoretical analysis extends search theory and Lazear’s model to changing market conditions and reconciles their predictions on the relationship. The empirical analysis refines the investigation of the price-TOM relationship by revealing the cross-effect of market conditions and TOM on price. The findings confirm that the price-TOM relationship can indeed be positive or negative depending on these conditions. However, except for the case of an extremely bad market, the relationship is generally positive. This outcome occurs because search effort (indicated by TOM) brings significant price benefit that is large enough to offset all but the worst market price declines. Additional analysis confirms that the findings are not altered by the potential endogeneity between price and TOM.     

Weekly scheduling models for traveling therapists

This paper presents a series of models that can be used to find weekly schedules for therapists who provide ongoing treatment to patients throughout a geographical region. In all cases, patient-appointment times and visit days are known prior to the beginning of the planning horizon. Variations in the models include single vs. multiple home bases, homogeneous vs. heterogeneous therapists, lunch break requirements, and a nonlinear cost structure for mileage reimbursement and overtime. The single home base and homogeneous therapist cases proved to be easy to solve and so were not thoroughly investigated. This left two cases of interest: the first included only lunch breaks while the second added nonlinear overtime and mileage reimbursement costs. For the first case, 40 data sets were solved, each consisting of either 15 or 20 therapists and between roughly 300 and 540 patient visits over five days. For each instance, we were able to obtain the minimum cost of providing residential healthcare services using a commercial solver. The results showed that CPU time increases more rapidly than total cost as the total number of visits grows. For the second case, which was much more difficult, it was necessary to develop heuristics to find good solutions quickly. Results for 5- through 20-therapist instances are presented and compared to the linear programming relaxation lower bounds. In the first of two parametric analyses, the tradeoff between the number of therapists on staff and the cost of providing service was examined. In the second, a similar tradeoff was explored between cost can the number of home bases used by the therapists.     

Racialization and Rescaling: Post‐Katrina Rebuilding and the Louisiana Road Home Program

This article examines the interlocking nature of racialization and rescaling in post‐Katrina New Orleans, focusing specifically on the implementation of the Louisiana Road Home program, the largest housing recovery program in US history. Based on interviews and long‐term ethnographic fieldwork, I conceptualize the Road Home program as a racialized spatial strategy to revalorize disaster‐devastated spaces and enhance the exchangeability of damaged property. I trace the logic of rescaling in post‐Katrina New Orleans and reveal the ways in which state policies to accelerate the turnover time of flood‐damaged housing reflect and reinforce the racialization of space. New Orleans stands as a valuable laboratory for the study of government intervention under conditions of widespread upscaling, downscaling and outscaling processes, pushing trends found elsewhere to their limits while revealing the negative consequences of rescaling for local institutions and residents. The article illustrates the localized dynamics of rescaling in times of crisis and offers a novel processual account of the drivers and consequences of rescaling processes in a disaster‐impacted territory.