浅析混凝土检测方法

混凝土产生历史悠久、应用广泛,而且随着现代建筑行业的飞速发展,混凝土体现出的耐用性、广泛性和经济性是其他材料无法比拟的,因此混凝土成为一种重要的工程材料。由于其突出的优越性,在被广泛使用的同时,人们对它的安全性、强度提出了更高的要求,随之发展了多种混凝土的强度监测方法,比如说无损检测法包括:回弹法和超声法等;还有半破损法包括:钻芯法、拔出法和射钉法等;另外就是一些综合类的方法,它集成了上述的几种方法,具有更大的优越性和先进性。     

某高超音速导弹用新型天线透波隔热装置设计

透波隔热装置是高超音速导弹用天线设计的关键部件之一。通过石英纤维增强氮 化物陶瓷透波材料和二氧化硅气凝胶复合隔热材料的选用,采用合理隔热装置结构设计,经 样件 热防护性能测试,有效的降低了天线体及馈线温度,证明该方案满足高超音速导弹天线设计 需求,可在后续工程中推广使用。     

110 kV变电站防雷保护探析

文章分析了雷电对变电站一次、二次电气设备可能造成的干扰和损害,介绍了在变电站设计中常采取的防雷保护措施。     

Forward induction and entry deterrence: an experiment

The Dixit (Econ J 90:95–106, 1980) hypothesis that incumbents use investment in capacity to deter potential entrants has found little empirical support. Bagwell and Ramey (J Econ 27:660–680, 1996) propose a model where, in the unique game-theoretic prediction based on forward induction or iterated elimination of weakly-dominated strategies, the incumbent does not have the strategic advantage. We conduct an experiment with games inspired by these models. In the Dixit-style game, the incumbent monopolizes the market most of the time even without the investment in capacity. In our Bagwell-and-Ramey-style game, the incumbent also tends to keep the market, in contrast to the predictions of an entrant advantage. Nevertheless, we find strong evidence that forward induction affects the behavior of most participants. The results of our games suggest that players perceive that the first mover has an advantage without having to pre-commit capacity. In our Bagwell–Ramey game, evolution and learning do not drive out this perception. We back these claims with data analysis and a theoretical framework for dynamics. Financial support by the Spanish Ministerio de Ciencia and Tecnología (SEC2002-01352 and SEJ2006-11665-C02-01) and the Barcelona Economic Program of CREA and excellent research assistance by David Rodríguez are gratefully acknowledged. The authors thank Aurora García Gallego and Armin Schmutzler for helpful comments.     

江苏省金融业投入产出分析

主要应用投入产出分析方法及其模型,依据江苏省2007年投入产出表数据资料,计算出金融业及各部门的直接消耗系数、完全消耗系数、感应度系数等有关指标,从总产出及其使用情况、总投入及其结构、直接产业关联和完全产业关联等角度,就金融业对江苏省经济的直接影响和完全影响进行了实证分析。分析结果表明江苏省金融业是江苏省经济体系中极为重要的产业组成部分,但与其他产业关联度不高,对经济发展的拉动作用较弱,属于强制约力、弱辐射力的产业。     

Option hedging theory under transaction costs

The problem of option hedging in the presence of proportional transaction costs can be formulated as a singular stochastic control problem. Hodges and Neuberger [1989. Optimal replication of contingent claims under transactions costs. Review of Futures Markets 8, 222–239] introduced an approach that is based on maximization of the expected utility of terminal wealth. We develop a new algorithm to solve the corresponding singular stochastic control problem and introduce a new approach to option hedging which is closer in spirit to the pathwise replication of Black and Scholes [1973. The pricing of options and corporate liabilities. Journal of Political Economy 81, 637–654]. This new approach is based on minimization of a Black–Scholes-type measure of pathwise risk, defined in terms of a market delta, subject to an upper bound on the hedging cost. We provide an efficient backward induction algorithm for the problem of cost-constrained risk minimization, whose associated singular stochastic control problem is shown to be equivalent to an optimal stopping problem. This algorithm is then modified to solve the singular stochastic control problem associated with utility maximization, which cannot be reduced to an optimal stopping problem. We propose to choose an optimal parameter (risk-aversion coefficient or Lagrange multiplier) in either approach by minimizing the mean squared hedging error and demonstrate that with this “best” choice of the parameter, both approaches have similar performance. We also discuss the different notions of risk in both approaches and propose a volatility adjustment for the risk-minimization approach, which is analogous to that introduced by Zakamouline [2006. European option pricing and hedging with both fixed and proportional transaction costs. Journal of Economic Dynamics and Control 30, 1–25] for the utility maximization approach, thereby providing a unified treatment of both approaches.     

Treatment patterns,healthcare resource utilization,and costs in patients with acute myeloid leukemia in commercially insured and Medicare populations

Objective: To describe the setting, duration, and costs of induction and consolidation chemotherapy for adults with newly-diagnosed acute myeloid leukemia (AML), who are candidates for standard induction chemotherapy, in the US.

Methods: Adults newly-diagnosed with AML who received standard induction chemotherapy in an inpatient setting were identified from the Truven Health Analytics MarketScan (2006–2015) and SEER-Medicare (2007–2011) databases. Patients were observed from induction therapy start to the first of hematopoietic stem cell transplant, 180 days after induction discharge, health plan enrollment/data availability end, or death. Induction and consolidation chemotherapy were identified using Diagnosis-Related Group codes (chemotherapy with acute leukemia) or procedure codes for AML chemotherapy administration. AML treatment episode setting (inpatient or outpatient), duration, and costs (2015 USD, payers’ perspective) were described for commercially insured patients and Medicare beneficiaries.

Results: In total, 459 commercially insured patients and 563 Medicare beneficiaries (mean age?=?54 and 66 years; 53% and 54% male; respectively) were identified. For induction therapy, mean costs were $145,189 for commercially insured patients and $85,734 for Medicare beneficiaries, and median inpatient duration was 31 days (both). Following induction, 64% of commercially insured patients and 53% of Medicare beneficiaries had ≥1 consolidation cycle; 75% and 65% of consolidation cycles were in an inpatient setting, respectively. For consolidation cycles, in the inpatient setting, mean costs were $28,137 for commercially insured patients and $28,843 for Medicare beneficiaries, median cycle duration was 6 days (both); in the outpatient setting, mean costs were $11,271 for commercially insured patients and $5,803 Medicare beneficiaries, median duration was 5 days (both).

Limitations: Granular information on chemotherapy type administered was unavailable.

Conclusions: This is the first exploratory study providing a complete picture of recent AML treatment patterns and management costs among commercially insured patients and Medicare beneficiaries. There is substantial heterogeneity in the management and costs of AML.     

基于偏差校正和三重组合分析的主、被动微波土壤湿度数据融合

为了提高微波遥感土壤湿度产品在中国地区的精度,将多种主、被动微波土壤湿度产品进行融合。选取中国陆面数据同化系统(CLDAS)表层土壤湿度数据为参考进行偏差校正,通过对模型数据和主、被动微波遥感土壤湿度数据(ASCAT-A/B,AMSR2,SMOS微波土壤湿度产品)进行皮尔逊相关性分析和三重组合(triple collocation,TC)分析,计算主、被动微波土壤湿度数据的误差,在此基础上计算权重并采用加权平均方法实现微波遥感土壤湿度数据的融合。融合后的土壤湿度数据与ESA-CCI土壤湿度融合产品的平均相关系数为0. 62,前者比后者平均偏小0. 023m~3/m~3;与ERA-Interim土壤湿度再分析数据相比具有良好的相关性;与实测土壤湿度数据相比,融合数据的精度优于ESA-CCI融合产品和CLDAS表层土壤湿度产品,具有更高的相关系数,较低的平均偏差和均方根误差。     

射频电导轮廓的概念及应用

提出了粗糙表面射频电导轮廓的概念及物理意义,介绍了与射频电导轮廓相关的技术指标和测量、计算方法,对射频电导轮廓在分析计算粗糙表面射频等效电导率、优化射频微波器件加工工艺流程等方面的应用情况进行了简介。实验表明,研究成果与实测数据相吻合。     

The supply of education quality in a spatial model with asymmetric moving costs

The paper analyses the characteristics of the supply of higher education in different geographical macroareas using a strategic interaction framework. It focuses on universities operating in centralised funding system that autonomously set the quality of education showing that in equilibrium it is inversely related to students’ moving costs across areas. We show that in the presence of asymmetric information about workers’ ability and asymmetric costs of moving, the only PBE consistent with forward induction involves that only high ability workers acquire education and the quality of education is lower in macroareas where the moving costs are higher. Our model predicts that in economies with centralised university funding, educational policies must be regulated according to the specific socioeconomic characteristics of the area. Direct subsidies to universities may be ineffective in improving the quality of education in the less developed areas. When regional disparities are not too big, efficiency gains may be obtained by reducing moving costs.