膜下粮面施药与通风口施药熏蒸效果对比试验

通过对采用膜下粮面施药与通风口施药两种方式的试验对比，两种方式均能达到较好的杀虫效果。粮面施药需要进入仓房操作，而通风口施药是在露天环境下作业，简便、安全。熏蒸时可根据情况选择不同的施药方式。     

Machine learning for quantitative finance: fast derivative pricing,hedging and fitting

In this paper, we show how we can deploy machine learning techniques in the context of traditional quant problems. We illustrate that for many classical problems, we can arrive at speed-ups of several orders of magnitude by deploying machine learning techniques based on Gaussian process regression. The price we have to pay for this extra speed is some loss of accuracy. However, we show that this reduced accuracy is often well within reasonable limits and hence very acceptable from a practical point of view. The concrete examples concern fitting and estimation. In the fitting context, we fit sophisticated Greek profiles and summarize implied volatility surfaces. In the estimation context, we reduce computation times for the calculation of vanilla option values under advanced models, the pricing of American options and the pricing of exotic options under models beyond the Black–Scholes setting.     

Perceptual Density of Guava Juice: The Effect of Image Location and Surface Texture

Guava is known for its rough (astringent) appearance and texture; feature attached to its nutritional benefits but rejected from consumers’ point of view. This study deals with the rough property of guava juice through packaging expecting to influence its perceived density. Two studies were designed by manipulating (a) the location of the image on the bottle and (b) the surface texture of the bottle, controlling for transparency. Results confirm that it is possible to shift the perception of density in guava juice (a) locating the image of the fruit on the top (not the bottom) of the bottle and (b) using a smooth surface texture (not a rough) on an opaque bottle. Concerning practical implications, agribusinesses should enforce the use of sensory marketing strategies to sell the best of fruits and vegetables.     

Smooth and bid-offer compliant volatility surfaces under general dividend streams

Abstract

Given bid-offer quotes for a set of listed vanilla options, a fundamental need of option market makers is to interpolate and extrapolate the available quotes to a full arbitrage-free surface. We propose a methodology which directly controls the trade-off between smoothness and bid-offer compliance of the resulting volatility surface. Unlike previous literature, the method applies simultaneously to all listed maturities and aims to smooth the implied risk-neutral densities. Additionally, we consider asset dynamics which allow for general dividend streams—continuous, discrete yield and discrete cash—a modelling aspect of key importance in option markets.     

工程项目风险监控体系构建与实践

本文通过对工程项目全过程的监督及控制进行探索,对工程建设各个阶段的风险点监控进行了分析研究,创建工程项目的风险监控体系,提高了工程项目建设的质量和效率。     

面波法波速测试在岩土工程勘察中的应用

文章简述了面波法波速测试方法的工作原理、现场施测技术以及数据处理和资料分析过程,运用工程实例说明了面波法波速测试技术在岩土工程勘察设计中的应用和效果。     

Can we forecast the implied volatility surface dynamics of equity options? Predictability and economic value tests

We examine whether the dynamics of the implied volatility surface of individual equity options contains exploitable predictability patterns. Predictability in implied volatilities is expected due to the learning behavior of agents in option markets. In particular, we explore the possibility that the dynamics of the implied volatility surface of individual stocks may be associated with movements in the volatility surface of S&P 500 index options. We present evidence of strong predictable features in the cross-section of equity options and of dynamic linkages between the volatility surfaces of equity and S&P 500 index options. Moreover, time-variation in stock option volatility surfaces is best predicted by incorporating information from the dynamics in the surface of S&P 500 options. We analyze the economic value of such dynamic patterns using strategies that trade straddle and delta-hedged portfolios, and find that before transaction costs such strategies produce abnormal risk-adjusted returns.     

无铅化PCB工艺特点和表面材料研究

无铅化的PCB表层有多种形式,包括浸锡、浸银、浸金和有机焊接保护等,而PCB工艺技术包括电镀、化学镀和浸镀等多种方式。不同的工艺具有不同的优缺点,针对于不同的无铅化表层材料,其工艺与材料的兼容性也不同。本文主要从可生产性、制造型和匹配性等方面进行PCB表层技术进行分析,通过对可靠性的评估进行材料与工艺的匹配。     

英语教学中的素质教育初探

本文讨论了素质教育的定义、本质和特征 ,阐述了如何在课堂教学中贯彻素质教育 ,揭示了素质教育的一个重要特征就是重视所有的受教育者 ,并使其皆在原有的基础上取得进步 ,会自我发展。     

津头-白沙一带“红层”赋存特征及其找煤前景分析

文章探讨了龙永煤田津头-白沙一带"红层"沉积的特点,并分析其与下伏、周边地层及系地层接触关系,对"红层"沉积厚度进行了分析,探讨了津头-白沙一带"红层"不整合接触面倾角大小及其下伏地层埋藏厚度等两个因素决定了"红层"下找煤前景。