Pricing strategies for tied digital contents and devices

Media companies are increasingly offering digital content to consumers. Many of these companies are tying digital content with their proprietary digital devices. In this study, we develop a consumer demand model for digital device and digital content based on a constant elasticity demand function. In modeling consumer valuation of the digital device, we take consumer surplus on digital content into account. We further derive equilibrium prices for digital devices based on an oligopoly competition model with horizontal product differentiation. We analyze the equilibrium prices and how prices affect firm profits. We find product differentiation and the level of product substitutability affect prices. We also find that content price plays a significant role in affecting the price of the digital device. Content price can either increase or decrease the tied digital device price depending on the profit margin and demand elasticity of the digital content. We further analyze how content and device prices affect their respective profits and the overall profit of the firm. We extend our model to vertical product differentiation and find vertical product differentiation and the level of product quality affect prices.     

干扰约束下的认知无线电传输链路自适应算法

针对干扰约束下的认知无线电传输链路自适应算法开展研究,基于OFDM的认知用户与主用户共存,认知用户在保证对主用户干扰容限的前提下执行子载波与功率分配,以树形分支贪婪算法为基础,引入功率余量因子和干扰余量因子并通过比较余量因子相对大小来选择子载波,通过减小分支数以降低算法复杂度.仿真结果表明,改进的树形分支贪婪算法获得的...     

Effective dimensions and relative frequencies

Consider the problem of calculating the fractal dimension of a set X consisting of all infinite sequences S over a finite alphabet Σ that satisfy some given condition P on the asymptotic frequencies with which various symbols from Σ appear in S. Solutions to this problem are known in cases where

(i)

the fractal dimension is classical Hausdorff or packing dimension (by work of Volkmann and Olsen), or

(ii)

the fractal dimension is effective (even finite-state) and the condition Pcompletely specifies an empirical distribution π over Σ, i.e., a limiting frequency of occurrence for every symbol in Σ.

In this paper, we show how to calculate the finite-state dimension (equivalently, the finite-state compressibility) of such a set X when the condition P only imposes partial constraints on the limiting frequencies of symbols. Our results automatically extend to less restrictive effective fractal dimensions (e.g., polynomial-time, computable, and constructive dimensions), and they have the classical results (i) as immediate corollaries. Our methods are nevertheless elementary and, in most cases, simpler than those by which the classical results were obtained.     

移动分布感知的车载自组网络数据分发

提出了一种面向发布/订阅系统基于车辆移动分布感知的事件分发策略MDA(mobile distribution-aware data dissemination).基于车流的自组织性及自稳性的特点,建立VANET(vehicular ad hoc network)下的发布/订阅模型,通过计算车辆与移动订阅者的相遇概率,预测订阅者的移动分布,并以此为依据实时部署和调度广播令牌在网络中的转发,从而有效地控制事件代理的分布,保证了数据传递的有效性.与已有相关研究相比,MDA采用的启发式算法,能够使事件代理的分布更好地适应网络环境的动态变化.此外,MDA采用了一种基于概率预测密度的令牌控制算法,通过实时地调整令牌的数量,进而控制事件代理的数量,降低了整个网络的负载.模拟实验结果表明,与现有的几种消息分发算法相比,MDA能以较低的网络负载和传输延迟获得较高的数据传输成功率.     

便携式二氧化碳检测仪的设计

为了探测地震废墟狭小空间内幸存者的呼出气体,设计了便携式二氧化碳检测仪.检测仪采用红外二氧化碳传感器进行检测,通过单片机直接获取数字信号,并具有温度补偿功能.检测结果通过真空荧光显示屏显示,超过预设值触发声光报警.废墟实验表明:该检测仪适用于狭小空间内幸存者的搜索工作.     

高阶滑模微分器的分析与改进

首先采用Terminal吸引子函数代替原不连续函数,以避免滑模微分器的抖振;然后针对现有文献中高阶滑模微分器设计参数选取苛刻这一问题,放宽了设计参数选择范围,并分不同情况证明了高阶滑模微分器的稳定性．在此基础上,给出了高阶滑模微分器估计误差的上界与设计参数和滑模微分器阶次的关系式;通过对设计参数的选取和系统整体结构的分析,提出了高阶滑模微分器减小估计误差且更适于工程应用的设计方法,并给出所需条件．仿真结果表明了所得结论的正确性和有效性．     

基于FPGA的精密离心机光栅信号细分系统

介绍一种基于FPGA的精密离心机光栅信号细分系统。说明了光栅信号的产生过程和基本处理方法,提出了一种综合EDA技术与光栅莫尔条纹电子学细分技术的设计方案。通过VerilogHDL实现该系统的主要设计,并利用ISE软件进行了仿真试验。试验表明,该系统具有捕捉速度快、跟踪精度高、相位误差小、成本低廉等特点。     

皮肤流电响应监护系统与PC串口通信的设计

运用Visual Basic6.0开发了一套基于皮肤流电响应信号(GSR)的波形显示及分析系统.介绍了自行研制的皮肤流电响应硬件监护系统的硬件组成,利用VB中的MSComm控件实现计算机与GSR监护系统的串行通信,给出了详细的程序设计过程.     

基于权值的局部保持半监督降维算法*

针对现有的半监督降维算法没有考虑存在于数据集中的大量未标记信息,不能得到最好的降维效果的问题。本文提出了一种改进的基于权值的局部保持半监督降维算法。该算法在保持正、负约束信息的同时,还利用距离权值来保持数据集所在的局部结构,从而提高降维效果。在UCI数据集上的实验表明,该算法能够提高降维的效果,尤其是在数据分布特性不满足流形结构时,仍能得到较好的聚类结果。     

数学分离-多波长直线回归法测定鼻炎滴剂中的黄芩苷和盐酸麻黄碱

鼻炎滴剂是中西复方制剂,主要成分有黄芩苷、盐酸麻黄碱、金银花、辛夷油、冰片等.本文研究建立了数学分离-多波长直线回归法,用于测定鼻炎滴剂中黄芩苷和盐酸麻黄碱的含量.黄芩苷和盐酸麻黄碱的最大吸收波长分别为278.0 nm和257.0 nm,将2组分吸收强度较大的242.0 nm～283.0 nm选为测定范围.在测定范围内选择42个点进行测定,使用数学分离-多波长直线回归方法计算分析,直接测定了鼻炎滴剂中的黄芩苷和盐酸麻黄碱含量.本文研究使用的市售鼻炎滴剂中2种药效成分的平均回收率和相对标准偏差分别为102.0％,0.86％和98.2％,0.87％.数学分离-多波长直线回归法简单、快速、准确、适用于鼻炎滴剂的质量控制过程.