Digital at the edge – antecedents and performance effects of boundary resource deployment

With business ecosystems digitalizing by the force of digital innovation, the deployment of boundary resources (such as application programming interfaces: APIs) becomes a strategic option across contexts. We distinguish between boundary resources that provide access openness and those that provide resource openness, and theorize the antecedents and consequences of their deployment. Employing panel data regressions to a longitudinal cross-industry dataset, we find that the digital knowledge base of the focal firm and the existence of potential digital complementors drive boundary resource deployment. Such deployment benefits firm performance depending on the firm’s market power. From our empirical analysis, we reveal a differentiated perspective on the quality of the confined openness provided by boundary resources as well as the embeddedness of their deployment in the rationales and motivations of the associated actors in digital business ecosystems. We complement the existent theoretical framework on boundary resources and provide valuable insights to managers reflecting about deploying boundary resources in a beneficial way.     

小波预处理与语音识别

利用小波的带通性质 ,给出了一种新的小波预处理方法 .实验表明 ,经过小波预处理后提取的特征 ,提高了语音的识别率     

GOST 34.10—A brief overview of Russia's DSA

GOST 34.10 is Russia's DSA. Like its US counterpart, GOST is an ElGamal-like signature scheme used in Schnorr mode. It is similar to NIST DSA in many aspects. In this paper we will overview GOST 34.10 and discuss the three main differences between the two algorithms, (i) GOST's principal design criterion does not seem to be computational efficiency: the algorithm is 1.6 times slower than the DSA and produces 512-bit signatures. This is mainly due to the usage of the modulus q which is at least 254 bits long. During verification, modular inverses are computed by exponentiation (while the Extended Euclidian algorithm is roughly 100 times faster for this parameter size) and the generation of the public parameters is much more complicated than in the DSA. This choice of the parameters makes GOST 34.10 very secure. (ii) GOST signers do not have to generate modular inverses as the basic signature equation is s = xr + mk (mod q) instead of (mod q). (iii) GOST's hash function (the Russian equivalent of the SHA) is the standard GOST 34.11 which uses the block cipher GOST 28147 (partially classified) as a building block. The hash function will be briefly described. Copyright     

Modified criterion for global asymptotic stability of fixed-point state-space digital filters using two’s complement arithmetic

A criterion for the global asymptotic stability of fixed-point state-space digital filters using two’s complement arithmetic is presented. The criterion is a modified form of a well-known criterion due to Mills, Mullis, and Roberts. The criterion is in the form of linear matrix inequality and, hence, computationally tractable. An example shows the effectiveness of the modified criterion.     

Traceable content protection based on chaos and neural networks

In this paper, a media content encryption/decryption algorithm is designed based on a chaos system and neural networks, which generates random sequences with chaos, and encrypts or decrypts media contents with neural networks in a parallel way. In this scheme, different decryption keys can be used to recover the media content into different copies. That is, the decryption operation gets the content containing certain random sequence that can be used as the identification. With respect to this property, the scheme is used for secure content distribution. Taking the audio content for example, it is encrypted by a key at the sender side and decrypted by different keys at the receiver side. The differences between decryption keys lead to different decrypted audio copies. If one customer distributes his copy to other unauthorized customers, the chaotic sequence contained in the copy can tell the illegal customer. The performances, including security, imperceptibility and robustness, are analyzed, and some experimental results are given to show the scheme's practicability.     

基于多线程的音频设备上位机控制系统

设计一种音频设备的上位机控制系统,实现对多台音频设备的集中和远程控制。为了保证上位机在与设备通信的同时,能及时响应前台界面的用户操作,引入了多线程技术。同时,音频设备具有经常被持续、快速调节同一参数的特点,为解决在此情况下由于硬件通信速度有限而导致的设备滞后响应上位机用户操作的问题,设计了一种冗余命令剔除机制。该机制不仅有效地减少了通信占用的资源,而且更好地保证了用户对设备调节控制的实时性。     

Pricing schemes for digital content with DRM mechanisms

In this paper, utilizing game-theoretic model, we examine the impact of collaborative structure, content quality, and network environment on the development of pricing scheme and DRM protection policy of digital content. DRM protection level decreases and pirating activities becomes relatively tolerable as the content provider and platform provider operate collaboratively. Depending on the market structure, higher content quality may strengthen or weaken the adoption of DRM. However, it would seem that, as the network environment becomes more decentralized and uncontrolled, weaker DRM protection should be a better strategy.     

基于动态逻辑许可证的PDF版权管理系统

电子文档版权管理是数字版权管理的重要研究领域,提出一种PDF电子文档版权保护方案,该方案的权限管理基于一种具有强大表达力、灵活性和开放权限管理能力的动态逻辑许可证,具有详细的文档权限控制方法,并通过内容级的PDF文档加密方法增强文档的安全性。对系统模型、实现结构和方法进行说明,并与相关方法进行对比和应用示例。     

论数字图书馆系统中WEB服务器性能优化的方法

由于在数字图书馆系统中流通着的大多是数字化的索引、文摘、全文、图像或音频视频等多媒体信息,对Web服务器性能有着较高的要求.结合实际工程的经验,从硬件实现手段(缓存服务器、均衡负载设备、Web双机镜像等)和软件实现手段(多层软件结构设计、应用部署等)等两个大方面论述如何提高Web服务器性能,以便使用户能够更快捷、高效、安全地使用数字图书馆应用系统.     

逻辑综合在数字IC设计中的应用

随着数字IC的规模和复杂性不断增加,数字IC设计的难度也在加大,为了更好地进行数字IC设计,业界普遍采用了自动化的设计方式,通过应用工具软件,将IC设计的效率极大地提高.主要探讨了在IC设计当中逻辑综合方面的问题.