Secure collaborative supply chain planning and inverse optimization – The JELS model

It is a well-acknowledged fact that collaboration between different members of a supply chain yields a significant potential to increase overall supply chain performance. Sharing private information has been identified as prerequisite for collaboration and, at the same time, as one of its major obstacles. One potential avenue for overcoming this obstacle is Secure Multi-Party Computation (SMC). SMC is a cryptographic technique that enables the computation of any (well-defined) mathematical function by a number of parties without any party having to disclose its input to another party. In this paper, we show how SMC can be successfully employed to enable joint decision-making and benefit sharing in a simple supply chain setting. We develop secure protocols for implementing the well-known “Joint Economic Lot Size (JELS) Model” with benefit sharing in such a way that none of the parties involved has to disclose any private (cost and capacity) data. Thereupon, we show that although computation of the model’s outputs can be performed securely, the approach still faces practical limitations. These limitations are caused by the potential of “inverse optimization”, i.e., a party can infer another party’s private data from the output of a collaborative planning scheme even if the computation is performed in a secure fashion. We provide a detailed analysis of “inverse optimization” potentials and introduce the notion of “stochastic security”, a novel approach to assess the additional information a party may learn from joint computation and benefit sharing. Based on our definition of “stochastic security” we propose a stochastic benefit sharing rule, develop a secure protocol for this benefit sharing rule, and assess under which conditions stochastic benefit sharing can guarantee secure collaboration.     

微型光谱仪的数据噪声处理

原始信号的噪声处理是微型光谱仪器数据处理的重要组成部分,为了提高在弱光照射下便携式微型光谱仪的工作性能,在分析了线阵CCD探测器的各种噪声来源基础上,指出依靠硬件电路去除噪声在微型仪器设备应用的局限性。虽然判断一段离散数据曲线上噪声大小可以采用解析几何或者傅里叶变换得到特征频谱来判断,但是运算复杂,不利于在单片机应用中编程。通过对Freeman方向链码的分析,提出利用Freeman方向链码判断一段曲线上的噪声程度,量化后作为平滑窗口尺寸选择的依据。在处理线阵CCD输出信号中将该方法与固定窗口曲线平滑或者FFT数字滤波器进行了比较,证明了其可行性。Freeman链码的应用简化了在单片机编程中使用数字滤波器的大模块的编程,降低了编程难度,同时使信号噪声的处理仅仅在数学运算阶段中,不引入其他的电路噪声,从而达到比前期增加电子元件处理的方法能更好地抑制噪声的目的。     

Chemometric strategies for enhancing the chromatographic methodologies with second-order data analysis of compounds when peaks are overlapped

This overview covers the different chemometric strategies linked to chromatographic methodologies that have been used and presented in the recent literature to cope with problems related to incomplete separation, the presence of unexpected components in the sample, matrix effect and changes in the analytical signal due to pre-treatment of sample.Among the different chemometric strategies it focuses on pre-treatment of data to correct background and time shift of chromatographic peaks and the use of second-order algorithms to cope with overlapping peaks from analytes or from analytes and interferences in liquid chromatography coupled to diode array, fast-scanning fluorescence spectroscopy and mass spectrometry detectors. Finally the review presents the strategies used to deal with changes in the analytical response as result of matrix effect in liquid and gas chromatography, as well as the use of standardization strategies to correct modifications in the analytical signal as a consequence of sample pre-treatment in liquid chromatography.     

视频分享网站系统综合技术解决方案

今天,互联网越来越普及,互联网技术也在日新月异的变化,简单的、宣传栏式的网站,已越来越不能满足客户的要求,以及我们发展的需要,工欲成其事,必先利其器！建立充分反映视频分享网站是非常必要的。伴着新网站的建设与开通,我们有理由相信明天一定会更辉煌！     

Impact of polarization mode dispersion on the performance of optical CDMA transmission system

The impact of fiber polarization mode dispersion (PMD) on the bit error rate (BER) performance of a direct sequence optical code-division multiple-access system is analyzed by the split-step Fourier method based on the coupled nonlinear Schrödinger equation, the three-dimensional Poincare sphere theory and the Jones matrix method. When the incident pulse's width is bigness than the chip duration, which causes spreading and overlapping of chips and degrades system performance due to increased interchip interference and reduced received optical power conduce cannot decoding or error decoding. When the incident pulse's width is less than the chip duration, good encoding/decoding performance can be achieved.     

Modeling of 2.5 Gbps-intersatellite link (ISL) in inter-satellite optical wireless communication (IsOWC) system

Free-space optics (FSO) has the combined features of most dominated telecommunication technologies: wireless and fiber optics. Many of the aspects of FSO are related to fiber optics with an important difference of transmission medium which is air/free space rather than the glass of the fiber-optic cable. Inter-satellite optical wireless communication systems (IsOWC), one of the important applications of FSO/WSO technology, will be deployed in space in the near future as such systems provide a high bandwidth, small size, light weight, low power and low cost alternative to present microwave satellite systems. In this paper, we have designed a model of IsOWC system using OPTI-SYSTEM™ simulator to establish an inter-satellite link (ISL) between two satellites estranged by a distance of 1000 km at data rate of 2.5 Gbps which is not reported in previous investigated works.     

Speciality oils supply chain optimization: From a decoupled to an integrated planning approach

We study a problem of tactical planning in a divergent supply chain. It involves decisions regarding production, inventory, internal transportation, sales and distribution to customers. The problem is motivated by the context of a company in the speciality oils industry. The overall objective at tactical level is to maximize contribution and, in order to achieve this, the planning has been divided into two separate problems. The first problem concerns sales where the final sales and distribution planning is decentralized to individual sellers. The second problem concerns production, transportation and inventory planning through refineries, hubs and depots and is managed centrally with the aim of minimizing costs. Due to this decoupling, the solution of the two problems needs to be coordinated in order to achieve the overall objective. In the company, this is pursued through an internal price system aiming at giving the sellers the incentives needed to align their decisions with the overall objective. We propose and discuss linear programming models for the decoupled and integrated planning problems. We present numerical examples to illustrate potential effects of integration and coordination and discuss the advantages and disadvantages of the integrated over the decoupled approach. While the total contribution is higher in the integrated approach, it has also been found that the sellers’ contribution can be considerably lower. Therefore, we also suggest contribution sharing rules to achieve a solution where both the company and the sellers attain a better outcome under the integrated planning.     

基于密钥分散管理的服务器登录控制

文中提出了军队数据集中存储服务器的安全管理问题,分析了以矩阵为基础的密钥分散管理系统原理,从控制服务器管理员登录行为角度,研究基于密钥分散管理系统和USB-Key数字证书的服务器登录管理控制方法,对服务器管理员登录权限进行分割,实现了"必须有若干名管理员同时在场,才能登录服务器系统"的功能,有效解决了管理员私自登录、操作使用服务器的问题,提高了数据集中存储的安全性。     

Choice of low resolution sample sets for efficient super-resolution signal reconstruction

In applications such as super-resolution imaging and mosaicking, multiple video sequences are registered to reconstruct video with enhanced resolution. However, not all computed registration is reliable. In addition, not all sequences contribute useful information towards reconstruction from multiple non-uniformly distributed sample sets. In this paper we present two algorithms that can help determine which low resolution sample sets should be combined in order to maximize reconstruction accuracy while minimizing the number of sample sets. The first algorithm computes a confidence measure which is derived as a combination of two objective functions. The second algorithm is an iterative ranked-based method for reconstruction which uses confidence measures to assign priority to sample sets that maximize information gain while minimizing reconstruction error. Experimental results with real and synthetic sequences validate the effectiveness of the proposed algorithms. Application of our work in medical visualization and super-resolution reconstruction of MRI data are also presented.