The Seat Reservation Problem

We investigate the problem of giving seat reservations on-line. We assume that a train travels from a start station to an end station, stopping at k stations, including the first and last. Reservations can be made for any trip going from any station to any later station. The train has a fixed number of seats. The seat reservation system attempts to maximize income. We consider the case in which all tickets have the same price and the case in which the price of a ticket is proportional to the length of the trip. For both cases we prove upper and lower bounds of Θ(1/k) on the competitive ratio of any ``fair' deterministic algorithm. We also define the accommodating ratio which is similar to the competitive ratio except that the only sequences of requests allowed are sequences for which the optimal off-line algorithm could accommodate all requests. We prove upper and lower bounds of Θ(1) on the accommodating ratio of any ``fair' deterministic algorithm, in the case in which all tickets have the same price, but Θ(1/k) in the case in which the ticket price is proportional to the length of the trip. The most surprising of these results is that all ``fair' algorithms are at least 1/2 -accommodating when all tickets have the same price. We prove similar results bounding the performance of any ``fair' randomized algorithm against an adaptive on-line adversary. We also consider concrete algorithms; more specifically, First-Fit and Best-Fit. Received February 6, 1997; revised November 6, 1997.     

确定区域详细布线算法

提出了一种确定区域的详细布线算法,它能对不同设计模式进行布线。该算法能适用于任意多层布线情况,并且支持不同布线层具有的不同工艺参数,在构造布线树时,考虑芯片当前的走线拥挤度,使布线比较平均,并加快了算法运行速度、改善了布线质量,在连接两点线网时,构造基于二维迷宫布线结果的分层图,提出了一种对分层图的启发式染色算示来进行布线层分配,大大提高算法布线速度,采用拆线重布的方法来处理布线失败的线网。     

不同负载量下摘叶对‘美乐’葡萄果实着色的影响

为探究河西走廊酿酒葡萄果实着色与产量的关系,以5年生‘美乐’为试材,在不同产量水平下,于果实转色初期和中期进行摘叶处理。结果表明,摘叶处理总体提高果实的穗质量和可溶性固形物,降低可滴定酸含量。转色中期摘叶处理,300、500 kg·667m^-2产量水平下,显著提高果实的色泽指标L^*、C^*和b^*;500、800 kg·667m^-2产量水平下,提高果面的a*。转色初期和中期摘叶均显著提高果面的颜色指数(CIRG)。综合分析,800 kg·667m^-2产量水平下摘叶处理对‘美乐’果实的品质和色泽指数影响较为明显,在转色中期摘叶处理能有效改善‘美乐’葡萄的着色不良问题。     

气相色谱-质谱法测定自热食品接触用塑料制品所用着色剂中14种多氯联苯

该文建立了同时测定自热食品接触用塑料制品所用着色剂中的14种多氯联苯的气相色谱-串联质谱法。样品中的多氯联苯经有机溶剂超声提取，用浓硫酸磺化，气相色谱-串联质谱法分析，外标法定量。结果表明，14种多氯联苯在质量浓度为0.5~5 µg/L的范围内均线性良好，相关系数(R2)均大于0.99。14种多氯联苯的检出限均为5 μg/kg，定量限均为25 μg/kg。当添加量为5、10、 25 µg/kg时，14种多氯联苯在荧光红中的回收率为81.03%~105.72%之间，相对标准偏差(RSD)在1.51~10.52之间；在荧光黄中的回收率为80.11%~108.44%之间，RSD在0.69~11.10之间；在荧光蓝中的回收率为81.07%~102.56%之间，RSD在0.72~10.80之间；在荧光绿中的回收率为80.26%~109.37%之间，RSD在1.12~11.41之间；在荧光紫中的回收率为80.15%~105.80%之间，RSD在1.21~10.89之间。该方法快速准确，能够为自热食品接触材料着色剂安全性评价作技术参考。     

On the manipulation,and meaning(s), of color in food: A historical perspective

While there has long been public concern over the use of artificial/synthetic food colors, it should be remembered that food and drink products (e.g., red wine) have been purposefully colored for millennia. This narrative historical review highlights a number of reasons that food and drink have been colored, including to capture the shopper's visual attention through to signaling the likely taste/flavor. Over the course of the last century, there has, on occasion, also been interest in the playful, or sometimes even deliberately discombobulating, use of food coloring by modernist chefs and others. The coloring (or absence of color) of food and drink can, though, sometimes also take on more of a symbolic meaning, and, in a few cases, specific food colors may acquire a signature, or branded (i.e., semantic) association. That said, with food color being associated with so many different potential “meanings,” it is an open question as to which meaning the consumer will associate with any given instance of color in food, and what role context may play in their decision. Laboratory-based sensory science research may not necessarily successfully capture the full range of meanings that may be associated with food color in the mind of the consumer. Nevertheless, it seems likely that food color will continue to play an important role in dictating consumer behavior in the years to come, even though the visual appearance of food is increasingly being mediated via technological means, including virtual and augmented reality.     

Graph-Based Replication and Two Factor Authentication in Cloud Computing

Many cutting-edge methods are now possible in real-time commercial settings and are growing in popularity on cloud platforms. By incorporating new, cutting-edge technologies to a larger extent without using more infrastructures, the information technology platform is anticipating a completely new level of development. The following concepts are proposed in this research paper: 1) A reliable authentication method Data replication that is optimised; graph-based data encryption and packing colouring in Redundant Array of Independent Disks (RAID) storage. At the data centre, data is encrypted using crypto keys called Key Streams. These keys are produced using the packing colouring method in the web graph’s jump graph. In order to achieve space efficiency, the replication is carried out on optimised many servers employing packing colours. It would be thought that more connections would provide better authentication. This study provides an innovative architecture with robust security, enhanced authentication, and low cost.     

湿法磷酸浸提料浆中着色物质的鉴别

收集磷酸生产过程中的磷酸浸提料浆,通过N,N-二甲基甲酰胺、正己烷溶解得到溶液,水洗脱除可溶性磷酸及盐类后得到固体。采用气相色谱-质谱联用仪（GC-MS）判断小分子有机物组成及着色情况;利用X射线衍射（XRD）、X射线荧光光谱（XRF）表征手段,对水洗后固体样品进行鉴定,确定磷酸浸提料浆中着色物质的组成;利用热重和红外光谱对有机质的组成及含量进行测定;采用扫描电子显微镜对样品的存在状态进行表征。研究表明,磷酸浸提料浆中主要着色物质为二硫化铁与有机质组成的复合体,其赋存状态为有机质不完全包裹二硫化铁的形式,其中二硫化铁质量分数为10.70%（以铁元素计）,有机质质量分数为2.39%（以湿基计）。