Court Efficiency and Procurement Performance

Disputes over penalties for breaching a contract are often resolved in court. A simple model illustrates how inefficient courts can sway public buyers from enforcing a penalty for late delivery in order to avoid litigation, thereby inducing sellers to delay contract delivery. By using a large dataset on Italian public procurement, we empirically study the effects of court inefficiency on public work performance. Where courts are inefficient, we find the following: public works are delivered with longer delays; delays increase for more valuable contracts; contracts are more often awarded to larger suppliers; and a higher share of the payment is postponed after delivery. Other interpretations receive less support from the data.     

Intermediate Choice Lists: How Product Attributes Influence Purchase Likelihood in a Self-Imposed Delay

Many online retailers enable consumers to postpone a purchase decision by placing a desired item onto an intermediate choice list, such as a wish list or saved-for-later list. This research demonstrates that using a list in this way decreases purchase intent for the wait-listed products, relative to the same choice made without the option to delay the decision. The findings of five experiments show that purchase likelihood is affected by a shift in the importance, or weight, of product attributes. Specifically, the attributes that are weighted more heavily in the decision to place an item on an intermediate choice list are then weighted less heavily in the decision to purchase an item from that list. This shift in attribute weighting suggests that consumers may switch from more noncompensatory to more compensatory decision-making between the initial decision to use an intermediate choice list, and the later decision of whether to purchase the item from the list. This process tends to diminish the importance of the attractive attributes that encouraged consumers to put these items on lists in the first place. These findings have implications for retailers who wish to understand the risks and benefits of wish lists and related tools, and for consumers who desire to reduce impulsive purchases.     

一种新型正交相关延迟混沌开关键控系统

在相关延迟键控(CDSK)和混沌开关键控(COOK)这两种传统方案的基础上提出了一种新型的混沌键控方案——正交相关延迟混沌开关键控(OCD-COOK)。该方案结合了CDSK系统和COOK系统各自的特点，同时引入了一对简单的Walsh码序列，克服了CDSK系统误码性能差的缺点，具有比特误码率低、传输速率高、安全性好等优势。理论分析及仿真结果均表明，该系统的比特误码率低于CDSK和差分混沌键控(DCSK)，传输速率是DCSK的2倍，具有很好的实际应用价值。     

伪码信号辅助的CEI载波时延模糊度解算

针对连线干涉测量系统(CEI)在无模型时延或模型时延不准确条件下相位模糊度解算困难的问题，提出了利用伪码测距信号辅助的载波相位模糊解算方法。在测站距离约束下，根据两站所接收伪码信号的相对位置关系计算得到一个时延差作为解载波相位模糊的时延预报值。为了提高解模糊能力，引入了伪码捕获和跟踪的基本方法。仿真分析了不同信噪比下所能达到的最大精度，结果表明在信噪比高于0 dB时，可直接解算S频段的载波相位模糊；在信噪比较低时，可解算宽带群时延的相位模糊。在0dB和-30dB条件下重复试验1 000次，正确率分别达到99.88%和99.91%，证明了算法的有效性。     

基于非参量累积和的合作频谱感知

针对认知无线电网络中频谱感知的检测时延降低问题，提出了基于非参量累积和的合作频谱感知算法。本地认知用户预处理频谱观测数据，获得观测数据相对于信念值的正向漂移和负向漂移。为了缩短检测延迟，认知用户只将数据的正向漂移同步传输至融合中心。融合中心融合正向漂移得到判决信息，采用非参量累积和算法依时间序列顺序累加判决信息，判断主用户是否正在使用授权频段。为了解决不传输负向漂移引起的虚警问题，改进算法提出融合中心可以保留首次判决，经过等待时间间隔后再作出最终判决。相对于传统的软融合算法，改进融合规则的合作频谱感知算法具有较低的检测延迟。     

Determinants of flight delays at East Asian airports from an airport,route and network perspective

Previous studies on determinants of flight delays have been limited to the attributes of departure and arrival airports and routes and experiences in North America and Europe. This research extends the existing discussions by considering a network perspective to explore East Asian airports. A total of 4611 routes among 318 airports in the second half of 2017 are analyzed using panel data regressions. Results show that the attributes of airports and routes linked with the departure and arrival airports of a flight are the essential determinants of flight delays in East Asia. However, the congestion internalization and hubness effect of departure and arrival airports suggested in previous research are not observed in this region. The associations of slot control levels and route attributes with delays are varying between airports inside and outside China and domestic and international routes. This research supplements a new perspective to understand the determinants of flight delays in existing literature and provides a rarely observed knowledge to encourage East Asian airport operators and carriers developing management strategies for minimizing flight delays.     

耐贮大路货性果蔬品销售策略的探讨——以湖南石门柑桔销售为例讨论

对耐贮大路货性的果蔬品的销售策略有五条：树立果蔬的地方品牌和加强其食补价值的宣传;发展鲜品加工工业：扩大国际市场销售：政府适当的指导价及公示鲜果的平均种植成本：果蔬的物流增值——近／远距销售．应／延时销售。建立了销售价格g,销售成本c与物流距离x,销售延时t之间利润计算公式,并用示意图表明x和t与利润厂之间的关系,对销售经纪人有指导意义。     

信托受益权的法律性质探讨

对于"信托受益权"究竟是一种什么样的权利,无论是英美法系还是大陆法系持续争论了百余年。信托在现代商业和金融交易领域发挥着重要作用,我国广泛应用于证券投资基金、资金信托和资产证券化中。我国《信托法》是法律对信托社会需求的回应,更多地采纳了合同理论,为信托合同提供了一套强制性的标准化条款。我国应借鉴"物权说"完善信托财产登记制度,吸收"企业组织"理论强化信托的资产分割功能。     

On the replenishment policy when the market demand information is lagged

We consider a situation where the most up-to-date information on the market demand and the inventory levels is not available to a replenishment decision maker in a single echelon of a supply chain. The objective of the decision maker is to minimise the sum of the inventory and the production costs. An intuitively attractive strategy under this setting might be to reduce the information time lag as much as possible by utilising information technologies such as RFID. We call this strategy the Time lag Elimination Strategy (TES). However, this course of action requires investment in information systems and will incur a running cost. We propose an alternative strategy that has similar economic consequences as the TES strategy, but it does not require new information systems. We call this strategy the Controlling Dynamics Strategy (CDS). The benefit coming from CDS is quantified and is compared to that from TES. We also quantify the benefits gained from the combined use of these two strategies. A new ordering policy is introduced that is easy to implement without any forecasting systems and can reduce the production cost significantly.     

一种高精度动态测控信号模拟器

根据测控系统对动态模拟器的要求，即模拟动态范围宽、模拟精度高、逼真度高，设计了采用两级数字存储器对信号进行粗细时延组合控制的转发式模拟器。根据运动方程高逼真度地模拟飞行目标的动态特性，该模拟器可以实现距离模拟范围千万公里时，精度优于1 cm；速度模拟范围每秒几十公里时，精度优于1 mm/s的高精度动态模拟。