Inconvenience cost of mobile communication failure: The case of South Korea

Mobile communication failure can occur when mobile traffic exceeds the manageable level. This depends on frequency bandwidth. Mobile communication failure causes inconveniences in a user's daily life that lead to social and economic damage. To address this issue, mobile telecommunications companies deploy additional bandwidths and develop new technologies, but these are costly strategies. This study applies a spike model based on a contingent valuation method (CVM) to measure the inconvenience cost resulting from mobile communication failure. The mean monthly willingness-to-pay (WTP) to avoid communication failure per user is estimated to be KRW 898.14 (USD 0.80) over a period of five years in our study. The inconvenience cost borne by the population is estimated to be KRW 2.97 trillion (USD 2.61 billion). Users experiencing greater frequency of communication failure are found to be willing to pay more to avoid the inconvenience. When excluding respondents citing zero-WTP, the mean WTP per user was calculated to be KRW 3426.41 (USD 3.01). Data traffic usage and frequency at which communication failure is experienced are variables that exhibit statistically significant effects on WTP to avoid mobile communication failure. Overall, estimation results show that a price discrimination based on data traffic usage or quality can be considered by mobile telecommunications companies and regulators to address the issue of data traffic inducing mobile communication failure.     

Operational efficiency analysis of Beijing multi-airport terminal airspace

Multi-airport systems are growing in number and size globally, despite being afflicted by known inefficiencies due to the interferences between the flows of neighbouring airports. A macroscopic empirical approach is proposed in this paper to estimate the capacity penalties and demonstrated by a numerical case study for Beijing, which is projected to become one of the busiest metroplexes in Asia. The Pareto envelopes of the theoretical and observed peak hour capacities are statistically analysed to quantify the penalties in a comparable metroplex and are subsequently modulated by a sigmoid correlation function. The analysis predicts the practical capacity of Daxing, the penalty incurred by the pre-existing Capital airport and by the total multi-airport system. Various findings are drawn and discussed, highlighting the needs for further research.     

Duration of price promotion and product profit: An in-depth study based on point-of-sale data

Anecdotal evidence has shown that retail price promotions can help small and medium-sized retailers enhance their sales, and thus profits. However, most marketing managers usually stop a promotion after a certain duration. This study aims to explain why these retailers discontinue their price promotion. Our approach posits that overall contributions of a price promotion to the product profit progressively diminish with time. In this study, we present a theoretical framework to explain the relationship between duration and profit effects of price promotion and propose statistical models to empirically examine this framework using point-of-sale (POS) data. Our findings provide empirical support that the effect of price promotion on the product profit has a downward trend with elapsed time. The results are helpful for marketers to understand how price promotions dynamically influence product profit and when the promotion should be terminated.     

铁路空铁联运车站发展分析及建议

空铁联运是综合交通一体化发展的重要组成部分,欧美国家已积累了许多经验,我国也逐渐出现一批与民航机场建设在一起的铁路车站,探索空铁联运的发展模式。对现有铁路空铁联运车站的布局特征、服务特征和运量特征进行分析,总结规律、提出建议,为我国空铁联运的发展方向提供参考。     

Cost savings from trajectory deviations in the European air space

Air transport deregulation has lead to an increase of air traffic, together with a reduction of air fares. Air fare reduction has narrowed operational margins of airlines, bringing financial and employment instability. This has brought airlines to pay increasing attention to flying costs reduction. Two important components of flying costs airlines can try to cut modifying the planned flight are en route charges and operational costs. We rely on Demand Data Repository (DDR2) data to calculate deviations from planned flight trajectories to analyse the extent to what airlines try to cut operational costs making shorter flights than planned if possible, and cut en route charges providing a planned flight with lower en route charges than the planned flight. Our findings show that there is no generalised strategy among airlines to reduce en-route charges asking for deviations of the planned route. On the other hand, airlines are achieving savings of operational costs regularly. Higher savings per nautical mile are obtained in night flights, with longer planned distance and operated by low cost carriers.     

Laypeople roles at road traffic crash scenes: a systematic review

This study aimed to identify the roles of laypeople at road traffic injuries (RTIs). A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The key words of ‘laypeople’, ‘layman’, ‘layperson’, ‘bystander’, ‘first responder’, ‘lay first responder’, ‘road traffic’, ‘road traffic injury’, ‘crash injury’, ‘crash scene’, ‘emergency’, ‘trauma care’, and ‘prehospital trauma care’ were used in combination with the Boolean operators OR and AND. We did electronic search on Google Scholar, PubMed, ISI Web of Science, CINAHL, Science Direct, Scopus, ProQuest. Based on the reviewed studies, some factors such as cultural conditions, knowledge, relief agencies, and demographic factors affect the interventions of laypeople at the crash scene in functional areas. Regarding the permanent presence of people at the crash scene, the present study can provide an opportunity to reduce different side effects of RTIs imposed on the society.     

集装箱港区物流及周边道路交通系统规划研究

结合周边道路交通对集装箱港区物流系统进行现状评估及预测,并通过建模分析提出规划方案,对于紧临城市中心的集装箱港区的建设与改造有着重要的参考价值。     

都市圈综合交通规划研究

分析了都市圈的交通结构,提出了都市圈交通网络规划原则和基本程序。最后,对都市圈综合交通一体化进行了研究。     

上海市中心区实施非机动车绿色通道的理念与方法研究

在分析上海市中心区交通特征基础上,根据非机动车交通出行特征,强调了非机动车绿色通道的重要性,并阐述了建议非机动车绿色通道的理念与方法。