Massively Parallel Discovery of Loosely Moving Congestion Patterns from Trajectory Data

The efficient discovery of significant group patterns from large-scale spatiotemporal trajectory data is a primary challenge, particularly in the context of urban traffic management. Existing studies on group pattern discovery mainly focus on the spatial gathering and moving continuity of vehicles or animals; these studies either set too many limitations in the shape of the cluster and time continuity or only focus on the characteristic of the gathering. Meanwhile, little attention has been paid to the equidirectional movement of the aggregated objects and their loose coherence moving. In this study, we propose the concept of loosely moving congestion patterns that represent a group of moving objects together with similar movement tendency and loose coherence moving, which exhibit a potential congestion characteristic. Meanwhile, we also develop an accelerated algorithm called parallel equidirectional cluster-recombinant (PDCLUR) that runs on graphics processing units (GPUs) to detect congestion patterns from large-scale raw taxi-trajectory data. The case study results demonstrate the performance of our approach and its applicability to large trajectory dataset, and we can discover some significant loosely moving congesting patterns and when and where the most congested road segments are observed. The developed algorithm PDCLUR performs satisfactorily, affording an acceleration ratio of over 65 relative to the traditional sequential algorithms.

ANALISIS CALENDAR ANOMALIES DI PASAR SAHAM INDONESIA TAHUN 1998 – 2018

ABSTRACT The Efficient Market Hypothesis Theory of Fama states that stock prices cannot be predicted by its movement tendency (random walk). In some stock markets, the movement of stock prices has a seasonal effect, which is the repetition of stock movements at a certain time that can be called a calendar anomalies. The repetition or seasonal effect on rate of return shows that the stock price can be predicted, thus it can be exploited by investors to get the probability of a higher rate of return. This research aims to see whether calendar anomalies prevail in the Indonesian stock market by using the daily and monthly rate of return of LQ45 and the Jakarta Composite Index (JCI) with an observation period of 21 years from 1998 to 2018 and estimated using the GARCH-M model (1,1). The results of this research are the existence of daily anomalies on Monday as the day with the lowest rate of return and Wednesday as the day with the highest rate of return. In addition, we also get the results of monthly anomalies in August as the month with the lowest rate of return and December as the month with the highest rate of return.

Abiotic and Biotic Influences on the Movement of Reintroduced Chinese Giant Salamanders (Andrias davidianus) in Two Montane Rivers

Understanding animal movement is a key question in ecology and biodiversity conservation, which is particularly important for the success of reintroduction projects. The movement of critically endangered Chinese giant salamander (Andrias davidianus) remains poorly understood due to the rareness of wild individuals of this species. We lack movement details about the full annual cycle after reintroduction, especially the abiotic and biotic influences that affect its movement. We utilized pilot reintroduction projects as opportunities to fill in some knowledge gaps on their movement ecology. We released 31 juvenile captive-reared Chinese giant salamanders of two age groups in two rivers in the Qinling Mountains of central China and monitored their daily movements for 16 months using surgically implanted radio transmitters. We examined the impacts of individual traits (body mass, body condition) and environmental conditions (temperature, precipitation, and moon phase) on their daily movement patterns. Data were analyzed using a mixed-effects logistic regression model to understand the drivers of their movement tendency (i.e., whether they move or not) and a linear mixed-effects model was used to understand the drivers of their movement distance. We found that movement tendency of the older salamander cohort was positively affected by the moon phase, increasing near the Full Moon, whereas the younger cohort of animals were not impacted by the moon phase. For daily distance moved, we found temperature had a strong positive effect on both cohorts, whereas precipitation had moderate but opposite effects on the two cohorts Body mass and body condition did not have any significant impacts on either age classes’ movement tendency or distance. This study provides insight into the abiotic factors that impact the temporal and spatial movement ecology of reintroduced giant salamander, which will in turn help with designing best practices for future releases and conservation of this iconic montane aquatic predator.

Trajectory Data Compression Algorithm Based on Motion State Changing

The trajectory information generated by the moving object plays an important role in studying the object movement. In this paper, a trajectory data compression algorithm based on the motion state changing is proposed to reduce trajectory data storage space and increase compression speed, which can accurately show the motion state and trajectory characteristics. This study has certain significance for the exploration of mass traffic data and the planning of traffic network. Combining the angle threshold with the velocity threshold of a moving object, the key data points are found and the redundant information is removed. Subsequently, the compressed trajectory is obtained. The experimental results show that the new algorithm can help to improve compression efficiency. The compressed trajectory has high similarity with the original trajectory in movement tendency.

Collision-avoidance and flocking in the Cucker–Smale-type model with a discontinuous controller

<p style='text-indent:20px;'>The collision-avoidance and flocking of the Cucker–Smale-type model with a discontinuous controller are studied. The controller considered in this paper provides a force between agents that switches between the attractive force and the repulsive force according to the movement tendency between agents. The results of collision-avoidance are closely related to the weight function <inline-formula><tex-math id="M1">\begin{document}$ f(r) = (r-d_0)^{-\theta } $\end{document}</tex-math></inline-formula>. For <inline-formula><tex-math id="M2">\begin{document}$ \theta \ge 1 $\end{document}</tex-math></inline-formula>, collision will not appear in the system if agents' initial positions are different. For the case <inline-formula><tex-math id="M3">\begin{document}$ \theta \in [0,1) $\end{document}</tex-math></inline-formula> that not considered in previous work, the limits of initial configurations to guarantee collision-avoidance are given. Moreover, on the basis of collision-avoidance, we point out the impacts of <inline-formula><tex-math id="M4">\begin{document}$ \psi (r) = (1+r^2)^{-\beta } $\end{document}</tex-math></inline-formula> and <inline-formula><tex-math id="M5">\begin{document}$ f(r) $\end{document}</tex-math></inline-formula> on the flocking behaviour and give the decay rate of relative velocity. We also estimate the lower and upper bound of distance between agents. Finally, for the special case that agents moving on the 1-D space, we give sufficient conditions for the finite-time flocking.</p>

Analysis Of Non-Performing Loans Movement And Profitability Of The Banking Market In BH

The main motive of business operations of any bank is to achieve the highest profit possible and utilise it to increase dividends to shareholders, as well as to create conditions to increase their financial and credit potential by reinvesting in shares. The most important quality indicator of a loan portfolio is the share of non-performing loans to total operating assets and liabilities. In the first quarter of 2013, a trend of increasing non-performing loans in the legal entities sector increased by 2.6%, while there was stagnation with the population, i.e. slight decrease. The main objective of this paper is to examine the impact of the global financial crisis on the movement tendency of non-performing loans in the banking market in B&H, and their interdependence with the movement of profitability indicators by a simple regression equation.

HYSTERETIC CHARACTERISTIC WITH P-Δ EFFECT AND ITS INFLUENCE ON COLLAPSE RESISTANCE CAPACITY OF STRUCTURE UNDER EARTHQUAKES

P-Δ effect is one of the crucial reasons causing the collapse of structures under strong earthquake excitations. Numerical example shows that the lateral stiffness of structure decreases when the P-Δ effect is considered, and the backbone curve is easy to behave a negative slope when the geometric nonlinearity and the material nonlinearity are combined. A simplified trilinear curve including the elastic range, the yield range and the softening range is used to simulate the characteristic of the backbone curve, and the hysteretic models including the nonlinear elastic model, the full elasto-plastic model and the Clough model are developed. The influence of the hysteretic characteristic on the collapse resistance capacity of the structure is researched by a series of incremental dynamic analysis (IDA) for the single-degree-of-freedom (SDOF) system. The results demonstrate that the collapse resistance capacity of the structure is not always proportional to the energy dissipation capacity, while the biasing movement tendency when the structure goes into the negative stiffness branch is the main reason causing the collapse of the structure.

Water and Salt Regulation Mode of Soil Salinization Based on Change of Land Utilization

Soil Salinization poses a potential threat to human health, socio-economic development, national food security, local ecological environment, and also leads to substantial risks. Therefore, non-engineering and engineering control measures are required to reduce the risks and hazard levels. To achieve the goal, the nature of factors, which affect the salinity formation whether it can be regulated or not, had been first made a thorough analysis. Then the combined control mode which was water and salt regulation management simulation model of soil salinization based on change of land utilization had been put into pratice in Songyuan irrigated district. The specific process is as follows: under the premise of land utilization re-adjustment, three-dimensional hydrogeological numerical model was used as a tool to evaluate the distribution ratio of surface water and groundwater, taking the water table changes as clues to achieve the goal that verifies the mode of soil salinization in Songyuan irrigated district, and can forecast the water and salt movement tendency. On the other hand, from the perspective of critical groundwater depth of soil salinization to analyze its variation trend, different management measures were suggested. The research results showed that the mode of regulation can effectively head off the deterioration of salinization, and taking environmental and economic benefits into account, it can also provide basis for scientific amelioration and field management for saline soil.

Between Elite Interests and Pro-Poor Resistance: The Nigerian Courts and Labour-Led Anti-Fuel Price Hike Struggles (1999–2007)

Between 1999 and 2007, a popular Labour-led movement led a pro-poor struggle to resist the fuel price hike policy of the Nigerian government. Waged in the context of the poverty in which nearly 70 per cent of Nigerians lived, the operation of powerful incentives to raise fuel prices, and Labour's extraordinary socio-political leverage, these struggles triggered much government frustration. One of the strategies adopted by the government to legitimize its attempt to repress the movement was to resort to the courts. This article analyses, from a socio-legal perspective, the key cases relating to the validity of the government's attempts to repress the struggles. The article concludes that, although both pro- and anti-movement trends can be observed in the jurisprudence, the anti-movement tendency having so far prevailed in terms of formal legal precedent, the pro-movement (ie pro-poor) decisions have, as a result of their massive popular legitimacy, actually functioned as the “living law.”