A location-based personal task reminder for mobile users

[[abstract]]Personal task reminders have been indispensable for modern people, in order to remind them of their tasks at specific circumstances. Traditional paper-based reminders are still useful, but they cannot be organized efficiently. Electronic reminders based on the calendar in cell phones are more efficient and gaining popularity, but such reminders are mostly triggered by time. In many situations, tasks are only meaningful to be performed at a specific location, so it would be useful if reminders for those tasks can be triggered only when the person to be reminded is physically near or located at that location. Therefore, in this research, we develop a location-based personal task reminder for Android-based smartphones and tablets. To distinguish our work from existing ones that rely solely on the GPS technology, we take advantage of the ubiquity of IEEE 802.11 WLAN infrastructure to compliment the “blind spots” of GPS location sensing. Combining the two technologies makes it possible for the personal task reminder to be effective in both indoor and outdoor environments. We also propose two operating models for the personal task reminder to boost the usability of the application. Furthermore, as long as the WLAN infrastructure is available, our work as a foundation of location-based services can easily be extended to be used in many other scenarios, such as guiding in public transportation systems or tourist attractions, location-based learning, and even caring of the Dementia residents.[[incitationindex]]SCI[[booktype]]電子版[[booktype]]紙

Threshold Effects in Cigarette Addiction: An Application of the Threshold Model in Dynamic Panels

We adopt the threshold model of myopic cigarette addiction to US state-level panel data. The threshold model is used to identify the structural effects of cigarette demand determinants across the income stratification. Furthermore, we apply a bootstrap approach to correct for the small-sample bias that arises in the dynamic panel threshold model with fixed effects. Our empirical results indicate that there exists the heterogeneity of smoking dynamics across consumers.Cigarettes demand, price elasticity, threshold regression model, dynamic panel model, bias correction, bootstrap

A Crowdsourcing Approach to Promote Safe Walking for Visually Impaired People

[[abstract]]Visually impaired people have difficulty in walking freely because of the obstacles or the stairways along their walking paths, which can lead to accidental falls. Many researchers have devoted to promoting safe walking for visually impaired people by using smartphones and computer vision. In this research we propose an alternative approach to achieve the same goal - we take advantage of the power of crowdsourcing with machine learning. Specifically, by using smartphones carried by a vast amount of visually normal people, we can collect the tri-axial accelerometer data along with the corresponding GPS coordinates in large geographic areas. Then, machine learning techniques are used to analyze the data, turning them into a special topographic map in which the regions of outdoor stairways are marked. With the map installed in the smartphones carried by the visually impaired people, the Android App we developed can monitor their current outdoor locations and then enable an acoustic alert whey they are getting close to the stairways.[[notice]]補正完

Non-repudiation in pure mobile ad hoc network

Within the last decade, the use of wireless technologies has become more prevalent. Wireless networks have flexible architectures with data transferred via radio waves and can be divided into two categories; infrastructure-based wireless networks and mobile ad hoc network. The mobile ad hoc network (MANET) is an autonomous system which can be dynamically built without pre-existing infrastructure or a trusted third party (TTP). Due to these infrastructure-less and self-organized characteristics, MANET encounters different problems from infrastructure-based wired network, such as key management, power shortage, and security issues. This paper will further divide MANETs into pure ad hoc networks which do not contain a TTP and organized ad hoc networks which contain an offline TTP, and then focus on the security issues especially the non-repudiation issue between two mobile nodes which communicate in pure ad hoc networks

QoS Issues of Using Probabilistic Non-Repudiation Protocol in Mobile Ad Hoc Network Environment

So as to guarantee the fairness of electronic transactions, users may require a NonRepudiation (NR) service in any type of network. However, most existing NR protocols cannot work properly in a Mobile Ad hoc Network (MANET) due to their characteristics (e.g. limited resources and lack of central authority). The design of the Probabilistic NonRepudiation Protocol (PNRP) is comparatively suitable for the nature of a MANET, but it still poses some QoS issues. This article points out the QoS issues which are caused by using PNRP in a MANET environment. These issues explain the difficult of performing PNRP in such an infrastructureless environment

Orderly Spanning Trees with Applications

We introduce and study the {\em orderly spanning trees} of plane graphs. This algorithmic tool generalizes {\em canonical orderings}, which exist only for triconnected plane graphs. Although not every plane graph admits an orderly spanning tree, we provide an algorithm to compute an {\em orderly pair} for any connected planar graph $G$, consisting of a plane graph $H$ of $G$, and an orderly spanning tree of $H$. We also present several applications of orderly spanning trees: (1) a new constructive proof for Schnyder's Realizer Theorem, (2) the first area-optimal 2-visibility drawing of $G$, and (3) the best known encodings of $G$ with O(1)-time query support. All algorithms in this paper run in linear time.Comment: 25 pages, 7 figures, A preliminary version appeared in Proceedings of the 12th Annual ACM-SIAM Symposium on Discrete Algorithms (SODA 2001), Washington D.C., USA, January 7-9, 2001, pp. 506-51

Data Citation Practices among Taiwan Social Scientists: Some Preliminary Findings

This poster describes some preliminary findings from a larger study that investigates the characteristics of social sciences papers that have used externally acquired datasets in the empirical analyses. Specifically, this poster will focus the characteristics of data reporting and data citation behaviors. Using 511 sample articles published within 2011 and 2015, the distributions of data reporting and data citation as well as paper locations where data were mentioned will be described and discussed

Three Tramp Dacetine Ants in Taiwan

Trabalho de projeto do mestrado em Economia (Economia Financeira), apresentado à Faculdade de Economia da Universidade de Coimbra.Neste trabalho, as taxas forward foram utilizadas para prever os valores futuros da Estrutura de Prazo das Taxas de Juro, em diferentes pontos desta estrutura, e em diferentes contextos do sistema financeiro, e abrange o período que vai do final de 2004 ao final de 2014. As taxas spot e forward foram construidas a partir do modelo de Nelson, Siegel e Svensson (1994), e para a anlisar a relação existente entre estes dois tipos de taxas, recorreu-se o método de cointegração proposto por Johansen (1988, 1991). Para períodos mais curtos, foram construídas taxas forward instantâneas, que antecipam as taxas spot instantâneas a distâncias que vão de 1 a 10 dias. Para períodos mais longos, foram construídas taxas forward com prazo de 1 mês, que antecipam as taxas spot com o mesmo prazo, a distâncias que vão de 1 a 12 meses. Nas taxas instantâneas, verificou-se que existe cointegração entre todas as taxas forward e as taxas spot que antecipam, nas estimações que abrangem a totalidade da amostra, e para alguns casos quando se divide a amostra em sub-períodos. Nas taxas mensais, pelo contrário, apenas em alguns casos foi constatada a existência de cointegração, quer para a totalidade do período quer para os sub-períodos. De seguida, foi estimado o Modelo de Correção dos Erros proposto por Johansen (1988, 1991), e recorreu-se à analise da função impulso-resposta, para as taxas cointegradas. As taxas mensais apresentaram sempre um comportamento mais instável, quando comparadas com as taxas instantâneas. Entretanto, com a divisão do período, as taxas instantâneas apresentaram um comportamento instável, principalmente para o sub-período 2012-2014