Using incomplete online metric maps for topological exploration with the Gap Navigation Tree

This paper presents a general, global approach to the problem of robot exploration, utilizing a topological data structure to guide an underlying Simultaneous Localization and Mapping (SLAM) process. A Gap Navigation Tree (GNT) is used to motivate global target selection and occluded regions of the environment (called “gaps”) are tracked probabilistically. The process of map construction and the motion of the vehicle alters both the shape and location of these regions. The use of online mapping is shown to reduce the difficulties in implementing the GNT.

Minimizing information leakage of tree-based RFID authentication protocols using alternate tree-walking

The privacy of efficient tree-based RFID authentication protocols is heavily dependent on the branching factor on the top layer. Indefinitely increasing the branching factor, however, is not a viable option. This paper proposes the alternate-tree walking scheme as well as two protocols to circumvent this problem. The privacy of the resulting protocols is shown to be comparable to that of linear-time protocols, where there is no leakage of information, whilst reducing the computational load of the database by one-third of what is required of tree-based protocols during authentication. We also identify and address a limitation in quantifying privacy in RFID protocols.

Meeting under the “Omei” Tree in the Torres Strait Islands : networks and funds of knowledge of mathematical ideas

This paper focuses on the turning point experiences that worked to transform the researcher during a preliminary consultation process to seek permission to conduct of a small pilot project on one Torres Strait Island. The project aimed to learn from parents how they support their children in their mathematics learning. Drawing on a community research design, a consultative meeting was held with one Torres Strait Islander community to discuss the possibility of piloting a small project that focused on working with parents and children to learn about early mathematics processes. Preliminary data indicated that parents use networks in their community. It highlighted the funds of knowledge of mathematics that exist in the community and which are used to teach their children. Such knowledges are situated within a community’s unique histories, culture and the voices of the people. “Omei” tree means the Tree of Wisdom in the Island community.

The benefits of tree-based models for stock selection

The identification of the primary drivers of stock returns has been of great interest to both financial practitioners and academics alike for many decades. Influenced by classical financial theories such as the CAPM (Sharp, 1964; Lintner, 1965) and APT (Ross, 1976), a linear relationship is conventionally assumed between company characteristics as derived from their financial accounts and forward returns. Whilst this assumption may be a fair approximation to the underlying structural relationship, it is often adopted for the purpose of convenience. It is actually quite rare that the assumptions of distributional normality and a linear relationship are explicitly assessed in advance even though this information would help to inform the appropriate choice of modelling technique. Non-linear models have nevertheless been applied successfully to the task of stock selection in the past (Sorensen et al, 2000). However, their take-up by the investment community has been limited despite the fact that researchers in other fields have found them to be a useful way to express knowledge and aid decision-making...

Synchrony of planting and proportions of susceptible varieties affect rice tungro disease epidemics in the Philippines.

Surveys were conducted in the Philippines from 1995 to 1997 to examine relationships between production environment variables (agroecosystem, synchrony of planting, and varieties planted) and the occurrence of rice tungro disease epidemics using correspondence analyses. The sites covered were Isabela, Nueva Ecija, North Cotabato, and Bohol provinces as well as Bicol region. Tungro disease incidence in farmers’ fields was assessed visually based on typical symptoms. In addition, leaf samples were collected from each field and indexed serologically by enzyme-linked immunosorbent assay for the presence of Rice tungro bacilliform (RTBV) and Rice tungro spherical (RTSV) viruses. Thus, relationships between the production environment variables and four disease variables — visual incidence and double RTBV and RTSV, single RTSV, and single RTBV infections — were examined. A higher association was observed between site and varieties planted as well as site and synchrony of planting than between site and agroecosystem or site and disease variables (visual incidence, double RTBV and RTSV and single RTSV infections). Disease variables depended on both varieties planted and synchrony of planting and correspondence analysis revealed that the low disease incidence in Nueva Ecija was associated with synchronous planting while the high disease incidence in Isabela was associated with the planting of susceptible varieties and asynchronous planting. Such findings suggest that the relationship between the last two factors at a given site is critical to predicting tungro occurrence. Moreover, correspondence analysis of the relationship among disease variables revealed that tungro incidence is associated with not only double RTBV and RTSV infections but also single RTSV infections. Implications of these results on tungro epidemiology and management are discussed.

Will the application of spatial multi criteria evaluation technique enhance the quality of decision-making to resolve boundary conflicts in the Philippines?

Systematic studies that evaluate the quality of decision-making processes are relatively rare. Using the literature on decision quality, this research develops a framework to assess the quality of decision-making processes for resolving boundary conflicts in the Philippines. The evaluation framework breaks down the decision-making process into three components (the decision procedure, the decision method, and the decision unit) and is applied to two ex-post (one resolved and one unresolved) and one ex-ante cases. The evaluation results from the resolved and the unresolved cases show that the choice of decision method plays a minor role in resolving boundary conflicts whereas the choice of decision procedure is more influential. In the end, a decision unit can choose a simple method to resolve the conflict. The ex-ante case presents a follow-up intended to resolve the unresolved case for a changing decision-making process in which the associated decision unit plans to apply the spatial multi criteria evaluation (SMCE) tool as a decision method. The evaluation results from the ex-ante case confirm that the SMCE has the potential to enhance the decision quality because: a) it provides high quality as a decision method in this changing process, and b) the weaknesses associated with the decision unit and the decision procedure of the unresolved case were found to be eliminated in this process.

Abundance of Natural Riparian Forests and Tree Plantations in the Amudarya Delta of Uzbekistan and their impact on emissions of soil-borne greenhouse gases

Through a forest inventory in parts of the Amudarya river delta, Central Asia, we assessed the impact of ongoing forest degradation on the emissions of greenhouse gases (GHG) from soils. Interpretation of aerial photographs from 2001, combined with data on forest inventory in 1990 and field survey in 2003 provided comprehensive information about the extent and changes of the natural tugai riparian forests and tree plantations in the delta. The findings show an average annual deforestation rate of almost 1.3% and an even higher rate of land use change from tugai forests to land with only sparse tree cover. These annual rates of deforestation and forest degradation are higher than the global annual forest loss. By 2003, the tugai forest area had drastically decreased to about 60% compared to an inventory in 1990. Significant differences in soil GHG emissions between forest and agricultural land use underscore the impact of the ongoing land use change on the emission of soil-borne GHGs. The conversion of tugai forests into irrigated croplands will release 2.5 t CO2 equivalents per hectare per year due to elevated emissions of N2O and CH4. This demonstrates that the ongoing transformation of tugai forests into agricultural land-use systems did not only lead to a loss of biodiversity and of a unique ecosystem, but substantially impacts the biosphere-atmosphere exchange of GHG and soil C and N turnover processes.

Towards configuring the Internet for social development in the Philippines

The Internet is one of the most significant information and communication technologies to emerge during the end of the last century. It created new and effective means by which individuals and groups communicate. These advances led to marked institutional changes most notably in the realm of commercial exchange: it did not only provide the high-speed communication infrastructure to business enterprises; it also opened them to the global consumer base where they could market their products and services. Commercial interests gradually dominated Internet technology over the past several years and have been a factor in the increase of its user population and enhancement of infrastructure. Such commercial interests fitted comfortably within the structures of the Philippine government. As revealed in the study, state policies and programs make use of Internet technology as an enabler of commercial institutional reforms using traditional economic measures. Yet, despite efforts to maximize the Internet as an enabler for market-driven economic growth, the accrued benefits are yet to come about; it is largely present only in major urban areas and accessible to a small number of social groups. The failure of the Internet’s developmental capability can be traced back to the government’s wholesale adoption of commercial-centered discourse. The Internet’s developmental gains (i.e. instrumental, communicative and emancipatory) and features, which were always there since its inception, have been visibly left out in favor of its commercial value. By employing synchronic and diachronic analysis, it can be shown that the Internet can be a vital technology in promoting genuine social development in the Philippines. In general, the object is to realize a social environment of towards a more inclusive and participatory application of Internet technology, equally aware of the caveats or risks the technology may pose. It is argued further that there is a need for continued social scientific research regarding the social as and developmental implications of Internet technology at local level structures, such social sectors, specific communities and organizations. On the meta-level, such approach employed in this research can be a modest attempt in increasing the calculus of hope especially among the marginalized Filipino sectors, with the use of information and communications technologies. This emerging field of study—tentatively called Progressive Informatics—must emanate from the more enlightened social sectors, namely: the non-government, academic and locally-based organizations.

Transmission system expansion planning considering combined operation of wind farms and energy storage systems

An energy storage system (ESS) can provide ancillary services such as frequency regulation and reserves, as well as smooth the fluctuations of wind power outputs, and hence improve the security and economics of the power system concerned. The combined operation of a wind farm and an ESS has become a widely accepted operating mode. Hence, it appears necessary to consider this operating mode in transmission system expansion planning, and this is an issue to be systematically addressed in this work. Firstly, the relationship between the cost of the NaS based ESS and its discharging cycle life is analyzed. A strategy for the combined operation of a wind farm and an ESS is next presented, so as to have a good compromise between the operating cost of the ESS and the smoothing effect of the fluctuation of wind power outputs. Then, a transmission system expansion planning model is developed with the sum of the transmission investment costs, the investment and operating costs of ESSs and the punishment cost of lost wind energy as the objective function to be minimized. An improved particle swarm optimization algorithm is employed to solve the developed planning model. Finally, the essential features of the developed model and adopted algorithm are demonstrated by 18-bus and 46-bus test systems.

An HIV epidemic is ready to emerge in the Philippines

Background: The state of the HIV epidemic in the Philippines has been described as "low and slow", which is in stark contrast to many other countries in the region. A review of the conditions for HIV spread in the Philippines is necessary. Methods: We evaluated the current epidemiology, trends in behaviour and public health response in the Philippines to identify factors that could account for the current HIV epidemic, as well as to review conditions that may be of concern for facilitating an emerging epidemic. Results: The past control of HIV in the Philippines cannot be attributed to any single factor, nor is it necessarily a result of the actions of the Filipino government or other stakeholders. Likely reasons for the epidemic's slow development include: the country's geography is complicated; injecting drug use is relatively uncommon; a culture of sexual conservatism exists; sex workers tend to have few clients; anal sex is relatively uncommon; and circumcision rates are relatively high. In contrast, there are numerous factors suggesting that HIV is increasing and ready to emerge at high rates, including: the lowest documented rates of condom use in Asia; increasing casual sexual activity; returning overseas Filipino workers from high-prevalence settings; widespread misconceptions about HIV/AIDS; and high needle-sharing rates among injecting drug users. There was a three-fold increase in the rate of HIV diagnoses in the Philippines between 2003 and 2008, and this has continued over the past year. HIV diagnoses rates have noticeably increased among men, particularly among bisexual and homosexual men (114% and 214% respective increases over 2003-2008). The average age of diagnosis has also significantly decreased, from approximately 36 to 29 years. Conclusions: Young adults, men who have sex with men, commercial sex workers, injecting drug users, overseas Filipino workers, and the sexual partners of people in these groups are particularly vulnerable to HIV infection. There is no guarantee that a large HIV epidemic will be avoided in the near future. Indeed, an expanding HIV epidemic is likely to be only a matter of time as the components for such an epidemic are already present in the Philippines.

HCI for city farms : design challenges & opportunities

Urban agriculture plays an important role in many facets of food security, health and sustainability. The city farm is one such manifestation of urban agriculture: it functions as a location centric social hub that supplies food, education, and opportunities for strengthening the diverse sociocultural fabrics of the local community. This paper presents the case of Northey Street City Farm in Brisbane, Australia as an opportunity space for design. The paper iden-tifies four areas that present key challenges and opportunities for HCI design that support social sustainability of the city farm: A preference for face-to-face contact leads to inconsistencies in shared knowledge; a dependence on volun-teers and very limited resources necessitates easily accessible interventions; other local urban agricultural activity needing greater visibility; and the vulner-ability of the physical location to natural phenomenon, in this instance flooding, present a design challenge and a need to consider disaster management.

The Indigenous digital collectif : the case among the iTadian of Northern Philippines

This paper reports on an adaptation of Callon and Law’s (1995) hybrid collectif derived from research conducted on the usage of mobile phones and internet technologies among the iTadian indigenous people of the Cordillera region, northern Philippines. Results brings to light an indigenous digital collectif—an emergent effect from the translation of both human and non-human heterogeneous actors as well as pre-existent networks, such as: traditional knowledge and practices, kinship relations, the traditional exchange of goods, modern academic requisites, and advocacies for indigenous rights. This is evinced by the iTadian’s enrolment of internet and mobile phone technologies. Examples include: treating these technologies as an efficient communicative tool, an indicator of well-being, and a portable extension of affective human relationships. Alternatively, counter-enrolment strategies are also at play, which include: establishing rules of acceptable use on SMS texting and internet access based on traditional notions of discretion, privacy, and the customary treatment of the dead. Within the boundaries of this digital collectif reveal imbrications of pre-existing networks like traditional customs, the kinship system across geophysical boundaries, the traditional exchange of mail and other goods, and the advocacy of indigenous rights. These imbrications show that the iTadian digital collectif fluently configures itself to a variety of networked ontologies without losing its character.

Cost and environmental efficiency of rice farms in South Korea

We examine cost and nutrient use efficiency of farms and determine the cost to move farms to nutrient-efficient operation using Data Envelopment Analysis (DEA) with a dataset of 96 rice farms in Gangwon province of South Korea from 2003 to 2007. Our findings show that improvements in technical efficiency would result in both lower production costs and better environmental performance. It is, however, not costless for farms to move from their current operation to the environmentally efficient operation. On average, this movement would increase production costs by 119% but benefit the water system through an approximately 69% reduction in eutrofying power (EP). The average estimated cost of each EP kg of aggregate nutrient reduction is approximately one thousand two hundred won. For technically efficient farms, there is a trade-off between cost and environmental efficiency. We also find that the environmental performance of farms varies across farms and regions. We suggest that agri-environmental policies should be (re)designed to improve both cost and environmental performance of rice farms.