title: Learning to extract geographic information from internet router hostnames

authors: Luckie, Matthew John

subjects: computer science

abstract: Geolocating Internet routers is a long-standing and notoriously difficult challenge, and current solutions lack the accuracy and adaptability to yield reliable results. We revisit this problem, designing a solution capable of accurately and comprehensively extracting geographic information that network operators embed into router interface hostnames. We train our system using dictionaries that map geographic codes to known locations, and constrain inferences with delay measurements conducted from a distributed set of vantage points. While most operators use known geographic codes, some devise their own mnemonic codes for locations, which our system also extracts and interprets. We evaluate our system on Internet-wide topology datasets, automatically learning regular expressions (regexes) for 1023 different domain suffixes with IPv4 routers, and 241 different domain suffixes with IPv6 routers. We received ground truth from operators of 13 domain suffixes, all of whom confirmed the correctness of our learned regexes, and that our system correctly interpreted 78.6% of the custom geographic codes. For these 13 suffixes, our solution more accurately extracts and interprets geographic information than the previous state-of-the-art, correctly geolocating 94.0% of router hostnames with a geohint compared to DRoP (56.6%) and HLOC (73.1%). This work advances the ability of researchers and network operators to characterize the location of critical Internet infrastructure, a foundational building block of network performance, security, and resilience analysis. We release the source code of our system and our inferred regexes.

text: Learning to extract geographic information from internet router hostnames Geolocating Internet routers is a long-standing and notoriously difficult challenge, and current solutions lack the accuracy and adaptability to yield reliable results. We revisit this problem, designing a solution capable of accurately and comprehensively extracting geographic information that network operators embed into router interface hostnames. We train our system using dictionaries that map geographic codes to known locations, and constrain inferences with delay measurements conducted from a distributed set of vantage points. While most operators use known geographic codes, some devise their own mnemonic codes for locations, which our system also extracts and interprets. We evaluate our system on Internet-wide topology datasets, automatically learning regular expressions (regexes) for 1023 different domain suffixes with IPv4 routers, and 241 different domain suffixes with IPv6 routers. We received ground truth from operators of 13 domain suffixes, all of whom confirmed the correctness of our learned regexes, and that our system correctly interpreted 78.6% of the custom geographic codes. For these 13 suffixes, our solution more accurately extracts and interprets geographic information than the previous state-of-the-art, correctly geolocating 94.0% of router hostnames with a geohint compared to DRoP (56.6%) and HLOC (73.1%). This work advances the ability of researchers and network operators to characterize the location of critical Internet infrastructure, a foundational building block of network performance, security, and resilience analysis. We release the source code of our system and our inferred regexes.

year: 2021

title: Canine (Canis familiaris) scent detection of invasive brown bullhead catfish (Ameiurus nebulosus) in water samples, and the effects of sample preservation

authors: Denby, Renee

abstract: Brown bullhead catfish (Ameiurus nebulosus) are an invasive freshwater fish widely recognised as a threat to New Zealand’s aquatic ecosystems. Early detection of new incursions increases the chances of eradication or control, but current survey methods such as netting and electrofishing are expensive and time consuming when fish are at low abundances. Domestic dogs (Canis familiaris) have previously demonstrated the ability to detect the presence of catfish in laboratory water samples, while discriminating against non-target species. The aim of this research was to investigate whether scent detection dogs could plausibly be employed in aquatic biosecurity programmes. The first experiment used a probe design to determine the scent-detection limits for catfish biomass under laboratory conditions. Water samples taken from tanks containing a standard catfish biomass concentration of 15.5 g/L (equivalent to 38,700 kg/ha) were assessed by the dogs and progressively diluted following the successful attainment of identification and discrimination criteria. All three participating dogs were able to detect the presence of catfish at biomass concentrations ≤12.6 kg/ha, with one dog achieving 4.6 kg/ha. Concurrently, the dogs were also able to successfully discriminate against a goldfish (Carassius auratus) distractor scent indicating that they are able to distinguish specific species of fish in the environment. The effects of sample preservation on dogs’ ability to identify and discriminate target scents have rarely been investigated. In practice, field samples from the environment would likely necessitate the preservation of samples prior to assessment by dogs. A second study used a repeated-measures reversal design to investigate dogs’ abilities to detect catfish at a standard biomass concentration of 310 kg/ha which had been refrigerated or frozen for up to 1-week. No statistically significant difference in hit rates between unpreserved (baseline 1: 93%, baseline 2: 98%), refrigerated (97%), and frozen (96%) samples was apparent; (F(3, 6) = 2.061502, p = 0.2069). These results indicate that dogs are capable of detecting and discriminating the scent of catfish at biomass concentrations typical of many freshwater ecosystems in the Waikato region. Further, limited periods of freezing or refrigeration appear to have no significant effect on the scent-detection abilities of dogs. Future research needs to be conducted with field samples from lakes and could explore the effects of preservation on low biomass concentrations. The results from this study are promising for the potential future employment of scent detection dogs in aquatic biosecurity monitoring.

text: Canine (Canis familiaris) scent detection of invasive brown bullhead catfish (Ameiurus nebulosus) in water samples, and the effects of sample preservation Brown bullhead catfish (Ameiurus nebulosus) are an invasive freshwater fish widely recognised as a threat to New Zealand’s aquatic ecosystems. Early detection of new incursions increases the chances of eradication or control, but current survey methods such as netting and electrofishing are expensive and time consuming when fish are at low abundances. Domestic dogs (Canis familiaris) have previously demonstrated the ability to detect the presence of catfish in laboratory water samples, while discriminating against non-target species. The aim of this research was to investigate whether scent detection dogs could plausibly be employed in aquatic biosecurity programmes. The first experiment used a probe design to determine the scent-detection limits for catfish biomass under laboratory conditions. Water samples taken from tanks containing a standard catfish biomass concentration of 15.5 g/L (equivalent to 38,700 kg/ha) were assessed by the dogs and progressively diluted following the successful attainment of identification and discrimination criteria. All three participating dogs were able to detect the presence of catfish at biomass concentrations ≤12.6 kg/ha, with one dog achieving 4.6 kg/ha. Concurrently, the dogs were also able to successfully discriminate against a goldfish (Carassius auratus) distractor scent indicating that they are able to distinguish specific species of fish in the environment. The effects of sample preservation on dogs’ ability to identify and discriminate target scents have rarely been investigated. In practice, field samples from the environment would likely necessitate the preservation of samples prior to assessment by dogs. A second study used a repeated-measures reversal design to investigate dogs’ abilities to detect catfish at a standard biomass concentration of 310 kg/ha which had been refrigerated or frozen for up to 1-week. No statistically significant difference in hit rates between unpreserved (baseline 1: 93%, baseline 2: 98%), refrigerated (97%), and frozen (96%) samples was apparent; (F(3, 6) = 2.061502, p = 0.2069). These results indicate that dogs are capable of detecting and discriminating the scent of catfish at biomass concentrations typical of many freshwater ecosystems in the Waikato region. Further, limited periods of freezing or refrigeration appear to have no significant effect on the scent-detection abilities of dogs. Future research needs to be conducted with field samples from lakes and could explore the effects of preservation on low biomass concentrations. The results from this study are promising for the potential future employment of scent detection dogs in aquatic biosecurity monitoring.

year: 2021

title: Transformative pedagogy and language learning in Maori and Irish contexts

authors: Glynn, Ted

subjects: transformative pedagogy

abstract: Establishing positive learning communities in classrooms where pedagogies are socially and culturally responsive and centred on shared life experiences is critical for the revitalisation of minoritised languages such as Irish and Māori, which lack the dominance and power of the wider languages of government and communication. Transformative pedagogy and pedagogical re-positioning of teachers are essential to legitimising and affirming minoritised languages in the classroom. Three small-scale New Zealand studies of emerging literacy in Māori are introduced, exemplifying a responsive and transformative pedagogy that enables teachers to position themselves as socially and culturally responsive participants within classroom contexts. These studies offer strategies that might facilitate the development of similar transformative pedagogy in Irish contexts also.

text: Transformative pedagogy and language learning in Maori and Irish contexts Establishing positive learning communities in classrooms where pedagogies are socially and culturally responsive and centred on shared life experiences is critical for the revitalisation of minoritised languages such as Irish and Māori, which lack the dominance and power of the wider languages of government and communication. Transformative pedagogy and pedagogical re-positioning of teachers are essential to legitimising and affirming minoritised languages in the classroom. Three small-scale New Zealand studies of emerging literacy in Māori are introduced, exemplifying a responsive and transformative pedagogy that enables teachers to position themselves as socially and culturally responsive participants within classroom contexts. These studies offer strategies that might facilitate the development of similar transformative pedagogy in Irish contexts also.

year: 2009