title: Measuring cybercrime in calls for police service

authors: Kwon, D

abstract: Conventional police databases contain much information on cybercrime, but extracting it remains a practical challenge. This is because these databases rarely contain labels that could be used to automatically retrieve all cybercrime incidents. In this article, we present a supervised machine learning method for extracting cybercrime incidents in calls for police service datasets. Data from the Korean National Police (2020, 9 months, N = 15 million call logs) is used for the demonstration. We combined methods of keyword query selection, minority oversampling, and majority voting techniques to develop a classifier. Three classification techniques, including Naïve Bayes, linear SVM, and kernel SVM, were tested, and the kernel model was chosen to build the final model (accuracy, 93.4%; F1-score, 92.4). We estimate that cybercrime only represents 4.6% of the cases in the selected dataset (excluding traffic-related incidents), but that it can be prevalent with some crime types. We found, for example, that about three quarters (76%) of all fraud incidents have a cyber dimension. We conclude that the cybercrime classification method proposed in this study can support further research on cybercrime and that it offers considerable advantages over manual or keyword-based approaches.

text: Measuring cybercrime in calls for police service Conventional police databases contain much information on cybercrime, but extracting it remains a practical challenge. This is because these databases rarely contain labels that could be used to automatically retrieve all cybercrime incidents. In this article, we present a supervised machine learning method for extracting cybercrime incidents in calls for police service datasets. Data from the Korean National Police (2020, 9 months, N = 15 million call logs) is used for the demonstration. We combined methods of keyword query selection, minority oversampling, and majority voting techniques to develop a classifier. Three classification techniques, including Naïve Bayes, linear SVM, and kernel SVM, were tested, and the kernel model was chosen to build the final model (accuracy, 93.4%; F1-score, 92.4). We estimate that cybercrime only represents 4.6% of the cases in the selected dataset (excluding traffic-related incidents), but that it can be prevalent with some crime types. We found, for example, that about three quarters (76%) of all fraud incidents have a cyber dimension. We conclude that the cybercrime classification method proposed in this study can support further research on cybercrime and that it offers considerable advantages over manual or keyword-based approaches.

year: 2024

title: Evaluating biochar and fungi for the remediation of PFAS in landfill leachates.

authors: Chauhan, Rushirajsinh

abstract: Per- and polyfluoroalkyl substances (PFAS) have become widespread environmental 
contaminants, often detected in various ecosystems, including waterways, and found in 
numerous products such as cosmetics. In New Zealand, PFAS contamination poses a 
significant risk to both environmental and human health. This study works towards developing 
an innovative PFAS removal technology utilizing biochar to adsorb PFAS and fungi to degrade 
PFAS. The work was broken into several stages, the first finding suitable growing conditions 
for fungi on biochar and attempting to quantify the growth, the second examining biochar 
adsorption properties, first with humic acid and the second with PFAS. Three different types 
of fungi, Oyster, Shiitake, and Pekepeke (native to New Zealand), were cultivated on biochar 
and substrates made from woodchips and other organic materials. Growth was best on a 
combination of biochar and woodchip. The chloroform fumigation method showed that the 
oyster/biochar culture had a growth of 17.6 mg/g/day, while shitake/biochar was 14.6 mg/g/day 
and the oyster/biochar/woodchip had a growth of 20.7 mg/g/day.
Biochar had a low adsorption capacity (5 mg/g) and affinity for humic acid. The Freundlich 
isotherm gave a marginally better fit to adsorption data than the Langmuir and SIPS isotherms. 
The low adsorption was due to both humic acid and biochar having predominantly negative 
charges, biochar had a surface charge of 0.824 mM -ve charges/g biochar, six times that of dry 
soil which has a surface charge of 0.125 mM/g soil. Biochar was tested for its ability to adsorb 
three species of PFAS (PFBSA, PFHexA, PHHepA). Under the environmentally relevant 
PFAS concentration ranges tested, biochar adsorbed all of the PFAS, resulting in no PFAS 
being able to be detected in solution. PFAS adsorption to the biochar is predominantly by 
hydrogen bonding

text: Evaluating biochar and fungi for the remediation of PFAS in landfill leachates. Per- and polyfluoroalkyl substances (PFAS) have become widespread environmental 
contaminants, often detected in various ecosystems, including waterways, and found in 
numerous products such as cosmetics. In New Zealand, PFAS contamination poses a 
significant risk to both environmental and human health. This study works towards developing 
an innovative PFAS removal technology utilizing biochar to adsorb PFAS and fungi to degrade 
PFAS. The work was broken into several stages, the first finding suitable growing conditions 
for fungi on biochar and attempting to quantify the growth, the second examining biochar 
adsorption properties, first with humic acid and the second with PFAS. Three different types 
of fungi, Oyster, Shiitake, and Pekepeke (native to New Zealand), were cultivated on biochar 
and substrates made from woodchips and other organic materials. Growth was best on a 
combination of biochar and woodchip. The chloroform fumigation method showed that the 
oyster/biochar culture had a growth of 17.6 mg/g/day, while shitake/biochar was 14.6 mg/g/day 
and the oyster/biochar/woodchip had a growth of 20.7 mg/g/day.
Biochar had a low adsorption capacity (5 mg/g) and affinity for humic acid. The Freundlich 
isotherm gave a marginally better fit to adsorption data than the Langmuir and SIPS isotherms. 
The low adsorption was due to both humic acid and biochar having predominantly negative 
charges, biochar had a surface charge of 0.824 mM -ve charges/g biochar, six times that of dry 
soil which has a surface charge of 0.125 mM/g soil. Biochar was tested for its ability to adsorb 
three species of PFAS (PFBSA, PFHexA, PHHepA). Under the environmentally relevant 
PFAS concentration ranges tested, biochar adsorbed all of the PFAS, resulting in no PFAS 
being able to be detected in solution. PFAS adsorption to the biochar is predominantly by 
hydrogen bonding

year: 2024-10-20

title: What are Bicultural Psychological Services?

authors: Thomas, David R.

subjects: Maori students

abstract: The present paper is intended to stimulate discussion on the development of bicultural psychological services in Aotearoa/New Zealand, focusing primarily on services provided by psychologists trained in tertiary educational institutions. Patterns of biculturalism emerging among human services in New Zealand are briefly described, then topics relevant to the provision of bicultural psychological services, that are appropriate for both Maori and Pakeha, in Aotearoa are discussed.

text: What are Bicultural Psychological Services? The present paper is intended to stimulate discussion on the development of bicultural psychological services in Aotearoa/New Zealand, focusing primarily on services provided by psychologists trained in tertiary educational institutions. Patterns of biculturalism emerging among human services in New Zealand are briefly described, then topics relevant to the provision of bicultural psychological services, that are appropriate for both Maori and Pakeha, in Aotearoa are discussed.

year: 1993