DOPING: Generative Data Augmentation for Unsupervised Anomaly Detection with GAN

Recently, the introduction of the generative adversarial network (GAN) and its variants has enabled the generation of realistic synthetic samples, which has been used for enlarging training sets. Previous work primarily focused on data augmentation for semi-supervised and supervised tasks. In this paper, we instead focus on unsupervised anomaly detection and propose a novel generative data augmentation framework optimized for this task. In particular, we propose to oversample infrequent normal samples - normal samples that occur with small probability, e.g., rare normal events. We show that these samples are responsible for false positives in anomaly detection. However, oversampling of infrequent normal samples is challenging for real-world high-dimensional data with multimodal distributions. To address this challenge, we propose to use a GAN variant known as the adversarial autoencoder (AAE) to transform the high-dimensional multimodal data distributions into low-dimensional unimodal latent distributions with well-defined tail probability. Then, we systematically oversample at the `edge' of the latent distributions to increase the density of infrequent normal samples. We show that our oversampling pipeline is a unified one: it is generally applicable to datasets with different complex data distributions. To the best of our knowledge, our method is the first data augmentation technique focused on improving performance in unsupervised anomaly detection. We validate our method by demonstrating consistent improvements across several real-world datasets.Comment: Published as a conference paper at ICDM 2018 (IEEE International Conference on Data Mining

Gender Differences, Risk and Probability Weights in Financial Decisions

Numerous studies have shown that decision makers do not usually treat probabilities linearly. Instead, people tend to overweight small probabilities and underweight large probabilities. The purpose of this research is to investigate whether women weigh probabilities differently than men. Besides that, this research also aims to examine whether women exhibit greater financial risk aversion than men. Women are commonly stereotyped as more risk averse than men in financial decision making. To examine some of the beliefs and preferences that underlie this difference, a stratified sample of 289 working adults (144 males and 145 females) aged 20–54 were interviewed within randomly selected geographical area across Penang Island. With this field experiment, we wish to generate a more credible and accurate results as compared to previous studies that used students as their subjects. This study confirmed the findings of previous researches that men and women differ in their financial decisions. In the gain domains, men tend to overweight smaller probabilities more than women (risk seeking) and women tend to underweight larger probabilities more than men (risk averse). While in the loss domains, when the probabilities were small, women were risk averse because they tend to overweight smaller probabilities more than men. When the probability became larger, women were exhibited as risk seeking as men because both of them perceived to have low chance of losin

Assessing the expected current and future competencies of quantity surveyors in the Malaysian built environment

Purpose: Quantity surveying is a profession that blends engineering, construction and economics. To be competent is to have the ability to apply the set of related knowledge, skills and abilities to perform a task effectively. This paper examines the competency requirements for quantity surveyors (QSs) in the face of changing and increasing client needs. Design/methodology/approach: Based on a detailed meta-analysis of the literature, 12 basic/core and 16 evolving competencies are identified. Primary data were gathered through a field survey involving practicing QSs from client, consultant and contractor organisations, and university students undertaking QS programmes in Malaysia. The data obtained were analysed using both descriptive and inferential statistical tools. Findings: The significance of the basic/core and evolving competencies are presented. Overall, the most important contemporary skills are cost planning, valuation of works, measurement/quantification and contract documentation. The evolved roles require expertise in communication and negotiation, ethics and professional conduct and value management. The analysis of variance (ANOVA) indicates there are misaligned expectations of the proficiency levels needed to provide contemporary and future services between practitioners in client/consultant organisations, contractors and new generation students. Originality/value: The findings provide guidance on the education, training and practice of quantity surveying to deal with emerging challenges in the dynamic built environments in Malaysia and beyond.</p

Fast and Efficient Malware Detection with Joint Static and Dynamic Features Through Transfer Learning

In malware detection, dynamic analysis extracts the runtime behavior of malware samples in a controlled environment and static analysis extracts features using reverse engineering tools. While the former faces the challenges of anti-virtualization and evasive behavior of malware samples, the latter faces the challenges of code obfuscation. To tackle these drawbacks, prior works proposed to develop detection models by aggregating dynamic and static features, thus leveraging the advantages of both approaches. However, simply concatenating dynamic and static features raises an issue of imbalanced contribution due to the heterogeneous dimensions of feature vectors to the performance of malware detection models. Yet, dynamic analysis is a time-consuming task and requires a secure environment, leading to detection delays and high costs for maintaining the analysis infrastructure. In this paper, we first introduce a method of constructing aggregated features via concatenating latent features learned through deep learning with equally-contributed dimensions. We then develop a knowledge distillation technique to transfer knowledge learned from aggregated features by a teacher model to a student model trained only on static features and use the trained student model for the detection of new malware samples. We carry out extensive experiments with a dataset of 86709 samples including both benign and malware samples. The experimental results show that the teacher model trained on aggregated features constructed by our method outperforms the state-of-the-art models with an improvement of up to 2.38% in detection accuracy. The distilled student model not only achieves high performance (97.81% in terms of accuracy) as that of the teacher model but also significantly reduces the detection time (from 70046.6 ms to 194.9 ms) without requiring dynamic analysis.Comment: Accepted for presentation and publication at the 21st International Conference on Applied Cryptography and Network Security (ACNS 2023

Behavioural and neurophysiological differences in working memory function of depressed patients and healthy controls

OBJECTIVE: Major depressive disorder (MDD) is associated with deficits in working memory. Several cognitive subprocesses interact to produce working memory, including attention, encoding, maintenance and manipulation. We sought to clarify the contribution of functional deficits in these subprocesses in MDD by varying cognitive load during a working memory task. METHODS: 41 depressed participants and 41 age and gender-matched healthy controls performed the n-back working memory task at three levels of difficulty (0-, 1-, and 2-back) in a pregistered study. We assessed response times, accuracy, and event-related electroencephalography (EEG), including P2 and P3 amplitudes, and frontal theta power (4-8 Hz). RESULTS: MDD participants had prolonged response times and more positive frontal P3 amplitudes (i.e., Fz) relative to controls, mainly in the most difficult 2-back condition. Working memory accuracy, P2 amplitudes and frontal theta event-related synchronisation did not differ between groups at any level of task difficulty. CONCLUSIONS: Depression is associated with generalized psychomotor slowing of working memory processes, and may involve compensatory hyperactivity in frontal and parietal regions. SIGNIFICANCE: These findings provide insights into MDD working memory deficits, indicating that depressed individuals dedicate greater levels of cortical processing and cognitive resources to achieve comparable working memory performance to controls

Identifying the Public’s Psychological Concerns in Response to COVID-19 Risk Messages in Singapore

Understanding the social-psychological processes that characterize communities’ reactions to a pandemic is the first step toward formulating risk communications that can lead to better health outcomes. This study examines comments on Facebook pages of five Singapore media outlets to understand what topics are being discussed by the public in reaction to the implemented precautionary measures in Singapore so as to infer their psychological concerns. Using Anchored Correlation Explanation as a topic modelling technique, this study examines around 10,000 comments and identifies 21 topics that are discussed. The 21 topics were categorized and organized into seven broad themes of psychological concerns. Implications for theory and practice are then discussed

A study of cycling intention among Universiti Utara Malaysia

Recently, the fast growing trend in the logistics industry causes the concern towards the green transportation arises from the society. Universiti Utara Malaysia (UUM), which having a 1061 hectares campus, would requires sufficient transportation for students to travel around the campus. The main mode of transportation provides by UUM management is buses.However, the shuttle bus services cannot fulfill the huge demand of students. So, many of the students prefer to drive their own private vehicles rather than using shuttle bus in campus. This would increase the carbon footprint and rate of accidents happened.In order to maintain the green environment, cycling behavior should be encourage for every students. Thus, this study aimed to determine factors that influence the student’s cycling intentions in campus by using Ajzen's Theory of Planned Behavior such as attitude, social environment, perception and infrastructure as a theoretical framework. Approximately 400 undergraduate students in UUM are chosen to complete the questionnaire provided by using convenience technique.The results of Cronbach’s alpha score for the independent variables (IV) and dependent variable (DV) is 0.944.There is significant relationship between IVs and DV among UUM students

Neuropsychiatric aspects of frontal lobe meningioma

© 2017 Elsevier B.V. This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/Brain tumours are known to typically present with neurological signs. Rarely, psychiatric symptoms can be the only manifestation of a brain tumour (Madhusoodanan et al., 2015). Though it is not uncommon for patients to present with psychiatric symptoms as the first clinical manifestation of a brain tumour, they are often non-specific and do not assist in localising the lesion. With the limited available research, it is found that neuropsychiatric disturbances are more frequently associated with frontal and temporolimbic lesions (Filley and Kleinschmidt-DeMasters, 1995). We present a case of a woman with frontal lobe meningioma who presented with a neuropsychiatric syndrome. Ms S is a 50 years old woman with chronic schizophrenia that was stable for several years on a combination of 4 mg of Risperidone and 50 mg of Quetiapine. In early April, she presented with abrupt onset of fever, tremors, generalised weakness, lethargy, confusion, vomiting and loose bowels. On examination, she was noted to have a body temperature of 37.8 °C with borderline tachycardia, bradykinesia, cogwheel rigidity and increased deep tendon reflexes. She did not have diaphoresis or autonomic instability. Laboratory tests showed elevated Creatine Kinase (CK) of 1800 U/L and neutrophilia. With clinical suspicion for NMS, her antipsychotic medications were ceased leading to a decrease in her CK to 60. She was discharged after being commenced on Olanzapine 2.5 mg daily, with positive effect for her psychotic symptoms. Nine days following discharge Ms S presented again with some symptoms of NMS such as worsening tremors, two episodes of fever, rigidity, bradykinesia and was disoriented to time. Her CK and white cell count, however, were within normal levels. She also had catatonic features such as increasingly withdrawn behaviour, mutism and negativism. On hospital presentation, she was afebrile and septic screen was negative, and she was admitted to the psychiatric unit for further investigation. Whilst assessment by the emergency physician suggested that the etiology of her symptoms were related to psychotropic drugs, the psychiatrist opined that it was more likely to be delirium and also considered a differential diagnosis of organic catatonia. CT head was done following the recommendation of the psychiatrist and it showed left frontal lobe meningioma with 12 cm midline shift with surrounding oedema. Ms S then was referred to the neurosurgery department and underwent surgical resection of the meningioma, which was successful. Ms S was a patient with a stable psychiatric illness, who presented with overlapping features of NMS and catatonia but no overt psychotic symptoms. Her neuropsychiatric symptoms were likely to be the pressure effect of a left frontal meningioma. The nature of her presentation made the process of diagnosis challenging, especially with the initial absence of neuroimaging, which resulted in a delay in diagnosis and appropriate treatment. Frontal lobe tumours have higher chances of producing mental status and personality changes with left sided lesions being more associated with inhibition of motor activity, impairment in motor and initiative aspect of speech, diminished generalization ability and general inertia of mental processes as seen in Ms S (Belyi, 1987). Given the absence of frank neurological symptoms to help localise the lesion, a high degree of clinical suspicion is usually required for early diagnosis. In patients suffering from schizophrenia, these symptoms can be explained by the illness itself and the side effects of the medications, thereby increasing the chances of missing the organic pathology due to diagnostic overshadowing of the primary psychiatric illness. Neuroimaging should be considered in patients with atypical psychiatric symptoms, new-onset psychosis, recurrence of previously well-controlled psychiatric symptoms, and if they become refractory to psychiatric treatment (Madhusoodanan et al., 2015). Clinical suspicion must be raised when these symptoms are vague, rare, non-specific, with no clear cause or trigger and are associated with several causative etiologies. Despite the many studies that have been done to correlate clinical presentation to the location of brain lesions, symptoms are still extremely unreliable diagnostic tools, and neuroimaging should be done when there is high suspicion index for organic pathology

Association between knowledge, attitude, and practice of nutrition and food labels among selected higher educational institution students in Klang Valley

Nutrition information on food labels guides consumers to purchase healthier food choices. Besides nutrition information, other factors influence a purchase. This study aims to determine the association between the knowledge, attitude, and practice (KAP) among tertiary students on nutrition and food labels. In this cross-sectional study, a total of 190 students from three tertiary institutions within Klang Valley completed an online survey. Self-administered questionnaires on sociodemographic profiles and KAP questions, available in Malay and English, were distributed. Association between KAP was determined using Spearman's Rho test, while multiple linear regression was used to assess predictors of KAP scores. Mean body mass index (BMI) of the respondents were 20.8 kg/m2. The total mean score for knowledge on food labels was 8.93, followed by attitude and practice with 3.86 and 3.11, respectively. There was a significant correlation between attitude and practice (p<0.005). Nutrient and total calorie information on food labels influenced purchases, with 56.3% of respondents reported looking at the total calorie content, followed by 55.7% and 49.5% checking on sugar and fats, respectively. In addition, other factors such as expiry date (60.9%) and price (59.9%) also influenced purchases. Overall, respondents have a positive attitude on food selection, but male respondents have better knowledge levels than females. However, female respondents interpret food labelling effectively compared to male respondents. Despite having good knowledge and attitude towards nutrition, respondents were still making poor choices. A more extensive range of healthier food options and targeted healthy eating campaigns may empower students to choose more nutritious foods