Enforcement and Spectrum Sharing: Case Studies of Federal-Commercial Sharing

To promote economic growth and unleash the potential of wireless broadband, there is a need to introduce more spectrally efficient technologies and spectrum management regimes. That led to an environment where commercial wireless broadband need to share spectrum with the federal and non-federal operations. Implementing sharing regimes on a non-opportunistic basis means that sharing agreements must be implemented. To have meaning, those agreements must be enforceable.\ud \ud With the significant exception of license-free wireless systems, commercial wireless services are based on exclusive use. With the policy change facilitating spectrum sharing, it becomes necessary to consider how sharing might take place in practice. Beyond the technical aspects of sharing, that must be resolved lie questions about how usage rights are appropriately determined and enforced. This paper is reasoning about enforcement in a particular spectrum bands (1695-1710 MHz and 3.5 GHz) that are currently being proposed for sharing between commercial services and incumbent spectrum users in the US. We examine three enforcement approaches, exclusion zones, protection zones and pure ex post and consider their implications in terms of cost elements, opportunity cost, and their adaptability

Enforcement in Dynamic Spectrum Access Systems

The spectrum access rights granted by the Federal government to spectrum users come with the expectation of protection from harmful interference. As a consequence of the growth of wireless demand and services of all types, technical progress enabling smart agile radio networks, and on-going spectrum management reform, there is both a need and opportunity to use and share spectrum more intensively and dynamically. A key element of any framework for managing harmful interference is the mechanism for enforcement of those rights. Since the rights to use spectrum and to protection from harmful interference vary by band (licensed/unlicensed, legacy/newly reformed) and type of use/users (primary/secondary, overlay/underlay), it is reasonable to expect that the enforcement mechanisms may need to vary as well.\ud \ud In this paper, we present a taxonomy for evaluating alternative mechanisms for enforcing interference protection for spectrum usage rights, with special attention to the potential changes that may be expected from wider deployment of Dynamic Spectrum Access (DSA) systems. Our exploration of how the design of the enforcement regime interacts with and influences the incentives of radio operators under different rights regimes and market scenarios is intended to assist in refining thinking about appropriate access rights regimes and how best to incentivize investment and growth in more efficient and valuable uses of the radio frequency spectrum

The Cost of Knowing: An Economic Evaluation of Context Acquisition in DSA Systems

Much of the research in Dynamic Spectrum Access (DSA) has focused on the details of the enabling technologies. While this has been quite useful in establishing the technical feasibility of DSA systems, it has missed an important aspect of the overall DSA problem space: in order for operators, regulators and users to be interested in deploying DSA based networks, the expected costs should be in proportion to what the users are realistically willing to pay for services. Consequently, it is important to conduct cost estimates for different DSA approaches in parallel with the technical research.\ud \ud In this paper, we will explore how the cost experienced by primary and secondary users can influence their incentives for participation in DSA. To do this, we compare the costs and cost structures of four context awareness approaches from each of them. The costs we will consider are incremental capital costs over a basic software radio using four different context acquisition approaches (sensing, databases, sensor networks, and cooperative sharing). Since DSA is still a relatively new research field, there is a lot of uncertainty associated with incremental cost analyses. As a result, the cost analysis is parameterized to allow for explicit reasoning about the bounds of cost components

Enforcement and Network Capacity in Spectrum Sharing: Quantifying the Benefits of Different Enforcement Scenarios

Recent studies have forecasted major growth in mobile broadband traffic. Due to the predicted high growth rate of mobile broadband traffic over the coming years (demand), there is a need for more wireless network capacity (supply). One of the major approaches to expand mobile wireless capacity is to add more spectrum to the market by enabling “spectrum sharing”. The FCC has issued many reports indicating that the US is dangerously close to running out of capacity for mobile data, which is why the FCC and the NTIA have been working continually to enable spectrum sharing.\ud \ud Spectrum sharing has moved from being a radical notion to a principal policy focus in the past decade. Enabling spectrum sharing regimes means that sharing agreements must be implemented. To have meaning, those agreements must be enforceable. The focus of this paper is to determine the relationship between enforcement methodologies and benefits of spectrum sharing through sharing between government and commercial users. Sharing between the government incumbents (i.e. Federal or non-Federal agencies) and commercial wireless broadband operators/users is one of the key forms of spectrum sharing that is recommended by the NTIA, the FCC, and the PCAST report. To address this problem, we build a model to quantitatively examine the relationships between different enforcement scenarios and sharing benefits. We model two case studies, 1695-1710 MHz band and 3550-3650 MHz band

Invasiveness of pharmacokinetic studies in children: a systematic review

Objectives: To explore whether pharmacokinetic (PK) studies in paediatric patients are becoming less invasive. This will be evaluated by analysing the number of samples and volume of blood collected for each study within four different decades. Methods: A systematic literature review was performed to identify PK papers describing number of samples and volume of blood collected in studies of children aged 0–18 years. The following databases were searched: MEDLINE (1946 to December 2015), EMBASE (1974 to December 2015), International Pharmaceutical Abstracts (1970 to December 2015), CINAHL and Cochrane Library. Results: A total of 549 studies were identified between 1974 and 2015. There were 52 studies between 1976 and 1985, 105 between 1986 and 1995, 201 between 1996 and 2005 and 191 between 2006 and 2015. The number of blood samples collected per participant increased between the first two decades (p=0.013), but there was a decrease in the number of samples in the subsequent two decades (p=0.044 and p<0.001, respectively). Comparing the first and last decades, there has been no change in the number of blood samples collected. There were no significant differences in volume collected per sample or total volume per child in any of the age groups. There was however a significant difference in the frequency of blood sampling between population PK studies (median 5 (IQR 3–7)) and non-population PK studies (median 8 (IQR 6–10); p=<0.001). Conclusions: The number of blood samples collected for PK studies in children rose in 1985–1995 and subsequently declined. There was no overall change in the volume of blood collected over the 4 decades. The usage of population PK methods reduces the frequency of blood sampling in children

Identifying Fake Facebook Profiles Using Data Mining Techniques

Facebook, the popular online social network, has changed our lives. Users can create a customized profile to share information about themselves with others that have agreed to be their 'friend'. However, this gigantic social network can be misused for carrying out malicious activities. Facebook faces the problem of fake accounts that enable scammers to violate users' privacy by creating fake profiles to infiltrate personal social networks. Many techniques have been proposed to address this issue. Most of them are based on detecting fake profiles/accounts, considering the characteristics of the user profile. However, the limited profile data made publicly available by Facebook makes it ineligible for applying the existing approaches in fake profile identification. Therefore, this research utilized data mining techniques to detect fake profiles. A set of supervised (ID3 decision tree, k-NN, and SVM) and unsupervised (k-Means and k-medoids) algorithms were applied to 12 behavioral and non-behavioral discriminative profile attributes from a dataset of 982 profiles. The results showed that ID3 had the highest accuracy in the detection process while k-medoids had the lowest accuracy

Variation in clearance and invasiveness of pharmacokinetic studies in children

Inter-individual variation in pharmacokinetic parameters of drugs can have profound effects on drug safety in children. Midazolam and morphine are among the most commonly used drugs in critically children. Theophylline has seen several cycles of enthusiasm and unpopularity over the years, although oral theophylline is now rarely used, IV aminophylline is still used regularly in severe asthma. These drugs are metabolised by hepatic enzymes (CYP3A4, CYP1A2 and glucuronidation) which have variable expression. Three systematic reviews were conducted in order to explore the inter-individual variation of clearance of these drugs in children. The first systematic review evaluated the inter-individual variability of midazolam clearance in children. Midazolam is predominantly metabolised by CYP3A4. Twenty two PK studies were identified. The mean clearance of midazolam varied between 0.78 to 3.5 ml/min/kg in neonates and 1.1 to 15 ml/min/kg in children. Age was a statistically significant predictor of clearance (p<0.05). Critical illness was however not a statistically significant predictor of midazolam clearance after adjusting for other covariates (p=0.279). There was a statistically significant difference between the coefficient of variation of midazolam clearance in preterm neonates (91%) and children (40%) (p=0.002). However, there was no significant difference between the CV in critically ill and non-critically ill children. A second systematic review evaluated the variability of theophylline clearance. Theophylline is metabolised by CYP1A2. Twenty nine studies were identified. Mean clearance of theophylline varied between 0.2 and 2 ml/min/kg. Age was a significant predictor of theophylline clearance (p<0.05). There was, however, no significant difference between the CV of theophylline in any age group. The CV of theophylline clearance was not significantly different between critically ill (35%) and non-critically ill (39%) (p=0.403). A sub-analysis of children also did not show any significant difference between critically ill and non-critically ill (p=0.418). A third systematic review evaluated the variability of morphine clearance in children. Morphine is metabolised by UGT. Twenty studies were identified. The mean clearance of the studies identified varied between 2 and 16 ml/min/kg in neonates and 19 to 52 ml/min/kg in children. Critical illness was not a statistically significant predictor of morphine clearance. Analyses of the limited data showed no statistically significant differences in CV between any age groups. There was also no statistically significant difference between the CV in critically ill and non-critically ill children. In all the studies, a major limitation was the limited number of PK studies in children. Invasive studies should be avoided in children therefore, a final systematic review evaluated the invasiveness of PK studies over two decades. The number of blood samples collected per child was significantly lower in studies carried out between 2004-2014 than those between 1981-1990 (p=0.013). Furthermore, the total volume of blood collected in 24 hours for PK studies was significantly lower in new decade than old (p=0.025). However, there was no difference in the volume of blood collected per sample. There were 35 population PK studies, all of which were new studies. The median number of blood samples in population PK studies (median 6, [IQR: 4-9]) was significantly lower than non-population PK studies (median: 8, [IQR: 6-10]) (p=0.007). In conclusion, age is a risk factor for inter-individual variation of midazolam clearance in children. It is also an important predictor of midazolam, morphine and theophylline clearance in children. Therefore, age appropriate dosing is important. More PK studies are required to determine the effect of critical illness on the variability of clearance of these drugs. The utilisation of population PK methods should be encouraged to minimise invasiveness of PK studies. New methodologies for reducing sample volumes and frequency should be considered in all studies

Variation in clearance and invasiveness of pharmacokinetic studies in children

Inter-individual variation in pharmacokinetic parameters of drugs can have profound effects on drug safety in children. Midazolam and morphine are among the most commonly used drugs in critically children. Theophylline has seen several cycles of enthusiasm and unpopularity over the years, although oral theophylline is now rarely used, IV aminophylline is still used regularly in severe asthma. These drugs are metabolised by hepatic enzymes (CYP3A4, CYP1A2 and glucuronidation) which have variable expression. Three systematic reviews were conducted in order to explore the inter-individual variation of clearance of these drugs in children. The first systematic review evaluated the inter-individual variability of midazolam clearance in children. Midazolam is predominantly metabolised by CYP3A4. Twenty two PK studies were identified. The mean clearance of midazolam varied between 0.78 to 3.5 ml/min/kg in neonates and 1.1 to 15 ml/min/kg in children. Age was a statistically significant predictor of clearance (p<0.05). Critical illness was however not a statistically significant predictor of midazolam clearance after adjusting for other covariates (p=0.279). There was a statistically significant difference between the coefficient of variation of midazolam clearance in preterm neonates (91%) and children (40%) (p=0.002). However, there was no significant difference between the CV in critically ill and non-critically ill children. A second systematic review evaluated the variability of theophylline clearance. Theophylline is metabolised by CYP1A2. Twenty nine studies were identified. Mean clearance of theophylline varied between 0.2 and 2 ml/min/kg. Age was a significant predictor of theophylline clearance (p<0.05). There was, however, no significant difference between the CV of theophylline in any age group. The CV of theophylline clearance was not significantly different between critically ill (35%) and non-critically ill (39%) (p=0.403). A sub-analysis of children also did not show any significant difference between critically ill and non-critically ill (p=0.418). A third systematic review evaluated the variability of morphine clearance in children. Morphine is metabolised by UGT. Twenty studies were identified. The mean clearance of the studies identified varied between 2 and 16 ml/min/kg in neonates and 19 to 52 ml/min/kg in children. Critical illness was not a statistically significant predictor of morphine clearance. Analyses of the limited data showed no statistically significant differences in CV between any age groups. There was also no statistically significant difference between the CV in critically ill and non-critically ill children. In all the studies, a major limitation was the limited number of PK studies in children. Invasive studies should be avoided in children therefore, a final systematic review evaluated the invasiveness of PK studies over two decades. The number of blood samples collected per child was significantly lower in studies carried out between 2004-2014 than those between 1981-1990 (p=0.013). Furthermore, the total volume of blood collected in 24 hours for PK studies was significantly lower in new decade than old (p=0.025). However, there was no difference in the volume of blood collected per sample. There were 35 population PK studies, all of which were new studies. The median number of blood samples in population PK studies (median 6, [IQR: 4-9]) was significantly lower than non-population PK studies (median: 8, [IQR: 6-10]) (p=0.007). In conclusion, age is a risk factor for inter-individual variation of midazolam clearance in children. It is also an important predictor of midazolam, morphine and theophylline clearance in children. Therefore, age appropriate dosing is important. More PK studies are required to determine the effect of critical illness on the variability of clearance of these drugs. The utilisation of population PK methods should be encouraged to minimise invasiveness of PK studies. New methodologies for reducing sample volumes and frequency should be considered in all studies

A Forensic Scheme for Revealing Post-processed Region Duplication Forgery in Suspected Images

Recent researches have demonstrated that local interest points alone can be employed to detect region duplication forgery in image forensics. Authentic images may be abused by copy-move tool in Adobe Photoshop to fully contained duplicated regions such as objects with high primitives such as corners and edges. Corners and edges represent the internal structure of an object in the image which makes them have a discriminating property under geometric transformations such as scale and rotation operation. They can be localised using scale-invariant features transform (SIFT) algorithm. In this paper, we provide an image forgery detection technique by using local interest points. Local interest points can be exposed by extracting adaptive non-maximal suppression (ANMS) keypoints from dividing blocks in the segmented image to detect such corners of objects. We also demonstrate that ANMS keypoints can be effectively utilised to detect blurred and scaled forged regions. The ANMS features of the image are shown to exhibit the internal structure of copy moved region. We provide a new texture descriptor called local phase quantisation (LPQ) that is robust to image blurring and also to eliminate the false positives of duplicated regions. Experimental results show that our scheme has the ability to reveal region duplication forgeries under scaling, rotation and blur manipulation of JPEG images on MICC-F220 and CASIA v2 image datasets