Optional Features Research Articles

Security and Protocol Exploit Analysis of the 5G Specifications

The third generation partnership project released its first 5G security specifications in March 2018. This paper reviews the proposed security architecture and its main requirements and procedures and evaluates them in the context of known and new protocol exploits. Although security has been improved from previous generations, our analysis identifies potentially unrealistic 5G system assumptions and protocol edge cases that can render 5G communication systems vulnerable to adversarial attacks. For example, null encryption and null authentication are still supported and can be used in valid system configurations. With no clear proposal to tackle pre-authentication message-based exploits, mobile devices continue to implicitly trust any serving network, which may or may not enforce a number of optional security features, or which may not be legitimate. Moreover, several critical security and key management functions are considered beyond the scope of the specifications. The comparison with known 4G long-term evolution protocol exploits reveals that the 5G security specifications, as of Release 15, Version 1.0.0, do not fully address the user privacy and network availability challenges.

International Real Estate Review

This paper develops a pricing model and derives a closed-form formula for valuing mortgage-backed securities (MBSs) that embed a barrier option feature while the optimal prepayment or refinancing choices of borrowers are endogenously determined. Given that ¡§real estate investors¡¨ tend to prepay a loan relentlessly, an MBS with a high concentration of investor borrowers implies a lower MBS value. We specify the prepayment behavior of borrowers by using the first hitting time as a proxy for the trigger point of prepayment when house prices or interest rates hit a pre-determined barrier. Our results show that the MBS value is positively related to loan to value and house price volatility while negatively related to the proportion of real estate investors and interest rate volatility. We also find evidence which shows that the MBS value may increase due to the effects of the ¡§longevity¡¨ of mortgages, which outweigh the effects of default or prepayment as house price volatility increases. This model provides a faster pricing tool of MBSs than Monte Carlo simulation while retaining higher model accuracy and consistency than the hazard model approach.

Characterization of GNSS observations from a Nexus 9 Android tablet

Global navigation satellite system (GNSS) raw data were made available in the application programming interface (API) starting from version 7.0 of the Android operating system. This opens possibilities for precise positioning with Android devices, as externally generated GNSS corrections can now be included in the positioning estimation in a convenient way. The Nexus 9 tablet is a good candidate for an early assessment of the raw GNSS observables and the corresponding derived precise positions, as it also supports many of the optional features and observation types presented by the API, including carrier phase observations which play an important role in many precise positioning techniques. It is known from the previous studies that poor handling of multipath in smartphones and tablets is a big challenge when it comes to precise GNSS positioning with these kinds of devices. Hence, this study assesses the raw GNSS observations and the calculated precise positions of the Nexus 9 tablet in two experimental setups with different multipath impacts. In addition, various biases of the observations are determined, some of which is not present on high-grade geodetic receivers. The analysis is done for GPS and GLONASS, which are supported by the Nexus 9 tablet. The study shows that multipath plays an important role for the expected accuracy of the calculated precise positions, both due to the induced error on the measurements, and due to loss of lock of the GNSS signals, which significantly affects precise positioning from carrier-phase measurements. Position accuracy ranges from just below 1 m to a few decimeters between the experimental setups with moderate and low levels of multipath respectively, for positioning based on carrier-phase observations. It is, furthermore, demonstrated that consideration of code inter-system biases and code inter-frequency biases of the Nexus 9 tablet are crucial for differential GNSS with multiple GNSS systems and when GLONASS observations are used in the positioning solutions. Besides these expected biases, also other less expected behaviors were discovered in the Nexus 9 GNSS observations, including various drifts for the code and phase observations. This study also proposes some strategies to handle these.

POEMS syndrome: clinical update

POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M-protein, skin changes) is a rare paraneoplastic syndrome, caused by a plasma cell proliferative disorder, which is most commonly lambda restricted. The neurological hallmark, which forms one of the mandatory criteria for diagnosis, is a subacute onset demyelinating neuropathy, which can be rapidly disabling and painful. A number of multi-system features are also characteristic of this disorder, and certainly not restricted to those included in its acronym, which though limited, remains a useful and memorable name, helping distinguish POEMS syndrome from other paraproteinaemic neuropathies. The discovery of vascular endothelial growth factor (VEGF) in association with POEMS syndrome has been extremely useful in aiding clinical diagnosis, and monitoring response to treatment, as well as helping understand the underlying mechanism of disease. Interestingly, however, treatment targeting VEGF has been disappointing, suggesting other disease mechanisms or inflammatory processes are also important. Current understanding of the pathogenesis of POEMS syndrome is outlined in detail in the accompanying article by Cerri et al. Here, we review the clinical features of POEMS syndrome, differential diagnosis and available treatment options, based on current literature.

Concept and features of entrepreneurial activity as an object of administrative and legal protection

The article is devoted to the study of the category “entrepreneurial activity”, its definition in legal sense, as well as clarification of the legal nature and characteristics. On the basis of a comprehensive analysis of the existing national legislation, as well as systematization of scientific views on the establishment of the content and essence of entrepreneurial activity, the authorʼs definition of this type of socially useful economic activity is formulated.
 Under the entrepreneurial activity it is proposed to understand the independent type of economic activity, which is carried out at its own risk and under its responsibility by the subjects of entrepreneurial activity (individuals and legal entities registered in the manner prescribed by law), which is systematic, initiative, lawful and innovative and aimed at obtaining personal income and public benefit.
 The main and additional features that are characteristic of entrepreneurial activity in the conditions of modern development of the state economy and financial level of life of the society are determined and described. The main features of entrepreneurial activities include: systematic, innovative, risk-taking, initiative, full property liability, focus on personal profit, legality. To the optional (additional) features of entrepreneurial activity include: high degree of adaptability to existing socio-economic, political and legal conditions in the state, focus on achieving public economic results, substantiation, directness and mediation of such activities.
 Generalized functions of entrepreneurial activity, through which the legal aspects of the content and features of this type of economic activity, are revealed.

Coding Prony\u2019s method in MATLAB and applying it to biomedical signal filtering

BackgroundThe response of many biomedical systems can be modelled using a linear combination of damped exponential functions. The approximation parameters, based on equally spaced samples, can be obtained using Prony’s method and its variants (e.g. the matrix pencil method). This paper provides a tutorial on the main polynomial Prony and matrix pencil methods and their implementation in MATLAB and analyses how they perform with synthetic and multifocal visual-evoked potential (mfVEP) signals.This paper briefly describes the theoretical basis of four polynomial Prony approximation methods: classic, least squares (LS), total least squares (TLS) and matrix pencil method (MPM). In each of these cases, implementation uses general MATLAB functions. The features of the various options are tested by approximating a set of synthetic mathematical functions and evaluating filtering performance in the Prony domain when applied to mfVEP signals to improve diagnosis of patients with multiple sclerosis (MS).ResultsThe code implemented does not achieve 100%-correct signal approximation and, of the methods tested, LS and MPM perform best. When filtering mfVEP records in the Prony domain, the value of the area under the receiver-operating-characteristic (ROC) curve is 0.7055 compared with 0.6538 obtained with the usual filtering method used for this type of signal (discrete Fourier transform low-pass filter with a cut-off frequency of 35 Hz).ConclusionsThis paper reviews Prony’s method in relation to signal filtering and approximation, provides the MATLAB code needed to implement the classic, LS, TLS and MPM methods, and tests their performance in biomedical signal filtering and function approximation. It emphasizes the importance of improving the computational methods used to implement the various methods described above.

Social and demographic characteristics, features of disease course and treatment options of inflammatory bowel disease in Russia: results of two multicenter studies

Social and demographic characteristics, features of disease course and treatment options of inflammatory bowel disease in Russia: results of two multicenter studies

Lentiviral transduction of mammalian cells for fast, scalable and high-level production of soluble and membrane proteins.

Structural, biochemical and biophysical studies of eukaryotic soluble and membrane proteins require their production in milligram quantities. Although large-scale protein expression strategies based on transient or stable transfection of mammalian cells are well established, they are associated with high consumable costs, limited transfection efficiency or long and tedious selection of clonal cell lines. Lentiviral transduction is an efficient method for the delivery of transgenes to mammalian cells and unifies the ease of use and speed of transient transfection with the robust expression of stable cell lines. In this protocol, we describe the design and step-by-step application of a lentiviral plasmid suite, termed pHR-CMV-TetO2, for the constitutive or inducible large-scale production of soluble and membrane proteins in HEK293 cell lines. Optional features include bicistronic co-expression of fluorescent marker proteins for enrichment of co-transduced cells using cell sorting and of biotin ligase for in vivo biotinylation. We demonstrate the efficacy of the method for a set of soluble proteins and for the G-protein-coupled receptor (GPCR) Smoothened (SMO). We further compare this method with baculovirus transduction of mammalian cells (BacMam), using the type-A γ-aminobutyric acid receptor (GABAAR) β3 homopentamer as a test case. The protocols described here are optimized for simplicity, speed and affordability; lead to a stable polyclonal cell line and milligram-scale amounts of protein in 3-4 weeks; and routinely achieve an approximately three- to tenfold improvement in protein production yield per cell as compared to transient transduction or transfection.

SOME ASPECTS OF LEGAL REGULATION OF THE USE OF VEHICLES THAT ARE REGISTERED IN THE EUROPEAN UNION (“EUROCARS”)

The article considers the legal regimes for the use of vehicles registered outside theterritoryofUkraine(«Eurocar»), identifies the main and optional features of such cars. Also, the actual definition of the category of «Eurocar» is proposed. Within the framework of the work, the judicial practice is analyzed in the sphere of bringing the person to responsibility for non-payment of customs payments within the term established by law, as well as possible options for solving the issue.

Progress in the Conceptual Design of the Helical Fusion Reactor FFHR-d1

The LHD-type helical fusion reactor FFHR has been studied to realize steady-state fusion power generation without a need for current drive and free from disruption. The conceptual design studies of FFHR are steadfastly progressing based on the presently ongoing experiments in the Large Helical Device (LHD). In order to enhance the attractive features of the base option of FFHR-d1A, which is similar to LHD, configuration optimization is being considered for FFHR-d1C. Slight modification of the helical coil trajectory gives an improved condition both for the plasma confinement and the MHD stability. In order to overcome the difficulty for construction and maintenance associated with the three-dimensional structure, innovative ideas are being explored for the superconducting magnet, divertor, and blanket. For the superconducting helical coils, the joint-winding method confirms a fast manufacturing process. The helical divertor is reexamined and practical feasibility is discussed. The maintenance method of the helical divertor and the helically-segmented breeder blanket is a serious issue and a plausible solution is proposed.

Circumstances and their Roles in the Development of Editorials

The study identified and categorised the features of the circumstantial options in the selected newspaper editorials and interpreted the content expressed by the options. The options were then compared to the opinions expressed in the text. These were done with a view to investigating the roles played by circumstances in the development of editorials. Data for the study were elicited from newspapers. Seven editorials were purposively selected from the 28 editorials collected. The selected editorials cut across different aspects of life, including safety and security, crime, politics, economics and religion. Each editorial was broken down into sentences, but only the main clauses in the sentences were analysed. The findings revealed that some circumstantial options were prominent in the texts. These included location, manner, extent and cause. They also revealed that with circumstances in editorials, editorials can help to articulate a better understanding of the news media, the unique handling of language and text, and the impact on thought and culture. The study concluded that the experiential meta-function in systemic functional linguistics helped to highlight the features of editorials.

Word order preferences of Tagalog-speaking adults and children

This article investigates the word order preferences of Tagalog-speaking adults and five- and seven-year-old children. The participants were asked to complete sentences to describe pictures depicting actions between two animate entities. Adults preferred agent-initial constructions in the patient voice but not in the agent voice, while the children produced mainly agent-initial constructions regardless of voice. This agent-initial preference, despite the lack of a close link between the agent and the subject in Tagalog, shows that this word order preference is not merely syntactically-driven (subject-initial preference). Additionally, the children’s agent-initial preference in the agent voice, contrary to the adults’ lack of preference, shows that children do not respect the subject-last principle of ordering Tagalog full noun phrases. These results suggest that language-specific optional features like a subject-last principle take longer to be acquired.

Biogas upgrading by amine scrubbing: solvent comparison between MDEA and MDEA/MEA blend

Biogas upgrading to biomethane has received particular attention in recent years as a key strategy to produce a natural gas-substitute from biomass. Among the available upgrading technologies, amine-based absorption is an interesting option because of its low electric power consumption and very high methane recovery rates. This paper assesses the energy and economic performance of a biogas upgrading process involving chemical absorption with two different aqueous solvent formulations: 50%w MDEA and a 20%w/20%w MDEA/MEA blend. The process performance is evaluated with Aspen Plus and the optimal process conditions are determined with a multi-objective optimization approach targeting the maximum efficiency and minimum specific equipment cost. In the proposed scheme, to make the system energy-self-sufficient, an internal combustion engine burns a fraction of the raw biogas stream to co-generate both the electric power for the upgrading process and the thermal power required for solvent regeneration.Aqueous MDEA turns out to be more efficient (Pareto dominant curve) and less expensive than the MDEA/MEA blend, as a result of the lower regeneration energy (0.94 kJ/Nm3BM/h vs 1.43 kJ/Nm3BM/h) which yields to lower energy consumptions and smaller engine sizes. Even though the cost estimates are subject to a higher degree of uncertainty, the MDEA option features an expected specific total equipment cost as low as 1,550 €/(Nm3BM/h)) vs. 1,850 €/(Nm3BM/h)) for the MDEA/MEA blend.

Annuity Options in Public Pension Plans: The Curious Case of Social Security Leveling

Social Security Leveling is an annuity option that allows defined benefit pension participants to receive a level income throughout retirement by taking a larger pension benefit before they reach Social Security eligibility. This option can enable retirees to access a greater proportion of their employer pension wealth at younger ages and have a smoother income stream in retirement, at the cost of a lower pension payment during later retirement years. To evaluate the desirability of this option, a retiree must consider pricing, anticipated life expectancy, and income needs throughout retirement. We show that plan design features of this annuity option favor those who expect a shorter-than-average period of retirement and who have higher personal discount rates. This study uses detailed administrative records on all North Carolina state and local government retirees from 2009 through 2014. Among individuals claiming retirement benefits before age 62, over 20% chose the Social Security Leveling annuity option. Using multivariate regression analysis, this study finds evidence that North Carolina public sector retirees choose the Social Security Leveling option in a manner that is consistent with predictions.

Automated Versatile DIY Microscope Platform.

A versatile robot platform is presented that can be used to design low-cost custom made microscopes in do-ityourself construction. All components like the framework, the linear drives, robot controller and driver, the illumination and the camera are described as well as optional features like fluorescence microscopy and auto-focus. Finally, an application for automated imaging of 3D-cell cultures in 96-well microplates is presented.

On the history of studying of medieval Armenian fresco painting

The history of studying of Armenian medieval monumental painting, which covers the only one 20th century, is being analyzed in the article. Researchers of this important branch of the fine arts of Armenia were started comparatively late. The reasons which have been indicated were historical and political circumstances in the country, which for many centuries had been deprived of statehood; a fragmentary state of preservation of the artistic material; and as well as an erroneous ideas about the negative attitude of the Armenian Church to the images, which had coming from the Middle Ages. This errancy is existing in the modern times, even in the scientific community. The author traces the main stages in the study of the Armenian wall painting: from the first works of the Ani archaeological campaigns participants, on the borderline of the 19th and 20th centuries — to the activities of three outstanding scientists — L. A. Durnovo (1885–1963), S. Der Nersessian (1896–1989) and N. G. Kotanjyan (1928–2013). The history of art owes these people the existence of a holistic view of the medieval monumental painting of Armenia. Profound study of both the frescoes themselves and the medieval written sources related to them gave the possibility to these scientists to demonstrate the main development ways of Armenian mural painting, to reveal the artistic directions and peculiar national features of it; to determine the features of decorative programs and iconographic options, as well as the specific properties of Armenian prime coating under the murals and frescoes painting technique. The contribution of each of these scientists to the study of the monumental painting of medieval Armenia has been individually estimated.

Gamma Trading Skills in Hedge Funds

This paper explores the gamma trading, timing and managerial skills of individual hedge funds across categories. We replicate the non-linear payoffs of hedge funds with traded options, with the option features being endogenously defined in our replication model. On top of providing a flexible tool to create individual benchmarks for the payoff curvature of hedge fund, the model helps assigning hedge fund styles into three categories: directional with market timing skills, non-directional and market timers. Overall, our empirical results show that, on 30% of replicated funds in our sample (10,958 funds), there is no evidence of the presence of selection skills once a fund performance is adjusted with respect to the option-based benchmark and the traditional option-based factors of Agarwal and Naik (2004). This research has an incremental potential to stimulate additional research in the field of hedge funds performance replication through passive strategies.

Corticoinsular circuits encode subjective value expectation and violation for effortful goal-directed behavior

We are presented with choices each day about how to invest our effort to achieve our goals. Critically, these decisions must frequently be made under conditions of incomplete information, where either the effort required or possible reward to be gained is uncertain. Such choices therefore require the development of potential value estimates to guide effortful goal-directed behavior. To date, however, the neural mechanisms for this expectation process are unknown. Here, we used computational fMRI during an effort-based decision-making task where trial-wise information about effort costs and reward magnitudes was presented separately over time, thereby allowing us to model distinct effort/reward computations as choice-relevant information unfolded. We found that ventromedial prefrontal cortex (vmPFC) encoded expected subjective value. Further, activity in dorsal anterior cingulate (dACC) and anterior insula (aI) reflected both effort discounting as well as a subjective value prediction error signal derived from trial history. While prior studies have identified these regions as being involved in effort-based decision making, these data demonstrate their specific role in the formation and maintenance of subjective value estimates as relevant information becomes available.

Pricing convertible bonds

Abstract Convertible bonds are an important segment of the corporate bond market although their pricing is compromised by the presence of complex option features and difficulty in measuring the risk factors needed as inputs to standard valuation models. Using a unique sample of pure U.S. convertible bonds, devoid of other optionality, we show that underpricing is affected mainly by the degree of underlying asset volatility and liquidity. Convertible bonds with a greater debt component (more credit sensitive), longer time to maturity and lower quality credit ratings are also found to be more underpriced. The global financial crisis (GFC) is an episode with high-underlying asset volatility and one subject to short-selling constraints. During this period there was deep convertible bond discounting, which highlights the importance of market conditions and the temporal, rather than systematic, nature of the pricing errors.

The contrasting moderating effect of exploration on the relationship between stock options/stock ownership and a firm’s long-term performance

PurposeThe purpose of this paper is to investigate the contrasting moderating effect of a firm’s exploration on the relationship between the two types of long-term incentives (stock options/stock ownership) for the chief executive officers and a firm’s long-term performance. Even though the two types of incentives are designed to improve long-term performance, the degrees of impact on long-term performance differ. Based on behavioral agency theory, this study theoretically and empirically examines the role of a firm’s exploration on the above relationship.Design/methodology/approachThis study used three archival sources to obtain data on stock options, stock ownership, patents and exploration, financial measures, and others. Based on a sample of 1,963 firms in various industries from 1995 to 2006, this study tested the moderating effect of a firm’s exploration on the relationship between stock options/ownership and a firm’s performance.FindingsThis study reveals the contrasting moderating effect of a firm’s exploration on the relationship between stock options/ownership and a firm’s long-term performance: a positive moderating effect on the relationship between stock options and performance and a negative moderating effect on the relationship between stock ownership and performance. In addition, empirical evidence was added on the inverted U-shaped relationship between stock ownership and a firm’s long-term performance.Originality/valueThere is little research on a firm’s internal characteristics that strengthen or weaken the effects of stock options and stock ownership on firm performance. This study demonstrates the differential moderating effects of exploration on the relationship between stock options/stock ownership and long-term performance. Such effects of exploration come from the different risk features of stock options and stock ownership. The key implication is that stock options could be more effective than stock ownership to enhance a firm’s long-term performance when a firm has a strong exploration orientation.