Identifying non-pseudo-alternating knots by using the free factor property of minimal genus Seifert surfaces

Pseudo-alternating knots and links are defined constructively via their Seifert surfaces. By performing Murasugi sums of primitive flat surfaces, such a knot or link is obtained as the boundary of the resulting surface. Conversely, it is hard to determine whether a given knot or link is pseudo-alternating or not. A major difficulty is the lack of criteria to recognize whether a given Seifert surface is decomposable as a Murasugi sum. In this paper, we propose a new idea to identify non-pseudo-alternating knots. Combining with the uniqueness of minimal genus Seifert surface obtained through sutured manifold theory, we demonstrate that two infinite classes of pretzel knots are not pseudo-alternating.

Time

This chapter examines the Buddhist version of the eternalism-presentism dispute. While all Buddhists hold that no existing thing is eternal, some did claim that past and future things are existent in the same sense in which presently existing things are, while other Buddhists denied that past and future things may be said to exist. The chapter begins by discussing the question of whether time is itself a real entity, examining an argument developed by Nāgārjuna against the view that time serves as the container that makes temporal relations possible. The bulk of the chapter is given over to a prolonged examination of the arguments given for and against eternalism. A major difficulty for the eternalist is to reconcile their view with the Buddhist orthodoxy that all is impermanent. The presentist is faced with the problem of explaining just what the present is if there is no past or future.

Symbolic Dynamics for the Anisotropic N-Centre Problem at Negative Energies

The planar N-centre problem describes the motion of a particle moving in the plane under the action of the force fields of N fixed attractive centres: $$\begin{aligned} \ddot{x}(t)=\sum _{j=1}^N\nabla V_j(x(t)-c_j). \end{aligned}$$ x ¨ ( t ) = ∑ j = 1 N ∇ V j ( x ( t ) - c j ) . In this paper we prove symbolic dynamics at slightly negative energy for an N-centre problem where the potentials $$V_j$$ V j are positive, anisotropic and homogeneous of degree $$-\alpha _j$$ - α j : $$\begin{aligned} V_j(x)=|x|^{-\alpha _j}V_j\left( \frac{x}{|x|}\right) . \end{aligned}$$ V j ( x ) = | x | - α j V j x | x | . The proof is based on a broken geodesics argument and trajectories are extremals of the Maupertuis’ functional. Compared with the classical N-centre problem with Kepler potentials, a major difficulty arises from the lack of a regularization of the singularities. We will consider both the collisional dynamics and the non collision one. Symbols describe geometric and topological features of the associated trajectory.

Model for assessment of external transport costs

The term "external effect" can be explain as a condition that occurs when production or consumption activities of an entity affect the welfare of other(s) subject(s) without having to pay compensation for that impact. The major difficulty for determining external costs is that they cannot be confirmed through the application of market laws and well-known market analysis with interactive effects of demand and supply. The transport greatly affects the quality of life of people, flora and fauna. The interest of studying transport externalities is objective of several researches and special attention is given to how reduce these negative externalities of transport in practice. This paper considers the external transport costs, their significance and their monetary values estimated in relevant EU studies. The methodology for estimating external transport costs as well as specification of a model for assessment of these costs in Republic of North Macedonia is also shown in this paper. The results obtained by this model are discussed and commented.

Numerical Investigation of Gas-Liquid Two-Phase Flows in a Cylindrical Channel

Two-phase flows are widely encountered in many natural phenomena and industrial processes. The presence of one or more interfaces between the two phases presents a major difficulty which makes the modeling and the simulation of this type of flow complex. This work consists in performing a three-dimensional numerical simulation of a two-phase Hydrogen-Water flow inside a horizontal cylindrical channel. The results are obtained in the form of velocity contours, enthalpy and pressures.

Travelling Santa Problem: Optimization of a Million-Households Tour Within One Hour

Finding the shortest tour visiting all given points at least ones belongs to the most famous optimization problems until today [travelling salesman problem (TSP)]. Optimal solutions exist for many problems up to several ten thousand points. The major difficulty in solving larger problems is the required computational complexity. This shifts the research from finding the optimum with no time limitation to approaches that find good but sub-optimal solutions in pre-defined limited time. This paper proposes a new approach for two-dimensional symmetric problems with more than a million coordinates that is able to create good initial tours within few minutes. It is based on a hierarchical clustering strategy and supports parallel processing. In addition, a method is proposed that can correct unfavorable paths with moderate computational complexity. The new approach is superior to state-of-the-art methods when applied to TSP instances with non-uniformly distributed coordinates.

On the Application of Context Teaching in Teaching Chinese as a Foreign Language

Chinese culture is broad, profound and rich in connotation. Often a word, word, sentence in different chapters will have different meanings, which is undoubtedly a major difficulty for students learning Chinese as a second language. With the continuous development of context theory, the important position of context teaching method in the teaching process has gradually emerged. Therefore, this paper will combine the actual situation of TCFL classroom, analyze and research the application strategy of context teaching in TCFL classroom.

Therapeutic itinerary of people with leprosy: paths, struggles, and challenges in the search for care

ABSTRACT Objectives: to understand how the therapeutic itineraries of people affected by leprosy are processed. Methods: this is a descriptive, qualitative study, conducted in April 2018 in Barão de Grajaú in Maranhão, with interviews in the form of narratives of seven patients who had a late leprosy diagnosis. Results: the search for diagnosis is a major difficulty in accessing health services, resulting in a late diagnosis and, consequently, with the presence of visible deformities. It was noticed that the health units do not have a flow, nor protocols for comprehensive treatment, and these people are referred to a referral unit in another state to perform sputum smear microscopy. Final Considerations: leprosy control actions need reformulations that seek the relationship between operational activities, epidemiological indicators and risk factors, in accordance with the real needs of each region, thus highlighting the gaps evidenced in the therapeutic itineraries.

Building Lexical Resources for Dialectical Arabic

The natural language processing of Arabic dialects faces a major difficulty, which is the lack of lexical resources. This problem complicates the penetration and the business of related technologies such as machine translation, speech recognition, and sentiment analysis. Current solutions frequently use lexica, which are specific to the task at hand and limited to some language variety. Modern communication platforms including social media gather people from different nations and regions. This has increased the demand for general-purpose lexica towards effective natural language processing solutions. This chapter presents a collaborative web-based platform for building a cross-dialectical, general-purpose lexicon for Arabic dialects. This solution was tested by a team of two annotators, a reviewer, and a lexicographer. The lexicon expansion rate was measured and analyzed to estimate the overhead required to reach the desired size of the lexicon. The inter-annotator reliability was analyzed using Cohen's Kappa.

LAW REGULATION OF CALCULATION OF THE INDIVIDUAL DEBT RATIO OF LOCAL GOVERNMENT UNIT

The aim of the considerations is focused on the analysis of the law regulation of calculation of the individual debt ratio of local government unit. The new rules governing debt limits were introduced in 2014 (Articles 242-244 of the Act on Public Finance, hereinafter referred to as APF) and immediately became a major difficulty in planning and managing local finances in territorial self-government units. The next four years proved many defects and inconveniences in implementing new norms, while “creativity” of the financial sector of local authority units demonstrated that they were quite easy to evade. The structure of the maximum ratio limiting obligations due to titles specified by the lawmaker, due in a particular year, is closely related to the provisions of APF. For the first time it was used in evaluating the budgets passed for 2014. The essence of this legal regulation consists in comparing two ratios, presented in form of an equation (formula). In order to pass the budget local authorities need to obtain a relation in which the left side of the formula (annual debt repayment ratio) is lower than or equal to the right side (maximum debt repayment ratio) (Act of Public Ginance).