Defining C Preprocessor Macro Libraries with Functional Programs

The preprocessor of the C language provides a standard way to generate code at compile time. However, writing and understanding these macros is difficult. Lack of typing, statelessness and uncommon syntax are the main reasons of this difficulty. Haskell is a high-level purely functional language with expressive type system, algebraic data types and many useful language extensions. These suggest that Haskell code can be written and maintained easier than preprocessor macros. Functional languages have certain similarities to macro languages. By using these similarities this paper describes a transformation that translates lambda expressions into preprocessor macros. Existing compilers for functional languages generate lambda expressions from the source code as an intermediate representation. As a result it is possible to write Haskell code that will be translated into preprocessor macros that manipulate source code. This may result in faster development and maintenance of complex macro metaprograms

Evolvens csiga gyártási pontosságának vizsgálata kinematikai modell segítségével

Az evolvens csigák gyártáspontossága igen fontos követelmény, részben azért, mert a működő csigahajtás egyik elemét képezik, másrészt pedig azért, mert az evolvens fogazat lefejtő csigamarójának alapfelületét képezik. Jelen tanulmány összehasonlító vizsgálatot valósít meg az elméleti evolvens csavarfelület, a késsel gyártott elméleti, hibamente és a valós csavarfelületek között. A hibát az elméleti evolvens csavarfelület és a szimulált valós körülmények között létrejövő csavarfelület közötti, normálirányú különbségként értelmezzük. A hibát a lefejtő él magassághibája, a lefejtő él profilszöghibája, illetve a szerszámgép tengelypárhuzamosság- hibájának függvényében vizsgáltuk. Az elméleti vizsgálat eredményeként kijelenthetjük, hogy a legnagyobb hibát a kés profilhibája okozza. Ezután következik a párhuzamosságeltérés okozta hiba, és legvégül az él magassághibája

An Analysis of Manufacturing Precision of Involute Worms Using a Kinematical Model

The manufacturing precision of involute worms constitutes a major requirement. On the one hand, the worm constitutes the input element of the worm drive; secondly, the involute helical surface is the basic surface of an involute worm-hob. This paper presents an analytic comparison between the involute surfaces obtained using theoretical equations, kinematic simulation of the cutting and the surface charged with errors. The surface error is considered the distance along the normal direction to the theoretical surface, measured between this and the surface charged with simulated manufacturing errors. The main sources of errors are considered the center-error of the edge plane, the edge profile error and deviation of the axial feed direction from the axis of the worm. The theoretical results allow us to conclude that the influence of the edge profile error is the largest. It is followed by the parallelism error between the feed direction and the axis of the worm, and finally, the center error of the tool edge

How to Avoid Lower Priority for Smoking Cessation Support Content on Facebook: An Analysis of Engagement Bait

Facebook demotes “engagement bait” content that makes people interact. As a result of this sanctioning, public health content can reach fewer Facebook users. This study aims to determine the negative effect of engagement bait and find alternative techniques. In a three-year period, 791 smoking cessation support content was included (n = 791). The Facebook posts were classified into “engagement bait”, “alternative techniques” and control groups. Facebook metrics were compared between the study and control groups. The reach of Facebook page fans was significantly lower in the engagement bait group compared to the control group. On the other hand, the alternative techniques had a significantly lower rate of negative Facebook interactions, as well as significantly higher click rates compared to the control group. This is the first study to reveal the sanctioning of engagement bait on smoking cessation support Facebook posts. “Engagement bait” content has a lower ranking on the Facebook Fans’ Newsfeed page. Nevertheless, alternative techniques can circumvent the restrictions on engagement bait. At the same time, alternative techniques can stimulate the click rate and inhibit the rate of negative interactions

Smokers’ Engagement Behavior on Facebook: Verbalizing and Visual Expressing the Smoking Cessation Process

The “processes of change” and “motivational language” are common in smoker Facebook users’ comments under smoking cessation support contents. Smokers can combine this verbalization of the smoking cessation process with visual expression when they use comments and Facebook reactions at the same time. The aim of this study was to understand the relationship between processes of change, motivational language, and the Facebook reaction buttons. A total of 821 smokers’ comments were analyzed in the current study (n = 821), which responded to image-based smoking cessation support contents. The processes of change and the motivational language used in the investigated comments were identified. These linguistic categories were compared with the usage of reaction buttons. The Facebook users who used the “Haha” reaction button wrote a significantly higher proportion of sustain talk than those who used the “Like” or “Love” reaction buttons. The Facebook users who combined the comment and “Love” reaction wrote significantly more change talk than those who did not utilize these buttons. We suggest that the “Haha” reaction may be a negative indicator, the “Like” reaction may be a neutral indicator, and the “Love” reaction may be a positive engagement indicator in terms of the smoking cessation process during Facebook-based interventions. These results may highlight how to evaluate Facebook reactions relating to smoking cessation support contents

Moving on from Silicon to the Heavier Tetrels: Germyl- and Stannyl-Substituted Phosphole Derivatives

Germyl- and stannyl-substituted phospholes have been prepared and isolated. The increased reactivity of the tetrel carbon bond requires increased effort in purification by initial transformation to the chalcogen derivatives and subsequent reduction to the phosphole after subsequent to chromatographic purification for the germanium derivative. The photophysical properties of the germyl phosphole are comparable to that of its silyl analogue, whereas the stannyl phospholes turned out to be nonluminescent. All isolated compounds have been characterized by NMR spectroscopy, mass spectrometry, and elemental analysis. Furthermore, single-crystal X-ray diffraction and density functional theory (DFT) calculations have been performed on selected compounds

Conjugation between 3D and 2D aromaticity: does it really exist? The case of carborane-fused heterocycles

Although several synthesized icosahedral carborane fused 2D π-ring systems are known, and even considerable conjugation has been noted between them in some cases, the phenomenon itself is not fully understood. Based on the results of our computational study, it can be concluded that the 2D aromatic character of the fused (exo) five-membered ring is low, even in cases where significant conjugation was proposed in previous studies. Moreover, the carborane moiety constricts the bonding properties of the exo ring, thus prohibiting or promoting different Lewis resonance structures. These results will shed further light on the design and electronic modulation of new carborane-based materials