A Chemo- and Regioselective Tandem [3+2]Heteroannulation Strategy for Carbazole Synthesis: Synergizing Two Mechanistically Distinct Bond-Forming Processes

A modular approach to prepare tri- and tetracyclic carbazoles by a sequential [3+2]heteroannulation is described. First, op-timization of a Pd-catalyzed Buchwald-Hartwig amination followed by C/N-arylation in a one-pot process is established. Second, mechanistic analyses identified the origins of chemo- and regioselective sequential control of both bond-forming steps. Finally, the substrate scope is demonstrated by the preparation of a range of tri- and tetracyclic carbazoles, including expedient access to several natural products and anti-cancer agents.

Algorithmic Method for the Design of Sequential Circuits with the Use of Logic Elements

This article presents issues related to the design of sequential control systems. The algorithmic design method of sequential control systems is discussed, which allows the design of a diagram of any sequential system. The algorithmic method uses the description in the form of a connection formula. The connection formula defines the order of actuations of driver elements, in this case actuators. The algorithmic method is used, among others, for systems with actuators cooperating with distributors controlled electrically on both sides. The process of creating a system graph has been characterized. The operation of the system has been shown graphically. On the basis of the created graph describing the functions of signal processing, a method for rapid programming of sequential electro-pneumatic systems with the use of logic elements has been provided. A separate dedicated timing unit has been used to perform memory functions. Its operation is based on successive states, in such a way that the next state deletes the previous one. Graph-based systems have been validated through simulation using Festo’s FluidSim computer-aided design software.

Automatic migration from synchronous to asynchronous JavaScript APIs

The JavaScript ecosystem provides equivalent synchronous and asynchronous Application Programming Interfaces (APIs) for many commonly used I/O operations. Synchronous APIs involve straightforward sequential control flow that makes them easy to use and understand, but their "blocking" behavior may result in poor responsiveness or performance. Asynchronous APIs impose a higher syntactic burden that relies on callbacks, promises, and higher-order functions. On the other hand, their nonblocking behavior enables applications to scale better and remain responsive while I/O requests are being processed. While it is generally understood that asynchronous APIs have better performance characteristics, many applications still rely on synchronous APIs. In this paper, we present a refactoring technique for assisting programmers with the migration from synchronous to asynchronous APIs. The technique relies on static analysis to determine where calls to synchronous API functions can be replaced with their asynchronous counterparts, relying on JavaScript's async/await feature to minimize disruption to the source code. Since the static analysis is potentially unsound, the proposed refactorings are presented as suggestions that must be reviewed and confirmed by the programmer. The technique was implemented in a tool named Desynchronizer. In an empirical evaluation on 12 subject applications containing 316 synchronous API calls, Desynchronizer identified 256 of these as candidates for refactoring. Of these candidates, 244 were transformed successfully, and only 12 resulted in behavioral changes. Further inspection of these cases revealed that the majority of these issues can be attributed to unsoundness in the call graph.

ІНФОРМАЦІЙНЕ ЗАБЕЗПЕЧЕННЯ КОНТРОЛЮ ПОТОЧНОГО СТАНУ ІНФОКОМУНІКАЦІЙНОЇ МЕРЕЖІ В УМОВАХ ВПЛИВУ ЗОВНІШНІХ ЗАВАД

The processes of information support of situational management of infocommunication networks in the conditions of influence of external disturbances are considered in the work. The expediency of using the mathematical apparatus of information theory for the analysis of processes of control of parameters of infocommunication networks is substantiated. It is shown that periodic multiple sequential control of the parameters of the infocommunication network provides determination of the state of the network under the influence of external interference and the probability of its transition to a new state in the near future. The entropy of the controlled process changes with changing quantization step and multiple successive measurements. It is noted that in the case of periodic multiple consecutive control, the object is constantly in transition in terms of information. The entropy value of an object can be considered determined only for some short periods of time between measurements or when information about the object is not received. An important condition for improving the quality of control is to reduce and completely eliminate delays in the information process.