Piperidines, an important class of N‐heterocycles, are very common in naturally occurring bioactive compounds. Recently, functionalized piperidines, specifically, 1,2,6‐triaryl‐4‐arylamino‐piperidine‐3‐ene‐3‐carboxylates have drawn considerable attention due to its diverse pharmacological efficacies that include anti‐cancer, anti‐microbial, anti‐oxidant, anti‐fungal, anti‐inflammatory and acetylcholinesterase (AChE) inhibitory activities. As a result, during the last decade, a number of methods reported for the synthesis of 1,2,6‐triaryl‐4‐arylamino‐piperidine‐3‐ene‐3‐carboxylates via one‐pot pseudo five‐component reactions of aromatic aldehydes, anilines and β‐keto esters under various reaction conditions. The present review deals with the ‘‘up to date” developments on the synthesis of 1,2,6‐triaryl‐4‐arylamino‐piperidine‐3‐ene‐3‐carboxylates reported so far.

K. RANGANAYAKULU, M. VASUMATHI DEVI, R. BALAJI RAO, and K. RAJFSWARI. Can. J . Chem. 58, 1484(1980). The effect of the bulk of the sidechain on the rate of solvolysis of I-alkyl cyclopentyl, cyclohexyl, and cycloheptyl chlorides has been studied. With the exception of the t-butyl systems, the ratio of solvolysis rates for the three ring systems falls in agiven series. The slower rate of solvolysis in the six-membered ring system may be due to an extra activation energy contribution caused by the conversion of a neutral chair form to the twist boat or half chair conformation, prior to the actual solvolysis. In the case of five-and seven-membered ring systems the formation of an intermediate carbonium ion is sterically favoured (I-strain oreclipsing interaction) consistent with earlierfindings. The faster rate of solvolysisof I-t-butylcycloalkyl chlorides islikely due to arearrangement reaction where alkyl participation enhances the rate of solvolysis.K. RANGANAYAKULU, M. VASUMATHI DEVI, R. BALAJI RAO et K. RAJESWARI. Can. J. Chem. 58, 1484 (1980). On a etudik I'effet de I'encombrement de la chaine laterale sur la vitesse d e solvolyse des chlorures d'alkyl-l cyclopentyle, cyclohexyle et cycloheptyle. A I'exception des systemes tert-butyle, le rapport des vitesses d e solvolyse des trois systemes cycliques correspond 2 une serie donnee. L e fait que la vitesse de solvolyse est plus lente dans les cycles a 6 chainons peut i t r e due a une contribution supplementaire de I'energie d'activation provoquee par I'interconversion d'une forme chaise neutre en une forme bateau-croisee ou demi-chaise avant la solvolyse. Dans le cas des systkmes cycliques a 5 et 7 chainons, la formation d'un carbocation intermediaire est favorisee par des facteurs steriques (tension-I ou interaction kclipsee) en accord avec les resultats obtenus antkrieurement. L e fait que la vitesse de solvolyse des chlorures de tert-butyl-I cycloalkyle soit plus grande est probablement due a une reaction de transposition oG la participation du groupe alkyle augmente la vitesse d e solvolyse.[Traduit par le journal]

Human action recognition is an important branch of computer vision and is getting increasing attention from researchers. It has been applied in many areas including surveillance, healthcare, sports and computer games. This proposed work focuses on designing a human action recognition system for a human interaction dataset. Literature research is conducted to determine suitable algorithms for action recognition. In this proposed work, three machine learning models are implemented as the classifiers for human actions. An image processing method and a projection-based feature extraction algorithm are presented to generate training examples for the classifier. The action recognition task is divided into two parts: 4-class human posture recognition and 5-class human motion recognition. Classifiers are trained to classify input data into one of the posture or motion classes. Performance evaluations of the classifiers are carried out to assess validation accuracy and test accuracy for action recognition. The architecture designs for the centralized and distributed recognition systems are presented. Later these designed architectures are simulated on the sensor network to evaluate feasibility and recognition performance. Overall, the designed classifiers show a promising performance for action recognition.

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