We prove that a particular pushing-blocks puzzle is intractable in 2D, improving an earlier result that established intractability in 3D [OS99]. The puzzle, inspired by the game PushPush, consists of unit square blocks on an integer lattice. An agent may push blocks (but never pull them) in attempting to move between given start and goal positions. In the PushPush version, the agent can only pu...

The present paper examines secular trends of homicide rates by means of a systematic re-analysis of all available quantitative studies on pre-modern homicide. The results confirm, first, that homicide rates have declined in Europe over several centuries. Second, the empirical evidence shows, that unequivocal decline began in the early seventeenth century. Third, the data indicate that the secul...

Mexican immigrants were historically clustered in a few cities, mainly in California and Texas. During the past 15 years, however, arrivals from Mexico established sizeable immigrant communities in many “new” cities. We explore the causes and consequences of the widening geographic diffusion of Mexican immigrants. A combination of demand-pull and supply push factors explains most of the inter-c...

An understanding of how an athlete’s motivation is affected by coaching behaviours is vital information for a coach to acquire. This study examines the impact and need for a coach in optimising international athletes’ training and competition motivation within the framework of Cognitive Evaluation Theory. The participants were six long distance runners with international experience. Qualitative...

Takeuchi Mfg.'s core products are compact excavators, track loaders, and other compact construction equipment used to build homes and other buildings. Internet of Things (IoT) utilization has recently become a major topic in the manufacturing industry, and Takeuchi Mfg. has set its sights on leveraging IoT as it continues to push reforms, implement a wide variety of IT systems, and build new fa...

1.0 Introduction The million-dollar question for any production manager today is the selection between a push and a pull production system. Push and pull systems determine when and where to move material in a production process. A push system is characterized by a make to stock environment and a pull system is characterized by make to order. An appropriate system that would cater to the require...

Due to multiple-factors, bracketed popularly in ‘push-pull’ category, migration, both internal and external, is taking place in Bangladesh. In Bangladesh, the dominant form of migration is from rural to urban centers. For, Bangladesh is predominantly an agrian rural society for 80.0 percent of the total population lives in 87319 villages. The urban centers of Bangladesh are developing rapidly a...

We prove that two pushing-blocks puzzles are intractable in 2D. One of our constructions improves an earlier result that established intractability in 3D [OS99] for a puzzle inspired by the game PushPush. The second construction answers a question we raised in [DDO00] for a variant we call Push-1. Both puzzles consist of unit square blocks on an integer lattice; all blocks are movable. An agent...

Am ajor problem ofe-commerce is the high rate of customer initiated abortions of processes. It may be solved by the implementation of a Push System that supports the webshop. One major module of the Push System is the Pushflow Manager that proactively l eads customers through their processes by taking over tasks or triggering following activities. Its theoretical background, the Push Concepts, ...

School bullying is a serious problem among teenagers, causing depression, dropping out of school, or even suicide. It is thus important to develop antibullyingmethods.This paper proposes a physical bullying detectionmethod based on activity recognition. The architecture of the physical violence detection system is described, and a Fuzzy Multithreshold classifier is developed to detect physical ...