The availability of data for the size of the “Underground Economy” is important for macroeconomic policy. We use fuzzy set theory and fuzzy logic to construct an annual time-series for the (unobservable) New Zealand underground economy over the period 1968 to 1994. Two input variables are used – the effective tax rate and an index of the degree of regulation. The resulting underground economy t...

This paper presents an underground navigation app “mUvi”. For the indoor navigation of underground users, it only exploits the information from the environment of the user, collected by the internal sensors of the user’s smartphone. Based on an experimental study on the use of smartphone sensors for underground navigation the mobile app uses a combination of microphone and two additional sensor...

The research of unloading response characteristics caverns with weak structure has important engineering value for the development and construction underground space. In this paper, firstly, cross fault cavity model is established based on particle flow code (PFC) software, considering different dip angles. parallel bond (PBM) used in cavern smooth joint (SJM) model. Then, mechanical, acoustic ...

BACKGROUND Between September 17 and October 3, 2009, hundreds of workers employed in a manufacturing factory in Shenzhen, a city in south China developed a sudden onset of acute gastroenteritis. A retrospective cohort study is designed to identify the risk factors and control this outbreak. METHODS Information on demographic characteristics, working place, the history of contact with a person...

The projected increases in World population and need for food have recently motivated adoption of information technology solutions in crop fields within precision agriculture approaches. Internet of underground things (IOUT), which consists of sensors and communication devices, partly or completely buried underground for real-time soil sensing and monitoring, emerge from this need. This new par...

In underground mines and tunnels accurate and continuous positioning of moving machines and humans has been studied extensively. Geomagnetic field based positioning is an interesting possibility for this measurement need. Using a commercial smart phone and a new calculation service provided by a Finnish company, a feasibility and accuracy assertion tests were done in Finnish underground mine. F...

Wireless Underground Sensor Networks (WUSNs) are the networks of wireless sensors that operate in the underground soil medium. In this monograph, to realize reliable and efficient WUSNs, two enabling techniques are developed to address the challenges brought by the underground soil medium, including the EM wave-based WUSNs and the MI-based WUSNs. For EM wave-based WUSNs, the heterogeneous netwo...

A low cost, battery-operated, portable, real-time aerosol analyzer is not available for monitoring diesel particulate matter (DPM) concentrations in underground mines. This study summarizes a field evaluation conducted at an underground limestone mine to evaluate the potential of the TSI AM 510 portable photometer (equipped with a Dorr-Oliver cyclone and 1.0-mum impactor) to qualitatively track...

Over the years, cybercriminals increasingly joined the underground economy to exchange malicious services for conducting data breaches crimes. As many service providers are rippers, most cybercriminals rely on a few high quality services. To this end, cybercriminals post customer reviews evaluating the purchase experience and the service quality. To identify high quality services, researchers f...