The paper deals with the localization in a low-power wide-area-network (LPWAN) operating long-range wide-area-network (LoRaWAN) technology. The LoRaWAN is, today, one of the most widely used ...connectivity-enabling technologies for the battery-powered smart devices employed in a broad range of applications. Many of these applications either require or can benefit from the availability of geolocation information. The use of global positioning system (GPS) technology is restrained by the bad propagation of the signal when the device is hidden indoors, and by energy consumption such a receiver would require. Therefore, this paper focuses on an alternative solution implying the use of the information readily available in the LoRaWAN network and application of the time difference of arrival (TDoA) method for the passive geolocation of end-devices in the network. First, the limits of geolocation services in networks that use narrow-band communication channels are discussed, as well as the relevant challenges faced by the TDoA approach. Then, we select five classic TDoA algorithms and evaluate their performance using simulation. Based on these results, we select the two providing the best accuracy (i.e., Chan’s and Foy’s). These algorithms were tested by the field measurements, using the specially designed low-cost gateways and test devices to estimate their real-life performance.
The last decade has transformed wireless access technologies and crystallized a new direction for the internet of things (IoT). The modern low-power wide-area network (LPWAN) technologies have been ...introduced to deliver connectivity for billions of devices while keeping the costs and consumption low, and the range of communication high. While the 5G (fifth generation mobile network) LPWAN-like radio technologies, namely NB-IoT (narrowband internet of things) and LTE-M (long-term evolution machine type communication) are emerging, the long-range wide-area network (LoRaWAN) remains extremely popular. One unique feature of this technology, which distinguishes it from the competitors, is the possibility of supporting both public and private network deployments. In this paper we focus on this aspect and deliver original results comparing the performance of the private and public LoRAWAN deployment options; these results should help understand the LoRaWAN technology and give a clear overview of the advantages and disadvantages of the private versus public approaches. Notably, we carry the comparison along the three dimensions: the communication performance, the security, and the cost analysis. The presented results illustratively demonstrate the differences of the two deployment approaches, and thus can support selection of the most efficient deployment option for a target application.
Temperature-modulated space-charge-limited-current spectroscopy (TMSCLC) is applied to quantitatively evaluate the density of trap states in the band-gap with high energy resolution of semiconducting ...hybrid lead halide perovskite single crystals. Interestingly multicomponent deep trap states were observed in the pure perovskite crystals, which assumingly caused by the formation of nanodomains due to the presence of the mobile species in the perovskites.
The paper's main aim is to contribute to the empirical knowledge of women's entrepreneurship by utilizing the McKinsey 7S Model to explain the managerial phenomenon in women-led companies. The paper ...is based on secondary data sources. The data were collected from case studies presented in academic journals indexed in the Scopus and Web of Science databases. The data collection used the PRISMA 2009 method. The case studies of women-led companies were assessed in the McKinsey 7S model on a qualitative basis. The paper introduces women companies' managerial traits and procedures, which the McKinsey 7S model can recognize. In the chosen and analyzed sample of case studies dealing with female entrepreneurship, not even one directly used the McKinsey model for analysis. Results also showed that the 7S model should be used with primary data rather than to evaluate incomplete secondary data. Also, factors that lead women to start a business worldwide have been shown.
Nach einem jahrzehntelangen Bürgerkrieg erlangt die Republik Südsudan am 9. Juli 2011 ihre Unabhängigkeit. Doch trotz aller Bemühungen um einen friedlichen Staatsaufbau nimmt die erste Dekade der ...Eigenstaatlichkeit einen gewaltsamen Verlauf: Im Dezember 2013 schlittert der Südsudan in einen blutig geführten Bürgerkrieg, der sich nicht als einheitlicher Konflikt mit klar definierbaren Parteien, sondern zu einem Amalgam komplex verschachtelter Konfliktlandschaften entwickelt. In analytischen Vignetten, die verschiedene Regionen sowie die nationale und internationale Dimension des Bürgerkrieges untersuchen, gibt Jan Pospisil einen Einblick in die südsudanesische Konfliktrealität.
The paper aims to determine how students, ranking among one of the important tourism market segments, use social media during the overall travel process, as well as to explore the possible impact of ...cultural differences on the use of social media during the students' travel process. A structured questionnaire was employed for the quantitative research focusing on the use of social media during the three different phases of the travel process-pre-travel, on-travel, and post-travel. The data were collected by means of an online survey via Google Drive, and descriptive statistics was used to interpret the acquired data. The research offers an important insight into the use of social media among students. It shows what drives Czech students to use social media during the three phases of the travel process, and what the main reason is for social media use. Interestingly, 54% of students make use of social media during the travel process, because they want to get other people's opinions. Research has shown that the most popular social media site among traveling students was Facebook (82%), followed by Instagram (56%) and YouTube (35%). The research also showed that despite the abundant use of social media by students, conventional sources of information were still important, too. Contrary to theoretical assumptions, the research did not prove that cultural differences fundamentally influenced the use of social media among Czech and Croatian students. The results are useful for marketing professionals as the research yields highly valuable data on social media use by a particular group of Czech students. At the same time, the results are an important extension of the current theory on the use of social media during the travel process.
Purpose – The purpose of this research was to verify actual consumer behavior concerning different beer packaging material and how it influences the perception of beer taste. More precisely, the main ...aim of the paper was to explore whether beer packaging can influence consumers’ subjectively perceived taste of the beer they drink. Design/Methodology/Approach – Following the literature research, a questionnaire survey was conducted on a sample of average Czech beer consumers (n=220). A subsequent experiment involving a sample of Czech college students (n=30) aimed at exploring the actual consumer behavior. Findings and implications – The results of the experiment show that beer consumer behavior can be influenced by the beer packaging material. If consumers knew that the beer had been poured from a glass bottle, they assessed its taste better than if they had no information on the type of beer packaging. Similarly, the opposite was found to be true of the plastic bottle – if consumers knew that the beer had been poured from a plastic bottle, they said it tasted worse than if they had no such information. No statistically significant difference was found in the tasting of canned beer with or without the knowledge of the packaging material. Limitation – The main research limitations lie in its regionality as the survey and the experiment were conducted only in the Czech Republic, with college students as participants.Originality – As there is only a limited amount of research available on beer packaging and its influence on consumer behavior, this paper provides a valuable overview of the issue.
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