Companies that develop products with IC (Integrated Circuit) chipsets use toolkits provided by semiconductor suppliers to implement their own series of trial-and-error experiments ranging from concept creation to problem-solving in product developments. According to von Hippel (2001), toolkits have the following elements: (a) learning by doing via trial-and-error, (b) module libraries, (c) solution space, (d) user-friendly, and (e) translating user designs for production. This study defines (b) and (c) as the scope of support for toolkits and compares this scope for Android smartphone manufacturers (Samsung, Huawei, Vivo, and OPPO), which were provided by semiconductor suppliers (Qualcomm and Mediatek) in the 2010s. As a result, this study found that the scope of support of Mediatek’s toolkit is broader than Qualcomm’s. Compared to Samsung, Huawei, Vivo, and OPPO tended to adopt Mediatek’s toolkit to benefit from the broader scope of support in their Android smartphone developments.
The transformation of new and old kinetic energy is a new requirement for the new economy when China enters into the new era. When mankind experienced mechanization, electrification, automation, and finally entered the era of digital industry, human wisdom based on information technology will become a new energy source for the new era. The trend of Digital, networked, automated and intelligent economic development has become the main driving force of energy innovation under the background of big data, while smart city construction, as a kind of infrastructure investment, assumes the function of upstream industry and social leading capital in the conversion of new and old kinetic energy. The experience of leading the construction of smart city of Weifang based on the NB-IoT unified standards, sequential upgrading development, and people’s livelihood guidance has further proved that smart city construction is not only the specific application of big data in infrastructure construction, but a high point of development in the new round of digital economy and new and old energy conversion transformation.
The open source community (OSC) is a place to develop collective knowledge available to anyone, thereby inevitably engendering free riders. Despite this, many firms have contributed to OSCs. This study examines 10 Android smartphone manufacturers between 2010 and 2013 with regard to their (a) source code contributions and the relation of those contributions to (b) time to market as measured by the release of their first Android smartphones. The results of the analysis are divided into the following two groups: (A) a group that released smartphones faster than their competitors through source code contributions and (B) a group that made few source code contributions and was slower to release smartphones than group (A). In addition, in a few years, some firms were observed to have move from group (B) to group (A).
High energy cost is a big challenge faced by the current data centers, wherein computing energy and cooling energy are main contributors to such cost. Consolidating workload onto fewer servers decreases the computing energy. However, it may result in thermal hotspots which typically consume greater cooling energy. Thus the tradeoff between computing energy decreasing and cooling energy decreasing is necessary for energy saving. In this paper, we propose a minimized-total-energy virtual machine (VM for short) migration model called C2vmMap based on efficient tradeoff between computing and cooling energies, with respect to two relationships: one for between the resource utilization and computing power and the other for among the resource utilization, the inlet and outlet temperatures of servers, and the cooling power. Regarding online resolution of the above model for better scalability, we propose a VM migration algorithm called C2vmMap_heur to decrease the total energy of a data center at run-time. We evaluate C2vmMap_heur under various workload scenarios. The real server experimental results show that C2vmMap_heur reduces up to 40.43% energy compared with the non-migration load balance algorithm. This algorithm saves up to 3x energy compared with the existing VM migration algorithm.
The next generation mobile system “5G” are under research, development and standardization for a service start of around year 2020. It is likely to use frequency bands higher than existing bands to have wider bandwidth for high throughput services. This paper reviews technical issues on higher frequency bands applying mobile systems including system trials and use case trials. It identifies expectations for antennas & propagation studies toward 5G era.
The fifth generation mobile communications (5G) systems will need to support the ultra-reliable and low-latency communications (URLLC) to enable future mission-critical applications, e.g., self-driving cars and remote control. With the aim of verifying the feasibility of URLLC related 5G requirements in real environments, field trials of URLLC using a new frame structure are conducted in Yokohama, Japan. In this paper, we present the trial results and investigate the impact of the new frame structure and retransmission method on the URLLC performance. To reduce the user-plane latency and improve the packet success probability, a wider subcarrier spacing, self-contained frame structure, and acknowledgement/negative acknowledgement-less (ACK/NACK-less) retransmission are adopted. We verify the feasibility of URLLC in actual field tests using our prototype test-bed while implementing these techniques. The results show that for the packet size of 32 bytes the URLLC related requirements defined by the 3GPP are satisfied even at low signal-to-noise ratios or at non-line-of-sight transmission.
The analog-to-information converter (AIC) based on compressed sensing samples the analog signals at sub-Nyquist rate. This paper presents a low-cost hardware implementation of AIC based on random demodulation. The realization consists of a sampling part and a transmission part, which are connected by using a FPGA chip. In the former, the input analog signal is modulated with a pseudo-random sequence, and sampled with sub-Nyquist rate to obtain low-dimensional measurements. In the latter, the measurements are transmitted with user datagram protocol to the computer. The experimental results demonstrate the effectiveness of the hardware implementation.