[1] We analyze the ionospheric effect on the phase and amplitude of radio occultation (RO) signal. The introduced theoretical model predicts a correlation between the phase acceleration and intensity variations of RO signal and opens a way to locate layered structures in the propagation medium, in particular, in trans-ionospheric satellite-to-satellite links. For considered CHAllenging Minisatellite Payload (CHAMP) RO events, the locations of the inclined plasma layers in the lower ionosphere are estimated, and the electron density distribution is retrieved. By analysis of the CHAMP RO data, we reveal the dependence of the intensity variations of RO signal on sharp changes in the DST index and on the local time. Maps of the seasonal, geographical, and temporal distributions of the CHAMP RO events with amplitude scintillations, having high S 4 index values, and observed during the years 2001-2004 indicate dependence on solar activity. As follows from this analysis, the GPS signals in the trans-ionospheric links can be used for investigating the location and parameters of inclined plasma layers and monitoring the influence of solar activity on the ionosphere with global coverage.

No abstract

Objective: Few studies have analyzed the shapes of pillows. The purpose of this study was to investigate the relationship between the pillow shape design and subjective comfort level for asymptomatic subjects. Methods: Four basic pillow designs factors were selected on the basis of literature review and recombined into 8 configurations for testing the rank of degrees of comfort. The data were analyzed by the analytic hierarchy process method to determine the most comfortable pillow. Results: Pillow number 4 was the most comfortable pillow in terms of head, neck, shoulder, height, and overall comfort. The design factors of pillow number 4 were using a combination of standard, cervical, and shoulder pillows. A prototype of this pillow was developed on the basis of the study results for designing future pillow shapes. Conclusions: This study investigated the comfort level of particular users and redesign features of a pillow. A deconstruction analysis would simplify the process of determining the most comfortable pillow design and aid designers in designing pillows for groups.

[1] In this study, we show that the amplitude radio occultation (RO) method, which employs high-precision global positioning system (GPS) signals, allows one to determine the vertical gradients of refractivity and monitor wave structures in the atmosphere on a global scale at altitudes ranging from 10 to 40 km. We show that the sensitivity of the RO amplitude data to the wave structures in the atmosphere with vertical periods from 0.8 to 4 km exceeds one of the RO phase data by a factor of order 10. As an example of this approach, analytical results of the Challenging Minisatellite Payload's (CHAMP) RO events are presented. Wave clusters were found in the amplitude variations of the RO signals with interior vertical periods from 0.8 to 4 km in the tropopause and lower stratosphere within the heights of 15-24 km (low latitudes) to 10-15 km (moderate latitudes). We demonstrate that the amplitude variations can be considered as a radioholographic image of the wave structures in the atmosphere. For internal gravity waves (GW), we show that the GW portrait, which consists of the altitude dependence of the GW phase, amplitude and vertical spatial frequency, can be retrieved from the amplitude variations of the RO signal. The GW dispersion and polarization relationships allow one to estimate the vertical profile of the horizontal wind perturbations, its gradient and the GW intrinsic phase speed. In general, when the origin and type of internal waves are not known, the height dependence of the vertical gradient of refractivity can be applied for monitoring the seasonal and geographical distributions of wave activities at different levels in the atmosphere.

Industry 4.0 can enhance the operational efficiency of the supply chain, but the current research mainly focuses on analytics and smart things. Many companies integrate their organizations more closely with data by adopting Industry 4.0, but this study found that some companies have changed their leadership, organizational, and customer relationships through the adoption of CPS. Industry 4.0 is a socio-technical system that should be explored in terms of management practices, employee feedback, and the cause-and-effect relationship between them. This study proposes a modeling framework using the Su-field analysis of TRIZ method (Theory of Inventive Problem Solving) and applies the Partial Least Squares Structural Equation Modeling (PLS-SEM) method to investigate the relationship between leadership, organizational culture, and service management in the Taiwan industry. The results show that the data analysis, CPS, IoT, and intelligent technologies of Industry 4.0 can facilitate connections within the value chain and increase agility in response to environmental changes. Companies must have a good organizational culture and provide the right incentives to gain the organizational commitment of their employees to implement Industry 4.0.