36 research outputs found

    Next Generation Differential GPS Architecture

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    The United States Coast Guard is engaged in a project to re-capitalize Reference Station (RS) and Integrity Monitor (IM) equipment used in the Nationwide Differential Global Position System (NDGPS). The Coast Guard in partnership with industry is developing a new software application to run on an open architecture platform as a replacement for legacy equipment. Present commercially available off-the-shelf Differential Global Positioning System (DGPS) RS and IM equipment lacks the open architecture required to support long term goals and future system improvements. The utility of the proposed new hardware architecture and software application is impressive - nearly every aspect of performance and supportability significantly exceeds that of the legacy architecture. The flexibility of the new hardware and software architectures complement each other to offer promising possibilities for the future. For example, the new hardware architecture uses Ethernet for internal and external site equipment communications. Each Local Area Network (LAN) will be equipped with a router and two 24 port switches. Various levels of password protection are provided to manage security both locally and remotely. While the new software application directly supports the legacy RS-232/422 interfaces to devices such as GPS receivers, a system design goal includes the ability to directly address each device from NCS. With the use of TCP/IP to RS-232/422 port server devices, the system can meet these forward reaching goals while supporting legacy equipment. New system capabilities include remote software management, remote hardware configuration management, and flexible options for management of licenses. The new configurable RS and IM architecture is a PCbased emulation of legacy reference station and integrity monitor equipment. It supports fluid growth and exploitation of new signals, formats, and technology as they become available, while remaining backward compatible with legacy architecture and user equipment. Examples of new capabilities include enhanced data management & anomaly analysis, universal On Change Reference Station Integrity Monitor (RSIM) message scheduling, improved satellite clock handling, additional observation interval modes, and Range Rate Correction monitoring in the IM. Engineering initiatives under development such as implementation of pre-broadcast integrity are also presented. This paper details challenges and goals that drove software and hardware design approaches destined to become the backbone of the Next Generation Differential GPS Architecture. Functional differences between legacy and next generation operation are explored. The new DGPS system architecture will allow the USCG radiobeacon system to continue to deliver and improve navigation and positioning services to our nation and its territories. Reprinted with permission from The Institute of Navigation (http://ion.org/) and The Proceedings of the 18th International Technical Meeting of the Satellite Division of The Institute of Navigation, (pp. 816-826). Fairfax, VA: The Institute of Navigation

    Smartphone and social network addiction in early adolescents: The role of self-regulatory self-efficacy in a pilot school-based intervention

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    Background: Youths' online problematic behaviors, such as smartphone or social network sites (SNS) addiction, gained increasing attention nowadays, due to their impact on concurrent and later adjustment, such as emotional and/or behavioral problems, academic impairments, or relational issues. Aims: This study aims to evaluate the effectiveness of a pilot school-based intervention to contrast online addictive behaviors while fostering adolescents' self-regulative abilities. Materials & Methods: The intervention started in January 2022 in an Italian junior high school located in Rome, and consisted of four meetings with students. A total sample of 462 15-year-old adolescents (Mage = 15.2; SD = 0.50; 41% females; Ncontrol = 214; Nintervention = 248) was considered. Within the latent difference score framework, we examined short-term changes from the pre-to-the-postintervention levels of SNS and smartphone addiction, and self-regulatory self-efficacy (SRSE) beliefs as a possible booster of the intervention's effectiveness. Results: Results showed a significant decrease in both online addictions (SNS and smartphone addiction), controlling for age, gender, sexual orientation, and socioeconomic status, because of the short-term efficacy of the project. The buffering effect of SRSE beliefs was further supported. Conclusion: These findings emphasized the usefulness of promoting youths' self-regulative beliefs to contrast problematic tendencies, according to a Positive Youth Development perspective which focused on resources rather than only on the prevention of negative outcomes for youths' adjustment

    FAST INTEGER AMBIGUITY RESOLUTION IN GPS KINEMATIC POSITIONING USING LEFT NULL SPACE AND MULTI-TIME (INVERSE) PAIRED CHOLESKY DECORRELATION

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    Aiming at the problems that huge amount of computation in ambiguity resolution with multiple epochs and high-order matrix inversion occurred in the GPS kinematic relative positioning, a modified algorithm for fast integer ambiguity resolution is proposed. Firstly, Singular Value Decomposition (SVD) is applied to construct the left null space matrix in order to eliminate the baselines components, which is able to separate ambiguity parameters from the position parameters efficiently. Kalman filter is applied only to estimate the ambiguity parameters so that the real-time ambiguity float solution is obtained. Then, sorting and multi-time (inverse) paired Cholesky decomposition are adopted for decorrelation of ambiguity. After diagonal elements preprocessing and diagonal elements sorting according to the results of Cholesky decomposition, the efficiency of decomposition and decorrelation is improved. Lastly, the integer search algorithm implemented in LAMBDA method is used for searching the integer ambiguity. To verify the validity and efficacy of the proposed algorithm, static and kinematic tests are carried out. Experimental results show that this algorithm has good performance of decorrelation and precision of float solution, with computation speed also increased effectively. The final positioning accuracy result with static baseline error less than 1 cm and kinematic error less than 2 cm, which indicates that it can be used for fast kinematic positioning of high precision carrier

    Insecure Attachment and Technology Addiction Among Young Adults: The Mediating Role of Impulsivity, Alexithymia, and General Psychological Distress

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    Previous studies have emphasized the effect of insecurity attachment on youth's Internet and smartphone addiction. In this study, we examine the mediating role of alexithymia, impulsivity, and general psychological distress in the relationship between insecure attachment dimensions and technology addiction. Data were collected from 539 adolescents and young adults, mostly women (N = 378; 70.1 percent), aged 19.76 +/- 1.99 years. Participants completed self-report measures of attachment insecurity, psychological risk factors (i.e., impulsivity, psychological distress, and alexithymia), and technology addiction (i.e., problematic Internet use, smartphone, and Internet addiction). The gender-related (i.e., multi-group) mediation model was tested through a path analysis with both observed and latent variables. Attachment anxiety had no direct effect on technology addiction, whereas attachment avoidance had a small negative direct effect, but only among women. Insecure attachment dimensions were significantly associated with psychological risk factors, whereas the latter had a significant, direct association with technology addiction. Psychological risk factors significantly mediated the association between insecure attachment dimensions and technology addiction. Finally, the tested model was gender-invariant. Findings suggest that insecure attachment dimensions have an indirect effect on the development of technology addiction mediated almost entirely by higher levels of psychological risk factors. Such findings might have relevant implications to inform any treatment plan for young adults who are overinvolved with technology activities and so to deliver patient-tailored interventions

    Hysteroscopic polypectomy: a comparison between 22 Fr and 26 Fr resectoscopes under paracervical block anesthesia, a randomized controlled study

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    Objective: The aim of this study was to compare 22 Fr unipolar resectoscope with the traditional 26 Fr unipolar resectoscope in endometrial polypectomy performed under paracervical block anesthesia. Methods: The trial took place in Gynecologic Unit, Department of Surgery, Tor Vergata University Hospital, Rome. Inclusion criteria were: diagnosis of endometrial polyps <3 cm at office hysteroscopy; agreement of patients to perform surgery under paracervical block anesthesia but not in office setting. Patients with ASA physical status classes III or more and with contraindication to operative hysteroscopy were excluded. Before the procedure, the recruited patients were randomly assigned to two groups, 35 to the 22 Fr unipolar resectoscope group (group A) and 35 to the 26 Fr unipolar resectoscope group (group B). Primary endpoint was the time spent for cervical dilatation and resection. Secondary endpoints were pain during and after surgery, efficacy of paracervical block, use of analgesic drugs during and after the procedure, patients' satisfaction, correlation between pain and menopause or parity. Statistical analysis was performed by the SPSS software, and the tests used were Pearson Chi-Square, One-way ANOVA and Mann-Whitney test. A p value <.05 was considered significant. Results: The mean time for cervical dilatation was two minutes in group A (26 Fr) and five minutes in group B (22 Fr, p = .001). Operative mean time was four minutes in group A and seven minutes in group B (p = .001). Pain during dilatation was analogous (VAS = 6, p = .054), while during the procedure it was higher in group B (VAS = 1 vs VAS = 2, p = .003). Sufentanil was administered during resection in 19 patients of group A and in 22 patients of group B (p = .754). General anesthesia was never necessary. Postoperative pain was higher in group B (p = .01). Nine patients of group B needed analgesics, as opposed to no patient of group A (p = .002). Conclusions: The 22 Fr unipolar resectoscope appears advantageous compared to the 26 Fr resectoscope in the resection of endometrial polyps <3 cm, in terms of cervical dilatation and operative time, pain and need of postoperative analgesics. Paracervical block is useful and safe in compliant patients at high risk for general anesthesia

    Minimum Indicator Approach for Use with Precise Differential GPS

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