Analysis of Long-Term Prestress Loss in Prestressed Concrete (PC) Structures Using Fiber Bragg Grating (FBG) Sensor-Embedded PC Strands

This study aims to develop a prestressed concrete steel (PC) strand with an embedded optical Fiber Bragg Grating (FBG) sensor, which has been developed by the Korea Institute of Civil Engineering and Building Technology since 2013. This new strand is manufactured by replacing the steel core of the normal PC strand with a carbon-fiber-reinforced polymer (CFRP) rod with excellent tensile strength and durability. Because this new strand is manufactured using the pultrusion method, which is a composite material manufacturing process, with an optical fiber sensor embedded in the inner center of the CFRP Rod, it ensures full composite action as well as proper function of the sensor. In this study, a creep test for maintaining a constant load and a relaxation test for maintaining a constant displacement were performed on the proposed sensor-type PC strand. Each of the two tests was conducted for more than 1000 h, and the long-term performance verification of the sensor-type PC strand was only completed by comparing the performance with that of a normal PC strand. The test specimens were fabricated by applying an optical fiber sensor-embedded PC strand, which had undergone long-term performance verification tests, to a reinforced concrete beam. Depending on whether grout was injected in the duct, the specimens were classified into composite and non-composite specimens. A hydraulic jack was used to prestress the fabricated beam specimens, and the long-term change in the prestress force was observed for more than 1600 days using the embedded optical fiber sensor. The experimental results were compared with the analytical results to determine the long-term prestress loss obtained through finite-element analysis based on various international standards.

Towards an Integrated Vehicle Management System in DriveOS

Modern automotive systems feature dozens of electronic control units (ECUs) for chassis, body and powertrain functions. These systems are costly and inflexible to upgrade, requiring ever increasing numbers of ECUs to support new features such as advanced driver assistance (ADAS), autonomous technologies, and infotainment. To counter these challenges, we propose DriveOS, a safe, secure, extensible, and timing-predictable system for modern vehicle management in a centralized platform. DriveOS is based on a separation kernel, where timing and safety-critical ECU functions are implemented in a real-time OS (RTOS) alongside non-critical software in Linux or Android. The system enforces the separation, or partitioning, of both software and hardware among different OSes. DriveOS runs on a relatively low-cost embedded PC-class platform, supporting multiple cores and hardware virtualization capabilities. Instrument cluster, in-vehicle infotainment and advanced driver assistance system services are implemented in a Yocto Linux guest, which communicates with critical real-time services via secure shared memory. The RTOS manages a real-time controller area network (CAN) interface that is inaccessible to Linux services except via well-defined and legitimate communication channels. In this work, we integrate three Qt-based services written for Yocto Linux, running in parallel with a real-time longitudinal controller task and multiple CAN bus concentrators, for vehicular sensor data processing and actuation. We demonstrate the benefits and performance of DriveOS with a hardware-in-the-loop CARLA simulation using a real car dataset.

Impact of palliative care on end-of-life outcomes in hematologic malignancies.

12026 Background: Patients (pts) with hematologic malignancies (HMs) receive more aggressive end-of-life (EOL) care and often die in the hospital. The impact of palliative care (PC) on EOL quality outcomes in HMs has not been well described. In 2017 we embedded a PC specialist within our inpatient malignant hematology team to facilitate the use of early PC. We sought to determine if this practice was accompanied by a shift in EOL outcomes. Methods: We conducted a retrospective review of pts diagnosed with acute myeloid leukemia (AML) at our institution in the 2 years before (Cohort A) and after (Cohort B) implementation of embedded PC. We identified pts who received PC and if it was early (during initial inpatient stay) or late (sometime after). We then examined EOL quality outcomes: hospitalizations and intensive care (ICU) admissions in the last 30 days of life, chemotherapy use in the last 14 days of life, and use of hospice and death out of hospital (DOH), using Fisher’s exact test to compare proportions. Results: Among 139 AML pts, 46 in Cohort A, 93 in Cohort B, we identified 34 and 47 decedents in each cohort respectively. The use of PC was significantly higher in Cohort B (75% vs 43%, P= 0.0006), with a significant increase in early PC (52% vs 11%, P < 0.0001). There was no significant improvement in EOL quality outcomes between Cohort A and B, or uniquely among pts receiving early PC ( P > 0.05); however, PC use in general across all cohorts was associated with significant increase in hospice use and fewer ICU admissions ( P =0.016 and 0.0043, respectively). Among pts not receiving PC, a numerical improvement was noted in EOL metrics between Cohorts A and B ( P > 0.05; see table). Conclusions: PC for pts with AML was associated with significantly better EOL quality outcomes. We also observed improvement in EOL metrics over time among pts not receiving PC, which may indicate a culture shift with the embedded PC service, whose benefit extended to pts not directly receiving PC. Embedding a PC specialist and early PC in AML, however, was not significantly associated directly with EOL care improvements. The value of these interventions in HMs may be better measured using patient-reported outcomes and quality of life measures rather than strict EOL outcomes. Further research should consider potential differential role of PC among pts with HM undergoing aggressive/curative, or non-intense/palliative therapy. [Table: see text]

Unattended Sensors in Marine Environments

This chapter discusses the use of unattended sensors and its use in marine environment. The authors present challenges of designing a marine sensor in harsh environments and a case study in implementing a marine sensor to study hypoxia. Hypoxia is a world-wide anthropogenic phenomenon related to pollution. The authors describe the construction of an inexpensive sensor buoy system, Oxybuoy, designed for long-term unattended oxygen sensor measurements. The technology is available to construct such sensor buoys. The authors showed a prototype based on commercial off-the shelf components: an embedded PC, an optical dissolved oxygen sensor, a temperature sensor, a Wi-Fi transmitter and a satellite transmitter. Its total cost is around $5,000 to construct, program and test a proof of concept of such sensor. The authors describe the buoy's architectural design and three experiments that the authors carried out to demonstrate its viability.

IMPLEMENTASI NAVIGASI KENDARAAN DENGAN MENGGUNAKAN EMBEDDED PC DAN DETEKSI JALAN BERBASIS METODE TEXTURE FILTER

Navigasi kendaraan adalah proses pengenalan jalan dan mengarahkan kendaraan pada lintasan yang diinginkan. Penelitian tentang navigasi kendaraan umumnya berfokus pada pengembangan Advanced Driver Assistance System (ADAS) untuk meningkatkan keselamatan dalam berkendaradengan tujuan jangka panjang untuk mewujudkan kendaraan otonom. Pada umumnya navigasi kendaraan dilakukan dengan menggunakan banyak jenis instrumen pengukuran yang berukuran besar dan sulit diaplikasikan pada kendaraan secara umum. Penelitian ini dilakukan untuk menguji ADAS dengan menggunakan instrumen sederhana dan mudah untuk dipasang pada kendaraan. Navigasi dimulai dengan proses deteksi sisi jalan dengan mengamati area jalan pada jarak 10m hingga 14m di depan kendaraan menggunakan teknik pengolahan citra. Hasil deteksi sisi jalan digunakan untuk menghasilkan rekomendasi arah gerak kendaraan yang diubah ke dalam bentuk rekomendasi putaran kemudi bagi pengemudi. Rekomendasi arah gerak kendaraan diperoleh melalui perhitungan sudut yang dibentuk oleh kendaraan terhadap titik tengah lajur jalan pada jarak yang telah ditentukan. Pengujian dilakukan secara real-time dengan menggunakan sebuah Embedded PCdapat mencapai waktu pengolahan citra 13,962 ms dengan tingkat keberhasilan deteksi jalan sebesar 89,7% dan estimasi tingkat kesesuaian data rekomendasi putaran kemudi sebesar 91,04% yang dibandingkan terhadap putaran kemudi oleh pengemudi

A low-power data acquisition system for geomagnetic observatories and variometer stations

A modern geomagnetic observatory must provide data of high stability, continuity, and resolution. The INTERMAGNET network has therefore specified quantitative criteria to ensure a high quality standard of geomagnetic observatories. Here, we present a new data acquisition system which was designed to meet these criteria, in particular with respect to 1 Hz data. This system is based on a Raspberry Pi embedded PC and runs a C+ + data acquisition software. As a result, the data acquisition system is modular, cheap, and flexible, and it can be operated in remote areas with limited power supply. In addition, the system is capable of near-real-time data transmission, using a reverse SSH tunnel to work with any network available. The system hardware was successfully tested at the Niemegk observatory for a period of 1 year and subsequently installed at the Tatuoca observatory in Brazil.

A low-power data acquisition system for geomagnetic observatories and variometer stations

A modern geomagnetic observatory must provide data of high stability, continuity, and resolution. The INTERMAGNET network has therefore specified quantitative criteria to ensure a high quality standard of geomagnetic observatories. Here, we present a new data acquisition system which was designed to meet these criteria, in particular with respect to 1 Hz data. This system is based on a Raspberry Pi embedded PC and a modern 24 bit analog-to-digital converter and runs a C++ data acquisition software which is compatible with the POSIX standard. As a result, the data acquisition system is modular, cheap, flexible, and can be operated in remote areas with limited power supply. In addition, the system is capable of real-time data transmission, using a reverse SSH tunnel to work with any network available. We have successfully tested the system hardware at the Niemegk observatory for a period of one year and subsequently installed at the Tatuoca observatory in Brazil.