RF SSSL by an Autonomous UAV with Two-Ray Channel Model and Dipole Antenna Patterns

Advancements in unmanned aerial vehicle (UAV) technology have led to their increased utilization in various commercial and military applications. One such application is signal source search and localization (SSSL) using UAVs, which offers significant benefits over traditional ground-based methods due to improved RF signal reception at higher altitudes and inherent autonomous 3D navigation capabilities. Nevertheless, practical considerations such as propagation models and antenna patterns are frequently neglected in simulation-based studies in the literature. In this work, we address these limitations by using a two-ray channel model and a dipole antenna pattern to develop a simulator that more closely represents real-world radio signal strength (RSS) observations at a UAV. We then examine and compare the performance of previously proposed linear least square (LLS) based localization techniques using UAVs for SSSL. Localization of radio frequency (RF) signal sources is assessed based on two main criteria: 1) achieving the highest possible accuracy and 2) localizing the target as quickly as possible with reasonable accuracy. Various mission types, such as those requiring precise localization like identifying hostile troops, and those demanding rapid localization like search and rescue operations during disasters, have been previously investigated. In this paper, the efficacy of the proposed localization approaches is examined based on these two main localization requirements through computer simulations.Comment: 7 Pages, submitted to 2023 PIMR

Impact of 3D Antenna Radiation Pattern in UAV Air-to-Ground Path Loss Modeling and RSRP-based Localization in Rural Area

Ensuring reliable and seamless wireless connectivity for unmanned aerial vehicles (UAVs) has emerged as a critical requirement for a wide range of applications. The increasing deployment of UAVs has increased the significance of cellular-connected UAVs (C-UAVs) in enabling beyond-visual line of sight (BVLOS) communications. To ensure the successful operation of C-UAVs within existing terrestrial networks, it is vital to understand the distinctive characteristics associated with air-to-ground signal propagation. In this paper, we investigate the impact of 3D antenna patterns on a UAV air-to-ground path loss model, utilizing datasets obtained from a measurement campaign. We conducted UAV experiments in a rural area at various fixed heights, while also characterizing the 3D antenna radiation pattern by using an anechoic chamber facility. By analyzing reference signal received power (RSRP) using path loss models that account for antenna patterns, we observed that our measurement results, obtained at different UAV heights, aligned well with the two-ray path loss model when incorporating the measured antenna pattern. we propose an RSRP-based localization algorithm at a UAV that takes into account antenna patterns in both offline and online scenarios. Through our experimentation dataset, we show that incorporating measured antenna patterns significantly enhances the source localization accuracy

ACCURACY OF THE SOFTWARE GENLOCK WITH DIGITAL CAMCORDERS

Recently, digital camcorders have gained popularity as a viable means of recording movements in video motion analysis, mainly due to the ease of use and reasonably high image resolution. Digital camcorders, however, suffer from a major drawback, lack of the hardware genlock capability. Camcorders thus operate independently from each other and introduce time offsets among themselves. These time offsets in turn violate the requirement of simultaneous observations from multiple cameras in the 3·D analysis, producing erroneous real-life coordinates of the markers. This is especially true in fast motions, in which a small time offset can be translated into a large spatial error, and the time offsets must be corrected before the 3-D reconstruction. The genlock (synchronization) of the cameras can be potentially achieved by a software-based strategy, the software genlock. The purpose of this stUdy was to investigate the accuracy of the software genlock using digital camcorders

An Insufficient Preoperative Diagnosis of Borrmann Type 4 Gastric Cancer in Spite of EMR

Borrmann type 4 gastric cancers are notorious for the difficulty of finding cancer cells in the biopsy samples obtained from gastrofiberscopy. It is important to obtain the biopsy results for making surgical decisions. In cases with Borrmann type 4 gastric cancer, even though the radiological findings (such as an upper gastrointestinal series, abdominal computed tomography and positron emission tomography/computed tomography) or the macroscopic findings of a gastrofiberscopy examination imply a high suspicion of cancer, there can be difficulty in getting the definite pathologic results despite multiple biopsies. In these cases, we have performed endoscopic mucosal resection under gastrofiberscopy as an alternative to simple biopsies. Here we report on a case in which no cancer cells were found even in the endoscopic mucosal resection specimen, but the radiologic evidence and clinical findings were highly suspicious for gastric cancer. The patient finally underwent total gastrectomy with lymph node resection, and she was pathologically diagnosed as having stage IV gastric cancer postoperatively

Size distributions of atmospheric particulate matter and associated trace metals in the multi-industrial city of Ulsan, Korea

Particulate matter (PM) was collected using micro-orifice uniform deposit impactors from a residential (RES) site and an industrial (IND) site in Ulsan, South Korea, in September-October 2014. The PM samples were measured based on their size distributions (11 stages), ranging from 0.06 ??m to over 18.0 ??m. Nine trace metals (As, Se, Cr, V, Cd, Pb, Ba, Sb, and Zn) associated with PM were analyzed. The PM samples exhibited weak bimodal distributions irrespective of sampling sites and events, and the mean concentrations of total PM (TPM) measured at the IND site (56.7 ??g/m3) was higher than that measured at the RES site (38.2 ??g/m3). The IND site also showed higher levels of nine trace metals, reflecting the influence of industrial activities and traffic emissions. At both sites, four trace metals (Ba, Zn, V, and Cr) contributed to over 80% of the total concentrations in TPM. The modality of individual trace metals was not strong except for Zn; however, the nine trace metals in PM2.5 and PM10 accounted for approximately 50% and 90% of the total concentrations in TPM, respectively. This result indicates that the size distributions of PM and trace metals are important to understand how respirable PM affects public health

anti-9,10-Di(1-naphth­yl)anthracene pyridine disolvate

In the title compound, C34H22·2C5H5N, there is a crystallographic inversion center in the middle of the anthracene ring system. The dihedral angle between the mean planes of the anthracene and naphthalene ring systems is 83.96 (4)°. The crystal structure is stabilized by weak inter­molecular C—H⋯N and C—H⋯π inter­actions

Deterministic bead-in-droplet ejection utilizing an integrated plug-in bead dispenser for single bead-based applications

This paper presents a deterministic bead-in-droplet ejection (BIDE) technique that regulates the precise distribution of microbeads in an ejected droplet. The deterministic BIDE was realized through the effective integration of a microfluidic single-particle handling technique with a liquid dispensing system. The integrated bead dispenser facilitates the transfer of the desired number of beads into a dispensing volume and the on-demand ejection of bead-encapsulated droplets. Single bead-encapsulated droplets were ejected every 3 s without any failure. Multiple-bead dispensing with deterministic control of the number of beads was demonstrated to emphasize the originality and quality of the proposed dispensing technique. The dispenser was mounted using a plug-socket type connection, and the dispensing process was completely automated using a programmed sequence without any microscopic observation. To demonstrate a potential application of the technique, bead-based streptavidin-biotin binding assay in an evaporating droplet was conducted using ultralow numbers of beads. The results evidenced the number of beads in the droplet crucially influences the reliability of the assay. Therefore, the proposed deterministic bead-in-droplet technology can be utilized to deliver desired beads onto a reaction site, particularly to reliably and efficiently enrich and detect target biomolecules.112Ysciescopu

Steatocystoma Multiplex Confined to the Scalp with Concurrent Alopecia

Steatocystoma multiplex (SM) is an uncommon disorder of the pilosebaceous unit characterized by the development of numerous sebum-containing dermal cysts which rarely involves the scalp. Here, we report a case of a 50-year-old man with multiple cystic nodules and alopecic patches on his scalp. On histopathological examination, the folded cyst was found to be lined by stratified squamous epithelium, while flattened sebaceous gland cells were identified in the cystic wall. Pigment casts were present in the hair papillae and perifollicular regions, suggesting trichotillomania as a possible cause of the observed alopecia. This case appears to represent an unusual clinical manifestation of SM

The reliability of an easy measuring method for abutment convergence angle with a computer-aided design (CAD) system

PURPOSE. The purpose of this study was to evaluate the intra-rater reliability and inter-rater reliability of three different methods using a drawing protractor, a digital protractor after tracing, and a CAD system. MATERIALS AND METHODS. Twenty-four artificial abutments that had been prepared by dental students were used in this study. Three dental students measured the convergence angles by each method three times. Bland-Altman plots were applied to examine the overall reliability by comparing the traditional tracing method with a new method using the CAD system. Intraclass Correlation Coefficients (ICC) evaluated intra-rater reliability and inter-rater reliability. RESULTS. All three methods exhibited high intra-rater and inter-rater reliability (ICC>0.80, P<.05). Measurements with the CAD system showed the highest intra-rater reliability. In addition, it showed improved inter-rater reliability compared with the traditional tracing methods. CONCLUSION. Based on the results of this study, the CAD system may be an easy and reliable tool for measuring the abutment convergence angle.OAIID:oai:osos.snu.ac.kr:snu2014-01/102/2008003883/3SEQ:3PERF_CD:SNU2014-01EVAL_ITEM_CD:102USER_ID:2008003883ADJUST_YN:NEMP_ID:A078517DEPT_CD:861CITE_RATE:0FILENAME:j adv prosthodont 201406 6(3) 185-93.pdfDEPT_NM:치의학과SCOPUS_YN:NCONFIRM: