Search Results (233)

The high demands on datasets and computing resources in deep learning make the models vulnerable to a range of security threats such as backdoor learning. The study of backdoor learning also helps to improve the understanding of model security. In order to ensure the attack effect, the triggers and targets in the existing backdoor learning methods are usually fixed and single, so a single defense will lead to the failure of the attack. This paper proposes an invisible backdoor learning scheme in the transform domain with flexible triggers and targets. By adding different offsets of different frequencies in the transform domain, multiple triggers and multiple targets are controlled. The generated poisoning images are added to the training dataset and the model is fine-tuned. Under the conception, two modes of backdoor learning enable flexible triggers and targets. One mode is multi-triggers and multi-targets (MTMT), and it can implement multiple triggers corresponding to different activation targets. The other mode is multi-triggers and one-target (MTOT), and it can realize multiple trigger sets to activate the target together. The experimental results show that the attack success rate reaches 95% and the accuracy of the model decreases within 3% under the premise that the trigger is not visible. This scheme can resist the common defense methods and has a good sample of the visual quality. Full article

This article addresses the use of fixed-width confidence intervals (FWCIs) for comparing two independent Bernoulli populations in A/B testing scenarios. Two sequential estimation procedures are proposed: one for estimating the difference in log probabilities of success and the other for log odds ratios. Both methods showcase great efficiency, as established via theoretical analysis and Monte Carlo simulations. The practical utility of these methods is demonstrated through two real-world applications: analyzing retention rates in mobile game Cookie Cats and evaluating the effectiveness of online advertising. Full article

The use of zirconia for full-arch Implant-Supported Fixed Complete Dental Prostheses (ISFCDPs) is common and reliable, with different techniques available for their design and fabrication. This retrospective study investigated prosthetic and implant survival/success rates and patients’ satisfaction for ISFCDPs produced with three different techniques: zirconia-on-titanium (milled zirconia arch glued to a titanium bar), progressive monolithic zirconia (entirely made of zirconia and directly screwed to the implants) and zirconia-on-zirconia (milled esthetic zirconia crowns glued to a milled high resistance zirconia frame). Fourteen patients (five males, nine females) aged 52–80 and treated with 14 ISFCDPs (86 implants) were included in this analysis. The mean follow-up at the time of recall was 36 months. Prosthetic and implant-related success rates were, respectively, 92.86% and 95.35%. No failures have been reported. One case of prosthetic chipping was observed; however, it was successfully repaired intraorally. Patients’ satisfaction was high: 78.57% were completely satisfied, 14.53% very satisfied and 7.14% satisfied. In conclusion, all the patients recommend treatment with ISFCDPs as full-arch prosthetic rehabilitation. The present study demonstrates positive clinical outcomes and high patients’ satisfaction. Further long-term, prospective studies with a larger cohort of patients are needed to confirm the advantages of the different prosthetic designs. Full article

Sandblasting and acid etching are common procedures used to treat implant surfaces, enhancing osseointegration and improving clinical success rates. This clinical study aimed to evaluate the long-term outcomes of sandblasted and acid-etched implants. A total of 303 implants were placed in 114 partially and totally edentulous patients using a two-stage surgical technique and an early loading protocol (6–8 weeks). Clinical findings for implants and prosthetics were evaluated over a 12-year follow-up period. A total of 12 implants (3.9%) failed, with 3 failures occurring during the healing period before loading and 9 due to peri-implantitis. The cumulative survival rate for all implants was 96.1%. A total of 156 prostheses were placed on 300 implants, 87 single crowns, 45 partial fixed bridges, 9 full-arch fixed restorations, and 15 overdentures. The mean marginal bone loss was 1.18 mm. (SD. 0.64 mm.). Thirty-nine implants (13%) in twenty-four patients exhibited peri-implantitis. Technical complications, including prosthetic screw loosening or fracture, ceramic chipping, and acrylic fractures, were observed in 24 subjects (21.1%). Sandblasted and acid-etched surface implants placed in the maxilla and mandible reported favorable outcomes and stable tissue conditions with an early loading protocol. Full article

Candlestick charts provide a visual representation of price trends and market sentiment, enabling investors to identify key trends, support, and resistance levels, thus improving the success rate of stock trading. The research presented in this paper aims to overcome the limitations of traditional candlestick pattern analysis, which is constrained by fixed pattern definitions, quantity limitations, and subjectivity in pattern recognition, thus improving its effectiveness in dynamic market environments. To address this, a two-layer clustering method based on a candlestick sequence simlarity matching model is proposed for identifying valid candlestick patterns and constructing a pattern library. First, the candlestick sequence similarity matching model is used to address the pattern matching issue; then, a two-layer clustering method based on the K-means algorithm is designed to identify valid candlestick patterns. Finally, a valid candlestick pattern library is built, and the predictive ability and profitability of some patterns in the library are evaluated. In this study, ten stocks from different industries and of various sizes listed on the Shanghai Stock Exchange were selected, using nearly 1000 days of their data as the test set. The predictive ability of some patterns in the library was evaluated using out-of-sample data from the same period. This selection method ensures the diversity of the dataset. The experimental results show that the proposed method can effectively distinguish between bullish and bearish patterns, breaking through the limitations of traditional candlestick pattern classification methods that rely on predefined patterns. By clearly distinguishing these two patterns, it provides clear buy and sell signals for investors, significantly improving the reliability and profitability of trading strategies. Full article

Hemorrhage remains a leading cause of death in both military and civilian trauma settings. Oftentimes, the control and treatment of hemorrhage requires central vascular access and well-trained medical personnel. Automated technology is being developed that can lower the skill threshold for life-saving interventions. Here, we conduct independent evaluation testing of one such device, the Vu-Path™ Ultrasound Guidance system, or Vu-Path™. The device was designed to simplify needle insertion using a needle holder that ensures the needle is within the ultrasound field of view during its insertion into tissue, along with guidance lines shown on the user interface. We evaluated the performance of this device in a range of laboratory, animal, and human testing platforms. Overall, the device had a high success rate, achieving an 83% insertion accuracy in live animal testing across both normal and hypotensive blood pressures. Vu-Path™ was faster than manual, ultrasound-guided needle insertion and was nearly 1.5 times quicker for arterial and 2.3 times quicker for venous access. Human usability feedback highlighted that 80% of the participants would use this device for central line placement. Study users noted that the guidance lines and small form factor were useful design features. However, issues were raised regarding the needle insertion angle being too steep, with potential positioning challenges as the needle remains fixed to the ultrasound probe. Regardless, 75% of the participants believed that personnel with any level of clinical background could use the device for central vascular access. Overall, Vu-Path™ performed well across a range of testing situations, and potential design improvements were noted. With adjustments to the device, central vascular access can be made more accessible on battlefields in the future. Full article

The study aimed to assess the success and survival rates of post-extraction implants with immediate loading. A systematic search was performed in the Medline (PubMed), Cochrane Library (Wiley), and Scopus (Elsevier) databases to identify randomized and non-randomized studies of intervention (NRSI) on bone loss and success and survival rates in post-extraction implants with immediate, early, and delayed loading. Articles were selected based on predefined inclusion and exclusion criteria, and the risk of bias was assessed following Cochrane guidelines, and the Newcastle–Ottawa Scale was used to assess quality. A fixed-effect meta-analysis was conducted to evaluate bone loss using mean, median, and standard deviation, and to calculate odds ratios for success-survival rates. Of the 13 studies identified, three met the criteria for inclusion in the meta-analysis, involving a total of 178 patients and 296 post-extraction implants. Bone loss was the lowest in the delayed loading group (0.51 mm) compared to immediate (0.55 mm) and early loading (0.54 mm). Implant failures were similar in the immediate and early groups (one case each), while two failures were reported in the delayed group. Delayed loading reduced peri-implant bone loss, but immediate loading showed a slightly higher success-survival rate. Further high-quality studies are needed to strengthen the evidence on the long-term effects of the different implant loading protocols. Full article

This study addresses the challenges associated with single-system long-baseline real-time kinematic (RTK) navigation, including limited positioning accuracy, inconsistent signal reception, and significant residual atmospheric errors following double-difference corrections. This study explores the effectiveness of long-baseline RTK navigation using an integrated system of the BeiDou Navigation Satellite System (BDS), Global Positioning System (GPS), and Galileo Satellite Navigation System (Galileo). A long-baseline RTK approach that incorporates Kalman filtering and partial ambiguity resolution is applied. Initially, error models are used to correct ionospheric and tropospheric delays. The zenith tropospheric and inclined ionospheric delays and additional atmospheric error components are then regarded as unknown parameters. These parameters are estimated together with the position and ambiguity parameters via Kalman filtering. A two-step method based on a success rate threshold is employed to resolve partial ambiguity. Data from five long-baseline IGS monitoring stations and real-time measurements from a ship were employed for the dual-frequency RTK positioning experiments. The findings indicate that integrating additional GNSSs beyond the BDS considerably enhances both the navigation precision and the rate of ambiguity resolution. At the IGS stations, the integration of the BDS, GPS, and Galileo achieved navigation precisions of 2.0 cm in the North, 5.1 cm in the East, and 5.3 cm in the Up direction while maintaining a fixed resolution exceeding 94.34%. With a fixed resolution of Up to 99.93%, the integration of BDS and GPS provides horizontal and vertical precision within centimeters in maritime contexts. Therefore, the proposed approach achieves precise positioning capabilities for the rover while significantly increasing the rate of successful ambiguity resolution in long-range scenarios, thereby enhancing its practical use and exhibiting substantial application potential. Full article

Angiostrongylus vasorum is a metastrongyloid lungworm causing severe cardiovascular disease in domestic and wild animals. During its heteroxenous life cycle, A. vasorum requires obligate gastropod intermediate hosts. Little is known about A. vasorum larval organ tropism and development in gastropod intermediate hosts. Thus, the aim of this study was to analyze in vivo development of A. vasorum larval stages in experimentally infected African giant snails (Lissachatina fulica). Adult L. fulica (n = 26) were orally infected with A. vasorum-L1 and thereafter continuously euthanized. Gastropod organs were artificially digested and microscopically analyzed for the presence of A. vasorum larvae. Moreover, paraffin-fixed organs were investigated histologically for snail-borne innate immune response. In the current study, the success of L. fulica oral infection was demonstrated, thereby reaching larval recovery rates of up to 49.7%. During snail infection, an organ tropism of A. vasorum larvae was detected for the lungs and the foot muscular tissue. Overall, A. vasorum-driven gastropod innate immune reactions against larvae varied greatly. In some specimens, larvae were found effectively ensnared by recruited hemocytes, resulting in granuloma formation, whilst in others, hemocyte-mediated reactions were barely observed. Nevertheless, these evidences demand more studies on hemocyte-derived effector mechanisms against A. vasorum. Full article

Background: In recent years, advancements in digital dentistry have provided new opportunities for more predictable and efficient treatment options, particularly in patients with failing dentition. This study aimed to evaluate the effectiveness and accuracy of a fully digital workflow using stackable surgical templates for complete dental arch rehabilitation with implant-supported fixed restorations. Methods: Four patients, comprising two males and two females with a mean age of 66 years, were included in this case series. Each patient underwent meticulous digital planning, including CBCT and intraoral scanning, to create a virtual patient for preoperative assessment and virtual treatment planning. The assessment of the trueness of implant positioning was conducted in Geomagic Control X software (version 2017.0.3) by referencing anatomical landmarks from both the preoperative and one-year postoperative CBCT scans. Results: A total of 25 dental implants were placed in the maxilla, followed by the installation of long-term provisional restorations. The results showed minimal deviation between the planned and actual implant positions, with mean 3D coronal, apical, and angular discrepancies of 0.87 mm, 2.04 mm, and 2.67°, respectively. All implants achieved successful osseointegration, and no failures were recorded, resulting in a 100% survival rate at the one-year follow-up. Patients reported high satisfaction with both the esthetic and functional outcomes based on their subjective feedback. Conclusions: The findings suggest that the use of a fully digital workflow with stackable surgical templates is a reliable and effective approach for immediate implant placement and prosthetic rehabilitation, enhancing treatment precision and patient comfort. Full article

This study investigates the specific challenges and opportunities faced by organic farmers in Tamil Nadu, focusing on how region-specific practices influence the adoption and success of organic farming. It draws insights from a survey of 300 organic growers across five districts: Coimbatore, Dindigul, Erode, Tirupur, and Villupuram. This study is particularly relevant because there is a lack of comprehensive research on the specific challenges and opportunities faced by organic farmers in Tamil Nadu, with limited data on the long-term impact of government initiatives and region-specific management options, especially for smallholder farmers. Additionally, gaps exist in understanding the economic viability, market demand, and farmer perceptions of organic farming together with challenges like knowledge gaps, pest control, managing risks, and lower initial yields during the transition from conventional farming to organic farming. The research evaluated the factors affecting organic farming, including crop yield, the use of different organic formulations, the role of different information services, opportunities and challenges, and the impact on the perceived effectiveness of various agricultural outcomes. Various statistical analyses were performed, including K-means clustering, Poisson regression, and chi-square test. The results revealed significant variations in the adoption of various organic inputs and regionally practiced organic formulations. Crop residues (82.67%), Jeevamrith (78.33%), Amudhakaraisal (77.00%), and 3G-Extracts (74.00%) have high adoption rates, reflecting their perceived effectiveness and accessibility among farmers. However, the adoption of microbial bio-inputs such as Trichoderma viride (1.00%), Acetobacter spp. (19.00%), Azophos (consortium of phosphorus fixing microbes) (26.33%), and Azospirillum spp. (28.67%) was notably poor despite their known benefits for soil health and crop yield. The chi-square test also highlighted key challenges faced by farmers in adopting organic farming practices. The Poisson regression analysis showed significant positive impacts on crop growth and yield, disease resistance, insect control, overall plant health, and input efficiency due to organic farming. The study’s insights are essential for developing targeted strategies to overcome barriers, supporting the growth and sustainability of organic farming. Addressing these challenges and promoting effective information channels will better equip stakeholders to support organic growers, contributing to more resilient and productive agricultural systems in the region. Full article

Background/Objectives: Defects in maxillary and mandibular alveolar ridges are common in maxillofacial practice. Reconstruction with microvascular bone grafts and subsequent prosthetic rehabilitation is the gold standard treatment. This study investigated patients’ quality of life (QoL) after microvascular alveolar ridge reconstruction with subsequent dental rehabilitation. The effect of the underlying disease and success rates of the prosthetic treatment on QoL were analysed. Methods: OHIP-49 was used to evaluate oral health-related QoL (OHrQoL). The SF-36 was used to assess disease-nonspecific QoL. Results: Fifty-eight patients were enrolled and divided into four diagnostic (malignancy, osteoradionecrosis, benign disease, and cleft palate) and five prosthetic groups (no prosthetics, removable partial dentures, complete dentures, implant-supported removable dentures, and implant-supported fixed dentures). There was a significant difference between the diagnostic groups in the total score of their OHIP-49 (p = 0.008). Patients with malignant disease and osteoradionecrosis had worse QoL scores than those with benign diseases and cleft palate. Implant-supported prostheses had the best OHrQoL. Removable partial dentures and patients in whom dental rehabilitation was not possible had the worst OHrQoL (p = 0.042). The SF-36 subscale score showed no statistically significant differences between the diagnostic and prosthetic groups (p > 0.05). Conclusions: OHrQoL after microvascular alveolar ridge reconstruction differs significantly based on underlying diagnoses and prosthetic restorations. Benign diseases and implant-supported dentures have the highest scores. Full article

In recent years, unmanned aerial vehicles (UAVs) vision systems based on deep neural networks (DNNs) have made remarkable advancements, demonstrating impressive performance. However, due to the inherent characteristics of DNNs, these systems have become increasingly vulnerable to adversarial attacks. Traditional black-box attack methods typically require a large number of queries to generate adversarial samples successfully. In this paper, we propose a novel adversarial attack technique designed to achieve efficient black-box attacks with a minimal number of queries. We define a perturbation generator that first decomposes the image into four frequency bands using wavelet decomposition and then searches for adversarial perturbations across these bands by minimizing a weighted loss function on a set of fixed surrogate models. For the target victim model, the perturbation images generated by the perturbation generator are used to query and update the weights in the loss function, as well as the weights for different frequency bands. Experimental results show that, compared to state-of-the-art methods on various image classifiers trained on ImageNet (such as VGG-19, DenseNet-121, and ResNext-50), our method achieves a success rate over 98% for targeted attacks and nearly a 100% success rate for non-targeted attacks with only 1–2 queries per image. Full article

Low-power wide area network (LPWAN) technologies as part of IoT are gaining a lot of attention as they provide affordable communication over large areas. LoRa and Sigfox as part of LPWAN have emerged as highly effective and promising non-3GPP unlicensed band IoT technologies while challenging the supremacy of cellular technologies for machine-to-machine-(M2M)-based use cases. This paper presents the design goals of LoRa and Sigfox while throwing light on their suitability in congested environments. A practical traffic generator of both LoRa and Sigfox is introduced and further interpolated for understanding simultaneous operation of 100 to 10,000 such nodes in close vicinity while establishing deep understanding on effects of collision, re-transmissions, and link behaviour. Previous work in this field have overlooked simultaneous deployment, collision issues, effects of re-transmission, and propagation profile while arriving at a number of successful receptions. This work uses packet error rate (PER) and delivery ratio, which are correct metrics to calculate successful transmissions. The obtained results show that a maximum of 100 LoRa and 200 Sigfox nodes can be deployed in a fixed transmission use case over an area of up to 1 km. As part of the future scope, solutions have been suggested to increase the effectiveness of LoRa and Sigfox networks. Full article

This study examined whether fixed or flexible funding mechanisms influence crowdfunding success. Under the fixed funding mechanism, the pledges contributed to the crowdfunding campaign projects are returned to the backers if the project fails, whereas, under the flexible funding mechanism, the project creator can keep all the raised pledges, irrespective of whether the project succeeds or fails. Secondary data consisted of reward-based crowdfunding projects retrieved from The Crowd Data Centre. Logistic regression was employed to respond to research objectives. The results reveal that the fixed funding mechanism increases the probability of success more than flexible funding. Entrepreneur experience, spelling errors, and project description negatively affect crowdfunding success, and backers positively affect crowdfunding success. The findings guide entrepreneurs seeking financing to design and choose an appropriate funding mechanism that effectively reduces the failure rate. Although many entrepreneurs seek funding in the crowdfunding market, relatively little research has been conducted on the influence of flexible or fixed funding mechanisms on crowdfunding success in Africa. This study provides entrepreneurs with appropriate financing strategies that enhance crowdfunding success. The empirical literature indicates that the flexible funding mechanism creates distrust among backers due to unrealistic target amounts. Full article