Design a WLAN mini access point in the android platform

Mobile as a computing platform is becoming more and more popular. The amount of such devices shipped every year is growing rapidly, more than 1.2 billion in 2009. At the same time the WLAN is being widely adapted at various locations like campuses, meeting rooms, stations, etc. Currently almost all smart phones come with the support for the WLAN. However, most the mobile devices can only behavior as a client in the WLAN. It would be a remarkable feature if the mobile device is able to function as an Access Point (AP) and a modem which forwards data between the 3G network and the WLAN. Android designed for handheld devices has become a popular and powerful platform in both the industry and amateur developer community. Presently there is no WLAN AP mode supported in the Android platform, therefore it’s an interesting task for us to implement such a function. We start with studying the software AP hostapd. We set up a WLAN with hostapd running in a Ubuntu Linux platform, instead of a hardware AP. By doing this we figure out the elements needed to achieve the software AP functionality. Next we explore the Android building system, understand the mechanism the building system works, and learn the way add new modules that we prepare to add into the platform. With these basics we take all the elements needed into Android source code hierarchy and build them into the final executables. Testing cases are given both in Ubuntu Linux platform and the Android platform. To make the user experience better we design an application in the Android platform for controlling the AP built from hostapd and other components. Through the process we have done many experiments and have gained rich experience and knowledge in the Linux operating system, Linux wireless implementation, wireless drivers, Android building system, and Android application development. Some of them are enhancement to the existing knowledge in various websites, and some are new to all the members in the development community. These are all recorded in the thesis. For the final testing we succeed in both steps. First, the peripheral stations can discover the AP in the Android platform and all stations are able to connect to it. There is no difference between connection to the AP in the Android platform and connection to a normal hardware AP device. Secondly, the data packets are successfully transmitted between stations, which means there is no barrier in the AP in the Android platform for providing data service. From the view of networking layering, we conclude that we succeed in both link layer and application layer

An investigation into frequency resolution estimation model for impact signal analysis by using Hilbert spectrum and condition classification for marine diesel engine

In this paper, frequency resolution determination method is investigated according to Hilbert spectrum performance for impact signal analysis. A new constructed performance estimation model for the best frequency resolution is put forward in this research for the impact signal pattern recognition. Different parameters in the time-frequency distribution by using Hilbert spectrum are considered in this estimation model for the best frequency resolution determination. To verify the effectiveness of this estimation model, numerical simulation is used for Hilbert spectrum construction analysis. At the same time, different marine diesel engine working condition signals analysis are also used to illustrate the methodology developed in this research and verify the effectiveness. It can be concluded that this method can contribute the development for impact signal analysis by using Hilbert spectrum

Role of Zebrafish Lbx2 in Embryonic Lateral Line Development

Background: The zebrafish ladybird homeobox homologous gene 2 (lbx2) has been suggested to play a key role in the regulation of hypaxial myogenic precursor cell migration. Unlike their lbx counterparts in mammals, the function of teleost lbx genes beyond myogenesis during embryonic development remains unexplored. Principal Findings: Abrogation of lbx2 function using a specific independent morpholino oligonucleotide (MO) or truncated lbx2 mRNA with an engrailed domain deletion (lbx2 eh-) resulted in defective formation of the zebrafish posterior lateral line (PLL). Migration of the PLL primordium was altered and accompanied by increased cell death in the primordium of lbx2-MOinjected embryos. A decreased number of muscle pioneer cells and impaired expression pattern of sdf1a in the horizontal myoseptum was observed in lbx2 morphants. Significance: Injection of lbx2 MO or lbx2 eh- mRNA resulted in defective PPL formation and altered sdf1a expression, confirming an important function for lbx2 in sdf1a-dependent migration. In addition, the disassociation of PPL nerve extension with PLL primordial migration in some lbx2 morphants suggests that pathfinding of the PLL primordium and th

EAGAN: Efficient Two-stage Evolutionary Architecture Search for GANs

Generative adversarial networks (GANs) have proven successful in image generation tasks. However, GAN training is inherently unstable. Although many works try to stabilize it by manually modifying GAN architecture, it requires much expertise. Neural architecture search (NAS) has become an attractive solution to search GANs automatically. The early NAS-GANs search only generators to reduce search complexity but lead to a sub-optimal GAN. Some recent works try to search both generator (G) and discriminator (D), but they suffer from the instability of GAN training. To alleviate the instability, we propose an efficient two-stage evolutionary algorithm-based NAS framework to search GANs, namely EAGAN. We decouple the search of G and D into two stages, where stage-1 searches G with a fixed D and adopts the many-to-one training strategy, and stage-2 searches D with the optimal G found in stage-1 and adopts the one-to-one training and weight-resetting strategies to enhance the stability of GAN training. Both stages use the non-dominated sorting method to produce Pareto-front architectures under multiple objectives (e.g., model size, Inception Score (IS), and Fr\'echet Inception Distance (FID)). EAGAN is applied to the unconditional image generation task and can efficiently finish the search on the CIFAR-10 dataset in 1.2 GPU days. Our searched GANs achieve competitive results (IS=8.81$\pm$0.10, FID=9.91) on the CIFAR-10 dataset and surpass prior NAS-GANs on the STL-10 dataset (IS=10.44$\pm$0.087, FID=22.18). Source code: https://github.com/marsggbo/EAGAN.Comment: Accepted in ECCV2022, Guohao Yin and Xin He contributed equall

Efficient Multi-objective Evolutionary 3D Neural Architecture Search for COVID-19 Detection with Chest CT Scans

COVID-19 pandemic has spread globally for months. Due to its long incubation period and high testing cost, there is no clue showing its spread speed is slowing down, and hence a faster testing method is in dire need. This paper proposes an efficient Evolutionary Multi-objective neural ARchitecture Search (EMARS) framework, which can automatically search for 3D neural architectures based on a well-designed search space for COVID-19 chest CT scan classification. Within the framework, we use weight sharing strategy to significantly improve the search efficiency and finish the search process in 8 hours. We also propose a new objective, namely potential, which is of benefit to improve the search process's robustness. With the objectives of accuracy, potential, and model size, we find a lightweight model (3.39 MB), which outperforms three baseline human-designed models, i.e., ResNet3D101 (325.21 MB), DenseNet3D121 (43.06 MB), and MC3\_18 (43.84 MB). Besides, our well-designed search space enables the class activation mapping algorithm to be easily embedded into all searched models, which can provide the interpretability for medical diagnosis by visualizing the judgment based on the models to locate the lesion areas.Comment: Neural Architecture Search, Evolutionary Algorithm, COVID-19, C

Application of bioabsorbable screw fixation for anterior cervical decompression and bone grafting

OBJECTIVES: To examine the application of bioabsorbable screws for anterior cervical decompression and bone grafting fixation and to study their clinical effects in the treatment of cervical spondylosis. METHODS: From March 2007 to September 2012, 56 patients, 36 males and 20 females (38-79 years old, average 58.3±9.47 years), underwent a novel operation. Grafts were fixed by bioabsorbable screws (PLLA, 2.7 mm in diameter) after anterior decompression. The bioabsorbable screws were inserted from the midline of the graft bone to the bone surface of the upper and lower vertebrae at 45 degree angles. Patients were evaluated post-operatively to observe the improvement of symptoms and evaluate the fusion of the bone. The Japanese Orthopaedic Association (JOA) score was used to evaluate the recovery of neurological functions. RESULTS: All screws were successfully inserted, with no broken screws. The rate of symptom improvement was 87.5%. All of the grafts fused well with no extrusion. The average time for graft fusion was 3.8±0.55 months (range 3-5 months). Three-dimensional reconstruction of CT scans demonstrated that the grafts fused with adjacent vertebrae well and that the screws were absorbed as predicted. The MRI findings showed that the cerebrospinal fluid was unobstructed. No obvious complications appeared in any of the follow-up evaluations. CONCLUSIONS: Cervical spondylosis with one- or two-level involvement can be effectively treated by anterior decompression and bone grafting with bioabsorbable screw fixation. This operative method is safe and can avoid the complications induced by metal implants