Current Block Research Articles

An Improved Framework of Affine Motion Compensation in Video Coding.

Affine Motion Compensation (AMC) is a promising coding tool in Joint Exploration Model (JEM) developed by the Joint Video Exploration Team (JVET). AMC in JEM employs a 4-parameter affine model between the current block and its reference block. With this model, Motion Vectors (MV) of each sub-block can be derived from the MVs at two control points. In this paper, we present a practical framework to further improve the AMC in JEM. First, we introduce a multi-model AMC approach, which allows the encoder to select either the 4-parameter affine model or the 6-paramter affine model adaptively. Second, we improve the affine inter-mode in two aspects. For the normative part, we present an efficient affine motion coding method, which replaces the affine MV Prediction (MVP) candidates in JEM with more accurate but simpler ones, and employs a second-order MVP. For the non-normative part, we enhance the motion estimation process for AMC, by regulating the optimization algorithm. Finally, we propose to unify the affine merge-mode and the normal merge-mode into a unified merge-mode, which combine affine merge candidates and normal merge candidates in a single merge candidate list. Partial of these methods have been adopted into the next generation video coding standard named Versatile Video Coding (VVC). Simulation results show that the proposed methods can achieve 1.67% BD rate savings in average for the random access configurations.

Generation and Single-Molecule Characterization of a Sequence-Selective Covalent Cross-Link Mediated by Mechlorethamine at a C–C Mismatch in Duplex DNA for Discrimination of a Disease-Relevant Single Nucleotide Polymorphism

Many strategies for the detection of nucleic acid sequence rely upon Watson-Crick hybridization of a probe strand to the target strand, but the reversible nature of nucleic acid hybridization presents an inherent challenge: short probes that provide high target specificity have relatively low target affinity resulting in signal losses. Sequence-specific covalent cross-linking reactions have the potential to provide both selective target capture and durable signal. We explore a novel approach involving sequence-specific covalent cross-linking of a probe to target DNA combined with single-molecule nanopore detection of the cross-linked DNA. Here, we exploited the selective reaction of mechlorethamine at a C-C mismatch for covalent capture of a target DNA sequence corresponding to a cancer-driving mutation at position 1799 of the human BRAF kinase gene. We then demonstrated that the α-hemolysin protein nanopore can be employed for the unambiguous, single-molecule detection of the cross-linked probe-target complex. Cross-linked DNA generates an unmistakable deep and persistent current block (≥5 s) that is easily distinguished from the microsecond and millisecond blocks generated by translocation of single-stranded DNA and uncross-linked duplexes through the nanopore.

Deep Structural Framework and Genetic Analysis of Gold Concentration Areas in the Northwestern Jiaodong Peninsula, China: A New Understanding based on High‐Resolution Reflective Seismic Survey

AbstractThe gold concentration areas in the northwestern Jiaodong Peninsula constituted an important gold metallogenetic region in Eastern China during the Mesozoic. The deep geological bodies' texture characteristic is important for exploring the resources thoroughly and understanding the metallogenic process. The detailed textures were revealed using high‐resolution seismic profiles through the three major ore‐controlling structures‐Sanshandao fault zone, Jiaojia fault zone and Zhaoping fault zone. This study aims to establish a deep structural framework of this area. Based on their formation mechanism, the fault structures developed in the area can be divided into regional and local fault structures. The structural styles are characterised by superimposing their compressional, strike‐slip and extensional multi‐stage activities. The crust is cut by vertical structures corresponding to a left‐lateral strike‐slip fault system on the surface. Nearby these structures are the arc‐shape structures formed by multi‐stage magma intrusions into the upper crust. Bounded by the Tancheng–Lujiang and Muping–Jimo fault zones, the current Jiaodong block, developed a series of NE‐trending strike‐slip fault systems, was probably formed by the assemblage of several obliquely aligned blocks. The intensive magmatism and hydrothermal activity between the blocks induced large‐scale mineralisation. It provides a new angle of view for understanding the cratonic destruction and large ore‐concentration formed during the Mesozoic.

Combining multi-scale composite windows with hierarchical smoothing strategy for fingerprint orientation field computation

BackgroundOrientation field (OF) plays a very significant role in automatic fingerprint recognition systems. Many algorithms have been proposed for the estimation of fingerprints’ OF but it is hard to solve the dilemma of correcting spurious ridge structure and avoiding singularity location deviation, especially for poor images. So far, the following drawbacks still need to be solved for OF construction methods for practical application: (1) How to adaptively choose block scales to resolve the contradiction between accuracy and anti-noise, since small scale is beneficial to accuracy but is sensitive to noise, while large scale is more resistant to noise, but the accuracy is deteriorated. (2) How to construct the genuine OF in the areas close-by singular points and to evade singularity location deviation? Current block based methods give spurious OF estimates in the area near singular points because these areas have large curvature thus the detected singular points deviate from the genuine localizations. When these singular points are used as the anchor for referencing minutiae, it makes the average error of matching or recognition even larger. Therefore, it is essentials to construct the genuine OF in the areas close-by singular points and to evade singularity deviation.MethodsTo overcome the above-mentioned limitations, a novel method, combining a weighted multi-scale composite window (WMCM) with a hierarchical smoothing strategy has been proposed for the computation of fingerprint OF. This method mainly contains two procedures: the approximate OF estimation and the hierarchical OF smoothing. In the first procedure, a series of OFs are established under multiple scales of composite windows by using a gradient based method then a coarse OF is estimated using the weight of each scale determined by a squared gradient consistency. In the second procedure, the OF is first quantized into a two-digitized orientation zone and a two-orientation-zone filtering strategy is adapted to the OF blocks based on a filtering mask obtained after eliminating the isolated blocks. In the end a similar three-digitized orientation zone is performed to obtain an accurate and smooth OF. To validate the performance, the proposed method has been applied to OF computation using the FVC2004 databases and three experiments are designed. Experiment 1 aims to validate whether the weighted multi-scale composite window can balance the dilemma of accuracy and robustness more effectively than the previous works do. Experiment 2 is designed to examine whether the hierarchical smoothing method can correct the spurious ridge flow and preserve the genuine localization of singular points. The purpose of experiment 3 is to test the performance of the proposed method on OF reconstruction in low quality fingerprint images. The fingerprint databases FVC 2004 DB1–DB4 are employed in this study.ResultsThe results of experiment I shows that the proposed method is capable to extract the information of OF reliably and it is more robust against singularity localization deviation in comparison with the other three gradient based methods. The results of experiment II indicates that the proposed smoothing method can balance the contradiction in correcting spurious ridge structures and preserving genuine singularity localization. The results of experiment III illustrates that our approach combing WMCW with the hierarchical smoothing method is capable to extract the information of OF ridge reliably and it is more robust against singularity deviation in comparison with the other three gradient based methods. In a word, the experiment results demonstrate that the proposed method can correct spurious ridge structure and meanwhile avoid singularity deviation compared with the previous works.ConclusionsA novel gradient based algorithm has been proposed which is more reliable for the estimation of the ridge information for fingerprint OF and is more accurate in preserving the singularity localization. Compared with the previously proposed gradient based methods, the advantages of the proposed RBSF lie in three aspects. Firstly a weighted multi-scale composite window is put forward to replace the single window used by conventional gradient based methods and to adaptively choose the scales of the blocks. Secondly, a hierarchical smoothing strategy is proposed to enhance the OF by using the two-orientation-zone filtering and the three-orientation-zone filtering, aiming to correct the spurious ridges and preserving the genuine location of singular points. Finally, three experiments are designed to test the proposed algorithm together with other popular gradient based methods on real fingerprint images, which are selected from different categories and all are suffering from obvious noise effects. All the experiment results show that the proposed method is superior with respect to reliable OF construction and avoiding singularity localization deviation.

Efficient Inter-View Motion Vector Prediction in Multi-View HEVC

When multi-view video sequences are encoded, the efficient motion vector prediction (MVP) is one of the most important techniques to increase the coding performance. The predictive MV should be highly correlated with the actual MV of the current block to be encoded. In this paper, we explain the inefficiency of the MVP algorithm in the multi-view high efficiency video codec (MV-HEVC) standard. In order to solve the inefficiency problem, we propose an enhanced advanced motion vector prediction algorithm in which the geometry interrelation between two neighboring views is derived based on epipolar geometry, similarity transform, and affine transform, and then predicted motion vectors (PMVs) for efficient MV coding are generated using obtained geometry relation. The experiment results show that the proposed scheme outperforms conventional MV-HEVC with a 1.32%–1.19% coding gain because it provides more efficient PMVs than conventional algorithms.

Indigenous African Education for Socio- Economic Development

Education in Africa has been in existence since time immemorial. This study sought to examine the activities of Lantana in Benin on their specialised training, Dogon of Mali in their world view, Futo Toro of Senegal in their various trades, Poro of Sierra Leone in the training of the youth, Takensi of Ghana in their social order and the Akan of Ghana. Also examined are the activities of the Chamba and Yoruba of Nigeria in their adult centred training and forecasting of the future respectively. The Chagga of Tanzania and the Abakwayaare were also examined on their initiative plays and economic activities. The paper also studied the Ndembu of Zambia on the past analysis and the activities of the Mijikenda of Kenya among other Kenyan tribes. The study used the theoretical framework of Emile Durkheim on the social and moral order, while the design of the study was on content analysis of available information and expectations. The study recommends positive approaches in the indigenouseducation that can be adapted, mainly for Kenya in its desire to achieve Vision 2030. However, further research should be done on specific values, foods, attitudes and the rule of law, how achieve social, political and economic progress in African nations and especially how the current economic integration blocks have followed the same pattern of the communities and their values.

A Cable-Drop Compensated LDO for Rechargeable Battery Powered Systems With Load Current Management in Two-Cable or Three-Cable Structures

This paper presents a low-dropout (LDO) regulator structure that is aimed at rechargeable battery powered systems where direct sensing of the load voltage is not available. The cable connecting the regulated output to the load may create a voltage drop and cause error to the load voltage. Conventional methods address this issue by increasing the LDO output voltage to compensate the cable voltage drop. The proposed architecture extends this idea by including a calibration block that updates the required compensation voltage to track the cable resistance shift due to cable length or temperature change. The measured cable-drop error was reduced from 2.4% to ∼0.1% by iterating the proposed calibration process three times. Under the condition of time-varying temperature, the measured calibration process effectively reduced the cable-drop error due to the temperature-coefficient of the cable resistance. The proposed system also includes a current management block, by which the priority is set between the load current and the battery charging current. This paper proposes two architectures, the two-cable and the three-cable structures, to implement both the cable-drop calibration and the current management functions. Other functions such as input under-voltage-lockout and output current-limiting are also included and have been verified by experiment.

Preliminary Study of Time to Recovery of Rat Sciatic Nerve from High Frequency Alternating Current Nerve Block.

High-Frequency alternating current nerve block has great potential for neuromodulation-based therapies. However, no precise measurements have been made of the time needed for nerves to recover from block once the signal has been turned off. This study aims to characterise time to recovery of the rat sciatic nerve after 30 seconds of block at varying amplitudes and frequencies. Experiments were carried out invivo to quantify recovery times and recovery completeness within 0.7 s from the end of block. The sciatic nerve was blocked with an alternating square wave signal of amplitude and frequency ranging from 2 to 9mA and 10 to 50 kHz respectively. To determine the recovery dynamics the nerve was stimulated at 100 Hz after cessation of the blocking stimulus. Electromyogram signals were measured from the gastrocnemius medialis and tibialis anterior muscles during trials as indicators of nerve function. This allowed for nerve recovery to be measured with a resolution of 10 ms. This resolution is much greater than previous measurements of nerve recovery in the literature. Times for the nerve to recover to a steady state of activity ranged from 20 to 430 milliseconds and final relative recovery activity at 0.7 seconds spanned 0.2 to 1 approximately. Higher blocking signal amplitudes increased recovery time and decreased recovery completeness. These results suggest that blocking signal properties affect nerve recovery dynamics, which could help improve neuromodulation therapies and allow more precise comparison of results across studies using different blocking signal parameters.

Fully Connected Network-Based Intra Prediction for Image Coding.

This paper proposes a deep learning method for intra prediction. Different from traditional methods utilizing some fixed rules, we propose using a fully connected network to learn an end-to-end mapping from neighboring reconstructed pixels to the current block. In the proposed method, the network is fed by multiple reference lines. Compared with traditional single line-based methods, more contextual information of the current block is utilized. For this reason, the proposed network has the potential to generate better prediction. In addition, the proposed network has good generalization ability on different bitrate settings. The model trained from a specified bitrate setting also works well on other bitrate settings. Experimental results demonstrate the effectiveness of the proposed method. When compared with high efficiency video coding reference software HM-16.9, our network can achieve an average of 3.4% bitrate saving. In particular, the average result of 4K sequences is 4.5% bitrate saving, where the maximum one is 7.4%.

The Crucial Role of Nerve Depolarisation in High Frequency Conduction Block in Mammalian Nerves: Simulation Study.

Neurostimulations which use High Frequency Alternating Current (HFAC) block show great promise for neuromodulatory therapies. Treatments have been developed for various health conditions including obesity and obesity related health risks, and now even stomach cancer treatments are being considered. However the mechanism of the block is still not completely clear, as well as how various neural and electrode parameters affect it. In order to study conduction block during HF stimulation in mammalian axons, we describe a detailed computational model and perform comprehensive simulations. We establish relationships between the blocking frequency and amplitude versus fibre diameter and the distance between the electrode and fibre. We found that only a certain level of depolarisation will universally create a block irrespective of the fibre size, and it is in the range 24-30mV depending on the stimulus frequency. Our study crucially improves our knowledge about this important technique which is rapidly emerging as a commercially available therapy.

Investigating the Utilisation of Plastic Bottle as Aggregate Replacement for Concrete Block

Concrete block plays an important role in the construction industry. Concrete blocks have been used in the making of various buildings, retaining wall and others. In this modern era, various technologies have been presented and invented in order to upgrade the life quality of mankind. Unfortunately, there are some technologies that bring bad consequences to the environment. For instance, the production of cement will contribute to a high emission of bad gases such as carbon dioxide that may be harmful to human’s health. The manufacturing of cement is also emits hazardous fumes and dust that potentially can reduce the quality of air and lead to many respiratory problems. Therefore, the main objective of this paper is to search for a new alternative way to cope with this environmental problem. Plastic bottles such as Polyethylene terephthalate (PET) was used as the main component in construction of concrete blocks. After curing the blocks for 28 days, compression test and flexural test were prepared to test the ultimate strength of these concrete blocks. From both tests, it shows that bottle blocks were qualified to replace concrete blocks in walls as the maximum stress achieved by bottle blocks were higher than the minimum permissible compressive strength and flexural value. From these results, it can be concluded that plastic bottle has a potential to replace the current concrete blocks and further study about its other properties, such as lifespan and water cement ratio should be carried out.

Perancangan Aplikasi Kriptografi Asimetris Dengan Menerapkan Metode Elliptic Curve Cryptography

Cryptography is one of the sciences used to maintain confidentiality and data security has been developing since ancient Greece. One cryptographic method that is quite reliable, stable and the parent of the popular cryptographic algorithms today is Elliptic Curve Cryptography (ECC). In this case the previous block encryption results are feedback into current block encryption. The trick, the current plaintext block is XORed first with the ciphertext block from the previous encryption, then the XOR results are entered into the encryption function. With ECC mode, each ciphertext block depends not only on the plaintext block but also on the all previous plaintext blocks, Implementation of the Elliptic Curve Cryptography (ECC) algorithm in this study was carried out by using an application built using visual basic programming language. Net 2008..

Efficient image compression based on side match vector quantization and digital inpainting

In this paper, we propose two efficient compression schemes for digital images using an adaptive selection mechanism for vector quantization (VQ), side match vector quantization (SMVQ), and image inpainting. On the sender side, after the original image is divided into blocks, the compression is implemented block by block. In both schemes, blocks in pre-specified locations are first compressed by VQ. For each remaining block, the optimal compression method (for the first scheme, including VQ or inpainting, and for the second scheme, including VQ, SMVQ, and inpainting) is determined by computing the mean square error (MSE) between the original block and its inpainted result and then comparing it with a predefined threshold. If MSE is greater than the threshold, image inpainting continues to be used to compress the current block. Otherwise, the compression mode of VQ or SMVQ is selected to substitute image inpainting to maintain higher visual quality. With the assistance of transmitted indicator flags, the receiver side can execute the image inpainting and decompression successfully. Experimental results demonstrate the effectiveness and superiority of two proposed schemes.

Developing the capacity of general practice staff to support healthier weight status in children

BackgroundLambeth has implemented a healthy weight care pathway including capacity building of multi-agency staff. Successes include being the only borough in the country to see statistical reductions in childhood obesity over 5 years; but the challenge of 39.2% of 10–11-year olds leaving primary school as overweight/obese persists. When families approach GPs to validate the National Child Measurement Programme feedback, challenges include interpretation and explanation of body mass index (BMI). GPs have also felt uncomfortable raising the issue in routine consultations.AimTo understand potential enablers to raising the issue of unhealthy weight in children in general practice.Method70 staff (GPs 58%; Nurses 25%; GP registrar/trainee 7%; and HCA/other 10%) completed a bespoke childhood obesity capacity building workshop (accredited by the Royal College of GPs). Using scenario-based activities and end of session written questionnaire we gathered: knowledge and perceptions of weight measures, role of diet, nutrition and physical activity, as well as current blocks and potential enablers for brief intervention.ResultsLess than 5% of participants were able to identify a very overweight child by visual inspection. Confidence in raising the issue was reported due to enhanced knowledge of energy intake, physical activity and provision of a BMI wheel (40%), new ways of raising the issue (30%), understanding of supportive services in Lambeth (30%).ConclusionSupportive measures identified within a whole systems approach including role of schools, government, public health and the CCG are informing future planning.

Size-dependent interaction of a 3-arm star poly(ethylene glycol) with two biological nanopores.

We use two pore-forming proteins, alpha-hemolysin and aerolysin, to compare the polymer size-dependence of ionic current block by two types of ethyleneglycol polymers: 1) linear and 2) 3-arm star poly(ethylene glycol), both applied as a polydisperse mixture of average mass 1kDa under high salt conditions. The results demonstrate that monomer size sensitivity, as known for linear PEGs, is conserved for the star polymers with only subtle differences in the dependence of the residual conductance on monomer number. To explain this absence of a dominant effect of polymer architecture, we propose that PEG adsorbs to the inner pore wall in a collapsed, salted-out state, likely due to the effect of hydrophobic residues in the pore wall on the availability of water for hydration.

Multi stage OTA design: From matrix description to circuit realization

This paper presents a comprehensive approach to frequency compensating multistage amplifiers. Different stage cases have been considered namely, differential voltage and current blocks, and general compensation blocks for both voltage and current states. Then, a matrix description has been proposed to describe the configurations. The approach involved binary matrixes in order to model amplifiers with feedback networks. Evolutionary algorithms were used to find optimum numerical values and simplify symbolic transfer functions. Also a diagram-based design was used to find the appropriate MOSFET DC bias conditions and dimensions. Note that using simplified transfer functions to symbolically locate the poles and zeroes allowed a better circuit design knowledge compared to numerical approaches. To demonstrate the proposed procedure, two circuit were designed in TSMC 0.18 μm CMOS technology and simulated results successfully compared to linear models extracted from the matrix description. According to simulations, the proposed configurations in both voltage and current states show excellence performance versus previous works. Finally, special design cases such as multi-compensation blocks and N-stage approach were discussed.

Correction: Electrocardiographic Biomarkers for Detection of Drug-Induced Late Sodium Current Block.

[This corrects the article DOI: 10.1371/journal.pone.0163619.].

An image encryption scheme using self-adaptive selective permutation and inter-intra-block feedback diffusion

In recent years, several image encryption schemes have been proposed based on new chaotic maps. However, algorithmic design and innovation of the permutation-diffusion architecture are also important. In this paper, the selective permutation is designed as a self-adaptive method to replace the traditional confusion method, which means a novel technology can be used for permutation rule generation. Furthermore, we propose a feedback-based diffusion mechanism that can act on inter-intra blocks, so a slight modification can influence the values of the current block and another block. The security of the proposed scheme originates from the improved permutation-diffusion method, which makes the cryptosystem secure against statistical attacks and differential attack.

An edge-readout, multilayer detector for positron emission tomography.

PurposeWe present a novel gamma‐ray‐detector design based on total internal reflection (TIR) of scintillation photons within a crystal that addresses many limitations of traditional PET detectors. Our approach has appealing features, including submillimeter lateral resolution, DOI positioning from layer thickness, and excellent energy resolution. The design places light sensors on the edges of a stack of scintillator slabs separated by small air gaps and exploits the phenomenon that more than 80% of scintillation light emitted during a gamma‐ray event reaches the edges of a thin crystal with polished faces due to TIR. Gamma‐ray stopping power is achieved by stacking multiple layers, and DOI is determined by which layer the gamma ray interacts in.MethodThe concept of edge readouts of a thin slab was verified by Monte Carlo simulation of scintillation light transport. An LYSO crystal of dimensions 50.8 mm × 50.8 mm × 3.0 mm was modeled with five rectangular SiPMs placed along each edge face. The mean‐detector‐response functions (MDRFs) were calculated by simulating signals from 511 keV gamma‐ray interactions in a grid of locations. Simulations were carried out to study the influence of choice of scintillator material and dimensions, gamma‐ray photon energies, introduction of laser or mechanically induced optical barriers (LIOBs, MIOBs), and refractive indices of optical‐coupling media and SiPM windows. We also analyzed timing performance including influence of gamma‐ray interaction position and presence of optical barriers. We also modeled and built a prototype detector, a 27.4 mm × 27.4 mm × 3.0 mm CsI(Tl) crystal with 4 SiPMs per edge to experimentally validate the results predicted by the simulations. The prototype detector used CsI(Tl) crystals from Proteus outfitted with 16 Hamamatsu model S13360‐6050PE MPPCs read out by an AiT‐16‐channel readout. The MDRFs were measured by scanning the detector with a collimated beam of 662‐keV photons from a 137Cs source. The spatial resolution was experimentally determined by imaging a tungsten slit that created a beam of 0.44 mm (FWHM) width normal to the detector surface. The energy resolution was evaluated by analyzing list‐mode data from flood illumination by the 137Cs source.ResultWe find that in a block‐detector‐sized LYSO layer read out by five SiPMs per edge, illuminated by 511‐keV photons, the average resolution is 1.49 mm (FWHM). With the introduction of optical barriers, average spatial resolution improves to 0.56 mm (FWHM). The DOI resolution is the layer thickness of 3.0 mm. We also find that optical‐coupling media and SiPM‐window materials have an impact on spatial resolution. The timing simulation with LYSO crystal yields a coincidence resolving time (CRT) of 200–400 ps, which is slightly position dependent. And the introduction of optical barriers has minimum influence. The prototype CsI(Tl) detector, with a smaller area and fewer SiPMs, was measured to have central‐area spatial resolutions of 0.70 and 0.39 mm without and with optical barriers, respectively. These results match well with our simulations. An energy resolution of 6.4% was achieved at 662 keV.ConclusionA detector design based on a stack of monolithic scintillator layers that uses edge readouts offers several advantages over current block detectors for PET. For example, there is no tradeoff between spatial resolution and detection sensitivity since no reflector material displaces scintillator crystal, and submillimeter resolution can be achieved. DOI information is readily available, and excellent timing and energy resolutions are possible.

Non-Coherent Spatial Modulation and Optimal Multi-Ring APSK Constellation Design

A non-coherent spatial modulation scheme assuming no channel state information (CSI) at the receiver is proposed in this letter. Different from the differential spatial modulation, in which the difference between the previous information block and the current information block is employed, the proposed scheme only utilizes the estimation of the previous transmission block to eliminate the restriction of CSI. Moreover, a generalized multi-ring amplitude phase shift keying (APSK) constellation with arbitrary modulation order of PSK on each circle is used in the scheme, and the optimal one is found through the design method proposed in this letter. Simulation results show that, at the same spectral efficiency, the proposed scheme with optimal constellation outperforms the scheme with traditional PSK, QAM, and existing APSK in Rayleigh fading channel.