Range Block Research Articles

Silicon Nitride Building Blocks in the Visible Range of the Spectrum

Silicon Nitride Building Blocks in the Visible Range of the Spectrum

A Fast Factorized Back-Projection Algorithm Based on Range Block Division for Stripmap SAR

Fast factorized back-projection (FFBP) is a classical fast time-domain technique that has garnered significant success in spotlight synthetic aperture radar (SAR) signal processing. The algorithm’s efficiency has been extended to stripmap SAR through integral aperture determination and full-aperture data block processing while retaining its computational efficiency. However, the above method is only operated in the azimuth direction, and the computing efficiency needs to be urgently improved in the actual processing process. This paper proposes a fast factorized back-projection algorithm for stripmap SAR imaging based on range block division. The echo data are divided into multiple subblocks in the range direction, and FFBP processing is applied separately to each full-aperture subblock, further enhancing computational efficiency. The paper analyzes the algorithm’s principles, underscores the necessity of integral aperture determination and full-aperture data block processing, provides specific implementation steps, and applies the algorithm to point target simulation and experimental data from a vehicle-mounted ice radar. The experiments validate the algorithm’s efficiency in stripmap SAR imaging.

MULTIPARENT FRACTAL IMAGE CODING-BASED METHODS FOR SALT-AND-PEPPER NOISE REMOVAL

Salt-and-pepper noise consists of outlier pixel values which significantly impair image structure and quality. Multiparent fractal image coding (MFIC) methods substantially exploit image redundancy by utilizing multiple domain blocks to approximate the range block, partially compensating for the information loss caused by noise. Motivated by this, we propose two novel image restoration methods based on MFIC to remove salt-and-pepper noise. The first method integrates Huber M-estimation into MFIC, resulting in an improved anti-salt-and-pepper noise robust fractal coding approach. The second method incorporates MFIC into a total variation (TV) regularization model, including a data fidelity term, an MFIC term and a TV regularization term. An alternative iterative method based on proximity operator is developed to effectively solve the proposed model. Experimental results demonstrate that these two proposed approaches achieve significantly enhanced performance compared to traditional fractal coding methods.

Assessing the Yuli surface deformation from the 20220918 Chishang earthquake: an integrated RTK GNSS network approach

The 20220918 Chishang earthquake impacted the Yuli area in the Longitudinal Valley of eastern Taiwan. Longitudinal Valley is situated near the boundary of the Philippine Plate and Eurasian Plate boundary with frequent seismicity and historical earthquakes. This study uses RTK GNSS measurements to characterize the 0918 seismic effects, revealing different coseismic displacement patterns in the Central Range, Coastal Range, and Longitudinal Valley blocks. Ruptures were mainly in the Longitudinal Valley, extending into downtown Yuli township. The influence on these geological formations highlights the complex interactions between the structures and underlying tectonic forces. Our investigations show that the Central Range block experienced a 1.17 m SW horizontal displacement and 1.1 m vertical uplift, while the Coastal Range block displayed a 1.18 m NW horizontal displacement and 0.65 m subsidence. The Longitudinal Valley block was divided by recent ruptures, with its western part impacted by the Central Range block, experiencing a 0.79 m SW displacement and 0.63 m uplift, and its eastern part influenced by the Coastal Range block, experiencing a 1.02 m NW displacement and 0.13 m subsidence. Our data indicates that different blocks were all affected differently, reflecting complex relationships between the subsurface faults to the surface fault traces. The result suggests the Central Range Fault have triggered the Yuli Fault for west-side up motion and possess a westward dip connected to the Central Range Fault. The post-seismic surveys reveal complex interactions between the Central Range and Longitudinal Valley Faults, vital for advancing earthquake mitigation strategies.

Provenance and tectonic setting of the Yimianpo Group in the southeastern Songnen–Zhangguangcai Range Block: constraints on the closure of the Mudanjiang Ocean

Provenance and tectonic setting of the Yimianpo Group in the southeastern Songnen–Zhangguangcai Range Block: constraints on the closure of the Mudanjiang Ocean

Supercapacitor Modeling: A System Identification Approach

Recently a great deal of attention has been given to supercapacitors (SC) due to their outstanding power densities and long cycling life. Their behavior has been extensively analyzed and tested through several modeling approaches. One common technique for modeling the dynamic operation of SCs is through an electrical circuit model (ECM). This article presents a new approach to identifying ECM parameters by applying subspace system identification (SSID) algorithms and incorporating coulombic efficiency. This novel application of SSID improves model accuracy by almost 50% in some cases compared to the literature procedures. This was done without manual tuning of the parameters, risk of non-convergence or any prior knowledge. The approach was validated at three different temperatures and with experimental data from an electric motorcycle. The resulting models are ready to be used as building blocks in a wide range of applications such as energy management systems, renewable power generation, electric vehicles, and microgrids.

Fast Full-Search Algorithm of Fractal Image Compression for Acceleration Image Processing

A new processing algorithm based on fractal image compression is proposed for image processing efficiency. An image will partition into non-overlapping blocks called range blocks and overlapping blocks called domain blocks, with the domain blocks generally bigger than the range blocks, to achieve a rapid encoding time. This research introduced a new fast full-search algorithm approach that starts the search for the best matching domain in the range block from the closest points in the range blocks and expands the search until an acceptable match is found or the search is completed to save even more encoding time. The proposed fast full-search approach, despite its simplicity, is more efficient than the standard search method. The search reduction, peak signal to noise ratio, compression ratio, and encoding time of the suggested approach are all examined. The proposed method can encode a 512x512 grayscale Lena image in 0.36 seconds, with a total search reduction of 87% according to experimental results.

Digital Video Compression Using DCT-Based Iterated Function System (IFS)

Large video files processing involves a huge volume of data. The codec, storage systems and network needs resource utilization, so it becomes important to minimize the used memory space and time to distribute these videos over the Internet using compression techniques. Fractal image and video compression falls under the category of lossy compression. It gives best results when used for natural images.
 This paper presents an efficient method to compress an AVI (Audio Video Interleaved) file with fractal video compression(FVC). The video first is separated into a sequence of frames that are a color bitmap images, then images are transformed from RGB color space to Luminance/Chrominance components (YIQ) color space; each of these components is compressed alone with Enhanced Partition Iterated Function System (EPIFS), then fractal codes are saved.
 The classical IFS suffers from a very long encoding time that needed to find the best matching for each range block when compared with the domain image blocks. In this work, the (FVC) is enhanced by enhancing the IFS of the fractal image compression using a classification scheme based on the Discrete Cosine Transform (DCT). Experimentation is performed by considering different block sizes and jump steps to reduce number of the tested domain blocks. Results shows a significant reduction in the encoding time with good quality and high compression ratio for different video files.

Adaptive coding occurs in object categorization and may not be associated with schizotypal personality traits

Processing more likely inputs with higher sensitivity (adaptive coding) enables the brain to represent the large range of inputs coming in from the world. Healthy individuals high in schizotypy show reduced adaptive coding in the reward domain but it is an open question whether these deficits extend to non-motivational domains, such as object categorization. Here, we develop a novel variant of a classic task to test range adaptation for face/house categorization in healthy participants on the psychosis spectrum. In each trial of this task, participants decide whether a presented image is a face or a house. Images vary on a face-house continuum and appear in both wide and narrow range blocks. The wide range block includes most of the face-house continuum (2.50–97.5% face), while the narrow range blocks limit inputs to a smaller section of the continuum (27.5–72.5% face). Adaptive coding corresponds to better performance for the overlapping smaller section of the continuum in the narrow range than in the wide range block. We find that participants show efficient use of the range in this task, with more accurate responses in the overlapping section for the narrow range blocks relative to the wide range blocks. However, we find little evidence that range adaptation in our object categorization task is reduced in healthy individuals scoring high on schizotypy. Thus, reduced range adaptation may not be a domain-general feature of schizotypy.

A rORAM scheme with logarithmic bandwidth and logarithmic locality

Oblivious Random Access Machine (ORAM) is a kind of cryptographic primitive that allows a client to access its private data from the server without disclosing the access pattern. To deal with consecutive requested blocks at a time efficiently, range ORAM (rORAM) is presented. In the previous rORAM scheme, the locality, namely, the number of discontinuous seeks to complete a request, is reduced to O(log2 N), nevertheless, the bandwidth cost is increased to the poly-logarithmic level. Hence, there exists an open question, that is, whether rORAM can be constructed with the same bandwidth efficiency as a regular ORAM, that is, O(log N)-block? In this paper, we propose a new rORAM scheme, called L2-rORAM. In our scheme, a compatible superblock technique is proposed, and it is combined together with an eviction technique for range blocks, so that it avoids duplication of multiple copies and extra dummy access. As a result, it obtains O(log N)-block bandwidth cost, which affirmatively answers the above open question. Meanwhile, the data locality is reduced to O(log N). In addition, the client storage is maintained at the small level of O(log N)-block, and the server storage is maintained at the unexpanded level of O(N)-block. Finally, experimental results show that the average response time of our L2-rORAM is reduced by one order of magnitude over the state-of-the-art rORAM scheme.

Nondestructive identification of wood species by terahertz spectrum

AbstractTerahertz time‐domain spectroscopy (THz‐TDS) has become an emerging nondestructive detection technique due to the unique properties of THz waves; it offers safety, penetrability, and fingerprint identification, especially for commonly used non‐polar materials. Here, we measure the differences in THz spectra of four wood blocks (manglietia, amur linden, black walnut, and ebony) in the frequency range of 0.1–0.9 THz. In addition, we demonstrate the principal components analysis (PCA) applied in THz absorption spectra; the principal components extracted from original data by PCA can replace the original absorption coefficient data and can clearly distinguish the wood types. Results show that THz‐TDS combined with PCA can be used as an effective nondestructive identification method in the field of public security, food detection, and customs anti‐smuggling initiatives.

Structural styles, deformation, and uplift of the Olympic Mountains, Washington: Implications for accretionary wedge deformation

Abstract The Olympic subduction complex is the exposed subaerial Cascadia accretionary wedge in the Olympic Mountains of Washington State. Uplift of the mountains has been attributed to two competing models: margin-normal deformation from frontal accretion and underplating, and margin-parallel deformation from the clockwise rotation and northward movement of the Oregon Coast Range block compressing the Olympic Mountains block against the Canadian Coast Range. East-northeast–oriented folds and Quaternary thrust faults and paleostress analysis of faults in the Coastal Olympic subduction complex, west of the subduction complex massif, provide new evidence for north-south shortening in the Coastal Olympic subduction complex that fills a large spatial gap in the north-south shortening documented in prior studies, substantially strengthening the block rotation model. These new data, together with previous studies that document north-south shortening in the subduction complex and at numerous locations in the Coast Range terrane peripheral to the complex, indicate that margin-parallel deformation of the Cascadia forearc has contributed significantly to uplift of the Olympic Mountains. Coastal Olympic subduction complex shallow-level fold structural style and deformation mechanisms provide a template for analyzing folding processes in other accretionary wedges. Similar-shaped folds in shallow-level Miocene turbidite sediments of the Coastal Olympic subduction complex formed in two shortening phases not previously recognized in accretionary wedges. Folds began forming by bed-parallel flow of sediment into developing hinges. When the strata could no longer accommodate shortening by flexural flow, further shortening was taken up by flexural slip. Similar-shaped folds in the deeper accretionary wedge rocks of the subduction complex massif have a well-developed axial-surface cleavage that facilitated shear folding with sediment moving parallel to the axial surface into the hinges, a structural style that is common to accretionary wedges. The pressure-temperature conditions and depth at which the formation of similar folds transitions from bed-parallel to axial-surface–parallel deformation are bracketed.

Multifunctional fiber optic system for microwave signals transmitting in frequency range from 0.135 to 40 GHz

In article of the developed design of a fiber-optic system for transmitting microwave signals in radar is presented. The using the developed design of a fiber optic transmission system of microwave signal allows to increase the range of operating frequencies of the radar at least twice as well as its functional capabilities. The new method of realization design of a fiber optic transmission system of microwave signal is proposed. Its use allowed to reduce in the fiber optic system, the number of functional blocks in this frequency range of the radar work on the compared to previously used designs. The experimental research results are presented.

FAST FRACTAL IMAGE ENCODER DESIGN

Fractal theory has been widely applied in the filed of image compression due to the advantage of resolution independence, fast decoding, and high compression ratio. However, it has a fatal shortcoming of intolerant encoding time because that every range block is need to find its corresponding best matched domain block in the full image. Therefore, it has not been widely applied as other coding schemes in the field of image compression. In this paper, an algorithm is proposed to improve this time-consuming encoding drawback by the adaptive searching window, partial distortion elimination and characteristic exclusion algorithms. Proposed can efficient decrease the encoding time significantly. In addition, the compression ratio is also raised due to the reduced searching window. Conventional fractal encoding for a 512 by 512 image need search 247009 domain blocks for every range block. Experimental results show that our proposed method only search 120 domain blocks which is only 0.04858% compared to conventional fractal encoder for every range block to encode Lena 512 by 512 8-bit gray image at the bit rate of 0.2706 bits per pixel (bpp) while maintaining almost the same decoded quality as conventional fractal encoder does. This paper contributes to the research of encoder of fast image communication system.

Efficiency and Robustness Improvement of Airborne SAR Motion Compensation With High Resolution and Wide Swath

For airborne synthetic aperture radar (SAR) imaging with high resolution and wide swath, the atmospheric turbulence may produce serious range-dependent (RD) motion error. To estimate the RD motion error, traditional methods usually first divide the range full-aperture data into multiple range blocks, and then use phase gradient autofocus (PGA) to estimate the phase error of all range blocks one by one, which is inefficient. In addition, the robustness of PGA is also affected by the number of strong scattering points. To solve these two problems, a new motion compensation (MoCo) algorithm is proposed to improve the efficiency and robustness of airborne SAR MoCo. The real data-processing results are given to verify the effectiveness of the algorithm.

Super-resolution processing using luminance dispersion in local area

Based on super-resolution processing, reconstruction refers to the technique of transforming several low-resolution images into a high-resolution image as a general tendency. The fractal super-resolution method is the most effective technique for obtaining a high-resolution image from a single low-resolution image. This technology performs expansion by partitioning the original image into block groups in the local region, which are called range blocks, and block groups in the global region, which are called domain blocks. Further, it replaces a range block with the domain block that resembles it the most. In this study, blocks containing image edges are subjected to fractal super-resolution processing using luminance variance, and areas with gradual changes in density are expanded by interpolation.

Fractal Image Compression Using Block Indexing Technique: A Review

Fractal image compression depends on representing an image using affine transformations. The main concern for researches in the discipline of fractal image compression (FIC) algorithm is to decrease encoding time needed to compress image data. The basic technique is that each portion of the image is similar to other portions of the same image. In this process, there are many models that were developed. The presence of fractals was initially noticed and handled using Iterated Function System (IFS); that is used for encoding images. In this paper, a review of fractal image compression is discussed with its variants along with other techniques. A summarized review of contributions is achieved to determine the fulfillment of fractal image compression, specifically for the block indexing methods based on the moment descriptor. Block indexing method depends on classifying the domain and range blocks using moments to generate an invariant descriptor that reduces the long encoding time. A comparison is performed between the blocked indexing technology and other fractal image techniques to determine the importance of block indexing in saving encoding time and achieving better compression ratio while maintaining image quality on Lena image.

Multi-input single-output control for extending the operating range: Generalized split range control using the baton strategy

Split range control is used to extend the steady-state operating range for a single output (controlled variable) by using multiple inputs (manipulated variables). The standard implementation of split range control uses a single controller with a split range block, but this approach has limitations when it comes to tuning. In this paper, we introduce a generalized split range control structure that overcomes these limitations by using multiple independent controllers with the same setpoint. Undesired switching between the controllers is avoided by using a baton strategy where only one controller is active at a time. As an alternative solution we consider model predictive control (MPC), but it requires a detailed dynamic model and does not allow for using only one input at a time.

Impact of Spatial Dynamic Search With Matching Threshold Strategy on Fractal Image Compression Algorithm Performance: Study

Fractal image compression (FIC) is a very popular technique in image compression applications due to its simplicity and superior performance. However, it has a major drawback, which is the long encoding time. This is due to the requirement of performing huge similarity search for encoding each small portion in the image. Thus, reducing the search time of FIC while keeping the quality of reconstructed images at acceptable level is still an active research topic. Therefore, this paper has focused on studying the search problem of the conventional full-search FIC algorithm and the impact of employing a spatial dynamic search technique instead with the matching threshold strategy. Unlike the conventional full-search method that is a spatially static where the search starts from a fixed position (normally from the top-left corner of the image to the bottom-right corner) regardless of the position of the range block being encoding, the idea of the dynamic search method is simple, but effective, and it is based on starting the search from the closest domain block to the range block that needs to be encoded. These two search schemes are tested under different matching threshold values, in which the search is terminated whenever a domain block with an acceptable matching level is found. To make the study comprehensive, the test is performed for different image sizes and types, range block and partitioning step sizes, and quantization levels. The experimental results show the significant impact of using the dynamic search method instead of the conventional search method specifically when the threshold is large. For the best encoding parameters, the improvement amount that can be achieved is near to 90 % in terms of search reduction and 1.6 dB PSNR in terms of image quality.

Orthogonal sparse fractal coding algorithm based on image texture feature

Fractal image compression coding algorithm is a novel image compression technology; however, the long encoding time and unacceptable image reconstruction quality remain the primary obstacles in practical application. The purpose of this study is to improve the coding quality from the perspective of grey level transform and feature extraction. In this study, a novel orthogonal sparse fractal coding algorithm based on image texture feature is proposed. The authors define a normalised version as the new grey description feature of the image block so that two improved methods are scientifically combined in theory and algorithm. First, orthogonal sparse grey level transform based on sparse decomposition improves image reconstruction quality and decoding speed. Then, the similarity measure matrix, which stores the variance feature between range blocks and domain blocks, is used to reduce redundancies and encoding time. Simulation results show that the proposed algorithm in this study can obtain better image reconstruction quality and speed up encoding time significantly as compared to the conventional fractal coding schemes.