Width Mismatch Research Articles

Design and Implementation of a Width-Adjustable Asynchronous FIFO for Cross-Clock Domain Data Transmission

Existing research shows that asynchronous FIFO has been widely used in a variety of complex system designs, such as FPGA-based image processing systems, USB communication systems, and so on. To make the designed asynchronous FIFO more programmable and flexible, so that it can adapt to various application scenarios more quickly, this paper studies and designs an asynchronous FIFO with adjustable input and output bit width. In this study, according to the relationship between 24-bit input data and 32-bit storage space, four 24-bit data are selected to fill three RAM storage spaces at one time. According to the multiple relationships between 32-bit storage space and 128-bit output data, the reading pointer is enlarged by 4 times to realize the function of reading four 32-bit data at one time. This whole process realizes the conversion of data bit width through data splicing. Finally, the 24-bit RGB888 image data is successfully converted into 128-bit data and transmitted to the bus, which successfully solves the problem of data width mismatch.

Inversions of Surface Displacements in Scaled Experiments of Analog Magma Intrusion

AbstractStandard geodetic models simplify magma sheet injection to the opening of geometrically simple dislocations in a linearly elastic, homogeneous medium. Intrusion geometries are often complex, however, and non‐elastic deformation mechanisms can dominate the response of heterogeneous rocks to magma‐induced stresses. We used three‐dimensional near‐surface displacements of a scaled laboratory experiment in which a steeply inclined analog magma sheet was injected into granular material. We ran forward models and inverted for eight parameters of an “Okada‐type” tensile rectangular dislocation in a homogeneous, isotropic, and linearly elastic half‐space. Displacements generated by a forward model largely mismatch the experimental displacements, but full or restricted non‐linear inversions of geometrical parameters reduce the residual displacements. The intrusion opening, dip, depth, and to a lesser degree length and width mismatch the most between the experiment and inversion results, whereas location and strike mismatch the least. Our results challenge assumptions made by many analytical and geodetic models.

Mismatch between school furniture dimensions and anthropometric parameters is a risk for spinal deformities in secondary school students in Lagos, Nigeria: a cross-sectional study

BackgroundA mismatch between school furniture dimensions and anthropometric parameters has been well documented in adolescents, but there is a paucity of data on the impact of these mismatches on the students’ spinal health in Nigeria. This study therefore investigated the relationship of spinal deformities with selected anthropometric parameters and furniture dimensions of adolescents in secondary schools.MethodsThis study involved 540 apparently healthy students between the ages of 10 and 19 years from 9 public and private secondary schools in Lagos state, Nigeria. The furniture dimensions, anthropometric parameters, and spinal curvature disorders were evaluated using standard protocol. Data was analyzed using SPSS version 20.0 with a level of significance set at p < 0.05.ResultsTwo hundred two (37%) of the participants had abnormal spinal curvatures in varying types and degrees. There was a significant association at p ≤ 0.05 between the presence of spinal deformities and popliteal height to seat height mismatch (X2 = 175.67, p = 0.001), hip breadth to seat width mismatch (X2 = 293.14, p = 0.00), and shoulder height to backrest height mismatch (X2 = 788.16, p = 0.001).ConclusionAnthropometric parameters to furniture dimensions mismatch are significantly associated with the presence of spinal deformities among the students. The main cause of mismatch is using a homogeneous size of furniture for all students in addition to non-consideration of the students’ dimensions during furniture manufacturing.

Partial Parasagittal Patellectomy in Dogs: A Retrospective Case Series of 19 Dogs.

The aim of this study was to describe partial parasagittal patellectomy for the surgical management of patellar luxation, including surgical technique, proposed indications, complications, and outcomes in a cohort of dogs. This is a single-center retrospective clinical case series. Medical records (2019-2020) of dogs presenting for patellar luxation were reviewed. Clinical signs, luxation direction and grade, preoperative imaging and intraoperative findings, and complications were retrospectively retrieved. Owners were contacted via questionnaire for medium- and long-term follow-up. A total of 24 stifles in 19 dogs met the inclusion criteria. Intraoperative minor complications occurred in four stifles. A single minor complication occurred postoperatively with no major complications. Increased thickness and radiographic attenuation of the patellar ligament were noted in 14 stifles at radiographic reassessment. Re-luxation was not encountered, with long-term owner-assessed outcome as good to excellent in all cases. Partial parasagittal patellectomy, used in conjunction with block recession trochleoplasty and tibial tuberosity transposition, provided reliable resolution of patellar luxation in canine stifles with grade 2 or 3 luxation where width mismatch between the patella and the trochlea was noted intraoperatively. Long-term outcome appears to be good to excellent with a low rate of complication.

Shape-Based Peak Identity Confirmation in Liquid Chromatography.

Chromatography is used to separate analytes in a mixture. In the absence of a detector providing analyte-specific information, the retention time is used to identify the analyte, typically by comparing the retention time of the unknown with that of a standard. This is the simplest of identification routines, but it remains the most widely used. The challenge is that analyte retention times can and do shift; sole reliance on retention time for identification is not prudent. Retention time is influenced by the total sample concentration, elution of components near the peak of interest, aging of a column, and so on, complicating time window-based identification. We propose a sameness threshold (ST) that is based on numerical comparison of shapes of chromatographic peaks for identification confirmation. We demonstrate shape-based identification confirmation or lack thereof of an unconfirmed peak by comparison with a shape library of standards. In numerous cases we look at, only one analyte in the shape library fits the putative identity. ST can be based on r2, the commonly used coefficient of determination used in regression analysis, or on an "index of width mismatch" that compares the widths of the peaks throughout the available height range.

Topographic Analysis of Lateral Versus Medial Femoral Condyle Donor Sites for Oblong Medial Femoral Condyle Lesions

To analyze the topographic matching of oblong osteochondral allografts to treat large oval medial femoral condyle (MFC) lesions using computer simulation models. The secondary objective was to determine whether lateral femoral condyle (LFC) grafts would have a similar surface matching when compared with MFC grafts in this setting. Human femoral hemicondyles (10 MFCs, 7 LFCs) underwent 3-dimensional computed tomography. Models were created from computed tomography images and exported into point-cloud models. Donor-recipient matches with large condylar width mismatch were excluded. The remaining specimen were divided into 3 donor-recipient groups with 2 defect sizes (17× 30 mm and 20× 30 mm): 20 MFC donor (MFCd)-MFC recipient (MFCr), 27 ipsilateral LFC donor (LFCd)-MFCr, and 26 contralateral LFCd-MFCr. Grafts were optimally virtually aligned with the MFCr defect. Mismatch of the articular cartilage and subchondral bone surfaces between the graft and the defect and articular step-off were calculated. MFCd grafts resulted in articular cartilage surface mismatch and peripheral step of less than 0.5 mm for both defect sizes. The subchondral bone surface mismatch was significantly greater than the articular cartilage surface mismatch (P < .01) in both defect sizes). Conversely, the ipsilateral and contralateral LFCd grafts resulted in significantly greater articular cartilage surface mismatch and step-off for both defect sizes when compared to MFCd grafts (P < .01). Oblong MFC allografts provide acceptable topographic matching for large oval MFC lesions when condylar width differences are minimized. However, concern exists in using oblong LFC allografts for MFC defects, as this can result in increased peripheral step-off and surface mismatch. These data reinforce the ability to use oblong MFC osteochondral allograft for treating oval cartilage lesions of the MFC when condylar width is considered. Although other studies have demonstrated LFCs can be used to treat circular defects on the MFC, this may not be true for oblong grafts.

General Synthesis of Tapered Matching Sections for Single-Mode Operation Using the Coupled-Mode Theory

In this paper, a novel and general method to synthetize microwave waveguide tapers intended for single-mode operation is proposed. The technique is based on the use of an exact series solution of the inverse scattering synthesis problem. An additional strategy necessary for dealing with waveguides where the propagation constant varies with the position is included. The coupled-mode theory is employed to model the electromagnetic behavior of the taper with the inherent mismatch caused by the connection of the waveguides with different cross sections. The novel method allows us to synthesize the (classical) transmission line taper functions of Klopfenstein and Hecken, making them suitable for general waveguide tapers with single-mode operation. Additionally, a new type of taper functions, also suitable for general waveguide tapers, is presented. The novel functions are obtained by partially employing the frequency response of multisection transformers, resulting in fully smooth tapers that can offer shorter lengths than the classical proposals. The taper synthesis procedure is demonstrated in rectangular waveguide technology, by requiring realistic and challenging specifications for different cases with different waveguide cross sections to be matched: height mismatch, width mismatch, and simultaneous height and width mismatch. Several prototypes of Klopfenstein, Hecken, and novel function tapers have been fabricated in an aluminum alloy by means of an Additive Manufacturing technique (Direct Metal Laser Sintering). The simulation and measurement results obtained for the rectangular waveguide taper prototypes confirm the accuracy of the novel synthesis technique proposed.

Improved tri-state buffer in MOS current mode logic and its application

This paper presents a new topology to implement MOS current mode logic (MCML) tri-state buffer. The current source section of the available MCML tri-state buffer is modified in the proposed topology which improves output enable time and maintains the low power feature. The functionality of the proposed topology is verified through SPICE simulations by using 0.18 µm TSMC CMOS technology parameters. Its performance is compared with the available one for different values of bias current ranging from 50 to 200 µA. The delay decreases with increase in current and improvement in output enable time is visible throughout the current range. The impact of parameter variations at different design corners and width mismatch on the performance of both the proposed and the available tri-state buffers is also studied and similar variations are found. The significance of the improvement is demonstrated through the implementation of a tri-state buffer based edge triggered register, a key element in digital systems design.

Template–polymer commensurability and directed self‐assembly block copolymer lithography

ABSTRACTBlock copolymer directed self‐assembly (BCP) with chemical epitaxy is a promising lithographic solution for patterning features with critical dimensions under 20 nm. In this work, we study the extent to which lamellae‐forming poly(styrene‐b‐methyl methacrylate) can be directed with chemical contrast patterns when the pitch of the block copolymer is slightly compressed or stretched compared to the equilibrium pitch observed in unpatterned films. Critical dimension small angle X‐ray scattering complemented with SEM analysis was used to quantify the shape and roughness of the line/space features. It was found that the BCP was more lenient to pitch compression than to pitch stretching, tolerating at least 4.9% pitch compression, but only 2.5% pitch stretching before disrupting into dislocation or disclination defects. The more tolerant range of pitch compression is explained by considering the change in free energy with template mismatch, which suggests a larger penalty for pitch stretching than compressing. Additionally, the effect of width mismatch between chemical contrast pattern and BCP is considered for two different pattern transfer techniques. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 595–603

The anthropometric match between high school learners of the Cape Metropole area, Western Cape, South Africa and their computer workstation at school

Study designDescriptive study. ObjectiveThe objective of this study was to present anthropometric data from high school students in Cape Metropole area, Western Cape, South Africa that are relevant for chair design and whether the dimensions of computer laboratory chairs currently used in high schools match linear anthropometrics of high-school students. Summary of Background Data. Learner–chair mismatch is proposed as a cause of poor postural alignment and spinal pain in adolescents. A learner–chair mismatch is defined as the incompatibility between the dimensions of a chair and the anthropometric dimensions of the learner. Currently, there is no published research to ascertain whether the furniture dimensions in school computer laboratories match the anthropometrics of the students. This may contribute to the high prevalence of adolescent spinal pain. MethodsThe sample consisted of 689 learners, 13–18 years old. The following body dimensions were measured: stature, popliteal height, buttock-to-popliteal length and hip width. These measurements were matched with the corresponding chair seat dimensions: height, depth and width. Popliteal and seat height mismatch was defined when the seat height is either >95% or <88% of the popliteal height. Buttock–popliteal length and seat depth mismatch was defined when the seat depth is either >95% or <80% of the buttock–popliteal length. Seat width mismatch is defined where the seat width should be at least 10% and at the most 30% larger than hip width. ResultsAn 89% of learners did not match the seat. Five percent of learners matched the chair depth, the majority was found to be too big. In contrast, 65% of the learners matched the chair width dimension. ConclusionsA substantial mismatch was found. The school chairs failed standard ergonomics recommendations for the design of furniture to fit the user. This study supports the conclusion that there is no one-size-fits-all solution. There is an urgent need for chairs that are of different sizes or that are adjustable.

A new FIFO for transferring data between two unrelated clock domains

A new simple-to-design FIFO that allows data transfer between two clock domains of unrelated frequencies has been developed. The fully synchronous interfaces significantly ease the system-on-chip integration process. With a relatively low gate count, the proposed FIFO allows the producer and consumer to put/get data at their respective frequencies (1 datum/clock cycle) till it gets filled, then the rates converge to the lower of the two frequencies. The maximum initial latency is three cycles of the consumer's clock. Several manifestations of the FIFO have been developed for different design cases including producer/consumer data width mismatch. Operation of the FIFO has been verified using both gate-level simulations and SPICE simulations with a 0.13 µm, 1.2 V technology. An 8-cell FIFO showed proper operation at producer and consumer clock frequencies of 2 and 3.125 GHz, respectively, with a data transfer rate of more than 2 giga datum/s and an average power of 721 µW.

Width is a more important predictor in graft extrusion than length using plain radiographic sizing in lateral meniscal transplantation

Plain radiographs are frequently used to select appropriately sized meniscal allografts, of which the width and length cannot be always perfectly matched. The objective of this study was to decide which of these dimensions should be matched with a more priority considering proper position of the lateral meniscal transplants. The positions of 34 lateral, fresh-frozen meniscal allografts, transplanted using the central bone bridge method, were evaluated by magnetic resonance imaging (MRI) 2days after surgery. A size mismatch was defined as a difference between preoperative radiographic size and a real dimension of the transplants. The lateral subluxation of the mid-body on the coronal plane and the anterior and posterior horn positions on the sagittal plane were estimated on the MRIs. It was evaluated whether size mismatches were associated with the meniscal subluxation beyond articular cartilage margin on each plane. The mean lateral subluxation of the mid-body on the center of coronal sections was 1.7±1.8mm. The anterior and posterior horns were located 2.0±2.1mm and -3.8±2.7mm from the articular edge, respectively, in the center of sagittal images. Lateral subluxation was significantly associated with width mismatch (r=0.415-0.486, P<0.05), but length mismatch was not significantly correlated with the anterior or posterior horn position on sagittal images (n.s.). The results of this study suggest that width matching using plain radiographs would be more reliable than length matching when it is sought to assure adequate positioning of meniscal transplants, if both dimensions cannot be simultaneously matched. II.

Studies of excimer laser annealing of in situ deposited thin films of YBa 2Cu 3O 7−δ

Superconducting films of YBa 2Cu 3O 7−δ have been prepared on yttrium stabilized cubic zirconia in situ by laser (308 nm) ablation. Films have been deposited at 650°C with and without the presence of a second (annealing) excimer radiation pulse (308 nm) incident on the substrate. These films are compared to high-quality films prepared at 790 ° C. In annealing experiments, time delays between the synchronized excimer lasers were varied from 0 to 1000 μs to explore the effect of the annealing radiation throughout the mass arrival time range at the substrate. Little improvement was observed in the overall quality of the deposited films at any time delay. Model calculations indicate that a possible reason for the lack of improvement originates in a temporal width mismatch of the temperature increase of the substrate surface and the mass arrival of the ablated material.

Effects of System Inaccuracies on the Probability of Bit Error for Pulsed Communication Systems

Digital communication systems using the narrow pulses generated by a mode-locked laser are extremely efficient in their use of average laser power. However, these narrow pulses require precise system timing and decision intervals matched to the pulse width. This paper extends previous work by Gagliardi in this area to consider the effects of pulse timing errors and pulse width mismatch on the probability of bit error for on-off keying, binary pulse position modulation, and quarternary pulse position modulation formats. The general expressions are derived, and a number of examples are plotted.