High Frame Frequency Research Articles

Characteristics of high frame frequency contrast-enhanced ultrasound in renal tumors

ObjectiveThis study aims to analyze the characteristics of high frame rate contrast-enhanced ultrasound (H-CEUS) in renal lesions and to improve the ability for differential diagnosis of renal tumors.MethodsA total of 140 patients with renal lesions underwent contrast-enhanced ultrasound (CEUS) examination in the First Affiliated Hospital of Nanchang University from July 2022 to July 2023. Based on the tumor pathology and the results of enhanced CT, tumor patients were divided into malignant and benign groups. All subjects were examined using gray-scale ultrasound, conventional contrast-enhanced ultrasound (C-CEUS), and H-CEUS, and their dynamic images were recorded. Two radiologists independently analyzed and recorded the results of ultrasound, C-CEUS, and H-CEUS images and statistically analyzed the features of C-CEUS and H-CEUS images. The independent sample t-test was used to compare the difference in age and maximum diameter of nodules between the benign and malignant groups. The χ2 test was used to compare the sex, mode of operation, gray-scale ultrasound characteristics, and enhancement characteristics of the two CEUS modes (enhancement mode, regression mode, enhancement degree, enhancement uniformity, enhancement or not, enhancement direction, post-enhancement boundary and range, and pseudocapsule) between the benign and malignant groups. The difference in vascular morphology of malignant nodules of varying sizes under two angiographic modes.ResultsThere were significant differences in gender (χ2 = 10.408, P = 0.001), mode of operation (χ2 = 47.089, P < 0.001), nodule composition (χ2 = 7.481, P = 0.003), nodule echo (χ2 = 20.926, P < 0.001), necrosis (χ2 = 31.343, P < 0.001) and nodule blood flow (χ2 = 9.006, P = 0.029) between the benign and malignant groups. There were significant differences in the regression model (χ2 = 6.782, P = 0.034) and enhancement direction (χ2 = 13.771, P = 0.001) between the two radiographic techniques in the malignant group. There was a significant difference in the enhancement uniformity between the two CEUS techniques in the benign group (χ2 = 8.264, P = 0.004). There was a significant difference between the two CEUS techniques in displaying the vascular morphology in the malignant group with the maximum diameter of nodules ≤ 4.0 cm (χ2 = 11.421, P < 0.022). However, there was no significant difference between the two techniques in the malignant group with the maximum diameter of nodules > 4.0 cm.ConclusionIncreasing the frame rate of ultrasound images is helpful to accurately display the enhanced features and vascular morphology of renal tumors, especially for malignant tumors with a maximum diameter of ≤ 4.0 cm. Thus, H-CEUS can make up for the limitation of CEUS with regard to the display of vascular morphology.

High-Speed Fully Differential Two-Step ADC Design Method for CMOS Image Sensor

The application requirements of high frame rate CMOS image sensors (CIS) in the industry have not been satisfied due to the speed limitations in traditional single-slope and serial two-step analog-to-digital converters (ADCs). In this paper, a high-speed fully differential two-step ADC design method for CIS was proposed. The proposed method was based on differential ramp and time-to-digital conversion (TDC) technology. A parallel conversion mode was formed that is different from serial conversion, and the robustness of the system was ensured due to the existence of differential ramps. Aiming at the inconsistency between traditional TDC technology and single-slope ADC, a TDC technology based on level coding was proposed. The proposed technology achieves the TDC in the last clock cycle of analog-to-digital conversion, and realized a two-step conversion process at another level. This paper presents a complete circuit design, layout design, and test verification of the proposed design method based on the 55 nm 1P4M CMOS experimental platform. Under the design environment of the analog voltage of 3.3 V, the digital voltage of 1.2 V, the clock frequency of 100 MHz, and a dynamic input range of 1.6 V, this design was a 12-bit ADC with a conversion time of 480 ns, column-level power consumption of 62 μW, differential nonlinearity (DNL) of +0.6/-0.6 LSB, and integral nonlinearity (INL) of +1.2/-1.4 LSB. Furthermore, it achieved a signal-to-noise distortion ratio (SNDR) of 70.08 dB. The proposed design provided a large area array with a high frame rate, and compared with the existing advanced single-slope ADC, its conversion speed increased by more than 52%. It provides an effective solution for the implementation of high frame frequency CIS.

Design of infrared point source interference device with high frame frequency and wide temperature range

Design of infrared point source interference device with high frame frequency and wide temperature range

Exploring recurrent frames in written Chinese

Patterning in frames (i.e., discontinuous word sequences with at least one variable slot) involves both syntagmatic co-occurrences and paradigmatic variations, and this has received considerable attention in phraseological research. However, few studies have attempted to extract the full set of recurrent frames in written Chinese. This study sets out to do so based on an enormous Google database. Common quantitative measures adopted in previous studies are reconsidered. Owing to the considerable quantity of data, some of these measures become less sensitive. High-frequency frames are categorised according to the grammatical category of their components. The results lend cross-linguistic support to previous major findings and show language-specific distributional patterns. Moreover, high-frequency frames are categorised according to their dominant syntactic role in context. Finally, the semantic aspect of Chinese frames is addressed. A semantically hierarchical representational network of frames is established, and significant structural and semantic correlations are identified.

分时型长波红外高帧频偏振成像实验研究

分时型长波红外高帧频偏振成像实验研究

大面阵高帧频CMOS成像电子学系统设计

大面阵高帧频CMOS成像电子学系统设计

55-in. 8K4K IPS-LCDs with wide viewing angle, high frame frequency, wide color gamut, and stereoscopic

We have developed an 8K4K liquid-crystal display (LCD) with diagonal size of 55 inch with the backplane based on an amorphous silicon (a-Si) technology. The 8K4K-LCD has high frame frequency at 120 Hz, which is enabled by a unique technology to compensate the charging voltage of pixels. The achievement of a high resolution of 8K4K including high frame frequency of 120 Hz with a-Si backplanes is ground-breaking for LCDs. Furthermore, a backlight system with laser diode as light source expands the color gamut dramatically. This backlight system enables covering 99% of color space recommended in BT.2020. What is more, the 8K4K-LCD has evolved into a three-dimensional (3-D) display device by attaching a 3-D polarizing film. The vertical viewing angle of the 8K-3D LCD prototype is 8.6 deg at its optimal viewing position set to 1.2 m.

Locating of 2π-projection view and projection denoising under fast continuous rotation scanning mode of micro-CT

The fast continuous rotation scanning mode is suitable for situations when a higher scanning speed or a lower radiation dose is required for micro-CT. Under this scanning mode, the specimen rotates far beyond 2π, but not an integral multiple of 2π continuously while the detector collects projection images at a high frame frequency, which consequently produces uneven-distributed and redundant projections with a high level of noise. Therefore, for subsequent three-dimensional (3D) image reconstruction, each 2π-projection view during a whole rotation span must be accurately located, and image denoising is an essential pre-processing step for improving quality of reconstructed images. For matching the rotation angle with the projection image accurately under the fast continuous rotation scanning mode, a structure similarity (SSIM) coefficient was used as a control parameter for extraction of periodic projection sequences for 3D reconstruction. Meanwhile, an improved non-local means (NL-means) algorithm was proposed for noise reduction in projection sequences, and a graphic processing unit (GPU) capable of highly parallel and fast floating-point calculation was used for alleviating the computation cost of the algorithm. The experimental results show that the SSIM-based 2π-projection-view locating method is highly accurate in identifying periodic projection sequences and is easy to implement, and that the improved NL-means algorithm can well restrain the quantum noise while preserving detailed information.

Enhanced Adaptive Approach of Video Coding at Very Low Bit Rate Using MSPIHT Algorithm

Nowadays video coding approach is a major key in many applications for easy transmission and storage consumption. The process of transformation is based on the empirical wavelet transform (EWT). The encoding process of video data provides secure and less consumption of storage and the reconstruction process consists of the reverse process with the extraction. In this paper, the coding of video is carried out at a very low bit rate with the enhancement of performance by proposing an approach of modified Set Partitioning in Hierarchical Tree (MSPIHT). This method encodes the high frequency frames with the scheduling of wavelet transform for efficient performances of encoding and improves the ability of both the frequency and time. By applying empirical wavelet transform on each video frame, the component of video frequency is extracted and the low frequency frame is encoded by the H.264/AVC standard. The low coefficient values are ignored in applying the threshold and in the reconstruction process, HBLPCE method is used for imaging enhancement. The simulation of the proposed approach analysis shows better performance in reliable process and efficiency when compared to existing.

64.2: Panel and Circuit Designs for the World's First 65‐inch UHD OLED TV

We have developed the world's first 65‐inch UHD (also called 4K, 3840×2160) OLED TV with a coplanar‐type IGZO(Indium Gallium Zinc Oxide) TFTs. In this paper, we discuss our excellent WRGB panel designs and circuits to achieve the high frame frequency and the product reliability.

Dynamic Infrared Scene Simulation Study Based on DMD Imaging System

Dynamic infrared scene generator is one of the important means to test the detection,track and anti-interference performance of the infrared seeker. The article to a certain type of air-to-air missile seeker loop simulation application object, based on the micro-mirror array (DMD), Vega Prime software and its infrared module for the development of tools,Real-time infrared images with vary objects and backgrounds in different conditions are generated to simulate the infrared radiation at the pupil of the guide system.The radiation of blackbody is reflected and modulated by digital micro mirror device based on infrared video signal,which is used to test and evaluate the performance of infrared seeker.The results indicate that the system has the advantages of compact structure,high real-time performance,high frame frequency,high resolution,and great dynamic range.

Design of High Frame Frequency Data Communication System on Theodolite

The data communication system is the internal data exchange platform of theodolite, which completes data exchange among multiple subsystems. According to requirement of proving range to target attitude measurement, the rate of real time target image storage is quicker and quicker, as the synchronous measurement information deliverer, the communication frame frequency of data communication is also increasing. Adopting time pre-processing method resolves the problem that B code terminal cannot provide high frame frequency time information, The utilization of ARM processor built in watchdog counter function and configuration of external interruption signal can realize the precise time sequence control, and realize the synchronous transmission of measured data in case of high frame frequency, and the software realization method is provided.

Rapid survey of a circular zone using an IR scanning system with a photodetector array

This paper discusses a method of viewing a circular spatial zone by using a scanning thermal direction finder, based on a photodetector array with a high frame frequency and an ITR readout regime. A number of analytical relationships useful for the design of a scanning thermal direction finder are obtained, including the connection of the signal-accumulation time with the frame frequency, the angular frame size in the azimuthal scanning direction, and the radius of the circle of confusion of the detector objective. The proposed method provides high angular resolution, a signal-accumulation time to 2 ms, and increased sensitivity of the apparatus. The maximum information-renewal frequency, determined by the azimuthal-scanning frequency, reaches several hertz. The best conditions for using the proposed method are ensured when one works in the mid-IR region.

Celestial reference frames at multiple radio wavelengths

AbstractIn 1997 the IAU adopted the International Celestial Reference Frame (ICRF) built from S/X VLBI data. In response to IAU resolutions encouraging the extension of the ICRF to additional frequency bands, VLBI frames have been made at 24, 32, and 43 GHz. Meanwhile, the 8.4 GHz work has been greatly improved with the 2009 release of the ICRF-2. This paper discusses the motivations for extending the ICRF to these higher frequency radio bands. Results to date will be summarized including evidence that the high frequency frames are rapidly approaching the accuracy of the 8.4 GHz ICRF-2. We discuss current limiting errors and prospects for the future accuracy of radio reference frames. We note that comparison of multiple radio frames is characterizing the frequency dependent systematic noise floor from extended source morphology and core shift. Finally, given Gaia's potential for high accuracy optical astrometry, we have simulated the precision of a radio-optical frame tie to be ~10–15 μas (1-σ, per component).

空间光通信中高帧频相机动态调光技术研究

In order to satisfy the requirement of space optical communication system,and ensure relative stabilization of beaconing laser spot energy detected by photoelectric detector,an device for dynamic stabilizing laser energy is developed and dynamic light-adjusting technology of high frame frequency CCD camera based on liquid crystal is investigated.Compared with mechanical and electronic shutter,it proves the feasibility of dynamic light-adjusting technology based on liquid crystal.Then combined with the characteristic of space optical communication system,it is discussed the dynamic light-adjusting principle of high frame frequency CCD camera based on liquid crystal in detail.Finally,it presents the principle block diagram of the device,data and result of experiment.Experimental results indicate that the dynamic light-adjusting technology based on liquid crystal spatial light attenuator can achieve energy autocontrol of beaconing laser without moving optics,thereby ensuring relative stabilization of laser spot energy detected by photoelectric detector.It proves the feasibility of dynamic light-adjusting technology based on liquid crystal,at the same time it is pointed that liquid crystal as a new type dynamic optics module with flexible adjusting have wider application foreground in space optical communication system.

Design of High Speed and Parallel Compression System Used in the Big Area CCD of High Frame Frequency

According to the area CCD camera of characteristics, such as high resolution capacity and high frame frequency, this paper puts forward a high speed and parallel image compression system of high integration degree. Firstly, according to the work principle of the area CCD, FPGA is adopted to realize the timing driving and multichannel and parallel analog signal handling to raise the export frame frequency of the area CCD. Secondly, with an image compression scheme based on FPGA embedded processor MicroBlaze and ADV212 compression chip, real time image compression and the high speed area CCD are realized. Finally, by detecting the analog signal of the area CCD output, the real time compression of the big area CCD image is carried out in different compression ratios and the compression performance is analyzed. Experiment result shows that this scheme can realize real time image compression with the biggest data rate of 520Mbps. When compression bit ratio is 0.15, the signal-to-noise ratio of peak value can reach 36 dB. Image collection and image compression are integrated, which reduces the data transmission between them and improves systematic integration degree.

P‐10: Design for AMOLED Display with an Improved Uniformity and a Smaller Bezel

AbstractA new pixel circuit and an integrated small sized scan driver for Active Matrix Organic Light Emitting Diode (AMOLED) Display are proposed in this paper. It is found that the effective mobility reduction by the gate‐source voltage of the driving TFT (DTFT) increases the sampling error of threshold voltage (Vth) with shortened sampling time. To solve this problem, a new pixel circuit and a even &amp; odd driving scheme to increase sampling time of Vth is proposed for AMOLED display operating at high frame frequency such as 120 Hz or 240 Hz. For more compact displays, a new small sized scan driver is also proposed to reduce an area of bezel. The proposed circuits are verified by simulations.

Content Based Coarse to Fine Adaptive Interpolation Filter for High Resolution Video Coding

With the increasing demand of high video quality and large image size, adaptive interpolation filter (AIF) addresses these issues and conquers the time varying effects resulting in increased coding efficiency, comparing with recent H.264 standard. However, currently most AIF algorithms are based on either frame level or macroblock (MB) level, which are not flexible enough for different video contents in a real codec system, and most of them are facing a severe time consuming problem. This paper proposes a content based coarse to fine AIF algorithm, which can adapt to video contents by adding different filters and conditions from coarse to fine. The overall algorithm has been mainly made up by 3 schemes: frequency analysis based frame level skip interpolation, motion vector modeling based region level interpolation, and edge detection based macroblock level interpolation. According to the experiments, AIF are discovered to be more effective in the high frequency frames, therefore, the condition to skip low frequency frames for generating AIF coefficients has been set. Moreover, by utilizing the motion vector information of previous frames the region level based interpolation has been designed, and Laplacian of Gaussian based macroblock level interpolation has been proposed to drive the interpolation process from coarse to fine. Six 720p and six 1080p video sequences which cover most typical video types have been tested for evaluating the proposed algorithm. The experimental results show that the proposed algorithm reduce total encoding time about 41% for 720p and 25% for 1080p sequences averagely, comparing with Key Technology Areas (KTA) Enhanced AIF algorithm, while obtains a BDPSNR gain up to 0.004 and 3.122 BDBR reduction.

53.5: High‐Speed AMOLED Pixel Circuit and Driving Scheme

AbstractAn active matrix organic light emitting diode pixel circuit and its driving scheme for high frame frequency are proposed for implementation of a 3D display. The proposed pixel circuit can compensate the threshold voltage distribution of low temperature poly silicon‐thin film transistors at high‐speed operation of 240Hz or more. According to the simulation, current deviation of 1.73% and 3.94% are obtained at frame rates of 240Hz and 480Hz when Vth distribution is ±0.5 V.

Line-time extension driving method with image quality enhancement for LCD monitors and TVs

This paper discusses an image quality issue of TFT-LCD monitors and televisions. To make jaggies invisible in TFT-LCD monitors, the resolution should be at least 200 pixels per inch (ppi), and the frame frequency of 120 Hz or even up to 240 Hz is used to express natural motion pictures in TFT-LCD televisions. The requirement of both high-resolution and high frame frequency decreases the available row line time, which necessarily leads to the insufficient pixel charging ratio. To address the insufficient row line time issue, the Line Time Extension (LiTEX) driving method was previously proposed that can extend the effective row line time. However, an image artifact such as horizontal stripes is observed with the LiTEX driving method. This paper analyzes the cause of the image artifact by building a TFT-LCD pixel model and performing HSPICE simulations, and proposes an improved version of the LiTEX scanning patterns. The experimental results indicate that the image artifact can be successfully remedied with the improved LiTEX driving method.