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Purpose The goal of this study was to assess the feasibility of a cost‐effective prototype of a laser‐based respiratory motion detection system utilizing a Leuze LDS for breath monitoring through calibration and volunteer tests. Methods This study was performed using the Anzai AZ‐773 V and computerized imaging reference systems (CIRS) motion phantoms for calibration tests. The calibration of the laser‐based respiratory motion detection system involved spatial accuracy testing, amplitude calibration, and temporal accuracy. Volunteer testing was conducted on eight volunteers at the inferior end of the sternum and the abdomen area. The accuracy of the data recorded by the laser‐based respiratory motion detection system was validated against established clinical reference tracking systems namely real‐time position management (RPM) and Anzai AZ‐733 V system. Results Calibration with an Anzai AZ‐773 V and CIRS phantoms demonstrated an average error of 1.17% ± 0.64% and an average amplitude calibration correlation coefficient of 0.975 ± 0.004. Volunteer tests, compared to the Anzai AZ‐733 V clinical system and RPM system, revealed average correlation coefficients for deep inspiration breath‐hold are 0.931 ± 0.02 and 0.936 ± 0.03, respectively, and for free breathing are 0.85 ± 0.07 and 0.77 ± 0.1, respectively. Conclusions Overall, the data suggest that the in‐house laser‐based respiratory motion detection system performed well, with an error percentage below 10%. A reasonably good correlation coefficient was obtained, indicating that the readings obtained from the laser system are consistent with those set on the phantom and clinical respiratory motion detection systems. Although promising through the calibration process and volunteer tests, further studies are required to generate trigger data linked directly to computerized tomography and linear accelerator facilities, thereby advancing the clinical viability of this innovative laser‐based respiratory motion detection system.

Process analysis and monitoring during the manufacturing of the dripping pills are essential. However, research on developing sensor‐based technology or process analytical technology (PAT) tools to analyze and monitor the dripping process is minimal. The purpose of this work is to develop a fast and non‐destructive laser detection system for quantitative visualization of droplets, which involves detecting the size of the droplet and calculating the weight of the dripping pills during the dripping process. Several factors influencing the detection performance of the detection system and the detection system capability for quantitation of the pill weight were explored. The laser detection system accurately detects the weight of the dripping pills with the coefficients of determination (R2) higher than 0.99. It was also robust concerning the variation in critical process parameters and critical material attributes. Furthermore, the laser detection system was successfully applied to the production line of Ginkgo biloba leaf dripping pills to monitor the dripping pills weight. The proposed laser detection system can analyze and monitor the dripping process in dripping pill manufacturing with stable performance, high accuracy, and high efficiency.

In this paper, a method of color discrimination based on sample sensitivity to light wavelength is proposed based on the reflection spectra of a large number of samples and the statistical calculation of the measurement data. A laser detection system is designed to realize the color discrimination. For the color discrimination of polycrystalline silicon cells, the most sensitive wavelength, 434 nm, and the least sensitive wavelength, 645 nm, of polycrystalline silicon cells is obtained according to this method. A laser detection system was built to measure the polycrystalline silicon cells. This system consists of two lasers, optical shutters, collimating beam expanding systems, an optical coaxial system, sample platform, collecting lens, and optical power meter or optical sensor. Two laser beams of different wavelengths are beamed coaxially through the optical coaxial system onto a polycrystalline silicon cell and are reflected or scattered. The reflected or scattered lights are collected through a lens with a high number aperture and received separately by the optical power meter. Then the color value of the polycrystalline silicon cell in this system is characterized by the ratio of light intensity data received. The system measured a large number of previous polycrystalline silicon cells to form the different color categories of polycrystalline silicon cells of this system in the computer database. When a new polycrystalline silicon cell is measured, the color discrimination system can automatically classify the new polycrystalline silicon cell to a certain color category in order to achieve color discrimination.

We proposed a modification the procedure of genotyping based in labeled universal primer and tailed primer. In the standard protocol, three primers are used in the same PCR reaction, a forward primer with tail added at the 5′ end of the identical sequence to labeled universal primer with dye-fluorescent and a reverse primer. Unfortunately, the choice of a labeled primer characterized by a large number of complementary sequences in target genomes (which is more probable in larger genomes) result in unspecific amplifications (false positive) can cause absence or decrease amplification of the locus of interest and also false interpretation of the analysis. However, identification of possible homologies between the primer chosen for labelling and the genome is rarely possible from the available DNA data bases. In our approach, cycling is interrupted for the addition of the labeled primer only during the final cycles, thus minimizing unspecific amplification and competition between primers, resulting in the more fidelity amplification of the target regions.

A fully integrated four-input combining receiver front-end circuit is designed in a 0.18 μm CMOS technology for laser radar with a static unitary detector (STUD). This circuit consists of four independent transimpedance amplifiers, one signal combiner, a balun and an output buffer in one single integrated chip. The circuit provides 16.2 mW power consumption for a 1.8 V supplied voltage and 59.8 dBΩ transimpedance gain in the implemented experimental prototype for electrical pulse measurement. The fabricated prototype is worked exactly the same as the operation principle of the STUD in the two-dimensional optical pulse scanning measurement. Therefore, the proposed circuit is available for the STUD-based laser detection and ranging (LADAR) system as one integrated chip. This is the first demonstrated IC for the STUD-based laser radar system.

A dual‐mode transimpedance amplifier (TIA) is realised in a 0.18 μm CMOS technology for the applications of 1 Gbit/s laser detection and ranging (LADAR) systems. The proposed dual‐mode CMOS feed‐forward TIA consists of a voltage‐mode inverter input stage with a feedback resistor, followed by a current‐mode common‐gate amplifier with a feed‐forward technique applied at the gate so as to achieve low noise, low power consumption, high gain and wide bandwidth characteristics simultaneously. The measured results demonstrate 76 dBΩ transimpedance gain, 720 MHz bandwidth for 0.5 pF photodiode capacitance, −26.3 dBm sensitivity for 10−12 bit error rate and 20.7 mW power dissipation from a single 1.8 V supply.

Future wireless communications require higher security as well as a higher data rate. We have been studying physically secured wireless transmission systems and previously proposed encryption/decryption techniques based on the AND operation caused by coherent detection between two encrypted data sequences on two different terahertz carriers. Furthermore, we suggested that by employing the XOR operation as the decryption, the proposed system can be made more secure because XOR increases the computational complexity for eavesdroppers to recover the plaintext. In this paper, we propose the XOR operation between two data sequences on FSK-modulated terahertz waves. By constructing the XOR encryption transmitters/receivers, which consisted of high-speed wavelength tunable lasers and arrayed uni-traveling-carrier photodiodes (UTC-PDs), we successfully demonstrated the XOR operation between two data sequences on 200 GHz waves from the two transmitters.

Light detection and ranging (LiDAR) are fundamental sensors that help driving tasks for autonomous driving at various levels. Commercially available systems come in different specialized design schemes and involve plenty of specifications. In the literature, there are insufficient representations of the technical requirements for LiDAR systems in the automotive context, such as range, detection quality, resolving power, field of view, and eye safety. For this reason, the requirements above require to be derived based on ADAS functions. The requirements for various key LiDAR metrics, including detection range, field of view, angular resolution, and laser safety, are analyzed in this paper. LiDAR systems are available with various radiation patterns that significantly impact on detection range. Therefore, the detection range under various radiation patterns is firstly investigated in this paper. Based on ADAS functions, the required detection range and field of view for LiDAR systems are examined, taking into account various travel speeds to avoid collision and the coverage of the entire lane width. Furthermore, the angular resolution limits are obtained utilizing the KITTI dataset and exemplary 3D detection algorithms. Finally, the maximum detection ranges for the different radiation patterns are compared under the consideration of derived requirements and laser safety.

Laser-arc hybrid welding (LAHW), being a high-efficiency with excellent properties of high welding speed, deep penetration, and good bridging performance, has been paid close attention by domestic and overseas scholars. So far, the lack of suppression and detection of welding defects is still considered the critical technical obstacle that affects its welding quality, particularly for workpieces with industrial requirements. One vital method to conquer this challenging issue is the visual analysis technique with the combination of numerical simulation technique, which has been researched by abundant study outcomes. The primary target of detecting is to collect basic information and to understand the formation mechanism of welding defects. This review firstly describes welding defects online detection technology, such as high-speed image, electrical signal, acoustical signal, and optical signal detection technology. Then much emphasis has been placed on the internal mechanism of forming welding defects, including undercut, humping, porosity, and spatter defects. Particularly, the defect suppression methods are presented in order to restrain and address the welding defect problems. Finally, the current difficulties and potential remedies are discussed to supply an understanding on what still needs to be improved in the LAHW process. This comprehensive review is to offer guidance for those trying to reduce welding defects as they enhance the welding joints’ quality.

The estimation of single tree and complete stand information is one of the central tasks of forest inventory. In recent years, automatic algorithms have been successfully developed for the detection and measurement of trees with laser scanning technology. Nevertheless, most of the forest inventories are nowadays carried out with manual tree measurements using traditional instruments. This is due to the high investment costs for modern laser scanner equipment and, in particular, the time-consuming and incomplete nature of data acquisition with stationary terrestrial laser scanners. Traditionally, forest inventory data are collected through manual surveys with calipers or tapes. Practically, this is both labor and time-consuming. In 2020, Apple implemented a Light Detection and Ranging (LiDAR) sensor in the new Apple iPad Pro (4th Gen) and iPhone Pro 12. Since then, access to LiDAR-generated 3D point clouds has become possible with consumer-level devices. In this study, an Apple iPad Pro was tested to produce 3D point clouds, and its performance was compared with a personal laser scanning (PLS) approach to estimate individual tree parameters in different forest types and structures. Reference data were obtained by traditional measurements on 21 circular forest inventory sample plots with a 7 m radius. The tree mapping with the iPad showed a detection rate of 97.3% compared to 99.5% with the PLS scans for trees with a lower diameter at a breast height (dbh) threshold of 10 cm. The root mean square error (RMSE) of the best dbh measurement out of five different dbh modeling approaches was 3.13 cm with the iPad and 1.59 cm with PLS. The data acquisition time with the iPad was approximately 7.51 min per sample plot; this is twice as long as that with PLS but 2.5 times shorter than that with traditional forest inventory equipment. In conclusion, the proposed forest inventory with the iPad is generally feasible and achieves accurate and precise stem counts and dbh measurements with efficient labor effort compared to traditional approaches. Along with future technological developments, it is expected that other consumer-level handheld devices with integrated laser scanners will also be developed beyond the iPad, which will serve as an accurate and cost-efficient alternative solution to the approved but relatively expensive TLS and PLS systems. Such a development would be mandatory to broadly establish digital technology and fully automated routines in forest inventory practice. Finally, high-level progress is generally expected for the broader scientific community in forest ecosystem monitoring, as the collection of highly precise 3D point cloud data is no longer hindered by financial burdens.