Terrestrial laser scanning (TLS) and mobile (MLS) data can be used to obtain abundant precise side information of trees. Therefore, it enable extracting individual tree parameters, such as the height, crown size, base diameter at breast provide basic for forest research management. This study proposes a technical framework segmenting trees from TLS MLS data. contains six steps: 1) preprocessing, 2) octree construction, 3) spatial clustering, 4) stem detection, 5) initial segmentation, 6)...

Park green space is an important part of the infrastructure in a city, and urban park accessibility indicator for measuring city’s comprehensive strength, living environment, resident happiness, which greatly affects sustainable development construction city. The spatial syntax method can discuss parks from perspective topology, inherits objective stability topological relationship. There are few research studies on parks. Therefore, with support theory statistics method, this paper combined...

Information extraction and three-dimensional (3D) reconstruction of buildings using the vehicle-borne laser scanning (VLS) system is significant for many applications. Extracting LiDAR points, from VLS, belonging to various types building in large-scale complex urban environments still retains some problems. In this paper, a new technical framework automatic efficient point proposed, including three main steps: (1) voxel group-based shape recognition; (2) category-oriented merging; (3)...

We propose and experimentally demonstrate a quantum-enhanced fiber Mach-Zehnder interferometer for low-frequency phase measurement beyond the shot-noise limit using high-frequency squeezing technique. The local oscillator field is amplitude-modulated in MHz range then demodulated to avoid technical noise that occurs at low frequencies. After of frequency tens kHz, an improvement ∼2 dB relative level achieved. Additionally, amplitude modulation depth has no significant effect on when deployed...

Accurate and timely updated three-dimensional (3-D) model data of interchange bridges are significant for traffic navigation, landscape design, many other applications. In this study, we explore the potential using airborne light detection ranging (LiDAR) 3-D reconstruction large multilayer bridges. To reduce technical difficulty in process, propose a concept "structure unit." We new framework based on structure units bridge, including point cloud extraction, connectivity-based segmentation,...

LiDAR point registration is a key procedure for the acquisition of complete cloud datasets. It has great significance fusion multisource data. In general, widely used methods can be categorized into three types: auxiliary methods, direct and feature methods. However, complex objects (e.g., stadium tower), such may face varying degrees technical problems owing to unavailability data or targets, requirement sufficient overlapping areas, difficulty in extraction matching. real world, numerous...

This paper proposes a runoff-based hydroelectricity prediction method based on meteorological similar days and XGBoost model. Accurately predicting the supply demand is critical for conserving resources, ensuring power supply, mitigating impact of natural disasters. To achieve this, historical runoff data are analyzed to select that current data, forming day dataset. The model then trained used predict dataset obtain results. evaluate proposed method, cluster in Yunnan, China, as sample...

A new hierarchical method for the automatic registration of airborne and vehicle light detection ranging (LiDAR) data is proposed, using three-dimensional (3D) road networks 3D building contours. Firstly, are extracted from LiDAR then registered with trajectory lines. During lines, a network matching rate introduced determination reliable transformation matrix. Then, RIMM (reversed iterative mathematic morphological) height value accumulation employed to extract contours data, respectively....

A new automated approach to the high-accuracy registration of airborne and terrestrial LiDAR data is proposed, which has three primary steps. Firstly, are used extract building corners, known as corners respectively. Secondly, an initial matching relationship between automatically derived using a technique based on maximum corner pairs with minimum errors (MTMM). Finally, set leading points generated from matched shiftable point method proposed. The key feature this implementation concept in...

We report on the feedback-optimized extraordinary optical transmission of continuous-variable entangled states through a hexagonal metal-hole array. The entanglements from nondegenerate parametric amplifier are first demonstrated to survive after photon-plasmon-photon conversion process. By controlling reflected light array, significant enhancement quantum correlations has then been experimentally achieved, compared case without such coherent feedback control. This result presents useful...

This paper proposes a novel on-line steel bars counting and splitting method based on machine vision which uses concave dots matching to segment, K-level fault tolerance count visual feedback multiple split automatically. Firstly, it preprocesses images of connected area analysis obtain edge profile adherent bars, then scans areas in the contour find dots. Secondly, dot condition segment counts single bar after segmentation achieve purpose through movement estimation algorithm. Finally, is...

Objective Buildings are major spatial elements in urban areas, and 3D building models significant for construction of intelligent cities. Airborne light detection ranging(LiDAR) has the advantages low operation cost, fast acquisition, all-weather access to point cloud with high accuracy. As a high-quality data source, airborne LiDAR provides convenience extraction, feature recognition, model reconstruction. Extracting accurate complete contours from is important. However, due dispersion...

This paper implements a non-contact measurement system based on machine vision for industrial profiles section, which uses double telecentric lens optical as image acquisition device. The key procedures using to get cross section of measured profile are described in details. Based the characteristic itself, we applied smooth filtering and automatic threshold binarization algorithm preprocessing, improve detection accuracy through subpixel edge algorithm. Moreover, combined with high...

We propose a simple scheme using an unbalanced Mach-Zehnder interferometer to directly measure the entangled beams with correlation of amplitude quadratures and anticorrelation phase quadratures. In experiment, we use two fibers lengths 2 50 m construct interferometer. The variances difference sum from nondegenerate optical parametric amplifier are simultaneously measured be 1.79 1.62 dB below shot noise limit, respectively. Such convenient method has potential applications in quantum measurements.

Currently, the new space-based laser altimetry mission, Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2), is widely used to obtain terrain information. Photon cloud filtering a crucial step toward retrieving sub-canopy terrain. However, an unsuccessful photon performance weakens retrieval of In addition, would not be accurate in densely forested areas due existing sparse ground photons. This paper proposes method extraction accurately retrieve from ICESat-2 data. First, signal data were...

This paper proposed an automatic rebar splitting system counting by machine vision based on two-level transmission. Compared with other existing systems, this significantly reduces the space requirements for installation, can use of workshop more effectively. uses efficient algorithm to solve problems caused adhesion and sliding between rebar. By improving sub-steel machine, two-step visual verification technology split stacked exactly. makes little change production line runs fast,...

Three-dimensional (3D) model data of overpasses are significant for traffic navigation, landscape design, and many other applications. In this study, we use airborne light detection ranging (LiDAR) 3D reconstruction complex overpass. We propose a new technical framework overpass, including point cloud extraction, connectivity-based segmentation, determination structure units, occlusion restoration, modeling. To reduce the difficulty, concept "structure unit". The general idea is to divide an...

In the past decades, quantum plasmonics has become an active area due to its potential applications in on-chip plasmonic devices for information processing. However, fundamental physical process, i.e., how a state of light evolves photon-plasmon conversion not been described by detailed microscopic model. Here, we report complete characterization plasmon-assisted extraordinary optical transmission process through tomography. By inputting various coherent states interact with structure and...

This paper chooses Mean Shift algorithm to track target based on non-linear kernel density estimation and Kalman filter. Kernel is a probability method, which used detect moving update the color histogram. The interest targets are obtained by labeling connected region in detected binary image. filtering employed predict position of being tracked, giving starting searching window for tracking. Experimental results show that method proposed effective fast implementation, satisfies real-time...