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Plant chloroplasts conduct photosynthesis to convert solar energy into sugars for the carbon source essential for cell living and growth during the day. One fraction of photosynthetic products is stored in chloroplasts by forming starch granules to continue the provision of carbon energy during the night. Currently, profiling the starch temporal pattern requires either: (i) sacrificing the leaves, or (ii) generating transgenic plants at the risk of changing the metabolisms by incorporating a genetically modified granule-bound starch synthase (GBSS). In this paper, we demonstrated a nondestructive method using two-photon fluorescence (TPF) and second-harmonic generation (SHG) imaging to quantify starch granules within chloroplasts of fresh intact leaves across a day-night cycle. We did so using two Arabidopsis lines having normal and excess starch contents: wild-type (Columbia-0) and starch excess 1 (sex1). The starch granules were visualized by SHG imaging, while the chloroplasts in mesophyll cells were visualized by TPF imaging. Our results provided micron scale spatial resolution of starch distribution within leaves and showed starch circadian patterns consistent with those profiled by enzymatic assays in previous studies. We demonstrated that TPF-SHG imaging is a potential tool for revealing the real-time heterogeneity of starch circadian rhythm in leaf cells, without the need for destructive sample preparation.

The adsorption and desorption of electrolyte ions strongly modulates the carrier density or carrier type on the surface of monolayer-MoS

The sensitiveness of second-harmonic generation (SHG) signal to crystal lattice orientation and crystal symmetry makes it a powerful tool for structural characterization of low dimensional transition metal dichalcogenide (TMD) materials. In this paper, we report the strain-induced SHG enhancement at the edge of the monolayer MoS2 flakes. By performing raster mapping of SHG intensity, the images show an enhanced SHG intensity at the flake edge with cubic-power dependence. The AFM analysis of the MoS2 flake edge with enhanced SHG, indeed, detected a topographic height change as compared to the center region. Micro-Raman spectroscopy analysis shows a blue shift in A1g phonon mode at the flake edge. This edge-enhanced SHG may be attributed to the intrinsic strain effect induced during the chemical vapor deposition growth condition, which modulates the nonlinear susceptibility. The micro-Raman spectroscopy implies that the flake edge has a compressed and stiffened structure in an out-of-plane direction. This work brings out the awareness of the residual strain effect on 2D TMD device performance, and the adequate characterization of the strained structure by SHG intensity mapping.

Organic–inorganic hybrid two-dimensional (2D) perovskites have recently attracted great attention in optical and optoelectronic applications due to their inherent natural quantum-well structure. We report the growth of high-quality millimeter-sized single crystals belonging to homologous two-dimensional (2D) hybrid organic–inorganic Ruddelsden–Popper perovskites (RPPs) of (BA)2(MA)n−1PbnI3n+1 (n = 1, 2, and 3) by a slow evaporation at a constant-temperature (SECT) solution-growth strategy. The as-grown 2D hybrid perovskite single crystals exhibit excellent crystallinity, phase purity, and spectral uniformity. Low-threshold lasing behaviors with different emission wavelengths at room temperature have been observed from the homologous 2D hybrid RPP single crystals. Our result demonstrates that solution-growth homologous organic–inorganic hybrid 2D perovskite single crystals open up a new window as a promising candidate for optical gain media.

This research aims at the realization of charge equalization on series-connected battery modules by digital controller. A charge equalization system on high-voltage high-capacity series-connected lithium-iron batteries is developed. The system includes hardware, firmware, equalization strategy and protection peripherals. For the hardware, a capacitor is adopted as the intermediate for the charge transference between higher and lower charged modules. The charge transference between battery modules and capacitor is performed via bidirectional flyback converters. For the firmware, LPC122x series of 32-bit microcontrollers are used as the digital controllers, and a battery management IC is used to sense the battery information. The controller area network (CAN) bus provides the communication network for the modules in the system. The proposed battery modules with fast equalization can be achieved by executing the balancing strategy and protection circuits. Experimental results show that the charge equalization system could achieve module to module charge equalization between 22 battery modules accurately, making the voltage difference be less than 100 mV after equalization.

This paper proposes a kernel-based strategy to analyze the distribution of local point clouds and detect 3D lines from dense airborne LIght Detection and Ranging (LIDAR) data. The proposed method, namely topological elevation connection (TEC) analysis, employs geometric criteria with an automatic procedure instead of threshold operation. The focused targets include flat roofs with parapets, step roofs, hipped roofs, and gable roofs. By comparing with reference data, the accuracy between the detected lines and reference data can reach within 0.2 m. Three-dimensional boundaries and structure lines are essential for building modeling and data registration. Many related works have focused on the collection of co-planar LIDAR points to calculate intersection lines with optimized thresholds. In addition, they did not focus on parapets because of the limitations of developed assumptions and the criteria used. It is crucial to analyze the local point distribution for the automation improvement of detection proces...

The ISPRS Student Consortium is an international organization for students and young professionals in the fields of photogrammetry, remote sensing, and the geospatial information sciences. Since its start ten years ago, the number of members of the Student Consortium has been steadily growing, now reaching close to 1000. Its increased popularity, especially in recent years, is mainly due to the organization's worldwide involvement in student matters. The Student Consortium has helped organize numerous summer schools, youth forums, and student technical sessions at ISPRS sponsored conferences. In addition, the organization publishes a newsletter, and hosts several social media outlets in order to keep its global membership up-to-date on a regular basis. This paper will describe the structure of the organization, and it will give some example of its past student related activities.

Edges and corners are two major image features in the modelling of man-made objects; an edge provides strong geometric orientation and corners possess good localisation. Feature detection is the basis of image processing for numerous applications such as image registration and object modelling. Completeness and localisation are the two major considerations for these applications; however, illumination, reflectance and shadows may interfere with image grey values to produce various gradients along an edge. Thus, threshold selection is an important step in obtaining suitable features in target-dependent methods as improper selection might cause information loss and broken edges. Instead of threshold selection, this study therefore proposes a feature extraction method using topological gradient connection (TGC) analysis involving three steps: grey value refinement, gradient computation and topological connection analysis. The first step uses a Gaussian filter to smooth the grey value image. The second step computes directional gradients to identify ridge pixels and collect feature candidates. The third step analyses adjacent candidates based on the criterion of topological connection. This three-step tracing procedure combines these connected candidates into a single object. The proposed scheme employs different images derived from various sensors and compares them with the Canny operator (using manually selected thresholds) and manually plotted corners for detection ability assessment. Experimental results indicate that the automatic results are more complete for subtle feature lines than the Canny edges. In addition, the proposed method provides higher flexibility in selecting suitable feature layers for different applications. Resume Les bordures et les coins sont, dans les images, des objets tres importants pour la modelisation d'objets artificiels; une bordure fournit une orientation geometrique robuste et les coins ont une bonne localisation. La detection de formes est la base du traitement d'images pour nombre d'applications, comme le recalage d'images ou la modelisation d'objets. La completude et la localisation sont deux criteres essentiels pour de telles applications; toutefois, l'illumination, la reflectance et les ombres peuvent influencer les niveaux de gris de l'image et produire des gradients variables le long d'une bordure. La selection des seuils est donc une etape importante pour l'obtention de formes correctes avec des methodes dependantes de l'objet, car une selection inappropriee peut causer la perte d'informations et des cassures dans les bordures. Plutot que la selection des seuils, cette etude propose ainsi une methode d'extraction de formes basee sur une analyse de la connexion du gradient topologique (TGC), en trois etapes: rehaussement des niveaux de gris, calcul des gradients, et analyse des connexions topologiques. La premiere etape utilise un filtre gaussien pour lisser l'image de niveaux de gris. La deuxieme etape calcule des gradients directionnels pour identifier les pixels de bordures et collecter les formes candidates. La troisieme etape identifie les candidats adjacents selon un critere de connexion topologique. Cette procedure de reconstruction en trois etapes regroupe en un seul objet les candidats ainsi connectes. Le schema propose utilise des images issues de differents capteurs et compare les resultats avec l'operateur de Canny (utilisant des seuils definis manuellement) et avec des coins pointes a la main, pour evaluer la qualite de la detection. Des resultats experimentaux montrent que les resultats de la methode automatique donnent des resultats plus complets que les bordures de Canny pour des formes lineaires fines. En outre, la methode proposee permet une plus grande flexibilite dans la selection de couches d'information de forme pour differentes applications. Zusammenfassung Kanten und Eckpunkte sind zwei bedeutende Bildmerkmale zur Modellierung kunstlicher Objekte: eine Kante liefert wichtige Information zur geometrischen Orientierung und Eckpunkte sind genau zu lokalisieren. Die Detektion von Merkmalen ist von zentraler Bedeutung fur die Bildverarbeitung, fur die Bildregistrierung und zur Objektmodellierung. Vollstandigkeit und Lokalisierung spielen dabei die wichtigste Rollen, allerdings konnen Beleuchtung, Reflexion und Schatten die Grauwerte eines Bildes beeinflussen und z.B. verschiedene Gradienten entlang einer Kante produzieren. Die Auswahl von Schwellwerten ist ein entscheidender Schritt, um geeignete Merkmale zu erhalten. Eine ungunstige Wahl eines Schwellwerts kann Informationsverlust oder unterbrochene Kanten bedeuten. Statt der Auswahl eines Schwellwerts wird eine Merkmalsextraktionsmethode vorgeschlagen, die eine Analyse der topologischen Verbindung von Gradienten (TGC) nutzt. Es werden hierzu drei Schritte bearbeitet: Grauwertverfeinerung, Berechnung der Gradienten und Analyse der topologischen Beziehungen. Mit einem Gauss Filter wird das Grauwertbild geglattet. Im zweiten Schritt werden Richtungsgradienten berechnet, um Kantenpixel zu identifizieren und geeignete Kandidaten auszuwahlen. Im dritten Schritt werden benachbarte Kandidaten auf der Basis der topologischen Verbindung analysiert. Durch die drei Schritte werde nmiteinander verbundene Kandidaten in ein Einzelobjekt uberfuhrt. Das vorgeschlagene Schema wird auf verschiedene Bilder von verschiedenen Sensoren angewandt. Die Ergebnisse werden mit dem Canny Operator (mit manuell gewahlten Schwellwerten) und mit manuell erfassten Eckpunkten verglichen, um die Qualitat der Merkmalserkennung zu prufen. Die experimentell erzielten Ergebnisse zeigen, dass das vorgeschlagene automatische Verfahren hohere Vollstandigkeit fur nicht sehr ausgepragte Merkmale erzielt, als die, mit dem Canny Operator extrahierten Kanten. Daruber hinaus bietet dieses Verfahren eine hohere Flexibilitat fur die Wahl geeigneter Merkmalsstufen in verschiedenen Anwendungen. Resumen Aristas y esquinas son las dos principales caracteristicas que modelan los objetos hechos por el hombre. Una arista proporciona una fuerte orientacion geometrica y las esquinas dotan de una buena localizacion. La deteccion de caracteristicas es la base de numerosas aplicaciones en proceso de imagenes como el registro de imagenes y el modelado de objetos. Completitud y localizacion son las dos mayores consideraciones para estas aplicaciones. Sin embargo la iluminacion, los reflejos y las sombras interfieren con el valor de gris de las imagenes produciendo variaciones de gradiente a lo largo de una arista. Para obtener caracteristicas apropiadas en metodos dependientes de dianas es importante la seleccion de un limite sobre el gradiente. La inadecuada seleccion de este puede causar perdida de informacion y la fractura de aristas. En lugar de la seleccion de un limite se propone un metodo de extraccion de caracteristicas usando el analisis de conexion de gradiente topologico (TGC) que tiene tres pasos: refinamiento de los valores de gris, calculo del gradiente y analisis de conexion topologica. En el primer paso se usa un filtro Gausiano para suavizar los valores de gris de la imagen. En el segundo paso se calculan los gradientes direccionales para identificar los pixeles en la cresta y seleccionar los candidatos a pixel de caracteristica. En el tercer paso se analizan los candidatos adyacentes usando criterios de conexion topologica. Este procedimiento de tres pasos combina los candidatos adyacentes en un unico objeto. Este esquema se ha aplicado en imagenes de distintos sensores y sus resultados se han comparado con los del operador de Canny (usando limites seleccionados manualmente) y manualmente se han trazado las esquinas para valorar la capacidad de deteccion. Los resultados empiricos indican que los resultados automaticos son mas completos para caracteristicas lineales sutiles que el operador de Canny. Ademas el metodo propuesto proporciona mayor flexibilidad en seleccionar caracteristicas apropiadas para aplicaciones diferentes.

This paper reports a history and future prospects of the activities by Asian students and young scientists on photogrammetry and remote sensing. For future growths of academic fields, active communications among students and young scientists are indispensable. In some countries and regions in Asia, local communities are already established by youths and playing important roles of building networks among various schools and institutes. The networks are expected to evolve innovative cooperations after the youths achieve their professions. Although local communities are getting solid growth, Asian youths had had little opportunities to make contacts with youths of other countries and regions. To promote youth activities among Asian regions, in 2007, Asian Association on Remote Sensing (AARS) started a series of programs involving students and young scientists within the annual conferences, the Asian Conference on Remote Sensing (ACRS). The programs have provided opportunities and motivations to create networks among students and young scientists. As a result of the achievements, the number of youth interested and involved in the programs is on growing. In addition, through the events held in Asian region by ISPRS Student Consortium (ISPRSSC) and WG VI/5, the Asian youths have built friendly partnership with ISPRSSC. Currently, many Asian youth are keeping contacts with ACRS friends via internet even when they are away from ACRS. To keep and expand the network, they are planning to establish an Asian youth organization on remote sensing. This paper describes about the proposals and future prospects on the Asian youth organization.

Modern road systems have become complex networks with multiple layers, making three- dimensional (3D) road modeling an important task in the geoinformatic realm. Although traditional topographic maps contain explicit planimetric networks, they often lack sufficient elevation information to describe the vertical alignments in multi-layer road systems. In this investigation, we combine data from large-scale topographic maps and airborne light detection and ranging (LIDAR) data to reconstruct 3D road models. The proposed scheme includes two steps: planimetric networking and surface modeling. In the first part, road centerlines are determined then linked up and their topologies organized using the polylines extracted from large-scale topographic maps. In the second part, a filter is utilized for the extraction of road surface points from airborne LIDAR data. The three dimensional alignment of the profiles and cross-sections is then computed. Furthermore, to improve the realism of the road models, sur...