Identifying Complex Junctions in a Road Network

Automated generalization of road network data is of great concern to the map generalization community because of the importance of road data and the difficulty involved. Complex junctions are where roads meet and join in a complicated way and identifying them is a key issue in road network generalization. In addition to their structural complexity, complex junctions don’t have regular geometric boundary and their representation in spatial data is scale-dependent. All these together make them hard to identify. Existing methods use geometric and topological statistics to characterize and identify them, and are thus error-prone, scale-dependent and lack generality. More significantly, they cannot ensure the integrity of complex junctions. This study overcomes the obstacles by clarifying the topological boundary of a complex junction, which provides the basis for straightforward identification of them. Test results show the proposed method can find and isolate complex junctions in a road network with their integrity and is able to handle different road representations. The integral identification achieved can help to guarantee connectivity among roads when simplifying complex junctions, and greatly facilitate the geometric and semantic simplification of them.

Prognosys of dangerous geodynamic phenomena at the Kun-Manye field based on the analysis of digital elevation models

The Kuhn-Magnyo copper-nickel deposit is located in the southeast of the Aldan-Stanovoy shield. Based on the results of geological exploration, the object is assessed as promising. The ore field, within which the deposit is located, is confined to a complex junction of several regional tectonic structures. The area has an intensely dissected relief, increased seismicity. Therefore, an assessment of the possibility of dangerous geodynamic phenomena during its operation is required. This work describes its preliminary assessment based on the results of morphometry on digital elevation models (DEM). Several morphostructural elements have been identified that directly determine the geodynamics in the area of the earth’s crust containing the deposit. The result of the study revealed a potential hazard.

Follow the Leader

Two studies investigated the concept of following a lead vehicle as a navigational aid. The first video-based study (n=34) considered how drivers might use a real-world lead vehicle as a navigational aid, whist the second simulator-based study (n=22) explored how an Augmented Reality (AR) virtual car, presented on a head-up display (HUD), may aid navigation around a complex junction. Study 1 indicated that a lead vehicle is most valued as a navigation aid just before/during a required maneuver. During the second study the dynamic virtual car (which behaved like a real vehicle) resulted in greater confidence and lower workload than a static virtual car that “waits” at the correct junction exit, but resulted in more gaze concentration. It is concluded that a virtual car may be a valuable element of a navigation system, in combination with other forms of information, to completely fulfil all a driver's navigational task requirements.

A freeze-fracture and lanthanum tracer study of the complex junction between Sertoli cells of the canine testis.

What appear to be true septate junctions by all techniques currently available for the cytological identification of intercellular junctions are part of a complex junction that interconnects the Sertoli cells of the canine testis. In the seminiferous epithelium, septate junctions are located basal to belts of tight junctions. In thin sections, septate junctions appear as double, parallel, transverse connections or septa spanning an approximately 90-A intercellular space between adjacent Sertoli cells. In en face sections of lanthanum-aldehyde-perfused specimens, the septa themselves exclude lanthanum and appear as electron-lucent lines arranged in a series of double, parallel rows on a background of electron-dense lanthanum. In freeze-fracture replicas this vertebrate septate junction appears as double, parallel rows of individual or fused particles which conform to the distribution of the intercellular septa. Septate junctions can be clearly distinguished from tight junctions as tight junctions prevent the movement of lanthanum tracer toward the lumen, appear as single rows of individual or fused particles in interlacing patterns within freeze-fracture replicas, and are seen as areas of close membrane apposition in thin sections. Both the septate junction and the tight junction are associated with specializations of the Sertoli cell cytoplasm. This is the first demonstration in a vertebrate tissue of a true septate junction.

Fine structure of the antennal sensory appendix in the larva of Ctenicera destructor (Brown) (Elateridae: Coleoptera)

The antennal sensory appendix of Ctenicera destructor (Brown) appears to be a compound sensillum basiconicum formed by a union of about 12 individual sensilla. It is innervated by about 36 bipolar sense cells of type I, which occur usually in 12 groups of three neurons each. The sensory cuticle is large, cone-shaped, and abundantly perforated by a slit-tubule system. The dendrites of each group of neurons are enclosed distally by a single tubular cuticular sheath attached to the base of the cone by a suspensory fiber system. The ensheathed portion of the dendrites lies in a receptor-lymph cavity formed by the tormogen and accessory trophic cells. Distal dendritic branches pass below and occasionally enter inner pockets in the sensory cuticle, but no connections were seen between the slit-tubule system and the dendritic surfaces. About 12 of each of four types of cells are associated with the neurons in this sensillum: tormogen, trichogen, accessory trophic, and neurilemma. The ultrastructure and probable function of each type is described. A central, complex junction body region divides each dendrite into morphologically distinct distal and proximal region. All the cells associated with the sensillum are in a compact bundle, which is separated from adjacent sensilla within the antenna by a membranous septum. It is suggested that this sense organ has an olfactory function.