SPRIG: A Learned Spatial Index for Range and kNN Queries

The North coast of Java is increasingly exposed to flood risks due to land subsidence and climate change, resulting in sea-level rise. This paper developed a flood risk spatial index model in the coastal Pekalongan. The model was systematically arranged from various flood risk indicators related to the social, economic, and environment of coastal Pekalongan based on surveys and interviews with the communities and regional governments. These indicators are then integrated into hazard and vulnerability as components of risk. Using the index system method and ArcGIS, the risk index is classified into five levels (very high, high, medium, low, very low) and generated into a flood risk spatial distribution map. We found that the risk in the study area varies between a medium to a very high level of risk. The very high level of risk was located in Tratebang, Pecakaran, and Tegaldowo Village. A risk spatial distribution map can be used to evaluate potential risks and flood mitigation.

Download Full-text

Efficient Geo-Textual Hybrid Indexing Techniques for Moving Objects and Queries

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.f9142.038620 ◽

2020 ◽

Vol 8 (6) ◽

pp. 4419-4428

Keyword(s):

Moving Objects ◽

Traffic Monitoring ◽

Spatial Index ◽

Index Structure ◽

Maintenance Cost ◽

Hybrid Index ◽

Indexing Techniques ◽

Inverted List ◽

Textual Data ◽

Future Position

Advancements of various Geographic Information Technologies have resulted in huge growth in Geo-Textual data. Many Indexing and searching algorithms are developed to handle this Geo-Textual data which contains spatial, textual and temporal information. In past, Indexing and searching algorithms are developed for the applications in which the object trajectory or velocity vector is known in advance and hence we can predict the future position of the objects. There are real time applications like emergency management systems, traffic monitoring, where the objects movements are unpredictable and hence future position of the objects cannot be predicted. Techniques are required to answer the geo-textual kNN query where the velocity vectors or trajectories of moving and moving queries are not known. In case of moving objects, capturing current position of the object and maintaining spatial index optimally is very much essential. The hybrid indexing techniques used earlier are based on R-tree spatial index. The nodes of the R-tree index structure are split or merged to maintain the locations of continuously moving objects, increasing the maintenance cost as compared to the grid index. In this paper a solution is proposed for creating and maintaining hybrid index for moving objects and queries based on grid and inverted list hybrid indexing techniques. The method is also proposed for finding Geo-Textual nearest neighbours for static and moving queries using hybrid index and conceptual partitioning of the grid. The overall gain reported by the experimental work using hybrid index over the non- hybrid index is 30 to 40 percent depending on the grid size chosen for mapping the data space and on the parameters of queries.

Download Full-text

UASI—Urban Agriculture Spatial Index

Specifics ◽

10.1515/9783868598803-042 ◽

2021 ◽

pp. 206-210

Author(s):

Gesa Königstein ◽

Anne-Katrin Fenk

Keyword(s):

Urban Agriculture ◽

Spatial Index

Download Full-text

Spatial Index Structure

10.1007/springerreference_62927 ◽

2011 ◽

Keyword(s):

Spatial Index ◽

Index Structure

Download Full-text

Gridvoronoi: An Efficient Spatial Index for Nearest Neighbor Query Processing

IEEE Access ◽

10.1109/access.2019.2937667 ◽

2019 ◽

Vol 7 ◽

pp. 120997-121014 ◽

Cited By ~ 3

Author(s):

Chongsheng Zhang ◽

George Almpanidis ◽

Faegheh Hasibi ◽

Gaojuan Fan

Keyword(s):

Query Processing ◽

Nearest Neighbor ◽

Spatial Index ◽

Nearest Neighbor Query

Download Full-text

Extended Spatial-Index LED Modulation for Optical MIMO-OFDM Wireless Communication

Electronics ◽

10.3390/electronics9010168 ◽

2020 ◽

Vol 9 (1) ◽

pp. 168 ◽

Cited By ~ 4

Author(s):

Hany S. Hussein ◽

Mohamed Hagag ◽

Mohammed Farrag

Keyword(s):

Time Domain ◽

Spectral Efficiency ◽

Orthogonal Frequency Division Multiplexing ◽

Light Emitting Diode ◽

Visible Light Communication ◽

Spatial Domain ◽

Spatial Modulation ◽

Spatial Index ◽

Power Weight ◽

Modulation Technique

An efficient optical modulation technique for multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) visible light communication system is proposed in this paper. The proposed modulation technique is termed as extended spatial-index light-emitting diode (LED) modulation. In the proposed technique, the indices (the spatial domain) of the LEDs are exploited in a dynamic style to not only get rid of the optical OFDM time-domain ( OFDM t d ) shaping problem but also to expand the LED indices spatial modulation domain. The indices of the active LEDs in the proposed technique are changed from the two LEDs active situation to the situation where all or several LEDs are active. Moreover, within the selected active LED indices, the power weight distribution and the positions of the OFDM components are varied to expand the resultant spatial domain. Therefore, the proposed technique offers a considerable spectral efficiency improvement over the up-to-date LED index OFDM modulation schemes even with a lower number of LEDs. The key idea of the proposed technique is to maximize the LEDs’ indices spatial position (spatial domain) utilization, where both the power weight allocation and the positions of the complex OFDM time domain components are varying several times over the same active LED indices combination, which improve the optical system spectral efficiency. The simulation results asserted the superiority of the proposed technique, as it improves both the average bit error rate (ABER) and the achievable data rate (R) compared with existing up-to-date OFDM-LED index modulations with even lower computational complexity.

Download Full-text