scholarly journals Modeling User Mobility via User Psychological and Geographical Behaviors Towards Point of-Interest Recommendation

Author(s):  
Yan Chen ◽  
Xin Li ◽  
Lin Li ◽  
Guiquan Liu ◽  
Guangdong Xu
Author(s):  
Gisèle Nicolas ◽  
Jean-Marie Bassot ◽  
Marie-Thérèse Nicolas

The use of fast-freeze fixation (FFF) followed by freeze-substitution (FS) brings substantial advantages which are due to the extreme rapidity of this fixation compared to the conventional one. The initial step, FFF, physically immobilizes most molecules and therefore arrests the biological reactions in a matter of milliseconds. The second step, FS, slowly removes the water content still in solid state and, at the same time, chemically fixes the other cell components in absence of external water. This procedure results in an excellent preservation of the ultrastructure, avoids osmotic artifacts,maintains in situ most soluble substances and keeps up a number of cell activities including antigenicities. Another point of interest is that the rapidity of the initial immobilization enables the capture of unstable structures which, otherwise, would slip towards a more stable state. When combined with electrophysiology, this technique arrests the ultrastructural modifications at a well defined state, allowing a precise timing of the events.We studied the epithelium of the elytra of the scale-worm, Harmothoe lunulata which has excitable, conductible and bioluminescent properties. The intracellular sites of the light emission are paracrystals of endoplasmic reticulum (PER), named photosomes (Fig.1). They are able to flash only when they are coupled with plasma membrane infoldings by dyadic or triadic junctions (Fig.2) basically similar to those of the striated muscle fibers. We have studied them before, during and after stimulation. FFF-FS showed that these complexes are labile structures able to diffentiate and dedifferentiate within milliseconds. Moreover, a transient network of endoplasmic reticulum was captured which we have named intermediate endoplasmic reticulum (IER) surrounding the PER (Fig.1). Numerous gap junctions are found in the membranous infoldings of the junctional complexes (Fig.3). When cryofractured, they cleave unusually (Fig.4-5). It is tempting to suggest that they play an important role in the conduction of the excitation.


2017 ◽  
Vol 42 ◽  
pp. 42-45
Author(s):  
Alessandro Mei ◽  
Ciro Manzo ◽  
Emiliano Zampetti ◽  
Francesco Petracchini ◽  
Lucia Paciucci

2020 ◽  
Vol 10 (2) ◽  
pp. 53-59
Author(s):  
Bharathi M ◽  
Mullaikodi O ◽  
Rajalingam D ◽  
Gnanasekar N ◽  
Kesavan M

A Microsponge (MS) is an extremely interconnected, permeable, polymeric structure that involves permeable microparticles trapping and discharging through the skin for a considerable time period. Drug delivery system (DDS) offer extended discharge with less degradation, improved physical stability along with better tolerance. The main intend of any DDS is to achieve the required amount of drug in plasma to produce the desired therapeutic and non-poisonous effect over a prolonged period of time. Specific methods for preparing MS were reviewed in this current investigation, and their pharmaceutical implementations were signed. MS have major DDS point of interest. It also improves stability, increased flexibility in formulation and increased elegance. In fact, numerous studies have reported that MS supplies are not allergic, mutagenic, and poisonous. MS creativity is used in products such as sunscreen, prescription, cosmetics, and OTC skin care. This inquiry primarily focuses on the different methods used to identify, plan and exploit MS.


CYCLOTRON ◽  
2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Sabri Balafif ◽  
Tining Haryanti

Abstrak— Penelitian ini bertujuan untuk mengetahui pola trafik internet pada beberapa lokasi yang diteliti. Pengamatan dilakukan selama dua belas (12) bulan. Data diolah dengan metode statistika untuk mendapatkan proyeksi pengguna internet dan kebutuhan titik hotspot. Penelitian menghasilkan rekomendasi kebutuhan hotspot dengan mempertimbangkan mobilitas pengguna internet dan countur lokasi. Rekomendasi perangkat berbeda pada tiap lokasi dari sisi geografis dan padatnya area. Line of Sight mempengaruhi kemampuan perangkat dalam memancarkan signal internet.Hasil penelitian menunjukkan terjadinya peningkatan pengguna internet pada hari raya umat Islam, Hal ini diduga karena mayoritas masyarakat pada lokasi tersebut muslim. Proyeksi pelanggan di 300 desa didapatkan minimum penetrasi 36,7% dan maksimal 85.2%. Rekomendasi sejumlah 940 Titik hotspot dengan area bandwith secara statik sebesar 3Mbps (aggregate download dan upload).  Penelitian memperhitungkan Link Budget perangkat backhoul tier 3 dengan frekuensi 24Ghz. Setiap  perangkat dapat menangani rata-rata jumlah device yang terkoneksi secara bersama sejumlah > 200 Device teknologi Wi-Fi (IEEE 802.11). Beban total trafik  > 1,6 GBPS. Rekomendasi Arsitektur  broadband wireless access Berbasis Hotspot Di Jawa Timur yaitu Surabaya 140 lokasi dengan 400 titik hotspot, Mojokerto sejumlah 70 lokasi dengan 210 titik hotspot. Pandaan sejumlah 80 lokasi dengan 240 titik hotspot Malang  43 lokasi dengan 90 titik hotspot.Kata kunci: Broadband Wireless Access, Hotspot, Line Of SightAbstract— This study aims to determine the pattern of internet traffic in several locations in Jawa Indonesia. Observations were made for twelve (12) months. Data is processed using statistical methods to obtain projections of internet users and hotspot needs. This study produces recommendations for hotspot needs by considering internet user mobility and location contours. Device recommendations vary by location in terms of geography and crowded areas. Line of Sight affects the ability of the device to emit internet signals. The results showed an increase in internet users on Muslim holidays. Projected customers in 300 villages have a minimum penetration of 36.7% and a maximum of 85.2%. The recommended number of 940 hotspots with a static area of 3Mbps (download aggregate and upload). This study takes into account the tier 3 Link Budget backhoul device with a frequency of 24Ghz. Each device can handle the average number of devices that are connected together by> 200 Wi-Fi technology devices (IEEE 802.11). Total traffic load> 1.6 GBPS. Architectural recommendations for broadband wireless access based on hotspots in East Java, Surabaya, 140 locations with 400 hotspots, Mojokerto with 70 locations with 210 hotspots. Pandaan a total of 80 locations with 240 Malang hotspots 43 locations with 90 hotspots Keywords: Broadband Wireless Access, Hotspot, Line Of Sight


Author(s):  
Giannis Christoforidis ◽  
Pavlos Kefalas ◽  
Apostolos N. Papadopoulos ◽  
Yannis Manolopoulos

2021 ◽  
Vol 13 (6) ◽  
pp. 1098
Author(s):  
Egor Prikaziuk ◽  
Peiqi Yang ◽  
Christiaan van der Tol

In this study, we demonstrate that the Google Earth Engine (GEE) dataset of Sentinel-3 Ocean and Land Color Instrument (OLCI) level-1 deviates from the original Copernicus Open Access Data Hub Service (DHUS) data by 10–20 W m−2 sr−1μμm−1 per pixel per band. We compared GEE and DHUS single pixel time series for the period from April 2016 to September 2020 and identified two sources of this discrepancy: the ground pixel position and reprojection. The ground pixel position of OLCI product can be determined in two ways: from geo-coordinates (DHUS) or from tie-point coordinates (GEE). We recommend using geo-coordinates for pixel extraction from the original data. When the Sentinel Application Platform (SNAP) Pixel Extraction Tool is used, an additional distance check has to be conducted to exclude pixels that lay further than 212 m from the point of interest. Even geo-coordinates-based pixel extraction requires the homogeneity of the target area at a 700 m diameter (49 ha) footprint (double of the pixel resolution). The GEE OLCI dataset can be safely used if the homogeneity assumption holds at 2700 m diameter (9-by-9 OLCI pixels) or if the uncertainty in the radiance of 10% is not critical for the application. Further analysis showed that the scaling factors reported in the GEE dataset description must not be used. Finally, observation geometry and meteorological data are not present in the GEE OLCI dataset, but they are crucial for most applications. Therefore, we propose to calculate angles and extraterrestrial solar fluxes and to use an alternative data source—the Copernicus Atmosphere Monitoring Service (CAMS) dataset—for meteodata.


2021 ◽  
Vol 13 (2) ◽  
pp. 444
Author(s):  
Xucai Zhang ◽  
Yeran Sun ◽  
Ting On Chan ◽  
Ying Huang ◽  
Anyao Zheng ◽  
...  

Urban vibrancy contributes towards a successful city and high-quality life for people as one of its vital elements. Therefore, the association between service facilities and vibrancy is crucial for urban managers to understand and improve city construction. Moreover, the rapid development of information and communications technology (ICT) allows researchers to easily and quickly collect a large volume of real-time data generated by people in daily life. In this study, against the background of emerging multi-source big data, we utilized Tencent location data as a proxy for 24-h vibrancy and adopted point-of-interest (POI) data to represent service facilities. An analysis framework integrated with ordinary least squares (OLS) and geographically and temporally weighted regression (GTWR) models is proposed to explore the spatiotemporal relationships between urban vibrancy and POI-based variables. Empirical results show that (1) spatiotemporal variations exist in the impact of service facilities on urban vibrancy across Guangzhou, China; and (2) GTWR models exhibit a higher degree of explanatory capacity on vibrancy than the OLS models. In addition, our results can assist urban planners to understand spatiotemporal patterns of urban vibrancy in a refined resolution, and to optimize the resource allocation and functional configuration of the city.


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