Point-of-Interest Recommender Systems based on Location-Based Social Networks: A Survey from an Experimental Perspective

Point-of-Interest recommendation is an increasing research and developing area within the widely adopted technologies known as Recommender Systems. Among them, those that exploit information coming from Location-Based Social Networks (LBSNs) are very popular nowadays and could work with different information sources, which pose several challenges and research questions to the community as a whole. We present a systematic review focused on the research done in the last 10 years about this topic. We discuss and categorize the algorithms and evaluation methodologies used in these works and point out the opportunities and challenges that remain open in the field. More specifically, we report the leading recommendation techniques and information sources that have been exploited more often (such as the geographical signal and deep learning approaches) while we also alert about the lack of reproducibility in the field that may hinder real performance improvements.

THE STRATEGIC CHOICES IN ACHIEVING TOURISM'S COMPETITIVENESS AND PERFORMANCE AMONG HOTELS IN INDONESIA

The current debate between external strategy and a resource-based approach as a driver of competitiveness is rarely investigated in a developing region. This study investigates whether an external focus or a resource-based strategy is better for leveraging the hotel industry's competitiveness and performance in a developing area in Indonesia. The authors obtained saturated responses from 204 managers and analyzed them with PLS-SEM's two-stage and repeated indicator approach while interviewing some of them. This study developed a formative model in PLS-SEM as a better method for investigating an organization's performance than a reflective approach. Quantitative analysis revealed the resource-based view as a better basis for supporting hotels' competitiveness and performance; however, the interview revealed considerable concerns over arising externalities. This paper suggests that hotel managers improve their internal core competence instead of wasting resources and worrying about external issues.

Phase Formation and the Electrical Properties of YSZ/rGO Composite Ceramics Sintered Using Silicon Carbide Powder Bed

Fully stabilized zirconia/graphene composites are very promising advanced structural materials having mixed ion–electron conductivity for energy storage and energy conversion applications. The existing methods of the composite manufacturing have a number of disadvantages that limit their practical use. Thus, the search for new sintering methods is an actively developing area. In this work, we report for the first time the application of the SiC powder bed sintering technique for fully stabilized zirconia (YSZ) composite fabrication. The reduced graphene oxide (rGO) was used as a graphene derivative. As a result, well-formed ceramics with high density and crystallinity, the maximal microhardness of 13 GPa and the values of the ionic conductivity up to 10−2 S/cm at 650 °C was obtained. The effects of the sintering conditions and rGO concentration on the microstructure and conductivities of ceramics are discussed in detail. The suggested powder bed sintering technique in a layered graphite/SiC/graphite powder bed allowed well-formed dense YSZ/rGO ceramics fabrication and can become a suitable alternative to existing methods for various oxide ceramic matrix composite fabrication: both conventional sintering and non-equilibrium (SPS, flash sintering) approaches.

UNITY OF MATERIAL AND SPIRITUAL IN THE LIGHT OF COEVOLUTION

Целью статьи является анализ обоснование необходимости пересмотра одностороннего представления о взаимодействии духа и материи, бытия и сознания. Основным методом исследования является диалектический анализ взаимосвязи и неразрывного единства противоположных начал человеческого бытия (материи и духа). Результатом исследования является попытка доказать, что материя и дух образуют живую материально-духовную действительность, единую непротиворечивую субстанцию, которая не нуждается в другом основании как условии своего существования, а выступает своей собственной основой. Заслуга авторов состоит в доказательстве того, что существует единая субстанция, - духоматерия, которая содержит в себе и материальную действительность, и потенциально заложенную в ней духовную деятельность человека как естественно развивающуюся область мироздания, заключающую в себе всё многообразие социально-духовного бытия человека, ибо человек как материальное явление, так и его духовность - это результат развития единой всеобщей космической субстанции мироздания - духоматерии. Теоретическая и практическая значимость статьи содержится в попытке доказать не просто взаимосвязь материального и духовного начал, но определить основы взаимодействия этих начал как двух сторон единой космической субстанции мироздания и их диалектического взаимоперехода на разных этапах конкретных форм существования. Авторам удалось углубить предложенную проблематику, что может быть использовано для дальнейшего теоретического анализа проблемы. The purpose of the article is to analyze the substantiation of the need to revise the onesided idea of the interaction of spirit and matter, being and consciousness. The main research method is the dialectical analysis of the relationship and indissoluble unity of the opposite principles of human existence (matter and spirit). The result of the study is an attempt to prove that matter and spirit form a living material-spiritual reality, a single consistent substance that does not need another basis as a condition for its existence, but acts as its own basis. The merit of this approach consists in proving that there is a single substance - spirit-matter, which contains both material reality and the potential spiritual activity of a person embedded in it as a naturally developing area of the universe, containing all the diversity of social and spiritual life of a person, for a person as a material both the phenomenon and its spirituality are the result of the development of a single universal cosmic substance of the universe - spirit matter. The theoretical and practical significance of the article is presented in an attempt to prove not just the relationship between material and spiritual principles, but to determine the basis of the interaction of these principles as two sides of a single cosmic substance of the universe and their dialectical transition at different stages of specific forms of existence. The outlined conclusions should lead to further theoretical analysis of this problem.

Design and Analysis of Low-Power and High Speed Approximate Adders Using CNFETs

Adders are constituted as the fundamental blocks of arithmetic circuits and are considered important for computation devices. Approximate computing has become a popular and developing area, promising to provide energy-efficient circuits with low power and high performance. In this paper, 10T approximate adder (AA) and 13T approximate adder (AA) designs using carbon nanotube field-effect transistor (CNFET) technology are presented. The simulation for the proposed 10T approximate adder and 13T approximate adder designs were carried out using the HSPICE tool with 32 nm CNFET technology. The metrics, such as average power, power-delay product (PDP), energy delay product (EDP) and propagation delay, were carried out through the HSPICE tool and compared to the existing circuit designs. The supply voltage Vdd provided for the proposed circuit designs was 0.9 V. The results indicated that among the existing full adders and approximate adders found in the review of adders, the proposed circuits consumed less PDP and minimum power with more accuracy.

River ice phenology and thickness from satellite altimetry: potential for ice bridge road operation and climate studies

River ice is a key component of the cryosphere. Satellite monitoring of river ice is a rapidly developing area of scientific enquiry, which has wide-ranging implications for climate, environmental and socioeconomic applications. Spaceborne radar altimetry is widely used for monitoring river water regimes; however, its potential for the observation of river ice processes and properties has not been demonstrated yet. Using Ku-band backscatter measurements from the Jason-2 and Jason-3 satellite missions (2008–2019), we demonstrate the potential of radar altimetry for the retrieval of river ice phenology dates and ice thickness for the first time. The altimetric measurements were determined to be sensitive enough to detect the first appearance of ice and the beginning of thermal breakup on the lower Ob River (Western Siberia). The uncertainties in the retrieval of ice event timing were within the 10 d repeat cycle of Jason-2 and Jason-3 in 88 %–90 % of the cases analysed. The uncertainties in the river ice thickness retrievals made via empirical relations between the satellite backscatter measurements and in situ observations, expressed as the root mean square error (RMSE), were of 0.07–0.18 m. A novel application of radar altimetry is the prediction of ice bridge road operations, which is demonstrated herein. We established that the dates of ferry closing and ice road opening and closing in the city of Salekhard can be predicted with an accuracy (expressed as RMSE) of 3–5 d.

“Is It Removed During Dialysis?”—Cognitive Dysfunction in Advanced Kidney Failure—A Review Article

Cognitive impairment is independently associated with kidney disease and increases in prevalence with declining kidney function. At the stage where kidney replacement therapy is required, with dialysis or transplantation, cognitive impairment is up to three times more common, and can present at a younger age. This is not a new phenomenon. The cognitive interactions of kidney disease are long recognized from historical accounts of uremic encephalopathy and so-called “dialysis dementia” to the more recent recognition of cognitive impairment in those undergoing kidney replacement therapy (KRT). The understanding of cognitive impairment as an extra-renal complication of kidney failure and effect of its treatments is a rapidly developing area of renal medicine. Multiple proposed mechanisms contribute to this burden. Advanced vascular aging, significant multi-morbidity, mood disorders, and sleep dysregulation are common in addition to the disease-specific effects of uremic toxins, chronic inflammation, and the effect of dialysis itself. The impact of cognitive impairment on people living with kidney disease is vast ranging from increased hospitalization and mortality to decreased quality of life and altered decision making. Assessment of cognition in patients attending for renal care could have benefits. However, in the context of a busy clinical service, a pragmatic approach to assessing cognitive function is necessary and requires consideration of the purpose of testing and resources available. Limited evidence exists to support treatments to mitigate the degree of cognitive impairment observed, but promising interventions include physical or cognitive exercise, alteration to the dialysis treatment and kidney transplantation. In this review we present the history of cognitive impairment in those with kidney failure, and the current understanding of the mechanisms, effects, and implications of impaired cognition. We provide a practical approach to clinical assessment and discuss evidence-supported treatments and future directions in this ever-expanding area which is pivotal to our patients' quality and quantity of life.

Diagnosis and treatment of flexibacteriosis of koi carp (Cyprinus carpio koi)

Ornamental fish farming is an intensively developing area in aquaculture. A significant volume of contraband products and the lack of sanitary and quarantine measures is an important problem associated with the development of this knowledge area. The article is devoted to the problem of timely detection and diagnosis of flexibacteriosis of carp, affecting one of the most popular and expensive objects of ornamental fish farming, koi carp. The main causes of fish diseases are natural outbreaks of infections and infection with pathogens from water sources, as well as violations of the rules of transportation and quarantine of imported fish. Timely and constant veterinary control makes it possible to assess the epizootic situation for fish diseases, the degree of pollution of the fishery reservoir and make recommendations for optimizing preventive measures that ensure the epizootic well-being of the fishery reservoir in the conditions of integrated technology. The cultivation of koi by amateurs in private ponds, aquariums poses a danger of introducing infections into other reservoirs, including natural ones, as well as regions where the outbreak has never been recorded. The main task is the prevention of diseases, which can be ensured by monitoring the water quality of the water supply source, as well as the use of a complex of veterinary and sanitary measures, including veterinary control over the transportation of fish, preventive quarantine of imported material and quarantine in dysfunctional farms, preventive disinfection and disinfection of structures, inventory, pond beds; regular ichthyopathological examination of the farm; preventive antiparasitic treatment of fish.

STUDY OF CHRONIC TOXICITY PARAMETERS OF A DRUG WITH HEPATOPROTECTIVE ACTIVITY

Currently, the most promising and developing area in the field of veterinary pharmacology is the method of obtaining and using an innovative dosage form such as phytosomes. The article presents the results of studies to determine the chronic toxicity of a phytosomal complex with hepatoprotective activity, including silymarin, dihydroquercetin and lecithin. It was determined that its application to laboratory nonlinear rats for sixty days at doses of 150, 75 and 30 mg per animal does not have a negative effect on the organism of rats and the biochemical parameters of their blood. The preservation index in all groups was 100%. The phytosomal complex stimulates body weight gains in animals, with a difference relative to control analogs – 24.2% (group 1), 22.3% (group 2) and 8.1% (group 3). Its long-term use improves the indicators of protein and lipid metabolism, as well as the functional state of the liver within the reference values. Autopsy of laboratory animals showed no signs of intoxication. Thus, long-term use of the phytosomal complex is harmless to warm-blooded animals.

The Development of African History as a Discipline in the English-Speaking World: a Study of Academic Infrastructure

<p>This thesis examines the infrastructure behind the academic discipline of African History. By looking at government reports, a selection of reflective essays and memoirs written by key historians, and the key precolonial sources that have driven select studies, my thesis explains how African History emerged in British and U.S. universities. Key factors include the English colonisation of Sierra Leone in 1787, the affiliation of Fourah Bay College with the University of Durham in 1876, and the creation of universities in 1948 in Nigeria, Sudan, Uganda and Ghana. In Britain, the importance of African territories resulted in a series of influential reports that shifted missionary controlled education on the African continent to colonial government control. After 1945 a series of pivotal government reports established the impetus and funding for the academic institutionalisation of African History in the United Kingdom. The influence of an English academic recognition of African History provided a transnational current of ideas that flowed between Africa and the United Kingdom, and from there to the United States. With the advent of the Cold War the United States recognised the importance of developing Area Studies programmes, including African Studies, and during the 1960s and 1970s became world leaders in the field. Crucial to this development was the role of pioneering historians who travelled to Africa to teach and research, and who then returned to train a new generation of Africanists. Africanist scholars, recognising the importance of African agency, expanded the shape of the discipline through investigation of oral sources and reexamination of extant pre1800 European written records. 'Charter historians' established university programmes that would produce scholars with the necessary skills required to sustain the new discipline. The infrastructure that undergirded and positioned African History in the mainstream of academia is analysed indepth, and is, as such, the central theme of this thesis.</p>