Comparative Analysis of Classic Clustering Algorithms and Girvan-Newman Algorithm for Finding Communities in Social Networks

Nowadays finding patterns in large social network datasets is a growing challenge and an important subject of interest. One of current problems in this field is identifying clusters within social networks with large number of nodes. Social network clusters are not necessarily disjoint sets; rather they may overlap and have common nodes, in which case it is more appropriate to designate them as communities. Although many clustering algorithms handle small datasets well, they are usually extremely inefficient on large datasets. This paper shows comparative analysis of frequently used classic graph clustering algorithms and well-known Girvan-Newman algorithm that is used for identification of communities in graphs, which is especially optimized for large datasets. The goal of the paper is to show which of the algorithms give best performances on given dataset. The paper presents real problem of data clustering, algorithms that can be used for its solution, methodology of analysis, results that were achieved and conclusions that were derived. This work is licensed under a&nbsp;Creative Commons Attribution-NonCommercial 4.0 International License.</p

Comparative Analysis of Classic Clustering Algorithms and Girvan-Newman Algorithm for Finding Communities in Social Networks

Nowadays finding patterns in large social network datasets is a growing challenge and an important subject of interest. One of current problems in this field is identifying clusters within social networks with large number of nodes. Social network clusters are not necessarily disjoint sets; rather they may overlap and have common nodes, in which case it is more appropriate to designate them as communities. Although many clustering algorithms handle small datasets well, they are usually extremely inefficient on large datasets. This paper shows comparative analysis of frequently used classic graph clustering algorithms and well-known Girvan-Newman algorithm that is used for identification of communities in graphs, which is especially optimized for large datasets. The goal of the paper is to show which of the algorithms give best performances on given dataset. The paper presents real problem of data clustering, algorithms that can be used for its solution, methodology of analysis, results that were achieved and conclusions that were derived. This work is licensed under a&nbsp;Creative Commons Attribution-NonCommercial 4.0 International License.</p

Hip-hop from dancers’ viewpoint: Dance, lifestyle, and/or subculture?

The paper presents the results of field research on the population of dancers – members of the hip-hop community who are “contestants” in battles. The field research was carried out in April 2022 on a sample of dancers aged 17 to 40 (N = 31). The research results indicate that the hip-hop community in Serbia is small, but that such battles in specific forms contribute to the community’s maintenance and expansion. Battles also play a significant role in the progression and expression of dancers as individuals. Dancers consider hip-hop to be not only an art form but much more, hip-hop is synonymous with a lifestyle and a “way of looking at the world” for dancers. Although the research was carried out on a small sample, it represents the author’s pioneering contribution to a deeper understanding of the hip-hop community in Serbian society. It also indicates the need to carry out compatible research in the future

Primjena polutrajnih i konvencionalnih cemenata s modificiranom tehnikom cementiranja u dentalnoj implantologiji

Objectives: The aim of this study was to evaluate the influence of artificial ageing on the retention force of original semipermanent cements, as well as the possibility of using conventional cements for semipermanent cementation with adequate modification of the cementing protocol. Material and methods: Forty CoCrMo alloy crowns were divided in four groups (each group n=10) and fixed with two semipermanent cements (resin-based and glass ionomer-based cements) and one conventional (zinc phosphate), using conventional and modified cementation techniques on titanium abutments. The samples were stored in humid conditions for 24 hours at 37°C and subjected to thermocycling (500 cycles) and mechanical cyclic loading (7 days, 3, 6, 9 and 12 months function simulation). The cast crowns were removed and the retention force was recorded. Results: The highest initial retention force measured was for zinc-phosphate cement - conventional cementing (198,00±61,90 N), followed in descending order by zinc-phosphate cement - modified cementing technique (152,00±45,42 N), long term temporary cement – GC Fuji Temp LT (57,70±20,40 N), and semipermanent cement - Te-lio CS Cem Implant (56,10±18,68 N). After 12 months, the highest retention force measured was for zinc-phosphate cement - conventional cementing (88, 90±14, 45 N), followed by zinc-phosphate cement – modified cementing (48, 15±14,41N), semipermanent cement GC Fuji Temp LT (16,55±3,88 N) and Telio CS Cem Implant (15,55±5,52 N). Conclusions: Zinc-phosphate cement - modified cementing technique and original semipermanent cements can be recommended for conditional permanent cementing of implant supported crowns. Clinical relevance: The use of semipermanent cements and zinc-phosphate cement - modified cementing technique provides a predictable retrievability of implant-supported crowns.Cilj: Željelo se ispitati kakav je utjecaj umjetnoga starenja na retencijsku silu originalnih (polutrajnih) semipermanentnih cemenata i mogućnost upotrebe konvencionalnih cemenata za polutrajno pričvršćivanje, uz odgovarajuću prilagodbu protokola cementiranja. Materijal i metode: U četiri skupine raspoređeno je 40 krunica izrađenih od Co-Cr-Mo legure (svaka skupina n = 10) i fiksiranih dvama polutrajnim cementima (cementi na bazi smola i staklenoionomera) i jednim konvencionalnim (cink-fosfatni cement), učvršćene konvencionalnom i prilagođenom tehnikom cementiranja na titanijevim nadogradnjama (engl. abutment). Uzorci su bili 24 sata pohranjeni u vlažnim uvjetima na temperaturi od 37 °C nakon čega su podvrgnuti termocikliranju (500 ciklusa) i mehaničkim cikličnim opterećenjima (simulacija 7 dana, 1, 3, 6, 9 i 12 mjeseci u funkciji). Krunice su uklonjene i zabilježena je retencijska sila. Rezultati: Najvišu inicijalnu retencijsku silu pokazao je cink-fosfatni cement – konvencionalno cementiranje (198,00 ± 61,90 N), a slijede ga u silaznom nizu cink-fosfatni cement – prilagođena tehnika cementiranja (152,00 ± 45,42 N), dugotrajni privremeni cement – GC Fuji LT (57,70 ± 20,40 N) i semipermanentni cement Telio CS (56,10 ± 18,68 N). Poslije 12 mjeseci najviša retencijska sila izmjerena je za cink-fosfatni cement – konvencionalno cementiranje (88, 90 ± 14,45 N), a slijede cink-fosfatni cement – prilagođena tehnika cementiranja (48,15 ± 14,41 N) te semipermanentni cementi GC Fuji Temp LT (16,55 ± 3,88 N) i Telio CS Cem Implant (15,55 ± 5,52 N). Zaključak: Cink-fosfatni cement – prilagođena tehnika cementiranja i originalni polutrajni cementi (semipermanentni) mogu se preporučiti za uvjetno trajno cementiranje krunica postavljenih na implantate jer omogućuje optimalnu mogućnost uklanjanja krunica postavljenih na implantate

Application of the Schroth Method in the Treatment of Idiopathic Scoliosis: A Systematic Review and Meta-Analysis

Background: Idiopathic scoliosis can be defined as a complex three-dimensional deformity of the spine and trunk, which occurs in basically healthy children. Schroth scoliosis-specific exercises have shown good results in reducing idiopathic scoliosis progression. This study aimed to critically evaluate the effect size of Schroth’s method through a systematic review and meta-analysis. Methods: Four databases were included in the search: PubMed, Cochrane Library, Web of Science, and Google Scholar. The following keywords were used: “Schroth exercise”, “idiopathic scoliosis”, “Cobb angle”, “angle of trunk rotation”, and “quality of life”. Only articles written in English that met the following criteria were included in our study: subjects who had idiopathic scoliosis, the Schroth method was applied, and Cobb angle or angle of trunk rotation or quality of life as outcomes. Results: Ten randomized controlled trials were included in this study. The effect size of the Schroth exercise ranged from almost moderate to large, for the outcomes used: Cobb angle (ES = −0.492, p ˂ 0.005); ATR (ES = −0.471, p = 0.013); QoL (ES = 1.087, p ˂ 0.001). Conclusions: The current meta-analysis indicates that the Schroth method has a positive effect on subjects with idiopathic scoliosis

THE INCIDENCE OF POSTURAL DISORDERS WITH REGARD TO DEGREE OF NUTRITIONAL STATUS IN ADOLESCENTS

The aim of this research was to analyze postural disorders and nutritional status in adolescents, and to compare the incidence of postural disorders with regard to category of nutritional status and gender dimorphism. The sample of subjects comprised of 305 adolescents, 11 - 14 years old, of both gender (158 girls and 147 boys), students of the primary school from Vojvodina. Postural status was assessed by Napoleon Volanski method. Body mass index (BMI) was calculated by standard procedure. In establishment of differences in postural status, with regard to the age and the gender dimorphism, we used χ2 test. In order to establish differences in cumulative evaluation of postural status, we applied rank-sum Mann-Whitney Z-test. In establishment of differences in groups of subjects formed on the basis of degree of nutritional status, we applied Kruskall-Wollis test. The survey results show a statistically significant difference acording to the gender, in subjects aged 13 to 14 years, and a significant positive correlation of these two indicators

Odnos posturalnog statusa stopala i eksplozivne snage nogu adolescenata / Relation Between the Postural Feet Status and Explosive Strength of Lower Extremities in Adolescents

The aim of this study was to determine the differences in the manifestation of explosive strength of legs and pelvis girdle regarding the degree of drooping medial arch of the feet and also according to gender differences. The research covered 90 respondents (45 males and 45 females), from the Secondary School Economics in Novi Sad, aged 15 ± 0.5. The status of the foot arch was determined by using the clinical method, and the explosive strength by motoric tests of standing long jump and triple jump. For identifying the differences, One-Factor Analysis of Variance was used, χ2 - test and Student t - test for independent samples, at the final degree of p≤0.00. Statistically significant differences were identified between the respondents with good and extremely poor foot status (p≤0.00) and the respondents with poor foot status (p≤0.000). Also, when it comes to gender, there were statistically significant differences in foot arch status and both motor tests (χ2=9.867; p≤0.007)

Real-time thermographic analysis of low-density bone during implant placement: a randomized parallel-group clinical study comparing lateral condensation with bone drilling surgical technique

Objectives: To compare the effect of two surgical techniques, lateral condensation and bone drilling, on changes in temperature of the adjacent low-density bone during implant placement into posterior maxilla and to investigate the influence of the host factors - age, gender, region of implantation, bone density, and thickness of the cortical bone at the recipient sites. Material and methods: Local bone temperature was measured thermographically during implant placement into posterior maxilla following lateral bone condensing (test group) or bone drilling (controls). The main study outcomes were baseline bone temperature prior to implantation and maximum bone temperature recorded during implantation. Early implant success was evaluated after 6 months of healing. Results: A total of 40 implants were randomly allocated to test and control groups and placed into maxillary premolar and/or molar region of 18 participants of both genders and average age of 51.74 years. All recorded bone temperatures were below the threshold for thermal necrosis. Although both groups showed significant increase in bone temperature during implant placement procedure (P lt = 0.0005), it was significantly higher for bone condensing compared with drilling (P lt = 0.0005; 3.79 +/- 1.54 degrees C; 1.91 +/- 0.70 degrees C respectively). No host factor was singled out as a significant predictor of bone temperature changes, although trend of higher increase was observed in young patients, regardless of gender, during implant placement procedure into maxillary first premolar region with bone density type 3 and cortical layer thicker than 1 mm. Early implant success rate after 6 months follow-up was 100%. Conclusion: Although both surgical techniques, bone condensing and bone drilling, can be considered safe regarding their thermal effect on the bone of posterior maxilla, bone drilling is associated with fewer local bone heating during implantation. Host factors do not affect the bone thermal changes significantly

An in vitro study of temperature changes in type 4 bone during implant placement: bone condensing versus bone drilling

Objective. The aim of this study was to compare changes in temperature of the surrounding bone at various osteotomy depths during implant site preparation by bone condensing and by bone drilling as well as the dynamics of their change. Study design. In the present "in vitro" study, pig ribs with uniform thickness of cortical bone of 2 mm were used. Lateral bone-condensing (experimental group) and bone-drilling techniques (control group) were performed. Temperature changes were recorded at a distance of 0.5 mm from the final test osteotomy by 3 thermocouples at the depths of 1, 5, and 10 mm in tripod configuration. Data were collected from 48 measurements, 24 for each group. Results. Significantly higher mean temperature increase at the depth of 5 mm was observed during bone drilling compared with bone condensing, whereas for the depths of 1 and 10 mm differences were not significant between the 2 surgical techniques. During bone condensing, the mean temperature rise was continuously decreasing with increasing depth of osteotomies, whereas during bone drilling the mean temperature rise was first increased and reached a peak at the depth of 5 mm and then began to decrease with increasing depth of the osteotomies. Conclusions. The bone-condensing technique applied in the jaw bone class D4 offers an advantage over bone drilling because it generates a significantly smaller amount of heat. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 112: 28-33

A 1-Year Prospective Clinical and Radiographic Study of Early-Loaded Bone Level Implants in the Posterior Maxilla

PurposesThe primary aim of the study was to investigate a 1-year success rate of early-loaded bone level implants with a chemically modified sand-blasted, large grit, acid-etched surface (SLActive (R), Institut Straumann AG, Basel, Switzerland) in the posterior maxilla. Secondary objectives included stability of these implants and peri-implant bone level. Materials and MethodsBone level (R) implants (Institut Straumann AG) inserted into premolar and/or molar maxillary sites were loaded after 6 weeks of healing. The implants were monitored for 1 year using the following outcome measures: implant success, primary and secondary stability, and peri-implant bone level. ResultsOut of 37 implants placed in 13 patients, 36 reached sufficient stability and were early loaded, whereas one underwent a delayed loading protocol. One-year success rate of early-loaded implants was 100%. Implant stability at baseline was 71.75. 6 to be steadily increased thereafter up to 1 year (80.3 +/- 3.3), except at 2 weeks when a nonsignificant decrease was noticed (71.9 +/- 3.9). Continuous and significant bone loss was observed, reaching 0.4 +/- 0.1mm in the first postoperative year. ConclusionBone level implants with the SLActive surface placed into low-density bone and loaded after 6 weeks of healing can predictably achieve and maintain a successful tissue integration