scholarly journals Test for Detection of Weak Graphic Passwords in Passpoint Based on the Mean Distance between Points

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 777
Author(s):  
Joaquín Alberto Herrera-Macías ◽  
Carlos Miguel Legón-Pérez ◽  
Lisset Suárez-Plasencia ◽  
Luis Ramiro Piñeiro-Díaz ◽  
Omar Rojas ◽  
...  

This work demonstrates the ineffectiveness of the Ripley’s K function tests, the distance to the nearest neighbor, and the empty space function in the Graphical Authentication scenario with Passpoint for the detection of non-random graphical passwords. The results obtained show that none of these tests effectively detect non-random graphical passwords; the reason for their failure is attributed to the small sample of the spatial pattern in question, where only the five points of the graphical password are analyzed. Consequently, a test based on mean distances is proposed, whose experiments show that it detects with good efficiency non-random graphical passwords in Passpoint. The test was designed to be included in the Graphical Authentication systems with Passpoint to warn the user about a possibly weak password during the registration phase, and in this way, the security of the system is increased.

Author(s):  
Phawis Thammasorn ◽  
Wanpracha A. Chaovalitwongse ◽  
Daniel S. Hippe ◽  
Landon S. Wootton ◽  
Eric C. Ford ◽  
...  

2013 ◽  
Vol 6 (2) ◽  
pp. 310-319 ◽  
Author(s):  
Wanying Zhao ◽  
Charles Goebel ◽  
John Cardina

AbstractPrivet has escaped from cultivation and is invading natural areas throughout eastern North America. Understanding the pattern of invasion over time could help us develop more efficient management strategies. We studied the invasion history and spatial distribution pattern of privet by mapping age and spatial data for established patches in a 132-ha (326 ac) forested natural area in northeast Ohio. We determined the age of 331 geo-referenced patches by counting annual rings, and mapped them with corresponding land habitat. Age distribution and cumulative number of privet patches over about 40 yr showed three phases of invasion. The initial 19-yr lag phase was characterized as a dispersed spatial pattern (based on nearest neighbor analysis), with patches located mostly at edges of different habitats and open places. In a second phase of about 15 yr, an average of 19 patches were initiated yearly, in a pattern that trended towards clustered. The final phase began around 2007, as the rate of new patch establishment declined, possibly because of saturation of the suitable habitat. Establishment of new patches was not associated with specific habitats. Aggregation of patches with similar ages increased after 1998 and became significantly clustered. Mapping of clusters of old and young patches identified invasion hot spots and barriers. Results affirmed that the best time for invasive control is during the lag phase. By monitoring edge habitats associated with early establishment, managers might detect and control early invaders and delay the onset of the expansion phase.


1989 ◽  
Vol 38 (1-2) ◽  
pp. 65-69 ◽  
Author(s):  
Yoko Imaizumi

AbstractNation-wide data in Japan on births and prenatal deaths of 16 sets of quintuplets during 1974-1985 were analysed. Among the 16 sets, 3 sets were liveborn, 8 were stillborn, and 5 were mixed, with a stillbirth rate of 0.64 (51/80). Effects of sex, maternal age and birth order on the stillbirth rate were not considered because of the small sample size. Effects of gestational age and birthweight on stillbirth rate were also examined. The mean weight of the 40 quintuplet individuals was 1,048 g.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Bui Duc Tinh ◽  
Nguyen Quang Hoc ◽  
Dinh Quang Vinh ◽  
Tran Dinh Cuong ◽  
Nguyen Duc Hien

The analytic expressions for the thermodynamic and elastic quantities such as the mean nearest neighbor distance, the free energy, the isothermal compressibility, the thermal expansion coefficient, the heat capacities at constant volume and at constant pressure, the Young modulus, the bulk modulus, the rigidity modulus, and the elastic constants of binary interstitial alloy with body-centered cubic (BCC) structure, and the small concentration of interstitial atoms (below 5%) are derived by the statistical moment method. The theoretical results are applied to interstitial alloy FeC in the interval of temperature from 100 to 1000 K and in the interval of interstitial atom concentration from 0 to 5%. In special cases, we obtain the thermodynamic quantities of main metal Fe with BCC structure. Our calculated results for some thermodynamic and elastic quantities of main metal Fe and alloy FeC are compared with experiments.


2011 ◽  
Vol 25 (12n13) ◽  
pp. 1041-1051 ◽  
Author(s):  
HO KHAC HIEU ◽  
VU VAN HUNG

Using the statistical moment method (SMM), the temperature and pressure dependences of thermodynamic quantities of zinc-blende-type semiconductors have been investigated. The analytical expressions of the nearest-neighbor distances, the change of volumes and the mean-square atomic displacements (MSDs) have been derived. Numerical calculations have been performed for a series of zinc-blende-type semiconductors: GaAs , GaP , GaSb , InAs , InP and InSb . The agreement between our calculations and both earlier other theoretical results and experimental data is a support for our new theory in investigating the temperature and pressure dependences of thermodynamic quantities of semiconductors.


2014 ◽  
Author(s):  
Kolea Zimmerman ◽  
Daniel Levitis ◽  
Ethan Addicott ◽  
Anne Pringle

We present a novel algorithm for the design of crossing experiments. The algorithm identifies a set of individuals (a ?crossing-set?) from a larger pool of potential crossing-sets by maximizing the diversity of traits of interest, for example, maximizing the range of genetic and geographic distances between individuals included in the crossing-set. To calculate diversity, we use the mean nearest neighbor distance of crosses plotted in trait space. We implement our algorithm on a real dataset ofNeurospora crassastrains, using the genetic and geographic distances between potential crosses as a two-dimensional trait space. In simulated mating experiments, crossing-sets selected by our algorithm provide better estimates of underlying parameter values than randomly chosen crossing-sets.


2020 ◽  
Author(s):  
Guilang Zheng ◽  
Chuxing Xie ◽  
Dongli Liu ◽  
Guojing Ye ◽  
Xiaoqian Chen ◽  
...  

Abstract Background: The number of coronavirus disease 2019 (COVID-19) cases caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has significantly increased, and the disease is rapidly spreading to all parts of the country and around the world. A retrospective study of children with SARS-CoV-2 provides a reference for the diagnosis and treatment of children during this epidemic.Methods: We retrospectively studied 12 cases of children with viral infection caused by SARS-CoV-2 admitted to 6 hospitals in Guangdong Province between January 25, 2020, and February 12, 2020, and analyzed the clinical features and outcomes of the patients.Results: A total of 12 children with SARS-CoV-2 infection from 6 hospitals were enrolled in the study; 6 were boys. The mean age was 9.8 ± 4.7 years, with a minimum age of 2 years and 10 months. The mean body weight was 37.3 ± 23.6 kg, with a minimum body weight of 13.0 kg. There were no severe cases or critical severe cases. There were 2 cases of mild pneumonia (16.7%), 7 cases of acute upper respiratory tract infection (58.3%), and 3 cases of latent infection (25.0%). In terms of symptoms, there were 7 cases of fever (58.3%), 5 cases of cough (41.7%), 3 cases of runny nose (25.0%), 2 cases of systemic fatigue and soreness (16.7%), and 4 cases of no symptoms (33.3%). Three patients (75.0%) showed decreased white blood cell (WBC) counts for their first complete blood count (CBC) after admission, and one patient (8.3%) had a low lymphocyte count. There were no obvious abnormalities in C-reactive protein (CRP, 1.53 ± 2.28 mg/l), procalcitonin (PCT, 0.21 ± 0.13 ng/ml), or coagulation function. No abnormalities were detected for creatine kinase (CK), creatine kinase-MB (CKMB), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and serum creatinine (Scr). Six cases (50.0%) were positive for Mycoplasma pneumoniae antibodies. 2 cases showed pulmonary exudative lesions on chest X-ray or computed tomography (CT). All children tested positive for SARS-CoV-2 by real-time reverse-transcription–polymerase-chain-reaction (RT-PCR) assays of throat swabs. 9 patients received antiviral treatment with lopinavir/ritonavir. All patients received symptomatic supportive treatment and were quarantined, and their conditions improved. There was no respiratory failure, acute respiratory distress syndrome, shock complications, or death observed for any case. All patients recovered and were discharged, with an average length of hospital stay of 14 days.Conclusions: This study with a small sample size suggests that all SARS-CoV-2-infected children had normal or reduced WBCs; however, fever was not as common as expected, and a decrease in lymphocyte count was rare. The clinical manifestations of SARS-CoV-2 infection in children are mild, COVID⁃19 is rare, and the prognosis is good. But the presence of latent SARS-CoV-2 infection in children presents new challenges for effective clinical prevention and control.


2021 ◽  
Vol 6 (2) ◽  
pp. 385-400
Author(s):  
Lia Warlina ◽  
Lusia Elsa Dika Damayanty

This study aims to identify the expansion and spatial patterns of shopping and tourism services facilities and evaluate whether the locations are aligned with the spatial plan map of the North Bandung region. The research was conducted by taking inventory of shopping and tourism services facilities in 2010, 2012, 2014, 2016, and 2018. The locations were plotted into maps to calculate each point's spatial pattern for each period using the nearest neighbor analysis method. The 2018 map was overlaid with a spatial plan map to identify whether the existing location aligns with the regional plan. The first results were the expansion and spatial pattern maps of shopping North Bandung area for 2010, 2012, 2014, 2016, and 2018; that show the broadest expansion of shopping facility in 2018 with a clustered pattern. The second results were expansion, and spatial pattern maps of tourism service facilities in the same period show that since 2014 the expansion started with clustered patterns. The evaluation results show that only convenience stores were located in protected areas, but all tourist service facilities were located in these locations. This finding is essential for local governments in monitoring spatial use.


2019 ◽  
Vol 1 (1) ◽  
pp. 30-39
Author(s):  
Yila Caiaphas Makadi ◽  
Abecca Stephen Sati ◽  
Ismail Dankaka

The paper reviews research tradition of accessibility level and spatial distribution of student in public secondary school in gombe local government area, Gombe state. Primary and secondary data were used for the study. Primary data was collected using questionnaire and a hand-held GPS receiver to capture the coordinate points of schools and other relevant data. Secondary data include administrative map, population figures of both students and Teachers, Names and addresses of the secondary schools in the study area. The data were analyzed using geographic information techniques. From the data survey carried out, the result of the analysis showed the accessibility level and spatial distribution of school in Gombe were seventeen (17) public senior secondary and total number of students were nineteen thousand and eleven (19,011). The nearest neighbor analysis (NNA) for the spatial pattern of school were carried out based on each ward in study area which as ten (10) wards in each ward revealed two major spatial distributions. The spatial pattern of the Gombe LGA has Nearest Neighbour Ratio (NNR): 3.385087, Bolari East ward with NNR: 3.385087 and Shamaki wards NNR: 1.600148, which showed dispersed pattern, while Jekada Fari ward with NNR: 0.214890, Pantami ward with NNR: 0.226863, and Herwo Gana wards with NNR: 0.185239, were showed clustered pattern. The nearest neighbor index shows clustered pattern for all the wards in the local government area except Bolari East and Shamaki wards that has dispersed pattern of distribution. The implication of these two patterns means that accessibility is poor in the study area. Students travel than normal to overcome the function of distance.


Author(s):  
Jamileh Fatahi ◽  
Maryam Amiri Jahromi ◽  
Fahimeh Hajiabolhassan ◽  
Amirsalar Jafarpisheh ◽  
Nariman Rahbar ◽  
...  

Background and Aim: The quick speech in noise (Q-SIN) test shows the difficulty of spee­ch perception in noise by specifying signal to noise ratio (SNR) loss. Although the Persian version of Q-SIN has been already constructed, the high-frequency emphasis version of this test is not available. The present study aimed to construct six lists with high-frequency emphasis and implement it. Methods: We are going to prepare a high-frequ­ency emphasis version of Q-SIN and then test it on a small sample. First, researchers designed the relevant sentences; then experts examined their content and face validity. According to the criteria for developing the Q-SIN test, six lists with high-frequency emphasis were prepared. The test was examined on 26 (13 male and 13 female), 18−35 years old individuals with nor­mal hearing. To determine the test reliability, it was re-administered three weeks later with the same conditions. Results: Of 76 sentences prepared, 36 sentences received enough credit after determination of their content and face validity. These 36 senten­ces were used to make 6 lists. The mean value of SNR50 in the Persian language was obtained -4 dB. The mean values of SNR loss in 6 lists were -1.65, -1.8, -2.23, -1.61, -2.38 and -2.07. The results showed equivalency of lists 1, 2, 3, 4, and 6. Examination of test-retest reliability indicated that all lists except the list 2were reliable. Conclusion: The lists of 1, 3, 4, and 6 are reli­able and equivalent and can be used in clinical application.


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