Space filling curves (SFCs) are widely used in the design of indexes for spatial and temporal data. Clustering is a key metric for an SFC, that measures how well the curve preserves locality in moving from higher dimensions to a single dimension. We present the onion curve, an SFC whose clustering performance is provably close to optimal for cube and nearcube shaped query sets, irrespective of ...

equitable distribution of health system resources has been a serious challenge for long ago among the health policy makers. conducted studies have mostly ever had emphasis on equality rather than equity. in this paper we have attempted to examine both equality and equity in resources distribution.this is an applied and descriptive study in which we plotted lorenz and concentration curves to des...

background: one of the important aspects of equity in health is equality in the distribution of resources in this sector. the present study aimed to assess the distribution of hospital beds in shiraz in 2014.   methods: in this retrospective cross-sectional study, the population density index and fair distribution of beds were analyzed by lorenz curve and gini coefficient, respectively. descrip...

background: carpet weaving is an occupation that requires sufficient and appropriate lighting. the lighting in carpet weaving workshops affects the productivity and the physical and mental health of workers. therefore, the evaluation of the illumination and the identification of work stations requiring lighting modifications will be helpful in promotion of the health and safety of workers in ca...

in this paper, we study spacelike dual biharmonic curves. we characterize spacelike dual biharmonic curves in terms of their curvature and torsion in the lorentzian dual heisenberg group . we give necessary and sufficient conditions for spacelike dual biharmonic curves in the lorentzian dual heisenberg group . therefore, we prove that all spacelike dual biharmonic curves are spacelike dual heli...

background: gastric cancer is the fourth common malignancy and the second prevalent cause of cancer death in the world. genetic and environmental factors play an important role in the development of this cancer. nutritional and epidemiological studies have indicated that folate status modulates the risk of developing cancer and apoptosis has been reported to play a decisive role in precancerous...

background: reference percentile curves are usually used as a screening tool to determine growth disorders. anthropometric indices are population-dependent and may differ according to ethnicity, dietary pattern and lifestyle habits. this study aims to compare the curves of anthropometric measures obtained in two national studies conducted among iranian children and adolescents in 2003-2004 and ...

objective: to determine the diagnostic value of blood cells surface markers in patients with acute appendicitis. methods: in this cross-sectional study, 71 patients who underwent appendectomy following a diagnosis of appendicitis were recruited during a one-year period. the patients were divided into two groups: patients with histopathologically confirmed acute appendicitis and subjects with no...

background: lymphocyte-dicentric assay is the most generally accepted method for biological dosimetry of overexposed individuals. in this study, the frequency of unstable chromosome aberration in blood lymphocytes was used to estimate radiation dose received by individuals. evaluation of dose using a calibration curve produced elsewhere may have a significant uncertainty therefore, experiments ...

proton exchange membrane fuel cells (pemfcs) with a dead-ended anode and cathode can obtain high hydrogen and oxygen utilization by a comparatively simple system. nevertheless, the accumulation of the water in the anode and cathode channels might cause a local fuel starvation degrading the performance and durability of pemfcs. in this study, a brand new design for a polymer electrolyte membrane...