PROFILE OF STUDENTS' SPATIAL ABILITY IN SOLVING GEOMETRY PROBLEMS IN TERMS OF DAVID KEIRSEY'S PERSONALITY TYPES

This study aims to describe the ability of spatial geometry of class XI MIPA 1 SMA Negeri 2 Jember in terms of David Keirsey's personality type. Spatial ability in this study is the ability to understand the world of space based on elements of spatial abilities which include: spatial perception, mental rotation, and spatial visualization. This type of research is a descriptive study with a qualitative approach. The data collection method in this research is questionnaire, spatial test, and interview. Then, based on the results of the test and interview analysis, it was found that the Guardian students could fulfill all spatial indicators. Artisan students in imagining and rotating spaces can think quickly and answer questions correctly, compared to guardian and idealistic students. Idealistic students in the ability to see the surface of the unit cubic structure more than the point of view (from the front, right side, and top) cannot describe it precisely. Meanwhile, rational students on the mental rotation element for the first indicator are still unable to rotate a spatial shape and can imagine the rotation or rotation of a spatial shape accurately.

Assessment of stress state and dynamic characteristics of plane and spatial structure

This study is devoted to the assessment of the stress state and dynamic characteristics of various structures. The actual task at the design stage is to determine the parameters of a structure. In this article, a mathematical model was developed for assessing the stress state and dynamic characteristics of plane and spatial structures based on the Lagrange variational equation using the d’Alembert principle. The variational problem for the structures considered by the finite element method leads to the solution of nonhomogeneous algebraic equations or to the solution of algebraic eigenvalue problems. To assess the adequacy of the model and the accuracy of the numerical results obtained, a plane and spatial test problem with an exact solution was solved. Using the proposed model, the eigenfrequencies and modes of oscillations of the gravitational and earth dams (296 m high) of the Nurek reservoir were investigated. At that, it was revealed that in the natural modes of vibration of earth dams, the greatest displacements under low frequencies are observed at the crest part or at the middle of the slopes.

CALIBRATION OF NON-METRIC UAV CAMERA USING DIFFERENT TEST FIELDS

The paper deals with the calibration of a non-metric digital camera Nikon EOS 6D with a 50 mm lens that could be adapted as a potential UAV sensor for the purposes of aerial inspections. The determination of the internal orientation parameters and the image errors of the non-metric digital camera involved self-calibration with Agisoft Metashape software solving the network of the images obtained from different test fields: a chessboard field, a professional laboratory field and a spatially diverse research area. The results of the control measurement for the examined object distance of 6 meters do not differ significantly. The RMSE from the control measurement for the second analyzed object distance of 15 meters was calculated on the basis of the internal orientation elements. The images from the laboratory field, the spatial test area and the chessboard field were used, and the obtained results amounted to 7.9, 9.9 and 11.5 mm, respectively. The conducted studies showed that in the case of very precise photogrammetric measurements performed by means of the Nikon EOS 6D camera equipped with a 50 mm lens, it is optimal to conduct calibration in a laboratory test field. The greatest RMSE errors were recorded for the control images with the elements of the internal camera orientation calculated on the basis of the chessboard area. The results of the experiments clearly show a relation between the accuracy of the Nikon EOS 6D camera calibrations and the percentage of the frame area filled with the test field. This explains why the weakest calibration results were obtained from the chessboard test field.

Effects of Acute Sleep Deprivation on Working Memory Capacity in Undergraduate Students

Sleep is a necessary staple in our everyday lives but with advancements in society and an increase in day to day commitments it feels as though there is not enough time in the day. One of the first things to be forsaken in the hopes of maintaining a work schedule or routine is sleep. While the lack of sleep is disproportionate in most demographics, in university students in particular, a lack of sleep is a common, consistent, and necessary plague. Students can be under the impression that the effects of sleep deprivation have mostly long-term repercussions; however, prior literature has indicated that sleep deprivation impacts not just long-term consolidation but also significantly affects memory in the short-term, specifically the working memory (Xie et al. 2019; Chee et al., 2006). In this investigation, we seek to understand the effects that acute sleep deprivation has on the working memory capacity of individuals using a 2-back spatial test. A sample of convenience of upper-class undergraduate students was chosen and the participants were asked to take a specific 2-back spatial test - twice on a day that they subjectively felt as having a regular sleep schedule and twice on a day that they subjectively felt as having sleep deprivation. The team predicted that working memory 2-back task scores will be adversely affected by sleep deprivation. While there was a statistically significant difference in the working memory scores on the full sample level, this was not reflected on the individual level. This indicates that the effects of sleep deprivation are not generalizable to a full population and that they must be reviewed on a case-by-case basis. Furthermore, since greater variation was observed in the sleep deprived scores in all individuals, it implies that sleep deprivation may indirectly affect the consistency of working memory by affecting attention span and concentration.

STUDY OF DIGITAL CAMERA CALIBRATION ON A FLAT TEST OBJECT

The paper presents a method for calibration of digital cameras based on the use of a flat test object. The main distinctive feature of this method is that the camera is fixed and does not change its position in space. A series of images of a flat test object (for example, a chessboard) is taken at various distances and inclination of the test object. One should tilt the test object relative to the image plane in order to avoid ambiguity in solving the problem. All these images are measured separately, and processing is performed together, counting them as one image with common exterior orientation elements. Experimental studies have shown sufficient efficiency of such calibration, which is easily implemented and gives positive results in comparison with the classical calibration of the camera on a spatial test object. The results of experimental studies on real images have shown that proposed calibration method gives the comparable with conventional method accuracy. Thus, it is possible to use simple and cheap flat calibration test object instead of spatial one. To achieve the maximum result in camera calibration accuracy, use this method to tilt the chessboard at angles in the range of 30–40 degrees to the optical axis of the camera being calibrated.

Understanding modern kinetic isotope effect in Anjohibe cave, in Northwestern Madagascar: a key to calibrate speleothem δ18O and δ13C

<p>Madagascar, an island located ~300km off the eastern coast of Africa, is a natural laboratory to study paleoclimate and paleoenvironment. It holds a key position in the Indian Ocean and in Africa, as information from it has particularly helped fill gaps in paleoclimate reconstruction in the Southern Hemisphere, where such information is still scarce. Madagascar is seasonally visited by the Intertropical Convergence Zone (ITCZ) and experiences monsoon during austral summers. Furthermore, it hosts caves where speleothems can be found. Speleothems preserve a range of continuous geochemical records, mainly stable isotopes, that allow scientists to predict changes happening in the past.  In Madagascar, speleothem studies have revealed distinct early, mid, and late Holocene climatic regimes that were linked to the latitudinal migration of the ITCZ, and the monsoonal responses associated with the migration. Other speleothem studies revealed evidence of the African Humid Period, rapid climate changes, and most importantly the shift in δ<sup>13</sup>C<sub>c</sub> starting ca. AD 800, that was attributed to anthropogenic activities. Although information from these speleothems is unquestionably significant, there are still gaps in isotopic proxies interpretation, mainly in linking modern environments where these speleothems grew and the signals they preserve. Such modern information is however fundamental to calibrate paleo-based climate and environmental reconstructions in Madagascar, which could be a key to refine their past interpretation. In this study, we performed an in-cave spatial test to understand kinetic isotope effect in Anjohibe Cave and to define oxygen isotopic fractionation between speleothem carbonate and its parent water and carbon isotopic fractionation between speleothem carbonate and the corresponding dissolved inorganic carbon (DIC). Results have been compared with modern calibration studies on speleothems from other locations worldwide, and we found that our data fit within the empirical relationship for cave-specific CaCO<sub>3</sub>-H<sub>2</sub>O isotope fractionation, grouping a range of monitored caves worldwide, 1000 ln α = 16.1 (10<sup>3</sup>T<sup>-1</sup>(°K))–24.6 of Tremaine et al. (2011). Other physico-chemical parameters in Anjohibe Cave have also been measured, and they will be used to discuss potential linkages with the spatial variability in the  modern speleothem stable isotopic values and their corresponding parent water and DIC.</p><p><em>Tremaine, D.M., Froelich, P.N., Wang, Y., 2011. Speleothem calcite farmed in situ: Modern calibration of δ<sup>18</sup>O and δ<sup>13</sup>C paleoclimate proxies in a continuously-monitored natural cave system. Geochim Cosmochim Acta 75, 4929-4950.</em></p>

IMPROVING IMAGE MATCHING BY REDUCING SURFACE REFLECTIONS USING POLARISING FILTER TECHNIQUES

In dense stereo matching applications surface reflections may lead to incorrect measurements and blunders in the resulting point cloud. To overcome the problem of disturbing reflexions polarising filters can be mounted on the camera lens and light source. Reflections in the images can be suppressed by crossing the polarising direction of the filters leading to homogeneous illuminated images and better matching results.<br> However, the filter may influence the camera’s orientation parameters as well as the measuring accuracy. To quantify these effects, a calibration and an accuracy analysis is conducted within a spatial test arrangement according to the German guideline VDI/VDE 2634.1 (2002) using a DSLR with and without polarising filter. In a second test, the interior orientation is analysed in more detail. The results do not show significant changes of the measuring accuracy in object space and only very small changes of the interior orientation (&amp;Delta;c&amp;thinsp;&amp;leq;&amp;thinsp;4&amp;thinsp;&amp;mu;m) with the polarising filter in use.<br> Since in medical applications many tiny reflections are present and impede robust surface measurements, a prototypic trinocular endoscope is equipped with polarising technique. The interior and relative orientation is determined and analysed. The advantage of the polarising technique for medical image matching is shown in an experiment with a moistened pig kidney. The accuracy and completeness of the resulting point cloud can be improved clearly when using polarising filters. Furthermore, an accuracy analysis using a laser triangulation system is performed and the special reflection properties of metallic surfaces are presented.

Diagnostic relevance of spatial orientation for vascular dementia: A case study

ABSTRACT Spatial orientation is emerging as an early and reliable cognitive biomarker of Alzheimer’s disease (AD) pathophysiology. However, no evidence exists as to whether spatial orientation is also affected in vascular dementia (VaD). Objective: To examine allocentric (map-based) and egocentric (viewpoint-based) spatial orientation in an early stage VaD case. Methods: A spatial test battery was administered following clinical and neuropsychological cognitive evaluation. Results: Despite the patient’s complaints, little evidence of episodic memory deficits were detected when cueing was provided to overcome executive dysfunction. Similarly, medial temporal lobe-mediated allocentric orientation was intact. By contrast, medial parietal-mediated egocentric orientation was impaired, despite normal performance on standard visuospatial tasks. Conclusion: To our knowledge, this is the first in-depth investigation of spatial orientation deficits in VaD. Isolated egocentric deficits were observed. This differs from AD orientation deficits which encompass both allocentric and egocentric orientation deficits. A combination of egocentric orientation and executive function tests could serve as a promising cognitive marker for VaD pathophysiology.

Pemetaan Efek Spasial pada Data Kemiskinan Kota Bengkulu

Anti-poverty programs and policies are designed similar for all regions in Indonesia, disregarding the local socio-culture and the poverty spatial pattern of the regions. The approach is based on central government’s program and not based on each region’s locality. This generic programming approach caused the achievement of development goals decline. The effect of space on poverty can be identified by the presence of spatial autocorrelation, which is the link between the examined variable to itself in a spatial manner or commonly referred to as spatial dependence.The aim of this paper is to investigate the global and local spatial autocorrelation for micro poverty data set in Bengkulu City in order to identify spatial approach for its anti-poverty program. Global Moran Index (MI) tests identifies the overall occurrence of autocorrelation, meanwhile the local spatial test shows which subdistricts has the presence of autocorrelation. Global and local MI are popular tools utilized to calculate the spatial effect, particularly to present spatial dependencies. The relation between urban village linkages obtained an MI value of 0.322. This MI value indicates the presence of spatial autocorrelation for subdistricts located in cluster. In local spatial effect observation using Local Indicator of Spatial Autocorrelation (LISA), its discovered that there are several subdistricts having autocorrelation, meanwhile the rest are not significant. Cluster mapping on global MI and LISA shows high-high poverty districts are located in the south of the city, low-high poverty districts in the east, and low-low high-low poverty districts near the city center.