Box Grid Research Articles

PENGGUNAAN ALGORITMA GEOSHASHING DALAM PENCARIAN LETAK INFORMASI GEOGRAFIS PENGGANTI KOOORDINAT LATITUDE DAN LONGITUDE

In the digital age when the search for geographic data is becoming increasingly important in location applications, including mapping, navigation, and analysis of the environment of a place within a location. Geohashing algorithms offer an efficient approach to encoding and storing geographic data in string format, these strings use alphanumeric generated by geohashing of numbers and letters in the search for location points by coordinates, it can also offer an access layer of sensitive location data. This study aims to explore the application of geohashing algorithms in geographic data management. Geohashing algorithm in the search for the location of geographic information as an alternative to latitude and longitude coordinates. In particular, this study analyzes the efficiency of geohashing in data compression, the localization accuracy of geohashing use allows for better grouping of geographic data, and supports spatial data search such as location search and coordinate point search within a specific region. Geohashing algorithms are implemented in geographic data and tested for various search scenarios. From the results of the study showing that geohashing can significantly increase the speed of searching for geographic information, the geohashing algorithm proves its action as an effective tool in the management and search of geographic data, in the search for location coordinate data, it can also provide an alternative to get the latitude and longitude of a location. The results show that geohashing can significantly increase the speed of searching for geographic information, especially in reaching a location with a small and large data box grid level according to the entered string characters. The use of geohashing not only improves the efficiency and speed of searches but also provides additional benefits in terms of the management and protection of geographic data. Testing on this system is carried out by providing geographic access to the location application API that has been created on demand to obtain geographic data information and location points.

A Photogrammetry-Assisted Methodology for the Documentation of Complex Stratigraphic Relationships

ABSTRACTAt Tell Yunatsite, a prehistoric settlement mound located in the Upper Thracian plain of Bulgaria, stratigraphic relationships between archaeological deposits are incredibly complex. Such complexity then prompted our exploration into developing a new methodology for the documentation of complex stratigraphic relationships. Here, we present the results of a new photogrammetry-assisted methodology that was developed to compensate for the shortcomings of currently utilized stratigraphic documentation methods, such as the Wheeler-Kenyon box grid and the Harris Matrix. First, using a UAV drone, we produce a high-resolution photogrammetric model of the entire site. Second, with structure from motion photogrammetry, we produce 2.5D models of excavation units in stratigraphic succession. Finally, utilizing GIS and Blender (a 3D computer graphics software application), we digitize the horizontal extents of each archaeological deposit and “fill” the space between their successive surfaces (from top to bottom) until a faithful 3D model of each deposit is generated. These deposit models are then combined and rendered simultaneously to form 3D block models of the excavation units that may, in turn, be cross-sectioned in any direction to view stratigraphic relationships in virtual profile.

Eye spy: Gaze communication and deception during hide-and-seek

Gaze behaviour is an important component of successful social interactions. Existing research on social gaze and attention has largely focused on gaze detection and following, rather than the two-way communicative component of gaze that operates between individuals. The present study sought to address this in two experiments. First, “hiders” were eye-tracked while they selected hiding places among a grid of boxes on a computer screen; these boxes were either homogeneous or contained a visually unique pop-out item. Importantly, sometimes hiders believed that their gaze would be seen by hypothetical “seekers” who they might wish to deceive or communicate truthful information to; and sometime hiders believed that their gaze would be concealed. In a second experiment, seekers were asked to select the hiders' locations after viewing the hiders' gaze behaviour, including the eye movements that hiders had been (falsely) told would be concealed. Results indicate that seekers are most accurate when hiders use their gaze to truthfully communicate their selected locations and least accurate when hiders aim to deceive. Notably, both communication and interpretation strategies were affected by the visual display type (e.g., hiders looked to and preferentially selected pop-out items when communicating truthfully while seekers interpreted gaze differently when allocated to these pop-out items), indicating that the visual context can be integrated with gaze to facilitate mis/communication. Our study illuminates how the gaze of an individual acquires and signals information, and that individuals will spontaneously adjust the balance between these two functions based on their current goal and visual environment.

Lenticular burns following PASCAL photocoagulation.

Lenticular burns following PASCAL photocoagulation.

Using a Table Tennis Game, “Elemental Knock-Out”, To Increase Students’ Familiarity with Chemical Elements, Symbols, and Atomic Numbers

A motivating and fun activity for students in introductory chemistry has been designed to increase familiarity with the chemical elements, symbols, and atomic numbers in the periodic table. This activity, Elemental Knock-Out, is a table tennis game, and the gameplay is adapted from a box grid baseball game. Playing in teams for fun and enjoyment, students work cooperatively with others to compete against an opposing team. The game is designed for first-year undergraduate students. The cost of one set of game materials is less than $50. The average time required to complete one game, i.e., to become familiar with the chemical elements and atomic numbers, is about 120 min for a class of 60 students. This game was implemented with 118 students including different grade classes. The results were interpreted through poll and quiz before and after the activity. The results of the study revealed that most of the students had positive impressions of the game and considered it to be a fun way of interacting with t...

Radiographic location of the femoral footprint of the cranial cruciate ligament in dogs.

To describe the radiographic location of the center of the femoral footprint of the cranial cruciate ligament (CrCL) in dogs. Using femora from 49 adult, orthopedically sound dogs (bodyweight≥20 kg), a radiopaque marker was placed on the cranial border of the femoral footprint of the CrCL. Computed tomography and threedimensional (3D) reconstruction of each femur was performed subsequently, followed by manual segmentation of the footprint on the 3D models and calculation of its center. Finally, virtual digital radiographs in two planes were produced and the location of the calculated center of the CrCL was expressed using three different methods (4x4 box grid method and percentage position for the medio-lateral projection; o'clock position for the disto-proximal projection). In the medio-lateral radiographs the center of the femoral footprint was consistently located in the second rectangle from the top of the most caudal column of the 4x4 grid. The mean percentage caudo-cranial and proximo-distal location was 20.2% (±2.2) and 33.8% (±3.7), respectively. In the disto-proximal radiograph, the o'clock position of the CrCL center was between 2 and 3 o'clock in 97.6% of cases. The radiographic location of the center of the femoral footprint can be consistently predicted in medio-lateral and disto-proximal stifle radiographs of dogs over 20 kg. The reported data can be used to plan and verify the placement of the femoral tunnel opening for intra-articular anatomic CrCL repair.

Eighteenth International Istanbul Theatre Festival (review)

Reviewed by: Eighteenth International Istanbul Theatre Festival Amy E. Hughes Eighteenth International Istanbul Theatre Festival. Istanbul, Turkey. 10 May-5 June 2012. Turkish theatre today is on the verge of enormous change. Arguably, the current situation can be traced to April 2011, when a 31-year-old woman walked out of a play. The woman was Sümeyye Erdoǧan, the youngest daughter of Prime Minister Recep Tayyip Erdoǧan—the leader of the ruling Justice and Development Party (AKP), a neoliberal political organization whose conservative religiosity and attempts to suppress free speech have increasingly polarized Turkey over the past decade. At the performance in a state theatre in Ankara, an actor (who claimed not to have recognized her) allegedly mocked Sümeyye during an improvisational sequence; feeling insulted, she left. A year later, Istanbul mayor Kadir Topbaş (a protégé of Erdoǧan) instituted new rules regarding repertory selection for the city's municipal theatres, including an ambiguous mandate requiring that all plays reflect the "ethical values of the society." Angry resignations and vehement protests by artists and audiences followed, to no avail. The prime minister seized the opportunity to rail against Turkey's theatre-makers and spectators, characterizing them as arrogant elitist outliers. Even more distressingly, Erdoǧan threatened to terminate all governmental subsidies for state theatres. The eighteenth International Istanbul Theatre Festival (2012) opened shortly after this highly publicized debate over artistic expression and public funding. The festival program included almost forty productions by Turkish companies, as well as five shows from other countries. Istanbul Kültür Sanat Vakfı (Istanbul Foundation for Culture and Arts [IKSV]), one of Turkey's most important cultural organizations, organizes the biannual theatre festival, as well as festivals showcasing film, music, dance, design, and visual art (the internationally acclaimed Istanbul Biennial). The founder of the republic, Mustafa Kemal Atatürk, began supporting Western artistic practices as a way to modernize Turkey; since then, subsidized arts companies have provided opportunities for reflection and experimentation. In light of the uncertainty surrounding the future of theatre here, the festival's theme in 2012 ("Freedom-Questionings") seemed particularly relevant. Click for larger view View full resolution Members of Diyarbakır Şehir Tiyatrosu performing Antigone. (Photographer unknown.) The sense of uncertainty that permeated the festival was evident to me even during Samuel Beckett's Play, directed by Şahika Tekand under the aegis of Istanbul Şehir Tiyatroları (Istanbul Municipal Theatres). Tekand has attracted considerable attention internationally since founding her own company, Studio Oyunculari, in 1990. Her productions have been featured at prominent venues and festivals in Germany, Greece, and Japan, among other countries. Tekand's stunning, thoroughly engrossing rendition of Play (in Turkish translation) constituted her first project with Istanbul's municipal theatre. In Turkish, the word for a theatrical play is oyun, a homonym that can also mean "game" (similar to Spiel); Tekand consciously mined and explored this double entendre. As written, Play depicts three people—M, W1, and W2—interred in urns up to their necks. The members of this love triangle bitterly complain about the light, their lives, and one another. In Tekand's production, each actor (fifteen in all) inhabited one square of a massive grid of boxes that filled the stage. Although the actors could not see one another, their bodies were fully visible to the audience. During a fast and furious sixty minutes, [End Page 258] the musicality of Beckett's text was foregrounded through repetition, stylized gestures, and text spoken in unison. Words flew by with amazing speed; small gestures and strange postures took on incredible (if illegible) weight; and the buoyant energy of the performers was palpable. The ensemble's precision was reminiscent of a dance troupe—a result of Tekand's distinctive directorial approach, which she calls the "Performative Staging and Acting Method." Light was deployed in such exacting and assertive ways that it seemed like a character in itself. During quiet moments, disembodied heads emerged slowly from the black void; during more tumultuous sequences, the claustrophobic compartments were illuminated in a flash—just long enough for a performer to stomp a foot, or guffaw, or hiccup—before the play/game mercilessly moved on, built to a crescendo...

An assessment of surgeons' abilites to site colostomies accurately

The ability of surgeons to site a colostomy is assessed in a clinical model. In addition, the tuition received by surgical trainees in stoma siting is also reviewed. Eleven surgeons (trainees--six, colorectal subspeciality interest--two) were asked to site an end colostomy on nine patients using an adhesive disc (diameter--1cm). The position of the stoma was then measured on the 'x' and 'y' axis of a 2cm box grid, (maximum error--1cm) which was placed on the abdomen and centred on the umbilicus. The positions were then compared with that chosen by the stoma nurse who was taken as the gold standard. Results were compared using ANOVA and the Mann Whitney--U test. A telephone questionnaire was then undertaken to review the training of junior surgeons. There was variance present within the group of surgeons studied (p<0.01). Trainees and consultants had a similar accuracy in stoma-siting (p<0.2). Consultants with a colorectal subspeciality interest were better at placing stomas than those with a general interest (p<0.002). Badly placed stomas were three times more likely to be too low than too high (p<0.002). Thirty of 37 trainees reported receiving no undergraduate training from a specialist stoma nurse. Ninety per cent received postgraduate training from another surgeon while a specialist nurse trained only 35%. There was no difference between trainees and consultants in their ability to site a colostomy. However, surgeons with a subspeciality interest chose stoma sites that were more consistent with the specialist nurse than general surgeons. Training is haphazard and ability is frequently assumed rather than proven.

Neither Separate nor Equal: Women, Race, and Class in the South

Neither Separate Nor Equal: Women, Race, and Class the South. Edited by Barbara Ellen Smith. Women the Political Economy. (Philadelphia: Temple University Press, c. 1999. Pp. x, 286. Paper, $19.95, ISBN 1-56639-680-8; cloth, $59.50, ISBN 1-56639-679-4.) This collection of thirteen essays about women the contemporary South offers a heartening example of social science informed by an appreciation of history. The authors--a diverse group of scholars (sociologists, anthropologists, and others) and non-scholars (including organizers and writers)--have produced a coherent volume that should interest many historians. The editor of Neither Separate Nor Equal, Barbara Smith, argues that the South has much to teach us about the nation and the international economy. The traits that once made the region appear backward--racial violence, a gulf between rich and poor, minimal social programs, weak unions, widespread religious fundamentalism, and, arguably, antifeminism--now place the South in the vanguard of national trends (p. 1). The South's current function as a layover on capital's flight to cheaper labor (p. 114), for example, should make it a subject of study for scholars of so-called globalization. Smith calls for a renaissance southern studies that will pay attention to transnational migration, international economic restructuring, and multiracial feminism. This anthology makes an admirable start toward that objective. The authors explore race, class, gender, and sexuality as social relationships, which is to say that they understand difference as relational (and hierarchical). Smith dislikes the post-structuralist tendency to treat differences as identities voluntarily and individually constructed, that is, as discursive performances (p. 14). She also criticizes the pop variant of multiculturalism that conceptualizes society as a grid of boxes (differences) into which individual members fit, and across which enlightened individuals must try to connect (p. 14). Different groups of southern women already are connected, whether they like it or not. The book's four sections address the history, economic roles, community-building activities, and changing possibilities of southern women. The first article draws on work by feminist historians and analyzes the linkages between white supremacy and male supremacy the late-nineteenth-century South. Two essays on Native American women then challenge the bipolar racial construction of southern history. Of these, Darlene Wilson and Patricia Beaver's study of the historical erasure and contemporary reclaiming of Melungeon heritage by Appalachians descended from native American women and European men is particularly intriguing. …

Seismicity and self-organized criticality.

Distributed seismicity appears to fit the definition of a self-organized, critical phenomenon. In this paper a cellular-automata model is presented as an analog to distributed seismicity. We consider a grid of boxes with a fractal distribution of sizes. Particles are randomly added to the boxes. When the number of particles reaches a critical value they are redistributed to adjacent boxes and edge or corner boxes lose particles off the grid. The addition of particles is analogous to crustal strain and the redistribution from a box is equivalent to a characteristic earthquake on a fault. A redistribution from a small box (a foreshock) may trigger an instability in a larger box (the main shock). A redistribution from a large box always triggers many instabilities in adjacent smaller boxes (aftershocks). The frequency-size statistics for both main shocks and aftershocks satisfy the Gutenberg-Richter relation. Model foreshocks occur 28% of the time, in good agreement with actual foreshocks. No systematic precursors are observed prior to model earthquakes, also in agreement with the present status of earthquake prediction studies.

A scale‐invariant cellular‐automata model for distribited seismicity

In the standard cellular‐automata model for a fault an element of stress is randomly added to a grid of boxes until a box has four elements, these are then redistributed to the adjacent boxes on the grid. This redistribution may result in one or more of these boxes having four or more elements in which case further redistributions are required. On the average added elements are lost from the edges of the grid. We have modified this model so that the boxes have a scale‐invariant distribution of sizes. The objective is to model a scale‐invariant distribution of fault sizes. When a redistribution from a box occurs it is equivalent to a characteristic earthquake on the fault. A redistribution from a small box (a foreshock) may trigger an instability in a large box (the main shock). A redistribution from a large box always triggers many instabilities in the smaller boxes (aftershocks). The frequency‐size statistics for both main shocks and aftershocks satisfy the Gutenberg‐Richter relation with b = 0.835 for main shocks and b = 0.635 for aftershocks. Model foreshocks occur 28% of the time.

Efficient algorithm for estimating the correlation dimension from a set of discrete points.

We present an algorithm which computes the standard Grassberger-Procaccia correlation dimension of a strange attractor from a finite sample of N points on the attractor. The usual algorithm involves measuring the distances between all pairs of points on the attractor, but then discarding those distances greater than some cutoff ${r}_{0}$. Our idea is to avoid computing those larger distances altogether. This is done with a spatial grid of boxes (each of size ${r}_{0}$) into which the points are organized. By computing distances between pairs of points only if those points are in the same or in adjacent boxes, we get all the distances less than ${r}_{0}$ and avoid computing many of the larger distances. The execution time for the algorithm depends on the choice of ${r}_{0}$, the smaller ${r}_{0}$, the fewer distances to calculate, and in general the shorter the run time. The minimum time scales as O(NlogN); this compares with the O(${N}^{2}$) time that is usually required. Using this algorithm, we have obtained speedup factors of up to a thousand over the usual method.

A Two–Dimensional Global Climatic Model

Abstract A two–dimensional global climatic model has been developed, using a 10° longitude by 10° latitude box grid and a one-month time step. The lapse rates of temperature and the meridional component of the flow in the oceans and atmosphere and of specific humidity in the atmosphere are parameterized in terms of their respective sea-level values. The model then utilizes the vertically-averaged thermodynamic energy equation, the equation of motion for the boundary layer, the thermal wind equation, the hydrostatic equation, the surface water balance equation, and empirical relations between the sea-level temperature and pressure gradient fields and between cloud cover and precipitation to determine the global distribution by months of sea-level pressure, temperature, wind speed and direction, and relative humidity, precipitation, evaporation, runoff, soil mositure content, ice and snow cover and thickness, cloud cover, and poleward energy transport. A simple ocean model is included. Two 100 model-year ru...

A Refined Prediction Method for the Unsteady Aerodynamics of Supersonic Elastic Aircraft

This paper interprets the inaccuracies arising from the Mach box evaluation of unsteady aerodynamic forces based on the method of Aerodynamic Influence Coefficients (AIC), and proposes refinements to minimize these inaccuracies. The basic equations of inviscid flow are reviewed and the assumptions and restrictions inherent in present application of the AIC method are discussed. The inaccuracies, which result in large fluctuations of the pressure distribution, stem primarily from distortion of the leading edge which results from a Mach box grid representation of the wing planform. The refinement consists of a subdivision of the grid of pulse-sending boxes while maintaining the original grid of pulse-receivi ng box control points. Numerical examples are included to demonstrate its efficiency. The downwash singularity near a subsonic leading edge is also considered and a numerical procedure for evaluating its effect is shown. Nomenclature A = integrated area and integration constant a = speed of sound aj = amplitude of the y th mode oscillation br = reference length Z>! = chordwise dimension of Mach box ki = reduced frequency based on b^k^ = L = lift force M = Mach number in uniform flow condition TV = subdivision factor P = pressure <2i j = Generalized force for the /th elastic mode and loading for