scholarly journals Calibration of Photometry from the Gemini Multi-Object Spectrograph on Gemini North

2009 ◽  
Vol 26 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Inger Jørgensen
Keyword(s):  
Systematic Errors ◽  
Random Errors ◽  
Standard Star ◽  
Primary Mirror ◽  
Color Terms ◽  
User Community ◽  
Color Term ◽  
The Individual ◽  
Zero Points

AbstractAll available observations of photometric standard stars obtained with the Gemini Multi-Object Spectrograph at Gemini North in the period from August 2001 to December 2003 have been used to establish the calibrations for photometry obtained with the instrument. The calibrations presented in this paper are based on significantly more photometric standard star observations than usually used by the individual users. Nightly photometric zero points as well as color terms are determined. The color terms are expected to be valid for all observations taken prior to UT 2004 November 21 at which time the Gemini North primary mirror was coated with silver instead of aluminium. While the nightly zero points are accurate to 0.02 mag or better (random errors), the accuracy of the calibrations is limited by systematic errors from so-called ‘sky concentration’, an effect seen in all focal reducer instruments. We conclude that an accuracy of 0.035 to 0.05 mag can be achieved by using calibrations derived in this paper. The color terms are strongest for very red objects, e.g. for objects with (r′ – z′) = 3.0 the resulting z′ magnitudes will be ≈0.35 mag too bright if the color term is ignored. The calibrations are of importance to the large Gemini user community with data obtained prior to UT 2004 November 21, as well as future users of achive data from this period in time.

SET UP ERRORS AND RECOMMENDED SAFETY MARGINS IN THE PELVIC RADIOTHERAPY FIELDS OF CANCER CERVIX PATIENTS: AN INSTITUTIONAL EXPERIENCE

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Jitendra Nigam ◽  
Piyush Kumar ◽  
Uthya Balan
Keyword(s):  
Safety Margin ◽  
Conformal Radiotherapy ◽  
Systematic Errors ◽  
Random Errors ◽  
Cancer Cervix ◽  
Lateral Field ◽  
Bony Landmarks ◽  
Safety Margins ◽  
Set Up ◽  
The Individual

INTRODUCTION: Uncertainty exists in radiotherapy delivery due to daily patients set up errors resulting in a difference between planned and delivered dose. The conformal radiotherapy requires reduced margins around the clinical target volume (CTV) with respect to traditional radiotherapy technique and hence these positioning errors are accounted in CTV-PTV margin calculations. The primary aim of this study is to evaluate the set up errors and find out the optimum safety margins for the anterior and lateral fields of pelvis in the patients of cancer cervix treated with 3DCRT by four field box technique. The secondary objective was to study the adequacy of safety margin using the dosimetric and volumetric DVH data. METHODS AND MATERIALS: Study was conducted on twenty one patients of cancer cervix. All patients were immobilsed by full body Vaclok cushions. The radiotherapy to whole pelvis was planned by four field (Anterio-posterior, Posterio-anterior and two laterals) box technique with shielding of corners using multieaf collimators in Varian CLINAC 2300C/D. Weekly EPID images were acquired with Varian aS500 for each patient and were compared with the DRR images using the Portal Vision (Version 7.3.10). The displacement of EPID image from the DRR image was measured by defining reproducible bony landmarks in directions- X (Left to right (LR)), Z (Superior to inferior (SI)) in Anterio-posterior field, and Y (Anterior to posterior (AP)) in lateral field. The systematic and random set up errors for individual and population were calculated. Then the adequate safety margins were calculated by Stroom’s formula. RESULTS: A total of 242 images (42 DRR images and 200 portal images) and 363 match points were evaluated. Set up errors were -7.9 to 8.1mm (LR), -7.3 to 7.3mm (AP) and -9.9 to 8.2mm (SI). The individual systematic errors ranged from -6.6 to 4.9mm (LR), -4.9 to 3.5mm (AP) and -6.3 to 6.5mm (SI) while the individual random errors ranged from 0.5 to 8.3mm (LR), 0.7 to 5.2mm (AP) and 1.1 to 4.6mm (SI). The adequate safety margins which ensures at least 95% of prescribed dose to 99% of the CTV calculated by using Stroom’s formula were 7.9mm (LR), 7.0mm (AP) and 9.1mm (SI). The effect of dose was calculated by simulating a plan by shifting the isocenter along the three axes, where each shift corresponds to the displacement. Dose received by 99% of CTV volume for treatment plans with and without shifts was 99.51±0.81 and 98.63±1.46 respectively. CONCLUSION: In this study, the effect of the systematic errors and the random errors on dose distribution shows that the safety margin of 1 cm appears to be adequate for all the patients.

scholarly journals A Robust Extended Kalman Filter Applied to Ultrawideband Positioning

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Chuanyang Wang ◽  
Houzeng Han ◽  
Jian Wang ◽  
Hang Yu ◽  
Deng Yang
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Robust Estimation ◽  
Hypothesis Test ◽  
Systematic Errors ◽  
Random Errors ◽  
Model Errors ◽  
Global Test ◽  
Practical Applications ◽  
The Individual

Ultrawideband (UWB) is well-suited for indoor positioning due to its high resolution and good penetration through objects. The observation model of UWB positioning is nonlinear. As one of nonlinear filter algorithms, extended Kalman filter (EKF) is widely used to estimate the position. In practical applications, the dynamic estimation is subject to the outliers caused by gross errors. However, the EKF cannot resist the effect of gross errors. The innovation will become abnormally large and the performance and the reliability of the filter algorithm are inevitably influenced. In this study, a robust EKF (REKF) method accompanied by hypothesis test and robust estimation is proposed. To judge the validity of model, the global test based on Mahalanobis distance is implemented to assess whether the test statistical term exceeds the threshold for outlier detection. To reduce and eliminate the effects of the individual outlier, the robust estimation using scheme III of the Institute of Geodesy and Geophysics of China (IGGIII) based on local test of the normalized residual is performed. Meanwhile, three kinds of stochastic models for outliers are expressed by modeling the contaminated distributions. Furthermore, the simulation and measurement experiments are performed to verify the effectiveness and feasibility of the proposed REKF for resisting the outliers. Simulation experiment results are given to demonstrate that the outliers following all the three kinds of contaminated distributions can be detected. The proposed REKF can effectively control the influences of the outliers being treated as systematic errors and large variance random errors. When the outliers come from the thick-tailed distribution, the robust estimation does not play a role, and the REKF are equivalent to the EKF method. The measured experiment results show that the outliers will be generated in the nonline-of-sight environment whose impact is abnormally serious. The robust estimation can provide relatively reliable optimized residuals and control the influences of the outliers caused by gross errors. We can believe that the proposed REKF is effective to resist the effects of outliers and improves the positioning accuracy compared with least-squares (LS) and EKF method. Moreover, the adaptive filter and ranging error model should be considered to compensate the state model errors and ranging systematic errors respectively. Then, the measurement outliers will be detected more correctly, and the robust estimation will be used effectively.

scholarly journals FIGURATIVE CONSTITUENTS OF THE CONCEPT COLOR IN SPANISH AND UKRAINIAN (BASED ON FICTION TEXTS)

2018 ◽  
pp. 67-74
Author(s):  
Ekaterina Lesnevskaya
Keyword(s):  
Sampling Method ◽  
Gabriel Garcia Marquez ◽  
Altered States ◽  
Camilo Jose Cela ◽  
Color Terms ◽  
Continuous Sampling ◽  
Black And White ◽  
Color Term ◽  
The Subject ◽  
The Individual

The article features the results of a contrastive analysis of the figurative characteristics of color terms as elements of the conceptual worldview of Spaniards and Ukrainians. In this regard we consider the following topics: concept COLOR as a cross-object of conceptology, linguistic culture and discourse; color terms as an element of the conceptual worldview of Spaniards and Ukrainians; ethno-specific contrasts of the figurative constituents of the color terms black, white, red, blue, yellow, green in Spanish and Ukrainian in fiction. This study explores the linguocultural concept of COLOR from the cognitive, ethno-cultural and discursive perspectives, and therefore the concept can be considered as the subject matter of such disciplines as anthropology, linguocultural science and discourse theory. The corpus of the study was formed using the continuous sampling method from multi-genre prose written by contemporary Spanish (Carlos Ruiz Zafón, Camilo José Cela, Gabriel García Márquez) and Ukrainian (Yurii Andrukhovych, Lyubko Deresh, Oksana Zabuzhko) writers. A common feature of the color term black in Spanish and Ukrainian fiction is its use in the description of human blood and its altered states. The color terms black and white characterizing such concepts as NIGHT, DEATH, EYES can be observed in the individual authors’ worldview of Spanish-speaking and Ukrainian writers despite the non-contiguous nature of the two languages and cultures. In the Spanish linguistic culture, the color term blue is used as an image of DEATH and LONELINESS, whereas in Ukrainian – as an image of RAGE, TENSION and ILLNESS.

Statistics and parallaxes

1978 ◽  
Vol 48 ◽  
pp. 7-29
Author(s):  
T. E. Lutz
Keyword(s):  
Experimental Design ◽  
Statistical Methods ◽  
Review Paper ◽  
Systematic Errors ◽  
Past Experience ◽  
Random Errors ◽  
Trigonometric Parallaxes ◽  
Systematic And Random Errors

This review paper deals with the use of statistical methods to evaluate systematic and random errors associated with trigonometric parallaxes. First, systematic errors which arise when using trigonometric parallaxes to calibrate luminosity systems are discussed. Next, determination of the external errors of parallax measurement are reviewed. Observatory corrections are discussed. Schilt’s point, that as the causes of these systematic differences between observatories are not known the computed corrections can not be applied appropriately, is emphasized. However, modern parallax work is sufficiently accurate that it is necessary to determine observatory corrections if full use is to be made of the potential precision of the data. To this end, it is suggested that a prior experimental design is required. Past experience has shown that accidental overlap of observing programs will not suffice to determine observatory corrections which are meaningful.

The Historical Change in the Role of the Two Hungarian Words for Red (Piros and Vörös) and Their Visual Semantics

2020 ◽  
Vol 65 (1) ◽  
pp. 285-302
Author(s):  
Beáta Bálizs
Keyword(s):  
Research Methods ◽  
International Research ◽  
Historical Change ◽  
Color Terms ◽  
Color Term ◽  
Linguistic Research ◽  
Red Color ◽  
History Of ◽  
Hungarian Language

The present study summarizes the key findings of a multi-year interdisciplinary investigation, performed using specific (ethnographic, anthropological, and linguistic) research methods, into the two color terms mentioned in the title. Originally intended as empirical research involving all Hungarian color terms and individual community-dependent relationships with colors, it was eventually supplemented by a text-based examination of the history of the color terms piros and veres/vörös. A further objective was to answer questions raised in the course of international research concerning the reason for the existence of two color terms with similar meanings in the Hungarian language to denote the red color range. Earlier studies had already suggested that the modern use of vörös, which has more ancient roots in the Hungarian language, may be related to the fact that this color term was previously used more extensively. However, the present research is unique in demonstrating the substantial changes that have taken place in the Hungarian language in relation to the role and meaning of these color terms. It has already been established that the two color terms switched places historically, and that piros today fulfills precisely the same function that for centuries belonged to veres/vörös, until the color term piros began to gain ground in the 19th century.

Establishing inherent uncertainty in the shifts determined by volumetric imaging

2017 ◽  
Vol 16 (3) ◽  
pp. 258-264
Author(s):  
Upendra Kumar Giri ◽  
Anirudh Pradhan
Keyword(s):  
Linear Accelerator ◽  
Systematic Errors ◽  
Cone Beam ◽  
Random Errors ◽  
Mean Values ◽  
Volumetric Imaging ◽  
X Ray ◽  
Image Quality Control ◽  
The Mean ◽  
Six Degree Of Freedom

AbstractObjectiveThis study was conducted for establishing inherent uncertainty in the shift determination by X-ray volumetric imaging (XVI) and calculating margins due to this inherent uncertainty using van Herk formula.Material and methodsThe study was performed on the XVI which was cone-beam computed tomography integrated with the Elekta AxesseTM linear accelerator machine having six degree of freedom enabled HexaPOD couch. Penta-Guide phantom was used for inherent translational and rotational shift determination by repeated imaging. The process was repeated 20 times a day without moving the phantom for 30 consecutive working days. The measured shifts were used for margins calculation using van Herk formula.ResultsThe mean standard deviations were calculated as 0·05, 0·05, 0·06 mm in the three translational (x, y and z) and 0·05°, 0·05°, 0·05° in the three rotational axes (about x, y, z). Paired sample t-test was performed between the mean values of translational shifts (x, y, z) and rotational shifts. The systematic errors were found to be 0·03, 0·04 and 0·03 mm while the random errors were 0·05, 0·06 and 0·06 mm in the lateral, cranio-caudal and anterio-posterior directions, respectively. For the rotational shifts, the systematic errors were 0·02, 0·03 and 0·03 and the random errors were 0·06, 0·05 and 0·05 in the pitch, roll and yaw directions, respectively.ConclusionOur study concluded that there was an inherent uncertainty associated with the XVI tools, on the basis of these six-dimensional shifts, margins were calculated and recorded as a baseline for the quality assurance (QA) programme for XVI imaging tools by checking its reproducibility once in a year or after any major maintenance in hardware or upgradation in software. Although the shift determined was of the order of submillimetre order, still that shift had great significance for the image quality control of the XVI tools. Every departments practicing quality radiotherapy with such imaging tools should establish their own baseline value of inherent shifts and margins during the commissioning and must use an important QA protocol for the tools.

scholarly journals Семантические особенности цветообозначения улан ‘красный’ в калмыцком языке и способы его перевода на немецкий язык (на примере калмыцких сказок в записи Г. Й. Рамстедта)

2021 ◽  
Vol 14 (1) ◽  
pp. 186-197
Author(s):  
Aleksandra T. Bayanova ◽  
Keyword(s):  
Research Methods ◽  
Original Text ◽  
Semantic Features ◽  
Color Terms ◽  
German Translation ◽  
Color Term ◽  
The World ◽  
Linguistic Intuition ◽  
Selection Of ◽  
Morphological Patterns

Introduction. Color terms constitute a most archaic lexical stratum of any language. Being characterized by vivid ethnocultural specifics, those serve as important elements to the linguistic view of the world. Goals. The paper seeks to analyze semantic features of the Kalmyk color term улан ‘red’ and its German translation equivalents. Materials and Methods. The work explores Kalmyk folktales recorded by the Finnish scholar G. J. Ramstedt during his 1903 scientific expedition to the Kalmyk Steppe. The analysis of the color term comprises both general research methods and specifically linguoculturological ones, such as linguoculturological and conceptual insights into folklore texts. Results. Impacts of color in world perception of the Kalmyks — just as for any other nation — are diverse enough. The folktale texts recorded by G. J. Ramstedt contain a total of five shades of the color, the lexeme улан ‘red’ being largely characterized by positive semantics. German translation variants are not always complete semantic equivalents of the color term which results from that color denoting lexemes — and those of red in particular — are integral to a certain ethnic worldview, this leading to some ambivalence of the color under study. Conclusions. The lexeme улан ‘red’ in its first nominative meaning denotes a color of an object, e.g., red proper, scarlet, ruddy, etc. In the Kalmyk language, it also serves to denote the prototypic color of blood and is often used to describe animal coat colors. The Finnish scholar employed different German translation means. In most cases, the selection of translation equivalents depends on the translator’s associative/visual thinking and perception of the world, as well as on lexical, semantic and morphological patterns of Kalmyk and German. Folklore texts are structured specifically, and a translator needs utmost attention and linguistic intuition to avoid any inaccuracies when communicating a color paradigm from the original text. The challenge be tackled by a translator of color terms in a folklore text is that he/she is supposed to bear both the linguocultures examined.

scholarly journals THE COLOR TERMS FOR BLACK AND WHITE IN BULGARIAN, POLISH AND LITHUANIAN PHRASEOLOGICAL UNITS

2021 ◽  
pp. 71-82
Author(s):  
Nadelina IVOVA
Keyword(s):  
Good Life ◽  
Contrastive Analysis ◽  
Color Terms ◽  
Figurative Meaning ◽  
Black And White ◽  
Cultural Connotation ◽  
Color Term ◽  
Cultural Connotations ◽  
The Way

The present paper is contrastive analysis of Bulgarian, Polish and Lithuanian phraseological units containing a color term naming black or white. It traces the way these components reflect the figurative meaning of the unit - through their color semantics or through their function as a cultural signs. The study classiffiеs Bulgarian, Polish and Lithuanian expressions as to their belongings to several groups, which refer to different concepts. In each group the comparison of the examples found in the three phraseological subsystems is based on their semantics, their lexical components and structure. Under observations are substantive, adjectival, adverbial and verbal phraseological units where the colors are used only as an adjective component. The analysis takes into consideration that black has negative symbolism and cultural connotations. Thus the phraseological units with black are linked mainly to the concepts such as death, sorrow, bad life, misfortune. The text suggests that color term for black is rarely used to express neutral or positive meanings. The white has a positive cultural connotation associated to whiteness, light, good life, goodness, but its meaning can vary to neutral or negative in phraseological system of the three languages. The present paper observes similarities of collected phraseological expressions and emphasizes their nation-specific features.

scholarly journals STUDI PERAMBATAN KESALAHAN SISTEMATIS LUAS LAHAN PARKIR KAMPUS MENGGUNAKAN PENDEKATAN LUAS SEGITIGA SEMBARANG

2019 ◽  
Vol 13 (1) ◽  
pp. 14
Author(s):  
Hendro Supratikno ◽  
David Premana
Keyword(s):  
Systematic Error ◽  
Error Propagation ◽  
Measurement Data ◽  
Systematic Errors ◽  
Random Errors ◽  
Land Area ◽  
Parking Lots ◽  
Parking Lot ◽  
Data Error ◽  
Definition Of

Parking is a condition of not moving a vehicle that is temporary because it was abandoned by the driver. Included in the definition of parking is every vehicle that stops at certain places whether stated by traffic signs or not, and not solely for the benefit of raising and / or lowering people and / or goods.Campus 3 Lumajang State Community Academy has facilities and infrastructure prepared by the Lumajang Regency government. However, the parking lots provided cannot accommodate vehicles optimally because of the ratio of the number of vehicles and the area of the parking area that is not appropriate. This is because the area of the parking lot is not analyzed by data error when measuring.Each measurement data is assumed to have errors both systematic errors, random errors, and large errors (blunders), so that in the measurement of parking lots certainly there are errors. From this the authors intend to conduct research to find out how the propagation of systematic errors and the large systematic errors of the area of campus parking lot 3 Lumajang Community Academy.The methods used in this study include preparing materials and tools, making land sketches, decomposing them, determining distances using theodolite, determining land area equations, and finding systematic error propagation. So that the final goal in this study is to find large systematic errors in the parking area of Campus 3 of the Lumajang State Community Academy

scholarly journals Calculating Point Cloud Object Volume Using Co-Opposite-Direction Slicing Method

2019 ◽  
Author(s):  
Bin Li ◽  
Xiaowei Bi ◽  
Cheng Peng ◽  
Yong Chen ◽  
Xiaofa Zhao ◽  
...  
Keyword(s):  
Full Advantage ◽  
Opposite Direction ◽  
Point Cloud ◽  
Systematic Errors ◽  
Random Errors ◽  
Improved Method ◽  
Cone Model ◽  
Slicing Method

Although the Slicing Method (SM) is effective for calculating the volume of point cloud objects (PCOs), it is restricted in terms of applicability and practicability because of a certain contingency and directional defects. The Co-Opposite-Direction Slicing Method (CODSM) proposed in this paper is an improved method for calculating PCO volume by increasing parallel (co-opposite-direction) observation and considering the two-way mean as the result. This method takes full advantage of the mutual offsetting of random errors and the compensation of systematic directional errors, which can effectively overcome (or mitigate) the effect of random errors and reduce the effect of systematic errors in SM. In this paper, two typical objects, a cone model and a stone lion base, are the examples for calculating PCO volume using CODSM. The results show that CODSM has all the inherent advantages of SM and effectively weakens the volatility of random errors and the directionality of systematic errors from SM. Therefore, CODSM is a robust configuration upgrade of SM.

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