1038+528 A, B: Phase-Reference and Spectral-Index Maps

On 1981 March 17–18 we undertook MkIII VLBI observations of the quasars 1038+528 A, B (Owen et al. 1979; Owen et al. 1980) with an array of 7 telescopes operating simultaneously at λ3.6 and λ13 cm with right circular polarization reception at each wavelength. Because the sources are ~33″ apart they could be observed simultaneously at every telescope. Thus the corrupting contributions of the propagation medium and the instrumentation were approximately the same for each of the quasars, hence allowing us to calibrate the structure phase of B with respect to a reference point chosen in the map of A using the expression where φB and φA are the observed fringe phases, φGB and φGA are the geometric contribution with respect to the reference points chosen in each map and φSA is the structure phase contribution with respect to the reference point chosen in the A map.

Download Full-text

Cognitive Reflection Effects on Time Discounting

Journal of Individual Differences ◽

10.1027/1614-0001/a000254 ◽

2018 ◽

Vol 39 (2) ◽

pp. 99-106 ◽

Cited By ~ 4

Author(s):

Michał Białek ◽

Przemysław Sawicki

Keyword(s):

Individual Differences ◽

Individual Difference ◽

Delay Discounting ◽

Reference Point ◽

Reference Points ◽

Cognitive Reflection Test ◽

Process Information ◽

Time Discounting ◽

Cognitive Reflection ◽

The Way

Abstract. In this work, we investigated individual differences in cognitive reflection effects on delay discounting – a preference for smaller sooner over larger later payoff. People are claimed to prefer more these alternatives they considered first – so-called reference point – over the alternatives they considered later. Cognitive reflection affects the way individuals process information, with less reflective individuals relying predominantly on the first information they consider, thus, being more susceptible to reference points as compared to more reflective individuals. In Experiment 1, we confirmed that individuals who scored high on the Cognitive Reflection Test discount less strongly than less reflective individuals, but we also show that such individuals are less susceptible to imposed reference points. Experiment 2 replicated these findings additionally providing evidence that cognitive reflection predicts discounting strength and (in)dependency to reference points over and above individual difference in numeracy.

Download Full-text

ILRS Reference Point Determination Using Close Range Photogrammetry

Applied Sciences ◽

10.3390/app11062785 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2785

Author(s):

Michael Lösler ◽

Cornelia Eschelbach ◽

Thomas Klügel ◽

Stefan Riepl

Keyword(s):

Reference Point ◽

Reference Points ◽

Geodetic Reference System ◽

Unscented Transformation ◽

Local Ties ◽

Close Range Photogrammetry ◽

Crucial Component ◽

Space Geodetic Techniques ◽

Close Range ◽

Point Determination

A global geodetic reference system (GGRS) is realized by physical points on the Earth’s surface and is referred to as a global geodetic reference frame (GGRF). The GGRF is derived by combining several space geodetic techniques, and the reference points of these techniques are the physical points of such a realization. Due to the weak physical connection between the space geodetic techniques, so-called local ties are introduced to the combination procedure. A local tie is the spatial vector defined between the reference points of two space geodetic techniques. It is derivable by local measurements at multitechnique stations, which operate more than one space geodetic technique. Local ties are a crucial component within the intertechnique combination; therefore, erroneous or outdated vectors affect the global results. In order to reach the ambitious accuracy goal of 1 mm for a global position, the global geodetic observing system (GGOS) aims for strategies to improve local ties, and, thus, the reference point determination procedures. In this contribution, close range photogrammetry is applied for the first time to determine the reference point of a laser telescope used for satellite laser ranging (SLR) at Geodetic Observatory Wettzell (GOW). A measurement campaign using various configurations was performed at the Satellite Observing System Wettzell (SOS-W) to evaluate the achievable accuracy and the measurement effort. The bias of the estimates were studied using an unscented transformation. Biases occur if nonlinear functions are replaced and are solved by linear substitute problems. Moreover, the influence of the chosen stochastic model onto the estimates is studied by means of various dispersion matrices of the observations. It is shown that the resulting standard deviations are two to three times overestimated if stochastic dependencies are neglected.

Download Full-text

An Alternative Perspective on Recruitment Overfishing and Biological Reference Points

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f87-110 ◽

1987 ◽

Vol 44 (4) ◽

pp. 913-918 ◽

Cited By ~ 173

Author(s):

M. P. Sissenwine ◽

J. G. Shepherd

Keyword(s):

Fisheries Management ◽

Reference Point ◽

Reference Points ◽

Fishing Mortality ◽

Alternative Perspective ◽

Conventional Models ◽

Definition Of ◽

Yield Per Recruit ◽

Spawning Biomass

Biological reference points are used to guide fisheries management decisions. The reference points most often used are expressed in terms of fishing mortality rate (F). Fmsy relates to the maximization of sustainable yield. In principle, it is a most useful reference point, but in practice it is difficult to estimate. Fmax and F0.1 relate to certain levels of yield per recruit and are easily estimated, but they ignore conservation of the resource. Recruitment overfishing has usually been understood to occur when a population has been fished down to a point where recruitment is substantially reduced or fails. It has not been used as a basis for a biological reference point because the definition is vague and cannot be readily related to fishing mortality. Levels of spawning biomass below which recruitment seems to be reduced have been used, but their determination from available data is usually difficult and controversial. We propose an alternative definition of recruitment overfishing in terms of the level of fishing pressure that reduces the spawning biomass of a year class over its lifetime below the spawning biomass of its parents on average. Conventional models and types of data can be used to determine this level of F, denoted as Frep, which clearly relates to the replacement of spawning biomass and thus to sustainability of a population and yield in the long term.

Download Full-text

Albanian Aorist and Time Reference Points

Journal of Educational and Social Research ◽

10.36941/jesr-2020-0051 ◽

2020 ◽

Vol 10 (3) ◽

pp. 115

Author(s):

Muhamet Reçica ◽

Naser Pajaziti

Keyword(s):

Reference Point ◽

Reference Points ◽

The Other ◽

Temporal Relations ◽

Time Dimension ◽

Relative Time ◽

Absolute Time ◽

Temporal System ◽

The Absolute

Topics related to the structure of the temporal system of Albanian language always give opportunities for new discussions to deal with certain aspects related to various forms of this system, and one of them is the aorist, as a tense containing many semantic, temporal, aspectual, stylistic values, etc. The relationships that exist between the verbal tenses in this system within the absolute time-relative time dimension, which relate to the independent or dependent use of temporal forms against one another in different discoursing contexts, make up an interpretation-based approach to interest. Hence, the essential objective of this paper will be specifically the relations of the Albanian aorist to the other verbal forms, always observed with a time reference point, to illuminate the character of these purely temporal relations against each other under all circumstances of the actions that take place and are displayed by verbal forms in different contexts, relying on the corpus of examined materials.

Download Full-text

Daily Labor Supply and Adaptive Reference Points

The American Economic Review ◽

10.1257/aer.20170768 ◽

2021 ◽

Vol 111 (8) ◽

pp. 2417-2443

Author(s):

Neil Thakral ◽

Linh T. Tô

Keyword(s):

Labor Supply ◽

Reference Point ◽

Structural Model ◽

Reference Points ◽

Degree Of Freedom ◽

Reference Dependence ◽

Field Evidence ◽

Dynamic View ◽

Expected Earnings ◽

Dependence Models

This paper provides field evidence on how reference points adjust, a degree of freedom in reference-dependence models. Examining this in the context of cabdrivers’ daily labor-supply behavior, we ask how the within-day timing of earnings affects decisions. Drivers work less in response to higher accumulated income, with a strong effect for recent earnings that gradually diminishes for earlier earnings. We estimate a structural model in which drivers work toward a reference point that adjusts to deviations from expected earnings with a lag. This dynamic view of reference dependence reconciles conflicting “neoclassical” and “behavioral” interpretations of evidence on daily labor-supply decisions. (JEL J22, J31, L94)

Download Full-text

Aspirations or survival: decision modeling and the effect of focus of attention in risky choice

Journal of Modelling in Management ◽

10.1108/jm2-01-2021-0006 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Guy Moshe Ross

Keyword(s):

Risk Taking ◽

Reference Point ◽

Effect Study ◽

Focus Of Attention ◽

Risky Choice ◽

Reference Points ◽

Aspiration Level ◽

Content Type ◽

Randomized Controlled Studies ◽

Risky Option

Purpose This research aims to test focus of attention effects in risky choice. Design/methodology/approach As opposed to traditional aspiration-level theory, the shifting-focus concept introduces a second reference point, the survival point, and assumes a shifting focus of attention between the two reference points. In this conceptualization, risk-taking is a function of focus of attention on the survival reference point or the aspiration-level and resources relative to the two reference points. Four randomized controlled studies tested this concept. Findings Study 1 showed that with aspiration focus the probability of choosing a risky option was higher below an aspiration-level than above it. With survival focus, the effect was reversed. Study 2 found that close to the survival reference point, the probability of choosing a risky option was higher with aspiration focus relative to survival focus. Study 3 revealed that with scarce resources the risk taken was higher with aspiration focus than with survival focus, and the scarcer the resources the stronger was the effect. Study 4 demonstrated that with aspiration focus the risk taken was higher below an aspiration-level than above it. With survival focus the effect was reversed. Originality/value In addition to providing support for the validity of the shifting focus concept, this paper elaborates on the theoretical model by providing evidence for moderation effects. Risk-taking was affected by a focus of attention on one of two reference points, and the effect was moderated by resources relative to the two focal points. An advanced model is proposed to capture the effects of focus of attention and resources on risk-taking behavior.

Download Full-text

Echocardiographic determination of valid zero reference levels in supine and lateral positions

American Journal of Critical Care ◽

10.4037/ajcc1993.2.1.72 ◽

1993 ◽

Vol 2 (1) ◽

pp. 72-80 ◽

Cited By ~ 12

Author(s):

LL Kee ◽

JS Simonson ◽

NA Stotts ◽

P Skov ◽

NB Schiller

Keyword(s):

Left Atrium ◽

Supine Position ◽

Right Atrium ◽

Reference Point ◽

Reference Points ◽

Pressure Measurements ◽

Proper Position ◽

External Reference ◽

External Point ◽

The Right

BACKGROUND: The phlebostatic axis--the junction of the fourth intercostal space and the midpoint of the anterior-posterior diameter--has been accepted as a reliable external reference point for the mid-right and mid-left atrium. Acceptance of this reference point is based upon research conducted in 1945 that measured venous pressures in the hands of subjects positioned with the head of the bed raised to different levels. The validity of this reference point for intracardiac pressure measurements in supine or laterally positioned patients has not been established. PURPOSE: To determine the validity of the phlebostatic axis in the supine and lateral positions. METHODS: To determine validity in the supine position, we compared the distance from the phlebostatic axis to a fixed external point (the bed surface) and the distance from the right and left atria in the supine position to this same fixed external point. The distances from the right and left atria to the bed surface were determined with echocardiography and were used as the standard for the proper position of external reference points. To determine the validity of the phlebostatic axis in lateral positions, we compared the distances from the right atrium and left atrium to the bed surface in the supine position with those distances in different lateral positions. RESULTS: We analyzed the data of 25 normal, healthy subjects. The study findings show that the phlebostatic axis is a valid reference point for the right atrium, and the phlebostatic axis and midanterior-posterior diameter are valid reference points for the left atrium in the supine position. However, neither is a valid external reference point in the lateral positions. Pressure measurements obtained when patients are in the lateral positions are not accurate. There remains a need to develop valid methods of accurate pressure measurements in various body positions.

Download Full-text

Capital Gains Overhang with a Dynamic Reference Point

Management Science ◽

10.1287/mnsc.2019.3404 ◽

2020 ◽

Vol 66 (10) ◽

pp. 4726-4745

Author(s):

Christopher Riley ◽

Barbara Summers ◽

Darren Duxbury

Keyword(s):

Stock Prices ◽

Reference Point ◽

Trading Volume ◽

Reference Points ◽

Capital Gains ◽

Share Price ◽

Purchase Price ◽

Cross Sectional ◽

Market Data ◽

Salient Points

Financial models incorporating a reference point, such as the Capital Gains Overhang (CGO) model, typically assume it is fixed at the purchase price. Combining experimental and market data, this paper examines whether such models can be improved by incorporating reference-point adjustment. Using real stock prices over horizons from 6 months to 5 years, experimental evidence demonstrates that a number of salient points in the prior share price path are key determinants of the reference point, in addition to the purchase price. Market data testing is then undertaken by using the CGO model. We show that composite CGO variables, created by using a mix of salient points with weights determined in the experiment, have greater predictive power than the traditional CGO variable in both cross-sectional U.S. equity-return analysis and when analyzing the performance of double-sorted portfolios. In addition, future trading volume is more sensitive to changes in the composite CGO variables than to the traditional CGO, further emphasizing the importance of adjusting reference points. This paper was accepted by Tyler Shumway, Finance.

Download Full-text

Space VLBI Observations of PKS 1921-293

Symposium - International Astronomical Union ◽

10.1017/s0074180900220706 ◽

2001 ◽

Vol 205 ◽

pp. 128-129

Author(s):

Zhi-Qiang Shen ◽

Philip G. Edwards ◽

Seiji Kameno ◽

Makoto Inoue ◽

James E. J. Lovell

Keyword(s):

Brightness Temperature ◽

Spectral Index ◽

Rest Frame ◽

The Core ◽

Vlbi Observations ◽

First Time

We present results of the first space VLBI observations of PKS 1921-293. An inner jet component about 1.5 mas north of the core is revealed for the first time. The compact core is partially resolved, but still has a brightness temperature (at the source rest frame) of 3.0×1012 K. A spectral index map made by combining the 1.6 GHz VSOP image with the 5.0 GHz VLBA+Y image at the first epoch is also presented.

Download Full-text

Preliminary study of the shape of eurypterid prosomas using Fourier analysis

The Paleontological Society Special Publications ◽

10.1017/s2475262200008546 ◽

1992 ◽

Vol 6 ◽

pp. 294-294

Author(s):

V.P. Tollerton

Keyword(s):

Fourier Analysis ◽

Reference Point ◽

Reference Points ◽

Shape Identification ◽

Size Classes ◽

Stage Of Development ◽

Limited Success ◽

Dimensional Shape ◽

Preliminary Study ◽

Simultaneous Identification

Shape identification of eurypterid prosomas currently uses the ratio of prosoma length to prosoma width and the lateral angle. Because many species of eurypterids have the same prosoma shape as determined by these criteria, the method is limited in its taxonomic applications. Thompson transformation grids are of little value due to the lack of sufficient topographic reference points, even though some limited success has been achieved in its application to allometry.Fourier analysis is a more rigorous mathematical descriptor of two-dimensional shape than is simple ratios. Being independent of topographic reference points and ratios, Fourier analysis is well suited, theoretically, to the identification of prosoma shape and potential taxonomic identifications. Problems arise, though, in that Fourier analysis is sensitive to distorted specimens.My study departs from previous methods of Fourier analysis in that the choice of the reference point from which to measure the radii is not the center of gravity, but instead is the midpoint between the eyes. My reasons for this unorthodox reference point are threefold: 1) this point is determinable on all specimens; 2) the position of the eyes is taxonomically significant (Kjellesvig-Waering, 1961) and 3) allows for the simultaneous identification of prosoma shape and the differentiation of taxa with similar outlines but different eye positions.As defined by current methods, the taxa used in this study (Eurypterus remipes, E. lacustris, E. pittsfordensis, and E. dekayi) all have similar prosoma shapes. When specimens of the same stage of development were compared statistically, Fourier analysis was successful in the differentiation between E. remipes, E. pittsfordensis and E. dekayi, and between E. lacustris, E. pittsfordensis and E. dekayi, but not between E. remipes and E. lacustris.The prosoma shapes as studied by Fourier analysis for both E. remipes and E. lacustris are also similar for all size classes examined. All size classes are dominated by the 4th harmonic. The contribution to the outline from other harmonics changes during ontogeny. The 3rd and 7th harmonics are the important components of the prosoma outline for the small size classes (classes 1-3 = maximum prosoma length of 17mm), while the 2nd and 7th harmonics are the important components for the larger size classes (classes 4-7). Further study involving other eurypterid taxa is in progress.

Download Full-text