scholarly journals ESTABLISHMENT OF NEW FITTED GEOID MODEL IN UNIVERSITI TEKNOLOGI MALAYSIA

Author(s):  
M. K. Ismail ◽  
A. H. M. Din ◽  
M. N. Uti ◽  
A. H. Omar

<p><strong>Abstract.</strong> The purpose of this study is to produce fitted geoid for Universiti Teknologi Malaysia (UTM), Johor Bahru by using precise levelling and 3D GNSS control network technique. This study focuses on the theory, computation method and analysis of fitted geoid around Universiti Teknologi Malaysia. The computation of accuracy fitted geoid model is based on the GNSS levelling and Precise Levelling. The achieved accuracy of UTM Fitted Geoid Model is at 8<span class="thinspace"></span>mm. In conclusion, this research can contribute to Universiti Teknologi Malaysia by providing good UTM fitted geoid model that can give better accuracy for various purposes of work related to surveying and mapping.</p>

2020 ◽  
Vol 61 (5) ◽  
pp. 64-70
Author(s):  
Ha Ngoc Hoang ◽  

One of the important contents to achieve the goal of modernization of the height system is connect the levelling observations between national levelling order I, II to the national GNSS Continuous Operating Reference Stations and the national gravity marks. Today, Vietnamese surveyors commonly use Geoid model 2010 that built based on more than 3000 gravity marks and over 800 GPS-levelling points. The processing combined GNSS-levelling and gravity obervations to improve the Geoid model for archiving accuracy from 4 to 10 centimeters, that can be possible to apply topographic heigh using GNSS accurately instead of traditional levelling is necessary for geomatics and mapping in Vietnam. There are some researchs in the literature aim to improving geoid model. In these research, the interpolation methods are mainly discussed such as collocation, linear function order 1, 2 or spline function. In this paper, the objective is to consider and propose a method of data processing using theothy of adjustment with contrainned codition and analyze the covariance matrix of the input data.


2011 ◽  
Vol 37 (1) ◽  
pp. 15-21
Author(s):  
Harli Jürgenson ◽  
Kristina Türk ◽  
Jüri Randjärv

This paper focuses on issues related to the calculation of a high-precision fitted geoid model on Estonian territory. Model Est-Geoid2003 have been used in Estonia several years in geodesy and other applications. New data from precise levelling, new global models and terrestrial gravity data give plenty of possibilities for updates and accuracy evaluation. The model is based on a gravimetric geoid. From the gravimetric data gathered, a gravimetric geoid for Estonia was calculated as an approximately 3-km net using the FFT method. After including the new gravimetric data gathered, the gravimetric geoid no longer had any significant tilt relative to the height anomalies derived from GPS-levelling points. The standard deviation between the points was 2.7 cm. The surface of the calculated gravimetric geoid was fitted by high-precision GPS-levelling points. As a result, a height transformation model was determined to reflect the differences between the normal heights of BK77 and the ellipsoidal heights of EUREF-EST97 on Estonian territory. The model was originally called Est-Geoid2003 and is part of the official national geodetic system in Estonia. The model is updated and evaluated here using precise GPS-levelling points obtained from different measurement campaigns. In 2008–2010 the preliminary results from the latest precise levelling sessions became available, leading to a significant increase in the number of precise GPS-levelling points. Both networks are part of the Estonian integrated geodetic network. Using very precise levelling connections from new levelling lines, normal heights of several RGP points were calculated additionally. Misclosure of 300 km polygons are less than 2–3 mm normally. Ealier all precisely levelled RGP points were included into fitting points. Now many new points are available for fitting and independent evaluation. However, the use of several benchmarks for the same RGP point sometimes results in a 1–2 cm difference in normal height. This reveals problems with the stability of older wall benchmarks, which are widely used in Estonia. Even we recognized, that 0.5 cm fitted geoid model is not achievable using wall benchmarks. New evaluation of the model Est-Geoid2003 is introduced in the light of preliminary data from new precise levelling. Model accuracy is recognised about 1.2 cm as rms. Santrauka Akcentuojami klausimai, susiję su tiksliausio Estijos geoido modelio skaičiavimu. Šis modelis Estijoje geodezijoje ir kitose mokslo bei technikos šakose taikomas nuo 2003 metų. Nauji precizinės niveliacijos duomenys, nauji globalieji geopotencialo modeliai ir žemyno gravimetriniai duomenys – prielaidos geoido modeliui atnaujinti ir jo tikslumui įvertinti. Modelio pagrindas – gravimetrinis geoidas. Pagal surinktus gravimetrinius duomenis Estijos geoidas buvo apskaičiuotas greitųjų Furjė tranformacijų (FFT) metodu, sukuriant apie 3 km akių tinklą. Įtraukus naujuosius gravimetrinius duomenis, gravimetrinis geoidas daugiau nebeturi aukščių anomalijų. Vidutinė kvadratinė paklaida – 2,7 cm. Apskaičiuoto gravimetrinio geoido paviršius susietas su aukščių sistema pagal GPS niveliacijos taškus. 2008–2010 m. gavus precizinės niveliacijos duomenis, žymiai padidėjo GPS niveliacijos taškų skaičius bei jų tikslumas, nes precizinės niveliacijos poligonų iki 300 km nesąryšiai gauti mažesni nei 2–3 mm. Įvertinus naujo Estijos geoido modelio tikslumą nustatyta 1,2 cm vidutinė kvadratinė paklaida. Резюме Акцентируются вопросы, касающиеся вычисления точной модели геоида Эстонии. Эта модель применяется в Эстонии с 2003 г. в геодезии и других отраслях науки и техники. Новые данные высокоточной нивеляции, новые глобальные модели геопотенциала, а также гравиметрические данные создают предпосылки для обновления модели геоида и оценки его точности. Модель основана на гравиметрическом геоиде. Модель геоида Эстонии была вычислена быстрым методом Фурье с использованием всех гравиметрических данных и созданием сети 3×3 км. После использования новых гравиметрических данных в геоиде не оказалось значительного превышения высот по сравнению с точками, измеренными методом GPS. Среднеквадратическая погрешность составила 2,7 см. Вычисленная модель геоида была соединена с системой высот по точкам GPSнивелирования. Благодаря новым данным по высокоточной нивеляции, полученным в 2008–2010 гг., значительно увеличилось количество точек GPSнивелирования и тем самым увеличилась точность геоида, так как невязки полигонов нивелирования составляют всего 2–3 мм. Оценив точность нового геоида Эстонии, выявлено среднеквадратическое отклонение в 1,2 см.


2017 ◽  
Vol 22 (1) ◽  
pp. 11-16
Author(s):  
Joel Weddington ◽  
Charles N. Brooks ◽  
Mark Melhorn ◽  
Christopher R. Brigham

Abstract In most cases of shoulder injury at work, causation analysis is not clear-cut and requires detailed, thoughtful, and time-consuming causation analysis; traditionally, physicians have approached this in a cursory manner, often presenting their findings as an opinion. An established method of causation analysis using six steps is outlined in the American College of Occupational and Environmental Medicine Guidelines and in the AMA Guides to the Evaluation of Disease and Injury Causation, Second Edition, as follows: 1) collect evidence of disease; 2) collect epidemiological data; 3) collect evidence of exposure; 4) collect other relevant factors; 5) evaluate the validity of the evidence; and 6) write a report with evaluation and conclusions. Evaluators also should recognize that thresholds for causation vary by state and are based on specific statutes or case law. Three cases illustrate evidence-based causation analysis using the six steps and illustrate how examiners can form well-founded opinions about whether a given condition is work related, nonoccupational, or some combination of these. An evaluator's causal conclusions should be rational, should be consistent with the facts of the individual case and medical literature, and should cite pertinent references. The opinion should be stated “to a reasonable degree of medical probability,” on a “more-probable-than-not” basis, or using a suitable phrase that meets the legal threshold in the applicable jurisdiction.


2016 ◽  
Vol 21 (6) ◽  
pp. 5-11
Author(s):  
E. Randolph Soo Hoo ◽  
Stephen L. Demeter

Abstract Referring agents may ask independent medical evaluators if the examinee can return to work in either a normal or a restricted capacity; similarly, employers may ask external parties to conduct this type of assessment before a hire or after an injury. Functional capacity evaluations (FCEs) are used to measure agility and strength, but they have limitations and use technical jargon or concepts that can be confusing. This article clarifies key terms and concepts related to FCEs. The basic approach to a job analysis is to collect information about the job using a variety of methods, analyze the data, and summarize the data to determine specific factors required for the job. No single, optimal job analysis or validation method is applicable to every work situation or company, but the Equal Employment Opportunity Commission offers technical standards for each type of validity study. FCEs are a systematic method of measuring an individual's ability to perform various activities, and results are matched to descriptions of specific work-related tasks. Results of physical abilities/agilities tests are reported as “matching” or “not matching” job demands or “pass” or “fail” meeting job criteria. Individuals who fail an employment physical agility test often challenge the results on the basis that the test was poorly conducted, that the test protocol was not reflective of the job, or that levels for successful completion were inappropriate.


1998 ◽  
Vol 3 (4) ◽  
pp. 6-6
Author(s):  
Marc T. Taylor

Abstract This article discusses two important cases that involve the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides). First, in Vargas v Industrial Com’n of Arizona, a claimant had a pre-existing non–work-related injury to his right knee as well as a work-related injury, and the issue was apportionment of the pre-existing injury. The court held that, under Arizona's statute, the impairment from the pre-existing injury should be subtracted from the current work-related impairment. In the second case, Colorado courts addressed the issue of apportionment in a workers’ compensation claim in which the pre-existing injury was asymptomatic at the time of the work-related injury (Askey v Industrial Claim Appeals Office). In this case, the court held that the worker's benefits should not be reduced to account for an asymptomatic pre-existing condition that could not be rated accurately using the AMA Guides. The AMA Guides bases impairment ratings on anatomic or physiologic loss of function, and if an examinee presents with two or more sequential injuries and calculable impairments, the AMA Guides can be used to apportion between pre-existing and subsequent impairments. Courts often use the AMA Guides to decide statutorily determined benefits and are subject to interpretation by courts and administrative bodies whose interpretations may vary from state to state.


Crisis ◽  
2015 ◽  
Vol 36 (2) ◽  
pp. 91-101 ◽  
Author(s):  
Marie Alderson ◽  
Xavier Parent-Rocheleau ◽  
Brian Mishara

Background: Research shows that there is a high prevalence of suicide among nurses. Despite this, it has been 15 years since the last literature review on the subject was published. Aim: The aim of this article is to review the knowledge currently available on the risk of suicide among nurses and on contributory risk factors. Method: A search was conducted in electronic databases using keywords related to prevalence and risk factors of suicide among nurses. The abstracts were analyzed by reviewers according to selection criteria. Selected articles were submitted to a full-text review and their key elements were summarized. Results: Only nine articles were eligible for inclusion in this review. The results of this literature review highlight both the troubling high prevalence of suicide among nurses as well as the persistent lack of studies that examine this issue. Conclusion: Considering that the effects of several factors related to nurses' work and work settings are associated with high stress, distress, or psychiatric problems, we highlight the relevance of investigating work-related factors associated with nurses' risk of suicide. Several avenues for future studies are discussed as well as possible research methods.


2010 ◽  
Vol 26 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Nale Lehmann-Willenbrock ◽  
Simone Kauffeld

In research on trust in the organizational context, there is some agreement evolving that trust should be measured with respect to various foci. The Workplace Trust Survey (WTS) by Ferres (2002) provides reliable assessment of coworker, supervisor, and organizational trust. By means of a functionally equivalent translation, we developed a German version of the questionnaire (G-WTS) comprising 21 items. A total of 427 employees were surveyed with the G-WTS and questionnaires concerning several work-related attitudes and behaviors and 92 of these completed the survey twice. The hypothesized three-dimensional conceptualization of organizational trust was confirmed by confirmatory factor analysis. The G-WTS showed good internal consistency and retest reliability values. Concerning convergent validity, all of the three G-WTS dimensions positively predicted job satisfaction. In terms of discriminant validity, Coworker Trust enhanced group cohesion; Supervisor Trust fostered innovative behavior, while Organizational Trust was associated with affective commitment. Theoretical and practical contributions as well as opportunities for future research with the G-WTS are discussed.


2004 ◽  
Vol 20 (4) ◽  
pp. 227-236 ◽  
Author(s):  
Sara Holmberg ◽  
Anders Thelin ◽  
Eva-Lena Stiernström

Summary: The concept of “sense of coherence” (SOC) has been widely recognized since it was first introduced by Antonovsky. The originality and usefulness of the SOC scale and its relation to other psychosocial measures has been the subject of lively debate. The aim of this paper was to test for associations between SOC and work-related psychosocial factors (mainly the Job Demand-Control model), general living conditions, education, and social network factors. Cross-sectional data from a population-based sample of 1782 rural males from nine counties in Sweden were analyzed with a multiple regression technique. The subjects were occupationally active at inclusion and the mean age was 50 years (range 40-60). SOC was assessed with the original 29-item questionnaire. Psychosocial variables and lifestyle factors were assessed using questionnaires and structured interviews. The mean SOC among the subjects was 152.3 (standard deviation, 19.4). A strong negative correlation was found between SOC and job demand, whereas a positive correlation with job control was demonstrated. A positive correlation with general living conditions and with social support was also found. However, there was no correlation to education and occupation. Thus, SOC was shown to be strongly correlated to work-related psychosocial factors and social support, but independent of sociodemographic factors.


Sign in / Sign up

Export Citation Format

Share Document