scholarly journals Ground-based astrometry calibrated by Gaia DR1: new perspectives in asteroid orbit determination

2017 ◽  
Vol 607 ◽  
pp. A21 ◽  
Author(s):  
F. Spoto ◽  
P. Tanga ◽  
S. Bouquillon ◽  
J. Desmars ◽  
D. Hestroffer ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Orbit Determination ◽  
The Past ◽  
Data Release ◽  
Impact Risk ◽  
Near Earth Asteroids ◽  
The Impact ◽  
Asteroid Orbit ◽  
Short Arc

Context. The Gaia Data Release 1 (GDR1) is a first, important step on the path of evolution of astrometric accuracy towards a much improved situation. Although asteroids are not present in GDR1, this intermediate release already impacts asteroid astrometry. Aims. Our goal is to investigate how the GDR1 can change the approach to a few typical problems, including the determination of orbits from short-arc astrometry, the exploitation of stellar occultations, and the impact risk assessment. Methods. We employ optimised asteroid orbit determination tools, and study the resulting orbit accuracy and post-fit residuals. For this goal, we use selected ground-based asteroid astrometry, and occultation events observed in the past. All measurements are calibrated by using GDR1 stars. Results. We show that, by adopting GDR1, very short measurement arcs can already provide interesting orbital solutions, capable of correctly identifying near-Earth asteroids (NEAs) and providing a much more accurate risk rating. We also demonstrate that occultations, previously used to derive asteroid size and shapes, now reach a new level of accuracy at which they can be fruitfully used to obtain astrometry at the level of accuracy of Gaia star positions.

scholarly journals Impact of Earthquakes on the Transportation Infrastructure of Indonesia: A Preliminary Study

2019 ◽  
Vol 21 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Anita Amirsardari ◽  
Massoud Sofi ◽  
Elisa Lumantarna ◽  
Iswandi Imran ◽  
Colin Duffield
Keyword(s):  
Risk Assessment ◽  
Seismic Risk ◽  
Transportation Infrastructure ◽  
Seismic Region ◽  
The Past ◽  
Preliminary Study ◽  
Critical Components ◽  
Future Work ◽  
The Impact ◽  
Economical Losses

Indonesia is a high seismic region and one of the most vulnerable countries prone to experiencing damaging earthquakes. It is critical that lifeline infrastructure remain operational or is quickly remediated after an earthquake to minimise physical, social, and economical losses. Not much work has been carried out in understanding the effect of earthquakes on transportation infrastructure systems. This study aims to gain a better understanding of the impact of earthquakes on the transportation infrastructure in Indonesia. This is achieved by firstly reviewing the frameworks and tools for conducting seismic risk assessment of lifeline infrastructure. The critical components of the transportation system are then identified. Various forms of transportation infrastructure damage caused by earthquakes are discussed. An overview of the damaging earthquakes for the past 20 years is presented. Finally, conclusions and recommendations are provided about the future work required for conducting risk assessment of the transportation infrastructure in Indonesia

scholarly journals Aggregated Risk Assessment and Survey for Risk Reduction in Oil Terminals

2021 ◽  
Vol 13 (21) ◽  
pp. 12169
Author(s):  
Robertas Alzbutas ◽  
Mindaugas Vaisnoras ◽  
Inga Saruniene ◽  
Ricardas Krikstolaitis ◽  
Mindaugas Valincius ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Risk Reduction ◽  
Hazard Analysis ◽  
Quantitative Risk Assessment ◽  
Study Results ◽  
Risk Aggregation ◽  
Risk Reduction Measures ◽  
The Impact

One of the goals of any oil terminal is to make a business while avoiding hazardous events and harmful effects for both humans and the environment. This can be achieved by creating a safe working place as well as by performing safe and acceptable activities regarding the impact on surrounding objects, including residential and industrial areas. The aim of the hazard analysis of the oil terminal is to assess the risks related to hazardous events or phenomena and to evaluate whether the assessed risks are acceptable. The hazard analysis and assessment of risk are also used for risk reduction while examining and limiting hazardous scenarios that, for instance, involve the loss-of-containment of flammable or combustible material. In this paper, the authors aim to contribute to risk research by providing a comprehensive methodology of risk assessment for oil terminals with case study results and discussion on features of the methodology, risk aggregation, its applicability for risk reduction, and industrial interests. The performed study considered the “Klaipedos Nafta AB” (an operator of the Klaipeda Oil Terminal, Lithuania) case study regarding hazardous materials that might be released from various tanks, devices, and associated pipelines. The performed quantitative risk assessment has enabled the determination of the probability regarding whether releases would ignite and, for instance, cause explosion. In the case study, the estimate of probability, i.e., the frequency, and the possible consequences of the hazardous events were evaluated, and both mitigation and risk reduction measures were also considered.

scholarly journals Irrigation Scheduling of Maize Grown on a Vertisol Soil Under Changing Climate of Sofia’s Field

2021 ◽  
Vol 24 (s1) ◽  
pp. 1-7
Author(s):  
Maria Ivanova ◽  
Zornitsa Popova
Keyword(s):  
Climate Adaptation ◽  
Irrigation Scheduling ◽  
Irrigation Season ◽  
Present Climate ◽  
Climate Conditions ◽  
The Past ◽  
The Impact ◽  
Very High ◽  
Irrigation Requirements

Abstract The purpose of this study is to evaluate the impact of climate uncertainties on maize irrigation requirements, grown on a Vertisol soil, Sofia’s field, Bulgaria. Through the validated WinIsareg model, four irrigation scheduling alternatives are simulated for the years of “very high“, “high“ and “average“ irrigation demands of past (1952–1984) and present (1970–2004) climate. Adaptation of irrigation scheduling to the present climate conditions during the “very dry“ years (P I ≤12%) consists of an extension of the irrigation season by 15–20 days and a need of additional irrigation relative to alternative 1 and two irrigation events at alternatives 2 and 3. During the past climate alternatives 2 and 3 led to savings of 30 mm of water, while up to the current climate conditions the three irrigations alternatives should provide 360 mm of irrigation water. To obtain maximum yields in “dry“ (P I = 12–30%) years, irrigation season should end by 05/09, as in the present climate, irrigation season has shifted about a week earlier for the three alternatives. In the “average“ (P I = 30–60%) years the adaptation consist in accurately determination of the last allowed date for irrigation.

scholarly journals Inversion of HIPPARCOS and Gaia photometric data for asteroids

2019 ◽  
Vol 631 ◽  
pp. A67 ◽  
Author(s):  
A. Cellino ◽  
D. Hestroffer ◽  
X.-P. Lu ◽  
K. Muinonen ◽  
P. Tanga
Keyword(s):  
Rotation Period ◽  
Simulated Data ◽  
Photometric Data ◽  
Small Samples ◽  
Triaxial Ellipsoid ◽  
Inversion Algorithm ◽  
Shape Model ◽  
The Past ◽  
Data Release

Context. Sparse photometric data can be used to determine the spin properties and infer information about the shapes of asteroids. The algorithm adopted for the inversion of Gaia photometric data assumes, for the sake of simplicity and to minimize CPU execution time, that the objects have triaxial ellipsoid shapes. In the past, this algorithm was tested against large sets of simulated data and small numbers of sparse photometric measurements obtained by HIPPARCOS. Aims. After the second Gaia data release, it is now possible to test the inversion algorithm against small samples of actual Gaia data for the first time. At the same time, we can attempt a new inversion of older HIPPARCOS measurements, using an updated version of the photometric inversion algorithm. Methods. The new version of our inversion algorithm includes the treatment of a Lommel-Seeliger scattering relation especially developed for the case of triaxial ellipsoid shapes. In addition, we also performed inversion attempts using a more refined shape model, based on the so-called cellinoid shapes. Results. With respect to the old inversion of HIPPARCOS data carried out in the past, we obtain only marginal improvements. In the case of Gaia data, however, we obtain very encouraging results. A successful determination of the rotation period is possible in most cases, in spite of the limited time span covered by data published in the second Gaia data release (GDR2), which makes the determination of the spin axis direction still uncertain. Even a small number of measurements, less than 30 in many cases, are sufficient to obtain a satisfactory inversion solution. Using the more realistic cellinoid shape model, we find further improvement in the determination of the spin period. Conclusions. This is a relevant validation of GDR2 photometry of asteroids, and proof of the satisfactory performances of the adopted inversion algorithm.

Property Risk Assessment for Combined Cycle Power Plants

2008 ◽  
Author(s):  
G. J. Orme ◽  
M. Venturini
Keyword(s):  
Risk Assessment ◽  
Power Plants ◽  
Combined Cycle ◽  
Sample Analysis ◽  
Electric Power Output ◽  
Customer Feedback ◽  
Benefit Evaluation ◽  
Assessment Procedures ◽  
The Impact

In the paper, a procedure for Property Risk Assessment is presented and discussed. The procedure is applied to some combined cycle power plants and the most common sources of loss are identified. The impact on operational costs is evaluated through the determination of two indices of risk. First, their dependence on combined cycle configuration and electric power output is established. Second, a sample analysis for risk/benefit evaluation is carried out to estimate whether the adoption of risk assessment procedures allows an actual profit for plant owners. Finally, customer feedback is also discussed.

scholarly journals ASSESSMENT RESIKO TEKNOLOGI PADA IMPLEMENTASI SISTEM INFORMASI AKADEMIK E-UNIVERSITY

2019 ◽  
Vol 1 (1) ◽  
pp. 54-60
Author(s):  
Yayuk Ike Meilani ◽  
Dedy Syamsuar ◽  
Yesi Novaria Kunang
Keyword(s):  
Risk Assessment ◽  
Information Technology ◽  
Information System ◽  
System Identification ◽  
Control Systems ◽  
Human Life ◽  
Business Activity ◽  
Academic Information ◽  
The Impact

Information technology has become an essential part of human life so as to facilitate a business activity. However, the use of information technology is not separated from the risks that can affect the process of the activity. As for the purpose of this study was to conduct an assessment of risk against potential vulnerabilities and threats that can attack the academic information system E-University all at once mempersiapan action anticipation towards things that can interfere with the the system. To do the assessment, this study uses the framework NIST SP 800-30r-1 consisting of nine stages to risk assessment i.e. in the characteristics of the system are used, identify the threats that attack system, identification of vulnerability, control systems, determine the likelihood of occurring (likelihood), determine the impact (impact), the determination of risks, control recommendations and documentation of results. The results of the risk assessment against the academic information system E-University is there are three risks disrupting existing activities in the system. Then from the results of the assessment of risks in the form of recommendations are used to minimize the risks that occur on the system

Sign in / Sign up

Export Citation Format

Share Document