Research on the Enhancement of Space-Tracking Ships' Orbit Determination Accuracy in Manned Space Engineering

2014 ◽  
Vol 536-537 ◽  
pp. 1097-1100
Author(s):  
Hui Fen Li ◽  
Guo Hu Xue ◽  
Jun Shan Mu ◽  
Xian Chun Xu ◽  
Sha Hao
Keyword(s):  
Orbit Determination ◽  
Calibration Method ◽  
Preliminary Treatment ◽  
Error Sources ◽  
Manned Space ◽  
Report Accuracy ◽  
And Control ◽  
Analysis Of Error ◽  
Selection Of

As China's space-tracking ships' missions change, there is ever higher demand on ships' orbit determination accuracy. This is reflected in Shenzhou missions, during which ships' orbit determination accuracy influences the whole tracking and control system. This paper bases its research on the analysis of error sources' influence on the determination of near-earth and near-round orbit, and proposes urgent problems and research prospects of maritime orbit determination accuracy enhancement. It establishes a model for adjusting ship attitude and speed, designs a self-adjusting information retrieval calibration method, realizes accurate simulation of ship complex error and researches on optimal selection of first-orbit root number based on sequence statistics. It also conducts research on improving preliminary treatment model and enhancing orbit report accuracy.

scholarly journals A Second-Order Time-Difference Position Constrained Reduced-Dynamic Technique for the Precise Orbit Determination of LEOs Using GPS

2021 ◽  
Vol 13 (15) ◽  
pp. 3033
Author(s):  
Hui Wei ◽  
Jiancheng Li ◽  
Xinyu Xu ◽  
Shoujian Zhang ◽  
Kaifa Kuang
Keyword(s):  
Orbit Determination ◽  
Dynamic Models ◽  
Precise Orbit Determination ◽  
Second Order ◽  
Time Difference ◽  
Error Sources ◽  
Precise Orbit ◽  
Unmodeled Dynamic ◽  
Reduced Dynamic

In this paper, we propose a new reduced-dynamic (RD) method by introducing the second-order time-difference position (STP) as additional pseudo-observations (named the RD_STP method) for the precise orbit determination (POD) of low Earth orbiters (LEOs) from GPS observations. Theoretical and numerical analyses show that the accuracies of integrating the STPs of LEOs at 30 s intervals are better than 0.01 m when the forces (<10−5 ms−2) acting on the LEOs are ignored. Therefore, only using the Earth’s gravity model is good enough for the proposed RD_STP method. All unmodeled dynamic models (e.g., luni-solar gravitation, tide forces) are treated as the error sources of the STP pseudo-observation. In addition, there are no pseudo-stochastic orbit parameters to be estimated in the RD_STP method. Finally, we use the RD_STP method to process 15 days of GPS data from the GOCE mission. The results show that the accuracy of the RD_STP solution is more accurate and smoother than the kinematic solution in nearly polar and equatorial regions, and consistent with the RD solution. The 3D RMS of the differences between the RD_STP and RD solutions is 1.93 cm for 1 s sampling. This indicates that the proposed method has a performance comparable to the RD method, and could be an alternative for the POD of LEOs.

scholarly journals Surveillance Aesthetics in Latin America: Work in progress

2012 ◽  
Vol 10 (1) ◽  
pp. 83-89 ◽  
Author(s):  
Fernanda Bruno ◽  
Paola Barreto ◽  
Milena Szafir
Keyword(s):  
Latin America ◽  
Los Angeles ◽  
Latin American ◽  
Satellite Images ◽  
Surveillance Culture ◽  
The Usa ◽  
On Line ◽  
And Control ◽  
Selection Of

This on line curatorship presents a selection of 11 works by Latin American artists who incorporate in their creations technologies traditionally linked to surveillance and control processes. By Surveillance Aesthetics we understand a compound of artistic practices, which include the appropriation of dispositifs such as closed circuit video, webcams, satellite images, algorithms and computer vision among others, placing them within new visibility, attention and experience regimes. The term referred to in the title of this exhibition is intended more as a vector of research rather than the determination of a field, as pointed by Arlindo Machado under the term “surveillance culture”. (Machado 1991) In this sense, a Latin America Surveillance Aesthetics exhibition is a way to propose, starting from the works presented here, a myriad of questions. How and to what extent do the destinies of surveillance devices reverberate or are subverted by market, security and media logics in our societies? If, in Europe and in the USA, surveillance is a subject related to the war against terror and border control, what can be said about Latin America? What forces and conflicts are involved? How have artistic practices been creating and acting in relation to these forces and conflicts? Successful panoramas of so called Surveillance Art already take place in Europe and North America for at least three decades, the exhibition “Surveillance”, at the Los Angeles Contemporary Exhibitions being one of the first initiatives in this domain. In Latin America however, art produced in the context of surveillance devices and processes is still seen as an isolated event. Our intention is to assemble a selection of works indicating the existence of a wider base of production, which cannot be considered eventual.The online exhibition can be accessed here.http://www.pec.ufrj.br/surveillanceaestheticslatina/

MEME: DAPATKAH MENINGKATKAN KEMAMPUAN SISWA DALAM MENULIS TEKS ANEKDOT?

2018 ◽  
Vol 2 (1) ◽  
pp. 105
Author(s):  
Fajar - Gumelar
Keyword(s):  
Project Based Learning ◽  
Student Centered ◽  
Student Centered Learning ◽  
Plan Selection ◽  
Productive Process ◽  
The Difference ◽  
Stage 1 ◽  
And Control ◽  
Selection Of

Writing anecdote text is a creative and productive process, meaning an ability that requires students to produce a product (writing) that aims to provide criticism/ satire accompanied by humor against an event that occurred. The fact that the ability to write anecdot text is still low, the difficulty in putting ideas and ideas into the main factor. The need for a model of learning with the use of media as a way to overcome these problems. Projects based learning assisted media meme are used based on literature review, which is a student-centered learning by applying the concept of the project (based on actual life that occurs) in order to solve the problem independently by using memes as a media that serves to clarify a message or content delivered. At the stage (1) the determination of fundamental questions about the events that occur (actual), (2) preparing the project plan (selection of data collection activities), (3) preparing a schedule (completion of activities), (4) monitoring project progress, (5) assessment of results, and (6) evaluation of experience (reflection of activities). This research aims to determine (a) the effectiveness of the model and (b) the effectiveness of the model in the experimental class (MIPA and IPS). The methodology used is a quasi experiment with 2 by 2 factorial research design. The results of research from data analysis, obtained (a) the difference in ability between the experimental class and control class students with N-gain experiments enter into medium category, while the N-gain controls enter into low category. (b) there is no difference ability in experimental class between MIPA and IPS class students. This shows that the model of Projects based learning assisted media meme effectively used in the class with the background of MIPA and IPS in SMA Negeri 15 Bandung. Keyword: writing anecdote text, project based learning, and media meme. 

scholarly journals ABOUT ORTHODOX EDUCATION IN MODERN RUSSIA

2020 ◽  
pp. 35-42
Author(s):  
T. S. Komashinskaya ◽  
Keyword(s):  
High School Teachers ◽  
Education Quality ◽  
Educational Models ◽  
Scientific Training ◽  
The Public ◽  
Methods Development ◽  
State Relations ◽  
And Control ◽  
Selection Of

The relevance of the study in regards to the science and theory is caused by the necessity of theoretical and pedagogical determination of the content of a new social and pedagogical reality developed due to the change of the place and status of religion in the public mind. The relevance of considering Orthodoxy in practice is caused by the search for ways for the spiritual revival of Russia as the society and the state desperately need educational models ensuring spiritual-moral components in the content of education. The paper analyzes the statistical data illustrating the dynamics of the Russians’ attitude to Orthodoxy. The author considers the legal and regulatory framework of Orthodox education. The author discusses the structure of Orthodox education in modern Russia. The paper describes the primary, secondary, vocational, and scientific training levels in Orthodox education and gives the typical forms of training for each level of education. The study shows that Orthodox learning uses both traditional and contemporary methods and techniques. In this respect, self-education is significant and necessary at all levels of Orthodox education. The main issues facing Orthodox education are associated with Orthodox education quality improvement, education forms and methods development, the training level of high-quality specialists for religious organizations, secondary and high school teachers, specialists in the sphere of inter-religious and church-state relations. One of the main problems at each level of learning is the specialization of education content and the selection of optimal ways of assessment and control for material retention. The author concludes that Russian people can get Orthodox education at any age, using various forms and methods of teaching.

scholarly journals Developments and Progress in Non-contact Eye Tonometer Calibration

2020 ◽  
Vol 20 (4) ◽  
pp. 171-177
Author(s):  
Peter Pavlásek ◽  
Jan Rybář ◽  
Stanislav Ďuriš ◽  
Branislav Hučko ◽  
Miroslav Chytil ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Calibration Method ◽  
Influential Factors ◽  
Measurement Standard ◽  
Detailed Characterization ◽  
Non Invasive ◽  
Air Stream ◽  
And Control ◽  
Traceable Calibration

AbstractThis paper focuses on the problematic of intraocular pressure (IOP) measurements, performed by non-invasive methods. More specifically, the devices that are connected with the presented finding are non-contact tonometers that use concentrated air stream and optical sensors to determine the IOP within a human’s eye. The paper analyzes various influential factors that have an effect on the determination of the IOP values originating from the patients themselves and from the non-contact tonometer devices. The paper furthermore elaborates on the lack of independent methods of calibration and control of these devices. In order to fill this gap a measurement standard device that is capable of calibrating and testing these devices with traceability to the basic SI unit is presented. A detailed characterization and the determination of the expected uncertainty of the device are provided. By introducing an independent and traceable calibration method and control of non-contact tonometers into the clinical practice, the reliability of the measured IOP that is the primary indicator of glaucoma can be improved.

Safety Materials and Control of Human-Cooperative Robots

1997 ◽  
Vol 9 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Toshio Morita ◽  
◽  
Shigeki Sugano
Keyword(s):  
Design Theory ◽  
Design Parameters ◽  
Personal Safety ◽  
Cooperative Robots ◽  
Safety Standards ◽  
Emergency Stop ◽  
And Control ◽  
Safety Guidelines ◽  
Selection Of

This paper discusses the design theory of a human-cooperative robot that has the capability of realizing both personal safety and cooperative work. The design parameters discussed in this paper include the safety materials, motion control, collision conditions, and safety standards that are necessary for realizing the symbiosis of robots with humans. To be concrete, the paper describes the modeling of shock-absorption materials, construction of an emergency stop system and a joint compliance control system, determination of collision simulation conditions, and the selection of a head injury standard equation. Next, the paper simulates collisions between a cooperatively working human and a robot by combining the parameters and straightens out the effects of various parameters regarding anticollision safety (presupposing collisions). Furthermore, the paper derives, based on experiments, a method of determining the parameters that are necessary for actually designing the system. Finally, the paper proposes safety guidelines and design points regarding human-cooperative robots by integrating the results of the above experiments and discussions.

Ultrastructural changes in sciatic nerve tissue: Effects of passive maternal smoking

1983 ◽  
Vol 41 ◽  
pp. 650-651
Author(s):  
Amankwah K.S. ◽  
A.D. Weberg ◽  
R.C. Kaufmann
Keyword(s):  
Sciatic Nerve ◽  
Maternal Smoking ◽  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Nerve Tissue ◽  
Ultrastructural Changes ◽  
Cacodylate Buffer ◽  
And Control ◽  
Spontaneous Delivery

Previous research has revealed that passive (involuntary inhalation) tobacco smoking during gestation can have adverse effects upon the developing fetus. These prior investigations did not concentrate on changes in fetal morphology. This study was undertaken to delineate fetal neural abnormalities at the ultrastructural level in mice pups exposed in utero to passive maternal smoking.Pregnant study animals, housed in a special chamber, were subjected to cigarette smoke daily from conception until delivery. Blood tests for determination of carbon monoxide levels were run at 15-18 days gestation. Sciatic nerve tissue from experimental and control animals were obtained following spontaneous delivery and fixed in 2.5% gluteraldehyde in 0.1M cacodylate buffer pH 7.3. The samples were post-fixed in osmium ferrocyanide (1:1 mixture of 1.5% aqueous OSO4 and 2.5% K4 Fe(CN)6). Following dehydration, the tissues were infiltrated with and embedded in Spurr. Sections were stained with uranyl acetate and lead citrate.

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