美赛数模论文 - 图文

Team # 35565 Page 41 of 47

After the suspicious wreckage sea area is determined, search and rescue air

craft find two pieces of wreckage far distance. For example, the sea area appears surface circulation from the west to the east, and two pieces of wreckage are in the northernmost and southernmost respectively. Then we should consider the existence of eddy.

In order to find the drift efficiently, not only should we refresh suspicious area constantly according to the Bayesian methods, but also we should refer the circulation field data with higher accuracy and numerical simulation method. Accurate numerical simulations results depend on the accurate si-mulation of eddy current. For the final confirmation of the wreckage distri-bution area, we should consider the sea surface of the wind speed, wind di-rection, solar radiation, the net surface heat flux, precipitation and evapora-tion, tide and so on. We can improve our established model through a higher precision and advanced analysis model.

9 Strengths and Weaknesses

9.1 Strengths

? Our basic model allows us to have a close look at the crashing behavior. This

model gives us critical data and serves as a stepping stone to our later study, hence improve the efficiency.

? We establish the differential equation model combined with the earth rotation,

which is based on practical situation. This model can also extend to other projects.

? Ocean currents are complicated and mixed due to many factors and indepen-dent on inertia. In the extended model, we extract the typical turbulence to representative ocean currents to enhance the applicability of model.

? The conclusive model are capable of utilizing data and results. We consider

the equivalent area to adjust searching recourses, which contributes to the op-timization of the searching rule.

Team # 35565 Page 42 of 47

? Our models are fairly robust to the changes in parameters based on sensitivity

analysis. It means a slight change in parameters will not cause a significant change in the result.

9.2 Weaknesses

? Factors of human judgments and natural factors may be over-simplified. We

simply overlooked the influencing ingredients in the crashing process respec-tively. Actual situation may be more complicated.

? We assumed that the velocity of the wreck stay the same compared with ve-locity of the plane. Actually, part of the energy was consumed to compensate for kinds of thermal energy to cause some change in velocity vectors.

? Some of the parameters were revised to simplify the simulation such as sea

water density, speed of sea water etc. We didn?t take these factors into con-sideration entirely.

? Some uncontrollable external factors may cause irreversible interference on

important evidence. Thus the evidence may not occur in a continuous mode. The Bayesian approach can play a smaller role.

10 Non-technical paper

The airlines held a press conference and announced that they already have a system could best determine the location of the lost plane which is crashed in the open water and the most optimized plan to arrange search planes for future searches.

In an aircraft crash, almost no one could survive. Furthermore, the wreckage of the lost plane is difficult to find due to the crash site in the open water. There is a clear request to locate the crashed plane，and to do so in a much efficient way.

In their search scheme，searchers should consider the impact of different types of lost aircraft on the splash position, the different effects of the search device equipped with aircraft and other factors in the search process. In fact, there are many factors that may affect the location of the plane crash. In order to improve the predicting effi-

Team # 35565 Page 43 of 47

ciency to determine the distribution of the aircraft wreckage and the implementation of optimal search scheme, the scheme divides the process that is from the point out of contact of the aircraft with satellite to the specific location of the wreck into four stages: the plane falling into the seafloor from point out of contact, the final distribu-tion of the plane wreckage in open water, determining the number of search aircraft and arranging the search plan.

As is known to all, the search of the lost plane is an extremely rigorous scientific scheme. The uncertainty of the cash point, restrictions of the search equipment and other factors make the search of work cannot be carried out smoothly. This scheme makes full use of the variously objective information of the lost aircraft at the point out of contact, including a predetermined speed, latitude and longitude at this point, and delimit fall within the scope of the position of the aircraft route.

For the final position of the crashed wreckage in the open water , the scheme incor-porates influence and restrictions of ocean currents, water fluid and seabed terrain conditions , by comparing the practical height decreasing with the depth of the ocean, with the practical horizontal displacement of plane as the final distribution of regional debris together. What even more surprising is that according to the data of current ve-locity that airlines provide as the impact of this variable factors on the results is tiny, it increases the robustness of the model.

When arranging the search planes to salvage, we innovate the scheme by searching twice of the area. First searching part of the search area to get an intuitive under-standing of search zone. As to the equivalent area, we calculate the probability distri-bution density to act as coefficient of the weight to multiple corresponding area.

Then according to maximum speed，initial distance to search zone, the search ability, the maximum battery life of search aircraft to carry out selecting of aircraft, to make the search region can be completely covered and the highest efficiency.

However, in practical situation, some conditions of the scheme ignored or over sim-plified may affect the results, the airlines also need to do further revisions to the scheme.

In brief, the four stages can apply to any kind of aircraft's search and determine which of search the plane arrangement scheme. Make full use of the existing information, you will find scientific ways to search for the lost plane.

Team # 35565 Page 44 of 47

References

[1] Wikipedia. Airplane. http://en.wikipedia.org/wiki/Airplane#Characteristics

[2] Juan Santos-Echeandía, Ricardo Prego& Antonio Cobelo-García. Influence of the heavy fuel spill from the Prestige tanker wreckage in the overlying seawater column levels of copper,

nickel and vanadium. Marine Research Institute. 2006

[3] A. Boultif & D. Lou?r. Powder pattern indexing with the dichotomy method. J. Appl.

Cryst. 2004

[4] L.D. Stone, Theory of Optimal Search, Operations Research Society of America, ORSA

Books, Arlington, VA, 1989

[5] Xing Shenwei. Research On Global Optimization Model and Simulation of Joint Aero-nautical and Maritime Search. Dalian Maritime University Traffic Engineering and Control. 2012

[6] Wikipedia. Lockheed SR-71 Blackbird.

http://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird#Overview.

[7] Aircraft types for charter. http://www.aircraft-charter-world.com/aircraft_types.htm.

[8] Parthapratim Biswas, P. Sa′nchez, Michael R. Swift, and P. J. King. Numerical

simulations of air-driven granular separation. School of Physics and Astronomy, University of Nottingham, Nottingham，2003

[9] Wikipedia. Latitude. http://en.wikipedia.org/wiki/Latitude

[10] Hert Susan, Lumelsky Valdimir. Polygon Area Decomposition for Multi-robot Workspace Division[J]. International Journal of Computational Geometry & Applications (S0218-1959), 1998,8(4):437-466.

[11] Tang Bohu, Where has the MH370 crashed http://i.ifeng.com/news/sharenews.f?aid=79537811

[12] The Beijing News.

http://news.ifeng.com/world/special/malaixiyakejishilian/content-4/detail_2014_04/08/35542