2022小美赛赛题的移动云盘下载地址 ; B9 f* M9 }/ G, P8 q3 |: q& a& V
https://caiyun.139.com/m/i?0F5CJAMhGgSJx4 @/ C8 c d; G+ [1 R* b) h
$ _( r" Q) |- s9 A5 Y2022 2 w7 r. b/ y6 Y3 @Certifificate Authority Cup International Mathematical Contest Modeling& g' x, f% a0 l& G
http://mcm.tzmcm.cn* f7 s- T" a) Z* [
Problem A (MCM); }( {" P) C: y" b! A
How Pterosaurs Fly , g4 a+ o a$ b( l) v* I H: T/ VPterosaurs is an extinct clade of flflying reptiles in the order, Pterosauria. They( J8 J$ b9 I I4 I
existed during most of the Mesozoic: from the Late Triassic to the end of ; ]6 R1 ^: s* e& b2 v# P+ m9 ^* D7 ithe Cretaceous. Pterosaurs are the earliest vertebrates known to have evolved S% }4 b2 h0 O
powered flflight. Their wings were formed by a membrane of skin, muscle, and( D" i' q+ G7 }$ ]
other tissues stretching from the ankles to a dramatically lengthened fourth 6 E+ ^. Y( ]' |6 b0 L' k9 Qfifinger[1]." G7 Q" _) Y9 q1 j& b
There were two major types of pterosaurs. Basal pterosaurs were smaller8 `" z0 e! x& @5 @9 L/ g
animals with fully toothed jaws and long tails usually. Their wide wing mem ! H5 Y2 r) D+ \) E& ^branes probably included and connected the hind legs. On the ground, they & z% P& V& A; h# n0 jwould have had an awkward sprawling posture, but their joint anatomy and1 S4 K6 O2 A. h- a
strong claws would have made them effffective climbers, and they may have lived . L' l! r2 P2 ^5 Bin trees. Basal pterosaurs were insectivores or predators of small vertebrates.8 {4 i, _( b3 G( K3 }6 K/ x
Later pterosaurs (pterodactyloids) evolved many sizes, shapes, and lifestyles. & l9 o, s' j* R) T3 H. t8 ~* I3 Z. XPterodactyloids had narrower wings with free hind limbs, highly reduced tails,* A, @6 k: G. a2 |* |% o; q( y% q7 K
and long necks with large heads. On the ground, pterodactyloids walked well on - N0 X- F f" h" \2 h( ]; sall four limbs with an upright posture, standing plantigrade on the hind feet and% d' N. I/ u' v. v5 j
folding the wing fifinger upward to walk on the three-fifingered “hand”. The fossil 2 f/ D6 S: b* `% Ftrackways show at least some species were able to run and wade or swim[2].& h6 v2 q3 ~3 r0 g7 X+ R; g) } }
Pterosaurs sported coats of hair-like fifilaments known as pycnofifibers, which 5 b$ c3 w) e. U1 Acovered their bodies and parts of their wings[3]. In life, pterosaurs would have1 Y, ]3 U$ P5 K% a5 E5 N7 o
had smooth or flfluffffy coats that did not resemble bird feathers. Earlier sug , Y: ~) K: I- Q/ V7 ?0 U- h; ~gestions were that pterosaurs were largely cold-blooded gliding animals, de # a( h) e: D) I! ^9 briving warmth from the environment like modern lizards, rather than burning 6 T2 e8 M' N- h9 N1 ?calories. However, later studies have shown that they may be warm-blooded ( s' J% e' h- ^4 d3 q% a: `6 l4 O(endothermic), active animals. The respiratory system had effiffifficient unidirec2 Z/ A/ I$ E u2 ^# W( {: s
tional “flflow-through” breathing using air sacs, which hollowed out their bones- K# `9 l3 A% y3 ^ F
to an extreme extent. Pterosaurs spanned a wide range of adult sizes, from & z& V% R* V( `( Ithe very small anurognathids to the largest known flflying creatures, including8 e/ T- Y: F8 \
Quetzalcoatlus and Hatzegopteryx[4][5], which reached wingspans of at least $ k' h3 \+ R2 nnine metres. The combination of endothermy, a good oxygen supply and strong2 m1 V$ l) W7 n) [: N# O' T1 X3 E
1muscles made pterosaurs powerful and capable flflyers.( ?. o0 p+ ?0 K" ~$ A% g
The mechanics of pterosaur flflight are not completely understood or modeled) c" T* X; X8 P2 M' J" f+ S
at this time. Katsufumi Sato did calculations using modern birds and concluded) N& L& `- M' Z% o9 |
that it was impossible for a pterosaur to stay aloft[6]. In the book Posture, : Q$ T# w9 b z: Q' M' JLocomotion, and Paleoecology of Pterosaurs it is theorized that they were able0 {9 l/ C: @' B
to flfly due to the oxygen-rich, dense atmosphere of the Late Cretaceous period[7]. - o0 N; W0 J9 L0 T7 J, W6 p& uHowever, both Sato and the authors of Posture, Locomotion, and Paleoecology 9 d9 _ p% M$ s9 ]9 t0 Rof Pterosaurs based their research on the now-outdated theories of pterosaurs6 ^" V9 [+ `6 I. w" }9 Y/ O
being seabird-like, and the size limit does not apply to terrestrial pterosaurs,& d0 |* G+ g: I
such as azhdarchids and tapejarids. Furthermore, Darren Naish concluded that/ W2 H% n$ E) b( @
atmospheric difffferences between the present and the Mesozoic were not needed 1 H5 H% Z5 O3 S% R& O* ?for the giant size of pterosaurs[8].; f, o" {, N% h) C6 r/ y9 g4 ]! P
Another issue that has been diffiffifficult to understand is how they took offff.0 v( G" ?8 j$ Y( t& ^: k" G$ ^6 G
If pterosaurs were cold-blooded animals, it was unclear how the larger ones 4 A7 C% ? ^5 t: Qof enormous size, with an ineffiffifficient cold-blooded metabolism, could manage ( r5 _# J0 R8 j+ k" b4 ta bird-like takeoffff strategy, using only the hind limbs to generate thrust for # J+ i3 e6 {$ v" e1 Z5 Igetting airborne. Later research shows them instead as being warm-blooded K0 G' K: X: k& g5 ?! band having powerful flflight muscles, and using the flflight muscles for walking as( J# r7 E3 Z- N1 X* r
quadrupeds[9]. Mark Witton of the University of Portsmouth and Mike Habib of7 r" |2 X+ n/ V) ^& B* Z1 Y% y
Johns Hopkins University suggested that pterosaurs used a vaulting mechanism- k, p+ ~' e7 z3 C! w7 [1 W
to obtain flflight[10]. The tremendous power of their winged forelimbs would/ u: i5 h% L& V* d& x8 ]& T* J1 ^ a! `
enable them to take offff with ease[9]. Once aloft, pterosaurs could reach speeds + M$ ~; x1 U# p3 wof up to 120 km/h and travel thousands of kilometres[10].# ^0 \3 ]8 O: J& Q, [% C& Y
Your team are asked to develop a reasonable mathematical model of the 0 x; N0 C5 ?4 Eflflight process of at least one large pterosaur based on fossil measurements and: D% ^# A2 Z; W/ a
to answer the following questions.+ O. }; n* n C7 k% e7 c4 N
1. For your selected pterosaur species, estimate its average speed during nor * c r4 L" B) Tmal flflight.+ |: i0 @$ f. Z3 a
2. For your selected pterosaur species, estimate its wing-flflap frequency during & q+ [# K9 r# J& B5 h( @6 Ynormal flflight. $ ?) c+ N' h# c8 j2 H, h; x: Y3. Study how large pterosaurs take offff; is it possible for them to take offff like/ ^0 S6 `0 A- U, f$ q8 |
birds on flflat ground or on water? Explain the reasons quantitatively. $ r, Z: e7 f7 a, }# ^References 1 O! X9 [* \* Q$ f, T[1] Elgin RA, Hone DW, Frey E (2011). The Extent of the Pterosaur Flight " G5 T: [) ~5 w- h2 A% C3 l5 y! DMembrane. Acta Palaeontologica Polonica. 56 (1): 99-111. x& e' Q$ V ~0 z2[2] Mark Witton. Terrestrial Locomotion. % C, a- I8 P* O6 a% ~9 ~6 ~# ahttps://pterosaur.net/terrestrial locomotion.php [6 H. q+ G# s. T4 k+ c4 {/ y# v[3] Laura Geggel. It’s Offiffifficial: Those Flying Reptiles Called Pterosaurs 0 r1 y& Z; E5 I, g0 C7 DWere Covered in Fluffffy Feathers. https://www.livescience.com/64324-2 f# O @; U% [# I) ]
pterosaurs-had-feathers.html9 o3 K2 w9 b/ G+ B6 Y& N5 S
[4] Wang, X.; Kellner, A.W.A.; Zhou, Z.; Campos, D.A. (2008). Discovery of a & X) t2 W5 D" [( X$ E/ Brare arboreal forest-dwelling flflying reptile (Pterosauria, Pterodactyloidea) 3 `) `! }" j5 f% A; wfrom China. Proceedings of the National Academy of Sciences. 105 (6): 6 K. `( U6 I2 X' ?* ?1983-87.. Q! y: ~, U! Y# t+ E; ~
[5] Buffffetaut E, Grigorescu D, Csiki Z. A new giant pterosaur with a robust % b9 @ ]! y+ D& O# `2 Q% cskull from the latest cretaceous of Romania. Naturwissenschaften. 89 (4):( b- }+ D& m6 n! v
180-84. ( i6 R! {* ^% T& W[6] Devin Powell. Were pterosaurs too big to flfly?: P1 M& A9 h* K& O7 ^% X. u0 U
https://www.newscientist.com/article/mg20026763-800-were-pterosaurs , [' J2 k1 W3 Gtoo-big-to-flfly/- m! p! z# Q# `3 z% K B+ ]: C* U
[7] Templin, R. J.; Chatterjee, Sankar. Posture, locomotion, and paleoecology, y2 q, q# }" K" `4 g% \
of pterosaurs. Boulder, Colo: Geological Society of America. p. 60.0 G# _( _% B6 f! s! v5 G( m
[8] Naish, Darren. Pterosaurs breathed in bird-like fashion and had inflflatable ) g3 S6 R- O- ^% X9 ?air sacs in their wings.9 i/ o9 ?1 }( K w* u
https://scienceblogs.com/tetrapodzoology/2009/02/18/pterosaur0 Z3 b2 o/ N+ c
breathing-air-sacs 4 O# N' C0 ^3 ?; I4 R7 W* y[9] Mark Witton. Why pterosaurs weren’t so scary after all. 3 [/ @0 Y- ^7 O* ? bhttps://www.theguardian.com/science/2013/aug/11/pterosaurs-fossils: d7 V8 J5 p3 N
research-mark-witton/ C H- S" Q# [! }9 L$ e3 g
[10] Jeffff Hecht. Did giant pterosaurs vault aloft like vampire bats?, F J4 n3 c: ?+ X& P9 i
https://www.newscientist.com/article/dn19724-did-giant-pterosaurs6 }: t+ N4 u* \8 B9 m/ n( q3 b# A
vault-aloft-like-vampire-bats/ ; ^, |. _0 `- L& D% c# ~ \ 1 X& U7 C. V+ Y( N2 y6 w* Q# z2022 1 z1 Z; u# p( F7 N1 z5 f& cCertifificate Authority Cup International Mathematical Contest Modeling0 H( M. P( |$ U5 }, d+ F* {4 U
http://mcm.tzmcm.cn+ S+ v& r1 m0 E* u4 R( \3 \
Problem B (MCM)+ Z( t+ J- l% m4 x# n5 r/ D9 d
The Genetic Process of Sequences4 P) C# Q6 y5 v
Sequence homology is the biological homology between DNA, RNA, or protein ' z0 \9 g6 d& P) d& _& ]7 Csequences, defifined in terms of shared ancestry in the evolutionary history of - n4 ?5 y2 O# o/ Mlife[1]. Homology among DNA, RNA, or proteins is typically inferred from their # O& J/ ~+ [ D# H: |3 ]nucleotide or amino acid sequence similarity. Signifificant similarity is strong 5 z0 G* }# ?% S8 Hevidence that two sequences are related by evolutionary changes from a common0 v& }/ P6 I% @0 B. q! U
ancestral sequence[2]. 5 `* [# j& T6 `. L. L0 e8 PConsider the genetic process of a RNA sequence, in which mutations in nu/ x+ q5 B# ~4 \! U
cleotide bases occur by chance. For simplicity, we assume the sequence mutation 8 X' t4 Q; }/ y: Narise due to the presence of change (transition or transversion), insertion and 3 e" I5 y# H7 {$ p! ~. vdeletion of a single base. So we can measure the distance of two sequences by e) I7 Q* s6 ^" Ethe amount of mutation points. Multiple base sequences that are close together0 Q+ F6 A: E5 x" i
can form a family, and they are considered homologous.2 V" i/ [# m2 f$ V7 W
Your team are asked to develop a reasonable mathematical model to com2 s! }- A5 o! i, t5 Y
plete the following problems. - B% m) b% F) x5 t" a1. Please design an algorithm that quickly measures the distance between " v& t" v0 F# w* u2 n( Q* Ztwo suffiffifficiently long(> 103 bases) base sequences.% e, B, y! J" v5 o- N+ g
2. Please evaluate the complexity and accuracy of the algorithm reliably, and ! i, x% x* Q6 h* cdesign suitable examples to illustrate it. + y* G4 U) u0 L( e$ C& k/ B5 l3. If multiple base sequences in a family have evolved from a common an2 ^- v7 W; e8 E6 O! P/ \) a( H
cestral sequence, design an effiffifficient algorithm to determine the ancestral8 R/ z$ c% H: f' N$ g- R. l' E6 O# l
sequence, and map the genealogical tree.' g- M" U% J6 [+ s) e
References ( m9 R# d9 k8 |: b8 c& m[1] Koonin EV. “Orthologs, paralogs, and evolutionary genomics”. Annual Re3 [" C2 l4 }6 V. ?# d2 p
view of Genetics. 39: 30938, 2005.4 G8 I3 I ?+ z" d$ `/ L$ }: N
[2] Reeck GR, de Han C, Teller DC, Doolittle RF, Fitch WM, Dickerson RE, / d; I0 u3 U+ }; N6 s9 p& h/ ^! pet al. “Homology” in proteins and nucleic acids: a terminology muddle and- @% M( L" S |5 x
a way out of it. Cell. 50 (5): 667, 1987. / J" J9 e* T% D3 f% J1 \) Q- d/ |" h% o5 W$ P
2022 , A( z' n2 o$ d q/ H$ |Certifificate Authority Cup International Mathematical Contest Modeling # j( o5 X+ Q7 j6 Rhttp://mcm.tzmcm.cn ' L: ~8 r% `( T: u1 JProblem C (ICM); Y, P* J1 i' y$ v6 a
Classify Human Activities A) t+ |5 d, S/ z4 ^" d0 V( j
One important aspect of human behavior understanding is the recognition and/ c' R: i" [% a2 \* _; F
monitoring of daily activities. A wearable activity recognition system can im9 Q& A7 g" }$ C0 b
prove the quality of life in many critical areas, such as ambulatory monitor 7 f, n0 U' h7 n+ ?8 e. F* ]/ _ing, home-based rehabilitation, and fall detection. Inertial sensor based activ9 p2 J! P; S3 t' R
ity recognition systems are used in monitoring and observation of the elderly 1 H& O/ H' V5 J% C7 ^remotely by personal alarm systems[1], detection and classifification of falls[2],9 f; h2 a+ ?' T8 s4 p$ L
medical diagnosis and treatment[3], monitoring children remotely at home or in 6 R' V+ n) b/ t' F9 E7 Aschool, rehabilitation and physical therapy , biomechanics research, ergonomics,/ I/ T9 ?+ x/ R/ N
sports science, ballet and dance, animation, fifilm making, TV, live entertain! ?: X) Z4 A! ~* k; S& T
ment, virtual reality, and computer games[4]. We try to use miniature inertial 7 t& _/ `3 _+ d+ [# s! Rsensors and magnetometers positioned on difffferent parts of the body to classify . r% D, O+ b, ?8 `$ nhuman activities, the following data were obtained.# u& `% _$ o2 w
Each of the 19 activities is performed by eight subjects (4 female, 4 male,; @' h4 X( T: W0 f- L. J
between the ages 20 and 30) for 5 minutes. Total signal duration is 5 minutes1 f" O( V( Q. q: c2 o! M4 U8 ]
for each activity of each subject. The subjects are asked to perform the activ: j5 ?9 }8 P: }; Y# k2 @8 H0 @
ities in their own style and were not restricted on how the activities should be ! A* |; d" B8 Z$ v& }( L- \- z; Jperformed. For this reason, there are inter-subject variations in the speeds and . S. }( ]) a" Bamplitudes of some activities. ' _! V& J/ [& y" B- l4 O8 q, U& qSensor units are calibrated to acquire data at 25 Hz sampling frequency. 4 n5 P' b: O, m6 H6 V- v' I( K' I. rThe 5-min signals are divided into 5-sec segments so that 480(= 60 × 8) signal0 Y" |2 c' W! {; C0 V$ i
segments are obtained for each activity. , X' L, q6 a9 n/ \! C" W/ MThe 19 activities are:2 G/ D) C: q) ^! i
1. Sitting (A1);6 u% S& y" ?& u' U0 F
2. Standing (A2);* s- o/ e& J c( m
3. Lying on back (A3); [3 R0 R' z& ?" r: Z0 y3 u( y5 \. |
4. Lying on right side (A4);& K' ~: E' z: T( H+ s$ e' E
5. Ascending stairs (A5); 4 [; {1 }9 n( E. t) Z+ a3 C16. Descending stairs (A6);4 P9 Z# h+ P& ?- w% M0 ^
7. Standing in an elevator still (A7);( C$ F, T1 I+ @+ K: h) `
8. Moving around in an elevator (A8); 7 g9 R6 C' z% \& C6 _9. Walking in a parking lot (A9);1 h, K6 V8 ?; k2 K+ u+ T. q
10. Walking on a treadmill with a speed of 4 km/h in flflat position and 15 deg+ @8 g+ P2 [" D2 x& K! M
inclined positions (A10); / B) ]9 N( N3 M6 b1 I5 N7 g- b11. Walking on a treadmill with a speed of 4 km/h in 15 deg inclined positions$ i. h F, ^6 |2 v
(A11);) g, D* N% t1 X9 g
12. Running on a treadmill with a speed of 8 km/h (A12); & Z7 ?' u$ D) J. _- `% f1 L13. Exercising on a stepper (A13);$ ]- z" T1 Y8 p% n; L$ ~1 G
14. Exercising on a cross trainer (A14);0 a, D. l; Q# I
15. Cycling on an exercise bike in horizontal position (A15);: @8 v# }) K6 P7 j
16. Cycling on an exercise bike in vertical position (A16); " F6 U6 t/ e. ?- E17. Rowing (A17); 6 M, @+ Y! C0 }$ U/ [7 U18. Jumping (A18);, g; @* R, O3 G
19. Playing basketball (A19). c! z8 p; [3 j
Your team are asked to develop a reasonable mathematical model to solve 1 O, e3 Y) \# |the following problems.: q+ p( _: s4 s, M$ A
1. Please design a set of features and an effiffifficient algorithm in order to classify- @! W3 \$ c* i' s& U
the 19 types of human actions from the data of these body-worn sensors. 8 } `! ^/ i) o2. Because of the high cost of the data, we need to make the model have# K/ U& t+ E7 t7 ]
a good generalization ability with a limited data set. We need to study1 e3 d' j! U$ J9 o* `2 M
and evaluate this problem specififically. Please design a feasible method to* F+ A% T7 H- Q( P
evaluate the generalization ability of your model. ' _% w N0 J' m3 C3. Please study and overcome the overfifitting problem so that your classififi-! s, _$ z- I: \
cation algorithm can be widely used on the problem of people’s action ! q3 C! k, F9 Z8 l, U2 Vclassifification. 2 |) i( G* K8 X# e BThe complete data can be downloaded through the following link:( Q# L) t) H$ ^* d t# F3 `
https://caiyun.139.com/m/i?0F5CJUOrpy8oq ' e2 M% B4 K" k( p/ |6 x2Appendix: File structure % I$ b" ]+ U9 H) D c• 19 activities (a) 7 ^8 U# y" [! Z2 G* b• 8 subjects (p) 5 b- H( f# @6 o* P/ b• 60 segments (s) 8 O7 W3 U, L0 M b- o( c9 g. k• 5 units on torso (T), right arm (RA), left arm (LA), right leg (RL), left1 {6 u$ o P$ W7 f
leg (LL)0 V }$ x1 l8 t; O- E. [' K
• 9 sensors on each unit (x, y, z accelerometers, x, y, z gyroscopes, x, y, z: t' z( Q0 N, g+ d1 q
magnetometers) : }- z" L* ^7 y, w uFolders a01, a02, ..., a19 contain data recorded from the 19 activities.8 L( B3 U- D c! d$ q
For each activity, the subfolders p1, p2, ..., p8 contain data from each of the6 m2 H" U+ i0 X* ?
8 subjects. " C) ^ C& q4 T0 E( |In each subfolder, there are 60 text fifiles s01, s02, ..., s60, one for each- Z/ e3 n8 o, ~
segment.2 c* H* ?' U. ~+ p: u8 F* ?
In each text fifile, there are 5 units × 9 sensors = 45 columns and 5 sec × 252 m* r0 k- n/ v+ u; x# G# ]
Hz = 125 rows.! w: x/ Q. a$ t9 U
Each column contains the 125 samples of data acquired from one of the* j6 a/ E$ N2 r
sensors of one of the units over a period of 5 sec. : @ g4 l" X; b# s6 AEach row contains data acquired from all of the 45 sensor axes at a particular8 t \3 R: t3 ~7 ~& t" N, R
sampling instant separated by commas. 5 I; _" l' @( d" k8 rColumns 1-45 correspond to: ' z. I1 j G( E4 l x6 Y% m• T_xacc, T_yacc, T_zacc, T_xgyro, ..., T_ymag, T_zmag,8 E; i' E' a4 n/ ]& a
• RA_xacc, RA_yacc, RA_zacc, RA_xgyro, ..., RA_ymag, RA_zmag,0 K% h% }. J8 b1 }) G/ `+ m* q
• LA_xacc, LA_yacc, LA_zacc, LA_xgyro, ..., LA_ymag, LA_zmag,9 ^5 R q; W1 F/ @/ A k
• RL_xacc, RL_yacc, RL_zacc, RL_xgyro, ..., RL_ymag, RL_zmag, 8 Q/ E$ V/ d }- F: Z {, b• LL_xacc, LL_yacc, LL_zacc, LL_xgyro, ..., LL_ymag, LL_zmag. + u. M4 Y+ U6 g# n/ J# T4 PTherefore, ; P4 w( h, l0 e" h6 C0 k• columns 1-9 correspond to the sensors in unit 1 (T), ! K0 m+ j$ D8 W8 t8 y5 | @9 ^• columns 10-18 correspond to the sensors in unit 2 (RA),; Q: A* e0 m! t! E
• columns 19-27 correspond to the sensors in unit 3 (LA),; c( n: S$ K- s4 }1 T
• columns 28-36 correspond to the sensors in unit 4 (RL),) `! ^7 A. B0 ~! n8 C2 o
• columns 37-45 correspond to the sensors in unit 5 (LL).- C$ L) [9 [" \" |; I/ g: W
3References - G2 M4 s% R" n0 f. c5 Y6 I- X[1] Mathie M.J., Celler B.G., Lovell N.H., Coster A.C.F. Classifification of basic6 J9 E5 ^8 v& t5 A# w8 r& K
daily movements using a triaxial accelerometer. Med. Biol. Eng. Comput.$ Y0 p- T4 i& O3 x
42(5), 679-687, 2004 4 y# l; B8 f$ P[2] Kangas M., Konttila A., Lindgren P., Winblad I., Ja¨msa¨ T. Comparison of1 h: E: P4 W+ ?# P) J! {
low-complexity fall detection algorithms for body attached accelerometers.* {" ?- K @1 n0 ?. a3 y9 d6 y
Gait Posture 28(2), 285-291, 2008 2 u! U0 C0 [' ~; {) Z* C0 B[3] Wu W.H., Bui A.A.T., Batalin M.A., Liu D., Kaiser W.J. Incremental diag; R( }' ~# [5 m) k7 p1 s
nosis method for intelligent wearable sensor system. IEEE T. Inf. Technol. 2 W5 ^3 l% P: V0 i* J9 DB. 11(5), 553-562, 2007 ' y- F1 n1 E, W, r0 m[4] Shiratori T., Hodgins J.K. Accelerometer-based user interfaces for the con* d# P0 w- I1 H$ u/ b2 v5 ~9 Q
trol of a physically simulated character. ACM T. Graphic. 27(5), 20087 b8 q) M, _5 Z+ M# z; q
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2022 M. V( h' I- |# d* d) C3 g
Certifificate Authority Cup International Mathematical Contest Modeling # O* Z4 P. {% K6 X! O! M1 thttp://mcm.tzmcm.cn& ^2 t1 w. [7 J! \( E, A) Z
Problem D (ICM)9 C. M8 z' I4 t! w" g9 T
Whether Wildlife Trade Should Be Banned for a Long& H& N" O7 b9 f6 T P# E4 N, \
Time: H; j C5 q( c; ^3 R
Wild-animal markets are the suspected origin of the current outbreak and the& n5 r, |% D" y4 M& J( H ~; ^
2002 SARS outbreak, And eating wild meat is thought to have been a source* d, N' u& z. J: _1 H
of the Ebola virus in Africa. Chinas top law-making body has permanently 6 n; f. X: c& l* h; L) \* i8 i) ztightened rules on trading wildlife in the wake of the coronavirus outbreak,- U- ^* e& Z" ^) }" U
which is thought to have originated in a wild-animal market in Wuhan. Some; p8 U/ F" S1 _! t1 [5 P
scientists speculate that the emergency measure will be lifted once the outbreak# E' F7 M* o9 i l% R; h
ends.7 X% d4 U' ?% ]0 M, F6 v1 ^
How the trade in wildlife products should be regulated in the long term? $ ? S$ ]$ ]" H0 V+ H( O* d/ p4 ?Some researchers want a total ban on wildlife trade, without exceptions, whereas 9 d( a r1 U3 Q f mothers say sustainable trade of some animals is possible and benefificial for peo% ?. b9 @% k6 p+ }4 e
ple who rely on it for their livelihoods. Banning wild meat consumption could+ K$ \& g$ O! ]6 O, v) o
cost the Chinese economy 50 billion yuan (US $ 7.1 billion) and put one mil % j+ R$ _. r' U0 klion people out of a job, according to estimates from the non-profifit Society of , ^" {. V. E: I# p, fEntrepreneurs and Ecology in Beijing.. g9 Z1 ]2 D" l/ N! Q
A team led by Shi Zheng-Li and Cui Jie of the Wuhan Institute of Virology 2 N" q _6 i! q! j* ~in China, chasing the origin of the deadly SARS virus, have fifinally found their . v8 l! ^. G" \$ P) Lsmoking gun in 2017. In a remote cave in Yunnan province, virologists have0 X2 g9 w8 x9 x2 f& H! K5 @5 \
identifified a single population of horseshoe bats that harbours virus strains with* [0 `& M5 [5 |! B" R! A; j
all the genetic building blocks of the one that jumped to humans in 2002, killing 6 n$ s$ m* k, u, galmost 800 people around the world. The killer strain could easily have arisen4 k* t! S' O7 _% g' q
from such a bat population, the researchers report in PLoS Pathogens on 30 5 k. u( M9 b2 h% I1 m) }; f# H% }November, 2017. Another outstanding question is how a virus from bats in* M6 J, T$ Y6 u2 U7 R7 R: N. D
Yunnan could travel to animals and humans around 1,000 kilometres away in , f3 t2 T2 L9 t& r& xGuangdong, without causing any suspected cases in Yunnan itself. Wildlife # H' E0 A$ o. |; dtrade is the answer. Although wild animals are cooked at high temperature. @2 o: V% m( M/ k3 ]' i
when eating, some viruses are diffiffifficult to survive, humans may come into contact 6 ?& z" O! _4 \' `with animal secretions in the wildlife market. They warn that the ingredients3 P$ S& M7 G5 Y1 l
are in place for a similar disease to emerge again. |) W4 D% A& {
Wildlife trade has many negative effffects, with the most important ones being:3 ^* {+ z& v* a, @% E
1Figure 1: Masked palm civets sold in markets in China were linked to the SARS; P8 T1 V0 p. H" q1 Q/ L. f
outbreak in 2002.Credit: Matthew Maran/NPL z: {- j! t4 J& C
• Decline and extinction of populations4 i( F% n1 n" C# } X
• Introduction of invasive species % H/ { d0 {+ l+ r• Spread of new diseases to humans" \1 M* w+ e5 C
We use the CITES trade database as source for my data. This database : A% l0 V9 C" |- |+ fcontains more than 20 million records of trade and is openly accessible. The ! J/ y e& X- b. @. M; cappendix is the data on mammal trade from 1990 to 2021, and the complete; a5 H4 K$ c% f) B: D7 t
database can also be obtained through the following link: / r" I) [5 x; V; G: ~! [2 ^https://caiyun.139.com/m/i?0F5CKACoDDpEJ 1 B7 A! }" }: `; DRequirements Your team are asked to build reasonable mathematical mod" C; V: x# N3 {) _% H1 K
els, analyze the data, and solve the following problems: 3 p$ V( g6 _: T1. Which wildlife groups and species are traded the most (in terms of live 1 y% c( q: p* _* _: A& K) Wanimals taken from the wild)?& y9 J0 v9 \+ @9 G0 o9 Y/ R8 o* x+ E
2. What are the main purposes for trade of these animals? 0 H' p7 S# r$ z% m$ P3. How has the trade changed over the past two decades (2003-2022)? 4 S3 ?& N% p- u& M, a4. Whether the wildlife trade is related to the epidemic situation of major ' n% `% }4 }0 @. Z2 iinfectious diseases?7 r! \. s M# \6 D p+ i
25. Do you agree with banning on wildlife trade for a long time? Whether it 8 |0 C6 g9 m1 Y* z% xwill have a great impact on the economy and society, and why? 0 `( y+ M' J0 U1 I0 l, s% }6. Write a letter to the relevant departments of the US government to explain$ }! {, v3 [* }; S5 O
your views and policy suggestions.- ?. B9 |# G% T+ X5 m" k
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