2022小美赛赛题的移动云盘下载地址 7 T$ n4 ^0 {5 Uhttps://caiyun.139.com/m/i?0F5CJAMhGgSJx, d) i# K/ w# b4 V) j4 R/ L9 J
% Z0 E4 c+ H- `+ G m# t* d
2022: k% s5 k: b) i" l+ f& E) H
Certifificate Authority Cup International Mathematical Contest Modeling ) h( c) \. T7 P" J/ Ohttp://mcm.tzmcm.cn : ~* H8 e/ }7 Q, J$ CProblem A (MCM)6 I z/ M0 X) T b4 c& }, z
How Pterosaurs Fly ) Q3 u, h' S; oPterosaurs is an extinct clade of flflying reptiles in the order, Pterosauria. They* l. H/ K/ m0 u1 b# W* t
existed during most of the Mesozoic: from the Late Triassic to the end of( K: }4 W# c+ K* D1 @7 x4 j1 |
the Cretaceous. Pterosaurs are the earliest vertebrates known to have evolved $ A/ g! a \; X5 e; ~7 G5 Lpowered flflight. Their wings were formed by a membrane of skin, muscle, and - w$ P/ @" Q! h9 @$ \- ~other tissues stretching from the ankles to a dramatically lengthened fourth8 J6 ]8 ]1 F0 d' T# ~
fifinger[1].) f$ @ L7 I) P7 |" Q v% z
There were two major types of pterosaurs. Basal pterosaurs were smaller " K3 o- q: K; p5 |4 _: Aanimals with fully toothed jaws and long tails usually. Their wide wing mem 3 d0 @, v( y5 q# B2 Dbranes probably included and connected the hind legs. On the ground, they9 H% k/ v, J+ _4 s' {6 D8 g9 J$ I
would have had an awkward sprawling posture, but their joint anatomy and 7 Q/ o. I% O% j. b5 cstrong claws would have made them effffective climbers, and they may have lived f4 d c- w& V Q1 e" |
in trees. Basal pterosaurs were insectivores or predators of small vertebrates. 4 t+ D. z; n6 J9 r I! l* NLater pterosaurs (pterodactyloids) evolved many sizes, shapes, and lifestyles. , R# J$ v4 L! w S f* c5 xPterodactyloids had narrower wings with free hind limbs, highly reduced tails, 4 y6 }$ H- L. r/ f- d1 Y6 Yand long necks with large heads. On the ground, pterodactyloids walked well on1 ^6 p! ^+ O/ n5 B6 ]' P) Y
all four limbs with an upright posture, standing plantigrade on the hind feet and% C E p$ E4 c- W x' K0 O
folding the wing fifinger upward to walk on the three-fifingered “hand”. The fossil , v- h' y, C# m/ ]* Wtrackways show at least some species were able to run and wade or swim[2]." `3 G9 i$ i6 k! y/ w! N
Pterosaurs sported coats of hair-like fifilaments known as pycnofifibers, which; N* c7 z+ a! K8 f9 Q4 O6 r4 ^
covered their bodies and parts of their wings[3]. In life, pterosaurs would have# ?! A& y: z1 j1 |$ g+ c
had smooth or flfluffffy coats that did not resemble bird feathers. Earlier sug % C9 {+ _' u2 i2 g, r8 i9 z pgestions were that pterosaurs were largely cold-blooded gliding animals, de$ r) @$ o# B% ]- N) T v
riving warmth from the environment like modern lizards, rather than burning5 f+ _; [8 q. @
calories. However, later studies have shown that they may be warm-blooded 4 u" a. J _1 l(endothermic), active animals. The respiratory system had effiffifficient unidirec # s/ X6 J- u8 E! Ztional “flflow-through” breathing using air sacs, which hollowed out their bones # w5 v0 B2 e/ E6 j* vto an extreme extent. Pterosaurs spanned a wide range of adult sizes, from1 S' y: K0 D, P6 K
the very small anurognathids to the largest known flflying creatures, including & y0 c' B7 a; g5 z) Q& g6 ]2 XQuetzalcoatlus and Hatzegopteryx[4][5], which reached wingspans of at least + F2 A8 V- O. R: r; n2 |, `, Ynine metres. The combination of endothermy, a good oxygen supply and strong! D @- o4 J7 y0 i7 y* K9 @
1muscles made pterosaurs powerful and capable flflyers.# |6 L9 d$ m) ]8 A# q" y& {9 I/ C% w
The mechanics of pterosaur flflight are not completely understood or modeled. h, e) {9 y' p2 s7 I( O" K. W( g
at this time. Katsufumi Sato did calculations using modern birds and concluded - V }' m+ m& B7 `. fthat it was impossible for a pterosaur to stay aloft[6]. In the book Posture,; n: I0 g& s3 _0 g( ~# X
Locomotion, and Paleoecology of Pterosaurs it is theorized that they were able + }" C& D( _$ eto flfly due to the oxygen-rich, dense atmosphere of the Late Cretaceous period[7].4 D; ~; z2 r$ y# _+ E0 x
However, both Sato and the authors of Posture, Locomotion, and Paleoecology* j2 T& p$ w4 _& n, U
of Pterosaurs based their research on the now-outdated theories of pterosaurs " b1 ^+ j# b- H& `' hbeing seabird-like, and the size limit does not apply to terrestrial pterosaurs, , c) K7 H9 L5 c# {8 `such as azhdarchids and tapejarids. Furthermore, Darren Naish concluded that- `# w; p n9 u3 `; t2 R1 c
atmospheric difffferences between the present and the Mesozoic were not needed " K1 k! Z1 }' Afor the giant size of pterosaurs[8]., h( D0 ~+ k) N, ~( B5 L! P- c3 E
Another issue that has been diffiffifficult to understand is how they took offff. 5 R7 ?" m( |( a- rIf pterosaurs were cold-blooded animals, it was unclear how the larger ones& k! Z( N1 b1 s4 u6 N6 S H" U9 |
of enormous size, with an ineffiffifficient cold-blooded metabolism, could manage- G+ M0 p( u/ T) _. ] l
a bird-like takeoffff strategy, using only the hind limbs to generate thrust for + x- l3 ?- U( r: l2 mgetting airborne. Later research shows them instead as being warm-blooded; f* M4 ^/ K: M) x
and having powerful flflight muscles, and using the flflight muscles for walking as! E7 ?4 N& [; r0 S U
quadrupeds[9]. Mark Witton of the University of Portsmouth and Mike Habib of5 K4 e) C' |, d2 n' p) e! q
Johns Hopkins University suggested that pterosaurs used a vaulting mechanism ( G# ]) ?* s- g: K# Tto obtain flflight[10]. The tremendous power of their winged forelimbs would : l+ x( R1 R9 O% Aenable them to take offff with ease[9]. Once aloft, pterosaurs could reach speeds* k5 O1 \7 J8 h4 a; N1 N
of up to 120 km/h and travel thousands of kilometres[10]. 9 m/ b5 c7 ], h, f5 c; bYour team are asked to develop a reasonable mathematical model of the5 Y2 G: j: ~, V" \/ U. G: ? y
flflight process of at least one large pterosaur based on fossil measurements and . F! |8 }+ U. {( G, {# Q4 \to answer the following questions./ z! b: Q0 e+ l3 ]5 B' v) A
1. For your selected pterosaur species, estimate its average speed during nor ) q4 b+ }0 [+ k+ b7 M+ ~0 @# R6 Amal flflight.6 U, [. {7 K' e2 X0 g2 I
2. For your selected pterosaur species, estimate its wing-flflap frequency during 1 M5 v' w& L1 T+ l: m6 Ynormal flflight. @2 \& M4 K' \3 Y; }
3. Study how large pterosaurs take offff; is it possible for them to take offff like4 H u8 K# Y8 _7 P
birds on flflat ground or on water? Explain the reasons quantitatively. , N' ~9 ]1 F: r9 Y' ]/ p: FReferences, T+ J% R S9 G8 G8 V
[1] Elgin RA, Hone DW, Frey E (2011). The Extent of the Pterosaur Flight% M% z4 k/ l( a4 [7 _. g
Membrane. Acta Palaeontologica Polonica. 56 (1): 99-111.7 B+ u6 p: M+ ~! s8 ~
2[2] Mark Witton. Terrestrial Locomotion.& W/ V. o% R' A/ K
https://pterosaur.net/terrestrial locomotion.php E- V! N& H% T) `0 J
[3] Laura Geggel. It’s Offiffifficial: Those Flying Reptiles Called Pterosaurs0 ?, {) m* V: N; b: Y2 o
Were Covered in Fluffffy Feathers. https://www.livescience.com/64324-8 r8 I8 w. W; b# W- ^
pterosaurs-had-feathers.html. \$ V1 a) _ ~5 C
[4] Wang, X.; Kellner, A.W.A.; Zhou, Z.; Campos, D.A. (2008). Discovery of a 0 n" b* i# p, s/ b& Jrare arboreal forest-dwelling flflying reptile (Pterosauria, Pterodactyloidea) 2 t* v( X& a- t$ j. r. [. efrom China. Proceedings of the National Academy of Sciences. 105 (6): : J* p' x |9 X: E3 F1983-87.7 o# B8 n4 y. r6 N
[5] Buffffetaut E, Grigorescu D, Csiki Z. A new giant pterosaur with a robust # U% S4 h- e& A8 M9 }+ d6 r' r; C9 Jskull from the latest cretaceous of Romania. Naturwissenschaften. 89 (4): 8 }2 l* `: K' c$ L. g9 ?180-84. ( E" A2 _- T8 @7 [' _[6] Devin Powell. Were pterosaurs too big to flfly?' I( {/ h- z% h5 c, j7 j6 [
https://www.newscientist.com/article/mg20026763-800-were-pterosaurs# a; u1 E6 p* }- Q1 C: C
too-big-to-flfly/) }" _, H" C6 v/ N$ k4 S
[7] Templin, R. J.; Chatterjee, Sankar. Posture, locomotion, and paleoecology * ]) L+ H- o# Y; ^" N5 P, [0 Nof pterosaurs. Boulder, Colo: Geological Society of America. p. 60. 3 ?, d w3 P4 T+ v# d4 \4 T[8] Naish, Darren. Pterosaurs breathed in bird-like fashion and had inflflatable' c+ @7 {1 _3 M2 R0 y0 l
air sacs in their wings. ' H1 ~* M2 @( `) _. bhttps://scienceblogs.com/tetrapodzoology/2009/02/18/pterosaur 2 b3 U" i/ z& d8 @4 t9 l: Abreathing-air-sacs ) C7 F$ \5 o2 c2 E: v) k* }6 u# {5 K[9] Mark Witton. Why pterosaurs weren’t so scary after all.: b+ L4 ~* u* {0 M, h
https://www.theguardian.com/science/2013/aug/11/pterosaurs-fossils ; J0 K7 ]2 e. }9 Aresearch-mark-witton, p& E/ b$ p2 h
[10] Jeffff Hecht. Did giant pterosaurs vault aloft like vampire bats?" i0 z, y" b& _" |# E3 ]
https://www.newscientist.com/article/dn19724-did-giant-pterosaurs 7 E9 H, F0 o' n5 E2 Q Tvault-aloft-like-vampire-bats/ & p1 t7 @1 F4 F3 @$ r/ k6 B0 e i2 m- d( u- d4 G4 e+ I
2022 6 K$ T* N. J" Q1 W2 uCertifificate Authority Cup International Mathematical Contest Modeling ) N: c2 K* \6 Z+ \http://mcm.tzmcm.cn : {- q! [! O n& wProblem B (MCM)9 Y& O& l1 W/ _ [( F
The Genetic Process of Sequences 3 y1 b# ]* x4 U$ B$ `7 E2 PSequence homology is the biological homology between DNA, RNA, or protein " [2 F; |$ i1 Fsequences, defifined in terms of shared ancestry in the evolutionary history of* L# W3 l6 C& m% d+ }, T
life[1]. Homology among DNA, RNA, or proteins is typically inferred from their' b1 G2 r! r' R$ |8 {3 f
nucleotide or amino acid sequence similarity. Signifificant similarity is strong 8 e+ W6 M, J! k3 m9 \* Jevidence that two sequences are related by evolutionary changes from a common # n2 K; \; z& G1 l; x$ ~ancestral sequence[2].. s2 T7 `$ {. L7 W+ ]" M1 \& }
Consider the genetic process of a RNA sequence, in which mutations in nu/ `) k0 ?! X5 x$ Q7 ?5 E$ f
cleotide bases occur by chance. For simplicity, we assume the sequence mutation , f$ G! x1 J, N$ Sarise due to the presence of change (transition or transversion), insertion and7 C3 i( `& k, a3 k: Q4 r! Z
deletion of a single base. So we can measure the distance of two sequences by% ^1 I4 H4 s4 `; I3 d: m
the amount of mutation points. Multiple base sequences that are close together 6 L' q, G9 X! Y1 dcan form a family, and they are considered homologous.- y+ P# O o) Z# y% Z L6 m
Your team are asked to develop a reasonable mathematical model to com ; Y. y' o% [0 I% y) Y& nplete the following problems. V8 a. A0 T" k9 [5 J
1. Please design an algorithm that quickly measures the distance between 0 i5 L( o$ S9 a$ btwo suffiffifficiently long(> 103 bases) base sequences. ; i4 r. Z) b" `: h2. Please evaluate the complexity and accuracy of the algorithm reliably, and q: @3 \" I+ L( \7 Ddesign suitable examples to illustrate it.) V$ a1 G; y0 A+ _9 x
3. If multiple base sequences in a family have evolved from a common an5 m% C4 y) Z0 |0 q
cestral sequence, design an effiffifficient algorithm to determine the ancestral) Q( g+ f0 B* j
sequence, and map the genealogical tree.% |( @, i; j3 _. b
References U5 P M9 D& P% I5 V& t! P- l2 f[1] Koonin EV. “Orthologs, paralogs, and evolutionary genomics”. Annual Re a) D% Q! f# {" a# z% sview of Genetics. 39: 30938, 2005.. h- ?/ D& @! m# k- X4 Q
[2] Reeck GR, de Han C, Teller DC, Doolittle RF, Fitch WM, Dickerson RE,; F* O" I* ?8 \( F
et al. “Homology” in proteins and nucleic acids: a terminology muddle and 7 O. K1 j [& g |( V- Ta way out of it. Cell. 50 (5): 667, 1987. [, ^) s, v- g3 @% T
* j( ^$ p5 D* Q- g4 @0 v- z8 G
2022 8 Q0 ?& p/ x& E& a9 \Certifificate Authority Cup International Mathematical Contest Modeling 4 l& C0 j% x4 M9 ]0 R5 q8 M$ Fhttp://mcm.tzmcm.cn 8 b) B7 |' H- d/ t7 A2 v0 TProblem C (ICM)" x( L1 \2 p4 ^6 Z _
Classify Human Activities- ~" M% F1 M8 h. T7 E6 j
One important aspect of human behavior understanding is the recognition and, X2 _3 M0 e8 B; [* c. _3 K
monitoring of daily activities. A wearable activity recognition system can im - h4 k# D# A5 E* x" { Z; s- nprove the quality of life in many critical areas, such as ambulatory monitor4 Q" R' C6 w* u P
ing, home-based rehabilitation, and fall detection. Inertial sensor based activ5 g- b# y! }. `
ity recognition systems are used in monitoring and observation of the elderly ! r) P7 u/ D* }2 qremotely by personal alarm systems[1], detection and classifification of falls[2],8 d2 u+ l# A# @
medical diagnosis and treatment[3], monitoring children remotely at home or in- n7 h$ F2 Q( f
school, rehabilitation and physical therapy , biomechanics research, ergonomics,+ i l1 N! }. @; d
sports science, ballet and dance, animation, fifilm making, TV, live entertain2 z( j' W& L6 n# M8 `4 u
ment, virtual reality, and computer games[4]. We try to use miniature inertial$ e) L- z- r. o1 R! L7 \
sensors and magnetometers positioned on difffferent parts of the body to classify( U* b) s2 e d& ]
human activities, the following data were obtained.8 w- G6 T# \6 R p: w: y/ Z% Q! _
Each of the 19 activities is performed by eight subjects (4 female, 4 male,; ~7 a( _0 I* x1 {+ _
between the ages 20 and 30) for 5 minutes. Total signal duration is 5 minutes, W( V. q. A3 J) Y
for each activity of each subject. The subjects are asked to perform the activ , \. J m- P1 D$ W6 S: q$ Lities in their own style and were not restricted on how the activities should be ! n G& y0 g% _8 q Yperformed. For this reason, there are inter-subject variations in the speeds and; W2 K2 ^9 w8 g6 j3 a- s8 L
amplitudes of some activities. * G$ R, E' h7 Q3 G' H/ ~Sensor units are calibrated to acquire data at 25 Hz sampling frequency.3 a* F, S$ r( \& H
The 5-min signals are divided into 5-sec segments so that 480(= 60 × 8) signal5 T* K6 y' u) W
segments are obtained for each activity., @5 H% [% m: S2 S. @( M H: Y
The 19 activities are:1 b6 U* T0 B& p4 e( w6 v3 C
1. Sitting (A1);5 r9 ^. F8 b# n7 z" X) q" r& ]. a# y9 @
2. Standing (A2);6 j) Y1 H! C5 {
3. Lying on back (A3); * C# b$ x) |# H" _3 T0 j7 J4. Lying on right side (A4); ) l9 V- x9 p) H5 e+ E# p m5. Ascending stairs (A5); & u0 m$ F& \: ^: w16. Descending stairs (A6); 1 P' f! P& `% ^3 a7. Standing in an elevator still (A7); . V6 n" Y6 k& ` t D8. Moving around in an elevator (A8); ( [* O5 p' j4 ^3 K# M1 w* S$ E9. Walking in a parking lot (A9); 6 u" k2 g& N* {( p5 r& P10. Walking on a treadmill with a speed of 4 km/h in flflat position and 15 deg2 F" n: F5 o. c5 n
inclined positions (A10); 9 S* d, y( B! ?" L D j$ u11. Walking on a treadmill with a speed of 4 km/h in 15 deg inclined positions$ o1 \# d( c$ V5 L5 |
(A11);" I0 L7 F% p6 H8 O5 d- P8 e4 k
12. Running on a treadmill with a speed of 8 km/h (A12);# n) r/ g0 f; h* w
13. Exercising on a stepper (A13); 0 D) D& s; }4 C7 b. u6 N14. Exercising on a cross trainer (A14); R# e5 q5 L1 I15. Cycling on an exercise bike in horizontal position (A15); " A+ K0 p0 u9 I# n# w2 [1 m16. Cycling on an exercise bike in vertical position (A16); ' n" x$ m) ~* V7 J/ d: f" O17. Rowing (A17); ) s# A: `7 |' x% I18. Jumping (A18);( [& H9 _, Y @3 @
19. Playing basketball (A19). / W+ J) I" C% ]5 h& fYour team are asked to develop a reasonable mathematical model to solve , i. i2 }$ V( S S6 ^- ethe following problems.* P% E9 n% G. F" t3 d
1. Please design a set of features and an effiffifficient algorithm in order to classify 5 L, H7 ]& b: |4 A; ethe 19 types of human actions from the data of these body-worn sensors.4 M& @5 X' h( ^$ H2 m4 `- F/ T. [) [
2. Because of the high cost of the data, we need to make the model have" l: B& X& Z0 Z4 z& o
a good generalization ability with a limited data set. We need to study3 g5 j+ n6 f9 B; B; ]
and evaluate this problem specififically. Please design a feasible method to7 y# X% B- s$ ^4 ^
evaluate the generalization ability of your model. " Z/ t& \7 S+ q0 I2 N* W1 S* f) d3. Please study and overcome the overfifitting problem so that your classififi- + r$ x- x* p/ h0 f: A1 Lcation algorithm can be widely used on the problem of people’s action 6 s7 E( k. G9 R$ V' K7 Jclassifification. / V/ W+ h7 ]8 d x9 y8 A5 R, o6 uThe complete data can be downloaded through the following link:( r7 _2 T; |0 ~2 q* U
https://caiyun.139.com/m/i?0F5CJUOrpy8oq9 \5 s) }# j- ?# e
2Appendix: File structure ( K3 r! n/ n9 A" o& ?/ ]$ Z- |• 19 activities (a) ) u# O6 f& j: x5 N• 8 subjects (p)8 A1 p6 z9 E9 ?/ ^1 P
• 60 segments (s)3 ]( r) U9 g2 l- A# [& M
• 5 units on torso (T), right arm (RA), left arm (LA), right leg (RL), left . q# L t9 K2 |' Q O7 o$ bleg (LL)3 v0 @1 w5 t; w+ V& {$ Z' x$ |7 |
• 9 sensors on each unit (x, y, z accelerometers, x, y, z gyroscopes, x, y, z % I+ k# [3 S6 L6 |magnetometers)7 I$ ` X8 M! n: t) c$ s1 x
Folders a01, a02, ..., a19 contain data recorded from the 19 activities. ! Z2 \ m5 }7 m7 _/ M; yFor each activity, the subfolders p1, p2, ..., p8 contain data from each of the % x8 ? O- }( B- s1 u8 subjects.. t' H* L* t& A2 m3 K6 [
In each subfolder, there are 60 text fifiles s01, s02, ..., s60, one for each ! }4 p) U2 }2 u" u* [segment. r# q+ ]4 ^ N/ N. D FIn each text fifile, there are 5 units × 9 sensors = 45 columns and 5 sec × 25 5 {! C3 y9 \. y8 P3 Y8 T1 X5 aHz = 125 rows.6 h& g# @1 [; b9 ^" ]
Each column contains the 125 samples of data acquired from one of the 3 h& b" D3 c& S6 I" v- ^% S9 \. [sensors of one of the units over a period of 5 sec. l# }# M; {9 i* H; P. ~
Each row contains data acquired from all of the 45 sensor axes at a particular# ^/ j# s ~7 G1 X5 B8 `
sampling instant separated by commas. / p( c! I* I. VColumns 1-45 correspond to:" f$ x* [9 l4 O% [# o( ]0 v: b+ V
• T_xacc, T_yacc, T_zacc, T_xgyro, ..., T_ymag, T_zmag,. ]) @' Q% l4 J# Y, h) q5 l
• RA_xacc, RA_yacc, RA_zacc, RA_xgyro, ..., RA_ymag, RA_zmag,+ l2 \% _& `4 G: [
• LA_xacc, LA_yacc, LA_zacc, LA_xgyro, ..., LA_ymag, LA_zmag, 9 T$ b+ s+ P2 c• RL_xacc, RL_yacc, RL_zacc, RL_xgyro, ..., RL_ymag, RL_zmag, 7 Y, T( x: b9 k p& Y# }• LL_xacc, LL_yacc, LL_zacc, LL_xgyro, ..., LL_ymag, LL_zmag. ) t4 s5 ?( ^' f2 ]3 MTherefore,0 _5 G6 r x/ k& n' h5 x7 f7 p
• columns 1-9 correspond to the sensors in unit 1 (T),6 b8 @5 P4 n2 z5 m W; `; |
• columns 10-18 correspond to the sensors in unit 2 (RA), n2 L' Y! V3 i
• columns 19-27 correspond to the sensors in unit 3 (LA), & \" O; @! @, T/ Y* f• columns 28-36 correspond to the sensors in unit 4 (RL), $ F7 t) t& k% f% k) `! i; o/ j• columns 37-45 correspond to the sensors in unit 5 (LL). 1 |$ f! v& o+ F; ~" a3References' d* p! A( V* A0 E: t0 ^
[1] Mathie M.J., Celler B.G., Lovell N.H., Coster A.C.F. Classifification of basic 9 r8 Q4 q% M" z7 P3 xdaily movements using a triaxial accelerometer. Med. Biol. Eng. Comput.- P% F3 Q/ T; x% |
42(5), 679-687, 2004 8 b* ?# h- o, H: G9 g[2] Kangas M., Konttila A., Lindgren P., Winblad I., Ja¨msa¨ T. Comparison of0 e, W7 {) l- U; I6 I7 l
low-complexity fall detection algorithms for body attached accelerometers. 8 j6 w( u( ^% U2 {* Y+ ^. v4 i. WGait Posture 28(2), 285-291, 2008 G8 _' r) ]+ C0 U, ]- D) j" l% S
[3] Wu W.H., Bui A.A.T., Batalin M.A., Liu D., Kaiser W.J. Incremental diag % ]* ?/ u: z6 C% h6 ~# Bnosis method for intelligent wearable sensor system. IEEE T. Inf. Technol.! k) f2 z4 O& X( t
B. 11(5), 553-562, 2007" m1 B3 @ V& i: _, O
[4] Shiratori T., Hodgins J.K. Accelerometer-based user interfaces for the con $ E+ y! E; W) f7 p) ntrol of a physically simulated character. ACM T. Graphic. 27(5), 2008 ; t. K5 e+ V& u Z l7 q6 i E! g: I' T& ` X
2022, H( ?1 {' u& x# L. g+ I4 x
Certifificate Authority Cup International Mathematical Contest Modeling- z& T' I% x4 ]( B0 I- x
http://mcm.tzmcm.cn 4 Y" n9 R: Q* K+ E! @/ EProblem D (ICM); i5 ?; G$ t1 r0 k, p
Whether Wildlife Trade Should Be Banned for a Long $ Q" T/ O3 e+ l$ ]% W7 }; `2 {7 tTime% _ H, E, @, j$ d( M; ^* K
Wild-animal markets are the suspected origin of the current outbreak and the ' Y7 ^ J6 U2 z1 s2 e% A2002 SARS outbreak, And eating wild meat is thought to have been a source( j; n! \9 M Z' Q
of the Ebola virus in Africa. Chinas top law-making body has permanently y( N i0 ]1 `& {6 o8 {7 ktightened rules on trading wildlife in the wake of the coronavirus outbreak,3 [' N! ^* e# w [) d
which is thought to have originated in a wild-animal market in Wuhan. Some $ z8 y4 D. \) D' A Fscientists speculate that the emergency measure will be lifted once the outbreak 8 o' z! F8 X* Oends. ' W0 F7 @# L% O% n8 S, F5 o; [0 tHow the trade in wildlife products should be regulated in the long term?$ a. Z& {8 H q3 l9 ]$ X8 X
Some researchers want a total ban on wildlife trade, without exceptions, whereas 3 e9 W9 X" y, i9 w# Z1 Yothers say sustainable trade of some animals is possible and benefificial for peo : O3 S( |" n4 N+ zple who rely on it for their livelihoods. Banning wild meat consumption could: s/ w2 j+ H# ?# ]/ l1 S# D
cost the Chinese economy 50 billion yuan (US $ 7.1 billion) and put one mil ' Z4 V* e3 x/ d. Klion people out of a job, according to estimates from the non-profifit Society of 4 A, {7 J' U4 W6 hEntrepreneurs and Ecology in Beijing.5 Q; E% n/ s6 T9 D! H Q
A team led by Shi Zheng-Li and Cui Jie of the Wuhan Institute of Virology % o% W; o, F8 |* R: b" ~/ E2 g+ V1 rin China, chasing the origin of the deadly SARS virus, have fifinally found their # q# P2 B: k/ u2 U dsmoking gun in 2017. In a remote cave in Yunnan province, virologists have; E- L) G9 ]# d3 d
identifified a single population of horseshoe bats that harbours virus strains with $ w* Y$ g2 Q0 j2 K$ s3 c9 {all the genetic building blocks of the one that jumped to humans in 2002, killing; _: ]$ L7 S( g* c2 t: f) @
almost 800 people around the world. The killer strain could easily have arisen , \2 ?9 l% X8 g5 |from such a bat population, the researchers report in PLoS Pathogens on 30& `5 {/ o' P& I: j' R0 T! M- [
November, 2017. Another outstanding question is how a virus from bats in H4 G: B( d! t t3 PYunnan could travel to animals and humans around 1,000 kilometres away in+ H2 F5 a a* X6 N
Guangdong, without causing any suspected cases in Yunnan itself. Wildlife 1 a- h/ o0 l/ htrade is the answer. Although wild animals are cooked at high temperature * Q% T; S) H' k: twhen eating, some viruses are diffiffifficult to survive, humans may come into contact ) n& B+ H# D! b0 u# M9 vwith animal secretions in the wildlife market. They warn that the ingredients" C8 E5 l7 }$ l5 s
are in place for a similar disease to emerge again.7 u( F# ^" e% w
Wildlife trade has many negative effffects, with the most important ones being: ( c2 D) S. m5 S4 v1Figure 1: Masked palm civets sold in markets in China were linked to the SARS, q8 L! o" x9 j& U& q
outbreak in 2002.Credit: Matthew Maran/NPL * p6 y. j; K* o( W& Q! U• Decline and extinction of populations: x( Q9 Y9 d5 K8 {
• Introduction of invasive species % B* j& x: y6 b• Spread of new diseases to humans' U. J7 W; q G: L1 ]
We use the CITES trade database as source for my data. This database 3 U( i2 f5 V+ _, t. P. A9 O7 Kcontains more than 20 million records of trade and is openly accessible. The4 z5 {- A( J% X1 Q/ c' f& y& E
appendix is the data on mammal trade from 1990 to 2021, and the complete 3 n# O5 O- D1 t1 V5 m) ?database can also be obtained through the following link:/ T$ r8 [1 C2 k. ~
https://caiyun.139.com/m/i?0F5CKACoDDpEJ. i9 R+ v' |8 r' d' k/ D
Requirements Your team are asked to build reasonable mathematical mod% Z' _5 {; V' |
els, analyze the data, and solve the following problems: # D# t+ @( k0 |0 r0 v7 l1. Which wildlife groups and species are traded the most (in terms of live " T+ R& U0 A% l+ x) k8 s6 h3 Tanimals taken from the wild)? 7 E) o9 u, y! q2. What are the main purposes for trade of these animals?/ ]0 P- r" M' R9 r. b
3. How has the trade changed over the past two decades (2003-2022)?0 R# ?. [+ h* V
4. Whether the wildlife trade is related to the epidemic situation of major* x7 I% r. B1 ^" P1 X4 z
infectious diseases? " z9 X3 _8 I$ X! _25. Do you agree with banning on wildlife trade for a long time? Whether it3 C3 k: B1 L8 t! e4 w- S6 B
will have a great impact on the economy and society, and why? @4 E; b% H- M5 K7 A; e
6. Write a letter to the relevant departments of the US government to explain2 o- m4 c# n7 s; o
your views and policy suggestions.. b- u- f E, h6 L2 w