u. {/ Z/ M- k I2 r! S" T2022$ I m0 X0 a- ^" s t
Certifificate Authority Cup International Mathematical Contest Modeling 4 k8 b8 U8 w* c" D; Y8 t. r5 xhttp://mcm.tzmcm.cn 4 x) `0 D _% S6 L, B: {/ e ZProblem A (MCM) # w/ K5 S2 M3 F) p9 t9 z+ O2 LHow Pterosaurs Fly1 P6 P, j* K( V5 U& B- i E+ a M
Pterosaurs is an extinct clade of flflying reptiles in the order, Pterosauria. They + Z m# k; c0 \existed during most of the Mesozoic: from the Late Triassic to the end of' ^: `( W6 A+ ?7 V: E1 G I1 Z
the Cretaceous. Pterosaurs are the earliest vertebrates known to have evolved; ]5 X+ l, |+ g4 s1 P B) A, \
powered flflight. Their wings were formed by a membrane of skin, muscle, and # |2 t: A0 q1 o% q4 n* w& m6 Zother tissues stretching from the ankles to a dramatically lengthened fourth) V3 M" p2 ^- V% j. t2 Q! E t0 u
fifinger[1].4 {: o% n9 d; e3 n; M: J) d) e
There were two major types of pterosaurs. Basal pterosaurs were smaller % q |" u! f( P; {3 _animals with fully toothed jaws and long tails usually. Their wide wing mem6 g( {3 G/ [9 n2 Y x
branes probably included and connected the hind legs. On the ground, they |6 g& r6 v( l t8 ^+ P" X; z/ xwould have had an awkward sprawling posture, but their joint anatomy and5 P9 l- A5 K' y0 Q+ O0 m( q
strong claws would have made them effffective climbers, and they may have lived 3 |3 M0 F4 i2 f) ?* @2 Hin trees. Basal pterosaurs were insectivores or predators of small vertebrates. 7 {# \$ ~$ _2 L. M) E {! uLater pterosaurs (pterodactyloids) evolved many sizes, shapes, and lifestyles. ! I* V+ Y0 Z, p) G6 c7 \Pterodactyloids had narrower wings with free hind limbs, highly reduced tails, $ U1 D# ?6 o8 [% z6 }! rand long necks with large heads. On the ground, pterodactyloids walked well on0 p% k. a+ ?* _
all four limbs with an upright posture, standing plantigrade on the hind feet and . A2 |* Z# A5 B5 d$ b* R4 C7 ifolding the wing fifinger upward to walk on the three-fifingered “hand”. The fossil , n# U E% w1 j' G: x& s# u/ _6 h% mtrackways show at least some species were able to run and wade or swim[2].: u6 n, y2 f7 ]* ]
Pterosaurs sported coats of hair-like fifilaments known as pycnofifibers, which; x3 c2 \8 r9 h" v7 e7 {
covered their bodies and parts of their wings[3]. In life, pterosaurs would have) J4 X, h; u1 f/ [4 X, P! \" C. C
had smooth or flfluffffy coats that did not resemble bird feathers. Earlier sug 6 U a/ ?% {. j, ugestions were that pterosaurs were largely cold-blooded gliding animals, de7 Q: a4 c, c# Y
riving warmth from the environment like modern lizards, rather than burning 0 o. Z) n0 [, @2 n1 w9 J% ^& Dcalories. However, later studies have shown that they may be warm-blooded6 T3 q, c3 |" y" I L! X, z
(endothermic), active animals. The respiratory system had effiffifficient unidirec & X3 t) R5 n3 s7 B4 z1 Utional “flflow-through” breathing using air sacs, which hollowed out their bones 2 T$ \+ c3 [3 |% }7 x( }to an extreme extent. Pterosaurs spanned a wide range of adult sizes, from: c- P7 O. D5 i+ Y1 @% J% u( Z. P0 E6 g
the very small anurognathids to the largest known flflying creatures, including2 ^9 g/ c; y! [
Quetzalcoatlus and Hatzegopteryx[4][5], which reached wingspans of at least! I, u4 Y9 u! N& x. @
nine metres. The combination of endothermy, a good oxygen supply and strong) [/ n# L6 R2 ?4 z! D
1muscles made pterosaurs powerful and capable flflyers.& C5 V# [: Q3 P" `9 m
The mechanics of pterosaur flflight are not completely understood or modeled( g% N( p% C4 f8 Y$ u8 e
at this time. Katsufumi Sato did calculations using modern birds and concluded% c$ R, \4 p- I# c& j6 I! X
that it was impossible for a pterosaur to stay aloft[6]. In the book Posture,* T# k$ o+ W8 L; Q0 [/ m* X6 {0 S3 O
Locomotion, and Paleoecology of Pterosaurs it is theorized that they were able ; v+ F& l) E2 D5 Z/ J, L! Wto flfly due to the oxygen-rich, dense atmosphere of the Late Cretaceous period[7]. / O3 ]1 x8 {* p- B* f( bHowever, both Sato and the authors of Posture, Locomotion, and Paleoecology 3 f- [ Q2 v. @+ Y* n- Y- t/ Q- O. ?of Pterosaurs based their research on the now-outdated theories of pterosaurs $ [3 O+ e$ X- ^$ |8 M. D( Ubeing seabird-like, and the size limit does not apply to terrestrial pterosaurs,& t7 p/ |% g8 h' I& o
such as azhdarchids and tapejarids. Furthermore, Darren Naish concluded that + }3 \/ f8 l2 A# [$ satmospheric difffferences between the present and the Mesozoic were not needed# @# O6 W* @/ D, `: d
for the giant size of pterosaurs[8].2 ?+ n; Q: G/ N# c1 y+ [) t# i
Another issue that has been diffiffifficult to understand is how they took offff.1 J; B$ ~& c$ |: v5 }, e ?/ b
If pterosaurs were cold-blooded animals, it was unclear how the larger ones ' O5 Y( A3 J& C$ Z- zof enormous size, with an ineffiffifficient cold-blooded metabolism, could manage: x2 S0 F$ X/ |% X2 x
a bird-like takeoffff strategy, using only the hind limbs to generate thrust for ' @2 F8 W N0 E6 Kgetting airborne. Later research shows them instead as being warm-blooded' O5 ]0 ~+ L0 x" D! B1 L
and having powerful flflight muscles, and using the flflight muscles for walking as7 _- p7 u- b# e
quadrupeds[9]. Mark Witton of the University of Portsmouth and Mike Habib of 5 l* h" r- \- s9 X& G1 R6 nJohns Hopkins University suggested that pterosaurs used a vaulting mechanism , M$ K; ~3 o6 uto obtain flflight[10]. The tremendous power of their winged forelimbs would 6 q/ m) ~8 ~+ l. Venable them to take offff with ease[9]. Once aloft, pterosaurs could reach speeds5 ?/ n$ G; Z+ J6 l# p0 O: `, d1 E
of up to 120 km/h and travel thousands of kilometres[10].$ V" c7 ~- q$ v* y
Your team are asked to develop a reasonable mathematical model of the0 }! [" G e" {& A4 d9 b! t' F
flflight process of at least one large pterosaur based on fossil measurements and0 Y X# C2 t+ I9 R
to answer the following questions. % S, p, ^: ]; [" T- a) b1. For your selected pterosaur species, estimate its average speed during nor! D8 E# d E0 B3 O9 v5 V5 N
mal flflight.0 r0 @# k9 W8 W* `4 s
2. For your selected pterosaur species, estimate its wing-flflap frequency during ' [0 m/ d: w, W3 W, ynormal flflight. 4 W8 k7 { Y% k3. Study how large pterosaurs take offff; is it possible for them to take offff like! m" W* ?4 G8 f( U: \9 h7 h9 g
birds on flflat ground or on water? Explain the reasons quantitatively. / y! D6 S1 w7 RReferences% D8 ^" p) V Z- n6 T m$ w! c) [+ @
[1] Elgin RA, Hone DW, Frey E (2011). The Extent of the Pterosaur Flight " V/ [5 w1 g) X* \ WMembrane. Acta Palaeontologica Polonica. 56 (1): 99-111.% J" i+ p! {% ]. p
2[2] Mark Witton. Terrestrial Locomotion.) f, X2 B' W3 E+ a( R+ \1 Y
https://pterosaur.net/terrestrial locomotion.php , l6 T6 D8 V# S. N, n[3] Laura Geggel. It’s Offiffifficial: Those Flying Reptiles Called Pterosaurs/ X0 a0 x* N" S( x7 v% o# s4 q
Were Covered in Fluffffy Feathers. https://www.livescience.com/64324- # |' l+ ~, D4 @& Vpterosaurs-had-feathers.html# N/ U4 T/ y+ s3 C* [2 B
[4] Wang, X.; Kellner, A.W.A.; Zhou, Z.; Campos, D.A. (2008). Discovery of a 2 M) x2 u6 G( d) n+ E' [; P: B9 Rrare arboreal forest-dwelling flflying reptile (Pterosauria, Pterodactyloidea) 6 D6 I6 e6 d: cfrom China. Proceedings of the National Academy of Sciences. 105 (6):9 K4 Y9 Z# R" j6 n8 E) n
1983-87.4 T; y/ J' ~* u- F7 ]. E( ]" Y5 L
[5] Buffffetaut E, Grigorescu D, Csiki Z. A new giant pterosaur with a robust ( k* x3 C1 w) Uskull from the latest cretaceous of Romania. Naturwissenschaften. 89 (4): 3 A2 K$ }! w& ^3 N180-84. 3 ^* e$ j* C. _$ E6 B. p[6] Devin Powell. Were pterosaurs too big to flfly?5 r4 e2 R B! h
https://www.newscientist.com/article/mg20026763-800-were-pterosaurs / A$ q! S, ]. x5 A7 q3 C4 `9 ~+ L7 Gtoo-big-to-flfly/: g0 c1 a) {" ~# g8 @, v
[7] Templin, R. J.; Chatterjee, Sankar. Posture, locomotion, and paleoecology - N3 N# v. K8 d$ V7 Pof pterosaurs. Boulder, Colo: Geological Society of America. p. 60.5 N) r1 N' c3 q9 o4 ?% C
[8] Naish, Darren. Pterosaurs breathed in bird-like fashion and had inflflatable7 ?9 Y' M9 @+ q, n% o
air sacs in their wings. : Q0 f9 o2 I: W' q( \. I" Jhttps://scienceblogs.com/tetrapodzoology/2009/02/18/pterosaur# x- y: [( o C* R- a
breathing-air-sacs 8 D. R, } x) z# j) X7 b[9] Mark Witton. Why pterosaurs weren’t so scary after all. $ _$ r; [. w; H" G8 s/ [https://www.theguardian.com/science/2013/aug/11/pterosaurs-fossils 5 C4 w `# [5 p, B& n, a* ?2 |research-mark-witton " L3 C$ @* C$ L: R: t1 }[10] Jeffff Hecht. Did giant pterosaurs vault aloft like vampire bats?& W. ?0 q' W1 Z- N) y1 z
https://www.newscientist.com/article/dn19724-did-giant-pterosaurs D. J5 d! P Svault-aloft-like-vampire-bats/ 2 N1 r' w1 `- h. O' ]7 _% v ' C* U8 Z) x% T& G, b, x6 ^2022+ Y/ @/ H1 v/ s9 |& P+ J; j
Certifificate Authority Cup International Mathematical Contest Modeling 8 s2 P$ [* b0 u3 u7 K$ b. G8 Fhttp://mcm.tzmcm.cn! [+ h D4 W: z$ T1 C- |
Problem B (MCM) 0 o. `, V! Z. tThe Genetic Process of Sequences/ b' X# O! O/ ~0 C x
Sequence homology is the biological homology between DNA, RNA, or protein) b8 y# c1 g$ U) {) F
sequences, defifined in terms of shared ancestry in the evolutionary history of . Z: w! ]- G' `- `$ x0 jlife[1]. Homology among DNA, RNA, or proteins is typically inferred from their # A. N* s1 v/ q. K5 _7 S5 jnucleotide or amino acid sequence similarity. Signifificant similarity is strong : m0 s I S3 x/ }evidence that two sequences are related by evolutionary changes from a common' o. W7 g# l- D5 d$ B E
ancestral sequence[2]. + E" L' A; S/ W. V' a2 f6 ?Consider the genetic process of a RNA sequence, in which mutations in nu & I4 z3 U, r1 o6 Q8 jcleotide bases occur by chance. For simplicity, we assume the sequence mutation( t; F: h, J Z$ u( L0 w
arise due to the presence of change (transition or transversion), insertion and4 k, ?' i! {; L) H5 [. @
deletion of a single base. So we can measure the distance of two sequences by 4 }/ _/ g) e5 w7 G: w3 }the amount of mutation points. Multiple base sequences that are close together3 A5 e" [/ ^# `
can form a family, and they are considered homologous.- L- d2 W$ \% E9 ^4 E
Your team are asked to develop a reasonable mathematical model to com9 g, c6 J3 {( D" a; s( a
plete the following problems. 3 x/ Y) T. p9 `% M4 R& @" M2 ^1. Please design an algorithm that quickly measures the distance between' i. q7 ~5 t7 |6 B: r' d9 L
two suffiffifficiently long(> 103 bases) base sequences. ) U2 c2 r# c* h0 m9 e2. Please evaluate the complexity and accuracy of the algorithm reliably, and2 h9 {, r( o4 M; f; \0 k- p
design suitable examples to illustrate it. 7 t% [$ L- o* h# }' P T) f3. If multiple base sequences in a family have evolved from a common an 4 v1 B: ?8 j. \5 Lcestral sequence, design an effiffifficient algorithm to determine the ancestral " j, e: O# C( Z8 q( k% K4 nsequence, and map the genealogical tree.7 ?- I) u. H) K7 ]; o( z' {/ X
References+ F! t1 `2 c) Y7 J& k4 K
[1] Koonin EV. “Orthologs, paralogs, and evolutionary genomics”. Annual Re 1 S: c8 v1 l9 X: F, z- a! D" Qview of Genetics. 39: 30938, 2005.0 z& Y. B2 Z0 i' @
[2] Reeck GR, de Han C, Teller DC, Doolittle RF, Fitch WM, Dickerson RE, ; B8 P6 Q7 Y4 i0 Y6 j! T) ]et al. “Homology” in proteins and nucleic acids: a terminology muddle and; }; s, O' X8 _7 [5 C7 a7 p5 g/ u
a way out of it. Cell. 50 (5): 667, 1987. A. |, s+ n/ g
s1 S% P( l' a2 m8 b9 Z
2022 5 k2 ~+ `5 m/ Z& g# y8 Y# e3 LCertifificate Authority Cup International Mathematical Contest Modeling% k/ ~+ o8 Q7 `2 F) ?. g
http://mcm.tzmcm.cn' P2 R/ V- M$ l. [
Problem C (ICM) 2 {. W4 N: ~$ iClassify Human Activities) q3 p) B5 T, j
One important aspect of human behavior understanding is the recognition and4 V" _9 z8 n' e. `4 C
monitoring of daily activities. A wearable activity recognition system can im ! ?4 x6 n1 K5 P- r* Rprove the quality of life in many critical areas, such as ambulatory monitor, C1 E5 k7 D" _, `% e8 e3 @
ing, home-based rehabilitation, and fall detection. Inertial sensor based activ & s3 j0 i S9 X' y I8 [) w9 sity recognition systems are used in monitoring and observation of the elderly0 K C5 ^# Z. K, P0 }5 ?
remotely by personal alarm systems[1], detection and classifification of falls[2], 9 U$ S: k9 d2 k! k5 p/ hmedical diagnosis and treatment[3], monitoring children remotely at home or in- }$ l9 C2 U5 b# G; B% q
school, rehabilitation and physical therapy , biomechanics research, ergonomics, 9 J% J5 }1 Q1 u+ n9 Y2 Ksports science, ballet and dance, animation, fifilm making, TV, live entertain; ~+ [2 d7 G! t2 A- {
ment, virtual reality, and computer games[4]. We try to use miniature inertial 5 g- c8 e/ }5 o+ s2 R' x& c ?sensors and magnetometers positioned on difffferent parts of the body to classify & B& [: L! Y) \! Q( T+ N0 zhuman activities, the following data were obtained. 3 z2 n. w5 I! y+ |! @- v) vEach of the 19 activities is performed by eight subjects (4 female, 4 male, A; H) c9 T' y4 f3 I0 l4 I
between the ages 20 and 30) for 5 minutes. Total signal duration is 5 minutes3 P5 T! p- h' _% }/ r
for each activity of each subject. The subjects are asked to perform the activ, b8 k$ o$ E7 S' n/ x! ^2 E; U
ities in their own style and were not restricted on how the activities should be! ?$ N- k8 c4 M; b* B
performed. For this reason, there are inter-subject variations in the speeds and6 n9 V7 `; @4 }: E1 `2 e
amplitudes of some activities.; D# y$ `) Z1 ]2 K8 t0 d! r
Sensor units are calibrated to acquire data at 25 Hz sampling frequency. 9 ^' j# p( D) K8 OThe 5-min signals are divided into 5-sec segments so that 480(= 60 × 8) signal7 h9 Q. q4 _. y; W1 H: F1 r
segments are obtained for each activity.( m. Y# ^% p/ |: _
The 19 activities are:+ @6 h7 ~+ Q* J0 Y, U6 `
1. Sitting (A1);8 b3 ~* J% ^' y1 O
2. Standing (A2); 9 s8 L) B7 H" }# G3. Lying on back (A3);2 u# U3 M+ x6 b4 V7 m
4. Lying on right side (A4); : R+ Q0 r& p0 G$ B5. Ascending stairs (A5); 6 W: h. u/ {. G, l0 o16. Descending stairs (A6); 7 e1 N) {0 S$ ?/ n7. Standing in an elevator still (A7);7 }- [% j% ^6 O D% R6 t) t
8. Moving around in an elevator (A8);7 l9 ~- q+ S. u1 Y) v% Y
9. Walking in a parking lot (A9);% P# ]8 K% U" b w2 ~* o7 W) u2 W
10. Walking on a treadmill with a speed of 4 km/h in flflat position and 15 deg" ~/ L& o- Y( e
inclined positions (A10); * `. H5 G/ @) c, i( g8 B11. Walking on a treadmill with a speed of 4 km/h in 15 deg inclined positions8 Q& Y3 _, M! r8 a3 z: j; F i9 N, Z
(A11); 3 c1 L+ U* X- @3 d$ }12. Running on a treadmill with a speed of 8 km/h (A12); E c2 _, h' o/ Z) L13. Exercising on a stepper (A13); , b" a$ M' {% g* R- G14. Exercising on a cross trainer (A14);+ D) u2 F7 K2 j
15. Cycling on an exercise bike in horizontal position (A15); ! P' L- ~- S: k* S16. Cycling on an exercise bike in vertical position (A16);. v! z; Y( v9 D% N4 p1 T3 Y
17. Rowing (A17);! }, ]7 u7 c0 a% M* @' v
18. Jumping (A18); # P* ?* w$ z- i) {; {19. Playing basketball (A19). . V+ \' U: p$ p! O% {# ~5 | AYour team are asked to develop a reasonable mathematical model to solve; {+ s; z2 _* t6 a. m5 z
the following problems.. o" E. c) K! r# |
1. Please design a set of features and an effiffifficient algorithm in order to classify " V& n3 I4 U/ M7 Nthe 19 types of human actions from the data of these body-worn sensors. ; k9 S3 G$ o# k2. Because of the high cost of the data, we need to make the model have- S0 v) f" \* } e5 y: D' ~
a good generalization ability with a limited data set. We need to study' `7 W, b& {) b9 z, ]
and evaluate this problem specififically. Please design a feasible method to $ Z% d8 {% d' s7 qevaluate the generalization ability of your model. + H/ s8 A0 _' Q: ~" C, ^3. Please study and overcome the overfifitting problem so that your classififi-) }, B7 K& S' x5 M3 I m9 I
cation algorithm can be widely used on the problem of people’s action & {$ u- q& g! A: V# F+ t: m& Y3 b' lclassifification. w4 u/ I4 N! V- h/ b
The complete data can be downloaded through the following link: & x0 z1 _$ J& F4 V3 v2 Ehttps://caiyun.139.com/m/i?0F5CJUOrpy8oq& z* t/ p+ z& R' ^0 Q% w! M
2Appendix: File structure4 g+ t! g# h) J# c; s
• 19 activities (a) % P4 u" I+ U N• 8 subjects (p) 6 x7 ~ o+ { ]5 r9 k% F• 60 segments (s) 2 N- |9 G c4 n6 d: }. p; z• 5 units on torso (T), right arm (RA), left arm (LA), right leg (RL), left $ H0 P, Y. k& eleg (LL) 5 E# n; j: F Z& {& u# n8 N2 x• 9 sensors on each unit (x, y, z accelerometers, x, y, z gyroscopes, x, y, z , N. B$ o) ], h' qmagnetometers) % R4 x4 V! S& x: j; UFolders a01, a02, ..., a19 contain data recorded from the 19 activities. : Z9 u3 n# ?( j5 y9 kFor each activity, the subfolders p1, p2, ..., p8 contain data from each of the7 v: i' \8 s1 G4 ^' P
8 subjects. ( E% K% F3 i" c3 lIn each subfolder, there are 60 text fifiles s01, s02, ..., s60, one for each! {6 M7 Z$ @- E( Q
segment.* S1 y6 t, |3 [8 P6 {. N; b
In each text fifile, there are 5 units × 9 sensors = 45 columns and 5 sec × 25 . D, P; P" i& V: `6 i7 K3 i& b6 \Hz = 125 rows.# G" Y* I# R% h: J6 F
Each column contains the 125 samples of data acquired from one of the - w5 l' B% L( b/ X1 Msensors of one of the units over a period of 5 sec.2 ~+ L' J ?& N, G( u
Each row contains data acquired from all of the 45 sensor axes at a particular$ h }; T9 p, ~
sampling instant separated by commas.1 L: c; g* x2 v+ J/ p( a8 i
Columns 1-45 correspond to: M) N$ r+ i* \' J4 ~• T_xacc, T_yacc, T_zacc, T_xgyro, ..., T_ymag, T_zmag, - n g: \3 w# O6 v• RA_xacc, RA_yacc, RA_zacc, RA_xgyro, ..., RA_ymag, RA_zmag,% Z( u8 h# p P- r; ?9 _+ _. j( F* j
• LA_xacc, LA_yacc, LA_zacc, LA_xgyro, ..., LA_ymag, LA_zmag,( R0 p' q1 C, u# N: ~* C- ?
• RL_xacc, RL_yacc, RL_zacc, RL_xgyro, ..., RL_ymag, RL_zmag,; p) j7 s; U7 f7 B
• LL_xacc, LL_yacc, LL_zacc, LL_xgyro, ..., LL_ymag, LL_zmag. % A* Z. M3 A6 N: A6 \. ZTherefore, 4 n: |5 }! P, H U• columns 1-9 correspond to the sensors in unit 1 (T), * k) a9 W6 u8 \ W7 L1 {/ I/ R' y• columns 10-18 correspond to the sensors in unit 2 (RA), L: V1 ?7 B' P& y3 f* h# X
• columns 19-27 correspond to the sensors in unit 3 (LA),, i+ z+ k; P- b, m9 K3 e' M3 d
• columns 28-36 correspond to the sensors in unit 4 (RL), 2 O7 { n# U0 M0 r6 a- s• columns 37-45 correspond to the sensors in unit 5 (LL). & m8 E. g( @% t3References 0 `$ l% ~! k' q1 K" \2 ^[1] Mathie M.J., Celler B.G., Lovell N.H., Coster A.C.F. Classifification of basic7 U3 {3 |* w% n
daily movements using a triaxial accelerometer. Med. Biol. Eng. Comput.( v6 G9 z- r' y" Q+ r
42(5), 679-687, 2004 . @& S9 z: v; ]" y* A[2] Kangas M., Konttila A., Lindgren P., Winblad I., Ja¨msa¨ T. Comparison of ) }) E: z ?. M0 ?) ^7 Alow-complexity fall detection algorithms for body attached accelerometers. 5 z; a: \& @/ L, rGait Posture 28(2), 285-291, 2008 7 G, _) s" f2 s A, D7 H4 v( L[3] Wu W.H., Bui A.A.T., Batalin M.A., Liu D., Kaiser W.J. Incremental diag5 n; S4 l" h# B. X
nosis method for intelligent wearable sensor system. IEEE T. Inf. Technol. 0 G/ q& O) R3 c0 ~; l6 C) dB. 11(5), 553-562, 2007 ! H& s7 o- K7 v[4] Shiratori T., Hodgins J.K. Accelerometer-based user interfaces for the con 9 q8 M/ |; @8 h! Q5 ^trol of a physically simulated character. ACM T. Graphic. 27(5), 2008) p* B" o$ o- E3 K" i
" c6 `8 f" P" l3 F# X$ M+ e
2022 % X- n$ h+ c0 `- u# R3 ]Certifificate Authority Cup International Mathematical Contest Modeling * a6 E. U' ] _http://mcm.tzmcm.cn+ G$ j ^8 R3 B) O" C7 H: f0 k' s
Problem D (ICM) , y: d8 s) \: n( E5 YWhether Wildlife Trade Should Be Banned for a Long* s! }( j: v4 E6 c
Time ( c% d. a6 c% ?Wild-animal markets are the suspected origin of the current outbreak and the % N* |/ B* G8 {2 g( o2002 SARS outbreak, And eating wild meat is thought to have been a source 9 ?+ I& x7 W4 t2 z; L7 }0 X% Aof the Ebola virus in Africa. Chinas top law-making body has permanently( _* P' l4 y+ `
tightened rules on trading wildlife in the wake of the coronavirus outbreak, ; T u2 z& g7 f s9 U zwhich is thought to have originated in a wild-animal market in Wuhan. Some, D! D% _. I1 ~: k" [& b
scientists speculate that the emergency measure will be lifted once the outbreak 5 J0 Z3 S9 ]5 B. Z i6 _ends.! {( J% {8 q1 L/ J% Q
How the trade in wildlife products should be regulated in the long term?9 I6 @4 e, }! T
Some researchers want a total ban on wildlife trade, without exceptions, whereas 6 y8 q- _7 ]% Y7 [! P7 o/ O# w' o8 r0 r0 Zothers say sustainable trade of some animals is possible and benefificial for peo ' R5 F" A9 j0 o: R9 o* Xple who rely on it for their livelihoods. Banning wild meat consumption could& J* H: v7 V1 d; \! s; N' [
cost the Chinese economy 50 billion yuan (US $ 7.1 billion) and put one mil6 l6 v! \0 a7 \
lion people out of a job, according to estimates from the non-profifit Society of 6 U+ q$ d% ?2 k: R, \ zEntrepreneurs and Ecology in Beijing.$ K0 h$ v* U3 k+ I' R
A team led by Shi Zheng-Li and Cui Jie of the Wuhan Institute of Virology6 z! S( E' A8 J
in China, chasing the origin of the deadly SARS virus, have fifinally found their 4 K& b: T6 t1 p7 `( X: Esmoking gun in 2017. In a remote cave in Yunnan province, virologists have 1 j" p! f2 Y/ c( j% }: Pidentifified a single population of horseshoe bats that harbours virus strains with+ _, c- o u A( e" b7 F
all the genetic building blocks of the one that jumped to humans in 2002, killing% N& \7 \- i) W0 y- L0 h
almost 800 people around the world. The killer strain could easily have arisen " g" D- w: |- Q/ I5 a; Jfrom such a bat population, the researchers report in PLoS Pathogens on 30 ( P5 K1 j' V# S6 O0 bNovember, 2017. Another outstanding question is how a virus from bats in& w3 u* g: v1 B2 T
Yunnan could travel to animals and humans around 1,000 kilometres away in & x- r: B! A' E0 p# F. k; |5 B+ j2 zGuangdong, without causing any suspected cases in Yunnan itself. Wildlife ; i; I2 p4 w* s; [ ~trade is the answer. Although wild animals are cooked at high temperature ) z9 K4 Z8 y) iwhen eating, some viruses are diffiffifficult to survive, humans may come into contact 8 Z% f/ y5 @1 q+ Owith animal secretions in the wildlife market. They warn that the ingredients , z: O# ~2 i, C; Q4 Ware in place for a similar disease to emerge again. - ]2 w' i. e) u7 G ]Wildlife trade has many negative effffects, with the most important ones being: 7 J( T* }3 x/ x6 g& ]' Z9 J1Figure 1: Masked palm civets sold in markets in China were linked to the SARS * n5 U2 u1 s0 |# P0 z) poutbreak in 2002.Credit: Matthew Maran/NPL) |" z; g( x; M# G' E1 J
• Decline and extinction of populations! Z& ~. K7 q6 ^' ~# M
• Introduction of invasive species7 y# B# R M6 o' s( o, M" \
• Spread of new diseases to humans, u3 K h" |" X3 ]
We use the CITES trade database as source for my data. This database, C$ s0 V& V' ^* ~: h0 J; r9 y
contains more than 20 million records of trade and is openly accessible. The $ ~/ q: s. [1 i9 M6 y6 Tappendix is the data on mammal trade from 1990 to 2021, and the complete f& w% s9 |4 M3 r0 Bdatabase can also be obtained through the following link:" X3 R2 j. s( ^% d3 f
https://caiyun.139.com/m/i?0F5CKACoDDpEJ1 ~! k, f0 D- R0 i: z3 U- m
Requirements Your team are asked to build reasonable mathematical mod; x; O' ]1 j, F7 p; p- T( ]" f
els, analyze the data, and solve the following problems:+ H3 R. q3 y4 e
1. Which wildlife groups and species are traded the most (in terms of live 1 y, W! R S, A* C9 \/ R& Sanimals taken from the wild)?% E; ]0 [" [* `) b; H
2. What are the main purposes for trade of these animals?2 M, [5 J6 p% U
3. How has the trade changed over the past two decades (2003-2022)? # q" E7 B2 E# i7 t k8 y: U4. Whether the wildlife trade is related to the epidemic situation of major 9 r& G! F! w3 I& `infectious diseases?8 d/ U& e$ H1 N5 n6 \
25. Do you agree with banning on wildlife trade for a long time? Whether it6 b! z( Y* L m+ s! Z+ i' W
will have a great impact on the economy and society, and why?% ]* ^( f* R( @% X5 L7 H- d: I4 _
6. Write a letter to the relevant departments of the US government to explain$ S+ S5 m) H+ T% x
your views and policy suggestions.9 ^6 ?, R: Z8 i5 J- S [0 k