LNG portfolio optimization, approach by stochastic programming techniques

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HAL Id: pastel-00645441

https://pastel.archives-ouvertes.fr/pastel-00645441

Submitted on 5 Dec 2011

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LNG portfolio optimization, approach by stochastic

programming techniques

Zhihao Cen

To cite this version:

Zhihao Cen. LNG portfolio optimization, approach by stochastic programming techniques. Optimiza-tion and Control [math.OC]. Ecole Polytechnique X, 2011. English. �pastel-00645441�

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❚❤ès❡ ❞❡ ❞♦❝t♦r❛t ▼❛t❤é♠❛t✐q✉❡s ❆♣♣❧✐q✉é❡s ♣♦✉r ♦❜t❡♥✐r ❧❡ ❣r❛❞❡ ❞❡ ❉♦❝t❡✉r ❞❡ ❧✬➱❝♦❧❡ P♦❧②t❡❝❤♥✐q✉❡ ❈♦♥❢✐❞❡♥t✐❡❧

▲◆● ♣♦rt❢♦❧✐♦ ♦♣t✐♠✐③❛t✐♦♥

❛♣♣r♦❛❝❤ ❜② st♦❝❤❛st✐❝ ♣r♦❣r❛♠♠✐♥❣ t❡❝❤♥✐q✉❡s ♣rés❡♥té❡ ♣❛r ❩❤✐❤❛♦ ❈❊◆ s♦✉s ❧❛ ❞✐r❡❝t✐♦♥ ❞❡ ❏✳❋ré❞ér✐❝ ❇❖◆◆❆◆❙ s♦✉t❡♥✉❡ ♣✉❜❧✐q✉❡♠❡♥t ❧❡ ✷✷ ♥♦✈✳ ✷✵✶✶ ❏✉r② ❘❛♣♣♦rt❡✉rs✿ ❘❡♥é ❍❊◆❘■❖◆ ❲❡✐❡rstr❛ss ■♥st✐t✉t❡✱ ❇❡r❧✐♥ ●✐❧❧❡s P❆●➮❙ ▲P▼❆✱ ❯P▼❈ ❊①❛♠✐♥❛t❡✉rs✿ P✐❡rr❡ ❇❖◆❆▼■ ▲■❋✱ ❆✐① ▼❛rs❡✐❧❧❡ ❯♥✐✈❡rs✐té ❚❤✐❜❛✉❧t ❈❍❘■❙❚❊▲ ❚♦t❛❧ ▼✐❝❤❡❧ ❉❊ ▲❆❘❆ ❈❊❘▼■❈❙✱ ❊◆P❈ ❊♠♠❛♥✉❡❧ ●❖❇❊❚ ❈▼❆P✱ ➱❝♦❧❡ P♦❧②t❡❝❤♥✐q✉❡ ❉✐r❡❝t❡✉r ❞❡ t❤ès❡ ❏✳❋ré❞ér✐❝ ❇❖◆◆❆◆❙ ■◆❘■❆ ✫ ❈▼❆P✱ ➱❝♦❧❡ P♦❧②t❡❝❤♥✐q✉❡ ❈❡♥tr❡ ❞❡ ▼❛t❤é♠❛t✐q✉❡s ❆♣♣❧✐q✉é❡s ✕ ❯▼❘ ✼✻✹✶ ■◆❘■❆ ❙❛❝❧❛② ✲ ❰❧❡ ❞❡ ❋r❛♥❝❡

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❆❝❦♥♦✇❧❡❞❣❡♠❡♥t

❚❤✐s t❤❡s✐s ✐s t❤❡ ❢r✉✐t ♦❢ t❤r❡❡ ②❡❛rs ♦❢ r❡s❡❛r❝❤ ■ s♣❡♥t ❜❡t✇❡❡♥ t❤❡ ❈❖▼▼❆◆❉❙ t❡❛♠ ♦❢ t❤❡ ❈❡♥t❡r ♦❢ ❆♣♣❧✐❡❞ ▼❛t❤❡♠❛t✐❝s ✭❈▼❆P✮ ❛t ❊❝♦❧❡ P♦❧②t❡❝❤♥✐q✉❡✱ ❛♥❞ t❤❡ ◗✉❛♥t✐t❛t✐✈❡ ❆♥❛❧②s✐s t❡❛♠ ♦❢ ❚♦t❛❧ ●❛s ❛♥❞ P♦✇❡r✳ ❉✉r✐♥❣ t❤✐s t✐♠❡✱ ■ ❤❛✈❡ ❤❛❞ t❤❡ ♣❧❡❛s✉r❡ t♦ ✇♦r❦ ✇✐t❤ s❡✈❡r❛❧ ♣❡♦♣❧❡ ✇❤♦s❡ ✈❛r✐♦✉s ❝♦♥tr✐❜✉t✐♦♥s ✇❤❡r❡ ✐♥✈❛❧✉❛❜❧❡ t♦ t❤❡ ❛❝❝♦♠♣❧✐s❤♠❡♥t ♦❢ ♠② r❡s❡❛r❝❤ ❛♥❞ t♦ t❤❡ ♣r♦❞✉❝t✐♦♥ ♦❢ t❤✐s ♠❛♥✉s❝r✐♣t✳ ■t ✐s ♠② ♣❧❡❛s✉r❡ t♦ ❝♦♥✈❡② ♠② s✐♥❝❡r❡ ❣r❛t✐t✉❞❡ t♦ t❤❡♠ ❛❧❧✳ ❋♦r❡♠♦st✱ ■ t❤❛♥❦ ♠② t❤❡s✐s s✉♣❡r✈✐s♦r ❋ré❞ér✐❝ ❇♦♥♥❛♥s✱ ❢♦r ❤✐s ❝♦♥st❛♥t s✉♣♣♦rt✱ ❡♥❝♦✉r❛❣❡♠❡♥t✱ ❡♥t❤✉s✐❛s♠✱ ❛♥❞ ♦✉tst❛♥❞✐♥❣ ❣✉✐❞❛♥❝❡ ✐♥ ❛❧❧ ❛s♣❡❝t ♦❢ t❤❡ ✇♦r❦✿ ❢r♦♠ t❤❡ r❡s❡❛r❝❤ ❛①✐s✱ t♦ t❤❡ ❞❡t❛✐❧s ♦❢ t❤❡ ❛❧❣♦r✐t❤♠✳ ■ ❝♦✉❧❞ ♥❡✈❡r ❤❛✈❡ ❤♦♣❡❞ ❢♦r ❜❡tt❡r s✉✲ ♣❡r✈✐s✐♦♥✳ ■ ✐♠♠❡♥s❡❧② ❛♣♣r❡❝✐❛t❡ t❤❡ ❡①❝❡❧❧❡♥t ❡①❛♠♣❧❡ ❤❡ ❤❛s s❡t ❢♦r ♠❡ ❛s ❛ r❡s❡❛r❝❤❡r✱ ♠❛t❤❡♠❛t✐❝✐❛♥ ❛♥❞ ♣r♦❢❡ss♦r✳ ▼② s♣❡❝✐❛❧ t❤❛♥❦s ❛❧s♦ ❣♦❡s t♦ ❚❤✐❜❛✉❧t ❈❤r✐st❡❧✱ ♠② ❛❞✈✐s♦r ❛t ❚♦t❛❧✳ ■ ❛♣♣r❡❝✐❛t❡ ❤✐s ❣✉✐❞❛♥❝❡ ✐♥ ♠② ✜rst st❛❣❡ ♦❢ ♠② t❤❡s✐s✱ ❛♥❞ ❤✐s ♥✉♠❡r♦✉s r❡♠❛r❦s r❡❣❛r❞✐♥❣ t❤❡ ✜♥❛❧ ❛rt✐❝❧❡s ❛♥❞ ♠❛♥✉s❝r✐♣t✳ ■t ✐s ❛♥ ❤♦♥♦r ❢♦r ♠❡ t♦ ❤❛✈❡ ❘❡♥é ❍❡♥r✐♦♥ ❛♥❞ ●✐❧❧❡s P❛❣ès ❛s ♠② r❛♣♣♦rt❡✉rs✳ ▼❛♥② t❤❛♥❦s ✐s s❡♥❞ t♦ ❛❧❧ ♠❡♠❜❡rs ♦❢ t❤❡ t❤❡s✐s ❥✉r②✿ P✐❡rr❡ ❇♦♥❛♠✐✱ ▼✐❝❤❡❧ ❉❡ ▲❛r❛✱ ❊♠♠❛♥✉❡❧ ●♦❜❡t✳ ■ ❣r❛t❡❢✉❧❧② ❛❝❦♥♦✇❧❡❞❣❡ ❲❛❧❧✐s✱ ◆❛ssér❛✱ ❙❛♥❞r❛✱ ❆❧❡①❛♥❞r❛✱ t❤❡ ❛ss✐st❛♥ts ❛t ❈▼❆P✱ ❢♦r ♣r♦✈✐❞✐♥❣ ❛ ♣❧❡❛s❛♥t ❡♥✈✐r♦♥♠❡♥t ❢♦r r❡s❡❛r❝❤ ❛♥❞ ✇♦r❦✳ ▼❛♥② t❤❛♥❦s t♦ ❙②❧✈❛✐♥✱ ♦✉r ■❚ ❛ss✐st❛♥t✱ ❢♦r ❤✐s ❝♦♥st❛♥t s✉♣♣♦rt✳ ▼② t✐♠❡ ❛t ❈▼❆P✱ ❊❝♦❧❡ P♦❧②t❡❝❤♥✐q✉❡ ✇❛s ♠❛❞❡ ❡♥❥♦②❛❜❧❡ ✐♥ ❧❛r❣❡ ♣❛rt ❞✉❡ t♦ t❤❡ ♠❛♥② ❝♦❧❧❡❛❣✉❡s✿ ❑❤❛❧✐❧✱ ❊♠✐❧✐❡✱ t❤❡ t✇♦ ❈❛♠✐❧❧❡✭s✮✱ ❙♦❧❡❞❛❞✱ ❋r❛♥❝✐s❝♦✱ ❋❧♦r❡♥t✱ ❈❧é✲ ♠❡♥t✱ ❩✐①✐❛♥✱ ❳❛✈✐❡r✱ ▲❛✉r❡♥t✱ ❳✐❛♦❧✉✱ ❈❤❛♦✱ ❑❤❛❧✐❞✱ ▼❛①✐♠❡✱ ❖❧✐✈✐❡r✱ ▼✐❝❤❛ë❧✱ ❆♥❦✐t✳ ❆ s♣❡❝✐❛❧ t❤❛♥❦s ✐s ❣✐✈❡♥ t♦ ❙②❧✈✐❡ ❢♦r ❤❡r ❝❧✉❜ ♦❢ ❇❡❧❣✐✉♠ ❝❤♦❝♦❧❛t❡✳ ▼② ❤❡❛rt❢❡❧t ❣r❛t✐t✉❞❡ ❣♦❡s t♦ t❤❡ ◗✉❛♥t✐t❛t✐✈❡ ❆♥❛❧②s✐s t❡❛♠ ❛t ❚♦t❛❧ ●❛s ❛♥❞ P♦✇❡r ❢♦r t❛❦✐♥❣ ♠❡ ✐♥ ❛s ❛♥ ✐♥t❡r♥ t❤r❡❡ ②❡❛rs ❛❣♦ ❛♥❞ ❢♦r t❤❡ t✐♠❡ ■ s♣❡♥t ✇✐t❤ ❞✉r✐♥❣ ♠② ✜rst st❛❣❡ ❛s P❤✳❉✳ st✉❞❡♥t✳ ❙♣❡❝✐❛❧ t❤❛♥❦s ❛r❡ ❣✐✈❡♥ t♦ ❏✲❈✳ Pr❡✈❡❧ ❢♦r tr✉st✐♥❣ ♠❡ t♦ ✇♦r❦ ♦♥ t❤✐s r❡s❡❛r❝❤ ♦♣♣♦rt✉♥✐t②✱ ❛♥❞ t♦ ❆✳ ❇♦✐ss♦♥ ❢♦r ♣r♦✈✐❞✐♥❣ ♠❡ ✇✐t❤ ❛ ❣r❡❛t r❡s❡❛r❝❤ ❡♥✈✐r♦♥♠❡♥t✳ ■ ❛❧s♦ ✇❛♥t t♦ ♠❡♥t✐♦♥ s♦♠❡ ♦t❤❡r ❝♦❧❧❡❛❣✉❡s ❢♦r t❤❡✐r ✉s❡❢✉❧ ❞✐s❝✉ss✐♦♥ ❛♥❞ ❢♦r t❤❡✐r ❡①❝❡❧❧❡♥t s✉♣♣♦rt✿ ❖✳ ❙♦❧❞❛t♦s✱ ❈✳ ❩❤❛♥❣✱ ●✳ ▲❡❣r❛♥❞✱ ❉✳ ❇❡s♦♠❜❡s✱ ❏✳ ❈❤❛❜❛✉❞✳ ■ ❛❧s♦ ❣✐✈❡ t❤❛♥❦s t♦ ❚♦t❛❧ ❙❆✳ ❛♥❞ t❤❡ ❆ss♦❝✐❛t✐♦♥ ◆❛t✐♦♥❛❧ ❘❡❝❤❡r❝❤❡ ❚❡❝❤♥♦❧♦❣✐❡ ✭❆◆❘❚✮ ❢♦r ♣r♦✈✐❞✐♥❣ ❢✉♥❞✐♥❣ ❢♦r t❤✐s r❡s❡❛r❝❤✳ ✐

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■ ✇♦✉❧❞ ❧✐❦❡ t♦ ❡①♣r❡ss ♠② ❣r❛t✐t✉❞❡ t♦ ❛❧❧ ♠② ♣r♦❢❡ss♦rs ♦❢ ♠② s❡❝♦♥❞ ②❡❛r ♠❛st❡r ❖❏▼❈✿ P✳ ❈♦♠❜❡tt❡✱ ❙✳ ❙♦r✐♥✱ ❙✳ ●❛✉❜❡rt✱ ❏✲❇✳ ▲❛ss❡rr❡ ❛s ✇❡❧❧ ❛s t❤♦s❡ ♦❢ ♠② t❤✐r❞ ②❡❛r ♦❢ st✉❞② ✐♥ ❊◆❙❚❆✿ P✳ ❈❛r♣❡♥t✐❡r✱ ❏✲P✳ ▲❛✉♠♦♥❞✱ ✇❤♦ ❣❛✈❡ ♠❡ t❤❡ s♦❧✐❞ ❦♥♦✇❧❡❞❣❡ ❛♥❞ ❞❡❡♣ ✉♥❞❡rst❛♥❞✐♥❣ ✐♥ ♦♣t✐♠✐③❛t✐♦♥✱ ❝♦♥tr♦❧ t❤❡♦r② ❛♥❞ t❤❡✐r ✈❛r✐♦✉s ❛♣♣❧✐❝❛t✐♦♥s✱ ❛♥❞ ❡♥❝♦✉r❛❣❡❞ ♠❡ t♦ ❝♦♥t✐♥✉❡ ♠② st✉❞② ❛s ❛ P❤✳❉✳ st✉❞❡♥t✳ ▲❛st ❜✉t ♥♦t ❧❡❛st✱ ■ ✇♦✉❧❞ ❧✐❦❡ t♦ t❤❛♥❦ ♠② ❢❛♠✐❧② ❢♦r ❛❧❧ t❤❡✐r ❧♦✈❡ ❛♥❞ ❡♥❝♦✉r❛❣❡✲ ♠❡♥t✳ ❋♦r ♠② ♣❛r❡♥ts ❛♥❞ ♠② ❣r❛♥❞ ♣❛r❡♥ts ✇❤♦ r❛✐s❡❞ ♠❡ ✇✐t❤ ❛ ❞❡❡♣ ❧♦✈❡ ❛♥❞ s✉♣♣♦rt ♠❡ ✐♥ ❛❧❧ ♠② ♣✉rs✉✐ts✳ ❆♥❞ ♠② t❤❛♥❦s ❣♦ t♦ ❛❧❧ ♠② ❝❧♦s❡ ❢r✐❡♥❞s ✐♥ ❈❤✐♥❛ t♦ ❣✐✈❡ ♠❡ t❤❡✐r s✉♣♣♦rt ❞✉r✐♥❣ t❤✐s ♣❡r✐♦❞✳ ❚❤❛♥❦ ②♦✉✳ ✐✐

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❆❜str❛❝t

❚❤❡ ✇♦r❦ ♣r❡s❡♥t❡❞ ✐♥ t❤✐s P❤✳❉ ❞✐ss❡rt❛t✐♦♥ ✐s ♠♦t✐✈❛t❡❞ ❜② t❤❡ ♣r♦❜❧❡♠ ♦❢ ♠❛♥❛❣❡✲ ♠❡♥t ♦❢ ❛ ✢❡❡t ♦❢ ❝❛r❣♦s tr❛♥s♣♦rt✐♥❣ ❧✐q✉❡✜❡❞ ♥❛t✉r❛❧ ❣❛s ✭▲◆●✮ ✐♥✐t✐❛❧❧② ♣r♦♣♦s❡❞ ❜② ❚♦t❛❧✳ ❚❤❡ ❤♦❧❞❡r ♦❢ t❤❡ ♣♦rt❢♦❧✐♦ ❤❛s t♦ ♠❡❡t ✐ts ❝♦♠♠✐t♠❡♥ts t♦✇❛r❞s ✐ts ❝♦✉♥t❡r✲ ♣❛rts ✇❤✐❧❡ tr②✐♥❣ t♦ ❣❡♥❡r❛t❡ ♣r♦✜ts t❤r♦✉❣❤ ❛r❜✐tr❛t✐♥❣ ❞✐✛❡r❡♥t ❝♦♠♠♦❞✐t✐❡s ♠❛r❦❡t✳ ❚❤✉s✱ t❤❡ ♠❛♥❛❣❡♠❡♥t ♦❢ ♣♦rt❢♦❧✐♦ ❝❛♥ ❜❡ ♠♦❞❡❧❡❞ ❛s ❛ st♦❝❤❛st✐❝✱ ❞②♥❛♠✐❝ ❛♥❞ ✐♥t❡❣❡r ♦♣t✐♠✐③❛t✐♦♥ ♣r♦❜❧❡♠✳ ❚❤✐s P❤✳❉ ❞✐ss❡rt❛t✐♦♥ ✐s ♦r❣❛♥✐s❡❞ ❛s ❢♦❧❧♦✇s✿ ❈❤❛♣t❡r ■ ❲❡ ✜rst ♣r❡s❡♥t t❤❡ ▲◆● ♣♦rt❢♦❧✐♦ ♠❛♥❛❣❡♠❡♥t ♣r♦❜❧❡♠ ❛♥❞ ❣✐✈❡ t❤❡ ♠❛t❤❡♠❛t✐❝❛❧ ♠♦❞❡❧✳ ❚❤❡♥ ✇❡ s✉♠♠❛r✐③❡ t❤❡ ♠❛✐♥ r❡s✉❧ts ♦❢ t❤✐s ✇♦r❦✳ ❈❤❛♣t❡r ■■ ❲❡ ✐♥tr♦❞✉❝❡ ❛ ♥✉♠❡r✐❝❛❧ ♠❡t❤♦❞ ❢♦r s♦❧✈✐♥❣ ❝♦♥t✐♥✉♦✉s r❡❧❛①❛t✐♦♥ ♣r♦❜✲ ❧❡♠✳ ❲❡ ♣r♦♣♦s❡ ❛♥ ❛❧❣♦r✐t❤♠ ❜❛s❡❞ ♦♥ t❤❡ ❝♦♠❜✐♥❛t✐♦♥ ♦❢ t❤❡ ✈❡❝t♦✲ r✐❛❧ q✉❛♥t✐③❛t✐♦♥ ♠❡t❤♦❞ ❛s ❞✐s❝r❡t✐③❛t✐♦♥ ♠❡t❤♦❞ ❛♥❞ t❤❡ ❞✉❛❧ ❞②♥❛♠✐❝ ♣r♦❣r❛♠♠✐♥❣ ❛♣♣r♦❛❝❤✳ ❲❡ s❤♦✇ t❤❡ ❝♦♥✈❡r❣❡♥❝❡ ♦❢ ♥✉♠❡r✐❝❛❧ s❝❤❡♠❛ ❛♥❞ ❣✐✈❡ t❤❡ ❡rr♦r ❛♥❛❧②s✐s ♦♥ t❤❡ ❞✐s❝r❡t✐③❛t✐♦♥ ❜② q✉❛♥t✐③❛t✐♦♥✳ ❙♦♠❡ ♥✉♠❡r✐❝❛❧ t❡sts ♦♥ r❡❛❧ ❡♥❡r❣② ♠❛r❦❡t ♣r♦❜❧❡♠ ❛r❡ ♣❡r❢♦r♠❡❞✳ ❈❤❛♣t❡r ■■■ ❲❡ ❛❧s♦ st✉❞② t❤❡ r✐s❦ ❛✈❡rs❡ ♦♣t✐♠✐③❛t✐♦♥ ❜② ✉s✐♥❣ ❝♦♥❞✐t✐♦♥❛❧ ✈❛❧✉❡ ❛t r✐s❦ ✭CVaR✮ ❛s ❝r✐t❡r✐♦♥✳ ❲❡ s❤♦✇ t❤❛t t❤❡ ❛❧❣♦r✐t❤♠ ♣r♦♣♦s❡❞ ✐♥ ❝❤❛♣✲ t❡r ■■ ✐s ❛❧s♦ ❛❞❛♣t❡❞ t♦ s✉❝❤ ❢♦r♠✉❧❛t✐♦♥✳ ❋✉rt❤❡r♠♦r❡✱ ✇❡ ♣r♦♣♦s❡ t❤❡ t❡❝❤♥✐q✉❡ ♦❢ ❝❤❛♥❣❡s ✐♥ ♣r♦❜❛❜✐❧✐t② ♠❡❛s✉r❡ ✐♥ st♦❝❤❛st✐❝ ♣r♦❣r❛♠♠✐♥❣ ✐♥ ♦r❞❡r t♦ ✐♠♣r♦✈❡ r❛r❡ s❝❡♥❛r✐♦ s✐♠✉❧❛t✐♦♥✳ ❙❛♠❡ ♥✉♠❡r✐❝❛❧ t❡st ❛s ✐♥ ❈❤❛♣t❡r ■■ ✐s ♣❡r❢♦r♠❡❞ ✐♥ ♦r❞❡r t♦ ♠❛❦❡ ❝♦♠♣❛r✐s♦♥✳ ❈❤❛♣t❡r ■❱ ❲❡ st✉❞② t❤❡ s❡♥s✐t✐✈✐t② ♦❢ t❤❡ ♣♦rt❢♦❧✐♦ ✇✐t❤ r❡s♣❡❝t t♦ s❡✈❡r❛❧ ♣❛r❛♠✲ ❡t❡rs ✐♥ t❤❡ ♠❛r❦❡t ♣r✐❝❡ ♠♦❞❡❧✳ ❲❡ ♣r♦♣♦s❡❞ ❛ ♥✉♠❡r✐❝❛❧ ♠❡t❤♦❞ t♦ ❝♦♠♣✉t❡ s❡♥s✐t✐✈✐t② ✈❛❧✉❡ ❜❛s❡❞ ♦♥ ❉❛♥s❦✐♥✬s t❤❡♦r❡♠✳ ❚❤❡ ❝♦♥✈❡r❣❡♥❝❡ ♦❢ s❡♥s✐t✐✈✐t② ✈❛❧✉❡ ♦❢ ❞✐s❝r❡t✐③❡❞ ♣r♦❜❧❡♠ t♦ t❤❡ ♦♥❡ ♦❢ ♦r✐❣✐♥❛❧ ♣r♦❜❧❡♠ ✐s ♣r♦✈❡❞✳ ❈♦♠♣❛r✐s♦♥ ❜❡t✇❡❡♥ r❡s✉❧t ♦❜t❛✐♥❡❞ ❜② ❛❧❣♦r✐t❤♠ ✐♥ ❝❤❛♣t❡r ■■ ❛♥❞ ♦t❤❡r ❝❧❛ss✐❝❛❧ ♠❡t❤♦❞s ❛r❡ ♣r♦✈✐❞❡❞✳ ❈❤❛♣t❡r ❱ ❲❡ st✉❞② t❤❡ st♦❝❤❛st✐❝ ✐♥t❡❣❡r ♣r♦❣r❛♠♠✐♥❣ ♣r♦❜❧❡♠✳ ❚❤❡ ✐♥t❡❣r❛❧✐t② ❝✉tt✐♥❣ ♣❧❛♥❡ ♠❡t❤♦❞ ✐s ❛♣♣❧✐❡❞ t♦ ❛♣♣r♦①✐♠❛t❡ t❤❡ ✐♥t❡❣❡r ♣r♦❜❧❡♠✳ ❲❡ s❤♦✇ t❤❛t ✐t ✐s ✐♠♣♦ss✐❜❧❡ t♦ ❝♦♥✈❡r❣❡ t♦ t❤❡ ✐♥t❡❣❡r s♦❧✉t✐♦♥ ❜❡❝❛✉s❡ ♦❢ t❤❡ ♥♦♥ ❝♦♥✈❡①✐t② ❛♥❞ ❞✐s❝♦♥t✐♥✉✐t② ♦❢ t❤❡ ❇❡❧❧♠❛♥ ✈❛❧✉❡ ❢✉♥❝t✐♦♥✳ ❲❡ ❛♣♣❧② ❛ ❤❡✉r✐st✐❝ ♠❡t❤♦❞ ❛♥❞ ♣r♦♣♦s❡ ❛ s♠❛❧❧ ✐♠♣r♦✈❡♠❡♥t✳ ❙♦♠❡ ♥✉♠❡r✐❝❛❧ t❡sts ❛r❡ ❛❧s♦ ♣r♦✈✐❞❡❞✳ ✐✐✐

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❑❡②✇♦r❞s✿ st♦❝❤❛st✐❝ ♣r♦❣r❛♠♠✐♥❣✱ ✈❡❝t♦r✐❛❧ q✉❛♥t✐③❛t✐♦♥ ♠❡t❤♦❞✱ ❞✉❛❧ ❞②♥❛♠✐❝ ♣r♦✲ ❣r❛♠♠✐♥❣✱ s❡♥s✐t✐✈✐t② ❛♥❛❧②s✐s✱ ✐♥t❡❣❡r ♣r♦❣r❛♠♠✐♥❣✱ ❋❡♥❝❤❡❧ ❝✉t✱ ♣♦rt❢♦❧✐♦ ♠❛♥❛❣❡✲ ♠❡♥t✳