مجله مدل‌سازی پیشرفته ریاضی

مجله مدل‌سازی پیشرفته ریاضی

یک روش جدید برای حل دستگاه معادلات چندخطی

نوع مقاله : مقاله پژوهشی

نویسندگان
1 گروه ریاضی، دانشکده مهندسی سیستم های هوشمند و علوم داده، دانشگاه خلیج فارس، بوشهر، ایران
2 گروه ریاضی، دانشکده مهندسی سیستم‌های هوشمند و علوم داده، دانشگاه خلیج فارس، بوشهر، ایران
چکیده
فرض کنید f : Rn → Rn، ﺗﺎﺑﻌﯽ ﻏﯿﺮﺧﻄﯽ ﺑﺎﺷﺪ. ﯾﮑﯽ ﺍﺯ ﺭﻭﺵ ﻫﺎﯼ ﻣﺘﺪﺍﻭﻝ ﺑﺮﺍﯼ ﺣﻞ
ﻣﻌﺎﺩﻟﻪ ﯼ ﻏﯿﺮ ﺧﻄﯽ f(x) = ۰، ﺭﻭﺵ ﻧﯿﻮﺗﻦ ﺍﺳﺖ. ﺍﯾﻦ ﺭﻭﺵ، ﺣﺘﯽ ﺑﺎ ﺍﻧﺘﺨﺎﺏ ﺣﺪﺱ ﺍﻭﻟﯿﻪ ﻣﻨﺎﺳﺐ،
ﻣﻤﮑﻦ ﺍﺳﺖ ﺑﺎ ﺷﮑﺴﺖ ﻣﻮﺍﺟﻪ ﺷﻮﺩ ﻭ ﯾﺎ ﻭﺍﮔﺮﺍ ﺷﻮﺩ. ﺍﯾﻦ ﻣﺸﮑﻞ، ﺑﻪ ﻭﯾﮋﻩ ﺯﻣﺎﻧﯽ ﮐﻪ ﺗﺎﺑﻊ ﺩﺭ ﻫﻤﺴﺎﯾﮕﯽ ﺟﻮﺍﺏ
ﻣﻌﺎﺩﻟﻪ ﻧﺎ ﻫﻤﻮﺍﺭ ﻭ ﯾﺎ ﻫﻤﻮﺍﺭﯼ ﺿﻌﯿﻔﯽ ﺩﺍﺷﺘﻪ ﺑﺎﺷﺪ ﻭ ﯾﺎ ﺣﺪﺱ ﺍﻭﻟﯿﻪ ﻧﺰﺩﯾﮏ ﺭﯾﺸﻪ ﻣﺸﺘﻖ ﺗﺎﺑﻊ f ﺍﻧﺘﺨﺎﺏ
ﺷﻮﺩ، ﺑﺮﺟﺴﺘﻪ ﺗﺮ ﺧﻮﺍﻫﺪ ﺷﺪ.
ﺩﺭ ﺍﯾﻦ ﻣﻘﺎﻟﻪ، ﺑﺮﺍﯼ ﺭﻓﻊ ﺍﯾﻦ ﻣﻌﺎﯾﺐ، ﺑﺎ ﺍﺳﺘﻔﺎﺩﻩ ﺍﺯ ﯾﮏ ﺗﺎﺑﻊ ﮐﻤﮑﯽ ﻣﺎﺗﺮﯾﺴﯽ، ﻣﻌﺎﺩﻟﻪ ﯼ ﺍﺻﻠﯽ ﺭﺍ ﺑﻪ ﯾﮏ

،f(x) = ۰ﻣﻌﺎﺩﻟﻪ ﯼ ﻣﻌﺎﺩﻝ ﺗﺒﺪﯾﻞ ﻣﯽ ﮐﻨﯿﻢ. ﻭﯾﮋﮔﯽ ﺗﺎﺑﻊ ﮐﻤﮑﯽ ﺁﻥ ﺍﺳﺖ ﮐﻪ ﺩﺭ ﻫﻤﺴﺎﯾﮕﯽ ﺟﻮﺍﺏ ﻣﻌﺎﺩﻟﻪ ﯼﻣﺸﺘﻖ ﭘﺬﯾﺮ ﻭ ﻧﺎﻣﻨﻔﺮﺩ ﺑﻮﺩﻩ ﻭ ﺑﻪ ﮔﻮﻧﻪ ﺍﯼ ﺍﻧﺘﺨﺎﺏ ﻣﯽ ﺷﻮﺩ ﮐﻪ ﺗﺎﺑﻊ ﺟﺪﯾﺪ، ﻫﻤﻮﺍﺭﯼ ﻣﻨﺎﺳﺐ ﺗﺮﯼ ﻧﺴﺒﺖ ﺑﻪ ﺗﺎﺑﻊ
ﺍﺻﻠﯽ ﺩﺍﺷﺘﻪ ﺑﺎﺷﺪ. ﺳﭙﺲ، ﺑﺮﺍﯼ ﯾﺎﻓﺘﻦ ﺗﻘﺮﯾﺒﯽ ﺍﺯ ﺟﻮﺍﺏ ﻣﻌﺎﺩﻟﻪ ﯼ ﺍﺻﻠﯽ، ﺭﻭﺵ ﻧﯿﻮﺗﻦ ﺭﺍﯾﺞ ﺭﺍ ﺑﺮﺍﯼ
ﻣﻌﺎﺩﻟﻪ ﯼ ﻣﻌﺎﺩﻝ ﺑﻪ ﮐﺎﺭ ﻣﯽ ﮔﯿﺮﯾﻢ.
ﺳﻮﺍﻟﯽ ﮐﻪ ﻣﻄﺮﺡ ﻣﯽ ﺷﻮﺩ ﺁﻥ ﺍﺳﺖ ﮐﻪ ﺁﯾﺎ ﺑﺎ ﺑﻪ ﮐﺎﺭ ﮔﯿﺮﯼ ﺭﻭﺵ ﻧﯿﻮﺗﻦ ﺑﺮﺍﯼ ﻣﻌﺎﺩﻟﻪ ﯼ ﺟﺪﯾﺪ، ﻫﺰﯾﻨﻪ ﻣﺤﺎﺳﺒﺎﺕ
ﻭ ﭘﯿﭽﯿﺪﮔﯽ ﻣﺴﺎﻟﻪ ﺑﯿﺸﺘﺮ ﻧﻤﯽ ﺷﻮﺩ؟ ﺩﺭ ﭘﺎﺳﺦ ﺑﻪ ﺍﯾﻦ ﺳﻮﺍﻝ، ﺑﺎﯾﺪ ﮔﻔﺖ ﮐﻪ ﺍﻧﺘﺨﺎﺏ ﺗﺎﺑﻊ ﮐﻤﮑﯽ ﻣﻬﻢ ﺍﺳﺖ
ﻭ ﺑﺎﯾﺴﺘﯽ ﺑﻪ ﮔﻮﻧﻪ ﺍﯼ ﺍﻧﺘﺨﺎﺏ ﺷﻮﺩ ﮐﻪ ﺭﻭﺵ ﻧﯿﻮﺗﻦ ﺳﺎﺩﻩ ﺳﺎﺯﯼ ﺷﻮﺩ. ﻣﺎ ﺩﺭ ﺍﯾﻦ ﻣﻘﺎﻟﻪ ﺑﺎ ﺍﻧﺘﺨﺎﺏ ﺗﺎﺑﻊ ﮐﻤﮑﯽ
ﻣﻨﺎﺳﺐ ﻭ ﺑﺎ ﺑﻪ ﮐﺎﺭﮔﯿﺮﯼ ﺭﻭﺵ ﭘﯿﺸﻨﻬﺎﺩﯼ ﺑﺮﺍﯼ ﺣﻞ ﺩﺳﺘﮕﺎﻩ ﻣﻌﺎﺩﻻﺕ ﭼﻨﺪ ﺧﻄﯽ، ﮐﺎﺭﺍﯾﯽ ﺭﻭﺵ ﺟﺪﯾﺪ ﺭﺍ
ﺑﺮﺭﺳﯽ ﻣﯽ ﮐﻨﯿﻢ.
کلیدواژه‌ها
موضوعات

عنوان مقاله English

A new method for solving multilinear systems

نویسندگان English

Saeed Karimi 1
Negar Ajdari 2
1 Mathematics Department, Faculty of Intelligent Systems Engineering and Data Science, Persian Gulf University, Bushehr, Iran
2 Department of Mathematics, Faculty of Intelligent Systems Engineering and Data Science, Persian Gulf University, Bushehr, Iran.
چکیده English

The Newton method is one of the common methods for solving nonlinear equations
f : Rn →Rn,
f(x) = 0.
This method, even the appropriate initial guess, may fail or diverge. This problem becomes particularly
pronounced when the function f has irregular behavior or weak smoothness in the neighborhood of the
equation’s solution, or when the initial guess is chosen near the root of the derivative of f.
In this paper, to remedy these issues, we reduce the main equation to an equivalent equation by using
an auxiliary matrix function. Its auxiliary function feature is that it is differentiable and nonsingular in the
neighborhood of the solution of f(x) = 0, and it is chosen in such a way that the reduced function has
better smoothness compared to the original funtion. Then, we apply the Newton method for solving the
reduced equation to obtain the approximate solution of the original equation.
Now, there is this question. Do the the comutational cost and compexity of the problem increase by
applying the Newton method to the equivalent equation? In response to this question, the importance
of choosing the proper auxiliary function increases, and it should be selected in sucha way that reduces
computationalcosts. In this paper, by choosing a suitable auxiliary function and applying the proposed
method to solve the system of nonlinear equations, we investigate the efficiency of the new method.

کلیدواژه‌ها English

Newton method
nonlinear equation
nonlinear system
tensor equation

  • تاریخ دریافت 19 فروردین 1405
  • تاریخ بازنگری 26 خرداد 1405
  • تاریخ پذیرش 17 مرداد 1405