Davaajargal Jargalsaikhan

Mr. Davaajargal Jargalsaikhan

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Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 December 2023 in Journal of Institute of Mathematics and Digital Technology
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Journal Article
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DJDavaajargal Jargalsaikhan
Davaajargal Jargalsaikhan
EREnkhbat Rentsen
Enkhbat Rentsen
DBDulguuntuya Bataa
Dulguuntuya Bataa
Bayanjargal DarkhijavBayanjargal Darkhijav
Bayanjargal Darkhijav
Sangaku problem is one of Japanese Temple Geometry problems which was studied in Hidetoshi Fukugawa[1]. One of the Sangaku problem is packing 6 equal circles in rectangle of 1:1.934798 size. We examine the problem from a view point of optimization theory and algorithm. We show that Sangaku optimization problem belongs to a class of nonconvex optimization and propose a penalty method for solving the problem numerically. In numerical expirements, we consider equal and unequal 6 circles. Computational results obtained on Python Jupyter Notebook are provided. Сангаку бодлогыг оптимизацийн аргаар бодох нь Хураангуй: Сангаку бодлого нь Японы эртний геометрийн бодлого юм. Энэхүү судалгаандаа бид Хидетоши Фукугава эрдэмтний судалсан 1:1.934798 хэмжээтэй тэгш өнцөгтөд 6 ижил тойрог багтаах сангаку бодлогыг авч үзэв. Энэ бодлогыг хучилтын бодлогын хүрээнд оптимизацийн аргаар бодсон ба энэ нь гүдгэр бус максимумчлалын бодлого болно.Бодлогыг өргөтгөж, ижил бус 6 тойргын хувьд бодож торгуулийн функцийн аргаар нэмж тооцооллыг хийв. Python Jupyter Notebook программ дээр тооцооллыг хийж үр дүнг гаргасан болно. Түлхүүр үгс: Сангаку бодлого, хучилтын бодлого, тойрог, оптимизацийн арга

26 December 2022 in Journal of Institute of Mathematics and Digital Technology
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DJDavaajargal Jargalsaikhan
Davaajargal Jargalsaikhan
BDBayarjargal Darkhijav
Bayarjargal Darkhijav
We consider the problem of minimizing a sums of ratios that belong to a class of global optimization problems. Since the problem is nonconvex, the application of local search algorithms cannot always guarantee to find a global solution. It has been shown that problem can be solved by DC programming methods and algorithms. Dinkelbach-type algorithms are more efficient techniques because fractional problems reduce to a scalarized optimization problem. For solving the problem, we apply a generalized Dinkelbach algorithm requires finding the roots of a nonlinear equation. The numerical experiments were conducted on Python Jupyter Notebook for a box constrained set. The problem also has been solved by a gradient descent method and compared with the Dinkelbach algorithm. Numerical results are provided. Бутархай Програмчлалын Нийлбэр Хэлбэрийн Бодлогыг Минимумчлах нь Хураангуй: Энэхүү судалгаандаа бид глобал оптимизацийн ангилалд багтах бутархай программчлалын минимумчлах бодлогыг авч үзсэн болно. Бодлого нь ерөнхий тохиол-долд гүдгэр биш тул локал хайлтын аргаар бодоход үргэлж глобал шийд олдохгүй. Энэ төрлийн бодлогыг DC програмчлалын аргаар шийдэж болохыг харуулсан. Динкельбах алгоритм нь бутархай программчлалын бодлогыг энгийн оптимизацийн бодлогод шилжүүлдэг тул илүү үр дүнтэй арга юм. Иймд энэ бодлогыг бодоход Динкельбах алгоритм ашиглан олон хувьсагчтай шугаман бус тэгшитгэлийн шийдийг олох арга руу шилжүүлэх боломжтой байдаг. Тооцооллыг Python Jupyter Notebook дээр 100 хүртэлх хэмжээ-сийн хувьд хийсэн ба үүний зэрэгцээ градиент бууралтын арга дээр үр дүнгийн туршилтхийж, Динкельбах алгоритмтай харьцуулсан болно. Түлхүүр үгс: Динкелбах алгоритм, градиент бууралтын арга

29 December 2025 in Proceedings of the Mongolian Academy of Sciences
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Journal Article
Open access
DJDavaajargal Jargalsaikhan
Davaajargal Jargalsaikhan
Bayanjargal DarkhijavBayanjargal Darkhijav
Bayanjargal Darkhijav
MAMunkh-Erdene Altangerel
Munkh-Erdene Altangerel
EREnkhbat Rentsen
Enkhbat Rentsen
Traditionally, a variety of unsupervised methods have been used for analyzing remotely-sensed imagery. Although popular clustering techniques such as K-means, Mini-Batch K-means, and Fuzzy C-means are widely applied, their classification accuracy is often limited. This study proposes a new clustering method, called Multi-Criteria Mean Clustering (MCMC), to classify and extract forest areas from remote sensing images. The proposed method is based on a multi-criteria optimization framework, and leverages Pareto-optimal solutions arising from multiple clustering objectives. We show that K-means and Mini-Batch K-means can be viewed as specific instances of the proposed MCMC approach. For experimental evaluation, Root Mean Square Error (RMSE), Structural Similarity Index (SSIM), Overall Accuracy (OA), and Intersection over Union (IU) were used to assess performance. The results demonstrate that the proposed MCMC method provides more accurate and reliable classification, achieving lower RMSE, higher SSIM, higher OA, and higher IU compared to conventional clustering techniques. The study area is Bogd Khan Mountain, located in Central Mongolia, on the southern fringes of Ulaanbaatar. Sentinel-2B remote sensing data were employed for this research, and all computational experiments were conducted in Python Jupyter Notebook.

2 January 2026
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Book Chapter
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DJDavaajargal Jargalsaikhan
Davaajargal Jargalsaikhan
RERentsen Enkhbat
Rentsen Enkhbat