[ 134  ]  MR3034492 Beasley, LeRoy B.; Song, Seok-Zun; Kang, Kyung-Tae; Lee, Sang-Gu A comparison of term ranks of symmetric matrices and their preservers. Linear Algebra Appl. 438 (2013), no. 10, 3745–3754. 15A86


[ 133  ] Ham, Yoonmee; Lee, Sang-Gu*; Phong, Vu Quoc. A HOPF BIFURCATION IN A THREE-COMPONENT REACTION-DIFFUSION SYSTEM WITH A CHEMOATTRACTION IN ONE DIMENSION, Abstract and Applied Analysis. Article ID 830386, 11 pages http://dx.doi.org/10.1155/2013/830386   SCI IF 1.32  (2013)


[ 132  ]  Sang-Gu LEE*, Kyung-Won KIM and Jae Hwa LEE,  Sage matrix calculator and full Sage contents for linear algebra, Sage 행렬계산기와 선형대수학 Sage 콘텐츠, Korean J. Math. 20 (2013), No. 4, pp.  503-521.    (KCI).


[ 131  ]  이상구*,박종윤,김채식,이재화, 수학자 보재 이상설(李相卨)의 근대자연과학 수용- 백승호초(百勝胡艸)를 중심으로,  Sang-Seol Lee's manuscript on modern physics in the late 19th century Korea, J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education, Vol. 27, No. 4, 487-498, 韓國數學敎育學會誌 시리즈 E <數學敎育 論文集> 제 27집 제 4호, 2013, 487-498, (KCI-A). http://dx.doi.org/10.7468/jksmee.2013.27.4.487


[ 130  ]  Sang-Gu Lee*, Kyung-Won Kim, 모바일 선형대수학 스마트폰 콘텐츠 개발과 활용, Development of smart-phone contents for mobile linear algebra, J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education, Vol. 27, No. 2, 121-134, 韓國數學敎育學會誌 시리즈 E <數學敎育 論文集> 제 27집 제 2호, 2013. 121-134 (KCI-A).


[ 129  ]  Sang-Gu Lee*, 장지은 and Kyung-Won Kim, Sage와 GeoGebra를 이용한 선형대수학 개념의 Visual-Dynamic 자료 개발과 활용, Visualization of Linear Algebra concepts with Sage and GeoGebra, J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education, Vol. 27, No. 1, 1-17, 韓國數學敎育學會誌 시리즈 E <數學敎育 論文集> 제 27집 제 1호, 2013. 1-17 (KCI-A).


[ 128  ]  MR2954494 Reviewed Lee, Sang-Gu; Vu, Quoc-Phong Simultaneous solutions of matrix equations and simultaneous equivalence of matrices. Linear Algebra Appl. 437 (2012), no. 9, 2325–2339. 15A24 (15A21 47A13)



[ 127  ] Yongkeun SON, Chae Sik KIM, Sang-Gu LEE* and Jae Hwa LEE,  19th Century Chemistry Book of Korean Mathematician Sang-Seol LEE, 한국 근대수학교육의 아버지 李相卨이 쓴 19세기 근대화학 강의록 화학계몽초(化學啓蒙抄), Korean J. Math. 20 (2012), No. 4, pp. 541-563.  http://dx.doi.org/10.11568/kjm.2012.20.4.541  (KCI).


[ 126  ] Sang-Gu Lee*, Jae Hwa Lee and YoonMee Ham,   초기 선형대수학의 역사, Early History of Linear algebra, J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education, Vol. 26, No. 4, 351-362, 韓國數學敎育學會誌 시리즈 E <數學敎育 論文集> 제 26집 제 4호, 2012. 351-362 (KCI-A).


[ 125  ] An Analysis of Recent Research on the Method of Excess and Deficit (Ying Nü and Ying Buzu Shu), 영륙과 盈不足術에 관한 최근 동서양의 연구 분석,  Sang-Gu Lee and Jae Hwa Lee, Korean J. Math. 20 (2012), No. 1, pp. 137-159.


[ 124  ] Ki-Won Chang, The first specialist on the history of Korean mathematics (최초의 한국수학사 전문가 張起元),  Sang-Gu Lee and Jae Hwa Lee, J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 26, No. 1, 1-13, 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 26집 제 1호, 2012. 2. 1-13. (KCI-A).


[ 123  ] Lee, Sang-Gu; Vu, Quoc-Phong Simultaneous solutions of Sylvester equations and idempotent matrices separating the joint spectrum. Linear Algebra Appl. 435 (2011), no. 9, 2097–2109. 15A24 (15A27 47A13 47A62)


[ 122  ] Das, Kinkar Ch.; Bhatti, Faqir M.; Lee, Sang-Gu; Gutman, Ivan Spectral properties of the He matrix of hexagonal systems. MATCH Commun. Math. Comput. Chem. 65 (2011), no. 3, 753–774. (Reviewer: Rong Si Chen) 05C50 (05C90)


[ 121  ] Ham, Yoonmee; Lee, Sang-Gu; Phong, Vu Quoc Characterization of the determinant of a Laguerre matrix. J. Appl. Math. Comput. 36 (2011), no. 1-2, 233–239. (Reviewer: Peter Szabó) 65H05 (15B05)


[ 120  ] 安鍾和의 수학책 <數學節要> 연구, 이상구*, 이재화, 변형우, <A study on An abridged version of the Joseon Mathematics (Su-Hak-Jeol-Yo), a mathematics book written by Jong-Hwa AN, by Sang-Gu Lee*, Jae Hwa Lee, Hyungwoo Byun>, J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 25, No. 3, 641-352, 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 25집 제 4호, 2011. 11. 641-352. (KCI-A)


[ 119  ] Botany: A Modern Natural Science Book written by Mathematician Sang-Seol Lee (수학자 이상설이 소개한 근대자연과학: <植物學>), Young Min Park,  Chae Sik Kim, Sang-Gu Lee*, Jae Hwa Lee, J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 25, No. 2, 341-360, 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 25집 제 2호, 2011. 5. 41-360. (KCI-A)


[ 118  ] Excel Grapher: Dynamical Graphing Tool(Excel Grapher: 역동적 함수 그래프 도구), Kyung-Won Kim, Sang-Gu Lee* and Jae Hwa Lee, 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 25집 제 2호, 2011. 5. 309-321,  J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 25, No. 2, May. 2011. 309-321(KCI-A))


[ 117  ]   Y. Ham, Lee, Sang-Gu*, P. Vu; Characterization of the determinant of a Laguerre matrix,  Journal of Applied Mathematics and Computing, Volume 36, Issue 1-2 (2011), Page 233-239.  ISSN: 1598-5865, Springer (Scopus, KCI-A) The article is also available electronically on SpringerLink: http://www.springerlink.com/openurl.asp?genre=article&id=doi:10.1007/s12190-010-0399-2.


[ 116  ] A study on mathematics books of Joseon Dynasty (조선시대 산서(算書) 연구, - 규장각 소장 산서 연구의 분석을 중심으로), Sang-Gu Lee with Jae Hwa Lee*, 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 25집 제 1호, 2011. 2. 1-19,  J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 25, No. 1, Feb. 2011. 1-19(KCI-A)


[ 115  ] Horoldagva, Batmend; Lee, Sang-Gu Comparing Zagreb indices for connected graphs. Discrete Appl. Math. 158 (2010), no. 10, 1073–1078. 05C90 (05C35)


[ 114  ] Das, Kinkar Ch.; Lee, Sang-Gu; Cheon, Gi-Sang On the conjecture for certain Laplacian integral spectrum of graphs. J. Graph Theory 63 (2010), no. 2, 106–113. (Reviewer: Bhaba Kumar Sarma) 05C50 (15A18)


[ 113  ] Cheon, Gi-Sang; Lee, Sang-Gu; Shapiro, Louis W. The Fine numbers refined. European J. Combin. 31(2010), no. 1, 120–128. (Reviewer: Martin Klazar) 05A15 (11B75)


[ 112  ] Mobile Sage-Math for Linear Algebra and its Application, Duk-Sun Kim, Sang-Gu Lee*, Greg Markowsky,Electronic Journal of Mathematics & Technology (eJMT)  https://php.radford.edu/~ejmt/ContentIndex.php V.4, No. 3, p.1-13, Oct 2010.  ISSN 1933-2823.


[ 111  ] Mathematical Modelling of the H1N1 Influenza, 신종 인플루엔자의 수학적 모델링, Sang-Gu Lee with Rae Young Ko*, Jae Hwa Lee, 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 24집 제 4호, 2010. 11. 877-889,  J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 24, No. 4, Nov.  2010. 877-889(KCI)


[ 110  ] Sang-Gu Lee, Han-Guk Seol, 한국 최초의 수학 및 과학 저널-數理學雜誌, First Mathematical Science Journal of Korea in 1905, The Korean Journal for History of Mathematics, V.23, No. 2, p.1-22, June 2010. (KCI-A)


[ 109  ] Fibonacci sequences and the winning conditions for the blackout game, Sang-Gu Lee with Duk-Sun Kim, Faqir M. Bhatti, International Journal of Contemporary Mathematical Sciences, Vol. 5, 2010, no. 30, 1471 - 1485 ISSN: 1312-7586


[ 108  ] 19世紀 朝鮮의 數學 敎科書, Mathematics Textbooks in the 19th Century Chosun, Sang-Gu Lee with Sung Sa Hong, Young Hee Hong,  Chae Whan Oh, The Korean Journal for History of Mathematics, 2010. 2., v.23, n.1, pp.1-24. (KCI-A)


[ 107  ] Sakthivel, R.; Anandhi, E. R.; Lee, Sang-Gu Approximate controllability of impulsive differential inclusions with nonlocal conditions. Dynam. Systems Appl. 18 (2009), no. 3-4, 637–653. (Reviewer: Nazim I. Mahmudov)93B05 (34G25 34K35 34K45)


[ 106  ] MR2547916 Reviewed Das, Kinkar Ch.; Lee, Sang-Gu On the Estrada index conjecture. Linear Algebra Appl. 431 (2009), no. 8, 1351–1359. (Reviewer: Zoran S. Radosavljevi?) 05C50 (05C05 05C90)


[ 105  ] Ham, Yoon Mee; Lee, Sang-Gu; Kim, Duk-Sun A modified family of Laguerre iteration functions of quartically convergence. Int. J. Pure Appl. Math. 54 (2009), no. 1, 19–26. (Reviewer: Gert Van den Eynde) 65H05


[ 104  ] Sakthivel, R.; Mahmudov, N. I.; Lee, Sang-Gu Controllability of non-linear impulsive stochastic systems. Internat. J. Control 82 (2009), no. 5, 801–807. (Reviewer: Zhichun Yang) 93B05 (49N25 93E03 93E20)


[ 103  ]  李相卨의 算書 數理, Lee Sang Seol's mathematics book <Su Ri>, Sang-Gu Lee with Sung Sa Hong and Young Hee Hong , The Korean Journal for History of Mathematics, 2009. 11., v.22, n.4, pp.1-14. (KCI-A)


[ 102  ] Educational policy and curriculums of Korean school mathematics in the late 19th and early 20th century, Sang-Gu Lee with  Jihwa Noh and Sung-Yell Song, 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 23권 제4호. 2009. 11. 1093-1130,  J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 23 No 4, Nov. 2009. 1093-1130 (KCI)


[ 101  ] 모바일 환경에서의 Sage-Math의 개발과 선형대수학에서의 활용, Development of Mobile Sage-math and its use in Linear Algebra, Sang-Gu Lee with  Rae-Young Ko, Duk-Sun Kim and Jin-Yeong Bak, 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 23집 제 4호, 2009. 11. 483-506,  J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 23, No. 4, Nov.  2009. 483-506 (KCI)


[ 100  ] Sang-Seol LEE: Father of Modern Mathematical Education in Korea, Sang-Gu Lee with Han-Guk Seol, The Korean Journal for History of Mathematics, 2009, v.22, n.3, pp.79-102. (KCI-A)


[  99 ] Comparison of early tertiary mathematics in USA and Korea, Sang-Gu Lee with  Han-Guk Seol and YoonMee Ham, 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 23집 제 4호, 2009. 11. 523-535,  J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 23 No 4, Nov. 2009. 523-535 (KCI)


[  98 ] Korean tertiary mathematics and curriculum in early 20th century, Sang-Gu Lee with Y. Ham,  The Korean Journal for History of Mathematics, 2009, v.22, n.3, pp.207-254. (KCI-A)


[  97 ] Ham, Yoon Mee; Lee, Sang-Gu; Kim, Duk-Sun A modified family of Laguerre iteration functions of quartically convergence. Int. J. Pure Appl. Math. 54 (2009), no. 1, 19--26. 65H05 PDF Doc Del Clipboard


[  96 ] Contribution of Oswald Veblen to AMS and its meaning in Korea, Sang-Gu Lee with with Y. Ham, The Korean Journal for History of Mathematics, 2009, v.22, n.2, pp.27-52. (KCI-A)


[  95 ]   History of mathematical modeling on the Blackout game, Sang-Gu Lee with D.-S Kim, C.-W. Ryu, Y.-M. Song, The Korean Journal for History of Mathematics, 2009, v.22, n.1, pp.53-74. (KCI-A)


[ 94  ] MathML and JAVA Implementation in Linear Algebra, Sang-Gu Lee with with Duk-Sun Kim, The Electronic Journal of Mathematics and Technology, Volume 3, Number 1, 1-11, ISSN 1933-2823, (2009)


[  93 ] Ham, YoonMee; Chun, Changbum; Lee, Sang-Gu Some higher-order modifications of Newton's method for solving nonlinear equations. J. Comput. Appl. Math. 222 (2008), no. 2, 477–486. (Reviewer: Gerd Pönisch)65H05


[  92 ]  Lee, Sang-Gu; Ham, YoonMee A Hopf bifurcation in a radially symmetric free boundary problem. Dyn. Partial Differ. Equ. 5 (2008), no. 2, 173–183. (Reviewer: Christos V. Nikolopoulos) 35R35 (35B10 35B32 35K57 37L10) Editor: Y. Charles Li, S.-T. Yau (Harvard)


[ 91  ] Lee, Sang-Gu; Seol, Han-Guk; Yang, Jeong-Mo Bound for 2-exponents of primitive extremal tournaments. Ars Combin. 87 (2008), 3–12. 05C20, PDF Clipboard Journal Article


[  90 ] 113.  Applications on the image processing using singular value preservers, Sang-Gu Lee with with Duk-Sun Kim, Image and Signal Processing, 2008. CISP '08. Congress, (ISSN 978-0-7695-3119-9 )  537 - 541 .


[ 89  ] 107. A GENERATION OF A DETERMINANTAL FAMILY OF ITERATION FUNCTIONS AND ITS CHARACTERIZATION,  (with YOONMEE HAM and JERRY RIDENHOUR), Korean J. Math. 16 (2008), No. 4, pp. 481-494.


[ 88  ] 114. The educational models using enhanced mathematics ICT in the Korean IT environments, 21세기 선진형 ICT 수학 교육 방법론 모델, (with Jin-Yeong Bak and Duk-Sun Kim) 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 22집 제4호. 2008. 11. 533-543 ,  J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 22 No 4, Nov. 2008. 533-543, (KCI)


[ 87  ] 113. The Analytic Hierarchy Process and related Matrix Theory , (with Jeong-Mo Yang) 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 22집 제4호. 2008. 11. 459-469 ,  J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education,  Vol. 22 No 4, Nov. 2008. 459-469, (KCI)


[ 86  ] 114. Repulsive fixed-points of the Laguerre-like iteration functions, (with YoonMee Ham), Korean Journal of Mathematics, 16 (2008), No. 1, pp. 51-55, April 2008 (KCI)


[ 85  ] 110.  R. L. Moore's Moore Method and its meaning in Korea, The Korean Journal for History of Mathematics, 2008, v.21, n.1, pp.77-88, (with Sangwook Ree and Duk-Sun Kim) (KCI-A)


[ 84  ] 109. 선형대수학 교육에 적용되는 양방향 콘텐츠 기반의 MathML 과 JAVA 도구에 관한 연구, J. Korea Soc. Math. Ed. Ser. A: The Mathematical Education,  Vol. 47 No 1, Feb. 2008. 76-90 (with Duk-Sun Kim and Kyung-Hoon Jung, 설한국) (KCI)


[ 83  ] MR2365067 Reviewed Cheon, Gi-Sang; Hwang, Suk-Geun; Lee, Sang-Gu Several polynomials associated with the harmonic numbers. Discrete Appl. Math. 155 (2007), no. 18, 2573–2584. (Reviewer: Volker Strehl) 11B68 (05A19 11B73)


[ 82  ] Beasley, Leroy B.; Guterman, Alexander E.; Lee, Sang-Gu; Song, Seok-Zun Frobenius and Dieudonné theorems over semirings. Linear Multilinear Algebra 55 (2007), no. 1, 19–34. (Reviewer: Natalia Bebiano) 15A15


[ 81  ] 100.  Ground of the revolutionary change in early 20C American Mathematics, The Korean Journal for History of Mathematics, v.20, n.3, pp.127-146  (with S.-G. Hwang, G.-S. Cheon) (2007) (KCI-A)


[ 80  ] 108. LINEAR OPERATORS PRESERVING MAXIMAL COLUMN RANKS OF NONNEGATIVE REAL MATRICES,  by KYUNG-TAE KANG, DUK-SUN KIM, SANG-GU LEE¤, and HAN-GUK SEOL, Kangweon-Kyungki Math. Jour. 15 (2007), No. 2, pp. 101-114


[ 79  ] 104. 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 21집 제4호. 2007. 11. 621-646 ,   J. Korea Soc. Math. Ed. Ser. E: Communications of Mathematical Education, Vol. 21 No 4, Nov. 2007. 621-646, 시각화를 이용한 선형대수학 교수학습모델 - R^n 의 부분공간,  김 덕 선 (성균관대학교) 이 상 구 (성균관대학교)* 정 경 훈 (성균관대학교)  http://km.naver.com/list/view_detail.php?dir_id=70301&docid=34314443


[ 78  ] 105. 韓國數學敎育學會誌 시리즈 E  <數學敎育 論文集>  제 21집 제4호. 2007. 11. 597-612,   J. Korea Soc. Math. Ed. Ser. E:  Communications of Mathematical Education, Vol. 21 No 4, Nov. 2007. 597-612, m by n  크기의 일반적인 흑백 게임의최적해와 타일링, 김덕선(성균관대) 이상구(성균관대) * http://km.naver.com/list/view_detail.php?dir_id=70301&docid=34314116


[ 77  ] MR2218803 Reviewed Lee, Sang-Gu; Yang, Jeong-Mo Linear algebraic approach on real σ-game. J. Appl. Math. Comput. 21(2006), no. 1-2, 295–305. 91A46 (68Q45)


[ 76  ] [89] MR2190705 Lee, Sang-Gu; Seol, Han-Guk Graph representations of normal matrices. J. Korean Math. Soc. 43 (2006), no. 1, 215--224. 05C50 (15A57)  (SCIE)                     


[  75 ] 97. 수리과학 디지털 도서관: Math Science Digital Library,  Journal of Korean Soc. Math. Ed. Ser. E: Comm. of Mathematical Education, Nov. 2006, Vol. 20, No. 4, 537-549


[ 74  ] 94. 근대 계몽기 일제강점기 수학교육과 해방이후 한국수학계, The Korean Journal for History of Mathematics 2006, v.19, n.3, pp.71-84 , (with J.-M. Yang, Y. Ham)


[  73 ] 95. 실베스터와 클라인 그리고 19세기 미국 수학, 한국수학사학회지, The Korean Journal for History of Mathematics, 2006, v.19, n.2, pp.77-88, J. J. Sylvester , F. Klein and and American Mathematics in 19th Century", (with Yoonmee Ham)


[ 72  ] Lee, Sang Gu; Yang, Jeong Mo Bound for 2-exponents of primitive extremal ministrong digraphs. Commun. Korean Math. Soc. 20 (2005), no. 1, 51—62. 05Cxx   KCI-A   


[ 71  ] Hwang, Suk-Geun; Kim, Ik-Pyo; Kim, Si-Ju; Lee, Sang-Gu The number of zeros of a tight sign-central matrix. Linear Algebra Appl. 407 (2005), 296--310. 15A99  (SCI)


[ 70  ]    Kim, Ik-Pyo; Lee, Sang-Gu; Seol, Han-Guk Matrices with prescribed permanent using binary number system of integers. Int. J. Pure Appl. Math. 19 (2005), no. 3, 415--420. 15A15 (15A36)


[  69 ] Beasley, LeRoy B.; Guterman, Alexander E.; Lee, Sang-Gu; Song, Seok-Zun Linear preservers of zeros of matrix polynomials. Linear Algebra Appl. 401 (2005), 325—340. 15A04 (SCI)


[ 68  ] New Curriculum Models for Mathematics Department in Korean College,  Journal of Korean Soc. Math. Ed. Ser. E: Comm. of Mathematical Education, Nov. 2005, Vol. 19, No. 4, 671-682 (with Choon Ho Lee, Suk-Bong Yoon)


[ 67  ]   A Research on a Model of BL-PBL Self -Directed Linear Algebra Lecture at College, Journal of Korean Soc. Math. Ed. Ser. E: Comm. of Mathematical Education, Nov. 2005, Vol. 19, No. 4, 769-785 (with Han-Guk, Seol, Shin Il, Han) http://km.naver.com/list/view_detail.php?dir_id=70301&docid=1658674


[ 66  ] "New Learning Environment of Linear Algebra in Korea (with Y. Ham),   Journal of Korean Soc. Math. Ed. Ser. D: Research in Mathematical Education, March 2005, Vol. 9, No. 1, 57-66


[ 65  ] Beasley, LeRoy B.; Guterman, Alexander E.; Lee, Sang-Gu; Song, Seok-Zun Linear transformations preserving the Grassmannian over $\scr M\sb n(\bold Z\sb +)$. Linear Algebra Appl. 393 (2004), 39—46. 15A04 (SCI)


[ 64   ] Ham, YoonMee; Lee, Sang-Gu Effects on global coupling of an interface problem in an activator-inhibitor system. J. Comput. Appl. Math. 162 (2004), no. 2, 393--409. (Reviewer: L. Hsiao) 35K45 (35B10 35B25 35K57 37L10) (SCI)


[ 63  ] A study on prevention of  private information outflows and an analysis of current status on Korean membership website" (with Duk-Sun Kim),  National Security Reaerch Institute. WISC 2004, Proc. of The 16th Workshop on Information and Security and Crptography, 901-911 (2004)   


[  62 ] "Activity of a Gifted Student Who Found Linear Algebraic Solution of Blackout Puzzle" (with J.-B. Park and J.-M. Yang),   Journal of Korean Soc. Math. Ed. Ser. D: Research in Mathematical Education, Oct. 2004, Vol. 8, No. 3, 215-226


[ 61  ] "Linear algebra algorithm for the optimal solution in the Blackout game" (with J.-B. Park, J.-M. Yang, and Ik-Pyo Kim),   Journal of Korean Soc. Math. Ed. Ser. A: The Mathematical Education, Feb. 2004, Vol. 43, No. 1, 87-96


[ 60  ] "흑백퍼즐의 선형대수학적 해법을 통해 본 영재 교육 " (with J.-B. Park and J.-M. Yang),   Journal of Korean Soc. Math. Ed. Ser. E: Communications of   Mathematical Education, Oct. 2004, Vol. 18, No. 3, 227-228


[ 59  ] 대학에서의 수학교육 환경 : 현재와 미래, Learning Environment at College Mathematics Education : Current Status and Future Directions , (with 김덕선, 양정모), Journal of Korean Soc. Math. Ed. Ser. E:  Communications of Mathematical Education, Aug. 2004, Vol. 18, No. 2, 35-45


[ 58  ] [5] MR2024831 (2004j:91071) Jin, Ming-Ai; Lee, Sang-Gu; Neal, Cora; Ree, Sangwook A matrix method for the input-output analysis of economic systems. Int. Math. J. 4 (2003), no. 6, 515--525. 91B02 (15A48)

                        

[ 57  ] [6] MR1980657 (2004d:15035) Beasley, LeRoy B.; Lee, Sang-Gu; Seol, Han-Guk Inverse principally centrogonal matrices. Int. J. Pure Appl. Math. 5 (2003), no. 3, 315--321. 15A57

                        

[ 56  ] [7] MR1976930 (2004b:15004) Beasley, LeRoy B.; Lee, Sang-Gu; Lee, You-Ho A characterization of strong preservers of matrix majorization. Linear Algebra Appl. 367 (2003), 341--346. (Reviewer: Peter \v Semrl) 15A04 (15A21) (SCI)


[ 55  ] 80. "Exponents of r-regular primitive digraphs", (with Ming Aei Jin and Han-Guk Seol),  Trends in Math., ICMS, 6, 2, 51-57, (2003)


[ 54  ] [8] MR1913345 (2003k:11024) Lee, Gwang-Yeon; Kim, Jin-Soo; Lee, Sang-Gu Factorizations and eigenvalues of Fibonacci and symmetric Fibonacci matrices. A special tribute to Calvin T. Long. Fibonacci Quart. 40 (2002), no. 3, 203--211. (Reviewer: Shiro Ando) 11B39 (15A23 15A36 15A42) (SCIE)


[ 53  ] [9] MR1906757 (2003g:15004) Beasley, LeRoy B.; Lee, Sang-Gu; Song, Seok-Zun Linear operators that preserve pairs of matrices which satisfy extreme rank properties. Linear Algebra Appl. 350 (2002), 263--272. (Reviewer: Alexander E. Guterman) 15A04 (15A03 15A15 47B49) (SCI)


[ 52  ] [10] MR1903621 (2003d:15002) Beasley, LeRoy B.; Lee, Sang-Gu; Lee, You-Ho Resolution of the conjecture on strong preservers of multivariate majorization. Bull. Korean Math. Soc. 39 (2002), no. 2, 283--287. (Reviewer: Chong Guang Cao) 15A04 (KCI-A)


[ 51  ] [11] MR1928400 (2003m:15005) Beasley, Leroy B.; Song, Seok-Zun; Lee, Sang-Gu Zero-term rank preservers. Linear preserver problems (Lisbon, 1999). Linear and Multilinear Algebra 48 (2001), no. 4, 313--318. (Reviewer: Richard D. Hill) 15A04 (15A33) (SCIE)


[ 50  ] [12] MR1829526 (2002b:11027) Lee, Gwang-Yeon; Lee, Sang-Gu; Kim, Jin-Soo; Shin, Hang-Kyun The Binet formula and representations of $k$-generalized Fibonacci numbers. Fibonacci Quart. 39 (2001), no. 2, 158--164. (Reviewer: Shiro Ando) 11B39 (15A15) (SCIE)


[ 49  ] [13] MR1825067 (2001m:11019) Lee, Gwang-Yeon; Kim, Jin-Soo; Lee, Sang-Gu A representation and some properties for $k$-Fibonacci sequences. Missouri J. Math. Sci. 13 (2001), no. 2, 92--102. (Reviewer: Curtis N. Cooper) 11B39


[ 48  ] 59."A survey on the matrix completion problem", (with Han-Guk Seol), Trends in Math., ICMS, Vol. 4, No. 1, June 2001 pp. 38~43



[ 47  ] 60. "Weights of Idempotent Matrices", (with L. B. Beasley and Se-Won Park), Trends in Math., ICMS,4, 1, 95-100 June (2001)


[ 46  ] 62. "7차 교육과정의 수학에서 공학적 도구의 이용에 관하여" , J. Korean Soc. Math. Ed. Ser. E; Communications of Mathematical Education, Vol. 11, Jan. (2001), 355-365. http://km.naver.com/list/view_detail.php?dir_id=70301&docid=393090


[ 45  ] [14] MR1817961 (2001m:15044) Park, S.-W.; Beasley, L. B.; Lee, S.-G. Idempotence of $(1,-1)$-matrices. Proceedings of the Thirty-first Southeastern International Conference on Combinatorics, Graph Theory and Computing (Boca Raton, FL, 2000). Congr. Numer. 146 (2000), 17--28. 15A36

                        

[ 44  ] [15] MR1757591 (2001d:15010) Kim, Jin-Soo; Lee, Sang-Gu; Lee, Gwang-Yeon; Song, Seok-Zun On the spectral norm and eigenvalues of $W\sb c$-companion matrices. Int. J. Appl. Math. 2 (2000), no. 9, 1061--1072. (Reviewer: Chi-Kwong Li) 15A18

                        

[ 43  ] [16] MR1734203 (2000i:15005) Beasley, LeRoy B.; Lee, Sang-Gu Linear operators preserving multivariate majorization. Linear Algebra Appl. 304 (2000), no. 1-3, 141--159. (Reviewer: Peter \v Semrl) 15A04 (15A21 15A30) (SCI)


[ 42  ] 61. "A survey on Majorizations and its preservers ", (with You- Ho Lee), Trends in Math., ICMS, Vol. 3, Dec. (2000), 60-68.



[ 41  ] [17] MR1757158 (2001c:15004) Beasley, LeRoy B.; Song, Seok-Zun; Lee, Sang-Gu Linear operators that preserve zero-term rank of Boolean matrices. J. Korean Math. Soc. 36 (1999), no. 6, 1181--1190. (Reviewer: Peter \v Semrl) 15A04 (15A03 15A33) (SCIE)


[ 40  ] [18] MR1734314 (2000j:35278) Ham, YoonMee; Lee, Sang-Gu A Hopf bifurcation of interfaces in a Dirichlet problem. Southwest J. Pure Appl. Math. 1999, no. 2, 47--60 (electronic). (Reviewer: Vladimir Grebenev) 35R35 (34C23 35B32 37G15 37L10)

                        

[ 39  ] [19] MR1698689 (2000f:15002) Beasley, LeRoy B.; Lee, Sang-Gu; Lee, You-Ho Linear operators strongly preserving multivariate majorization with $T(I)=I$. Kyungpook Math. J. 39 (1999), no. 1, 191--194. (Reviewer: Chi-Kwong Li) 15A04 (15A21 15A30)

                        

[ 38  ] [20] MR1659324 (99h:15023) Cheon, G.-S.; Johnson, C. R.; Lee, S.-G.; Pribble, E. J. The possible numbers of zeros in an orthogonal matrix. Electron. J. Linear Algebra 5 (1999), 19—23 (electronic). 15A57 (SCIE)


[ 37  ] 64.  "Linear algebra education through the use of Korean softwares" (with G.-S. Cheon), 교육논충, 대진대학교, V.2 pp.375-386 (1999)


[ 36  ] 53. "Linear Algebra with Advanced Technique", (with Eun-Tae Kim and Kyung-Hun Chung), J. Bas. Sci., Sungkyunkwan Univ. Vol. 50, (1999), pp.23-51.


[ 35  ] 52. "A construction of (0,1)-matrices with prescribed permanent using binary number system of integers (with Han-Guk Seol), J. Bas. Sci., Sungkyunkwan Univ. Vol. 50, pp.17-22., (1999)


[ 34  ] 20. On a sign pattern and it's related algorithm for L-matrix " (with H.G. Seol and Y.H. Kim), J. KSIAM. Vol.3, No.1, 43-53, 1999.


[ 33  ] [21] MR1732696 (2000k:15046) Park, S.-W.; Seol, H.-G.; Lee, S.-G. A characterization of minimal semipositivity of sign pattern matrices. Commun. Korean Math. Soc. 13 (1998), no. 3, 465--473. 15A48

                        

[ 32  ] [22] MR1483520 (98i:15006) Lee, Sang-Gu; Park, Se-Won; Seol, Han-Guk Linear operators strongly preserving matrices whose sign patterns require the Perron property. Linear Algebra Appl. 269 (1998), 53--63. (Reviewer: N. J. Pullman) 15A04


[ 31  ] 21. "Sign Nonsingularity and it's related algorithm for the determination of L-matrix" (with H.G. Seol and Y.H. Kim), J. of Nat. Sci. SKKU. Vol. 48, 15-29, (1997)


[ 30  ] [23] MR1443283 (98a:15004) Lee, G.-Y.; Lee, S.-G.; Song, S.-Z. Linear operators that strongly preserves [preserve] the sign-central matrices. Bull. Korean Math. Soc. 34 (1997), no. 1, 51--61. (Reviewer: Walter S. Sizer) 15A04 (15A48)

                        

[ 29  ] [24] MR1421266 (97g:15026) Lee, G.-Y.; Lee, S.-G.; Shin, H.-G. On the $k$-generalized Fibonacci matrix $Q\sb k$. Linear Algebra Appl. 251 (1997), 73--88. (Reviewer: J. L. Brenner) 15A57 (60C05)


[ 28  ] 19. "On an algorithm for the determination of L-matrix" (with H.G. Seol)  Proc. Workshops in Pure Math. V. 16, part I (1997) pp.165-178.


[ 27  ] 18. "Sign Nonsingularity and it's related algorithm for the determination of L-matrix" (with H.G. Seol and Y.H. Kim), J. of Nat. Sci. SKKU. Vol. 48, 15-29, (1997)


[ 26  ] 17. "Linear Operators Strongly Preserving Multivariate Majorization " (with Y.H. Lee) Proc. Workshops in Pure Math. V. 17, part I (1997) pp.113-118.


[ 25  ] 16. "Sign patterns with minimal semipositivity and inverse nonnegativity" (with H.K. Seol and S.W. Park),  Proc. Workshops in Pure Math. V. 17, part I (1997) pp.155-164.


[ 24  ] 14. "A Characterization of Strong Preservers on Multivariate Majorization", Proc. of InHa Symposium on Pure and appl. Math.,June , pp.17-30  (1997)


[ 23  ] [25] MR1419750 (97h:15001) Beasley, LeRoy B.; Lee, Gwang-Yeon; Lee, Sang-Gu Linear transformations that preserve the assignment. II. J. Korean Math. Soc. 33 (1996), no. 3, 527--539. (Reviewer: D. J. Hartfiel) 15A04 (15A15)


[ 22  ] 15. "Differential Operators that Preserve Differential Equations" (with S.Z.Song),  J. of Nat. Sci. SungKyunKwan Univ. V.47 No.2 pp. 1-9 (1996)


[ 21  ] [33] MR1703450 Beasley, LeRoy B.; Lee, Sang-Gu; Lee, You-Ho Linear operators strongly preserving multivariate majorization. Proceedings of the Prague Mathematical Conference 1996, 19--22, Icaris, Prague, 199?. 15A04 (15A21)


[ 20  ] 12. "Linear Operators strongly preserving matrices whose sign-pattern require the Perron property" (with S.W. Park and H.G. Seol), Proc. Workshops in Pure Math. V. 16, part I , pp.213-220 (1996)


[ 19  ] [26] MR1430413 (98c:15051) Lee, Sang-Gu; Park, Se-Won The allowance of idempotent of sign pattern matrices. Commun. Korean Math. Soc. 10 (1995), no. 3, 561--573. (Reviewer: Jaroslav Zemánek) 15A30

                        

[ 18  ] [27] MR1355672 (96k:15001) Song, Seok-Zun; Lee, Sang-Gu Column ranks and their preservers of general Boolean matrices. J. Korean Math. Soc. 32 (1995), no. 3, 531--540. (Reviewer: N. J. Pullman) 15A03 (15A33)

                        

[ 17  ] [28] MR1337800 (96f:11025) Lee, Gwang-Yeon; Lee, Sang-Gu A note on generalized Fibonacci numbers. Fibonacci Quart. 33 (1995), no. 3, 273--278. (Reviewer: Shiro Ando) 11B39 (15A15 15A36)


[ 16  ] 13. "Linear operators strongly preserving multivariate majorization"(with Y.H. Lee), J. of Nat. Sci. SungKyunKwan Univ. V.47 No.1 pp. 1-9 (1995)


[ 15  ] 10. "For inverse sign-pattern matrices" (with S.W. Park, G.H. Kim) J. of Nat. Sci. SungKyunKwan Univ. V.46 No.1 pp.57-62 (1995)


[ 14  ] [29] MR1306988 (95i:15007) Beasley, LeRoy B.; Lee, Gwang-Yeon; Lee, Sang-Gu Linear transformations that preserve the assignment. Proceedings of the 3rd ILAS Conference (Pensacola, FL, 1993). Linear Algebra Appl. 212/213 (1994), 387--395. (Reviewer: D. J. Hartfiel) 15A15

                        

[ 13  ] [30] MR1297422 (96a:05029) Beasley, LeRoy B.; Lee, Sang-Gu Linear $p(X)=X$ preservers over general Boolean semirings. J. Korean Math. Soc. 31 (1994), no. 3, 353--365. (Reviewer: S. Lajos) 05B20 (15A24 15A33)


[ 12  ] 11. "For the positive definite sign pattern matrices" (with S.W. Park) J. of Nat. Sci. SungKyunKwan Univ. V.45 No.2 pp.63-68 (1994)


[ 11   ] 9. "Evaluation on the structure of expressways of Korea using transportation matrix" (with G.Y. Lee) J. of Nat. Sci.     SungKyunKwan Univ. V.45 No.1, 33-43. (1994)


[ 10  ] [31] MR1308697 (96a:16051) Beasley, LeRoy B.; Lee, Sang-Gu Linear operators strongly preserving $r$-cyclic matrices over semirings. Linear and Multilinear Algebra 35 (1993), no. 3-4, 325--337. (Reviewer: Chong Guang Cao) 16Y60 (15A33)


[ 9  ] 8. "Linear Transformations that preserve the Assignment on nonnegative reals" (with G.Y. Lee), Proc. Workshops in Pure Math V. 13, part I , pp.137-146 (1993)


[ 8  ] 7. "Sensitivity analysis on Linear Programming algorithm", J. Nat. Sci. SungKyunKwan Univ. V.44, No.2, 47-55. (1993)


[ 7  ] 6. "A Linearization of a Free Boundary problem with the generalized Mckean kinetics" (with Y.M.Ham), J. of Nat. Sci. SungKyunKwan Univ. V.44 No. 2, 17-24.(1993)


[ 6  ] 5. "On a Question of Kostin" (with S.W.Park), J. of Nat. Sci. SungKyunKwan Univ. V.44 No.1, 71-74. (1993)


[ 5  ] 4. "Equivalent Factors in Gaussian Elimination and Conjugate direction Method" (with Y.H. Lee and Y.M. Ham), J. of Nat. Sci. SungKyunKwan Univ. V.44 No.1, 61-69.(1993)


[ 4  ] [32] MR1148418 (93a:15029) Beasley, LeRoy B.; Lee, Sang-Gu Linear operators strongly preserving $r$-potent matrices over semirings. Directions in matrix theory (Auburn, AL, 1990). Linear Algebra Appl. 162/164 (1992), 589--599. (Reviewer: Walter S. Sizer) 15A99 (16Y60)


[ 3  ] 3. "A Proof on a Simpler Construction of the Jordan Canonical Form", J. Nat. Sci. Sung Kyun Kwan Univ. V.43, No 1, 43-46. (1992)


[ 2  ] 2. "Linear operators strongly preserving polynomial equations over antinegative semirings ", Ph.D. Dissertation, Utah State University, 1991


[  1 ] 1. "On the generalization of the Gershgorin theorem", M.S. thesis, Utah State University, 1987