Liu Gang (born 30 January 1961) is a Chinese
scientist
A scientist is a person who conducts Scientific method, scientific research to advance knowledge in an Branches of science, area of the natural sciences.
In classical antiquity, there was no real ancient analog of a modern scientist. Instead, ...
and
revolutionary
A revolutionary is a person who either participates in, or advocates a revolution. The term ''revolutionary'' can also be used as an adjective, to refer to something that has a major, sudden impact on society or on some aspect of human endeavor.
...
who founded the
Beijing Students' Autonomous Federation
The Beijing Students' Autonomous Federation ( zh, s=北京高校学生自治联合会, p=Běijīng gāoxiào xuéshēng zìzhì liánhé huì) was a self-governing student organization, representing multiple Beijing universities, and acting as the ...
. He was a prominent student leader at the
Tiananmen Square protests of 1989
The Tiananmen Square protests, known in Chinese as the June Fourth Incident (), were student-led demonstrations held in Tiananmen Square, Beijing during 1989. In what is known as the Tiananmen Square Massacre, or in Chinese the June Fourth ...
. Liu holds a M.A. in physics from
Peking University
Peking University (PKU; ) is a public research university in Beijing, China. The university is funded by the Ministry of Education.
Peking University was established as the Imperial University of Peking in 1898 when it received its royal charter ...
and a M.A. in
computer science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...
from
Columbia University
Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...
. After his exile to the United States in 1996, Liu studied technology and physics at
Bell Labs
Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984),
then AT&T Bell Laboratories (1984–1996)
and Bell Labs Innovations (1996–2007),
is an American industrial research and scientific development company owned by mult ...
in
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
. Liu was employed at
Morgan Stanley
Morgan Stanley is an American multinational investment management and financial services company headquartered at 1585 Broadway in Midtown Manhattan, New York City. With offices in more than 41 countries and more than 75,000 employees, the fir ...
as a
Wall Street
Wall Street is an eight-block-long street in the Financial District of Lower Manhattan in New York City. It runs between Broadway in the west to South Street and the East River in the east. The term "Wall Street" has become a metonym for t ...
IT analyst.
Student activist
As an undergraduate student at
University of Science and Technology of China
A university () is an educational institution, institution of higher education, higher (or Tertiary education, tertiary) education and research which awards academic degrees in several Discipline (academia), academic disciplines. Universities ty ...
in
Hefei
Hefei (; ) is the capital and largest city of Anhui Province, People's Republic of China. A prefecture-level city, it is the political, economic, and cultural center of Anhui. Its population was 9,369,881 as of the 2020 census and its built-up ( ...
, Liu met
Fang Lizhi
Fang Lizhi (also Li-Zhi; February 12, 1936 – April 6, 2012) was a Chinese astrophysicist, vice-president of the University of Science and Technology of China, and activist whose liberal ideas inspired the pro-democracy student movement ...
, a pro-democracy activist. Then, at
Peking University
Peking University (PKU; ) is a public research university in Beijing, China. The university is funded by the Ministry of Education.
Peking University was established as the Imperial University of Peking in 1898 when it received its royal charter ...
, Liu organized "Democracy Salons". Wang Dan later held a position there.
Liu was a 28-year-old graduate when the 1989 demonstrations began. He organized the
Beijing Students' Autonomous Federation
The Beijing Students' Autonomous Federation ( zh, s=北京高校学生自治联合会, p=Běijīng gāoxiào xuéshēng zìzhì liánhé huì) was a self-governing student organization, representing multiple Beijing universities, and acting as the ...
and joined the movement's organizing body. As a result, he was sixth on a list of twenty-one activists whose arrests were ordered by the government. Liu went into hiding as a fugitive, but on 15 June 1989, Liu was arrested and charged with attempted subversion of the
Communist Party of China
The Chinese Communist Party (CCP), officially the Communist Party of China (CPC), is the founding and sole ruling party of the People's Republic of China (PRC). Under the leadership of Mao Zedong, the CCP emerged victorious in the Chinese Civil ...
. In 1991, he was convicted and sentenced to six years imprisonment at
Qincheng Prison
The Ministry of Public Security Qincheng Prison () is a maximum-security prison located in Qincheng Village, Xingshou, Changping District, Beijing in the People's Republic of China. The prison was built in 1958 with aid from the Soviet Union ...
.
After his release from prison in 1996, Liu continued to advocate for
human rights in China
Human rights in mainland China are periodically reviewed by the United Nations Human Rights Committee (UNHRC), on which the Chinese Communist Party (CCP), government of the People's Republic of China (PRC) and various foreign governments and h ...
and organized an underground democracy movement.
After moving to the United States, Liu continued his studies at Columbia University in New York City.
From there, he continued to support the Chinese democracy movement and in 2011, initiated further
pro-democracy protests.
Scientific research
China
In 1982, Liu received a bachelor's degree in modern mechanics from the
University of Science and Technology of China
A university () is an educational institution, institution of higher education, higher (or Tertiary education, tertiary) education and research which awards academic degrees in several Discipline (academia), academic disciplines. Universities ty ...
. He was employed by the
Aviation Industry Corporation of China
Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air craft such as hot air ...
in
Shenyang
Shenyang (, ; ; Mandarin pronunciation: ), formerly known as Fengtian () or by its Manchu language, Manchu name Mukden, is a major China, Chinese sub-provincial city and the List of capitals in China#Province capitals, provincial capital of Lia ...
in the field of
aerodynamics
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
. He worked in partnership with
Luo Yang, and was promoted to head of
aircraft design. Liu's field of research was the theory of
air resistance
In fluid dynamics, drag (sometimes called air resistance, a type of friction, or fluid resistance, another type of friction or fluid friction) is a force acting opposite to the relative motion of any object moving with respect to a surrounding flu ...
, and he worked on problems of double-sided entry and
radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...
technology.
In 1984, Liu received a master's degree in
optics
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviole ...
from the Department of Physics at
Peking University
Peking University (PKU; ) is a public research university in Beijing, China. The university is funded by the Ministry of Education.
Peking University was established as the Imperial University of Peking in 1898 when it received its royal charter ...
in
Beijing
}
Beijing ( ; ; ), alternatively romanized as Peking ( ), is the capital of the People's Republic of China. It is the center of power and development of the country. Beijing is the world's most populous national capital city, with over 21 ...
. While there, he was an assistant teacher. Liu returned to work at the China Soft Science Research Institute but was also acting assistant director at the University of Science and Technology of China.
In 1988, Liu became an assistant and associate researcher at the Wear-Resistant Materials Development Company of the National Ministry of Higher Education & the
Dalian Institute of Technology
Dalian University of Technology (DUT) (), colloquially known in Chinese as Dagong (), is a public research university located in Dalian, Liaoning, China, with an additional campus in Panjin, Liaoning. Established in April 1949, it is the ...
. He was then transferred to research in the Department of Physics at the
Chinese Academy of Sciences
The Chinese Academy of Sciences (CAS); ), known by Academia Sinica in English until the 1980s, is the national academy of the People's Republic of China for natural sciences. It has historical origins in the Academia Sinica during the Republ ...
.
United States
In 1996, Liu received a master's degree in computer science from Columbia University. He was invited to speak at the
New York Academy of Sciences
The New York Academy of Sciences (originally the Lyceum of Natural History) was founded in January 1817 as the Lyceum of Natural History. It is the fourth oldest scientific society in the United States. An independent, nonprofit organization wit ...
. Liu gained employment as a member of technical staff (MTS) at the Mathematics of Networks and Systems Research Department at Bell Laboratories in
Murray Hill, New Jersey. There he worked on
Optical telecommunication
Optical communication, also known as optical telecommunication, is communication at a distance using light to carry information. It can be performed visually or by using electronic devices. The earliest basic forms of optical communication date b ...
network design and planning,
routing
Routing is the process of selecting a path for traffic in a network or between or across multiple networks. Broadly, routing is performed in many types of networks, including circuit-switched networks, such as the public switched telephone netw ...
algorithms
In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific problems or to perform a computation. Algorithms are used as specifications for performing c ...
,
optimization
Mathematical optimization (alternatively spelled ''optimisation'') or mathematical programming is the selection of a best element, with regard to some criterion, from some set of available alternatives. It is generally divided into two subfi ...
techniques, and
economic model
In economics, a model is a theoretical construct representing economic processes by a set of variables and a set of logical and/or quantitative relationships between them. The economic model is a simplified, often mathematical, framework desig ...
s and
strategy
Strategy (from Greek στρατηγία ''stratēgia'', "art of troop leader; office of general, command, generalship") is a general plan to achieve one or more long-term or overall goals under conditions of uncertainty. In the sense of the "art ...
analysis.
Liu's areas of research included: SPIDER, a design tool for fast-restoration in all-optical networks; VPNStar, a system for provisioning multi-service
VPNs
A virtual private network (VPN) extends a private network across a public network and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network. The be ...
with
Quality of service
Quality of service (QoS) is the description or measurement of the overall performance of a service, such as a telephony or computer network, or a cloud computing service, particularly the performance seen by the users of the network. To quantitat ...
guarantees over
Internet Protocol
The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.
IP h ...
; in software design, a management system for Lambda Router in all-optical networks; and analysis of
Internet
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...
pricing.
During his days at Bell Laboratories, Liu introduced the A*Prune (1999, ) with K. G. Ramakrishnan, to describe a new class of
Algorithm
In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specificat ...
. This opened a new research direction in
theoretical science
Basic research, also called pure research or fundamental research, is a type of scientific research with the aim of improving scientific theory, theories for better understanding and prediction of natural or other phenomena. In contrast, applied ...
. He found that A*Prune is comparable to the current best known-approximate algorithms for most randomly generated
graphs
Graph may refer to:
Mathematics
*Graph (discrete mathematics), a structure made of vertices and edges
**Graph theory, the study of such graphs and their properties
*Graph (topology), a topological space resembling a graph in the sense of discre ...
. The algorithm constructs paths, starting at the source and going towards the destination. But, at each iteration, the
algorithm
In mathematics and computer science, an algorithm () is a finite sequence of rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specificat ...
is rid of all paths that are guaranteed to violate the constraints, thereby keeping only those partial paths that have the potential to be turned into feasible paths, from which the
optimal
Mathematical optimization (alternatively spelled ''optimisation'') or mathematical programming is the selection of a best element, with regard to some criterion, from some set of available alternatives. It is generally divided into two subfi ...
paths are drawn.
Liu also proposed a special class of Optical devices called SPIDER (2001, ); optical routers, dense
wavelength division multiplexing
In fiber-optic communications, wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i.e., colors) of laser light. This techniq ...
(DWDM) systems, and cross-connects of unprecedented capacities. Liu and his colleagues are developing techniques for efficient and reliable
optical network
Optical networking is a means of communication that uses signals encoded in light to transmit information in various types of telecommunications networks. These include limited range local-area networks (LAN) or wide-area networks (WAN), which cr ...
design, covering decentralized dedicated protection to shared path-based mesh restoration.
Since 2011, Liu had been involved in a bitter divorce with his former wife, the judge presided the case had declared him mentally unstable, and appointed a custodian guardian to represent him against his wish; among Liu's accusations: his wife was a spy sent by Chinese Communist central committee to monitor him, and his ex-employer Morgan Stanley fired him to appease the
Chinese government
The Government of the People's Republic of China () is an authoritarian political system in the People's Republic of China under the exclusive political leadership of the Chinese Communist Party (CCP). It consists of legislative, executive, mili ...
.
References
External links
Quatratic.com— A website solver for Convex Nonlinear Programming
{{DEFAULTSORT:Liu, Gang
1961 births
Living people
Mathematicians from Jilin
Chinese revolutionaries
21st-century American physicists
American financiers
Number theorists
Theoretical physicists
Scientists at Bell Labs
Morgan Stanley employees
Citigroup employees
People's Republic of China emigrants to the United States
University of Science and Technology of China alumni
Peking University alumni
New York University alumni
Columbia University alumni
Chinese political writers
Prisoners and detainees of the People's Republic of China
1989 Tiananmen Square protesters
Chinese dissidents
Chinese human rights activists
People from Liaoyuan