NP-hardness is a classification used in computational complexity theory to describe certain types of problems. Specifically, a problem is said to be NP-hard if: 1. **It is at least as hard as the hardest problems in NP (nondeterministic polynomial time)**: This means that any problem in NP can be reduced to it in polynomial time. In more technical terms, if you can solve an NP-hard problem efficiently (in polynomial time), you can also solve any NP problem efficiently.

Phra Malai is a Buddhist figure prominent in Thai folklore and religious beliefs. He is often depicted as a monk who has the ability to travel between the earthly realm and the afterlife, especially in the context of guiding and helping souls in the process of rebirth.

Cândido Rondon refers to a notable Brazilian figure, Cândido Mariano da Silva Rondon (1865–1958), who was a prominent explorer, military officer, and protector of indigenous peoples in Brazil. He is best known for leading expeditions into the Amazon rainforest and for his efforts to promote the welfare of indigenous communities, advocating for their rights and integration into Brazilian society without disrupting their cultures.

Disjunctivism is a philosophical position in the field of epistemology and perception. It primarily addresses the nature of perceptual experiences and the conditions under which they can be considered knowledge. The view is notably associated with discussions about the distinction between "veridical" experiences (those that correctly reflect reality) and "non-veridical" experiences (those that do not, such as illusions or hallucinations).

GW190521 is the designation for a gravitational wave event detected by the LIGO and Virgo observatories on May 21, 2019. This event is particularly significant because it was caused by the merger of two black holes, resulting in the formation of a more massive black hole. The detection of GW190521 provided important insights into the population of black holes in the universe.

George Cybenko is an American mathematician and computer scientist known for his contributions to fields such as neural networks, control systems, and computational mathematics. He is particularly recognized for his work on the theory of neural networks and the development of the Cybenko theorem, which establishes conditions under which neural networks can approximate any continuous function. Cybenko has had a significant academic career, holding positions at various institutions, including being a professor at Dartmouth College.

Igor Mezić is a prominent researcher and mathematician known for his contributions to fields such as systems theory, control theory, and dynamical systems. He has worked extensively on topics that involve mathematical modeling and analysis of complex systems. Mezić is particularly recognized for his work on system dynamics, spectral analysis, and techniques related to the Koopman operator, which plays a crucial role in the study of nonlinear dynamical systems.

Richard A. Tapia is a prominent American mathematician and educator known for his contributions to the fields of mathematics, particularly in the areas of numerical analysis and computational mathematics. He is also recognized for his advocacy for diversity in education and for promoting the involvement of underrepresented groups in STEM (Science, Technology, Engineering, and Mathematics) fields. Tapia has served as a professor at Rice University in Houston, Texas, where he has made significant contributions to both research and teaching.

Richard Askey was an American mathematician recognized for his contributions to the fields of mathematical analysis, special functions, and approximation theory. He had a long and distinguished career, often noted for his work in the theory of orthogonal polynomials and special functions. Askey was also known for his efforts in mathematics education and mentoring students, significantly influencing the field through both research and teaching. He held a faculty position at the University of Wisconsin-Madison and authored numerous papers, books, and educational materials.

Richard P. Brent is a prominent mathematician known for his contributions to several areas of mathematics, including numerical analysis, computer algorithms, and computational number theory. He is particularly recognized for his work on integer factorization, which is a crucial topic in cryptography. Brent is also noted for developing efficient algorithms for arithmetic operations and has made significant contributions to the field of high-precision computation.

Lee McIntyre is a philosopher and author known for his work in the areas of science, philosophy of science, and the social implications of scientific understanding. He has written several books that focus on topics such as the nature of truth, the concept of evidence, and the challenges posed by misinformation and pseudoscience. One of his notable works is "Post-Truth," in which he explores the cultural and political implications of the rejection of objective truth in contemporary society.

A static mixer is a device used in various industries to continuously mix two or more fluids or gases without the use of moving parts. Instead of mechanical components, static mixers rely on the design of internal mixing elements or structures that facilitate the mixing process as the fluids flow through the mixer. **Key Characteristics of Static Mixers:** 1. **No Moving Parts**: Static mixers do not have moving components, which reduces maintenance requirements and enhances reliability.

The number 249 is an integer that comes after 248 and before 250. It can be broken down into its prime factors, which are 3, 83 (since 249 = 3 × 83). In Roman numerals, it is represented as CCXLIX. The number is also considered an odd number.

Hans-Wilhelm Knobloch is a German mathematician known for his work in statistics, particularly in the areas of robust statistics and time series analysis. He has made significant contributions to the field and has published various papers and research on statistical methods and their applications.

"Identric" is not a widely recognized term or concept in common usage or in well-known disciplines. It's possible that it could refer to a company name, a specific product, a niche concept, or a term that has emerged after my last update in October 2021.

Harold Stephen Black is best known as an American electrical engineer, inventor, and academic. He is particularly recognized for his development of the "Black amplifier," also known as the negative feedback amplifier, which significantly improved the performance of electronic amplifiers by reducing distortion and increasing stability. His work in the field of feedback systems has had a lasting impact on electronic engineering, influencing the design of a wide variety of electronic devices.

Homayoun Seraji refers to a Persian classical musician and composer, known for his contributions to Persian traditional music. He is particularly recognized for his expertise with the santur, a traditional Persian stringed instrument. Seraji's music often features a blend of classical Persian melodies and modern influences, reflecting a deep understanding of the historical and cultural aspects of Persian music. He may also be involved in teaching, promoting, and preserving Persian musical traditions through performances and recordings.

Jack K. Hale is a mathematician known primarily for his work in the field of dynamical systems, particularly in relation to nonlinear analysis and the theory of differential equations. He has published several influential papers and books on these subjects. One of his notable contributions is the study of the stability of dynamical systems and the qualitative behavior of solutions to differential equations. His works are often referenced in the mathematical literature related to these topics.

James Truchard is a prominent figure in the field of engineering and technology, best known as the co-founder and CEO of National Instruments (NI), a company that specializes in automated test equipment and virtual instrumentation software. Truchard played a pivotal role in the development of LabVIEW, a graphical programming environment widely used for data acquisition, instrument control, and industrial automation.

John J. Leonard is an individual known for his work in robotics and artificial intelligence, particularly in the field of mobile robotics and machine learning. He is a professor at the Massachusetts Institute of Technology (MIT) and has contributed to various research projects related to perception, navigation, and autonomous systems. His research often involves the development and application of algorithms for robotic systems to understand and interact with their environments.