There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

/pdf/the-theory-of-industrial-organization-19bejph0ej.pdf

The Theory of Industrial Organization

Computational geometry

[서평]「Component Software」 - Beyond Object-Oriented Programming -

Safety critical systems involve the tight coupling between potentially conflicting control objectives and safety constraints. As a means of creating a formal framework for controlling systems of this form, and with a view toward automotive applications, this paper develops a methodology that allows safety conditions—expressed as control barrier functions —to be unified with performance objectives—expressed as control Lyapunov functions—in the context of real-time optimization-based controllers. Safety conditions are specified in terms of forward invariance of a set, and are verified via two novel generalizations of barrier functions; in each case, the existence of a barrier function satisfying Lyapunov-like conditions implies forward invariance of the set, and the relationship between these two classes of barrier functions is characterized. In addition, each of these formulations yields a notion of control barrier function (CBF), providing inequality constraints in the control input that, when satisfied, again imply forward invariance of the set. Through these constructions, CBFs can naturally be unified with control Lyapunov functions (CLFs) in the context of a quadratic program (QP); this allows for the achievement of control objectives (represented by CLFs) subject to conditions on the admissible states of the system (represented by CBFs). The mediation of safety and performance through a QP is demonstrated on adaptive cruise control and lane keeping, two automotive control problems that present both safety and performance considerations coupled with actuator bounds.

https://ieeexplore.ieee.org/ielaam/9/7993115/7782377-aam.pdf

Control Barrier Function Based Quadratic Programs for Safety Critical Systems

This paper proposes an approach to optimally synthesize quantum circuits by symbolic reachability analysis, where the primary inputs and outputs are basis binary and the internal signals can be nonbinary in a multiple-valued domain. The authors present an optimal synthesis method to minimize quantum cost and some speedup methods with nonoptimal quantum cost. The methods here are applicable to small reversible functions. Unlike previous works that use permutative reversible gates, a lower level library that includes nonpermutative quantum gates is used here. The proposed approach obtains the minimum cost quantum circuits for Miller gate, half adder, and full adder, which are better than previous results. This cost is minimum for any circuit using the set of quantum gates in this paper, where the control qubit of 2-qubit gates is always basis binary. In addition, the minimum quantum cost in the same manner for Fredkin, Peres, and Toffoli gates is proven. The method can also find the best conversion from an irreversible function to a reversible circuit as a byproduct of the generality of its formulation, thus synthesizing in principle arbitrary multi-output Boolean functions with quantum gate library. This paper constitutes the first successful experience of applying formal methods and satisfiability to quantum logic synthesis

/pdf/optimal-synthesis-of-multiple-output-boolean-functions-using-3w9i46iby0.pdf

Optimal synthesis of multiple output Boolean functions using a set of quantum gates by symbolic reachability analysis

Based on an algorithm derived from the new Chinese remainder theorem I, we present three new residue-to-binary converters for the residue number system (2/sup n/-1, 2/sup n/, 2/sup n/+1) designed using 2n-bit or n-bit adders with improvements on speed, area, or dynamic range compared with various previous converters. The 2n-bit adder based converter is faster and requires about half the hardware required by previous methods. For n-bit adder-based implementations, one new converter is twice as fast as the previous method using a similar amount of hardware, whereas another new converter achieves improvement in either speed, area, or dynamic range compared with previous converters.

/pdf/adder-based-residue-to-binary-number-converters-for-2-sup-n-4e975fpuo7.pdf

Adder based residue to binary number converters for (2/sup n/-1, 2/sup n/, 2/sup n/+1)

Logic synthesis for reversible logic differs considerably from standard logic synthesis. The gates are multi-output and the unutilized outputs from these gates are called “garbage”. One of the synthesis tasks is to reduce the number of garbage signals. Previous approaches to reversible logic synthesis minimized either only the garbage or (predominantly) the number of gates. Here we present for the first time a method that minimizes concurrently the number of gates, their total delay and the total garbage. Our method adopts for reversible logic many ideas developed previously for standard logic synthesis (such as Ashenhurst/Curtis Decomposition, Dietmeyer’s Composition, non-linear preprocessing for BDDs), methods created in ReedMuller Logic (such as Pseudo-Kronecker Decision Diagrams with Complemented Edges, Pseudo-Kronecker Lattice Diagrams and their generalizations) and introduces also new methods specific to reversible logic.

/pdf/a-general-decomposition-for-reversible-logic-1v3rbti523.pdf

A General Decomposition for Reversible Logic

A clustering-based method for unsupervised intrusion detections

Traditional ROBDD-based methods of automated verification suffer from the drawback that they require a binary representation of the circuit. To overcome this limitation we propose a broader class of decision graphs, called {\em Multiway Decision Graphs} (MDGs), of which ROBDDs are a special case. With MDGs, a data value is represented by a single variable of abstract type, rather than by 32 or 64 boolean variables, and a data operation is represented by an uninterpreted function symbol. MDGs are thus much more compact than ROBDDs, and this greatly increases the range of circuits that can be verified. We give algorithms for MDG manipulation, and for implicit state enumeration using MDGs. We have implemented an MDG package and provide experimental results.

Xiaoyu Song

Papers

Optimal synthesis of multiple output Boolean functions using a set of quantum gates by symbolic reachability analysis

Adder based residue to binary number converters for (2/sup n/-1, 2/sup n/, 2/sup n/+1)

A General Decomposition for Reversible Logic

A clustering-based method for unsupervised intrusion detections

Multiway Decision Graphs for Automated Hardware Verification