3,286 research outputs found
On the intersection of tolerance and cocomparability graphs.
It has been conjectured by Golumbic and Monma in 1984 that the intersection of tolerance and cocomparability graphs coincides with bounded tolerance graphs. Since cocomparability graphs can be efficiently recognized, a positive answer to this conjecture in the general case would enable us to efficiently distinguish between tolerance and bounded tolerance graphs, although it is NP-complete to recognize each of these classes of graphs separately. The conjecture has been proved under some – rather strong – structural assumptions on the input graph; in particular, it has been proved for complements of trees, and later extended to complements of bipartite graphs, and these are the only known results so far. Furthermore, it is known that the intersection of tolerance and cocomparability graphs is contained in the class of trapezoid graphs. In this article we prove that the above conjecture is true for every graph G, whose tolerance representation satisfies a slight assumption; note here that this assumption concerns only the given tolerance representation R of G, rather than any structural property of G. This assumption on the representation is guaranteed by a wide variety of graph classes; for example, our results immediately imply the correctness of the conjecture for complements of triangle-free graphs (which also implies the above-mentioned correctness for complements of bipartite graphs). Our proofs are algorithmic, in the sense that, given a tolerance representation R of a graph G, we describe an algorithm to transform R into a bounded tolerance representation R ∗ of G. Furthermore, we conjecture that any minimal tolerance graph G that is not a bounded tolerance graph, has a tolerance representation with exactly one unbounded vertex. Our results imply the non-trivial result that, in order to prove the conjecture of Golumbic and Monma, it suffices to prove our conjecture. In addition, there already exists evidence in the literature that our conjecture is true
Recursive circulants and their embeddings among hypercubes
AbstractWe propose an interconnection structure for multicomputer networks, called recursive circulant. Recursive circulant G(N,d) is defined to be a circulant graph with N nodes and jumps of powers of d. G(N,d) is node symmetric, and has some strong hamiltonian properties. G(N,d) has a recursive structure when N=cdm, 1⩽c<d. We develop a shortest-path routing algorithm in G(cdm,d), and analyze various network metrics of G(cdm,d) such as connectivity, diameter, mean internode distance, and visit ratio. G(2m,4), whose degree is m, compares favorably to the hypercube Qm. G(2m,4) has the maximum possible connectivity, and its diameter is ⌈(3m−1)/4⌉. Recursive circulants have interesting relationship with hypercubes in terms of embedding. We present expansion one embeddings among recursive circulants and hypercubes, and analyze the costs associated with each embedding. The earlier version of this paper appeared in Park and Chwa (Proc. Internat. Symp. Parallel Architectures, Algorithms and Networks ISPAN’94, Kanazawa, Japan, December 1994, pp. 73–80)
A Portrait of Emotion: Empowering Self-Expression through AI-Generated Art
We investigated the potential and limitations of generative artificial
intelligence (AI) in reflecting the authors' cognitive processes through
creative expression. The focus is on the AI-generated artwork's ability to
understand human intent (alignment) and visually represent emotions based on
criteria such as creativity, aesthetic, novelty, amusement, and depth. Results
show a preference for images based on the descriptions of the authors' emotions
over the main events. We also found that images that overrepresent specific
elements or stereotypes negatively impact AI alignment. Our findings suggest
that AI could facilitate creativity and the self-expression of emotions. Our
research framework with generative AIs can help design AI-based interventions
in related fields (e.g., mental health education, therapy, and counseling).Comment: Accepted CogSci 202
MCM8-9 complex promotes resection of double-strand break ends by MRE11-RAD50-NBS1 complex.
MCM8-9 complex is required for homologous recombination (HR)-mediated repair of double-strand breaks (DSBs). Here we report that MCM8-9 is required for DNA resection by MRN (MRE11-RAD50-NBS1) at DSBs to generate ssDNA. MCM8-9 interacts with MRN and is required for the nuclease activity and stable association of MRN with DSBs. The ATPase motifs of MCM8-9 are required for recruitment of MRE11 to foci of DNA damage. Homozygous deletion of the MCM9 found in various cancers sensitizes a cancer cell line to interstrand-crosslinking (ICL) agents. A cancer-derived point mutation or an SNP on MCM8 associated with premature ovarian failure (POF) diminishes the functional activity of MCM8. Therefore, the MCM8-9 complex facilitates DNA resection by the MRN complex during HR repair, genetic or epigenetic inactivation of MCM8 or MCM9 are seen in human cancers, and genetic inactivation of MCM8 may be the basis of a POF syndrome
Inhomogeneous Kondo destruction by RKKY correlations
The competition between the indirect exchange interaction (IEC) of magnetic
impurities in metals and the Kondo effect gives rise to a rich quantum phase
diagram, the Doniach Diagram. In disordered metals, both the Kondo temperature
and the IEC are widely distributed due to the scattering of the conduction
electrons from the impurity potential. Therefore, it is a question of
fundamental importance, how this Doniach diagram is modified by the disorder,
and if one can still identify separate phases. Recently, it has been
investigated the effect of Ruderman-Kittel-Kasuya-Yosida (RKKY) correlations on
the Kondo effect of two magnetic impurities, renormalizing the Kondo
interaction based on the Bethe-Salpeter equation and performing the poor men's
renormalization group (RG) analysis with the RKKY-renormalized Kondo coupling.
In the present study, we extend this theoretical framework, allowing for
different Kondo temperatures of two RKKY-coupled magnetic impurities due to
different local exchange couplings and density of states. As a result, we find
that the smaller one of the two Kondo temperatures is suppressed more strongly
by the RKKY interaction, thereby enhancing their initial inequality. In order
to find out if this relevance of inequalities between Kondo temperatures
modifies the distribution of the Kondo temperature in a system of a finite
density of randomly distributed magnetic impurities, we present an extension of
the RKKY coupled Kondo RG equations. We discuss the implication of these
results for the interplay between Kondo coupling and RKKY interaction in
disordered electron systems and the Doniach diagram in disordered electron
systems
Leakage Minimization Technique for Nanoscale CMOS VLSI
Because of the continued scaling of technology and supply-threshold voltage, leakage power has become more significant in power dissipation of nanoscale CMOS circuits. Therefore, estimating the total leakage power is critical to designing low-power digital circuits. In nanometer CMOS circuits, the main leakage components are the subthreshold, gate-tunneling, and reverse-biased junction band-to-band-tunneling (BTBT) leakage currents
Accurate Macro-Modeling for Leakage Current for I\u3csub\u3eDDQ\u3c/sub\u3e Test
This paper proposes a new precise macro-modeling for leakage current in BSIM4 65nm technology considering subthreshold leakage, gate tunneling leakage, stack effect, and fanout effect. Using the accurate macro-model, a heuristic algorithm is developed to estimate the leakage power and generate input test pattern for minimum leakage. The algorithm applies to ISCAS85 benchmark circuits, and the results are compared with the results of Hspice. The experimental result shows that the leakage power estimation using our macro-model is within 5% difference when comparing to Hspice results
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