Application of Quantum Annealing to Nurse Scheduling Problem

Quantum annealing is a promising heuristic method to solve combinatorial optimization problems, and efforts to quantify performance on real-world problems provide insights into how this approach may be best used in practice. We investigate the empirical performance of quantum annealing to solve the Nurse Scheduling Problem (NSP) with hard constraints using the D-Wave 2000Q quantum annealing device. NSP seeks the optimal assignment for a set of nurses to shifts under an accompanying set of constraints on schedule and personnel. After reducing NSP to a novel Ising-type Hamiltonian, we evaluate the solution quality obtained from the D-Wave 2000Q against the constraint requirements as well as the diversity of solutions. For the test problems explored here, our results indicate that quantum annealing recovers satisfying solutions for NSP and suggests the heuristic method is sufficient for practical use. Moreover, we observe that solution quality can be greatly improved through the use of reverse annealing, in which it is possible to refine a returned results by using the annealing process a second time. We compare the performance NSP using both forward and reverse annealing methods and describe how these approach might be used in practice.Comment: 20 pages, 13 figure

Adaptive measurement strategy for quantum subspace methods

Estimation of physical observables for unknown quantum states is an important problem that underlies a wide range of fields, including quantum information processing, quantum physics, and quantum chemistry. In the context of quantum computation, in particular, existing studies have mainly focused on holistic state tomography or estimation on specific observables with known classical descriptions, while this lacks the important class of problems where the estimation target itself relies on the measurement outcome. In this work, we propose an adaptive measurement optimization method that is useful for the quantum subspace methods, namely the variational simulation methods that utilize classical postprocessing on measurement outcomes. The proposed method first determines the measurement protocol based on QSE calculation for classically simulatable states, and then adaptively updates the protocol according to the quantum measurement result. As a numerical demonstration, we have shown for excited-state simulation of molecules that (i) we are able to reduce the number of measurements by an order of magnitude by constructing an appropriate measurement strategy (ii) the adaptive iteration converges successfully even for strongly correlated molecule of H$_4$. Our work reveals that the potential of the QSE method can be empowered by elaborated measurement protocols, and opens a path to further pursue efficient quantum measurement techniques in practical computations.Comment: 9 pages, 4 figure

Berberine and palmatine inhibit the growth of human rhabdomyosarcoma cells

Published online: 29 Aug 2019A natural isoquinoline alkaloid, berberine, has been known to exhibit anti-tumor activity in various cancer cells via inducing cell cycle arrest. However, it has not been investigated whether berberine and its analogs inhibit the growth of rhabdomyosarcoma (RMS), which is the most frequent soft tissue tumor in children. The present study examined the anti-tumor effects of berberine and palmatine on expansions of three human embryonal RMS cell lines; ERMS1, KYM1, and RD. Intracellular incorporation of berberine was relatively higher than that of palmatine in every RMS cell line. Berberine significantly inhibited the cell cycle of all RMS cells at G(1) phase. On the other hand, palmatine only suppressed the growth of RD cells. Both of berberine and palmatine strongly inhibited the growth of tumorsphere of RD cells in three-dimensional culture. These results indicate that berberine derivatives have the potential of anti-tumor drugs for RMS therapy.ArticleBIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY. 84(1):63-75 (2020)journal articl

Bounding of a two-legged robot using CPG-based controller inspired by a cheetah simple model

The 11th International Symposium on Adaptive Motion of Animals and Machines. Kobe University, Japan. 2023-06-06/09. Adaptive Motion of Animals and Machines Organizing Committee.Poster Session P

Identification of the Myogenetic Oligodeoxynucleotides (myoDNs) That Promote Differentiation of Skeletal Muscle Myoblasts by Targeting Nucleolin

Herein we report that the 18-base telomeric oligodeoxynucleotides (ODNs) designed from the Lactobacillus rhamnosus GG genome promote differentiation of skeletal muscle myoblasts which are myogenic precursor cells. We termed these myogenetic ODNs (myoDNs). The activity of one of the myoDNs, iSN04, was independent of Toll-like receptors, but dependent on its conformational state. Molecular simulation and iSN04 mutants revealed stacking of the 13–15th guanines as a core structure for iSN04. The alkaloid berberine bound to the guanine stack and enhanced iSN04 activity, probably by stabilizing and optimizing iSN04 conformation. We further identified nucleolin as an iSN04-binding protein. Results showed that iSN04 antagonizes nucleolin, increases the levels of p53 protein translationally suppressed by nucleolin, and eventually induces myotube formation by modulating the expression of genes involved in myogenic differentiation and cell cycle arrest. This study shows that bacterial-derived myoDNs serve as aptamers and are potential nucleic acid drugs directly targeting myoblasts.ArticleFRONTIERS IN CELL AND DEVELOPMENTAL BIOLOGY. 8:616706 (2021)journal articl

High-resolution spectroscopy and single-photon Rydberg excitation of reconfigurable ytterbium atom tweezer arrays utilizing a metastable state

We present an experimental system for Rydberg tweezer arrays with ytterbium (Yb) atoms featuring internal state manipulation between the ground ${}^1$S$_0$ and the metastable ${}^3$P$_2$ states, and single-photon excitation from the ${}^3$P$_2$ to Rydberg states. In the experiments, single Yb atoms are trapped in two-dimensional arrays of optical tweezers and are detected by fluorescence imaging with the intercombination ${}^1$S$_0 \leftrightarrow {}^3$P$_1$ transition, and the defect-free single atom arrays are prepared by the rearrangement with the feedaback. We successfully perform high-resolution ${}^1$S$_0\leftrightarrow {}^3$P$_2$ state spectroscopy for the single atoms, demonstrating the utilities of this ultranarrow transition. We further perform single-photon excitation from the ${}^3$P$_2$ to Rydberg states for the single atoms, which is a key for the efficient Rydberg excitation. We also perform a systematic measurement of a complex energy structure of a series of D states including newly observed ${}^3$D$_3$ states. The developed system shows feasibility of future experiments towards quantum simulations and computations using single Yb atoms.Comment: 10 pages, 9 figure

Active Initialization Experiment of Superconducting Qubit Using Quantum-circuit Refrigerator

The initialization of superconducting qubits is one of the essential techniques for the realization of quantum computation. In previous research, initialization above 99\% fidelity has been achieved at 280 ns. Here, we demonstrate the rapid initialization of a superconducting qubit with a quantum-circuit refrigerator (QCR). Photon-assisted tunneling of quasiparticles in the QCR can temporally increase the relaxation time of photons inside the resonator and helps release energy from the qubit to the environment. Experiments using this protocol have shown that 99\% of initialization time is reduced to 180 ns. This initialization time depends strongly on the relaxation rate of the resonator, and faster initialization is possible by reducing the resistance of the QCR, which limits the ON/OFF ratio, and by strengthening the coupling between the QCR and the resonator