Real-time rss-based indoor navigation for autonomous UAV flight

Navigation for the autonomous flight of Unmanned Aerial Vehicles (UAVs) in an indoor space has attracted much attention recently. One of the main goals of an indoor navigation system is developing an alternative method to obtain position information that can replace or complement the global positioning system. While much research has focused on vision-based indoor navigation systems, this paper aims to develop a Received Signal Strength (RSS)-based navigation system, which is a more cost effective alternative. Then, the position and attitude of a UAV can be computed by the fusion of RSS measurements and measurements from the onboard inertial measurement unit. In order to improve the estimation accuracy, we first consider a mathematical model of the RSS-based navigation system and formulate optimization problems to compute the parameter values which minimize the RSS measurement error. Using the optimal parameters, an autonomous flight system is developed whose estimator and controller components are designed to work well with the RSS-based navigation system. Simulations and experiments using a quadrotor demonstrate the feasibility and performance of the proposed RSS-based navigation system for UAVs operating in indoor environments

Quantum Error Correcting Codes and Fault-Tolerant Quantum Computation over Nice Rings

Quantum error correcting codes play an essential role in protecting quantum information from the noise and the decoherence. Most quantum codes have been constructed based on the Pauli basis indexed by a finite field. With a newly introduced algebraic class called a nice ring, it is possible to construct the quantum codes such that their alphabet sizes are not restricted to powers of a prime. Subsystem codes are quantum error correcting schemes unifying stabilizer codes, decoherence free subspaces and noiseless subsystems. We show a generalization of subsystem codes over nice rings. Furthermore, we prove that free subsystem codes over a finite chain ring cannot outperform those over a finite field. We also generalize entanglement-assisted quantum error correcting codes to nice rings. With the help of the entanglement, any classical code can be used to derive the corresponding quantum codes, even if such codes are not self-orthogonal. We prove that an R-module with antisymmetric bicharacter can be decomposed as an orthogonal direct sum of hyperbolic pairs using symplectic geometry over rings. So, we can find hyperbolic pairs and commuting generators generating the check matrix of the entanglement-assisted quantum code. Fault-tolerant quantum computation has been also studied over a finite field. Transversal operations are the simplest way to implement fault-tolerant quantum gates. We derive transversal Clifford operations for CSS codes over nice rings, including Fourier transforms, SUM gates, and phase gates. Since transversal operations alone cannot provide a computationally universal set of gates, we add fault-tolerant implementations of doubly-controlled Z gates for triorthogonal stabilizer codes over nice rings. Finally, we investigate optimal key exchange protocols for unconditionally secure key distribution schemes. We prove how many rounds are needed for the key exchange between any pair of the group on star networks, linear-chain networks, and general networks

Missio Dei in Worship Service : a case study of the Christian Church of Groningen

Masterthesis Missiologi

The Dynamics of Productivity Changes in Agricultural Sector of Transition Countries

Relying on frontier production approach (e.g., Luenberger's shortage function), we investigated the performance of agricultural sector in transition countries and its changes over time, especially focusing on the dynamics of productivity changes. We found that; (i) CEE countries have improved their performance during the sample period whereas CIS have not; (ii) productivity changes in the last decade was attributable to the technical progress; (iii) overall performance was decelerated for the second 5-year sub-period (1997-2001) in both regions; (iv) agricultural reform has positive effects on the productivity and its components especially in CEE countries.transition countries, productivity, directional distance function, agricultural reform, Productivity Analysis,

Gravitational waves from first-order phase transitions: Towards model separation by bubble nucleation rate

We study gravitational-wave production from bubble collisions in a cosmic first-order phase transition, focusing on the possibility of model separation by the bubble nucleation rate dependence of the resulting gravitational-wave spectrum. By using the method of relating the spectrum with the two-point correlator of the energy-momentum tensor \left, we first write down analytic expressions for the spectrum with a Gaussian correction to the commonly used nucleation rate, $\Gamma \propto e^{\beta t}\rightarrow e^{\beta t-\gamma^2t^2}$, under the thin-wall and envelope approximations. Then we quantitatively investigate how the spectrum changes with the size of the Gaussian correction. It is found that the spectral shape shows ${\mathcal O}(10)\%$ deviation from $\Gamma \propto e^{\beta t}$ case for some physically motivated scenarios. We also briefly discuss detector sensitivities required to distinguish different spectral shapes.Comment: 36 pages, 13 figures, 1 figure from arXiv:1605.0140

The Neural Basis of Sodium Appetite

Fluid homeostasis, which maintains a stable internal environment, is critical for survival. Body fluid is tightly monitored and regulated through its main components, water and salt. Here, I focus on the aspect of sodium regulation when sodium is the main cation in the extracellular fluid and is also required for primary metabolism. The depletion of sodium induces the retention of sodium but also a central mechanism to obtain sodium from the external sources. This need for sodium specifically drives animals towards sodium consumption, called sodium appetite. Even though sodium appetite is specific for only sodium ion, sodium appetite observed as an innate behavior across the animal kingdom. Sodium appetite is strictly regulated by both peripheral sensory signals and central appetite signals. Due to the development of genetic tools, I was able to investigate the neural basis of sodium appetite from searching sodium appetite dedicated neurons. Here, I identify two genetically defined neural circuits in mice that control sodium intake. The activation of these neurons drives robust sodium intake in sated animals. Particularly, prodynorphin expressing neurons in the pre-locus coeruleus shown specific consumption to sodium compounds, including rock salt. In terms of loss-of-function, inhibition of these neurons selectively reduced sodium consumption. It was further shown that these neurons receive sodium depleted signals by aldosterone-sensitive neurons. Previously, it was suggested that taste signals have a central role in sodium satiation. I demonstrate that the oral detection of sodium rapidly suppresses sodium appetite neurons. The blockage of the sodium taste or gastric infusion of sodium abolished the sodium suppression in the sodium appetite neurons. Consistently, gastric infusion of sodium did not cause sodium satiation. Moreover, retrograde-viral methods showed that specific inhibitory neurons partially mediate sensory modulation in the bed nucleus of the stria terminalis. Together, I identified a specific neural population as a functional unit for sodium appetite. By knowing the dedicated circuits for sodium appetite, I demonstrated chemosensory and physiological signals regulate the neural circuits. The genetically defined neural population can be handle as an entry point of further investigation of the neural basis of sodium appetite.</p

X-ray scattering studies of charge density waves in cuprate and pnictide superconductors

The phase diagrams of unconventional superconductors exhibit many different broken-symmetry phases near superconductivity, such as antiferromagnetism, charge density wave, spin density wave, and nematic order. The proximity and similar temperature scales of these orders suggest superconductivity and other order parameters are intertwined, and how they intertwine is a longstanding problem in condensed matter physics. Among the phases found in the vicinity of superconductivity, charge density wave (CDW) has been found in nearly all cuprate superconductors and observed to have an intimate relationship with superconductivity. Thus, characterizing the nature of CDWs is crucial for understanding the mechanism of unconventional superconductivity. Here, we studied CDWs in cuprate and pnictide superconductors using various x-ray scattering techniques. We discovered new CDW phases in BaNi2As2 and Co-, Sr-doped systems, confirming a generic presence of CDW in the phase diagram of unconventional superconductors, and the nature of the superconductivity in these systems are closely related to the presence of CDW. We also precisely measured the temperature and doping evolution of the CDW wave vector in La1.8-xEu0.2SrxCuO4, revealing the effect of the finite charge compressibility and the coupling of charge and spin order on the wave vector change. Furthermore, energy- and time-resolved resonant soft x-ray scattering experiments on the CDW in La2-xBaxCuO4 were performed to reveal a previously unidentified fluctuating nature of the CDW

Neural Control and Modulation of Thirst, Sodium Appetite, and Hunger

The function of central appetite neurons is instructing animals to ingest specific nutrient factors that the body needs. Emerging evidence suggests that individual appetite circuits for major nutrients—water, sodium, and food—operate on unique driving and quenching mechanisms. This review focuses on two aspects of appetite regulation. First, we describe the temporal relationship between appetite neuron activity and consumption behaviors. Second, we summarize ingestion-related satiation signals that differentially quench individual appetite circuits. We further discuss how distinct appetite and satiation systems for each factor may contribute to nutrient homeostasis from the functional and evolutional perspectives