361 research outputs found
Edge of emergence : landscape as a journey of memory
These principles formulate the strategies and finally create the six themes in the design. The whole journey in landscape is a linear system, but the stimulation in each theme is a networked system. During the whole journey, people’s emotions will be triggered when they encounter a new theme. Between each theme, they have space and time to process their emotions and adjust their experiential state. In the end, when people finish the whole journey, they will not only have their past memories brought back but also will have built new memories for future events. In this way the past, present, and future potential memories overlap spatially and intertemporally
Solid Polymer Electrolytes from Crosslinked Polytetrahydrofuran for Calcium Ion Conduction
Polytetrahydrofuran (PTHF) and 3,4-epoxycyclohexylmethyl 3ʹ,4ʹ-epoxycyclohexane carboxylate (Epoxy) were crosslinked by photocuring via active monomer mechanism to make solid state networks. The networks were loaded with various amounts of calcium salt and calcium nitrate to create calcium ion solid state electrolytes. The loading range includes both salt-in-polymer and polymer-in-salt regimes. The O:Ca ratios range from 1.1 to 13.8. The ion-conductivity determined by electrochemical spectroscopy impedance and thermal properties (TGA, DSC) and Raman spectroscopy of PTHF-Epoxy/Ca(NO3)2 polymer electrolytes were measured. All samples were rubber-like and stable at temperatures from room temperature to 120 °C. With increase of salt loading, ion-conductivities of electrolytes first increase and then decrease. The one with highest ion-conductivity had a O:Ca ratio at 1.9 and conductivity of 1.14×10-4 S/cm at room temperature (25°C). At about 110°C, this electrolyte presents the highest conductivity at 0.0157 S/cm. Thermal analysis shows the material has an amorphous structure and high thermal stability. This system provides a route to create calcium ion solid state electrolytes
Bayesian Modeling of COVID-19 Positivity Rate -- the Indiana experience
In this short technical report we model, within the Bayesian framework, the rate of positive tests reported by the the State of Indiana, accounting also for the substantial variability (and overdispeartion) in the daily count of the tests performed. The approach we take, results with a simple procedure for prediction, a posteriori, of this rate of ’positivity’ and allows for an easy and a straightforward adaptation by any agency tracking daily results of COVID-19 tests. The numerical results provided herein were obtained via an updatable R Markdown document
Essays on oil price shocks and financial markets
This thesis is composed of three chapters, which can be read independently.
The first chapter investigates how oil price volatility affects the investment
decisions for a panel of Japanese firms. The model is estimated using a
system generalized method of moments technique for panel data. The results
are presented to show that there is a U-shaped relationship between oil price
volatility and Japanese firm investment. The results from subsamples of
these data indicate that this U-shaped relationship is more significant for
oil-intensive firms and small firms.
The second chapter aims to examine the underlying causes of changes
in real oil price and their transmission mechanisms in the Japanese stock
market. I decompose real oil price changes into three components; namely,
oil supply shock, aggregate demand shock and oil-specific demand shock, and
then estimate the dynamic effects of each component on stock returns using
a structural vector autoregressive (SVAR) model. I find that the responses
of aggregate Japanese real stock returns differ substantially with different
underlying causes of oil price changes. In the long run, oil shocks account
for 43% of the variation in the Japanese real stock returns. The response
of Japanese real stock returns to oil price shocks can be attributed in its
entirety to the cash flow variations.
The third chapter tests the robustness of SVAR and investigates the
impact of oil price shocks on the different U.S. stock indices. I find that the
responses of real stock returns of alternate stock indices differ substantially
depending on the underlying causes of the oil price increase. However, the
magnitude and length of the effect depends on the firm size. The response
of U.S. stock returns to oil price shocks can be attributed to the variations
of expected discount rates and expected cash flows
Tunable THz Surface Plasmon Polariton based on Topological Insulator-Layered Superconductor Hybrid Structure
We theoretically investigate the surface plasmon polariton (SPP) at the
interface between 3D strong topological insulator (TI) and layered
superconductor-magnetic insulator structure. The tunability of SPP through
electronic doping can be enhanced when the magnetic permeability of the layered
structure becomes higher. When the interface is gapped by superconductivity or
perpendicular magnetism, SPP dispersion is further distorted, accompanied by a
shift of group velocity and penetration depth. Such a shift of SPP reaches
maximum when the magnitude of Fermi level approaches the gap value, and may
lead to observable effects. The tunable SPP at the interface between layered
superconductor and magnetism materials in proximity to TI surface may provide
new insight in the detection of Majorana Fermions.Comment: 6 pages, 4 figure
Double Asynchronous Switching Control for Takagi–Sugeno Fuzzy Markov Jump Systems via Adaptive Event-Triggered Mechanism
This article addresses the issue of adaptive event- triggered H∞ control for Markov jump systems based on Takagi-Sugeno (T-S) fuzzy model. Firstly, a new double asynchronous switching controller is presented to deal with the problem of the mismatch of premise variables and modes between the controller and the plant, which is widespread in real network environment. To further reduce the power consumption of communication, a switching adaptive event-triggered mechanism is adopted to relieve the network transmission pressure while ensuring the control effect. In addition, a new Lyapunov-Krasovskii functional (LKF) is constructed to reduce conservatism by introducing the membership functions (MFs) and time-varying delays informa- tion. Meanwhile, the invariant set is estimated to ensure the stability of the system. And the disturbance rejection ability is measured by the optimal H∞ performance index. Finally, two examples are presented to demonstrate the effectiveness of the proposed approach
Synchronous MDADT-Based Fuzzy Adaptive Tracking Control for Switched Multiagent Systems via Modified Self-Triggered Mechanism
In this paper, a self-triggered fuzzy adaptive switched control strategy is proposed to address the synchronous tracking issue in switched stochastic multiagent systems (MASs) based on mode-dependent average dwell-time (MDADT) method. Firstly, a synchronous slow switching mechanism is considered in switched stochastic MASs and realized through a class of designed switching signals under MDADT property. By utilizing the information of both specific agents under switching dynamics and observers with switching features, the synchronous switching signals are designed, which reduces the design complexity. Then, a switched state observer via a switching-related output mask is proposed. The information of agents and their preserved neighbors is utilized to construct the observer and the observation performance of states is improved. Moreover, a modified self- triggered mechanism is designed to improve control performance via proposing auxiliary function. Finally, by analysing the re- lationship between the synchronous switching problem and the different switching features of the followers, the synchronous slow switching mechanism based on MDADT is obtained. Meanwhile, the designed self-triggered controller can guarantee that all signals of the closed-loop system are ultimately bounded under the switching signals. The effectiveness of the designed control method can be verified by some simulation results
Sentiment Analysis of Name Entity for Text
Abstract-Recent years, big data has attracted increasing interest. Sentiment analysis from microblog as one kind of big data also receive great attention. Some recent research works are not suitable for sentiment analysis as the result that users prefer to express their feelings in individual ways. In this paper, a framework is proposed to calculate sentiment for aspects of event. Based on some state of art technologies, we build up one flowchart to get sentiment for aspects of event. During the process, name entities with the same meaning are clustered and sentiment carrier are filtered. In this way sentiment can be got even user express feeling for the same object with different words
Clinical characteristics and long term post-operative outcome of cardiac myxoma
Background and aim: Myxoma is the most common type of primary cardiac neoplasm, but the clinical characteristics and long term outcome are less known in the elderly in China.
Methods: We analyzed medical records of 112 consecutive patients who underwent operative resection of cardiac myxoma between December 1988 and December 2010 in our hospital. Their data were retrospectively analyzed and the difference between two age groups (< 60 years, n = 87 and ≥ 60 years, n = 25) was compared.
Results: The mean age of 112 patients was 48.8 ± 12.5 (range 13 ~ 75) years, and 66 patients (58.9 %) were female. The interval from onset of symptoms to diagnosis was 12 months and the most common presenting symptoms were chest distress (66 patients 58.9 %), followed by palpitations (55 patients, 49.1 %) and dyspnea (47 patients, 42.0 %). Mitral valve diastolic murmur was heard in 67 (59.1 %) patients. The tumor was located in the left atrium in 96 (85.8 %) patients. There were no in-hospital death. During follow-up ranged between one and twenty-one (7.3 ± 5.3) years, there was no malignancy. Myxoma recurred in 3 (2.7 %) patients and deaths occurred in 5 (4.5 %) patients. The 5 and 15 years survival was 97.8 % and 89.5 %, respectively. To compare with the younger patients, the elderly have higher ratios of concomitant hypertension, fewer complaints of dyspnea and chest distress (p < 0.05).
Conclusion: The elderly have lower complaints of dyspnea and chest distress, surgical treatment is associated with low long-term mortality and recurrence rate even in the elder patients
Magnetic field induced discontinuous spin reorientation in ErFeO3 single crystal
The spin reorientation of ErFeO3 that spontaneously occurs at low temperature has been previously determined to be a process involving the continuous rotation of Fe3þ spins. In this work, the dynamic process of spin reorientation in ErFeO3 single crystal has been investigated by AC susceptibility measurements at various frequencies and static magnetic fields. Interestingly, two completely discontinuous steps are induced by a relatively large static magnetic field due to the variation in the magnetic anisotropy during this process. It provides deeper insights into the intriguing magnetic exchange interactions which dominate the sophisticated magnetic phase transitions in the orthoferrite systems
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