Rurality Within the City: a study of the interrelationship between urban and rural areas

My project proposal is to produce a new type of contemporary self-sufficient architectural place to deal not only with the economic and education issues that the rurals are lacking in but also with environmental and unemployment issues that the big cities are lacking in. While it is important to retain the countryside feel in the current suburbs, some issues to improve on for the new city area are to cater towards a younger generation’s needs. As opposed to those who are retired and are looking for a quiet place to settle down for the rest of their life in the suburbs, those moving out of the cities are looking for jobs, education for their children, and an affordable but satisfying quality of life

Unbounded Scalable Hardware Verification.

Model checking is a formal verification method that has been successfully applied to real-world hardware and software designs. Model checking tools, however, encounter the so-called state-explosion problem, since the size of the state spaces of such designs is exponential in the number of their state elements. In this thesis, we address this problem by exploiting the power of two complementary approaches: (a) counterexample-guided abstraction and refinement (CEGAR) of the design's datapath; and (b) the recently-introduced incremental induction algorithms for approximate reachability. These approaches are well-suited for the verification of control-centric properties in hardware designs consisting of wide datapaths and complex control logic. They also handle most complex design errors in typical hardware designs. Datapath abstraction prunes irrelevant bit-level details of datapath elements, thus greatly reducing the size of the state space that must be analyzed and allowing the verification to be focused on the control logic, where most errors originate. The induction-based approximate reachability algorithms offer the potential of significantly reducing the number of iterations needed to prove/disprove given properties by avoiding the implicit or explicit enumeration of reachable states. Our implementation of this verification framework, which we call the Averroes system, extends the approximate reachability algorithms at the bit level to first-order logic with equality and uninterpreted functions. To facilitate this extension, we formally define the solution space and state space of the abstract transition system produced by datapath abstraction. In addition, we develop an efficient way to represent sets of abstract solutions involving present- and next-states and a systematic way to project such solutions onto the space of just the present-state variables. To further increase the scalability of the Averroes verification system, we introduce the notion of structural abstraction, which extends datapath abstraction with two optimizations for better classification of state variables as either datapath or control, and with efficient memory abstraction techniques. We demonstrate the scalability of this approach by showing that Averroes significantly outperforms bit-level verification on a number of industrial benchmarks.PhDComputer Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133375/1/suholee_1.pd

The Splashback Mass Function in the Presence of Massive Neutrinos

We present a complementary methodology to constrain the total neutrino mass, $\sum m_{\nu}$, based on the diffusion coefficient of the splashback mass function of dark matter halos. Analyzing the snapshot data from the Massive Neutrino Simulations, we numerically obtain the number densities of distinct halos identified via the SPARTA code as a function of their splashback masses at various redshifts for two different cases of $\sum m_{\nu}=0.0$ eV and $0.1$ eV. Then, we fit the numerical results to the recently developed analytic formula characterized by the diffusion coefficient that quantifies the degree of ambiguity in the identification of the splashback boundaries. Our analysis confirms that the analytic formula works excellently even in the presence of neutrinos and that the decrement of its diffusion coefficient with redshift is well described by a linear fit, $B(z-z_{c})$, in the redshift range of $0.2\le z\le 2$. It turns out that the massive neutrino case yields significantly lower value of $B$ and substantially higher value of $z_{c}$ than the massless neutrino case, which indicates that the higher masses the neutrinos have, the more severely the splashback boundaries become disturbed by the surroundings. Given our result, we conclude that the total neutrino mass can in principle be constrained by measuring how rapidly the diffusion coefficient of the splashback mass function diminishes with redshifts at $z\ge 0.2$. We also discuss the anomalous behavior of the diffusion coefficient found at lower redshifts for both of the $\sum m_{\nu}$ cases, and ascribe it to the fundamental limitation of the SPARTA code at $z\le 0.13$.Comment: Accepted for publication in ApJ, 5 figures, 1 tabl

Breaking the Dark Degeneracy with the Drifting Coefficient of the Field Cluster Mass Function

We present a numerical analysis supporting the evidence that the redshift evolution of the drifting coefficient of the field cluster mass function is capable of breaking several cosmic degeneracies. This evidence is based on the data from the CoDECS and DUSTGRAIN-pathfinder simulations performed separately for various non-standard cosmologies including coupled dark energy, $f(R)$ gravity and combinations of $f(R)$ gravity with massive neutrinos as well as for the standard $\Lambda$CDM cosmology. We first numerically determine the field cluster mass functions at various redshifts in the range of $0\le z\le 1$ for each cosmology. Then, we compare the analytic formula developed in previous works with the numerically obtained field cluster mass functions by adjusting its drifting coefficient, $\beta$, at each redshift. It is found that the analytic formula with the best-fit coefficient provides a good match to the numerical results at all redshifts for all of the cosmologies. The empirically determined redshift evolution of the drifting coefficient, $\beta(z)$, turns out to significantly differ among different cosmologies. It is also shown that even without using any prior information on the background cosmology the drifting coefficient, $\beta(z)$, can discriminate with high statistical significance the degenerate non-standard cosmologies not only from the $\Lambda$CDM but also from one another. It is concluded that the evolution of the departure from the Einstein-de Sitter state and spherically symmetric collapse processes quantified by $\beta(z)$ is a powerful probe of gravity and dark sector physics.Comment: accepted for publication in ApJ, minor revision after referee's report, 15 figures, 2 table

Comparison of lower limb muscle activation according to horizontal whole-body vibration frequency and knee angle

Whole-body vibration refers to an exercise that stimulates the muscles, using a vibration with an amplitude and power, however, there are few studies that have dealt with fundamental questions such as optimal frequency or body position. This study aims to compare lower limb activation, according to horizontal whole-body vibration frequency and knee flexion angle, in healthy adults. Using 18 healthy adults aged 21–30, this study measured and analysed the activities of the vastus lateralis (VL), biceps femoris (BF), tibialis anterior (TA), and gastrocnemius (GCM) muscles, for different horizontal whole-body vibration frequencies (0 Hz, 2 Hz, and 4 Hz) and knee flexion angles (0°, 30°, and 60°), using surface electromyography (sEMG). There was a statistically significant increase in lower limb muscle activation according to horizontal whole-body vibration frequency and knee flexion angle: comparing muscle activation with frequency, the muscle activation of VL, BF, TA, and GCM increased with increase in frequency (p<0.05). The muscle activation of VL and TA increased with increase in knee flexion angle (p<0.05). In this study, it was observed that for whole-body vibration provided in a horizontal direction, larger the frequency and higher the knee flexion angle, greater the lower limb activation

Effect of Multiple Quantum Well Periods on Structural Properties and Performance of Extended Short-Wavelength Infrared LEDs

We present research on the role of multiple quantum well periods in extended short-wavelength infrared InGaAs/InAsPSb type-I LEDs. The fabricated LEDs consisted of 6, 15, and 30 quantum well periods, and we evaluated the structural properties and device performance through a combination of theoretical simulations and experimental characterization. The strain and energy band offset was precisely controlled by carefully adjusting the composition of the InAsPSb quaternary material, achieving high valence and conduction band offsets of 350 meV and 94 meV, respectively. Our LEDs demonstrated a high degree of relaxation of 94-96 %. Additionally, we discovered that the temperature-dependent dark current characterization attributed to generation-recombination and trap-assign tunneling, with trap-assign tunneling being more dominant at lower current injections. Electroluminescence analysis revealed that the predominant emission mechanism of the LEDs originated from localized exciton and free exciton radiative recombination, which the 30 quantum wells LED exhibited the highest contribution of the localized exciton/free exciton radiative recombination. We observed that increasing the quantum well periods from 6 to 15 led to an increase in the 300 K electroluminescence intensity of the LED. However, extending the quantum well period to 30 resulted in a decline in emission intensity due to the degradation of the epitaxial film quality