Energy Efficient Transmission over Space Shift Keying Modulated MIMO Channels

Energy-efficient communication using a class of spatial modulation (SM) that encodes the source information entirely in the antenna indices is considered in this paper. The energy-efficient modulation design is formulated as a convex optimization problem, where minimum achievable average symbol power consumption is derived with rate, performance, and hardware constraints. The theoretical result bounds any modulation scheme of this class, and encompasses the existing space shift keying (SSK), generalized SSK (GSSK), and Hamming code-aided SSK (HSSK) schemes as special cases. The theoretical optimum is achieved by the proposed practical energy-efficient HSSK (EE-HSSK) scheme that incorporates a novel use of the Hamming code and Huffman code techniques in the alphabet and bit-mapping designs. Experimental studies demonstrate that EE-HSSK significantly outperforms existing schemes in achieving near-optimal energy efficiency. An analytical exposition of key properties of the existing GSSK (including SSK) modulation that motivates a fundamental consideration for the proposed energy-efficient modulation design is also provided

Toward Sovereignty: Zhang Zhidong’s Military Strengthening of China, 1884-1901

The conventional history of China’s late nineteenth-century Self-Strengthening movement charted a failure of military reforms. My research explores this period through the perspective of the prominent governor-general Zhang Zhidong. From 1884-1901, Zhang consistently pursued new military academies and western-style armies aiming to secure the nation against foreign imperialist incursion. At the same time, the governor’s understanding of regional differences as well as his increasing experience in military affairs distinctly shaped his effective new military institutions. At the turn of the century, Zhang Zhidong’s military apparatus was arguably one of the best in China. In the wider analysis of Chinese military history, the governor’s career contrasted with other historical figures by its peripatetic nature and its continuity through the Sino-Japanese War and Boxer Rebellion. Zhang’s many jurisdictions showed not only his consistent dedication to military power as a means to national sovereignty, but also created numerous military institutions for study. More importantly, the continuity in the governor’s effective military reforms underlined fundamental historical misunderstandings about the nature of late-Qing China. First, Zhang’s successful military institutions contended with China’s deterioration narrative from 1895 to the dynastic fall in 1911. Second, the reason for historical misinterpretation stemmed from the obscuring of both late-Qing historians’ and the historical actors’ perceptions by the influences of western imperialism. Ultimately, the study of Zhang Zhidong’s military reforms shows a discontinuity in the conventional historical narrative, and thus creates space for increased Chinese agency in their own history

Anomalous physical properties of underdoped weak-ferromagnetic superconductor RuSr2_2EuCu2_{2}O8_{8}

Similar to the optimal-doped, weak-ferromagnetic (WFM induced by canted antiferromagnetism, T$_{Curie}$ = 131 K) and superconducting (T$_{c}$ = 56 K) RuSr$_{2}$GdCu$_{2}$O$_{8}$, the underdoped RuSr$_{2}$EuCu$_{2}$O$_{8}$ (T$_{Curie}$ = 133 K, T$_{c}$ = 36 K) also exhibited a spontaneous vortex state (SVS) between 16 K and 36 K. The low field ($\pm$20 G) superconducting hysteresis loop indicates a weak and narrow Meissner state region of average lower critical field B$_{c1}^{ave}$(T) = B$_{c1}^{ave}$(0)[1 - (T/T$_{SVS}$)$^{2}$], with B$_{c1}^{ave}$(0) = 7 G and T$_{SVS}$ = 16 K. The vortex melting transition (T$_{melting}$ = 21 K) below T$_{c}$ obtained from the broad resistivity drop and the onset of diamagnetic signal indicates a vortex liquid region due to the coexistence and interplay between superconductivity and WFM order. No visible jump in specific heat was observed near T$_{c}$ for Eu- and Gd-compound. This is not surprising, since the electronic specific heat is easily overshadowed by the large phonon and weak-ferromagnetic contributions. Furthermore, a broad resistivity transition due to low vortex melting temperature would also lead to a correspondingly reduced height of any specific heat jump. Finally, with the baseline from the nonmagnetic Eu-compound, specific heat data analysis confirms the magnetic entropy associated with antiferromagnetic ordering of Gd$^{3+}$ (J = S = 7/2) at 2.5 K to be close to $\it{N_{A}k}$ ln8 as expected.Comment: 7 figure

Magnetic Hydrogen Atmosphere Models and the Neutron Star RX J1856.5-3754

RX J1856.5-3754 is one of the brightest nearby isolated neutron stars, and considerable observational resources have been devoted to it. However, current models are unable to satisfactorily explain the data. We show that our latest models of a thin, magnetic, partially ionized hydrogen atmosphere on top of a condensed surface can fit the entire spectrum, from X-rays to optical, of RX J1856.5-3754, within the uncertainties. In our simplest model, the best-fit parameters are an interstellar column density N_H \approx 1x10^20 cm^-2 and an emitting area with R^infty \approx 17 km (assuming a distance to RX J1856.5-3754 of 140 pc), temperature T^infty \approx 4.3x10^5 K, gravitational redshift z_g \sim 0.22, atmospheric hydrogen column y_H \approx 1 g cm^-2, and magnetic field B \approx (3-4)x10^12 G; the values for the temperature and magnetic field indicate an effective average over the surface. We also calculate a more realistic model, which accounts for magnetic field and temperature variations over the neutron star surface as well as general relativistic effects, to determine pulsations; we find there exist viewing geometries that produce pulsations near the currently observed limits. The origin of the thin atmospheres required to fit the data is an important question, and we briefly discuss mechanisms for producing these atmospheres. Our model thus represents the most self-consistent picture to date for explaining all the observations of RX J1856.5-3754.Comment: 11 pages, 8 figures; MNRAS, accepte

Diffusion, Perfusion, and Histopathologic Characteristics of Desmoplastic Infantile Ganglioglioma.

We present a case series of a rare tumor, the desmoplastic infantile ganglioglioma (DIG) with MRI diffusion and perfusion imaging quantification as well as histopathologic characterization. Four cases with pathologically-proven DIG had diffusion weighted imaging (DWI) and two of the four had dynamic susceptibility contrast imaging. All four tumors demonstrate DWI findings compatible with low-grade pediatric tumors. For the two cases with perfusion imaging, a higher relative cerebral blood volume was associated with higher proliferation index on histopathology for one of the cases. Our results are discussed in conjunction with a literature review

GENDER DIFFERENCE IN KNEE MOTION PATTERN DURING VERTICAL JUMP

Several factors have been proposed as contributors to increase the injuries rate on noncontact ACL rupture among female athletes. Altered movement pattern may results in increased incidence of non-contact ACL injuries for female athletes. Therefore, the purpose of this study was to compare the knee kinematics difference between male and female athletes. Eighteen athletes were participated in this study, including 10 male and 8 female. The Zebris 3 D ultrasound-based system was used to measurement the knee kinematics during vertical jump. The results were shown that there had significant difference in knee maximal flexion, internal rotation, and flexion angle at maximal knee abduction between male and female athlete during vertical jump. Female athletes had showed little change of flexion angle and internal rotation angle of knee during vertical jump

GENDER DIFFERENCE IN KNEE MOTION PATTERN DURING VERTICAL JUMP

Several factors have been proposed as contributors to increase the injuries rate on noncontact ACL rupture among female athletes. Altered movement pattern may results in increased incidence of non-contact ACL injuries for female athletes. Therefore, the purpose of this study was to compare the knee kinematics difference between male and female athletes. Eighteen athletes were participated in this study, including 10 male and 8 female. The Zebris 3 D ultrasound-based system was used to measurement the knee kinematics during vertical jump. The results were shown that there had significant difference in knee maximal flexion, internal rotation, and flexion angle at maximal knee abduction between male and female athlete during vertical jump. Female athletes had showed little change of flexion angle and internal rotation angle of knee during vertical jump

Phase separation in the trapped spinor gases with anisotropic spin-spin interaction

We investigate the effect of the anisotropic spin-spin interaction on the ground state density distribution of the one dimensional spin-1 bosonic gases within a modified Gross-Pitaevskii theory both in the weakly interaction regime and in the Tonks-Girardeau (TG) regime. We find that for ferromagnetic spinor gas the phase separation occurs even for weak anisotropy of the spin-spin interaction, which becomes more and more obvious and the component of $m_F=0$ diminishes as the anisotropy increases. However, no phase separation is found for anti-ferromagnetic spinor gas in both regimes.Comment: 5pages, 4 figure