Joint design of ordered QR precoding and SIC detection for MIMO VLC systems.

Ordered successive interference cancellation (OSIC) detection has been investigated to mitigate the high spatial correlation for multiple-input multiple-output (MIMO) visible light communication (VLC) systems. However, existing OSIC schemes have to perform reordering and matrix inversion for each detected symbol, which may lead to high complexity when a large number of symbols are transmitted. In this work, a joint design of ordered QR decomposition precoding and SIC detection (OQR-SIC) is proposed for MIMO VLC systems. This work jointly investigates OQR precoding and SIC detection to reduce the detection complexity while alleviating spatial correlation issue for MIMO VLC systems. In OQR-SIC, with the upper triangular matrix obtained by QR decomposition, the SIC detector can detect the symbol sequentially without reordering and matrix inversion calculations. To improve the system data rate, we further optimize the ordering of the columns of the channel matrix before QR decomposition and the power allocation of transmitted signals under the constraints of dimming control, total electrical power and reliable SIC detection. Simulation results demonstrate that the proposed OQR-SIC achieves 2 dB and 9.8 dB signal-to-noise ratio gains compared to conventional QR-SIC in 4 × 4 and 9 × 9 MIMO VLC systems, respectively, when the bit error rate is 10-3.

Downregulation of CDC20 suppressed cell proliferation, induced apoptosis, triggered cell cycle arrest in osteosarcoma cells, and enhanced chemosensitivity to cisplatin.

Osteosarcoma (OS) is a common malignant bone tumor that occurs in adolescents or children under the age of 20, which is extremely difficult to cure and has a high recurrence rate. Recent studies showed that cell division cycle 20 (CDC20) overexpression is associated with poor prognosis in patients with osteosarcoma. However, the function of CDC20 in osteosarcoma has not been investigated clearly. In this study, we aim to explore the role of CDC20 in two independent human OS cell lines' biological phenotype and chemotherapy sensitivity. We applied multiple approaches to measure cell growth, cell cycle, and apoptosis with or without deregulation or overexpression of CDC20. We found that the downregulation of CDC20 by siRNA or apcin suppressed cell proliferation, induced apoptosis, and triggered cell cycle arrest. Consistently, overexpression of CDC20 in normal cells promoted cell growth, inhibited apoptosis. What's more, the additional treatment with siCDC20 or Apcin achieved better anticancer effects than that of cisplatin alone. Furthermore, Bim and p21 were upregulated in OS cells following Apcin treatment. Altogether, the results of the present study demonstrated that targeting CDC20 could be useful for the treatment of OS, and might be a promising solution for the treatment of the OS with cisplatin insensitivity.

Power efficient LED placement algorithm for indoor visible light communication.

This paper proposes a novel power-efficient light-emitting diode (LED) placement algorithm for indoor visible light communication (VLC). In the considered model, the LEDs can be designedly placed for high power efficiency while satisfying the indoor communication and illumination requirements. This design problem is formulated as a power minimization problem under both communication and illumination level constraints. Due to the interactions among LEDs and the illumination uniformity constraint, the formulated problem is complex and non-convex. To solve the problem, we first transform the complex uniformity constraint into a series of linear constraints. Then an iterative algorithm is proposed to decouple the interactions among LEDs and transforms the original problem into a series of convex sub-problems. Then, we use Lagrange dual method to solve the sub-problem and obtain a convergent solution of the original problem. Simulation results show that the proposed LED placement algorithm can harvest 14% power consumption gain when compared with the baseline scheme with centrally placed LEDs.

Received signal strength assisted perspective-three-point algorithm for indoor visible light positioning.

In this paper, a received signal strength assisted perspective-three-point positioning algorithm (R-P3P) is proposed for visible light positioning (VLP) systems. Due to the directional propagation of visible light, the orientations of light-emitting diodes (LEDs) and receivers can affect the positioning accuracy seriously. To circumvent this challenge, R-P3P is proposed to mitigate the limitation on LEDs' and receiver's orientation in VLP systems. The basic idea of R-P3P is to jointly utilize visual and strength information to estimate the receiver position using 3 LEDs regardless of the orientations of LEDs and receivers. Simulation results show that R-P3P can achieve positioning accuracy within 10 cm over 70% of an indoor area with low complexity.

Computation Offloading in a Cognitive Vehicular Networks with Vehicular Cloud Computing and Remote Cloud Computing.

To satisfy the explosive growth of computation-intensive vehicular applications, we investigated the computation offloading problem in a cognitive vehicular networks (CVN). Specifically, in our scheme, the vehicular cloud computing (VCC)- and remote cloud computing (RCC)-enabled computation offloading were jointly considered. So far, extensive research has been conducted on RCC-based computation offloading, while the studies on VCC-based computation offloading are relatively rare. In fact, due to the dynamic and uncertainty of on-board resource, the VCC-based computation offloading is more challenging then the RCC one, especially under the vehicular scenario with expensive inter-vehicle communication or poor communication environment. To solve this problem, we propose to leverage the VCC's computation resource for computation offloading with a perception-exploitation way, which mainly comprise resource discovery and computation offloading two stages. In resource discovery stage, upon the action-observation history, a Long Short-Term Memory (LSTM) model is proposed to predict the on-board resource utilizing status at next time slot. Thereafter, based on the obtained computation resource distribution, a decentralized multi-agent Deep Reinforcement Learning (DRL) algorithm is proposed to solve the collaborative computation offloading with VCC and RCC. Last but not least, the proposed algorithms' effectiveness is verified with a host of numerical simulation results from different perspectives.

A Model-Based System for Real-Time Articulated Hand Tracking Using a Simple Data Glove and a Depth Camera.

Tracking detailed hand motion is a fundamental research topic in the area of human-computer interaction (HCI) and has been widely studied for decades. Existing solutions with single-model inputs either require tedious calibration, are expensive or lack sufficient robustness and accuracy due to occlusions. In this study, we present a real-time system to reconstruct the exact hand motion by iteratively fitting a triangular mesh model to the absolute measurement of hand from a depth camera under the robust restriction of a simple data glove. We redefine and simplify the function of the data glove to lighten its limitations, i.e., tedious calibration, cumbersome equipment, and hampering movement and keep our system lightweight. For accurate hand tracking, we introduce a new set of degrees of freedom (DoFs), a shape adjustment term for personalizing the triangular mesh model, and an adaptive collision term to prevent self-intersection. For efficiency, we extract a strong pose-space prior to the data glove to narrow the pose searching space. We also present a simplified approach for computing tracking correspondences without the loss of accuracy to reduce computation cost. Quantitative experiments show the comparable or increased accuracy of our system over the state-of-the-art with about 40% improvement in robustness. Besides, our system runs independent of Graphic Processing Unit (GPU) and reaches 40 frames per second (FPS) at about 25% Central Processing Unit (CPU) usage.

Correlations Between Hector Battifora Mesothelial-1 (HBME-1) Expression and Clinical Pathological Characteristics and Prognosis of Osteosarcoma Patients.

BACKGROUND The aim of this study was to investigate the correlation between Hector Battifora mesothelial-1 (HBME-1) expression and the clinical pathological characteristics and prognosis of osteosarcoma (OS). MATERIAL AND METHODS HBME-1 expression was assessed using immunohistochemistry in OS tissues (n=152), osteochondroma tissues (n=91), and normal bone tissues (n=74). We carried out a follow-up lasting 8-60 months to investigate HBME-1 expression and its correlations with the clinical pathological characteristics and prognosis of OS. RESULTS HBME-1 was highly expressed in OS tissues compared with osteochondroma tissues and normal bone tissues, and was highly expressed in osteochondroma tissues compared with normal bone tissues (all P<0.05). HBME-1 expression was correlated with clinical stages, postoperative recurrence, metastasis, and 5-year survival (all P<0.05). The area under the receiver operating characteristics curve of HBME-1 expression was 0.864, with sensitivity of 80.92%, specificity of 91.89%, and accuracy of 84.51%. The survival rate was lower in the HBME-1 positive expression group than the HBME-1 negative expression group (P<0.05). Clinical stages, metastasis, and HBME-1 expression were independent risk factors for the survival of patients with OS (all P<0.05). CONCLUSIONS HBME-1 expression was correlated with the occurrence and development of OS. HBME-1 positive expression was a risk factor for the prognosis of OS.

Serum Eosinophil Cationic Protein Is a Useful Marker for Assessing the Efficacy of Inhaled Corticosteroid Therapy in Children with Bronchial Asthma.

Bronchial asthma (BA) is a chronic inflammatory disorder of airways for which the effective therapies include inhaled corticosteroids (ICS) and short-acting ß2-adrenoreceptor agonist (SABA). Serum eosinophil cationic protein (ECP) has been reported to reflect the degree of airway inflammation. We, therefore, explored the implication of serum ECP in assessing the efficacy of ICS therapy in BA children. Our prospective randomized control study enrolled 126 BA children and 78 healthy children (the control group). The BA patients were randomly assigned as two groups; 59 children were treated with ICS, twice a day, for three months and 67 patients received SABA inhalation only if necessary. After the 3-month therapy, the serum levels of ECP, endothelin-1, and nitric oxide and the eosinophil percentage (EOS%) in induced sputum were significantly lower in the ICS group, compared with the SABA group, but were still higher than the control group (all P < 0.05). The forced expiratory volume (FEV1%pred) and forced vital capacity (FEV1/FVC) were improved to the levels of the control group after therapy. Pearson correlation analysis presented that higher serum ECP levels were associated with higher EOS% in serum and with lower pulmonary function indices (FEVl%pred and FEV1/FVC). Importantly, the ICS group exhibited higher quality of life scores and lower symptom scores compared with the SABA group (all P < 0.05). ROC results revealed the diagnostic efficiency of serum ECP levels on the efficacy of ICS. In conclusion, measuring serum ECP levels is helpful for assessing the efficacy of ICS therapy in BA children.

Spatial dimming scheme for optical OFDM based visible light communication.

A new dimming control scheme termed spatial dimming orthogonal frequency division multiplexing (SD-OFDM) is proposed for multiple-input and multiple output OFDM based visible light communication. The basic idea of SD-OFDM is that the illumination can be represented by the number of glared light emitting diodes (LEDs) in an LED lamp. As the biasing level of LEDs does not adjust to represent the required illumination level, the proposed scheme can significantly mitigate the clipping noise compared to analogue dimming schemes. Furthermore, unlike digital dimming schemes that control illumination levels by setting different duty cycles of pulse width modulation, the proposed scheme is always in the "on-state" for varied illumination levels. Both analytical and simulation results indicate that the proposed scheme is an efficient and feasible dimmable scheme.

Lightweight 3D Lithiophilic Graphene Aerogel Current Collectors for Lithium Metal Anodes.

Constructing three-dimensional (3D) current collectors is an effective strategy to solve the hindrance of the development of lithium metal anodes (LMAs). However, the excessive mass of the metallic scaffold structure leads to a decrease in energy density. Herein, lithiophilic graphene aerogels comprising reduced graphene oxide aerogels and silver nanowires (rGO-AgNW) are synthesized through chemical reduction and freeze-drying techniques. The rGO aerogels with large specific surface areas effectively mitigate local current density and delay the formation of lithium dendrites, and the lithiophilic silver nanowires can provide sites for the uniform deposition of lithium. The rGO-AgNW/Li symmetric cell presents a stable cycle of about 2000 h at 1 mA cm-2. When coupled with the LiFePO4 cathode, the assembled full cells exhibit outstanding cycle stability and rate performance. Lightweight rGO-AgNW aerogels, as the host for lithium metal, can significantly improve the energy density of lithium metal anodes.