Experimental demonstration of SCMA for visible light communications

We propose an experimental demonstration of sparse code multiple access (SCMA) based visible light communications (VLC) system, in which the multi-dimensional codewords selected from a predefined codebook set are used to encode the transmitted data and a message passing algorithm (MPA) based multi-user receiver is used to detect the multiplexed codewords. Compared with the orthogonal frequency-division multiple access scheme, the SCMA scheme offers 150% overloading gain in the number of supported users at the cost of slightly decreased transmission performance

Experimental Demonstration of an Indoor VLC Positioning System Based on OFDMA

We propose an indoor visible light communication (VLC) and positioning system using the orthogonal frequency division multiplexing access (OFDMA) scheme, which can provide both indoor positioning and communications. Three subcarriers with the maximum received signal intensity with respect to three light-emitting diodes (LEDs) are selected for indoor positioning based on the trilateration algorithm. The experiment results show that the proposed system with quadrature phase shift keying (QPSK) mapping offers a mean positioning error and an error vector magnitude of 1.68 cm and more than 15 dB, respectively

KINEMATICS ANALYSIS OF THE UPPER EXTREMITY DURING THE TWOHANDED BACKHAND DRIVE VOLLEY FOR FEMALE TENNIS PLAYERS

The purpose of this study was to discuss the motion characteristics of the arms in the two-handed backhand drive volley. Five elite female tennis players participated in this study, their two-handed backhand drive volley strokes were analysed, and all participants are right handed. Motion Analysis System with 10 Eagle Digital inferred high speed cameras at 200Hz were used for this study. The results show a similar elbow and wrist speed strategy in x-axis between two-handed ground stroke and drive volley, our study also found that the rear arm dominates the stroke and mainly provide the topspin that is required for the skill of the drive volley. In order to create better stroke efficiency, the right elbow reached peak velocity first, followed by the right wrist before racket impact with the ball

Experimental demonstration of PAM-DWMT for passive optical network

We experimentally demonstrate a discrete wavelet multitone (DWMT) modulation scheme based on pulse amplitude modulation (PAM) for next generation passive optical network (PON), which offers high tolerance against chromatic dispersion, high spectral efficiency, low peak to average power ratio (PAPR) and low side lobes. The experimental results show the chromatic dispersion induced power penalties are negligible after 20km fiber transmission. Compared with orthogonal frequency division multiplexing (OFDM), DWMT offers a better receiver sensitivity

Bridging the Digital Divide: A Case Study of Middle-age Women in Taiwan

This article reports a study of how middle-age and elder women adopt ICT through the social intervention and support from the non-profit organizations (NPOs) which they are associated with. By interviewing 30 participants of the Taiwan Women Up project, we reveal the barriers that may hinder women from learning ICT and the forces which can facilitate women in their adoption of ICT at three levels: individual, family and social group. Our findings show that, for our participants who are middle-class housewives over 40, their bonding with the NPOs serves as the main force for them to join the Taiwan Women Up project and adopt ICT. When ICT related difficulty occurs, they approach to the members of the NPOs and receive support from them while their families turn them down initially. After this project, the participants develop confidence and, accordingly, the digital divide is narrowed. Yet, there is little sign that any change of the traditional gender role has occurred

Experimental demonstration of IDMA-OFDM for passive optical network

We present interleave division multiple access (IDMA) scheme combined with orthogonal frequency division multiplexing (OFDM) for passive optical network, which offers improved transmission performance and good chromatic dispersion tolerance. The interleavers are employed to separate different users and the generated chips are modulated on OFDM subcarriers. The feasibility of IDMA-OFDM-PON is experimentally verified with a bitrate of 3.3 Gb/s per user. Compared with OFDMA, IDMA-OFDM offers 8 and 6 dB gains in term of receiver sensitivity in the cases of 2 and 4 users, respectively

Experimental Demonstration of OFDM/OQAM Transmission for Visible Light Communications

We propose a modified orthogonal frequency division multiplexing/offset quadrature amplitude modulation (OFDM/OQAM) scheme for visible light communications (VLC). The OFDM/OQAM VLC system can efficiently boost the data rate, and combat multipath induced the inter symbol interference (ISI) and inter carrier interference (ICI). To combat the effect of intrinsic imaginary interference, intrasymbol frequency-domain averaging and minimum mean squared error (MMSE), combined with interference approximation method, are proposed. The experiment results show that the proposed system offers similar bit error rate performance to that of OFDM, while the bit rate is increased by 9% for the elimination of cyclic-prefix and guard band

One-step metallization of weft-knitted fabrics for wearable biaxial strain sensors

One-step direct patterning of high definition conductive tracks in textiles is realized through laser direct writing in combination with a silver organometallic ink developed in-house. Photoreduction, nano-crystallization, and sintering are accomplished in one pass under the irradiation of a CW green laser light (λ = 532 nm) at moderate intensities (I ≥ 95 mW/mm(2)). By tailoring the surface tension and viscosity of the ink, high-definition conductive tracks are formed in weft-knitted polyester-Spandex composite fabrics, well-following the laser’s profile with negligible coffee stain effect. Length resistance as low as 4 Ω/cm is measured and anisotropy of the gauge factor as high as 25 is achieved. The metallized fabric exhibits reversible and hysteresis-free electromechanical responses subject to high strains. Durability assessment qualifies that the as-metallized strain sensors are able to sustain their performance for over 5000 stretch/release cycles, demonstrating its potential applications in biaxial strain sensing and interactive smart textiles

CCN2 Enhances Resistance to Cisplatin-Mediating Cell Apoptosis in Human Osteosarcoma

Osteosarcoma (OS) is the most common form of malignant bone tumor and is an aggressive malignant neoplasm exhibiting osteoblastic differentiation. Cisplatin is one of the most efficacious antitumor drugs for osteosarcoma patients. However, treatment failures are common due to the development of chemoresistance. CCN2 (also known as CTGF), is a secreted protein that binds to integrins, modulates the invasive behavior of certain human cancer cells. However, the effect of CCN2 in cisplatin-mediated chemotherapy is still unknown. Here, we found that CCN2 was upregulated in human osteosarcoma cells after treatment with cisplatin. Moreover, overexpression of CCN2 increased the resistance to cisplatin-mediated cell apoptosis. In contrast, reduction of CCN2 by CCN2 shRNA promoted the chemotherapeutic effect of cisplatin. We also found that CCN2 provided resistance to cisplatin-induced apoptosis through upregulation of Bcl-xL and survivin. Knockdown of Bcl-xL or survivin removed the CCN2-mediated resistance to apoptosis induced by cisplatin. On the other hand, CCN2 also promoted FAK, MEK, and ERK survival signaling pathways to enhance tumor survival during cisplatin treatment. In a mouse xenograft model, overexpression of CCN2 promoted resistance to cisplatin. However, knockdown of CCN2 increased the therapeutic effect of cisplatin. Therefore, our data suggest that CCN2 might be a critical oncogene of human osteosarcoma for cisplatin-resistance and supported osteosarcoma cell growth in vivo and in vitro