Applying uses and gratifications theory (UGT) and social capital theory, our study examined users of four social networking sites (SNSs) (Facebook, Twitter, Instagram, and Snapchat), and their ...influence on online bridging and bonding social capital. Results (N = 297) found that Twitter users had the highest bridging social capital, followed by Instagram, Facebook, and Snapchat, while Snapchat users had the highest bonding social capital, followed by Facebook, Instagram, and Twitter. SNS intensity, trust, tie strength, homophily, privacy concerns, introversion, and attention to social comparison were also found to moderate the relationship between SNS use and online bridging and bonding social capital.
•Uses and gratification theory (UGT) was applied to explain social networking site usage.•Facebook, Twitter, Instagram, and Snapchat influence bridging/bonding social capital.•SNS intensity, tie strength, privacy, introversion, and social comparison are moderators.
A wideband and low-power distributed cascode mixer is implemented for future mobile communications. The distributed design inspired by the distributed amplifier (DA) enables a mixer to operate in a ...wide band. In addition, the cascode structure and inductive positive feedback design allow high conversion gain with low-power consumption. The proposed mixer is fabricated using a 130 nm commercial complementary metal-oxide-semiconductor (CMOS) process. It consists of three cascode gain cells and operates with a drain voltage of 1.5 V and a gate voltage of 0.5 to 0.7 V. The fabricated mixer exhibits conversion gain of -2.9 to 3.1 dB at the radio frequencies (RFs) of 4 to 30 GHz and -1.9 to 0.4 dB at RFs of 54 to 66 GHz under the conditions of 8 to 10 dBm of local oscillator (LO) power and 650 MHz of intermediate frequency (IF). The LO-RF isolation is more than 15 dB over the entire measurement band (0.2 to 67 GHz) as the RF and LO signals are applied to different transistors owing to the cascode structure. The total power consumption is only within 12 mW, and the chip size is 0.056 mm
, making it possible to implement a compact mixer. The proposed mixer shows broadband characteristics covering from ultra-wideband (UWB) and the 28 GHz fifth-generation (5G) communication band to the 60 GHz wireless gigabit alliance (WiGig) band.
To date, various nanomaterials with the ability for gene delivery or photothermal effect have been developed in the field of biomedicine. The therapeutic potential of these nanomaterials has raised ...considerable interests in their use in potential next-generation strategies for effective anticancer therapy. In particular, the advancement of novel nanomedicines utilizing both therapeutic strategies of gene delivery and photothermal effect has generated much optimism regarding the imminent development of effective and successful cancer treatments. In this review, we discuss current research progress with regard to combined gene and photothermal therapy. This review focuses on synergistic therapeutic systems combining gene regulation and photothermal ablation as well as logically designed nano-carriers aimed at enhancing the delivery efficiency of therapeutic genes using the photothermal effect. The examples detailed in this review provide insight to further our understanding of combinatorial gene and photothermal therapy, thus paving the way for the design of promising nanomedicines.
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•Snapchat is used for passing time, sharing problems, and social knowledge.•Instagram is used for showing affection, following fashion, and sociability.•Twitter users had highest brand community ...identification and membership intention.•Instagram users had highest brand community engagement and commitment.•Social comparison, trust, tie strength, and network homophily are moderators.
Applying uses and gratifications theory (UGT), this study examined consumers’ use of one of four social networking sites (SNSs): Facebook, Twitter, Instagram, or Snapchat, for following brands, and their influence on brand community-related outcomes. Results (N=297) indicated Snapchat users scored highest for passing time, sharing problems, and improving social knowledge, while Instagram users scored highest for showing affection, following fashion, and demonstrating sociability. Twitter users had highest brand community identification and membership intention, while Instagram users had highest brand community engagement and commitment. Attention to social comparison, SNS trust, tie strength, and homophily also significantly moderated the relationship between frequent use of each SNS to follow brands, and brand community-related outcomes. Implications for future research on SNS users’ goal-directed consumption behaviors are discussed.
•Effects of self-endorsed Snapchat geofilter ads on brand outcomes were assessed.•Self-brand congruity significantly affected brand attitude and purchase intention.•Self-referencing significantly ...affected brand attitude and purchase intention.•Perceived humor significantly affected brand attitude and purchase intention.•Self-brand congruity, self-referencing and humor interacted to affect brand outcomes.
Snapchat geofilter advertisements use augmented reality (AR) technology to place consumers in photographs embellished with branded content. This study examined the joint influence of self-brand congruity, self-referencing and perceived humor in these self-endorsed geofilter brand advertisements on consumers’ brand-related preferences. Results revealed that self-brand congruity, self-referencing and perceived humor exerted significant main effects on consumers’ post-use brand attitude and purchase intention. Self-brand congruity also significantly interacted with self-referencing and perceived humor to affect brand attitude and purchase intention, while self-referencing significantly interacted with perceived humor to affect purchase intention, but not brand attitude. Theoretical and managerial implications of the research are discussed.
A new gallium nitride (GaN) high electron mobile transistor (HEMT) small-signal model is proposed considering source via effects. In general, GaN HEMTs adopt a source via structure to reduce device ...degradation due to self-heating. In this paper, the modified drain-source capacitance (Cds) circuit considering the source via structure is proposed. GaN HEMTs fabricated using a commercial 0.15 μm GaN HEMT process are measured with a 67 GHz vector network analyzer (VNA). The fabricated device is an individual source via (ISV) type. As a result, it is difficult to predict the measured S12 in the conventional small-signal model equivalent circuit. This causes errors in maximum stable gain/maximum available gain (MSG/MAG) and stability factor (K), which are important for circuit design. This paper proposes a small-signal equivalent circuit that adds the drain-source inductance to the drain-source capacitance considering the source via structure. The proposed equivalent circuit better reproduces the measured S12 without compromising the accuracy of other S-parameters up to 67 GHz and improves the accuracy of MSG/MAG and K. It is expected that the proposed model can be utilized in a large-signal model for 5G millimeter-wave GaN HEMT power amplifier design in the future.
With the advancement of electronic devices, the generation of heat and electromagnetic (EM) waves has increased. Therefore, it is essential to properly manage these heat and EM waves, while ensuring ...the flame retardancy and mechanical properties of the materials used in these devices. In this study, to compensate for the low thermal and electrical conductivity of Poly(p-phenylene-2,6-benzobisoxazole) (PBO), which was used as the matrix, reduced graphene oxide aerogel (rGOA) with high electrical conductivity and electromagnetic interference shielding effectiveness (EMI SE) performance and boron nitride (BN) with high thermal conductivity were selected as fillers (rGOA/BN). To significantly improve the compatibility of the filler with the matrix, PBO fiber was grafted onto the rGOA/BN filler. The fabricated composites exhibited high electrical conductivity of 21.1 S/cm and thermal conductivity of 4.81 W/m∙K, and the EMI SE and tensile strength were improved to up to 78.42 dB and 201.8 MPa, respectively.
This article proposes a modified nonuniform distributed power amplifier (NDPA) design to increase the output power and power-added efficiency (PAE) in wideband. In the proposed NDPA, drain-line ...impedances are recalculated, including the drain-source capacitances, which cannot be ignored as the transistor size becomes larger at high frequencies. In addition, instead of using a large-sized transistor in the first section of the NDPA, the design proposes a method of halving the characteristic impedance by doubling the phase of the drain line. When compared with the conventional NDPA, the modified NDPA shows the power gain and output power characteristics close to those of the ideal NDPA. To obtain high efficiency in the NDPA, a programmable gate-line termination resistance switching technique (PGT) is proposed. The power gain is increased by using the standing wave generated from the mismatched termination, enhancing the PAE. For design verification, two modified NDPA monolithic microwave integrated circuits (MMICs) were fabricated using a commercial 0.25-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> gallium nitride (GaN) high-electron-mobility transistor (HEMT) process. The two-way power-combined NDPA shows an average output power of 20 W or more and a power density of 1.9 W/mm 2 from 6 to 18 GHz. The NDPA using the proposed PGT accomplishes an average output power of 10 W and an average PAE of 20% or more from 6 to 18 GHz.
Based on a nuanced understanding of immersion and sense of presence (SoP) as two key aesthetic effects that the application of virtual reality (VR) to cinema is believed to innovate, this paper ...develops the concept of synthetic vision as fundamental to understanding the visual experience of VR media, particularly VR documentaries. The concept contends that viewers’ experience in VR is based on two visions that seemingly contradict each other: first, a disembodied vision that transports them to a simulated world, and second, an embodied vision guaranteed by the freedom to control kinesthetic movement and direction of gaze. This serves to advance the idea that immersion and SoP are not unified but rather multifaceted concepts premised on a nuanced understanding of the varying relationships between the technological system of VR, its media content, and its user. For the concept of synthetic vision points to the paradoxical coexistence of viewers’ presence in the virtual world and their structural absence from the world that lays the groundwork for their immersive experience. By classifying three generic categories of contemporary VR documentaries (humanitarian and journalism documentaries, documentaries about nature, travel, and museum visits, and documentaries based on the reenactment of conscious or mnemonic realities), and by examining the aesthetic and ethical underpinnings VR brings to each of them, I argue that it hinges upon what kind of cinematic conventions and genres are remediated to determine the effective synthesis of the two visions. The varying effects of synthetic vision in the three subgenres of VR documentary stress that immersion and SoP have different political and ethical consequences of media witnessing. In the conclusion, I recapitulate multiple implications that the concept of synthetic vision has in regards to both the studies on VR and the recently flourishing investigation into cinematic VR artifacts.
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