Online reputation management: estimating the impact of management responses on consumer reviews

We investigate the relationship between a firm’s use of management responses and its online reputation. We focus on the hotel industry and present several findings. First, hotels are likely to start responding following a negative shock to their ratings. Second, hotels respond to positive, negative, and neutral reviews at roughly the same rate. Third, by exploiting variation in the rate with which hotels respond on different review platforms and variation in the likelihood with which consumers are exposed to management responses, we find a 0.12-star increase in ratings and a 12% increase in review volume for responding hotels. Interestingly, when hotels start responding, they receive fewer but longer negative reviews. To explain this finding, we argue that unsatisfied consumers become less likely to leave short indefensible reviews when hotels are likely to scrutinize them. Our results highlight an interesting trade-off for managers considering responding: fewer negative ratings at the cost of longer and more detailed negative feedback.Accepted manuscrip

Hollow core large mode area fibre employing a subwavelength grating reflector

Hollow core large mode area fibres are ideal candidates to guide light at high powers while avoiding non-linear effects and, as such, they are generating much scientific interest. A variety of fibres have been investigated, including tube lattice photonic bandgap fibres and Kagomé-latticed photonic crystal fibres. One of the major challenges in obtaining low loss hollow core fibres is related to the unavoidable perturbations induced by the coupling between the core and cladding modes which is responsible for the increase of leakage loss. Recent approach based on the insertion of additional antiresonant elements demonstrates the significance of fibre geometrical parameters and shows leakage loss of an order of ~10-4 dB/m. In this paper, we present preliminary results of a novel approach to fibres that guide light in a large hollow core, starting from the high index contrast grating reflector platform. Subwavelength gratings have been used to achieve broadband mirrors with reflectivity greater than 99%. Importantly, the physical dimensions of the grating must be smaller than the wavelength of incident light, which implies that the diffraction order of interest is 0th. Under a surface normal incidence on diffraction grating, evanescent orders in the direction parallel to the grating period overlap with the leaky mode of the grating leading to the effect of guided mode resonance and a destructive interference effect between the two grating modes, which results in high reflection

Bragg grating design method for the implementation of an optimised symmetric add/drop multiplexer

An efficient and simple method is proposed for the design of a novel Bragg grating based optical add/drop multiplexer. Central to this method is the existence of generic engineering curves that relate for any BG of a specific apodization profile, its penetration slope α = Lp/Lg to its reflectivity. The implemented by this method, interferometric device based on a full-cycle waveguide coupler exhibits symmetric and simultaneously optimised add/drop responses, of zero loss

Children's preferences in types of assignments

Thesis (Ed.M.)--Boston Universit

Short-wavelength transmission-loss suppression in fibre Bragg gratings

Fibre Bragg Gratings (FBGs) are known to suffer from short-wavelength, transmission losses due to resonant coupling into backward-propagating cladding modes. Figure 1 shows a typical transmission spectrum of a 10cm standard FBG. The cladding mode losses increase with grating reflectivity and could eventually impose severe limitations in the use of FBGs. The problem can be quite acute in the case that FBG wavelength-multiplexing is required. So far, several attempts have been made to eliminate the short-wavelength, transmission losses and improve grating performance. In all cases, the resonant coupling of the forward-propagating core mode to the backward-propagating cladding modes is minimised by reducing the coupling strength. In this paper, we report on a novel method for reducing cladding-mode transmission losses in standard FBGs. We show that short-wavelength, transmission losses can be practically eliminated by damping the resonant excitation of the cladding modes. The damping is achieved by properly introducing a substantial propagation loss into the cladding modes. For maximum effect, the core mode should experience no extra propagation losses. By applying a thin lossy layer on the fibre cladding surface, a reduction of cladding-mode-losses of about 12dB was achieved

Extending snBench to Support Hierarchical and Configurable Scheduling

It is useful in systems that must support multiple applications with various temporal requirements to allow application-specific policies to manage resources accordingly. However, there is a tension between this goal and the desire to control and police possibly malicious programs. The Java-based Sensor Execution Environment (SXE) in snBench presents a situation where such considerations add value to the system. Multiple applications can be run by multiple users with varied temporal requirements, some Real-Time and others best effort. This paper outlines and documents an implementation of a hierarchical and configurable scheduling system with which different applications can be executed using application-specific scheduling policies. Concurrently the system administrator can define fairness policies between applications that are imposed upon the system. Additionally, to ensure forward progress of system execution in the face of malicious or malformed user programs, an infrastructure for execution using multiple threads is described

The rise of the sharing economy: estimating the impact of Airbnb on the hotel industry

Peer-to-peer markets, collectively known as the sharing economy, have emerged as alternative suppliers of goods and services traditionally provided by long-established industries. We explore the economic impact of the sharing economy on incumbent firms by studying the case of Airbnb, a prominent platform for short-term accommodations. We analyze Airbnb's entry into the state of Texas, and quantify its impact on the Texas hotel industry over the subsequent decade. We estimate that in Austin, where Airbnb supply is highest, the causal impact on hotel revenue is in the 8-10% range; moreover, the impact is non-uniform, with lower-priced hotels and those hotels not catering to business travelers being the most affected. The impact manifests itself primarily through less aggressive hotel room pricing, an impact that benefits all consumers, not just participants in the sharing economy. The price response is especially pronounced during periods of peak demand, such as SXSW, and is due to a differentiating feature of peer-to-peer platforms -- enabling instantaneous supply to scale to meet demand.Accepted manuscrip

Effects of high temperature and pressure on silica optical fibre sensors

We report on the effects of liquids at high temperature and pressure on silica optical fibres, sensors and gratings. We propose that the diffusion of molecules into the silica and the resultant expansion of the network are responsible for observed fibre expansions of up to 0.2% and Bragg wavelength increases of 2nm at 1525nm. Amorphous carbon hermetic coating has shown a reduction of these effects by an order of magnitude at 300°C. These results have strong implications for the deployment of fibre sensors in oil wells