The aim of this study is to analyze the use of different media channels occurred within a natural disaster situation. This research focuses specifically on charting the factors that affect audiences in their choice of media channels and how these factors ultimately lead to the complimentarily use of sources. This study is based on channel complementarity theory and utilizes a qualitative method consisting of semi-structured interviews and has been complemented with a survey that respondents were required to complete prior to the interview. The twelve college students that made up the sample for this study were selected through convenient and purposive means and have personally been involved in natural disaster situations without exception. Final results and analysis suggest that individuals utilize several media channels combined, at different points in time or simultaneously, and in random order during a natural disaster. The analysis of the results also shows that individuals use this variety of media channels in order to obtain two different perspectives: broad and narrow. Traditional media channels such as radio and television are shown to be used in order to obtain the broader perspective during a natural disaster event. In contrast, social media like Instagram, Facebook, and Snapchat are used to gain the narrower perspective. The findings of this study also suggest that factors affecting media choices are accentuated by a crisis such as a natural disaster and are intrinsically connected to specific needs audiences have at one particular point in time. The most relevant factors contributing to the choice of media type and leading to channel complementarity found in this study are accessibility, compatibility of sources, tailorability, and humor appeal. Controversially, credibility appears to be disregarded as a key factor, even though it is still perceived as an influential characteristic.

The mineralocorticoid hormone, aldosterone, classically acts via the Mineralocorticoid Receptor (MR) to promote sodium transport in aldosterone target tissues, such as the kidney, thereby controlling long-term electrolyte homeostasis and blood pressure (BP). Aldosterone biosynthesis by the adrenal gland is regulated by a negative feedback loop called the Renin Angiotensin Aldosterone System (RAAS). The glucocorticoid cortisol (corticosterone in rodents), which has a very similar structure to aldosterone, shares with aldosterone an equal affinity for the MR. Typically, plasma cortisol levels are approximately 1000-fold higher than plasma aldosterone, and so the ligand specificity for aldosterone must be imposed on MR by other, non-structural, means. This specificity is important in order to retain electrolyte and BP balance within the control of the RAAS. The co-localisation of the enzyme 11β-Hydroxysteroid Dehydrogenase Type 2 (11β-HSD2) with the MR in aldosterone target tissues provides the MR with the aldosterone specificity it inherently lacks. 11β-HSD2 achieves this by converting active cortisol to its inactive 11-keto metabolite, cortisone (dehydrocorticosterone in rodents). In humans with the monogenetic Syndrome of Apparent Mineralocorticoid Excess (SAME), inactivating mutations in the HSD11B2 gene allows cortisol unregulated access to the MR. Resultant symptoms include severe hypertension and life-threatening hypokalemia. Individuals heterozygous for SAME display no overt phenotypes. However, some studies have associated SAME heterozygosity and loss-of-function polymorphisms within the HSD11B2 gene with essential and/or salt-sensitive hypertension in the general population. Targeted disruption of the Hsd11b2 gene in mice (Hsd11b2-/-) faithfully reproduces with all the major phenotypes of SAME patients. Mice heterozygote for the targeted gene (Hsd11b2+/-) have no phenotype and display a normal BP. In the present study, Hsd11b2+/- mice were used to explore the relationship between reduced 11β-HSD2 enzyme activity and salt-sensitive hypertension. On a high salt diet, Hsd11b2+/- mice were found to have increased BP and impaired natriuresis, compared to wild-type controls (Hsd11b2+/+). Further studies used pharmacological blockade of the Epithelial Sodium Channel (ENaC) and MR to ascertain the contributions of these pathways towards the observed phenotypes. These identified a deregulation of ENaC activity pertaining to an inability to regulate sodium appropriately. Investigations into the contributions of the RAAS and the Hypothalamus Pituitary Adrenal (HPA) axis have revealed valuable insights into their roles in this model. There is an implication that the RAAS has increased sensitivity in Hsd11b2+/-, further exacerbated by increased dietary sodium, and that the regulation of corticosteroids may also be altered. Novel observations have suggested that oxidative stress in response to a high salt diet could also be involved, as a study administering an antioxidant drug in conjunction with a high salt diet prevented the manifestation of a phenotype in Hsd11b2+/-. Finally, the generation of a floxed Hsd11b2 targeting construct for tissue-specific deletion of 11β-HSD2 will allow future studies into the contributions of specific 11β-HSD2 expression sites (such as the kidney) towards the phenotypes of both homozygous and heterozygous mice.

This study aims to map out how small designintensive businesses combine multiple channels to achieve competitive advantage. The internet has provided retailers with a competing channel and while this can be a source of competitive advantage, it also provides the risk of cannibalization. More and more businesses choose to apply a multi-channel strategy, but there are decisions to be made concerning this strategy as both advantages and disadvantages are to be found in a multi-channel strategy. This study is performed with a qualitative approach via semi-structured interviews with four companies applying a multi-channel strategy, exploring the perspective of the businesses. In contrast to previous research, results show that businesses tend to view a second sales channel mainly as a way of expanding the service offered in their primary sales channel. Further conclusions that can be drawn are that an integrated organizational structure and complementing channels are being used and are creating synergies. A unified view of the channels is communicated and consumers are encouraged to combine channels at a purchase. The channels are also used as tools for marketing each other. / Denna studie syftar till att kartlägga hur designintensiva småföretag kombinerar flera olika försäljningskanaler för att uppnå konkurrensfördelar. Internet har försett återförsäljare med en konkurrerande kanal till den fysiska butiken, vilket kan ge konkurrensfördelar men medför även en risk för kannibalisering kanalerna emellan. Fler och fler företag väljer nu att använda sig av en flerkanalstrategi, men vissa avväganden måste göras då både för- och nackdelar finns med implementering av en flerkanalstrategi. Studien har genomförts med en kvalitativ ansats genom semi-strukturerade intervjuer då författarna ämnar att undersöka flerkanalåterförsäljarnas egna perspektiv. I kontrast till tidigare studier visar resultaten att företagen tenderar att betrakta en andra försäljningskanal främst som ett sätt att utöka den service de erbjuder i sin primära kanal. Ytterligare slutsatser som framkommit är att en integrerad organisationsstruktur och kanaler som kompletterar varandra används och upplevs skapa synergier hos företagen. Fortsatt kommuniceras en enhetlig bild mellan kanalerna och konsumenter uppmuntras kombinera kanalerna vid köp. Kanalerna används även som marknadsföring för varandra.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This project investigates the feasibility of position detection in an office or industrial setting. The objective is to design a low-cost positioning system that uses the unlicensed 5.7 GHz ISM band, with centimeter accuracy and limited range. During the conceptual design phase of the system, indoor channel models will be investigated to determine which of a variety of architectures will be useful. For triangulating the position, an array of widely spaced stationary receivers and a mobile transmitter is proposed.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / Combating harsh and unpredictable channel environments is a part of the design of any in-situ communication system (i.e. rover to lander, rover to orbiter, etc.). Channel characteristics can range from simple additive white Gaussian noise (AWGN) channels to more bursty fading channels found in rover to orbiter links (i.e. canyon scenarios and typical orbiter passes around mountain ranges). A combination of forward error correction and automatic repeat request (ARQ) schemes are commonly used to provide a more robust communications link. ARQ enhances the communication link particularly for bursty fading channels. Go-Back-N is a commonly used ARQ scheme and is an option in the newly developed Consultative Committee for Space Data Systems (CCSDS) Proximity-1 Link protocol [7], a data link layer protocol targeted specifically for in-situ applications. Optimization of frame sizes and retransmission persistence of the ARQ scheme require a good analytical model of how the scheme performs over various channel conditions. In this paper, an analytical framework for modeling the COP-1 protocol is presented for both AWGN channels along with bursty fading channels. A Gilbert-Elliot two-state Markov model is used to model a bursty fading channel.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Low-Density Parity-Check (LDPC) codes are powerful codes capable of nearly achieving the Shannon channel capacity. This paper presents a tutorial introduction to LDPC codes, with a detailed description of the decoding algorithm. The algorithm propagates information about bit and check probabilities through a tree obtained from the Tanner graph for the code. This paper may be useful as a supplement in a course on error-control coding or digital communication.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Telemetry for Earth-Observation missions is characterized by very high data rates and stringent requirements. Channel codes both power and bandwidth efficient must be used to improve downlink performance and to achieve the very low values of error rates needed at the received side. In this paper, we review and analyzed three codes of possible interest for these applications: turbo codes, serial turbo codes and product codes. These schemes are evaluated and compared both by simulation and analytical techniques. A particular attention is devoted to complexity, a key issue for practical implementation at high data rates.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Dynamic hardware and software schemes for trajectory based simulation of LEO satellite channel are presented and evaluated. The simulation models are based on the practical LEO satellite channels and change dynamically with the trajectory using the latitude and longitude of the LEO satellite as input. The hardware simulator is consisted of a trajectory based selective fade generator, a trajectory based Doppler shifter, trajectory based time shadowing simulator and a standard channel for addition of noise, ACI and CCI. A FQPSK modulated signal is passed through a trajectory based dynamic fade generator and the spectrum is distorted. Then the resulting signal is exposed to a trajectory based dynamic Doppler Shifter, simulating the passage of the satellite overhead. Then the proper AWGN, ACI or CCI is added to the signal. At the final stage the signal is passed through a trajectory based time Shadowing simulator. The software simulator is a dynamic real time simulator written in MatLab and its structure is similar to the hardware simulator.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Advancing technology continually generates larger quantities of data at increasingly high transfer rates which fuels the need for instrumentation to take up the challenge of efficiently managing the collection of data. This defines the driving force behind the desire for increased channel capacity of PCM data formatters. By incorporating state-of-the-art Digital Signal Processing (DSP) technology coupled with high-performance Field Programmable Gate Arrays (FPGA), Inter-Coastal Electronics has designed the IF-810, a PCM data formatter. The IF-810 allows eight channels of PCM data, one voice channel and an InterRange Instrumentation Group (IRIG)-B channel to be combined and formatted for recording onto the TEAC RX-800 series recorders using a Hi8 8mm video cassette as the recording media. During playback, the IF-810 clocks the PCM data out using a reconstructed version of the input clock. With this unique design, the PCM data and clock outputs are input directly to a decommutator which eliminates the need for costly bit-synchronizers. This paper discusses the integration of the DSP, FPGA and buffering techniques into a low-cost and efficient multi-channel PCM data formatter that accommodates high data rate inputs, all without the need of a bit-synchronizer for decommutation.

Digital Wireless communications has been one of the fastest growing communication techniques during the last decade. Today there exists several different communication systems that use wireless techniques. They share one common property that they transmit data through a radio interface. The radio channel is a tough channel that will both distort and disturb the transmitted signal in various ways. In Jörgen Nordberg's PhD-thesis "Signal Enhancement in Wireless Communications Systems" several different signal enhancement schemes are presented. They have the objective to minimize the impact of the channel. The main part of this thesis presents work on interference cancellation, i.e. how to reduce the impact of other interfering signals on the channel of interest. This is achieved by utilizing the spatial domain, i.e. the receiver is using several antennas to receive the transmitted signals. By using a multitude of antennas techniques like spatial diversity, adaptive antenna arrays, signal separation and beamforming can be applied to combat the interfering signals. In the single antenna case there is often a need to do channel equalization. Since, channel equalization is an inverse filtering, it will often result in estimation of equalization filter parameters of very high order. To reduce the both the complexity and improve the convergence speed of the equalization filter parameter estimation subband processing techniques can be used. In this case the received signal is separated up into different frequency bands (subbands) and decimated according to the bandwidth of the signal. The channel equalization problem is then solved for each subband at a lower sampling rate. Hence, the channel equalization problem is transformed from estimating the parameters of a high order filter into estimating several filter of much lower order. / Ett av områdena inom telekommunikation som har ökat mest de senaste åren är radio kommunikation. Det finns många olika varianter av trådlösa radio system, men de har alla en sak gemensamt, de överför information/data via ett radiogränssnitt. Signaler som sänds över en radiokanal kommer på grund av många olika anledningar att bli störda eller distorderade. I Jörgen Nordbergs doktorsavhandling ?Signal Enhancement in Wireless Communication Systems? presenteras flera metoder för att förbättra kvaliten i de mottagna signalerna vilket ger betydande kvalitetsförbättring. Huvuddelen av denna doktorsavhandling behandlar interferensundertrycking, d.v.s. hur man undertrycker oönskad störning på den egna radiokanalen. Dessa metoder är baserade på användning av flera antenner i mottagaren. Genom att ta emot signalerna med flera antenner så kan metoder såsom diversitetskombinering, adaptiva antenner, lobformning, signal separation användas för att förbättra kvaliteten i den mottagna signalen. Om mottagaren har en antenn så behövs oftast kanalutjämning för att förbättra den mottagna signalen och undertrycka intersymbolinterferens. Eftersom kanalutjämning är en typ av inversfiltrering leder detta ofta till estimering av filterparametrar av hög ordning. Estimeringsproblem av hög ordning leder ofta till komplexitetsproblem och konvergensproblem hos estimerings algoritmen. För att motverka dessa problem så presenteras i denna avhandling en kanalutjämnare som är baserad på subbandsteknik. I denna kanalutjämnare så delas den mottagna signalen upp i flera frekvensband (subband) som decimeras till en takt som motsvarar subbandets bandbredd varefter filterparametrarna estimeras i denna lägre takt. Därvid har estimeringsproblemet delats upp i flera små problem som kan hanteras enklare.