Alternative Positioning Research Articles

The “indie” premium: how independent firms create product value across cultures

PurposeAlthough firm growth through the acquisition of independent players is at a record high, market reports reveal a parallel increase in independent firms that enjoy noticeable consumer support across industries and threaten MNC-owned brands in several countries. Despite this evident contrast, no research has investigated how independent firms stack up against their non-independent counterparts from a consumer perspective. This study examines this standoff and proposes that independent firms outperform their non-independent contenders in fostering perceptions of product craftmanship and warmth in specific product categories and cultures.Design/methodology/approachThree experimental studies were conducted across five countries (Study 1: N = 360; USA and China – Study 2: N = 487; UK and India – Study 3: N = 323; Italy). Data were analysed using experimental techniques (Analysis of Variance) and conditional process analyses (Moderated Mediation) using PROCESS.FindingsThe findings suggest that (1) firm independence fosters perceptions of product craftmanship and warmth in individualistic cultures, (2) consumers view products sold by independent firms as warmer and more authentic than products sold by non-independent firms in hedonic but not in utilitarian product categories, (3) the positive effects of firm independence on product craftmanship and warmth are neutralized for vertically collectivist cultures (India) and reversed in horizontally collectivist cultures (China), (4) loss of firm independence leads to higher drops in perceived craftmanship and product preference when it is caused by a takeover from a foreign multinational (compared to a domestic corporation).Originality/valueThis research provides a first account of how perceptions of firm independence drive assessments of product craftmanship and authenticity, elicit feelings of warmth and build product preference. The findings inform decisions of multinational corporations regarding (1) how to communicate the acquisition of independent firms in local markets, (2) how to balance an international brand portfolio in culturally diverging markets and different product industries, (3) how to optimize brand architecture through the relative exposure of the corporate brand image vis-à-vis the image of standalone brands owned by the corporation and (4) offer smaller independent players an alternative positioning strategy to differentiate from global competitors enjoying the resources or support of bigger corporations.

Z-split myectomy versus 7/8 posterior tenectomy for Brown syndrome

Brown syndrome is an extraocular muscle disorder that can cause motility restrictions, diplopia, and alternate head positioning. Multiple surgical techniques have been developed to resolve this problem. One technique, the superior oblique Z-split, lengthens the superior oblique tendon by partial-thickness cuts. Another technique, posterior 7/8 tenectomy, weakens the superior oblique while preserving its torsional action. This study aims to compare the outcomes of both surgeries.

I Am Not Afraid of the GPS Jammer: Resilient Navigation Via Signals of Opportunity in GPS-Denied Environments

I am not afraid of the GPS jammer, as long as there are ambient signals of opportunity (SOPs) to exploit in the environment. In environments where GPS signals are challenged (e.g., indoors and deep urban canyons) or denied (e.g., under jamming and spoofing attacks), SOPs could serve as an alternative positioning, navigation, and timing (PNT) source to GPS, and more generally, to global navigation satellite systems (GNSS). This article presents a radio simultaneous localization and mapping (radio SLAM) approach that enables the exploitation of SOPs for resilient and accurate PNT. Radio SLAM estimates the states of the navigator-mounted receiver simultaneously with the SOPs’ states. Radio SLAM could produce an SOP-derived navigation solution in a standalone fashion or by fusing SOPs with sensors [e.g., inertial measurement unit (IMU), lidar, etc.], digital maps, and/or other signals (e.g., GNSS). This article presents the first published experimental results evaluating the efficacy of radio SLAM in a real GPS-denied environment. These experiments took place at Edwards Air Force Base, California, USA, during which GPS was intentionally jammed with jamming-to-signal ratio as high as 90 dB. This article evaluates the timing of two cellular long-term evolution (LTE) SOPs located in the jammed environment, showing timing stability over 95 min of GPS jamming. Moreover, the article presents navigation results showcasing a ground vehicle traversing a trajectory of about 5 km in 180 s in the GPS-jammed environment. The vehicle's GPS-IMU system drifted from the vehicle's ground truth trajectory, resulting in a position root mean-squared error (RMSE) of 238 m. In contrast, the radio SLAM approach with a single cellular LTE SOP whose position was poorly known (an initial uncertainty on the order of several kilometers) achieved a position RMSE of 32 m.

SFOL DME Pulse Shaping Through Digital Predistortion for High-Accuracy DME

The Stretched-FrOnt-Leg (SFOL) pulse is a high-accuracy distance measuring equipment (DME) pulse developed to support alternative positioning and navigation for aircraft during global navigation satellite system outages. To facilitate the use of the SFOL pulse, it is best to use legacy DMEs that are already deployed to transmit the SFOL pulse, rather than the current Gaussian pulse, through software changes only. When attempting to transmit the SFOL pulse in legacy DMEs, the greatest challenge is the pulse shape distortion caused by the pulse-shaping circuits and power amplifiers (PAs) in the transmission unit such that the original SFOL pulse shape is no longer preserved. This letter proposes an inverse-learning-based DME digital predistortion method and presents successfully transmitted SFOL pulses from a testbed based on a commercial legacy DME that was designed to transmit Gaussian pulses.

Heuristic search for multi‐distance measuring equipment station selection

To support alternative positioning, navigation and timing (A-PNT), multi-DME with better geometry than distance measuring equipment (DME)/DME can be used to improve the performance. Different from the existing station selection methods that have been proposed for DME/DME, a station selection method for multi-DME should be considered in order to prevent unnecessary emission of navigation signals because DME receivers have limited number of channels and constrained real-time processing power, and also to limit DME to GNSS L5/E5a interference. A heuristic algorithm is constructed to determine the quasi-optimal selection of DME stations based on geometrical and computational cost restrictions, which is different from a brute-force method checking all possible subsets and selecting the best one. A station selection method for multi-DME is proposed based on the heuristic search. Meanwhile, the degradation of GNSS L5/E5a signal processing that is caused by DME signals is discussed. An advanced station selection method where the DME to GNSS signal interference is taken into account is also proposed. The experimental results show that the methods based on heuristic search can effectively select the quasi-optimal subset of DME stations with less computational expense.

Thou shalt not waste: Unpacking consumption of local food

Consumption of local and seasonal produce has been identified as an important element of sustainable food consumption. Alternative food networks (AFNs) play an important role in local food distribution and the socio-technical innovations in this space provide for rich exploration. The aim of this paper is to investigate how households’ food practices are emerging within the new material infrastructures of two AFNs – one community supported agriculture (CSA) and one food assembly (FA), based in Ireland. A social practice theory (SPT) approach was adopted to explore the nature of meanings, competencies, and the role of these new infrastructures in relation to the consumption of local and seasonal food. A mixed-method approach of ethnographic-style in-depth interviews, non-participant observation and photo food diaries were used to explore the everyday food practices and routines of 10 CSA members (rural-based) and 10 FA customers (urban-based). The findings offer insights into the role these two AFNs play in sustainable food consumption via the meanings ascribed to 'local' food, how such foods were incorporated into routine consumption practices, and the ways in which surplus and unfamiliar foods were diverted from waste streams. The findings suggest a strong aversion to wasting local food. Food surplus or unfamiliar foods acquired via the AFNs, rather than succumbing to the waste stream becomes part of a flexible and resourceful approach to circularity. Households engaged in creative cooking and preservation practices and conduits for disposal such as the fridge and freezer played an important role in housing surplus as it awaited recovery. The higher value placed on food acquired from both AFNs safeguarded it from the waste stream and instead was creatively transformed, preserved, and otherwise recovered and revalued to re-enter the cooking space as raw material for use. This paper presents evidence of how the alternative positioning of AFNs can enable alternative consumption routines, where a reorganisation of practices occurs within the household to account for surplus or unfamiliar local produce.

Multi-DMEs for alternative position, navigation and timing (A-PNT)

AbstractDistance measuring equipment (DME/DME) as the main reversionary method provides alternative positioning, navigation and timing (A-PNT) services for use during a Global Navigation Satellite System (GNSS) outage. Considering the geometry limitation of DME/DME, multi-DMEs with better geometry can be used to increase the accuracy and integrity performance of positioning. This paper discusses the opportunities and challenges related to use of multi-DMEs as an alternate source of positioning, navigation and timing. To support the performance for A-PNT, the basic idea is considering the existing installed equipment. In this paper, barometer altimeter and TACAN are used to help improve the performance of A-PNT provided by multi-DMEs both in accuracy and integrity. Based on the database of EUROCONTROL, the test results demonstrate that 79⋅7% of a reference area roughly matching with the continental European locations achieve RNP 1 using multi-DMEs when the DME measurement accuracy is 0⋅2 NM (95%). When the DME measurement accuracy is 0⋅1 NM (95%), 87⋅9% of the reference area can achieve RNP 1 using multi-DMEs. The usage of barometer/TACAN measurements aided multi-DMEs improves the performance of the accuracy and integrity monitoring.

A CASE STUDY OF PEDESTRIAN POSITIONING WITH UWB AND UAV CAMERAS

Abstract. The development and availability on consumer devices of the global navigation satellite systems (GNSS) have dramatically changed the everyday-life of most of the human population, enabling real time navigation on almost any smart device produced in the last years. However, such strong dependence on the availability of the GNSS limits the further spread of location based services to the areas where GNSS is not available or reliable. Motivated by these considerations, several research groups recently considered the problem of developing alternative positioning systems able to compensate the unavailability of GNSS in certain areas. Similarly, this paper also investigates the performance of certain alternative methods, which aim at partially substitute GNSS. In particular, the positioning performance of an affordable Ultra Wide-Band system is compared with that of a vision approach, based on the use of visual information acquired by an Unmanned Aerial Vehicle (UAV) flying over the area of interest. In accordance with the results obtained in our dataset, the drone-based vision system usually allow to obtain better positioning results when the pedestrians are visible in the drone video frames (median 2D positioning error less than 25 cm). Nevertheless, the combination of such strategies shall also be investigated in order to obtain a more robust positioning system.

ASSESSMENT OF CAR COLLABORATIVE POSITIONING WITH UWB AND VISION

Abstract. During the last decades the role of positioning and navigation systems is drastically changed in the everyday life of common people, influencing people behavior even multiple times each day. One of the most common applications of this kind of systems is that of terrestrial vehicle navigation: the use of GPS in the automotive navigation sector started thirty years ago, and, nowadays, it commonly assists drivers in reaching most of their non-standard destinations. Despite the popularity of global navigation satellite systems (GNSS), their usability is quite limited in certain working conditions, such as in urban canyons, in tunnels and indoors. While the latter case is typically not particularly interesting for the automotive sector, the first two scenarios represent important cases of interest for automotive navigation. In addition to the market request for increasing the usability of navigation systems on consumer devices, the recent increasing eagerness for autonomous driving is also attracting a lot of researchers’ attention on the development of alternative positioning systems, able to compensate for the unavailability or unreliability of GNSS. In accordance with the motivations mentioned above, this paper focuses on the development of a positioning system based on collaborative positioning between vehicles with UltraWide-Band devices and vision. To be more specific, this work focuses on assessing the performance of the developed system in successfully accomplishing three tasks, associated to different levels of gathered information: 1) assessing distance between vehicles, 2) determining the vehicle relative positions, 3) estimating the absolute car positions. The obtained results show that a) UWB can be reliably used (error of few decimeters error) to assess distances when vehicles are relatively close to each other (e.g. less than 40 m), b) the combination of UWB and vision allows to obtain good results in the computation of relative positions between vehicles, c) UWB-based collaborative positioning can be used for determining the absolute vehicle positions if a sufficient number of UWB range measurements can be ensured (sub-meter error for vehicles connected with a static UWB infrastructure, whereas error at meter level for those exploiting only vehicle-to-vehicle UWB communications).

Automatic Dependent Surveillance‐Broadcast (ADS‐B) Universal Access Transceiver (UAT) transmissions for Alternative Positioning, Navigation, and Timing (APNT): Concept & practice

<h3>Abstract</h3> The vulnerability of Positioning, Navigation, and Timing (PNT) services derived from Global Navigation Satellite Systems (GNSS) makes having a resilient and accurate Alternative PNT (APNT) based on high-power terrestrial radio sources necessary. The L-band is very crowded spectral real estate with GNSS, Distance Measuring Equipment (DME) and Air Traffic Control Beacon System (ATCRBS) signals occupying the band from 900–1600 MHz. Thus, as getting new signal and spectrum for APNT would be difficult, we must leverage existing transmissions and infrastructure. The ∼660 Automatic Dependent Surveillance-Broadcast (ADS-B) ground stations in the United States represent significant infrastructure that can be leveraged for APNT. However, as ADS-B was designed for surveillance, it does not inherently possess features necessary to support APNT goals. This paper describes and demonstrates techniques for using ADSB Universal Access Transceiver (UAT) signals for PNT. We develop methods to use all ground UAT signals to provide robust, multi-frequency pseudoranges. We examine the ranging and positioning performance of the UAT signal on the ground and in flight, to demonstrate its ranging accuracy, and hence the timing and synchronization of the station. We demonstrate and analyze navigation using UAT signals, as well as the intra-system interference challenges of using multiple UAT stations.

Molecular basis of C-S bond cleavage in the glycyl radical enzyme isethionate sulfite-lyase

SummaryDesulfonation of isethionate by the bacterial glycyl radical enzyme (GRE) isethionate sulfite-lyase (IslA) generates sulfite, a substrate for respiration that in turn produces the disease-associated metabolite hydrogen sulfide. Here, we present a 2.7 Å resolution X-ray structure of wild-type IslA from Bilophila wadsworthia with isethionate bound. In comparison with other GREs, alternate positioning of the active site β strands allows for distinct residue positions to contribute to substrate binding. These structural differences, combined with sequence variations, create a highly tailored active site for the binding of the negatively charged isethionate substrate. Through the kinetic analysis of 14 IslA variants and computational analyses, we probe the mechanism by which radical chemistry is used for C-S bond cleavage. This work further elucidates the structural basis of chemistry within the GRE superfamily and will inform structure-based inhibitor design of IsIA and thus of microbial hydrogen sulfide production.

Evaluation of Alternative Navigation, Positioning and Timing Systems Based on Their Performance and Additional Characteristics

The aim of this paper is to provide performance assessment of Alternative Navigation Positioning and Timing (APNT) systems considered possible GNSS backup in European region. The performance of the APNT systems is assessed based on their performance characteristics such as accuracy, integrity, and by additional beneficial abilities, that could help by implementation or could provide different added value in terms of solving certain issues in the Communication, Navigation and Surveillance (CNS) domain.

1090 MHz ADS-B-Based Wide Area Multilateration System for Alternative Positioning Navigation and Timing

The use of the automatic dependent surveillance-broadcast (ADS-B) as a source of alternative positioning, navigation, and timing is attractive as the system has been or soon will be fielded. In this study, a wide-area multilateration (WAM) testbed was developed that implements a time difference of arrival (TDOA) positioning algorithm using the 1090 MHz ADS-B Mode S ES signal in the Taiwan area. The positioning performance of the TDOA-based WAM is influenced by the geometric distribution of ground stations. Common requirements for terrestrial navigation systems target nominal horizontal dilution of precision (HDOP) of 2.828 or lower to support aviation navigation and surveillance [1] – [7] . Meeting such a requirement would necessitate a significant and geometrically diverse number of stations which limits the WAM implementation in countries with limited real estate. It also makes implementation expensive in general. Provided the measurements have adequate accuracy, it is still possible to meet position accuracy targets without such a geometry requirement. However, reducing geometry requirements presents issues with regards to developing a reliable and accurate position solution. This paper proposes a reasonable means of providing an accurate solution given limited station availability and demonstrates the concept in a testbed system implemented in Taiwan. In order to provide more reliable solution, a positioning algorithm is proposed that combines iterative and non-iterative methods to provide reliable convergence to the near optimal solution given the available measurements and the addition of barometric altitude from ADS-B to improve geometry. Importantly, the paper demonstrates positioning performance that meets the requirements for aviation navigation and surveillance services collected with actual flight data and the developed WAM.

A Qualitative Analysis of Vehicle Positioning Requirements for Connected Vehicle Applications

Many Connected Vehicle (CV) applications, including safety-critical ones such as collision warning, require lane-level positioning accuracy to function correctly. However, differential GNSS, the primary positioning method used by CVs in current deployments across the U.S., cannot always provide this level of accuracy. This is particularly true in urban environments. Alternative positioning methods or strategies must be developed to fill this gap. To determine what strategies are appropriate, we first identify the positioning requirements of each CV application listed in the USDOT?s Connected Vehicle Reference Implementation Architecture (CVRIA). These requirements include accuracy, integrity, update rate, and type of positioning (relative or absolute). Based on our overall analysis, we recommend two general positioning strategies: 1) utilize other sources of positioning information whenever possible (particularly at intersections), and 2) estimate the uncertainty of the positioning solution and use this uncertainty as an input to CV applications themselves.

Molecular Basis of C–S Bond Cleavage in the Glycyl Radical Enzyme Isethionate Sulfite-Lyase

Desulfonation of isethionate by the bacterial glycyl radical enzyme (GRE) isethionate sulfite-lyase (IslA) generates sulfite, a substrate for sulfite respiration that in turn produces the disease-associated metabolite hydrogen sulfide. Here, we present a 2.7 A resolution X-ray structure of wild-type IslA from Bilophila wadsworthia with isethionate bound. In comparison to other GREs, alternate positioning of the active site β strands allows for distinct residue positions to contribute to substrate binding. These structural differences combined with sequence variations create a highly tailored active site for the binding of the negatively charged isethionate substrate. Through the kinetic analysis of fourteen IslA variants, we probe the mechanism by which radical chemistry is used for C–S bond cleavage. This work further elucidates the structural basis of chemistry within the GRE superfamily and will inform structure-based inhibitor design of IsIA and thus of microbial hydrogen sulfide production.

Conventional and alternative preimplantation ECG screening for subcutaneous ICD in high risk hypertrophic cardiomyopathy patients

IntroductionPatients with hypertrophic cardiomyopathy (HCM) relatively often fail preimplantation ECG screening for subcutaneous implantable cardioverter-defibrillator (S-ICD). We aimed to evaluate impact of conventional and alternative ECG electrodes placement on eligibility for S-ICD implantation in HCM patients at high risk of sudden cardiac death (SCD). We hypothesized that modified electrodes placement will influence QRS-T morphology and thus it will increase S-ICD eligibility in the screening process. Material and methodsThis study enrolled 17 HCM patients at high risk of SCD (5-year SCD risk above 5%) referred for an ICD implantation. ECG screening for S-ICD eligibility in horizontal and vertical position was performed in each patient, in two different screening electrodes configuration: conventional (recommended by manufacturer) and alternative (precordial electrodes shifted rightwards and lateral electrodes dorsally). We evaluated QRS and T waves amplitude as well as T wave index. Primary, secondary and alternate sensing vectors were assessed. ResultsPreimplantation ECG screening with alternative electrodes placement resulted in more sensing vectors that were screened successfully (77 vs. 88, p = 0.05). Modified screening combined with a standard one allowed more patients to qualify for S-ICD implantation (17/17 vs. 12/17, p = 0.04). Electrocardiographically, the alternative positioning of ECG electrodes resulted in significant decrease in absolute values of QRS complex and T waves amplitudes in almost all sensing vectors, which was responsible for successful screening. ConclusionsThe use of alternative placement of screening electrodes may be a valuable method to increase eligibility for S-ICD implantation in HCM patients at high risk of SCD.

POSITIONING OF AIRCRAFT ON RELATION OF RUNWAY STRIP BY LASER-LOCATOR WHEN LANDING

Currently, ILS (Instrumental Landing Systems) operating in the meter and decimeter wavelength range are used. Systems have a number of drawbacks. International Civil Aviation Organization decided on the feasibility of creating alternative positioning systems. In this paper, it was proposed to use a LL (Laser-Locator) system for landing an aircraft. In this case, the output of the aircraft on the trajectory lying in the plane of the glide path, and keeping on this plane by lateral deviations, it is advisable to do with the help of the azimuth-distance measuring system of the RRT (Request-Response Type). The SD (Standard Deviation) of the RRT measurements while keeping the aircraft on the glide path is 12 m. Such errors provide contact with the runway, but unacceptably large to control the decrease of aircraft altitude when flying along the glide path. The use of the LL system provides measurement of the flight altitude above the runway with errors two orders of magnitude less than the RRT, and also provides highprecision measurements of the roll and pitch angles of the aircraft relative to the runway. The analysis showed that the accuracy of the roll estimation corresponds to the SD of 0.2°, and the pitch of 0.055°. The height estimation SD is less than 0.025 m. The proposed method of positioning the aircraft relative to the runway differs from the known higher accuracy, noise immunity. The method can be applied when landing on airfields that are not equipped with ILS. It provides autonomous operation in conditions of onboard navigation system failure. In this case, an accurate movement along the glide path with simultaneous measurement of the angular orientation of the aircraft relative to the runway is ensured.

A COMPARISON OF UWB AND MOTION CAPTURE UAV INDOOR POSITIONING

Abstract. The number of applications involving unmanned aerial vehicles (UAVs) grew dramatically during the last decade. Despite such incredible success, the use of drones is still quite limited in GNSS denied environment: indeed, the availability of a reliable GNSS estimates of the drone position is still fundamental in order to enable most of the UAV applications. Given such motivations, in this paper an alternative positioning system for UAVs, based on low cost ultra-wideband band (UWB) is considered. More specifically, this work aims at assessing the positioning accuracy of UWB-based positioning thanks to the comparison with positions provided by a motion capture (MoCap) system. Since the MoCap accuracy is much higher than that of the UWB system, it can be safely used as a reference trajectory for the validation of UWB estimates. In the considered experiment the UWB system allowed to obtain a root mean square error of 39.4 cm in 3D positioning based on the use of an adaptive extended Kalman filter, where the measurement noise covariance was adaptively estimated.

Genesis Standing Alone as a Luxury Sedan Brand in the U.S. Market : Barriers against the Market Performance

A decade has passed since the first generation of Genesis was launched in the U.S. with the plaque of Hyundai-Genesis. Genesis Motors was separated from Hyundai Motor in 2015, and has struggled to have the Genesis stand alone in the competitive U.S. luxury sedan market. The present case study aims to find challenges facing the Genesis, which Hyundai has positioned as a luxury sedan competing against conventional luxury brands such as BMW, Mercedes-Benz, and Lexus; evaluate Genesis Motors’ strategic response to meet these challenges; and explore an alternative positioning strategy. Specifically, the present case study addresses barriers against the Genesis’ market performance, by focusing on the obstacles rooted in the consumer perception as well as the obstacles that stem from the change in the U.S. automobile industry and the nascent network of the Genesis dealership. Genesis Motors’ current strategies are evaluated, and an alternative strategy is explored that is largely based on the American consumers’ perceptions of the Genesis vis-à-vis conventional luxury brands and outperforming midsize brands.

Genesis Standing Alone as a Luxury Sedan Brand in the U.S. Market

A decade has passed since the first generation of Genesis was launched in the U.S. with the plaque of Hyundai-Genesis. Genesis Motors was separated from Hyundai Motor in 2015, and has struggled to have the Genesis stand alone in the competitive U.S. luxury sedan market. The present case study aims to find challenges facing the Genesis, which Hyundai has positioned as a luxury sedan competing against conventional luxury brands such as BMW, Mercedes-Benz, and Lexus; evaluate Genesis Motors’ strategic response to meet these challenges; and explore an alternative positioning strategy. Specifically, the present case study addresses barriers against the Genesis’ market performance, by focusing on the obstacles rooted in the consumer perception as well as the obstacles that stem from the change in the U.S. automobile industry and the nascent network of the Genesis dealership. Genesis Motors’ current strategies are evaluated, and an alternative strategy is explored that is largely based on the American consumers’ perceptions of the Genesis vis-à-vis conventional luxury brands and outperforming midsize brands.