An Evaluation of Touch and Pressure-Based Scrolling and Haptic Feedback for In-car Touchscreens

An in-car study was conducted to examine different input techniques for list-based scrolling tasks and the effectiveness of haptic feedback for in-car touchscreens. The use of physical switchgear on centre consoles is decreasing which allows designers to develop new ways to interact with in-car applications. However, these new methods need to be evaluated to ensure they are usable. Therefore, three input techniques were tested: direct scrolling, pressure-based scrolling and scrolling using onscreen buttons on a touchscreen. The results showed that direct scrolling was less accurate than using onscreen buttons and pressure input, but took almost half the time when compared to the onscreen buttons and was almost three times quicker than pressure input. Vibrotactile feedback did not improve input performance but was preferred by the users. Understanding the speed vs. accuracy trade-off between these input techniques will allow better decisions when designing safer in-car interfaces for scrolling applications

Production sharing in East Asia : who does what for whom, and why?

The authors analyze empirical information on the nature and magnitude of, and motivation for, international production sharing in East Asia. To do so, they use a largely untapped source of data on inter- and intra-regional trade in parts and components. Some of their findings: East Asian trade in components is considerably greater than often recognized. Regional global exports of parts and components totaled $178 billion in 1996, and imports of those products about$12 billion less. Components now constitute one-fifth of East Asian exports of manufactures. Imports of components, measured as a share of all manufactures, are growing considerably faster in East Asia than in OECD Europe or North America. The value of East Asian global imports of components rose more than ninefold over the period 1985-96. Almost three-quarters of all East Asian imports of telecommunications equipment are components for further assembly. East Asian global exports of components grew faster then any other major product group over 1984-96, when their exchange increased 15 percent a year (compared with 11 percent for all products ). Although Japanese exports declined slightly in 1997, shipments from most other East Asian countries increased 9 to 16 percent. Why did production sharing expand? Analyses of traditionally revealed comparative advantage use export statistics to determine whether a country has a comparative advantage in the production of a good. The same indices, calculated using import statistics for components, can show whether a country has a comparative advantage in the assembly of a product. Using statistics on component imports, the authors find that: Japan, Singapore, and Taiwan (China)--which are exiting most assembly operations--increased their specialization in the manufacture of components. Assembly operations, which are labor-intensive, tend to migrate to low-wage East Asian countries. Indonesia, Malaysia, and Thailand have the broadest and most mature assembly capacity for components. But no East Asian country has developed its domestic assembly operations as much as Mexico, which has a comparative advantage in 70 percent of all component groups. Collectively, East Asian countries are strengthening their comparative advantage in the production of components; the results are mixed for assembly operations.Environmental Economics&Policies,Trade Policy,Earth Sciences&GIS,Economic Theory&Research,General Manufacturing,Economic Theory&Research,Environmental Economics&Policies,Trade Policy,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Earth Sciences&GIS

Export profiles of small landlocked countries : a case study focusing on their implications for Lesotho

World Bank demographic and country characteristic statistics identify 16 small landlocked countries that are similar to Lesotho. The authors attempt to determine what useful policy information can be derived from the recent trade performance of these"comparators."Among questions they pose are whether the trade profiles of the comparators suggest potentially promising export ventures for Lesotho, do they indicate directions for a geographic diversification of trade, or do they suggest products in which Lesotho might acquire a comparative advantage. The authors also use U.S. partner country statistics to evaluate Lesotho's export performance in this major market. The U.S. data indicate Lesotho lost competitive export shares for about three-quarters of its major clothing products during the late 1990s. The data show these losses were primarily to the North America Free Trade Agreement (NAFTA) countries in the Caribbean. Lesotho was competing on basically equal terms and did not fare well. But it is generallyheld that the most efficient clothing exporters are in the Far East and not Latin America. Lesotho's difficulties in competing with the latter have worrisome implications for its ability to compete with East Asian exporters when the Multifiber Arrangement is phased out. The comparative advantage profiles of the landlocked comparator countries suggest Lesotho's options for a greatly needed export diversification may be wider than is assumed. One or more of the comparator countries developed a comparative advantage in 110 four-digit SITC (non-clothing) manufactures which are generally labor-intensive in production. Many of these goods should also be suitable for production and export by Lesotho. International production sharing often involves the importation and further assembly of components in developing countries. This activity can significantly broaden the range of new products in which a country can diversify. Statistics show many landlocked comparator countries have moved into component assembly operations, and it appears this activity could contribute to Lesotho's export diversification and industrialization. But the quality problems associated with Lesotho's trade statistics makes it impossible to determine the extent to which local production sharing is occurring. A special effort is needed to tabulate reliable statistics on Lesotho's current involvement in this activity. Finally, the authors attempt to determine how the commercial policy environment in Lesotho compares with that in other countries. Policymakers previously had difficulty in addressing this issue, but several recent efforts to compile comprehensive cross-country indices of the quality of governance and commercial policies now provide relevant information. These statistics suggest domestic commercial policies make Lesotho relatively less attractive to foreign investment than many other developing countries. Less than 20 percent of all Latin American countries have a domestic commercial environment judged to be inferior to that in Lesotho, while the corresponding share for East Asia is under 30 percent. Overall, almost 70 percent of all developing countries appear to pursue commercial policies that make them as, or more, attractive to foreign investment than Lesotho.Markets and Market Access,Economic Theory&Research,Agribusiness&Markets,Environmental Economics&Policies,Trade Policy,Economic Theory&Research,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Environmental Economics&Policies,Trade Policy,Agribusiness&Markets

Estimating the rational expectations model of speculative storage : a Monte Carlo comparison of three simulation estimators.

The non-negativity constraint on inventories imposed on the rational expectations theory of speculative storage implies that the conditional mean and variance of commodity prices are non-linear in lagged prices and have a kink at a threshold point. In this paper, the structural parameters of this model are estimated using three simulation-based estimators. In a Monte Carlo experiment, the finite sample properties of the simulated methods of moments estimator of Duffie and Singleton (1993, Econometrica 61 (4), 929–952) the indirect inference estimator of Gourieroux et al. (1993, Journal of Applied Economterics 8, S85–S118) and the efficient method of moments estimator of Gallant and Tauchen (1996, Econometric Theory 12, 657–681) are assessed. Exploiting the invariant distribution implied by the theory allows us to evaluate the error induced by simulations. Our results show that the estimators differ in their sensitivity to the sample size, the number of simulations, choice of auxiliary models, and computation demands. For some estimators, the test for overidentifying restrictions exhibit significant size distortions in small samples. Overall, while the simulation estimators have small bias, they are less efficient than pseudo-maximum likelihood (PMLE). Hence for the small sample sizes considered, the simulation estimators are still inferior to the PMLE estimates in a mean-squared sense.

Comparing Evaluation Methods for Encumbrance and Walking on Interaction with Touchscreen Mobile Devices

In this paper, two walking evaluation methods were compared to evaluate the effects of encumbrance while the preferred walking speed (PWS) is controlled. Users frequently carry cumbersome objects (e.g. shopping bags) and use mobile devices at the same time which can cause interaction difficulties and erroneous input. The two methods used to control the PWS were: walking on a treadmill and walking around a predefined route on the ground while following a pacesetter. The results from our target acquisition experiment showed that for ground walking at 100% of PWS, accuracy dropped to 36% when carrying a bag in the dominant hand while accuracy reduced to 34% for holding a box under the dominant arm. We also discuss the advantages and limitations of each evaluation method when examining encumbrance and suggest treadmill walking is not the most suitable approach to use if walking speed is an important factor in future mobile studies

I Am The Passenger: How Visual Motion Cues Can Influence Sickness For In-Car VR

This paper explores the use of VR Head Mounted Displays (HMDs) in-car and in-motion for the first time. Immersive HMDs are becoming everyday consumer items and, as they offer new possibilities for entertainment and productivity, people will want to use them during travel in, for example, autonomous cars. However, their use is confounded by motion sickness caused in-part by the restricted visual perception of motion conflicting with physically perceived vehicle motion (accelerations/rotations detected by the vestibular system). Whilst VR HMDs restrict visual perception of motion, they could also render it virtually, potentially alleviating sensory conflict. To study this problem, we conducted the first on-road and in motion study to systematically investigate the effects of various visual presentations of the real-world motion of a car on the sickness and immersion of VR HMD wearing passengers. We established new baselines for VR in-car motion sickness, and found that there is no one best presentation with respect to balancing sickness and immersion. Instead, user preferences suggest different solutions are required for differently susceptible users to provide usable VR in-car. This work provides formative insights for VR designers and an entry point for further research into enabling use of VR HMDs, and the rich experiences they offer, when travelling

An efficient shooting algorithm for Evans function calculations in large systems

In Evans function computations of the spectra of asymptotically constant-coefficient linear operators, a basic issue is the efficient and numerically stable computation of subspaces evolving according to the associated eigenvalue ODE. For small systems, a fast, shooting algorithm may be obtained by representing subspaces as single exterior products \cite{AS,Br.1,Br.2,BrZ,BDG}. For large systems, however, the dimension of the exterior-product space quickly becomes prohibitive, growing as $\binom{n}{k}$, where $n$ is the dimension of the system written as a first-order ODE and $k$ (typically $\sim n/2$) is the dimension of the subspace. We resolve this difficulty by the introduction of a simple polar coordinate algorithm representing ``pure'' (monomial) products as scalar multiples of orthonormal bases, for which the angular equation is a numerically optimized version of the continuous orthogonalization method of Drury--Davey \cite{Da,Dr} and the radial equation is evaluable by quadrature. Notably, the polar-coordinate method preserves the important property of analyticity with respect to parameters.Comment: 21 pp., two figure

Leg Sympathetic Response to Noxious Skin Stimuli is Similar in High and Low Level Human Spinal Cord Injury

Objective To determine if sympathetically mediated vasoconstriction in the lower extremities is injury level dependent. Although sympathetic responses have been measured in the limbs of people with high and low level SCI using blood flow measurements, including Doppler ultrasound and venous plethysmography, a direct comparison between injury levels has not been made. Methods Volunteers with chronic SCI were grouped according to injury level. Above T6: high level (HL, n = 7), and T6 and below: low level (LL, n = 6). All subjects had complete motor and sensory loss. Leg arterial flows were recorded by venous occlusion plethysmography, and continuous heart rate and mean arterial pressure (MAP) were measured. The conditioning stimulus consisted of transcutaneous stimulation to the arch of the contralateral foot. Results HL and LL subjects demonstrated a significant decrease in arterial conductance during stimulation with no significant difference found between groups. As expected, only group HL demonstrated a significant increase in MAP. Conclusions These results support our hypothesis that local (leg) sympathetic responses are similar for both high and low level SCI. Significance While low level SCI does not typically present with autonomic dysreflexia, bouts of increased reflex sympathetic activity could have ramifications for metabolism as well as renal and motor system functio

Evaluation of Haptic Patterns on a Steering Wheel

Infotainment Systems can increase mental workload and divert visual attention away from looking ahead on the roads. When these systems give information to the driver, provide it through the tactile channel on the steering, it wheel might improve driving behaviour and safety. This paper describes an investigation into the perceivability of haptic feedback patterns using an actuated surface on a steering wheel. Six solenoids were embedded along the rim of the steering wheel creating three bumps under each palm. Maximally, four of the six solenoids were actuated simultaneously, resulting in 56 patterns to test. Participants were asked to keep in the middle road of the driving simulator as good as possible. Overall recognition accuracy of the haptic patterns was 81.3%, where identification rate increased with decreasing number of active solenoids (up to 92.2% for a single solenoid). There was no significant increase in lane deviation or steering angle during haptic pattern presentation. These results suggest that drivers can reliably distinguish between cutaneous patterns presented on the steering wheel. Our findings can assist in delivering non-critical messages to the driver (e.g. driving performance, incoming text messages, etc.) without decreasing driving performance or increasing perceived mental workload