CAD Model-based 3D Object Pose Estimation using an Edge-Based Nonlinear Model Fitting Algorithm

[[abstract]]This paper addresses the design of a model-based 3D object pose estimation algorithm, which is one of the major techniques to develop a robust robotic vision system using a monocular camera. The proposed system first extracts line features of a captured image by using edge detection and Hough transform techniques. Given a CAD model of the object-of-interest, the 6-DOF pose of the object can then be estimated via a novel edge-based nonlinear model fitting algorithm, which is a nonlinear optimization process for estimating the optimal object pose based on an edge-based distance metric. Experimental results validate the performance of the proposed system.[[notice]]補正完

The Appell Function F1F_1 and Regge String Scattering Amplitudes

We show that each 26D open bosonic Regge string scattering amplitude (RSSA) can be expressed in terms of one single Appell function $F_1$ in the Regge limit. This result enables us to derive infinite number of recurrence relations among RSSA at arbitrary mass levels, which are conjectured to be related to the known SL(5,C) dynamical symmetry of $F_1$. In addition, we show that these recurrence relations in the Regge limit can be systematically solved so that all RSSA can be expressed in terms of one amplitude. All these results are dual to high energy symmetries of fixed angle string scattering amplitudes discovered previously [4-8].Comment: 12 pages,no figur

Intertemporal Quality Discrimination

New technology is usually expensive and it takes time for manufacturers to make the technology more accessible. In the stereo industry, the first Super Audio Compact Disk (SACD) player made by Sony, SCD-1, sold for $5,000 in 1999; in 2002 the cheapest of Sony's new SACD players, SCD-CE775, had a$250 MSRP, while the SCD-1 continued to be Sony's flagship model. The electrostatic speaker manufacturer MartinLogan developed a technology trademarked ClearSpars for their Statement e2 speakers, which came to the market in 2000 with a list price of $80,000 per pair. MartinLogan later applied the technology to their mid-price ($3300 per pair) Aeon i in 2003. The amplifier manufacturer Conrad-Johnson introduced in 2000 its current top pre-amplifier, ART Series 2, and in 2003 added to their product line a stripped-down version of the ART, the Premier 17LS, whose price is less than one-third the price of the ART. The four-wheel-drive vehicle manufacturer Land Rover introduced their mid-price model Discovery in 1986, after they remodeled their luxury line Range Rover in the early 80s. In these examples, before the firms could scale down their new technologies for the mass markets, they sold only the high-end products; and after the more affordable low-end products became available, they sold both kinds of products. Furthermore, these products are durable goods, and so by the time the firms introduced the low-end products, the consumers who had bought the high-end products were no longer in the market. In this paper we abstract from the inter-firm competition. That is, we assume that the durable goods market is monopoly, and study the quality decision and the pricing of the durable goods monopolist whose first-generation product has higher quality than the second-generation one, which is not available at the time the first-generation product is first introduced to the market. In addition to Coasian dynamics, or intertemporal price discrimination, the issue involves intertemporal quality discrimination. Our analysis focuses on whether the monopolist would produce goods with qualities higher than the optimum. In static quality (or quantity) discrimination models, where a monopolist can use several quality-price packages to screen consumers, it is well known that a monopolist would discriminate the consumers by offering the efficient quality only to the consumer with the highest valuation, and offering everyone else a quality less than the optimum. In no circumstances could the consumers get above-optimum quality in the static model. [See Mussa and Rosen (1978) and Maskin and Riley (1984).] However, in our model of intertemporal quality discrimination, we find that the monopolist will produce goods of above-optimum quality in its product line when the discount factor is small.Coase conjecture, durable goods monoply, quality discrimination, screening

Postwar Slowdowns and Long-Run Growth: A Bayesian Analysis of Structural-Break Models

Using Bayesian methods, we re-examine the empirical evidence from Ben-David, Lumsdaine and Pappell (“Unit Roots, Postwar Slowdowns and Long-Run Growth: Evidence from Two Structural Breaks”, Empirical Economics, 28, 2003) regarding structural breaks in the long-run growth path of real output series for a number of OECD countries. Our Bayesian framework allows the number and pattern of structural changes in trend and variance to be endogenously determined. We find little evidence of postwar growth slowdowns across countries, and we find smaller output volatility for most of the developed countries after the end of World War II. Our empirical findings are consistent with neoclassical growth models, which predict increasing growth over the long run. The majority of the countries we analyze have grown faster in the postwar era as opposed to the period before the first break.

A novel simultaneous dynamic range compression and local contrast enhancement algorithm for digital video cameras

[[abstract]]This article addresses the problem of low dynamic range image enhancement for commercial digital cameras. A novel simultaneous dynamic range compression and local contrast enhancement algorithm (SDRCLCE) is presented to resolve this problem in a single-stage procedure. The proposed SDRCLCE algorithm is able to combine with many existent intensity transfer functions, which greatly increases the applicability of the proposed method. An adaptive intensity transfer function is also proposed to combine with SDRCLCE algorithm that provides the capability to adjustably control the level of overall lightness and contrast achieved at the enhanced output. Moreover, the proposed method is amenable to parallel processing implementation that allows us to improve the processing speed of SDRCLCE algorithm. Experimental results show that the performance of the proposed method outperforms three state-of-the-art methods in terms of dynamic range compression and local contrast enhancement.[[incitationindex]]SCI[[booktype]]電子

A location-based personal task reminder for mobile users

[[abstract]]Personal task reminders have been indispensable for modern people, in order to remind them of their tasks at specific circumstances. Traditional paper-based reminders are still useful, but they cannot be organized efficiently. Electronic reminders based on the calendar in cell phones are more efficient and gaining popularity, but such reminders are mostly triggered by time. In many situations, tasks are only meaningful to be performed at a specific location, so it would be useful if reminders for those tasks can be triggered only when the person to be reminded is physically near or located at that location. Therefore, in this research, we develop a location-based personal task reminder for Android-based smartphones and tablets. To distinguish our work from existing ones that rely solely on the GPS technology, we take advantage of the ubiquity of IEEE 802.11 WLAN infrastructure to compliment the “blind spots” of GPS location sensing. Combining the two technologies makes it possible for the personal task reminder to be effective in both indoor and outdoor environments. We also propose two operating models for the personal task reminder to boost the usability of the application. Furthermore, as long as the WLAN infrastructure is available, our work as a foundation of location-based services can easily be extended to be used in many other scenarios, such as guiding in public transportation systems or tourist attractions, location-based learning, and even caring of the Dementia residents.[[incitationindex]]SCI[[booktype]]電子版[[booktype]]紙

Structural change in the forward discount: a Bayesian analysis of forward rate unbiasedness hypothesis

Using Bayesian methods, we reexamine the empirical evidence from Sakoulis et al. (2010) regarding structural breaks in the forward discount for G-7 countries. Our Bayesian framework allows the number and pattern of structural changes in level and variance to be endogenously determined. We find different locations of breakpoints for each currency; mostly, fewer breaks are present. We find little evidence of moving toward stationarity in the forward discount after accounting for structural change. Our findings suggest that the existence of structural change is not a viable justification for the forward discount anomaly.Bayesian method, structural change, forward discount anomaly, Gibbs-sampling