Approximate Inference in Continuous Determinantal Point Processes

Determinantal point processes (DPPs) are random point processes well-suited for modeling repulsion. In machine learning, the focus of DPP-based models has been on diverse subset selection from a discrete and finite base set. This discrete setting admits an efficient sampling algorithm based on the eigendecomposition of the defining kernel matrix. Recently, there has been growing interest in using DPPs defined on continuous spaces. While the discrete-DPP sampler extends formally to the continuous case, computationally, the steps required are not tractable in general. In this paper, we present two efficient DPP sampling schemes that apply to a wide range of kernel functions: one based on low rank approximations via Nystrom and random Fourier feature techniques and another based on Gibbs sampling. We demonstrate the utility of continuous DPPs in repulsive mixture modeling and synthesizing human poses spanning activity spaces

Electromechanical and Dynamic Characterization of In-House-Fabricated Amplified Piezo Actuator

A diamond-shaped amplified piezo actuator (APA) fabricated using six multilayered piezo stacks with maximum displacement of 173 μm at 175V and the amplification factor of 4.3. The dynamic characterization of the actuator was carried out at different frequencies (100 Hz–1 kHz) and at different AC voltages (20V–40V). The actuator response over this frequency range was found neat, without attenuation of the signal. Numerical modeling of multilayered stack actuator was carried out using empirical equations, and the electromechanical analysis was carried out using ABAQUS software. The block force of the APA was 81 N, calculated by electromechanical analysis. This is similar to that calculated by dynamic characterization method

Low Power Reversible Parallel Binary Adder/Subtractor

In recent years, Reversible Logic is becoming more and more prominent technology having its applications in Low Power CMOS, Quantum Computing, Nanotechnology, and Optical Computing. Reversibility plays an important role when energy efficient computations are considered. In this paper, Reversible eight-bit Parallel Binary Adder/Subtractor with Design I, Design II and Design III are proposed. In all the three design approaches, the full Adder and Subtractors are realized in a single unit as compared to only full Subtractor in the existing design. The performance analysis is verified using number reversible gates, Garbage input/outputs and Quantum Cost. It is observed that Reversible eight-bit Parallel Binary Adder/Subtractor with Design III is efficient compared to Design I, Design II and existing design.Comment: 12 pages,VLSICS Journa

A preliminary geometric morphometrics assessment of two forensically important blow fly larvae in Malaysia, Chrysomya megacephala (Fabricius) and Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae)

In forensic entomology, the age of blow fly larvae (Diptera: Calliphoridae) that feed on decomposing human tissues can be used as reference in minimum post mortem interval (mPMI) estimation. To establish mPMI based on larval age, it is important to correctly identify larva species based on their morphological characteristics as larval developments from where they were collected are species-specific. Recently, landmark-based geometric morphometric analysis has been found useful to discriminate species and provide visual shape variations. The objective of this study was to assess the utilization of this technique on two forensically important blow fly species in Malaysia, i.e. the Chrysomya megacephala (Fabricius) and Chrysomya rufifacies (Macquart) based on the cephalopharyngeal skeletons of the larvae. A total of 10 landmarks on cephalopharyngeal skeleton were established and analyzed with geometric morphometric functions in MorphoJ™ software. Cephalopharyngeal skeleton centroid size, which represented the individual cephalopharyngeal skeleton shape profile, were statistically different between C. megacephala and C. rufifacies (p<0.001). Based on the landmark plot shifts, the two species could be differentiated based of parastomal bar, the clipeal arc, apical hook, upper margin of ventral cornu and lower margin of ventral cornu. These differences were well defined in visual presentation by using principal component analysis with 100% cross validation reassignment percentage. However, large scale study should be considered for a more complete cephalopharyngeal skeleton shapes profiles of forensically important Calliphoridae

A forecast for the ensuing oil-sardine fishery

The ability to foreca st the course of events likely to be encountered during the approaching fishery season enhances the value of fishery research in the eyes of those in the industry , As Simpson (1956) has put it, "Apart from the value to the industry of forecasting, predicting what is going to happen and checking it against the actual events is to the fishery biologist one form of the universal research tool of formulating a hypothesis and putting it to test

Patterns of sex ratio in the oil-sardine, Sardinella longiceps Val., at Calicut

Categorising the fish according to maturity, montti of capture and length groups, the data on the sex distribution of the Indian oil-sardine (5flrrfwW/fl/ong'/fepj) collected at Calicut during 1959-60 to 1965-66 seasons are subjected to statistical tests to find outthe nature and cause of dominance of either sex, if any. For the immature fish the overall inference is that there may not be any significant difierences in the annual recruited population. In the adult fish the possibility of more males in May is suggested as due to the fact that the males may start maturing a little earlier than the females. The dominance of males in 140-150 mm group and that of females in 170-190 mm groups is brought about by differential growth, the females growing faster during June to October period. It is recommended that the size of each sample for sex ratio studies should be at least 50. Based on the earlier and the present studies of this author, It is indicated that 375 million ova can be expected from a tonne of adult biomass of the oil-sardine population

Our pelagic fishery resources Present and potential harvest

The two primary divisions of the oceans are (1) the benthic and (2) the pelagic, the former referring to the ocean floor which supports the demersal resources and the latter, the entire column of water , accomodating the pelagic resources. The pelagic region is a part of the marine biocycle and geographically, it is divisible into Atlantic and Indo-Pacific. Ecologically, the pelagic realm can b e bifurcated as neritic (inshore) and oceanic (opens e a) provinces d epending on the depth to which light penetrates and to the extent and depth of the continental slop