NScluster: An R Package for Maximum Palm Likelihood Estimation for Cluster Point Process Models Using OpenMP

NScluster is an R package used for simulation and parameter estimation for NeymanScott cluster point process models and their extensions. For parameter estimation, NScluster uses the maximum Palm likelihood estimation procedure. As some estimation procedures proposed herein require heavy calculation, NScluster can use parallel computation via OpenMP and achieve significant speedup in some cases. In this paper, we discuss results obtained using a laptop PC and a shared memory supercomputer. In addition, we examine the performance characteristics of parallel computation via OpenMP

Fish assemblages associated with three types of artificial reefs: density of assemblages and possible impacts on adjacent fish abundance

We evaluated the effectiveness of wooden artificial reefs (ARs) as fish habitat. Three types of ARs, made of cedar logs, broadleaf tree logs, and PVC pipes, respectively, were deployed in triplicate at 8-m depth off Maizuru, Kyoto Prefecture, Sea of Japan, in May 2004. Fish assemblages associated with each of the nine ARs were observed by using SCUBA twice a month for four years. Fish assemblages in the adjacent habitat were also monitored for two years before and four years after reef deployment. In the surveyed areas (ca. 10 m2) associated with each of the cedar, broadleaf, and PVC ARs, the average number of fish species was 4.14, 3.49, and 3.00, and the average number of individuals was 40.7, 27.9, and 20.3, respectively. The estimated biomass was also more greater when associated with the cedar ARs than with other ARs. Visual censuses of the habitat adjacent to the ARs revealed that the number of fish species and the density of individuals were not affected by the deployment of the ARs. Our results support the superiority of cedar as an AR material and indicate that deployment of wooden ARs causes no reduction of fish abundance in adjacent natural reefs

Formation mechanism of plateau, rapid fall and tail in phosphorus diffusion profile in silicon based on the pair diffusion models of vacancy mechanism and interstitial mechanism

P diffuses predominantly by the interstitial mechanism in Si. Assuming that there is a strong binding energy between P and I, therefore, the basic process of P diffusion is the diffusion of (PI), where I and (PI) represent self-interstitials and P-I pairs, respectively. In the high-P-concentration region, excess I is generated by the dissociation of (PI) and the limiting process of P diffusion depends on whether or not excess I is controlled. That is, if the concentration of excess I decreases relatively to the equilibrium I concentration due to the effect of the decrease in quasi self-interstitial formation energy, or if excess I is removed by the recombination with vacancies, P diffuses fast and the plateau is formed; if not, P diffuses slowly and the rapid fall is formed. In the tail region, the P concentration is low and the limiting process of P diffusion is the basic process of P diffusion, that is, the diffusion of (PI). Excess I generated in the high-P-concentration region diffuses into the low-P-concentration region, and I is supersaturated there. Therefore, the concentration of (PI) increases, resulting in the fast diffusion of P and the formation of the tail

Design and Implementation of a DMARC Verification Result Notification System

Damages caused by spoofed e-mails as sent from a bank, a public organization and so on become serious social problems. In such e-mails attackers forge the sender address to defraud receivers of their personal and/or secret information. As a countermeasure against spoofed e-mails, sender domain authentication methods such as SPF and DKIM are frequently utilized. However, since most spoofed e-mails do not include DKIM signature in their e-mail header, those e-mails cannot be authenticated by the conventional system. Additionally DKIM has a problem that cannot determine whether the attached signature is legitimate. In this paper, we propose a method to detect spoofed e-mails and alert the user without DKIM signature by utilizing DMARC and implement a system that sends DMARC verification results to receivers. By utilizing this system, the users can obtain alerts for spoofed e-mails that the existing systems cannot warn

Exploration of new chemical materials using black-box optimization with the D-wave quantum annealer

In materials informatics, searching for chemical materials with desired properties is challenging due to the vastness of the chemical space. Moreover, the high cost of evaluating properties necessitates a search with a few clues. In practice, there is also a demand for proposing compositions that are easily synthesizable. In the real world, such as in the exploration of chemical materials, it is common to encounter problems targeting black-box objective functions where formalizing the objective function in explicit form is challenging, and the evaluation cost is high. In recent research, a Bayesian optimization method has been proposed to formulate the quadratic unconstrained binary optimization (QUBO) problem as a surrogate model for black-box objective functions with discrete variables. Regarding this method, studies have been conducted using the D-Wave quantum annealer to optimize the acquisition function, which is based on the surrogate model and determines the next exploration point for the black-box objective function. In this paper, we address optimizing a black-box objective function containing discrete variables in the context of actual chemical material exploration. In this optimization problem, we demonstrate results obtaining parameters of the acquisition function by sampling from a probability distribution with variance can explore the solution space more extensively than in the case of no variance. As a result, we found combinations of substituents in compositions with the desired properties, which could only be discovered when we set an appropriate variance.Comment: 14pages, 4figures, 4table