Showing papers in "The annual research report in 2015"

Mathematical analysis of plasmonic nanoparticles: the scalar case

Abstract: Localized surface plasmons are charge density oscillations confined to metallic nanoparticles. Excitation of localized surface plasmons by an electromagnetic field at an incident wavelength where resonance occurs results in a strong light scattering and an enhancement of the local electromagnetic fields. This paper is devoted to the mathematical modeling of plasmonic nanoparticles. Its aim is fourfold: (1) to mathematically define the notion of plasmonic resonance and to analyze the shift and broadening of the plasmon resonance with changes in size and shape of the nanoparticles; (2) to study the scattering and absorption enhancements by plasmon resonant nanoparticles and express them in terms of the polarization tensor of the nanoparticle; (3) to derive optimal bounds on the enhancement factors; (4) to show, by analyzing the imaginary part of the Green function, that one can achieve super-resolution and super-focusing using plasmonic nanoparticles. For simplicity, the Helmholtz equation is used to model electromagnetic wave propagation.

An Explicit Implicit Scheme for Cut Cells in Embedded Boundary Meshes

Abstract: We present a new mixed explicit implicit time stepping scheme for solving the linear advection equation on a Cartesian cut cell mesh. We use a standard second-order explicit scheme on Cartesian cells away from the embedded boundary. On cut cells, we use an implicit scheme for stability. This approach overcomes the small cell problem--that standard schemes are not stable on the arbitrarily small cut cells--while keeping the cost fairly low. We examine several approaches for coupling the schemes in one dimension. For one of them, which we refer to as flux bounding, we can show a TVD result for using a first-order implicit scheme. We also describe a mixed scheme using a second-order implicit scheme and combine both mixed schemes by an FCT approach to retain monotonicity. In the second part of this paper, extensions of the second-order mixed scheme to two and three dimensions are discussed and the corresponding numerical results are presented. These indicate that this mixed scheme is second-order accurate in $$L^1$$L1 and between first- and second-order accurate along the embedded boundary in two and three dimensions.

Reduced order methods for uncertainty quantification problems

Abstract: This work provides a review on reduced order methods in solving uncertainty quantification problems. A quick introduction of the reduced order methods, including proper orthogonal decomposition and greedy reduced basis methods, are presented along with the essential components of general greedy algorithm, a posteriori error estimation and Offline-Online decomposition. More advanced reduced order methods are then developed for solving typical uncertainty quantification problems involving pointwise evaluation and/or statistical integration, such as failure probability evaluation, Bayesian inverse problems and variational data assimilation. Three expository examples are provided to demonstrate the efficiency and accuracy of the reduced order methods, shedding the light on their potential for solving problems dealing with more general outputs, as well as time dependent, vectorial noncoercive parametrized problems.

Improving Information-Sharing Across Law Enforcement: Why Can't We Know?:

Abstract: Law enforcement capabilities increasingly depend on records management systems and computer-aided dispatch systems, and there are increasing demands to share information across regional, state, and federal repositories. But there are limitations to existing information-sharing technology and policy. This report addresses both short-term and long-term approaches to overcoming those barriers.

Hybrid Warfare: Preparing for Future Conflict

Abstract: : Hybrid warfare will be the most likely type of conflict the US and its allies will face in the future. Hybrid warfare is the use of conventional and unconventional ways and means by any combination of state and non-state actors within the same battlespace. Conventional and unconventional ways and means include forces, weapons and tactics, and are characterized by the use of modern technology and a high degree of unity of effort between regular and irregular forces. The argument that hybrid warfare will be the most likely type of conflict the US and its allies will face in the future is based on a convergence of three geopolitical drivers. These include, the transformation of traditional governing structures, disputes over political power caused by long-standing cultural differences and state sponsorship of insurgencies and revolutions. Traditional security interests will lead to state sponsorship of internal conflicts as states choose sides in these struggles for power. The wars that result will be characterized by conventional and unconventional ways and means, producing hybrid war. Our own security interests and the interests of our allies will draw us into these wars, as we seek to maintain international order and prevent the spillover effects of war. The strategic framework for preventing hybrid wars and deterring/defeating hybrid adversaries is based on two pillars. The first pillar consists of actions to assist and support weak or failing states. The second pillar consists of actions directed toward the hybrid adversary, which will most likely be a combination of a non-state actor and an internationally recognized state actor. Through use of the ongoing conflict in Ukraine as a case study, the implications of the analysis argue for building a balanced force that can simultaneously employ across the full spectrum of operations and rapidly deploy to all areas of the globe.

Second-Kind Boundary Integral Equations for Scattering at Composite Partly Impenetrable Objects

Abstract: We consider acoustic scattering of time-harmonic waves at objects composed of several homogeneous parts. Some of those may be impenetrable, giving rise to Dirichlet boundary conditions on their surfaces. We start from the second-kind boundary integral approach of [X. Claeys, and R. Hiptmair, and E. Spindler. A second-kind Galerkin boundary element method for scattering at composite objects. BIT Numerical Mathematics, 55(1):33-57, 2015] and extend it to this setting. Based on so-called global multi-potentials, we derive variational second-kind boundary integral equations posed in $L^2(\Sigma)$, where $\Sigma$ denotes the union of material interfaces. To suppress spurious resonances, we introduce a combined-field version (CFIE) of our new method. Thorough numerical tests highlight the low and mesh-independent condition numbers of Galerkin matrices obtained with discontinuous piecewise polynomial boundary element spaces. They also confirm competitive accuracy of the numerical solution in comparison with the widely used first-kind single-trace approach.

Natural Resource Management Dynamics in Border Communities of Kyrgyzstan and Tajikistan

Abstract: The Research paper provides insight into the institutions and local dynamics involved in natural resource management in border communities, and to provide solutionoriented recommendations to address natural resource management challenges. The research was conducted between September 2015 and February 2016 in Batken and Soghd oblasts within the framework of the project “Reducing conflict over water and pastures in Kyrgyzstan and Tajikistan.” This Research report was prepared with support from the British Embassy in Kyrgyzstan. The views expressed in this publication do not necessarily reflect the official views or opinions of the Embassy. Acknowledgements The authors wish to thank the following individuals and organizations for their support in the production of this report: Mirzo Mirzoev and Ikhtiyor Aliyorov from MSDSP Tajikistan for their support in conducting research in Soghd oblast; the UNDP office in Batken and Khujand; the Batken and Soghd Water Department and oblast administrations for their participation in expert interviews; Gulnara Temirbekova and Bakhram Rakhmankulov from the FTI office in Batken and Janatay Asanova from the Belek NGO for their valuable comments in the selection stage of case study locations; Alois Schlaeffer, Peter Naderer and the CAMP Alatoo team for their feedback on the research questions in the early stage of their development; Alisher Shabdolov for his feedback on the preliminary findings; and finally, MSRI colleagues for their assistance in research and the preparation of this report.

Existence, uniqueness, and regularity for stochastic evolution equations with irregular initial values

Abstract: We consider stochastic evolution equations (SEEs) of parabolic type in Hilbert space with smooth coefficients, driven by multiplicative, not necessarily trace class, Gaussian noise. We present the notion of extended transition semigroups for such equations and we show, under suitable assumptions, that the extended transition semigroup is a solution to the Kolmogorov equation in infinite dimensions. In addition, Fr\'{e}chet differentiability of the extended transition semigroup in negative order spaces is established. The order of smoothness is the same as the order of smoothes of the coefficients of the corresponding equation. In order to define the extended transition semigroup, stochastic evolution equations with irregular initial values and initial singularities in the coefficients are investigated and an abstract existence and uniqueness result for such equations is presented.

Fee structure, return chasing and mutual fund choice

Abstract: We present an experiment that investigates the effect of the fee structure and past returns on mutual fund choice. We find that subjects pay too little attention to the (periodic and small) operation expenses fee, but that the more salient front-end load is used as a commitment device and leads to lock-in into one of the funds. In addition we find that, even when subjects know that future returns are independent of past returns, these past returns are an important determinant of subjects’ investment choices.

Pengelolaan pembuatan soal berbasis literasi sains

Abstract: The science teacher at SMP Muhammadiyah Kota Batu understand and realize that science education has an important role in preparing qualified human resources to face the era of industrialization and globalization, one of them with literacy skills. The method used is the passage and mentoring training includes socializing, iscussions, workshops, training, direct practice, and evaluation. Results of the analysis of the situation to the problems solved jointly greed priorities 4 junior high science teacher, two teachers of SMP Muhammadiyah 8 and 2 teachers of SMP Muhammadiyah 2 Batu. Conclusion of the activity: 1) the science teachers at SMP Muhammadiyah Kota Batu has increased its ability to understand the assessment of authentic, assessment Traditionally, the concept of literacy, and the nature of scientific literacy, 2) There are 23 questions that are prepared teachers include: a) seven items for the dimension " measuring the ability of knowledge concepts ", b) there are no items to dimension" to measure the ability to use scientific knowledge in analyzing a text or article ", c) seven items for the dimensions" measure using knowledge or concepts significantly ", d) nine items for the imension "measures the ability to analyze and evaluate the use of data or events", and e) none of the items to dimension "measure problem-solving skills".

Multilevel Quasi-Monte Carlo Methods for Lognormal Diffusion Problems

Abstract: In this paper we present a rigorous cost and error analysis of a multilevel estimator based on randomly shifted Quasi-Monte Carlo (QMC) lattice rules for lognormal diffusion problems. These problems are motivated by uncertainty quantification problems in subsurface flow. We extend the convergence analysis in [Graham et al., Numer. Math. 2014] to multilevel Quasi-Monte Carlo finite element discretizations and give a constructive proof of the dimension-independent convergence of the QMC rules. More precisely, we provide suitable parameters for the construction of such rules that yield the required variance reduction for the multilevel scheme to achieve an e-error with a cost of O(e � ) with θ < 2, and in practice even θ ≈ 1, for sufficiently fast decaying covariance kernels of the underlying Gaussian random field inputs. This confirms that the computational gains due to the application of multilevel sampling methods and the gains due to the application of QMC methods, both demonstrated in earlier works for the same model problem, are complementary. A series of numerical experiments confirms these gains. The results show that in practice the multilevel QMC method consistently outperforms both the multilevel MC method and the single-level variants even for non-smooth problems.

High-resolution gridded data generation and performance assessment of multiple statistical downscaling methods for South Korea

Abstract: Eum, Hyung-Il.2015.High-resolution gridded data generation and performance assessment of multiple statistical downscaling methods for South Korea,Report,BusanAPCC,Research Report/2015-05

Political and administrative managements after converting status from the villages into the kelurahan (Study on Dadaprejo and Nganglik Kelurahan of Batu Local Government)

Abstract: The implementation of the status changing from the administrative village become the administrative of kelurahan is a pilot project, this is based on the perspective of the Act number 32 year 2004 regarding the local government, which is followed by the Government Regulation No 72 year 2005 regarding Village and the Government Regulation No 73 Year 2005 about kelurahan. Nowadays, the status of Batu is the autonomy region in the form of the municipality. The provision is derivated from those above mentioned Laws which is also stipulated in the Regulation of Home Affair Ministry Number 28 Year 2006 regarding the formation, the deletion, the merger and the changing of Status of Villages become Kelurahan. As the response of that changing, then the regulation of Batu municipality No 4 Year 2007 regarding the changing status of Villages become Kelurahan was issued. Afterwards, the regulation of Batu municipality No 13 Year 2010 regarding the changing status the village of Dadaprejo become the Kelurahan Dadaprejo was imposed. On the contrary, the process of changing status of the Kelurahan of Ngaglik was based on the perspective of the Act Number 5 Year 1974 regarding the principles of local governments and the Act Number 5 year 1979 regarding the village governments. At the time of changing status of the Ngaglik kelurahan in 1982, the context of Batu in the form of Kecamatan or subdistrict which is part of the Government Level II of Malang Regency. The comparison of these two models of the changing status processes within the different of regimes is proposed as knowledge enrichment of the local government practice.

Discurso Web, Modelos Teóricos e Sistemas de Argumentação: Implicações para a Tomada de Decisão

Abstract: The growing importance given by organizations to decision-making in the web context requires more efficient mechanisms to be defined and implemented, in order to support its activities. Social networks whilst collaboration spaces, enable social actors to interact regardless of their location. An important aspect of virtual environments is that, one way or another, argumentative discussions exist and the web is constituted as an excellent tool to support representation, dissemination and knowledge retrieval, as it can enhance the argumentative expression due to its ubiquity and openness. By capturing and analyzing web discourses, organizations can obtain relevant information reflecting the expression of viewpoints that might be useful for decision-making. To achieve this goal, and since words and phrases are always charged with meanings and intentions that might be defined in different ways, it is important to identify and understand the structure of the actors’ social network, communication, context, language, linguistics and content of web discourse. Argumentation has its focus on dialogues, aiming to increase or decrease the acceptance of a point of view in order to reach a conclusion through logical reasoning. In this context, we have seen a significant development of web-centric collaboration systems, which act as argumentation facilitators. Within these systems, different viewpoints can be presented, challenged and evaluated, while collaborative decision-making is carried out through debates and negotiations between groups. Given this new paradigm, this study aims to consolidate existing knowledge on web discourse, argumentation and decision, argumentation theoretical models and argumentation computational systems for the web.