Causality relations between foreign direct investment and portfolio investment volatility

Following the liberalization of financial markets, Goldstein and Razin (2006) show that there is an information based trade-off between foreign direct investment and foreign portfolio investment, our paper examines the causality relations between foreign direct investment and volatility of foreign portfolio investment. Utilizing monthly and quarterly data set of Czech Republic, Poland, Russia and Turkey, volatility of portfolio investments, which indicated evidence of ARCH effects for all four countries, have been estimated by best fitting GARCH (p,q) models. Further, potential causality has been examined by Granger (1969), Sims (1972) and Toda and Yamamoto (1995) test methods. Results indicated that, for Russia and Turkey foreign direct investment has a significant cause on portfolio investment volatility. However for Czech Republic and Poland, there is no such significant relationship has been found. Finally further investigation of a possible structural break due to EU membership could not provide such evidence for Czech Republic and Poland in related variables.Foreign Direct Investment, Foreign Portfolio Investment, Eastern Europe, Causality

Survivability in hierarchical telecommunications networks under dual homing

Cataloged from PDF version of article.The motivation behind this study is the essential need for survivability in the telecommunications networks. An optical signal should find its destination even if the network experiences an occasional fiber cut. We consider the design of a two-level survivable telecommunications network. Terminals compiling the access layer communicate through hubs forming the backbone layer. To hedge against single link failures in the network, we require the backbone subgraph to be two-edge connected and the terminal nodes to connect to the backbone layer in a dual-homed fashion, i.e., at two distinct hubs. The underlying design problem partitions a given set of nodes into hubs and terminals, chooses a set of connections between the hubs such that the resulting backbone network is two-edge connected, and for each terminal chooses two hubs to provide the dual-homing backbone access. All of these decisions are jointly made based on some cost considerations. We give alternative formulations using cut inequalities, compare these formulations, provide a polyhedral analysis of the smallsized formulation, describe valid inequalities, study the associated separation problems, and design variable fixing rules. All of these findings are then utilized in devising an efficient branch-and-cut algorithm to solve this network design problem

Release Time Scheduling and Hub Location for Next-Day Delivery

Cataloged from PDF version of article.Inspired by a real-life problem faced by one of the largest ground-based cargo companies of Turkey, the current study introduces a new facet to the hub location literature. The release time scheduling and hub location problem aims to select a specified number of hubs from a fixed set of demand centers, to allocate each demand center to a hub, and to decide on the release times of trucks from each demand center in such a way that the total amount of cargo guaranteed to be delivered to every potential destination by the next day is not below a threshold and the total routing cost is minimized. The paper introduces integer programming models to solve this problem in the special cases when the cargo uniformly arrives to each demand center during the day and the more realistic pattern of when the cargo arrivals exhibit a piecewise linear form. Several classes of valid inequalities are proposed to strengthen the formulations. Extensions with multiple service levels and discrete sets for release times are also discussed. Computational results show the computational viability of the models under realistic scenarios as well as the validity of the proposed problems in answering several interesting questions from the cargo sector’s perspective

SHOP2: An HTN Planning System

The SHOP2 planning system received one of the awards for distinguished performance in the 2002 International Planning Competition. This paper describes the features of SHOP2 which enabled it to excel in the competition, especially those aspects of SHOP2 that deal with temporal and metric planning domains

Template free preparation of nanoporous organically modified silica thin films on flexible substrates

Cataloged from PDF version of article.We report the preparation and characterization of nanoporous organically modified silica (ormosil) thin films at room temperature and neutral pH conditions from homogeneous methyl silsesquioxane (MSQ) gels. Universally applicable and stable colloidal ormosil suspensions are prepared from the gels by sonication and coated to the substrates including glass, paper and plastics. The nanoporosity and thickness of the films can be tuned, which makes them suitable for certain applications including sensing, functional coatings, and low-dielectric materials. We demonstrate the antireflection property of the films on glass, cellulose acetate (CA) and polyetherimide (PEI) substrates. The films on CA and PEI retain their antireflection property after multiple bending cycles. Furthermore, films are intrinsically hydrophobic, over a wide pH range, with static contact angles up to 143° on paper and 123° on glass and CA. Producing nanoporous ormosil thin films on flexible substrates may expand their use in low cost electronic, optical devices and sensors, and lab-on-paper applications

All-chalcogenide glass omnidirectional photonic band gap variable infrared filters

Cataloged from PDF version of article.We report on the design, fabrication, and characterization of spatially variable infrared photonic band gap filter that consists of thermally evaporated, high refractive index contrast, amorphous chalcogenide glass multilayers. Due to graded thickness structure, the filter exhibits a position dependent stop band and a cavity mode ranging from 1.8 to 3.4 μm wavelengths. Reflection measurements on the variable filter agree well with theoretical calculations. These results pave the way to low-loss infrared mirrors, filters, spectral imaging, and miniaturized spectrometers at infrared region. © 2009 American Institute of Physics

Causality relations between foreign direct investment and portfolio investment volatility

Following the liberalization of financial markets, Goldstein and Razin (2006) show that there is an information based trade-off between foreign direct investment and foreign portfolio investment, our paper examines the causality relations between foreign direct investment and volatility of foreign portfolio investment. Utilizing monthly and quarterly data set of Czech Republic, Poland, Russia and Turkey, volatility of portfolio investments, which indicated evidence of ARCH effects for all four countries, have been estimated by best fitting GARCH (p,q) models. Further, potential causality has been examined by Granger (1969), Sims (1972) and Toda and Yamamoto (1995) test methods. Results indicated that, for Russia and Turkey foreign direct investment has a significant cause on portfolio investment volatility. However for Czech Republic and Poland, there is no such significant relationship has been found. Finally further investigation of a possible structural break due to EU membership could not provide such evidence for Czech Republic and Poland in related variables

Operator representation and logistic extension of elementary cellular automata

We redefine the transition function of elementary cellular automata (ECA) in terms of discrete operators. The operator representation provides a clear hint about the way systems behave both at the local and the global scale. We show that mirror and complementary symmetric rules are connected to each other via simple operator transformations. It is possible to decouple the representation into two pairs of operators which are used to construct a periodic table of ECA that maps all unique rules in such a way that rules having similar behavior are clustered together. Finally, the operator representation is used to implement a generalized logistic extension to ECA. Here a single tuning parameter scales the pace with which operators iterate the rules. We show that, as this parameter is tuned, many rules of ECA undergo multiple phase transitions between periodic, locally chaotic, chaotic and complex (Class 4) behavior

Energy loss and longitudinal wakefield of relativistic short proton bunches in electron clouds

The aim of our study is the numerical computation of the wakefield and energy loss per unit length for relativistic, short (<10  ns) proton bunches interacting with an electron cloud inside the beam pipe. We present analytical expressions for the energy loss in the impulse kick approximation. For the simulation of the wakefields a 2D self-consistent, electrostatic particle-in-cell (PIC) code is employed. Results for the energy loss and for the wakefields are presented for the parameter scope of the CERN LHC and SPS. For selected parameters the results are compared to a three-dimensional (3D) electromagnetic PIC code

Survivability in hierarchical telecommunications networks under dual homing

The motivation behind this study is the essential need for survivability in the telecommunications networks. An optical signal should find its destination even if the network experiences an occasional fiber cut. We consider the design of a two-level survivable telecommunications network. Terminals compiling the access layer communicate through hubs forming the backbone layer. To hedge against single link failures in the network, we require the backbone subgraph to be two-edge connected and the terminal nodes to connect to the backbone layer in a dual-homed fashion, i.e., at two distinct hubs. The underlying design problem partitions a given set of nodes into hubs and terminals, chooses a set of connections between the hubs such that the resulting backbone network is two-edge connected, and for each terminal chooses two hubs to provide the dual-homing backbone access. All of these decisions are jointly made based on some cost considerations. We give alternative formulations using cut inequalities, compare these formulations, provide a polyhedral analysis of the smallsized formulation, describe valid inequalities, study the associated separation problems, and design variable fixing rules. All of these findings are then utilized in devising an efficient branch-and-cut algorithm to solve this network design problem. © 2014 INFORMS