The suitability of a monetary union in East Asia: What does the cointegration approach tell?

The issue of whether or not to form a monetary union in East Asia remains a hot issue in the study of the East Asian economies. Most of the existing studies apply a framework focusing on the symmetric issue of the fundamental shocks and the extent of correlations by applying the Blanchard and Quah [O.J. Blanchard, D. Quah, The dynamic effects of aggregate demand and supply disturbances, American Economic Review 79 (1989) 655–673] structural vector autoregression (VAR) technique, which includes first-differenced variables in the model and examines only the bilateral relationships. However, the shock symmetry does not necessarily require the co-movements of the real output variables between the countries concerned. The present paper employs the Johansen [S. Johansen, Statistical analysis of cointegration vectors, Journal of Economic Dynamics and Control 12 (1988) 231–254] cointegration approach to check the long-run co-movements of real outputs among the East Asian countries, Japan and the United States to draw some implications about forming a monetary union in the region. The results suggest that some groups of Asian NIEs plus the United States will be potential candidates to form a monetary union. Mainland China is not suggested as a member country of a monetary union with any of the grouped economies. More interestingly, the ASEAN countries alone are not a feasible group to form a monetary union unless Japan is included, which has important implications for the role of Japan towards the formation of a regional monetary union.     

In situ XAFS analysis of Pd–Pt catalysts during hydrotreatment of model oil

Supported Pd–Pt catalysts are efficient for hydrodesulfurization (HDS) and hydrodearomatization (HDA) reactions of diesel fuel and their activity varied with the kinds of supports. Concerning HDA, alumina supported catalysts showed four times higher TOF (turn over frequency) than silica supported one. In order to elucidate the difference in activity, the structural analysis of the active phase was performed. After reduction pretreatment, relatively uniform and large metallic alloy Pd–Pt particles were formed on SiO₂, whereas, Pd and Pt atoms formed rather segregated particles on Al₂O₃. Subsequent X-ray absorption of fine structure (XAFS) analysis under HDS conditions showed no contribution of sulfur for SiO₂ supported catalyst, whereas, formation of sulfided metal species was observed in XAFS spectra for the Al₂O₃ supported catalyst. It is suggested that on Pd–Pt/SiO₂, thin sulfide layer on the metal cluster surface blocked the active sites and lowered the HDA activity. Presence of partially sulfided phase originated from rather segregated structure like Pd–Pt/Al₂O₃ is thought to be requisite for high HDA activity.     

Peritectic transformation during cooling of iron-carbon alloy

Peritectic transformation behavior during cooling of iron-carbon alloys is simulated by a numerical analysis. The peritectic transformation, δ+L=γ, is divided into δ-γ transformation at δ/γ interface and L-γ solidification at γ/L interface, and proceeds by the following two mechanisms: (1) carbon diffusion from liquid (referred to as L) through austenite (γ) into δ-ferrite (δ) and (2) precipitation of austenite from δ-ferrite and crystallization of it from liquid due to cooling. Approximately 80% of the austenite formed during the peritectic transformation is the products of δ-y transformation, which may cause the generation of tensile stress in the solidification shell of cast steels due to the difference in density between δ-ferrite and austenite The amount of the δ-γ transformation is largest, when the initial carbon content is 0.17 mass%. However, when the transformation in a well-developed dendrite network structure is focused on, the carbon content for the maximum amount of the δ-γ transformation decreases to 0.14–0.16 mass%, which corresponds to the carbon content at which surface cracking of continuously cast slabs is reported to be most frequent     

Laser Beam Machining of Porous Woodceramics

Laser beam machining was tested as a practical method for machining porous woodceramics (WCS). A black carbonized layer is generally formed on the processed surface when woody materials are processed with laser beam machining. This problem does not occur on the WCS because they are burned. The processed surface temperature during laser beam machining can be estimated from the relationship between the burning temperature and C and O₂ component concentrations. Burning (scorching) on the processed surface decreases slightly as the feed speed of the workpiece increases. WCS are more easily processed with laser machining after being burned, using pulse oscillation to reduce the thermal influence.     

Improvement of a Real Gas-Sensor for the Origin of Methane Selectivity Degradation by µ-XAFS Investigation

Nano-Micro Letters - We have directly investigated the chemical state of the Pd species in a real μ-gas sensor device by examining the μ-fluorescence X-ray absorption fine structure. The...     

Molecular catalysts confined on and within molecular layers formed on a si(111) surface with direct si-C bonds

Two examples of confined molecular catalysts are presented. PtCl(4) (2-) complexes are attached to a thiol-terminated monolayer by ligand exchange of Cl(-) with a thiolate group and incorporated in a multilayer of viologen moieties by ion exchange. All Cl(-) ligands are replaced by OH(-) or H(2) O before HER takes place. Ex situ and in situ XAFS measurements confirm that the Pt complexes accelerate HER without being converted into Pt particles.     

Electroplasticity memory devices using conducting polymers and solid polymer electrolytes

Erasable memory devices are fabricated by the combination of a conducting polymer and solid polymer electrolyte. The former is used as a memory channel and the latter as an electrolyte medium. The channel conductivity can be controlled over 3-4 orders of magnitude by electrochemical doping through a writing electrode. The response time, depending on the writing voltage, is several seconds. The characteristics of the memory device are discussed.     

Neural network approach to acquiring free-gait motion of quadruped robots in obstacle avoidance

In obstacle avoidance by a legged mobile robot, it is not necessary to avoid all of the obstacles by turning only, because it can climb or stride over some of them, depending on the obstacle configuration and the state of the robot, unlike a wheel-type or a crawler-type robot. It is thought that mobility efficiency to a destination is improved by crawling over or striding over obstacles. Moreover, if robots have many legs, like 4-legged or 6-legged types, then the robot's movement range is affected by the order of the swing leg. In this article a neural network (NN) is used to determine the action of a quadruped robot in an obstacle-avoiding situation by using information about the destination, the obstacle configuration, and the robot's self-state. To acquire a free gait in static walking, the order of the swing leg is realized using an alternative NN whose inputs are the amount of movement and the robot's self-state. The design parameters of the former NN are adjusted by a genetic algorithm (GA) off-line. This work was presented in part at the 9th International Symposium on Artificial Life and Robotics, Oita, Japan, January 28–30, 2004     

Development of Broadband Telecommunications System for Railways Using Laser Technology

We developed a high‐speed telecommunication system for use on railways to improve customer service and the efficiency of operator's telecommunications between ground facilities and trains under operation. We built a mobile telecommunication system, capable of achieving a transfer rate of 1 Gbps in theory, by utilizing laser beam communications technology. We carried out a field test using trains in active service, and obtained results in which a transfer rate of approximately 700 Mbps in the TCP layer was achieved between the ground and a train running at a speed of approximately 130 km/h .     

Finding all solutions of piecewise‐linear resistive circuits using the dual simplex method

An efficient algorithm is proposed for finding all solutions of piecewise‐linear (PWL) resistive circuits using linear programming (LP). This algorithm is based on a simple test (termed the LP test) for non‐existence of a solution to a system of PWL equations in a given region. In the conventional LP test, the system of PWL equations is transformed into an LP problem, to which the simplex method is applied. However, this algorithm requires a very large number of pivotings because the simplex method is applied on many regions. In this paper, we introduce the dual simplex method to the LP test, which makes the average number of pivotings per region much smaller (less than one, for example) and makes the algorithm very efficient. By numerical examples, it is shown that the proposed algorithm could find all solutions of large‐scale problems, including those where the number of variables is 300 and the number of linear regions is 10³⁰⁰, in practical computation time. Copyright © 2002 John Wiley & Sons, Ltd.