Possibility Of Structural Changes Research Articles

Study on needle-punched non-woven fabrics made from shrinkable and non-shrinkable acrylic blends. Part II: transmission behaviour

This paper reports the transmission characteristics, i.e. air permeability, thermal conductivity and moisture vapour transmission, of needle-punched non-woven fabrics made from shrinkable and non-shrinkable acrylic blends. The basic idea of this work is to explore the possibility of structural changes in needle-punched non-woven fabrics made from blends of shrinkable and non-shrinkable acrylic-fibres, as in case of an acrylic bulked-yarn. The effects of variables, namely fabric mass per unit area, needling density and the proportion of shrinkable acrylic-fibre in the blend, on various transmission-related properties of needle-punched non-woven fabrics have been studied by relaxing shrinkable component of the fabric using hot steam treatment. A three-variable factorial design technique proposed by Box and Behnken was used to investigate the combined interaction effect of the above variables on transmission properties of these fabrics. Shrinkable acrylic proportion found to have significant effect on transmission properties after steam treatment.

Study on needle-punched non-woven fabrics made from shrinkable and non-shrinkable acrylic blends. Part I: compressional behaviour

This paper reports the compressional characteristics of needle-punched non-woven fabrics made from shrinkable and non-shrinkable acrylic blends. The basic idea of this work is to explore the possibility of structural changes in needle-punched non-woven fabrics made from blends of shrinkable and non-shrinkable acrylic fibres, as in case of an acrylic bulked-yarn. The effects of variables, namely fabric mass per unit area, needling density and the proportion of shrinkable acrylic fibre in the blend, on various compression-related properties of needle-punched non-woven fabrics have been studied by relaxing shrinkable component of the fabric, using hot steam treatment. A three-variable factorial design technique proposed by Box and Behnken was used to investigate the combined interaction effect of the above variables on compressional properties of these fabrics. Before steam treatment, the needling density and mass per unit area have significant effect on the compression, recovery and resilience parameters of the needle-punched non-woven fabrics but shrinkable acrylic does not have any significant effect before steam treatment. But after the steam treatment, the proportion of shrinkable acrylic also has considerable effect on these parameters.

Is the Backward-Looking Component Important in a New Keynesian Phillips Curve?

New Keynesian Phillips curves (NKPC) have recently been modified to include additionallagsofinflationinthespecificationinordertocapturetheconsiderablepersistenceinpostwarU.S.inflation. Furthermore, many researchers have agreed on the existence of structural changes in thepersistence of inflation. Continuing with these literatures, we investigate the nature of structuralchanges in the hybrid NKPC and reconsider the role of the backward-looking component in theNKPC, taking into account the possibility of structural changes in the steady-state inflation rate.Our empirical results show multiple structural breaks in the NKPC in 1974 and 1982. Accountingfor these structural changes, the backward-looking component is no longer significant throughoutthe whole sample period. In other words, the significant role of the backward-looking componentin the earlier literature might be spuriously capturing the structural changes in the steady-stateinflation rate. Thus, U.S. inflation dynamics are well explained by a pure NKPC if we take intoaccount the possibility of structural changes in the steady-state inflation rate.

Growth, optical and thermal characterization of bis(thiourea)zinc chloride single crystals

Single crystals of nonlinear optical material bis(thiourea)zinc chloride (BTZC) were successfully grown by the temperature lowering method and also by the slow evaporation method at constant temperature 28.5°C from its aqueous solutions having various pH values. The best quality crystal was obtained at pH value of 3.13. Studies on structural, thermal properties of the crystals have been carried out on the basis of X-ray diffraction (XRD), infrared spectroscopy (IR), differential thermal analysis (DTA) and thermogravemetric analysis (TGA). DTA study indicates the possibility of structural changes without weight loss. The values of specific heat calculated from DSC data indirectly demonstrate the high damage threshold of BTZC crystal. The crystals possess wide optical transmission window between 290nm and 2000nm. Kurtz powder SHG measurement confirms the nonlinear optical property of the grown crystals.

The Narrow Money Demand Behaviour in Indonesia, 1970– 2005

This paper specifies a simple partial adjustment model of narrow money demand for Indonesia in an open economy context and estimates it with annual data for the period 1970-2005. Empirical results suggest that real income, inflation (a proxy for expected inflation), and the return on foreign financial assets are the major determinants of narrow money demand in this country. The deposit rate of interest (a proxy for the interest rate on alternative domestic financial assets) is statistically insignificant. The CUSUM and CUSUMSQ of residuals' tests suggest that the narrow money demand function remained stable during the sample period of study. Having selected an empirically parsimonious model, both the recursive and rolling regression techniques are applied to investigate the possibility of structural change in the regression coefficients possibly due to financial reforms and innovations since the early 1990s. Empirical results suggest that since the late 1990s the long-run income elasticity of the demand for narrow money has remained relatively stable around a value not different from one while the narrow money demand elasticities with respect to the rates of inflation and the return on foreign financial assets have declined markedly. The paper interprets the overall empirical results in a historical context and draws implications on the strategy of monetary policy in Indonesia.

Biases in appraisal land price information: the case of Japan

PurposeThis paper seeks to investigate the nature and magnitude of the distortion in appraisal land price information according to change in the market, with a special focus on the Government's Published Land Prices.Design/methodology/approachIn Japan, there is an item of land price information, so‐called Koji‐Chika (PLPS: Published Land Price Information System), that is a survey of fair market value by the qualified appraisers. The valuation error of this land price information was analyzed using the following method. First, hedonic price indices were constructed based on both actual transaction prices and the Published Land Prices, they were then compared to detect possible distortions in the governmental price information. Also the possibility of structural change in the Japanese real estate markets was studied and its effect on price indices was considered. Analysis of the Tokyo metropolitan area in Japan took place between 1975 and 1999FindingsLarge and systematic discrepancies between actual transaction prices and the Published Land Prices were identified, which might suggest that there are serious problems in the governmental information system. It is believed that it is necessary to consider this issue in the context of the entire real estate appraisal system in Japan.Research limitations/implicationsLimitations stem from the nature of Japanese data. Future research will seek to look at values on an IPD index.Originality/valueThe land market in Tokyo experienced a so‐called Bubble economy, and the rapid rise and fall of the land price were generated for this period.

Electroreduction of oxygen at polyoxometallate-modified glassy carbon-supported Pt nanoparticles

Platinum nanoparticles of ca. 8 nm diameter (that had been first deposited on glassy carbon) were subsequently modified with ultra-thin films of polyoxometallates through their spontaneous adsorption on solid (platinum and carbon) surfaces. The following polyoxometallates (Keggin type heteropolyacids), H 3SiW 12O 40, H 3SiMo 12O 40, H 3PW 12O 40 and H 3PMo 12O 40, were considered as potential activating agents. Rotating disk voltammetry was used to probe the electroreduction of dioxygen in 0.5 mol dm −3 H 2SO 4 at 25 °C. For the same loading and the approximately identical distribution of platinum nanoparticles on glassy carbon, the statistically higher (in comparison to bare Pt) electrocatalytic currents for the oxygen reduction were observed upon introduction of monolayers of heteropolyanions. Out of polyoxometallates considered, the system modified with heteropolytungstate (H 3PW 12O 40) seemed to be the most effective in electrocatalysis. Although the possibility of structural changes cannot be excluded, the synergistic effect originated presumably from the bifunctional activity of the electrocatalyst. While Pt retained its usual reactivity towards the oxygen reduction, H 3PW 12O 40 could act as both effective mediator (e.g. for the reduction of the hydrogen peroxide intermediate) and the source of mobile protons at the electrocatalytic interface.

A Theory-Based, State-Dependent Phillips Curve and its Estimation

To explain the existing empirical irregularity about the slope of a Phillips curve, this article provides a model of imperfect competition to short that the slope of a Phillips curve is shock-dependent. We empirically apply a state-space, Markov-switching model to examine the impact of inflation surprise on the unemployment gap, resulting in the state-dependent Phillips curve fitting quite well. Our empirical evidence indicates that an unexpected monetary, expansion does produce effects in reducing unemployment rates and that supply shocks should not be ignored in estimating the Phillips curve because they dominate demand shocks in several nonoil shock periods. (JEL C51, E24, E52) I. INTRODUCTION It is well known that a downward-sloping short-run Phillips curve implies a trade-off between the inflation rate and unemployment rate. However, empirical findings point out that the slope of the Phillips curve depends on the selected sample periods. (1) Does any theoretical model explain the changes in the slope of a short-run Phillips curve as displayed in the data? Can we find empirical support for our model that implies a slope-changeable Phillips curve? To answer these questions, this article provides a theoretical model implying that the slope of the Phillips curve is shock-dependent. We then apply a state-space, Markov-switching model to investigate the empirical support of the theoretical model. Although a stable, negative, short-run Phillips curve is crucial for producing inflation forecasts in policy-making institutions, there is no general consensus about the negative slope of the Phillips curve in empirical literature. (2) One of the explanations to the previous empirical irregularity, as suggested by King and Watson (1994) is that the relationship between unemployment and inflation is shock-dependent, which means that the slope of a Phillips curve relies on the dominance of the demand or supply shocks. Therefore the conventional single-equation regression based on the state independent framework is not appropriate. Apart from neglecting the state-dependent characteristic of the Phillips curve, there are several other drawbacks for conventional empirical studies when investigating the Phillips curve. First, many articles assume that forecast errors of inflation are homoscedastic, which is challenged in the literature. The homoscedastic assumption is debatable because several studies, such as Engle (1983), Jansen (1989), Evans (1991), and Brunner and Hess (1993), point out significant heteroscedasticity in the U.S. inflation rate. ARCH- or GARCH-type models provide estimates of how the conditional variance of inflation varies over time within a given structure and therefore they ignore the possibility of structural changes caused by changing regimes. A Markov-switching heteroscedasticity model is an alternative that allows regime changes in the variance structure. Instead of applying ARCH-type models to estimate the time-varying conditional variance of inflation within a given structure, this article takes into account the influence of regime changes on inflation's variance. We apply the state-dependent conditional heteroscedasticity approach provided by Brunner and Hess (1993) and Evans and Wachtel (1993) to estimate the forecasting errors of inflation. The second drawback is a constant natural rate assumption. The unemployment gap is the difference between the unemployment rate and the natural rate. Conventional literature assumes a constant natural rate, which is challenged theoretically and empirically as stated by Gordon (1997). The existence of unionization, unemployment insurance programs, and labor force demographics leads to a highly persistent unemployment rate. We therefore assume that the unobservable natural rate is time-varying and behaves in accordance with the hysteresis of unemployment rates. (3) Recent empirical works of a regime-switching approach on the Phillips curve have focused on whether the relationship between inflation and unemployment rates is nonlinear, as in Ferri et al. …

Democracy in South Asia: Getting beyond the Structure-Agency Dichotomy

With reference to South Asia, we argue that recourse to the conventional structuralist and transition accounts of democratisation sustains an unhelpful dichotomy. Those approaches tend towards either determinism or agent-driven contingency. In contrast, an alternative approach that recognises the relevance of both structure and agency is proposed. In certain circumstances, human agency opens up the possibility of the relatively rapid transformation of structures. In particular, there are periods of political openness when structures are malleable, and individuals, or individuals acting collectively, are able to reshape structures. Decolonisation both constituted a moment of transition and opened up the possibility of structural change in the context of enhanced elite agency. For the purposes of comparison, the discussion covers the three cases of India, Pakistan and Sri Lanka. Particular attention is drawn to political parties and the structure of ethnic diversity as leading explanatory variables.

Long-Run Purchasing Power Parity with Asymmetric Adjustment

1. Introduction Despite its intuitive appeal, there is inconclusive evidence supporting purchasing power parity (PPP) between countries with low inflation rates during the post-Bretton Woods period. For example, Enders (1988), Taylor (1988), and MacDonald (1993) use various forms of cointegration tests-called stage-three tests-and find that real exchange rates exhibit large fluctuations with slow rates of decay toward a long-run mean. Froot and Rogoff's (1995) literature review presents a consensus estimate that deviations from long-run PPP have a half-life of about three years. This is somewhat disappointing since stage-three tests seem to be well suited to the task-they require no assumptions concerning exogeneity and they imply a sensible dynamic relationship among price levels and the exchange rate. The vast literature on PPP is indicative of the importance of the issue and the ambiguity of the findings. It is well recognized that standard cointegration tests have low power to reject the null hypothesis of no cointegration. This observation is especially relevant for PPP since any mean reversion in real rates is very gradual and the length of the post-Bretton Woods period sample period is relatively short. Efforts to increase the power of unit-root and stage-three tests have had mixed success. For example, Lothian and Taylor (1996) and Mark (1990) have tried to circumvent the low power of stage-three tests by using long spans of time-series data. Unfortunately, the use of long time spans raises the possibility of structural changes occurring during the period being examined. Panel unit-root tests are generally more supportive of PPP than are bilateral tests of real exchange rate behavior. For example, Oh (1996), Wei and Parsley (1995), and Wu (1996) have used panel data in order to enhance the power of standard unit-root tests. Although these particular articles are supportive of PPP, panel studies must deal with the thorny issues of cross-sectional correlation and the choice of the nations to include in the panel. Papell (1997) finds that allowing for serial correlation substantially weakens the evidence in favor of long-run PPP. O'Connell (1998) applies generalized least squares to panel data to eliminate any contemporaneous correlation in the error structure and finds no evidence supporting PPP The second problem with the standard unit-root and cointegration tests is that they implicitly assume symmetric adjustment. However, official intervention in the foreign exchange market means that nominal exchange rate adjustment may be asymmetric. Under a managed float, for example, one of the monetary authorities might be more willing to tolerate currency appreciation than depreciation. Similarly, a currency band mitigates exchange rate movements until the level of the band is altered. Furthermore, the slow adjustment of real exchange rates is often explained by the stickiness of national price levels. For example, in the well-known Dornbusch (1976) overshooting model, prices and the exchange rate move in the same proportion as the money supply in the very long run. However, in the short run, prices are sticky and monetary shocks cause PPP deviations since the exchange rate moves proportionately more than prices. Rhee and Rich (1995) and Madsen and Yang (1998) provide empirical evidence corroborating the implications of the asymmetric price adjustment models. The key point to note is that, if prices are primarily sticky in the downward direction, there is no reason to presuppose that real exchange rate adjustment is symmetric. In spite of the evidence supportive of asymmetric exchange rate and price adjustments, there are only a few nonlinear tests of PPP Although they do not explicitly test for PPP, Michael, Nobay, and Peel (1997) and Taylor and Sarno (1998) estimate real exchange rates as smooth-- transition threshold adjustment processes. Enders and Falk (1998) formally apply various nonlinear unit-root tests to real exchange rates and find little evidence of PPP. …

NONLINEAR AND NON-GAUSSIAN STATE SPACE MODELING USING SAMPLING TECHNIQUES

In this paper, the nonlinear non-Gaussian filters and smoothers are proposed using the joint density of the state variables, where the sampling techniques such as rejection sampling (RS), importance resampling (IR) and the Metropolis- Hastings independence sampling (MH) are utilized. Utilizing the random draws generated from the joint density, the density-based recursive algorithms on filtering and smoothing can be obtained. Furthermore, taking into account possibility of structural changes and outliers during the estimation period, the appropriately chosen sampling density is possibly introduced into the suggested nonlinear non-Gaussian filtering and smoothing procedures. Finally, through Monte Carlo simulation studies, the suggested filters and smoothers are examined.

Protein crystallization by design: chymotrypsinogen without precipitants

Protein crystals are usually obtained by an empirical approach based on extensive screening to identify suitable crystallization conditions. In contrast, we have used a systematic predictive procedure to produce data-quality crystals of bovine chymotrypsinogen A and used them to obtain a refined X-ray structure to 3 Å resolution. Measurements of the osmotic second virial coefficient of chymotrypsinogen solutions were used to identify suitable solvent conditions, following which crystals were grown for approximately 30 hours by ultracentrifugal crystallization, without the use of any precipitants. Existing structures of chymotrypsinogen were obtained in solutions including 10–30 % ethanol, whereas simple buffered NaCl solutions were used here. The protein crystallized in the tetragonal space group P41212, with one molecule per asymmetric unit. The quality of the refined map was very high throughout, with the main-chain atoms of all but four residues clearly defined and with nearly all side-chains also defined. Although only minor differences are seen compared to the structures previously reported, they indicate the possibility of structural changes due to the crystallization conditions used in those studies. Our results show that more systematic crystallization of proteins is possible, and that the procedure can expand the range of conditions under which crystals can be grown successfully and can make new crystal forms available.

Proprioceptive control of wrist extensor motor units in humans: dependence on handedness

The effectiveness of the monosynaptic proprioceptive assistance to the wrist extensor motoneurone activity was investigated during voluntary contraction in relation to the subjects' handedness. The reflex responses of 411 single motor units to homonymous tendon taps were recorded in the wrist extensor carpi radialis muscles in both arms of five right-handed and five left-handed subjects. In the right-handed subjects, the motor unit reflex responses were clearly lateralized in favour of their right arm, whereas no side-related differences were observed in the left-handed subjects, whatever the motor units' mechanical properties and firing rates. When the muscle spindle sensitivity was by-passed by electrically stimulating the primary afferents in both arms of three right-handed and three left-handed subjects, no side-related differences were observed in the Hoffmann reflex (H-reflex) amplitude in either of the two lateralization groups. The effectiveness of the primary afferent synapses on to the motoneurones therefore does not seem to depend on the subject's handedness. Without excluding the possibility of structural changes being involved at the periphery, the comparisons carried out on the data obtained using electrical vs mechanical stimulation suggest that the asymmetrical effectiveness of the proprioceptive assistance observed in favour of the right arm in the right-handed subjects might result from either the gamma or beta drive being more efficient. This asymmetry might result from the preferential use of the right hand in skilled movements. In a predominantly right-handed world, however, left-handed people might tend to develop the ability to use their right arm almost as skillfully as their preferred left arm, which could explain the symmetrical effectiveness of the proprioceptive assistance observed here in the left-handers' wrist extensor muscles.

Further analysis of official and black market exchange rates in Brazil: data transformations and structural changes

This paper extends the previous results in Bessler and Yu (1994) on the official and black market exchange rates in Brazil. Rather than taking instantaneous data transformations to produce a stable long-run equilibrium relationship as Bessler and Yu did, the possibility of structural changes in the long-run relationship was considered. It is found that the two approaches have quite different implications on the long-run dynamics of the data series. It is claimed that to fully understand the dynamics of the exchange rate data series, it is necessary to consider the possibility of structural change and explicitly model it.

Variable betas on the Stockholm exchange 1971-1989

The present study presents models of the systematic risk of 10 individual assets on the Stockholm exchange. A model for the β of the equally weighted portfolio of all 10 is also presented. Three different models for the risk coefficient in addition to the constant coefficient model are considered: the mean reverting model, the random coefficients model and the random walk model. The possibility of structural change is also considered resulting in a division of the sample from January 1971 to December 1989 in two or more subsamples for some of the stocks. The model that is 'best' for each stock was the one with the lowest Akaike information criterion. This criterion was then compared to the out of sample forecasting ability of the models. While no one model is consistently the best, the random walk model is preferred, as it forecasts on the average slightly better than the other ones.

On the Behavior of Import Demand of Korea

In this paper, I provide estimates of the Import demand function for Korea for the period of 1971 – 1988. Second, considering the possibility of structural change in our data period, we test the stability of the coefficients. Cusum of squares test result shows the constancy of the parameters broken between pre-1980 and post-1981 data. The estimation result based on data only after 1981 shows that the income elasticity becomes less responsive over time and the relative prices do not exercise significant influence on Korean imports.

Structural Change in Factor Substitution in Finnish Manufacturing

The possibility of structural change in Finnish factor substitution relations between energy and nonenergy factors is analyzed. The standard generalized Leontief KLEMF cost function is modified so that the substitution parameters related to electricity and fuel factors may shift to new levels over time. The initial point of transition is 1974, during which the first energy crises took place. Likelihood ratio tests confirm that there has indeed been a statistically significant change in energy versus nonenergy substitution. Our estimates imply stronger substitutability for most input pairs after the energy crisis.

Spastic dysphonia and denervation signs in a young man with tardive dyskinesia

Pathophysiological theories of tardive dyskinesia (TD) suggest the possibility of structural changes in the central nervous system of patients with TD. This report describes a case of choreoathetoid dyskinesia and spastic dysphonia associated with clinical and electromyographic signs of muscle denervation. The findings of this case suggest that the neurological syndrome originates within basal ganglia nuclei but may also extend to the peripheral neuromuscular system.

The Underwriting Cycle and the Risk Manager: Authors' Reply

We would like to take the opportunity to reply to Mark Jablonowski's comment on our article entitled Underwriting Cycle and the Risk Manager. We believe that the statistical algorithm used in our article is not novel in its approach. Instead it merely takes the basic cycle algorithm a step further. The fact that this algorithm takes into consideration the possibility of structural change, in this instance the upward trend in combined ratios over time, makes it an appropriate tool for this analysis. One can always argue as to the ability of econometric tools to evaluate any set of variables over time. In his own articles (see Jablonowski's references), no statistical basis for his conclusions about the underwriting cycle is offered. Obviously, we differ with Jablonowski as to the ability of econometric tools to determine or evaluate an underwriting cycle, but argue that our statistical approach is not novel. Our sample size was not small. We looked at the combined ratio for the years 1945 to 1983. This provided us with 39 years of data. This is more than an adequate number of data points for our statistical model. We could not have realistically expanded our data base. The primary purpose of the article was to attempt to statistically measure if an underwriting cycle existed over previous years (1945-83). In our opinion, we adequately showed that a cycle of approximately six years in length existed over the years studied. It was not our intent to attempt to predict future cycles. We never hypothesized a six-year cycle. However, the upward trend in combined ratio from 1979 to 1984 does not disconfirm the existence of a six-year underwriting cycle over the years 1945 to 1983. It does confirm our conclusion that the magnitude of the peaks in the cycle have been increasing over time. Perhaps this explains Jablonowski's observation of the steady upward trend in combined ratio from 1979 to 1984. Perhaps if one were to change the time period considered from 1945-1983 to 1975-1988 the

Effect of high pressure on radiative recombination in hydrogenated amorphous silicon

The first studies of photoluminescence (PL) at high pressure in hydrogenated amorphous silicon are reported. A cryogenic diamond-anvil press is employed in the range 0-75 kbars, 10-110 K. Whereas the PL intensity is strongly quenched by compression, the peak position is only weakly shifted to lower energy. This interesting dichotomy indicates that compression affects radiative and nonradiative processes differently. The quenching data suggest an increase in the intragap defect density by \ensuremath{\sim}${10}^{17}$ ${\mathrm{cm}}^{\ensuremath{-}3}$, after pressurizing to 42 kbars and lowering to 1 atm. This is interpreted as evidence for compression-induced structural changes, associated with voids, which augment the nonradiative defect population. Although the pressure coefficient, -2.0\ifmmode\pm\else\textpm\fi{}0.5 meV/kbar for the PL peak is similar to that of the absorption edge in crystalline (and amorphous) Si, the possibility of structural changes discourages a direct connection between the two. Useful "Gruneisen parameter" expressions, which are derived for the Stokes shift and PL linewidth, indicate marginal compatibility between the Stokes-shift hypothesis and the pressure data. No strong effect of pressure on the PL thermal behavior is observed. With increasing pressure the radiative decay rate exhibits nonmonotonic behavior, first increasing to a maximum at 23 kbars and then decreasing. This complex dependence, which could not be explained within a simple (donor-acceptor-type) radiative tunneling picture, may reflect details of the recombination process. A model is suggested involving small-polaron hopping between inequivalent sites.