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This study aims to reasonably evaluate VXO (volatility index option) prices on the Taiwan stock index using four popular pricing models, namely, Black-Scholes (BS), square root (SQR), log-normal Ornstein-Uhlenbeck (LOU), and GARCH models. Since VXOs have not been traded yet in Taiwan options market, we directly employ the physical probability measure to evaluate the VXOs. This study examined the Taiwan and CBOE VIX data from December 2006 to January 2018 and found that the estimated option prices generally appear in the descending order as GARCH > BS > SQR > LOU. That is, when VIX has heteroscedasticity, the BS model could undervalue the VXOs. Additionally, when VIX has no mean-reverting property, the SQR and LOU models could seriously undervalue the VXOs, especially for the long-term maturity options. While existing studies have not sufficiently evaluated the Taiwan VXOs, the results of this study can provide future reference for investors and securities companies when evaluating the Taiwan VXOs.

In this paper, we report a novel nanoelectromagnetic system using multiferroic/magnetoelectric Ni-nano-chevron/PMN-PT heterostructure to demonstrate an electric-field-controlled permanent magnetic single-domain transformation. The heterostructure consists of a magnetostrictive Ni-nano-chevron, Pt top and bottom electrodes, and a piezoelectric PMN-PT substrate. In initial state (as demagnetized), the magnetization of the magnetic single-domain is stably along the long axis of the nano-chevron. A magnetic field of 3000 Oe (along 45 degree of nano-chevron) is applied to magnetize the Ni-nano-chevron from stable single-domain to metastable two-domains. After this, an electric field of 0.8MV/m is applied to the PMN-PT substrate to produce the converse magnetoelectric effect to transform the two-domains. After the electric field is removed, the two-domains are further transformed back to the single-domain. Finally, when comparing the domains before and after applying our approach, approximately 50 % of single-domains are successfully and permanently switched (i.e., magnetization-direction is permanently rotated 180 degrees).

In this paper, we demonstrate a novel robust miniature three-axis vibrational energy-harvester using a mechanical-piezoelectric configuration. Using the configuration, the harvester employs Newton’s law of inertia and the piezoelectric effect to convert either the $x$ -axis or $y$ -axis in-plane and $z$ -axis out-of-plane ambient vibrations into piezoelectric voltage-responses. Under the $x$ -axis vibration (sine-wave, 75 Hz, 3.5 g), our modeled, finite-element analyzed/simulated, and experimental root mean square voltage-response with power-outputs of the harvester (stimulated in resonant with the optimum load) is 525.36 mV with 0.477 $\mu \text{W}$ , 516.51 mV with 0.461 $\mu \text{W}$ , and 548 mV with 0.519 $\mu \text{W}$ , respectively. Under the $z$ -axis vibration (sine-wave, 95 Hz, 3.8 g), the modeled, finite-element analyzed/simulated, and experimental root mean square voltage-response with power-output of the harvester (stimulated in resonant with the optimum load) is 157.35 mV with 0.066 $\mu \text{W}$ , 170.25 mV with 0.0772 $\mu \text{W}$ , and 168 mV with 0.075 $\mu \text{W}$ , respectively. These show that not only both of our modeling and finite-element analysis/simulation can successfully predict the experimental results, but also our harvester is capable of harnessing three-axial ambient vibrations. Moreover, through the piezoelectric lead–zirconate–titanate-connected-in-series approach, the voltage and power outputs are increased. According to these achievements, we believe that our harvester would be an important design reference in industry for future development of microfabrication-based (MEMS-based) three-axial piezoelectric energy harvesters and accelerometers.

This study develops a truncated Gram–Charlier expansion (TGCE) option pricing model, which simultaneously considers the skewness, kurtosis and essentially truncated (bounded) interval in the underlying asset return. In addition to TGCE, a truncated Black–Scholes model is proposed also. The two truncated models are compared to four prevalent option pricing models, including Black–Scholes (constant variance model), Hull–White (a mean-reverting variance model), GARCH (a time-varying volatility clustering model), and Gram–Charlier expansion (GCE) models. Using ARPE (absolute relative pricing error) as the criterion in Taiwan option market (TXO), the result demonstrates that TGCE model overall performs the best. Besides, truncated Black–Scholes model generally dominates Black–Scholes model, and GCE model generally dominates Black–Scholes, Hull–White and GARCH models. This result consists with the fact that stock return distributions are usually asymmetric and nonmesokurtic as well as essentially not unbounded. This finding implies that an accurate option pricing model should simultaneously consider skewness and kurtosis and truncated interval in the underlying asset return. Additionally, the ARPE against moneyness for all option pricing models forms a negative slope smile curve. Moreover, the pricing performance of TGCE model is so stable to moneyness.

The effects of B2O3additive on the microstructures, the phase formation and the microwave dielectric properties of MgTiO3–CaTiO3ceramics were investigated. The sintering temperature of B2O3-doped 0.95MgTiO3–0.05CaTiO3ceramics can be lowered to due to the liquid phase effect. Formation of second phase MgTi2O5can be effectively restrained through the addition of B2O3. The microwave dielectric properties are found strongly correlated with the sintering temperature as well as the amount of B2O3addition. At , 0.95MgTiO3–0.05CaTiO3ceramics with 10 wt% B2O3addition possesses a dielectric constant of 18.3, aQ×fvalue of 20,000 (at 7 GHz) and a value of −6.12 ppm/. In comparison with pure 0.95MgTiO3–0.05CaTiO3ceramics, the doped sample shows not only a 22% loss reduction but also a lower sintering temperature. That makes it a very promising material to replace the present one for GPS patch antennas.

The effects of 3Z2B addition on the microwave dielectric properties and the microstructures of (1-x)(Mg0.95Co0.05)TiO3-xCa0.6La0.8/3TiO3ceramics prepared with conventional solid-state route have been investigated. Doping with 3Z2B can effectively promote the densification and the microwave dielectric properties of (1-x)(Mg0.95Co0.05)TiO3-xCa0.6La0.8/3TiO3ceramics. It was found that (1-x)(Mg0.95Co0.05)TiO3-xCa0.6La0.8/3TiO3ceramics can be sintered at 1150°C due to the liquid phase effect of 3Z2B additions observed by SEM. TheQ×fvalue of (1-x)(Mg0.95Co0.05)TiO3-xCa0.6La0.8/3TiO3ceramics decreased with increasing 3Z2B content. At 1150°C, 0.9(Mg0.95Co0.05)TiO3-0.1Ca0.6La0.8/3TiO3ceramics with 1.0wt% 3Z2B addition possesses a εrvalue of 22.6, a Qfvalue of 49,000 (GHz) and a τfvalue of-10.7 ppm/°C.

This study, which is the first to apply Vogelsang's (1998) t - PS T 1 test, shows that trends in presale house prices in Taiwan's largest urban areas are stochastic. Contrary to previous studies, this study's cointegration analysis clearly demonstrates that Taipei is not isolated from long-run price trends. Furthermore, as indicated by weak exogeneity tests, both Taipei and Kaohsiung are long-run leaders in house prices. Moreover, Granger causality test results reveal a strong lead-lag interdependence of house price changes among Taiwan's largest urban areas. These findings have important implications for housing policymakers, mortgage lending institutions, and property investors.

This study investigates the bias adjustment for mean–variance efficient portfolio frontiers due to population mean and variance estimation error in Taiwan stock market. Although Siegel and Woodgate (2007; Management Science, 53, 1005–1015) and Kan and Smith (2008; Management Science, 54, 1364–1380) suggested two portfolio frontiers that improved upon the out-of-sample performance of a traditional sample portfolio frontier. However, this study shows that, using the copula function and Gram-Charlier series, the two frontiers are theoretically biased toward the actual frontier unless returns behave normally, and the bias is related to the return skewness and kurtosis. Indeed, the two frontiers are empirically biased to the lower-left side of the actual ones, because the Taiwan stock returns are right-skewed and highly leptokurtic. Thus, this study thus proposes revised portfolio frontiers that are closer to the actual frontier than unrevised ones. This improvement may enhance the estimation accuracy of the capital market line, and hence this study can provide an effective investment reference.

The effect of V2O5addition on the microstructures and the microwave dielectric properties of 0.9CaWO4-0.1Mg2SiO4(9CWMS) ceramics prepared by conventional solid-state routes have been investigated. The V2O5were selected as liquid phase sintering aids to lower the sintering temperature of 9CWMS ceramics. A small amount of V2O5(0.25~1 wt%) were used for sintering aid and led to high densification at 1050°C. The dielectric properties of 9CWMS ceramics with V2O5additions are strongly dependent on the densification, the microstructure. As the amount of V2O5additives increased from 0.25 to 1.0 wt%, the dielectric constantsεrdecreased following the trend with density. The quality valuesQdecreased with the increase of V2O5amount for all sintering temperatures. The 0.25 wt% V2O5-doped 0.9CaWO4-0.1Mg2SiO4ceramicssintered at 1080°C for 2 h had the optimum dielectric properties: εr= 5.7;Q×f= 73000 (at 14 GHz).

In the piecewise function evaluation with polynomial approximation, nonuniform segmentation can effectively reduce the size of lookup tables for some arithmetic functions compared to uniform segmentation approaches, at the cost of the extra segment address (index) encoder that results in area and delay overhead. Also, it is observed that the nonuniform segmentation reflects a design tradeoff between the ROM size and the area cost of the subsequent arithmetic computation hardware. In this paper, we propose a new nonuniform segmentation method that searches for the optimal segmentation scheme with the goal of minimized ROM, total area, or delay. For some high-variation arithmetic functions, the proposed segmentation method achieves significant area reduction compared to the uniform segmentation method. We also demonstrate the design tradeoff among uniform and nonuniform segmentation, and degree-one and degree-two polynomial approximations, with respect to precision ranging from 12 to 32 bits for the elementary function of reciprocal.

This study investigates the relationship between managerial optimism, investment efficiency and firm valuation. This study follows the Campbell’s measurement for managerial optimism and investigates the influences of the different levels of managerial optimism on improving investment efficiency and firm value when firms tend to under-invest or over-invest. The results indicate that an under-invested firm with a CEO who has a higher level of managerial optimism can improve the firm’s investment efficiency by reducing the degree of underinvestment, which further increases the firm’s value. However, when firms tend to overinvest, there is insufficient evidence to show that a firm with a lower level of CEO managerial optimism will effectively improve the firm’s investment efficiency and increase firm value by reducing the degree of overinvestment.The results generated in this study help scholars and practitioners understand how managerial optimism affects the investment efficiency of firms

In this paper, we report an electrical control of magnetic multi-domain-walls transformation in an N-shape-patterned Ni nanostructures on a piezoelectric [Pb(Mg1/3Nb2/3)O3]0.68–[PbTiO3]0.32 substrate. Based on the converse-magnetoelectric-effect induced domain-wall transformation and the specific N-shape geometry guided domain-wall motion, the domain walls are successfully transformed by an applied electric field of 0.8 MV/m from the transverse domain wall state into the flux closure vortex domain state. These experimental results achieve the electrical control of multi-domain-walls transformation and would create more data storage and memory applications in the future.

This study applies backpropagation neural network for forecasting TXO price under different volatility models, including historical volatility, implied volatility, deterministic volatility function, GARCH and GM-GARCH models. The sample period runs from 2008 to 2009, and thus contains the global financial crisis stating in October 2008. Besides RMSE, MAE and MAPE, this study introduces the best forecasting performance ratio (BFPR) as a new performance measure for use in option pricing. The analytical result reveals that forecasting performances are related to the moneynesses, volatility models and number of neurons in the hidden layer, but are not significantly related to activation functions. Implied and deterministic volatility function models have the largest and second largest BFPR regardless of moneyness. Particularly, the forecasting performance in 2008 was significantly inferior to that in 2009, demonstrating that the global financial crisis during October 2008 may have strongly influenced option pricing performance.

We follow the measurement of Campbell et al. (2011) for managerial optimism and investigate the influences of the different levels of managerial optimism on improving the investment efficiency when firms tend to under-invest or over-invest. The results indicate that an under-invested firm with a CEO that has a high level of managerial optimism can improve the firm's investment efficiency by reducing the degree of underinvestment, further increasing the value of a firm.

Focal adhesion kinase (FAK) and human p70 ribosomal S6 kinase (S6K1) are non-receptor protein tyrosine plays a vital role in cell signaling pathways, such as cell proliferation, survival, and migration. In this study, the 3D structure of FAK (PDB ID: 2AL6) and S6K1 (3A60) were chosen for docking 60 natural compounds attempted to identify novel and specific inhibitors from them. The 30 selected molecules with high scores were further analyzed using DSSTox tools and DS 3.5 ADMET software. Based on a high docking score and energy interaction, 3 of the 9 candidate compounds, neferine B, neferine A, and antroquinonol D, were identified and the inhibitory activity of these compounds were subsequently validated in the C6 glioma cell line. All three selected compounds show potential effects on cell viability by MTT assay. Neferine B, neferine A, and antroquinonol D showed an IC50 value of 10-, 12-, and 16-μM, respectively. Moreover, these compounds decreased the p-FAk and p-S6k1 proteins in a dose-dependent manner. The results of best docked neferine B, neferine A, and antroquinonol D have the potential for further development as a supplement to treat tumorigenesis and metastasis.

We report a magnetic-field-assisted electric-field-controlled approach to rotate magnetic stripe domains in a magnetoelectric Ni-microbar/[Pb(Mg1/3Nb2/3)O3]0.68–[PbTiO3]0.32 heterostructure. A magnetic field is applied for magnetizing the microbar’s stripe domains along the microbar’s short/magnetic-hard axis. Subsequently, an electric field is applied for induction of a transformation of domains through the converse magnetoelectric effect. Owing to the microbar’s geometry, the transformation causes the stripe domains to rotate away from the short/magnetic-hard axis toward the long/magnetic-easy axis. The rotation angle increases in proportion to the increasing electric field intensity. A maximal rotation of 90° is obtained at the electric field intensity of 0.8 MV/m. The rotation state persists after removing the electric field.

With miniaturization of RF-SAW filter package, we should not only take the electromagnetic effects of package into consideration but also the electromagnetic effects of pattern on the SAW substrate. In this paper, the high frequency structure simulator (HFSS) is employed to investigate the crosstalk effects on SAW substrate and mutual coupling effects between pattern on the SAW substrate and package. Special attention has been paid to model SAW filter pattern. It is found that an RF SAW filter device is sensitive to crosstalk between package and pads on the substrate. So the crosstalk effects must be taken into account in the design process. Our approach has been applied to two cases. One is SMD package 3mm/spl middot/3mm with ladder type SAW filter at 881 MHz and the other is flip chip package 2.5 mm/spl middot/2.0 mm with ladder type SAW filter at 1842.5 MHz. Measurement is also carried out to verify our results. Good agreements are obtained.