A ship motion simulation system

In this article, efficient computational models for ship motions are presented. These models are used to simulate ship movements in real time. Compared with traditional approaches, our method possesses the ability to cope with different ship shapes, engines, and sea conditions without the loss of efficiency. Based on our models, we create a ship motion simulation system for both entertainment and educational applications. Our system assists users to learn the motions of a ship encountering waves, currents, and winds. Users can adjust engine powers, rudders, and other ship facilities via a graphical user interface to create their own ship models. They can also change the environment by altering wave frequencies, wave amplitudes, wave directions, currents, and winds. Therefore, numerous combinations of ships and the environment are generated and the learning becomes more amusing. In our system, a ship is treated as a rigid body floating on the sea surface. Its motions compose of 6 degrees of freedom: pitch, heave, roll, surge, sway, and yaw. These motions are divided into two categories. The first three movements are induced by sea waves, and the last three ones are caused by propellers, rudders, currents, and winds. Based on Newton’s laws and other basic physics motion models, we deduce algorithms to compute the magnitudes of the motions. Our methods can be carried out in real time and possess high fidelity. According to ship theory, the net effects of external forces on the ship hull depend on the ship shape. Therefore, the behaviors of the ship are influenced by its shape. To enhance our physics models, we classify ships into three basic types. They are flat ships, thin ships, and slender ships. Each type of ship is associated with some predefined parameters to specify their characteristics. Users can tune ship behaviors by varying the parameters even though they have only a little knowledge of ship theory.     

Adaptive blind receivers for MC‐CDMA communication systems

In this paper, we propose three adaptive blind algorithms for multiuser multicarrier code division multiple‐access systems in multipath fading channels. The proposed adaptive blind receivers are based on the property of the discreteness of the input data symbol and are updated in every symbol interval. We also use the concept that the variance of the output signal approaches to the variance of the desired signal to get the cost function. The three proposed receiver structures are the traditional finite impulse response (FIR) structure, the despreading (DES) filter structure and the generalized sidelobe canceller (GSC) structure. The advantage of the FIR filter is that the length of the filter weights does not have to be the same length as the spreading code. For the DES filter, the combination of the adaptive weight and the despreading code has the simplest structure than the other two proposed receiver structures. The constrained GSC filter is superior to the other two proposed receiver structures in the environments dominated by multiple‐access interference. By this constraint, the blind GSC filter can guarantee to converge to the desired solution. Simulation results are given to show the effectiveness and comparison of the proposed adaptive blind receivers. Copyright © 2012 John Wiley & Sons, Ltd.     

Modulation of cytochrome P-450-dependent monooxygenases, glutathione and glutathione S-transferase in rat liver by geniposide from Gardenia jasminoides

Geniposide is an iridoid glycoside extracted from the fruits of Gardenia jasminoides, which are used as a food colorant and as a traditional Chinese medicine for treatment of hepatic and inflammatory diseases. The effects of geniposide and G. jasminoides fruit crude extract on liver cytochrome P-450 (P-450)-dependent monooxygenases, glutathione and glutathione S-transferase were investigated using rats treated orally with the iridoid glycoside (0.1 g/kg body weight/day) or the fruit crude extract (2 g/kg/day) for 4 days. The treatments decreased serum urea nitrogen level but increased liver to body weight ratio, total hepatic glutathione content and hepatic cytosolic glutathione S-transferase activity. Treatments with geniposide and G. jasminoides decreased P-450 content, benzo[a]pyrene hydroxylation, 7-ethoxycoumarin O-deethylation, and erythromycin N-demethylation activities in liver microsomes without affecting aniline hydroxylation activity. The natural products had no effect on glutathione content and monooxygenase activities in kidney microsomes. Immunoblotting analyses of liver microsomal proteins using mouse monoclonal antibody 2-13-1 to rat P4503A1/2 revealed that geniposide and G. jasminoides crude extract decreased the intensity of a P4503A-immunorelated protein. Protein blots probed with mouse monoclonal antibody 1-12-3 to rat P4501A1 and rabbit polyclonal antibody against human P4502E1 showed that both treatments had little or no effect on P4501A and 2E proteins. The present findings demonstrate that geniposide from G. jasminoides has the ability to inhibit a P4503A monooxygenase and increase glutathione content in rat liver.     

G2 Continuity for Multiple Surfaces Fitting

Fitting 3D known data into sculptured surfaces has received extensive attention. However, most algorithms available are suitable only for an isolated surface. A part typically contains multiple surface regions that must be blended to a degree of continuity. The conventional approach based on blending, lofting, stitching, etc. cannot guarantee the quality of the surface near the jointed area. The purpose of this work is to present a surface-fitting algorithm for multiple sets of data, concentrating on G 2 continuity across the boundary of the fitted surfaces. The proposed surface-fitting algorithm essentially fits several sets of data simultaneously, and yields a B-spline surface for each set of data. The G 0 ,G 1 , and G 2 continuity conditions between B-spline surface patches were addressed. Based on these results, additional constraints were specified to achieve G 2 continuity across the surface boundary. A successful demonstration of the proposed strategy is provided also.     

Interblock memory for turbo coding

We investigate a binary code, which is implemented by serially concatenating a multiplexer, a multilevel delay processor, and a signal mapper to a binary turbo encoder. To achieve improved convergence behavior, we modify the binary code by passing only a fraction of the bits in the turbo code through the multilevel delay processor and the signal mapper. Two decoding methods are discussed and their performances are evaluated.     

Performance of High-Reliability and High-Linearity InGaP/GaAs HBT PAs for Wireless Communication

An InGaP heterojunction-bipolar-transistor (HBT) power amplifier with the best linearity and high reliability is presented in this paper for use in wireless digital mobile communication systems. We optimized the linearity of a novel HBT device and investigated its reliability. Using SILVACO software, we performed a simulation of the HBT device. The best linearity, which was revealed for the device with a capacitance ratio C_bc (0/6 V), is 1.25 at a BV_ceo of 22 V. After the device was fabricated, a reasonably high PAE, i.e., ~ 55%, was obtained at 2.0 GHz, and an adjacent channel power ratio of over -48 dBc was achieved. In the reliability testing, the device, which was stressed at V_ce = 3 V and J_C = 25 kA/cm² under 85°C ambient temperature and 85% humidity, showed no failure for more than 1100 h. No significant beta degradation was observed under an extreme current J_C = 200 kA/cm² stress under wafer-level electrical/thermal overstress tests.     

Complex time series from a modulated semiconductor laser: itsdeterminism exploration

A singular value decomposition (SVD) eigenvalue spectrum is employed to explore the deterministic nature of the complex time series from a modulated semiconductor laser. With this method, the signature of chaos can be quickly identified and the noise contamination ratio can also be estimated. Relations between the supplied modulation of laser diode and the noise level are illustrated. The connection between relative intensity noise and the noise floor in the SVD spectrum has also been clarified     

Proximate composition, total phenolic content, and antioxidant activity of seagrape (Caulerpa lentillifera)

The proximate composition of seagrape (Caulerpa lentillifera) from culture ponds in Penghu, Taiwan was analyzed. The phenolic content and the antioxidant activities including the 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity, ferric ion-reducing activity, hydrogen peroxide scavenging activity, and ferrous ion chelating (FIC) activity of the ethanolic extracts of dry seagrape samples using 2 drying methods of freeze drying and thermal drying were compared with the ethanolic extract of Oolong tea as a reference. The contents (dry weight basis) of carbohydrate, crude protein, crude lipid, crude fiber, and ash of seagrape obtained from culture ponds in Taiwan were 64.00%, 9.26%, 1.57%, 2.97%, and 22.20%, respectively. The total phenolic content (1.30 mg gallic acid equivalent [GAE]/g dry weight) of the ethanolic extract of thermally dried seagrape was significantly lower (P < 0.05) than that (2.04 mg GAE/g dry weight) of freeze-dried seagrape, and both were significantly lower than that (13.58 mg GAE/g dry weight) of Oolong tea. At the same phenolic content, the antioxidant activities of freeze-dried seagrape were significantly higher (P < 0.05) than those of thermally dried seagrape. Compared with Oolong tea, seagrape, irrespective of drying method used, generally had strong hydrogen peroxide scavenging activity; but it was weak in DPPH radical scavenging activity, ferric ion-reducing activity, and FIC activity. The antioxidant activity of seagrape and Oolong tea was significantly influenced by their phenolic contents. PRACTICAL APPLICATION: The proximate composition, total phenolic content, and antioxidant activity of seagrape (Caulerpa lentillifera) in Taiwan were determined in this research to indicate nutritionally of this edible seaweed to human health, and compared these results to previous studies.     

Closed management and percutaneous fixation of unstable proximal humerus fractures

BACKGROUND: In dealing with displaced proximal humerus fractures, there is still much controversy in treatment modalities. The latest investigations emphasize the concept of minimal exposure and rigid fixation. METHODS: The technique of closed reduction and percutaneous fixation with cannulated screws and k-pins was performed on 19 patients with two- and three-part proximal humerus fractures. The outcomes were evaluated with a mean follow-up of 21 months. RESULTS: All except one case had a solid union of the fracture. Sixteen of 19 patients (84%) acquired good or excellent results according to Neer's classification. No further collapse or avascular necrosis was found. CONCLUSION: The method of closed reduction and percutaneous fixation, although technically demanding, yields satisfactory results in displaced proximal humerus fracture. Cannulated screws provided rigid fixation that was the underlying tenet for early functional retrieval.