Philips

About: Philips is a company organization based out in Vantaa, Finland. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 68260 authors who have published 99663 publications receiving 1882329 citations. The organization is also known as: Koninklijke Philips Electronics N.V. & Royal Philips Electronics.

Line-Interactive UPS Using a Fuel Cell as the Primary Source

Abstract: This paper proposes a line-interactive fuel-cell-powered uninterruptible-power-supply system. A three-port bidirectional converter connects a fuel cell and a supercapacitor to a grid-interfacing inverter. The system can operate in both stand-alone and grid-connected modes. Moreover, an active filtering function is integrated into the system. It is shown that a supercapacitor can serve as both an active and a reactive energy storage and can buffer the periodical low-frequency ripple in the requested power. For connecting the system to the utility grid, a high-performance single-phase phase-locked loop that incorporates an orthogonal filter is presented. Resonant controllers for both the voltage and current regulations eliminate steady-state error and implement selective harmonic compensation. Simulation and experimental results are provided to show the feasibility of the proposed system and the effectiveness of the control methods.

Insitu photopolymerization of an oriented liquid-crystalline acrylate .2.

Abstract: The photoinitiated polymerization of 4-biphenylyl 4-(6-acryloyloxyhexyloxy)benzoate (1) in its oriented liquid-crystalline state was studied. Monomer 1 has a thermotropic nematic phase between 88°C and 98°C, a monotropic nematic phase between 76°C and 88°C, and a monotropic smectic phase below 76°C. The orientation of 1 was established in a glass cell provided with a rubber polyimide coating and characterized by birefringence measurements. During polymerization both the birefringence and the liquid-crystalline transition temperatures increase, indicating that the orientation was maintained. The oriented poly(1) is polycrystalline at room temperature, becomes smectic at 90°C, nematic at 172°C, and isotropic at 190°C. The order parameter of the nematic poly(1) is lower than that of the nematic monomer1 at equal reduced temperatures.

Scaling up fast evolutionary programming with cooperative coevolution

Abstract: Evolutionary programming (EP) has been applied with success to many numerical and combinatorial optimization problems in recent years. However, most analytical and experimental results on EP have been obtained using low-dimensional problems. It is interesting to know whether the empirical results obtained from the low-dimensional problems still hold for high-dimensional cases. It was discovered that neither classical EP (CEP) nor fast EP (FEP) performed satisfactorily for some large-scale problems. The paper shows empirically that FEP with cooperative coevolution (FEPCC) can speed up convergence rates on the large-scale problems whose dimension ranges from 100 to 1000. Cooperative coevolution adopts the divide-and-conquer strategy. It divides the system into many modules, and evolves each module separately and cooperatively. The results of FEPCC on the problems investigated here are something of a surprise. The time used by FEPCC to find a near optimal solution appears to scale linearly; that is, the time used seems to go up linearly as the dimensionality of the problems studied increases.

Defect pool in amorphous-silicon thin-film transistors.

Abstract: Amorphous-silicon thin-film transistors show a threshold voltage shift when subjected to prolonged bias stress For transistors made with silicon oxide as the gate dielectric, the threshold shift induced under positive bias is due to the creation of dangling-bond states in the a-Si:H at low energy (${\mathit{D}}_{\mathit{e}}$ states) The threshold shift induced by negative bias stress is due to the creation of dangling-bond states at a higher energy (${\mathit{D}}_{\mathit{h}}$ states) In transistors made with silicon nitride as the gate dielectric, positive bias stress causes an increase in the density of ${\mathit{D}}_{\mathit{e}}$ states, but negative bias stress causes mainly a reduction in the density of ${\mathit{D}}_{\mathit{e}}$ states Positive bias annealing of both oxide and nitride transistors leads to an increase in the density of ${\mathit{D}}_{\mathit{e}}$ states and a reduction in the density of ${\mathit{D}}_{\mathit{h}}$ states Negative bias annealing leads to a reduction in the density of ${\mathit{D}}_{\mathit{e}}$ states and an increase in the density of ${\mathit{D}}_{\mathit{h}}$ states The magnitude of each change depends on the initial Fermi-level position, which is the main difference between our oxide and nitride transistors The results are explained by a defect-pool model for the dangling-bond states in a-Si:H Dangling bonds are formed by a chemical equilibration process, resulting in the formation of dangling bonds in each of the possible charge states This leads to a density of states in a-Si:H consisting of coexisting components formed as negatively charged dangling bonds (${\mathit{D}}_{\mathit{e}}$ states), positively charged dangling bonds (${\mathit{D}}_{\mathit{h}}$ states), and neutral dangling bonds (${\mathit{D}}_{0}$ states)Fitting the calculated density of states to the experimental results determined from the transistor characteristics leads to the conclusion that the density of ${\mathit{D}}_{\mathit{e}}$ and ${\mathit{D}}_{\mathit{h}}$ states dominates over the ${\mathit{D}}_{0}$ states, for all Fermi-level positions We therefore conclude that there must be substantial densities of charged dangling bonds, even in undoped a-Si:H Because of the wide energy separation of the ${\mathit{D}}_{\mathit{e}}$,${\mathit{D}}_{0}$, and ${\mathit{D}}_{\mathit{h}}$ states, virtually all the states in the lower part of the gap are ${\mathit{D}}_{\mathit{e}}$ states and all the states in the upper part of the gap are ${\mathit{D}}_{\mathit{h}}$ states Raising the Fermi level increases the density of ${\mathit{D}}_{\mathit{e}}$ states and lowers the density of ${\mathit{D}}_{\mathit{h}}$ states, but the density of ${\mathit{D}}_{0}$ states remains the same Lowering the Fermi level increases the density of ${\mathit{D}}_{\mathit{h}}$ states and reduces the density of ${\mathit{D}}_{\mathit{e}}$ states Bias stress of nitride transistors, at much higher fields, leads to larger threshold voltage shifts, due to charge trapping in the nitride Subsequent annealing leads to a new zero-bias thermal-equilibrium density of states Transistor characteristics can be optimized in this way

User interface/entertainment device that simulates personal interaction and responds to user's mental state and/or personality

Abstract: An interaction simulator uses computer vision, and inputs of other modalities, to analyze the user"s mental state and/or personality. The mental state and/or personality are classified and this information used to guide conversation and other interaction. In a chatterbot embodiment, the substance of the conversation may be altered in response to the mental state and/or personality class, for example, by changing the topic of conversation to a favorite subject when the user is sad or by telling a joke when the user is in a good mood.