Typical Hybrid Research Articles

Energy and fuel efficient parallel mild hybrids for urban roads

Fuel economy improvements and battery energy savings can promote the adoption of parallel mild hybrids for urban driving conditions. The aim of this study is to establish these benefits through two operating modes: an energy saving mode and a fuel saving mode. The performances of a typical parallel mild hybrid using these modes were analysed over urban driving cycles, in the US, Europe, and India, with a particular focus on the Indian urban conditions. The energy pack available from the proposed energy-saving operating mode, in addition to the energy already available from the conventional mode, was observed to be the highest for the representative urban driving cycle of the US. The extra energy pack available was found to be approximately 21.9 times that available from the conventional mode. By employing the proposed fuel saving operating mode, the fuel economy improvement achievable in New York City was observed to be approximately 22.69% of the fuel economy with the conventional strategy. The energy saving strategy was found to possess the lowest payback periods and highest immunity to variations in various cost parameters.

Hybridization and introgression in two ecologically dissimilar Fundulus hybrid zones.

Hybridization and introgression appear more common in rapidly evolving groups, suggesting an important role in the evolutionary process. Detailed studies of how extrinsic or intrinsic forces regulate hybridization and introgression have the potential for broadening our understanding of mechanisms generating diversity. Species in the Fundulus notatus species complex have broad overlapping ranges and occur in replicated hybrid zones along predictable stream gradients. Typical hybrid zone structure has Fundulus olivaceus in headwaters, F. notatus downstream, and hybrid zones near confluences or abrupt shifts in habitat. Rarely, the typical upstream-downstream orientation is reversed raising questions as to how hybrid zones are formed and maintained. We used next-generation sequencing data to study hybridization and introgression in hybrid zones in neighboring drainages that differ in orientation (typical and reversed). We predicted extrinsic forces linked to stream gradients would result in noticeable differences between the two. Contrary to predictions, the data indicate the hybrid zones are remarkably similar. We used individual-based simulations to explore the potential role of intrinsic and extrinsic forces in generating and maintaining typical and reversed hybrid zones. Simulation results were consistent with reversed hybrid zones being formed from stochastic processes combined with strong intrinsic forces and weak extrinsic forces.

Impossible Differential Cryptanalysis on DVB-CSA

The Digital Video Broadcasting-Common Scrambling Algorithm is an ETSI-designated algorithm designed for protecting MPEG-2 signal streams, and it is universally used. Its structure is a typical hybrid symmetric cipher which contains stream part and block part within a symmetric cipher, although the entropy is 64 bits, there haven’t any effective cryptanalytic results up to now. This paper studies the security level of CSA against impossible differential cryptanalysis, a 20-round impossible differential for the block cipher part is proposed and a flaw in the cipher structure is revealed. When we attack the block cipher part alone, to recover 16 bits of the initial key, the data complexity of the attack is O(2 44.5 ), computational complexity is O(2 22.7 ) and memory complexity is O(2 10.5 ) when we attack CSA-BC reduced to 21 rounds. According to the structure flaw, an attack on CSA with block cipher part reduced to 21 rounds is proposed, the computational complexity is O(2 21.7 ), data complexity is O(2 43.5 ) and memory complexity is O(2 10.5 ), we can recover 8 bits of the key accordingly. Taking both the block cipher part and stream cipher part of CSA into consideration, it is currently the best result on CSA which is accessible as far as we know.

In search of the right fusion recipe: the role of legitimacy in building a social enterprise model

Social enterprises, as typical hybrid organisations, are embedded in a plural institutional environment in which some stakeholders regard achieving social goals as fundamental, while others see economic profit as the priority. A great challenge for social enterprises is dealing with the conflicts resulting from the diverse expectations of stakeholders. Based on the existing works on organisational legitimacy and the social business model, we propose a legitimacy‐based social enterprise model composed of three main phases, namely, legitimacy proposition, legitimacy strategy planning, and legitimacy strategy implementation. Our model is meant to serve as an effective legitimacy‐building tool for social enterprises of various kinds.

Effects of alicyclic moiety incorporation on the properties of polyimide/silica hybrid films

Polyimide (PI)/silica hybrid films were prepared from tetraethyl orthosilicate (TEOS) using a sol‐gel process as well as pyromellitic dianhydride and 4,4‐oxydianiline. 1,4‐Cyclohexanedicarboxylic acid (1,4‐CHDA) was added as a coupling agent. The PI/silica hybrid films were characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, differential scanning calorimetry and wide‐angle X‐ray diffraction. The thermal, tensile and dielectric properties of the hybrid films were measured. The results showed that the tensile and dielectric properties of the hybrid films improved with increasing silica concentration and 1,4‐CHDA content in the PI matrix. Covalent ester bonds were formed between SiOH groups of silica and carboxyl groups of 1,4‐CHDA. As a result, the silica particle size was reduced and dispersed homogeneously in the PI matrix, leading to increased tensile strength and tensile modulus of the typical hybrid film with 1,4‐CHDA (PI‐2), when compared with the PI/silica hybrid film without 1,4‐CHDA at the same silica contents. The presence of an alicyclic moiety containing silica in PI reduced the dielectric constant considerably to 2.83, which was lower than that of pristine PI. Copyright © 2016 John Wiley & Sons, Ltd.

Commutation failure and voltage sensitivity analysis in a hybrid multi-infeed HVDC system containing modular multilevel converter

Summary A typical hybrid dual-infeed high-voltage direct current (HVDC) system includes two types of links—line-commutated converter (LCC) HVDC and voltage-source converter (VSC) HVDC in proximity. When faults occur in the LCC-HVDC side, the VSC-HVDC link sufficiently can compensate power to the LCC-HVDC system; thus, voltage fluctuation is suppressed. In recent years, the modular multilevel converter (MMC) has been a promising type of VSC. This paper presents a novel hybrid dual-infeed HVDC system consisting of an LCC-HVDC link and an MMC-HVDC link, and the two links are interconnected through a tie line between buses in the inverter side. The positive contribution of the MMC-HVDC link to the LCC-HVDC link in the area of commutation failure immunity index, effective short circuit ratio, voltage sensitivity factor, temporary overvoltage, and DC line fault recovery are investigated. Investigations show that the stability of system has been enhanced significantly with MMC, and the contributors are physical structure change and the control strategy of the MMC-HVDC system. The modelling and simulation of the steady state and transient performance of hybrid HVDC system are conducted in PSCAD/EMTDC. Finally, the simulation results verify the enhancement in sensitivity and stability of the dual-infeed HVDC system. Copyright © 2016 John Wiley & Sons, Ltd.

Load Frequency Control of Multi - area Hybrid Power System by Artificial Intelligence Techniques

paper presents the application of different Artificial intelligence techniques on the tuning of PID controller in a load frequency control system. The algorithms of PSO technique, Genetic algorithm technique, and Artificial Bee Colony technique has been applied on four area power system with six tie lines. The system dynamic model is formulated in state variables form. A comparison between these techniques with different performance indices is presented. The effect of including different types of generating units (i.e. a hybrid power system) on the dynamical performance of a load frequency control is also presented. Three types of control criterion are adopted. Simulation of the applied artificial techniques on a typical hybrid power system has been carried out. It is observed that a hybrid power system can track the load fluctuation quickly.

Competition and compromise between discotic and calamitic mesogens in triphenylene and azobenzene based shape-amphiphilic liquid crystals

Nirvana Phoenix: a shot showing the transformation from dendritic to focal conic fan-shaped POM texture of different type of lamello-columnar mesophases of a typical disc-rod hybrid dimer TP6–AZO6 reminiscent of the sacred scene of nirvana phoenix.

Are Mobilities in Hybrid Organic-Inorganic Halide Perovskites Actually "High"?

We present an experimental and theoretical viewpoint on the electronic carrier mobilities of typical hybrid organic-inorganic perovskites (HOIPs). While these mobilities are often quoted as high, a review of them shows that although otherwise the semiconducting properties of HOIPs are impressively good, mobilities of HOIPs used in most solar cells are actually not that high. This is especially apparent if they are compared to those of inorganic semiconductors used in other high efficiency solar cells. We critically examine possible causes and focus on electron-lattice coupling mechanisms that are active at room temperature, and can lead to carrier scattering. From this, we propose scattering due to acoustic phonons or polarons as possible causes, but also point out the difficulties with each of these in view of additional experimental and theoretical findings in the literature. Further research in this direction will contribute to making HOIP solar cells even more efficient than they already are.

Design, Synthesis, and Evaluation of Orally Available Clioquinol-Moracin M Hybrids as Multitarget-Directed Ligands for Cognitive Improvement in a Rat Model of Neurodegeneration in Alzheimer's Disease.

A novel series of clioquinol-moracin hybrids were designed and synthesized by fusing the pharmacophores of clioquinol and moracin M, and their activities as multitarget-directed ligands against Alzheimer's disease were evaluated. Biological activity results demonstrated that these hybrids possessed significant inhibitory activities against phosphodiesterase 4D (PDE4D) and Aβ aggregation as well as remarkable antioxidant effects and excellent blood-brain barrier permeability. The optimal compound, 18d (WBQ5187), exhibited excellent PDE4D inhibitory potency (IC50 = 0.32 μM), significant antioxidant effects, appropriate biometal chelating functions, and interesting properties that modulated self- and metal-induced Aβ aggregation. Two-dimensional NMR studies revealed that 18d had significant interactions with Aβ1-42 at the R5, H6, H14, Q15, and F20 residues. Furthermore, this typical hybrid possessed preeminent neuroprotective effects against inflammation in microglial cells. Most importantly, oral administration of 18d·HCl demonstrated marked improvements in cognitive and spatial memory in a rat model of Alzheimer's disease and protected hippocampal neurons from necrosis.

장경간 건축구조를 위한 하이브리드 OCB보의 개발

최근 국내의 건축구조는 공간활용을 극대화할 수 있도록 계획되고 있다. 공간활용의 장점을 실현하기 위하여 하이브리드 OCB(Optimized Composite Beam)보를 개발하였다. 본 논문에서 개발된 건축용 OCB보는 부모멘트 구간에서는 노출강연선으로 보강된 H형강으로 구성되고 정모멘트 영역에서는 프리텐션 방식의 PSC 구조로 구성된다. 본 연구에선 유한요소법을 이용하여 건축용 OCB보의 휨성능을 조사하였다. 15m, 20m, 30m 길이의 OCB모형을 구성하여 재료 및 기하학적 비선형 정적해석을 수행하였다. 해석결과로부터 다음과 같은 결과를 얻었다. 1)해석모델의 초기균열은 사용하중이상에서 모두 발생되었다. 2)사용하중단계에서 처짐은 건축구조설계기준에 제시된 허용처짐량 이내로 만족하였다. 3)유한요소모델의 파괴 시 극한하중은 모두 단면의 설계공칭강도 이상에서 발생되었다. 해석결과로부터 건축용 OCB보의 구조적인 신뢰성이 입증되었다. The building structure in Korea is planned to maximize the use of space in recent. The hybrid OCB(Optimized Composite Beam) beam is developed to take advantage of using the space. The OCB beam is composed of the steel H-beam section reinforced by open strands in negative moment zone and the pretensioned PSC concrete section in positive zone. Flexural behavior of typical architectural hybrid OCB beam section was investigated by F.E.M. The 15m, 20m, 30m OCB models were tested on nonlinear material and geometry under static loading system. Following results are obtained from the analysis; 1)The OCB beam develop initial flexural cracking over full service loading. 2)Overall deflections of OCB beam under the service loads are less than those of the allowable limits in KCI Code(2012). 3)The ultimate load capacity get over the nominal strength of the OCB main section. The OCB beam is verified of structural reliability from the finite element analysis.

Processing and characterization of reclaimed rubber composite materials

The dynamic mechanical properties of environment-friendly elastomeric composites consisting of reclaimed rubber (r-rubber), a waste product of roller processing of textile mill, and organic hindered phenol compound 4,4′-thio-bis(6-tert-butyl-m-methyl phenol) (AO-300) were investigated. With incorporation of AO-300 into the r-rubber, the storage modulus (E′) and loss modulus (E′′) of r-rubber were found to increase sharply, the maximum loss factor (tanδ) peak value increased from 0.49 to 1.01, and tanδ peak position was significantly shifted from 6.19 to 34.42 °C, indicating that r-rubber/AO-300 composite is a promising damping material. Furthermore, r-rubber/AO-300 systems exhibited an exceptional damping performance in the wide temperature range and with increasing AO-300 content, the effective temperature range increased from 55.32 to 63.14 °C. Meanwhile, the presence of intermolecular hydrogen bonds in the composite was confirmed by FTIR. Furthermore, from the SEM analysis of various r-rubber/AO-300 systems, it could be seen that by introduction of a small amount of AO-300 to the r-rubber, a typical complex morphology and hybrid state were coexistent in the composites. When the AO-300 content was larger than the critical value, more excess AO-300 molecules were crystallized. Thus, a new type of environment-friendly r-rubber based high-performance damping materials with a broad temperature range of damping behavior was developed.

Correctional DP-Based Energy Management Strategy of Plug-In Hybrid Electric Bus for City-Bus Route

Typical plug-in hybrid electric buses (PHEBs) with a fast-charged lithium titanate battery, which might fulfill about 70% of the distance of a representative city-bus route, have been adopted in many Chinese cities. Considering that the detailed information of the driving cycle could be deduced with the historical driving data and online estimation methods, there might be an opportunity for applying the dynamic programming (DP)-based global optimal energy management strategy for these PHEBs. However, road slopes or variable loads might induce transient fluctuations of the driving resistance in a given driving cycle. Meanwhile, the single-shaft parallel configuration, with automatic mechanical transmission (AMT), might constrain the implementability of the optimal energy distribution from a DP-based strategy. Therefore, in this paper, a novel correctional DP algorithm is brought forward to balance the optimization of fuel economy and drivability. Simulation results demonstrate that, integrated with the correctional logic of AMT gear shifting, the proposed energy management strategy can guarantee that the engine and the electric machine work in the high-efficiency area with optimal energy distribution, while keeping drivability in the variation of road slope and loads. The proposed method might give a technical solution to these typical PHEBs with a lower cost system configuration of the powertrain in China.

Vehicle height control of electronic air suspension system based on mixed logical dynamical modelling

Due to the coexistence and coupling of continuous variables and discrete events, the vehicle height adjustment process of electronic air suspension system can be regarded as a typical hybrid system. Therefore, the hybrid system theory was applied to design a novel vehicle height control strategy in this paper. A nonlinear mechanism model of the vehicle height adjustment system was established based on vehicle system dynamics and thermodynamic theory for variable-mass gas charge/discharge system. In order to model both the continuous/discrete dynamics of vehicle height adjustment process and the on-off statuses switching of solenoid valves, the framework of mixed logical dynamical (MLD) modelling was used. On the basis of the vehicle height adjustment control strategy, the MLD model of the adjustment process was built by introducing auxiliary logical variables and auxiliary continuous variables. Then, the co-simulation of the nonlinear mechanism model and the MLD model was conducted based on the compiling of HYSDEL. The simulation and experimental results show that the proposed control strategy can not only adjust the vehicle height effectively, but also achieve the on-off statuses direct control of solenoid valves.

Fractional charge and spin errors in self-consistent Green's function theory.

We examine fractional charge and spin errors in self-consistent Green's function theory within a second-order approximation (GF2). For GF2, it is known that the summation of diagrams resulting from the self-consistent solution of the Dyson equation removes the divergences pathological to second-order Møller-Plesset (MP2) theory for strong correlations. In the language often used in density functional theory contexts, this means GF2 has a greatly reduced fractional spin error relative to MP2. The natural question then is what effect, if any, does the Dyson summation have on the fractional charge error in GF2? To this end, we generalize our previous implementation of GF2 to open-shell systems and analyze its fractional spin and charge errors. We find that like MP2, GF2 possesses only a very small fractional charge error, and consequently minimal many electron self-interaction error. This shows that GF2 improves on the critical failings of MP2, but without altering the positive features that make it desirable. Furthermore, we find that GF2 has both less fractional charge and fractional spin errors than typical hybrid density functionals as well as random phase approximation with exchange.

Simulations with an Accurately Calibrated Electrochemical Model of Li-Ion Battery to Determine Additional Aging Mechanisms

The growing number of electrified vehicles remains particularly constrained by the performance of the energy storage system, which is a complex and expensive component in the vehicle. Li-ion batteries seem to be the best candidates due to their suitable performances for plug in or full electric vehicle application. However, the aging phenomena in those batteries will have a direct impact on the autonomy, power and maintenance costs of the vehicle and are not yet clearly understood. For automotive industry, this kind of information is critical in determining the performance and durability of the battery in traction applications. For that reason, there is an urgent need of validated predictive models for the long term behavior of those electrochemical components, ensuring an optimal battery sizing on one hand, and a proper energy management onboard on the other hand. The aging of a Li-ion battery is mainly due to a modification of its electrochemical properties which will lead to a loss of capacity (decrease of the autonomy) and an increase of its internal impedance (loss of power). A simplified electrochemical model has already been developed at IFP Energies Nouvelles[1] taking into account the loss of cyclable lithium due to the growth of the Solid electrolyte Interphase (SEI) and the modification of the porosity of the graphite electrode as aging mechanisms. This model allows us to estimate the evolution of the performance (power and autonomy) of a Graphite/LiFePO4-based battery as if it was used on a typical hybrid or electric vehicle. In order to ensure the reliability of this model, a sensitivity analysis based on Zhang et al. work[2] has been performed to find out the impact of the variation of each parameters on the model output (Voltage, Temperature) and determine the optimal testing conditions for this model calibration. Moreover, the discrepancies observed during the validation of our properly calibrated model with experimental data highlighted an additional capacity loss due to another aging mechanism than SEI growth. According to our previous research and to the literature, we decided to add a mechanical stress based mechanism involving cracking into the electrode that leads to a loss of active materials or enhances the loss of lithium inventory. Therefore, specific experiments inducing stress during intercalation of lithium ions in the negative electrode have been carried out to gather data to identify parameters of the new mechanism added to our model. Afterwards, the behavior of this new aging model will be validated on dynamic PHEV duty profiles to ensure its good reliability.

Control and Modelling of PV –Wind Hybrid Energy Sources for Desalination System

Hybrid renewable energy based on PV and wind systems complemented with battery storage system are starting to play a vital role over the world to supply power to distant regions. This paper proposes the combination of lead acid battery system with a typical hybrid PV-wind energy system for supplying the electrical load of a desalination system at Mersa Matrouh. Solar and wind are sources of energy and battery unit is considered as a storage unit to meet the load demand. Simulation model with MATLAB/Simulink for the hybrid power system has been developed considering power supply variation in solar and wind hybrid power system caused due to disturbed power supply from wind turbine generator and solar system. A control strategy using Neural Network Control (NNC) is being offered and analyzed. The final result of the simulation indicates an effective operation of battery. DOI: http://dx.doi.org/10.11591/telkomnika.v14i1.7650

English

Renewable energy sources play an important role in electrical energy generation. The drawbacks of Renewable energy sources have been overcome by the use of hybrid power generating unit. A typical hybrid renewable energy system (HRES) combines several renewable energy sources such as wind turbine (WT) and photovoltaic (PV) panels as primary energy sources and an energy storage system (ESS) based on fuel cell and battery. All of the energy sources are connected together to a central dc bus by means of power converters. This paper includes a supervisory control called hysteresis switching algorithm which determines the power that must be generated by/stored in the fuel cell and battery, taking into account the control demand by the grid, the offered power, the hydrogen reservoir point and the state-of-charge (SOC) of the battery. The proposed EMS is compared with classical EMS composed of state based supervisory control system based on states and inverter control system based on PI controller. Dynamic simulation results of the proposed EMS demonstrate the better performance than the classical EMS.

Improved parallel mild hybrids for urban roads

The major challenge to the large-scale commercialisation of hybrid electric vehicles is their high initial and operating costs, although a mild hybrid is generally cheaper than a full hybrid of the same performance. Hence, the average operating efficiency of the internal combustion engine of a parallel hybrid and the energy saved by its battery modules when running on urban roads have been key research subjects. In this paper, a method for maximising the performance of heavyweight hybrid vehicles is proposed. Because the manipulation of the thresholds of the state of charge window of the battery of a parallel hybrid affects the performance of the vehicle when using the commonly employed electric power-assist strategy, we developed a method for determining the optimal sizes of the vehicle components that afford the most feasible operations using the conventional and modified power-assist strategies. Furthermore, the performances of the vehicle in both modes were analysed for various urban driving conditions representative of those encountered in the USA, Europe, and India. The results showed that energy saving in the battery pack after a typical urban driving cycle was higher in India than in the USA and Europe. The saving in India was determined to be 3.34%, whereas those in the USA and Europe were 3.13% and 0.23%, respectively. The energy savings in the battery pack of the same vehicle under identical conditions were determined using a simple internal resistance battery model and a resistance–capacitance battery model. The performance of a typical parallel mild hybrid capable of operating in the modified power-assist mode was also compared with that of an equivalent internal combustion engine vehicle presently on the Indian market.

Generalised Hough Transform for Speech Pattern Classification

While typical hybrid neural network architectures for automatic speech recognition (ASR) use a context window of frame-based features, this may not be the best approach to capture the wider temporal context, which contains phonetic and linguistic information that is equally important. In this paper, we introduce a system that integrates both the spectral and geometrical shape information from the acoustic spectrum, inspired by research in the field of machine vision. In particular, we focus on the Generalized Hough Transform (GHT), which is a sophisticated technique that can model the geometrical distribution of speech information over the wider temporal context. To integrate the GHT as part of a hybrid-ASR system, we propose to use a neural network, with features derived from the probabilistic Hough voting step of the GHT, to implement an improved version of the GHT where the output of the network represents the conventional target class posteriors. A major advantage of our approach is that each step of the GHT is highly interpretable, particularly compared to deep neural network (DNN) systems which are commonly treated as powerful black-box classifiers that give little insight into how the output is achieved. Experiments are carried out on two speech pattern classification tasks. The first is the TIMIT phoneme classification, which demonstrates the performance of the approach on a standard ASR task. The second is a spoken word recognition challenge, which highlights the flexibility of the approach to capture phonetic information within a longer temporal context.