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BACKGROUND:
While hearing aids for a contralateral routing of signals (CROS-HA) and bone conduction devices have been the traditional treatment for single-sided deafness (SSD) and asymmetric hearing loss (AHL), in recent years, cochlear implants (CIs) have increasingly become a viable treatment choice, particularly in countries where regulatory approval and reimbursement schemes are in place. Part of the reason for this shift is that the CI is the only device capable of restoring bilateral input to the auditory system and hence of possibly reinstating binaural hearing. Although several studies have independently shown that the CI is a safe and effective treatment for SSD and AHL, clinical outcome measures in those studies and across CI centers vary greatly. Only with a consistent use of defined and agreed-upon outcome measures across centers can high-level evidence be generated to assess the safety and efficacy of CIs and alternative treatments in recipients with SSD and AHL.
METHODS:
This paper presents a comparative study design and minimum outcome measures for the assessment of current treatment options in patients with SSD/AHL. The protocol was developed, discussed, and eventually agreed upon by expert panels that convened at the 2015 APSCI conference in Beijing, China, and at the CI 2016 conference in Toronto, Canada.
RESULTS:
A longitudinal study design comparing CROS-HA, BCD, and CI treatments is proposed. The recommended outcome measures include (1) speech in noise testing, using the same set of 3 spatial configurations to compare binaural benefits such as summation, squelch, and head shadow across devices; (2) localization testing, using stimuli that rove in both level and spectral content; (3) questionnaires to collect quality of life measures and the frequency of device use; and (4) questionnaires for assessing the impact of tinnitus before and after treatment, if applicable.
CONCLUSION:
A protocol for the assessment of treatment options and outcomes in recipients with SSD and AHL is presented. The proposed set of minimum outcome measures aims at harmonizing assessment methods across centers and thus at generating a growing body of high-level evidence for those treatment options.
The effect of fluctuating maskers on speech understanding of high-performing cochlear implant users
(2016)
Objective: The present study evaluated whether the poorer baseline performance of cochlear implant (CI) users or the technical and/or physiological properties of CI stimulation are responsible for the absence of masking release. Design: This study measured speech reception thresholds (SRTs) in continuous and modulated noise as a function of signal to noise ratio (SNR). Study sample: A total of 24 subjects participated: 12 normal-hearing (NH) listeners and 12 subjects provided with recent MED-EL CI systems. Results: The mean SRT of CI users in continuous noise was −3.0 ± 1.5 dB SNR (mean ± SEM), while the normal-hearing group reached −5.9 ± 0.8 dB SNR. In modulated noise, the difference across groups increased considerably. For CI users, the mean SRT worsened to −1.4 ± 2.3 dB SNR, while it improved for normal-hearing listeners to −18.9 ± 3.8 dB SNR. Conclusions: The detrimental effect of fluctuating maskers on SRTs in CI users shown by prior studies was confirmed by the current study. Concluding, the absence of masking release is mainly caused by the technical and/or physiological properties of CI stimulation, not just the poorer baseline performance of many CI users compared to normal-hearing subjects. Speech understanding in modulated noise was more robust in CI users who had a relatively large electrical dynamic range.
Covert channels have been known for a long time because of their versatile forms of appearance. For nearly every technical improvement or change in technology, such channels have been (re-)created or known methods have been adapted. For example, the introduction of hyperthreading technology has introduced new possibilities for covert communication between malicious processes because they can now share the arithmetic logical unit as well as the L1 and L2 caches, which enable establishing multiple covert channels. Even virtualization, which is known for its isolation of multiple machines, is prone to covert- and side-channel attacks because of the sharing of resources. Therefore, it is not surprising that cloud computing is not immune to this kind of attacks. Moreover, cloud computing with multiple, possibly competing users or customers using the same shared resources may elevate the risk of illegitimate communication. In such a setting, the “air gap” between physical servers and networks disappears, and only the means of isolation and virtual separation serve as a barrier between adversary and victim. In the work at hand, we will provide a survey on vulnerable spots that an adversary could exploit trying to exfiltrate private data from target virtual machines through covert channels in a cloud environment. We will evaluate the feasibility of example attacks and point out proposed mitigation solutions in case they exist.
Structured Innovation with TRIZ in Science and Industry - Creating Value for Customers and Society
(2016)
Serendipities in der Medizin
(2016)
Zufälle begleiten unser Leben. Auch bei wichtigen Entdeckungen und Entwicklungen in der Medizin spielt der „Zufall“ (engl. „serendipity“) eine Rolle. Hierzu gehören u. a. die Mendelschen Gesetze, die Ermittlung der menschlichen Chromosomenzahl, die Entdeckung der DNS durch Watson und Crick, der PAP-Test oder die Entdeckung der Röntgenstrahlung und der Radioaktivität. Aber auch und gerade in der Pharmakologie gibt es viele Beispiele für Serendipitäten. Einige gehen eng mit Zufällen bei der Entdeckung der Bakteriologie einher.
Selective separation of CO2-CH4 mixed gases via magnesium aminoethylphosphonate nanoparticles
(2016)
We present a novel scheme for Slotted ALOHA random access systems that combines physical-layer network coding (PLNC) with multiuser detection (MUD). The PLNC and MUD are applied jointly at the physical layer to be able to extract any linear combination of messages experiencing a collision within a slot. The set of combinations extracted from a whole frame is then processed by the receiver to recover the original packets. A simple precoding stage at the transmitting terminals allows the receiver to further decrease the packet loss rate. We present results for the decoding at the physical layer as well as several performance measures at frame level, namely, throughput, packet loss rate, and energy efficiency. The results we present are promising and suggest that a cross-layer approach leveraging on the joint use of PLNC and MUD can significantly improve the performance of random access systems in the presence of slow fading.
Der Beitrag behandelt ausgewählte Themenkomplexe im Zusammenhang mit der Vorspannung von Schraubenverbindungen im Stahlbau. Es werden verschiedene Anwendungen und damit verbundene Aspekte beleuchtet und diskutiert, zum Beispiel die Schraubensicherung durch Vorspannung oder die Steifigkeit der Verbindung. Dem vorangestellt ist eine kurze Einführung in die mechanische Wirkung der Vorspannung in der Verbindung sowie eine Vorstellung der Vorspannverfahren.
In recent years simple CAD systems have entered the market, which are offered as freeware or open source projects. These systems prove to be a key technology especially for the further expansion of 3D printing, because a 3D model of the object to be printed is a prerequisite for the use of a 3D printer. Therefore, this contribution reviews several common simple CAD systems. Thus technical and economic criteria are evaluated. It is also demonstrated how the models designed in this manner can be used in 3D printing. A case study shows the possibilities and limitations to be expected when using simple CAD systems.
Physics-based Modeling of the Electric Arc furnace Process using Object-Oriented Language Modelica
(2016)
Electric arc furnaces (EAF) are complex industrial plants whose actual behavior depends upon numerous factors. Due to its energy intensive operation, the EAF process has always been subject to optimization efforts. For these reasons, several models have been proposed in literature to analyze and predict different modes of operation. Most of these models focused on the processes inside the vessel itself. The present paper introduces a dynamic, physics-based model of a complete EAF plant which consists of the four subsystems vessel, electric system, electrode regulation, and off-gas system. Furthermore the solid phase is not treated to be homogenous but a simple spatial discretization is employed. Hence it is possible to simulate the energy input by electric arcs and fossil fuel burners depending on the state of the melting progress. The model is implemented in object-oriented, equation-based language Modelica. The simulation results are compared to literature data.
Electric arc furnaces (EAF) are complex industrial plants whose actual behavior depends upon numerous factors. Due to its energy intensive operation, the EAF process has always been subject to optimization efforts. For these reasons, several models have been proposed in literature to analyze and predict different modes of operation. Most of these models focused on the processes inside the vessel itself. The present paper introduces a dynamic, physics-based model of a complete EAF plant which consists of the four subsystems vessel, electric system, electrode regulation, and off-gas system. Furthermore the solid phase is not treated to be homogenous but a simple spatial discretization is employed. Hence it is possible to simulate the energy input by electric arcs and fossil fuel burners depending on the state of the melting progress. The model is implemented in object-oriented, equation-based language Modelica. The simulation results are compared to literature data.
Proton Exchange Membrane Fuel Cells (PEMFC) are energy efficient and environmentally friendly alternatives to conventional energy conversion systems in many yet emerging applications. In order to enable prediction of their performance and durability, it is crucial to gain a deeper understanding of the relevant operation phenomena, e.g., electrochemistry, transport phenomena, thermodynamics as well as the mechanisms leading to the degradation of cell components. Achieving the goal of providing predictive tools to model PEMFC performance, durability and degradation is a challenging task requiring the development of detailed and realistic models reaching from the atomic/molecular scale over the meso scale of structures and materials up to components, stack and system level. In addition an appropriate way of coupling the different scales is required.
This review provides a comprehensive overview of the state of the art in modeling of PEMFC, covering all relevant scales from atomistic up to system level as well as the coupling between these scales. Furthermore, it focuses on the modeling of PEMFC degradation mechanisms and on the coupling between performance and degradation models.
The ability to detect a target signal masked by noise is improved in normal-hearing listeners when interaural phase differences (IPDs) between the ear signals exist either in the masker or in the signal. To improve binaural hearing in bilaterally implanted cochlear implant (BiCI) users, a coding strategy providing the best possible access to IPD is highly desirable. In this study, we compared two coding strategies in BiCI users provided with CI systems from MED-EL (Innsbruck, Austria). The CI systems were bilaterally programmed either with the fine structure processing strategy FS4 or with the constant rate strategy high definition continuous interleaved sampling (HDCIS). Familiarization periods between 6 and 12 weeks were considered. The effect of IPD was measured in two types of experiments: (a) IPD detection thresholds with tonal signals addressing mainly one apical interaural electrode pair and (b) with speech in noise in terms of binaural speech intelligibility level differences (BILD) addressing multiple electrodes bilaterally. The results in (a) showed improved IPD detection thresholds with FS4 compared with HDCIS in four out of the seven BiCI users. In contrast, 12 BiCI users in (b) showed similar BILD with FS4 (0.6 ± 1.9 dB) and HDCIS (0.5 ± 2.0 dB). However, no correlation between results in (a) and (b) both obtained with FS4 was found. In conclusion, the degree of IPD sensitivity determined on an apical interaural electrode pair was not an indicator for BILD based on bilateral multielectrode stimulation.
Two closely related series of paddle-wheel-based triazolyl isophthalate MOFs are presented. Thermal and CO2 adsorption studies reveal network flexibility induced by alkyl substituents of the linker. By choice of the substituent, the pore volumes and pore diameters can be adjusted. Fine-tuning of the gate opening pressure and the hysteresis shape is possible by modulating the substitution pattern and by choice of the metal ion.
Optimal microgrid scheduling with peak load reduction involving an electrolyzer and flexible loads
(2016)
This work consists of a multi-objective mixed-integer linear programming model for defining optimized schedules of components in a grid-connected microgrid. The microgrid includes a hydrogen energy system consisting of an alkaline electrolyzer, hydrogen cylinder bundles and a fuel cell for energy storage. Local generation is provided from photovoltaic panels, and the load is given by a fixed load profile combined with a flexible electrical load, which is a battery electric vehicle. The electrolyzer has ramp-up constraints which are modeled explicitly. The objective function includes, besides operational costs and an environmental indicator, a representation of peak power costs, thus leading to an overall peak load reduction under optimized operation. The model is used both for controlling a microgrid in a field trial set-up deployed in South-West Germany and for simulating the microgrid operation for defined period, thus allowing for economic system evaluation. Results from defined sample runs show that the energy storage is primarily used for trimming the peak of electricity drawn from the public grid and is not solely operated with excess power. The flexible demand operation also helps keeping the peak at its possible minimum.
The existence of acoustic waves with displacements localized at the tip of an isotropic elastic wedge was rigorously proven by Kamotskii, Zavorokhin and Nazarov. This proof, which is based on a variational approach, is extended to rectangular anisotropic wedges. For two high-symmetry configurations of rectangular edges in elastic media with tetragonal symmetry, a criterion is derived that allows identifying the boundary between the regions of existence for wedge modes of even and odd symmetry in regions of parameter space, where even- and odd-symmetry modes do not exist simultaneously. Furthermore, rectangular edges with non-equivalent surfaces are analyzed, and it is shown that at rectangular edges of cubic elastic media with one (110) surface and one (001) surface, a tip-localized guided wave always exists, apart from special cases that are characterized.
The famous violin virtuoso Nicolò Paganini (born on 27 October 1782 in Genoa, died on 27 May 1840 in Nice) left us with many puzzles. An interesting aspect is his hair: In the 19th century, hair given away as a token of friendship or romantic love became very popular, and Paganini also seems to have made use of this fad. In 2009, a lock of hair, purportedly that of Paganini, kept in a locked presentation box together with a bilingual autograph inscription saying: "Alla Signora Chatterton avec les compliments de Nicolò Paganini" was bought at an auction. From this hair lock a sample was taken and was investigated morphologically by using digital light microscopy (digital microscope VHX-100, Keyence) in reflected and transmitted light with and without polarization at different magnifications up to 1:5,000. The sample was then compared with a hair sample from the possession of the Paganini family, which had been microscopically examined in 2012 by the co-author of this paper yielding numerous figures with measurement results that had been stored and could be retrieved for direct comparison. The hair sample consisted of ten strands of hair or hair fragments and was investigated with great effort for the following parameters: exogenous hair damage, especially feeding traces caused by parasites, modeling and angulation of hairs, hair thickness, medulla and pigmentation, curling and mercury load on the trace material. After evaluation of all findings not only a non-exclusion of identity can be determined, but due to the broad match of also rare findings there is no reasonable doubt about their identity. In addition, the findings suggest that the studied hair samples are in fact from Paganini's head. The present case of Nicolò Paganini's hair lock is also an excellent starting point for reflections on the probative value of trace hair investigations. This point is also critically discussed in the paper. Finally, this study shows that said lock of hair had probably really been dedicated and given to Eliza Davenport Latham (born on 25 November 1806, died on 9 January 1877), the future wife of the, at that time, best-known and most famous English harpist John Balsir Chatterton (born on 25 November 1804, died on 9 April 1871). Paganini must have met her on his concert tour 1831/32, where he had travelled to Paris, London, the rest of England, Scotland and Ireland.
Lithium–oxygen cells with nonaqueous electrolyte show high overpotentials during charge, indicating asymmetric charge/discharge reaction mechanisms. We present a kinetic modeling and simulation study of the lithium–oxygen cell cycling behavior. The model includes a multistep reaction mechanism of the cell reaction (2Li + O2 ⇄ Li2O2) forming lithium peroxide by precipitation, coupled to a 1D porous-electrode transport model. We apply the model to study the asymmetric discharge/charge characteristics and analyze the influence of a redox mediator dissolved homogeneously in the liquid electrolyte. Model predictions are compared to experimental galvanostatic cycling data of cells without and with 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) as redox mediator. The predicted discharge behavior shows good agreement with the experimental results. A spatiotemporal analysis of species concentrations reveals inhomogeneous distributions of dissolved oxygen and reaction products within the cathode during discharge. The experimentally observed charge overpotentials as well as their reduction by using a redox mediator can be qualitatively reproduced with a partially irreversible reaction mechanism. However, the proposed models fail to reproduce the particular shape of the experimental charge curve with continuously increasing charge overpotential, which implies that part of the reaction mechanism is still open for investigation in future work.
MITK-OpenIGTLink for combining open-source toolkits in real-time computer-assisted interventions
(2016)
PURPOSE:
Due to rapid developments in the research areas of medical imaging, medical image processing and robotics, computer-assisted interventions (CAI) are becoming an integral part of modern patient care. From a software engineering point of view, these systems are highly complex and research can benefit greatly from reusing software components. This is supported by a number of open-source toolkits for medical imaging and CAI such as the medical imaging interaction toolkit (MITK), the public software library for ultrasound imaging research (PLUS) and 3D Slicer. An independent inter-toolkit communication such as the open image-guided therapy link (OpenIGTLink) can be used to combine the advantages of these toolkits and enable an easier realization of a clinical CAI workflow.
METHODS:
MITK-OpenIGTLink is presented as a network interface within MITK that allows easy to use, asynchronous two-way messaging between MITK and clinical devices or other toolkits. Performance and interoperability tests with MITK-OpenIGTLink were carried out considering the whole CAI workflow from data acquisition over processing to visualization.
RESULTS:
We present how MITK-OpenIGTLink can be applied in different usage scenarios. In performance tests, tracking data were transmitted with a frame rate of up to 1000 Hz and a latency of 2.81 ms. Transmission of images with typical ultrasound (US) and greyscale high-definition (HD) resolutions of [Formula: see text] and [Formula: see text] is possible at up to 512 and 128 Hz, respectively.
CONCLUSION:
With the integration of OpenIGTLink into MITK, this protocol is now supported by all established open-source toolkits in the field. This eases interoperability between MITK and toolkits such as PLUS or 3D Slicer and facilitates cross-toolkit research collaborations. MITK and its submodule MITK-OpenIGTLink are provided open source under a BSD-style licence ( http://mitk.org )
Mit der Messung des Wärme- und Kälteverbrauchs im Labor gelingt es, sowohl thermisch träge als auch agile Flächentemperiersysteme unter praxisnahen, dynamischen Bedingungen messtechnisch zu bewerten. Werden Nutzwärme- und Nutzkältebedarf berechnet und ins Verhältnis zu den gemessenen Verbräuchen gesetzt, können die Aufwandzahlen für die Nutzenübergabe ece für verschiedene Flächentemperiersysteme und in Kombinationen mit anderen Übergabesystemen unter verschiedenen Nutzungsbedingungen und für unterschiedliche Betriebsführungsstrategien bestimmt werden. Damit stehen Aufwandszahlen auf Basis kalorischer Messungen zur Verfügung, die je nach Aufgabenstellung entweder produkt- oder objektbezogen in der Planung komplexer Energiekonzepte verwendet werden können und die tatsächlichen Aufwandszahlen eh, ce für den Heizfall bzw. ec, ce für den Kühlfall genauer als Literaturwerte bzw. projektbezogen beschreiben
In this study the dynamics and stability of thin and electrically conductive aqueous films under the influence of a time-periodic electric field are explored. With the help of analytical linear stability analysis for long wavelength disturbances, the stability threshold of the system as a function of various electrochemical parameters and transport coefficients is presented. The contributions of parameters like surface tension, disjoining pressure, electric double layer (Debye length and interfacial zeta potential), and unsteady Maxwell and viscous stresses are highlighted with the help of appropriate dimensionless groups. The physical mechanisms affecting the stability of thin films are detailed with the above-mentioned forces and parametric dependence of stability trends is discussed.
Cardiac resynchronization therapy is an established therapy for heart failure patients. The aim of the study was to evaluate electrical left cardiac atrioventricular delay and interventricular desynchronization in sinus rhythm cardiac resynchronization therapy responder and non-responder. Cardiac electrical desynchronization were measured by surface ECG and focused transesophageal bipolar left atrial and left ventricular ECG before implantation of cardiac resynchronization therapy defibrillators. Preoperative electrical cardiac desynchronization was 195.7 ± 46.7 ms left cardiac atrioventricular delay and 74.8 ± 24.5 ms interventricular delay in cardiac resynchronization therapy responder. Cardiac resynchronization therapy responder New York Heart Association class improved during long term biventricular pacing. Transesophageal left cardiac atrioventricular delay and interventricular delay may be additional useful parameters to improve patient selection for cardiac resynchronization therapy.
Laser pulses focused near the tip of an elastic wedge generate acoustic waves guided at its apex. The shapes of the acoustic wedge wave pulses depend on the energy and the profile of the exciting laser pulse and on the anisotropy of the elastic medium the wedge is made of. Expressions for the acoustic pulse shapes have been derived in terms of the modal displacement fields of wedge waves for laser excitation in the thermo-elastic regime and for excitation via a pressure pulse exerted on the surface. The physical quantity considered is the local inclination of a surface of the wedge, which is measured optically by laser-probe-beam deflection. Experimental results on pulse shapes in the thermo-elastic regime are presented and confirmed by numerical calculations. They pertain to an isotropic sharp-angle wedge with two wedge-wave branches and to a non-reciprocity phenomenon at rectangular silicon edges.
Die Namen Cormack und Hounsfield sind für den Radiologen zu einem wichtigen Synonym für die Computertomographie (CT) geworden. Der mathematische Wegbereiter für die CT, Johann Radon, kommt in der radiologischen Diskussion und den historischen Rückblicken hingegen oft zu Unrecht zu kurz. Die folgende Kurzübersicht möchte daher dem interessierten Leser die wichtigsten historischen Eckdaten zu dem in vielerlei Hinsicht bewegenden Leben und Wirken dieses großen Mathematikers näherbringen.
Im Rahmen der Cochleaimplantat (CI)-Versorgung werden sowohl intraoperativ als auch postoperativ verschiedene elektrische und elektrophysiologische Diagnostikverfahren eingesetzt, bei denen elektrische Messgrößen vom CI erfasst und elektrophysiologische Messungen bei CI-Patienten durchgeführt werden. Zu den elektrophysiologischen Diagnostikverfahren zählen die Messung der elektrisch evozierten Summenaktionspotenziale des Hörnervs, die Registrierung der elektrisch evozierten auditorischen Hirnstammpotenziale und die Erfassung der elektrisch evozierten auditorischen kortikalen Potenziale. Diese Potenziale widerspiegeln die Erregung des Hörnervs und die Reizverarbeitung in verschiedenen Stationen der aufsteigenden Hörbahn bei intracochleärer elektrischer Stimulation mittels eines CI. Bei den aktuellen CI sind die Beurteilung der Elektrodenlage sowie die Prüfung der Ankopplung des Implantats an den Hörnerv wichtige Anwendungsgebiete der elektrophysiologischen Diagnostikverfahren. Ein weiteres bedeutendes Einsatzfeld stellt die Prüfung der Reizverarbeitung in der Hörbahn dar. Das Hauptanwendungsgebiet dieser Verfahren bildet jedoch die Unterstützung der Anpassung der CI-Sprachprozessoren bei Säuglingen und Kleinkindern auf der Basis elektrophysiologischer Schwellen.
The interaural time difference (ITD) is an important cue for the localization of sounds. ITD changes as little as 10 μs can be detected by the human auditory system. By provision of one ear with a cochlear implant (CI) ITD are altered due to the partial replacement of the peripheral auditory system. A hearing aid (HA), in contrast, does not replace but adds a processing delay component to the peripheral auditory system extending ITD. The aim of the present study was to quantify interaural stimulation timing between these different modalities to estimate the need for central auditory temporal compensation in single sided deaf CI users or bimodal CI/HA users. For this purpose, wave V latencies of auditory brainstem responses evoked either acoustically (ABR) or electrically via the CI (EABR) have been measured. The sum of delays consisting of CI signal processing measured in the MED-EL OPUS2 audio processor and EABR wave V latencies evoked on different intracochlear sites allowed an estimation of the entire CI channel-specific delay for MED-EL MAESTRO CI systems. We compared these values with ABR wave V latencies measured in the contralateral normal hearing or HA provided ear in different frequency bands. The results showed that EABR wave V latencies were consistently shorter than those evoked acoustically in the unaided normal hearing ear. Thus, artificial delays within the audio processor can be implemented to adjust interaural stimulation timing. The currently implemented group delays in the MED-EL CI system turned out to be reasonably similar to those of the unaided ear. For adjustment of CI and contralateral HA, in contrast, an adjustable additional across-frequency delay in the range of 1–11 ms implemented in the CI would be required. Especially for bimodal CI/HA users the adjustment of interaural stimulation timing may induce improved binaural hearing, reduced need for central auditory temporal compensation and increased acceptance of the CI/HA provision.
To do justice to the legacy of Alexander von Humboldt, a 19th century German scientist and explorer an information and knowledge management system is required to preserve the author’s original intent and promote an awareness of all his relevant works. Although all of Humboldt's works can be found on the internet as digitized papers, the complexity and internal interconnectivity of the writings is not very transparent. Humboldt's concepts of interaction cannot be adequately represented only by digitized papers or scanned documents.
The Humboldt Portal is an attempt to create a new generation of digital libraries, providing a new form of interaction and synthesis between humanistic texts and scientific observation. The digital version of his documents supplies dynamic links to sources, maps, images, graphs and relevant texts in accordance with his visions, because “everything is interconnectedness”.
This is a commentary note on the situation of functional neuroimaging in psychiatry. With this we would like to encourage psychiatrists and the journal editors of psychiatric and related journals to at least rethink the role of functional neuroimaging in this discipline and use these imaging techniques in their various aspects of clinical diagnosis and therapy regimens,respectively.
Fans stärken Marken
(2016)
The effective executing innovation projects requires multiple estimation of market success of new product features in the early stages of customer-centered innovation process such as strategy formulation, evaluation of ideas and concepts and also at a stage close to the market launch. The attempts to integrate customers for estimation of the market success often result in time-consuming customer interviews or lengthy field research. For this reason, industrial companies usually try to skip customer surveys even if they risk that their innovations will fail to bring the anticipated economic outcomes. In many practical cases, the customer surveys are simply not feasible or too expensive. As a result, the internal assessments within companies are frequently the only resource available in innovation process in the industrial environment. The paper discusses the possibilities of the fast identification of promising innovation opportunities and new product features based on the internal competences of companies. It compares the results of customer surveys with the estimation of internal company-experts and analyses the accuracy and validity of the expert assessments. The presented case studies demonstrate the accuracy rate between 43% and 77% for prediction of new product features with high market potential by company-internal experts. The paper proposes the evaluation methods to increase the accuracy rate and outlines that one of the essential requirements for reliable forecasting by the experts is their profound understanding of the customer working process, the ability to estimate the importance of customer needs and to assess the level of customer satisfaction with current products on the market.
Passive solar elements for both direct and indirect gains, are systems used to maintain a comfortable living environment while saving energy, especially in the building energy retrofit and adaptation process. Sunspaces, thermal mass and glazing area and orientation have been often used in the past to guarantee adequate indoor conditions when mechanical devices were not available. After a period of neglect, nowadays they are again considered as appropriate systems to help face environmental issues in the building sector, and both international and national legislation takes into consideration the possibility of including them in the building planning tools, also providing economic incentives. Their proper design needs dynamic simulation, often difficult to perform and time consuming. Moreover, results generally suffer from several uncertainties, so quasi steady-state procedures are often used in everyday practice with good results, but some corrections are still needed. In this paper, a comparative analysis of different solutions for the construction of verandas in an existing building is presented, following the procedure provided by the slightly modified and improved Standard EN ISO 13790:2008. Advantages and disadvantages of different configurations considering thermal insulation, windows typology and mechanical ventilation systems are discussed and a general intervention strategy is proposed. The aim is to highlight the possibility of using sunspaces in order to increase the efficiency of the existing building stock, considering ease of construction and economic viability.
Energy Performance of Verandas in the Building Retrofit Process (PDF Download Available). Available from: https://www.researchgate.net/publication/303093420_Energy_Performance_of_Verandas_in_the_Building_Retrofit_Process [accessed Jul 5, 2017].
Electrochemical impedance spectroscopy (EIS) is a widely-used diagnostic technique to characterize electrochemical processes. It is based on the dynamic analysis of two electrical observables, that is, current and voltage. Electrochemical cells with gaseous reactants or products (e.g., fuel cells, metal/air cells, electrolyzers) offer an additional observable, that is, the gas pressure. The dynamic coupling of current and/or voltage with gas pressure gives rise to a number of additional impedance definitions, for which we use the term electrochemical pressure impedance. It also gives rise to different experimental probing approaches. In this article we present a model-based study of electrochemical pressure impedance spectroscopy (EPIS). Possible quantifications and realizations of EPIS are discussed. The study of generic cell geometries consisting of gas reservoir, diffusion layer(s) and electrochemically active layer(s) reveals distinct spiral-shaped features in the Nyquist plot. Using the example of a sodium/oxygen (Na/O2) cell, the dynamic spatiotemporal behavior of the state variables is quantified and interpreted. Results are compared to first experimental EPIS measurements by Hartmann et al. [J. Phys. Chem. C118, 1461, 2014]. A sensitivity analysis highlights the properties of EPIS with respect to geometric, transport, and kinetic parameters. We demonstrate that EPIS is sensitive to transport parameters that are not well-accessible with standard EIS.
Im vorliegenden Beitrag wird beschrieben, wie bereits entworfene Zustandsregler für proportional geregelte Systeme ohne Rechentotzeit auf einfache Art und Weise für Systeme mit Reglerintegratoren bzw. mit Rechentotzeit erweitert werden können. Das Ziel ist hierbei, den Aufwand zur Ermittlung der Reglermatrix zu reduzieren. Hierbei soll die bereits vorhandene, optimierte Regelkreisdynamik so wenig wie möglich verändert werden, wodurch bei Mehrgrößensystemen hinzukommende Freiheitsgrade sinnvoll festgelegt werden. Die Betrachtungen erfolgen für lineare zeitdiskrete Systeme und werden anhand eines Beispiels aus der elektrischen Antriebstechnik veranschaulicht.
This paper presents the results of the idea generation experiment that repeats the study originally conducted at RMIT. In order to establish the influence that the experimental treatments make on the number and the breadth of solution ideas proposed by problem solvers with different knowledge levels, students from different years of study were recruited. Ninety students from the Offenburg University of Applied Sciences, Germany were divided into three groups. All students were asked to generate ideas on cleaning lime deposits from the inside of a water pipe and were given 16 minutes to record their individual ideas. Students of two experimental groups were shown some words for two minuted each. The Su-Field group was exposed to the eight fields of MATCEMIB. The Random Word group was shown eight random words every two minutes. The Su-Field group outperformed both the Control group and the Random Word group in the number of ideas generated. It was also found that the students from the Su-Field group proposed significantly broader solutions than the students from the Control and Random Word groups. The overall results of the experiment support the conclusions made by the RMIT researchers that simple ideation techniques can significantly improve idea generation and that the systematised Substance-Field Analysis is a suitable heuristic for engineering students.
A new yield function for lamellar gray cast iron materials is proposed. The new model is able to describe the results of recently performed microstructure-based finite-element computations that resolve the three dimensional yield surface of three different gray cast irons. The yield function requires only the yield stress in tension and compression of the respective material as model parameters. Furthermore, the algorithmic formulation of the new model is assessed for numerical robustness and efficiency.
This paper presents an overview of the coding aspects of a GNSS receiver. Coding allows detection and correction of channel-induced errors at the receiver, here the focus is on the mitigation of threats from malicious interferences. Although the effects of interference at different stages of GNSS baseband processing has been deeply analyzed in the literature, little attention was devoted to its impact on the navigation message decoding stage. Theis paper provides an introduction to the various coding schemes employed by current GNSS signals, discussing their performance in the presence of noise in terms of block-error rate. Additionally, the benefits of soft-decoding schemes for navigation message decoding are highlighted when jamming interferences are present. The proposed scheme requires estimating the noise plus interference power, yielding to enhanced decoding performances under severe jamming conditions. Finally, cryptographic schemes as a means of providing anti-spoofing for geosecurity location-based services, and their potential vulnerability are discussed, with particular emphasis on the dependence on the dependence of the scheme on successful navigation message decoding
Bud type carbon nanohorns (CNHs) are composed of carbon and have a closed conical tip at one end protruding from an aggregate structure. By employing a simple oxidation process in CO2 atmosphere, it is possible to open the CNH tips which increases their specific surface area by four fold. These tip opened CNHs combine the microporous nature of activated carbons and the crystalline mesoporous character of carbon nanotubes. The results for the high pressure CO2 gas adsorption of tip opened CNHs are reported herein for the first time and are found to be superior to traditional CO2 adsorbents like zeolites. The modified CNHs are also found to be promising materials for lithium ion batteries and the performance is found to be on a par with carbon nanotubes and carbon nanofibers.
Nickel cobalt aluminum oxide (NCA) based lithium-ion battery electrodes exhibit a distinct asymmetry in discharge/charge behavior towards high bulk stoichiometry (low state of charge). We show that basic electrochemical relationships, that is, the Nernst equation and the Butler-Volmer equation, are able to reproduce this behavior when a two-step reaction mechanism is assumed. The two-step mechanism consists of (1) lithium-ion adsorption from the electrolyte onto the active material particle surface under electron transfer, and (2) intercalation of surface-adsorbed lithium atoms into the bulk material. The asymmetry of experimental half-cell data of an NCA electrode cycled at 0.1 C-rate can be quantitatively reproduced with this simple model. The model parameters show two alternative solutions, predicting either a saturated (highly-covered) or a depleted surface for high bulk lithiation.
n this work a mathematical model for describing the performance of lithium-ion battery electrodes consisting of porous active material particles is presented. The model represents an extension of the Newman-type model, accounting for the agglomerate structure of the active material particles, here Li(Ni1/3Co1/3Mn1/3)O2 (NCM) and Li(Ni1/3Co1/3Al1/3)O2 (NCA). To this goal, an additional pore space is introduced on the active material level. The space is filled with electrolyte and a charge-transfer reaction takes place at the liquid-solid interface within the porous active material particles. Volume-averaging techniques are used to derive the model equations. A local Thiele modulus is defined and provides an insight into the potentially limiting factors on the active material level. The introduction of a liquid-phase ion transport within the active material reduces the overall transport losses, while the additional active surface area within the agglomerate lowers the charge-transfer resistance. As a consequence, calculated discharge capacities are higher for particles modeled as agglomerates. This finding is more pronounced in the case of high C-rates
There is increasing evidence of central hyperexcitability in chronic whiplash-associated disorders (cWAD). However, little is known about how an apparently simple cervical spine injury can induce changes in cerebral processes. The present study was designed (1) to validate previous results showing alterations of regional cerebral blood flow (rCBF) in cWAD, (2) to test if central hyperexcitability reflects changes in rCBF upon non-painful stimulation of the neck, and (3) to verify our hypothesis that the missing link in understanding the underlying pathophysiology could be the close interaction between the neck and midbrain structures. For this purpose, alterations of rCBF were explored in a case-control study using H215O positron emission tomography, where each group was exposed to four different conditions, including rest and different levels of non-painful electrical stimulation of the neck. rCBF was found to be elevated in patients with cWAD in the posterior cingulate and precuneus, and decreased in the superior temporal, parahippocampal, and inferior frontal gyri, the thalamus and the insular cortex when compared with rCBF in healthy controls. No differences in rCBF were observed between different levels of electrical stimulation. The alterations in regions directly involved with pain perception and interoceptive processing indicate that cWAD symptoms might be the consequence of a mismatch during the integration of information in brain regions involved in pain processing.
All you need is sleep
(2016)
In 21st century, the century when the humanity hopes to embark on interplanetary travel, we are yet to fully reach an understanding of our very own idiosyncratic terra incognita – the human sleep. Sleep is a highly conserved evolutionary process that constitutes approximately one third of our life, and the lack or inadequate sleep may lead to impairment across multiple cognitive domains (Tononi and Cirelli, 2014; Lim and Dinges, 2010). Sleep deprivation also leads to aberrant brain functioning, immunological and metabolic collapse, and if it is sufficiently prolonged it will ultimately lead to death (Tononi and Cirelli, 2014).
There is a growing trend for the use of thermo-active building systems (TABS) for the heating and cooling of buildings, because these systems are known to be very economical and efficient. However, their control is complicated due to the large thermal inertia, and their parameterization is time-consuming. With conventional TABS-control strategies, the required thermal comfort in buildings can often not be maintained, particularly if the internal heat sources are suddenly changed. This paper shows measurement results and evaluations of the operation of a novel adaptive and predictive calculation method, based on a multiple linear regression (AMLR) for the control of TABS. The measurement results are compared with the standard TABS strategy. The results show that the electrical pump energy could be reduced by more than 86%. Including the weather adjustment, it could be demonstrated that thermal energy savings of over 41% could be reached. In addition, the thermal comfort could be improved due to the possibility to specify mean room set-point temperatures. With the AMLR, comfort category I of the comfort norms ISO 7730 and DIN EN 15251 are observed in about 95% of occasions. With the standard TABS strategy, only about 24% are within category I.
Adaptive predictive control of thermo-active building systems (TABS) based on a multiple regression algorithm: First practical test. Available from: https://www.researchgate.net/publication/305903009_Adaptive_predictive_control_of_thermo-active_building_systems_TABS_based_on_a_multiple_regression_algorithm_First_practical_test [accessed Jul 7, 2017].