TY - THES
AB - Ultraschall-Drahtbonden ist eine Standardtechnologie im Bereich der Aufbau- und Verbindungstechnik von Leistungshalbleitermodulen. Um Prozessschritte und damit wertvolle Zeit zu sparen, sollen die Kupferdickdrähte für die Leistungshalbleiter auch für die Kontaktierung von eingespritzten Anschlusssteckern im Modulrahmen verwendet werden. Das Kontaktierungsverfahren mit diesen Drähten auf Steckern in dünnwandigen Kunststoffrahmen führt häufig zu unzureichender Bondqualität. In dieser Arbeit wird das Bonden von Anschlusssteckern experimentell und anhand von Simulationen untersucht, um die Prozessstabilität zu steigern.
Zunächst wurden Experimente auf Untergründen mit hoher Steifigkeit durchgeführt, um Störgrößen von Untergrundeigenschaften zu verringern. Die gewonnenen Erkenntnisse erlaubten die Entwicklung eines Simulationsmodells für die Vorhersage der Bondqualität. Dieses basiert auf einer flächenaufgelösten Reibarbeitsbestimmung im Fügebereich unter Berücksichtigung des Ultraschallerweichungseffektes und der hierdurch entstehenden hohen Drahtverformung.
Experimente an den Anschlusssteckern im Modulrahmen zeigten eine verringerte Relativverschiebung zwischen Draht und Stecker, was zu einer deutlichen Verringerung der Reibarbeit führt. Außerdem wurden verminderte Schwingamplituden des Bondwerkzeugs nachgewiesen. Dies führt zu einer weiteren Reduktion der Reibarbeit. Beide Effekte wurden mithilfe eines Mehrmassenschwingers modelliert. Die gewonnenen Erkenntnisse und die erstellten Simulationsmodelle ermöglichen die Entwicklung von Klemmvorrichtungen, welche die identifizierten Störgrößen gezielt kompensieren und so ein verlässliches Bonden der Anschlussstecker im gleichen Prozessschritt ermöglichen, in dem auch die Leistungshalbleiter kontaktiert werden.
AU - Althoff, Simon
ID - 41971
KW - heavy copper bonding
KW - wire bonding
KW - quality prediction
KW - friction model
KW - point-contact-element
SN - 978-3-8440-8903-5
TI - Predicting the Bond Quality of Heavy Copper Wire Bonds using a Friction Model Approach
VL - 15
ER -
TY - JOUR
AB - We study how competition between physicians affects the provision of medical care. In
our theoretical model, physicians are faced with a heterogeneous patient population, in which patients
systematically vary with regard to both their responsiveness to the provided quality of care and their
state of health. We test the behavioral predictions derived from this model in a controlled laboratory
experiment. In line with the model, we observe that competition significantly improves patient benefits
as long as patients are able to respond to the quality provided. For those patients, who are not able
to choose a physician, competition even decreases the patient benefit compared to a situation without
competition. This decrease is in contrast to our theoretical prediction implying no change in benefits for
passive patients. Deviations from patient-optimal treatment are highest for passive patients in need of
a low quantity of medical services. With repetition, both, the positive effects of competition for active
patients as well as the negative effects of competition for passive patients become more pronounced. Our
results imply that competition can not only improve but also worsen patient outcome and that patients’
responsiveness to quality is decisive.
AU - Brosig-Koch, Jeannette
AU - Hehenkamp, Burkhard
AU - Kokot, Johanna
ID - 44092
JF - Health Economics
KW - physician competition
KW - patient characteristics
KW - heterogeneity in quality responses
KW - fee-for-service
KW - laboratory experiment
TI - Who benefits from quality competition in health care? A theory and a laboratory experiment on the relevance of patient characteristics
ER -
TY - GEN
AB - We consider a model where for-profit providers compete in quality in a price-regulated market that has been opened to competition, and where the incumbent is located at the center of the market, facing high costs of relocation. The model is relevant in markets such as public health care, education and schooling, or postal services. We find that, when the regulated price is low or intermediate, the entrant strategically locates towards the corner of the market to keep the incumbent at the low monopoly quality level. For a high price, the entrant locates at the corner of the market and both providers implement higher quality compared to a monopoly. In any case, the entrant implements higher quality than the incumbent provider. Social welfare is always higher in a duopoly if the cost of quality is low. For higher cost levels welfare is non-monotonic in the price and it can be optimal to the regulator not to use its entire budget. Therefore, the welfare effect of entry depends on the price and the size of the entry cost, and the regulator should condition the decision to allow entry on an assessment of the entry cost.
AU - Hehenkamp, Burkhard
AU - Kaarbøe, Oddvar M.
ID - 44093
KW - Quality competition
KW - Price regulation
KW - Location choice
KW - Product differentiation
TI - Price Regulation, Quality Competition and Location Choice with Costly Relocation
ER -
TY - JOUR
AB - Brainwaves have demonstrated to be unique enough across individuals to be useful as biometrics. They also provide promising advantages over traditional means of authentication, such as resistance to external observability, revocability, and intrinsic liveness detection. However, most of the research so far has been conducted with expensive, bulky, medical-grade helmets, which offer limited applicability for everyday usage. With the aim to bring brainwave authentication and its benefits closer to real world deployment, we investigate brain biometrics with consumer devices. We conduct a comprehensive measurement experiment and user study that compare five authentication tasks on a user sample up to 10 times larger than those from previous studies, introducing three novel techniques based on cognitive semantic processing. Furthermore, we apply our analysis on high-quality open brainwave data obtained with a medical-grade headset, to assess the differences. We investigate both the performance, security, and usability of the different options and use this evidence to elicit design and research recommendations. Our results show that it is possible to achieve Equal Error Rates as low as 7.2% (a reduction between 68–72% with respect to existing approaches) based on brain responses to images with current inexpensive technology. We show that the common practice of testing authentication systems only with known attacker data is unrealistic and may lead to overly optimistic evaluations. With regard to adoption, users call for simpler devices, faster authentication, and better privacy.
AU - Arias-Cabarcos, Patricia
AU - Fallahi, Matin
AU - Habrich, Thilo
AU - Schulze, Karen
AU - Becker, Christian
AU - Strufe, Thorsten
ID - 48063
IS - 3
JF - ACM Transactions on Privacy and Security
KW - Safety
KW - Risk
KW - Reliability and Quality
KW - General Computer Science
SN - 2471-2566
TI - Performance and Usability Evaluation of Brainwave Authentication Techniques with Consumer Devices
VL - 26
ER -
TY - JOUR
AU - Winkel, Fabian
AU - Deuse-Kleinsteuber, Johannes
AU - Böcker, Joachim
ID - 48058
JF - IEEE Transactions on Reliability
KW - Electrical and Electronic Engineering
KW - Safety
KW - Risk
KW - Reliability and Quality
SN - 0018-9529
TI - Run-to-Failure Relay Dataset for Predictive Maintenance Research With Machine Learning
ER -
TY - CONF
AB - Quality diversity (QD) is a branch of evolutionary computation that gained increasing interest in recent years. The Map-Elites QD approach defines a feature space, i.e., a partition of the search space, and stores the best solution for each cell of this space. We study a simple QD algorithm in the context of pseudo-Boolean optimisation on the "number of ones" feature space, where the ith cell stores the best solution amongst those with a number of ones in [(i - 1)k, ik - 1]. Here k is a granularity parameter 1 {$\leq$} k {$\leq$} n+1. We give a tight bound on the expected time until all cells are covered for arbitrary fitness functions and for all k and analyse the expected optimisation time of QD on OneMax and other problems whose structure aligns favourably with the feature space. On combinatorial problems we show that QD finds a (1 - 1/e)-approximation when maximising any monotone sub-modular function with a single uniform cardinality constraint efficiently. Defining the feature space as the number of connected components of a connected graph, we show that QD finds a minimum spanning tree in expected polynomial time.
AU - Bossek, Jakob
AU - Sudholt, Dirk
ID - 48872
KW - quality diversity
KW - runtime analysis
SN - 9798400701191
T2 - Proceedings of the Genetic and Evolutionary Computation Conference
TI - Runtime Analysis of Quality Diversity Algorithms
ER -
TY - CONF
AB - Manufacturing companies face the challenge of reaching required quality standards. Using
optical sensors and deep learning might help. However, training deep learning algorithms
require large amounts of visual training data. Using domain randomization to generate synthetic
image data can alleviate this bottleneck. This paper presents the application of synthetic
image training data for optical quality inspections using visual sensor technology. The results
show synthetically generated training data are appropriate for visual quality inspections.
AU - Gräßler, Iris
AU - Hieb, Michael
ID - 52816
KW - synthetic training data
KW - machine vision quality gates
KW - deep learning
KW - automated inspection and quality control
KW - production control
T2 - Lectures
TI - Creating Synthetic Training Datasets for Inspection in Machine Vision Quality Gates in Manufacturing
ER -
TY - JOUR
AB - Encrypting data before sending it to the cloud ensures data confidentiality but requires the cloud to compute on encrypted data. Trusted execution environments, such as Intel SGX enclaves, promise to provide a secure environment in which data can be decrypted and then processed. However, vulnerabilities in the executed program give attackers ample opportunities to execute arbitrary code inside the enclave. This code can modify the dataflow of the program and leak secrets via SGX side channels. Fully homomorphic encryption would be an alternative to compute on encrypted data without data leaks. However, due to its high computational complexity, its applicability to general-purpose computing remains limited. Researchers have made several proposals for transforming programs to perform encrypted computations on less powerful encryption schemes. Yet current approaches do not support programs making control-flow decisions based on encrypted data.
We introduce the concept of
dataflow authentication
(DFAuth) to enable such programs. DFAuth prevents an adversary from arbitrarily deviating from the dataflow of a program. Our technique hence offers protections against the side-channel attacks described previously. We implemented two flavors of DFAuth, a Java bytecode-to-bytecode compiler, and an SGX enclave running a small and program-independent trusted code base. We applied DFAuth to a neural network performing machine learning on sensitive medical data and a smart charging scheduler for electric vehicles. Our transformation yields a neural network with encrypted weights, which can be evaluated on encrypted inputs in
\( 12.55 \,\mathrm{m}\mathrm{s} \)
. Our protected scheduler is capable of updating the encrypted charging plan in approximately 1.06 seconds.
AU - Fischer, Andreas
AU - Fuhry, Benny
AU - Kußmaul, Jörn
AU - Janneck, Jonas
AU - Kerschbaum, Florian
AU - Bodden, Eric
ID - 31844
IS - 3
JF - ACM Transactions on Privacy and Security
KW - Safety
KW - Risk
KW - Reliability and Quality
KW - General Computer Science
SN - 2471-2566
TI - Computation on Encrypted Data Using Dataflow Authentication
VL - 25
ER -
TY - CONF
AB - Generating instances of different properties is key to algorithm selection methods that differentiate between the performance of different solvers for a given combinatorial optimization problem. A wide range of methods using evolutionary computation techniques has been introduced in recent years. With this paper, we contribute to this area of research by providing a new approach based on quality diversity (QD) that is able to explore the whole feature space. QD algorithms allow to create solutions of high quality within a given feature space by splitting it up into boxes and improving solution quality within each box. We use our QD approach for the generation of TSP instances to visualize and analyze the variety of instances differentiating various TSP solvers and compare it to instances generated by established approaches from the literature.
AU - Bossek, Jakob
AU - Neumann, Frank
ID - 48861
KW - instance features
KW - instance generation
KW - quality diversity
KW - TSP
SN - 978-1-4503-9237-2
T2 - Proceedings of the Genetic and Evolutionary Computation Conference
TI - Exploring the Feature Space of TSP Instances Using Quality Diversity
ER -
TY - CONF
AB - Recently different evolutionary computation approaches have been developed that generate sets of high quality diverse solutions for a given optimisation problem. Many studies have considered diversity 1) as a mean to explore niches in behavioural space (quality diversity) or 2) to increase the structural differences of solutions (evolutionary diversity optimisation). In this study, we introduce a co-evolutionary algorithm to simultaneously explore the two spaces for the multi-component traveling thief problem. The results show the capability of the co-evolutionary algorithm to achieve significantly higher diversity compared to the baseline evolutionary diversity algorithms from the literature.
AU - Nikfarjam, Adel
AU - Neumann, Aneta
AU - Bossek, Jakob
AU - Neumann, Frank
ED - Rudolph, Günter
ED - Kononova, Anna V.
ED - Aguirre, Hernán
ED - Kerschke, Pascal
ED - Ochoa, Gabriela
ED - Tu\v sar, Tea
ID - 48894
KW - Co-evolutionary algorithms
KW - Evolutionary diversity optimisation
KW - Quality diversity
KW - Traveling thief problem
SN - 978-3-031-14714-2
T2 - Parallel Problem Solving from Nature (PPSN XVII)
TI - Co-Evolutionary Diversity Optimisation for the Traveling Thief Problem
ER -
TY - JOUR
AB - This investigation concentrates on the association of intergenerational value
similarity and adult children’s and parents’subjective well-being, on the linkage
between relationship quality and subjective well-being. Mediation effects of
the relationship quality on the associations between value similarity and
subjective well-being were focused. The sample consisted of 600 adult
German children (53.8% women) and their parents. Dyadic correlations were
constructed to determine the value similarity. In this study, the general value
orientation and the family values were objects of research. We measured the
subjective well-being with the Satisfaction with Life Scale and we used the
Network of Relationships Inventory (NRI) to measure the relationship
quality. Associations between subjective well-being and value similarity, and
between subjective well-being and relationship quality, as well as mediation
effects, were found. All effects depend on gender and perspective.
AU - Hoellger, Christian
AU - Sommer, Sabrina
AU - Buhl, Heike M.
ID - 32561
JF - Journal of Family Issues
KW - adult child–parent dyads
KW - relationship quality
KW - life satisfaction
KW - parent–child relationship
KW - intergenerational stake hypothesis
KW - mediation analyses
SN - 0192-513X
TI - Intergenerational Value Similarity and Subjective Well-Being
ER -
TY - CONF
AB - In the industry 4.0 era, there is a growing need to transform unstructured data acquired by a multitude of sources into information and subsequently into knowledge to improve the quality of manufactured products, to boost production, for predictive maintenance, etc. Data-driven approaches, such as machine learning techniques, are typically employed to model the underlying relationship from data. However, an increase in model accuracy with state-of-the-art methods, such as deep convolutional neural networks, results in less interpretability and transparency. Due to the ease of implementation, interpretation and transparency to both domain experts and non-experts, a rule-based method is proposed in this paper, for prognostics and health management (PHM) and specifically for diagnostics. The proposed method utilizes the most relevant sensor signals acquired via feature extraction and selection techniques and expert knowledge. As a case study, the presented method is evaluated on data from a real-world quality control set-up provided by the European prognostics and health management society (PHME) at the conference’s 2021 data challenge. With the proposed method, our team took the third place, capable of successfully diagnosing different fault modes, irrespective of varying conditions.
AU - Aimiyekagbon, Osarenren Kennedy
AU - Muth, Lars
AU - Wohlleben, Meike Claudia
AU - Bender, Amelie
AU - Sextro, Walter
ED - Do, Phuc
ED - King, Steve
ED - Fink, Olga
ID - 27111
IS - 1
KW - PHME 2021
KW - Feature Selection Classification
KW - Feature Selection Clustering
KW - Interpretable Model
KW - Transparent Model
KW - Industry 4.0
KW - Real-World Diagnostics
KW - Quality Control
KW - Predictive Maintenance
T2 - Proceedings of the European Conference of the PHM Society 2021
TI - Rule-based Diagnostics of a Production Line
VL - 6
ER -
TY - JOUR
AB - Through co-occurrence analysis of 1139 documents (1964-2018) we identified trends in the discussions about the implementation of student teaching evaluation (SET). We found that: (1) Attention to SET originated in the US in the 1970s, spreading to German-speaking countries in the mid-1990s and continuing in China and Latin America in the early 2000s. (2) SET is commonly viewed as a control tool deserving methodological improvement, while bias is debated in the US. We also found local trajectories: (3) Whereas in the US and Latin America SET is primarily seen as a management tool, German-speaking and Chinese authors reflect more on improving teaching. Chinese scholars consider SET a valid instrument for state control associated with artificial intelligence. Also, (4) SET is commonly used in medical education in the US and the German-speaking region and in physical education in China. We conclude that SET is discussed cross-nationally but affected by national path dependencies.
AU - Pineda, Pedro
AU - Steinhardt, Isabel
ID - 27117
JF - Teaching in Higher Education
KW - academic discourse
KW - bibliometric review
KW - quality assurance
KW - student evaluation of teaching
KW - teaching evaluation
SN - 1356-2517
TI - The Debate on student evaluations of teaching: global convergence confronts higher education traditions
ER -
TY - JOUR
AB - This investigation concentrates on value similarity between parents and their children during adulthood. The interplay between gender, age, relationship quality, and frequency of contact on value similarity was analyzed. A total of 600 adult German children (53.8% women) and their parents took part in a questionnaire study. Value orientation was measured with a short version of Schwartz’s Portrait Values Questionnaire, and relationship quality with the Network of Relationships Inventory (Furman & Buhrmeister, 1992).Value similarity was higher in mother–daughter dyads compared to mother–son dyads, but in the other dyads, no significant differences were found. Regarding relationship quality, verbal intimacy was not related to value similarity. Parental satisfaction was associated with value similarity in the father–child dyads. Satisfaction, as perceived by adult children, was linked to value similarity in mother–child and father–son dyads. Furthermore, the frequency of contact related to value similarity between mothers and sons.
AU - Hoellger, Christian
AU - Sommer, Sabrina
AU - Albert, Isabelle
AU - Buhl, Heike M.
ID - 32559
IS - 6
JF - Journal of Family Issues
KW - Adult child–parent dyads
KW - value similarity
KW - relationship quality
KW - frequency of contact
KW - parent-child-relationship
SN - 0192-513X
TI - Intergenerational Value Similarity in Adulthood
VL - 42
ER -
TY - CONF
AB - Service Level Agreements are essential tools enabling clients and telco operators to specify required quality of service. The 5GTANGO NFV platform enables SLAs through policies and custom service lifecycle management components. This allows the operator to trigger certain lifecycle management events for a service, and the network service developer to define how to execute such events (e.g., how to scale). In this demo we will demonstrate this unique 5GTANGO concept using an elastic proxy service supported by a high availability SLA enforced through a range of traffic regimes.
AU - Soenen, Thomas
AU - Vicens, Felipe
AU - Bonnet, José
AU - Parada, Carlos
AU - Kapassa, Evgenia
AU - Touloupou, Marious
AU - Fotopulou, Eleni
AU - Zafeiropoulos, Anastasios
AU - Pol, Ana
AU - Kolometsos, Stavros
AU - Xilouris, George
AU - Alemany, Pol
AU - Vilalta, Ricard
AU - Trakadas, Panos
AU - Karkazis, Panos
AU - Peuster, Manuel
AU - Tavernier, Wouter
ID - 15368
KW - 5G mobile communication
KW - contracts
KW - quality of service
KW - telecommunication traffic
KW - virtualisation
KW - custom service lifecycle management components
KW - lifecycle management events
KW - network service developer
KW - elastic proxy service
KW - SLA-controlled proxy service
KW - customisable MANO
KW - operator policies
KW - Service Level Agreements
KW - unique 5G TANGO concept
KW - 5G TANGO NFV platform
KW - quality of service
KW - traffic regimes
KW - high availability SLA
KW - Monitoring
KW - Probes
KW - Portals
KW - Quality of service
KW - Tools
KW - Servers
KW - Graphical user interfaces
SN - 1573-0077
T2 - 2019 IFIP/IEEE Symposium on Integrated Network and Service Management (IM)
TI - SLA-controlled Proxy Service Through Customisable MANO Supporting Operator Policies
ER -
TY - JOUR
AB - We study the historical development of Slovenian Accounting Standards (SAS) and their association with accounting quality (AQ). We focus on private firms where the financial reporting process is characterised by low demand for high-quality reporting. We investigate three distinct editions of SAS since 1994 and test how their development towards international standards is related to AQ. Aggregate earnings management measures indicate that the use of accounting discretion decreases with less earnings smoothing over time. The main features of AQ have been consistent throughout historical development. Asymmetric timeliness of earnings, the ability of earnings to predict future cash flows, and the ability of accruals to mitigate mismatching are all present throughout. We also document typical departures from properties of high AQ. For example, accruals do not (always) facilitate timely recognition of losses. However, these can be attributed to the overwhelming influence of reporting incentives (e.g. taxation, debt, size) rather than to the (lower) quality of accounting standards.
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Abstract
We study the historical development of Slovenian Accounting Standards (SAS) and their association with accounting quality (AQ). We focus on private firms where the financial reporting process is characterised by low demand for high-quality reporting. We investigate three distinct editions of SAS since 1994 and test how their development towards international standards is related to AQ. Aggregate earnings management measures indicate that the use of accounting discretion decreases with less earnings smoothing over time. The main features of AQ have been consistent throughout historical development. Asymmetric timeliness of earnings, the ability of earnings to predict future cash flows, and the ability of accruals to mitigate mismatching are all present throughout. We also document typical departures from properties of high AQ. For example, accruals do not (always) facilitate timely recognition of losses. However, these can be attributed to the overwhelming influence of reporting incentives (e.g. taxation, debt, size) rather than to the (lower) quality of accounting standards.
AU - Valentincic, Aljosa
AU - Novak, Ales
AU - Kosi, Urska
ID - 3542
IS - 3
JF - Accounting in Europe
KW - private firms
KW - accounting quality
KW - development of accounting standards
KW - IFRS-like standards
KW - Slovenia
TI - Accounting quality in private firms during the transition towards international standards
VL - 14
ER -
TY - GEN
AB - On an intermediate goods market we consider vertical and horizontal product differentiation and analyze the impact of simultaneous competition for resources and the demand of customers on the market outcome. Asymmetries between intermediaries may arise due to distinct product qualities as well as by reasons of different production technologies. The intermediaries compete on the output market by choosing production quantities sequentially and for the supplies of a monopolistic input supplier on the input market. It turns out that there exist differences in product quality and productivities such that an intermediary being the Stackelberg leader has no incentive to procure inputs, whereas in the role of the Stackelberg follower will participate in the market. Moreover, we find that given an intermediary is more competitive, his equilibrium output quantity is higher when being the leader than when being the follower. Interestingly, if the intermediary is less competitive and goods are complements, there may exist asymmetries such that an intermediary being in the position of the Stackelberg follower offers higher output quantities in equilibrium than when being in the position of the Stackelberg leader.
AU - Manegold, Jochen
ID - 2570
KW - Input Market
KW - Product Quality
KW - Quantity Competition
KW - Stackelberg Competition
KW - Product Innovation
TI - Stackelberg Competition among Intermediaries in a Differentiated Duopoly with Product Innovation
VL - 98
ER -
TY - JOUR
AB - We examine whether the mandated introduction of International Financial Reporting Standards (IFRS) is associated with the propensity to access the public rather than private debt market and the cost of debt. We use a global sample of public bonds and private loans and find that mandatory IFRS adopters are more likely, post-IFRS, to issue bonds than to borrow privately. We also find that mandatory IFRS adopters pay lower bond yield spreads, but not lower loan spreads, after the mandate. These findings are consistent with debt providers responding positively to financial reporting of higher quality and comparability, but only when there is a greater reliance on publicly available financial statements than private communication. Lastly, we document that the observed debt market benefits are concentrated in countries with larger differences between domestic GAAP and IFRS and are present even for EU countries that did not experience concurrent financial reporting enforcement or other institutional reforms. Overall, our study documents positive economic consequences around the mandated IFRS adoption for corporate debt financing and, in particular, for bond financing.
AU - Florou, Annita
AU - Kosi, Urska
ID - 4035
IS - 4
JF - Review of Accounting Studies
KW - Accounting regulation
KW - IFRS
KW - Accounting quality
KW - Public and private debt markets
KW - Cost of debt
TI - Does mandatory IFRS adoption facilitate debt financing?
VL - 20
ER -
TY - CONF
AB - In order to increase mechanical strength, heat dissipation and ampacity and to decrease failure through fatigue fracture, wedge copper wire bonding is being introduced as a standard interconnection method for mass production. To achieve the same process stability when using copper wire instead of aluminum wire a profound understanding of the bonding process is needed. Due to the higher hardness of copper compared to aluminum wire it is more difficult to approach the surfaces of wire and substrate to a level where van der Waals forces are able to arise between atoms. Also, enough friction energy referred to the total contact area has to be generated to activate the surfaces. Therefore, a friction model is used to simulate the joining process. This model calculates the resulting energy of partial areas in the contact surface and provides information about the adhesion process of each area. The focus here is on the arising of micro joints in the contact area depending on the location in the contact and time. To validate the model, different touchdown forces are used to vary the initial contact areas of wire and substrate. Additionally, a piezoelectric tri-axial force sensor is built up to identify the known phases of pre-deforming, cleaning, adhering and diffusing for the real bonding process to map with the model. Test substrates as DBC and copper plate are used to show the different formations of a wedge bond connection due to hardness and reaction propensity. The experiments were done by using 500 $\mu$m copper wire and a standard V-groove tool.
AU - Althoff, Simon
AU - Neuhaus, Jan
AU - Hemsel, Tobias
AU - Sextro, Walter
ID - 9868
KW - adhesion
KW - circuit reliability
KW - deformation
KW - diffusion
KW - fatigue cracks
KW - friction
KW - interconnections
KW - lead bonding
KW - van der Waals forces
KW - Cu
KW - adhering process
KW - adhesion process
KW - ampacity improvement
KW - bond quality improvement
KW - cleaning process
KW - diffusing process
KW - fatigue fracture failure
KW - friction energy
KW - friction model
KW - heat dissipation
KW - mechanical strength
KW - piezoelectric triaxial force sensor
KW - predeforming process
KW - size 500 mum
KW - total contact area
KW - van der Waals forces
KW - wedge copper wire bonding
KW - Bonding
KW - Copper
KW - Finite element analysis
KW - Force
KW - Friction
KW - Substrates
KW - Wires
T2 - Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th
TI - Improving the bond quality of copper wire bonds using a friction model approach
ER -
TY - JOUR
AB - (K,Na)NbO3 ceramics have attracted much attention as lead-free piezoelectric materials with high piezoelectric properties. High-quality (K,Na)NbO3 ceramics can be sintered using KNbO3 and NaNbO3 powders synthesized by a hydrothermal method. In this study, to enhance the quality factor of the ceramics, high-power ultrasonic irradiation was employed during the hydrothermal method, which led to a reduction in the particle size of the resultant powders.
AU - Isobe, G.
AU - Maeda, Takafumi
AU - Bornmann, Peter
AU - Hemsel, Tobias
AU - Morita, Takeshi
ID - 9878
IS - 2
JF - Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
KW - Q-factor
KW - ceramics
KW - crystal growth from solution
KW - particle size
KW - piezoelectric materials
KW - potassium compounds
KW - powders
KW - sintering
KW - sodium compounds
KW - ultrasonic effects
KW - (K0.48Na0.52)NbO3
KW - KNbO3 powders
KW - NaNbO3 powders
KW - high-power ultrasonic irradiation
KW - lead-free piezoelectric materials
KW - lead-free piezoelectric powders
KW - particle size reduction
KW - piezoelectric properties
KW - quality factor
KW - sintered (K0.48Na0.52)NbO3 ceramics
KW - sintering
KW - ultrasonic-assisted hydrothermal method
KW - Acoustics
KW - Ceramics
KW - Lead
KW - Piezoelectric materials
KW - Powders
KW - Radiation effects
KW - Transducers
SN - 0885-3010
TI - Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics
VL - 61
ER -
TY - JOUR
AU - Vidor, F.F.
AU - Wirth, G.I.
AU - Hilleringmann, Ulrich
ID - 39483
IS - 12
JF - Microelectronics Reliability
KW - Electrical and Electronic Engineering
KW - Surfaces
KW - Coatings and Films
KW - Safety
KW - Risk
KW - Reliability and Quality
KW - Condensed Matter Physics
KW - Atomic and Molecular Physics
KW - and Optics
KW - Electronic
KW - Optical and Magnetic Materials
SN - 0026-2714
TI - Low temperature fabrication of a ZnO nanoparticle thin-film transistor suitable for flexible electronics
VL - 54
ER -
TY - CONF
AB - A model approach for wedge/wedge bonding copper wire is presented. The connection between wire and substrate is based on a variety of physical effects, but the dominant one is the friction based welding while applying ultrasound. Consequently, a friction model was used to investigate the welding process. This model is built up universal and can be used to describe the formation of micro welds in the time variant contact area between wire and substrate. Aim of the model is to identify the interactions between touchdown, bond normal force, ultrasonic power and bonding time. To do so, the contact area is discretized into partial areas where a Point Contact Model is applied. Based on this approach it is possible to simulate micro and macro slip inside the contact area between wire and substrate. The work done by friction force is a main criterion to define occurring micro joints which influence the subsequent welding.
AU - Althoff, Simon
AU - Neuhaus, Jan
AU - Hemsel, Tobias
AU - Sextro, Walter
ID - 9797
KW - Wire bonding
KW - friction modeling
KW - wire bond quality
KW - contact element modeling
T2 - IMAPS 2013, 46th International Symposium on Microelectronics
TI - A friction based approach for modeling wire bonding
ER -
TY - JOUR
AB - Employing a Hausman–Taylor instrument variable (HT–IV) estimator to data from 558 microfinance institutions (MFIs) in 80 developing countries for the period from 2002 to 2007, this paper provides empirical evidence for a positive impact of a country's external governance quality and outcome on local microbanks' economic success in terms of profitability and sustainability. Evidence as well suggests a negative relationship between external governance and the microbanks' social success measured by the depth of outreach. In this context, our analysis reveals that a country's political stability, governance effectiveness, regulatory quality and rule of law are significant key elements of external governance affecting the MFIs' functional performance. Moreover, results from sensitivity analyses indicate that the relationship between external governance quality and microfinance functional performance significantly depends on the microbanks' business concepts, their lending methodologies and sources of funding.
AU - Uhde, André
AU - Müller, Oliver
ID - 4398
IS - 2/3
JF - International Journal of Monetary Economics and Finance
KW - microfinance
KW - external governance
KW - economic success
KW - social success
KW - developing countries
KW - profitability
KW - sustainability
KW - microbanks
KW - outreach
KW - political stability
KW - governance effectiveness
KW - regulatory quality
KW - rule of law
KW - governance quality
KW - lending methodologies
KW - funding sources
TI - External governance outcome and microfinance success
VL - 6
ER -
TY - JOUR
AB - This contribution presents and discusses main results of a new survey on the assessment of supervisory quality among German banks in 2010. In particular, it is analyzed if and how supervised banks’ perception of the quality of supervisory authorities and their instruments has changed due to the financial crisis starting in mid-2007. Subsequently, results from the recent survey are compared with findings provided by a former study carried out by the authors in 2006 (Paul, Stein and Uhde, 2008).
AU - Paul, Stephan
AU - Stein, Stefan
AU - Uhde, André
ID - 4402
IS - 3
JF - Journal of Governance and Regulation
KW - banking supervision
KW - quality
KW - assessment
KW - banking sector
TI - Measuring the quality of banking supervision revisited - Assessments by German banks before and during the financial crisis
VL - 1
ER -
TY - JOUR
AB - The successful implementation of a harmonised regulatory framework for the global banking system is still a long way off. This mainly results from (a) different traditions in banking regulation and supervision at the national level, (b) different national emphases on regulatory sub-goals such as efficiency or the protection and promotion of national financial markets, and (c) different institutional settings and conditions. In this context, studies on the banking industry's assessment of supervisory processes and instruments highlight how effectively and efficiently individual nation states are implementing international frameworks such as Basel II and the Capital Requirements Directive for Europe. In November 2005, the German Government commissioned an evaluation of the supervisory processes and instruments of the country's banking authorities, BaFin and Bundesbank. The study aimed to determine the options for further optimising supervision, reducing regulatory burden and bureaucracy, and otherwise restricting supervision. This paper presents the most important findings from the survey, analyses significant differences in assessments given by various banking groups, empirically evaluates significant drivers of banks' overall satisfaction with banking supervision, and drafts proposals for improving banking regulation and supervision in Germany. Finally, aspects of further research are discussed.
AU - Paul, Stephan
AU - Stein, Stefan
AU - Uhde, André
ID - 4407
IS - 1
JF - Journal of Risk Managment in Financial Institutions
KW - banking supervision
KW - quality
KW - assessment
KW - banking sector
TI - Measuring the relationship between supervisory authorities and banks: An assessment of the German banking sector
VL - 2
ER -
TY - JOUR
AB - The feature of this paper is a critical assessment of the current discourses about quality of life (QoL) and their implications for Social Work. At first it pictures some major historical backgrounds of the discussion on the improvement of life quality as an aim of societal development. In particular three crucial shifts in the politics of QoL - its 'individualisation', its 'informalisation' and its 'culturalisation' - and their implications for Social Work are critically examined theoretically and empirically referring to the results of an own community-study. The paper concludes with an alternative suggestion reflecting the idea of an 'autonomy-based' approach of democratic equality.
AU - Landhäußer, Sandra
AU - Ziegler, Holger
ID - 35910
IS - 1
JF - Social Work & Society
KW - Critical
KW - quality
KW - Social
TI - Social Work and the Quality of Life Politics - A Critical Assessment
VL - 3
ER -