@article{NedopilDhaliwalHowelletal.2022, author = {Nedopil, Alexander J. and Dhaliwal, Anand and Howell, Stephen M. and Hull, Maury L.}, title = {A surgeon that switched to unrestricted kinematic alignment with manual instruments has a short learning curve and comparable resection accuracy and outcomes to those of an experienced surgeon}, series = {Journal of Personalized Medicine}, volume = {12}, journal = {Journal of Personalized Medicine}, number = {7}, issn = {2075-4426}, doi = {10.3390/jpm12071152}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-281842}, year = {2022}, abstract = {After starting an orthopedic practice, a surgeon with a fellowship in mechanically aligned (MA) TKA initiated this study to characterize their learning curve after they switched to unrestricted kinematic alignment (KA) TKA using manual instruments. Accordingly, the present study determined for the inexperienced (IE) surgeon the number of cases required to achieve consistent femoral resections and operating times, and whether the femoral resection accuracy, patient-reported outcome measures (PROMs), and component alignment were different from an experienced (E) surgeon. This prospective cohort study analyzed the IE surgeon's first 30 TKAs, all performed with KA, and 30 consecutive KA TKAs performed by an E surgeon. The resection accuracy or deviation was the calipered thickness of the distal and posterior medial and lateral femoral resections minus the planned resection thickness, which was the thickness of the corresponding condyle of the femoral component, minus 2 mm for cartilage wear, and 1 mm for the kerf of the blade. Independent observers recorded the femoral resection thickness, operative times, PROMs, and alignment. For each femoral resection, the deviation between three groups of patients containing ten consecutive KA TKAs, was either insignificant (p = 0.695 to 1.000) or within the 0.5 mm resolution of the caliper, which indicated no learning curve. More than three groups were needed to determine the learning curve for the operative time; however, the IE surgeon's procedure dropped to 77 min for the last 10 patients, which was 20 min longer than the E surgeon. The resection deviations of the IE and E surgeon were comparable, except for the posterolateral femoral resection, which the IE surgeon under-resected by a mean of -0.8 mm (p < 0.0001). At a mean follow-up of 9 and 17 months, the Forgotten Joint Score, Oxford Knee Score, KOOS, and the alignment of the components and limbs were not different between the IE and E surgeon (p ≥ 0.6994). A surgeon that switches to unrestricted KA with manual instruments can determine their learning curve by computing the deviation of the distal and posterior femoral resections from the planned resection. Based on the present study, an IE surgeon could have resection accuracy, post-operative patient outcomes, and component alignment comparable to an E surgeon.}, language = {en} } @article{UmHinrichsenKwonetal.2015, author = {Um, Jaegon and Hinrichsen, Haye and Kwon, Chulan and Park, Hyunggyu}, title = {Total cost of operating an information engine}, series = {New Journal of Physics}, volume = {17}, journal = {New Journal of Physics}, number = {085001}, doi = {10.1088/1367-2630/17/8/085001}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-148286}, year = {2015}, abstract = {We study a two-level system controlled in a discrete feedback loop, modeling both the system and the controller in terms of stochastic Markov processes. We find that the extracted work, which is known to be bounded from above by the mutual information acquired during measurement, has to be compensated by an additional energy supply during the measurement process itself, which is bounded by the same mutual information from below. Our results confirm that the total cost of operating an information engine is in full agreement with the conventional second law of thermodynamics. We also consider the efficiency of the information engine as a function of the cycle time and discuss the operating condition for maximal power generation. Moreover, we find that the entropy production of our information engine is maximal for maximal efficiency, in sharp contrast to conventional reversible heat engines.}, language = {en} } @phdthesis{Reeg2017, author = {Reeg, Johannes}, title = {Empirical Studies of Contemporaneous Banking Research}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-153581}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2017}, abstract = {Banks perform important functions for the economy. Besides financial intermediation, banks provide information, liquidity, maturity- and risk-transformation (Fama, 1985). Banks ensure the transfer of liquidity from depositors to the most profitable investment projects. In addition, they perform important screening and monitoring services over investments hence contributing steadily to the efficient allocation of resources across the economy (Pathan and Faff, 2013). Since banks provide financial services all across the economy, this exposes banks (as opposed to non-banks) to systemic risk: the recent financial crisis revealed that banks can push economies into severe recessions. However, the crisis also revealed that certain bank types appear far more stable than others. For instance, cooperative banks performed better during the crisis than commercial banks. Different business models may reason these performance-differences: cooperative banks focus on relationship lending across their region, hence these banks suffered less from the collapse of the US housing market. Since cooperative banks performed better during the crisis than commercial banks, it is quite surprising that research concerning cooperative banks is highly underrepresented in the literature. For this reason, the following three studies aim to contribute to current literature by examining three independent contemporaneous research questions in the context of cooperative banks. Chapter 2 examines whether cooperative banks benefit from revenue diversification: Current banking literature reveals the recent trend in the overall banking industry that banks may opt for diversification by shifting their revenues to non-interest income. However, existing literature also shows that not every bank benefits from revenue diversification (Mercieca et al., 2007; Stiroh and Rumble, 2006; Goddard et al., 2008). Stiroh and Rumble (2006) find that large commercial banks (US Financial Holding Companies) perceive decreasing performance by shifting revenues towards non-interest income. Revenues from cooperative banks differ from those of commercial banks: commercial banks trade securities and derivatives, sell investment certificates and other trading assets. Concerning the lending business, commercial banks focus on providing loans for medium-sized and large companies rather than for small (private) customers. Cooperative banks rely on commission income (fees) from monetary transactions and selling insurances as a source of non-interest income. They generate most of their interest income by providing loans to small and medium-sized companies as well as to private customers in the region. These differences in revenues raise the question whether findings from Stiroh and Rumble (2006) apply to cooperative banks. For this reason, Chapter 2 evaluates a sample of German cooperative banks over the period 2005 to 2010 and aims to investigate the following research question: which cooperative banks benefit from revenue diversification? Results show that findings from Stiroh and Rumble (2006) do not apply to cooperative banks. Revenue concentration is positive related to risk-adjusted returns (indirect effect) for cooperative banks. At the same time, non-interest income is more profitable than interest income (direct effect). The evaluation of the underlying non-interest income share shows that banks who heavily focus on non-interest income benefit by shifting towards non-interest income. This finding arises due to the fact, that the positive direct effect dominates the negative indirect effect, leading in a positive (and significant) net effect. Furthermore, results reveal a negative net effect for banks who are heavily exposed to interest generating activities. This indicates that shifting to non-interest income decreases risk-adjusted returns for these banks. Consequently, these banks do better by focusing on the interest business. Overall, results show evidence that banks need time to build capabilities, expertise and experience before trading off return and risk efficiently with regard on revenue diversification. Chapter 3 deals with the relation between credit risk, liquidity risk, capital risk and bank efficiency: There has been rising competition in the European banking market due to technological development, deregulation and the introduction of the Euro as a common currency in recent decades. In order to remain competitive banks were forced to improve efficiency. That is, banks try to operate closer to a "best practice" production function in the sense that banks improve the input - output relation. The key question in this context is if banks improve efficiency at a cost of higher risk to compensate decreasing earnings. When it comes to bank risk, a large strand of literature discusses the issue of problem loans. Several studies identify that banks hold large shares of non-performing loans in their portfolio before becoming bankrupt (Barr and Siems, 1994; Demirg{\"u}c-Kunt, 1989). According to efficiency, studies show that the average bank generates low profits and incorporates high costs compared to the "best practice" production frontier (Fiordelisi et al., 2011; Williams, 2004). At first glance, these two issues do not seem related. However, Berger and DeYoung (1997) show that banks with poor management are less able to handle their costs (low cost-efficiency) as well as to monitor their debtors in an appropriate manner to ensure loan quality. The negative relationship between cost efficiency and non-performing loans leads to declining capital. Existing studies (e.g. Williams, 2004; Berger and DeYoung, 1997) show that banks with a low level of capital tend to engage in moral hazard behavior, which in turn can push these banks into bankruptcy. However, the business model of cooperative banks is based on the interests of its commonly local customers (the cooperative act: \S 1 GenG). This may imply that the common perception of banks engaging in moral hazard behavior may not apply to cooperative banks. Since short-term shareholder interests (as a potential factor for moral hazard behavior) play no role for cooperative banks this may support this notion. Furthermore, liquidity has been widely neglected in the existing literature, since the common perception has been that access to additional liquid funds is not an issue. However, the recent financial crisis revealed that liquidity dried up for many banks due to increased mistrust in the banking sector. Besides investigating moral hazard behavior, using data from 2005 to 2010 this study moves beyond current literature by employing a measure for liquidity risk in order to evaluate how liquidity risk relates to efficiency and capital. Results mostly apply to current literature in this field since the empirical evaluation reveals that lower cost and profit-efficiency Granger-cause increases in credit risk. At the same time, results indicate that credit risk negatively Granger-causes cost and profit-efficiency, hence revealing a bi-directional relationship between these measures. However, most importantly, results also show a positive relationship between capital and credit risk, thus displaying that moral hazard behavior does not apply to cooperative banks. Especially the business model of cooperative banks, which is based on the interests of its commonly local customers (the cooperative act: \S 1 GenG) may reason this finding. Contrary to Fiordelisi et al. (2011), results also show a negative relationship between capital and cost-efficiency, indicating that struggling cooperative banks focus on managing their cost-exposure in following periods. Concerning the employed liquidity risk measure, the authors find that banks who hold a high level of liquidity are less active in market related investments and hold high shares of equity capital. This outcome clearly reflects risk-preferences from the management of a bank. Chapter 4 examines governance structures of cooperative banks: The financial crisis of 2007/08 led to huge distortions in the banking market. The failure of Lehman Brothers was the beginning of government interventions in various countries all over the world in order to prevent domestic economies from even further disruptions. In the aftermath of the crisis, politicians and regulators identified governance deficiencies as one major factor that contributed to the crisis. Besides existing studies in the banking literature (e.g. Beltratti and Stulz, 2012; Diamond and Rajan, 2009; Erkens et al., 2012) an OECD study from 2009 supports this notion (Kirkpatrick, 2009). Public debates increased awareness for the need of appropriate governance mechanisms at that time. Consequently, politicians and regulators called for more financial expertise on bank boards. Accordingly, the Basel Committee on Banking Supervision states in principle 2 that "board members should remain qualified, individually and collectively, for their positions. They should understand their oversight and corporate governance role and be able to exercise sound, objective judgement about the affairs of the bank." (BCBS, 2015). Taking these perceptions into consideration the prevailing question is whether financial experts on bank boards do really foster bank stability? This chapter aims to investigate this question by referring to the study from Minton et al. (2014). In their study, the authors investigate US commercial bank holding companies between the period 2003 and 2008. The authors find that financial experts on the board of US commercial bank holding companies promote pro-cyclical bank performance. Accordingly, the authors question regulators view of more financial experts on the board leading to more banking stability. However, Minton et al. (2014) do not examine whether their findings accrue due to financial experts who act in the interests of shareholders or due to the issue that financial experts may have a more risk-taking attitude (due to a better understanding of financial instruments) than other board members. Supposed that their findings accrue due to financial experts who act in the interests of shareholders. Then financial experts on the board of banks where short-term shareholder interests play no role (cooperative banks) may prove beneficial with regard on bank performance during the crisis as well as in normal times. This would mean that they use their skills and expertise to contribute sustainable growth to the bank. Contrary, if this study reveals pro-cyclical bank performance related to financial experts on the board of cooperative banks, this finding may be addressed solely to the risk-taking attitude of financial experts (since short-term shareholder interests play no role). For this reason, this chapter aims to identify the channel for the relation of financial experts and bank performance by examining the following research question: Do financial experts on the board promote pro-cyclical bank performance in a setting where short-term shareholder interests play no role? Results show that financial experts on the board of cooperative banks (data from 2006 to 2011) do not promote pro-cyclical bank performance. Contrary, results show evidence that financial experts on the board of cooperative banks appear to foster long-term bank stability. This suggests that regulators should consider ownership structure (and hence business model of banks) when imposing new regulatory constraints for financial experts on the bank board.}, language = {en} } @phdthesis{JagiellowiczKaufmann2016, author = {Jagiellowicz-Kaufmann, Monika Sarah}, title = {Akzeptable und effektive Pedal- und Motorkennlinien zur Unterst{\"u}tzung von Eco-Driving im Elektrofahrzeug}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137031}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2016}, abstract = {Die begrenzte Reichweite ist einer der Hauptgr{\"u}nde f{\"u}r das derzeitige mangelnde Kaufinteresse an Elektrofahrzeugen. Neben rein komponentenoptimierenden Maßnahmen, wie der Verbesserung der Batterie, ist die F{\"o}rderung von Eco-Driving, also einer energieeffizienten Fahrweise, ein effektiver Ansatz zur Steigerung der Reichweite. Trainings und visuell dargebotene Eco-Assistenten k{\"o}nnen Eco-Driving wirksam steigern, sch{\"o}pfen aber nicht dessen gesamtes Potential aus. Angepasste Pedal- und Motorkennlinien k{\"o}nnten Eco-Driving zus{\"a}tzlich f{\"o}rdern. F{\"u}r deren Bewertung sind die Wirksamkeit und Akzeptanz bisher nicht gemeinsam ber{\"u}cksichtig worden oder sie wurden nicht im Elektrofahrzeug evaluiert und validiert. Zu diesen Anpassungen z{\"a}hlen eine Ver{\"a}nderung des Beschleunigungspedals, sodass mit diesem gleichzeitig beschleunigt und rekuperiert werden kann, die Limitierung von Drehmoment und Leistung und der Einsatz eines aktiven Beschleunigungspedals, welches Widerst{\"a}nde abh{\"a}ngig von Fahrzeug- oder Situationsparametern aktiviert. F{\"u}r diese Arbeit habe ich daher die Pedal- und Motorkennlinien entsprechend angepasst und in ein validiertes Elektroautomodell implementiert. Ziel war es, verschiedene Fahrverhaltensbereiche im Elektrofahrzeug, die Eco-Driving kennzeichnen (energieoptimales Beschleunigen und Verz{\"o}gern, Einhalten von Geschwindigkeitsbegrenzungen, vorausschauendes Fahren), benutzerfreundlich, akzeptabel und wirksam zu unterst{\"u}tzen. Zu diesem Zweck habe ich vier Probandenstudien im bewegten Fahrsimulator durchgef{\"u}hrt und geeignete Pedal- und Motorkennlinien empirisch bestimmt. In der ersten Studie habe ich untersucht, ob und warum eine Pedalkennlinie zu bevorzugen ist, bei der mit dem Beschleunigungspedal anstelle des Bremspedals rekuperiert wird. Das Ziel der zweiten Studie war es, eine geeignete Rekuperationsst{\"a}rke f{\"u}r ein kombiniertes Beschleunigungspedal, bei dem mit dem Beschleunigungspedal rekuperiert wird, zu bestimmen. In der dritten Studie habe ich evaluiert, ob die Limitierung der Leistung oder die des Drehmoments zu bevorzugen ist, um das Beschleunigungsverhalten zu optimieren und wie stark die Limitierungen optimaler Weise sein sollten. Basierend auf den Ergebnissen der dritten Studie, habe ich schließlich einen optimierten Limitierungsansatz konzipiert, diesen mit einem aktiven Beschleunigungspedal verglichen und bestimmt, welcher Ansatz zu bevorzugen ist. Aufgrund der Studienergebnisse werden folgende Ans{\"a}tze f{\"u}r die jeweiligen Eco-Driving-Fahrverhaltensbereiche empfohlen und es werden folgende Gestaltungsempfehlungen abgeleitet: Zur F{\"o}rderung eines energieeffizienten Beschleunigungsverhaltens ist die Limitierung von Drehmoment und Leistung geeignet. Die Limitierung des Drehmoments ist hierbei besonders wirksam in geringen, die Limitierung der maximalen Leistung in h{\"o}heren Geschwindigkeitsbereichen. Zu empfehlen sind parallele mittelstarke Limitierungen von maximalem Drehmoment und maximaler Leistung, die Beschleunigungen mit 2.0 m/s² erlauben, bei gleichzeitiger Bereitstellung eines Kick-Downs. Ein aktives Beschleunigungspedal ist insbesondere aus Gr{\"u}nden der Benutzerfreundlichkeit zur F{\"o}rderung eines energieeffizienten Beschleunigungsverhaltens nur eingeschr{\"a}nkt empfehlenswert. Zur F{\"o}rderung eines energieeffizienten Verz{\"o}gerungsverhaltens wird die Implementierung der Rekuperationsfunktion auf dem Beschleunigungspedal anstelle des Bremspedals empfohlen, da dies einerseits erm{\"o}glicht, auf hydraulisches Bremsen zu verzichten und gleichzeitig mehr Energie rekuperiert werden kann. Ersteres tr{\"a}gt zu einer hohen Akzeptanz bei, letzteres zu einer g{\"u}nstigen Energiebilanz. Besonders effektiv und akzeptabel ist ein kombiniertes Fahrbremspedal, wenn es eine starke Rekuperation erm{\"o}glicht (zwischen -1.7 und -2.1 m/s²). Weiterhin ist ein aktives Beschleunigungspedal, das den geeigneten Zeitpunkt f{\"u}r eine maximal energieeffiziente Verz{\"o}gerung mit einem kombinierten Fahrbremspedal anzeigt, wirksam, um die rekuperierte Energie zu steigern. Auf diese Weise kann zudem eine vorausschauende Fahrweise unterst{\"u}tzt werden. Hierbei muss jedoch die Funktionalit{\"a}t und Benutzerfreundlichkeit optimiert werden, um eine gesteigerte kognitive Fahrerbeanspruchung und Minderungen der Akzeptanz zu vermeiden. Zur Unterst{\"u}tzung der Einhaltung von Geschwindigkeitsbegrenzungen ist ebenfalls das aktive Beschleunigungspedal geeignet. Der Fahrer sollte hierbei aber die M{\"o}glichkeit haben, individuell Grenzwerte einzustellen. Die Verkn{\"u}pfung eines kombinierten Fahrbremspedals mit einer Limitierung von Drehmoment und Leistung sowie einem aktiven Beschleunigungspedal kann abschließend, unter Ber{\"u}cksichtigung der abgeleiteten Gestaltungsempfehlungen, als effektive und akzeptable M{\"o}glichkeit zur F{\"o}rderung unterschiedlicher Verhaltensbereiche von Eco-Driving bewertet werden. Die erwarteten Synergieeffekte der evaluierten Ans{\"a}tze in Verbindung mit Eco-Trainings und visuell dargebotenen Eco-Feedback-Assistenten sowie deren Langfristigkeit sollten Gegenstand weiterf{\"u}hrender Forschung sein.}, subject = {Elektrofahrzeug}, language = {de} } @phdthesis{Selbach2005, author = {Selbach, Ralph}, title = {Ver{\"a}nderung der Prozessabl{\"a}ufe durch die vollst{\"a}ndige Digitalisierung einer R{\"o}ntgenabteilung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-23196}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2005}, abstract = {An der Missions{\"a}rztlichen Klinik erfolgte im April 2000 mit der Einf{\"u}hrung der digitale Lumineszenzradiographie (DLR), eines radiologischen Informationssystems (RIS) und eines Bildarchivierungs und -kommunikationssystems (PACS) die vollst{\"a}ndige Digitalisierung der R{\"o}ntgenabteilung. Die durch diese Umstellung bedingten zeitlichen Ver{\"a}nderungen der Prozessabl{\"a}ufe in der R{\"o}ntgenabteilung wurden untersucht. In Form einer Vorher-Nachher-Studie wurde 1999 im konventionellen und 2001 im digitalen Routinebetrieb eine Analyse der Prozessabl{\"a}ufe durchgef{\"u}hrt. Die Untersuchungsdauer f{\"u}r den Patienten verk{\"u}rzte sich signifikant. Die Aufnahmen k{\"o}nnen vom Zeitpunkt der Untersuchung an gerechnet im Mittel fr{\"u}her befundet werden. Die schriftlichen Befund sind schneller verf{\"u}gbar. Die Befundung am Monitor zeigte gegen{\"u}ber dem Alternator keine zeitlichen Nachteile. Die vollst{\"a}ndige Digitalisierung der R{\"o}ntgenabteilung f{\"u}hrte zu einer erhebliche Verk{\"u}rzung fast aller Arbeitsabl{\"a}ufe. Positive Auswirkungen auf die Prozessqualit{\"a}t des gesamten Krankenhauses gegen{\"u}ber dem konventionellen Film-Folien-Systemen sind zu erwarten.}, language = {de} } @phdthesis{Pretzell2005, author = {Pretzell, Constance Barberine}, title = {Chirurgische Therapie des prim{\"a}ren Hyperparathyreoidismus : Untersuchungen zu Effizienz und Sicherheit der offenen minimal invasiven Parathyreoidektomie}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-16445}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2005}, abstract = {Minimal invasive chirurgische Techniken zur Therapie des prim{\"a}ren Hyperparathyreoidismus (pHPT) konkurrieren mit dem bisherigen Standardverfahren, der bilateralen zervikalen Exploration, sofern eine lokalisierte Eindr{\"u}senerkrankung vorliegt. Zus{\"a}tzlich vorhandene, operationspflichtige Schilddr{\"u}senknoten k{\"o}nnen jedoch ein minimal invasives Vorgehen verhindern. Ziel der hier vorliegenden Untersuchung war es f{\"u}r das eigene Krankengut prospektiv zu analysieren, ob die minimal invasive offene Parathyreoidektomie (MIOP) zur Therapie des pHPT bei Eindr{\"u}senerkrankungen sicher durchf{\"u}hrbar war, ob die postoperativen Ergebnisse denen des konventionellen Vorgehens entsprechen und mit welcher Genauigkeit der intraoperative Parathormonschnelltest (PTH-Quick-Test) die biochemische Heilung des Patienten vorhersagen bzw. eine Mehrdr{\"u}senerkrankung ausschließen konnte.}, language = {de} }