In the first essay, we provide new evidence on the relationship between order flow and prices, an issue that is central to asset pricing and market microstructure. We examine proprietary data on a broad panel of NYSE-listed stocks that reveal daily order imbalances by institutions, individuals, and market makers. We can further differentiate regular institutional trades from institutional program trades. Our results indicate that order imbalances from different trader types play distinctly different roles in price formation. Institutions and individuals are contrarians with respect to previous-day returns but differ in the effect their order imbalances have on contemporaneous returns. Institutional imbalances are positively related to contemporaneous returns, and cross-sectional evidence suggests this relationship is likely to be the result of firm-specific information institutions have. Individuals, specialists, and other market makers appear to provide liquidity to these actively trading institutions. Our results also suggest a special role for institutional program trades. Institutions choose program trades when they have no firm-specific information and can afford to trade passively. As a result, program trades provide liquidity to the market. Finally, both institutional non-program and individual imbalances have predictive power for next-day returns. In the second essay, based on daily shorting flow data for a large sample of NYSE-listed stocks, we show that short sellers enhance the relative efficiency of transaction prices. We also provide new evidence on the recent suspension of the Uptick Rule for Regulation SHO Pilot stocks. Relative to matched control stocks, pilot stocks experience some improvement in price efficiency associated with increased shorting activity after the tick test was suspended. The third essay studies demutualization of stock exchanges. Using panel data on 132 major stock exchanges in 114 countries from 1990 to 2003, we examine the effect of demutualization on an exchange’s performance in its primary product markets: trading and listings. We document some evidence that demutualization is associated with improved competitiveness in attracting trading volume. Results on listings following demutualization are weak.

In the first essay, we provide new evidence on the relationship between order flow and prices, an issue that is central to asset pricing and market microstructure. We examine proprietary data on a broad panel of NYSE-listed stocks that reveal daily order imbalances by institutions, individuals, and market makers. We can further differentiate regular institutional trades from institutional program trades. Our results indicate that order imbalances from different trader types play distinctly different roles in price formation. Institutions and individuals are contrarians with respect to previous-day returns but differ in the effect their order imbalances have on contemporaneous returns. Institutional imbalances are positively related to contemporaneous returns, and cross-sectional evidence suggests this relationship is likely to be the result of firm-specific information institutions have. Individuals, specialists, and other market makers appear to provide liquidity to these actively trading institutions. Our results also suggest a special role for institutional program trades. Institutions choose program trades when they have no firm-specific information and can afford to trade passively. As a result, program trades provide liquidity to the market. Finally, both institutional non-program and individual imbalances have predictive power for next-day returns. In the second essay, based on daily shorting flow data for a large sample of NYSE-listed stocks, we show that short sellers enhance the relative efficiency of transaction prices. We also provide new evidence on the recent suspension of the Uptick Rule for Regulation SHO Pilot stocks. Relative to matched control stocks, pilot stocks experience some improvement in price efficiency associated with increased shorting activity after the tick test was suspended. The third essay studies demutualization of stock exchanges. Using panel data on 132 major stock exchanges in 114 countries from 1990 to 2003, we examine the effect of demutualization on an exchange’s performance in its primary product markets: trading and listings. We document some evidence that demutualization is associated with improved competitiveness in attracting trading volume. Results on listings following demutualization are weak.

Background:   Problem:   Purpose:   Method:   Conclusion: Based on our findings we do not advocate short sale regulations tobe introduced on the Swedish financial market. Neither does our analysis indicate that the market performance is significantly affected by shorting, nor does restrictions work as intended which we have seen in other countries during the fall of 2008. The analysis have been drawn from four cornerstones; previousresearch, actions of other countries’, a statistical analysis and interview findings. We have examined and compiled different strategies for restricting short sales around the world as well as conducted a cross-correlation analysis to investigate if share price is related to stock loan. Furthermore we have interviewed a professional investor and a middle manager at the Swedish Financial Supervisory Board to obtain experts’ views on the subject. With background of other countries’ actions, the purpose of thisreport is to investigate why, if at all, short sale regulations should be introduced on the Swedish financial market. Is there a correlation between the number of shorted shares and thechange in overall and individual stock price? What actions have been taken by countries in Europe, Asia and the United States regarding short selling during the fall of 2008 and what is SFSB’s attitude towards the subject? Are there any benefits for the Swedish financial market from shorting regulations? In times of financial crisis short selling is often quickly blamed for price volatility and media broadcasts pleads for prohibitions and restrictions. Extensive research, however, cannot find any empirical evidence that shorting is affecting markets negatively; often it is the other way around. Sweden has been relatively liberal when it comes to shorting restrictions and even though share lending has increased since the start of the year, no actions have been taken by the Swedish Financial Supervisory Board.

<p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p> </p><p><strong><strong><p>Background:</p></strong><p> </p><strong><strong><p>Problem:</p></strong><p> </p><strong><strong><p>Purpose:</p></strong><p> </p><strong><strong><p>Method:</p></strong><p> </p><strong><strong><p>Conclusion:</p></strong></strong>Based on our findings we do not advocate short sale regulations to<p>be introduced on the Swedish financial market. Neither does our</p><p>analysis indicate that the market performance is significantly affected</p><p>by shorting, nor does restrictions work as intended which we have</p><p>seen in other countries during the fall of 2008.</p></strong>The analysis have been drawn from four cornerstones; previous<p>research, actions of other countries’, a statistical analysis and</p><p>interview findings. We have examined and compiled different</p><p>strategies for restricting short sales around the world as well as</p><p>conducted a cross-correlation analysis to investigate if share price is</p><p>related to stock loan. Furthermore we have interviewed a</p><p>professional investor and a middle manager at the Swedish Financial</p><p>Supervisory Board to obtain experts’ views on the subject.</p></strong>With background of other countries’ actions, the purpose of this<p>report is to investigate why, if at all, short sale regulations should be</p><p>introduced on the Swedish financial market.</p></strong>Is there a correlation between the number of shorted shares and the<p>change in overall and individual stock price? What actions have been</p><p>taken by countries in Europe, Asia and the United States regarding</p><p>short selling during the fall of 2008 and what is SFSB’s attitude</p><p>towards the subject? Are there any benefits for the Swedish financial</p><p>market from shorting regulations?</p></strong>In times of financial crisis short selling is often quickly blamed for</p><p>price volatility and media broadcasts pleads for prohibitions and</p><p>restrictions. Extensive research, however, cannot find any empirical</p><p>evidence that shorting is affecting markets negatively; often it is the</p><p>other way around. Sweden has been relatively liberal when it comes</p><p>to shorting restrictions and even though share lending has increased</p><p>since the start of the year, no actions have been taken by the</p><p>Swedish Financial Supervisory Board.</p><p> </p><p> </p>

Electrical shorting through the proton exchange membrane (PEM) is a form of early failure commonly found in PEM fuel cells. In order to improve the durability and thus the commercial potential for PEM fuel cells, this form of failure must be understood and mitigated. This research investigates whether complete penetration is the most likely cause of shorting and establishes general parameters (force, contact pressure, temperature, and time) that lead to shorting in a typical PEM material, Nafion® NRE211. Data was obtained from a novel indentation apparatus that was coupled with an electrical circuit to assess the force and depth of penetration at which shorting occurs in a PEM at temperatures ranging from 70ï °C to 100ï °C. The results show that shorting occurs when full penetration is reached, based on both displacement at shorting, and resistance of the electrical circuit at shorting. In addition, a finite element model was created in a commercial finite element tool (Abaqus) in an attempt to predict time to penetration under loads and geometric configurations typically found in PEM fuel cells. The finite element model was investigated for use with standard Abaqus material modules (e.g. two-layer viscoplastic and hyperelastic-viscoelastic) describing Nafion® behavior. The results suggest that the standard material models do not sufficiently describe Nafion® behavior in this particular application and suggest the need for alternative material models that capture both the viscous and plastic nature of Nafion®. / Master of Science

Inicialmente neste trabalho são apresentados os conceitos básicos de média e variância e como estes se aplicam na caracterização de um ativo ou carteira de investimento. Posteriormente são apresentadas as estratégias ótimas de investimento para o modelo de Markowitz sem posições a descoberto em ativos de risco, e sem tal restrição. Ainda neste trabalho é apresentada uma breve revisão do modelo de tempo contínuo para o problema de média-variância sem posições a descoberto em ativos de risco, e como objetivo principal do mesmo é proposto um modelo em tempo discreto multiperíodo a partir do modelo de tempo contínuo, o qual é implementado computacionalmente para o mercado de capitais brasileiro. O resultado obtido é comparado com a estratégia de período único do modelo de Markowitz sem posições a descoberto em ativos de risco, sendo este modelo aplicado sequencialmente no horizonte de tempo considerado para o modelo multiperíodo. / Initially in this work are presented the basics concepts of mean and variance and how they are applied to quantify an asset or a portfolio. After this we present the optimal investment strategy of the Markowitz no-shorting constraints mean-variance portfolio selection in single period and the Markowitz optimal investment strategy without such constrain. Following this, we present a short review of the continuous-time dynamic model for the mean-variance portfolio selection with no-shorting constraints in risky assets problem. As the main objective of this work we propose a discrete time multiperiod model based on the continuous-time portfolio selection with no-shorting constraints in risky assets, that is applied to the Brazilian financial market. This result is compared with the investment strategy of the Markowitz no-shorting constraints mean-variance portfolio selection in single period applied sequentially in the multiperiod case.

In modern high-speed digital circuits, the space of the traditional single-layered or double-layered circuit board is not enough, therefore multi-layered circuit and stacked distribution technology are widely applied to many applications. The signal via is a vertical interconnection structure to communicate different signal layers, which will be seriously interfere with the simultaneous switching noise by via through the parallel plate cavity that consists of power and ground plane. It is an important issue to minimize the influence from noise. In multi-layered printed circuit boards, shorting vias are usually utilized to interconnect the planes with the same voltage level. The major theme of this thesis is the placement of shorting vias affecting plane cavity mode. And we propose a design rule of the shorting vias to significantly decrease the simultaneous switching noise and improve the power integrity of multi-layered circuit board.

Inicialmente neste trabalho são apresentados os conceitos básicos de média e variância e como estes se aplicam na caracterização de um ativo ou carteira de investimento. Posteriormente são apresentadas as estratégias ótimas de investimento para o modelo de Markowitz sem posições a descoberto em ativos de risco, e sem tal restrição. Ainda neste trabalho é apresentada uma breve revisão do modelo de tempo contínuo para o problema de média-variância sem posições a descoberto em ativos de risco, e como objetivo principal do mesmo é proposto um modelo em tempo discreto multiperíodo a partir do modelo de tempo contínuo, o qual é implementado computacionalmente para o mercado de capitais brasileiro. O resultado obtido é comparado com a estratégia de período único do modelo de Markowitz sem posições a descoberto em ativos de risco, sendo este modelo aplicado sequencialmente no horizonte de tempo considerado para o modelo multiperíodo. / Initially in this work are presented the basics concepts of mean and variance and how they are applied to quantify an asset or a portfolio. After this we present the optimal investment strategy of the Markowitz no-shorting constraints mean-variance portfolio selection in single period and the Markowitz optimal investment strategy without such constrain. Following this, we present a short review of the continuous-time dynamic model for the mean-variance portfolio selection with no-shorting constraints in risky assets problem. As the main objective of this work we propose a discrete time multiperiod model based on the continuous-time portfolio selection with no-shorting constraints in risky assets, that is applied to the Brazilian financial market. This result is compared with the investment strategy of the Markowitz no-shorting constraints mean-variance portfolio selection in single period applied sequentially in the multiperiod case.

Denna kandidatuppsats undersöker huruvida aktiemarknaden reagerar på publiceringen av blankningsrapporter. När företag ägnar sig åt bedrägligt beteende spelar blankare och blankningsföretag en avgörande roll för att uppdaga dessa olagliga aktiviteter och för att avslöja övervärderade aktier som påverkar samhället och aktiemarknaden som helhet. För att förklara skillnader mellan olika stora marknadsreaktioner på blankningsrapporter undersöks också free float (andelen aktier som inte ägs av aktörer med kontrollintresse och som fritt kan handlas på marknaden) för att förstå varför vissa reaktioner är större än andra. Denna studie baseras på en eventstudie av 135 blankningsrapporter för att undersöka marknadens reaktion. Resultaten av uppsatsen visar att ja, marknaden reagerar negativt på informationen i blankningsrapporterna där den kumulativa abnormala avkastningen i uppsatsens eventfönster på 21 dagar uppgår till -17,84 %. Vidare finner undersökningen ingen signifikant skillnad mellan företag med hög free float och låg free float gällande storleken på marknadsreaktionen. Reaktionen på blankningsrapporten är större dagarna innan publicering, som sannolikt beror på att blankningsföretagen har tagit omfattande blankningspositioner innan publicering samt potentiellt informationsläckage. / This bachelor's thesis seeks to investigate whether or not the stock market reacts to the publication of short selling reports. As companies indulge in fraudulent behavior, short sellers and research firms play a crucial part in finding overpriced and illegal activities that affect society and the stock market as a whole. To assist our paper we use free float (the proportion of shares freely traded on the market, not under a controlling interest)  to understand why some reactions were greater than others. This bachelor's thesis is based on an event study of 135 short reports, with daily stock prices combined with a global index to investigate this further. Furthermore this study uses free float data to gain a greater understanding of the reactions of different companies. The results of the study is: yes, short reports have a documented effect on returns and in our event window of 21 days the cumulative average abnormal returns is down by 17,84 %. Moreover, our sample does not show any documented effect of free float where firms with high free float do not show a smaller market reaction compared to those with low free float. The reaction is greater in the days before publication, which probably depends on the shorting positions of research firms as well as potential leakage of information beforehand.

With the advances in wireless communication systems, antennas with different shapes and design have achieved great demand and are desirable for many uses such as personal communication systems, and other applications involving wireless communication. This has resulted in different shapes and types of antenna design in order to achieve different antenna characteristic. One attractive approach to the design of antennas is to suppress or attenuate harmonic contents due to the non-linear operation of the Radio Frequency (RF) front end. The objectives of this work were to investigate, design and implement antennas for harmonic suppression with the aid of a genetic algorithm (GA). Several microstrip patch antennas were designed to operate at frequencies 1.0, 1.8 and 2.4 GHz respectively. The microstrip patch antenna with stub tuned microstrip lines was also employed at 1.0 and 1.8 GHz to meet the design objectives. A new sensing patch technique is introduced and applied in order to find the accepted power at harmonic frequencies. The evaluation of the measured power accepted at the antenna feed port was done using an electromagnetic (EM) simulator, Ansoft Designer, in terms of current distribution. A two sensors method is presented on one antenna prototype to estimate the accepted power at three frequencies. The computational method is based on an integral equation solver using adaptive surface meshing driven by a genetic algorithm. Several examples are demonstrated, including design of coaxially-fed, air-dielectric patch antennas implanted with shorting and folded walls. The characteristics of the antennas in terms of the impedance responses and far field radiation patterns are discussed. The results in terms of the radiation performance are addressed, and compared to measurements. The presented results of these antennas show a good impedance matching at the fundamental frequency with good suppression achieved at the second and third harmonic frequencies.