Sverige anses idag vara ett av det mest jämställda länderna i världen. Även om kvinnor idag besitter över 50 procent av chefspositionerna inom både landsting och kommun så besitts endast 38,2 procent av chefspositioner inom samtliga sektorer på arbetsmarknaden av kvinnor. Minst kvinnor i chefspositioner finns inom den privata sektorn. Detta trots att företagsledare säger sig vilja ha jämställda arbetsplatser och styrelser. Syftet med vår studie är att undersöka om en bidragande faktor till den skeva könsfördelningen mellan män och kvinnor, i chefspositioner inom mansdominerade branscher, kan vara vad företagen uttrycker sig eftersöka för typ av egenskaper i sina rekryteringsannonser. Det finns tidigare forskning som visar att en kvinna inte är benägen att söka ett arbete där det i rekryteringsannonsen eftersökes stereotypiska manliga egenskaper. Vår studie utgår ifrån begreppen transaktionellt ledarskap och transformativt ledarskap. Transaktionellt ledarskap kopplas till typiskt manliga ledaregenskaper och transformativt ledarskap kopplas till typiskt kvinnliga ledaregenskaper. / Sweden is today considered to be one of the most equal countries in the world. Although women today hold over 50 percent of the management positions in Botha county councils and municipalities, only 38.2 percent of managerial positions in all sectors of the labor market are owned by women. The least amount of women in managerial positions are in the private sector. This is despite the fact that business leaders say they want equal workplaces and boards. The purpose of our study is to see if a contributing factor to the skewed gender distribution between men and women in managerial positions, in male-dominated industries, can be what the companies express themselves to search for the type of properties in their recruitment ads. There is previous research that shows that a woman is not inland to seek a job where in the recruitment advertisement, stereotypical male attributes are sought. Our study is based on the concepts of transactional leadership and transformative leadership. Transactional leadership is linked to typically male leadership qualities and transformative leadership is linked to typically female leadership qualities. This thesis is written in swedish.

<p>HIV poses considerable social and health challenges in South Africa, particularly among young people aged 15-24. Research indicates a strong link between risky sexual behaviour and alcohol and illicit drugs. In the Western Cape drug-related behaviours is a growing concern among young people because of relatively high prevalence rates of drug abuse, particularly methamphetamine. Previous South African studies have tended to focused on the link between substance use and risky sexual behaviour among commercial sex workers. The theoretical approach of this study is the information motivation behavioural skills model. Participants were selected using non-probability sampling of 279 first year students registered for Psychology I at the University of the Western Cape. This study employed a quantitative research approach using a survey design. Results: Forty-six percent of students do not believe that the use of illicit drugs has an impact on a person&rsquo / s sexual behavior. However, the findings also showed that only 45% of students believed that there was a difference between illicit drug users correctly using condoms when compared to non-users. Data was analysed using descriptive and inferential statistics. Conclusion: Prevention is our best and most effective means of decreasing risk-taking behaviours associated with HIV infection. Information is the first line of intervention that is necessary to reduce risk-taking behaviours / however prevention strategies and interventions of risk-taking behaviours should aim to increase motivation and help young people integrate information in a way that it is personally relatable. This is vital to address the inconsistencies between perceptions of risk and the realities of risk-taking behaviour.</p>

La evolución tecnológica en el diseño de microprocesadores ha conducido a sistemas paralelos con múltiples hilos de ejecución. Estos sistemas son más difíciles de programar y presentan overheads mayores que los sistemas uniprocesadores tradicionales, que pueden limitar su rendimiento y escalabilidad: sincronización, coherencia, consistencia y otros mecanismos requeridos para garantizar una ejecución correcta. La programación paralela tradicional se basa en primitivas de sincronización como barreras y locks de lectura/escritura, con alta tendencia a fallos de programación. La Memoria Transaccional (TM) oculta estos problemas de sincronización al programador; sin embargo, múltiples sistemas TM aún se basan en locks, y se beneficiarían de una implementación eficiente de los mismos.Esta tesis presenta nuevas técnicas hardware para acelerar la ejecución de estos programas paralelos. Proponemos un sistema TM híbrido basado en locks de lectura/escritura, que minimiza los overheads del software cuando la aceleración hardware está presente. Desarrollamos un mecanismo para garantizar fairness entre transacciones hardware y software. Introducimos un mecanismo distribuido de aceleración de locks de lectura/escritura, llamado Lock Control Unit. Finalmente, proponemos una organización de multiprocesadores basadas en Kilo-Instruction Processors que garantiza Consistencia Secuencial y permite especulación en secciones críticas. / Technological evolution in microprocessor design has led to parallel systems with multiple execution threads. These systems are more difficult to program and present higher performance overheads than the traditional uniprocessor systems, what may limit their performance and scalability: synchronization, coherence, consistency and other mechanisms required to guarantee a correct execution. Traditional parallel programming is based on synchronization primitives such as barriers, critical sections and reader/writer locks, highly prone to programming errors. Transactional Memory (TM) removes the synchronization problems from the programmer. However, many TM systems still rely on reader/writer locks, and would get benefited from an efficient implementation.This thesis presents new hardware techniques to accelerate the execution of such parallel programs. We propose a Hybrid TM system based on reader/writer locks, which minimizes the software overheads when acceleration hardware is present, still allowing for correct software-only execution. We propose a mechanism to guarantee fairness between hardware and software transactions is provided. We introduce a low-cost distributed mechanism named the Lock Control Unit to handle fine-grain reader-writer locks. Finally, we propose an organization of a mutiprocessor based on Kilo-Instruction Processors, which guarantees Sequential Consistency while allowing for speculation in critical sections.

El dret concursal és la resposta legal a una realitat financera que prové de l'economia del mercat. Els negocis poden fracassar. Quan les empreses i les persones fallen a l'hora de complir amb les seves obligacions de deute i els seus actius no són suficients per cobrir els crèdits, esdevenen insolvents i fan fallida. Per tal de regular les demandes dels creditors i resoldre el dilema dels creditors com a grup, la Llei concursal es converteix en un mètode ordenat per maximitzar els actius del deutor i protegir uns grups d'interès determinats. Aquesta dissertació vol contribuir a conèixer el problema concursal. Així mateix, té l'objectiu d'identificar factors clau per mesurar l'eficiència per mitjà dels costos de transacció utilitzant-ne de directes i d'indirectes, d'ex ante i d'ex post, com també els costos d'informació, de coordinació i d'execució, i després comparar-los amb un altre sistema, en aquest cas el règim colombià, i crear una metodologia per mesurar l'eficiència.La dissertació també tracta la racionalitat. La racionalitat concursal és maximitzar el valor dels actius del deutor per tal de pagar els seus deutes. També implica mantenir en el mercat companyies viables, tenint en compte en aquest cas que el valor de l'empresa insolvent com a unitat operativa és més elevat que com a liquidada, i retirar del mercat aquells negocis que no es poden mantenir com a empreses en funcionament.L'objectiu principal de qualsevol sistema concursal és protegir el crèdit i proporcionar un fòrum per als creditors perquè coordinin accions i, d'aquesta manera, redueixin els costos de transacció. La racionalitat bàsica del sistema és que aquests acords beneficien tots els creditors i es respecten les preferències donades per llei per a uns determinats tipus de creditors.Un sistema concursal eficient evitarà l'error del tipus 1 i l'error del tipus 2, és a dir, mantenir empreses inviables o liquidar empreses viables.La dissertació tracta de l'eficiència i la racionalitat a través de mitjans empírics. S'ha fet una revisió àmplia de la bibliografia en àrees com ara el reflotament empresarial, els costos de transacció, la racionalitat limitada, la teoria de jocs i la Llei concursal, per tal de seleccionar-ne variables i formular-ne hipòtesis. La recerca inclou 15 anys d'història peruana (1992-2007) sota quatre règims concursals diferents, i utilitza metodologia qualitativa i quantitativa.En l'etapa qualitativa, es van entrevistar setanta experts. Són jugadors clau en l'àmbit acadèmic Indecopi, bancs, companyies administradores, interventors. Les entrevistes van generar vuit categories útils per comprendre per què els diferents grups d'interès es comporten tal com ho fan.Es va tenir cura a l'hora de seleccionar codis clau per tal de provar-los posteriorment en l'etapa quantitativa.Les entrevistes semiestructurades als experts proporcionen un marc conceptual per comprendre la conducta que correspon a indústries regulades com ara la banca. Per tal de provar les hipòtesis, es van estudiar 359 empreses. L'estudi inclou una extensa documentació retrospectiva en els arxius centrals d'Indecopi. La mostra es va incrementar a 3.386 empreses a efectes de la mineria de dades.Les dades de les empreses es va extreure dels expedients oficials que es guarden a Indecopi. Es va emprar SPSS per provar les hipòtesis i Clementine per a la mineria de dades. Totes les companyies es van classificar per sector econòmic, és a dir, indústries extractives o primàries (mineria, pesca, agricultura, gas i petroli), indústries secundàries/manufactureres (tèxtils, fabricants d'automòbils, acereries), comerç (botigues per departament, venda de vehicles, mercats, supermercats) i serveis (transport, serveis públics). Els resultats mostren que el sistema concursal peruà és ineficient, irracional, impredictible i inconsistent. També mostra que no hi ha una correlació positiva entre el sistema concursal i el cost del crèdit. El sistema està dissenyat per incentivar el comportament estratègic dels creditors privilegiats.L'estudi mostra que la decisió final de liquidar o salvar una empresa depèn del sector econòmic i no de la viabilitat de l'empresa, més en línia amb els interessos dels creditors específics.L'etapa final de l'estudi proporciona unes premisses empresarials útils per als propietaris i els gerents de les petites i les mitjanes empreses respecte dels seus creditors. L'estudi limita la racionalitat al marc del dret econòmic que es va utilitzar per privatitzar el procés concursal al Perú, limitant l'acció i l'abast d'Indecopi.L'estudi subratlla la necessitat de coordinar les diferents regulacions legals que afecten els grups d'interès, principalment els bancs, que actuen més en resposta als accionistes i als dipositants. Si tenim en compte que tots els comportaments són el resultat d'una anàlisi cost-benefici, la manca d'un superprivilegi per al deute postconcursal, el craw down i altres mesures de reconstitució de capital de treball implicaran més liquidacions. Es proposen un conjunt de normes legislatives amb una anàlisi cost-benefici, entre les quals hi ha la reducció del percentatge del quòrum per reestructurar la firma i modificar l'ordre de prelació, derogar la liquidació automàtica per situació de balanç, crear la figura jurídica del promotor i permetre la difusió del procediment mitjançant una pàgina web. Pel que fa als procediments:Atorgar competències i facultats a les sales superiors comercials en els procediments concursals.Quant a la Superintendència de la Banca i les Assegurances, rebaixar el nivell de provisió bancària quan els crèdits reestructurats es considerin en la categoria normal. Proposar canvis en el reglament de valors d'empreses en concurs, privilegiant la negociabilitat lliure d'aquests crèdits, amb la finalitat de donar suport a les empreses viables i crear un fons de reactivació econòmica per incentivar el refinançament.Aquest estudi és útil per formular polítiques governamentals i també per a les polítiques d'empreses amb dificultats.L'ús indirecte de les mesures de recuperació i el gran nombre d'empreses amb dades incompletes són les limitacions d'aquest estudi. Les línies futures de recerca han d'abastar estudis comparatius en altres latituds sud-americanes utilitzant sistemes judicials i administratius, i després comparar països desenvolupats i no desenvolupats fent servir les mateixes variables i els mètodes per provar la metodologia. / El derecho concursal es la respuesta legal a una realidad financiera que proviene de la economía del mercado. Los negocios pueden fracasar. Cuando las compañías y personas fallan en el cumplimiento de sus obligaciones de deuda y sus activos no son suficientes para cubrir sus créditos caen en insolvencia y quiebran. Para regular las demandas de los acreedores y resolver el dilema de los acreedores como grupo la Ley concursal se convierte en un método ordenado para maximizar los activos del deudor y proteger a determinados grupos de interés. El propósito de esta disertación ha sido la de contribuir al conocimiento del problema concursal. Su objetivo es identificar factores claves para medir la eficiencia a través de los costos de transacción utilizando directos e indirectos, ex ante y ex post, a si como los costos de información, coordinación y ejecución y luego comparar estos contra otro sistema en este caso el Régimen colombiano, creando una metodología para medir la eficiencia.La disertación también cubre racionalidad. La racionalidad concursal es maximizar el valor de los activos del deudor a fin de pagar sus deudas. Es también mantener en el mercado compañías viables considerando en este caso que el valor de la empresa insolvente como una unidad operativa vale más que liquidada y retirar del mercado aquellos negocios que no pueden mantenerse como empresas en marcha. El principal propósito de cualquier sistema concursal es proteger el crédito y proveer un foro para los acreedores a fin que coordinen acciones y de este modo reduzcan costos de transacción. La racionalidad básica del sistema es que estos acuerdos benefician a todos los acreedores y se respeten las preferencias dadas por ley para ciertas clases de acreedores. Un sistema concursal eficiente evitará el error tipo 1 y el error tipo 2, es decir, mantener empresas inviables o liquidar empresas viables.La disertación trata sobre la eficiencia y racionalidad a través de medios empíricos. Una revisión extensa de la literatura se llevo a cabo en áreas como reflotamiento empresarial, costos de transacción, racionalidad limitada, teoría de juegos y Ley concursal a fin de seleccionar variables y formular hipótesis.La investigación cubre 15 años (1992-2007) de historia peruana bajo cuatro diferentes regímenes concursales, utilizando metodología cualitativa y cuantitativa.En la etapa cualitativa se entrevisto a 70 expertos. Ellos son jugadores claves en el mundo académico Indecopi, bancos, compañías administradoras, interventores, las entrevistas generaron ocho categorías útiles para comprender porque los diferentes grupos de interés se comportan como lo hacen. Se tuvo cuidado en seleccionar códigos claves para luego probar estos en la etapa cuantitativa.Las entrevistas semiestructuradas a los expertos proveen un marco conceptual para comprender la conducta que corresponde a industrias reguladas como la banca. A fin de probar las hipótesis se estudiaron 359 compañías. El estudio cubre una extensa documentación retrospectiva en los archivos centrales del Indecopi. La muestra fue incrementada a 3 386 empresas para efectos de la minería datos. La data de las empresas se tomo de los expedientes oficiales que se guardan en Indecopi. SPSS se utilizo para probar las hipótesis y CLEMENTINE para minería de datos. Todas las compañías fueron clasificadas por sector económico es decir, industrias extractivas o primarias (minería, pesquería, agricultura, gas y petróleo) industrias secundarias - manufactureras (textileras, fabricantes de autos, acerías) comercio (tiendas por departamento, venta de carros, mercados, supermercados) servicios (transporte, servicios públicos) los resultados muestran que el sistema concursal peruano es ineficiente, irracional, impredecible e inconsistente. También muestra que no existe correlación positiva entre el sistema concursal y el costo del crédito. El sistema esta diseñado para incentivar el comportamiento estratégico de acreedores privilegiados.El estudio muestra que la decisión final de liquidar o salvar una compañía depende del sector económico y no de la viabilidad de la empresa, más en línea con los intereses de acreedores específicos.La etapa final del estudio proporciona premisas empresariales útiles para los dueños y gerentes de pequeñas y medianas empresas frente a sus acreedores. El estudio trae la racionalidad limitada al marco del derecho económico que fue utilizado para privatizar el proceso concursal en el Perú limitando la acción y alcance de Indecopi.El estudio remarca la necesidad de coordinar las diferentes regulaciones legales que afectan a los grupos de interés principalmente bancos quienes actúan más en respuesta a sus accionistas y depositantes. Considerando que todo comportamiento es el resultado de un análisis costo beneficio la falta de superprivilegio para la deuda post concursal, craw down y otras medidas de reconstitución de capital de trabajo llevaran a mayores liquidaciones. Se propone un conjunto de normas legislativas con un análisis costo beneficio, entre estas reducir el porcentaje del quórum para reestructurar la firma y la modificación del orden de prelación, derogar la liquidación automática por situación de balance, crear la figura jurídica del Promotor y permitir la difusión del procedimiento vía página web.A nivel de procedimientos:Otorgar competencias y facultades a las Salas Superiores en lo Comercial en los procedimientos concursales. En lo que respecta a la Superintendencia de Banca y Seguros rebajar el nivel de provisión bancaria al considerar los créditos reestructurados en la categoría normal.Proponer cambios en el reglamento de Valores de Empresas en Concurso privilegiando la libre negociabilidad de estos créditos y con la finalidad de apoyar a empresas viables crear un Fondo de Reactivación Económica para incentivar la refinanciación.El presente estudio es útil para la formulación de políticas gubernamentales así como para las políticas de empresas en dificultades.Limitaciones de este estudio son el uso indirecto de las medidas de recuperación así como el gran número de compañías con data incompleta. Futuras líneas de investigación deben abarcar estudios comparativos en otras latitudes sudamericanas utilizando sistemas judiciales y administrativos y luego comparar países desarrollados y no desarrollados utilizando las mismas variables y métodos para probar la metodología. / Bankruptcy law is the legal response to a financial reality which arises from the market economy. Business can fail. When companies and persons fail to comply with their debt obligations and assets are not enough to cover credits they go under in insolvency. To regulate creditor's demands and solve creditor's pool dilemma bankruptcy law becomes an orderly method to maximize debtor assets and protect qualified stakeholders. The purpose of this dissertation has been to make a contribution to the knowledge of the bankruptcy problem. Its aim is to identify key factors to measure efficiency through transactional cost using direct and indirect ones, ex ante and ex post as well as information, coordination and execution ones and then compare those against another system, in this case the Colombian one, creating a methodology to measure efficiency.The dissertation also covers rationality. Bankruptcy rationality is to maximize the debtor asset value in order to pay his debts. It is also to maintain in the market viable companies considering in this case that the value of the insolvent company as an operating unit is worth more than liquidated and also to take out of the market those businesses which are not on going concerns.The main purpose of any bankruptcy system is to protect credit and provide a forum for creditors to coordinate actions and in doing so reduce transactional costs. The basic rationality of the system is that these agreements with benefits all creditors and respect preferences given by law to certain creditors classes.An efficient bankruptcy system will avoid error type one and error type two, namely, maintain unviable companies or liquidate viable companies.The dissertation addresses efficiency and rationality by empirical means. An extensive review of the literature was carried out in subjects as turnaround, transactional cost, bankruptcy legislation, bounded rationality, game theory and bankruptcy law in order to select variables and to formulate hypothesis.The research covers fifteen years (1992-2007) of Peruvian history under four different legal bankruptcy regimes, using qualitative and quantitative methodology.In the qualitative stage seventy experts were interviewed. They are key players in academics, Indecopi, banks; administrative companies, Trustees, interviews provided eight categories all useful to understand why different stake holders behave as they do.Great care was taken to select key codes to later test in quantitative stage. Semi structured interviews to experts provide a framework to understand behavior which respond to regulate industries as banking. In order to test hypothesis 359 companies were studied. The study covers an extensive retrospective documentary research in Indecopi Central Archives. The sample was increased to 3386 companies for data mining purposes.Data from companies was taken from official files kept in Indecopi. SPSS was used to test hypothesis and Clementine for data mining. All companies were classified by economic sector, namely, Primary or Extractive Industries (Mining, fishing, agriculture, oil and gas) Secondary Industries -manufacturing (textiles, car making, steel mills), Commerce (Department stores, car dealers, super markets), Services (transport, utilities).Results show that the Peruvian bankruptcy system is inefficient, irrational, unpredictable and inconsistent. It also shows no positive correlation between the bankruptcy system and credit cost. The system as designed encourage strategy behavior of privilege creditors. The study shows that final decision to liquidate or save a company depend on the economic sector and not the viability of the company, more in line with the interest of specific creditors. The final stage of the study provides useful business premises to owners and managers of small and medium size companies before creditors. The study brings bounded rationality into law and economic framework which was used to privatize the bankruptcy process in Peru limiting Indecopi actions and scope.The study point out the need to coordinate different legal regulations affecting stakeholders, mainly banks which act more in response to shareholders and savers. Considering that all behavior is the result of cost and benefit analysis lack of super privilege for post bankruptcy debt, cram down and others measures to reinstate working capital will lead to increase liquidations.The study presents a group legislative proposals based on the empirical findings of the present research, proposals which are formulated with a cost - benefit analysis.Among others the reduction of the voting percentage needed to restructuring a company.The change of the preference order of certain credits, the abrogation of the automatic business liquidation in regard of balance sheet situation.The creation of the promoter figure and the diffusion of the procedure through web pages.With regard to competences award the Commercial Superior Courts the power to act in bankruptcy procedures. With regard to the SBS to reduce banking provisions considering restructured credits as normal ones.The study also proposes changes in the regulation of bankruptcy company credits, giving priority to free negotiability of these credits.Also the creation of a reactivation fund to support viable companies and to promote refinancing.The present study is usefully for government policies formulation as well as business policy for companies in distress.Limitations of this study are the indirect measure of recovering as well as the large number of companies with incomplete data. Future research should cover comparative studies in other South American latitudes using administrative and Court systems, and then compare under develop and develop countries using same variables and methods in order to test methodology.

Since North Africa is considered as one of the future hot spots for tourism development, western hotel chains increasingly expand to this region. Especially in the opening phase, these hotel groups tend to fill leading positions with male and female western managers. However, we assume that since the Arab culture is very male-dominated, the employment of women managers might cause cultural conflicts. Thus, our thesis aims to identify possible barriers for women to succeed in hotels in North Africa as well as to elaborate critical success factors for future female western leaders to overcome these barriers and to manage effectively. In order to find out about underlying attitudes towards foreigners and female superiors, we conducted a survey among Arabic hotel employees at an international five star hotel in Egypt. The results of our survey were topped up with insights from the literature and the remaining knowledge gaps were filled by holding conversations with industry experts. The findings of our study indicate a trend towards a more liberal Arabic society as well as certain openness towards foreigners and women, which could be ascribed to driving forces, such as globalization and a rise in information technology. However, there are still cases of gender inequality and religious intolerance, which shows that social practices have not yet completely changed. It is thus suggested that female western leaders still face barriers, such as chauvinistic behavior as well as suggestiveness. In order to be able to deal with these barriers, we developed critical success factors for future women managers, such as being cultural intelligent, being interested in the employees, being a coach and a team player, and trusting yourself. In addition, we provided general implications for women operating in other seemingly hostile environments, such as male-dominated industries or women-aversive surroundings.

Workplace accidents and injuries are a growing problem for organizations in Sweden as well as in many other countries. As a consequence, improving workplace safety has become an area of increasing concern for employers and politicians as well as researchers. The aim of this thesis was to contribute to an increased understanding of how leadership and management practices can influence safety in organizations. In Study I, three leadership styles were investigated to determine their relative importance for different safety outcomes. A leadership style specifically emphasizing safety was found to contribute the most to employee safety behaviors; transformational leadership was found to be positive for safety behaviors only when it also involved a safety focus; and a transactional leadership style (management-by-exception active) was shown to be slightly negatively related to workplace safety. Study II examined the role of leader communication approaches for patient safety and the mechanisms involved in this relationship. Support was found for a model showing that one-way communication of safety values and leader feedback communication were both related to increased patient safety through the mediation of different employee safety behaviors (safety compliance and organizational citizen behaviors). Study III explored whether and in what ways the use of staff bonus systems may compromise safety in high-risk organizations. The three investigated systems were all found to provide limited incentives for any behavioral change. However, the results indicate that design characteristics such as clearly defined and communicated bonus goals, which are perceived as closely linked to performance and which aim at improved safety, are imperative for the influence that bonus programs have on safety. Group-directed goals also appeared to be more advantageous than corporate- or individual-level goals. The thesis highlights the importance of actively emphasizing and communicating safety-related issues, both through leadership and in managerial practices, for the achievement of enhanced workplace safety. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 1: Manuscript.</p>

Applications must be able to synchronize accesses to operating system (OS) resources in order to ensure correctness in the face of concurrency and system failures. This thesis proposes system transactions, with which the programmer specifies atomic updates to heterogeneous system resources and the OS guarantees atomicity, consistency, isolation, and durability (ACID). This thesis provides a model for system transactions as a concurrency control mechanism. System transactions efficiently and cleanly solve long-standing concurrency problems that are difficult to address with other techniques. For example, malicious users can exploit race conditions between distinct system calls in privileged applications, gaining administrative access to a system. Programmers can eliminate these vulnerabilities by eliminating these race conditions with system transactions. Similarly, failed software installations can leave a system unusable. System transactions can roll back an unsuccessful software installation without disturbing concurrent, independent updates to the file system. This thesis describes the design and implementation of TxOS, a variant of Linux 2.6.22 that implements system transactions. The thesis contributes new implementation techniques that yield fast, serializable transactions with strong isolation and fairness between system transactions and non-transactional activity. Using system transactions, programmers can build applications with better performance or stronger correctness guarantees from simpler code. For instance, wrapping an installation of OpenSSH in a system transaction guarantees that a failed installation will be rolled back completely. These atomicity properties are provided by the OS, requiring no modification to the installer itself and adding only 10% performance overhead. The prototype implementation of system transactions also minimizes non-transactional overheads. For instance, a non-transactional compilation of Linux incurs negligible (less than 2%) overhead on TxOS. Finally, this thesis describes a new lock-free linked list algorithm, called OLF, for optimistic, lock-free lists. OLF addresses key limitations of prior algorithms, which sacrifice functionality for performance. Prior lock-free list algorithms can safely insert or delete a single item, but cannot atomically compose multiple operations (e.g., atomically move an item between two lists). OLF provides both arbitrary composition of list operations as well as performance scalability close to previous lock-free list designs. OLF also removes previous requirements for dynamic memory allocation and garbage collection of list nodes, making it suitable for low-level system software, such as the Linux kernel. We replace lists in the Linux kernel's directory cache with OLF lists, which currently requires a coarse-grained lock to ensure invariants across multiple lists. OLF lists in the Linux kernel improve performance of a filesystem metadata microbenchmark by 3x over unmodified Linux at 8 CPUs. The TxOS prototype demonstrates that a mature OS running on commodity hardware can provide system transactions at a reasonable performance cost. As a practical OS abstraction for application developers, system transactions facilitate writing correct application code in the presence of concurrency and system failures. The OLF algorithm demonstrates that application developers can have both the functionality of locks and the performance scalability of a lock-free linked list. / text

Advances in data collection and data storage technologies have given way to the establishment of transactional databases among companies and organizations, as they allow enormous volumes of data to be stored efficiently. Most of the times, these vast amounts of data cannot be used as they are. A data processing should first take place, so as to extract the useful knowledge. After the useful knowledge is mined, it can be used in several ways depending on the nature of the data. Quite often, companies and organizations are willing to share data for the sake of mutual benefit. However, these benefits come with several risks, as problems with privacy might arise, as a result of this sharing. Sensitive data, along with sensitive knowledge inferred from these data, must be protected from unintentional exposure to unauthorized parties. One form of the inferred knowledge is frequent patterns, which are discovered during the process of mining the frequent itemsets from transactional databases. The problem of protecting such patterns is known as the frequent itemset hiding problem. In this thesis, we review several techniques for protecting sensitive frequent patterns in the form of frequent itemsets. After presenting a wide variety of techniques in detail, we propose a novel approach towards solving this problem. The proposed method is an approach that combines heuristics with linear-programming. We evaluate the proposed method on real datasets. For the evaluation, a number of performance metrics are presented. Finally, we compare the results of the newly proposed method with those of other state-of-the-art approaches. / Η ραγδαία εξέλιξη των τεχνολογιών συλλογής και αποθήκευσης δεδομένων οδήγησε στην καθιέρωση των βάσεων δεδομένων συναλλαγών σε οργανισμούς και εταιρείες, καθώς επιτρέπουν την αποδοτική αποθήκευση τεράστιου όγκου δεδομένων. Τις περισσότερες φορές όμως, αυτός ο τεράστιος όγκος δεδομένων δεν μπορεί να χρησιμοποιηθεί ως έχει. Μια πρώτη επεξεργασία των δεδομένων πρέπει να γίνει, ώστε να εξαχθεί η χρήσιμη πληροφορία. Ανάλογα με τη φύση των δεδομένων, αυτή η χρήσιμη πληροφορία μπορεί να χρησιμοποιηθεί στη συνέχεια αναλόγως. Αρκετά συχνά, οι εταιρείες και οι οργανισμοί είναι πρόθυμοι να μοιραστούν τα δεδομένα μεταξύ τους με στόχο το κοινό τους όφελος. Ωστόσο, αυτά τα οφέλη συνοδεύονται με διάφορους κινδύνους, καθώς ενδέχεται να προκύψουν προβλήματα ιδιωτικής φύσης, ως αποτέλεσμα αυτής της κοινής χρήσης των δεδομένων. Ευαίσθητα δεδομένα, μαζί με την ευαίσθητη γνώση που μπορεί να προκύψει από αυτά, πρέπει να προστατευτούν από την ακούσια έκθεση σε μη εξουσιοδοτημένους τρίτους. Μια μορφή της εξαχθείσας γνώσης είναι τα συχνά μοτίβα, που ανακαλύφθηκαν κατά την εξόρυξη συχνών στοιχειοσυνόλων από βάσεις δεδομένων συναλλαγών. Το πρόβλημα της προστασίας συχνών μοτίβων τέτοιας μορφής είναι γνωστό ως το πρόβλημα απόκρυψης συχνών στοιχειοσυνόλων. Στην παρούσα διπλωματική εργασία, εξετάζουμε διάφορες τεχνικές για την προστασία ευαίσθητων συχνών μοτίβων, υπό τη μορφή συχνών στοιχειοσυνόλων. Αφού παρουσιάσουμε λεπτομερώς μια ευρεία ποικιλία τεχνικών απόκρυψης, προτείνουμε μια νέα προσέγγιση για την επίλυση αυτού του προβλήματος. Η προτεινόμενη μέθοδος είναι μια προσέγγιση που συνδυάζει ευρετικές μεθόδους με γραμμικό προγραμματισμό. Για την αξιολόγηση της προτεινόμενης μεθόδου χρησιμοποιούμε πραγματικά δεδομένα. Για τον σκοπό αυτό, παρουσιάζουμε επίσης και μια σειρά από μετρικές αξιολόγησης. Τέλος, συγκρίνουμε τα αποτελέσματα της νέας προτεινόμενης μεθόδου με άλλες κορυφαίες προσεγγίσεις.

The aim of this study in social work was to investigate, describe and analyze six Swedish men’s description and experiences of relationships with bargirls in Thailand, whom the men initially paid for sexual services. We also aim to find out how these men look upon prostitu-tion, masculinity and gender and we analyze these themes in relation to the men’s description of their relationships. The theoretical approach was social constructivist theories of masculini-ty in combination with gender theory. The study was conducted using qualitative individual half structured definition interviews with six men living in Thailand and the interviews were conducted in Pattaya, Thailand. The results show that the men’s view of prostitution differs from what they experience in Thailand and that they therefore don’t perceive it as prostitution. This is partly a consequence of their view of masculinity, which includes that the man shall have economic responsibility for women. The men find it harsh to adapt to the gender equali-ty discourse in Sweden and express that they appreciate that the relations with the bargirls consists of separate duties for the sexes.

Due to the fact that the environment in which companies in 'South Africa are operating is constantly changing, these companies are undergoing a process of transformation. Organisations that intend competing successfully within this changing environment will have to have the right kind of leaders in order to stay afloat and even flourish. It is expected from companies' leaders at all levels to successfully navigate these troubled waters. Much of leadership has to do with the way in which leaders motivate their subordinates. Research has shown that there are succinctly different styles of leadership, and that each type of style has a different influence on the motivation of workers. Another factor, equally important, is the concept of locus of control. Research has also shown that people perceive differently, that which controls their destiny. Does the leader feel that he/she is controlled by this constantly changing environment in which he/she has to lead, or is he/she as the leader of an organisation in control of him-herself and his/her actions, and therefore also in control of the company itself? The question that inevitably arises is the following: is there any relationship between the style of leadership and the locus of control of the leader, and if so, what is the nature of this relationship? A quantitative design (two test survey design on a large population) was used to take the measurements on the style of leadership and the locus of control of the leaders. The Locus of Control Inventory (LCI) of Schepers (1998) and the Multifactor Leadership Questionnaire (MLQ), form 5R of Bass and Avolio (1995), were administered. A statistical analysis was then carried out in order to determine the relationship that exists between the two measurements, as well as the nature of the relationship. There were 221 respondents from organisations in South Africa, most of whom were in a middle level of leadership. The results showed that an internal locus of control and a disposition towards autonomy were associated with a laissez-faire leadership style as well as a transformational leadership style. It also showed that an external locus of control was associated with a laissez-faire leadership style. Recommendations for organisations and for future research were made. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2004.