Ingeniero Civil Industrial / Para las plataformas de subastas pay-to-bid como Ganeselo.com, el principal problema que enfrentan a diario es qué producto subastar y a qué hora del día. El presente trabajo de título tuvo como objetivo diseñar una herramienta que permita apoyar la planificación del mix diario, considerando factores de rentabilidad, temporalidad y variabilidad. El estudio se centro en identificar las variables relevantes que influyen en el mix, definir criterios de variedad y desarrollar un prototipo que entregue de manera rápida una solución de surtido que pueda ser puesta en práctica en la página y posteriormente ser evaluada. La metodología propone el desarrollo de un modelo de comportamiento, uno de decisión asociado a este y un conjunto de sugerencias para un post-procesamiento. Con el primero se busca describir la conducta de juego de los usuarios para las diferentes tipos de subastas, para posteriormente realizar una estimación de la demanda para las próximas publicaciones. El modelo de decisión asociado definirá, basado en una serie de reglas del negocio, el mejor intervalo del día para publicar las subastas que completarán el mix diario. Luego de encontrar el tipo de subasta (tipo producto, tipo de juego), se definirá el producto en específico que se publicará. Esto último con una constante comunicación con los usuarios para observar preferencias. Analizando 6.461 subastas finalizadas, se identifica como la opción de Buy now hace diferencias en el precio final alcanzado, los productos más caros son los más influyentes dentro del surtido, y publicándose en horas peak de visitas, las utilidades pueden ser mucho mayores. El prototipo indica un ajuste R2 del 39%. Además presenta una utilidad más de 30 veces mayor que el promedio de los días de estudio, usando el 90% del presupuesto promedio. Al aplicar variaciones en sus parámetros, el modelo propuesto pronostica una distribución de utilidades con una desviación un 14% menor, por ende más estable que el método usado actualmente en la firma. En base a los resultados, se concluye que al aplicar el modelo propuesto la empresa obtiene un método más robusto para planificar el surtido diario, considerando factores de rentabilidad, variedad y atractivo. Por otro lado se evita dependencia en una persona y el constante monitoreo, entregando indicadores que permiten más y mejores análisis para la toma de decisiones futuras.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20753号 / 理博第4329号 / 新制||理||1622(附属図書館) / 京都大学大学院理学研究科数学・数理解析専攻 / (主査)教授 森脇 淳, 教授 雪江 明彦, 教授 並河 良典 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

IDS (Intrusion Detection System) detect intrusions and generate alerts to administrator. With Internet more and more popular, IDS products a lot of alerts make administrators spend much time to analyze to understand the network situation. Many online services record services details on the log, as the same administrators spend much time to analyze logs. IDS suffer from several limitations : amount of alerts, most of the alerts are false positive, certain attacks may not be detected by IDS. To solve limitations of IDS, four alert correlation techniques : alert attributions similarity, predefined attack scenarios, multi-stage approaches, verification to filter positive alerts. Network attack consist of multiple steps, each step may leave evidences on log or detected by IDS. Service logs record normal and abnormal detail behaviors, IDS alerts record single attack step. Alerts and logs first merge into meta-alert and meta-log. Second, we use two features to filter meta-log. Then, correlate meta-alert and filtered meta-log to produce report to administrators.

In this thesis, a CMOS tunable second-order log-domain filter using pseudo-exponential approximation is proposed. MOSFETs in the circuit are working in the saturation region. This filter has higher frequency response than that of weak inversion CMOS filter. The circuit has been fabricated with 0.35um CMOS technology. It operates with a supply voltage 3V, internal capacitance C is 1pF, the biasing current varies from 2uA~10uA. The cutoff frequency can be turned from 2MHz~37.5MHz. The harmonic distortion is 0.93% and the power consumption is 772uW.

Zugl.: Münster (Westfalen), Univ., Diss., 2008

The thesis project is aimed to automate ultrasonic Time-of-Flight (ToF) technique for saw log classification using signal processing. The ToF technique works in such a way that ultrasonic tone-burst pulses are sent into a saw log, and then the ToF that the pulses take for the propagation is measured and used to calculate the sound speed and further, the Modulus of Elasticity (MoE). Based on the MoE, the quality of the logs is predicted and presorted before sawing. Development of matched filters is the central task for automating the ToF technique.  The whole project was carried out in two different parts: 1) Fundamentals and MATLAB implementation, and 2) Real-time implementation based on digital signal processor.     In the first part, fundamentals on the ToF technique and matched filters have been studied, and then MATLAB simulations of matched filters for automating the technique have been made. After this, test measurements have been conducted. The test results are shown to be consistent with the simulation: matched filtering works well for automating the ToF technique. In the second part of the report, an embedded algorithm has been developed and implemented on a Digital Signal Processor. The algorithm is the first step in the automation of measurements. Eventually, two test measurements have been performed with the DSP. The results were obtained using both oscilloscope to visualize and MATLAB to plot the obtained debug log, and they have shown that the algorithm works, and can automatically measure the ToF, which is in turn used to calculate the sound speed and MoE. The further work on the project that needs to be done, is to applying the developed system to the real situations in sawmills, and improving it according to their requirements.

To improve the performance of the conventional nail laminated bridge deck, three generations of innovative decks have been developed during the last three decades: (a) the stress laminated wood deck, (b) the stressed log bridge, and (c) the grout laminated wood deck. The grout laminated wood deck, the most recent wood deck, consists of trimmed logs interconnected with internal grout cylinders, in compression or tension. Previous research has shown that the grout cylinders have superior load distribution characteristics, but the cost of trimming the treated logs was found to be relatively high. Recently, research has been conducted to develop the next generation of the bridge wood decks, called the anchored log decks. The anchored log deck, meant for use as decking of steel girder bridges, consists of untrimmed discarded utility timber poles which have been treated with preservatives. The logs are held together by means of unstressed transverse proprietary Cintec anchors. The anchors consist of stainless steel rods encased in grout cylinders. Panels, each comprising of 5 to 6 logs, are preassembled to fit on a flatbed trailer for shipping. The smooth wearing surface over the log deck is provided by longitudinal sawn timber planks, with high-density foam filling the gap between the logs and the planks. The panels are inter-connected through inclined anchors passing through adjacent logs. At the University of Manitoba, an anchored log deck with five preassembled panels was constructed and tested to failure at several locations under both static and fatigue loads. The test results have shown that anchored log decks have the potential of being economical preassembled decks for steel girder bridges.

Zugl.: Berlin, Freie Univ., Diplomarbeit, 2007. / Hergestellt on demand.

Bachelor-Arbeit Univ. St. Gallen, 2008.

Thesis (Ph. D.)--University of Washington, 1986. / Vita. Bibliography: leaves [111]-118.