Three Essays on Behavioral and Applied Game Theory.

no abstract availableGame theory;

Experimental Study of Machine-Learning-Based Detection and Identification of Physical-Layer Attacks in Optical Networks

Optical networks are critical infrastructure supporting vital services and are vulnerable to different types of malicious attacks targeting service disruption at the optical layer. Due to the various attack techniques causing diverse physical- layer effects, as well as the limitations and sparse placement of optical performance monitoring devices, such attacks are difficult to detect, and their signatures are unknown. This paper presents a Machine Learning (ML) framework for detection and identification of physical-layer attacks, based on experimental attack traces from an operator field-deployed testbed with coherent receivers. We perform in-band and out-of-band jamming signal insertion attacks, as well as polarization modulation attacks, each with varying intensities. We then evaluate 8 different ML classifiers in terms of their accuracy, and scalability in processing experimental data. The optical parameters critical for accurate attack identification are identified and the generalization of the models is validated. Results indicate that Artificial Neural Networks (ANNs) achieve 99.9% accuracy in attack type and intensity classification, and are capable of processing 1 million samples in less than 10 seconds

Does Finance Bolster Superstar Companies? Banks, Venture Capital, and Firm Size in Local U.S. Markets

We study the relative effect of venture capital and bank finance on large manufacturing firms in local U.S. markets. Theory predicts that with venture capital, the firm size distribution should become more stretched-out to the right, but it’s ambiguous on the effect of banks on large firms. The empirical evidence suggests that while the average size of firms in the top bin of the firm size distribution has remained unaffected by banking sector developments, it has increased with venture capital investment. We argue that this is due to the emergence of new corporate giants rather than the growth of existing ones. JEL Classification: G24, J24, L11banking, firm size, Venture Capital

Business and technical aspects of mobile peer-to-peer social networks

Introduction of mobile high-capacity networks, as well as the widespread penetration of powerful mobile handsets provide a good basis for the development of peer-to-peer applications in the mobile environment. However, it is not certain if the P2P services that were well adopted in the fixed In-ternet can also be successfully launched in the mobile environment.   This article dissertation presents research results of mobile community service provisioning using P2P technology. The study was carried out on two levels: technical and business. On the business level the dissertation discusses the mobile P2P service provisioning ecosystem including analysis of stakeholder needs as well as potential scenarios for mobile P2P services. The dissertation presents the results of a user survey and a literature study. The presented material reveals that there is room for P2P services in the mobile environment, however user requirements are different than in the fixed environment. The dissertation also presents a scenario planning methodology that proposes the Schoemaker’s variant of scenario planning as a suitable method for evaluating emerging mobile services. Consistent and coherent learning scenarios that were developed using the proposed methodology are also presented.   On the technical level, the dissertation presents P2P system architectures, protocols, and algorithms that enable the provision of community services in the mobile environment. In particular, the dissertation describes the world first resource sharing system that works on top of SIP networks. The system enables mobile phone users to share resources with each other and does not require any changes to the basic SIP infrastructure. A Social DHT architecture that allows for efficient formation of mobile communities is also presented. The dissertation shows how the P2P infrastructure can become a feasible cost efficient replacement for a mobile infrastructure by presenting a Distributed IP Multimedia Subsystem as well as a pioneering new mobile P2PSIP system for real-time communication services. The dissertation discusses an implementation of a P2P system that allows mobile phone users to search for knowledge in their trusted social communities overcoming the problems identified in the business study of the dissertation. The results of measurements and trials conducted show the technical feasibility of mobile community service provisioning using P2P technology

Regulation of Angiogenesis : Role of R-Ras, furin and syndecan 4 in retinal angiogenesis

Angiogeneesi, eli verisuonten uudismuodostus on tärkeää normaalin kehityksen ja kudoksen tasapainon kannalta. Useissa sairauksissa muutoin tarkkaan säädellyt mekanismit järkkyvät, mikä voi johtaa verisuonten hallitsemattomaan kasvuun. Patologista uudisverisuonitusta esiintyy useissa näköa heikentävissä ja sokeuttavissa silmänpohjan sairauksissa sekä useissa syövissä. Tiedetään, että verisuonten endoteelikasvutekijä (VEGF) on merkittävassä roolissa edistämässä haitallista verisuonten kasvua, ja sen estäjiä käytetäänkin hoitona useissa neovaskulaarisissa sairauksissa. Nämä hoidot eivät aina kuitenkaan ole tarpeeksi tehokkaita, ja uusia tehokkaampia ja spesifisempia hoitomuotoja tarvitaan. Tämän takia angiogeneesin liittyvien tapahtumien parempi molekulaarinen tietämys on tarpeen. Tämän väitöskirjan tavoitteena oli tutkia eri geenien vaikutusta angiogeneesiin ja läytää uusia angiogeneesin säätelyyn osallistuvia tekijöitä. Väitöskirja koostuu neljästä osatyöstä, jotka käsittelevät angiogeneesia retinan kehityksen aikana sekä osana silmäsairauksia. Osatöissä on suurelta osin käytetty kokeellisia hiirimalleja, jotka mallintavat iskeemisia retinopatioita. Lisäksi käytössä on ollut lasiaisenpoistoleikkauksen yhteydessä saatuja potilasnäytteitä proliferatiivista diabeettista retinopatiaa ja verkkokalvon verisuonitukosta sairastavailta potilailta. Ensimmäisessä osatyössä Rras geenin roolia tutkittiin iskeemisen retinopatian angiogeneesissa, ja todettiin geenin merkittavä osallisuus verkkokalvon verisuonten läpäisevyyden säätelyssä. Meyloidisolujen furin geenin merkitystä verkkokalvon verisuonten kasvuun tutkittiin toisessa osatyössä ja havaittiin sen edistävän verisuonten kasvua. Kolmannessa osatyössä kokeellisesta iskeemisestä verkkokalvon angiogeneesimallista tehtiin tähän mennessä laajin hiiren verkkokalvon proteomin kartoittava seulontatutkimus. Tutkimuksessa löydettiin proteiineja, jotka mahdollisesti osallistuvat verkkokalvon haitallisen uudisverisuonitukseen muodostumiseen hiirimallissa sekä ihmisen iskeemisissä retinopatioissa. Viimeisessä osatyössä tutkittiin syndekaani-4 -geenin (Sdc4) merkitystä angiogeneesille useissa eri malleissa ja havaittiin SDC4:n merkittävä rooli VEGFA-välitteisen patologisen verisuonituksen muodostumisessa ja VE-kadheriinin toiminnassa. SDC4 terapeuttista potentiaalia testattiin kokeellisessa silmänpohjan ikärappeumamallissa, ja todettiin SDC4 toiminnan eston olevan yhtä tehokas kuin ikärappeuman hoidossa kliinisessä käytössä oleva lääke. Tutkimuksessa saadut tulokset lisäävät tietämystä angiogeneesiin vaikuttavista tekijöistä. Ne voivat olla hyödyllisiä kehitettäessä uusia potentiaalia lääkkeitä sairauksiin, joihin liittyy haitallinen verisuonten uudismuodostus.Angiogenesis, the formation of new blood vessels, is important for normal development and the maintenance of tissue homeostasis. However, in many diseases, the events that are normally tightly controlled become disrupted, which can lead to aberrant and extensive growth of the blood vessels. Pathological angiogenesis is a key feature in many vision-threatening eye diseases and in cancers. Vascular endothelial growth factor (VEGF) is the main driver of pathological angiogenesis and VEGF- inhibitors are commonly used as a treatment for neovascular diseases. However, the therapies are not always sufficiently effective, and resistance to them can develop. Thus, more effective and specific therapeutics are needed. For this reason, the better understanding of the molecular mechanisms behind the pathologies is important. The main aim of this dissertation was to study the effect of different genes on the formation of new blood vessels and to identify new factors that contribute to the regulation of angiogenesis. The dissertation consists of four studies that addressed the role of angiogenesis mainly in eye diseases. These studies made use of experimental models of retinopathies as well as samples from human patients with proliferative diabetic retinopathy and retinal vein occlusion. The first study investigated the role of R-Ras in the regulation of angiogenesis in ischemic retinopathy. We found that R-Ras was important for the maintenance of vascular stability. The same ischemic retinopathy model was used in the second study, in which we showed that the function of myeloid-specific furin for retinal angiogenesis plays a role in retinal revascularization. In the third study we performed the most comprehensive proteomic profiling of the oxygen-induced retinopathy model to date. We identified novel proteins that may drive the pathogenesis and neovascularization in the mouse retinopathy model. These proteins may have relevance to human retinopathy as well as new potential drug targets. The fourth study explored the role of syndecan 4 (SDC4) in angiogenesis using several angiogenesis models. We demonstrated that SDC4 is needed for VEGF-\- driven pathological angiogenesis and VE-cadherin trafficking. The therapeutic potential of SDC4 inhibition was tested in an experimental model of wet age-related macular degeneration (AMD), and we found that it was as effective as a drug commonly used in the clinic for the treatment of wet AMD. The results of these studies improve the knowledge of the factors that affect angiogenesis. These results could be useful in the future development of new drugs for diseases that involve pathological angiogenesis