Detection of False Data Injection Attacks in Multi-Microgrid

In this thesis an Intrusion Detection System was developed to fight False Data Injection Attacks in Multi-Microgrids. Multi-Microgrids are a part of future power systems and they form the core part of critical infrastructure where resiliency and availability are exceedingly important. Severe consequences in the main power grid can happen if security is not taken into account. The Energy Management System has to be protected against cyber-attacks and one of the dire threats is a False Data Injection Attack. False Data Injections in Energy Management Systems are among the critical threats that need to be taken seriously as they can cause a major harm. In this thesis, the impact of a False Data Injection Attack on Multi-Microgrids and Energy Management Systems has been explored. It has also been researched how to detect these attacks by designing and developing a Multi-Microgrid model in MATLAB/Simulink for emulating the operation of Multi-Microgrid. The MATLAB/Simulink model simulates a Multi-Microgrid environment over the course of 24 hours. To detect False Data Injection Attacks from the data created in this simulation a Kalman Filter based Intrusion Detection System was developed. The Kalman Filter based Intrusion Detection System analyzes simulation data for possible False Data Injection Attacks. Further analysis was done based on the results of the Kalman Filter based Intrusion Detection System implementation. The implementation was tested with a set of attack simulations. The results analysis revealed that developed Kalman Filter based Intrusion Detection System is suitable for detecting simple attacks but it has low accuracy for complex intrusion attacks. With taking into account only the types of attacks the implementation was initially planned to detect the detection rate averaged to 87 %. The detection accuracy could be improved in future work by considering complex attack types early on in the implementation of the detection system. Securing power systems against malicious actors from causing harm or gaining financial benefits is a far-reaching research topic with plenty of future paths to explore. Kalman Filter based methods are one of the potential methods for detecting False Data Injection Attacks in Energy Management Systems. More research on Kalman Filter based protections is part of the ongoing race in protecting ourselves from cyber-attacks against critical infrastructure

Virtuaalitodellisuuslaitteiden sovellutukset kuntoutuksessa ja havainnoinnin analysoinnissa : suunnittelu ja toteutus

Työn tarkoituksena oli tutkia virtuaalitodellisuusteknologioita ja toteuttaa kaksi erillistä järjestelmää aivohalvauspotilaiden kuntoutukseen sekä havainnoinnin analysointiin ajotilanteessa. Opinnäytetyössä tutustuttiin virtuaaliteknologioiden osa-alueisiin ja määritelmiin. Teoriaosuudessa käytiin läpi virtuaalitodellisuusteknologioiden vahvuuksia sekä kehityskohteita. Opinnäytetyön teoriaosuudessa tehtiin lisäksi vertailu markkinoilla olevista pelimoottoreista ja virtuaalitodellisuuslaseista kehitysosiota varten. Työssä kehitettiin tutkimustyön avulla kaksi virtuaalitodellisuuslaitteita hyödyntävää sovellusta, jotka pyrkivät auttamaan muita tieteenaloja ongelmien ratkaisussa. Aivohalvauspotilaiden kuntoutukseen suunnitellussa OcuTread-projektissa vastattiin teknisestä kehityksestä. Havainnointikykyä analysoivassa OcuCar-projektissa vastattiin virtuaalitodellisuuslasien käytöstä, rattiohjaimen ja automekaniikkojen valinnasta sekä signaalien arkkitehtuurisesta suunnittelusta. Opinnäytetyössä käytiin läpi kehitettyjen töiden keskeiset kehityskohteet ja tuotiin esille töiden toiminnallisuutta. Lopputuloksena valmistui kaksi virtuaalitodellisuutta hyödyntävää ohjelmaa projektien asiakkaiden käyttöön.The purpose of this study was to research the use of virtual reality technologies and to develop two different systems for stroke patient rehabilitation and perception analysis in a driving environment. Types and definitions of virtual reality technologies were explored during the writing of this thesis. The theoretical part of this thesis examines the benefits of virtual reality examined together with the evaluation of the possibilities and development areas of virtual reality. Additionally, a comparison of available game engines and virtual reality glasses was also made in the theoretical part of this thesis. Two programs utilizing virtual reality devices were developed on the practical part of the thesis, to help finding solutions on the other branches of science. In the stroke patient rehabilitation project, the development was carried out on the technical side. On the perception analysis project, the responsibility was on the virtual reality glasses, choice of driving wheel and car mechanics and the architectural design of the signals. The practical part of the thesis discusses the key aspects of development and presents the functionality of the programs. Two programs utilizing virtual reality were developed as a result

Postoperative computed tomography imaging of pediatric patients with craniosynostosis : radiation dose and image quality comparison between multi-slice computed tomography and O-arm cone-beam computed tomography

BackgroundWhen postoperative multi-slice computed tomography (MSCT) imaging of patients with craniosynostosis is used, it is usually performed a few days after surgery in a radiology department. This requires additional anesthesia for the patient. Recently, intraoperative mobile cone-beam CT (CBCT) devices have gained popularity for orthopedic and neurosurgical procedures, which allows postoperative CT imaging in the operating room.ObjectiveThis single-center retrospective study compared radiation dose and image quality of postoperative imaging performed using conventional MSCT scanners and O-arm CBCT.Materials and methodsA total of 104 pediatric syndromic and non-syndromic patients who were operated on because of single- or multiple-suture craniosynostosis were included in this study. The mean volumetric CT dose index (CTDIvol) and dose-length product (DLP) values of optimized craniosynostosis CT examinations (58 MSCT and 46 CBCT) were compared. Two surgeons evaluated the subjective image quality.ResultsCBCT resulted in significantly lower CTDIvol (up to 14%) and DLP (up to 33%) compared to MSCT. Multi-slice CT image quality was considered superior to CBCT scans. However, all scans were considered to be of sufficient quality for diagnosis.ConclusionThe O-arm device allowed for an immediate postoperative CBCT examination in the operating theater using the same anesthesia induction. Radiation exposure was lower in CBCT compared to MSCT scans, thus further encouraging the use of O-arms. Cone-beam CT imaging with an O-arm is a feasible method for postoperative craniosynostosis imaging, yielding less anesthesia to patients, lower health costs and the possibility to immediately evaluate results of the surgical operation.Peer reviewe