Comparative Study of Anti-cheat Methods in Video Games

Online gaming is more popular than ever and many video game companies are reliant on the cash flow generated by online games. If a video game company wants its game to be successful, the game has to be resilient against cheating, the presence of which can ruin an otherwise successful game. Cheating in a video game can bankrupt an entire company as the non-cheating players leave the game because of unscrupulous individuals using cheats to gain an unfair advantage. Cheating can also involve criminal activity where maliciously acquired in-game items are traded against real money online. Commercial cheat programs are sold on online black markets and are available even to players who have no deep technical knowledge. The widespread availability and easy accessibility of cheats compounds the issue. This thesis will categorize different anti-cheat techniques and give a brief history of anti-cheat starting from the early 1980s. The history section describes how the fight against online cheating began and how it has evolved over the years. This thesis will compare different anti-cheat methods, both on the client-side and server-side, and draw conclusions about their viability. It will also look at scenarios where different anti-cheat methods are combined to create more powerful systems. All the anti-cheat methods will be evaluated based on five different criteria on a scale of 1 to 4, with one being the lowest score and four the highest. The thesis will use a custom-built client-server game as an example to illustrate many of the anti-cheat techniques. Requirements of different types of games, such as first-person shooters and strategy games, will also be considered when reviewing the anti-cheat techniques. Lastly, the thesis will look into the future of anti-cheat and introduce video game streaming and the use of machine learning as possible new solutions to tackle cheating. The conclusion will summarize the advantages and disadvantages of different methods and show which techniques are preferable based on the analysis

Phenotypic characters of static homology increase phylogenetic stability under direct optimization of otherwise dynamic homology characters

Direct optimization of unaligned sequence characters provides a natural framework to explore the sensitivity of phylogenetic hypotheses to variation in analytical parameters. Phenotypic data, when combined into such analyses, are typically analyzed with static homology correspondences unlike the dynamic homology sequence data. Static homology characters may be expected to constrain the direct optimization and thus, potentially increase the similarity of phylogenetic hypotheses under different cost sets. However, whether a total-evidence approach increases the phylogenetic stability or not remains empirically largely unexplored. Here, I studied the impact of static homology data on sensitivity using six empirical data sets composed of several molecular markers and phenotypic data. The inclusion of static homology phenotypic data increased the average stability of phylogenetic hypothesis in five out of the six data sets. To investigate if any static homology characters would have similar effect, the analyses were repeated with randomized phenotypic data, and with one of the molecular markers fixed as static homology characters. These analyses had, on average, almost no effect on the phylogenetic stability, although the randomized phenotypic data sometimes resulted in even higher stability than empirical phenotypic data. The impact was related to the strength of the phylogenetic signal in the phenotypic data: higher average jackknife support of the phenotypic tree correlated with stronger stabilizing effect in the total-evidence analysis. Phenotypic data with a strong signal made the total-evidence trees topologically more similar to the phenotypic trees, thus, they constrained the dynamic homology correspondences of the sequence data. Characters that increase phylogenetic stability are particularly valuable for phylogenetic inference. These results indicate an important role and additive value of phenotypic data in increasing the stability of phylogenetic hypotheses in total-evidence analyses

The complete plastid genome sequence of Trichomanes trollii (Hymenophyllaceae)

Plastid genomes have become an important source of information for clarifying phylogenetic relationships especially where traditional molecular systematic studies have failed to produce strongly supported hypotheses. The exact phylogenetic position of an early diverging fern order Hymenophyllales has remained uncertain due to poor support in published phylogenetic studies. High-throughput sequencing of the first complete plastid genome of the genus Trichomanesrevealed genome structure similar to the closest relatives and the phylogenetic analysis resulted in equally poorly supported topology as the previous studies that were based on only a few molecular markers. It seems that, at least with the current poor taxonomic sampling of complete plastid genomes, the exact relationships between Hymenophyllales, Gleicheniales, and other nonosmundalean leptosporangiate ferns cannot be firmly established. </p

EXTREFLOOD – tulvariskien hallinta yhdyskuntasuunnittelussa

Tutkimuksessa tarkasteltiin yhdyskuntasuunnittelun ja tulvariskien hallinnan välisiä yhteyksiä kunnissa. Tutkimuksen tavoitteena oli kartoittaa tähän liittyviä mahdollisuuksia, asenteita, ohjauskeinoja ja toimintatapoja sekä tarkastella tulvakysymyksiin liittyvää toimijoiden välistä yhteistyötä ja mahdollisia ristiriitoja. Tutkimusaineisto koottiin sähköpostikyselyllä, joka suunnattiin suurtulvatyöryhmän (2003) nimeämiin, merkittävimmillä tulvavahinkoalueilla sijaitseviin kuntiin. Kyselyaineistoa täydensivät ryhmähaastattelut. Tutkimuksen tuloksena voidaan todeta, että tulvariskien huomioiminen yhdyskuntasuunnittelussa jää kauaksi suurtulvatyöryhmän esittämästä tasosta. Tulvariskiä lisäävät kuntien rakentamispaineet sekä ranta-rakentamisen suuri suosio. Tulvariskien huomioimista vaikeuttavat lisäksi maankäytön suunnitteluun liittyvät ristiriidat. Tiedon taso tulvariskeistä vaihtelee kunnissa. Tietoa harvinaisista (HW 1/100) tulvatilanteista on kunnissa hyvin vähän. Ilmastonmuutoksen uhka otetaan todesta, mutta se ei ole vielä vaikuttanut tulvariskien uudelleenarviointiin. Tulvat huomioidaan paremmin asemakaavoituksessa kuin yleispiirteisissä kaavoissa. Ongelmana on, että koko vesistöalueen kattava tulvasuojelu vaatii kuntarajat ylittävää yhteistyötä. Maakuntakaavassa tulvariskien huomioiminen on kaikkein heikointa. Kaiken kaikkiaan kuntien valmiudet vaihtelevat, mikä korostaa alueellisten ympäristö-keskusten roolia tulvariskien hallinnassa. Alueellisten ympäristö-keskuksia pidetään kunnissa keskeisinä yhteistyökumppaneina tulvariskien hallinnassa ja yhteistyö ympäristökeskusten kanssa koetaan toimivaksi. Raportti on osa EXTREFLOOD –hanketta (EXTREFLOOD: Tulvavahinkojen ennaltaehkäisy – suurtulvien mallinnus, tulvaskenaariot ja tulvatiedon interaktiivinen välittäminen), jota ovat rahoittaneet maa- ja metsätalousministeriö ja ympäristöministeriön ympäristöklusterin tutkimusohjelma vuosina 2003-2005. Raportin loppuun on koottu aiheeseen liittyviä jatkotutkimustarpeita

Actualización del conocimiento de los géneros Echinodorus y Helanthium (Alismataceae) en Venezuela

  Se actualiza la información taxonómica de las especies venezolanas del género Echinodorus sensu lato. Basados en análisis moleculares recientes, el género Echinodorus es dividido en Echinodorus y Helanthium. Dos especies de Helanthium, y diez especies de Echinodorus son reconocidas para Venezuela. En este trabajo se reporta por primera vez la presencia de E. berteroi y E. longipetalus en la flora nativa de Venezuela. Varias especies fueron descritas a partir de una o unas pocas colecciones, dado que la flora acuática de Venezuela aún está pobremente documentada.</p

Tipificaciones y sinónimos nuevos en Echinodorus Engelm. y Sagittaria L. (Alismataceae) de la Flora del Paraguay

AbstractLehtonen, S. & L. Ramella (2017). Typifications and new synonyms in Echinodorus Engelm. and Sagittaria L. (Alismataceae) of the Flora of Paraguay. Candollea 72: 405–407. In Spanish, English and Spanish abstracts. DOI: http://dx.doi.org/10.15553/c2017v722a17The lectotype specimen of Echinodorus longipetalus Micheli is designated acording to the rules, correcting a prior but erroneous lectotypification. Four infraspecific names in Sagittaria L. are formally treated as synonyms, remaining one dubious name. Sagittaria montevidensis f. flaviflora Chodat is lectotypified.ResumenLehtonen, S. & L. Ramella (2017). Tipificaciones y sinónimos nuevos en Echinodorus Engelm. y Sagittaria L. (Alismataceae) de la Flora del Paraguay. Candollea 72: 405–407. En español, resúmenes en inglés y español. DOI: http://dx.doi.org/10.15553/c2017v722a17El lectótipo de Echinodorus longipetalus Micheli está designado aquí de acuerdo a las reglas, rectificando una lectotipificación previa errónea. Se publica formalmente la sinonimia de cuatro nombres infraespecíficos en Sagittaria L., quedando un solo nombre dudoso. Se efectúa la lectotipificación del nombre Sagittaria montevidensis f. flaviflora Chodat.<br /

Actualización del conocimiento de los géneros Echinodorus y Helanthium (Alismataceae) en Venezuela

RESUMENSe actualiza la informaci&oacute;n taxon&oacute;mica de las especies venezolanas del g&eacute;nero Echinodorussensu lato. Basados en an&aacute;lisis moleculares recientes, el g&eacute;nero Echinodorus esdividido en Echinodorus y Helanthium. Dos especies de Helanthium, y diez especies deEchinodorus son reconocidas para Venezuela. En este trabajo se reporta por primera vez lapresencia de E. berteroi y E. longipetalus en la flora nativa de Venezuela. Varias especiesfueron descritas a partir de una o unas pocas colecciones, dado que la flora acu&aacute;tica de Venezuelaa&uacute;n est&aacute; pobremente documentada.ABSTRACTThe taxonomical information of the Venezuelan species of genus Echinodorus sensulato is updated. Based on molecular systematic studies, the genus is now divided in Echinodorusand Helanthium. Two Helanthium species, and ten species of Echinodorus are recognizedin Venezuela. The presence of E. berteroi and E. longipetalus in the native floraof Venezuela is reported for the first time. Several species are still known from one or a fewcollections due to the aquatic flora of Venezuela remains poorly documented