100 research outputs found
Modular reinforcement learning : a case study in a robot domain
The behaviour of reinforcement learning (RL) algorithms is best understood in completely observable, finite state- and action-space, discrete-time controlled Markov-chains. Robot-learning domains, on the other hand, are inherently infinite both in time and space, and moreover they are only partially observable. In this article we suggest a systematic design method whose motivation comes from the desire to transform the task-to-be-solved into a finite-state, discrete-time, "approximately" Markovian task, which is completely observable, too. The key idea is to break up the problem into subtasks and design controllers for each of the subtasks. Then operating conditions are attached to the controllers (together the controllers and their operating conditions which are called modules) and possible additional features are designed to facilitate observability. A new discrete time-counter is introduced at the "module-level" that clicks only when a change in the value of one of the features is observed. The approach was tried out on a real-life robot. Several RL algorithms were compared and it was found that a model-based approach worked best. The learnt switching strategy performed equally well as a handcrafted version. Moreover, the learnt strategy seemed to exploit certain properties of the environment which could not have been seen in advance, which predicted the promising possibility that a learnt controller might overperform a handcrafted switching strategy in the future
Az AlaptörvĂ©ny Ă©s az alkotmánybĂrĂłsági gyakorlat megjelenĂ©se a rendes bĂrĂłságok gyakorlatában – 2012–2016
Az AlaptörvĂ©ny Ă©s az alkotmánybĂrĂłsági gyakorlat megjelenĂ©se a rendes bĂrĂłságok gyakorlatában, 2012-2016
BezĂĽge auf das Grundgesetz und die Rechtsprechung des Verfassungsgerichts in der Praxis der ordentlichen Gerichte, 2012-2016
Resolution of ibuprofen with primary amine carbamates in supercritical carbon dioxide
Three new, successful resolving agents, namely (S)-2-phenylglycinol, (R)-1-phenylethanaminium (R)-(1-phenylethyl) carbamate and (S)-2-hydroxy-1-phenylethanaminium (S)-(2-hydroxy-1-phenylethyl) carbamate of ibuprofen are presented. The carbamate salts are stable white crystals, they can be easily stored and handled. All salt forming resolution were performed in supercritical carbon dioxide as the only solvent. The enantioseparations were efficient (approx. 50 % enantiomeric purities, > 90 % yields in the crystalline phase) and robust. Unlike previous experiences with primary amine resolving agents, the diastereomeric salt formations and resolutions were competed in short times, even within one hour suggesting that the carbamates are intermediates of the salt formation reaction
Az MBL-hez kapcsolódó szerin proteázok szubsztrát specificitása és fiziológiai jelentősége = Substrate specificity and physiological relevance of MBL-associated serine proteases
A komplement rendszer aktiválĂłdásának lektin Ăştja az egyik elsĹ‘ vĂ©delmi vonalnak tekinthetĹ‘ a szervezet fertĹ‘zĂ©sek elleni vĂ©dekezĂ©sĂ©ben. A mannĂłz kötĹ‘ lektin (MBL) baktĂ©rium felszĂnhez valĂł kötĹ‘dĂ©se után szerin proteáz zimogĂ©nek (MASP= MBL-kötött szerin proteáz) aktiválĂłdnak, melyek többfĂ©le mechanizmus rĂ©vĂ©n járulnak hozzá az idegen mikroorganizmus megsemmisĂtĂ©sĂ©hez ill. eltávolĂtásához. Munkánk során felderĂtettĂĽk, a proteolitikus kaszkádrendszer beindĂtásáért felelĹ‘s MASP-2 enzim autoaktiválĂłdásásnak mechanizmusát atomi szinten. FelfedeztĂĽk a MASP-2 egy eddig ismeretlen biolĂłgiai funkciĂłját, amely kapcsolatot teremt a vĂ©ralvadási Ă©s a komplement kaszkád között. A MASP-2 hasĂtja Ă©s aktiválja a protrombint. Ugyancsak rĂ©szletesen tanulmányoztuk a MASP-1 trombin-szerű aktivitását is. Ezek az eredmĂ©nyek arra utalnak, hogy a vĂ©rben lĂ©vĹ‘ kĂ©t proteolitikus kaszkádrendszer szoros evolĂşciĂłs Ă©s funkcionális kapcsolatban van egymással, a komplement lektin Ăştja által indukált limitált koaguláciĂł az immunvĂ©dekezĂ©s egy Ĺ‘si formájának tekinthetĹ‘. | The lectin pathway of the complement system forms one of the first defence lines against the infections in our body. Upon MBL (mannose-binding lectin) binds to the bacterial surface serine protease zymogens (MASP=MBL-associated serine protease) become activated, and the active MASPs contribute to the inactivation and elimination of the foreign microorganism in several ways. In the course of our work we revealed the detailed atomic mechanism of the autoactivation of MASP-2 that is responsible for the initiation of the complement cascade. We discovered a new biological function of MASP-2 which makes contact between the complement and the coagulation cascades. MASP-2 cleaves and activates prothrombin. We also studied the thrombin-like activity of MASP-1 in detail. These results suggest that the two proteolytic cascade systems are in close evolutionary and functional relationship. The limited coagulation induced by the lectin pathway of the complement system can be regarded as an ancient form of immunity
Könyvszemle
Buda BĂ©la: A lĂ©lek egĂ©szsĂ©ge. A mentálhigiĂ©nĂ© alapkĂ©rdĂ©sei; PikĂł Bettina: KultĂşra, társadalom Ă©s lĂ©lektan; Gyöngyösi Zoltán: Az Ă©let Ă©s test feletti rendelkezĂ©sek joga; Desmond Morris: BensĹ‘sĂ©ges kötelĂ©kek; Em Griffin: EgyĂĽtt-lĂ©t. MitĹ‘l jĂł egy csoport?; David Lewis: Hogyan Ă©rtessĂĽk meg magunkat? A hatĂ©kony kommunikáciĂł gyakorlati ĂştmutatĂłja; Horányi Ă–zsĂ©b (szerk.): A sokarcĂş kĂ©p. Válogatott tanulmányok a kĂ©pek logikájárĂłl; NyĂri KristĂłf - Kovács Gábor (szerk.): Virtuális egyetem Magyarországon
- …