Scavenging quantum information: Multiple observations of quantum systems

Given an unknown state of a qudit that has already been measured optimally, can one still extract any information about the original unknown state? Clearly, after a maximally informative measurement, the state of the system `collapses' into a post-measurement state from which the {\em{same}} observer cannot obtain further information about the original state of the system. However, the system still encodes a significant amount of information about the original preparation for a second observer who is unaware of the actions of the first one. We study how a series of independent observers can obtain, or scavenge, information about the unknown state of a system (quantified by the fidelity) when they sequentially measure it. We give closed-form expressions for the estimation fidelity, when one or several qudits are available to carry information about the single-qudit state, and study the `classical' limit when an arbitrarily large number of observers can obtain (nearly) complete information on the system. In addition to the case where all observers perform most informative measurements we study the scenario where a finite number of observers estimate the state with equal fidelity,regardless of their position in the measurement sequence; and the scenario where all observers use identical measurement apparata (up to a mutually unknown orientation) chosen so that a particular observer's estimation fidelity is maximized.Comment: 17 pages, 1 figur

Direct versus measurement assisted bipartite entanglement in multi-qubit systems and their dynamical generation in spin systems

We consider multi-qubit systems and relate quantitatively the problems of generating cluster states with high value of concurrence of assistance, and that of generating states with maximal bipartite entanglement. We prove an upper bound for the concurrence of assistance. We consider dynamics of spin-1/2 systems that model qubits, with different couplings and possible presence of magnetic field to investigate the appearance of the discussed entanglement properties. We find that states with maximal bipartite entanglement can be generated by an XY Hamiltonian, and their generation can be controlled by the initial state of one of the spins. The same Hamiltonian is capable of creating states with high concurrence of assistance with suitably chosen initial state. We show that the production of graph states using the Ising Hamiltonian is controllable via a single-qubit rotation of one spin-1/2 subsystem in the initial multi-qubit state. We shown that the property of Ising dynamics to convert a product state basis into a special maximally entangled basis is temporally enhanced by the application of a suitable magnetic field. Similar basis transformations are found to be feasible in the case of isotropic XY couplings with magnetic field.Comment: (14 pages, 7 figures, RevTeX4

Determining human plasma glycoproteins

Glikozilacija je skup čestih i složenih kotranslacijskih/postranslacijskih kovalentih modifikacija lipida i proteina. One su od velike važnosti jer utječu na funkciju i strukturu takvih kompleksnih molekula. Istraživanja kompleksnih molekula su vrlo zahtjevna i često koriste kombinacije metoda. Jedna od važnih grupa metoda koje se koriste u takvim istraživanjima su bioinformatičke metode. One se uglavnom fokusiraju na analizu podataka i simulacije. Kako raste broj radova na tu temu, raste i količina podataka koje bioinformatički alati trebaju koristiti te je nužno razvijati nove alate koji će omogućiti lakše i brže istraživanje složenih mo lekula. Ovaj diplomski rad je pokušaj razvijanja takvog alata koji olakšava pretraživanje glikoproteoma UniProt baze podataka. Razvijeni alat je testiran na 592 anotirana glikoproteina humane plazme. Računalnom analizom tih glikoproteina utvrđeno je da su oni većinom manji od 1000 aminokiselina i mase obično ispod 100 kDa. Također je utvrđeno da su njihove proteinske strukture hidrofilne i da je najčešći tip glikozilacije zabilježenih proteina humane plazme Nglikozilacija. Analiza je provedena i na peptidima proteina nastalih računalnom tripsinskom razgradnjom proteina. Tom analizom je utvrđeno da je većina takvih peptida neglikozilirana, većinom manje mase od 10 kDa, odnosno duljine 100 aminokiselina te da su manje hidrofilni od izvornih glikoproteina od kojih potječu.Glycosylation is a collection of complex cotranslational/posttranslational covalent modifications of lipids and proteins. These modifications are of great importance as they affect the function and structure of such complex molecules. Researching complex molecules is very demanding and often requires combination of different types of methods. One such group includes bioinformatic methods whose main goals are data analysis and simulations. As the number of research papers grows, the amount of data on these molecules grows as well which consequently requires better and faster tools for data analysis. This Master’s thesis was an attempt of developing such a tool to improve the ones already available for UniProt database. The developed tool was tested on a set of 592 annotated human plasma glycoproteins. Computer analysis of the aforementioned set yielded the insight that most of these proteins were smaller than 1000 amino acids with masses under 100 kDa. It has also showed that most of these glycoprotein structures are hydrophilic in nature and that by far the most common type of glycosylation is the N-glycosylation. Analysis of peptides acquried by computer trypsine digestion was conducted as well. It showed that most of such peptides are much smaller than their glycoprotein counterparts, mostly ranging in size under 10 kDa or 100 amino acids in length and are less hydrophilic than full glycoproteomic structures

Empirical examination of Hamilton's kin selection theory

Tema ovog rada bila je empirijska provjera Hamiltonove teorije srodničkog altruizma. U toj teoriji, nazivanom još i teorijom ukupne reproduktivne uspješnosti, govori se o tome da su pojedinci skloniji više pomagati srodnicima, nego nesrodnicima te da su skloniji više pomagati genetski bližim nego genetski daljim srodnicima. Kroz različita istraživanja, kao što su istraživanja na nekim životinjskim vrstama ili kao što je istraživanje ponašanja ljudi u kriznoj i po život opasnoj situaciji, testirani su različiti aspekti altruizma te različiti faktori koji bi mogli utjecati na iskazivanje ili neiskazivanje altruizma prema drugoj osobi koja je genetski povezana sa osobom koja tu pomoć pruža. Neki od tih faktora bili su spol pomagača, reproduktivna vrijednost primatelja pomoći, stupanj genetske povezanosti pomagača i primatelja pomoći. Sva promatrana istraživanja, iako su koristila različite metode (ankete, upitnici, eksperimenti), služila su kao nalazi u prilog Hamiltonove teorije. Njegova teorija je, nakon što je empirijski provjerena, pružila uvid u još jednu sferu ljudskog ponašanja koje ne samo da je zbunjivalo znanstvenike, nego i ljude općenito. Svako od tih istraživanja jedinstveno je po svojoj ideji pristupa testiranju teorije srodničkog altruizma te je svako od tih istraživanja otvorilo novi put u provjeravanju ne samo ove teorije, nego i sličnih drugih teorija postavljenih u okvirima evolucijske psihologije

Recycling of quantum information: Multiple observations of quantum systems

Given a finite number of copies of an unknown qubit state that have already been measured optimally, can one still extract any information about the original unknown state? We give a positive answer to this question and quantify the information obtainable by a given observer as a function of the number of copies in the ensemble, and of the number of independent observers that, one after the other, have independently measured the same ensemble of qubits before him. The optimality of the protocol is proven and extensions to other states and encodings are also studied. According to the general lore, the state after a measurement has no information about the state before the measurement. Our results manifestly show that this statement has to be taken with a grain of salt, specially in situations where the quantum states encode confidential information.Comment: 4 page

Magazine and tool changer of a milling multi-purpose machining center with a horizontal spindle axis

Práca sa zoberá automatickou výmenou nástrojov u frézovacieho multifunkčného obrábacieho centra s vodorovnou osou vretena. Je zameraná najmä na systémy, ktoré sa v súčasnosti používajú a na ich základné delenie. Prvá časť práce je spoločná. V tejto časti práce je opísaný návrh stroja s jeho hlavnými parametrami. Druhá časť práce je samostatná, zoberá sa návrhom výmenníka a zásobníka nástrojov spolu s ich konštrukčným riešením.The thesis deals with automatic tool change in milling multifunctional machining center with horizontal spindle axis. It describes the systems that are currently in use and their base division. The first part of the work is common. In this part of the thesis is a machine design with its parameters. The second part is independent, deals with the design of the exchanger and tool magazine together with their design solution.

Control of three-axis manipulator

Práca sa zaoberá riadením a presným polohovaním dopravníka v 3D priestore. Pre riadenie, polohovania bolo využité hardwarové a softvérové vybavenie od spoločnosti Bernecker&Reiner. Medzi ciele práce patrilo aj oboznámenie sa z programovacím prostredím AUTOMATION STUDIO, v ktorom prebiehala celá práca.This thesis deal swith controlling and precision positioning of conveyor in 3D space. Equipment for controling of positioning is made by Bernecker&Reinercompany. Important objective of work is also familiarization with programing environment AUTOMATION STUDIO, which powers whole operation.

A Comparison of Precise Fertilization Prescription Rates to a Conventional Approach Based on the Open Source GIS Software

Fertilization is one of the most important components of precision agriculture, ensuring high and stable crop yields. The process of spatial interpolation of soil sample data is recognized as a reliable method of determining the prescription rates for precise fertilization. However, the application of a free open-source geographic information system (GIS) software was often overlooked in the process. In this study, a method of precise fertilization prescription map creation was developed using an open-source GIS software to enable a wider and cheaper availability of its application. The study area covered three independent locations in Osijek-Baranja County. A method was developed for the fertilization of sugar beet with phosphorous pentoxide, but its application is universal with regard to the crop type. An ordinary kriging was determined as an optimal interpolation method for spatial interpolation, with the mean RMSE of 1.8754 and R2of 0.6955. By comparing the precision fertilization prescription rates to a conventional approach, the differences of 4.1 kg ha-1 for Location 1, 15.8 kg ha-1 for Location 2, and 11.2 kg ha-1 for Location 3 were observed. These values indicate a general deficit in soil phosphorous pentoxide, and precise fertilization could ensure its optimal content in the future sowing seasons

Utjecaj koncentracije digestata prilikom uzgoja na kvalitetu bioplina dobivenoga anaerobnom digestacijom vodene leće (Spirodela polyrhiza)

Duckweed is a widespread type of tiny free-floating plants of the flowering class. A typical representative of the family of the cowhide (Lemnaceae) is a large duckweed (Spirodela polyrhiza) and it is very common on Croatian inland waters. Like all other species of duckweeds, it is characterized by the possibility of vegetative and sexual reproduction and very rapid growth. It has the ability to remove nitrogen, phosphorus and some heavy metals from the substrate and is considered a very desirable raw material for biogas production for several reasons. The necessity of reducing environmental pollution of nitrates from agricultural production and the ability to grow water lenses under eutrophic conditions have sparked this research. The primary objective of the study is to determine the possibilities of continuously growing large duckweed at different concentrations of digestates for the purpose of biogas production. The secondary goal is to determine the dependence between the different digestate concentrations used for the duckweed green mass production and the quantity and quality of the biogas obtained through the anaerobic digestion process at thermophilic conditions.Vodena leća je široko rasprostranjena vrsta sitnih slobodno plivajućih biljaka iz razreda cvjetnica. Tipičan predstavnik porodice kozlačevki (Lemnaceae) je velika vodena leća (Spirodela polyrhiza) i vrlo je česta na vodenim površinama kontinentalne Hrvatske. Kao i sve ostale vrste vodenih leća, karakterizira ju mogućnost vegetativnoga i spolnog razmnožavanja te vrlo brz rast. Smatra se vrlo poželjnom sirovinom za proizvodnju bioplina iz nekoliko razloga. Nužnost smanjenja zagađenja okoliša nitratima iz poljoprivredne proizvodnje te sposobnost rasta vodenih leća u eutrofnim uvjetima potaknuli su ovo istraživanje. Primarni cilj istraživanja jest utvrditi mogućnosti kontinuiranoga uzgoja velike vodene leće na različitim koncentracijama digestata, sa ciljem proizvodnje bioplina. Sekundarni je cilj utvrditi zavisnost između različitih koncentracija digestata korištenih za proizvodnju zelene mase vodene leće te kvantitete i kvalitete bioplina dobivenog postupkom anaerobne digestije pri termofilnim uvjetima