Blockchain Papers

Ludovic Desmedt

Bicoin, Cryto-monnaies

Chiara Frigerio, Federico Rajola

No abstract is available for this record.

Guillermo Zaera Vidal

The object of the present paper is to study the Bitcoin and its application as currency or investment, tandem that leads us to find out the main initiatives as far as legislation and customs related with this cryptocurrency, ie, know both theoretical and practical basis. The empirical application focuses on the behavior in the last years explained with certain relevant variables.

jwmars

No abstract is available for this record.

Andrei Alexandru Dinu

Five years after the introduction of the peer-to-peer payment system and digital currency bitcoin, cryptocurrencies have flourished and become a global phenomenon. Concerns regarding the impact of cryptocurrency on financial stability and the conduct of monetary policy have drawn regulatory scrutiny and formal policy stances on this emerging phenomenon. The main purpose of the present research is to determine whether cryptocurrencies are scarce and can, by this virtue, be regarded as money. Cryptocurrencies such as bitcoin and litecoin are programmed to have supply scarcity, however the fact that myriad digital coins can be created effortless by emulation raises the question of whether the total combined supply of this potential money is indeed scarce or not. The primary focus of the paper is to determine empirically if the two main cryptocurrencies, bitcoin and litecoin are actually perceived by the market as being different. In order to determine whether bitcoin and litecoin are perceived as similar or not by the market, I conduct an empirical analysis using daily closing price and trade volumes data from major exchanges Bitstamp and BTC-e. I calculate correlations on a monthly and weekly frequency to investigate price co-movement and its dynamics. Complementarity and substitutability for the entire sample and for 4 separate subsamples is formally analyzed through the calculation of direct price elasticities and of cross-price elasticities of volume. I show that in spite of negligible fundamental differences that would lead us to believe that the two cryptocoins are interchangeable and fungible to a great extent, the empirical landscape is more complex, with fair evidence in favor of substitutability, i.e. them being effectively perceived as different monies. The implication of this finding is that the supply scarcity of any individual coin is not placed under question by the potentially infinite aggregate supply of all cryptocurrencies. Cryptocurrencies can posses scarcity, and, other properties left aside, can be regarded as money.

Sebastian Pfeiffer

No abstract is available for this record.

Artur Dobosz

No abstract is available for this record.

Emil Dahlberg, Lillemor Holmberg

Många länder går mot ett samhälle där kontanter används till en mindre grad vilket har lett till en ökning av elektroniska betalningsmetoder. Utöver kortbetalningsmetoder har andra mer hög teknologiska betalningsmetoder vuxit fram. Bland dem är Bitcoin ett nytt system som vuxit sig relativt stor under de senaste åren. Bitcoin är både kritiserat och hyllat i olika medier. Utifrån de två väletablerade teorierna; Diffusion av innovation och Teknologi acceptans modellen avser studien att identifiera betydande faktorer i Svenska företags adaption av Bitcoin. Denna kvalitativa studie bygger på strukturerade telefon- och mailintervjuer i samband med samling av sekundärdata vilket tillsammans skapar empirins underlag. Studien består av åtta telefonintervjuer och tre mailsvar Studien är av deduktiv natur då den undersöker innovationen utifrån redan befintliga teorier. I användandet av teorin återfinns ingen undersökning av innovationen, istället har innovationer av närliggande karaktär studerats för stödjande av faktorernas vikt för adaptionen av innovationen. Resultaten visar att relativa fördela, kompatibilitet, svårighet att använda och uppfattad risk bör vara de främsta faktorerna. Utöver dessa faktorer finns bevis som pekar på att sociala influenser och tekniskt intresse även är viktiga för Bitcoins adaption.

Anuraj C.K

This paper introduce a dynamic audit service for integrity verification of untrusted and outsourced storages. Our audit service is constructed based on the techniques, fragment structure, random sampling, and index-hash table, supporting provable updates to outsourced data and timely anomaly detection. Constructed on interactive proof system (IPS) with the zero knowledge property, our audit service can provide public auditability without downloading raw data and protect privacy of the data. Also, our audit system can support dynamic data operations and timely anomaly detection with the help of several effective techniques, such as fragment structure, random sampling, and index-hash table (IHT). We also propose an efficient approach based on probabilistic query and periodic verification for improving the performance of audit services. A proof-ofconcept prototype is also implemented to evaluate the feasibility and viability of our proposed approaches. Our experimental results not only validate the effectiveness of our approaches, but also show that our system does not create any significant computation cost and require less extra storage for integrity verification.

Linda Spáčilová

The diploma work is concerned with the evaluation of issues in financing community budget. The work is divided into four chapters. The first chapter deals with a public administration, decentralization and fiscal decentralization. After the revolution in 1989 was performed the public administration reform in Slovakia, with a main target to create municipal governments and to transfer competences of a state administration to the municipal government. For that reason communities and towns started to economize with public finance on the basis of community budgets. Therefore the second chapter is aimed at financing of the community, following of budget’s process. This chapter deals with the municipal taxes because they are the main part of revenues of the community budget. The budget of the town Sv. Jur for 2014 with an outlook to the next two years is analysed in the third chapter. The following analysis deals with revenues and expenditures of particular years from closing accounts from 2009 to 2013. Issues in financing community budget are evaluated through of analysis of revenues and expenditures of budget in monitored period in the fourth chapter of the work.

Barbara Majovská

The purpose of my thesis is to analyse the tools and consequences of the fiscal federalism in Spain. Decentralization process has started along with democratization since passing new Constitution in 1978. It has been mainly reaction to cultural, historical and political reasons of creation of Autonomous Communities. Economic crisis stroke the Spanish economy very strongly and has been a challenge for the whole financing model. Thus, the main aim of my thesis is to deal with the recent development of the financing model. Since Spain is a member of the European Union, I describe also tools of the fiscal federalism put forward by the European Union. Spain is considered to be one of the most decentralized countries in Europe. In my thesis I want to prove that further decentralization has been confirmed by reforms responding to the economic crisis. Then, I want to show that used tools of fiscal federalism are profitable for both state and autonomous communities and positively affect economy of Spain and that they has helped to deal with economic crisis. Finally, I want to show that Spain is getting closer to federal arrangement of government. As has been proved, decentralization is still prevailing tendency in financing model of autonomous communities. But central government has been proposing...

Arizal Arizal

Abstrak PT.XYZ merupakan suatu cabang perusahaan dari salah satu perusahaan industri gas di indonesia. PT.XYZ bekerja sebagai distributor gas untuk daerah ,melayani penjualan untuk perindustrian, rumah sakit, maupun perorangan. Produk yang didistribusikan tersedia dalam tabung gas berbagai ukuran. Penerapan sistem informasi PT. XYZ saat ini masih dikatakan kurang. Semua proses pembukuan stok dan laporan keluar-masuknya barang masih dilakukan dengan menggunakan cara manual  dengan cara mencatat pada form di kertas dan kemudian di salin di buku besar. Sistem yang akan dibuat berupa pengolahan data-data yang berkaitan dengan bagian inventori seperti halnya master tabung gas yang menyimpan info detail setiap tabung gas yang berisi kode, jenis produk , ukuran dan juga status tabung tersebut. Selain itu sistem ini juga mempunyai form-form mutasi yang bersangkutan dengan order dan keluar masuknya barang. Sistem ini memiliki fasilitas untuk mencetak data-data, seperti form keluar, form kembali, form masuk form retur ,dan juga laporan-laporan yang dibutuhkan bagi perusahaan yaitu laporan berdasarkan periode tertentu dan juga stock opname. Laporan-laporan ini nantinya dapat digunakan untuk peningkatan kuantitas layanan maupun meminimalisasi kesalahan-kesalahan yang mampu merugikan perusahaan maupun pelanggan. Sistem informasi inventory control ini terdiri dari 3 bagian penting, yaitu pengelolaan data master, pengelolaan proses mutasi barang, dan pengelolaan laporan data. Kata Kunci: Sistem Informasi Inventory Control, Perusahaan Gas PT.XYZ. Abstract PT. XYZ constitutes a corporate branch of one of gas industrial enterprise at indonesian. PT. XYZ works as distributor of gas for region, servicing sell for about industry, hospital, and also individual. Product that is distributed is of service deep gasometer various measure .  PT's information system implement. XYZ is currently is still to be said less. All stock book keeping process and reporting goes in and out it goods be still by use of been done manual trick by notes on form at paper and then at saline at ledger. System who will be made as data processing that gets bearing with sectioned inventory as well as master gasometer that keep detail's info each gasometer which contains code, product type, measure and also that tube state. Besides this system also has pertinent mutation form form with order and goes in and out it goods. This system have facility to print datas, as form issue, form returns, form comes in form retur, and also reporting which are needed for firm which is reporting bases particular period and also hospitalization stock. This reporting its following can be utilized for increase amount services and also minimization is fault who can disadvantage firm and also customer. This inventory control's information system consisting of 3 a part essentials, which is master's data management, management processes goods mutation, and data reporting management. Keywords: Inventory Control’s Information System, PT. XYZ Gas Company.

Linda Marešová

This thesis discusses symmetric random walk, its definition and basic properties. The outset is focused on the probabilistic model and subsequently on basic properties, such as the final position at time n, its mean value and variance. Furthermore, we will see what the scaling must be for the walk to converge to zero, precisely what is the consequence of the strong law of large numbers. In the second chapter we will examine the distribution of the maximum of the symmetric random walk. In chapter 3 we will define stopping time and Markov property of random walks. Then we proof many auxiliary lemmas using basic knowledge of combinatorics. The final part is devoted to the proof of the arcsine distribution, which shows great persistence of the symmetric random walk. Powered by TCPDF (www.tcpdf.org)

Nicolás Della Penna, P M Krafft

We study herding behavior of traders in a cryptocurrency exchange

Alexander C. Standridge

No abstract is available for this record.

Gideon Samid

No abstract is available for this record.

Sergio Fogel

No abstract is available for this record.

G. Shams Ghahfarokhi

Risk and reliability analysis is presently being performed in almost all fields of engineering depending upon the specific field and its particular area. Probabilistic risk analysis (PRA), also called quantitative risk analysis (QRA) is a central feature of hydraulic engineering structural design. Actually, probabilistic methods, which consider resistance and load parameters as random variables, are more suitable than conventional deterministic methods to determine the safety level of a hydraulic structure. In fact, hydraulic variables involved in hydraulic structures, such as discharge, flow depth and velocity, are stochastic in nature, which maybe represented by relevant probability distributions. Therefore, the optimal design of hydraulic structures needs to be modelled by probabilistic methods. Reliability analysis methods are being adopted for use to develop risk management programs. Implementing the programs will ensure that safety is maintained to a robust and acceptable level. Any simple reliability analysis should include the following steps: The main work carried out relates to three different subjects in the general area of dam structures failure. These included the probabilistic methods work on: o Geometry of plunge pool downstream of flip bucket spillway o Evaluation of superelevation in open channel bends o Hydrodynamic loading on buildings by floods 1. Geometry of plunge pool downstream of flip bucket spillway Extreme scouring can gradually undermine the foundations of structures such as spillway and body dams and the areas downstream of dams. Extensive plunge pools downstream of flip bucket spillway structures, which are caused by jets of different configurations, form an important field of research. The plunge pool mechanism is more complex because of difficulties arising from the modelling of bed rock and sediment load flow in and around the scour hole caused by the jet effect of the flow downstream of flip bucket spillway. The experimental study of plunge pool has been limited to the consideration of variables involved in the plunge pool geometry. The reliability-based assessment of the geometry of the plunge pool downstream of a flip bucket spillway. Experimental data obtained from a model of a flip bucket spillway has been used to develop a number of equations for the prediction of scour geometry downstream from a flip bucket spillway of a large dam structure. The accuracy of the developed equations was examined both through statistical and experimental procedures with satisfactory results. 2. Evaluation of superelevation in open channel bends The so-called centrifugal force caused by flow around a curve results in a rise in the water surface at the outside wall and a depression of the surface along the inside wall. This phenomenon is called superelevation. The problems associated with flow through open channel bends deserve special attention in hydraulic engineering. Water surface slopes have been frequently reported to be a function of the curvature. But due to the difficulties in operation, the theoretical basis of superelevation has been discussed in depth in the literature. Furthermore, experience indicates that existing theory does not lead to good results at the present status. Superelevation in the Ziaran Flume (Iran) has led to severe erosion of the bank and has undermined the structure. Therefore, this study aims to cast light on the cause of overtopping by superelevation. By means of direct observation on the flume’s hydraulic performance, during full discharge, and from generalization of the field data, a more reliable prediction method of the magnitude of superelevation has become possible. The probabilistic analysis is shown to have several advantages in comparison with deterministic analysis methods. 3. Hydrodynamic loadings on buildings by floods Assessing the vulnerability of buildings in flood-prone areas is a key issue when evaluating the risk induced by flood events, particularly because of its proved direct influence on the loss of life during catastrophes. Hydrodynamic loads are caused by water flowing along, against and around a structural element or system. Hydrodynamic loads are basically of the lateral type and are related to direct impulsive loads by the moving mass of water, and to drag forces as the water flows around the obstruction. Where application of hydrodynamic loads is required, the loads shall be calculated or estimated by recognized engineering and reliable methods. A comprehensive methodology for risk assessment of buildings subjected to flooding is nevertheless still missing. A new set of experiments has been performed in this thesis with the aim of shedding more light on dynamics of flood induced loads and their effects on buildings with state of the art benchmarks. In this research, an overview is given of flood induced load on buildings, the new experimental work is then presented, together with results from preliminary analysis. Initial results suggest that use of existing prediction methods might be unsafe and that impulsive loading might be critical for both the assessment of the vulnerability of existing structures and the design of new flood-proof buildings. The research presented in this thesis is focused on developing and applying probabilistic design, safety, system reliability and risk based design in the field of hydraulic structures design in the open channel bends, plunge pool downstream of flip bucket spillway and dam break analysis. Probabilistic design approach is a powerful tool in reliability assessment of civil hydraulic engineering. Uncertainty and risk are central features of hydraulic engineering. Hydraulic design is subject to uncertainties due to the randomness of natural phenomena, data sample limitations and errors, modelling reliability and operational variability. Uncertainties can be measured in terms of the probability density function, confidence interval, or statistical moment such as standard deviation or coefficient of variation of the stochastic parameters. Outcomes from this thesis are beneficial to the design of hydraulic structures in many ways; not only minimizing cost, but also educating and providing valuable knowledge for structural operators. Probabilistic methods and reliability analysis can increase the quality and value of the achievements compared to traditional dam engineering approaches. Since the goal is to avoid the dam failures by reducing risk to almost zero with optimum cost, dam safety risk analysis has a key role in modern dam safety programs. It is hoped that illustrations provided in this thesis are applicable to other civil engineering structures of similar concerns.

Sebastian Faust, Pratyay Mukherjee, Jesper Buus Nielsen, Daniele Venturi

Non-malleable codes are a natural relaxation of error correcting/detecting codes that have useful applications in the context of tamper resilient cryptography. Informally, a code is non-malleable if an adversary trying to tamper with an encoding of a given message can only leave it unchanged or modify it to the encoding of a completely unrelated value. This paper introduces an extension of the standard non-malleability security notion ‐ so-called continuous non-malleability ‐ where we allow the adversary to tamper continuously with an encoding. This is in contrast to the standard notion of non-malleable codes where the adversary only is allowed to tamper a single time with an encoding. We show how to construct continuous non-malleable codes in the common split-state model where an encoding consist of two parts and the tampering can be arbitrary but has to be independent with both parts. Our main contributions are outlined below: 1. We propose a new uniqueness requirement of split-state codes which states that it is computationally hard to find two codewords C = (X0;X1) and C 0 = (X0;X 0 1 ) such that both codwords are valid, butX0 is the same in bothC andC 0 . A simple attack shows that uniqueness is necessary to achieve continuous non-malleability in the split-state model. Moreover, we illustrate that non of the existing constructions satisfies our uniqueness property and hence is not secure in the continuous setting. 2. We construct a split-state code satisfying continuous non-malleability. Our scheme is based on the inner product function, collision-resistant hashing and non-interactive zero-knowledge proofs of knowledge and requires an untamperable common reference string. 3. We apply continuous non-malleable codes to protect arbitrary cryptographic primitives against tampering attacks. Previous applications of non-malleable codes in this setting required to perfectly erase the entire memory after each execution and and required the adversary to be restricted in memory. We show that continuous non-malleable codes avoid these restrictions.

Joan Marí Yern, Jordi Herrera‐Joancomartí

El bitcoin es una moneda virtual descentralitzada que es basa en la criptografia per al seu correcte funcionament. S'utilitza la criptografia en diversos processos de la moneda: creacio de comptes, validacio de transaccions, generacio de moneda, etc. La mineria es el proces mitjancant el qual les transaccions son validades i a la vegada tambe es el proces amb el qual es genera nova moneda. Aquest projecte esta centrat en l'analisi d'aquest proces.

David Christopher Vitt

I explore a popular Bitcoin futures market and make empirical observations on the divergence between standard futures model and the observed futures prices by backing out what the implied risk-free rate of return would be if the standard assumptions held for this exchange. Intended as a blog post.

Chris LeRoux

In On the Origins of Money (1892), Carl Menger explains that in a barter situation, some commodities are more commonly demanded than others, are more saleable. In order to overcome the double coincidence of wants, people naturally begin trading their goods first for a more saleable good in order to then trade for their final objective. Menger (1892) describes it thus, «Men have been led, with increasing knowledge of their individual interests, each by his own economic interests, without convention, without legal compulsion, nay, even without any regard to the common interest, to exchange goods destined for exchange (their “wares”) for other goods equally destined for exchange, but more saleable.» Lud-wig von Mises restated the same insight in Human Action (1940), «[Money] is the most marketable good which people acquire be-cause they want to offer it in later acts of interpersonal exchange. Money is the thing which serves as the generally accepted and commonly used medium of exchange.»
 As ever more people discovered the advantages of using a more saleable good in indirect exchange, one commodity became increasingly adopted until it eventually became money, the most marketable of all goods, the good that can generally be traded for all other goods within the market. As Menger said (1892), «And so it has come to pass, that as man became increasingly conversant with these economic advantages… those commodities, which relatively to both space and time are most saleable, have in every market become the wares, which it is not only in the interest of every one to accept in exchange for his own less saleable goods, but which also are those he actually does readily accept.»

Niels Samwel

No abstract is available for this record.

Olof Vestling

I dagens samhälle används en mängd metoder och verktyg för att nå kunder och eftersom konkurrensen är knivskarp är det extra viktigt att skapa personliga relationer till sina kunder. Syftet med denna uppsats är att studera bitcoin, en virtuell valuta, som ett verktyg för att skapa, underhålla och fördjupa dessa relationer. Bitcoin accepteras idag som betalningsmedel av en mängd olika företag och det är därför intressant att undersöka varför de gör detta. Genom att utföra en enkätstudie och intervjuer kan det konstateras att användningen av bitcoin bland företag har ökat stadigt det senaste halvåret. Det visar sig också att företagen använder sig av bitcoin som marknadsföringsverktyg på två olika sätt; dels som ett betalningsalternativ inom traditionell butikshandel men också som en belöning inom ett lojalitetsprogram. Det kan konstateras att företagen använt bitcoin som ett verktyg för att komma i kontakt med nya kunder och för att utmärka sig inom sin bransch. Dock använder företagen inte bitcoin som ett verktyg för att bygga långvariga relationer. Därför är slutsatsen att bitcoin inte används på ett relationsmarknadsföringsmässigt sätt och således inte heller leder till några förstärkta kundrelationer.