Cryptocurrencies are a type of digital currencies that are relying on cryptographic proofs for confirmation of transactions. Cryptocurrencies usually achieve a unique combination of three features: ensuring limited anonymity, independence from central authority and double spending attack protection. No other group of currencies, including fiat currencies, has this combination of features. We will define cryptocurrency ownership and account anonymity. We will define cryptocurrency ownership and account anonymity. We will introduce a classification of the types of approaches to regulation of cryptocurrencies by various individual countries. We will present the risks that the use of cryptocurrencies involves and the possibilities of prevention of those risks. We will present the possible use of cryptocurrencies for the benefit of the state. The conclusion addresses the implications of adoption of a cryptocurrency as a national currency.

Possible State Approaches to Cryptocurrencies

Cryptocurrencies are currently traded worldwide, with hundreds of different currencies in existence and even more on the way. This study implements some statistical and machine learning approaches for cryptocurrency investments. First, we implement GJR-GARCH over the GARCH model to estimate the volatility of ten popular cryptocurrencies based on market capitalization: Bitcoin, Bitcoin Cash, Bitcoin SV, Chainlink, EOS, Ethereum, Litecoin, TETHER, Tezos, and XRP. Then, we use Monte Carlo simulations to generate the conditional variance of the cryptocurrencies using the GJR-GARCH model, and calculate the value at risk (VaR) of the simulations. We also estimate the tail-risk using VaR backtesting. Finally, we use an artificial neural network (ANN) for predicting the prices of the ten cryptocurrencies. The graphical analysis and mean square errors (MSEs) from the ANN models confirmed that the predicted prices are close to the market prices. For some cryptocurrencies, the ANN models perform better than traditional ARIMA models.

GJR-GARCH Volatility Modeling under NIG and ANN for Predicting Top Cryptocurrencies

With the continued growth in the business environment and Industry 4.0 companies are taking new business opportunities while facing new business risks at the same time. Risk management tools include a modern audit, which evaluates risk through analytical approaches.The objective of this article is therefore to verify the analytical possibilities of the audit to detect and eliminate the selected risks. The methodological processing of this goal is addressed by analysing the risks of marketing communication and audit testing on the Generation Z sample for which the on-line environment is part of everyday life.Audit results reveal specific risks in marketing communications and suggest recommendations for their adequate reduction. These recommendations can then be used to innovate marketing strategies.

/pdf/risk-audit-of-marketing-communication-4pjnwmrdhz.pdf

Risk Audit of Marketing Communication

The Russian agricultural sector has experienced many problems since the beginning of the 1990s that resulted in a fall in farm output. Employing a production function approach and, unlike other studies, farmlevel data on more than 20,000 Russian large-scale farms for the period 1995-2000, this study analyzes the impact of both production (land, labour, capital, materials) and financial (debts and budget transfers) determinants on the productivity. Inter-regional differences such as weather conditions and farm-specific features such as geographical location, management and soil quality are taken into account employing the fixed-effect estimation. The findings show that Russian farms operate under liquidity constraints that lower their productivity.

LIQUIDITY AND PRODUCTIVITY IN RUSSIAN AGRICULTURE: FARM DATA EVIDENCE / доклад на 25 конференции IAAE, Reshaping Agriculture’s Contribution to Society, International Convention Centre, Durban, South Africa, 16-23 August 2003

Photo lineups play a significant role in the eyewitness identification process. This method is used to provide evidence in the prosecution and subsequent conviction of suspects. Unfortunately, there are many cases where lineups have led to the conviction of an innocent suspect. One of the key factors affecting the incorrect identification of a suspect is the lack of lineup fairness, i.e. that the suspect differs significantly from all other candidates. Although the process of assembling fair lineup is both highly important and time-consuming, only a handful of tools are available to simplify the task. In this paper, we describe our work towards using recommender systems for the photo lineup assembling task. We propose and evaluate two complementary methods for item-based recommendation: one based on the visual descriptors of the deep neural network, the other based on the content-based attributes of persons. The initial evaluation made by forensic technicians shows that although results favored visual descriptors over attribute-based similarity, both approaches are functional and highly diverse in terms of recommended objects. Thus, future work should involve incorporating both approaches in a single prediction method, preference learning based on the feedback from forensic technicians and recommendation of assembled lineups instead of single candidates.

Towards Recommender Systems for Police Photo Lineup

Cryptocurrencies are a type of digital currencies based on
cryptography principles. Cryptocurrencies are a unique
combination of three characteristics: they provide anonymity,
they are independent of central authority and they provide
protection from double spending attack. The aim of this paper
is to capture trends in the area of significant
cryptocurrencies price developments and to explain their
causes. The current research in this area is exclusively
limited to an analysis of the price developments of the most
important Bitcoin cryptocurrency; our research is the first to
focus on other cryptocurrencies too. The economic perspective
on cryptocurrencies is based on IT knowledge regarding the
principles of their functioning. We have created a database of
prices of 1278 cryptocurrencies from 2013 to 2016. This
database is publicly available. To analyse the data, SQL query
language was used.

/pdf/analysis-of-cryptocurrencies-price-development-22h4oyeoan.pdf

Analysis of Cryptocurrencies Price Development

The traditional content-based retrieval approaches usually use flat querying, where whole multimedia database is searched for a result of some similarity query with a user specified query object. However, there are retrieval scenarios (e.g., multimedia exploration), where users may not have a clear search intents in their minds, they just want to inspect a content of the multimedia collection. In such scenarios, flat querying is not suitable for the first phases of browsing, because it retrieves the most similar objects and does not consider a view on part of a multimedia space from different perspectives. Therefore, we defined a new Multilayer Exploration Structure (MLES), that enables exploration of a multimedia collection in different levels of details. Using the MLES, we formally defined popular exploration operations (zoom-in/out, pan) to enable horizontal and vertical browsing in explored space and we discussed several problems related to the area of multimedia exploration.

MLES: Multilayer Exploration Structure for Multimedia Exploration

This article is based on empirical research and 2007–2012
statistical data from joint stock companies which were active
in the agriculture sector of the Czech Republic. It deals with
the wider aspects of liquidity and stability using suitable
liquidity indicators and a vertical financial analysis over a
sufficient period of time providing valid results for assessing
liquidity and stability of agriculture in relation to cyclic
fluctuations. The vertical financial analysis was performed to
determine the liquidity structure at current assets and short
term debts. Then convenient indicators of current ratio, quick
ratio, and cash ratio were applied and interpreted in relation
to cyclical deviations and agriculture specifics. From the
viewpoint of liquidity measured using the current ratio,
agriculture in the Czech Republic is stable and the current
ratio values bear witness to solid liquidity, whereby the
short-term assets exceed the short-term external funds.
Research is to show whether the agriculture sector is liquid
and whether the liquidity indicators provide the basis for
solvency in the given field.

https://www.sciendo.com/pdf/10.1515/sab-2017-0024

Liquidity and Stability of Agriculture in the Czech Republic

Multimedia exploration is an entertaining approach for multimedia retrieval enabling users to interactively browse and navigate through multimedia collections in a content-based way. The multimedia exploration approach extends the traditional query-by-example retrieval scenario to be a more intuitive approach for obtaining a global overview over an explored collection. However, novel exploration scenarios require many user studies demonstrating their benefits. In this paper, we present results of an extensive user study focusing on the comparison of 3-layer Multilayer Exploration Structure MLES structure with standard flat k-NN browsing. The results of the user study show that principles of the MLES lead to better effectiveness of the exploration process, especially when searching for a first object of the searched concept in an unknown collection.

Evaluating Multilayer Multimedia Exploration

The content of the subject Application Software at VSFS (University of Finance and Administration) includes three basic applications MS Word, MS PowerPoint and MS Excel. The paper deals with the new concept of teaching this subject by means of practical problems solving with a solution guide. We have written two Collections of Practical Problems with a Solution Guide (8, 9) to facilitate the teaching. Each collection includes 11 problems (Word, PowerPoint, and Excel) which correspond to the syllabus of the subject. This paper explains the principles of the above mentioned new teaching method and its comparison with the up to now used classic method. Most universities in the Czech Republic have introduced subjects teaching basic MS Office applications. The knowledge of MS Office is crucial for university students while fulfilling assignments in other subjects. The students use MS Word to write seminar papers and later also Bachelor's and Master's degree theses. MS PowerPoint is used to present the results of individual or team projects and also for Bachelor's and Master's degree thesis defence. MS Excel is used in subjects concerned with statistics and finance. The knowledge of MS Office is essential for university graduates if they want to assert themselves in the labour market. The graduates will use MS Office to create a great number of files; they will often use mass correspondence and forms. They will use MS PowerPoint to present the results of their work within the company and a well prepared presentation may also help to gain new clients. The graduate will, on daily basis, work with data stored in MS Excel, analyse and evaluate it. The University of Finance and Administration provides subjects teaching the applications Word, Excel and PowerPoint. The subjects are included in the first year of Bachelor's degree program for all fields of study (except the field of study Applied Informatics). The course is divided into two one semester subjects. Word and PowerPoint are taught in the subject B_AS1 Application Software 1 in the winter semester and advanced tools of Word and Excel are included in B_AS2 Application Software 2 in the summer semester. In this paper, we will call both the subjects Application Software whenever the information applies to both the semesters. The course is included in the full-time and also part- time form of study. This paper is concerned only with the full-time form of study. The course is divided into twelve ninety minute weekly lessons in each semester. Each lesson of the subject Application Software is divided into three parts - theoretic, demonstration and practical. Application Software is usually taught by 7-10 different teachers and each of them prefers different proportion of the individual parts of the lesson.  Theoretic part: The teacher introduces the lesson content and motivates the students to learn it, explaining its importance. The teacher explains the use of the acquired knowledge and skills in the study of other subjects and in the students' future career.

Jan Lánský

Papers

Analysis of Cryptocurrencies Price Development

MLES: Multilayer Exploration Structure for Multimedia Exploration

Liquidity and Stability of Agriculture in the Czech Republic

Evaluating Multilayer Multimedia Exploration

Teaching by means of practical problems solving with a solution guide