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Aircraft manufacturers for a long time have been looking to reduce the weight of on board equipment to enhance performance both from commercial aspect and from military aspect. The existing wired technology, using cables to connect different on board line replaceable unit apart from increasing the weight also increases the complexity related to electromagnetic interference, installation and maintenance. With continuous technology upgradation in the wireless domain, aviation industry is in the process of using wireless technology for intra-aircraft communication. Wireless technology can meet most of the challenges of modern avionics systems and significantly reduce the weight. This paper aims to look at various aspects of implementing a wireless network including issues related to wired network, aircraft channel, interference issues, suitable wireless protocols for aircraft applications and security aspects.

The paper has relied on literature study on wireless avionics intra-communications (WAIC) and the research work carried out in specific areas related to channel inside an aircraft, interference issues of wireless systems with onboard and external systems operating in the same band and security issues related to wireless network and security requirements of implementing an avionics wireless network (AWN). To identify suitable wireless protocol for AWN literature review and simulation to compare different protocols was carried out.

A single wireless protocol may not be suitable for all aircraft systems, and therefore, there may be a requirement to use multiple technologies. Mutual interference is not expected between WAIC systems with on board and external systems operating in the same band. The channel inside an aircraft is expected to be Rician (LOS) or Rayleigh (NLOS). However, additional measurements may have to be undertaken to have a generalized channel model. Security aspects in an AWN are critical and needs to be analyzed in detail prior to any wireless deployment.

Implementation of wireless technology can pave the way for usage of wireless technology for future generation avionics. With International Telecommunication Union allotting dedicated band for WAIC operations, considerable amount of research has been initiated in this field. It is believed that in the coming 2-3 years, the designers will be ready to replace the existing data wires with wireless transceivers. With radio technical commission for aeronautics and EURACAE involved in development of minimum operations performance standards for WAIC systems use of wireless for intra communication is bound to happen. Therefore, it is necessary to look at different issues for integrating wireless in the avionics domain.

The existing studies have been carried out in individual domains of using wireless in avionics. Separate studies and research work has been carried out for identifying wireless protocols, aircraft channel models, interference issues and security aspects. The paper has attempted to look at all these aspects together including certification.

One of the most important sources of energy in the world, due to its great impact on the global economy, is the crude oil. Due to the instability of oil prices which exhibit extreme fluctuations during periods of different times of market uncertainty, it became hard to the governments to predict accurately the prices of crude oil in order to build their financial budgets. Therefore, this study aims to analyse and model crude oil price using the hidden Markov process (HMM).

Traditional mathematical approaches of time series may be not give accurate results to measure and analyse the crude oil price, since the latter has an unstable and fluctuating nature, hence, its prediction forms a challenge task. A novel methodology that is so-called the HMM is proposed that takes into account the heterogeneity in prices as well as their hidden state-based behaviour.

Using the Bayesian approach, several estimated models with different ranks are fitted to a non-homogeneous data of Iraqi crude oil prices from January 2010 into December 2021. The model selection criteria and measures of the prediction performance of each model are applied to choose the best model. Movements of crude oil prices exhibit extreme fluctuations during periods of different times of market uncertainty. The processes of model estimation and the model selection were conducted in Python V.3.10, and it is available from the first author on request.

Using the Bayesian approach, several estimated models with different ranks are fitted to a non-homogeneous data of Iraqi crude oil prices from January 2010 to December 2021.

The purpose of this paper is to investigate how the selection of return distribution impacts estimated volatility in China’s stock market.

The authors use a Bayesian analysis of fat-tailed stochastic volatility (SV) model with Student’s t-distribution, and conduct an out-of-sample test with realized volatility.

Empirical analysis results indicate that fat-tailed SV model performs better in capturing the dynamics of daily returns. The authors find that asymmetry, holiday and day of the week effects are detected in estimated volatility. However, the out-of-sample comparison shows that fat-tailed SV models fail to outperform SV models with normal distribution in fitting and predicting realized volatility.

The contribution of this paper to existing literature is twofold. First, it proves that fat-tailed SV models with Student’s t-distribution perform better than normally distributed SV models in fitting daily returns of China’s stock market. Second, this paper takes asymmetry, holiday and day of the week effects into consideration at the same time in the fat-tailed SV model.

There is abundant literature analyzing the determinants of banks’ profitability through its main component: the net interest margin. Some of these determinants are suggested by seminal theoretical models and subsequent expansions. Others are ad-hoc selections. Up to now, there are no studies assessing these models from a Bayesian model uncertainty perspective. This paper aims to analyze this issue for the EU-15 countries for the period 2008-2014, which mainly corresponds to the Great Recession years.

It follows a Bayesian variable selection approach to analyze, in a first step, which variables of those suggested by the literature are actually good predictors of banks’ net interest margin. In a second step, using a model selection approach, the authors select the model with the best fit. Finally, the paper provides inference and quantifies the economic impact of the variables selected as good candidates.

The results widely support the validity of the determinants proposed by the seminal models, with only minor discrepancies, reinforcing their capacity to explain net interest margin disparities also during the recent period of restructuring of the banking industry.

The paper is, to the best of the knowledge, the first one following a Bayesian variable selection approach in this field of the literature.

The purpose of this paper is to outline a novel concept of radio altimeter CRW-13 that has been designed and developed in the Lukasiewicz Research Network – Institute of Aviation as a result of the need to update the outdated structure of RWL-750M.

The new design of the device consists of integral antennas and signal processor for smart digital signal filtering.

As a result of a number of laboratory tests and flight tests of the device installed on MP-02 “Czajka” ultralight aircraft promising results were achieved. They allow to move on to the next stage of implementation and preparation for the device certification.

The CRW-13 meets with great interest of civilian and military potential customers. It is an ideal solution for airplanes, helicopters, unmanned and guided missiles. The universal design enables installation on many different platforms where exact height measurement is needed and crucial.

At the origin of the new concept was the need to replace the separate transmitting and receiving antennas with one unit comprising two planar microstrip antennas placed directly next to each other on a common plate block in the transceiver. This solution eliminates thick antenna cables and coaxial connectors, which are the most unreliable and problematic elements of radio altimeters. The new concept of integral antennas and the use of signal processors for smart digital signal filtration made it possible to take the technology to the next level.

The purpose of this paper is to examine Czech traditions of outdoor games and sports, turistika activities and education in nature programmes, which have continued to develop during periods of oppression and provided opportunities to preserve the Czech culture.

A review of the historical, cultural and political context of education in nature traditions in Czech was proposed.

Late 19th century organisations such as the Turistický klub and Sokol were instrumental in developing a range of indigenous turistika activities involving active movement. The early 20th century influences were the Czech scouting movement, summer camps and Woodcraft. Charles University provided the first tertiary outdoor educational programmes in Prague in the 1950s. Their foundation course “Turistika and Outdoor Sports” is still compulsory for all students studying physical education and sport. Turistika activities and outdoor sports and games continued to be developed throughout the liberalization of the socialist regime in the 1960s.

Following the Prague Spring in 1968, and under the guise of the Socialist Youth Union organization, new experimental forms of outdoor education emerged.

Since the Velvet Revolution in 1989 organisations have reconnected with Czech outdoor traditions that flourished before 1948 and other organisations have developed education in nature programs. The commercial sphere, which did not exist before 1989, has now been established in the outdoor area. However, traditional participation in turistika activities has been impacted by other external motivations as a broader range of opportunities have become available and accepted, and tourism outside of Czech and Europe has become increasingly popular and accessible.

The originality of this paper is to provide an overview of Czech political and cultural history and how it has shaped people's relationship, particularly children and youth, with the outdoors.

This paper aims to examine the evolution of a competitive market structure over time through the lens of competitive group membership dynamics.

A new hidden Markov modeling approach is devised that accounts for the three sources of competitive heterogeneity involving managerial strategy, corporate performance and the impact of strategy on performance. In addition, some observed “entry” and “exit” states are considered to model firms’ entry into and exit from the market. The proposed model is illustrated with an investigation of the US banking industry based on a data set created from the COMPUSTAT database. This paper estimated the model within the Bayesian framework and devised a reversible jump Markov chain Monte Carlo estimation procedure to determine the number of latent competitive groups and uncover the characteristics of each group.

This paper shows that the US banking industry, contrary to the prior findings of having a relatively stable structure, has, in fact, gone through dramatic changes in the past number of decades.

Contrary to prior work that has primarily focused on managerial strategy to study market evolutions, the competitive groups perspective accounts for all three sources of intra-industry competitive heterogeneity. In addition, unlike prior research, the analysis is not limited to firms remaining in the panel of study for the entire observation period. Such limitation results in missing the various changes that occur in the competitive market structure because of the new entrants or the struggling firms that do not survive in the market.

The purpose of this paper is to elaborate the feasibility of market based estimations of the value of human capital in firms.

The concept of intangible assets and market‐based valuation of human capital is presented. Cases of extreme estimates of human capital values are presented. The possibility of extremely low or even negative human capital values is examined.

It is demonstrated that odd human capital values can be explained by referring to principles of valuating fixed assets and intangible liability.

The paper demonstrates that market‐based methods for estimating the value of human capital of the firm can be feasible despite the existence of very odd human capital values.

The findings of the paper adds to the discussion of how to valuate human capital in intellectual capital accounts in general and human capital accounts in particular.

This paper aims to appraise the roles of whistleblowing policy as a tool for combating corruption in Nigeria. Methodologically, it examines how the policy could be strengthened to effectively address the challenges of corruption in Nigeria.

This paper is essentially a desk research with reliance on the secondary source of data. Relevant materials were collected in an eclectic manner from official documents, statutes and other published outlets such as books, journal publications, online articles, news reports and newspaper articles. Its scope is limited to issue and content analysis relating to the use of whistleblowing policy as a tool to combat corruption.

The paper finds that whistleblowing policy is an effective anti-corruption instrument that has facilitated discovery and recovery of looted public resources and prosecution of culprits in Nigeria.

This paper demonstrates how whistleblowing as an anti-corruption mechanism could be strengthened in Nigeria when the legislator finally passed the Whistleblower Protection Bill into law.

Job advertisements are important means of communicating role expectations for management accountants to the labor market. They provide information about which roles are sought and expected. However, which roles are communicated in job advertisements is unknown so far.

With a text-mining approach on a large sample of 889 job ads, the authors extract information on roles, type of firm and hierarchical position of the management accountant sought.

The results indicate an apparent mix of different role types with a strong focus on a classic watchdog role. However, the business partner role is more often sought for leadership positions or in family businesses and small- and medium-sized enterprises (SME).

The main limitation is the lack of an agreed-upon measurement instrument for roles in job offers. The study results imply that corporate practice is not as theory-driven as is postulated and communicated in the management accounting community. This indicates the existence of a research-practice gap and tensions between different actors in the management accounting field.

The results challenge the current role discussion of professional organizations for management accountants as business partners.

The authors contribute the first study, which explicitly analyzes the communication of roles in job offers for management accountants. It indicates a discrepancy between scholarly discussion on roles and management accountants' work from an employer's perspective.