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Article
Publication date: 1 January 2001

Christian J. Nothiger, Michael Bründl and Walter J. Ammann

During the analysis of the 1999 avalanche winter and of the winter storm Lothar on 26 December 1999, the Swiss Federal Institute for Snow and Avalanche Research SLF, Davos…

107

Abstract

During the analysis of the 1999 avalanche winter and of the winter storm Lothar on 26 December 1999, the Swiss Federal Institute for Snow and Avalanche Research SLF, Davos conducted an inquiry of the cable car‐ and ski lift‐companies in German‐ and French speaking part of Switzerland. This arti‐cle presents the results in detail. In the whole of Switzerland there were 1'821 cable cars and ski lifts in 1999 (not counting 550 small ski lifts). The SLF sent its questionnaire to 117 companies. A considerable proportion of them (79%) have been returned. In February 1999 avalanches and snow pressure induced damages on 44 cable cars and ski lifts; repairs cost more than 17 Mio. SFr. Due to high avalanche danger, 37% of all lift facilities had to be closed for an average of seven days. The loss of earnings for Switzerland (without Ticino) is estimated at 78 Mio. SFr. compared to February 1998. The winter storm Lothar caused damage to 127 cable cars and ski lifts. The cost of damage repairs is estimated at 7.6 Mio. SFr. The storm interrupted power supply for 14% of the lift facilities; 58% had to be closed down due to high wind speeds. The loss of earnings caused by winter storm Lothar amounts to approx. 39 Mio. SFr. for the Swiss cable car and ski lift companies (without Ticino). Immediately after the events of 1999, 32% of the companies interviewed took measures to reduce the negative consequences (e.g. price reductions, press releases or publicity campaigns). To improve public relations is considered to be an important measure to cope with consequences of natural hazards in the future by 39% of the companies.

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Tourism Review, vol. 56 no. 1/2
Type: Research Article
ISSN: 1660-5373

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Article
Publication date: 8 June 2020

Vandana Bagde and Dethe C. G

A recent innovative technology used in wireless communication is recognized as multiple input multiple output (MIMO) communication system and became popular for quicker data…

167

Abstract

Purpose

A recent innovative technology used in wireless communication is recognized as multiple input multiple output (MIMO) communication system and became popular for quicker data transmission speed. This technology is being examined and implemented for the latest broadband wireless connectivity networks. Though high-capacity wireless channel is identified, there is still requirement of better techniques to get increased data transmission speed with acceptable reliability. There are two types of systems comprising of multi-antennas placed at transmitting and receiving sides, of which first is diversity technique and another is spatial multiplexing method. By making use of these diversity techniques, the reliability of transmitting signal can be improved. The fundamental method of the diversity is to transform wireless channel such as Rayleigh fading into steady additive white Gaussian noise (AWGN) channel which is devoid of any disastrous fading of the signal. The maximum transmission speed that can be achieved by spatial multiplexing methods is nearly equal to channel capacity of MIMO. Conversely, for diversity methods, the maximum speed of broadcasting is much lower than channel capacity of MIMO. With the advent of space–time block coding (STBC) antenna diversity technique, higher-speed data transmission is achievable for spatially multiplexed multiple input multiple output (SM-MIMO) system. At the receiving end, detection of the signal is a complex task for system which exhibits SM-MIMO. Additionally, a link modification method is implemented to decide appropriate coding and modulation scheme such as space diversity technique STBC to use two-way radio resources efficiently. The proposed work attempts to improve detection of signal at receiving end by employing STBC diversity technique for linear detection methods such as zero forcing (ZF), minimum mean square error (MMSE), ordered successive interference cancellation (OSIC) and maximum likelihood detection (MLD). The performance of MLD has been found to be better than other detection techniques.

Design/methodology/approach

Alamouti's STBC uses two transmit antennas regardless of the number of receiver antennas. The encoding and decoding operation of STBC is shown in the earlier cited diagram. In the following matrix, the rows of each coding scheme represent a different time instant, while the columns represent the transmitted symbols through each different antenna. In this case, the first and second rows represent the transmission at the first and second time instant, respectively. At a time t, the symbol s1 and symbol s2 are transmitted from antenna 1 and antenna 2, respectively. Assuming that each symbol has duration T, then at time t + T, the symbols –s2* and s1*, where (.)* denotes the complex conjugate, are transmitted from antenna 1 and antenna 2, respectively. Case of one receiver antenna: The reception and decoding of the signal depend on the number of receiver antennas available. For the case of one receiver antenna, the received signals are received at antenna 1 , hij is the channel transfer function from the jth transmit antenna and the ith receiver antenna, n1 is a complex random variable representing noise at antenna 1 and x (k) denotes x at time instant k ( at time t + (k – 1)T.

Findings

The results obtained for maximal ratio combining (MRC) with 1 × 4 scheme show that the BER curve drops to 10–4 for signal-to-noise (SNR) ratio of 10 dB, whereas for MRC 1 × 2 scheme, the BER drops down to 10–5 for SNR of 20 dB. Results obtained in Table 1 show that when STBC is employed for MRC with 1 × 2 scheme (one antenna at transmitter node and two antennas at receiver node), BER curve comes down to 0.0076 for Eb/N0 of 12. Similarly, when MRC with 1 × 4 antenna scheme is implemented, BER drops down to 0 for Eb/N0 of 12. Thus, it can be concluded from the obtained graph that the performance of MRC with STBC gives improved results. When STBC technique is used with 3 × 4 scheme, at SNR of 10 dB, BER comes nearer to 10–6 (figure 7.3). It can be concluded from the analytics observed between AWGN and Rayleigh fading channel that for AWGN channel, BER is found to be equal to 0 for SNR value of 13.5 dB, whereas for Rayleigh fading channel, BER is observed nearer to 10–3 for Eb/N0 = 15. Simulation results (in figure 7.2) from the analytics show BER drops to 0 for SNR value of 12 dB.

Research limitations/implications

Optimal design and successful deployment of high-performance wireless networks present a number of technical challenges. These include regulatory limits on useable radio-frequency spectrum and a complex time-varying propagation environment affected by fading and multipath. The effect of multipath fading in wireless systems can be reduced by using antenna diversity. Previous studies show the performance of transmit diversity with narrowband signals using linear equalization, decision feedback equalization, maximum likelihood sequence estimation (MLSE) and spread spectrum signals using a RAKE receiver. The available IC techniques compatible with STBC schemes at transmission require multiple antennas at the receiver. However, if this not a strong constraint at the base station level, it remains a challenge at the handset level due to cost and size limitation. For this reason, SAIC technique, alternative to complex ML multiuser demodulation technique, is still of interest for 4G wireless networks using the MIMO technology and STBC in particular. In a system with characteristics similar to the North American Digital mobile radio standard IS-54 (24.3 K symbols per sec. with an 81 Hz fading rate), adaptive retransmission with time deviation is not practical.

Practical implications

The evaluation of performance in terms of bit error rate and convergence time which estimates that MLD technique outperforms in terms of received SNR and low decoding complexity. MLD technique performs well but when higher number of antennas are used, it requires more computational time and thereby resulting in increased hardware complexity. When MRC scheme is implemented for singe input single output (SISO) system, BER drops down to 10–2 for SNR of 20 dB. Therefore, when MIMO systems are employed for MRC scheme, improved results based on BER versus SNR are obtained and are used for detecting the signal; comparative study based on different techniques is done. Initially ZF detection method is utilized which was then modified to ZF with successive interference cancellation (ZFSIC). When successive interference cancellation scheme is employed for ZFSIC, better performance is observed as compared to the estimation of ML and MMSE. For 2 × 2 scheme with QPSK modulation method, ZFSIC requires more computational time as compared to ZF, MMSE and ML technique. From the obtained results, the conclusion is that ZFSIC gives the improved results as compared to ZF in terms of BER ratio. ZF-based decision statistics can be produced by the detection algorithm for a desired sub-stream from the received vector whichs consist of an interference which occurred from previous transmitted sub-streams. Consequently, a decision on the secondary stream is made and contribution of the noise is regenerated and subtracted from the vector received. With no involvement of interference cancellation, system performance gets reduced but computational cost is saved. While using cancellation, as H is deflated, coefficients of MMSE are recalculated at each iteration. When cancellation is not involved, the computation of MMSE coefficients is done only once, because of H remaining unchanged. For MMSE 4 × 4 BPSK scheme, bit error rate of 10–2 at 30 dB is observed. In general, the most thorough procedure of the detection algorithm is the computation of the MMSE coefficients. Complexity arises in the calculation of the MMSE coefficients, when the antennas at the transmitting side are increased. However, while implementing adaptive MMSE receivers on slow channel fading, it is probable to recover the signal with the complications being linear in the antennas of transmitter node. The performance of MMSE and successive interference cancellation of MMSE are observed for 2 × 2 and 4 × 4 BPSK and QPSK modulation schemes. The drawback of MMSE SIC scheme is that the first detected signal observes the noise interference from (NT-1) signals, while signals processed from every antenna later observe less noisy interference as the process of cancellation progresses. This difficulty could be overcome by using OSIC detection method which uses successive ordering of the processed layers in the decreasing power of the signal or by power allocation to the signal transmitted depending on the order of the processing. By using successive scheme, a computation of NT delay stages is desired to bring out the abandoned process. The work also includes comparison of BER with various modulation schemes and number of antennas involved while evaluating the performance. MLD determines the Euclidean distance among the vector signal received and result of all probable transmitted vector signals with the specified channel H and finds the one with the minimum distance. Estimated results show that higher order of the diversity is observed by employing more antennas at both the receiving and transmitting ends. MLD with 8 × 8 binary phase shift keying (BPSK) scheme offers bit error rate near to 10–4 for SNR (16 dB). By using Altamonti space ti.

Social implications

It should come as no surprise that companies everywhere are pushing to get products to market faster. Missing a market window or a design cycle can be a major setback in a competitive environment. It should be equally clear that this pressure is coming at the same time that companies are pushing towards “leaner” organizations that can do more with less. The trends mentioned earlier are not well supported by current test and measurement equipment, given this increasingly high-pressure design environment: in order to measure signals across multiple domains, multiple pieces of measurement equipment are needed, increasing capital or rental expenses. The methods available for making cross-domain, time-correlated measurements are inefficient, reducing engineering efficiency. When only used on occasion, the learning curve to understand how to use equipment for logic analysis, time domain and RF spectrum measurements often requires an operator to re-learn each piece of separate equipment. The equipment needed to measure wide bandwidth, time-varying spectral signals is expensive, again increasing capital or rental expenses. What is needed is a measurement instrument with a common user interface that integrates multiple measurement capabilities into a single cost-effective tool that can efficiently measure signals in the current wide-bandwidth, time-correlated, cross-domain environments. The market of wireless communication using STBCs has large scope of expansion in India. Therefore, the proposed work has techno-commercial potential and the product can be patented. This project shall in turn be helpful for remote areas of the nearby region particularly in Gadchiroli district and Melghat Tiger reserve project of Amravati district, Nagjira and so on where electricity is not available and there is an all the time problem of coverage in getting the network. In some regions where electricity is available, the shortage is such that they cannot use it for peak hours. In such cases, stand-alone space diversity technique, STBC shall help them to meet their requirements in making connection during coverage problem, thereby giving higher data transmission rates with better QOS (quality of service) with least dropped connections. This trend towards wireless everywhere is causing a profound change in the responsibilities of embedded designers as they struggle to incorporate unfamiliar RF technology into their designs. Embedded designers frequently find themselves needing to solve problems without the proper equipment needed to perform the tasks.

Originality/value

Work is original.

Details

International Journal of Intelligent Unmanned Systems, vol. 10 no. 2/3
Type: Research Article
ISSN: 2049-6427

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Book part
Publication date: 20 July 2017

Neal M. Ashkanasy, Ashlea C. Troth, Sandra A. Lawrence and Peter J. Jordan

Scholars and practitioners in the OB literature nowadays appreciate that emotions and emotional regulation constitute an inseparable part of work life, but the HRM literature has…

Abstract

Scholars and practitioners in the OB literature nowadays appreciate that emotions and emotional regulation constitute an inseparable part of work life, but the HRM literature has lagged in addressing the emotional dimensions of life at work. In this chapter therefore, beginning with a multi-level perspective taken from the OB literature, we introduce the roles played by emotions and emotional regulation in the workplace and discuss their implications for HRM. We do so by considering five levels of analysis: (1) within-person temporal variations, (2) between persons (individual differences), (3) interpersonal processes; (4) groups and teams, and (5) the organization as a whole. We focus especially on processes of emotional regulation in both self and others, including discussion of emotional labor and emotional intelligence. In the opening sections of the chapter, we discuss the nature of emotions and emotional regulation from an OB perspective by introducing the five-level model, and explaining in particular how emotions and emotional regulation play a role at each of the levels. We then apply these ideas to four major domains of concern to HR managers: (1) recruitment, selection, and socialization; (2) performance management; (3) training and development; and (4) compensation and benefits. In concluding, we stress the interconnectedness of emotions and emotional regulation across the five levels of the model, arguing that emotions and emotional regulation at each level can influence effects at other levels, ultimately culminating in the organization’s affective climate.

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Research in Personnel and Human Resources Management
Type: Book
ISBN: 978-1-78714-709-6

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Book part
Publication date: 14 June 2024

Felix Wortmann, Heiko Gebauer, Claudio Lamprecht and Elgar Fleisch

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Understanding Products as Services: How the Internet and AI are Transforming Product Companies
Type: Book
ISBN: 978-1-83797-824-3

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Book part
Publication date: 23 September 2013

Susanne Scheibe and Hannes Zacher

Researchers in the field of occupational stress and well-being are increasingly interested in the role of emotion regulation in the work context. Emotion regulation has also been…

Abstract

Researchers in the field of occupational stress and well-being are increasingly interested in the role of emotion regulation in the work context. Emotion regulation has also been widely investigated in the area of lifespan developmental psychology, with findings indicating that the ability to modify one’s emotions represents a domain in which age-related growth is possible. In this chapter, we integrate the literatures on aging, emotion regulation, and occupational stress and well-being. To this end, we review key theories and empirical findings in each of these areas, summarize existing research on age, emotion regulation, and stress and well-being at work, and develop a conceptual model on how aging affects emotion regulation and the stress process in work settings to guide future research. According to the model, age will affect (1) what kinds of affective work events are encountered and how often, (2) the appraisal of and initial emotional response to affective work events (emotion generation), and (3) the management of emotions and coping with affective work events (emotion regulation). The model has implications for researchers and practitioners who want to understand and facilitate successful emotion regulation and stress reduction in the workplace among different age groups.

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The Role of Emotion and Emotion Regulation in Job Stress and Well Being
Type: Book
ISBN: 978-1-78190-586-9

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Book part
Publication date: 22 December 2016

Hongbo Cai and Eleonora Cutrini

The objective of this chapter is to provide a first assessment on the evolution of spatial distribution of foreign firms in China.

Abstract

Purpose

The objective of this chapter is to provide a first assessment on the evolution of spatial distribution of foreign firms in China.

Methodology/approach

We examine the overall changes in the location of foreign firms in China over the period 1999–2009. Then, we distinguish two time periods, 1998–2001 and 2002–2009 so as to analyze whether foreign firms’ agglomeration across regions has changed significantly after the China’s entry into the WTO (2001) and the first launch of the Chinese government policies to develop western internal areas.

Findings

Our analysis suggests that foreign-invested enterprises (FIEs) with higher foreign capital shares are more geographically clustered in coastal regions than other enterprises with lower foreign capital shares. This group with the highest intensity of foreign involvement in firm capital also experienced the most relevant changes over the decade of our analysis becoming more localized between the core-periphery divide (coastal provinces and the rest of mainland China).

Research limitations

The main limitation refers to poor data availability, data matching problems, and measurement errors in the database used, as highlighted by Nie, Jiang, and Yang (2012).

Practical implications

A general analysis of location patterns and the role of public policies may inform foreign companies in their entry strategy in the Chinese market.

Originality/value

Very few studies have explored location patterns with detailed geographical data and, at the same time, with data disaggregated by foreign ownership shares.

Details

China and Europe’s Partnership for a More Sustainable World
Type: Book
ISBN: 978-1-78635-331-3

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Book part
Publication date: 27 November 2023

Adelina Broadbridge

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The Emerald Handbook of Appearance in the Workplace
Type: Book
ISBN: 978-1-80071-174-7

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Book part
Publication date: 27 November 2023

Adelina Broadbridge

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The Emerald Handbook of Appearance in the Workplace
Type: Book
ISBN: 978-1-80071-174-7

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Article
Publication date: 11 October 2021

Junwoo Jeon, Emrah Gulay and Okan Duru

This research analyzes the cycle of the dry bulk shipping market (DBSM) as a representative of spot and period charter rates in dry bulk shipping to develop strategies for…

1603

Abstract

Purpose

This research analyzes the cycle of the dry bulk shipping market (DBSM) as a representative of spot and period charter rates in dry bulk shipping to develop strategies for investment timing (i.e. asset play) and fleet trading (chartering strategy).

Design/methodology/approach

Spectral analysis is a numerical approach to extract significant cyclicality, which may be utilized to develop trading strategies. Instead of working with a single dataset (univariate), a system approach can be utilized to observe a significant shipping market cycle in its multi-variate circumstance. In this paper, a system dynamics design is employed to extract cyclicality in the DBSM in its particular industrial environment. The system dynamic design has competitive forecasting accuracy relative to univariate time series models and artificial neural networks (ANNs) in terms of forecasting outcomes.

Findings

The results show that the system dynamic design has a better forecasting performance according to three evaluation metrics, mean absolute scale error (MASE), root mean square error (RMSE) and mean absolute percentage error (MAPE).

Originality/value

Cyclical analysis is a significantly useful instrument for shipping asset management, particularly in market entry–exit operations. This paper investigated the cyclical nature of the dry bulk shipping business and estimated significant business cycle periodicity at around 4.5-year frequency (i.e. the Kitchin cycle).

Details

Maritime Business Review, vol. 8 no. 1
Type: Research Article
ISSN: 2397-3757

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Book part
Publication date: 27 November 2023

Bahaudin G. Mujtaba, Frank J. Cavico and Tipakorn Senathip

Appearance is part of a person's non-verbal communication, and looks are often associated with the perceived ‘attractiveness’ of individuals for hiring practices in the workplace…

Abstract

Appearance is part of a person's non-verbal communication, and looks are often associated with the perceived ‘attractiveness’ of individuals for hiring practices in the workplace. As such, physical attractiveness can be a ‘prized possession’ when it comes to leaving a positive impression on managers who are interviewing candidates. In the twenty-first century environment, our society seems to be more obsessed with physical appearance than ever before because society has conditioned us to associate beauty with other favourable characteristics. Of course, such appearance norms, regarding attractiveness, ‘good looks’ and beauty are linked to years of socialisation in culture, cultural norms and materialistic personality standards.

In a business context, managers and employers often make hiring decisions based on the appearance and attractiveness of the job applicants since outward appearance seems to play a significant role in which candidates eventually might get the job. Physically attractive job applicants and candidates tend to benefit from the unearned privilege, which often comes at a cost to others who are equally qualified. Preferring employees who are deemed to be attractive, and consequently discriminating against those who are perceived as unattractive, can present legal and ethical challenges for employers and managers. In this chapter, we provide a discussion and reflection of appearance-based hiring practices in the United States with relevant legal, ethical and practical implications for employers, human resources professionals and managers. We focus on ‘lookism’ or appearance discrimination, which is discrimination in favour of people who are physically attractive. As such, we examine federal, state and local laws regarding appearance discrimination in the American workplace. We also offer sustainable policy recommendations for employers, HR professionals and managers on how they can be fair to all candidates in order to hire, promote and retain the most qualified professionals in their departments and organisations.

Details

The Emerald Handbook of Appearance in the Workplace
Type: Book
ISBN: 978-1-80071-174-7

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