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Article

Junhua Zhang, Jianping Yuan, Wei Wang and Jiao Wang

The purpose of this paper is to obtain the reachable domain (RD) for spacecraft with a single normal impulse while considering both time and impulse constraints.

Abstract

Purpose

The purpose of this paper is to obtain the reachable domain (RD) for spacecraft with a single normal impulse while considering both time and impulse constraints.

Design/methodology/approach

The problem of RD is addressed in an analytical approach by analyzing for either the initial maneuver point or the impulse magnitude being arbitrary. The trajectories are considered lying in the intersection of a plane and an ellipsoid of revolution, whose family can be determined analytically. Moreover, the impulse and time constraints are considered while formulating the problem. The upper bound of impulse magnitude, “high consumption areas” and the change of semi-major axis and eccentricity are discussed.

Findings

The equations of RD with a single normal impulse are analytically obtained. The equations of three scenarios are obtained. If normal impulse is too large, the RD cannot be obtained. The change of the semi-major axis and eccentricity with large normal impulse is more obvious. For long-term missions, the change of semi-major axis and eccentricity leaded by multiple normal impulses should be considered.

Practical implications

The RD gives the pre-defined region (all positions accessible) for a spacecraft under a given initial orbit and a normal impulse with certain magnitude.

Originality/value

The RD for spacecraft with normal impulse can be used for non-coplanar orbital transfers, emergency evacuation after failure of rendezvous and docking and collision avoidance.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 7
Type: Research Article
ISSN: 1748-8842

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Article

Ali Akbar Abbasian Arani, Ali Arefmanesh and Hamidreza Ehteram

The purpose of this paper is to recommend a validated numerical model for simulation the flue gases heat recovery recuperators. Due to fulfill of this demand, the…

Abstract

Purpose

The purpose of this paper is to recommend a validated numerical model for simulation the flue gases heat recovery recuperators. Due to fulfill of this demand, the influences of ash fouling characteristics during the transient/steady-state simulation and optimization of a 3D complex heat exchanger equipped with inner plain fins and side plate fins are studied.

Design/methodology/approach

For the particle dispersion modeling, the discrete phase model is applied and the flow field has been solved using SIMPLE algorithm.

Findings

According to obtained results, for the recuperator equipped with combine inner plain and side plate fins, determination of ash fouling characteristics is really important, effective and determinative. It is clear that by underestimating the ash fouling characteristics, the achieved results are wrong and different with reality.

Originality/value

Finally, the configuration with inner plain fins with characteristics of: di =5 mm, do = 6 mm, dg = 2 mm, dk = 3 mm and NIPFT = 9 and side plate fins with characteristics of: TF = 3 mm, PF = 19 mm, NSPF = 17·2 = 34, WF = 10 mm, HF = 25 mm, LF = 24 mm and ß = 0° is introduced as the optimum model with the best performance among all studied configurations.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 30 no. 5
Type: Research Article
ISSN: 0961-5539

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Article

Yao-Chin Wang and Chen-Tsang Simon Tsai

The purpose of this paper is to understand consumers’ passion types in online food group buying (OFGB) and the following outcomes in buying behavior and mental status.

Abstract

Purpose

The purpose of this paper is to understand consumers’ passion types in online food group buying (OFGB) and the following outcomes in buying behavior and mental status.

Design/methodology/approach

The research setting of this study is a Facebook group specifically for food buying, with population of 2,387 members who are interested in OFGB. Among 2,387 members in the case group, there were 1,286 members clicked on the questionnaire, and 254 of them participated in the survey and returned valid responses. In total, 254 valid questionnaires were collected for 19.75 percent usable response rate (254 out of 1,286).

Findings

Results of this study proved that harmonious passion can improve both long-term intrinsic enjoyment and short-term positive feelings, while exert no effects on impulse buying. On the other hand, obsessive passion can significantly stimulate both impulse buying and compulsive buying, and strengthen short-term positive feelings as well.

Originality/value

It is interesting to find that buying more does not make consumers feel better based on the evidence that impulse buying and compulsive buying performed no positive influences to both short-term and long-term mental status.

Details

British Food Journal, vol. 119 no. 6
Type: Research Article
ISSN: 0007-070X

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Article

Jonas Hahn, Verena Keil, Thomas Wiegelmann and Sven Bienert

The purpose of this paper is to estimate the impact of changes in macro-economic conditions going forward, focusing on a change in interest policy, with regard to office…

Abstract

Purpose

The purpose of this paper is to estimate the impact of changes in macro-economic conditions going forward, focusing on a change in interest policy, with regard to office letting and investment markets.

Design/methodology/approach

For this analysis, the authors constructed two vector-autoregressive models, measuring the response of office rents and capital values in Germany to economic impulses. The authors isolated effects of unique exogenous positive shocks (such as economic growth or interest leaps) on the basis of impulse-response functions in order to understand the complex dynamic interdependence between several economic factors and office performance changes.

Findings

The authors initially find a moderately positive development of both office performance components even although supposing an increase in interest level. In terms of capital values, the authors find that they do not drop before 1.5 years after the interest impulse and the negative effect peaks after approximately nine quarters. Furthermore, the reaction to a change in GDP is significantly lower than a reaction to the interest rate, but impulses in other macro-economic factors provoke stronger reactions. Finally, the authors find that a positive interest shock leads to a comparably robust development and economic sustainability in office rents throughout a consideration horizon of 24 quarters.

Research limitations/implications

Estimations are based on observations from a time period containing two rather extraordinary market phases. As they included bubble growth and the low-interest environment, the authors find that certain patterns in both phases neutralize each other when looking at the total time frame. The authors constructed sub-samples to compensate for this. However, the research does not provide to what extent the measured impulse-responses stay forecast-proof, if the market moves into a phase of short-term normalization.

Practical implications

This paper provides insights into estimated impulse-response patterns on a hypothetical sudden increase of several macro-economic determinants. On this basis, the probable reaction to an increase in, for example, the interest rate level can be approximated. Also, the paper provides a fundamental understanding of the economic sustainability of German office properties in terms of their value and rent performance in the case of exogenous shocks.

Originality/value

This paper contains the first vector-autoregressive, impulse-response analysis of office markets in Germany in the context of several macro-economic drivers, including the interest level. It delivers insights into market reaction patterns on the basis of simulated one standard deviation shocks in all included variables.

Details

Journal of Property Investment & Finance, vol. 34 no. 5
Type: Research Article
ISSN: 1463-578X

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Article

Hans‐Peter Wiendahl and Horst Ahrens

The University of Hannover has studied the fundamental factors affecting the process of vibratory feeding. From this research a step‐by‐step procedure for the design of…

Abstract

The University of Hannover has studied the fundamental factors affecting the process of vibratory feeding. From this research a step‐by‐step procedure for the design of vibratory bowl feeders has been derived.

Details

Assembly Automation, vol. 4 no. 4
Type: Research Article
ISSN: 0144-5154

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Article

Sven Modell

The purpose of this paper is to review extant accounting research combining institutional and critical theories to examine whether the paradigmatic tensions associated…

Abstract

Purpose

The purpose of this paper is to review extant accounting research combining institutional and critical theories to examine whether the paradigmatic tensions associated with such research can be alleviated whilst engendering politically engaged scholarship aimed at facilitating processes of emancipation in organisational fields.

Design/methodology/approach

The paper provides a review of relevant accounting research and offers recommendations for how to combine institutional and critical research approaches in a paradigmatically consistent way.

Findings

Extant accounting research combining institutional and critical theories has not dealt effectively with the partly inter-related problems of ontological drift (i.e. misalignment of ontological assumptions and epistemological commitments) and the conflation of notions of agency and structure. If such problems remain unaddressed institutional research aimed at generating politically engaged scholarship and human emancipation is unlikely to progress in a paradigmatically consistent direction. Recommendations for how to address these issues, grounded in recent advances in critical realism, are elaborated upon. This results in a contingent view of the ontological possibilities of emancipation in organisational fields as well as the epistemological premises that need to be filled to engender processes of emancipation.

Originality/value

The paper reviews an emerging body of research seeking to radicalise institutional accounting research and enhance its contributions to democratic debate in organisations and society. It also outlines how some pertinent paradigmatic tensions associated with such research may be addressed.

Details

Accounting, Auditing & Accountability Journal, vol. 28 no. 5
Type: Research Article
ISSN: 0951-3574

Keywords

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Article

Wahid Murad and Janek Ratnatunga

The key purpose of this paper is to examine the causality and long‐run relationship between CO2 emission and agricultural output for an agriculture‐dependent developing…

Abstract

Purpose

The key purpose of this paper is to examine the causality and long‐run relationship between CO2 emission and agricultural output for an agriculture‐dependent developing country, namely Bangladesh.

Design/methodology/approach

In order to attain the objective, this study has used long‐time series data and employed advanced econometric techniques of unit root test, nonlinear least square estimation, Vector Error Correction estimation and Granger causality test.

Findings

The empirical results of the study reveal that Bangladesh agricultural output is not a Granger causal for Bangladesh CO2 emission, but the country's CO2 emission is a Granger causal for its agricultural output. The results also reveal for Bangladesh that any disequilibrium between CO2 emissions and agricultural output could take approximately 17 years to converge to the long‐run equilibrium. The results further reveal that the adjustment rate for Bangladesh agricultural output is positive and quite fast at the rate of 69 percent a year. So any disequilibrium will be corrected mostly by the adjustment in Bangladesh agricultural output.

Practical implications

The current CO2 emission in Bangladesh is still below the equilibrium level, which is considered to be an advantage for the country, particularly its agriculture sector which will reasonably not face any stricter CO2 emissions controlling policies and regulations in the near future.

Originality/value

The originality of this study lies on the extent to which an agriculture‐dependent developing country such as Bangladesh does not have greater concern about the CO2 emission for now and the near future. The originality does also lie on the fact that no other study has yet examined this issue.

Details

Management of Environmental Quality: An International Journal, vol. 24 no. 2
Type: Research Article
ISSN: 1477-7835

Keywords

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Article

Tian Han, Bo‐Suk Yang and Zhong‐Jun Yin

The purpose of this paper is to identify the efficiency of vibration signals for fault diagnosis system of induction motors.

Abstract

Purpose

The purpose of this paper is to identify the efficiency of vibration signals for fault diagnosis system of induction motors.

Design/methodology/approach

A fault diagnosis system for induction motors using vibration signals is designed based on pattern recognition. Genetic algorithm is used for feature reduction and neural network tuning.

Findings

The usage of genetic algorithm improves the system performance through selecting significant features and optimizing network structure. The efficiency of vibration signals is demonstrated.

Practical implications

Condition monitoring and fault diagnosis for induction motors is one of the main industry maintenance parts. Motors faults usually result in whole production line breakdown. In this paper, one fault diagnosis system is proposed for induction motors based on feature recognition through combination of feature extraction, genetic algorithm and neural network techniques. From the paper, one can learn practically the whole procedure of feature‐based fault diagnosis system and the efficiency of GA and vibration signals for motor fault diagnosis. One real test has been done to validate the system performance. The results indicate that this system is promising for the real application in industry.

Originality/value

The use of genetic algorithm for feature selection and neural network tuning; the choice of vibration analysis for fault diagnosis of induction motor.

Details

Journal of Quality in Maintenance Engineering, vol. 13 no. 2
Type: Research Article
ISSN: 1355-2511

Keywords

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Book part

Oleg S. Glazachev

The deteriorating relationship between humans and the environment is a cause for our concern. On one hand, the human influence on nature has resulted in global climate…

Abstract

The deteriorating relationship between humans and the environment is a cause for our concern. On one hand, the human influence on nature has resulted in global climate change and a decline in the health of the world's oceans. On the other hand, it is evident that humans cannot adapt to new ecological conditions, as evidenced by new diseases. Is there any way out of the crisis?

Details

Cultures of Contamination
Type: Book
ISBN: 978-0-7623-1371-6

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Book part

Knut J. Ims and Ove D. Jakobsen†

The purpose of the chapter is to explore peace economics in the perspective of an organic worldview. Peace economics are discussed on two levels – the level of individual…

Abstract

The purpose of the chapter is to explore peace economics in the perspective of an organic worldview. Peace economics are discussed on two levels – the level of individual economic actor and the macro level related to the systemic interplay between economic actors. The main argument is that a change from shallow authenticity and competition towards deep authenticity and cooperation presupposes a paradigmatic shift from a mechanical to an organic worldview. Such a change in mindset should be supported by introducing peace economics in the curriculum on different levels of education. In an education for peace-building there should be a focus on what constitutes true personal development in the sense of obtaining more ‘inner’ peace as well as more peaceful interpersonal interactions. On the ‘outer’ spheres, the need for equity and joint projects is fundamental. The concept of equity emphasizes mutuality, equality and co-creative responsibility.

Details

Business, Ethics and Peace
Type: Book
ISBN: 978-1-78441-878-6

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