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Article
Publication date: 4 February 2020

Dong Tang, Li Wang, Yang Liu, Ning Liu, Yuzhe Wu and Lie Chen

This paper aims to design and optimize the threaded fastener of leakage current particulate matter (PM) sensor. The corresponding air-tight test is conducted to ensure the…

Abstract

Purpose

This paper aims to design and optimize the threaded fastener of leakage current particulate matter (PM) sensor. The corresponding air-tight test is conducted to ensure the reliability of the installation strategy with screw connection.

Design/methodology/approach

Research on the pressure-deformation curve of seal gasket was conducted and the vibration load of engine was considered for the calculation of the minimum installation pre-tightening force. Simultaneously, the danger threaded section area was calculated, and the carrying capacity was verified. The height of the welding line was studied to ensure the reliability of the application. FEA was carried out to acquire the relationship between local structure size and local stress for continuous improvement of thread connection. The installation torque range was acquired from the torque control principle for the pre-tightening force. The sealing reliability of the connector was proved with leakage.

Findings

The air tightness of the thread connector is proved to be fine. When the pre-tightening force is over 8,000 N, and its length reaches 2 mm, the connector has good reliability at ambient temperature. The tightening torque of 60-74 Nm can guarantee the reliable fixing ability of thread connector, and its plastic non-deformation ability in the process of repeated tearing down.

Originality/value

This paper provides an installation strategy and an optimization of PM sensor, which has a positive effect on the study and the manufacture of PM sensor. It is helpful to further develop PM sensor and after-treatment technology. This kind of real-time monitoring PM sensor needs to be studied further to achieve its commercial application.

Details

Sensor Review, vol. 40 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 6 October 2021

Kuo-Ning Liu and Clark Hu

The purpose is to understand the importance of brand experience in the Taiwan hotel branding process; also, this study is to investigate the moderating effect of brand…

Abstract

Purpose

The purpose is to understand the importance of brand experience in the Taiwan hotel branding process; also, this study is to investigate the moderating effect of brand experience on the relationship between brand positioning and non-financial brand performance in Taiwan upscale hotels, focusing on mainland Chinese tourists.

Design/methodology/approach

The structural equation modeling (SEM) analysis was used to conduct questionnaire analysis. This study examined data collected from Chinese tourists who stayed at Taiwan upscale hotels.

Findings

The brand experience of an upscale hotel brand can affect its brand image, product attributes, brand loyalty and customer satisfaction. By investigating the moderating effect of brand experience, the study revealed the brand image perceptions of hotel guests with a positive brand experience to significantly influence non-financial brand performance. The product attribute perceptions of hotel guests with a more positive brand experience were also found to have a more significant effect on nonfinancial brand performance.

Originality/value

In the highly competitive hotel industry, the application of brand experience to marketing practice has drawn much industry attention. There is a strong possibility that upscale hotel companies will eventually find value in adopting the measurement instruments and suggestions presented here to assess and guide their marketing practices.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 34 no. 7
Type: Research Article
ISSN: 1355-5855

Keywords

Article
Publication date: 10 December 2021

Kuo-Ning Liu and Clark Hu

This study aims to address research gaps by constructing critical success factors (CSFs) in the context of green hotel investment in Taiwan. It contributes to the domain…

Abstract

Purpose

This study aims to address research gaps by constructing critical success factors (CSFs) in the context of green hotel investment in Taiwan. It contributes to the domain knowledge to cultivate Taiwan’s green hotel development in the future.

Design/methodology/approach

The authors secured 20 prominent green hotel management/owners/architects as crucial informants. The first stage used the Delphi method to collect expert opinions (i.e. CSFs) and the second stage applied the analytic hierarchy process to analyze the importance of CSFs.

Findings

The results show that the “financial investment benefits” is considered the most crucial success factor for the green hotel investment. However, to balance long-term economic development with environmental impact, green hotel investors should consider other aspects of the research to sustain future financial performance returns.

Research limitations/implications

Further studies should consider regional characteristics to accommodate geographic/social differences and hotel types to explore possible CSFs for the green hotel investment. The authors suggest including panel experts from government officials and prominent scholars to represent a broader but different view on subject matters. They also offer implications for investors’ governmental policies, hotelier cognition and customer-related aspects in green hotel investment.

Originality/value

This study built a hierarchical framework based on the CSF concept by evaluating priority differences between hotel management and hotel owners/architects. Such findings help investors’ effective decision-making through considering factors’ relative importance for green hotel investments.

Details

International Journal of Contemporary Hospitality Management, vol. 34 no. 3
Type: Research Article
ISSN: 0959-6119

Keywords

Article
Publication date: 6 February 2017

Hong Gao, Tianxiang Yao and Xiaoru Kang

The purpose of this paper is to predict the population of Anhui province. The authors analyze the trend of the main demographic indicators.

Abstract

Purpose

The purpose of this paper is to predict the population of Anhui province. The authors analyze the trend of the main demographic indicators.

Design/methodology/approach

On the basis of the main methods of statistics, this paper studies the tendency of the population of Anhui province. It mainly analyzes the sex structure and the age structure of the current population. Based on the GM(1,1) model, this paper forecasts the total population, the population sex structure, and the population age structure of Anhui province in the next ten years.

Findings

The results show that the total population was controlled well, but there have been many problems of the population structure, such as the aging population, high sex ratio, heavy social dependency burden, and the declining labor force.

Social implications

This paper forecasts the main indexes of the population of Anhui province and provides policy recommendations for the government and the relevant departments.

Originality/value

This paper utilizes data analysis method and the grey forecasting model to study the tendency of the population problems in Anhui province.

Details

Grey Systems: Theory and Application, vol. 7 no. 1
Type: Research Article
ISSN: 2043-9377

Keywords

Article
Publication date: 6 June 2016

Ema Kusen and Mark Strembeck

Ever since Mark Weiser coined the term “ubiquitous computing” (ubicomp) in 1988, there has been a general interest in proposing various solutions that would support his…

Abstract

Purpose

Ever since Mark Weiser coined the term “ubiquitous computing” (ubicomp) in 1988, there has been a general interest in proposing various solutions that would support his vision. However, attacks targeting devices and services of a ubicomp environment have demonstrated not only different privacy issues, but also a risk of endangering user’s life (e.g. by modifying medical sensor readings). Thus, the aim of this paper is to provide a comprehensive overview of security challenges of ubicomp environments and the corresponding countermeasures proposed over the past decade.

Design/methodology/approach

The results of this paper are based on a literature review method originally used in evidence-based medicine called systematic literature review (SLR), which identifies, filters, classifies and summarizes the findings.

Findings

Starting from the bibliometric results that clearly show an increasing interest in the topic of ubicomp security worldwide, the findings reveal specific types of attacks and vulnerabilities that have motivated the research over the past decade. This review describes most commonly proposed countermeasures – context-aware access control and authentication mechanisms, cryptographic protocols that account for device’s resource constraints, privacy-preserving mechanisms, and trust mechanisms for wireless ad hoc and sensor networks.

Originality/value

To the best of our knowledge, this is the first SLR on security challenges in ubicomp. The findings should serve as a reference to an extensive list of scientific contributions, as well as a guiding point for the researchers’ novel to the security research in ubicomp.

Details

International Journal of Pervasive Computing and Communications, vol. 12 no. 2
Type: Research Article
ISSN: 1742-7371

Keywords

Article
Publication date: 3 April 2017

Xin Li, Jianzhong Shang and Hong Zhu

This paper aims to consider a problem of assembly sensitivity in a multi-station assembly process. The authors focus on the assembly process of aircrafts, which includes…

Abstract

Purpose

This paper aims to consider a problem of assembly sensitivity in a multi-station assembly process. The authors focus on the assembly process of aircrafts, which includes cabins and inertial navigation system (INSs), and establish the assembly process state space model for their assembly sensitivity research.

Design/methodology/approach

To date, the process-related errors that cause large variations in key product characteristics remains one of the most critical research topics in assembly sensitivity analysis. This paper focuses on the unique challenges brought about by the multi-station system: a system-level model for characterizing the variation propagation in the entire process, and the necessity of describing the system response to variation inputs at both station-level and single fixture-level scales. State space representation is used to describe the propagation of variation in such a multi-station process, incorporating assembly process parameters such as fixture-locating layout at individual stations and station-to-station locating layout change.

Findings

Following the sensitivity analysis in control theory, a group of hierarchical sensitivity indices is defined and expressed in terms of the system matrices in the state space model, which are determined by the given assembly process parameters.

Originality/value

A case study of assembly sensitivity for a multi-station assembly process illustrates and validates the proposed methodology.

Details

Assembly Automation, vol. 37 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 10 June 2022

Minjuan Zhang, Ning Jing, Zhen Liu, Chunyang Li and Ning Zhang

An interferogram is produced by modulating the difference between the extraordinary refractive index and the ordinary refractive index for photoelastic crystals in…

Abstract

Purpose

An interferogram is produced by modulating the difference between the extraordinary refractive index and the ordinary refractive index for photoelastic crystals in photoelastic-modulated Fourier transform spectrometers (PEM-FTs). Due to the influence of the refractive index dispersion characteristics on the maximum optical path difference of the interferogram, it is necessary to study wavelength calibration methods.

Design/methodology/approach

A wavelength calibration method for PEM-FTs was proposed based on the modulation principle of the photoelastic-modulated interferometer and the relationship between the maximum optical path difference and the refractive index difference. A 632.8 nm narrow-pulse laser was used as a reference source to measure the maximum optical path difference () of the interferogram, and the parameter was used to calculate the discrete frequency points in the frequency domain. To account for the influence of refractive index dispersion on the maximum optical path difference, the refractive index curve for the photoelastic crystal was used to adjust the discrete frequency coordinates.

Findings

The error in the reconstructed spectral frequency coordinates clearly decreased. The maximum relative error was 2.5%. A good solar absorption spectrum was obtained with a PEM-FT experimental platform and the wavelength calibration method.

Originality/value

The interferogram is produced by adjusting the difference between extraordinary refractive index and ordinary refractive index for the photoelastic crystal in the PEM-FTs. Given the wavelength dependence on the refractive indices, in view of the modulation principle of the photoelastic modulated interferometer, the relationship between the maximum optical path difference and the refractive index difference, the variation law of the refractive index of the photoelastic crystal and the process of spectral reconstruction is presented in this paper.

Details

Sensor Review, vol. 42 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 9 August 2019

Ijlal Şimşek

This paper aims to investigate the effects of second phase precipitate size on microstructure, hardness, density, corrosion and electrical conductivity of 7075 aluminum…

Abstract

Purpose

This paper aims to investigate the effects of second phase precipitate size on microstructure, hardness, density, corrosion and electrical conductivity of 7075 aluminum alloy fabricated by the powder metallurgy method and aged at 120°C for various aging periods.

Design/methodology/approach

For the aging process (T6), these alloys were solution-treated at 485°C for 2 h, quenched, aged at 120°C for four various periods and finally air cooled. After the aging process, these alloys were examined with scanning electron microscope, X-ray diffraction, density and hardness measurements. The corrosion tests were carried out using the potentiodynamic polarization technique; electrical conductivity values were measured as IACS%.

Findings

Results showed that the precipitate size increased with increasing aging period and the maximum precipitate size was achieved for the sample aged for 28 h. The maximum hardness was attained for the sample aged for 24 h, while the same specimen obtained the lowest electrical conductivity and corrosion resistance.

Originality/value

In this research, second phase precipitates of heat treatment processing affected the electrical conductivity and corrosion behavior of the 7075 aluminum alloy. Also it is understood that the heat treatment period is an effective parameter on these properties.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 30 June 2022

Miguel Ángel Caminero, Ana Romero Gutiérrez, Jesús Miguel Chacón, Eustaquio García-Plaza and Pedro José Núñez

The extrusion-based additive manufacturing method followed by debinding and sintering steps can produce metal parts efficiently at a relatively low cost and material…

Abstract

Purpose

The extrusion-based additive manufacturing method followed by debinding and sintering steps can produce metal parts efficiently at a relatively low cost and material wastage. In this study, 316L stainless-steel metal filled filaments were used to print metal parts using the extrusion-based fused filament fabrication (FFF) approach. The purpose of this study is to assess the effects of common FFF printing parameters on the geometric and mechanical performance of FFF manufactured 316L stainless-steel components.

Design/methodology/approach

The microstructural characteristics of the metal filled filament, three-dimensional (3D) printed green parts and final sintered parts were analysed. In addition, the dimensional accuracy of the green parts was evaluated, as well as the hardness, tensile properties, relative density, part shrinkage and the porosity of the sintered samples. Moreover, surface quality in terms of surface roughness after sintering was assessed. Predictive models based on artificial neural networks (ANNs) were used for characterizing dimensional accuracy, shrinkage, surface roughness and density. Additionally, the response surface method based on ANNs was applied to represent the behaviour of these parameters and to identify the optimum 3D printing conditions.

Findings

The effects of the FFF process parameters such as build orientation and nozzle diameter were significant. The pore distribution was strongly linked to the build orientation and printing strategy. Furthermore, porosity decreased with increased nozzle diameter, which increased mechanical performance. In contrast, lower nozzle diameters achieved lower roughness values and average deviations. Thus, it should be noted that the modification of process parameters to achieve greater geometrical accuracy weakened mechanical performance.

Originality/value

Near-dense 316L austenitic stainless-steel components using FFF technology were successfully manufactured. This study provides print guidelines and further information regarding the impact of FFF process parameters on the mechanical, microstructural and geometric performance of 3D printed 316L components.

Article
Publication date: 7 July 2022

Jintian Hu, Jin Liu, Yidi Wang and Xiaolin Ning

This study aims to address the problem of the divergence of traditional inertial navigation system (INS)/celestial navigation system (CNS)-integrated navigation for…

Abstract

Purpose

This study aims to address the problem of the divergence of traditional inertial navigation system (INS)/celestial navigation system (CNS)-integrated navigation for ballistic missiles. The authors introduce Doppler navigation system (DNS) and X-ray pulsar navigation (XNAV) to the traditional INS/CNS-integrated navigation system and then propose an INS/CNS/DNS/XNAV deep integrated navigation system.

Design/methodology/approach

DNS and XNAV can provide velocity and position information, respectively. In addition to providing velocity information directly, DNS suppresses the impact of the Doppler effect on pulsar time of arrival (TOA). A pulsar TOA with drift bias is observed during the short navigation process. To solve this problem, the pulsar TOA drift bias model is established. And the parameters of the navigation filter are optimised based on this model.

Findings

The experimental results show that the INS/CNS/DNS/XNAV deep integrated navigation can suppress the drift of the accelerometer to a certain extent to improve the precision of position and velocity determination. In addition, this integrated navigation method can reduce the required accuracy of inertial navigation, thereby reducing the cost of missile manufacturing and realising low-cost and high-precision navigation.

Originality/value

The velocity information provided by the DNS can suppress the pulsar TOA drift, thereby improving the positioning accuracy of the XNAV. This reflects the “deep” integration of these two navigation methods.

Details

Aircraft Engineering and Aerospace Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1748-8842

Keywords

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