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Article
Publication date: 19 June 2017

Jun Huang, Haibo Wang and Gary Kochenberger

The authors develop a framework to build an early warning mechanism in detecting financial deterioration of Chinese companies. Many studies in the financial distress and…

Abstract

Purpose

The authors develop a framework to build an early warning mechanism in detecting financial deterioration of Chinese companies. Many studies in the financial distress and bankruptcy prediction literature rarely do they examine the impact of pre-processing financial indicators on the prediction performance. The purpose of this paper is to address this shortcoming.

Design/methodology/approach

The proposed framework is evaluated by using both original and discretized data, and a least absolute shrinkage and selection operator (LASSO) selection technique for choosing an appropriate subset of financial ratios for improved predictive performance. The financial ratios are then analyzed by five different data mining techniques. Managerial insights, using data from Chinese companies, are revealed by the methodology employed.

Findings

The prediction accuracy increases after we discretized the continuous variables of financial ratios. A better prediction performance can be achieved by including fewer, but relatively more significant variables. Random forest has the highest overall performance following closely by SVM and neural network.

Originality/value

The contribution of this study is fourfold. First, the authors add to the literature on defaults by showing variable discretization to be an essential pre-processing step to improve the prediction performance for classification problems. Second, the authors demonstrate that machine learning approaches can achieve better performance than traditional statistical methods in classification tasks. Third, the authors provide the evidence for the adoption of C5.0 over other methods because rules generated with C5.0 provide managerial insights for managers. Finally, the authors demonstrate the effectiveness of the LASSO technique for identifying the most important financial ratios from each category, enabling one to build better predictive models.

Details

Management Decision, vol. 55 no. 5
Type: Research Article
ISSN: 0025-1747

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Article
Publication date: 28 May 2021

Zhibin Xiong and Jun Huang

Ensemble models that combine multiple base classifiers have been widely used to improve prediction performance in credit risk evaluation. However, an arbitrary selection…

Abstract

Purpose

Ensemble models that combine multiple base classifiers have been widely used to improve prediction performance in credit risk evaluation. However, an arbitrary selection of base classifiers is problematic. The purpose of this paper is to develop a framework for selecting base classifiers to improve the overall classification performance of an ensemble model.

Design/methodology/approach

In this study, selecting base classifiers is treated as a feature selection problem, where the output from a base classifier can be considered a feature. The proposed correlation-based classifier selection using the maximum information coefficient (MIC-CCS), a correlation-based classifier selection under the maximum information coefficient method, selects the features (classifiers) using nonlinear optimization programming, which seeks to optimize the relationship between the accuracy and diversity of base classifiers, based on MIC.

Findings

The empirical results show that ensemble models perform better than stand-alone ones, whereas the ensemble model based on MIC-CCS outperforms the ensemble models with unselected base classifiers and other ensemble models based on traditional forward and backward selection methods. Additionally, the classification performance of the ensemble model in which correlation is measured with MIC is better than that measured with the Pearson correlation coefficient.

Research limitations/implications

The study provides an alternate solution to effectively select base classifiers that are significantly different, so that they can provide complementary information and, as these selected classifiers have good predictive capabilities, the classification performance of the ensemble model is improved.

Originality/value

This paper introduces MIC to the correlation-based selection process to better capture nonlinear and nonfunctional relationships in a complex credit data structure and construct a novel nonlinear programming model for base classifiers selection that has not been used in other studies.

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Article
Publication date: 9 May 2016

Jun Huang, Weiwen Li, Canhua Qiu, Frederick Hong-kit Yim and Junbao Wan

The purpose of this paper is to draw on the theory of servant leadership to examine the influence of chief executive officer (CEO) servant leadership on firm performance…

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Abstract

Purpose

The purpose of this paper is to draw on the theory of servant leadership to examine the influence of chief executive officer (CEO) servant leadership on firm performance in the hospitality industry. It examined the mediating role of the service climate and the moderating role of competitive intensity in the relationship between CEO servant leadership and firm performance.

Design/methodology/approach

Multiple regression was used to analyze multi-wave, multi-source data from 92 hotels in China. A moderated path analysis was used to test the moderating effects.

Findings

CEO servant leadership positively influenced firm performance via the service climate in the hospitality industry. Competitive intensity strengthened the direct effect of the service climate on firm performance, and the indirect effect of CEO servant leadership on firm performance via service climate.

Research limitations/implications

The findings offer managerial insights into CEO succession, service management and human resource management.

Originality/value

This is one of the first studies to investigate how and when CEO servant leadership might shape firm outcomes in the hospitality industry. Theoretically, the findings enrich our understanding of how CEO leadership might shape firm-level outcomes.

Details

International Journal of Contemporary Hospitality Management, vol. 28 no. 5
Type: Research Article
ISSN: 0959-6119

Keywords

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Article
Publication date: 29 July 2021

Xingquan Wang, Xiuyuan Lu, Wei Chen, Fengpeng Wang, Jun Huang, Lingli Liu, Mengchao Li and Kui Lin

This paper aims to improve the general circuit of driving and protection based on insulated gate bipolar transistor (IGBT) in dielectric barrier discharge power supply by…

Abstract

Purpose

This paper aims to improve the general circuit of driving and protection based on insulated gate bipolar transistor (IGBT) in dielectric barrier discharge power supply by designing a novel half-bridge inverter circuit with discrete components.

Design/methodology/approach

With one SG3524 chip, the structure based on discrete components is used to design the IGBT drive circuit. The driving waveform is isolated and sent out by photo-coupler 6N137. The protection circuit is realized by Hall sensor directly detecting the main circuit current, supplemented by a few components, including diodes, resistors, capacitors and triodes. It improves the reliability of the protection circuit.

Findings

In the driving circuit, the phase difference of signals from two channels are 180°. Moreover, when the duty cycle is set at 40%, it can ensure sufficient pulse width modulation response time. In the protection circuit, when over-current occurs, an intermittent output signal is automatically sent out. Furthermore, the over-current response time can be controlled independently. The peak voltage can be adjusted continuously from 0 to 30 kV with its frequency from 8 to 25 kHz and the power output up to 150 W.

Originality/value

The novel circuit of driving and protection makes not only its structure simpler and easier to be realized but also key parameters, such as frequency, the duty cycle and the driving voltage, continuously adjustable. Moreover, the power supply is suitable for other discharges such as corona discharge and jet discharge.

Details

Circuit World, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 8 May 2017

Jun Huang and Haibo Wang

The purpose of this paper is to identify a subset of key financial ratios and factors that provide the best discriminating power to distinguish between creditworthy…

Abstract

Purpose

The purpose of this paper is to identify a subset of key financial ratios and factors that provide the best discriminating power to distinguish between creditworthy companies (CWCs) and less creditworthy companies (LCWCs) in the USA with the proposed method.

Design/methodology/approach

A proposed framework of Bisection Method Based on Tabu Search + Support Vector Machines (BMTS + SVM) is used to select subset of financial ratios from a pool of candidate ratios. The selected ratios and their corresponding financial factors are considered as the key financial ratios and factors that provide the best discriminating power to distinguish between CWCs and LCWCs. The authors collected financial data for the US companies and then identify the key financial ratios and factors which the selected key financial ratios belong.

Findings

It is found that the four selected financial ratios from the proposed method and eight financial ratios which are used by Standard & Poor for their credit-rating system can be attributed to the same four financial factors, namely, cash flow factor, profitability factor, solvency factor and leverage factor. This result lends support that the proposed method can be applied to identify key financial factors to differentiate CWCs and LCWCs.

Practical implications

This study provides a tool for managers in financial institutions to gain better understanding about the credit risk of their applicants by focusing on a parsimonious model with fewer ratios in the key financial factors. In addition, companies that attempt to borrow money from financial institutions can also use these key financial ratios and factors as reference to attain clearer vision on what are the most important factors for being considered a creditworthy company and thus develop specific strategies to improve their financial performance.

Originality/value

Based on data analytic techniques, this paper identifies key financial ratios and factors for examining the creditworthiness of US companies with the proposed framework using BMTS + SVM method.

Details

Journal of Modelling in Management, vol. 12 no. 2
Type: Research Article
ISSN: 1746-5664

Keywords

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Article
Publication date: 5 March 2018

Guo Zhong, Jun Huang and Mingxu Yi

The purpose of this paper is to reduce the acoustic noise of helicopter ducted tail rotor.

Abstract

Purpose

The purpose of this paper is to reduce the acoustic noise of helicopter ducted tail rotor.

Design/methodology/approach

To predict the noise accurately, a thin-body boundary element method (BEM)/Ffowcs Williams–Hawkings method is developed in this paper. It is a hybrid method combining the BEM with computational aeroacoustics and can be used efficiently to predict the propagation of sound wave in the duct.

Findings

Compared with the experimental results, the proposed method of acoustic noise is rather desirable.

Practical implications

Then several geometry parameters are modified to investigate the noise reduction of ducted tail rotor by using the numerical prediction method.

Originality/value

The aerodynamic and acoustic performance of different modification tasks is discussed. These results demonstrate the validity of design parameters modification of ducted tail rotor in acoustic noise reduction.

Details

Aircraft Engineering and Aerospace Technology, vol. 90 no. 2
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 12 February 2019

Yalin Pan and Jun Huang

The purpose of this study is to analyze influence of airfoil profile on lateral-directional flying quality of flying wing aircraft. The lateral-directional stability is…

Abstract

Purpose

The purpose of this study is to analyze influence of airfoil profile on lateral-directional flying quality of flying wing aircraft. The lateral-directional stability is always insufficient for aircraft with the layout due to the absence of vertical stabilizer. A flying wing aircraft with double-swept wing is used as research object in the paper.

Design/methodology/approach

The 3D model is established for the aircraft with flying wing layout, and parametric modeling is carried out for airfoil mean camber line of the aircraft to analyze lateral-directional stability of the aircraft with different camber line parameters. To increase computational efficiency, vortex lattice method is adopted to calculate aerodynamic coefficients and aerodynamic derivatives of the aircraft.

Findings

It is found from the research results that roll mode and spiral mode have a little effect on lateral-directional stability of the aircraft but Dutch roll mode is the critical factor affecting flying quality level of such aircraft. Even though changes of airfoil mean line parameters can greatly change assessment parameters of aircraft lateral-directional flying quality, that is kind of change cannot have a fundamental impact on level of flying quality of the aircraft. In case flat shape parameters are determined, the airfoil profile has a limited impact on Dutch roll mode.

Originality/value

Influences of airfoil profile on lateral-directional flying quality of aircraft with double-swept flying wing layout are revealed in the thesis and some important rules and characteristics are also summarized to lay a theoretical basis for design of airfoil and flight control system of aircraft with the layout.

Details

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

Keywords

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Article
Publication date: 11 June 2020

Shaoze Lu, Jun Huang and Mingxu Yi

By reducing the coating thickness of the weak scattering source, the coating weight of the absorbing material can be reduced by 35% with little effect on the RCS.

Abstract

Purpose

By reducing the coating thickness of the weak scattering source, the coating weight of the absorbing material can be reduced by 35% with little effect on the RCS.

Design/methodology/approach

To alleviate the weight-increasing problem caused by a large number of coating of absorbing materials, a method for zonal coating of absorbing materials for a stealth helicopter was proposed. By appropriately reducing the thickness of the coating at the secondary scattering locations, the amount of coating used is significantly reduced.

Findings

Compared with the full-coated, the zonal coating scheme achieves the corresponding RCS reduction effect.

Practical implications

Zonal coating design can achieve the effect of reducing coating weight and cost.

Originality/value

The effects of different coating methods on RCS were verified by electromagnetic scattering simulation, and the applicability of the zonal coating design of the absorbing material to the stealth helicopter was verified.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 7
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 23 July 2019

Yacong Wu, Jun Huang, Mingxu Yi and Chaopu Zhang

The purpose of this paper is to introduce the theoretical basis of N-order spectral spreading-compressing (SSC) frequency shift interference algorithm and expand it to…

Abstract

Purpose

The purpose of this paper is to introduce the theoretical basis of N-order spectral spreading-compressing (SSC) frequency shift interference algorithm and expand it to active cancellation. An active cancellation simulation and verification system based on N-order SSC algorithm is established and carried out; simultaneously, the absorbing material coating stealth simulation of two kinds of thickness is carried out to compare the stealth effect with active cancellation system.

Design/methodology/approach

The active cancellation method based on N-order SSC algorithm is proposed based on theoretical formula derivation; the active cancellation simulation and verification system is established in MATLAB/Simulink. The full-size model is built by CATIA and meshed by hypermesh. The omnidirectional radar cross section (RCS) is calculated in cadFEKO, and the results are analyzed in postFEKO.

Findings

The simulations are implemented on a stealth fighter, and results show that after active cancellation, the peak of spectrum analyzer has reduced in all azimuths, the omnidirectional RCS has also decreased and the detection probability of almost all azimuths has dropped under 50 per cent. The absorbing material coating stealth simulations of two kinds of thickness are carried out, and results show that the stealth effect of active cancellation is much better than absorbing material coating.

Practical implications

An active cancellation system based on SSC algorithm is proposed in this paper, and the effect of active cancellation is verified and compared with that of absorbing materials. A new method for the current active stealth is provided in this paper.

Originality/value

Active cancellation simulation and verification system is established. RCS calculation module, signal-to-noise-ratio (SNR) calculation module and detection probability module are built to verify the effect of active cancellation system. Simultaneously, the absorbing material coating stealth simulation is carried out, and the stealth effect of absorbing material coating and active cancellation are compared and analyzed.

Details

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

Keywords

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Article
Publication date: 17 October 2018

Jingcheng Fu, Jun Huang, Li-Bo Wang and Lei Song

The purpose of this paper is to propose an identification method of acquiring aircraft mode characteristics based on fast Fourier transform and half-power bandwidth…

Abstract

Purpose

The purpose of this paper is to propose an identification method of acquiring aircraft mode characteristics based on fast Fourier transform and half-power bandwidth method, aiming at the common oscillation met in flight test.

Design/methodology/approach

The feasibility of this method is demonstrated through derivation; the robustness analysis is conducted through three examples, and finally the method was applied on a set of sideslip angle record from flight test.

Findings

The derivation and numerical analysis both show that the presented method can have high accuracy and good robustness under coupled mode and noise condition.

Practical implications

The method proposed is of robustness, and it is concise and easy to apply on flight data record.

Originality/value

This paper demonstrates the feasibility of half power bandwidth to be applied on oscillation mode characteristics identification from flight data record, which is different from other method applied.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

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