Bong-Kuk Ko, Woo-Jung Lee and Jae-Hoon Lee
The purpose of this study is to understand what health and safety hazards low-income households are subject to by surveying the real conditions of the defective housing of…
Abstract
The purpose of this study is to understand what health and safety hazards low-income households are subject to by surveying the real conditions of the defective housing of low-income households, and to find improvement strategies. For this purpose, we visited the concentrated areas of the multi-dwelling unit (MDU) (also known as multi-family residential) housing in Jungwon-gu and Sujeong-gu in Seongnam City, Kyunggi-do, one of the representative areas in Korea with a massive distribution of the low-income class. Based on the survey data, the level of housing defects were comparison analyzed per income decile (decile 1, decile 2, deciles 3–4), and per housing location, in the categories of subsidence, cracks in the wall, delamination, water leakage/infiltration, condensation, and contamination. The housing condition per income class was more defective in the decile 2 households rather than in the decile 2 households, and in the substructure more than in the superstructure. Among the six defects, contamination problems, caused by sub-standard living conditions, were the most frequent cases. Structural defects, subsidence and cracks in the wall, were found in the main living areas—the bedrooms and the living rooms. It was confirmed in this study that the conditions of low-income housing are serious, and that it is necessary to explore specific countermeasures in the near future.
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Christopher F. Parmeter, Zhiyuan Zheng and Patrick McCann
The link between the magnitude of a bandwidth and the relevance of the corresponding covariate in a regression has recently garnered theoretical attention. Theory suggests that…
Abstract
The link between the magnitude of a bandwidth and the relevance of the corresponding covariate in a regression has recently garnered theoretical attention. Theory suggests that variables included erroneously in a regression will be automatically removed when bandwidths are selected via cross-validation procedure. However, the connections between the bandwidths of the variables that are smoothed away and the insights from these same variables when properly tested for statistical significance have not been previously studied. This paper proposes a variety of simulation exercises to examine the relative performance of both cross-validated bandwidths and individual and joint tests of significance. We focus on settings where the hypothesis of interest may focus on a single data type (e.g., continuous only) or a mix of discrete and continuous variables. Moreover, we propose an extension of a well-known kernel smoothing significance test to handle mixed data types. Our results suggest that individual tests of significance and variable-specific bandwidths are very close in performance, but joint tests and joint bandwidth recognition produce substantially different results. This underscores the importance of testing for joint significance when one is trying to arrive at the final nonparametric model of interest.
Zhibang Qiao, Shanshan Lv, Jiyou Gu, Haiyan Tan, Junyou Shi and Yanhua Zhang
The purpose of this paper is to obtain high-solids-content and low-viscosity starch adhesive, and improve bonding strength of the pure starch adhesive.
Abstract
Purpose
The purpose of this paper is to obtain high-solids-content and low-viscosity starch adhesive, and improve bonding strength of the pure starch adhesive.
Design/methodology/approach
Maize starch was treated by hydrochloric acid solution with different concentrations, and acid-thinned starch adhesive was prepared. Polyisocyanate as a crosslinking agent was added to improve water resistance of the pure starch adhesive.
Findings
The physical and chemical properties of the acid-thinned starch adhesive were characterised. Acid hydrolysis did not change structure of starch granules, but increased its crystallinity. After acid modification, starch granules became less smooth and some fragments appeared. Acid treatment had little influence on thermal stability of starch, when acid hydrolysis was not strong. High concentration of HCl solution led to starch granules being destroyed, resulting in decrease in bonding strength. The optimal HCl concentration was 0.5 mol/L. Polyisocyanate addition was beneficial to improve the bonding strength of the acid-thinned starch adhesive.
Research limitations/implications
Acid hydrolysis changed the properties of the starch adhesive.
Practical implications
Acid hydrolysis decreased viscosity of the starch adhesive and improved its solids content, which had a positive effect on the application of the starch adhesive.
Social implications
It was helpful to develop an environment-friendly, natural polymer-based wood adhesive.
Originality/value
The properties of acid-thinned starch and acid-thinned starch adhesive were studied.
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Zongwu Cai, Jingping Gu and Qi Li
There is a growing literature in nonparametric econometrics in the recent two decades. Given the space limitation, it is impossible to survey all the important recent developments…
Abstract
There is a growing literature in nonparametric econometrics in the recent two decades. Given the space limitation, it is impossible to survey all the important recent developments in nonparametric econometrics. Therefore, we choose to limit our focus on the following areas. In Section 2, we review the recent developments of nonparametric estimation and testing of regression functions with mixed discrete and continuous covariates. We discuss nonparametric estimation and testing of econometric models for nonstationary data in Section 3. Section 4 is devoted to surveying the literature of nonparametric instrumental variable (IV) models. We review nonparametric estimation of quantile regression models in Section 5. In Sections 2–5, we also point out some open research problems, which might be useful for graduate students to review the important research papers in this field and to search for their own research interests, particularly dissertation topics for doctoral students. Finally, in Section 6 we highlight some important research areas that are not covered in this paper due to space limitation. We plan to write a separate survey paper to discuss some of the omitted topics.
Wentao Gu, Lixiang Li, Shangfeng Zhang and Ming Yi
The purpose of this article is to explore the impact of the firm's entrepreneurship for the transformation of circular economy (CE). The role of entrepreneurship is thought to be…
Abstract
Purpose
The purpose of this article is to explore the impact of the firm's entrepreneurship for the transformation of circular economy (CE). The role of entrepreneurship is thought to be important for the process of four Rs in the CE, and the authors have tried to study the role and impact path of entrepreneurship in CE.
Design/methodology/approach
Empirical data from Chinese listed firms are collected, and a measure of digital technology is constructed by text mining method. Mediation analysis method is used to test the proposed hypothesis.
Findings
The results show that the innovation entrepreneurship has a significant positive impact upon the CE and digital technology is playing a mediating role in the impact path. However, the business entrepreneurship is negatively affecting the CE adoption. Also, the proportion of shares hold by the institution has a heterogenous influence for the innovation entrepreneurship.
Practical implications
This study guides policy makers about the role of entrepreneurship and the mediating effect of digital technology and to encourage the adoption of CE for firms.
Originality/value
This study reveals the mediation effect of digital technology in the impact of entrepreneurship on CE in the emerging market. The heterogeneity of the proportion of shares hold by the institutions is also analyzed in the empirical study.
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Chunxing Gu, Li Dai, Di Zhang and Shuwen Wang
This paper aims to study the startup performance of thrust bearing. The effects of acceleration scenarios, roughness, the area ratio of texture and texture depth on the transient…
Abstract
Purpose
This paper aims to study the startup performance of thrust bearing. The effects of acceleration scenarios, roughness, the area ratio of texture and texture depth on the transient startup performance of the thrust bearing were analyzed.
Design/methodology/approach
The lubrication model is solved by the Reynolds equation with the mass-conservation boundary condition. The Greenwood and Tripp contact model is used to predict asperity contact load. The finite volume method is used to discretize the governing equations.
Findings
By studying the bearing performance with different acceleration functions, it was found that the higher the acceleration at the beginning of the startup, the faster the thrust bearing operates under the hydrodynamic lubrication regime in the start stage. It appears that the friction and contact time of asperity increase with the increasing roughness. The optimal area ratio of texture is within 30%–50%. The depth of texture ranging from 1 to 2 is the best.
Originality/value
This paper proposes a transient mixed lubrication analysis model of the thrust bearing. This model can be used to analyze the variations of tribological performance and lubrication regime of the thrust bearing under different acceleration scenarios.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2022-0268/
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Julie Dona and Susan J. Ferguson
Structural factors during Chinese and Japanese immigration and settlement processes required families to adapt in ways that altered traditional gender behaviors. This study…
Abstract
Structural factors during Chinese and Japanese immigration and settlement processes required families to adapt in ways that altered traditional gender behaviors. This study examines how two factors – spousal immigration order and family economic structure – affected the gendered division of labor and how gender roles consequently were reconstructed for first and second generation Chinese Americans and Japanese Americans. These issues are investigated through secondary data analysis of 21 in‐depth interviews with daughters of Chinese and Japanese immigrants on the West Coast.
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Jinlong Gu, Yong Yang and Roger Strange
This paper aims to link location choice and ownership structure to the debate on the multinationality–performance relationship.
Abstract
Purpose
This paper aims to link location choice and ownership structure to the debate on the multinationality–performance relationship.
Design/methodology/approach
This paper draws on a panel data set that covers 1,321 emerging economy multinational enterprises (EMNEs) and includes 4,227 observations from 44 emerging economies between 2004 and, 2013.
Findings
The empirical results find that multinationality has a positive effect on EMNEs’ performance, and that this positive effect is larger for their investments in developed countries than in developing countries. The study also finds that this positive effect of foreign operation in developed countries switch to negative at higher levels of multinationality for privately owned EMNEs than for state-owned EMNEs.
Originality/value
This paper provides new empirical evidence to support an institutional perspective of the internationalisation of EMNEs that are investing in developed countries, contributing to the multinationality-performance literature, highlighting the importance of foreign direct investment location decision and ownership structure.
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Rui Xu, Xiaoxuan Zhu, Yu Wang, Jibao Gu and Christian Felzensztein
Innovativeness is crucial for industrial cluster firms to gain sustained competitive advantage. This study aims to investigate the effects of inter-firm coopetition on firm…
Abstract
Purpose
Innovativeness is crucial for industrial cluster firms to gain sustained competitive advantage. This study aims to investigate the effects of inter-firm coopetition on firm innovativeness within a cluster and examines the moderating role of institutional support.
Design/methodology/approach
This research adopts an empirical survey method using multi-source data from 181 industrial cluster firms. Regression is used to test the hypotheses of this study.
Findings
The results show that cooperation and constructive conflict promote firm innovativeness, while destructive conflict is detrimental to firm innovativeness. Moreover, the study also finds that cooperation interacts with both types of conflict to affect firm innovativeness, where cooperation and constructive conflict interact negatively on firm innovativeness, while cooperation and destructive conflict interact positively on firm innovativeness. In addition, institutional support weakens the effects of cooperation and destructive conflict on innovativeness, respectively, but has no significant moderating effect on the relationship between constructive conflict and innovativeness.
Originality/value
These findings enrich the current research on coopetition. The interaction effects of cooperation and both types of conflict on innovativeness deepen the concept of coopetition and responds to the call to further explore the interaction effects within coopetition. The moderating role of institutional support fills a gap in the empirical research on the role of institutional factors affecting coopetition on innovation and also provides valuable suggestions for firm managers and governments in industrial clusters.
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R.X. Cheng and J.Y. Gu
The purpose of this paper is to study the bonding properties of Larch with water‐based polymer isocynate (WPI) adhesive to provide theoretical instruction for practical production…
Abstract
Purpose
The purpose of this paper is to study the bonding properties of Larch with water‐based polymer isocynate (WPI) adhesive to provide theoretical instruction for practical production of Larch glued laminated timber with WPI adhesive.
Design/methodology/approach
This study adopted Japanese JIS K6806 standard to test bonding properties of Larch with WPI adhesive. Scanning electron microscope was used to observe morphography of Larch surface. Micro photos were adopted to show the penetration of WPI adhesive on the radial and tangential surfaces of Larch.
Findings
There was significant difference in bonding strength between Larch radial and tangential glue‐blocks glued with WPI adhesive. Dry compressing shear strength of Larch radial glue‐block bonded with WPI adhesive was 1.41 times that of Larch tangential glue‐block bonded with WPI adhesive in normal conditions. Wood failure showed that the difference between Larch radial and tangential glue‐block was caused by wood structure of Larch itself.
Research limitations/implications
The research conclusion that the dry compressing shear strength of Larch radial glue‐block bonded with WPI adhesive was bigger than that of Larch tangential glue‐block bonded in normal conditions. These would be changed if other adhesives were adopted to glue Larch wood.
Practical implications
The conclusion developed in this study provided a practical production instruction for Larch glued laminated timber with WPI adhesive. In order to obtain better bonding properties during the production of Larch glued laminated wood, Larch wood should be sawn into radial boards rather than tangential boards in order to obtain maximum bonding strength of Larch wood.
Originality/value
The paper shows that there was significant difference in bonding strength between Larch radial and tangential glue‐bonded blocks with WPI adhesive. Dry compressing shear strength of Larch radial glue‐block bonded with WPI adhesive was 1.41 times that of Larch tangential glue‐block bonded with WPI adhesive in normal conditions.