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1 – 10 of 416Ryuichi Kobayashi and Ming Yang
Orange peel formation remains to be understood clearly because it is difficult to directly observe a laser-sintered process in a partcake. Therefore, this study aims to provide…
Abstract
Purpose
Orange peel formation remains to be understood clearly because it is difficult to directly observe a laser-sintered process in a partcake. Therefore, this study aims to provide insight into the orange peel formation mechanism through the nondestructive observation of laser-sintered specimens and their surrounding powders.
Design/methodology/approach
This study observed polyamide 12 powder in the vicinity of a laser-sintered specimen via X-ray computed tomography (CT) scanning. The specimen for nondestructive observation was 3D modeled in a hollow box using 3D CAD software. The boxes built using a laser-sintering system contained unsintered surrounding powder and sintered specimens. The box contents were preserved even after the boxes were removed from the partcake. After X-ray CT scanning, the authors broke the boxes and evaluated the unevenness formed on the specimen surface (i.e. the orange peel evaluation).
Findings
Voids (not those in sintered parts) generated in the powder in the vicinity of the specimen triggered the orange peel formation. Voids were less likely to form in the build with a 178.5° powder bed than in the build with a 173.5° powder bed. Similarly, the increment in laser energy density effectively suppressed void formation, although there was a tradeoff with overmelting. Thin-walled parts avoided void growth and made the orange peel less noticeable.
Originality/value
To the best of the authors’ knowledge, this study is the first to observe and understand the relationship between voids generated in the powder in the vicinity of sintered parts and orange peel formation.
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Tong-Tong Lin, Ming-Zhi Yang, Lei Zhang, Tian-Tian Wang, Yu Tao and Sha Zhong
The aerodynamic differences between the head car (HC) and tail car (TC) of a high-speed maglev train are significant, resulting in control difficulties and safety challenges in…
Abstract
Purpose
The aerodynamic differences between the head car (HC) and tail car (TC) of a high-speed maglev train are significant, resulting in control difficulties and safety challenges in operation. The arch structure has a significant effect on the improvement of the aerodynamic lift of the HC and TC of the maglev train. Therefore, this study aims to investigate the effect of a streamlined arch structure on the aerodynamic performance of a 600 km/h maglev train.
Design/methodology/approach
Three typical streamlined arch structures for maglev trains are selected, i.e. single-arch, double-arch and triple-arch maglev trains. The vortex structure, pressure of train surface, boundary layer, slipstream and aerodynamic forces of the maglev trains with different arch structures are compared by adopting improved delayed detached eddy simulation numerical calculation method. The effects of the arch structures on the aerodynamic performance of the maglev train are analyzed.
Findings
The dynamic topological structure of the wake flow shows that a change in arch structure can reduce the vortex size in the wake region; the vortex size with double-arch and triple-arch maglev trains is reduced by 15.9% and 23%, respectively, compared with a single-arch maglev train. The peak slipstream decreases with an increase in arch structures; double-arch and triple-arch maglev trains reduce it by 8.89% and 16.67%, respectively, compared with a single-arch maglev train. The aerodynamic force indicates that arch structures improve the lift imbalance between the HC and TC of a maglev train; double-arch and triple-arch maglev trains improve it by 22.4% and 36.8%, respectively, compared to a single-arch maglev train.
Originality/value
This study compares the effects of a streamlined arch structure on a maglev train and its surrounding flow field. The results of the study provide data support for the design and safe operation of high-speed maglev trains.
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He Du, Ming Yang, Songyan Wang and Tao Chao
This paper aims to investigate a novel impact time control guidance (ITCG) law based on the sliding mode control (SMC) for a nonmaneuvering target using the predicted interception…
Abstract
Purpose
This paper aims to investigate a novel impact time control guidance (ITCG) law based on the sliding mode control (SMC) for a nonmaneuvering target using the predicted interception point (PIP).
Design/methodology/approach
To intercept the target with the minimal miss distance and desired impact time, an estimation of time-to-go is introduced. This estimation results in a precise impact time for multimissiles salvo attack the target at the same time. Even for a large lead angle, the desired impact time is achieved by using the sliding mode and Lyapunov stability theory. The singularity issue of the proposed impact time guidance laws is also analyzed to achieve an arbitrary lead angle with the desired impact time.
Findings
Numerical scenarios with desired impact time are presented to illustrate the performance of the proposed ITCG law. Comparison with the state-of-art impact time guidance laws proves that the guidance law in this paper can enable the missile to intercept the target with minimal miss distance and final impact time error. This method enables multiple missiles to attack the target simultaneously with different distances and arbitrary lead angles.
Originality/value
An ITCG law based on sliding mode and Lyapunov stability theory is proposed, and the switching surface is designed based on a novel estimation time-to-go for the missile to intercept the target with minimal miss distance. To intercept the target with initial arbitrary lead angles and desired impact time, the authors analysis the singular issue in SMC to ensure that the missile can intercept the target with arbitrary lead angle. The proposed approach for a nonmaneuvering target using the PIP has simple forms, and therefore, they have the superiority of being implemented easily.
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Duen-Ren Liu, Yang Huang, Jhen-Jie Jhao and Shin-Jye Lee
Online news websites provide huge amounts of timely news, bringing the challenge of recommending personalized news articles. Generative adversarial networks (GAN) based on…
Abstract
Purpose
Online news websites provide huge amounts of timely news, bringing the challenge of recommending personalized news articles. Generative adversarial networks (GAN) based on collaborative filtering (CFGAN) can achieve effective recommendation quality. However, CFGAN ignores item contents, which contain more latent preference features than just user ratings. It is important to consider both ratings and item contents in making preference predictions. This study aims to improve news recommendation by proposing a GAN-based news recommendation model considering both ratings (implicit feedback) and the latent features of news content.
Design/methodology/approach
The collaborative topic modeling (CTM) can improve user preference prediction by combining matrix factorization (MF) with latent topics of item content derived from latent topic modeling. This study proposes a novel hybrid news recommendation model, Hybrid-CFGAN, which modifies the architecture of the CFGAN model with enhanced preference learning from the CTM. The proposed Hybrid-CFGAN model contains parallel neural networks – original rating-based preference learning and CTM-based preference learning, which consider both ratings and news content with user preferences derived from the CTM model. A tunable parameter is used to adjust the weights of the two preference learnings, while concatenating the preference outputs of the two parallel neural networks.
Findings
This study uses the dataset collected from an online news website, NiusNews, to conduct an experimental evaluation. The results show that the proposed Hybrid-CFGAN model can achieve better performance than the state-of-the-art GAN-based recommendation methods. The proposed novel Hybrid-CFGAN model can enhance existing GAN-based recommendation and increase the performance of preference predictions on textual content such as news articles.
Originality/value
As the existing CFGAN model does not consider content information and solely relies on history logs, it may not be effective in recommending news articles. Our proposed Hybrid-CFGAN model modified the architecture of the CFGAN generator by adding a parallel neural network to gain the relevant information from news content and user preferences derived from the CTM model. The novel idea of adjusting the preference learning from two parallel neural networks – original rating-based preference learning and CTM-based preference learning – contributes to improve the recommendation quality of the proposed model by considering both ratings and latent preferences derived from item contents. The proposed novel recommendation model can improve news recommendation, thereby increasing the commercial value of news media platforms.
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In recent years, the airline industry has been growing and transforming rapidly in the Asia-Pacific area. This study analyzes and benchmarks the comparative operational…
Abstract
In recent years, the airline industry has been growing and transforming rapidly in the Asia-Pacific area. This study analyzes and benchmarks the comparative operational efficiencies of the major Asian air carriers. Data envelopment analysis model and disaggregate output efficiency measures are used to evaluate the operational efficiencies of 31 Asian airlines from 2015 to 2019. The findings suggest that nonflag carriers, low-cost carriers, and high-income regions' carriers have significantly higher levels of efficiency than flag carriers, full-service carriers, and low-income regions' carriers in overall, revenue, and passenger traffic efficiencies. The efficiencies between alliance carriers and nonalliance carriers along with those of ASEAN and non-ASEAN carriers are not significantly different.
This research aims to develop a moderated mediation model to examine the relationships among participants' motivation, organizational identification and participation loyalty with…
Abstract
Purpose
This research aims to develop a moderated mediation model to examine the relationships among participants' motivation, organizational identification and participation loyalty with perceived business practice corporate social responsibility (CSR) in philanthropic road-running events.
Design/methodology/approach
The data come from a questionnaire survey that was administered to a sample of 236 participants as runners at philanthropic road-running events. All hypotheses are tested using Statistical Product and Service Solutions (SPSS) and structural equation modeling (SEM)–Analysis of Moment Structures (AMOS) with a bootstrapping technique.
Findings
The results reveal that perceived business practice CSR moderates the relationship between extrinsic motivation and organizational identification and then influences the mediating effect of organizational identification on the relationship between extrinsic motivation and participation loyalty. This highlights the important role of perceived business practice CSR to participants' attitude and behavior when supporting philanthropic road-running events.
Originality/value
This research scrutinizes the role of perceived business practice CSR on philanthropic road-running events through an empirical study and resultant evidence. One recommendation is that when a firm intends to host a philanthropic road-running event, the firm must implement the reality of sound CSR in the firm's business practice.
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Tongzheng Pu, Chongxing Huang, Haimo Zhang, Jingjing Yang and Ming Huang
Forecasting population movement trends is crucial for implementing effective policies to regulate labor force growth and understand demographic changes. Combining migration theory…
Abstract
Purpose
Forecasting population movement trends is crucial for implementing effective policies to regulate labor force growth and understand demographic changes. Combining migration theory expertise and neural network technology can bring a fresh perspective to international migration forecasting research.
Design/methodology/approach
This study proposes a conditional generative adversarial neural network model incorporating the migration knowledge – conditional generative adversarial network (MK-CGAN). By using the migration knowledge to design the parameters, MK-CGAN can effectively address the limited data problem, thereby enhancing the accuracy of migration forecasts.
Findings
The model was tested by forecasting migration flows between different countries and had good generalizability and validity. The results are robust as the proposed solutions can achieve lesser mean absolute error, mean squared error, root mean square error, mean absolute percentage error and R2 values, reaching 0.9855 compared to long short-term memory (LSTM), gated recurrent unit, generative adversarial network (GAN) and the traditional gravity model.
Originality/value
This study is significant because it demonstrates a highly effective technique for predicting international migration using conditional GANs. By incorporating migration knowledge into our models, we can achieve prediction accuracy, gaining valuable insights into the differences between various model characteristics. We used SHapley Additive exPlanations to enhance our understanding of these differences and provide clear and concise explanations for our model predictions. The results demonstrated the theoretical significance and practical value of the MK-CGAN model in predicting international migration.
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Jasmin Lin, Qin Yang and Marcel C. Minutolo
This case study was built from secondary data such as news articles and videos. Several drafts of the case study with teaching note were tested in classroom settings and shared at…
Abstract
Research methodology
This case study was built from secondary data such as news articles and videos. Several drafts of the case study with teaching note were tested in classroom settings and shared at a case writing conference. The case was revised based on feedback from students and roundtable discussions from the conference.
Case overview/synopsis
“What’s next: Ever Given after the Suez Canal incident (Evergreen Marine Corporation in, 2022)” explores the situation of the firm Evergreen Marine Corporation, a world-leading cargo shipping company headquartered in Taiwan, and its efforts to deal with challenges stemming from a pandemic and the global supply chain transition. The case provides background on the latest changes in global business environments, the Suez Canal Incident stemming from the grounding of Ever Given and firm-specific information, which would help students to understand the context affecting Evergreen Marine Corporation’s (EMC) strategic decisions. The case enables students to evaluate EMC’s overall position and to analyze the actions that they can take to deal with these challenges in a dynamic global environment.
Complexity academic level
This case would be appropriate for a course in strategy or international business, especially with the topic of international supply chain management.
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Hsin-Yi Sandy Tsai and Hui-Fei Lin
This study aims to examine entertainment TV shows' social media accounts to theoretically and practically explore the relationship between social media engagement and the…
Abstract
Purpose
This study aims to examine entertainment TV shows' social media accounts to theoretically and practically explore the relationship between social media engagement and the performance (represented by ratings) of such shows.
Design/methodology/approach
By using the data of a popular TV show in the USA, The Voice, the present study examined the messages on the Facebook fan page of the show and how these messages correlated with the ratings of the show. Social media usage data in the course of three seasons (Seasons 10–12, 82 episodes in total) were collected from Facebook (N = 1,192,722 messages). Both regression and sentiment analysis were performed.
Findings
Overall, the findings revealed positive relationships of TV show ratings with both passive social media engagement (Facebook likes) and the number of official posts. However, active social media engagement was not positively related to show ratings.
Originality/value
By enhancing understanding of audience engagement with social media, our research extends knowledge related to the nature and development of viewer involvement with entertainment across different media platforms. Our results also help clarify how interpersonal communication (social media comments) and mass communication (TV programs) intersect. Practically, the findings could be applied to improve the interaction of TV audiences with show content, provide insights into the future of social TV development and inform decision-making amongst TV industry professionals.
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John Lee Candelaria and Fernan Talamayan
The analyses of civil–military relations during public health emergencies are traditionally confined to applications in international and humanitarian action related to conflict…
Abstract
The analyses of civil–military relations during public health emergencies are traditionally confined to applications in international and humanitarian action related to conflict and disaster. The expansive global response to the COVID-19 pandemic fused health and national security issues, and such a response involved extensive collaboration between the military and civil sectors. The expanded scope and centrality of the military in government pandemic response have been noted globally, and Southeast Asia presented interesting developments. This study investigates how the pandemic affected civil–military relations in the region by looking at the cases of the Philippines and Malaysia. First, it assesses the extent to which the pandemic has been framed within the security language through war analogies that rationalised military response. Second, it investigates the roles of the military in the respective governments’ public health emergency response, providing clues on how the increased military intervention affected people’s trust and confidence in public institutions during the pandemic. The study finds that securitising the pandemic correlated to expanding the military’s power and scope in the government response, but notes that civil–military relations remained dependent on the historical roles of the armed forces in politics and society. The two countries have similarly framed the pandemic as a security threat, but the military’s participation in Malaysia’s response shows development opportunities, while the case of the Philippines reveals how a military-centric pandemic response could lead to deleterious effects.
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