Search results

This paper aims to present an investigation on flight quality analysis and design of tilt-rotor aircraft combined with corresponding flight quality specifications.

From the perspective of modal characteristics of tilt-rotor aircraft, it focuses on the analysis of the change rules of the longitudinal short-term motion mode, lateral roll convergence mode, spiral mode and Dutch roll mode. Then, the flight quality design research is carried out using the explicit model tracking control method. The quantitative relationship between flight quality requirements and explicit model is established. Accordingly, the closed-loop flight quality of XV-15 tilt-rotor aircraft is evaluated.

The stability of spiral mode is the result of the interaction of various aerodynamic derivatives and spiral instability occurs in helicopter mode. The other motion modes are stable in full flight mode and meet the requirements of level 1 specified in ADS-33E-PRF and MIL-F-8785C flight quality specifications. There is a quantitative relationship between flight quality requirements and explicit model, and the flight quality of tilt-rotor aircraft is improved through the explicit model tracking control method.

The presented analysis results showed the influence of motion modes and flight quality and the effectiveness of explicit model tracking control method in flight quality improvement, which could be considered as new information for further flight quality design of tilt-rotor aircraft.

The originality of the paper lies in the proposed design and analysis method of the flight quality of tilt-rotor aircraft from the direction of the influence of its aerodynamic derivatives and motion modes.

Adaptive slicing is a key step in three-dimensional (3D) printing as it is closely related to the building time and the surface quality. This study aims to develop a novel adaptive slicing method based on ameliorative area ratio and accurate cusp height for 3D printing using stereolithography (STL) models.

The proposed method consists of two stages. In the first stage, the STL model is sliced with constant layer thickness, where an improved algorithm for generating active triangular patches, the list is developed to preprocess the model faster. In the second stage, the model is first divided into several blocks according to the number of contours, then an axis-aligned bounding box-based contour matching algorithm and a polygons intersection algorithm are given to compare the geometric information between several successive layers, which will determine whether these layers can be merged to one.

Several benchmarks are applied to verify this new method. Developed method has also been compared with the uniform slicing method and two existing adaptive slicing methods to demonstrate its effectiveness in slicing.

Compared with other methods, the method leads to fewer layers whilst keeping the geometric error within a given threshold. It demonstrates that the proposed slicing method can reach a trade-off between the building time and the surface quality.

Plant cultivation holds a pivotal role in agriculture, necessitating precise disease identification for the overall health of plants. This research conducts a comprehensive comparative analysis between two prominent deep learning algorithms, convolutional neural network (CNN) and DenseNet121, with the goal of enhancing disease identification in tomato plant leaves.

The dataset employed in this investigation is a fusion of primary data and publicly available data, covering 13 distinct disease labels and a total of 18,815 images for model training. The data pre-processing workflow prioritized activities such as normalizing pixel dimensions, implementing data augmentation and achieving dataset balance, which were subsequently followed by the modeling and testing phases.

Experimental findings elucidated the superior performance of the DenseNet121 model over the CNN model in disease classification on tomato leaves. The DenseNet121 model attained a training accuracy of 98.27%, a validation accuracy of 87.47% and average recall, precision and F1-score metrics of 87, 88 and 87%, respectively. The ultimate aim was to implement the optimal classifier for a mobile application, namely Tanamin.id, and, therefore, DenseNet121 was the preferred choice.

The integration of private and public data significantly contributes to determining the optimal method. The CNN method achieves a training accuracy of 90.41% and a validation accuracy of 83.33%, whereas the DenseNet121 method excels with a training accuracy of 98.27% and a validation accuracy of 87.47%. The DenseNet121 architecture, comprising 121 layers, a global average pooling (GAP) layer and a dropout layer, showcases its effectiveness. Leveraging categorical_crossentropy as the loss function and utilizing the stochastic gradien descent (SGD) Optimizer with a learning rate of 0.001 guides the course of the training process. The experimental results unequivocally demonstrate the superior performance of DenseNet121 over CNN.

In 2022, the International Network for Quality Assurance (QA) Agencies in Higher Education (INQAAHE) published the new guidelines by adding three QA modules in response to the changing higher education landscape. The paper aims to investigate the transformative focus of quality assurance in higher education globally as well as Asian response to three new QA modules according to the INQAAHE ISGs.

The research conducted a quantitative approach for data collection. An on-line survey was conducted to perceive QA practices, perceptions toward new emerging QA modules and challenges encountered. In total, there were 26 responses from 18 territories with 22 QA agencies. A total of 13 out of them have a national qualifications framework in place.

Three are three major findings in the study. First, national policy and criteria and standards in distance education have been developed in the majority of Asian nations. Second, non-signatories of the Tokyo Convention had a higher proportion of having related policies, regulations and criteria in CBHE and distance education. Third, national policies and regulations; and lack of professional staff are two common challenges implementing QA in new types of providers.

The findings are of value for policymakers, QA agencies and universities to advocate the new QA model as a systematic approach in response to changing higher education landscape in the post pandemic era.

The 2020 pandemic disrupted traditional student mobility and forced a larger majority of transnational programmes to switch to a virtual or hybrid mode, including joint and double degree programmes. Therefore, this study aims to perceive the linkage between quality assurance (QA) and delivery modes of cross-border higher education (CBHE) in Asia before and during the pandemic.

Through an online survey and semi-structured interviews, the process by which top 200 ranked universities in the 2022 QS global ranking responded to QA and qualification issues of joint/dual degree programs in conjunction with delivery modes was explored.

The study has discovered that most respondents from universities, to some extent, tended to be positive about the effectiveness of hybrid delivery of the joint/dual degree programs, even if they still preferred the physical mode to alternatives. Either “divergence” or “responsiveness” QA modes were not applied appropriately in most joint/dual degree programs of the selected universities during the pandemic. Moreover, a fair, transparent and convergent quality and qualification system should be established to facilitate agility and responsiveness of CBHE.

The findings are of value for policymakers, QA agencies and universities to advocate the new QA model for CBHE as a systematic approach in response to changing higher education landscape in the post-pandemic era.

A new cutting tool is always well-defined and sharp at the onset of the metal cutting process and gradually losses these properties as the machining process advances. Similarly, at the beginning of the machining process, amplitude of tool vibrations is considerably low and it increases gradually and peaks at the end of the service period of the cutting tool while machining. It is significant to provide a corresponding real-time varying damping to control this chatter, which directly influences accuracy and quality of productivity. This paper aims to review the literature related to the application of smart fluid to control vibration in metal cutting and also focused on the challenges involved in the implementation of active control system during machining process.

Smart dampers, which are used as semi-active and active dampers in metal cutting, were reviewed and the research studies carried out in the field of the magnetorheological (MR) damper were concentrated. In smart materials, MR fluids possess some disadvantages because of their sedimentation of iron particles, leakage and slow response time. To overcome these drawbacks, new MR materials such as MR foam, MR elastomers, MR gels and MR plastomers have been recommended and suggested. This review intents to throw light into available literature which exclusively deals with controlling chatter in metal cutting with the help of MR damping methods.

Using an MR damper popularly known for its semi-active damping characteristics is very adaptable and flexible in controlling chatter by providing damping to real-time amplitudes of tool vibration. In the past, many researchers have attempted to implement MR damper in metal cutting to control vibration and were successful. Various methods with the help of MR fluid are illustrated.

A new cutting tool is always well-defined and sharp at the onset of metal cutting process and gradually losses these properties as the machining process advances. Similarly, at the beginning of the machining process, amplitude of tool vibrations is considerably low and it increases gradually and peaks at the end of service period of cutting tool while machining. Application of MR damper along with the working methodology in metal cutting is presented, challenges met are analyzed and a scope for development is reviewed.

This study provides corresponding real-time varying damping to control tool vibration which directly influences accuracy and quality of productivity. Using an MR damper popularly known for its semi-active damping characteristics is very adaptable and flexible in controlling chatter by providing damping to real-time amplitudes of tool vibration.

This study attempts to implement smart damper in metal cutting to control vibrations.

It is significant to provide corresponding real-time varying damping to control tool vibration which directly influences accuracy and quality of productivity.

This paper aims to explore adolescents’ perceptions of child-parent dominance in family vacation decision-making (FVDM) by investigating child-parent relative influence (CPRI) and responsibility-sharing (RS) within the family in regard to 15 vacation issues.

This paper adopts Davis and Rigaux’s (1974) framework for identifying adolescents’ perceptions of child-parent dominance across a set of subjects concerning FVDM, by inspecting the distribution of family decision roles across 25 nations. This study then segments the issues regarding family vacations and nations, judging by CPRI and RS within the family. In addition, this paper introduces Hofstede’s cultural dimensions and diverse indices of development for each surveyed nation and compares their respective correlations with CPRI and RS at the national level.

The results, derived from data collected in 25 countries or territories, illustrate a climate of a parent-dominant-to-autonomous style of FVDM for all decision issues and all nations. Overall, both information availability and economizing attribute of issues are related to the democratization of FVDM. The relationship between the child-parent role distribution and national clusters varied across issue clusters. In addition, the paper found the national effectiveness more effective than the cultural dimension in explaining the dispersal of CPRI-RS profiles.

The data collected from 25 nations provide strong evidence for profiling child-parent dominance in FVDM. The data also serve as a basis for analyzing the role of sociocultural and ideological influences on child-parent dominance in FVDM, which was not established in previous research.

子女在家庭渡假决策中的主导地位：多国分析研究

中文摘要

我们针对15个度假决策项目，调查青少年子女与父母的相对影响力（CPRI）和责任分担（RS），以探讨青少年在家庭渡假决策（FVDM）中相对于父母的支配地位的看法。

我们应用戴维斯（Davis）和里加（Rigaux）发表于1974 年的理论架构，调查25国中家庭决策角色的分配情况，从而确定青少年在家庭渡假决策相关决策项目中，子女-父母主导地位之看法。此外，我们根据”相对影响力”和”责任分担”来分别区隔决策项目与国家。我们也应用霍夫斯泰德的文化维度和多元社会发展指数，比较它们与”相对影响力”和”责任分担”的相关性。

从25个国家或地区收集的数据得出的结果表明，对于所有决策问题和所有国家来说，家庭渡假决策属于父母主导或自治风格的氛围。总体而言，资讯的可用性和问题的节约属性都与家庭渡假决策的民主化有关。子女-父母角色分布与国家集群之间的关系因决策项目集群而异。此外，我们发现，在解释”相对影响力-责任分担”侧像的分散方面，国家效能比文化维度更具影响力。

我们从25个国家/地区收集的数据为分析家庭渡假决策中子女-父母的主导地位提供了有力的证据。并分析社会文化和意识形态影响对家庭渡假决策中子女-父母主导地位的基础，在现有的文献中尚未被建立。

Nosotros exploramos las percepciones adolescentes sobre la predominancia de padre e hijo en la toma de decisiones vacaciones en familiares (FVDM) mediante la investigación de la influencia relativa entre padres e hijos (CPRI) y la responsabilidad compartida (RS) dentro de la familia en relación con 15 temas de vacaciones.

Adaptamos el sistema de David and Rigaux para identificar las percepciones de adolescentes sobre el dominio padre e Hijo en un conjunto de temas relacionados con la FVDM, mediante la inspección de la distribución de los roles de decisión familiar a través de 25 países. Luego, segmentamos los problemas relacionados con las vacaciones familiares y naciones, juzgando por CPRI y RS con la familia. Además, presentamos las dimensiones culturales de Hofstede y los diversos índices de desarrollo para cada sociedad encuestada y comparamos sus respectivas correlaciones con CPRI y RS a nivel nacional.

Los resultados obtenidos de los casos recopilados en 25 países o territorios, ilustran un clima de estilo de FVDM de los padres en predominio autónomo para todos los temas de decisión y naciones. En general, tanto en los temas de disponibilidad de información como el atributo economizador están relacionadas con la democratización de la FVDM. La relación entre la distribución de roles de padres e hijos y los grupos nacionales vario entre los grupos temáticos. Además, encontramos que la eficacia nacional es más eficaz que la dimensión cultural para explicar la dispersión de los perfiles CPRI-RS.

Nuestros datos recopilados de 25 países proporcionan pruebas sólidas para perfilar el dominio de padres e hijos en la FVDM. Los datos también sirven como base para analizar el papel de la influencias socioculturales e ideológicas en el predominio de padres e hijos en la FVDM, que no se estableció en investigaciones anteriores.

In an adventure tourism context (i.e. sky diving, bungee jumping) the effect of the absence or presence of a travel companion; companion relative ability (i.e. perception of a companion’s possessed resources useful for the achievement of travel goals); and tourist gender on the impact of companion relative ability on tourists’ satisfaction and subjective well-being is examined. This paper aims to investigate the mediating role of satisfaction that combines companion relative ability, tourist gender, tourist satisfaction and subjective well-being.

This research uses three situational experiments. A one-factor between-subjects experimental design was used for Study 1. Studies 2 and 3 used a one-factor between-subjects and a 2 × 3 factorial between-subjects design. Participants included tourists visiting a national park in China assigned to scenarios using an anonymous intercept approach and an online survey.

Having a companion with greater/comparable relative ability produces a greater effect on tourist satisfaction and subjective well-being than having a companion with lower relative ability. Furthermore, the perceived relative ability of a travel companion results in a stronger positive effect on tourist satisfaction and subjective well-being for female tourists. Meanwhile, satisfaction fully mediates the impact of the interaction between companion relative ability and tourist gender on subjective well-being.

The current research validates the companion effect on adventure tourists’ satisfaction and subjective well-being. An additional contribution is an investigation into the effect of companion relative ability. The study is the only one the authors are aware of that examines the moderating role of tourist gender on the effect of companion relative ability on tourist satisfaction and subjective well-being and identifies the mechanism that combines companion relative ability, tourist gender, tourist satisfaction and subjective well-being.

同伴效应对冒险旅游者满意度与主观幸福感的影响：性别的调节作用

本研究探讨了在冒险旅游情境下, 有旅游同伴和感知同伴相对能力对旅游者满意度和主观幸福感的影响。

研究1采用了单因子组间设计。研究2采用了一个单因子组间设计和一个2×3双因子组间设计。

与拥有一个相对能力较低的同伴相比, 拥有一个相对能力较高/相等的同伴对旅游满意度和主观幸福感的影响更大。此外, 旅游同伴相对能力感知对女性旅游者的满意度和主观幸福感有较强的正向影响。同时, 满意度完全中介同伴相对能力与旅游者性别之间的交互效应对主观幸福感的影响。

本研究验证了同伴效应对冒险旅游者满意度和主观幸福感的影响。另一个贡献是对同伴相对能力影响的研究。本研究是我们唯一所知：1）检验旅游者性别在同伴相对能力对旅游者满意度和主观幸福感影响中的调节作用; 2）考察联结了同伴相对能力、旅游者性别、旅游者满意度和主观幸福感的机制。

El efecto Peer de la satisfacción y el bienestar subjetivo de los turistas de aventura: el efecto moderador del género

Este estudio investigó la influencia de la capacidad relativa de los pares y la percepción de los pares en la satisfacción de los turistas y el bienestar subjetivo en el contexto del Turismo de aventura.

En el estudio 1 se utilizó un diseño experimental de un solo factor entre sujetos.El estudio 2 utilizó un diseño factorial único entre sujetos y 2 □ 3 entre sujetos.

En comparación con los pares con menor capacidad relativa, los pares con mayor capacidad relativa tienen un mayor impacto en la satisfacción de los turistas y el bienestar subjetivo.Además, la capacidad relativa percibida de las mujeres turistas hacia sus pares tiene un fuerte efecto positivo en la satisfacción de los turistas y el bienestar subjetivo.Al mismo tiempo, la satisfacción mediaba plenamente la influencia de la interacción entre la capacidad relativa de los pares y el género de los turistas en el bienestar subjetivo.

Este estudio verificó la influencia del efecto Peer en la satisfacción y el bienestar subjetivo de los turistas de aventura.Otra contribución es el estudio de los efectos de la competencia relativa entre pares.Este estudio es el único que conocemos: 1) investigar el efecto moderador del género de los turistas en la capacidad relativa de los pares sobre la satisfacción de los turistas y el bienestar subjetivo; 2) determinar el mecanismo de combinación de la capacidad relativa de los pares, el género de los turistas, la satisfacción de los turistas y El bienestar subjetivo.

Control charts are widely used for both manufacturing and service industries. Traditional Shewart control chart is a very simple procedure, it works well for detecting large process shifts. A criticism of Shewhart charts is that they only use the information about the process contained in the last observation. One method of increasing the sensitivity of Shewhart charts to smaller process shifts is by introducing what are known as supplementary rules.

Integrated project delivery (IPD) project that does not use multiparty agreement is identified as IPD-ish. The use of IPD-ish arrangement by incorporating integration practices in conventional contract can be viewed as the part of the adoption process of IPD. Moreover, inappropriate integration practices invite new forms of risks and the absence of multiparty agreement adds to the challenges of risk management in IPD-ish projects. This study discusses such challenges and proposes the use of joint risk management to address the potential pitfalls in IPD-ish arrangement.

A mixed research method was applied. First, the criticality of IPD-ish general and integration-specific risks was examined through a survey. Second, a real IPD-ish project was used to exemplify the use of joint risk management (JRM) to manage IPD-ish risks.

Two types of risks, namely integration risks (IRs) and general risks (GRs), are identified in IPD-ish projects. Two major findings for the IRs: (1) the most critical IRs are related to unbalanced incentivization and inefficient multidisciplinary teams; and (2) only team formation related pre-contract JRM strategies affect IRs. As for the GRs, the most critical ones are associated with design issues and can be effectively mitigated by post-contract JRM.

Using IPD-ish arrangement is an inevitable part of implementation of full IPD. This happens as many change-averse owners would like to test the integration principles using a conventional contract that they are familiar with. In fact, success in IPD-ish would pave the path for further adoption of IPD. This study offers insight into categorization of risks in IPD-ish projects. Appropriate use of post-contract and organization related pre-contract JRM would improve the chance of teasing out the values of IPD through IPD-ish arrangements. Care should be taken to introduce some contracting integration initiatives, such as risk/reward sharing incentive.