Jiaxiang Hu, Xiaojun Shi, Chunyun Ma, Xin Yao and Yingxin Wang
The purpose of this paper is to propose a multi-feature, multi-metric and multi-loop tightly coupled LiDAR-visual-inertial odometry, M3LVI, for high-accuracy and robust state…
Abstract
Purpose
The purpose of this paper is to propose a multi-feature, multi-metric and multi-loop tightly coupled LiDAR-visual-inertial odometry, M3LVI, for high-accuracy and robust state estimation and mapping.
Design/methodology/approach
M3LVI is built atop a factor graph and composed of two subsystems, a LiDAR-inertial system (LIS) and a visual-inertial system (VIS). LIS implements multi-feature extraction on point cloud, and then multi-metric transformation estimation is implemented to realize LiDAR odometry. LiDAR-enhanced images and IMU pre-integration have been used in VIS to realize visual odometry, providing a reliable initial guess for LIS matching module. Location recognition is performed by a dual loop module combined with Bag of Words and LiDAR-Iris to correct accumulated drift. M³LVI also functions properly when one of the subsystems failed, which greatly increases the robustness in degraded environments.
Findings
Quantitative experiments were conducted on the KITTI data set and the campus data set to evaluate the M3LVI. The experimental results show the algorithm has higher pose estimation accuracy than existing methods.
Practical implications
The proposed method can greatly improve the positioning and mapping accuracy of AGV, and has an important impact on AGV material distribution, which is one of the most important applications of industrial robots.
Originality/value
M3LVI divides the original point cloud into six types, and uses multi-metric transformation estimation to estimate the state of robot and adopts factor graph optimization model to optimize the state estimation, which improves the accuracy of pose estimation. When one subsystem fails, the other system can complete the positioning work independently, which greatly increases the robustness in degraded environments.
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Jiaxiang Hu, Amy Z. Zeng and Lindu Zhao
The purpose of this paper is to study the managing of emergencies pertinent to public health which is critical to the well‐being of a society; as such, the management mechanisms…
Abstract
Purpose
The purpose of this paper is to study the managing of emergencies pertinent to public health which is critical to the well‐being of a society; as such, the management mechanisms employed should be of great interest and significance for research.
Design/methodology/approach
This paper first relies on extensive literature to describe the mechanism used in the USA from three aspects – organizational structure, management system, and logistics network. For the purpose of comparison, the Chinese version of the mechanism is presented from the same three aspects. The two management systems are then compared both qualitatively and quantitatively.
Findings
Deficient areas in Chinese public‐health management mechanism as well as challenging issues associated with supply chain design and coordination for emergency supplies in the context of large‐scale public health emergencies with low frequency but catastrophic impacts are found. Specifically, the following three important research problems are revealed from the comparative study: how to establish an efficient organizational structure that incorporates all the relevant entities in public‐health emergency management? How to establish an information system for emergency management that integrates disease surveillance, control, and prevention? How to design an efficient and cost‐effective logistics network to ensure prompt and sufficient delivery of emergency supplies?
Originality/value
To date, this research has been the first of its kind that compares two countries' emergency management systems in the context of public health management.
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In 2013, Honduras Congress passed the Zones for Employment and Economic Development (ZEDE) Organic Law, along with some constitutional changes, to create ZEDEs, which are…
Abstract
Purpose
In 2013, Honduras Congress passed the Zones for Employment and Economic Development (ZEDE) Organic Law, along with some constitutional changes, to create ZEDEs, which are essentially special economic zones with some unique features. Prospera Honduras Inc., a company with substantial United States investment, invested in Honduras relying on the ZEDE Organic Law and the Free Trade Agreement between Central America, the Dominican Republic and the United States of America (CAFTA-DR). In 2022, Honduras cancelled the ZEDE Organic Law, allegedly harming Prospera Honduras Inc.’s investments. Prospera and some other foreign investors have initiated an investor-state arbitration against Honduras for several alleged breaches of CAFTA-DR provisions. Honduras has remained silent and decided not to participate in the arbitration. This paper aims to examine whether the cancellation of the ZEDE Organic Law gives rise to international investment law obligations under the CAFTA-DR.
Design/methodology/approach
This is a doctrinal research and contains qualitative analysis.
Findings
The article concludes that CAFTA-DR preserves some regulatory space for host states; therefore, it would be wrong to assume that the arbitral decision in Prospera Inc. and others v. Honduras will favour only the foreign investors. This article also argues that, drawing insights from this dispute, future International Investment Agreements should better preserve Indigenous people’s rights. Moreover, the host states should reconsider whether they intend International Investment Agreements (IIAs) to apply to special economic zones in future.
Originality/value
There is no existing scholarly work examining the international investment law issues relating to the cancellation of ZEDEs in Honduras. Therefore, the findings of this article will be novel.
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The Korea-China-Japan Investment Promotion, Facilitation and Protection Agreement is the first treaty in the economic field that binds the three Northeast Asian countries together…
Abstract
The Korea-China-Japan Investment Promotion, Facilitation and Protection Agreement is the first treaty in the economic field that binds the three Northeast Asian countries together under a single legal instrument. The existence of effective dispute-settlement procedures under the treaty will contribute to the creation of a favourable investment climate in the host country. Nevertheless, there have been fears about frivolous or vexatious claims that could inhibit legitimate regulatory actions by governments. How to compose an investment chapter of the Korea-China-Japan FTA that is being negotiated is a pressing demand for all in the region. Any pertinent answers to such a quest require a thorough comparison of the benefits and drawbacks of any development of relevant rules and governance. In the end, a quest for better international investment governance in Northeast Asia in the future requires sound evaluation of lessons from the past and present.
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Bingjing Qiu, Jiyun Zhao and Jiaxiang Man
Aiming at improving the mechanical efficiency, the applicability and the working life of high water-based hydraulic motor (HWBHM) under working conditions at low speed and high…
Abstract
Purpose
Aiming at improving the mechanical efficiency, the applicability and the working life of high water-based hydraulic motor (HWBHM) under working conditions at low speed and high pressure, the friction performance of different matching materials for piston slipper – crankshaft pair with high water-based hydraulic fluid (HWBHF) under working conditions at low speed and high pressure – were studied.
Design/methodology/approach
The friction experiments for different materials (316L, 316L with surface coating OVINO – tetrahedral amorphous carbon [TAC; 316L-TAC] – 316L with surface coating OVINO-graphite intercalated compound [GIC; 316L-GIC] and polyetheretherketone [PEEK] reinforced with 30 per cent carbon fiber [PEEK-30CF]) under HWBHF lubrication were implemented on a pin-disk friction abrasion machine to determine the variations of coefficient of friction (CoF) and wear rate for each matching materials. In addition, the roughness and the morphology of worn surface of different matching materials were quantitatively characterized.
Findings
The study revealed that material combinations have different friction performances. Test results showed that the abrasion of matching type stainless steel (SS) and SS is rather serious, and the method of surface coating could improve the friction performance of SS when friction with other materials. For matching type of SS with surface treatment (SS-ST) and SS-ST, 316L-GIC and 316L-GIC have relatively stable CoF, and the wear rate was smaller than other matching materials, while 316L-TAC and 316L-TAC has the smaller CoF than that of 316L-GIC. Matching materials 316L-GIC with PEEK-30CF of matching type SS-ST and PEEK-30CF has more stable COF and better wear resistance than those of other matching materials.
Originality/value
This research has laid a foundation for the improvement of service life and working efficiency of friction pair in HWBHM under working conditions at low speed and high pressure.
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Zhenmin Wang, Wenyan Fan, Fangxiang Xie and Chunxian Ye
This paper aims to present an 8 kW LLC resonant converter designed for plasma power supply with higher efficiency and lighter structure. It presents how to solve the problems of…
Abstract
Purpose
This paper aims to present an 8 kW LLC resonant converter designed for plasma power supply with higher efficiency and lighter structure. It presents how to solve the problems of large volume and weight, low performance and low efficiency of traditional plasma power supply.
Design/methodology/approach
At present, conventional silicon (Si) power devices’ switching performance is close to the theoretical limit determined by its material properties; the next-generation silicon carbide (SiC) power devices with outstanding advantages can be used to optimal design. This 8 kW LLC resonant converter prototype with silicon carbide (SiC) power devices with a modulated switching frequency ranges from 100 to 400 kHz.
Findings
The experimental results show that the topology, switching loss, rectifier loss, transformer loss and drive circuit of the full-bridge LLC silicon carbide (SiC) plasma power supply can be optimized.
Research limitations/implications
Due to the selected research object (plasma power supply), this study may have limited universality. The authors encourage the study of high frequency resonant converters for other applications such as argon arc welding.
Practical implications
This study provides a practical application for users to improve the quality of plasma welding.
Originality/value
The experimental results show that the full-bridge LLC silicon carbide (SiC) plasma power supply is preferred in operation under conditions of high frequency and high voltage. And its efficiency can reach 98%, making it lighter, more compact and more efficient than previous designs.
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Thomas C. Tuttle, Chen Shengchang, John P. Heap and Tiano Yan
This paper aims to promote an expanded two‐way dialog between Chinese and Western leaders and executives which recognizes that “wisdom” can flow in both directions.
Abstract
Purpose
This paper aims to promote an expanded two‐way dialog between Chinese and Western leaders and executives which recognizes that “wisdom” can flow in both directions.
Design/methodology/approach
Interviews were undertaken with three Chinese executives and analyzed against a model of performance excellence.
Findings
An understanding of some of the similarities and differences of Western and Chinese business practices and a conclusion that there are lessons for Western businesses to learn.
Research limitations/implications
The work involved interviews with only three Chinese executives and thus represents a tiny sample.
Practical implications
Illustrates some of the practices that might be worth considering by the West as we climb out of the current economic depression and re‐focus business efforts for a longer‐term future.
Originality/value
The paper adopts a novel approach of analyzing interview outcomes against a reference model. The core value is, however, in highlighting the benefits that might arise from extended dialog.