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Urban logistics is important to a city's sustainable growth and development. With the increase in population and the economic growth in urban areas, the issue of congestion and the negative influence of transport of goods on people and the environment is one of the most important factors in the development of urban logistics. By determining the optimal location of urban logistics centres, total transport costs of logistics, the flow of goods in urban areas and the greenhouse gas emissions will be reduced. However, the traditional methods are easily influenced by the ambiguity of objective data, which makes it difficult to accurately describe the logistics demand in the urban area. To address this issue, the improved location–allocation model for urban logistics centres based on truck trajectory data is proposed. After extracting the origin–destination points, the logistics service demand can be estimated by the DBSCAN (density-based spatial clustering of applications with noise) clustering method. Then, the location–allocation of logistics centres is determined by an improved P-median method with the supply capacity limitation for simultaneous delivery of goods in the logistics centres. To validate the model, taking Wuhan, a central logistics city in China, as an example, the model can effectively ensure the equitable distribution of logistics facilities, minimize freight expenses, achieve more uniformity in logistics center services, and foster sustainable development of the city's logistics sector. [ABSTRACT FROM AUTHOR]

In 2020, the BeiDou-3 global navigation satellite system (BDS-3) was officially completed and put into service. Currently, network real-time kinematic (RTK) technology is considered the main means through which to improve the positioning accuracy of the BeiDou navigation satellite system (BDS). This paper proposes a long-range undifferenced network RTK (URTK) algorithm, based on multi-frequency observation data of the BDS. First, the multi-frequency phase integer ambiguity resolution (AR) model considering atmospheric error parameters is designed, and the multi-frequency phase integer ambiguity of the long-range BDS reference station is determined. Then, the undifferenced integer ambiguity of each reference station is obtained, using linear variation based on the accurately determined phase integer ambiguity between reference stations, and the undifferenced observation error of each reference station is calculated. Considering the weakening spatial correlation of the observation errors between long-range stations, undifferenced classification error corrections of a reference station network are separated, according to different error characteristics. Finally, the inverse distance weighting method is employed to calculate the classification undifferenced error correction of the rover station. The rover station corrects the observation error through applying the undifferenced error correction to achieve high-precision positioning. The measured data of a long-range continuous operation reference station (CORS) network are selected for an experiment. The results show that the proposed algorithm can quickly and accurately realize the resolution of the BDS integer ambiguity of a reference station network and establish an undifferenced area error correction model in order to achieve accurate classification of undifferenced error correction values for a rover station. In China, the BDS-3 is superior to the global positioning system (GPS) in terms of the satellite number, position dilution of precision (PDOP) value, AR success rate, stability, and convergence time. The results show that the AR success rate, stability, and convergence time increase with the operational frequency, and the BDS-3 can achieve centimeter-level positioning of single-system rover stations without relying on the GPS. [ABSTRACT FROM AUTHOR]

The LuTan-1(LT-1), known as the L-band differential interferometric synthetic aperture radar (SAR) satellite system, is an essential piece of civil infrastructure in China, providing extensive applications such as surface deformation monitoring and topographic mapping. To achieve high-resolution and wide-swath (HRWS) observation abilities, the LT-1 takes the dual receiving antenna (DRA) imaging mode as its working mode. However, amplitude and phase errors between channels lead to a mismatch between the reconstruction filter and the multichannel echo signal, worsen the reconstructed azimuth spectrum, and introduce ambiguity targets in the final imaging results, seriously affecting the final imaging quality. In order to better evaluate the channel error and azimuth ambiguity performance of the LT-1 system, this paper proposed an advanced channel consistency correction method and conducted many measured data experiments. The experimental results show that the proposed method is effective, and the LT-1 system has excellent channel error control and azimuth ambiguity performance. [ABSTRACT FROM AUTHOR]

Given the rapid development of the digital industry, the international use of XBRL as a computer language for the exchange of corporate financial data is of great significance in promoting the standardization of financial data. This paper provides an in-depth study and quantitative measurement of the applicability of the Chinese XBRL common taxonomy elements in enterprises, examining the interoperability of the elements between enterprises and the possible absence and ambiguity of the elements. The research study shows significant differences between the elements of XBRL defined in the general classification standard and the elements used in financial reports of listed companies in China. Furthermore, the quantitative interoperability model results show significant differences in the interoperability of elements between companies in the same industry and the same category of industries. Therefore, updates to the Chinese XBRL taxonomy should start from the underlying logic of accounting and improve the process of calling the elements in the accounting process. [ABSTRACT FROM AUTHOR]

We study adjustable distributionally robust optimization problems, where their ambiguity sets can potentially encompass an infinite number of expectation constraints. Although such ambiguity sets have great modeling flexibility in characterizing uncertain probability distributions, the corresponding adjustable problems remain computationally intractable and challenging. To overcome this issue, we propose a greedy improvement procedure that consists of solving, via the (extended) linear decision rule approximation, a sequence of tractable subproblems—each of which considers a relaxed and finitely constrained ambiguity set that can be iteratively tightened to the infinitely constrained one. Through three numerical studies of adjustable distributionally robust optimization models, we show that our approach can yield improved solutions in a systematic way for both two-stage and multistage problems. History: Accepted by Pascal Van Hentenryck, Area Editor for Computational Modeling: Methods & Analysis. Funding: Financial support by the Early Career Scheme from the Hong Kong Research Grants Council [Project No. CityU 21502820], the CityU Start-Up Grant [Project No. 9610481], the CityU Strategic Research Grant [Project No. 7005688], the National Natural Science Foundation of China [Project No. 72032005], and Chow Sang Sang Group Research Fund sponsored by Chow Sang Sang Holdings International Limited [Project No. 9229076] is gratefully acknowledged. Supplemental Material: The software that supports the findings of this study is available within the paper and its Supplemental Information (https://pubsonline.informs.org/doi/suppl/10.1287/ijoc.2021.0181), as well as from the IJOC GitHub software repository (https://github.com/INFORMSJoC/2021.0181). The complete IJOC Software and Data Repository is available at https://informsjoc.github.io/. [ABSTRACT FROM AUTHOR]

Background: Due to the increasing complexity in socioeconomic environments and the ambiguity in human cognition, decision makers prefer to give linguistic cognitive information with different granularities according to their own preferences. Consequently, to consider the uncertainty and preferences in the evaluation process, a method based on Multi-Granularity Linguistic Information (MGLI) for evaluating teleconsultation service quality is proposed, which provides a new research direction for scientific evaluation and improvement of teleconsultation service quality.Methods: Firstly, this paper explored a service quality evaluation system from the perspective of regional doctors. And then considering the uncertainty and preferences of decision makers, MGLI was used to optimize the index system according to the similarity degree between the linguistic evaluation information and a given linguistic term set. Finally, the empirical research was conducted using Henan Province Telemedicine Center of China (HTCC) as an example to identify the direction for improving the service quality in teleconsultation.Results: This study found that the number of consulting rooms, attitude of operators, consultation duration, charges, and attitude of experts are the key factors affecting the quality of teleconsultation service.Conclusions: Suggestions for improving the quality of teleconsultation service are put forward in terms of optimizing the allocation of consulting rooms, improving regional doctors' experience and standardizing charging standards, which provides a new direction for improving the quality of teleconsultation service. [ABSTRACT FROM AUTHOR]

Specifying a proper input distribution is often a challenging task in simulation modeling. In practice, there may be multiple plausible distributions that can fit the input data reasonably well, especially when the data volume is not large. In this paper, we consider the problem of selecting the best from a finite set of simulated alternatives, in the presence of such input uncertainty. We model such uncertainty by an ambiguity set consisting of a finite number of plausible input distributions and aim to select the alternative with the best worst-case mean performance over the ambiguity set. We refer to this problem as robust selection of the best (RSB). To solve the RSB problem, we develop a two-stage selection procedure and a sequential selection procedure; we then prove that both procedures can achieve at least a user-specified probability of correct selection under mild conditions. Extensive numerical experiments are conducted to investigate the computational efficiency of the two procedures. Finally, we apply the RSB approach to study a queueing system's staffing problem using synthetic data and an appointment-scheduling problem using real data from a large hospital in China. We find that the RSB approach can generate decisions significantly better than other widely used approaches. This paper was accepted by Noah Gans, stochastic models and simulation. [ABSTRACT FROM AUTHOR]

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The LuTan-1 (LT-1) mission, China's first civilian bistatic spaceborne Synthetic Aperture Radar (SAR) mission, comprises two L-band SAR satellites. These satellites operate in bistatic InSAR strip map mode, maintaining a formation flight with an adjustable baseline to generate global digital elevation models (DEMs) with high accuracy and spatial resolution. This research introduces a dedicated interferometric calibration model for LT-1, tackling the unique challenges of the bistatic system, such as interferometric parameter coupling and the π -ambiguity problem caused by synchronization phase errors. This study validates the model using SAR images from LT-1 and Xinjiang corner reflector data, achieving interferometric phase accuracy better than 0.1 rad and baseline accuracy better than 2 mm, thereby producing high-precision DEMs with a height accuracy meeting the 5 m requirement. [ABSTRACT FROM AUTHOR]

In the psychological and sociological framework of risk, we establish a static and dynamic equilibrium model for risk‐sharing institutional evolution. Particularly, through a comparative study of marine insurance development in China and Europe, we address a wide set of research questions concerning why China and Europe relied on different social organizations for risk sharing. [ABSTRACT FROM AUTHOR]

Tomographic Synthetic Aperture Radar (TomoSAR) is a breakthrough of the traditional SAR, which has the three-dimentional (3D) observation ability of layover scenes such as buildings and high mountains. As an advanced system, the airborne array TomoSAR can effectively avoid temporal de-correlation caused by long revisit time, which has great application in high-precision mountain surveying and mapping. The 3D reconstruction using TomoSAR has mainly focused on low targets, while there are few literatures on 3D mountain reconstruction. Due to the layover phenomenon, surveying in high mountain areas remains a difficult task. Consequently, it is meaningful to carry out the research on 3D mountain reconstruction using the airborne array TomoSAR. However, the original TomoSAR mountain point cloud faces the problem of elevation ambiguity. Furthermore, for mountains with complex terrain, the points located in different elevation periods may intersect. This phenomenon increases the difficulty of solving the problem. In this paper, a novel elevation ambiguity resolution method is proposed. First, Density-Based Spatial Clustering of Applications with Noise (DBSCAN) and Gaussian Mixture Model (GMM) are combined for point cloud segmentation. The former ensures coarse segmentation based on density, and the latter allows fine segmentation of the abnormal categories caused by intersection. Subsequently, the segmentation results are reorganized in the elevation direction to reconstruct all possible point clouds. Finally, the real point cloud can be extracted automatically under the constraints of the boundary and elevation continuity. The performance of the proposed method is demonstrated by simulations and experiments. Based on the airborne array TomoSAR experiment in Leshan City, Sichuan Province, China in 2019, the 3D model of the surveyed mountain is presented. Moreover, three kinds of external data are applied to fully verify the validity of this method. [ABSTRACT FROM AUTHOR]

The quality and availability of Uncalibrated Phase Delay (UPD) solutions are crucial to the Precise Point Positioning (PPP) service, and the long-term temporal variability and its contributing factors should be better understood. In this paper, we comprehensively investigate the long-term time-varying characteristics of each UPD product respectively generated by a global and regional network and their interoperable application in PPP-AR (ambiguity resolution), the sampling of the WL and NL UPDs are daily and 30 s, respectively. Firstly, in terms of our 30 day Wide-Lane (WL) UPD products of 31 satellites, the Standard Deviation (STD) of each satellite WL UPDs ranges from 0.04 to 0.06 cycles, indicating that the long-term prediction accuracy of satellite WL UPD is sufficient for fixing Wide-Lane ambiguities. Secondly, when a satellite in eclipsing the discontinulity may corrupt the determination of Narrow-Lane (NL) UPD in form of offset, as a result of lacking or poor satellite attitude dynamic modeling. When the influence of discontinuity is removed, the STD of our estimated satellite NL UPDs is less than 0.05 cycles. Thirdly, the STD of our estimated receiver WL UPDs is mainly below 0.2 cycles, which implies that its stability is one order poorer that of the satellite. In addition, if they are used for stations in and around the network covered region, the stability of the UPD products from the CMONOC (Crustal Movement Observation Network of China) is better than that from a global network, benefit from the fact that all the CMONOC stations are equipped with the same receiver type. Finally, the PPP-AR results show that a rate of 82.9% for stations with a WL-ambiguity-fixed rate of over 90% while 69.5% for stations with an NL-ambiguity-fixed rate of over 80% can be achieved when using UPD from the global network, which is worse than that of using UPD from the CMONOC (85.7% for stations with a WL-ambiguity-fixed rate of over 90% while 75% for stations with an NL-ambiguity-fixed rate of over 80%). The results of the experiment on the UPD interoperable application in PPP show that the global network UPD products can provide a fast AR at any single station, and the convergence time is well below 25 min. Particularly, when the location of a station is in and around the regional network, our results show that the PPP results obtained using regional UPDs enable the consistent use of global UPDs. When the location of a station is far away from the regional network, using the regional UPDs can not achieve PPP-AR. Finally, the WL UPDs of the previous day is used for forecasting to estimate the NL UPDs, the stability analysis results of NL UPDs solution and positioning results are demonstrate the validity of forecasted UPD products. [ABSTRACT FROM AUTHOR]

Knowledge management and manufacturing relocation have been treated as independent spheres. However, for a relocation to be fruitful, knowledge management needs to be incorporated. The purpose of this research is to shed light on the lack of knowledge management in dynamic manufacturing relocation. In particular, the research focuses on the ability to change, adapt and revert manufacturing relocation decisions, that is, the dynamic nature (or use) of the concept. A Swedish company was used as a case study. Nine in‐depth interviews were conducted with key informants at the company's headquarters in Sweden and its factory in China to capture a dyadic perspective. The findings demonstrate that: (1) knowledge transfer is crucial to create/sustain competitive advantage in the offshoring and reshoring phase; (2) lack of knowledge transfer results in limited learning outcomes with operational and strategic consequences in the relocation; (3) resistance to knowledge transfer in the offshoring creates a knowledge gap that consequently leads to relocation ambiguity in the reshoring phase; and (4) companies need to develop knowledge management strategies to promote knowledge transfer and learn from their international relocation, to cope with relocation ambiguity. Our theoretical contribution introduces the knowledge ambiguity framework, which is a result of insufficient knowledge transfer in the dynamic manufacturing relocation. Even if an organization relocates efficiently, it can fail to take advantage of knowledge transfer and development as potential learning for the organization. [ABSTRACT FROM AUTHOR]

Two new leafhopper species of Pediopsis Burmeister, Pediopsis albopicta Li & Dai, sp. nov. from Hunan and Guizhou provinces of central China and Pediopsis pianmaensis Li & Dai, sp. nov. from Yunnan Province of southwestern China, are described and illustrated. Ambiguity in the original description of P. bannaensis Yang & Zhang is discussed, and figures of the female holotype of P. femorata Hamilton are provided for the first time. A checklist and key to Chinese species of Pediopsis are also given. [ABSTRACT FROM AUTHOR]

We compare and contrast the UK and China as maximum variation cases for understanding long energy transitions from the state and the firm perspectives. We present case histories and corpus-based computer-assisted textual analyses on the long energy transitions in both countries. With these, we explore and explain how and why energy supply firms respond the way they do to the institutional ambiguities and complexities that characterize the long energy transitions in each case. Our findings demonstrate that a centrally coordinated and imposed approach by the state can generate institutional clarity in long energy transitions, which is quickly seized on by firms striving to preserve and increase their resources and influence. Such clarity and transition processes lose momentum owing to the perennial trilemma of energy affordability, security and sustainability. Market-based mechanisms to trigger and sustain long energy transitions, complemented with focused and continuous state interventions (e.g. incentives, taxation), provide a more effective and accountable institutional framework for the state and energy firms to deal with the energy trilemma. Irrespective of the logic of the type of economy that manifests the backdrop for any long energy transition process, institutional ambiguity and complexity never disappear completely, owing to both the energy trilemma and the institutional multiplicities. [ABSTRACT FROM AUTHOR]

The myriad of negative effects brought about by the incarceration of a family member have consistently been demonstrated in research. However, previous works have tended to focus on the perspectives of family members separately, rather than exploring the dynamic relationships within the family as an entire unit. Moreover, such research is still limited in the Chinese cultural context. Thus, the current study aimed to examine the applicability of the Family Process Theory on a small sample of Chinese fathers who were imprisoned and have returned to their communities, conceptualizing the challenges faced by their families under the theoretical elements of rules of transformation, rituals, ambiguous loss, and boundary ambiguity. A total of 17 participants were recruited through the assistance of service organizations, and data were collected via semi-structured interviews. As congruent with the theory, inmates' families were found to come across problems particularly in the transitioning phase and establishment of new rituals, while ambiguity surrounding the incarceration and the blurred role of the father led to problems with fatherhood identity both during and after the incarceration. Recommendations are made, in line with these findings and the suggestions of exprisoners, for services to have more of a focus on preserving the integrity of inmates' families. Given the right circumstances, families can even serve as a motivator for incarcerated fathers to improve themselves and mature, leveraging the important supportive role of the family and the fear of again being separated from one's family as effective deterrents to recidivism. [ABSTRACT FROM AUTHOR]

• This study examines the impact of national environment on managerial value systems by comparing representative samples of Chinese managers in the United States, Singapore and the People's Republic of China. • Two measures of managerial values are used. The dimensions of Western measures are Machiavellianism, Dogmatism, Locus of Control and Intolerance of Ambiguity. The Eastern measures comprise Integration, Confucian Dynamism, Human-heartedness and Moral Discipline. [ABSTRACT FROM AUTHOR]