A meta-analysis explains the variation in estimated trade effects of technical barriers to trade broadly defined, using available estimates from the empirical international trade literature, and accounting for data sampling and methodology differences. Agriculture and food industries tend to be more impeded by these barriers than other sectors. SPS regulations on agricultural trade flows from developing exporters to high-income importers tend to impede trade. Controlling for "multilateral resistance" lowers the propensity to find that these policies impede trade. Estimations correcting endogeneity by using panel data and time fixed effect yield more negative (or less positive) trade effects of technical measures.
This paper presents our efforts to characterize the candidate landing region (109°–133°E, 23°–30°N) for Tianwen‐1, China's first mission to Mars, in terms of engineering safety and scientific significance. Topographic analysis reveals that the region has a low elevation around −4,230 m, and 98% of the region have slopes smaller than 8°. The geomorphological mapping and analysis show that the region has an average crater density of about 28 craters (≥200 m in diameter) per 100 square kilometers, with several clusters of high crater densities distributed around the center of the region. There are also pitted cones distributed mainly in the southern part of the region, with a density of approximately 6.6 cones per 100 square kilometers in specific local areas. The region has rock abundances ranging from 1% to 23%, with local clusters of low and high rock abundances. The region comprises four main geological units, including a lowland unit formed in the Late Hesperian and a volcanic unit formed in the Amazonian and Hesperian period. Their specific surface ages are estimated through the analysis of crater size‐frequency distribution. Combining the engineering constraints on surface slopes, crater density, cone density, and rock abundance, a hazard map of the candidate landing region is generated for landing site evaluation and safety assessment. Based on the results, we further discuss the potential scientific outcomes from the exploration in this region. The findings will be helpful for the mission planning and maximization of the scientific return from Tianwen‐1, and complement existing Martian scientific research.
We propose aggregation indices of Non-Tariff Measures (NTMs) to quantify their protectionism relative to international standards. We apply the indices to national Maximum Residue Limit (MRL) regulations affecting agricultural and food trade and using a science-based criteria embodied in Codex Alimentarius international standards. The approach links two streams of the NTM literature, one concerned with the aggregation of various NTMs into operational indices for econometric and modeling purposes, and the other attempting to evaluate the protectionism of NTMs. The data used in the application come from a large international dataset on veterinary and pesticide MRLs and CODEX MRL standards for a large set of countries
KeywordsNTMs, non-tariff measures, barriers, protectionism, maximum residue limit, MRL
A meta-analysis explains the variation in estimated trade effects of technical barriers to trade broadly defined, using available estimates from the empirical international trade literature, and accounting for data sampling and methodology differences. Agriculture and food industries tend to be more impeded by these barriers than other sectors. SPS regulations on agricultural trade flows from developing exporters to high-income importers tend to impede trade. Controlling for "multilateral resistance" lowers the propensity to find that these policies impede trade. Estimations correcting endogeneity by using panel data and time fixed effect yield more negative (or less positive) trade effects of technical measures.
Statistical process control (SPC) tools are used for the investigation and identification of unnatural variations in the manufacturing, industrial, and service processes. The control chart, the basic and the most famous tool of SPC, is used for process monitoring. Generally, control charts are constructed under normality assumption of the quality characteristic of interest, but in practice, it is quite hard to hold the normality assumption. In such situations, parametric charts tend to offer more frequent false alarms and invalid out-of-control performance. To rectify these problems, non-parametric control charts are used, as these have the same in-control run length properties for all the continuous distributions and are known as in-control robust. This study intends to develop a new non-parametric exponentially weighted moving average (NPEWMA) chart based on sign statistics under a ranked set sampling scheme that is hereafter named (NPREWMA-SN). The run-length profiles of the NPREWMA-SN chart are computed using the Monte Carlo simulation method. The proposed scheme is compared with NPEWMA-SN and classical EWMA-X¯ charts, using different run length measures. The comparison reveals the in-control robustness and superiority of the proposed scheme over its competitors in detecting all kinds of shifts in the process location. A practical application related to the substrate manufacturing process is included to show the demonstration of the proposed chart.
The Southern Tianshan area is one of the most important gold belts identified by many world‐class, super large and large gold deposits such as Muruntau (Uzbekistan), Kumtor (Kyrgyzstan), and Jilau (Tajikistan). Some medium‐ to small‐scale gold deposits, such as Sawayaerdun and Bulong, have been discovered and reported in recent years at the China part of the belt. The study area, named the Wushitala area, is located in the eastern part of Southern Tianshan, and it has a strong potential for gold and other metallic mineral deposits. This study utilizes various image processing techniques, including false colour composite, band ratios, and matched filtering, to process Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and map the distribution of hydrothermal minerals (e.g., muscovite, kaolinite, chlorite, epidote, goethite, and malachite) related to the known deposits in the Wushitala area. The identified alteration zones are coincident with the known gold and copper deposits and field samples from the study area. The distribution of the alteration zones also indicates that the acid intrusions and regional structures play an important role in focusing the mineralizing fluids. The results show that ASTER data accompanied with image processing methods and reference spectra (e.g., JPL, lab, or field measured) could be an effective technique for mapping hydrothermal alteration zones in areas with no dominant vegetation cover. Due to the extensively distributed acid intrusions and structures along the Southern Tianshan Belt, the mineral prospecting methodology is suggested for application in similar geological settings in the belt.
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