Boosting Adversarial Training with Learnable Distribution

In recent years,various adversarial defense methods have been proposed to improve the robustness of deep neural networks.Adversarial training is one of the most potent methods to defend against adversarial attacks.However,the difference in the feature space between natural and adversarial examples hinders the accuracy and robustness of the model in adversarial training.This paper proposes a learnable distribution adversarial training method,aiming to construct the same distribution for training data utilizing the Gaussian mixture model.The distribution centroid is built to classify samples and constrain the distribution of the sample features.The natural and adversarial examples are pushed to the same distribution centroid to improve the accuracy and robustness of the model.The proposed method generates adversarial examples to close the distribution gap between the natural and adversarial examples through an attack algorithm explicitly designed for adversarial training.This algorithm gradually increases the accuracy and robustness of the model by scaling perturbation.Finally,the proposed method outputs the predicted labels and the distance between the sample and the distribution centroid.The distribution characteristics of the samples can be utilized to detect adversarial cases that can potentially evade the model defense.The effectiveness of the proposed method is demonstrated through comprehensive experiments.

The abundance,distribution,and enrichment mechanism of harmful trace elements in coals from Guizhou,Southwestern China

Coal seams can enrich a variety of harmful trace elements under specific geological conditions.The spatial distribution of harmful trace elements in coal is extremely uneven,and the distribution characteristics of each element content are different.The harmful elements released in the process of coal mining and utilization will cause serious harm to the environment and the human body.It is of great resource significance to study the geochemistry of coal that affects the enrichment and distribution characteristics of harmful trace elements.Based on the domestic and foreign literature on coal geochemistry in Guizhou published by previous investigators,this study counted 1097 sample data from 23 major coal-producing counties in Guizhou Province,systematically summarized the relevant research results of harmful trace elements in the coal of Guizhou,and revealed the overall distribution and enrichment characteristics of harmful trace elements in the coal of Guizhou.The results show that the average contents of Cd,Pb,Se,Cu,Mo,U,V,As,Hg,and Cr in coal of Guizhou are higher than those in Chinese coal and world coal.A variety of harmful trace elements in the coal of Guizhou have high background values,especially in Liupanshui,Xingyi and Qianbei coalfield.The enrichment of various harmful trace elements in the Late Permian coal in Guizhou is mainly related to the combined action of various geological and geochemical factors.The supply of terrigenous debris and sedimentary environment may be the basic background of the enrichment of harmful elements in western Guizhou,while low-temperature hydrothermal activity and volcanic ash deposition may be the main reasons for the enrichment of harmful elements in southwestern Guizhou.

Human Visual Attention Mechanism-Inspired Point-and-Line Stereo Visual Odometry for Environments with Uneven Distributed Features

Visual odometry is critical in visual simultaneous localization and mapping for robot navigation.However,the pose estimation performance of most current visual odometry algorithms degrades in scenes with unevenly distributed features because dense features occupy excessive weight.Herein,a new human visual attention mechanism for point-and-line stereo visual odometry,which is called point-line-weight-mechanism visual odometry(PLWM-VO),is proposed to describe scene features in a global and balanced manner.A weight-adaptive model based on region partition and region growth is generated for the human visual attention mechanism,where sufficient attention is assigned to position-distinctive objects(sparse features in the environment).Furthermore,the sum of absolute differences algorithm is used to improve the accuracy of initialization for line features.Compared with the state-of-the-art method(ORB-VO),PLWM-VO show a 36.79%reduction in the absolute trajectory error on the Kitti and Euroc datasets.Although the time consumption of PLWM-VO is higher than that of ORB-VO,online test results indicate that PLWM-VO satisfies the real-time demand.The proposed algorithm not only significantly promotes the environmental adaptability of visual odometry,but also quantitatively demonstrates the superiority of the human visual attention mechanism.

Zonal distribution features of high frequency planetary waves in the oceans derived from satellite altimeter data

Based on TOPEX/Poseidon (T/P) and ERS-1 and 2 satellite altimeter data between October 1992 and December 2000, high frequency oscillations with periods less than 150 d are analyzed and their spatial distributions are described. The ratio, instead of the energy itself, of the energy corresponding to certain frequency band from power spectrum relative to the total energy in the 20～143 d range is analyzed. The results show that the period of the most energetic oscillations in this band increases with latitude from about 1 month near the tropics to about 4 months near 30°, in agreement with the latitudinal dependency of the phase speed of westward propagating long Rossby waves,which dominate the variability in those latitudes.As a result,the global spatial distributions of the period of the dominant oscillations are largely zonal, with relatively small differences between different ocean basins. It suggests that the oscillations with periods around 60 d are mainly associated with planetary Rossby waves except the often regarded as tidal aliasing.

Cytogenetic Mapping of Disease Resistance Genes and Analysis of Their Distribution Features on Chromosomes in Maize

Cytogenetic maps of four clusters of disease resistance genes were generated by ISH of the two RFLP markers tightly linked to and flanking each of maize resistance genes and the cloned resistance genes from other plant species onto maize chromosomes, combining with data published before. These genes include Helminthosporium turcium Pass resistance genes Ht1, Htn1 and Ht2, Helminthosporium maydis Nisik resistance genes Rhm1 and Rhm2, maize dwarf mosaic virus resistance gene Mdm1, wheat streak mosaic virus resistance gene Wsm1, Helminthosporium carbonum ULLstrup resistance gene Hml and the cloned Xanthomonas oryzae pv. Oryzae resistance gene Xa21 of rice, Cladosporium fulvum resistance genes Cf-9 and Cf-2.1 of tomato,and Pseudomonas syringae resistance gene RPS2 of Arabidopsis. Most of the tested disease resistance genes located on the four chromosomes, i.e., chromosomes1, 3, 6 and 8, and they closely distributed at the interstitial regions of these chromosomal long arms with percentage distances ranging 31.44(±3.72)-72.40(±3.25) except for genes Rhm1, Rhm2, Mdm1 and Wsm1 which mapped on the satellites of the short arms of chromosome6. It showed that the tested RFLP markers and genes were duplicated or triplicated in maize genome. Homology and conservation of disease resistance genes among species, and relationship between distribution features and functions of the genes were discussed. The results provide important scientific basis for deeply understanding structure and function of disease resistance genes and breeding in maize.

Distributional features of temperature and salinity in the southern Taiwan Strait and its adjacent sea areas in late summer, 1994

Based on the CTD data obtained in the southern Taiwan Strait and its adjacent areas in August and September of 1994, the distributional features of the temperature and salinity in the studied area have been analyzed in detail. The results are as follows: (1) There are two low temperature and high salinity regions in the nearshore area between Dongshan and Shantou and in the southeastern Taiwan Shoal, respectively, which may be caused by upwellings. (2) There exists a cold eddy in the northwestern sea area and a warm eddy with two high temperature cores in the eastern sea area of the Dongsha Islands, which are related to the anti-cyclonic turning of the seawater near the Dongsha Islands. (3) A westward high temperature and high salinity water tongue extends through the northern Luzon Strait and reaches the sea areas near the Dengsha Islands and southern Taiwan Strait.

Petroleum Hydrocarbon Distribution Features in Water and Sediment off Fujian Shore

This study on the distribution features of petroleum hydrocarbon in water and sediment off the Fujian shore using data obtained from the baseline research on oceanic contamination in Fujian showed that: during the research period, petroleum hydrocarbon concentrations in water varied from 5.77 μg/L to 37.28 μg/L, averaged 14.48 μg/L; was lower in the wet season than in the dry season; and was highest in the Minjiang Estuary and Jiulong Estuary in both seasons. The petroleum hydrocarbon concentrations in shore sediment varied from 14.48 mg/kg to 784.36 mg/kg, averaged 133.3 mg/kg, and was closely related to sediment types (granularity).

CHANGING FEATURES AND TREND OF LIGHT INDUSTRY DISTRIBUTION IN NORTHEAST CHINA

Modern industry in northeast China started from light industry. From the end of 19th century to 1931 was the phase of initial development of light industry in northeast China. During this period, the development of light industry gave priority to grain processing industry. After occupying northeast China, Japanese vigorously developed heavy industry to meet the needs of munitions and paid more attention to raw materials and semi-finished articles industry for the purpose of the war. Light industry was impeded and developed slowly. After the founding of New China, large-scale economic construction took place in northeast and heavy industry received prior investment and equipment. Northeast region became the first heavy industry base through several five-year plans, the development of light industry made giant strides. The present features of light industry distribution are: difference of light industry distribution, similarity of light industry structure, and imbalance of light industry development.

Research on the Distributional Features of and Interrelationships Between the Dissolved Oxygen, Salinity, pH Value and Nutrient Salts in the Honghai Bay Waters

In this paper, the environmental factors are surveyed of the mariculture waters of the Honghai Bay from the late spring to the early summer (June) in 1998. The distributional features and variation laws of dissolved oxygen, salinity, pH value and nutrient salts in the sea water are expounded. Also discussed are their relationships between each other. The results show that the contents of dissolved oxygen and pH value in the sea water increase with the increasing temperature from north (except for No.15~17 stations) to south (expect for No.6 station). At the same time it is affirmed that photosynthesis is the major cause of the high contents of dissolved oxygen and pH value. And the nutrient salt shows a negative correlation with salinity. The total content of phytoplankton obviously increased with the reduction of nutrient salts from north to south.

Analysis of Temporal and Spatial Distribution and Large-Scale Circulation Features of Extreme Weather Events in Shanxi Province, China in Recent 30 Years

Extreme weather events such as persistent high temperatures, heavy rains or sudden cold waves in Shanxi Province in China have brought great losses and disasters to people’s production and life. It is of great practical significance to study the temporal and spatial distribution characteristics of extreme weather events and the circulation background field. We selected daily high temperature data (≥35°C), daily minimum temperature data and daily precipitation data (≥50 mm) from 109 meteorological stations in Shanxi Province, China from 1981 to 2010, then set the period in which the temperature is ≥35°C for more than 3 days as a high temperature extreme weather event, define the station in which 24 hour cumulative precipitation is ≥50 mm precipitation on a certain day (20 - 20 hours, Beijing time) as a rainstorm weather, and determine the cold air activity with daily minimum temperature dropped by more than 8°C for 24 hours, or decreased by 10°C for 48 h, and a daily minimum temperature of ≤4°C as a cold weather process. We statistically analyze the temporal and spatial characteristics and trends of high temperature, heavy rain and cold weather and the circulation background field. We count the number of extreme weather events such as persistent high temperatures, heavy rains and cold weather frosts in Shanxi, and analyze the temporal and spatial distribution characteristics, trends and general circulation background of extreme weather events. We analyze and find out the common features of the large-scale circulation background field in various extreme weather events. Through the study of the temporal and spatial distribution characteristics of extreme weather events in Shanxi, including persistent high temperature, heavy rain or sudden cold wave frost weather, we summarize the large-scale circulation characteristics of such extreme weather events. It will provide some reference for future related weather forecasting.

Effect of geomorphologic features and climate change on vegetation distribution in the arid hot valleys of Jinsha River,Southwest China

Rapid change of climate in vertical and considerable geomorphologic features form a typical diversity and distribution of biota in mountain ecosystems,i.e.,the subalpine forest zone(SFZ),the valley savanna zone(VSZ),and the transition zone between them.The arid hot valley in the middle and lower reaches of Jinsha River,China represents a well target area to study distribution and the driving factors in these typical mountain ecosystems.Therefore,this study selects four sub-sample areas in the arid-hot valley to explore the distinctive changes of vegetation during 1990 to 2020,and their driving factors in the three different vegetation zones on spatiotemporal scales.On the spatial scale,the Moran’s index was applied to identify the transition zone between the SFZ and the VSZ.Results show that the VSZ at low altitudes(less than 600-1000 m from the valley bottom)is mainly affected by geomorphologic features,especially the slope aspect.With increase in altitude,the climate factors(e.g.,humidity,temperature,etc.)play a more significant role in the development of the SFZ,while the effect of geomorphologic features gradually weakens.On the time scale,The SFZ at higher altitudes experienced more rapid changes in temperature(temperature increase of 1.41°C over the last 60 years)than the VSZ at lower altitudes(temperature increase of 0.172°C over the past 60 years).It caused the forest cover increase faster than that of savanna grassland.Humidity and heat conditions are altered by topography and climate conditions,which shapes the development and physiology of plants as they adapt to the different climatic zones.Furthermore,according to the driving factors(geomorphologic and climate factors)of vegetation distribution found in this study,it suggests that suitable tree species should be planted in the transition zone to evolve into the forest zone and making the forest zone to recover from high to low altitudes gradually.

Mesozoic Volcanic-Intrusive Complexes in the Coastal Area of Southeastern Zhejiang Province: Their Features, Petrogenesis and Distribution Pattern

On the basis of previous studies and by means of field geological, remote sensing, petrographical,mineralogical, petrochemical and geochemical investigations, the authors studied the temporal-spatial distribu-tion of the regional structures, volcanic structures and products of volcanic activity in the coastal area ofsoutheastern Zhejiang. On the basis and through a systematic comparison of the products of magmatism in thearea, it is considered that there exists a compsite volcanic structural belt composed of linear and circular struc-tures and it has been demonstrated that there exist volcanic intrusive complexes--'trinity' composed of vol-canic, subvolcanic and plutonic rocks. It is suggested that the volcanic intrusive complexes in the area belong tothe typical syntexis series and that its materials were derived from a mixed source of crust and mantle.

Statistical study on the spatial - temporal distribution features of the arctic sea ice extent

On the basis of the arctic monthly mean sea ice extent data set during 1953-1984, the arctic region is divided into eight subregions,and the analyses of empirical orthogonal functions, power spectrum and maximum entropy spectrum are made to indentify the major spatial and temporal features of the sea ice fluctuations within 32-year period. And then, a brief appropriate physical explanation is tentatively suggested. The results show that both seasonal and non-seasonal variations of the sea ice extent are remarkable, and iis mean annual peripheral positions as well as their interannu-al shifting amplitudes are quite different among all subregions. These features are primarily affected by solar radiation, o-cean circulation, sea surface temperature and maritime-continental contrast, while the non-seasonal variations are most possibly affected by the cosmic-geophysical factors such as earth pole shife, earth rotation oscillation and solar activity.

Feature Extraction Method Based on Pseudo-Wigner-Ville Distribution for Rotational Machinery in Variable Operating Conditions

In the case of fault diagnosis for roller bearings, the conventional diagnosis approaches by using the time interval of energy impacts in time-frequency distribution or the pass-frequencies are based on the assumption that machinery operates under a constant rotational speed. However, when the rotational speed varies in the broader range, the pass-frequencies vary with the change of rotational speed and bearing faults cannot be identified by the interval of impacts. Researches related to automatic diagnosis for rotational machinery in variable operating conditions were quite few. A novel automatic feature extraction method is proposed based on a pseudo-Wigner-Ville distribution （PWVD） and an extraction of symptom parameter （SP）. An extraction method for instantaneous feature spectrum is presented using the relative crossing information （RCI） and sequential inference approach, by which the feature spectrum from time-frequency distribution can be automatically, sequentially extracted. The SPs are considered in the frequency domain using the extracted feature spectrum to identify among the conditions of a machine. A method to obtain the synthetic symptom parameter is also proposed by the least squares mapping （LSM） technique for increasing the diagnosis sensitivity of SP. Practical examples of diagnosis for bearings are given in order to verify the effectiveness of the proposed method. The verification results show that the features of bearing faults, such as the outer-race, inner-race and roller element defects have been effectively extracted, and the proposed method can be used for condition diagnosis of a machine under the variable rotational speed.

Grid Side Distributed Energy Storage Cloud Group End Region Hierarchical Time-Sharing Configuration Algorithm Based onMulti-Scale and Multi Feature Convolution Neural Network

There is instability in the distributed energy storage cloud group end region on the power grid side.In order to avoid large-scale fluctuating charging and discharging in the power grid environment and make the capacitor components showa continuous and stable charging and discharging state,a hierarchical time-sharing configuration algorithm of distributed energy storage cloud group end region on the power grid side based on multi-scale and multi feature convolution neural network is proposed.Firstly,a voltage stability analysis model based onmulti-scale and multi feature convolution neural network is constructed,and the multi-scale and multi feature convolution neural network is optimized based on Self-OrganizingMaps(SOM)algorithm to analyze the voltage stability of the cloud group end region of distributed energy storage on the grid side under the framework of credibility.According to the optimal scheduling objectives and network size,the distributed robust optimal configuration control model is solved under the framework of coordinated optimal scheduling at multiple time scales;Finally,the time series characteristics of regional power grid load and distributed generation are analyzed.According to the regional hierarchical time-sharing configuration model of“cloud”,“group”and“end”layer,the grid side distributed energy storage cloud group end regional hierarchical time-sharing configuration algorithm is realized.The experimental results show that after applying this algorithm,the best grid side distributed energy storage configuration scheme can be determined,and the stability of grid side distributed energy storage cloud group end region layered timesharing configuration can be improved.

Medical Feature Selection Approach Based on Generalized Normal Distribution Algorithm

This paper proposes a new pre-processing technique to separate the most effective features from those that might deteriorate the performance of the machine learning classifiers in terms of computational costs and classification accuracy because of their irrelevance,redundancy,or less information;this pre-processing process is often known as feature selection.This technique is based on adopting a new optimization algorithm known as generalized normal distribution optimization(GNDO)supported by the conversion of the normal distribution to a binary one using the arctangent transfer function to convert the continuous values into binary values.Further,a novel restarting strategy(RS)is proposed to preserve the diversity among the solutions within the population by identifying the solutions that exceed a specific distance from the best-so-far and replace them with the others created using an effective updating scheme.This strategy is integrated with GNDO to propose another binary variant having a high ability to preserve the diversity of the solutions for avoiding becoming stuck in local minima and accelerating convergence,namely improved GNDO(IGNDO).The proposed GNDO and IGNDO algorithms are extensively compared with seven state-of-the-art algorithms to verify their performance on thirteen medical instances taken from the UCI repository.IGNDO is shown to be superior in terms of fitness value and classification accuracy and competitive with the others in terms of the selected features.Since the principal goal in solving the FS problem is to find the appropriate subset of features that maximize classification accuracy,IGNDO is considered the best.

Distribution and Length-weight Relationships of Glyptosternoid Fishes in the Drung River Basin, Yunnan

Glyptosternoid fishes are a group of sisorid catfishes living in torrents of rivers mainly originating from the Qinghai-Tibet Plateau. Based on our survey in the Drung River Basin, seven collecting sites were investigated and 271 glyptosternoid fishes caught belong to three species （Pareuchiloglanis kamengensis, Exostoma labiatum and Oreoglanis mocropterus）. Features of the distribution of the three catfishes were assessed. More individuals of E. labiatum were caught in the lower reaches of the Drung River with fast water velocity and it might be more adapted to a torrent habitat. The relationships between standard length （L） and weight （W） for P. kamengensis, E. labiatum and O. macropterus were also studied, and the parameter b of the L-W relationship （W = aL^b） ranged between 2. 8201 and 3. 0131. From the present study, all the three catfish species grow allometrically and the growth type of E. labiatum is the closest to a symmetrical one.

Transport and distribution of nutrients in anchovy spawning ground to the southern waters of Shandong Peninsula

The distribution of nutrients and the effect of side transport of nutrients on anchovy spawning ground to the southern waters of Shandong Peninsula are discussed based on the data collected in June 2000, May and June 2001. The coastal current and upwelling are the main physical processes of nutrient transport to the southern waters of Shandong Peninsula. The concentrations of nutrients, Chl-a, the density of anchovy eggs, larva and juvenile fish increase obviously where they are greatly affected by these processes, while the contents of nutrients and Chl-a, the density of anchovy eggs, larva and juvenile fish decrease significantly where these processes diminish or disappear. The investigation suggest that the side transport of nutrients by Lubei (North Shandong) coastal current in the northern area causes the Chl-a content to be high and dense anchovy eggs, larva and juvenile fish to be dense in the coastal area of the Chengshan Cape. In the southern area, the riverine input from Subei irrigation ditch with high content of nutrients inshore and upwelling in the western edge of the Huanghai Sea Cold Water offshore should be responsible for high Chl-a concentration and dense anchovy eggs, larva and juvenile fish. It is possible that these processes of nutrient transport have controlled the anchovy spawning ground to the southern waters of Shandong Peninsula.

Conflict between wild boars(Sus scrofa) and farmers:distribution, impacts,and suggestions for management of wild boars in the Three Gorges Reservoir Area

Economic losses caused by wild boars(Sus scrofa)continue to increase in the Three Gorges Reservoir Area.We selected 206 farmers in Wuqiaohe Basin as survey respondents using random stratified sampling.The distribution and impacts of wild boars were examined using a questionnaire survey and spatial analysis.The results showed that:(1)The density of farmer settlements is low and most peasants’households are located on the forest edge.Due to large-scale labor migration,a high proportion of farmland(25.85%)has been abandoned and an even higher proportion of farmland(40.48%)has been returned to forest.(2)The probability of wild boar damage to peasant households was 67.96%.Yields of corn and sweet potato decreased by 24.87%and 28.24%,respectively,with a total economic loss of approximately 2,590,100 RMB/yr in the Wuqiaohe basin.Sixty-five percent of the affected cultivatedlands were located within approximately 150 m of the forest edges.(3)The wild boar damage coefficient was significantly and negatively correlated with the distance between the peasants’household and the forest edge,the density of the settlements,and the area of cultivated land.The wild boar damage coefficient shows a significant positive correlation with the area of farmland returned to forest.(4)The damage activity caused by wild boars began to occur7-8 years ago,and the destruction has been more frequently and seriously observed in the last 4-5 years.(5)We make suggestions for wild boar control and management measures including developing a compensation policy.The compensation standard is related to the land area returning from farmland to forests and the actual cultivated land area.

Distribution of Pill Millipedes (Arthrosphaera) and Associated Soil Fauna in the Western Ghats and West Coast of India

Seven sampling sites in each of three biomes (Western Ghats, foothills of Western Ghats and west coast) of south- western India were investigated to study the distribution, abundance and ecology of pill millipedes (Arthrosphaera) and associated fauna in relation to edaphic features. Abundance and biomass of Arthrosphaera and other millipedes were the highest in Western Ghats, while earthworms were in foothills. Arthrosphaera magna and Arthrosphaera spp. were common in Western Ghats and foothills respectively, while no Arthrosphaera were found in the west coast. None of the sampling sites consisted of more than one species of Arthrosphaera. Biomass of Arthrosphaera, other millipedes and earthworms significantly differed in Western Ghats (P = 9.48 × 10-7) and foothills (P = 1.35 × 10-8), as did the biomass of species of Arthrosphaera (P = 2.76 × 10-7) between Western Ghats and foothills. Correlation analysis revealed that biomass of Arthrosphaera was significantly (P = 0.01, r = 0.45) correlated with soil organic carbon rather than other edaphic fea- tures (pH, phosphate, calcium and magnesium). Distribution pattern, abundance, biomass and ecology of Arthrosphaera of Western Ghats in relation to soil qualities were compared with millipedes of other regions of the world.