Current searches for gravitational microlensing events are being carried out only by a photometric method. In this review paper, we demonstrate that the nature of Galactic lenses can be significantly better constrained with the additional astrometric observations of microlensng events. First, by astromerically observing lensing events, one can resolve the lens parameter degeneracy, and thus the lens mass can be determined with improved precision. Second, by being free from the blending problem, astrometric observations of lensing events will allow one to improve the uncertainties in the determined Einstein time scales. Third, the lens brightness, which could not be measured photometrically, can be measured from the astrometric observations of lensing events, and thus the nature of lens matter can be better constrained. Finally, with the help of astrometric followup observations of a binary-lens event, one can uniquely determine the solution of lens parameters, allowing one to obtain important astronomical information about the source star and the lens itself.

Two cold-air outbreaks, one occurs in cold winter(1985-86) and the other in warm winter(1986-87) over Korea, are studied to represent maps of means, standard deviations maps and one-point correlation maps based on 1000mb and 500mb height fluctuations with different time scales during the cold-surge events. The filters are designed to isolate fluctuations with long time scales(periods longer than 70 days), intermediate time scales(10-70 day periods), short time scales(periods shorter than 10 days). The height fluctuations with long time scales are very similar to the climatological distributions of the wintertime geopotential height. In case of the intermediate time scales, the fluctuation fields reveal the long-wave patterns composed of 3-4 troughs and ridges around the midlatitude belt, in which trough along the East Asia coast and ridge over the Central Siberia and North Pacific are prominent and nearly stationary during the coldJsurge events. For short time scales, the dominent patterns consist of very short wave trains(wavelength 3000-4000㎞) which propagate sortheastward with a phase speed of 8-10 lat./days from the Barents Sea, through Northeast Siberia, toward Korea. The surface temperature fluctuations with small amplitude during the cold-surge events are coincident with this short wave trains passing through the Korean Peninsula.

This study investigated characteristics of meteorological parameters and ionic components of PM2.5 during Asian dust events on November 28 and 30, 2018 at Busan, Korea. The seasonal occurrence frequencies of Asian dust during 1960∼2019 (60 years) were 81.7% in spring, 12.2% in winter, and 6.1% in autumn. Recently, autumn Asian dust occurrence in Busan has shown an increasing trend. The result of AWS (automatic weather station), surface weather chart, and backward trajectory analyses showed that the first Asian dust of Nov. 28, 2018, in Busan came with rapid speed through inner China and Bohai Bay from Mongolia. The second Asian dust of Nov. 30, 2018, in Busan seems to have resulted from advection and deposition of proximal residual materials. These results indicated that understanding the characteristics of meteorological parameters and ionic components of PM2.5 during Asian dust events could provide insights into establishing a control strategy for urban air quality.

The study was aimed to investigate the correlation between tidal effects and fog occurrence in Incheon and Mokpo, which are located in the middle and southern coasts of the West Sea of Korea, respectively. The investigation used meteorological data obtained from the automated synoptic observing systems and automatic weather stations and ocean data from tide stations from 2010 to 2019. Fog occurrence frequency was highest at high tide (Incheon, 41%; Mokpo, 45%). During fog event days at high tide, the dew-point depression was low (Incheon, 0.5 ℃; Mokpo, 0.4 ℃) and the relative humidity was high (Incheon, 97%; Mokpo, 9 8%). The w ind speed w as 2 . 4 m/s in I ncheon a nd 2 .0 m/s in M okpo, a nd t he m ain wind d irections w ere west-southwesterly from Incheon and southwesterly from Mokpo. In the fog case study, tidal flats were covered with water before and after the fog started. During the fog period, both stations experienced negative air-sea temperature differences, low dew-point depression, and high relative humidity were maintained, with weak winds forming from the tidal flats to the shore.

This paper has presented not only the spatial coverage change of climate extreme events in summer and winter seasons during the period of 2000-2017, but also their future projections in 2021-2100, South Korea through analysis of a Combined Climate Extreme Index (CCEI). The CCEI quantifies the spatial coverage of climate extreme events based on a set of five indicators. MK (Modified Korean)-PRISM (Parameter-elevation Regression on Independent Slopes Model)v1.2 (1×1km) and RCP scenario data (1×1km) were applied to CCEI. Results indicated that in average, 21.7% of the areas in the summer and 23.6% in the winter experienced climate extremes from 2000 to 2017 regardless of types of climate extreme events in South Korea. The summer of 2003 and 2009 was relatively cool and humid, while the summer of 2014 and 2015 was cool and dry and the summer of 2016 was warm and dry. The extreme events with much above normal maximum and minimum temperature during the study period were detected but not much below normal maximum and minimum temperature after 2015. For RCP2.6 and RCP8.5 scenarios, there were statistically significant trends with spatial coverage expansion of climate extreme events in the future. It might be concluded that climate extreme events in the summer and winter seasons were affected simultaneously by two or more indicators than a single indicator in South Korea.

In the era of network media, the outbreak of network social emotions will lead to the tearing and out of control situation of network public opinion ecology, resulting in the occurrence of public crisis. With the development of network media technology, we can deeply understand the social mentality of public events through the analysis and management of public network behavior. Grass roots governance is the basis of social governance. Urban community governance and rural village governance belong to the category of community governance. In the city, the community is the unit cell of social governance. The large-scale Internet platform has linked people, money, materials, and information related to personal life together. It not only provides solutions for the public's life problems but also provides a new digital social governance model. The modernization of community governance at the grassroots level also means reshaping the interpersonal relationship and power structure of the community, focusing on highlighting the subjectivity of the community residents and enhancing the emotional identity of the community. This paper puts forward the analysis framework of social public psychology and behavior in the face of public events, based on the management of public emotions reflected in the network media, to improve the modernization level of community governance and the ability to deal with public events

The purpose of this study is to examine the trends of extreme temperature events in East Asia over the past 40 years (1979-2018) and their potential relationships with recent changes in the Northern Hemisphere cryosphere. Analyses of Sen’s slope and Mann-Kendall tests are performed for time series data of extreme temperature events extracted from NCEP-DOE reanalysis II Gaussian grid daily 2-m air temperature data. As the result, it is found that extreme high temperature events exceeding the 99th percentile show more noticeable increasing trends than the magnitude of the decreasing extreme low temperature events below the 1st percentile particularly in Mongolia, Korean Peninsula and southern China due to unexpected cold events since the late 2000s. Correlation analyses based on Kendall’s tau indicate that the reduction of spring-early summer Eurasian snow cover (data from Rutgers University Global Snow Lab.) may lead to the increasing tendency of extreme high temperature events in East Asia through snow albedo feedbacks, while paradoxically the reducing autumn-early winter Arctic sea ice (data from NSIDC) due to global warming seems to cause more frequent extreme low temperature events in recent years through the amplification of Rossby waves. Thus, it is needed to continue monitoring the feedbacks between changing Arctic cryosphere and East Asian climate systems in the warmer 21st century.

Using the methods of literature， comparative research and logical analysis, this paper explores China's future development strategies of sports events and derivatives industrial ecology chains. The research shows that: (1) the ownership of event property and the substantiation of individual sports associations are the preconditions for sports companies to expand profit margins, cultivate brand events and maximize the dividends of event brands; (2) through the establishment of sports lotteries and the introduction of well-funded The TV stations bid for the copyright of the competitions, sports industry can realize the energy saving and income increase of the competitions and expand the profit points of the competitions; (3) the ability of the government departments to conduct competition monitoring, risk early warning and scientific decision － making is an important assessment indicator for the safety of major sports events in the future; (4) related institutions should strengthen the creative and design development of derivatives for sports events, enhance the economic, social and cultural benefits of the ecological chain of the derivatives and promote the further development of China's sports industry．

Several researchers have discussed which element is preferably chosen as a vehicle in metonymic constructions Langacker (1993) claims that, all other things being equal, these cognitive principles govern the choice of metonymic vehicle: human over non-human, whole over part, concrete over abstract, visible over non-visible. This claim has been made, but no previous case studies regarding these principles have been conducted. To remedy this gap, this paper examines 510 instances of PART FOR WHOLE metonymy in the names of events and accidents in Korean newspapers from 2010 through 2019. The result shows that AGENT is most frequently utilized to refer to whole events, supporting one principle of Langacker, human over nonhuman. CAUSE, PATIENT, and PLACE follows AGENT. INSTRUMENT is not very frequently used unless it achieves its salience through contexts. TIME is observed only once. Considering that TIME was used frequently to name past events, as in the 4.19 Revolution, 5.18 Democratic Movement, the 4.3 Events, the infrequent use of TIME reflects a cultural change in its cognitive salience.

Challenging Minisatellite Payload (CHAMP) satellite magnetic data are used to investigate the latitudinal variation of the storm-time meso-scale field-aligned currents by defining a new metric called the FAC range. Three major geomagnetic storm events are considered. Alongside SymH, the possible contributions from solar wind dynamic pressure and interplanetary magnetic field (IMF) BZ are also investigated. The results show that the new metric predicts the latitudinal variation of FACs better than previous studies. As expected, the equatorward expansion and poleward retreat are observed during the storm main phase and recovery phase respectively. The equatorward shift is prominent on the northern duskside, at ~58° coinciding with the minimum SymH and dayside at ~59° compared to dawnside and nightside respectively. The latitudinal shift of FAC range is better correlated to IMF BZ in northern hemisphere dusk-dawn magnetic local time (MLT) sectors than in southern hemisphere. The FAC range latitudinal shifts responds better to dynamic pressure in the duskside northern hemisphere and dawnside southern hemisphere than in southern hemisphere dusk sector and northern hemisphere dawn sector respectively. FAC range exhibits a good correlation with dynamic pressure in the dayside (nightside) southern (northern) hemispheres depicting possible electrodynamic similarity at day-night MLT sectors in the opposite hemispheres.

This study aims to analyze the change of onset and end dates of extreme temperature events and examine their relationships with global warming. The data used for this study are daily maximum temperature, daily minimum temperature, and global mean temperature anomaly. Results were similar to the trend of global temperature, showing that the onset date of extreme high temperature is advanced while the end date of extreme high temperature is delayed. Also, the change of onset (end) dates of extreme low temperature were clear, with coming later (earlier). There is more distinct change in extreme low temperature than extreme high temperature. The length between onset date and end date of extreme high (low) temperature is significantly longer (shorter). The onset (end) date of extreme high temperature has a negative (positive) relationship with global mean temperature. The onset (end) date of extreme low temperature has a positive (negative) relationship with global mean temperature. It might be concluded that the change of onset and end date of extreme temperature in South Korea has been affected by global warming.

This study examined the safety of nuclear spent-fuel (NSF) transport casks against accidental puncture events. Finite element analyses were conducted according to the accident conditions in NUREG-1536 and RG 7.8, which specify 1-m parallel and vertical drops on a rigid rod that has 15-cm diameter and 20-cm height. We focused on the safety evaluation of the cask body, baskets, and canister based on ASME BPVC Section III, and evaluated whether these elements would undergo excessive fracture or puncture.