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Introduction of GOCI-II Atmospheric Correction Algorithm and Its Initial Validations (GOCI-II 대기보정 알고리즘의 소개 및 초기단계 검증 결과)

  • Ahn, Jae-Hyun;Kim, Kwang-Seok;Lee, Eun-Kyung;Bae, Su-Jung;Lee, Kyeong-Sang;Moon, Jeong-Eon;Han, Tai-Hyun;Park, Young-Je
    • Korean Journal of Remote Sensing
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    • v.37 no.5_2
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    • pp.1259-1268
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    • 2021
  • The 2nd Geostationary Ocean Color Imager (GOCI-II) is the successor to the Geostationary Ocean Color Imager (GOCI), which employs one near-ultraviolet wavelength (380 nm) and eight visible wavelengths(412, 443, 490, 510, 555, 620, 660, 680 nm) and three near-infrared wavelengths(709, 745, 865 nm) to observe the marine environment in Northeast Asia, including the Korean Peninsula. However, the multispectral radiance image observed at satellite altitude includes both the water-leaving radiance and the atmospheric path radiance. Therefore, the atmospheric correction process to estimate the water-leaving radiance without the path radiance is essential for analyzing the ocean environment. This manuscript describes the GOCI-II standard atmospheric correction algorithm and its initial phase validation. The GOCI-II atmospheric correction method is theoretically based on the previous GOCI atmospheric correction, then partially improved for turbid water with the GOCI-II's two additional bands, i.e., 620 and 709 nm. The match-up showed an acceptable result, with the mean absolute percentage errors are fall within 5% in blue bands. It is supposed that part of the deviation over case-II waters arose from a lack of near-infrared vicarious calibration. We expect the GOCI-II atmospheric correction algorithm to be improved and updated regularly to the GOCI-II data processing system through continuous calibration and validation activities.

A Study on the Effect of Startup's Innovation Orientation on Growth Aspiration (창업기업의 혁신지향성이 성장열망에 미치는 영향에 관한 연구)

  • Oh, Hyemi;Lee, Chaewon;Kim, Jinsoo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.5
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    • pp.1-14
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    • 2021
  • Innovation and Scale-up of Start-up companies are becoming important national tasks. In the past, it was spread the start-up policy paradigm such as 'Start-up America', 'Start-up Chile', 'Start-up Britain' to overcome the recession globally. However as the economic recovery has become more visible recently in advanced economies, it is shifting from a start-up support policy to a scale-up oriented policy paradigm such as 'Scale-up America', Scale-up UK', 'Scale-up Denmark'. It is necessary to enter the scale-up phase beyond the start-up phase to increase the number of high-quality jobs and to continue economic growth. Therefore, it is necessary to grow the start-up into a strong medium-sized company and to lay the foundation for survival. Therefore, the purpose of this study is to consider the antecedent factors that influence the scale-up aspiration for the start-up firm to grow into a scale-up company, and empirically identifies the differences between the stages of economic development and entrepreneurs in the country. In order to accomplish the purpose, this study predicted scale-up by aspiration which is a predictor of scale-up behavior because it is difficult to achieve visible growth in a short period of time due to the characteristics of start-up companies. In order to empirically explore these relationships, the data were collected from nascent entrepreneurs who have less than 3.5 years of the Adult Population Survey(APS) among the subjects surveyed by the Global Entrepreneurship Monitor(GEM) and the national economic development stage are divided into Innovation-driven, Efficiency-driven, Factor-driven type economies. For the test hypotheses, this study adopted the multi-level model analysis for comparison between national economic development stages and using the R 3.5.0 program. The results of this study are as follows. There is difference between the national economic development and the entrepreneur in the relationship between innovation orientation of entrepreneurs and scale-up aspirations. As the economy of the country develops, the innovation activity of the entrepreneur becomes more active. Since start-ups are heavily influenced by entrepreneurs, there is a difference in the degree of aspiration depending on how innovative an entrepreneur is in the same environment. In terms of the relationship between innovation orientation and scale-up aspiration, the fear of failure was found to differ between national economic development and entrepreneurs. The fear of failure differ from country to country, and this is one of the important factors affecting entrepreneurial activities. It is expected that the factors influencing the growth of the start-up companies which are identified through the results of these studies, will be used to create a suitable scale-up ecosystem according to the national economic development stage.

Changes and Comparative Analysis of Job-offer, Job-search and Small and Medium-sized Companies Before and after the Corona Era (코로나 시대 이전과 이후의 구인·구직 및 중소기업의 변화 및 비교분석)

  • Kim, Youn Su;Chang, In Hong;Song, Kwang Yoon
    • Journal of Integrative Natural Science
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    • v.14 no.1
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    • pp.11-20
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    • 2021
  • On November 17, 2019, an infectious disease with symptoms of pneumonia, called the Wuhan virus at the time, occurred in Wuhan, China. Since then, the name has been changed to COVID-19, and the virus has spread all over the world, and the WHO has declared the highest warning level for infectious diseases, "Pandemic". The coronavirus has also caused great confusion in South Korea. This resulted in large infected people.The first confirmed cases occurred on January 20, 2020, and the number of infected patients is steadily increasing after experiencing several waves, and many corona confirmed cases are also occurring in 2021 after the year. As the whole world enters a pandemic, walls are created between people and people, companies and businesses, and countries and countries, and all growth stops or declines, including human relationships, domestic companies and industries, and foreign industries. As a result, society in general is experiencing a lot of stagnation. Among them, small and medium-sized enterprises (SMEs), which are the basis of all growth in Korea, and youth who are trying to contribute to the national development by entering society, are struggling to find jobs. Even before the coronavirus outbreak, the difficulty of job hunting and the prospect of small and medium-sized businesses were not very good. In this situation, as the country's overall economic situation is poor, the vitality of SMEs has decreased a lot, the prospects are not good, so jobs are reduced, and there are many difficulties due to reluctance to hire new employees. In this study, with 2019 before the corona era and 2020 after the corona era, we compare SMEs before and after the corona era and overall job search and job search activities through average difference analysis, and whether they are affecting through correlation analysis. Through this, it suggests a direction to increase job search through corporate and government policies after raising the prospects of SMEs first.

Exploring the Agency of a Student Leader in Collaborative Scientific Modeling Classes in an Elementary School (초등학교의 협력적 과학 모델링 수업에서 나타난 리더의 행위주체성 탐색)

  • Uhm, Janghee;Kim, Heui-Baik
    • Journal of The Korean Association For Science Education
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    • v.41 no.4
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    • pp.339-358
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    • 2021
  • This study explores the agency of a student leader, expressed through efforts to distribute power and encourage participation in elementary scientific modeling classes. The study also analyzes the context in which the leader's agency was expressed and the context in which the development of a collective agency was constrained. The participants were 22 fifth-grade students. The leader's agency was analyzed by examining his words and actions. As a result, at the outset of the study, the leader had the most power, performing all the activities as the sole authority in a non-cooperative participation pattern. However, with reflection and help from the researcher, the leader recognized the problem and facilitated the participation of other students. He developed an identity as a teacher and demonstrated the agency. The leader's agentic behaviors can be categorized into three aspects. First, regarding the cognitive aspect, the leader helped other students participate in modeling by sharing his knowledge. Second, regarding the normative aspect, he made rules to give all students an equal voice. Third, regarding the emotional aspect, the leader acknowledged the contribution of the students, increasing their confidence. The leader's agency temporarily helped the group to overcome the student hierarchy, facilitating a cooperative participation pattern. However, the development of a collective agency was constrained. The power of the leader was partially redistributed, and the other students did not position themselves as equal to the leader. To support the leader's agency to develop into a collective agency, it is necessary to redistribute the power of the leader more equally and to change the recognition of students.

Seroprevalence and Risk Factors for Severe Fever with Thrombocytopenia Syndrome among the Korea National Park Service Workers (국립공원 종사자의 중증열성혈소판감소증후군 혈청유병률 및 위험요인)

  • Kim, Dong-Hwi;Kim, Kye-Hyung;Yi, Jongyoun;Ko, Mee Kyung;Park, Sung-Jun;Yoo, Seok-Ju;Lee, Kwan;Park, Ji-Hyuk
    • Journal of agricultural medicine and community health
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    • v.46 no.3
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    • pp.162-170
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    • 2021
  • Objectives: This study was carried out to understand the seroprevalence and risk factors for severe fever with thrombocytopenia syndrome (SFTS) among the Korea National Park Service (KNPS) workers. Methods: We used the stored serum samples (763) and survey results collected from the previous investigation on scrub typhus and Lyme disease among the KNPS workers during 2016-2017. The serum samples were analyzed by double-antigen sandwich enzyme-linked immunosorbent assay, which was used to test the total antibody including IgG and IgM. Results: The SFTS seroprevalence among the KNPS worrkers was 1.4%. In multivariate logistic analysis, the national park exploration programs (odds ratio, 3.48; 95% confidence interval, 1.01-12.01) was significantly associated with the seroprevalence of SFTS. Conclusion: This study was the first serological study of SFTS among forestry workers in South Korea. Although the KNPS workers are at a high-risk group of SFTS, the prevention activities related to the working environment and habit was insufficient. Thus, systematic prevention education and training for the KNPS workers need to be strengthened.

Production of yuzu granules using enzyme treated yuzu pulp powder and evaluation of its physiochemical and functional characterization (유자박 식이섬유를 이용한 유자과립 제조 및 이화학적 특성조사)

  • Seong, Hyeon Jun;Lee, Bo-Bae;Kim, Duck-Hyun;Lee, Seung-Hyun;Ha, Ji-Young;Nam, Seung-Hee
    • Korean Journal of Food Science and Technology
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    • v.53 no.4
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    • pp.382-390
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    • 2021
  • In this study, solubilized yuzu pulp powder (EYP) was produced using enzyme treated yuzu pulp powder (YP) and used to manufacture yuzu granules (0-20% EYP content). The physicochemical, product stability, and functional properties of Yuzu granules were compared among five enzyme treatments. Among the five treatments, CL had the highest YP solubilization yield (48.68%). Microstructural observation of EYP using FE-SEM revealed that its surface became irregular and porous after enzymatic treatment. Compared to YP, EYP had 2 times lower insoluble dietary fibers and 3 times lower hemicellulose and cellulose content. Among the yuzu granules, IV (yuzu granules with 15% EYP) had an excellent water and oil holding capacity and flowability. IV granule had the highest narirutin and hesperidin content of 3.4 mg and 2.2 mg/g DW, respectively and the highest antioxidant (68.4%) and tyrosinase inhibitory activities (82.5%). Therefore, EYP or granule with EYP can be used as a functional component in food industry or pharmaceutical field.

Protective effect of Eucommia ulmoides oliver leaves against PM2.5-induced oxidative stress in neuronal cells in vitro (미세먼지(PM2.5)로 유도된 산화적 스트레스에 대한 두충(Eucommia ulmoides Oliver) 잎의 in vitro 뇌 신경세포 보호 효과)

  • Kim, Min Ji;Kang, Jin Yong;Park, Seon Kyeong;Kim, Jong Min;Moon, Jong Hyun;Kim, Gil Han;Lee, Hyo Lim;Jeong, Hye Rin;Heo, Ho Jin
    • Korean Journal of Food Science and Technology
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    • v.53 no.4
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    • pp.423-433
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    • 2021
  • This study was performed to examine the neuroprotective effect of the ethyl acetate fraction from Eucommia ulmoides oliver leaf (EFEL) on PM2.5-induced cytotoxicity. EFEL had higher total phenolic and flavonoid contents than the other fractions. In ABTS and DPPH radical scavenging activities, the IC50 of EFEL was measured as 212.80 and 359.13 ㎍/mL, respectively. To investigate the neuroprotective effect of EFEL, MTT and DCF-DA assays were performed on HT22, MC-IXC, and BV-2 cells. EFEL effectively decreased PM2.5-induced intercellular reactive oxygen species (ROS) content and inhibited PM2.5-induced cell death. In the results of protein expression related to cellular cytotoxicity on microglial cells (BV-2), EFEL had an improvement effect on cell apoptosis and inflammatory pathways. Rutin and chlorogenic acid were identified as the main physiological compounds. Moreover, it was expected that EFEL, including rutin and chlorogenic acid, could be functional food substances with neuroprotective effects against PM2.5-induced oxidative stress.

Monitoring of a Time-series of Land Subsidence in Mexico City Using Space-based Synthetic Aperture Radar Observations (인공위성 영상레이더를 이용한 멕시코시티 시계열 지반침하 관측)

  • Ju, Jeongheon;Hong, Sang-Hoon
    • Korean Journal of Remote Sensing
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    • v.37 no.6_1
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    • pp.1657-1667
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    • 2021
  • Anthropogenic activities and natural processes have been causes of land subsidence which is sudden sinking or gradual settlement of the earth's solid surface. Mexico City, the capital of Mexico, is one of the most severe land subsidence areas which are resulted from excessive groundwater extraction. Because groundwater is the primary water resource occupies almost 70% of total water usage in the city. Traditional terrestrial observations like the Global Navigation Satellite System (GNSS) or leveling survey have been preferred to measure land subsidence accurately. Although the GNSS observations have highly accurate information of the surfaces' displacement with a very high temporal resolution, it has often been limited due to its sparse spatial resolution and highly time-consuming and high cost. However, space-based synthetic aperture radar (SAR) interferometry has been widely used as a powerful tool to monitor surfaces' displacement with high spatial resolution and high accuracy from mm to cm-scale, regardless of day-or-night and weather conditions. In this paper, advanced interferometric approaches have been applied to get a time-series of land subsidence of Mexico City using four-year-long twenty ALOS PALSAR L-band observations acquired from Feb-11, 2007 to Feb-22, 2011. We utilized persistent scatterer interferometry (PSI) and small baseline subset (SBAS) techniques to suppress atmospheric artifacts and topography errors. The results show that the maximum subsidence rates of the PSI and SBAS method were -29.5 cm/year and -27.0 cm/year, respectively. In addition, we discuss the different subsidence rates where the study area is discriminated into three districts according to distinctive geotechnical characteristics. The significant subsidence rate occurred in the lacustrine sediments with higher compressibility than harder bedrock.

Numerical Calculations of IASCC Test Worker Exposure using Process Simulations (공정 시뮬레이션을 이용한 조사유기응력부식균열 시험 작업자 피폭량의 전산 해석에 관한 연구)

  • Chang, Kyu-Ho;Kim, Hae-Woong;Kim, Chang-Kyu;Park, Kwang-Soo;Kwak, Dae-In
    • Journal of the Korean Society of Radiology
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    • v.15 no.6
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    • pp.803-811
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    • 2021
  • In this study, the exposure amount of IASCC test worker was evaluated by applying the process simulation technology. Using DELMIA Version 5, a commercial process simulation code, IASCC test facility, hot cells, and workers were prepared, and IASCC test activities were implemented, and the cumulative exposure of workers passing through the dose-distributed space could be evaluated through user coding. In order to simulate behavior of workers, human manikins with a degree of freedom of 200 or more imitating the human musculoskeletal system were applied. In order to calculate the worker's exposure, the coordinates, start time, and retention period for each posture were extracted by accessing the sub-information of the human manikin task, and the cumulative exposure was calculated by multiplying the spatial dose value by the posture retention time. The spatial dose for the exposure evaluation was calculated using MCNP6 Version 1.0, and the calculated spatial dose was embedded into the process simulation domain. As a result of comparing and analyzing the results of exposure evaluation by process simulation and typical exposure evaluation, the annual exposure to daily test work in the regular entrance was predicted at similar levels, 0.388 mSv/year and 1.334 mSv/year, respectively. Exposure assessment was also performed on special tasks performed in areas with high spatial doses, and tasks with high exposure could be easily identified, and work improvement plans could be derived intuitively through human manikin posture and spatial dose visualization of the tasks.

The current state and prospects of travel business development under the COVID-19 pandemic

  • Tkachenko, Tetiana;Pryhara, Olha;Zatsepina, Nataly;Bryk, Stepan;Holubets, Iryna;Havryliuk, Alla
    • International Journal of Computer Science & Network Security
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    • v.21 no.12spc
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    • pp.664-674
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    • 2021
  • The relevance of this scientific research is determined by the negative impact of the COVID-19 pandemic on the current trends and dynamics of world tourism development. This article aims to identify patterns of development of the modern tourist market, analysis of problems and prospects of development in the context of the COVID-19 pandemic. Materials and methods. General scientific methods and methods of research are used in the work: analysis, synthesis, comparison, analysis of statistical data. The analysis of the viewpoints of foreign and domestic authors on the research of the international tourist market allowed us to substantiate the actual directions of tourism development due to the influence of negative factors connected with the spread of a new coronavirus infection COVID-19. Economic-statistical, abstract-logical, and economic-mathematical methods of research were used during the process of study and data processing. Results. The analysis of the current state of the tourist market by world regions was carried out. It was found that tourism is one of the most affected sectors from COVID-19, as, by the end of 2020, the total number of tourist arrivals in the world decreased by 74% compared to the same period in 2019. The consequence of this decline was a loss of total global tourism revenues by the end of 2020, which equaled $1.3 trillion. 27% of all destinations are completely closed to international tourism. At the end of 2020, the economy of international tourism has shrunk by about 80%. In 2020 the world traveled 98 million fewer people (-83%) relative to the same period last year. Tourism was hit hardest by the pandemic in the Asia-Pacific region, where travel restrictions are as strict as possible. International arrivals in this region fell by 84% (300 million). The Middle East and Africa recorded declines of 75 and 70 percent. Despite a small and short-lived recovery in the summer of 2020, Europe lost 71% of the tourist flow, with the European continent recording the largest drop in absolute terms compared with 2019, 500 million. In North and South America, foreign arrivals declined. It is revealed that a significant decrease in tourist flows leads to a massive loss of jobs, a sharp decline in foreign exchange earnings and taxes, which limits the ability of states to support the tourism industry. Three possible scenarios of exit of the tourist industry from the crisis, reflecting the most probable changes of monthly tourist flows, are considered. The characteristics of respondents from Ukraine, Germany, and the USA and their attitude to travel depending on gender, age, education level, professional status, and monthly income are presented. About 57% of respondents from Ukraine, Poland, and the United States were planning a tourist trip in 2021. Note that people with higher or secondary education were more willing to plan such a trip. The results of the empirical study confirm that interest in domestic tourism has increased significantly in 2021. The regression model of dependence of the number of domestic tourist trips on the example of Ukraine with time tendency (t) and seasonal variations (Turˆt = 7288,498 - 20,58t - 410,88∑5) it forecast for 2020, which allows stabilizing the process of tourist trips after the pandemic to use this model to forecast for any country. Discussion. We should emphasize the seriousness of the COVID-19 pandemic and the fact that many experts and scientists believe in the long-term recovery of the tourism industry. In our opinion, the governments of the countries need to refocus on domestic tourism and deal with infrastructure development, search for new niches, formats, formation of new package deals in new - domestic - segment (new products' development (tourist routes, exhibitions, sightseeing programs, special rehabilitation programs after COVID) -19 in sanatoriums, etc.); creation of individual offers for different target audiences). Conclusions. Thus, the identified trends are associated with a decrease in the number of tourist flows, the negative impact of the pandemic on employment and income from tourism activities. International tourism needs two to four years before it returns to the level of 2019.