• Title/Summary/Keyword: 우주 환경(space environment)

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Non-pneumatic Tire Design System based on Generative Adversarial Networks (적대적 생성 신경망 기반 비공기압 타이어 디자인 시스템)

  • JuYong Seong;Hyunjun Lee;Sungchul Lee
    • Journal of Platform Technology
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    • v.11 no.6
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    • pp.34-46
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    • 2023
  • The design of non-pneumatic tires, which are created by filling the space between the wheel and the tread with elastomeric compounds or polygonal spokes, has become an important research topic in the automotive and aerospace industries. In this study, a system was designed for the design of non-pneumatic tires through the implementation of a generative adversarial network. We specifically examined factors that could impact the design, including the type of non-pneumatic tire, its intended usage environment, manufacturing techniques, distinctions from pneumatic tires, and how spoke design affects load distribution. Using OpenCV, various shapes and spoke configurations were generated as images, and a GAN model was trained on the projected GANs to generate shapes and spokes for non-pneumatic tire designs. The designed non-pneumatic tires were labeled as available or not, and a Vision Transformer image classification AI model was trained on these labels for classification purposes. Evaluation of the classification model show convergence to a near-zero loss and a 99% accuracy rate confirming the generation of non-pneumatic tire designs.

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Legal Review on the Regulatory Measures of the European Union on Aircraft Emission (구주연합의 항공기 배출 규제 조치의 국제법적 고찰)

  • Park, Won-Hwa
    • The Korean Journal of Air & Space Law and Policy
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    • v.25 no.1
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    • pp.3-26
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    • 2010
  • The European Union(EU) has recently introduced its Directive 2008/101/EC to include aviation in the EU ETS(emissions trading system). As an amendment to Directive 2003/87/EC that regulates reduction of the green house gas(GHG) emissions in Europe in preparation for the Kyoto Protocol, 1997, it obliges both EU and non-EU airline operators to reduce the emission of the carbon dioxide(CO2) significantly in the year 2012 and thereafter from the level they made in 2004 to 2006. Emission allowances allowed free of charge for each airline operator is 97% in the first year 2012 and 95% from 2013 and thereafter from the average annual emissions during historical years 2004 to 2006. Taking into account the rapid growth of air traffic, i.e. 5% in recent years, airlines operating to EU have to reduce their emissions by about 30% in order to meet the requirements of the EU Directive, if not buy the emissions right in the emissions trading market. However, buying quantity is limited to 15% in the year 2012 subject to possible increase from the year 2013. Apart from the hard burden of the airline operators, in particular of those from non-European countries, which is not concern of this paper, the EU Directive has certain legal problems. First, while the Kyoto Protocol of universal application is binding on the Annex I countries of the Climate Change Convention, i.e. developed countries including all Member States of the European Union to reduce GHG at least by 5% in the implementation period from 2008 to 2012 over the 1990 level, non-Annex I countries which are not bound by the Kyoto Protocol see their airlines subjected to aircraft emissions reductions scheme of EU when operating to EU. This is against the provisions of the Kyoto Protocol dealing with the emissions of GHG including CO2, target of the EU Directive. While the Kyoto Protocol mandates ICAO to set up a worldwide scheme for aircraft emissions to contribute to stabilizing GHG concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system, the EU ETS was drawn up outside the framework of the international Civil Aviation Organization(ICAO). Second, EU Directive 2008/101 defines 'aviation activities' as covering 'flights which depart from or arrive in the territory of a Member State to which the [EU] Treaty applies'. While the EU airlines are certainly subject to the EU regulations, obliging non-EU airlines to reduce their emissions even if the emissions are produced during the flight over the high seas and the airspace of the third countries is problematic. The point is whether the EU Directive can be legally applied to extra-territorial behavior of non-EU entities. Third, the EU Directive prescribes 2012 as the first year for implementation. However, the year 2012 is the last year of implementation of the Kyoto Protocol for Annex I countries including members of EU to reduce GHG including the emissions of CO2 coming out from domestic airlines operation. Consequently, EU airlines were already on the reduction scheme of CO2 emissions as long as their domestic operations are concerned from 2008 until the year 2012. But with the implementation of Directive 2008/101 from 2012 for all the airlines, regardless of the status of the country Annex I or not where they are registered, the EU airlines are no longer at the disadvantage compared with the airlines of non-Annex I countries. This unexpected premium for the EU airlines may result in a derogation of the Kyoto Protocol at least for the year 2012. Lastly, as a conclusion, the author shed light briefly on how the Korean aviation authorities are dealing with the EU restrictive measures.

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Comparative Analysis of Heavy Metal Contamination, Mineral Composition and Spectral Characteristics of White, Reddish Brown and Mixed Precipitates Occurring at Osip Stream Drainage, Gangwondo, South Korea (강원도 오십천 수계에 분포하는 백색침전물, 적갈색침전물 및 혼합침전물의 중금속 오염, 광물조성 및 분광학적 특성의 비교분석)

  • Lim, Jeong Hwa;Yu, Jaehyung;Shin, Ji Hye;Koh, Sang-Mo
    • Economic and Environmental Geology
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    • v.52 no.1
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    • pp.13-28
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    • 2019
  • This study analyzed precipitation environment, heavy metal contamination, and mineral composition of white, reddish brown and mixed precipitates occurring at the Osip stream drainage, Gangwondo. Furthermore, spectral characteristics of the precipitates associated with heavy metal contamination and mineral composition was investigated based on spectroscopic analysis. The pH range of the precipitates was 4.43-6.91 for white precipitates, 7.74-7.94 for reddish brown precipitates, and 7.59-7.9 for the mixed precipitates, respectively. XRF analysis revealed that these precipitates were contaminated with Ni, Cu, Zn, and As. The white precipitates showed high Al concentration compared to reddish brown precipitates as much as 3.3 times, and the reddish brown precipitates showed high Fe concentration compared to white precipitates as much as 15 times. XRD analysis identified that the mineral composition of the white participates was aluminocoquimbite, gibbsite, quartz, saponite, and illite, and that of reddish brown precipitates was aluminum isopropoxide, kaolinite, goethite, dolomite, pyrophyllite, magnetite, quartz, calcite, pyrope. The mineral composition of the mixed precipitates was quartz, albite, and calcite. The spectral characteristics of the precipitates was manifested by gibbsite, saponite, illite for white precipitates, goethite, kaolinite, pyrophyllite for reddish brown precipitates, and albite for the mixed precipitates, respectively. The spectral reflectance of the precipitates decreased with increase in heavy metal contamination, and absorption depth of the precipitates indicated that the heavy metal ions were adsorbed to saponite and illite for white precipitates, and goethite and magnetite for reddish brown precipitates.

The Characteristic of the Carrier's Liability Due to the Illegal Act of the Crew during International Air Transportation (국제항공운송 과정에서의 기장 등의 직무상 불법행위에 기한 운송인의 손해배상책임이 가지는 특수성)

  • Kim, Min-Seok
    • The Korean Journal of Air & Space Law and Policy
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    • v.35 no.3
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    • pp.3-37
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    • 2020
  • The aircraft crew operating on international routes performs almost identical tasks as police officials in terms of dealing with the unlawful interference in the aircraft. This means that the liability question which is related to the law enforcement by the police officer may arise regarding the crew's performance of his or her duties. With regard to the carrier's liability due to the crew's unlawful action, there are distinctive characteristics from the liability due to police officers' unlawful action. In case of the claim for damages by the crew's unlawful action, the first question should be whether such action complies with the requirements under the Tokyo Convention 1963. If such action does not conform with the Tokyo Convention 1963, we should examine that claim under the State Compensation Act, the Montreal Convention 1999, and the Civil Act of Korea. The examination under the Tokyo Convention 1963 is not so different from the Korean Court's precedents. However, the court should consider the characteristics of the environment surrounding the crew. The action which is not indemnified under the Tokyo Convention 1963 should be examined under the tort laws. Because the aircraft crew is private persons entrusted with public duties under Korean Law, the State Compensation Act may apply. However, further studies regarding the harmonious interpretation with the Montreal Convention 1999 is needed. With regard to the carrier's liability, the Montreal Convention of 1999 should be applied to the crew's unlawful actions onboard. This is because the Montreal Convention of 1999 preempts the national law for the events that occurred during transportation, and there is no provision which excludes such unlawful actions from the scope of its application. On the other hand, the national law, such as the Civil Act of Korea, applies to unlawful actions taken after transportation. This is because the interpretation that infinitely expands the scope of the Montreal Convention 1999 should not be allowed. Given the foregoing, the standard of the claim for damages due to the crew's unlawful action varies depending on the place where the specific action was taken. As a result, the type of damage recoverable and the burden of proof also varies accordingly. Carriers and crew members must perform their duties with this in mind, but in particular, they should observe the proportionality, and when interpreting the law, it is necessary for the court or lawyer to consider the special characteristics of the work environment.

A Numerical Study on the Selection of Main Specification of the 18.5ft Bass Fishing Boat (18.5ft급 경기용 배스보트의 주요제원 선정에 관한 수치해석 연구)

  • Lim, Jun-Taek;Seo, Kwang-Cheol;Park, Geun-Hong;Kim, Sang-Won
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.7
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    • pp.945-952
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    • 2018
  • Recently, bass fishing has become a marine leisure sport in Korea. There are 4 major fishing associations in Korea, and each association holds 10-15 tournaments each year. However, supply of 17 ft bass boats, which are preferred in leagues, depends 100 % on imports. In this study, we have derived the main specifications to develop the initial hull forms of a 18.5ft bass boat through statistical analysis based on mothership data. In addition, CFD numerical analysis was carried out according to deadrise angle and longitudinal center of gravity, which strongly influenced the resistance and planing performance. For numerical analysis, design speed was set to $Fn=3.284 (Re=9.858{\times}10^7)$, the deadrise angle was set from 12 to $20^{\circ}$, and the longitudinal center of gravity was set in the range of 0 to $8%L_{wL}$ from the center of buoyancy to the stern. Based on the numerical results, we first set the range of these factors by resistance performance and immersion keel length. Furthermore, using a correlation graph of Savitsky's Drag-Lift ratio, we derived the deadrise angle ($14-16^{\circ}$) and longitudinal center of gravity ($4-6%L_{wL}$).

Accuracy Assessment of the Satellite-based IMERG's Monthly Rainfall Data in the Inland Region of Korea (한반도 육상지역에서의 위성기반 IMERG 월 강수 관측 자료의 정확도 평가)

  • Ryu, Sumin;Hong, Sungwook
    • Journal of the Korean earth science society
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    • v.39 no.6
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    • pp.533-544
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    • 2018
  • Rainfall is one of the most important meteorological variables in meteorology, agriculture, hydrology, natural disaster, construction, and architecture. Recently, satellite remote sensing is essential to the accurate detection, estimation, and prediction of rainfall. In this study, the accuracy of Integrated Multi-satellite Retrievals for GPM (IMERG) product, a composite rainfall information based on Global Precipitation Measurement (GPM) satellite was evaluated with ground observation data in the inland of Korea. The Automatic Weather Station (AWS)-based rainfall measurement data were used for validation. The IMERG and AWS rainfall data were collocated and compared during one year from January 1, 2016 to December 31, 2016. The coastal regions and islands were also evaluated irrespective of the well-known uncertainty of satellite-based rainfall data. Consequently, the IMERG data showed a high correlation (0.95) and low error statistics of Bias (15.08 mm/mon) and RMSE (30.32 mm/mon) in comparison to AWS observations. In coastal regions and islands, the IMERG data have a high correlation more than 0.7 as well as inland regions, and the reliability of IMERG data was verified as rainfall data.

An Analysis of STS Contents in the General Science Textbooks(Chemistry Parts) of High School (공통과학 교과서 화학영역의 STS 내용 분석)

  • Choi, In Young;Kim, Yun Hi;Lee, Seok Hee;Moon, Seong Bae
    • Journal of the Korean Chemical Society
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    • v.45 no.3
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    • pp.256-263
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    • 2001
  • The STS contents, emphasized in the 6th curriculum, in the chemistry parts of general science textbooks were analyzed. The STS contents of textbooks showed average of 24.4%. The chapter in "modern science and technology" were included 45.5% in STS contents, 38.7% in "environment", 29.1% in energy, and 14.0% in "materials". When the STS contents were analyzed by STS topics of Piel, the results are as follows; 38.3% on environmental quality and utilization of natural source, 29.6% on effect of technological developments, 7.9% on energy, and 0.6% on human engineering. However, there were no topics on population, space research and national defense. When the STS contents were analyzed by student activities of SATIS, most of the activities were research and case study. There were few field activities of role play, problem solving and decision making, and research design.

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Experiment on Low Light Image Enhancement and Feature Extraction Methods for Rover Exploration in Lunar Permanently Shadowed Region (달 영구음영지역에서 로버 탐사를 위한 저조도 영상강화 및 영상 특징점 추출 성능 실험)

  • Park, Jae-Min;Hong, Sungchul;Shin, Hyu-Soung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.5
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    • pp.741-749
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    • 2022
  • Major space agencies are planning for the rover-based lunar exploration since water-ice was detected in permanently shadowed regions (PSR). Although sunlight does not directly reach the PSRs, it is expected that reflected sunlight sustains a certain level of low-light environment. In this research, the indoor testbed was made to simulate the PSR's lighting and topological conditions, to which low light enhancement methods (CLAHE, Dehaze, RetinexNet, GLADNet) were applied to restore image brightness and color as well as to investigate their influences on the performance of feature extraction and matching methods (SIFT, SURF, ORB, AKAZE). The experiment results show that GLADNet and Dehaze images in order significantly improve image brightness and color. However, the performance of the feature extraction and matching methods were improved by Dehaze and GLADNet images in order, especially for ORB and AKAZE. Thus, in the lunar exploration, Dehaze is appropriate for building 3D topographic map whereas GLADNet is adequate for geological investigation.

Detection of Forest Fire Damage from Sentinel-1 SAR Data through the Synergistic Use of Principal Component Analysis and K-means Clustering (Sentinel-1 SAR 영상을 이용한 주성분분석 및 K-means Clustering 기반 산불 탐지)

  • Lee, Jaese;Kim, Woohyeok;Im, Jungho;Kwon, Chunguen;Kim, Sungyong
    • Korean Journal of Remote Sensing
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    • v.37 no.5_3
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    • pp.1373-1387
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    • 2021
  • Forest fire poses a significant threat to the environment and society, affecting carbon cycle and surface energy balance, and resulting in socioeconomic losses. Widely used multi-spectral satellite image-based approaches for burned area detection have a problem in that they do not work under cloudy conditions. Therefore, in this study, Sentinel-1 Synthetic Aperture Radar (SAR) data from Europe Space Agency, which can be collected in all weather conditions, were used to identify forest fire damaged area based on a series of processes including Principal Component Analysis (PCA) and K-means clustering. Four forest fire cases, which occurred in Gangneung·Donghae and Goseong·Sokcho in Gangwon-do of South Korea and two areas in North Korea on April 4, 2019, were examined. The estimated burned areas were evaluated using fire reference data provided by the National Institute of Forest Science (NIFOS) for two forest fire cases in South Korea, and differenced normalized burn ratio (dNBR) for all four cases. The average accuracy using the NIFOS reference data was 86% for the Gangneung·Donghae and Goseong·Sokcho fires. Evaluation using dNBR showed an average accuracy of 84% for all four forest fire cases. It was also confirmed that the stronger the burned intensity, the higher detection the accuracy, and vice versa. Given the advantage of SAR remote sensing, the proposed statistical processing and K-means clustering-based approach can be used to quickly identify forest fire damaged area across the Korean Peninsula, where a cloud cover rate is high and small-scale forest fires frequently occur.

Scientific Awareness appearing in Korean Tokusatsu Series - With a focus on Vectorman: Warriors of the Earth (한국 특촬물 시리즈에 나타난 과학적 인식 - <지구용사 벡터맨>을 중심으로)

  • Bak, So-young
    • (The) Research of the performance art and culture
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    • no.43
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    • pp.293-322
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    • 2021
  • The present study examined the scientific awareness appearing in Korean tokusatsu series by focusing on Vectorman: Warriors of the Earth. As a work representing Korean tokusatsu series, Vectorman: Warriors of the Earth achieved the greatest success among tokusatsu series. This work was released thanks to the continued popularity of Japanese tokusatsu since the mid-1980s and the trend of robot animations. Due to the chronic problems regarding Korean children's programs-the oversupply of imported programs and repeated reruns-the need for domestically produced children's programs has continued to come to the fore. However, as the popularity of Korean animation waned beginning in the mid-1990s, inevitably the burden fr producing animation increased. As a result, Vectorman: Warriors of the Earth was produced as a tokusatsu rather than an animation, and because this was a time when an environment for using special effects technology was being fostered in broadcasting stations, computer visual effects were actively used for the series. The response to the new domestically produced tokusatsu series Vectorman: Warriors of the Earth was explosive. The Vectorman series explained the abilities of cosmic beings by using specific scientific terms such as DNA synthesis, brain cell transformation, and special psychological control device instead of ambiguous words like the scientific technology of space. Although the series is unable to describe in detail about the process and cause, the way it defines technology using concrete terms rather than science fiction shows how scientific imagination is manifesting in specific forms in Korean society. Furthermore, the equal relationship between Vectorman and the aliens shows how the science of space, explained with the scientific terms of earth, is an expression of confidence regarding the advancement of Korean scientific technology which represents earth. However, the female characters fail to gain entry into the domain of science and are portrayed as unscientific beings, revealing limitations in terms of scientific awareness.