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K-DEV: A Borehole Deviation Logging Probe Applicable to Steel-cased Holes (철재 케이싱이 설치된 시추공에서도 적용가능한 공곡검층기 K-DEV)

  • Yoonho, Song;Yeonguk, Jo;Seungdo, Kim;Tae Jong, Lee;Myungsun, Kim;In-Hwa, Park;Heuisoon, Lee
    • Geophysics and Geophysical Exploration
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    • v.25 no.4
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    • pp.167-176
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    • 2022
  • We designed a borehole deviation survey tool applicable for steel-cased holes, K-DEV, and developed a prototype for a depth of 500 m aiming to development of own equipment required to secure deep subsurface characterization technologies. K-DEV is equipped with sensors that provide digital output with verified high performance; moreover, it is also compatible with logging winch systems used in Korea. The K-DEV prototype has a nonmagnetic stainless steel housing with an outer diameter of 48.3 mm, which has been tested in the laboratory for water resistance up to 20 MPa and for durability by running into a 1-km deep borehole. We confirmed the operational stability and data repeatability of the prototype by constantly logging up and down to the depth of 600 m. A high-precision micro-electro-mechanical system (MEMS) gyroscope was used for the K-DEV prototype as the gyro sensor, which is crucial for azimuth determination in cased holes. Additionally, we devised an accurate trajectory survey algorithm by employing Unscented Kalman filtering and data fusion for optimization. The borehole test with K-DEV and a commercial logging tool produced sufficiently similar results. Furthermore, the issue of error accumulation due to drift over time of the MEMS gyro was successfully overcome by compensating with stationary measurements for the same attitude at the wellhead before and after logging, as demonstrated by the nearly identical result to the open hole. We believe that the methodology of K-DEV development and operational stability, as well as the data reliability of the prototype, were confirmed through these test applications.

Operation Measures of Sea Fog Observation Network for Inshore Route Marine Traffic Safety (연안항로 해상교통안전을 위한 해무관측망 운영방안에 관한 연구)

  • Joo-Young Lee;Kuk-Jin Kim;Yeong-Tae Son
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.2
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    • pp.188-196
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    • 2023
  • Among marine accidents caused by bad weather, visibility restrictions caused by sea fog occurrence cause accidents such as ship strand and ship bottom damage, and at the same time involve casualties caused by accidents, which continue to occur every year. In addition, low visibility at sea is emerging as a social problem such as causing considerable inconvenience to islanders in using transportation as passenger ships are collectively delayed and controlled even if there are local differences between regions. Moreover, such measures are becoming more problematic as they cannot objectively quantify them due to regional deviations or different criteria for judging observations from person to person. Currently, the VTS of each port controls the operation of the ship if the visibility distance is less than 1km, and in this case, there is a limit to the evaluation of objective data collection to the extent that the visibility of sea fog depends on the visibility meter or visual observation. The government is building a marine weather signal sign and sea fog observation networks for sea fog detection and prediction as part of solving these obstacles to marine traffic safety, but the system for observing locally occurring sea fog is in a very insufficient practical situation. Accordingly, this paper examines domestic and foreign policy trends to solve social problems caused by low visibility at sea and provides basic data on the need for government support to ensure maritime traffic safety due to sea fog by factually investigating and analyzing social problems. Also, this aims to establish a more stable maritime traffic operation system by blocking marine safety risks that may ultimately arise from sea fog in advance.

Protective Effects of Trifolium pratense L. Extract against H2O2-induced Oxidative Stress in HaCaT Keratinocytes (인간 피부각질세포에서 Hydrogen peroxide로 유도된 산화적 스트레스에 대한 붉은 토끼풀 추출물의 세포 보호 효과)

  • Mi Song Shin;You Kyeong Lee;Seo Young Choi;Ji Sun Hwang;Parkyong Song;Hyeon Cheal Park;Keun Ki Kim;Hong-Joo Son;Yu-Jin Kim;Kwang Min Lee
    • Journal of the Korean Applied Science and Technology
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    • v.40 no.2
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    • pp.223-232
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    • 2023
  • Oxidative stress plays a significant role in the pathogenesis of various skin conditions, resulting in cellular and tissue damage that can contribute to the development of skin tone unevenness, roughness and wrinkles. In this study, we found that Trifolium pratense L. extract (TE) attenuated oxidative-induced damage in HaCaT cells and elucidated the underlying molecular mechanism. Our finding demonstrated that TE effectively protected HaCaT cells against H2O2-induced cell death by inhibiting caspase-3 activation, downregulating Bax and upregulating Bcl-2, and attenuating the activation of three mitogen-activated protein kinases (MAPKs). Our results suggest that TE has remarkable cytoprotective properties against oxidative damage in HaCaT cells and could serve as a complementary or alternative approach to prevent and treat skin damage.

Stress Variation Characteristics of Temporary Fixed Steel Rod in FCM Bridge Construction Method (FCM 교량 가설 공법에서 임시 고정 강봉의 응력 변화 특성 )

  • Hyun-Euk Kang;Wan-Shin Park;Young-Il Jang;Sun-Woo Kim;Hyun-Do Yun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.3
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    • pp.21-29
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    • 2023
  • In this study, the stress characteristics of temporary fixed steel rods were analyzed in the "temporary fixing system using internal prestressing tension", which is mainly applied to the construction of superstructures by FCM. It was difficult to confirm the changes in initial tensile force in this system because the steel rod was internally connected to the pier and the PSC BOX. Therefore, measurement was performed before and after the completion of each segment using an FBG sensor to measure the change in the micro length of the steel rod. The results of the analysis showed that 75% to 90% of the maximum vertical contraction of the steel rod that occurred until the completion of the cantilever segment occurred in the fixing ~ 1segment, and the maximum loss of initial prestressing force was 39%. Such excessive loss of tension force to 1 segment means that tension is needed to improve the precision of construction during the fixation, and re-tension is needed to secure stability for conduction of cantilever segments after the completion of 1segment. In the 2 ~ last segment, the stress of the steel rod decreased gradually, and in the summer, the decrease in stress tended to partially recover due to the increase in the length of the steel rod corresponding to the increase in the vertical volume of PSC BOX. The dominant factor in the stress change in 2~ last segment in this phenomenon is judged to be the change in the length of the steel rod according to the temperature. Unlike the change in length, the relaxation was 1.2-2.7%, which was mostly offset by the opposite stress corresponding to the temperature stress. Therefore, a plan was proposed to improve the internal stress, such as adjusting the fixation time.

Biochemical Methane Potential Analysis of Mushroom Waste Medium (버섯 폐배지의 생화학적 메탄퍼텐셜 분석)

  • Kim, Chang-Gyu;Lee, Jun-Hyeong;Yoon, Young-Man
    • Journal of the Korea Organic Resources Recycling Association
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    • v.30 no.1
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    • pp.13-21
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    • 2022
  • Mushroom waste medium refers to the waste biomass generated after mushroom cultivating. And, the burden of treatment on mushroom farmhouse is increasing due to the absence of appropriate treatment method and increase of treatment costs of the mushroom waste medium. In this study, in order to assess the energy value of mushroom waste medium by an anaerobic digestion, methane potential and anaerobic organic matter decomposition characteristics were investigated. The theoretical methane potential(Bth) of mushroom medium(MM) was 0.481 Nm3-CH4/kg-VSadded, and the Bth of mushroom waste medium(MWM) was 0.451 Nm3-CH4/kg-VSadded. The biochemical methane potential(Bu-exp) of MWM was increased by 18% from 0.155 for MM to 0.183 Nm3-CH4/kg-VSadded for MWM. In the reaction kinetics analysis by the Modified Gompertz model, the maximum methane production rate(Rm) was increased from 4.59 for MM to 7.21 mL/day for MWM and the lag growth phase time(λ) was decreased from 2.78 for MM to 1.96 days for MWM. In the reaction kinetics analysis by the parallel first order kinetics model, the easily degradable organic matter(VSe) content was increased by 5.89% and the persistently degradable organic matter(VSp) content was 2.03% in MWM, and the non-degradable organic matter(VSNB) content was decreased by 7.85%. Therefore, it was evaluated that the anaerobic digestion efficiency of MWM was increased. The anaerobic digestion efficiency of MWM was assessed to be more improved than that of MM.

Square and Court -Social Imagination of Korean Cinema in Blacklist Era (광장과 법정 -블랙리스트 시대 한국영화의 사회적 상상력)

  • Song, Hyo-Joung
    • Journal of Popular Narrative
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    • v.25 no.4
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    • pp.159-190
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    • 2019
  • This paper aims to examine to the political unconsciousness of social movies that have caused social repercussions in the 2010s, and to study the social imagination of Korean films at that time. Korean Movies such as (2013), <1987>(2017) and (2017) reflect the ethos of civil society based on common sense and justice. The epic structure was the same as that of ordinary citizens, who move toward a public space (court, square) after awakening their political correctness. More than anything else, the fact that such films were based on "a historical fact" could have been a strategy to avoid censorship in the era of the blacklist. In these social films, courts and squares have become places for democracy. The conservative government of the time was tired of anti-government resistance and the politics of the square. Thus, films from directors and producers blacklisted were difficult to produce. That's why the court in the movie during this period could become a symbolic proxy for the "legitimate" reenactment of the politics of the square, which was subject to censorship and avoidance by the regime of the time. Meanwhile, the square has gradually become the main venue for political films that advocate "historic true stories." The square of the 1980s, which appeared in the movies, will be connected to the Gwanghwamun candlelight square that audiences experienced in 2017. Furthermore, it was able to reach the concept of an abstract square as an "open space for democracy." At the foundation of these works is a psychological framework that equates the trauma of the failed democratic movement of the 1980s to the trauma of the failed progressive movement of the 2010s. Through this study, we were able to see that social political films in the 2010s were quite successful, emphasizing "political correctness" and constitutional common sense. But they also had limitations as "de-political popular films" that failed to show imagination beyond the censorship of the blacklist era.

An Oral History Study of Overseas Korean Astronomer: John D. R. Bahng's Case (한국천문연구원 원외 원로 구술사연구 - 방득룡 전임 노스웨스턴 대학교 천문학 교수 사례 -)

  • Choi, Youngsil;Seo, Yoon Kyung;Lee, Hyung Mok
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.73.4-74
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    • 2021
  • 한국천문연구원은 2017년 제1차 구술채록사업에 이어 2020년 제2차 사업을 진행하면서 최초로 원외 원로에 대한 구술채록을 시도하였다. 국가 대표 천문연구의 산실로서 연구원 존재 의의를 확립하기 위하여 원내 원로에 국한되었던 구술자 대상을 확장한 것이다. 그 첫 외부 구술 대상자로 방득룡 전임 노스웨스턴 천문학과 교수를 선정하여 2020년 7월부터 준비단계에 들어갔다. 방득룡 전(前)교수가 첫 번째 한국천문연구원 원외 인사 구술자로 선정된 이유는, 그가 우리나라 천문대1호 망원경 구매 선정에 개입한 서신(1972년)이 자료로 남아있었기 때문이다. 한국천문연구원에서 2017년에 수행한 제1차 구술채록사업에서 구술자로 참여한 오병렬 한국천문연구원 원로가 기증한 사료들은 대부분 연구원 태동기 국립천문대 구축과 망원경 구매 관련 자료였으며 이 가운데 1972년 당시 과학기술처 김선길 진흥국장에게 Boller and Chivesns(사(社))의 반사경을 추천한 방득룡 전(前)교수의 서신은 한국 천문학 발전사에서 중요한 사료였다. 연구진은 이 자료를 시작으로, 방득룡 전(前)교수의 생존 여부와 문서고의 공기록물들에서 그의 흔적을 찾아가기 시작했다. 놀랍게도 그는 실제 세계와 한국천문연구원 문서고 깊숙이 기록물들 모두에서 상존하고 있었다. 1927년생인 방득룡 전(前)교수, Dr. John D. R.은 미국 플로리다 한 실버타운에서 건강한 정신으로 생존하여 있었고 연구진의 인터뷰에 흔쾌히 응했다. 2020년 9월 16일에 한국천문연구원 본원 세종홀 2층 회의실에서 영상통신회의로 그와의 구술인터뷰가 진행되었다. 이 구술인터뷰는 원외 인사가 대상이란 점 외에도 방법적으로는 전형적인 대면 방식이 아닌 영상 인터뷰였다는 점에서 코로나 시대의 대안이 되는 실험적 시도였다. 현대 한국천문학 발전사의 재조명 측면에서도 의미가 있었다. 1960년대 초반부터 1992년 정년퇴임까지 30년을 미국 유수 대학교 천문학과 교수로 재직하며 활발한 활동을 해 온 한국계 천문학자가 우리나라 최초 반사망원경 구매 선정에 적극 개입하였던 역사는, 공문서 자료들과 서신 사료들에 이어 그의 육성으로 나머지 의구심의 간극이 채워졌다. 또 구술자 개인이 주관적으로 중요하다고 여기는 '기억'이 중요한 아카이빙 콘텐츠 확장의 단초가 될 수 있다는 것을 보여줌으로써 구술사 연구에 있어서도 중요한 관점을 주었다. 애초 연구진이 방득룡 전(前)교수의 공식 기록에서 아카이빙의 큰 줄기로 잡았던 것은 1948년 도미, 1957년 위스콘신 대학교 천문학 박사학위 취득, 1962년부터 노스웨스턴 대학(일리노이주 에반스턴)의 천문학 교수진, 1992년 은퇴로 이어진 생애였다. 그러나 그와의 구술 준비 서신 왕래와 구술을 통하여 알게 된 그가 인생에서 중요시 여겼던 지점은, 1948년 도미 무렵 한국의 전쟁 전 상황과 당시 비슷한 시기에 유학한 한국 천문학자들의 동태, 그리고 1957년부터 1962년까지 프린스턴 대학교에서 M. Schwarzschild 교수와 L. Spitzer 교수를 보조하며 Stratoscope Project를 연구하였던 경험이었다. 기록학적 의미에서도, 전자를 통해서 그와 함께 동시대 한국 천문학을 이끌었던 인재들의 맥락정보를 얻을 수 있었으며, 후자를 통해서는 세계 천문학사에 큰 영향을 미친 석학에 대한 아카이브 정보와의 연계 지점과 방득룡 전(前)교수의 연구 근원을 찾을 수 있었다. 이들은 추후 방득룡 콘텐츠 서비스 시에 AIP, NASM, Lyman Spitzer 콘텐츠, 평양천문대, 화천조경천문대, 서울대와 연세대, 그리고 한국천문연구원까지 연계되어 전 세계 폭넓은 이용자들의 유입을 유도할 수 있는 검색 도구가 될 수 있다. 이번 방득룡 구술사 연구에서 구술자 개인의 주관적인 소회가 공식 기록이 다가갈 수 없는 역사적 실체에 일정 부분 가까울 수 있다는 것, 그리고 이를 통하여 개인의 역사는 공동체의 역사로 확장될 수 있다는 사실을 발견할 수 있었다. 또 연구진은 방득룡 전(前)교수의 회상을 통하여 구술자 개인의 시각으로 한국과 미국 천문학계의 공동체 역사를 재조명할 수 있었고, 이것을 아카이브 콘텐츠 확장 서비스에 반영할 수 있다는 기대를 가지게 되었다. 무엇보다 이 연구를 통하여 다양한 주제의 아카이브로 연동될 수 있는 주제어와 검색도구를 구술자 개인의 회상으로부터 유효하게 도출할 수 있다는 것을 확인하였다. 그리고 향후 한국천문 구술아카이브의 확장을 통하여 보다 다양한 활용과 연구 재활용의 선순환이 가능하다는 것도 알 수 있었다. 이는 최근 기록학계에서 대두되고 있는 LOD(Linked Open Data)의 방향성과도 흡사하여 한국천문학 구술사연구의 차세대 통합형 기록관리의 미래모형을 기대케 하는 대목이다.

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A Study on Image Copyright Archive Model for Museums (미술관 이미지저작권 아카이브 모델 연구)

  • Nam, Hyun Woo;Jeong, Seong In
    • Korea Science and Art Forum
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    • v.23
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    • pp.111-122
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    • 2016
  • The purpose of this multi-disciplinary convergent study is to establish Image Copyright Archive Model for Museums to protect image copyright and vitalize the use of images out of necessity of research and development on copyright services over the life cycle of art contents created by the museums and out of the necessity to vitalize distribution market of image copyright contents in creative industry and to formulate management system of copyright services. This study made various suggestions for enhancement of transparency and efficiency of art contents ecosystem through vitalization of use and recycling of image copyright materials by proposing standard system for calculation, distribution, settlement and monitoring of copyright royalty of 1,000 domestic museums, galleries and exhibit halls. First, this study proposed contents and structure design of image copyright archive model and, by proposing art contents distribution service platform for prototype simulation, execution simulation and model operation simulation, established art contents copyright royalty process model. As billing system and technological development for image contents are still in incipient stage, this study used the existing contents billing framework as basic model for the development of billing technology for distribution of museum collections and artworks and automatic division and calculation engine for copyright royalty. Ultimately, study suggested image copyright archive model which can be used by artists, curators and distributors. In business strategy, study suggested niche market penetration of museum image copyright archive model. In sales expansion strategy, study established a business model in which effective process of image transaction can be conducted in the form of B2B, B2G, B2C and C2B through flexible connection of museum archive system and controllable management of image copyright materials can be possible. This study is expected to minimize disputes between copyright holder of artwork images and their owners and enhance manageability of copyrighted artworks through prevention of such disputes and provision of information on distribution and utilization of art contents (of collections and new creations) owned by the museums. In addition, by providing a guideline for archives of collections of museums and new creations, this study is expected to increase registration of image copyright and to make various convergent businesses possible such as billing, division and settlement of copyright royalty for image copyright distribution service.

A Study on the Development of Textile Design Contents Reflecting The Cultural Characteristics of Multi-cultural Society - Focused on Folk Paintings in China, Vietnam and Japan - (다문화사회의 문화적 특성을 반영한 텍스타일디자인 콘텐츠 개발 연구 - 중국, 베트남, 일본의 민화를 중심으로 -)

  • Park, Sang Oh
    • Korea Science and Art Forum
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    • v.30
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    • pp.119-127
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    • 2017
  • Multi-cultural societies in the era of globalization are now common phenomena all over the world. Since our country has already entered into a multi-cultural society, we can no longer stay in the ideology of a single nation. However, current national policies and researches related to multi-cultural society in Korea are limited to institutional aspects and unilateral education of Korean culture. Therefore, this study aims to overcome these practical limitations. The purpose of this study is to acquire design resources in the folk paintings reflecting the culture of each country. And We will develop textile design content that can be applied to most closely related textile products in daily life. Through this, it is aimed to raise awareness of various cultures and to suggest a communication method through cultural exchange. Therefore, this study has developed color and textile pattern design contents through analysis of characteristics of China, Vietnam, and Japan peoples of the three most frequent countries based on the status of domestic marriage immigrants. And tried to apply it immediately to various textile products. The results and contents of the study are as follows. First, the domestic multi-cultural society was formed through international marriage, and the largest number of marriage immigrants came from China, Vietnam, Japan, the Philippines, Cambodia, Thailand, Mongolia and others. Second, folk paintings are suitable for developing textile design contents as an important factor implied by different cultures of different countries. Thirdly, we have developed the pattern and coloring DB and textile pattern design contents by using folk paintings of China, Vietnam and Japan. As a result, we could verify the utilization of contents reflecting the cultural characteristics of each country and the possibility of commercialization. Based on the results of this research, we hope to contribute to the harmonization of the emotional and artistic aspects that naturally share the culture among multi-cultural society members and to develop differentiated related products.

Visible and SWIR Satellite Image Fusion Using Multi-Resolution Transform Method Based on Haze-Guided Weight Map (Haze-Guided Weight Map 기반 다중해상도 변환 기법을 활용한 가시광 및 SWIR 위성영상 융합)

  • Taehong Kwak;Yongil Kim
    • Korean Journal of Remote Sensing
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    • v.39 no.3
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    • pp.283-295
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    • 2023
  • With the development of sensor and satellite technology, numerous high-resolution and multi-spectral satellite images have been available. Due to their wavelength-dependent reflection, transmission, and scattering characteristics, multi-spectral satellite images can provide complementary information for earth observation. In particular, the short-wave infrared (SWIR) band can penetrate certain types of atmospheric aerosols from the benefit of the reduced Rayleigh scattering effect, which allows for a clearer view and more detailed information to be captured from hazed surfaces compared to the visible band. In this study, we proposed a multi-resolution transform-based image fusion method to combine visible and SWIR satellite images. The purpose of the fusion method is to generate a single integrated image that incorporates complementary information such as detailed background information from the visible band and land cover information in the haze region from the SWIR band. For this purpose, this study applied the Laplacian pyramid-based multi-resolution transform method, which is a representative image decomposition approach for image fusion. Additionally, we modified the multiresolution fusion method by combining a haze-guided weight map based on the prior knowledge that SWIR bands contain more information in pixels from the haze region. The proposed method was validated using very high-resolution satellite images from Worldview-3, containing multi-spectral visible and SWIR bands. The experimental data including hazed areas with limited visibility caused by smoke from wildfires was utilized to validate the penetration properties of the proposed fusion method. Both quantitative and visual evaluations were conducted using image quality assessment indices. The results showed that the bright features from the SWIR bands in the hazed areas were successfully fused into the integrated feature maps without any loss of detailed information from the visible bands.