• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.35.5-36
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• 2021

'역상고성'은 '신법산서'에 수록되어 있는 티코브라헤의 역법체계와 그 밖의 천문 내용들을 중국인 천문학자들에 의하여 확실하게 정리를 하였지만 '역상고성'에 따른 추보는 천상과 불일치를 보게 되었다. 藪內淸(야부우치 키요시) 저(1969), 유경로 역(1985)에 의하면 이러한 불일치는 옹정 8년 6월 초 1일의 일식이었는데 예보의 오류를 정정한다는 것을 중국 천문학자들이 감당하기 어려웠다. 퀘글러(Ignatius Kögler, 戴進賢, 1680~1746)와 페레이라(Andreas Pereira, 서무덕(徐懋德), 1690-1743) 등의 선교사 천문학자들이 칙명을 받아 종사하게 되고, 이들이 중심이 되어 '역상고성'보다 더 진보된 서양천문 역법에 기초를 둔 역서가 편찬되게 되었다. '신법산서'와 '역상고성'은 모델에서는 평원(平圓)을 사용하지만 '역상고성후편'에서는 타원(楕圓) 모델을 사용하게 된다. 건륭 7년(1742년)에 10권이 완성되어 '역상고성후편'이라 명하였다. 타원모델을 채택하였지만 지동설에 대한 내용은 전혀 기술되어 있지 않다. 아마도 태양이나 달의 운동을 추보하는데 지구를 중심으로 해야 하기에 이에 대한 언급을 필요치 않았을 수도 있다. '역상고성후편' 은 태양과 달의 운행, 일식과 월식에 대해서만 다루고 있다.그러나 '역상고성'에서는 청몽기차나 지반경차를 티코브라헤의 표 값을 그대로 사용하였고, 이 값들이 관측과 관련이 되어 있음을 설명하려는 무리를 두고 있다. 너무 정확하게 값들이 관측 값들로부터 유도되어 의심이 갈 정도이다. 카시니(Giovanni Domenico Cassini, 喝西尼, 1625~1712)는 자신의 동료 리셰와 함께 파리와 프랑스령 기아나 카이엔에서 충의 위치에 있는 화성과 부근 별의 고도를 관측하여 충의 위치에 있는 화성의 시차를 측정하여 최초로 태양과 지구 사이의 거리를 어림하고, 태양의 지반 경차를 현재와 값과 거의 비슷하게 얻었다. '역상고성후편'에서는 이 내용을 상세하게 다루고 있다. 또한 대기에서 입사각과 굴절각 사이에 Snell의 법칙이 성립하는데 이를 이용하여 모호하게 알았던 청몽기차를 대기의 굴절을 이용하여 현재의 값과 비슷한 값을 얻어 사용할 수 있게 되었다. 이는 모든 천체의 위치를 관측하는데 있어서 매우 정확한 값들을 얻을 수 있게 되고 이에 따라 황도-적도 경사각도 정확하게 얻어진다. '역상고성후편'은 옹정원년을 역원으로 하고 있다. 태양의 운행에 있어서 케플러의 타원 궤도를 이용하게 된다. '신법산서'와 '역상고성'에서는 평균근점이각 M을 모델에서 보여 줄 수 있지만 타원 궤도에서는 이 각이 면적각으로 주어지고, 원 대신 타원을 다루기에 쉽지 않다. 현재는 케플러 방정식을 풀어 가감차를 구하게 되는데 이를 기하학적으로 풀이하는 차적구적법을 소개하고 있다. 이와 함께 면적을 이용하여 타원계각과 타원차각을 구하는 차각구각법도 소개한다. 타원계각과 타원차각을 모두 고려하였기에 현재의 태양의 운동을 기술하는 타원모델과 완벽하게 같다. 다만 사용하는 상수가 아주 조금 다를 분이다. 태양의 경도를 추보하는 방법도 동지점을 기준으로 하고 현재의 방법과 동일하다. 달의 운행도 타원 궤도를 사용한다. '역상고성후편'의 내용은 우리나라의 전해져서 1860년 남병길이 쓴 '시헌기요(時憲紀要)'에는 태양, 달, 일·월식, 오행성의 운동, 항성의 위치, 시간 등을 추보하는데 필요한 내용들이 매뉴얼화 되어 기록되어 있고, 1862년 남병철이 쓴 '추보속해(推步續解)'에도 같은 내용을 담고 있다.

• Tunnel and Underground Space
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• v.33 no.3
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• pp.109-125
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• 2023

Disposal repository for high-level radioactive waste secures its safety by means of engineered and natural barriers. The performance of these barriers should be tested and verified through various aspects in terms of short and/or long-term. KAERI has been conducting various in-situ demonstrations in KURT (KAERI Underground Research Tunnel). After completing previous experiment, a conceptual design of an improved in-situ experiment, i.e. K-COIN (KURT experiment of THMC COupled and INteraction), was established and detailed planning for the experiment is underway. Preliminary characterizations were conducted in KURT for siting a K-COIN test site. 15 boreholes with a depth of about 20 m were drilled in three research galleries in KURT and intact rock specimens were prepared for laboratory tests. Using the specimens, physical measurements, uniaxial compression, indirect tension, and triaxial compression tests were conducted. As a result, specific gravity, porosity, elastic wave velocities, uniaxial compressive strength, Young's modulus, Poisson's ratio, Brazilian tensile strength, cohesion, and internal friction angle were estimated. Statistical analyses revealed that there did not exist meaningful differences in intact rock properties according to the drilled sites and the depth. Judging from the uniaxial compressive strength, which is one of the most important properties, all the specimens were classified as very strong rock so that mechanical safety was secured in all the regions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4A
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• pp.281-290
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• 2009

In this study, an analysis technique of hybrid girder considering nonlinearity of steel-concrete contact surface is presented. Steel-concrete hybrid girder shows partial-interaction behavior due to the deformation of shear connectors, slip and detachment at the interface, and cracks under the applied loads. Therefore, the partial-interaction approach becomes more reasonable. Contact surface is modeled by interface element and analyzed nonlinearly because of cost of time and effort to detailed model and analysis. Steel and Concrete are modeled considering non-linearity of materials. Material property of contact surface is obtained from push-out test and input to interface element. For the constitutive models, Drucker-Prager and smeared cracking model are used for concrete in compression and tension, respectively, and a von-Mises model is used for steel. This analysis technique is verified by comparing it with test results. Using verified analysis technique, various analyses are performed with different parameters such as nonlinear material property of interface element and prestress. The results are compared with linear analysis result and analysis result with the assumption of full-interaction.

• Tunnel and Underground Space
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• v.33 no.5
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• pp.348-372
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• 2023

In relation to the high-level radioactive waste disposal project in deep fractured rock aquifer environments, it is essential to evaluate hydrogeological characteristics for evaluating the suitability of the site and operational stability. Such subsurface hydrogeological data is obtained through in-situ tests using boreholes excavated at the target site. The accuracy and reliability of the investigation results are directly related to the selection of appropriate test methods, the performance of the investigation system, standardization of the investigation procedure. In this report, we introduce the detailed procedures for the representative test method, the constant pressure injection test (CPIT), which is used to determine the key hydrogeological parameters of the subsurface fractured rock aquifer, namely hydraulic conductivity and storativity. This report further refines the standard test method suggested by the KSRM in 2022 and includes practical field application case conducted in volcanic rock aquifers where this investigation procedure has been applied.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.4
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• pp.233-257
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• 2023

Asbestos minerals are found at rocks and soils of the Hongseong and Bibong serpentine mines, western part of Chungnam. The area consists of and metasediment, and Mesozoic igneous intrusives with minor age-known gneiss complexes and Mesozoic sediments. With detailed geological investigations, rock samples for the serpentinite and amphibolite areas are collected at sites containing asbestos. Representative asbestos and rock samples are analysed by PLM, XRD, SEM and EPMA. Serpentinites are found as steeply dipping faults with adjacent gneiss complex to the NNE direction. Repeated alteration, including serpenitization and talcification, is found at the emplacement direction for the serpentinite body. Amphibollites occur as intrusives and stratiforms within the Precambrian gneiss complex. Serpentinite and amphibolite (or amphibole schist) contain amphiboles either as asbestiform or non-asbestiform. Varying amounts of asbestos minerals, including chrysotile, tremolite asbestos and actinolite asbestos, are found within the serpentinites. The asbestos minerals are found near the cracks or fractures and along the bedding plane. They occur as cross fiber, slip fiber and mass fiber types. Varying amounts of amphibole asbestos minerals, such as tremolite and actinolite asbestos, are found within amphibolites and as a mass fiber type. Overall results suggest that rocks of the serpentine mines contain serpentine and amphibole type asbestos minerals originated from the hydrothermal alteration. Considering construction nearby the mines and environmental risks by the asbestos, additional land management plans are required.

• Tunnel and Underground Space
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• v.34 no.3
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• pp.231-247
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• 2024

In the field of high-level radioactive waste disposal targeting deep rock environments, hydraulic characteristic information serves as the most important key factor in selecting relevant disposal sites, detailed design of disposal facilities, derivation of optimal construction plans, and safety evaluation during operation. Since various rock types are mixed and distributed in a small area in Korea, it is important to conduct preliminary work to analyze the hydrogeological characteristics of rock aquifers for various rock types and compile the resulting data into a database. In this paper, we obtained hydraulic conductivity data, which is the most representative field hydraulic characteristic of a high-depth volcanic bedrock aquifer, and also analyzed and evaluated the field data. To acquire field data, we used a high-performance hydraulic testing system developed in-house and applied standardized test methods and investigation procedures. In the process of hydraulic characteristic data analysis, hydraulic conductivity values were obtained for each depth, and the pattern of groundwater flow through permeable rock joints located in the test section was also evaluated. It is expected that the series of data acquisition methods, procedures, and analysis results proposed in this report can be used to build a database of hydraulic characteristics data for high-depth rock aquifers in Korea. In addition, it is expected that it will play a role in improving technical know-how to be applied to research on hydraulic characteristic according to various bedrock types in the future.

• The Journal of the Korea Contents Association
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• v.6 no.4
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• pp.146-157
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• 2006

Causal relationship means what relations the result occurred have with a fact as a reason. In general, a formular that no result exists without reasons is used for the method to confirm existence and inexistence of causal relationship. Problematic causal relationships in Private Law are reparations (Article No. 393 of Private Law) due to debt nonfulfillment and reparation due to tort (Application of Article No. 393 by Article No. 750, and No. 763 of Private Law). The purpose pursued by reparation system in private law is to promote equal burden of damages, and the range of reparation at this time is decided by the range of damage and the range of damage is decided by the principle of causal relationship. That the causal relationship theory fairly causes confusion by treating one problem and the other problem as the same thing, instead of dividing them according to the purpose of protection presented by the law is a reason of the criticism from different views.

• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.162-167
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• 2015

Although the perfomance indicators of the nuclear power plants in Korea show optimal, it requires detailed analysis and discussion centered on the radiation dose. As analysis methods, analysis on the radiation dose of nuclear power plants over the past five years was assessed by comparing the relevant radiation dose of radiation workers and per capita average annual radiation dose of the world's major nuclear power stations was also analyzed. The radiation workers over the annual radiation dose limit of 50 mSv were not. The contrast ratio of the radiation exposure according to the reactor type was the normal operation of PHWR was 6.2% higher than those of the PWR. This shows the radiation work of PHWR during normal driving operation is much more than those of PWR. According to the Performance Indicators of the World Association of Nuclear Operator, the annual radiation dose per unit in 2013 showed 527 man-mSv of Korea is the best country among the major nuclear power generating states, the world average was 725 man-mSv. The annual per capita radiation dose is about 80% less than 1 mSv of the public dose limit and also the average per capita dose showed a very low level as 0.82 mSv. Workers in related organizations showed 1.07 mSv, the non-destructive inspection agency workers showed 3.87 mSv. The remarkable results were due to radiation reduced program such as development of radiation shielding and radiation protection. In conclusion, the radiation exposured dose of nuclear power plants workers in Korea showed a trend which is ideally reduced. But more are expected to be difficul and the psychological insecurity against the operation of the nuclear power plants is existed to the residents near the nuclear power plants. So the radiation dose reduction policy and radiation dose follow up study of nuclear power plants will be continously excuted.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.1
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• pp.52-62
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• 2017

Overseas landscape practices have already benefited from the awareness of BIM while landscape-related organizations are encouraging its use and the number of landscape projects using BIM is increasing. However, since BIM has not yet been introduced in the domestic field, this study investigated and analyzed overseas landscape projects and discussed the positive effects and implementation of BIM. For this purpose, landscape projects were selected to show three effects of BIM: improvement of design work efficiency, building of a platform for cooperation, and performance of topography design. These three projects were analyzed across four aspects of implementation methods: landscape information, 3D modeling, interoperability, and visualization uses of BIM. First, in terms of landscape information, a variety of building information was constructed in the form of 3D libraries or 2D CAD format from detailed landscape elements to infrastructure. Second, for 3D modeling, a landscape space including simple terrain and trees was modeled with Revit while elaborate and complex terrain was modeled with Maya, a professional 3D modeling tool. One integrated model was produced by periodically exchanging, reviewing, and finally combining each model from interdisciplinary fields. Third, interoperability of data from different fields was achieved through the unification of file formats, conversion of differing formats, or compliance with information standards. Lastly, visualized 3D models helped coordination among project partners, approval of design, and promotion through public media. Reviewing of the case studies shows that BIM functions as a process to improve work efficiency and interdisciplinary collaboration, rather than simply as a design tool. It has also verified that landscape architects could play an important role in integrated projects using BIM. Just as the introduction of BIM into the architecture, engineering and construction industries saw great benefits and opportunities, BIM should also be introduced to landscape architecture.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.367-418
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• 2018

Just as safety is the most important thing in aviation, safety is the most important in the operation of unmanned aircraft (RPA), and safety operation is the most important in the legal responsibility of the operator of the unmanned aircraft. In this thesis, the legal responsibility of the operator of the unmanned aircraft, focusing on the responsibility of the operator of the unmanned aircraft, was discussed in depth with the issue of insurance, which compensates for damages in the event of an accident First of all, the legal responsibility of the operator of the unmanned aircraft was reviewed for the most basic : definition, scope and qualification of the operator of the unmanned aircraft, and the liability of the operator of the Convention On International Civil Aviation, the ICAO Annex, the RPAS Manual, the Rome Convention, other major international treaties and Domestic law such as the Aviation Safety Act. The ICAO requires that unmanned aircraft be operated in such a manner as to minimize hazards to persons, property or other aircraft as a major principle of the operation of unmanned aircraft, which is ultimately equivalent to manned aircraft Considering that most accidents involving unmanned aircrafts fall to the ground, causing damage to third parties' lives or property, this thesis focused on the responsibility of operators under the international treaty, and the responsibility of third parties for air transport by Domestic Commercial Act, as well as the liability for compensation. In relation to the Rome Convention, the Rome Convention 1952 detailed the responsibilities of the operator. Although it has yet to come into effect regarding liability, some EU countries are following the limit of responsibility under the Rome Convention 2009. Korea has yet to sign any Rome Convention, but Commercial Act Part VI Carriage by Air is modeled on the Rome Convention 1978 in terms of compensation. This thesis also looked at security-related responsibilities and the responsibility for privacy infringement. which are most problematic due to the legal responsibilities of operating unmanned aircraft. Concerning insurance, this thesis looked at the trends of mandatory aviation insurance coverage around the world and the corresponding regulatory status of major countries to see the applicability of unmanned aircraft. It also looked at the current clauses of the Domestic Aviation Business Act that make insurance mandatory, and the ultra-light flight equipment insurance policy and problems. In sum, the operator of an unmanned aircraft will be legally responsible for operating the unmanned aircraft safely so that it does not pose a risk to people, property or other aircraft, and there will be adequate compensation in the event of an accident, and legal systems such as insurance systems should be prepared to do so.