• Title/Summary/Keyword: 안전구조

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A Study on the Deep Neural Network based Recognition Model for Space Debris Vision Tracking System (심층신경망 기반 우주파편 영상 추적시스템 인식모델에 대한 연구)

  • Lim, Seongmin;Kim, Jin-Hyung;Choi, Won-Sub;Kim, Hae-Dong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.9
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    • pp.794-806
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    • 2017
  • It is essential to protect the national space assets and space environment safely as a space development country from the continuously increasing space debris. And Active Debris Removal(ADR) is the most active way to solve this problem. In this paper, we studied the Artificial Neural Network(ANN) for a stable recognition model of vision-based space debris tracking system. We obtained the simulated image of the space environment by the KARICAT which is the ground-based space debris clearing satellite testbed developed by the Korea Aerospace Research Institute, and created the vector which encodes structure and color-based features of each object after image segmentation by depth discontinuity. The Feature Vector consists of 3D surface area, principle vector of point cloud, 2D shape and color information. We designed artificial neural network model based on the separated Feature Vector. In order to improve the performance of the artificial neural network, the model is divided according to the categories of the input feature vectors, and the ensemble technique is applied to each model. As a result, we confirmed the performance improvement of recognition model by ensemble technique.

A Study on the Causes of Hwa-byung and Practical Use of Psychodrama for Treatment of Hwa-byung : (focused on middle-aged women) (화병(火病)의 원인과 치료를 위한 사이코드라마의 활용 방안 연구 : 중년여성을 중심으로)

  • Byun, Sang-Hae;Eo, Ji-Sung
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.4 no.2
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    • pp.1-19
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    • 2009
  • American Psychiatric Association defined hwa-byung as a unique mental illness of Korea, a kind of anger syndrome. This illness caused by the Korean culture is more often found on women than men, especially middle-aged women. The cause of hwa-byung mainly depends on the traditional family structure of Korea formed by Confucianism. Other causes that many middle-aged women suffer from hwa-byung are that their low education level originated in their wrong-recognized position in society and poverty in the past makes them not to be able to control their minds effectively(social psychological factor), and that they get stressed and depressed because of loss of their position in the family after their children leave home and the menopause which hurts their feminine beauty (physiological factor). So, this program aims at letting them to; 1) experience catharsis of the negative feelings which causes hwa-byung by expressing in psychodrama, 2) ease the symptoms of hwa-byung by relaxing their mind, 3) understand themselves through sharing their feelings and thinking at the group level, 4) acquire the opportunities to stabilize and expand their role in their real lives through the role playing.

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A Reliability Analysis of Liquefaction Potential Induced by Ocean Wave (해양(海洋) 구조물(構造物) 지반(地盤)의 액상화(液狀化) 가능성(可能性)에 대한 신뢰도(信賴度) 해석(解析))

  • Kim, Joon Seok;Lee, In Mo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.4
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    • pp.41-48
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    • 1988
  • A model for predicting the probability of liquefaction induced by the ocean storm-wave is developed. Many uncertainties are encountered in the analysis of liquefaction potential for the foundation of offshore structures : (1) the storm-wave duration, (2) the effect of reconsolidation, (3) the effect of patial drainage, etc. These uncertainties are formulated in probabilistic terms and used to assess the risk of liquefaction for a given offshore site. The model developed is applied to the Ekofisk oil storage tank in the North Sea installed in 1973. Reasonable comparison is obtained between the probabilities of liquefaction obtained and the results of deterministic models or the field observations. Among the un certainties encountered, it is revealed that the effect of reconsolidation is the most critical factor. Since many problems are encountered in the deterministic models developed so far, the probabilistic model developed in this paper might be a resonable alternative tool and can be used in the design of new offshore structures.

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3D Finite Element Simulation of Pellet-Cladding Mechanical Interaction (3차원 유한요소를 이용한 핵연료와 피복관 기계적 거동 해석)

  • Seo, Sang Kyu;Lee, Sung Uk;Lee, Eun Ho;Yang, Dong Yol;Kim, Hyo Chan;Yang, Yong Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.5
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    • pp.437-447
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    • 2016
  • In a nuclear power plant, the fuel assembly, which is composed of fuel rods, burns, and the high temperature can generate power. The fuel rod consists of pellets and a cladding that covers the pellets. It is important to understand the pellet-cladding mechanical interaction with regard to nuclear safety. This paper proposes simulation of the PCMI. The gap between the pellets and the cladding, and the contact pressure are very important for conducting thermal analysis. Since the gap conductance is not known, it has to be determined by a suitable method. This paper suggests a solution. In this study, finite element (FE) contact analysis is conducted considering thermal expansion of the pellets. As the contact causes plastic deformation, this aspect is considered in the analysis. A 3D FE module is developed to analyze the PCMI using FORTRAN 90. The plastic deformation due to the contact between the pellets and the cladding is the major physical phenomenon. The simple analytical solution of a cylinder is proposed and compared with the fuel rod performance code results.

Fire Service Policy Theory for Establishing Fire Science (소방학의 학문적 정체성 확립을 위한 소방정책론 정립방안)

  • Ryu, Sang-Il;Lee, Jae-Eun
    • The Journal of the Korea Contents Association
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    • v.10 no.2
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    • pp.421-432
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    • 2010
  • In Korea, about 80 academic departments related to fire science are in operation throughout the country, but fire science is not included as a branch science in the science classification system acknowledged by the Ministry of Education, Science and Technology and its position as a science is not solid yet. In response to this problem, research is being made actively to establish fire science recently. This study aims at composing the fire service policy theory which is one of sub areas of fire science. First, the concept of fire service policy should be established, and fire service policies should be divided into different types. In addition, it is necessary to examine the direction of the development of fire service policies in Korea, and the unique characteristics of fire service policies should be described. Next, we will mention fire service policy making and participants, theories on the determinants of fire service policies, the execution of fire service policies, and the evaluation of fire service policies. Particularly, based on the peculiarity of fire service, it is necessary to explain policies on fire prevention and precaution, fire investigation, rescue and first aid, public campaigns for safety and prevention, fire insurance, etc. Finally, we suggest the future directions of fire service policies according to the change of environment in the future.

400 MeV/nucleon 12C Ions Shielding Benchmark Calculations using MCNPX with Different Nuclear Data Libraries (400 MeV/nucleon 12C 이온의 MCNPX 와 핵자료를 이용한 차폐 벤치마킹 계산)

  • Shin, Yun Sung;Kim, yong min;Kim, dong hyun;Jung, nam suk;Lee, hee seock
    • Journal of the Korean Society of Radiology
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    • v.9 no.5
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    • pp.295-300
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    • 2015
  • There are various type of particle accelerators such as Kyoungju 100-MeV proton beam accelerator in Korea. And Korea plans to build large particle accelerator such as heavy ion accelerator and 4th generation light source facility. The accelerated high energy particles of these facility produce 2nd neutron after nuclear reaction with target materials. And then these 2nd neutron activate structural materials and surrounding environment. Accordingly, it is important to consider the activation and shielding calculation on design of facility for safety operation. In this study, we tried to calculate and compare the neutron flux from the interaction $^{la}150$ beam with target material(Cu) according to thickness of iron and concrete shielding material by MCNPX 2.7 with nuclear library JENDL/HE 07and la150. To verify the properties of nuclear library, we compared computational results with experimental value. These results can be used for dose evaluation technology in planning of the shielding of large particle accelerator.

Evaluation of Magnetic Resonance Imaging using Image Co-registration in Stereotactic Radiosurgery (정위방사선수술시 영상공동등록을 이용한 자기공명영상 유용성 평가)

  • Jin, Seongjin;Cho, Jihwan;Park, Cheolwoo
    • Journal of the Korean Society of Radiology
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    • v.11 no.4
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    • pp.235-240
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    • 2017
  • The purpose of this study is to confirm the safety of the clinical application of image co - registration in steteotactic radiosurgery by evaluating the 3D positioning of magnetic resonance imaging using image co-registration. We performed a retrospective study using three-dimensional coordinate measurement of 32 patients who underwent stereotactic radiosurgery and performed magnetic resonance imaging follow-up using image co-registration. The 3 dimensional coordinate errors were $1.0443{\pm}0.5724mm$ (0.10 ~ 1.89) in anterior commissure and $1.0348{\pm}0.5473mm$ (0.36 ~ 2.24) in posterior commissure. The mean error of MR1 (3.0 T) was lower than that of MR2 (1.5 T). It is necessary to minimize the error of magnetic resonance imaging in the treatment planning using the image co - registration technique and to confirm it.

Diagnostic Techniques for SARS-CoV-2 Detection (SARS-CoV-2의 진단기술)

  • Kim, Jong-Sik;Kang, Na-Kyung;Park, Seon-Mi;Lee, Eun-Joo;Chung, Kyung Tae
    • Journal of Life Science
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    • v.30 no.8
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    • pp.731-741
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    • 2020
  • Coronavirus disease 19 (COVID-19) is caused by SARS-CoV-2 (Severe Acute Respiratory SyndromeCoronavirus 2). To date, seven coronaviruses that can infect humans were reported. Among them, infections with four coronavirus strains (HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1) resulted in mild symptoms such as common cold, whereas SARS-CoV and MERS-CoV caused severe symptoms and epidemics in 2002 and 2012, respectively. In the most recent, SARS-CoV-2 was first reported in Wuhan, China in December 2019 and became a notorious cause of the ongoing global pandemics. To diagnose, treat, and prevent COVID-19, the development of rapid and accurate diagnostic tools, specific therapeutic drugs, and safe vaccines essentially are required. In order to develop these powerful tools, it is prerequisite to understand a phenotype, a genotype, and life cycle of SARS-CoV-2. Diagnostic techniques have been developing rapidly around world and many countries take the fast track system to accelerate approval. Approved diagnostic devices are rapidly growing facing to urgent demand to identify carriers. Currently developed commercial diagnostic devices are divided into mainly two categories: molecular assay and serological & immunological assay. Molecular assays begins the reverse transcription step following polymerase chain reaction or isothermal amplification. Immunological assay targets SARS-CoV-2 antigen or anti-SARS-CoV-2 antibody of samples. In this review, we summarize the phenotype, genome structure and gene expression of SARS-CoV-2 and provide the knowledge on various diagnostic techniques for SARS-CoV-2.

Three Melanogenesis Inhibitors from the Roots of Veratrum nigrum (여로의 멜라닌 생성 억제 물질)

  • Kim, Ho-Jeong;Kang, Sang-Jin;Kang, Seh-Hoon;Kim, Chul-Hwan;Jung, Min-Hwan;Jin, Mu-Hyun
    • Korean Journal of Pharmacognosy
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    • v.33 no.4 s.131
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    • pp.399-403
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    • 2002
  • Three melanogenesis inhibitors were isolated from the roots and rhizomes of Veratrum nigrum L. and were identified as (3S,20S,25S)-22,26-iminocholesta-5,22(N)-dien-3-ol (verazine), (3S,2OR,25S)-22,26-iminocholesta-5,22(N)-dien-3-ol (epi-verazine) and (3R,23R)-14,15,16,17- tetradehydroveratraman-3,23-diol (veratramine) on the basis of their spectroscopic data. It was turned out that these compounds did not directly inhibit tyrosinase activity, the key enzyme responsible for the formation of melanin pigment while these compounds showed strong inhibition on the melanogenesis in B16 F1 mouse melanoma $(IC_{50}<1\;{\mu}g/ml)$. Due to the strong inhibitory activity and safety compared to current whitening agents such as arbutin, kojic acid and AHA, the compound can be a good candidate for new skin whitening agents.

Energy Based Source Location by Using Acoustic Emission for Damage Detection in Steel and Composite CNG Tank (금속 및 복합재 CNG 탱크에서의 손상 검출을 위한 음향방출 에너지 기반 위치표정 기술)

  • Kim, Il-Sik;Han, Byeong-Hee;Park, Choon-Su;Yoon, Dong-Jin
    • Journal of the Korean Society for Nondestructive Testing
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    • v.35 no.5
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    • pp.332-340
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    • 2015
  • Acoustic emission (AE) is an effective nondestructive test that uses transient elastic wave generated by the rapid release of energy within a material to detect any further growth or expansion of existing defects. Over the past decades, because of environmental issues, the use of compressed natural gas (CNG) as an alternative fuel for vehicles is increasing because of environmental issues. For this reason, the importance and necessity of detecting defects on a CNG fuel tank has also come to the fore. The conventional AE method used for source location is highly affected by the wave speed on the structure, and this creates problems in inspecting a composite CNG fuel tank. Because the speed and dispersion characteristics of the wave are different according to direction of structure and laminated layers. In this study, both the conventional AE method and the energy based contour map method were used for source location. This new method based on pre-acquired D/B was used for overcoming the limitation of damage localization in a composite CNG fuel tank specimen which consists of a steel liner cylinder overwrapped by GFRP. From the experimental results, it is observed that the damage localization is determined with a small error at all tested points by using the energy based contour map method, while there were a number of mis-locations or large errors at many tested points by using the conventional AE method. Therefore, the energy based contour map method used in this work is more suitable technology for inspecting composite structures.