• Title/Summary/Keyword: model investigation

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网络流行语"X+人"探析 - 从"打工人", "尾款人", "工具人"等谈起

  • Yu, Cheol
    • 중국학논총
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    • no.71
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    • pp.41-59
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    • 2021
  • With the progress of social economy and science and technology, network media technology has developed rapidly, China has ushered in the network information age, and the network buzzwords emerged to reflect the interaction and influence between language and society. The network buzzwords of "X+ ren "indirectly show the social psychology and value orientation of modern people with their unique structural characteristics, semantic connotation and cultural deposits, and so on. Based on this, we have conducted a multi-angle investigation on the network buzzwords "X+ ren". This paper first analyzes the structure types and syntactic functions of the lexical model of "X+ ren ", then makes a semantic analysis of the lexical model of "X+ Ren ", and finally investigates the causes and influences of the popularity of "X+ ren ". Through the investigation, we believe that "X+ ren "will continue to grow, and "X+ ren" will continue to attract the attention of the academic community.

Q1D modeling of hydrodynamic instabilities in solid rocket motors

  • M., Grossi;D., Bianchi;B., Favini
    • Advances in aircraft and spacecraft science
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    • v.9 no.5
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    • pp.479-491
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    • 2022
  • This work concerns the investigation of a Q1D methodology employed to study pressure oscillations in solid rocket motors driven by hydrodynamic instabilities. A laboratory-scale solid motor designed to develop vortex-shedding phenomena is analyzed for the whole firing time. The comparison between numerical results and experimental data shows good agreement regarding pressure oscillations signature, especially in the flute-mode behavior, the typical oscillations frequency trend present in any motor liable to hydrodynamic instabilities. Such result ensures the model capability to cope with this particular kind of pressure oscillations source, allowing the investigation of the phenomenon with a lighter and cost savings methodology than CFD simulations.

The Prediction of Water Quality in Ulsan Area Using Material Cycle Model (물질순환모델을 이용한 울산해역의 수질예측)

  • SHIN BUM-SHICK;KIM KYU-HAN;PYUN CHONG-KUN
    • Journal of Ocean Engineering and Technology
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    • v.20 no.1 s.68
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    • pp.55-62
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    • 2006
  • Recently, pollution by development in coastal areas is going from bad to worse. The Korean government is attempting to make policies that prevent water pollution, but it is still difficult to say whether such measures are lowering pollution to an acceptable level. More specifically, the general investigation that has been done in KOREA does not accurately reflect the actual conditions of pollution in coastal areas. An investigation that quantitatively assesses water quality management using rational prediction technology must be attempted, and the ecosystem model, which incorporates both the 3-dimensional hydrodynamic and material cycle models, is the only one with a broad enough scope to obtain accurate results. The hydrodynamic model, which includes advection and diffusion, accounts for the ever-changing flow and (quality) of water in coastal areas, while the material cycle model accounts for pollutants and components of decomposition as sources of the carbon, phosphorus, and nitrogen cycles. In this paper, we simulated the rates of dissolved oxygen (DO), chemical oxygen demand (COD), total nitrogen(T-N) and total-phosphorous(T-P) in Korea's Ulsan Area. Using the ecosystem model, we did simulations using a specific set of parameters and did comparative analysis to determine those most appropriate for the actual environmental characteristics of Ulsan Area. The simulation was successful, making it now possible to predict the likelihood of coastal construction projects causing ecological damage, such as eutrophication and red tide. Our model can also be used in the environmental impact assessment (EIA) of future development projects in the ocean.

Development and Enhancement of Conceptual Site Model for Subsurface Environment Management (지중환경 관리를 위한 부지개념모델 구축 및 개선)

  • Bae, Min Seo;Kim, Juhee;Lee, Soonjae;Kwon, Man Jae;Jo, Ho Young
    • Journal of Soil and Groundwater Environment
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    • v.27 no.spc
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    • pp.1-18
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    • 2022
  • A conceptual site model is used to support decision-making of response strategy development, determination, and implementation within a risk-based contaminated site management system. It aims to provide base information of the relevant site characteristics and surface/subsurface conditions in order to understand the contaminants of concern and the associated risk they pose to the receptors. This study delineated the technical details of conceptual site model development, and discussed the possibility of applying it in domestic subsurface contamination management. Conceptual site models can be developed in various formats such as tables, diagrams, flowcharts, and figures. Contaminated sites are managed for a long period of time following the steps of investigation, remediation design, remediation, verification, and post-remedation management. The conceptual site model can be enhanced in each stage of the contaminated site management based on the continuously updated information on the site's subsurface environment. In the process of enhancement for conceptual site model, precision is gradually improved, and it can evolve from a conceptual and qualitative form to a more quantitatvive and three-dimensional model. In soil pollution management, it is desirable to incorporate the conceptual site model into the soil scrutiny system to better assess the current status of the contaminated site and support follow-up investigation and management.

Comparison of Systemic Accident Investigation Techniques Based on the Sewol Ferry Capsizing

  • Kee, Dohyung
    • Journal of the Ergonomics Society of Korea
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    • v.36 no.5
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    • pp.485-498
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    • 2017
  • Objective: This study aims to survey and compare three systemic accident investigation techniques of Accimap, STAMP and FRAM, based on the application studies of the Sewol ferry accident. Background: Traditional accident investigation methods such as domino models, FTA, etc. work well for losses caused by physical component failures or actions of human in relatively simple systems, but are unable to depict mechanisms generating errors and violations in the current complex socio-technical systems. For better understanding the structure and behavior of the socio-technical systems, systemic techniques have been developed and used. Method: This study was mainly based on survey of literatures through surfing webpages of ScienceDirect and Google, and ergonomics relevant journals. The key words of Sewol, Sewol ferry, Sewol ferry accident, etc. were used in the survey. Results: Three systemic accident investigation methods included similar actors in the Sewol ferry accident including government, Ministry of Ocean and Fisheries, Korean Coast Guard, Korean Register of Shipping, Korea Shipping Association, Chonghaejin Marine Company, crew members. The methods graphically represented each level's failures or performance variabilities of relevant functions and relationships between them. It was shown that the systemic methods consider the entire system, ranging from the environment in which the accident occurred, to the role of government in shaping the system of work. Each method has its own comparative pros and cons, but the Accimap has advantages in terms of time of analysis, data required, model complexity and degree of comprehensiveness. Conclusion: This study reviewed and compared three systemic accident investigation methods, which showed that there are systemic characteristics and pros and cons in the methods. Application: The results would be used as a guideline when selecting accident investigation methods.

Enhancing maintenance performance of tunnel drainage using vibration from polyvinylidene fluoride(PVDF) film (압전필름의 진동을 활용한 터널배수재 유지관리 성능 개선)

  • Xin, Zhen-Hua;Moon, Jun-Ho;Song, Young-Karb;Kim, Young-Uk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.822-826
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    • 2015
  • This study investigated the possible use of vibration from polyvinylidene fluoride(PVDF) film to enhance the performance of the deteriorated tunnel drainage due to physical/chemical clogging of the fine particles through a series of laboratory experiments. The test program was consisted of two different experiments, fundamental investigation and drainage model test. In the fundamental investigation, flow of clay slurry mixed with 50% water (freshwater and brine) on PVDF film with various frequencies was examined. In the model tests, slurry clogging to the woven fiber attached to drainage pipe and its reduction by vibration was investigated. Results of the experiment show that vibration from PVDF film enhances the drain performance significantly. Based upon the investigation, it gives an essential data that are needed for a potential use of hybrid drainage system with PVDF.