• Title/Summary/Keyword: Quantitative Functions

Search Result 486, Processing Time 0.031 seconds

Design Exploration of High-Lift Airfoil Using Kriging Model and Data Mining Technique

  • Kanazaki, Masahiro;Yamamoto, Kazuomi;Tanaka, Kentaro;Jeong, Shin-Kyu
    • International Journal of Aeronautical and Space Sciences
    • /
    • v.8 no.2
    • /
    • pp.28-36
    • /
    • 2007
  • A multi-objective design exploration for a three-element airfoil consisted of a slat, a main wing, and a flap was carried out. The lift curve improvement is important to design high-lift system, thus design has to be performed with considered multi-angle. The objective functions considered here are to maximize the lift coefficient at landing and near stall conditions simultaneously. Kriging surrogate model which was constructed based on several sample designs is introduced. The solution space was explored based on the maximization of Expected Improvement (EI) value corresponding to objective functions on the Krigingmodels. The improvement of the model and the exploration of the optimum can be advanced at the same time by maximizing EI value. In this study, a total of 90 sample points are evaluated using the Reynolds averaged Navier-Stokes simulation(RANS) for the construction of the Kriging model. In order to obtain the information of the design space, two data mining techniques are applied to design result. One is functional Analysis of Variance(ANOVA) which can show quantitative information and the other is Self-Organizing Map(SOM) which can show qualitative information.

Assessment of the ATC Effect for Paddy Field and Forest Using Landsat Images and In-situ Measurement (Landsat영상과 현지조사에 의한 여름철 논과 산림의 기온저감효과 평가)

  • Park, Jong-Hwa;Na, Sang-Il;Kim, Jin-Soo
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2007.05a
    • /
    • pp.1943-1947
    • /
    • 2007
  • The objective of this research was to find a direct and indirect method to estimate land surface temperature (LST) efficiently, using Landsat images and in-situ measurement. Agricultural fields including paddy fields have long been known to have multi-functions beneficial to the environment and ecology of the urban surrounding areas. Among these functions, the ambient temperature cooling (ATC) effect are widely acknowledged. However, quantitative and regional assessment of such effect has not had many investigations. Thermal remote sensing has been used over urban areas to assess ATC effect, to perform land cover classifications and as input for models of urban surface atmosphere exchange. Here, we review the use of thermal remote sensing in the study of paddy fields and urban climates, focusing primarily on the ATC effect. Landsat satellite images were used to determine the surface temperatures of different land cover types of a $441km^2$ study area in Cheongju, Korea. The results show that the ATC are a function of paddy area percentage in Landsat pixels. Pixels with higher paddy area percentage have more significant cooling effect.

  • PDF

Analysis of the Relationship Between Land Cover and Land Surface Temperature at Cheongju Region Using Landsat Images in Summer Day (LANDSAT영상을 이용한 여름철 청주지역의 토지피복과 지표면온도와의 관계 분석)

  • Park, Jong-Hwa;Kim, Jin-Soo;Na, Sang-Il
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.48 no.5
    • /
    • pp.39-48
    • /
    • 2006
  • The objective of this research was to find an indirect method to estimate land surface temperature (LST) efficiently, using Landsat images. Agricultural fields including paddy fields have long been known to have multi-functions beneficial to the environment and ecology of the urban surrounding areas. Among these functions, the ambient temperature cooling (ATC) effect is widely acknowledged. However, quantitative and regional assessment of such effect has not been performed. Thermal remote sensing has been used over urban areas to assess the ATC effect, Thermal Island Effect(TIE), and as input for models of urban surface atmosphere exchange. Here, we review the use of thermal remote sensing in the study of paddy fields and urban climates, focusing primarily on the ATC effect. Landsat satellite images were used to determine the surface temperatures of different land cover types of a $44km^{2}$ study area in Cheongiu, Korea. The results show that the ATC is a function of paddy area percentage in Landsat pixels. Landsat pixels with higher paddy area percentage have much more cooling effect. The use of satellite data may contribute to a globally consistent method for analysis of ATC effect.

Analysis of Typhoon Vulnerability According to Quantitative Loss Data of Typhoon Maemi (태풍 매미의 피해 데이터 기반 국내 태풍 취약성 분석에 관한 연구)

  • Ahn, Sung-Jin;Kim, Tae-Hui;Kim, Ji-Myong
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2019.05a
    • /
    • pp.125-126
    • /
    • 2019
  • This study aims to recognize damage indicators of typhoon and to develop damage function's indicators, using information derived from the actual loss of typhoon Maemi. As typhoons engender significant financial damage all over the world, governments and insurance companies, local or global, develop hurricane risk assessment models and use it in quantifying, avoiding, mitigating, or transferring the risks. For the reason, it is crucial to understand the importance of the risk assessment model for typhoons, and the importance of reflecting local vulnerabilities for more advanced evaluation. Although much previous research on the economic losses associated with natural disasters has identified the risk indicators that are indispensable, more comprehensive research addressing the relationship between vulnerability and economic loss are still called for. Hence this study utilizes and analyzes the actual loss record of the typhoon Maemi provided by insurance companies to fill such gaps. In this study, natural disaster indicators and basic building information indicators are used in order to generate the vulnerability functions; and the results and indicators suggest a practical approach to create the vulnerability functions for insurance companies and administrative tasks, while reflecting the financial loss and local vulnerability of the actual buildings.

  • PDF

Computational electroencephalography analysis for characterizing brain networks

  • Sunwoo, Jun-Sang;Cha, Kwang Su;Jung, Ki-Young
    • Annals of Clinical Neurophysiology
    • /
    • v.22 no.2
    • /
    • pp.82-91
    • /
    • 2020
  • Electroencephalography (EEG) produces time-series data of neural oscillations in the brain, and is one of the most commonly used methods for investigating both normal brain functions and brain disorders. Quantitative EEG analysis enables identification of frequencies and brain activity that are activated or impaired. With studies on the structural and functional networks of the brain, the concept of the brain as a complex network has been fundamental to understand normal brain functions and the pathophysiology of various neurological disorders. Functional connectivity is a measure of neural synchrony in the brain network that refers to the statistical interdependency between neural oscillations over time. In this review, we first discuss the basic methods of EEG analysis, including preprocessing, spectral analysis, and functional-connectivity and graph-theory measures. We then review previous EEG studies of brain network characterization in several neurological disorders, including epilepsy, Alzheimer's disease, dementia with Lewy bodies, and idiopathic rapid eye movement sleep behavior disorder. Identifying the EEG-based network characteristics might improve the understanding of disease processes and aid the development of novel therapeutic approaches for various neurological disorders.

A Study on Analysis of Source Code for Program Protection in ICT Environment (ICT 환경에서 프로그램보호를 위한 소스코드 분석 사례 연구)

  • Lee, Seong-Hoon;Lee, Dong-Woo
    • Journal of Convergence for Information Technology
    • /
    • v.7 no.4
    • /
    • pp.69-74
    • /
    • 2017
  • ICT(Information Communication Technology) is a key word in our society on today. Various support programs by the government have given many quantitative and qualitative changes to the software industries. Software is instructions(Computer Program) and data structure. Software can be divided into Application program and System program. Application programs have been developed to perform special functions or provide entertainment functions. Because of this rapid growth of software industries, one of the problems is issue on copyright of program. In this paper, we described an analysis method for program similarity based on source code in program.

Error estimation for 2-D crack analysis by utilizing an enriched natural element method

  • Cho, J.R.
    • Structural Engineering and Mechanics
    • /
    • v.76 no.4
    • /
    • pp.505-512
    • /
    • 2020
  • This paper presents an error estimation technique for 2-D crack analysis by an enriched natural element (more exactly, enriched Petrov-Galerkin NEM). A bare solution was approximated by PG-NEM using Laplace interpolation functions. Meanwhile, an accurate quasi-exact solution was obtained by a combined use of enriched PG-NEM and the global patch recovery. The Laplace interpolation functions are enriched with the near-tip singular fields, and the approximate solution obtained by enriched PG-NEM was enhanced by the global patch recovery. The quantitative error amount is measured in terms of the energy norm, and the accuracy (i.e., the effective index) of the proposed method was evaluated using the errors which obtained by FEM using a very fine mesh. The error distribution was investigated by calculating the local element-wise errors, from which it has been found that the relative high errors occurs in the vicinity of crack tip. The differences between the enriched and non-enriched PG-NEMs have been investigated from the effective index, the error distribution, and the convergence rate. From the comparison, it has been justified that the enriched PG-NEM provides much more accurate error information than the non-enriched PG-NEM.

Review of Genetic Diagnostic Approaches for Glanzmann Thrombasthenia in Korea

  • Shim, Ye Jee
    • Journal of Interdisciplinary Genomics
    • /
    • v.3 no.2
    • /
    • pp.41-46
    • /
    • 2021
  • Inherited platelet function disorders (IPFDs) are a disease group of heterogeneous bleeding disorders associated with congenital defects of platelet functions. Normal platelets essential role for primary hemostasis by adhesion, activation, secretion of granules, aggregation, and procoagulant activity of platelets. The accurate diagnosis of IPFDs is challenging due to unavailability of important testing methods, including light transmission aggregometry and flow cytometry, in several medical centers in Korea. Among several IPFDs, Glanzmann thrombasthenia (GT) is a most representative IPFD and is relatively frequently found compare to the other types of rarer IPFDs. GT is an autosomal recessive disorder caused by mutations of ITGA2B or ITGB3. There are quantitative or qualitative defects of the GPIIb/IIIa complex in platelet, which is the binding receptor for fibrinogen, von Willbrand factor, and fibronectin in GT patients. Therefore, patients with GT have normal platelet count and normal platelet morphology, but they have severely decreased platelet aggregation. Thus, GT patients have a very severe hemorrhagic phenotypes that begins at a very early age and persists throughout life. In this article, the general contents about platelet functions and respective IPFDs, the overall contents of GT, and the current status of genetic diagnosis of GT in Korea will be reviewed.

Analysis of Supporting Function for Invigorating Aerospace Cluster focused on the case of Gyeongsangnam-do (항공산업 클러스터 활성화를 위한 지원 기능 분석 -경남을 중심으로-)

  • Han, Kwan-Hee;Jeong, Dong-Min;Ok, Ju-Seon;Jeon, Jeong-Hwan
    • The Journal of the Korea Contents Association
    • /
    • v.14 no.4
    • /
    • pp.314-324
    • /
    • 2014
  • Aerospace industry is a combination of high technologies which has several characteristics such as product reliability, precision, light weight, and energy efficiency. Nowadays, each country is trying to invigorating knowledge and information sharing between the companies for the synergy effect of aerospace industry. However, the research and empirical analysis on the vitalization of aerospace industry cluster are insufficient. Therefore, this study aims to firstly classify the supporting functions of government for aerospace industry cluster into five types by analyzing existing literatures and status reports issued by government. Secondly, companies are surveyed on the five classified types of supporting functions by questionnaire. Questionnaire survey responded by 30 aerospace companies in Gyeongnam aerospace industry cluster are analyzed. Quantitative analysis methods were used for statistical analysis. Based on the analysis, improvement directions of government supporting functions are suggested. The results of this study is expected to help policy making for invigorating the aerospace industry cluster.

A Study on Surveying Functions of RBI Software (RBI 소프트웨어의 기능에 관한 조사연구)

  • Song J S;Shim S H;No W H;Park J H;Choi S C;Kwon J R;Kim J Y;Yoon K B
    • Journal of the Korean Institute of Gas
    • /
    • v.5 no.4 s.16
    • /
    • pp.56-61
    • /
    • 2001
  • Recently RBI softwares have received widespread interests from various industries. The available RBI softwares have variety of levels of analysis, fields of applications and damage mechanisms considered, which depend on the software developing institutes. In this paper results of a GSP(Group Sponsored Project) entitled 'Study on Surveying Functions of Foreign RBI Softwares' are summarized. A part of the study is explained in detail as a sample case for showing the contents of the project. Based on the demo softwares as well as the open documents and contents obtained in the web pages of the developer critical comparisons of the well-known RBI softwares were made. The required functions of the optimal RBI software is also discussed from the review results of this study.

  • PDF