• Title/Summary/Keyword: Empirical Knowledge

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A Semi-empirical Model for Microwave Polarimetric Radar Backscattering from Bare Soil Surfaces

  • Oh, Yi-Sok
    • Korean Journal of Remote Sensing
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    • v.10 no.2
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    • pp.17-35
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    • 1994
  • A semi-empirical model for microwave polarimetric radar backscattering from bare soil surfaces was developed using polarmetric radar measurements and the knowledge based on the theoretical and numerical solutions. The microwave polarimetric backscatter measurements were conducted for bare soil surfaces under a variety of roughness and moisture conditions at L-, C-, and X-band frequencies at incidence angles ranging from 10` to 70`. Since the accrate target parameters as well as the radar parameters are necessary for radar scattering modeling, a complete and accurate set of ground truth data were also collected using a laser profile meter and dielectric probes for each surface condition, from which accurate measurements were made of the rms height, correlation length, and dielectric constant. At first, the angular and spectral dependencies of the measured radar backscatter for a wide range of roughnesses and moisture conditions are examined. Then, the measured scattering behavior was tested using theoretical and numerical solutions. Based on the experimental observations and the theoretical and numerical solutions, a semi-empirical model was developed for backscattering coeffients in terms of the surface roughness parameters and the relative dielectric constant of the soil surface. The model was found to yield very good agreement with the backscattering measurements of this study as well as with independent measurements.

Comparison of Structural Change Tests in Linear Regression Models

  • Kim, Jae-Hee
    • The Korean Journal of Applied Statistics
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    • v.24 no.6
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    • pp.1197-1211
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    • 2011
  • The actual power performance of historical structural change tests are compared under various alternatives. The tests of interest are F, CUSUM, MOSUM, Moving Estimates and empirical distribution function tests with both recursive and ordinary least-squares residuals. Our comparison of the structural tests involves limiting distributions under the hypothesis, the ability to detect the alternative hypotheses under one or double structural change, and smooth change in parameters. Even though no version is uniformly superior to the other, the knowledge about the properties of those tests and connections between these tests can be used in practical structural change tests and in further research on other change tests.

An Empirical Study on The Types and Characteristics of Technological Capability: Electronic and IT Firms of Korea (국내 기업의 기술력과 기업특성에 관한 실증연구: 전자/통신 기업을 중심으로)

  • 김성한;박용태
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2000.10a
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    • pp.251-254
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    • 2000
  • In the knowledge-based economy, technological capability is critical for the survival and growth of firms. Technological capability differs across firms depending on the structural and environmental conditions. In nature, the evaluation of technological capability is an intractable task and thus previous studies often employ such proxy measures as patent, productivity, or profitability. In this research, we define technological capability as a combination of the above three measures and investigate, by using the multi-variate statistical analysis, the characteristics of technological capability of electronics/IT firms of Korea. We first propose a taxonomy in which firms are classified into four clusters based on the differences in the nature of technological capability. Then, across clusters, we comparatively analyze the relationship between technological capability and structural/environmental factors of firms. Finally, the implications of empirical findings will be discussed. This study is a small-scale, descriptive one but will be extended and elaborated by augmenting the database and/or incorporating more variables.

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Return on Leadership

  • Martensen, Anne;Gronholdt, Lars
    • International Journal of Quality Innovation
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    • v.6 no.3
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    • pp.19-37
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    • 2005
  • It is generally accepted that leadership is the foundation for creation of a company's business results. However, empirical evidence is lacking. This paper examines the relationship between leadership and key performance results based on a Return on Leadership Model. The model links Denison's four leadership traits to people results, customer results, and ultimately key performance results. Further specified, the model is a structural equation model with nine latent variables, each measured by a set of indicators, observed by survey questions. To validate the model, an empirical study was conducted, and 379 managers from medium-sized and large companies in Denmark participated. The estimation of the model shows that the model structure explains return on leadership very well, and the findings support the developed model. We are able to quantify the relationships from leadership to people results, customer results and key performance results and, in this way, the data presented here provide evidence that leadership is linked to key performance results. Several results and applications of the model are shown. The findings provide new knowledge about how leadership can be linked to performance, and how excellent leadership creates key performance results.

Entrepreneur, Environment, Strategy, Structure, and Performance Changes of High-Tech Ventures (벤처기업의 기업가, 환경, 전략, 그리고 조직구조 특성과 성과변화)

  • 장수덕;이장우
    • Journal of the Korean Operations Research and Management Science Society
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    • v.28 no.2
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    • pp.35-59
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    • 2003
  • Generally high-tech ventures have few resources with which to withstand unpredictable environmental jolts. Therefore environmental changes may have severe effects on the performance of high-tech ventures. Unfortunately previous empirical studies for predicting the performance of ventures hardly deal with such dynamic changes of performance. We try to examine the performance changes of ventures through a longitudinal study before and after severe environmental changes, namely IMF Bailout Memorandum. For the empirical study, we classified venture firms into four types based on entrepreneur's assessment of their performance changes and investigated how these four types differ in characteristics of entrepreneurs, environment, strategy, and organizational features. We found that differentiation strategies, fit between strategy and environmental changes, entrepreneur's trust and activities such as networking and knowledge accumulation about customers, and decentralized organizational structure were important to the performance changes of high-tech ventures.

Empirical Comparisons of Clustering Algorithms using Silhouette Information

  • Jun, Sung-Hae;Lee, Seung-Joo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.10 no.1
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    • pp.31-36
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    • 2010
  • Many clustering algorithms have been used in diverse fields. When we need to group given data set into clusters, many clustering algorithms based on similarity or distance measures are considered. Most clustering works have been based on hierarchical and non-hierarchical clustering algorithms. Generally, for the clustering works, researchers have used clustering algorithms case by case from these algorithms. Also they have to determine proper clustering methods subjectively by their prior knowledge. In this paper, to solve the subjective problem of clustering we make empirical comparisons of popular clustering algorithms which are hierarchical and non hierarchical techniques using Silhouette measure. We use silhouette information to evaluate the clustering results such as the number of clusters and cluster variance. We verify our comparison study by experimental results using data sets from UCI machine learning repository. Therefore we are able to use efficient and objective clustering algorithms.

Analysis and Evaluation of a Nursing Research Paper on Secondary Prevention Program for Stroke (일 뇌졸중 이차예방프로그램 논문의 분석 및 평가)

  • Seo, Eun Hui;Park, Seon-Il
    • Journal of Korean Academy of Rural Health Nursing
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    • v.5 no.1
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    • pp.16-24
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    • 2010
  • Nursing theory is used to explain the goals and functions of nursing and improve practical affairs by providing information and knowledge about the principles which become the foundation of nursing practical affairs. Theoretical analytical compliance with C-T-E (Conceptual-Theoretical-Empirical) structures by Fawcett (1999) whose evaluation method illustrates the relationship of conceptual models, theory, research and structure. The evaluation allows the nurse to visualize the connection, evaluate research, and reduce errors in research. Consequently present doctorate dissertations in nursing science are theoretical propriety, connection in the structure of concepts, theory, research methods, and evaluation to reduce errors in future research plans and division of theoretical development process. So the following verifies logicality, propriety, and reliability which must apply to research in various different fields.

The Relationship between IT Capability and the Key Success Factors for New Product Competitive Advantages (정보기술 역량과 신제품 성공 요인간의 관계)

  • Jung, Seung-Min
    • Journal of Information Technology Applications and Management
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    • v.17 no.2
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    • pp.91-109
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    • 2010
  • The success of new product is a key factor for getting competitive advantages. Marketing research has been investigating marketing capability, manufacturing technical capability, cross-functional integration, market knowledge competence, and competitive environment as the key success factors of new product advantage. Recently, the role of IT capability in enhancing new product advantage is assumed in the literature. However, the empirical studies on the role of IT capability are lacking. The purpose of this study is to identify the effects of IT capability on new product competitive advantages and the relationship between IT capability and the key success factors for new product advantage. Conducting an empirical field study, the IT capability is shown to have a direct effect on new product competitive advantages, and to be also the key success factor to make up for marketing capability and manufacturing technical capability. This study develops a conceptual model on the role of IT capability in enhancing new product competitive advantages by integrating marketing research and IS research.

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Mechanisms, Experimental Results, Empirical Correlations and Analytic Models of Beat Transfer in Containment Building Following a LOCA (냉각재 상실 사고시 격납 용기내에 있어서의 열전달에 관한 기구, 실험결과, 선험 관계식 및 해석적 모형들에 관한 고찰)

  • Jong Ho Choi;Soon Heung Chang
    • Nuclear Engineering and Technology
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    • v.15 no.2
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    • pp.123-134
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    • 1983
  • Estimates of the rate of heat removal from the containment atmosphere following a loss of colant accident (LOCA) are important to the prediction of containment peak pressure and temperature which are essential parameters in designing the containment building. An overall survey and discussion of mechanisms, experimental results, empirical correlations and analytical models that are relevant to the heat transfer inside the containment have been made. As a result of this review, the current state of the knowledge about tile containment heat transfer can be understood and it is known that more investigations are needed to avoid the misuse of various correlations.

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Knowledge Production Function in South Korea : An Empirical Analysis (우리나라 지식생산함수 : 실증분석)

  • Cho, Sang-Sup;Jung, Dong-Jin
    • Journal of Korea Technology Innovation Society
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    • v.10 no.3
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    • pp.383-405
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    • 2007
  • In this paper we estimate knowledge production function for 15 South Korean industry sectors using panel data. To accommodate the influence of inter-sectoral interactions on the creation of knowledge, we estimate parameters for related knowledge production functions using the Dynamic Seemingly Unrelated Regression(DSUR) model proposed by Mark et al. (2005). We find the elasticity of knowledge production with respect to the size of research staff to be 0.25 and that with respect to the existing stock of knowledge to be 0.35. The fact that the elasticity of new knowledge creation with regard to the existing knowledge stock is below 1 in South Korea corroborates the view that the rate of long-term growth of her economy is chiefly determined by the elasticity related to production functions of goods and services and the rate of population growth, and that her government policy, to ensure a continued growth for the Korean economy, must shift the focus of R&D policies from the current direct intervention-centered model to one consisting of indirect measures, namely supporting knowledge management and diffusion and the creation of a knowledge sharing system. In terms of R&D policy implications it could be consider that the national knowledge production system should strengthen the cumulative process of knowledge accumulation and population for research and development. Our country R&D policy, also, need to adopt a global approach to increase knowledge stock at the highest levels of a country.

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