• New & Renewable Energy
• /
• v.3 no.3
• /
• pp.54-62
• /
• 2007

The present paper describes the scale effect correction methods for scaled NREL Phase VI wind turbines by using CFD[computational fluid dynamics). For the corrections of wind turbine scale effect, various researches on the helicopter rotor scale effect were investigated and the feasibility study of the methods was performed to correct wind turbine scale effect. The present paper also introduces scale effect correction methods based on two dimensional lift slope. In order to test the present method, performance analyses of NREL Phase VI wind turbines under various scale conditions were carried out and new correction method was applied. Granting that the new correction method is valid only above Reynolds No. 100,000, it showed reasonable agreement between model and full scale wind turbines in the linear torque region.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.28 no.2
• /
• pp.235-242
• /
• 2004

The purpose of this study was to develop a scale for the evaluation of the subjective fabric hand. In order to find out the appropriate method for the evaluation, bipolar adjectives were compared to unipolar adjectives. One hundred female university students we.e selected as judges. They assessed 9 fabrics using the 9 point scale system for both bipolar and unipolar adjectives. When using the bipola. scale, judges responded more consistently showing smaller deviation among their responses. The Judges seemed to understand the meanings of adjectives in the bipolar scale more clearly than in the unipolar scale. Unipolar scale has twice the number of questions than bipolar scale does. Therefore. judges often felt bored responding to the questions using unipolar adjectives. If the appropriate antonym can be found through verified method, bipolar scale seems to have more advantages than unipolar scale.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.7
• /
• pp.107-114
• /
• 2004

This paper presents a two-time scale approach for vibration reduction of a high speed Cartesian manipulator. High speed manipulators would be subject to mechanical vibration due to high inertia forces acting on linkages. To achieve high throughput capability, such motion induced vibration would have to be damped quickly, to reduce settling time of the manipulator end-effector. This paper develops a two-time scale model fer a structurally-flexible Cartesian manipulator. Based on the two-time scale model, a composite controller consisting of a computed torque method for the slow time-scale rigid body subsystem, and a linear quadratic state-feedback regulator for the fast time-scale flexible subsystem, is designed. Simulation results show that the proposed two time-scale controller yields good performance in attenuating structural vibration arising due to excitation from inertial forces.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2001.02a
• /
• pp.214-214
• /
• 2001

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.8 no.6
• /
• pp.589-601
• /
• 2016

The hybrid grid was adopted and numerical prediction analysis of propeller unsteady bearing force considering free surface was performed for mode and full-scale KCS hull-propeller-rudder system by employing RANS method and VOF model. In order to obtain the propeller velocity under self-propulsion point, firstly, the numerical simulation for self-propulsion test of full-scale ship is carried out. The results show that the scale effect of velocity at self-propulsion point and wake fraction is obvious. Then, the transient two-phase flow calculations are performed for model and full-scale KCS hull-propeller-rudder systems. According to the monitoring data, it is found that the propeller unsteady bearing force is fluctuating periodically over time and full-scale propeller's time-average value is smaller than model-scale's. The frequency spectrum curves are also provided after fast Fourier transform. By analyzing the frequency spectrum data, it is easy to summarize that each component of the propeller bearing force have the same fluctuation frequency and the peak in BFP is maximum. What's more, each component of full-scale bearing force's fluctuation value is bigger than model-scale's except the bending moment coefficient about the Y-axis.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.20 no.3
• /
• pp.147-160
• /
• 2007

Background and Objective : The facial nerve grading system proposed by House and Brackmann is most widely accepted for the clinical assessment of facial nerve injury. Because of the limitations and subjectivity of the House-Brackmann scale, several new scales of varying degrees of objectivity and ease of use have been introduced. To assess methods of evaluating the function of the facial nerve that have been introduced over the past 20 years, We compared with the House-Brackmann scale. Method : We referred to the information through Entrez Pubmed and Korean studies information(KSI) from 1985 to 2006 about methods of evaluating facial nerve function. We choose 7 scales that focused on objective and easy of use. Result and conclusion : Sunnybrook scale is a weighted, subjective scale with incorporation of secondary defects into a single composite score. Sunnybrook scale can be recommended over House-Brackmann scale.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1999.08a
• /
• pp.412-422
• /
• 1999

Scale defects generated on the strip surface in a tandem finishing mill line are collected from the strip trapped among the production mills by freezing the growing scale on the strip by the melt glass coating and shutting down the line simultaneously. The samples observed of its cross sectional figure showed the process of scale defect formation where the defects are formed at the base metal surface by thicker oxidized scale during each rolling passes. The properties of the oxidized layer growth both at rolling and inter-rolling are detected down sized rolling test simulating carefully the rolling condition of the production line. The thickness of the oxidized layer at each rolling pass are simulated numerically. The critical scale thickness to avoid the defect formation is determined through the expression of mutual relation between oxidized layer thickness and the lanks of the strip called quality for the scale defects. The scale growth of scale less than the critical thickness and also to keep the bulk temperature tuning the water flow rate and cooling time appropriately. Two units of Inerstand Cooler are designed and settled among the first three stands in the production line. Two units of scale defect is counted from the recoiled strip and the results showed distinct decrease of the defects comparing to the conventionaly rolled products.

• Corrosion Science and Technology
• /
• v.7 no.3
• /
• pp.182-186
• /
• 2008

The microstructures of the oxide scale developed at high temperature on steels are very complex and their development depends on many factors including time, temperature, oxidation conditions and alloying elements. The classical model of an oxide scale on steel consisting of wüstite, magnetite and haematite layers, is more complicated in reality and its properties change with the factors that affect their development. An understanding of the oxide scale formation and its properties can only be achieved by careful examination of the scale microstructure. The oxide scale microstructure may be difficult to characterise by conventional techniques such as optical or standard scanning electron microscopy. An unambiguous characterisation of the scale and the correct identification of the phases within the scale are difficult unless the crystallographic structure for each phase in the scale is considered and a simultaneous microstructure-microtexture analysis is carried out. In the current study Electron Backscatter Diffraction (EBSD) has been used to investigate the microstructure of iron oxide layers grown on low carbon steels at different times and temperatures. EBSD has proved to be a powerful technique for identifying the individual phases in the oxide scale accurately. The results show that different grain shapes and sizes develop for each phase in the scale depending on time and temperature.

• Journal of Korean Academy of Nursing Administration
• /
• v.20 no.3
• /
• pp.257-271
• /
• 2014

Purpose: This methodological study was done to develop a Nursing Competency Measurement Scale based on the clinical ladders of nurses working in wards. Methods: Thirty clinical experts and 501 ward nurses evaluated the content validity of the scale. A survey using the Nursing Competency Measurement Scale was conducted with 114 nurses to evaluate reliability and applicability of the instrument. Data were analyzed using SPSS/WIN 21.0. Results: A review of the literature identified 13 components of nursing competencies and 30 core nursing competencies based on each of the 4 grade clinical ladders. Cronbach's ${\alpha}$ coefficient for the total was .92. Cronbach's ${\alpha}$ reliabilities of each clinical ladder grade were .83 for Grade I, .84 for Grade II, .81 for Grade III, and .84 for Grade IV. The Content Validity Index (CVI) of the scale with 120 individual items was 0.976~1.000 for Grade I scale, 0.986~1.000 for Grade II scale, 0.984~1.000 for Grade III scale, and 0.992~1.000 for Grade IV scale. The expert group nurses' average degree of nursing competence measured using the scale was 3.38~3.75 out of 4.0. Conclusion: Through this process, 120 final questions were confirmed to represent items of the Nursing Competency Measurement Scale based on clinical grade.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.21 no.1
• /
• pp.11-16
• /
• 2010

This review aimed to assist clinicians in the identification and assessment of adult attention-deficit hyperactivity disorder (ADHD) with an emphasis on diagnostic and rating instruments. Pubmed and RISS were utilized to identify relevant studies and critical reviews on the diagnosis and assessment of adult ADHD, published between 1988 and 2010. The Adult ADHD Self-Report Scale-v1.1, the ADHD Rating Scale-IV, the Conners Adult ADHD Rating Scale, and the Current Symptoms Scale have been utilized for self-reporting of current ADHD symptoms. The Brown ADD Rating Scale, the ADHD Rating Scale-IV, the Current Symptoms Scale, and the Conners Adult ADHD Rating Scale have also been evaluated by an observer. The Childhood Symptom Scale and the Wender-Utah Rating Scale have been used for retrospective assessment of childhood ADHD symptoms and the Adult ADHD Investigator Symptom Rating Scale, the Adult Interview, the Brown ADD Diagnostic Form, the Conners adult ADHD diagnostic interview for DSM-IV, and the Wender-Reimherr Interview have been available as comprehensive diagnostic interviews. There is a wide variety of instruments available with respect to adult ADHD. The choice of appropriate instruments is essential for achieving accurate diagnosis and assessment of this disorder.