• Journal of Electrical Engineering and Technology
• /
• v.12 no.4
• /
• pp.1663-1674
• /
• 2017

This paper deals with the robust speed regulation of a surface-mounted permanent magnet synchronous motor (SPMSM) that is subject to parametric uncertainties and external disturbances. The proposed approach retains a conventional cascade control configuration composed of an outer-loop speed control module and inner-loop current control modules. Baseline proportional-integral (PI) controllers are designed for nominal modular systems without accounting for the uncertainties to set a desired control performance of the closed-loop system. After studied in both frequency and time domains, a reduced-order proportional-integral observer (PIO), as a modular disturbance observer, is incorporated with each control module to maintain the ideal performance of the modules. Theoretical analysis confirms the desired performance recovery of the augmented system with modular PIOs to the nominal system. Comparative computer simulations and experimental results validate the proposed cascade control method for SPMSM speed regulation.

• Steel and Composite Structures
• /
• v.24 no.3
• /
• pp.339-349
• /
• 2017

In this paper, a conventional refined plastic hinge analysis is improved to account for the effects of local buckling and lateral-torsional buckling. The degradation of flexural strength caused by these effects is implicitly considered using practical LRFD equation. The second-order effect is captured using stability functions to minimize modeling and solution time. An incremental-iterative scheme based on the generalized displacement control method is employed to solve the nonlinear equilibrium equations. A computer program is developed to predict the second-order inelastic behavior of space steel frames. To verify the accuracy and efficiency of the proposed program, the obtained results are compared with the existing results and those generated using the commercial finite element package ABAQUS. It can be concluded that the proposed program proves to be a reliable and effective tool for daily use in engineering design.

• The Korean Journal of Applied Statistics
• /
• v.6 no.1
• /
• pp.29-40
• /
• 1993

In a model-based sampling problem, it often happens that the functional form of variance of error terms in regression model cannot be specified in an exact form. The goal of error-robust sampling design will be to minimize the 'ill effects' resulting from a lack of knowledge of the error structure. A sampling criterion, which is optimal if it minimizes the average of an inefficiency measure when taken with respect to all candidate error structures, is proposed and a computer algorithm is developed for construction of optimal sampling plans. Auditing problem is of particular relevance because of the uncertainty that currently clouds specification of the error structure.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.1095-1096
• /
• 2006

Configuration management plays a key role in systems engineering process for any project from earlier stage of development. It consists of five major activities, ie., configuration management planing, configuration identification, configuration control, configuration status accounting and configuration verification and audit, and is essential to control system design development and operation throughout entire life cycle of the system development. And it is directly associated with other part of systems engineering management, ie., technical data management which provides traceability of important decisions and changes during development. In this paper, we describe how to apply CASE(Computer-aided Systems Engineering) tool-Cradle for the configuration management to achieve effectiveness of City Train Standard Specification Management process.

• Proceedings of the CALSEC Conference
• /
• 2003.09a
• /
• pp.178-183
• /
• 2003

Past commodities management concept that mean simple Management after goods purchase. Today, it developed to system that manages from purchasing plan to discard by Computer's development. But, kind of goods is very various from System Commodities to Spare Parts. Also, among use of goods, according to state, accounting operation should be associated but it is functionless real condition that can confirm uniformity goods availability actually. In this study, studied about plan that use Commodities Contents from purchase of goods to discard so that can do goods and accountant management.

• Advances in nano research
• /
• v.8 no.2
• /
• pp.149-156
• /
• 2020

The present paper explores forced vibrational properties of porosity-dependent functionally graded (FG) cylindrical nanoshells exposed to linear-type or triangular-type impulse load via classical shell theory (CST) and nonlocal strain gradient theory (NSGT). Employing such scale-dependent theory, two scale factors accounting for stiffness softening and hardening effects are incorporated in modeling of the nanoshell. Two sorts of porosity distributions called even and uneven have been taken into account. Governing equations obtained for porous nanoshell have been solved through inverse Laplace transforms technique to derive dynamical deflections. It is shown that transient responses of a nanoshell are affected by the form and position of impulse loading, amount of porosities, porosities dispensation, nonlocal and strain gradient factors.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.17 no.4
• /
• pp.1-7
• /
• 2009

The surge control system in unmanned turbojet engine must be capable of accounting uncertainties from engine transient conditions, random fluctuations of key parameters such as air pressure and fuel flow and engine modeling errors. In this paper, taking into consideration of its effectiveness as well as system stability, a fuzzy PI controller is proposed. The role of the fuzzy PI controller is to stabilize the unmanned aircraft upon occurring unexpected engine surge. The proposed control scheme is proved by computer simulation using a linear engine model. The simulation results on the state space model of a small turbojet engine illustrate the proposed control system achieves the desired performance.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2023.11a
• /
• pp.898-899
• /
• 2023

COVID-19 가 종식되어 관광산업이 활발해짐에 따라 외래관광객 데이터를 분석하여 활용할 필요가 있다. 한국관광 데이터랩의 외래관광객 조사 보고서는 설문을 통해 수집한 데이터에 대해 각 요인별 통계를 제공하고 있지만 복합적 요인으로 분석하기 어렵다. 본 연구는 2017 년부터 2022 년까지 한국관광 데이터랩의 외래관광객 조사 데이터를 Microsoft Power BI 를 통해 분석하여 여성 20대, 서구 관광객의 방한 활동과 방한 고려 요인 등 복합적 주요 영향 요인을 도출하고 그에 따른 발전 방향을 결론에서 제시한다.

• The Journal of Korean Association of Computer Education
• /
• v.6 no.1
• /
• pp.109-120
• /
• 2003

Recently, as more web-based applications are widely used, various methods for education are developed in practical areas. As a result, in many organizations, virtual educations such as WBI learning. CAI, and distance learning are offered actively. With the advantages of web-based education, in order to achieve feasible and efficient effects on education. a new web-based instruction model that considers the abilities, the interests, and the aptitudes of students individually is required. In this paper, a new web-based instruction model, called a hybrid model, is proposed and implemented. And then, two model - the stepwise model and the hybrid model- are applied to a computer accounting class of a vocational high school. Students attend the web-based class in a computer center for 100 minutes autonomously. After the classes, a questionnaire is made in order to analyze both the effect on that class and the learning fulfillment of the proposed instruction model.

• International Journal of Computer Science & Network Security
• /
• v.22 no.10
• /
• pp.291-297
• /
• 2022

Modern challenges in the educational environment force scientists and practitioners to search for an adequate answer. In particular, the war in Ukraine demonstrated the importance of developing information competence as one of the main means of distinguishing true information from a whole stream of fake news. This is especially relevant in connection with the introduction of distance learning when students must find and process a large amount of information on their own. Therefore, the purpose of the article is to analyze the training of higher education students through the prism of acquiring the necessary level of informational competence in war conditions. For this, general scientific and special research methods, as well as the experimental method, were used. In the results, the peculiarities of the interpretation of information competence in the distance form of education among modern researchers are determined, the psychological components of resistance to fakes are analyzed. Based on the conducted empirical measurements, it was established that thorough work on student education gives positive skills when working independently with Internet materials, strengthens the ability to distinguish false information and propaganda from the real state of affairs. The conclusions summarize the results of the empirical research and suggest ways to improve the situation with the formation of information competence.