• 대한전기학회논문지:시스템및제어부문D
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• 제49권9호
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• pp.495-503
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• 2000

In this paper we propose a design procedure of loop-shaping two-degree-of-freedom H$\infty$ digital controller for sampled-data system. We extend the continuous time loop-shaping two-degree-of-freedom H$\infty$ control problem to sampled-data system. The configuration of generalized plant is modified for sampled-data system. And then using continuous lifting we obtain the digital controller. In the final stage of loop-shaping procedure the problem of absorbing weighting functions is discussed. We summarize this study to the design procedure and illustrate the application for an inverted pendulum on the cart.

• 융합신호처리학회논문지
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• 제12권1호
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• pp.56-61
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• 2011

많은 제어기법들이 제어계의 제어성능을 개선하기 위해 제안되고 있다. 제어계에서 제어에 대한 자유도는 독립적으로 조정할 수 있는 페루프 전달함수의 수로 결정된다. 목표치 추종 및 외란억제에 2자유도 제어기법이 많이 이용되고 있다. 본 논문에서는 PID 제어기를 2자유도 제어기법을 이용하여 제어계를 설계할 수 있는 정규화법을 제안하였다. 제안한 설계법은 제어대상의 전달함수의 계수값을 이용하여 계의 전달함수를 정규화 하고, 제어기의 계수들이 결정되도록 하였다. 이 방법으로 설계된 제어계를 이용하여 2자유도 제어계를 구성하였고, 시뮬레이션 결과를 통하여 제안한 알고리즘의 유효성을 확인 하였다.

• 동력기계공학회지
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• 제10권1호
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• pp.12-18
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• 2006

A three-degree of freedom model of intake system was contrived and investigated in various ways for the purpose of the amelioration of the volumetric efficiency in a low and transient engine speed for a multi cylinder diesel engine. The basic concept beyond this model started from the theory that each degree of freedom model has volumetric efficiency peak as many as its number of the degree of freedom. The volumetric efficiency affects significantly to the engine performance; torque characteristics, fuel economy and emission level. For commercial vehicles and stationary engines, the engine is designed so as to produce their best performance near the normal engine speeds, thus the low engine speed area has a tendency of poor volumetric efficiency. The aim of this study was highlighted on the amelioration of volumetric efficiency of low engine speed area in a multi cylinder diesel engine matched with an additional Helmholtz resonator. By the use of VIS(variable induction system) volumetric efficiency at low engine speed range was significantly improved. The availability of control by combination of VIS and CIS(conventional induction system) will be proposed as a variable induction system that would be an appropriate model for amelioration of the volumetric efficiency at low engine speed.

• Ocean Systems Engineering
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• 제9권3호
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• pp.219-240
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• 2019

This paper presents the comparison between SFT response with linear and nonlinear cables. The dynamic response analysis of submerged floating tunnel (SFT) is presented computationally with linear and nonlinear tension legs cables. The analysis is performed computationally for two wave directions one at 90 degrees (perpendicular) to tunnel and other at 45 degrees to the tunnel. The tension legs or cables are assumed as linear and non- linear and the analysis is also performed by assuming one tension leg or cable is failed. The Response Amplitude Operators (RAO's) are computed for first order waves, second order waves for both failure and non-failure case of cables. For first order waves- the SFT response is higher for sway and heave degree of freedom with nonlinear cables as compared with linear cables. For second order waves the SFT response in sway degree of freedom is bit higher response with linear cables as compared with nonlinear cables and the SFT in heave degree of freedom has higher response at low time periods with nonlinear cables as compared with linear cables. For irregular waves the power spectral densities (PSD's) has been computed for sway and heave degrees of freedom, at $45^0$ wave direction PSD's are higher with linear cables as compared with nonlinear cables and at $90^0$ wave direction the PSD's are higher with non-linear cables. The mooring force responses are also computed in y and z directions for linear and nonlinear cables.

• The Journal of Asian Finance, Economics and Business
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• 제8권1호
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• pp.103-112
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• 2021

The labor force plays an important role in attracting foreign direct investment (FDI) both in developed and developing countries. In countries where there are appropriate policies for training human resources and maintaining the health of human resources, such countries have a competitive advantage and can attract FDI inflows, besides having a workforce to meet the needs of foreign investors. The purpose of this paper is to analyze the effect of the labor force and several other factors on FDI attraction in Vietnam. The empirical model is employed to perform regression and correlation on the impact of the labor force, real gross domestic product, inflation, index of business freedom, and index of investment freedom on Vietnam's FDI attraction by using a secondary time series data set during the period 1995-2018. The empirical results found that both labor force and inflation have a positive influence on FDI at a 5% significance level; index of business freedom has a positive impact on FDI at a 10% significance level, and real gross domestic product and index of investment freedom have a positive impact on FDI at a 1% significance level. From these results, this study proposes several important policy implications for Vietnam in attracting FDI in the future.

• 대순사상과 동아시아종교
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• 제2권2호
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• pp.51-72
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• 2023

This article explores the intersection of freedom of religion, sangsaeng, and symbiosis when considering the post-COVID study of religions, especially new religions. When it comes to the study of new and alternative religious groups, where there is more potential for misunderstanding and misinformation, it becomes all the more important-and indeed mutually beneficial, in the areas of religious liberty, religious freedom, and cross-cultural dialogue-to learn about a tradition by taking into account the spiritual life and practices of members themselves and their own sacred writings and practices. Daesoon Jinrihoe offers a case study of the importance of this principle and the notion of sangsaeng in particular is a fruitful utilitarian lens for thinking about how scholars, journalists, and others might approach the study of religion in our complex and global digital age of (mis) information. Daesoon Jinrihoe is also considered in light of Roy Wallis's typology of world-rejecting, world-affirming, and world-accommodating new religious movements. Open areas for sociological research are proposed and the nascent field of Daesoon studies is compared to some similar scholarly endeavors within NRM studies.

• 대순사상논총
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• 제19권
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• pp.193-211
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• 2005

Korean religionist have actively participated in the movements of national security and peace, human rights and dignity, freedom and equal rights, and other social issues. Recently, either progressive or conservative religionists have strongly shown their different approaches in solving social issues, i.e., national security and peace in connection of 'national security law.' A few religious leaders' public views have been misused by some politicians. It is important for both the religionists and journalists in religious newspapers how to bring a harmonious resolution among the people who are either in conservatism or in progressivism. Social participation of religionists is both to respond to the timely situation of civil society and to realize freedom, equality, and peace to the society. Although the principle of the separation of religion and state was established to secure both the right of politics and the freedom of beliefs, political groups have either utilized or suppressed religions. Some politicians have also wrongly applied separation of religion and state by excluding religious aspects in public schools. Religionists and journalists of the religious newspapers should not provide one-sided prejudice but to provide objective information and its righteous analysis to guide people in the right direction to solve social problems. Also, religious newspapers should open a field of discussion how to resolve some issues between the 'national security law' and freedom.

• Structural Engineering and Mechanics
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• 제28권1호
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• pp.107-127
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• 2008

Wind turbine blades are increasing in magnitude without a proportional increase of stiffness for which reason geometrical and inertial nonlinearities become increasingly important. Often these effects are analysed using a nonlinear truncated expansion in undamped fixed base mode shapes of a blade, modelling geometrical and inertial nonlinear couplings in the fundamental flap and edge direction. The purpose of this article is to examine the applicability of such a reduced-degree-of-freedom model in predicting the nonlinear response and stability of a blade by comparison to a full model based on a nonlinear co-rotating FE formulation. By use of the reduced-degree-of-freedom model it is shown that under strong resonance excitation of the fundamental flap or edge modes, significant energy is transferred to higher modes due to parametric or nonlinear coupling terms, which influence the response and stability conditions. It is demonstrated that the response predicted by such models in some cases becomes instable or chaotic. However, as a consequence of the energy flow the stability is increased and the tendency of chaotic vibrations is reduced as the number of modes are increased. The FE model representing the case of infinitely many included modes, is shown to predict stable and ordered response for all considered parameters. Further, the analysis shows that the reduced-degree-of-freedom model of relatively low order overestimates the response near resonance peaks, which is a consequence of the small number of included modes. The qualitative erratic response and stability prediction of the reduced order models take place at frequencies slightly above normal operation. However, for normal operation of the wind turbine without resonance excitation 4 modes in the reduced-degree-of-freedom model perform acceptable.

• 정보관리학회지
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• 제29권3호
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• pp.187-214
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• 2012

도서관은 시민의 지적자유를 보장하기 위해 설립된 기관이며, 시민은 그들이 요구하고, 접근하고, 이용한 정보가 기밀로 유지될 권리를 갖는다. 그들의 프라이버시 보호는 언론의 자유, 사고의 자유, 집회의 자유를 실현하는데 핵심이 된다. 도서관과 사서가 이용자의 프라이버시 문제를 심각하게 생각해야 하는 이유는 도서관 이용자의 개인정보 보호는 사서가 가장 중요하게 생각해야 하는 임무중의 하나이며, 이용자가 지적자유를 진정으로 누릴 수 있도록 하기 위함이다. 본 연구에서는 도서관에서 발생할 수 있는 프라이버시 침해가능성에 대해서 포괄적으로 조사 분석하고자 하였다. 그 결과 국가나 법률관련기관이 업무를 집행하는 과정에서 발생했던 프라이버시 침해 사례, 대출반납서비스, 참고서비스, 온라인탐색서비스 등 일상적인 도서관서비스를 하는 과정에서 발생했던 프라이버시 침해가능성 및 사례, 그리고 도서관업무를 아웃소싱하는 과정에서 발생할 수 있는 침해 가능성 및 사례 등이 있는 것으로 조사되었다.

• 한국컴퓨터정보학회논문지
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• 제17권5호
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• pp.177-183
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• 2012

익명성이라는 특성으로 인하여 사이버공간에서는 다양한 범죄가 발생한다. 그 중에서도 표현의 자유라는 이유로 타인에 대한 명예훼손행위가 가장 심각하다. 즉 사이버공간에서 일어나는 명예훼손은 그 침해가 순간적이고 광범위하며 피해자가 대응할 시간적 여유가 없다는 점에서 오프라인에서 발생하는 명예훼손과 비교할 때 피해의 충격성과 심각성은 매우 크다고 아니할 수 없다. 그러나 표현의 자유도 중요하지만 인간의 존엄과 가치를 존중하는 자유민주주의 사회에서는 헌법 제21조 제4항에 규정된 것처럼 언론 출판은 타인의 명예나 권리 또는 공중도덕이나 사회윤리를 침해해서는 안 된다. 표현의 자유 못지 않게 개인의 명예보호도 헌법상 보장된 기본권이며, 개인의 명예나 인격을 침해하는 행위까지 표현의 자유영역에 포함시킬 수 없기 때문이다. 이러한 점에서 명예훼손죄는 표현의 자유의 최소한의 한계라고 보아야 한다.