• 한국수학교육학회지시리즈A:수학교육
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• 제57권4호
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• pp.353-369
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• 2018

This study started with the following questions. Suppose that students do not accept various forms of geometric series tasks as the same task. Also, let's say that the approach was different for each task. Then, when they realize that they are the same task, how will students connect the different approaches? This study is a process of pro-actively confirming whether or not such a question can be made. For this purpose, three students in the second grade of high school participated in the teaching experiment. The results of this study are as follows. It also confirmed how the students think about the various types of tasks in the geometric series. For example, students have stated that the value is 1 in a series type of task. However, in the case of the 0.999... type of task, the value is expressed as less than 1. At this time, we examined only mathematical expressions of students approaching each task. The problem of reachability was not encountered because the task represented by the series symbol approaches the problem solved by procedural calculation. However, in the 0.999... type of task, a variety of expressions were observed that revealed problems with reachability. The analysis of students' expressions related to geometric series can provide important information for infinite concepts and limit conceptual research. The problems of this study may be discussed through related studies. Perhaps more advanced research may be based on the results of this study. Through these discussions, I expect that the contents of infinity in the school field will not be forced unilaterally because there is no mathematical error, but it will be an opportunity for students to think about the learning method in a natural way.

• 복식문화연구
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• 제24권5호
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• pp.670-686
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• 2016

The purpose of this study is to delineate and analyze the expression of the kidult and its characteristics and thereby provide data to be used for fashion design in various manners as well as to suggest creative and varied possibilities of fashion design. As a way to study, the author of this paper organized the general terms, concepts and definitions concerning the kidult in the previous papers and journals. The data was collected from the collections represent the characteristics of kidult especially from 2006 to 2015. The results are as follows: Firstly, The characters stimulating the innocence of children were used the most for infantile expression. Parody used characters in the movie or famous logos. Deformation was used to create designs by way of distortion and deformation. Exaggeration thereby showing visually strong impression and inducing surprise and unexpectedness. Depaysement was useful to let us describe concepts and enhance our infinite creativity and interests about objects using surrealistic. Secondly, Infantile characteristics used the images of toys with infantile imagination and sense of humor. Fantasy introduced objects or expressed a dream-like feeling. Unexpectedness used two-faced ideas or conflicting ideas to express conflicts, collision and an interchange with heterogeneous things, avoiding the limit of size and the simplicity of materials. Parody used jocular expressions, satire and ironic expressions to express the original image in a fun manner. Exaggeration transformed changed the structure to restructure objects in a subjective and creative manner, thereby expressing creative patterns using various subject matters by way of special modeling or distortion and transformation.

• 한국문헌정보학회지
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• 제51권1호
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• pp.289-306
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• 2017

본 연구는 공공도서관 '메이커스페이스' 구성 및 프로그램 운영을 분석함으로써 현재 14개 국내 공공도서관 메이커스페이스 사례인 '무한상상실' 프로그램의 현황 및 한계점을 도출하고, 향후 해외의 메이커스페이스와 같이 확대되고 지속가능한 모형으로 발전하기 위한 운영 방안을 제시하고자 하였다. 이를 위해 국내외 메이커스페이스에 관한 문헌 및 사례조사를 실시하였고 국내 공공도서관 메이커스페이스 현황조사를 통해 메이커스페이스의 발전과정, 프로그램 유형, 지원 유형 및 서비스 성과를 분석하였다. 아울러 국내외 공공도서관 메이커스페이스 전담사서와의 심층인터뷰를 진행함으로써 메이커스페이스의 개념 변화, 필요성, 효과성, 한계점 및 향후 발전방안 등을 조사 분석하였다. 그 결과 메이커스페이스의 지속가능한 운영을 위해 시급히 마련되어야 할 정책방안으로 다양하고 안정적인 재원 확보, 전문 인력 배치 및 훈련, 적극적인 자원봉사자 활용 방안, 홍보전략 수립, 지역주민이 소통하는 공간을 넘어 신기술을 통한 교육과 창조의 공간, 지역 아카이브 생성의 '메이킹' 공간이 되어야 한다는 것을 제안하였다.

• 대한수학회보
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• 제29권1호
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• pp.65-72
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• 1992

All rings are commutative, Noetherian with identity and of prime characteristic p, unless otherwise specified. First, we describe the definition of tight closure of an ideal and the properties about the tight closure used frequently. The technique used here for the tight closure was introduced by M. Hochster and C. Huneke [4,5, or 6]. Using the concepts of the tight closure and its properties, we will prove that if R is a complete local domain and F-rational, then R is Cohen-Macaulay. Next, we study the properties of R$^{+}$, the integral closure of a domain in an algebraic closure of its field of fractions. In fact, if R is a complete local domain of characteristic p>0, then R$^{+}$ is Cohen-Macaulay [8]. But we do not know this fact is true or not if the characteristic of R is zero. For the special case we can show that if R is a non-Cohen-Macaulay normal domain containing the rationals Q, then R$^{+}$ is not Cohen-Macaulay. Finally we will prove that if R is an excellent local domain of characteristic p and F-ratiional, then R is Cohen-Macaulay.aulay.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.825-829
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• 2005

This paper presents an approach for designing a fuzzy logic-based adaptive SVC damping In controller for damping low frequency power oscillations. Power systems are often subject to low Frequency electro-mechanical oscillations resulting from electrical disturbances. Generally, power system stabilizers are designed to provide damping against this kind of oscillations. Another means to achieve damping is to design supplementary damping controllers that are equipped with SVC. Various approaches are available for designing such controllers, many of which are based on the concepts of damping torque and others which treat the damping controller design as a generic control problem and apply various control theories on it. In our proposed approach, linear optimal controllers are designed and then a fuzzy logic tuning mechanism is constructed to generate a single control signal. The controller uses the system operating condition and a fuzzy logic signal tuner to blend the control signals generated by two linear controllers, which are designed using an optimal control method. First, we design damping controllers for the two extreme conditions; the control action for intermediate conditions is determined by the fuzzy logic tuner. The more the operating condition belongs to one of the two fuzzy sets, the stronger the contribution of the control signal from that set in the output signal. Simulation studies done on a one-machine infinite-bus and a four-machine two-area test system, show that the proposed fuzzy adaptive damping SVC controller effectively enhances the damping of low frequency oscillations.

• 정보관리학회지
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• 제31권2호
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• pp.7-40
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• 2014

본 연구에서는 최첨단기술을 적용한 디지털도서관서비스들을 발굴하고 이러한 기술과 서비스의 국내 도서관 적용가능성을 밝혀내고자 하였다. 이를 위해 차세대디지털도서관을 논하고 있는 주요 논문을 검토할 뿐만 아니라 기술관련 기사 및 논문 등 미래의 도서관에 응용될 수 있는 주요 기술들을 검토하였다. 그 결과 차세대디지털도서관의 핵심적인 기술, 개념, 도구는 클라우드서비스, 무한창조공간, 빅데이터, 증강현실, 상황인식기술, 구글글래스, 혁명적 디스플레이기술, 개방형의 연결된 콘텐츠제공방식이 될 것으로 분석되었다. 그리고 이러한 기술이나 개념을 적용한 구체적인 사례들도 나타나고 있는 것으로 조사되었다.

• 한국실내디자인학회논문집
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• 제23권4호
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• pp.52-62
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• 2014

The rapid growth of economy improves not only the life quality of people in this modern society but also standards of value in connection with how those people would spend money as they engage in various leisure and cultural activities. That being the case, hotels are currently changing into places of new concepts depending on those new lifestyles of these people, and in those new places, people can entertain and experience as enjoying cultures. The marketing collaboration of the hotels with brands can be used as a more inclusive way to enhance brand images. In addition, as having infinite possibilities of the collaboration's being able to create a new-concept space with an identity of a brand included, this collaboration makes it possible for the design hotels to decorate their interior spaces differently from those of other hotels. In the light of that, the brand collaboration is basically divided into three groups which are the fashion collaboration, the technique collaboration and the designer collaboration, and the brand collaboration is also able to express the interior spaces of the design hotels as working on those six components, such as reproduction, events, alteration, messages, culture and image. After all, through the brand collaboration marketing, this thesis expects an interior design of a new-concept design hotel which would play a role as a complex cultural space.

• ETRI Journal
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• 제35권4호
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• pp.697-705
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• 2013

Emerging trends in the area of digital very large scale integration (VLSI) signal processing can lead to a reduction in the cost of the cochlear implant. Digital signal processing algorithms are repetitively used in speech processors for filtering and encoding operations. The critical paths in these algorithms limit the performance of the speech processors. These algorithms must be transformed to accommodate processors designed to be high speed and have less area and low power. This can be realized by basing the design of the auditory filter banks for the processors on digital VLSI signal processing concepts. By applying a folding algorithm to the second-order digital gammatone filter (GTF), the number of multipliers is reduced from five to one and the number of adders is reduced from three to one, without changing the characteristics of the filter. Folded second-order filter sections are cascaded with three similar structures to realize the eighth-order digital GTF whose response is a close match to the human cochlea response. The silicon area is reduced from twenty to four multipliers and from twelve to four adders by using the folding architecture.

• 한국토양비료학회지
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• 제50권1호
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• pp.65-70
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• 2017

Soil was regarded as infinite resources but recently, soil is considered as invaluable resources that we need to protect and conserve. Main objective of this research was to evaluate soil value in terms of soil carbon contents. Soil was classified into forest, paddy, upland, and grass. Carbon contents in each soil was calculated based on soil chemical properties. Calculated soil carbon contents was ranged $15.31-108.86mg\;kg^{-1}$. Based on soil carbon contents, soil value was assumed adapting economic concepts. Calculated total soil value based on soil carbon contents was about 18.46 trillion won. Among others, carbon contents in forest was the highest and value was assumed 11.95 trillion won followed by paddy field (3.7 trillion won).

• Journal of Power Electronics
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• 제18권1호
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• pp.277-288
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• 2018

Wireless inductive power transfer (IPT) technology is used in many applications today. A compact and high-frequency primary side inverter is one of the most important parts of a WPT system. In this study, a modified class EF-type voltage-fed multi-resonant inverter has been proposed for WPT application at a frequency range of 85-100 kHz. Instead of an infinite input choke inductor, a resonant inductor is used to reduce loss and power density. The peak voltage stress across the MOSFET has been reduced to almost 60% from a class-E inverter using a passive clamping circuit. A simple yet effective design procedure has been presented to calculate the various component values of the proposed inverter. The overall system is simulated using MATLAB/SimPowerSystem to verify the theoretical concepts. A 500-W prototype was built and tested to validate the simulated results. The inverter exhibited 90% efficiency at nearly perfect alignment condition, and efficiency reduced gradually with the misalignment of WPT coils. The proposed inverter maintains zero-voltage switching (ZVS) during considerable load changes and possesses all the inherent advantages of class E-type inverters.