• 한국지구과학회지
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• 제30권7호
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• pp.897-908
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• 2009

시각자료는 과학교과서의 주된 구성 요소이며, 학습자에게 과학적 개념을 효과적으로 이해시키는 매개체가 된다. 본 연구에서는 제7차 교육과정에 따른 중학교 과학 교과서 지구과학 분야에 사용된 시각자료의 유형과 기능 및 구조를 분석하였다. 시각자료 유형에서는 사진과 삽화의 비율이 그래프와 표에 비해 매우 높게 나타났다. 시각자료의 기능에서는 예시적 기능과 보충적 기능의 비율이 높게 나타난 반면, 장식적 기능, 설명적 기능, 탐구적 기능의 비율은 낮게 나타났다. 시각자료의 구조에서는 단독의 비율이 다중에 비해 압도적으로 높았다. 또한 다중 구조에서 짝은 주로 대비에, 연속은 주로 순서를 표상하는데 사용되고 있었다. 시각자료의 유형, 기능, 구조 모두 교과서에 따라 유의미한 차이가 있었다. 이러한 연구 결과를 토대로 학교 과학에서 시각자료의 교육학적 의의에 대한 보다 나은 이해를 위해 지구과학 분야에서 시각자료의 기능과 구조에 대한 기호학적 연구를 제안하였다.

• 대한전기학회논문지
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• 제41권6호
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• pp.625-632
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• 1992

This paper presents a new dc-motor position control approached by Variable Structure System. In order to eliminate a steady-state position error, we propose a switching function composed of position error, velocity, and current ripple. The switching function has an advantage compared to other ones. To determine the control signal voltage, we use a fuzzy logic method. The simulation results show expected performances.

• 한국해양공학회지
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• 제17권4호
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• pp.66-72
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• 2003

This paper proposes an optimum, problematic design for structural and control systems, taking a 3-D truss structure as an example. The structure is subjected to initial static loads and time-varying disturbances. The structure is controlled by a state feedback H$_{\infty}$ controller which suppress the effects of disturbances. The design variables are the cross sectional areas of truss members. The structural objective function is the structural weight. For the control objective, we consider two types of performance indices, The first function represents the effect of the initial loads. The second function is the norm of the feedback gain, These objective functions are in conflict with each other but are transformed into one control objective by the weighting method. The structural objectives is treated as the constraint, By introducing the second control objective which considers the magnitude of the feedback gain, we can create a design to model errors.

• 건축역사연구
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• 제13권4호
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• pp.7-18
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• 2004

From the results of an examination of the transition process of the site plan divided into 5 stages based on literature and materials relating to the Sangju Confucian School as well as the construction history, we can see the general transition flow as follows. The arrangement form of Sangju Confucian School shows the structures with both the sacrificial rites function and the learning function in the early period. This shows a large general flow where the form with the learning function structure at the front and sacrificial rites function structure at the back changed to a form where the learning function structure was positioned behind the boarding facilities, after which there was a transformation which left only the learning function (the form where the learning function structure was positioned in front of the boarding facilities). The type where the learning function structure is positioned in front of the boarding facilities is hard to find in the Yeongnam area, also, there are not many examples of the 2 story Myeonglyundang (hall of confucianism teachings) throughout the country Sangju Confucian School which possess the value of rarity is appraised as being a precious material showing another area characteristic in Sangju of the Yeongnam area. Also, during the late Chosun period the scale of the Dongseojae (boarding facility) was reduced and the appearance of Yangsajae can be said to be a typical example of confucian school constructions of late Chosun era.

• 대한기계학회논문집A
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• 제41권4호
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• pp.279-289
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• 2017

본 논문에서는 제품을 구성하는 부품들을 통합시키기 위한 방법을 제안하였다. 제품을 구성하는 부품들의 관계를 분석하기 위하여 '관계기능'과 '관계기능구조'라는 새로운 개념을 도입하였다. 관계기능은 세 가지의 정보를 갖고 있으며 이것으로부터 관계기능구조를 정립할 수 있다. 정립된 관계기능구조를 부품 통합가능성의 관점에서 분석하기 위한 분석기준을 정립하고 제시하였다. 이 분석기준에 의하여 구성부품들이 통합될 수 있는 우선순위가 결정된다. 분석기준은 관계기능의 개수와 방향성, 직간접성의 세가지로 구분된다. 또한 본 논문에서는 부품통합을 위한 설계 알고리즘을 제안하였다. 이 알고리즘을 실제 제품에 적용하여 구성부품이 통합된 새로운 제품 개념안(design concept)을 도출하였다. 제시된 알고리즘을 이용하여 자전거용 브레이크 디스크 결합방식과 삼공천공기를 개선하기 위한 연구를 진행하였다. 그 결과 실제로 존재하는 개선된 제품과 유사한 관계기능구조가 만들어질 수 있음을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.936-941
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• 2004

An Optimal Feedforward Integral Variable Structure or FIVSC approach for an electrohydraulic position servo control system is presented in this paper. The FIVSC algorithm combines feedforward strategy and integral in the conventional Variable Structure Control (VSC) and calculating the control function to guarantee the existence of a sliding mode. Furthermore, the chattering in the control signal is suppressed by replacing the sign function in the control function with a smoothing function. The simulation results illustrate that the purposed approach gives a significant improvement on the tracking performances when compared with some existing control methods, like the IVSC and MIVSC strategies. Simulation results illustrate that the purposed approach can achieve a zero steady state error for ramp input and has an optimal motion with respect to a quadratic performance index. Moreover, Its can achieve accurate servo tracking in the presence of plant parameter variation and external load disturbances.

• 대한인간공학회지
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• 제20권2호
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• pp.29-46
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• 2001

This study is about the modeling of comfort feeling structure in indoor environments. To represent the degree of practical comfort feeling level in an environment, we measured elements of human sense and resultant elements of comfort feeling such as coziness, refreshment, and freshness with physical values(temperature, illumination, noise. etc.). The relationships of elements of human sense and elements of comfort feeling were formulated as a fuzzy model. And a hybrid-neural network with three layers were designed where obtained from fuzzy membership function values of the elements of human sense were used as inputs, and given as fuzzy membership function values of resultant elements of comfort feeling were used as outputs. Both kinds of fuzzy membership function values were obtained from physical values. The network was trained by measured data set. The proposed hybrid-neural network were tested and proposed a more realistic model of comfort feeling structure in indoor environments.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 춘계 학술발표회논문집
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• pp.45-49
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• 2003

The velocity structure beneath the CHNB broadband station is determined by receiver function analysis using by from teleseismic P waveforms. The detailed broadband receiver functions are obtained by stacking method for source-equalized vertical, radial and tangential components of teleseismic P waveforms. A time domain inversion uses the stacked radial receiver function to determine vertical P wave velocity structure beneath the station. The crustal velocity structures beneath the stations are estimated using the receiver function inversion method in the case at the crustal model parameterized by many thin, flat-tying, homogeneous layers. The result of crust at model inversion shows the crustal velocity structure beneath the CHNB station varies smoothly with increasing depth, and there are six discontinuity around 2.5km, 6.25km, 12.5km, 22.5km and 27.5km depth, with Moho discontinuity at about 32.5km depth.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 추계 학술발표회논문집
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• pp.3-7
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• 2003

The velocity structure beneath the CHNB broadband station is determined by receiver function analysis using by from teleseismic P waveforms. The detailed broadband receiver functions are obtained by stacking method for source-equalized vertical, radial and tangential components of teleseismic P waveforms. A time domain inversion uses the stacked radial receiver function to determine vertical P wave velocity structure beneath the station. The crustal velocity structures beneath the stations are estimated using the receiver function inversion method in the case at the crustal model parameterized by many thin, flat-lying, homogeneous layers. Events divide into 4 groups. four azimuths corresponding to events in group a(southwest), b(south), c(southeast), d(northeast). The result of crust at model inversion shows the crustal velocity structure beneath the CHNB station varies smoothly with increasing depth. The conard discontinuity lies around 18 km and moho discontinuity lies range from 30 to 34 km.

• Communications for Statistical Applications and Methods
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• 제28권3호
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• pp.281-294
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• 2021

In this paper, we propose an adaptive regression method based on the single-layer neural network structure. We adopt a symmetric activation function as units of the structure. The activation function has a flexibility of its form with a parametrization and has a localizing property that is useful to improve the quality of estimation. In order to provide a spatially adaptive estimator, we regularize coefficients of the activation functions via ℓ₁-penalization, through which the activation functions to be regarded as unnecessary are removed. In implementation, an efficient coordinate descent algorithm is applied for the proposed estimator. To obtain the stable results of estimation, we present an initialization scheme suited for our structure. Model selection procedure based on the Akaike information criterion is described. The simulation results show that the proposed estimator performs favorably in relation to existing methods and recovers the local structure of the underlying function based on the sample.