• Asia pacific journal of information systems
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• 제10권1호
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• pp.37-59
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• 2000

Recently, the rapid development of information technology has brought enormous changes in education. Consolidation of communications and multimedia technologies are enabling the new educational paradigm such as distance learning and virtual education. Furthermore, many studies in the education engineering field report that teaching using multimedia technologies more enhances students' performance than the traditional instructor-teaching method. However, little research regarding the education using multimedia has been done in the MIS filed. None of multimedia-related studies could be found in the top-ranked MIS journals published in Korea for the last five years, and only a few studies were found even worldwide. In this regard, the purpose of this study is to investigate which features of multimedia software are most important to enhance the teaching results of students, From the previous research, we found out the specific features of the educational multimedia software which are considered to affect the students' performance, and defined the research variables related to those educational software features, And, based on the constructivism and motivation theory of the education engineering field, a theoretical research model and research hypotheses were developed. Perceived usefulness of the class and a student's perceived interests in the class were used as surrogate variables to measure teaching performance. Total 277 students participated separately in one of the two multimedia classes which have continued for three weeks. One was C programming language class and the other was multimedia CD-title development class. Each student listened for the multimedia session of the class using multimedia software and, at the end of the multimedia session, answered the survey questionnaire, The results of the study show that motivation to the class and the contents of education were statistically significant to the students' performance in the class. That implies, not only in the traditional instructor-teaching method but also in the multimedia class, that the contents of education itself and student's motivation to the class are most important to raise instructional results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1334-1337
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• 2006

System identification is the field of modeling dynamic systems from experimental data. As a modeling technique, we can mention finite element method (FEM). In addition, we are able to measure modal data as the experimental data. The system can be generally categorized into a gray box and black box. In the gray box, we know mathematical model of a system, but we don't know structural parameters exactly, so we need to estimate structural parameters. In the black box, we don't know a system completely, so we need to identify system from nothing. To date, various system identification methods have been developed. Among them, we introduce system realization theory which uses Hankel matrix and Eigensystem Realization Algorithm (ERA) that enable us to identify modal parameters from noisy measurement data. Although we obtain noise-free data, however, we are likely to face difficulties in identifying a structure with hidden modes. Hidden modes can be occurred when the input or output position comes to a nodal point. If we change a system using a mode decoupling controller, the hidden modes can be revealed. Because we know the perturbation quantities in a closed loop system with the controller, we can realize an original system by subtracting perturbation quantities from the closed loop system. In this paper, we propose a novel method to identify a structure with hidden modes using the mode decoupling controller and the associated example is given for illustration.

• 환경영향평가
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• 제14권2호
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• pp.55-62
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• 2005

This study applied the Neural Network and Fuzzy theory to show water-purity control and preventive measure in water quality forecasting of the future river. This study picked out NAJU and HAMPYUNG as the subject of investigation and used monthly the water quality and the outflow data of KWANGJU2, NAJU, YOUNGSANNPO and HAMPYUNG from 1995 to 1999 to forecast BOD, COD, T-N, T-P water density. The datum from 1995 to 1999 are used for study and that of 2000 are used for verification. To develop model of water quality forecasting, firstly, this research formed Neural Network model and divided Neural Network model into two case - the case of considering lag and not considering. And this study selected optimal Neural Network model through changing the number of hidden layer based on input layer(n) from n to 3n. Through forecasting result, the case without considering lag showed more precise simulated result. Accordingly, this study intended to compare, analyse that Fuzzy model using the method without considering lag with Neural Network model. As a result, this study found that the model without considering lag in Neural Network Network shows the most excellent outcome. Thus this study examined a forecasting accuracy, analyzed result and verified propriety through appling the method of water quality forecasting using Neural Network and Fuzzy Algorithms to the actual case.

• 한국해안·해양공학회논문집
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• 제22권1호
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• pp.10-17
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• 2010

투과성 이중 반원통 구조물과 경사 입사파간의 상호작용문제를 선형포텐셜 이론을 사용하여 살펴보았다. 투과성 이중 반원통 구조물은 바닥에 고정된 동심원상으로 배열된 2개의 원통 구조물로 이루어지며 각 원통 구조물의 전면은 일정한 공극율을 갖는 투과벽으로 후면은 투명한 벽으로 구성된다. 전면 투과벽의 공극율과 간격 그리고 파랑특성(주파수, 입사각)을 변화시키면서 파랑하중과 처올림 파형 그리고 파 차단성능을 살펴보았다. 파 차단 성능의 척도로서 차단영역내의 평균제곱 변위의 제곱근(R.M.S.)을 사용하였다. 투과성 반원통 구조물은 불투과성 구조물과 비교하여 차단영역내의 파도응답을 감소시키며 구조물에 작용하는 파랑하중을 크게 줄여준다. 특히 이중 구조물은 고주파주 영역에서 단일 구조물보다 파를 차단하는데 효과적이다.

• 한국초등수학교육학회지
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• 제9권2호
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• pp.161-180
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• 2005

제7차 수학과 교육과정의 6개 영역 중 측정 영역은 수학의 실용적 가치의 측면에서 강조되고 있다. 이 중 삼각형과 사각형의 넓이 지도는 통합적인 수학적 능력이 요구되고, 측정 영역의 후속 단계 학습의 기초가 되므로 중요한 교수학적 의미를 가진다. 따라서 본 연구에서는 우리나라 제1차 교육과정에서부터 제7차 교육과정에 따른 초등학교 수학 교과서에 나타난 삼각형과 사각형의 넓이 지도 방법을 (1) 넓이의 개념과 (2) 삼각형과 사각형의 넓이 공식으로 나누어 범주를 구성하고, 지도시기 및 지도 순서와 지도 방법을 교수학적 변환의 관점에서 분석하였다.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 2002년도 추계공동학술대회
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• pp.461-467
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• 2002

뇌에서 얻은 시계열 신호들은 대부분 불규칙하고 복잡한 파형을 가지고 있으며, 1980년대 중반까지만 해도 이러한 신호들은 확률론 과정(stochastic process)으로 발생된 '소음'(noise)으로 여겨졌다. 하지만 최근 들어 뇌에 관한 연구가 활발히 진행되었고 EEG를 이용한 생체신호의 비선형 분석에 관한 연구가 진행되면서 뇌에서 발생되는 신호는 의미 있는 신호로 분석되어지고 있다. 이에 비선형 분석방법인 상관차원을 이용하여 라벤더 향기 전과 향기 후의 뇌파의 변화를 분석하고, 주파수 대역별로 delta파, theta파, alpha파, beta파로 나누어서 라벤더 향이 뇌에 미치는 영향을 분석한다. 즉, 뇌에서 발생되는 신호의 특징을 찾기 위해 다른 향보다 강하게 반응하는 라벤더 향을 후각 자극으로 제시하여 EEG를 측정한 후, 16채널에 대한 상관차원을 구하고 라벤더 향이 뇌에 미치는 영향을 분석한다.

• 가정과삶의질연구
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• 제31권6호
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• pp.97-112
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• 2013

This study was conducted to investigate the effect of sandplay therapy for couples on the self-differentiation, and heterosexual relationship satisfaction, of couples who are college students'. The subjects were four couples who are college students living in Seoul with low self-differentiation and heterosexual relationship satisfaction. I carried out sandplay therapy on four couples for once a week for 10 weeks, and each session was 70 minutes long. In this study, the self-differentiation scale was modified for Korea on the basis of Bowen's family systems theory (1976), and it was used as a research tool. Yu (2000) and Lee (2000) made a scale to measure heterosexual relationship satisfaction after they adjusted the Korea Marital Satisfaction Inventory (K-MSI). The scale was also used in order to compare pre-therapy and post-therapy traits and identify any changes. In addition, the group's behavior and interactions were observed and recorded in each session throughout the process of sandplay therapy with the couples, and the behanior and interactions were analyzed along with the change flow in the sand trays. The study's outcomes are summed up as follows. First, sandplay therapy with couples advances the level of self-differentiation in college students. Second, sandplay therapy with couples improves the heterosexual relationship satisfaction on college students. Third, the trays used in sandplay therapy with couples showed positive changes as the therapy progressed. As the sessions continued, negative factors in the trays decreased and the trays converged into one. As the sessions proceeded, it was observed that the couples became closer, felt more comfortable with each other, compromised and reflected on their relationship. The study's results show that sandplay therapy with couples increased the level of self-differentiation in college students and heterosexual relationship satisfaction, thus proving the therapy's effectiveness.

• 한국입자에어로졸학회지
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• 제12권1호
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• pp.21-26
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• 2016

In order to realize In-line and convenient measurement for solid-gas two phase flows, Light Transmission Fluctuation (LTF) based on the random variation of transmitted light intensity, light scattering theory and cross-correlation method was presented for online measurement of particle size, concentration and velocity. The statistical relationship among transmitted light intensity, particle size and particle number in measurement zone was described by Beer-Lambert Law. Accordingly, the particle size and concentration were determined from the fluctuation signal of transmitted light intensity. Simultaneously, the particle velocity was calculated by cross-correlation analysis of two neighboring light beams. By considering the influence of concentration variation in industrial applications, the improved algorithm based on spectral analysis of transmitted light intensity was proposed to improve measurement accuracy and stability. Therefore, the online measurement system based on LTF was developed and applied to measure pulverized coal in power station and raw material in cement plant. The particle size, concentration and velocity of powder were monitored in real-time. It can provide important references for optimal control, energy saving and emission reduction of energy-intensive industries.

• 한국조사연구학회지:조사연구
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• 제7권2호
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• pp.1-38
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• 2006

한국인이 생각하는 행복의 구성요소를 파악하고, 이를 바탕으로 행복지수 공식을 개발하기 위해 FGI(6l명)와 설문조사(1,503명)를 실시하였다. 연구결과 16개의 행복요인이 도출되었고, 이들 요인을 Alderfer(1972)의 생존 관계 성장 욕구위계 이론에 따라 3요소로 재분류한 뒤, LISREL을 이용하여 측정 모형에 의한 가중치를 분석하였다. 그 결과, 한국인의 행복지수 공식은 '행복=2.5*생존+2.5*관계+5*성장'으로 나타났고, 공식에 따른 한국인의 행복점수는 평균 57.71로 나타났다. 성별로는 여성보다 남성이 더 행복하다고 지각하고 있었고, 연령대에 따른 차이는 나타나지 않았다. 지역별로 살펴보면 서울과 대전 지역이 다른 지역보다 행복한 것으로 나타났고, 경제수준에 따라서는 250만원을 기준으로 행복감에서의 두드러진 차이를 보였다. 또한 행복점수에 따라 상위 33%(즉, 행복하다고 느끼는 집단)와 하위 33%(즉, 불행하다고 느끼는 집단)을 구분하여 평균차이를 분석한 결과, 생존과 관계요소에서의 차이보다는 개인적이고 심리적인 요인인 성장요소에서 큰 점수 차이를 보였다. 따라서 생존 요소와 관계 요소보다는 성장요소가 한국인의 행복감 지각에 상대적으로 더 큰 영향을 미치고 있는 것으로 해석할 수 있다. 마지막으로 한국인의 행복을 위한 제언을 소개하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.1130-1147
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• 2014

Large size ships have a very flexible construction resulting in low resonance frequencies of the structural eigen-modes. This feature increases the dynamic response of the structure on short period waves (springing) and on impulsive wave loads (whipping). This dynamic response in its turn increases both the fatigue damage and the ultimate load on the structure; these aspects illustrate the importance of including the dynamic response into the design loads for these ship types. Experiments have been carried out using a segmented scaled model of a container ship in a Seakeeping Basin. This paper describes the development of the model for these experiments; the choice was made to divide the hull into six rigid segments connected with a flexible beam. In order to model the typical feature of the open structure of the containership that the shear center is well below the keel line of the vessel, the beam was built into the model as low as possible. The model was instrumented with accelerometers and rotation rate gyroscopes on each segment, relative wave height meters and pressure gauges in the bow area. The beam was instrumented with strain gauges to measure the internal loads at the position of each of the cuts. Experiments have been carried out in regular waves at different amplitudes for the same wave period and in long crested irregular waves for a matrix of wave heights and periods. The results of the experiments are compared to results of calculations with a linear model based on potential flow theory that includes the effects of the flexural modes. Some of the tests were repeated with additional links between the segments to increase the model rigidity by several orders of magnitude, in order to compare the loads between a rigid and a flexible model.