환경교육을 위한 웹 기반 프로젝트 학습 시스템의 설계 및 구현

전우천,정효숙,김동용,엄종진,정성모,최수경 서울교육대학교 2001 한국초등교육 Vol.12 No.2

The use of the Web (World Wide Web) has been changing roles of traditional education style. Especially, the Web can overcome time and space limitations in the traditional schools. Teachers and students are now using the Web to access vast amounts of information and resources on cyber space. Also, the learning via the Web enables both synchronous and asynchronous communication. Despite of many benefits of the Web, it may weaken students motivation due to lack of face-to-face communication. In this paper, we provide a learning model called Web Project Learning, which is based on the contructivism, to provide motivation and collaborative learning for students in the Web environment. The model is based on the Project-Based Learning model and is revised for use in the Web. The model can also encourage the participation of parents as well as students, and be applied to any subject. We implement our model and show that the model can be used for environmental education as an instance.

상자형의 전단지연 현상과 유효폭에 관한 연구

鄭熺孝,金洪俊,李承烈,朴峻熙 경상대학교 생산기술연구소 2002 工學硏究院論文集 Vol.2 No.-

In a box girder, it is an accepted practice in structural engineering to represent the effect of 'shear lag' by adopting an 'effective width' concept. The actual width of flange plate (b) is replaced by a reduced width (b_e) over which the longitudinal stresses may be considered uniformly distributed and the application of the elementary theory of bending to the transformed girder cross section gives the correct value of maximum longitudinal stress (σ_max). This paper provides how to determine the magnitude of 'shear lag' and 'effective width ratio' in case of orthotropic box girder which is simply supported, symmetrically loaded only.

스트레인 게이지 브리지 종류에 따른 탄성계수의 실험적 연구

鄭熺孝,李承烈,朴泳珏,朴峻熙 경상대학교 생산기술연구소 2001 工學硏究院論文集 Vol.1 No.-

Strain gauges are widely used for physical force measurements in mechanical, marine, aircraft and civil engineering as well as the fields of architecture, automobiles, and medical science. Strain is measured to determine the degree and behavior of forces such as stress or load. Strain gauges are easy to use and offer a high degree of accuracy and stability. This paper is shown the accuracy of experimental elastic modulus in the tension test according to the strain gauges connections and bridge circuits which are Quarter Bridge(single active uni-axial gauge), Half Bridge(two active on possion gauge), Full Bridge(four active two possion gauge).

계층화된 퍼지 인지도를 이용한 신뢰기반 경매시스템

김현준,류정섭,권효석,조형래 경상대학교 생산기술연구소 2003 工學硏究院論文集 Vol.19 No.-

This paper introduces trust measurement that is composed of trust variables and fuzzy cognitive map. The improved trust measuring method using a stratified FCM can be used to measure the level of risk involved in a specific auction transaction concerned. To reduce the auction transaction cost and time, the proposed system recommends a differentiated transaction protocol according to the risk based on trust measurement. In this system, trust measurement can also be applied for differentiated and varied auction services.

노인에서 한국판 행동통제척도의 표준화 및 타당도 연구

김효진,이준영,정희연,나덕렬,조성진,조맹제,장성만 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.4

The aims of this study are to demonstrate the reliability and the validity of the Korean version of Behavioral Dyscontrol Scale (BDS-K.) and to present the normative values of BDS-K among the Korean elderly. The BDS-K was administered in a standardized manner to 1,389 healthy volunteers aged over 65 years recruited from the cornmunity. The elderly with serious neurological, medical or psychiatric disorders were excluded using screening tests. BDS-K showed good intemal consistency (Cronbach's alpha=0.812), test-retest reliability (r=0.88) and inter-rater reliability (r=0.99). Age and educational level were found to affect BDS-K score. Based on this result, normative values of BDS-K. were calculated by age and educational level. The validity of the BDS-K were demonstrated in comparison with MMSE-KC (r=0.72). BDS-K is reliable and valid instrument for measuring executive function of the elderly. The normative values suggested by this study can be widely used as reference values to objectively interpret BDS-K scores of the Korean elderly.

한계계단 응답특성을 이용한 영구자석형 동기전동기 속도제어

박승엽,전인효,최중경 창원대학교 공작기계기술연구센터 1999 연구업적집 Vol.1 No.1

본 논문에서는 한계계단 응답특성을 이용하여 영구자석형 동기전동기의 속도 제어계에 대한 새로운 자동 동조 PI(Proportional Integral)제어기를 설계하였다. 과도응답 기간동안 소위 한계입력이라고 하는 계단입력을 인가하여 PI 제어기의 자동동조를 위한 정보를 얻기 위한 기법을 제안한다. 시스템 파라메터 추정과 동시에 속도제어가 온라인으로 이루어지는데, 이것은 시스탬의 불확실성에도 불구하고 한계입력에 의해서 얻어진 시스템 파라메터 정보가 연속적으로 PI 제어기에 적용될 수 있다는 것이다. 제안된 자동동조 알고리즘은 단조증가 계단응답 특성을 갖는 영구 자석형 동기전동기의 속도제어에 대한 시뮬레이션과 실험결과를 통하여 그 유효함을 확인하였다. In this paper, a new auto-tuning PI controller for the speed servo system of a PMSM is designed by using limited step response characteristics. The method is proposed that gets information about auto-tuning of PI regulator by the injection fo step input, called limited input, during a transient response time of control. System parameter estimation and speed control could be continuously executed. This means that in despite of system uncertainty the system information obtained by limited input can be continuously applied to the PI regulator. We demonstrate the effectiveness of the proposed auto-tuning algorithm through simulation and experiment result of the speed control for a PMSM having monotone increasing step response.

철근콘크리트 T형교의 내하력 증진

남문희,정희효,이관희,박준용 慶尙大學校生産技術硏究所 1996 生産技術硏究所論文集 Vol.12 No.-

Even though there are a lot of methods of promotion of load resistance for reinforced concrete T-beam bridge, the methods have been faults respectively. In this study, we will convert simple supported T-beam into continuous T-beam for promotion of load resistance and cancel joint. This method is decidedly superior to another method in maintenance, construction, economics and external appearance.

온라인 동조 PI 제어기법을 이용한 영구자석형 동기전동기의 속도제어기 설계

林相德,朴勝燁,全寅孝,崔重暻 창원대학교 공작기계기술연구센터 1999 연구업적집 Vol.1 No.1

본 논문은 브러시리스 직류 전동기의 속도제어를 위해 파라메타의 추정 없이 입력과 출력의 패턴을 관찰하여 PI 이득을 온라인(On-line)으로 설정하는 방법을 제안한다. 비례이득은 한계입력을 인가하여 가장 빠른 속도 상승을 유도하는 과정에서 설정되고, 적분이득은 비례제어 과정 중에 오버슈트 방지와 안정된 수렴이 적적히 이루어지도록 설정된다. 따라서 제안된 PI이득 조정은 온라인으로 제어와 동시에 수행됨으로써 시스템 파라메타 추정 등의 부가적인 작업이 필요 없다. 본 논문에서 제안하는 PI이득 조절기법은 직류전동기의 속도제어에 있어서 빠른 응답과 오버슈트 문제를 동시에 해결할 수 있고, 기존의 Auto-tuning 방법보다 간편하고 실용적이다. 컴퓨터 시뮬레이션과 실제 실험을 통하여 제안하는 방법의 유용성과 안정성을 보인다. In this paper, a method of on-line PI gain-tuning is proposed for the speed control of brushless D.C. motor by investigating the pattern of input and output without estimating parameter. Proportional gain is tuned in the process to obtain a fast speed response by supplying the maximum constant input And integral gain is appropriately tuned in the process of proportional control so that the response may be stably converged and the overshoot may be prevented. Therefore because both control and gain-tuning are executed concurrently, additional works that estimate parameters and so on aren't required in the proposed method. In the proposed method, both fast-response and overshoot problem are well solved, and it is mire useful and convenient than existing auto-tuning methods in the speed control of D.C motor. It is illustrated by simulations and experimental results that the proposed method is useful and stable.

외기요법이 체표온도 변화에 미치는 영향

노일호,김병완,정광조,曺政孝,黃相畯,吳旼錫 대전대학교 한의학연구소 2003 한의학연구소 논문집 Vol.12 No.1

This study is about the relationship between the effect of Radiating Qui Therapy on human body and the resulting subjective qui sensation. Patients were between 30 and 50 years of age. n=21 persons received DITI (n=14 patients were provided, n=9 control group) twice examination with Radiating Qui Therapy. First all patients were examined by DITI. After treatment with Radiating Qui Therapy (n=14) both the treated and the control groups were eaxmined again. Radiating Qui Therapy is provided upright position. After Radiating Qui Therapy 92% of the treated group felt a significant qui sensation and 43.5 % felt a warmth at the abdomen and over the whole body. A data of this study show Radiating Qui Therapy has s stimulating effect on human skin temperature. As disease region and Qui sensation are very closely related to each other results strongly suggest that Radiating Qui Therapy could be used as a treatment for a several disease.

RF sputtering 법으로 제조된 CuInSe₂박막의 특성

김규호,김효준,이해석,김민호,정상현 嶺南大學校 工業技術硏究所 1998 工業技術硏究所論文集 Vol.26 No.1

CuInSe₂ thin films were prepared on Si(100) wafer by RF magnetron sputtering from powder target which was prepared by reacting high purity Cu₂Se and In₂Se₃(99.999%, Cu₂Se: In₂Se₃=1:1 mole ratio), in argon gas The XRD results suggest that deposited thin films were mainly composed of crystalline CuInSe₂ with the typical chalcopyrite structure, whereas film deposited showed the mixed phase of Cu₂Se+CuInSe₂at 50W. Deposited film showed (204), (220) preferred orientation at 50W and deposited films from 75W were strongly oriented along th e(112) plane. In the EDS analysis, Cu/In mole ratio of the thin films was decreased and Se/(Cu+In) mole ratio was increased with increasing RF power. The lattice parameters of a, c axis and c/a ratio of deposited films were decreased with increasing RF power. The grain size of the thin films measured by SEM became coarse with the increase of RF power.