• 제목/요약/키워드: interaction pattern

검색결과 770건 처리시간 0.029초

초음속 노즐에서의 약한 수직충격파와 난류경계층의 간섭(제1편, 시간적평균 흐름의 특성) (Weak Normal Shock Wave/Turbulent Boundary Layer Interaction in a Supersonic Nozzle(1st Report, Time-Mean Flow Characteristics))

  • 홍종우
    • 한국산업융합학회 논문집
    • /
    • 제2권2호
    • /
    • pp.115-124
    • /
    • 1999
  • The interaction of weak normal shock wave with turbulent boundary layer in a supersonic nozzle was investigated experimentally by wall static pressure measurements and by schlieren optical observations. The lime-mean flow in the interaction region was classified into four patterns according to the ratio of the pressure $p_k$ at the first kink point in the pressure distribution of the interaction region to the pressure $p_1$ just upstream of the shock. It is shown for any flow pattern that the wall static pressure rise near the shock foot can be described by the "free interaction" which is defined by Chapman et al. The ratio of the triple point height $h_t$ of the bifurcated shock to the undisturbed boundary layer thickness ${\delta}_1$ upstream of the interaction increases with the upstream Mach number $M_1$, and for a fixed $M_1$, the normalized triple point height $h_t/{\delta}_1$ decreases with increasing ${\delta}_1/h$, where h is the duct half-height.

  • PDF

웹 기반 원격교육에서 온라인 협력학습전략이 간호학전공 학습자의 소집단 상호작용 유형, 학습결과 및 학습태도에 미치는 효과 (Effect of Online Collaborative Learning Strategies on Nursing Student Interaction Patterns, Task Performance and Learning Attitude in Web Based Team Learning Environments)

  • 이선옥;서민희
    • 한국간호교육학회지
    • /
    • 제20권4호
    • /
    • pp.577-586
    • /
    • 2014
  • Purpose: This study investigates patterns of small group interaction and examines the influence among graduate nursing students of online collaborative learning strategies on small group interaction patterns, task performance and learning attitude in web-based team learning environments. Method: To analyze patterns of small group interaction, group discussion dialogues were reviewed by two instructors. Groups were divided into two categories depending on the type of feedback given (passive or active). For task performance, evaluation of learning processes and numbers of postings were examined. Learning attitude toward group study and coursework were measured via scales. Results: Explorative interactions were still low among graduate nursing students. Among the students given active feedback, considerable individual variability in interaction frequency was revealed and some students did not show any specific type of interaction pattern. Whether given active or passive feedback, groups exhibited no significant differences in terms of task performance and learning attitude. Also, frequent group interaction was significantly related to greater task performance. Conclusion: Active feedback strategies should be modified to improve task performance and learning attitude among graduate nursing students.

크리트 가진법을 이용한 타이어특성에 따른 로드노이즈 예측 연구 (Road Noise Prediction Based on Frequency Response Function of Tire Utilizing Cleat Excitation Method)

  • 박종호;황성욱;이상권
    • 한국소음진동공학회논문집
    • /
    • 제22권8호
    • /
    • pp.720-728
    • /
    • 2012
  • It is important for identification of noise and vibration problem of tire to consider influence of interaction between road and tire. A quantification of road noise is a challenging issue in vehicle NVH due to extremely complicated transfer paths of road noise as well as the difficulty in an experimental identification of input force from tire-road interaction. A noise caused by tire is divided into road noise(structure-borne noise) and pattern noise(air-borne noise). Pattern noise is caused by pattern shape of tire, which has larger than 500 Hz, but road noise is generated by the interactions between a tire and a vehicle body. In this paper, we define the quantitative analysis for road noise caused by interactions between tire and road parameters. For the identification of road noise, the chassis dynamometer that is equipped $10mm{\times}10mm $ square cleat in the semi-anechoic chamber is used, and the tire spindle forces are measured by load cell. The vibro-acoustic transfer function between ear position and wheel center was measured by the vibro-acoustic reciprocity method. In this study three tires with different type of mechanical are used for the experiment work.

An Exploratory Analysis of Constructivist Teaching Practices and Science Teaching Interactions in Earth Science Classes

  • Shin, Myeong-Kyeong
    • 한국지구과학회지
    • /
    • 제31권5호
    • /
    • pp.521-530
    • /
    • 2010
  • This study aimed to explore how to characterize the earth science inquiry in schools in terms of science teaching interaction and constructivist teaching practice. The constructivist teaching practices were analyzed with Reformed Teaching Observation Protocol (RTOP) in three aspects including (1) student oriented class implementation, (2) subject knowledge and representation, and (3) classroom communication. Fourteen earth science classes were observed and scored with RTOP. The class was evaluated to be transitional stage in terms of constructivist teaching, e.g., moving toward student-centered teaching practice. Especially, Korean teachers tend to lean their classes more on propositional knowledge than procedural knowledge. To interpret science teaching interactions, an earth science teacher with a RTOP top rank was selected. Her class was then videotaped for detailed analysis. I adopted the analytical framework of communicative approaches and discourse patterns among the five aspects of interactions presented by Mortimer and Scott (2003). It was found that this earth science teacher used more authoritative patterns than the dialogic. In addition, she used IRE discourse pattern more frequently. Interestingly, teachers interacted with their students more frequently in the form of repeated (or IRE chain pattern), that is IRFRF (teacher initiation-student response-teacher feedback-student response-teacher feedback) in the context of dialogic communicative approaches, while simple IRE occurred in an authoritative approach. In earth science classrooms, typical interaction may well be constructed in the form of IRFRF chains to allow students free conjectures and abduction.

줄무늬 셔츠의 시각적 감성에 대한 소비자 평가 - 세퍼레이션 배색을 중심으로 - (Consumer Evaluation on Visual Sensibility of Stripe Pattern Shirts - Focusing on Separation Coloration -)

  • 최수경
    • 한국의상디자인학회지
    • /
    • 제16권2호
    • /
    • pp.71-80
    • /
    • 2014
  • The purpose of this study was to investigate consumer evaluation on visual sensibility of stripe pattern shirts for separation coloration. The experimental materials developed for this study were a set of clothing stimuli and response scales. The clothing stimuli were 27 color pictures, in which separation color(white: W, gray: G, black: B), separation width(small: S, medium: M, large: L), and combination color(magenta and yellow: MY, magenta and cyan: MC, yellow and cyan: YC) were manipulated. The subjects of this research were female in their 20s to 30s living in Seoul, Gwangju, Daegu, Busan, and Changwon. The investigation was carried out at December 2013. The data were analyzed by using SPSS program. Analysis methods were factor analysis, ANOVA, and Duncan-test. Results of this study were as follow.; The factors of visual sensibility according to separation color, separation width, and combination color consisted of four dimensions of attractiveness, appeal, individuality freshness, and grace. Separation color showed an independent effect on appeal and individuality freshness. Combination color showed an independent effect on individuality freshness. Interaction effects of separation color and separation width on appeal were found. Interaction effects of separation color and combination color on individuality freshness and grace were found. The study results are highly expected to be used as useful sources in a fashion product.

  • PDF

Prosodic Disambiguation of Low versus High Syntactic Attachment across Lexical Biases in English

  • Jeon, Yoon-Shil;Yoon, Kyu-Chul
    • 말소리와 음성과학
    • /
    • 제4권1호
    • /
    • pp.55-65
    • /
    • 2012
  • In this study, the prosodic disambiguation of the syntactic attachment differences was investigated in relation to the effect of lexical bias. Speech materials were composed of N1-conj-N2-PP phrases such as "walkers and runners with dogs." The results show that the use of durational pattern is dominant over the pitch pattern to differentiate the attachment differences. The characteristic pitch contour was the rise and fall over N1 and N2 in the high attachment. The pitch contour in the low attachment was the rise and fall over N2 and N3 although the frequency of such patterns was lower for the low attachment case. For the durational pattern, the lengthening in the N2 region plays a significant role in the disambiguation of the syntactic attachments. The interaction between the lexical bias and the syntactic attachment was not statistically significant in the duration data.

A Structure and Framework for Sign Language Interaction

  • Kim, Soyoung;Pan, Younghwan
    • 대한인간공학회지
    • /
    • 제34권5호
    • /
    • pp.411-426
    • /
    • 2015
  • Objective: The goal of this thesis is to design the interaction structure and framework of system to recognize sign language. Background: The sign language of meaningful individual gestures is combined to construct a sentence, so it is difficult to interpret and recognize the meaning of hand gesture for system, because of the sequence of continuous gestures. This being so, in order to interpret the meaning of individual gesture correctly, the interaction structure and framework are needed so that they can segment the indication of individual gesture. Method: We analyze 700 sign language words to structuralize the sign language gesture interaction. First of all, we analyze the transformational patterns of the hand gesture. Second, we analyze the movement of the transformational patterns of the hand gesture. Third, we analyze the type of other gestures except hands. Based on this, we design a framework for sign language interaction. Results: We elicited 8 patterns of hand gesture on the basis of the fact on whether the gesture has a change from starting point to ending point. And then, we analyzed the hand movement based on 3 elements: patterns of movement, direction, and whether hand movement is repeating or not. Moreover, we defined 11 movements of other gestures except hands and classified 8 types of interaction. The framework for sign language interaction, which was designed based on this mentioned above, applies to more than 700 individual gestures of the sign language, and can be classified as an individual gesture in spite of situation which has continuous gestures. Conclusion: This study has structuralized in 3 aspects defined to analyze the transformational patterns of the starting point and the ending point of hand shape, hand movement, and other gestures except hands for sign language interaction. Based on this, we designed the framework that can recognize the individual gestures and interpret the meaning more accurately, when meaningful individual gesture is input sequence of continuous gestures. Application: When we develop the system of sign language recognition, we can apply interaction framework to it. Structuralized gesture can be used for using database of sign language, inventing an automatic recognition system, and studying on the action gestures in other areas.

Tangible AR interaction based on fingertip touch using small-sized non-square markers

  • Park, Hyungjun;Jung, Ho-Kyun;Park, Sang-Jin
    • Journal of Computational Design and Engineering
    • /
    • 제1권4호
    • /
    • pp.289-297
    • /
    • 2014
  • Although big-sized markers are good for accurate marker recognition and tracking, they are easily occluded by other objects and deteriorate natural visualization and level of immersion during user interaction in AR environments. In this paper, we propose an approach to exploiting the use of rectangular markers to support tangible AR interaction based on fingertip touch using small-sized markers. It basically adjusts the length, width, and interior area of rectangular markers to make them more suitably fit to longish objects like fingers. It also utilizes convex polygons to resolve the partial occlusion of a marker and properly enlarges the pattern area of a marker while adjusting its size without deteriorating the quality of marker detection. We obtained encouraging results from users that the approach can provide better natural visualization and higher level of immersion, and be accurate and tangible enough to support a pseudo feeling of touching virtual products with human hands or fingertips during design evaluation of digital handheld products.

A Parametric Study on Ice Scouring Mechanism for Determination of Pipeline Burial Depths

  • Park, Kyung-Sik;Lee, Jong-Ho
    • Journal of Ship and Ocean Technology
    • /
    • 제8권2호
    • /
    • pp.29-40
    • /
    • 2004
  • Interaction of grounded ice ridges with underlying seabed is one of the major considerations in the design of Arctic pipeline system. Previously several ice scour models were developed by researchers to describe the ice scour-seabed interaction mechanism. In this paper, a parametric study on ice scouring mechanism is performed and the limitation of ice scour-seabed interaction models is discussed. Simple laboratory tests are carried out and then the shape pattern of deposited soil around the ice is redefined. New ice scour model assumes trapezoidal cross section based on the field observation data. Ice scour depth and soil resistance forces on seabed are calculated with varying the keel angle of a model ice ridge.

빙쇄굴-해저지반 상호작용 모델 비교연구 (A Comparative Study of Ice Scour-Seabed Interaction Models)

  • 최경식;이종호
    • 한국해양공학회지
    • /
    • 제16권1호
    • /
    • pp.27-35
    • /
    • 2002
  • The interaction of grounded ice ridges with underlying seabed is one of the major considerations in the design of Arctic pipeline system. Previously several ice scour models were developed by researchers to describe the ice scour-seabed interaction mechanism. In view of possible improvements, a comparative study of those ice scour models is performed and their limitation in modeling is discussed. Simple laboratory tests are carried out and then the shape pattern of deposited soil around the ice model is newly defined. Unlike the rectangular idealization of an ice block, in this modified ice scour model, trapezoidal cross sections are assumed to represent the typical shape of an ice ridge based on the field observation data. With the horizontal and vertical motion of ice model, the ice scour depth and soil reacting forces on seabed are calculated with varying the keel angle of an ice ridge.