• International Journal of Naval Architecture and Ocean Engineering
• /
• v.7 no.1
• /
• pp.25-40
• /
• 2015

Understanding the effects of the parameters affecting the interaction of tandem hydrofoil system is a crucial subject in order to fully comprehend the aero/hydrodynamics of any vehicle moving inside a fluid. This study covers a parametric study on tandem hydrofoil interaction in both potential and viscous fluids using iterative Boundary Element Method (BEM) and RANSE. BEM allows a quick estimation of the flow around bodies and may be used for practical purposes to assess the interaction inside the fluid. The produced results are verified by conformal mapping and Finite Volume Method (FVM). RANSE is used for viscous flow conditions to assess the effects of viscosity compared to the inviscid solutions proposed by BEM. Six different parameters are investigated and they are the effects of distance, thickness, angle of attack, chord length, aspect ratio and tapered wings. A generalized 2-D code is developed implementing the iterative procedure and is adapted to generate results. Effects of free surface and cavitation are ignored. It is believed that the present work will provide insight into the parametric interference between hydrofoils inside the fluid.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.10 no.3
• /
• pp.31-38
• /
• 2010

In this study, it is suggested that it has to reliability-based design methodology with respect to bridge structure-rail longitudinal interaction and bridge structure-vehicle interaction. For the structural analysis, commercial package, ABAQUS, are used for a three-dimensional finite element analysis. The optimization process utilizes a well-known optimizer, ADS(Automated Design Synthesis). Optimization technique is utilized the ALM-BFGS method for global area search and Golden Section Method for 1-D search. In general, ALM-BFGS method don't need the 1-D search, and that algorithm converge a 0.1~0.2 of Push-Off factor. But in this study, value of Push-Off factor is used 90, therefore 1-D search should be needed for effective convergency. That algorithm contains the "heuristic decision method". As a result of optimum design of 2-main steel girder birdge with 5${\times}$(1@50m), design methodology suggested in this study was demonstrated more economic and efficient than existing design and LCC optimization not considering bridge-rail longitudinal interaction and bridge-vehicle interaction.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.14 no.4
• /
• pp.515-523
• /
• 2007

Purpose: The purposes of the study were to determine the effects of AIDS education which includes discussion on knowledge, prejudice, social interaction, and intention for AIDS prevention in college students. Method: A convenience sampling method was used to collect data, and 136 university students participated in the study. One group pretest-post test design was used and questionnaire for measuring knowledge about AIDS and attitude to AIDS were administered before and after 100 minutes of AIDS education, The education program consisted of a 50-minute lecture with video aids and 50 minutes of small group discussion. Means, SD, and paired t-test with the SPSS program were used to analyze the data. Results: There were significant increases in knowledge(p= .000) and social interaction(p= .002) after the education, but no significant changes in prejudice(p= .832) nor in intention for AIDS prevention(p= .074). Conclusion: AIDS education including discussion was found to be an effective method for improving knowledge and social interaction of college students. The results suggest that education which includes discussion sessions should be used with college students to improve social interaction with people who are HIV positive and enhance knowledge about AIDS.

• 한국HCI학회:학술대회논문집
• /
• 2009.02a
• /
• pp.62-67
• /
• 2009

Many interaction methods for augmented reality has attempted to reduce difficulties in tracking of interaction subjects by either allowing a limited set of three dimensional input or relying on auxiliary devices such as data gloves and paddles with fiducial markers. We propose Spatial Interaction (SPINT), a noncontact passive method that observes an occupancy state of the spaces around target virtual objects for interpreting user input. A depth-sensing camera is introduced for constructing the virtual space sensors, and then manipulating the augmented space for interaction. The proposed method does not require any wearable device for tracking user input, and allow versatile interaction types. The depth perception anomaly caused by an incorrect occlusion between real and virtual objects is also minimized for more precise interaction. The exhibits of dynamic contents such as Miniature AR System (MINARS) could benefit from this fluid 3D user interface.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.1
• /
• pp.124-130
• /
• 2009

Estimating genetic interaction effects in animal genomics would be one of the most challenging studies because the phenotypic variation for economically important traits might be largely explained by interaction effects among multiple nucleotide sequence variants under various environmental exposures. Genetic improvement of economic animals would be expected by understanding multi-locus genetic interaction effects associated with economic traits. Most analyses in animal breeding and genetics, however, have excluded the possibility of genetic interaction effects in their analytical models. This review discusses a historical estimation of the genetic interaction and difficulties in analyzing the interaction effects. Furthermore, two recently developed methods for assessing genetic interactions are introduced to animal genomics. One is the restricted partition method, as a nonparametric grouping-based approach, that iteratively utilizes grouping of genotypes with the smallest difference into a new group, and the other is the Bayesian method that draws inferences about the genetic interaction effects based on their marginal posterior distributions and attains the marginalization of the joint posterior distribution through Gibbs sampling as a Markov chain Monte Carlo. Further developing appropriate and efficient methods for assessing genetic interactions would be urgent to achieve accurate understanding of genetic architecture for complex traits of economic animals.

• Child Health Nursing Research
• /
• v.14 no.4
• /
• pp.370-378
• /
• 2008

Purposes: The purposes of this descriptive survey study were to describe levels of Maternal-Fetal Interaction Belief and Maternal-Fetal Interaction, and to define their correlation. Method: Data were collected from 273 pregnant women who visited one public health center and OB/GY clinic in Gangneung city. The instrument used for this study was a self-report questionnaire that included the Maternal-Fetal Interaction Belief scale(MFIBS) and maternal-fetal interaction. Results: The mean scores for maternal-fetal interaction belief and maternal-fetal interaction were $107.41{\pm}15.67$ and $31.75{\pm}5.92$ respectively. For maternal-fetal interaction belief, there were significant differences according to education, religion, income, feeding plan, marriage satisfaction, family support, and husband's love. For maternal-fetal interaction, there were significant differences according to mother's age, period of pregnancy, marriage satisfaction, family support, husband's love. There was a correlation between maternal-fetal interaction belief and maternal-fetal interaction. Conclusion: Maternal-fetal interaction belief is related to increase in maternal-fetal interaction and fetal development. It is essential to develop a maternal-fetal interaction program that includes maternal-fetal interaction belief.

• 유체기계공업학회:학술대회논문집
• /
• 2002.12a
• /
• pp.33-40
• /
• 2002

The hydraulic performance analysis of a pump system composed of an inducer and impeller for the application on turbopumps has been performed using three-dimensional Wavier-Stokes equations. A simple mixing-plane method and a full interaction method are used to simulate inducer/impeller interactions. The computations adopting two methods show almost similar results due to the weak interaction between the inducer and impeller since the inducer outlet blade angle is rather small. But, because the inducer and the impeller are closely spaced near the shroud region at the interface, flow angles at the impeller inlet show different results between two methods. Thus, the full interaction method predicted about $2\%$ higher pump performance than the mixing-plane method. And the effects of prewhirl at the impeller inlet are also investigated. As the inlet flow angle is increased, the head rise and the efficiency are decreased. The computational results are compared with experimental ones. The computational results at the design point show good agreements with experimental data. But the computation was found to under-predict the head rise at high mass flow rates compared to the experiment, further study must be followed in terms of the computation and experiment.

• 한국HCI학회:학술대회논문집
• /
• 2009.02a
• /
• pp.418-421
• /
• 2009

This paper presents a human-machine interaction based on a realtime upper limb motion prediction method using surface electromyography (sEMG). The motions were predicted using an artificial neural network algorithm and sEMG signals which are acquired from five muscles, and then a manipulator was controlled to follow after the predicted motions. Upper limb motions were restricted to 2D vertical plane with the contact condition between a user and an end-effector of manipulator. In order to demonstrate the feasibility of the proposed method, experiments using developed method and using a goniometer were performed. The results showed that the proposed real-time motion prediction method can be implemented a human-machine interaction system.

• Journal of Korea Multimedia Society
• /
• v.24 no.12
• /
• pp.1673-1681
• /
• 2021

Item cold start is a well studied problem in the research field of recommender systems. Still, many existing collaborative filters cannot recommend items accurately when only a few user-item interaction data are available for newly introduced items (Cold items). We propose a interaction feature prediction method to mitigate item cold start problem. The proposed method predicts the interaction features that collaborative filters can calculate for the cold items. For prediction, in addition to content features of the cold-items used by state-of-the-art methods, our method exploits the interaction features of k-nearest content neighbors of the cold-items. An attention network is adopted to extract appropriate information from the interaction features of the neighbors by examining the contents feature similarity between the cold-item and its neighbors. Our evaluation on a real dataset CiteULike shows that the proposed method outperforms state-of-the-art methods 0.027 in Recall@20 metric and 0.023 in NDCG@20 metric.

• 제어로봇시스템학회:학술대회논문집
• /
• 1986.10a
• /
• pp.547-549
• /
• 1986

This paper deals with large scale distributed packet switching system which is modeled by state space form and optimizing routing algorithms and buffer size via a hierachical system optimization method, the interaction prediction method.