• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.5
• /
• pp.415-419
• /
• 2010

A variety of methods for sound source localization have been developed and applied to several applications such as noise detection system, surveillance system, teleconference system, robot auditory system and so on. In the previous work, we proposed the sound source localization using the spatially mapped GCC functions based on TDOA for robot auditory system. Performance of the proposed one for the noise effect and estimation resolution was verified with the real environmental experiment under the single source assumption. However, since multi-talker case is general in human-robot interaction, multiple source localization approaches are necessary. In this paper, the proposed localization method under the single source assumption is modified to be suitable for multiple source localization. When there are two sources which are correlated, the spatially mapped GCC function for localization has three peaks at the real source locations and imaginary source location. However if two sources are uncorrelated, that has only two peaks at the real source positions. Using these characteristics, we modify the proposed localization method for the multiple source cases. Experiments with human speeches in the real environment are carried out to evaluate the performance of the proposed method for multiple source localization. In the experiments, mean value of estimation error is about $1.4^{\circ}$ and percentage of multiple source localization is about 62% on average.

• Journal of Technology Innovation
• /
• v.13 no.3
• /
• pp.27-49
• /
• 2005

In this Paper, we analyzed the relative importance of multiple sources and their effects on innovative activities. Through factor analysis, we found 5 sources of innovative activities; university/laboratory source, within firm source, general information source, vertical/competitive relation source, and horizontal relation source. Through regression analysis, we found that (1) 'within firm source' is the most important source on innovative activities, (2) from inputs' point of view, the more 'vertical/competitive relation source' is, the less innovative activities we, (3) from outputs' point of view, innovations are more activated when 'university/laboratory source' is abundant. but, they are less activated when 'general information source' and 'vertical/competitive relation source' is abundant, and (4) according to firm size and innovation stages(newproduct innovation, upgraded product innovation, and process innovation), the effect of sources on innovative activities is different.

• Journal of the Korean Society for Precision Engineering
• /
• v.33 no.8
• /
• pp.629-634
• /
• 2016

Laser-assisted machining (LAM) is one of the most effective methods of processing difficult-to-cut materials, such as titanium alloys and various ceramics. However, it is associated with problems such as the inability of the laser heat source to generate an appropriate preheating temperature. To solve the problem, thermally assisted machining with multiple heat sources is proposed. In this study, thermal analysis of multiple heat sources by laser and arc is performed according to power, heat source size, and leading heat source position. Then, the results are analyzed according to each condition. The results of this analysis can be used as a reference to predict preheating temperature in thermally assisted machining with multiple heat sources.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.234.1-234.1
• /
• 2014

Many studies have been investigated on high density plasma source (Electron Cyclotron Resonance[ECR], Inductively Coupled Plasma[ICP], Helicon plasma) for large area source after It is announced that productivity of plasma process depends on plasma density. Among them, Some researchers have been studied on multiple sources In this study, we attempted to determine the possibility of multiple inductively coupled plasma (ICP), and helicon plasma sources for large-area processes. Experiments were performed with the one and two coils to measure plasma and electrical parameters, and a circuit simulation was performed to measure the current at each coil in the 2-coil experiment. Based on the result, we could determine the possibility of multiple ICP sources due to a direct change of impedance due to current and saturation of impedance due to the skin-depth effect. However, a helicon plasma source is difficult to adapt to the multiple sources due to the consistent change of real impedance due to mode transition and the low uniformity of the B-field confinement. As a result, it is expected that ICP can be adapted to multiple source for large-area processes.

• Management & Information Systems Review
• /
• v.32 no.3
• /
• pp.127-151
• /
• 2013

This research was to investigate the role of message regulatory focus on the advertising effect of multiple models. The multiple models are limited to two models in one advertisement in this research. This research investigated the hypothesis that multiple models, in terms of multiple source effect and social consensus, appears specifically to enhance the relationship of consumer and commercial models on the conditions of promotion-focused message which leads to the information processing of relational elaboration. This research applied a between-subjects factorial design targeting 2(the number of model: single model vs. multiple models) by 2(message regulatory focus: promotion-focused message vs. prevention-focused message). As a result, multiple models showed more positive ad attitude, brand attitude, and purchase intention than did single model. And promotion-focused message with multiple models showed more positive ad attitude, brand attitude, and purchase intention than did prevention-focused message with multiple models. Also there was an interaction effect between the number of model and the type of message regulatory focus. It wasn't fully supported that there is no difference of advertising effect between promotion-focused message and prevention-focused message on the condition of single model.

• Knowledge Management Research
• /
• v.20 no.2
• /
• pp.1-24
• /
• 2019

This tutorial introduces procedures and methods for performing structural equation modeling using R. To do this, we present advanced analysis methods based on structural equation model such as mediation effect analysis, moderation effect analysis, moderated mediation effect analysis, and multiple-group analysis with R program code using R lavaan package that supports structural equation modeling. R is flexible and scalable, unlike traditional commercial statistical packages. Therefore, new analytical techniques are likely to be implemented ahead of any other statistical package. From this point of view, R will be a very appropriate choice for applying new analytical techniques or advanced techniques that researchers need. Considering that various studies in the social sciences are applying structural equations modeling techniques and increasing interest in open source R, this tutorial is expected to be useful for researchers who are looking for alternatives to existing commercial statistical packages.

• Journal of the Korea Society of Computer and Information
• /
• v.27 no.11
• /
• pp.257-270
• /
• 2022

This paper analyzes the effect of profit incentives within the setting of bounty open source project. A simple decision-making model based on classical utility maximization is presented for open source developers that includes income effects from the bounty prize. We then simulate the decisions of multiple developers to assess the effect from the bounty prize. Our result shows that learning costs can greatly reduce the software quality improvement benefit from bounty project. It also suggests that open source projects can benefit more when they have multiple small bounty projects than a single large bounty project since it reduces the learning cost and the opportunity cost for the open source developers.

• Proceedings of the KSPS conference
• /
• 2003.10a
• /
• pp.97-100
• /
• 2003

This paper addresses a method of convolutive source separation that based on SEONS (Second Order Nonstationary Source Separation) [1] that was originally developed for blind separation of instantaneous mixtures using nonstationarity. In order to tackle this problem, we transform the convolutive BSS problem into multiple short-term instantaneous problems in the frequency domain and separated the instantaneous mixtures in every frequency bin. Moreover, we also employ a H infinity filtering technique in order to reduce the sensor noise effect. Numerical experiments are provided to demonstrate the effectiveness of the proposed approach and compare its performances with existing methods.

• Proceedings of the Korean Society for Rock Mechanics Conference
• /
• 1995.03a
• /
• pp.108-108
• /
• 1995

There are always some difficulties to discriminate artificial exlposions from micro-earthquakes, furthermore more difficulties to identify and determine decoupled explosions and/or multiple explosions from micro-earthquakes. In this study we use the synthetic seismogram of the in homogeneous models between the source and the observation station in order to find the source effect of the geological environment. We have found some source characteristics of the air-filled and/or water-filled cavity that we can hardly see P-n and S- waves arrivals and that the high frequency coda waves are well observed compared to the coupled explosions or earthquakes.

• Journal of Industrial Technology
• /
• v.26 no.A
• /
• pp.119-127
• /
• 2006

The purpose of this study is to present quantitatively the influence of variables that had the largest effect on the changes in suspended solids(SS), which would cause turbid water phenomenon, among water quality factors of the non-point pollution source, and then to develop a multiple regression equation of SS and predict the water quality of ungaged watersheds so as to provide basic data to establish efficient management plans for SS which flow in rivers and lakes. To identify the correlation of SS with the amount of rainfall and the state of land use, a simple correlation analysis and a simple regression analysis were conducted respectively. Finally, a multiple regression analysis was conducted to provide that SS were set as dependent variables while the amount of rainfall, paddy fields and dry fields were set as independent variables. As a result, the amount of rainfall had the most significant influence on changes in SS, followed by dry fields and paddy fields. In addition, the multiple regression equation was developed to predict SS in unmeasurable watersheds.