• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.585-588
• /
• 1997

This paper presents a construction method of logic-based switching control system which operates in widely changing environments. The logic-based switching controller is composed of a family of candidate controllers together with a supervisor. The system does not require any identification schemes of environments. Switching from one candidate controller to another is carried out based on monitoring the output of the system. The basic ideas of adaptation are as follows: (1)each candidate controller is prepared for each environment in advance; (2)the supervisor applies a sequence of speculative controls to a plant with candidate controllers just after the control has started and just after the change of the environment has been detected. It is important that each candidate controller can keep the system stable during a sequence of speculative controls, and the most appropriate candidate controller for the environment to which the system is exposed can be selected before the last speculative control is ended. An application to an antiskid braking system clarifies the effectiveness of the proposed method.

• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.2
• /
• pp.47.2-47.2
• /
• 2017

We investigate the environmental effects on galaxy spin using the sample of ~1100 galaxies from the first public data of MaNGA integral field unit survey. We determine the spin parameter ${\lambda}_{Re}$ of galaxies by analyzing the two-dimensional stellar kinematic measurements within the effective radius, and study its dependence on the large-scale (background mass density determined with 20 nearby galaxies) and small-scale (distance to and morphology of the nearest neighbor galaxy) environments. We first examine the mass dependence of galaxy spin, and find that the spin parameter decreases with stellar mass at log ($M_{\ast}/M_{\odot}$) > 10, consistent with previous studies. We then divide the galaxies into three subsamples using their stellar masses to minimize the mass effects on galaxy spin. The spin parameter of galaxies in each subsample does not change with the background density, but do change with the distance to and morphology of the nearest neighbor. The spin parameter increases when late-type neighbors are within the virial radius, and decreases when early-type neighbors are within the virial radius. These results suggest that the large-scale environments hardly affect the galaxy spin, but the effects of small-scale environments such as hydrodynamic galaxy-galaxy interactions are substantial.

• The Bulletin of The Korean Astronomical Society
• /
• v.32 no.1
• /
• pp.50.2-50.2
• /
• 2007

• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.2
• /
• pp.37-37
• /
• 2014

Magnetic fields appear to be ubiquitous in astrophysical environments. The existence of magnetic fields in the large-scale structure of the universe has been established through observations of Faraday rotation and synchrotron emission, as well as through recent gamma-ray observations. Yet, the nature and origin of the magnetic fields remains controversial and largely unknown. In this talk, I briefly summarize recent developments in our understanding of the nature and origin of magnetic fields. I also describe a plausible scenario for the origin of the magnetic fields; seed fields were created in the early universe and subsequently amplified during the formation of the large-scale structure of the universe. I then discuss the prospect of observation of magnetic fields in the large-scale structure of the universe.

• Phonetics and Speech Sciences
• /
• v.15 no.3
• /
• pp.83-88
• /
• 2023

This study investigates the fine-tuning of large-scale Automatic Speech Recognition (ASR) models, specifically OpenAI's Whisper model, for domain-specific applications using the KsponSpeech dataset. The primary research questions address the effectiveness of targeted lexical item emphasis during fine-tuning, its impact on domain-specific performance, and whether the fine-tuned model can maintain generalization capabilities across different languages and environments. Experiments were conducted using two fine-tuning datasets: Set A, a small subset emphasizing specific lexical items, and Set B, consisting of the entire KsponSpeech dataset. Results showed that fine-tuning with targeted lexical items increased recognition accuracy and improved domain-specific performance, with generalization capabilities maintained when fine-tuned with a smaller dataset. For noisier environments, a trade-off between specificity and generalization capabilities was observed. This study highlights the potential of fine-tuning using minimal domain-specific data to achieve satisfactory results, emphasizing the importance of balancing specialization and generalization for ASR models. Future research could explore different fine-tuning strategies and novel technologies such as prompting to further enhance large-scale ASR models' domain-specific performance.

• Journal of The Korean Astronomical Society
• /
• v.46 no.1
• /
• pp.33-40
• /
• 2013

We investigate the dependence of the extended X-ray emission from the halos of optically luminous early-type galaxies on the small-scale (the nearest neighbor distance) and large-scale (the average density inside the 20 nearest galaxies) environments. We cross-match the 3rd Data Release of the Second XMMNewton Serendipitous Source Catalog (2XMMi-DR3) to a volume-limited sample of the Sloan Digital Sky Survey (SDSS) Data Release 7 with $M_r$ < -19.5 and 0.020 < z < 0.085, and find 20 early-type galaxies that have extended X-ray detections. The X-ray luminosity of the galaxies is found to have a tighter correlation with the optical and near infrared luminosities when the galaxy is situated in the low large-scale density region than in the high large-scale density region. Furthermore, the X-ray to optical (r-band) luminosity ratio, $L_X/L_r$, shows a clear correlation with the distance to the nearest neighbor and with large-scale density environment only where the galaxies in pair interact hydrodynamically with seperations of $r_p$ < $r_{vir}$. These findings indicate that the galaxies in the high local density region have other mechanisms that are responsible for their halo X-ray luminosities than the current presence of a close encounter, or alternatively, in the high local density region the cooling time of the heated gas halo is longer than the typical time between the subsequent encounters.

• 한국전산유체공학회:학술대회논문집
• /
• 2006.05a
• /
• pp.21-26
• /
• 2006

A large-scale finite element simulation and modeling method is presented for environmental flows in urban area. Parallel stabilized finite element method based on domain decomposition method is employed for the numerical simulation. Several GIS and CAD data are used for the preparation of the shape model for landform and urban structures. The present method Is applied to the simulation of flood flow and wind flow In urban area. The present method is shown to be a useful planning and design tool for the natural disasters and the change of environments in urban area.

• ETRI Journal
• /
• v.27 no.5
• /
• pp.595-607
• /
• 2005

The widespread use of the Internet has led to the problem of intellectual property and copyright infringement. Digital rights management (DRM) technologies have been developed to protect digital content items. Digital content can be classified into static content (for example, text or media files) and dynamic content (for example, VOD or multicast streams). This paper deals with the protection of a multicast stream on set-top boxes connected to an IP network. In this paper, we examine the following design and architectural issues to be considered when applying DRM functions to multicast streaming service environments: transparent streaming service and large-scale user environments. To address the transparency issue, we introduce a 'selective encryption scheme'. To address the second issue, a 'key packet insertion scheme' and 'hierarchical key management scheme' are introduced. Based on the above design and architecture, we developed a prototype of a multicasting DRM system. The analysis of our implementation shows that it supports transparent and scalable DRM multicasting service in a large-scale user environment.

• Journal of Sensor Science and Technology
• /
• v.33 no.2
• /
• pp.78-85
• /
• 2024

We proposed a method for visual place recognition that represents images using objects as visual words. Visual words represent the various objects present in urban environments. To detect various objects within the images, we implemented and used a zero-shot detector based on a large-scale image language model. This zero-shot detector enables the detection of various objects in urban environments without additional training. In the process of creating histograms using the proposed method, frequency-based weighting was applied to consider the importance of each object. Through experiments with open datasets, the potential of the proposed method was demonstrated by comparing it with another method, even in situations involving environmental or viewpoint changes.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 2008.04a
• /
• pp.386-392
• /
• 2008

The purpose of this study is to clarify playground types by characteristics of playground environment in child care facilities, to analyze the needs and estimation of users according to playground types. The subjects of this study were care-givers, who assist outdoor play activities of children and manage safety in playground, to estimate adequateness of playground's environment to children's outdoor plays and to report needs. The data were collected by field measurement survey for clarification playground environments in 21 child care facilities and structured-questionnaire for estimation and needs of 181 care-givers in them. The major results showed the following. 1) The playgrounds were clarified to five type according to number of child and size of playground. The five types include A-type as large-scale facility/small-size playground, B-type as small-scale facility/large-size playground, C-type as small-scale facility/small-size playground, D-type as middle-scale facility/large-size playground, and E-type as large-scale facility/large-size playground. 2) The adequateness of playground environment of D-type were estimate higher than others. C-type were estimated lower than other types in size and outdoor play areas organization of playground. 3) The care-givers in D-type and E-type wanted to install various play equipments, but the care-giver in C-type didn't wanted to install play equipment. 4) The various outdoor play areas were needed in D-type.