• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.5
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• pp.222-228
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• 2010

In this paper, we propose a new approach to noise estimation incorporating spectral deviation with soft decision scheme to enhance the intelligibility of the degraded speech signal in non-stationary noisy environments. Since the conventional noise estimation technique based on soft decision scheme estimates and updates the noise power spectrum using a fixed smoothing parameter which was assumed in stationary noisy environments, it is difficult to obtain the robust estimates of noise power spectrum in non-stationary noisy environments that spectral characteristics of noise signal such as restaurant constantly change. In this paper, once we first classify the stationary noise and non-stationary noise environments based on the analysis of spectral deviation of noise signal, we adaptively estimate and update the noise power spectrum according to the classified noise types. The performances of the proposed algorithm are evaluated by ITU-T P. 862 perceptual evaluation of speech quality (PESQ) under various ambient noise environments and show better performances compared with the conventional method.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.14-14
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• 2017

The discipline of plant breeding is experiencing a renaissance impacting crop improvement as a result of new technologies, however fundamental questions remain for predicting the phenotype and how the environment and genetics shape it. Inexpensive DNA sequencing, genotyping, new statistical methods, high throughput phenotyping and gene-editing are revolutionizing breeding methods and strategies for improving both quantitative and qualitative traits. Genomic selection (GS) models use genome-wide markers to predict performance for both phenotyped and non-phenotyped individuals. Aerial and ground imaging systems generate data on correlated traits such as canopy temperature and normalized difference vegetative index that can be combined with genotypes in multivariate models to further increase prediction accuracy and reduce the cost of advanced trials with limited replication in time and space. Design of a GS training population is crucial to the accuracy of prediction models and can be affected by many factors including population structure and composition. Prediction models can incorporate performance over multiple environments and assess GxE effects to identify a highly predictive subset of environments. We have developed a methodology for analyzing unbalanced datasets using genome-wide marker effects to group environments and identify outlier environments. Environmental covariates can be identified using a crop model and used in a GS model to predict GxE in unobserved environments and to predict performance in climate change scenarios. These new tools and knowledge challenge the plant breeder to ask the right questions and choose the tools that are appropriate for their crop and target traits. Contemporary plant breeding requires teams of people with expertise in genetics, phenotyping and statistics to improve efficiency and increase prediction accuracy in terms of genotypes, experimental design and environment sampling.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.32.1-32.1
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• 2018

Searching for low surface brightness (LSB) dwarf galaxies in low density environments (isolated and group) can help us resolve the discrepancy between observation and theory known as the 'missing satellite' problem. They are also important to study the evolution of low mass galaxies in these environments. Although the number of dwarfs in such environments is rapidly increasing in many recent studies, it is still not easy to characterize their general properties. Motivated by this, we present preliminary results of our search for LSB dwarf galaxies around 60 nearby galaxies (D<50Mpc) using deep optical images. Imaging data from Maidanak Astronomical Observatory (MAO) in Uzbekistan as a part of Intensive Monitoring Survey of Nearby Galaxies (IMSNG; Im in prep.) and other archival data are used to find previously unknown LSB dwarf galaxies. Extended LSB sources (central surface brightness ${\mu}_0$ > $23mag/arcsec^2$) are first selected in the ${\mu}_0$ - magnitude plane (Rines & Geller 2008). The dwarf galaxy candidates are chosen by visual inspection. We discuss whether these candidates are actual satellite galaxies, by measuring the projected number densities in group environments and in the field. Also, their structural and photometric properties are compared with those of previously discovered dwarf galaxies in the literature.

• Journal of Korea Multimedia Society
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• v.3 no.4
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• pp.389-398
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• 2000

The focus of this study is to investigate how personal display system - Head Mounted Display(HMD) and VDU-affect to the body in virtual environments. This prediction was tested by a comparing of playing 3D games while wearing a HMD and monitoring a VDU for an hour. As quantitative measuring and analyzing tools, SSQ, RSSQ, pre and post posture stability test and vision test are used. The results showed that SSQ and RSSQ total score (TS) are related with the results of pre and post posture stability test and SSQ and RSSQ TS of HMD is higher than TS of VDU by one point five times. Especially, TS of MRG3C, having large field of view, has a possibility by two times of simulator sickness (SS). And in order to investigate the degree of SS regarding to the simulator control condition, two conditions, subjective-passive and subjective-active environments were compared. However, there was no significant difference between two environments. The repetition of the same environment has no effect to reduce the SS. Disorientation and oculomotor scores of the SSQ and RSSQ are higher than that of another symptoms. In addition, RSSQ score of strain/confusion is higher than that of nausea. Therefore, we assume that personal fear could possibly increase the simulator sickness in virtual environments.

• Korean Institute of Interior Design Journal
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• v.22 no.5
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• pp.3-10
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• 2013

The principle of aging-in-place should be fundamental in designing post-retirement homes to support baby boomers' healthy aging in their current living conditions. This study investigated Korean-American baby boomers' opinions about their life images in their post-retirement homes and the needs for supportive services therein. A questionnaire survey was conducted, and a total of 247 responses were used for statistical analyses. As the most important life image for their post-retirement homes, baby boomers emphasized the living environments offering various recreational activities. They indicated the post-retirement homes close to their children or family members as the next important life image. These opinions differed depending on their socioeconomic characteristics. In particular, baby boomers with higher-income preferred housing environments offering diverse recreational activities while those with lower-income preferred the housing close to more employment opportunities. In terms of supportive services available in the post-retirement homes, they wanted 'healthcare assistance services' and 'diverse recreational programs.' Gender, educational attainment, and annual income affected their preferences in these services, though. Based on the findings, this study concluded that post-retirement housing environments should create spaces to accommodate various recreational activities and include places for them to work in near-home environments. In the community, various need-based customized recreational activities and educational programs should be planned considering different socioeconomic characteristics of baby boomers. All these considerations will provide supportive residential environments for their successful aging in place.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.617-628
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• 2005

The services for ubiquitous computing environments have to provide automatically user-specific adaptive services in dynamically changed environments with many informations provided by both a user and his/her environment. Workflows used in business and distributed computing environments support service automation by connecting many tasks with rules or orderings of tasks. Therefore we must specify context information on transition condition to support context-aware services by adapting a workflow to ubiquitous computing environments. In this paper, we present a structural context model to specify context information on transition constraints of the workflow. And we propose an uWDL Ubiquitous Workflow Description Language) based on web services, which provides web service interfaces which are standardized and independent on heterogeneous and various platforms, protocols, and languages. The uWDL tan be interpreted and executed by a workflow engine, and provide users autonomic services based on context-awareness.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.1
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• pp.80-85
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• 2009

The performance of the robot is very limited in the conventional model-based control methods when the environments around a robot are not structured or are varying dynamically. The reason for that is the methods are based on the model of the environments which is very difficult to match with the real environments and on a path planning which is complex and time-consuming. On the other hand, the behavior-based control methods are not dependant on the model of the environments nor a complex planning. In those methods, a specific behavior is coupled with a specific sensor output, so the response of a robot is quite reactive and timely in dynamic and unstructured environments. In this thesis, we propose a situation dependant behavior based control architecture, in which a robot may behave differently to the same sensor output depending on various situations. We also show some experimental results to show the feasibility of the proposed control architecture.

• The Journal of the Korea Contents Association
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• v.7 no.6
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• pp.154-160
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• 2007

The 'spatial sense' means an intuitive feel for one's surroundings and the objects in them. The early childhood is an important period to develop the 'spatial sense'. For young children, motion is a major way of extending their spatial awareness. Consequently, an important step in spatial sense instruction involves getting the children moving. This paper proposes four motion based-contents for improving the spatial sense of young children: a bubble game, a cyber goalkeeper game, a mud-huddle game, and a shape recognition game, The proposed four games are implemented to the virtual learning environments. Also, the virtual learning environments utilize the realistic interfaces which can recognize motions of young children and then interact with the games as they do the movement at the virtual environments provided. Using the realistic interfaces not only develops young children's spatial sense but also offers them the pleasure and interest of self-study.

• Journal of the Korea Society of Computer and Information
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• v.12 no.4
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• pp.53-59
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• 2007

A navigation system for virtual environments using low-qualify HMD(head mounted display) must quantize images when the system presents true-color image with restricted number of colors. Such navigation system quantizes an image by using fixed palette. If the system represents an image by using a variable palette which is made considering a region around the viewpoint then user can perceive a virtual environments more vividly because human visual system is sensitive to the colors variation in the region around the viewpoint. In this paper we propose a color quantization algorithm that quantize a region around the viewpoint more finely than other regions at each variation of viewpoint for virtual environments navigation system and compose virtual environments navigation system using proposed algorithm. The system quantizes an image at each variation of viewpoint and shows a quantized image to user through HMD. We tested user preferences for our proposed system and the results show that users preferred our system.

• School Mathematics
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• v.13 no.1
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• pp.107-125
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• 2011

In this paper, we investigated how the GSP environments impact students' conjecturing of geometric properties. And we wanted to draw some implication in teaching and learning geometry in dynamic geometric environments. As results, we conclude that when students were given the problem situations which almost has no condition, they were not successful, and rather when the problem situations had appropriate conditions students were able to generate many conditions which were not given in the original problem situations, and consequently they were more successful in conjecturing geometric properties. And the geometric properties conjectured in GSP environments are more complex and difficult to prove than those in paper and pencil environments. Also the function of moving screen with 'Alt' key is frequently used in conjecturing geometric properties with functions of measurement and calculation of GSP. And students felt happier when they discovered geometric properties than when they could prove geometric properties.