• Management & Information Systems Review
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• v.3
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• pp.15-45
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• 1999

Processing techniques of remote sensed image data using computer have been recognized very necessary techniques to all social fields, such as, environmental observation, land cultivation, resource investigation, military trend grasp and agricultural product estimation, etc. Especially, accurate classification and analysis to remote sensed image da are important elements that can determine reliability of remote sensed image data processing systems, and many researches have been processed to improve these accuracy of classification and analysis. Traditionally, remote sensed image data processing systems have been processed 2 or 3 selected bands in multiple bands, in this time, their selection criterions are statistical separability or wavelength properties. But, it have be bring up the necessity of bands selection method by data distribution characteristics than traditional bands selection by wavelength properties or statistical separability. Because data sensing environments change from multispectral environments to hyperspectral environments. In this paper for efficient data classification in multispectral bands environment, a band feature extraction method using the Rough sets theory is proposed. First, we make a look up table from training data, and analyze the properties of experimental multispectral image data, then select the efficient band using indiscernibility relation of Rough set theory from analysis results. Proposed method is applied to LANDSAT TM data on 2 June 1992. From this, we show clustering trends that similar to traditional band selection results by wavelength properties, from this, we verify that can use the proposed method that centered on data properties to select the efficient bands, though data sensing environment change to hyperspectral band environments.

• International Journal of Contents
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• v.4 no.4
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• pp.18-23
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• 2008

With the development of information communication and network technologies, ubiquitous era that supports various services regardless of places and time has been advancing. The development of such technologies has a great influence on educational environments. As a result, e-learning concepts that learners use learning contents in anywhere and anytime have been proposed. The various learning contents authoring systems that consider the e-learning environments have also been developed. However, since most of the existing authoring systems support only PC environments, they are not suitable for various ubiquitous mobile devices. In this paper, we design and implement a contents authoring system based on learning activities for u-learning environments. Our authoring system significantly improves the efficiency for authoring contents and supports various ubiquitous devices as well as PCs.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.5
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• pp.457-463
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• 2006

Recently proposed control scheme for a stable teleoperation, which was based on two-port time-domain passivity approach[21], has been successful for a contact with high stiffness environments. However, we found several conservatisms during the contact with deformable environments and unconstrained motion. The two-port time-domain passivity controller was excessively dissipating energy even though it was not necessary for some cases of an unconstrained motion and soft contact. The main reason of those conservatisms was on the fact that the two-port time-domain passivity controller was activated without considering the amount of energy dissipation at the master and slave manipulators. Especially, the exclusion of the slave manipulator from the two-port was the dominant reason of the conservatisms. In this paper, we consider the amount of energy dissipation at slave manipulator for designing the time-domain passivity observer and controller. The measured interaction force between slave manipulator and environment allow the time-domain passivity observer to include the amount of energy dissipation at the slave manipulator. Based on the modified passivity observer, reference energy following method[24] is applied to satisfy the passivity condition in real-time. The feasibility of the developed methods is proved with experiments. Improved performance is obtained for an interaction with deformable environments and an unconstrained motion.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.75-82
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• 2012

In order to enable network robots to effectively collaborate with smart environments, it is crucial that various types of heterogeneous device platforms can communicate each other in flexible and efficient manners. Most of existing software platforms for network robots adopted general-purpose middlewares such as CORBA, which are not suitable to the communication between robots and smart environments due to their heavy size and complexity. Moreover, they do not provide network robot-specific features. Therefore, we propose a new TCP-based Remote Method Invocation framework. We devide the middleware into two layers i. e. transport layers and rmi layers and provide key features to each layer so that network robots can effectively communicate with various devices in smart environments.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.568-580
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• 1997

In this paper we evaluate the performances of two types of 16-QAM system such as square QAM and star QAM. First we analyze the performances of QAM systems under AWGN(adaptive white Gaussian noise) and afterward analyze the performances under fading environments. The performances of QAM systems in case of using the PSAM(Pilot Symbol Assisted Modulation) are finally evaluated under fading environments. In conclusion, the Square QAM's performance is better than star QAM in AWGN. But the performances of the both QAM systems are very poor under the fading environments. QAM performance using the PSAM system is verified to be improved in that case, and the star QAM's performance is better than square QAM.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.648-651
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• 2002

In data broadcast environments, data is disseminated from a small number of sewers to a much larger number of clients. The advancing technology of hardware and increasing needs of users' have extended a broadcast environments. A mobile environment use the data broadcasting. A user carrying a portable computer can submit the operations of a transaction. Some limitations such as the poor-resource, user mobility, and low bandwidth are difficult to apply traditional transaction management to the mobile environments. So, the new mechanisms are needed and one of the them is the correctness criteria of transactions. Serializability is the most used criteria, but serializability is not appropriate to the broadcast environment because unnecessary abort and additional message exchanges are occurred. Hence, in this paper, we will address the need of the new correctness criteria weaker than serializability and describe the adoption of the update consistency.

• The KIPS Transactions:PartD
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• v.11D no.3
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• pp.533-544
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• 2004

Reports have a significant meaning in time-constrained large transaction environments, such as airplane control systems or wargame simulations. This is due to the necessity of generating reports within a given time limit without restraining the operation performance of large transaction environments. In order to generate reports in large transaction environments while satisfying time-constrained requirements, this paper proposes a model which combines the incremental operation mechanism and materialized view mechanism using triggers and stored procedures. Further, the implementation and evaluation of the proposed model provides the Identification of the characteristics of the proposed model.

• Journal of Environmental Health Sciences
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• v.33 no.3
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• pp.180-183
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• 2007

Over the last century the mercury (Hg) concentration in the environment has been increased by human activities with inputs from sources such as atmospheric deposition, urban runoff, and industrial effluents. Mercury can be transformed to methylmercury (MeHg) in anaerobic conditions by sulfate reducing bacteria (SRB) and sediments are the principal location for MeHg production in aquatic environments. Interest in bioaccumulation of Hg and MeHg into lower trophic levels of benthic and pelagic organisms stems from public health concerns as these organisms provide essential links for higher trophic levels of food chains such as fish and larger invertebrates. Fish consumption is the major exposure route of MeHg to humans. Recently, it was reported that blood samples in Korea showed much higher Hg levels (5-8 times) than those in USA and Germany. Although this brings much attention to Hg research in Korea, there are very few studies on Hg biogeochemical cycling and bioaccumulation in aquatic environments. Given the importance of Hg methylation and MeHg transfer through food chains in aquatic environments, it is imperative that studies should be done in much detail looking at the fate, transport, and bioaccumulation of Hg and MeHg in the environment. Moreover, there should be long-term monitoring plans in Korea to evaluate the environmental and health effects of Hg and MeHg.

• International Journal of High-Rise Buildings
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• v.7 no.2
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• pp.111-125
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• 2018

By the year 2050, the world population is set to increase to 9 billion people, of which 66% will be living in cities. It is argued that this will inevitably lead to further urban densification and soaring, inhumane and dense vertical environments. However, innovative and disruptive technologies impacting all realms of life means that we will also live, work, play, learn and make in novel ways, the beginnings of which are already becoming evident. These present opportunities for reimagining city environments, and in particular tall buildings, with a focus on reducing redundancies and re-appropriating existing buildings, creating novel hybrid environments, incorporating green and social democratic spaces, and integrating multiple modes of transport. This paper examines how vertical cities may perhaps be dense, resource efficient, and yet humane, presenting three possible scenarios for Singapore's context, which are, however, common to many Asian high-density urban environments. The scenarios presented are the outcome of Final-Year Thesis Projects undertaken by final-year architecture students at the National University of Singapore (NUS) in 2017.

• ETRI Journal
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• v.37 no.3
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• pp.606-616
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• 2015

In this paper, we propose a novel method for road recognition using 3D point clouds based on a Markov random field (MRF) framework in unstructured and complex road environments. The proposed method is focused on finding a solution for an analysis of traversable regions in challenging environments without considering an assumption that has been applied in many past studies; that is, that the surface of a road is ideally flat. The main contributions of this research are as follows: (a) guidelines for the best selection of the gradient value, the average height, the normal vectors, and the intensity value and (b) how to mathematically transform a road recognition problem into a classification problem that is based on MRF modeling in spatial and visual contexts. In our experiments, we used numerous scans acquired by an HDL-64E sensor mounted on an experimental vehicle. The results show that the proposed method is more robust and reliable than a conventional approach based on a quantity evaluation with ground truth data for a variety of challenging environments.