• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.4
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• pp.618-632
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• 2010

This paper presents a novel approach to control the augmented reality (AR) objects robustly in a marker-less AR system by fingertip tracking and hand pattern recognition. It is known that one of the promising ways to develop a marker-less AR system is using human's body such as hand or face for replacing traditional fiducial markers. This paper introduces a real-time method to manipulate the overlaid virtual objects dynamically in a marker-less AR system using both hands with a single camera. The left bare hand is considered as a virtual marker in the marker-less AR system and the right hand is used as a hand mouse. To build the marker-less system, we utilize a skin-color model for hand shape detection and curvature-based fingertip detection from an input video image. Using the detected fingertips the camera pose are estimated to overlay virtual objects on the hand coordinate system. In order to manipulate the virtual objects rendered on the marker-less AR system dynamically, a vision-based hand control interface, which exploits the fingertip tracking for the movement of the objects and pattern matching for the hand command initiation, is developed. From the experiments, we can prove that the proposed and developed system can control the objects dynamically in a convenient fashion.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.231-239
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• 2006

For such large-scale software as for operating a switching system, the use of real-time databases is essential for data exchanges among various functions and their data processing. Under the environment of developing the DBMS software for a switching system, the application program including database manipulations is first developed on a host computer and then the developed program is loaded into a switching system for its tests. To make it possible for DBMS manipulation software to be developed on a host computer rather than a switching system itself, we developed a host-based DBMS simulation system(HDBMS). In this paper we presented the roles and functions of HDBMS, its system structure, and the technical details for implementing HDBMS.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.360-370
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• 2012

Current ecological knowledge of methanotrophic biofilms is incomplete, although they have been broadly studied in biotechnological processes. Four individual DNA samples were prepared from a methanotrophic biofilm, and a multiplex 16S rDNA pyrosequencing was performed. A complete library (before being de-multiplexed) contained 33,639 sequences (average length, 415 nt). Interestingly, methanotrophs were not dominant, only making up 23% of the community. Methylosinus, Methylomonas, and Methylosarcina were the dominant methanotrophs. Type II methanotrophs were more abundant than type I (56 vs. 44%), but less richer and diverse. Dominant non-methanotrophic genera included Hydrogenophaga, Flavobacterium, and Hyphomicrobium. The library was de-multiplexed into four libraries, with different sequencing efforts (3,915 - 20,133 sequences). Sorrenson abundance similarity results showed that the four libraries were almost identical (indices > 0.97), and phylogenetic comparisons using UniFrac test and P-test revealed the same results. It was demonstrated that the pyrosequencing was highly reproducible. These survey results can provide an insight into the management and/or manipulation of methanotrophic biofilms.

• Korean Journal of Remote Sensing
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• v.20 no.1
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• pp.47-55
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• 2004

We have constructed a level-1 processor to generate brightness temperatures using the direct-broadcast data from the passive microwave radiometer onboard Aqua satellite. Although 50-minute half-orbit data, called a granule, are being routinely produced by global data centers, to our knowledge, this is the first attempt to process 10-minute long direct-broadcast (DB) data. We found that the processor designed for a granule needs modification to apply to the DB data. The modification includes the correction to path number, the selection of land mask and the manipulation of dummy scans. Pixel-to-pixel comparison with a reference indicates the difference in brightness temperature of about 0.2 K rms and less than 0.05 K mean. The difference comes from the different length of data between 50-minute granule and about 10-minute DB data. In detail, due to the short data length, DB data do not always have correct cold sky mirror count. The DB processing system is automated to enable the near-real time generation of brightness temperatures within 5 minutes after downlink. Through this work, we would be able to enhance the use of AMSR-E data, thus serving the objective of direct-broadcast.

• Journal of the Ergonomics Society of Korea
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• v.15 no.2
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• pp.165-176
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• 1996

Hand posture and force, which define aspects of the way an object is grasped, are features of robotic manipulation. A means for specifying these grasping "flavors" has been developed that uses an instrumented glove equipped with joint and force sensors. The new grasp specification system is being used at the Pennsylvania State University (Penn State) in a Virtual Reality based Point-and-Direct (VR-PAD) robotics implementation. In the Computer Integrated Manufacturing (CIM) Laboratory at Penn State, hand posture and force data were collected for manipulating bricks and other items that require varying amounts of force at multiple pressure points. The feasibility of measuring desired grasp characteristics was demonstrated for a modified Cyberglove impregnated with FSR (Force Sensitive Resistor) pressure sensors in the fingertips. A joint/force model relating the parameters of finger articulation and pressure to various lifting tasks was validated for the instrumented "wired" glove. Operators using such a modified glove may ultimately be able to configure robot grasping tasks in environments involving hazardous waste remediation, flexible manufactruing, space operations and other flexible robotics applications. In each case, the VR-PAD approach improved the computational and delay problems of real-time multiple- degree-of-freedom force feedback telemanipulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.41-43
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• 2021

Robot Operating System (ROS) has been a prominent and successful framework used in robotics business and academia.. However, the framework has long been focused and limited to navigation of robots and manipulation of objects in the environment. This focus leaves out other important field such as speech recognition, vision abilities, etc. Our goal is to take advantage of ROS capacity to integrate additional libraries of programming functions aimed at real-time computer vision with a depth-image camera. In this paper we will focus on the implementation of an upgraded vision with the help of a depth camera which provides a high quality data for a much enhanced and accurate understanding of the environment. The varied data from the cameras are then incorporated in ROS communication structure for any potential use. For this particular case, the system will use OpenCV libraries to manipulate the data from the camera and provide a face-detection capabilities to the robot, while navigating an indoor environment. The whole system has been implemented and tested on the latest technologies of Turtlebot3 and Raspberry Pi4.

• The Transactions of the Korea Information Processing Society
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• v.5 no.8
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• pp.2061-2074
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• 1998

In pattern recognition and image analysis upplications, a graph is a useful tool for complex obect representation and recognition. However it takes much time to pair proper nodes between the prototype graph and an input data graph. Futhermore it is difficult to decide whether the two graphs in a class are the same hecause real images are degradd in general by noise and other distortions. In this paper we propose a matching algorithm using a matrix. The matrix is suiable for simple and easily understood representation and enables the ordering and matching process to be convenient due to its predefined matrix manipulation. The nodes which constitute a gaph are ordered in the matrix by their geometrical positions and this makes it possible to save much comparison time for finding proper node pairs. for the classification, we defined a distance measure thatreflects the symbo's structural aspect that is the sum of the mode distance and the relation distance; the fornet is from the parameters describing the node shapes, the latter from the relations with othes node in the matrix. We also introduced a subdivision operation to compensate node merging which is mainly due t the prepreocessing error. The proposed method is applied to the recognition of musteal symbols and the result is given. The result shows that almost all, except heavily degraded symbols are recognized, and the recognition rate is approximately 95 percent.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3C
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• pp.398-407
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• 2004

In this paper, a blind watermarking method which is suitable to the video compression using 2-D discrete wavelet transform was proposed and implemented into the hardware using VHDL(VHSIC Hardware Description Language). The goal of the proposed watermarking algorithm is the authentication about the manipulation of the watermark embedded image and the detection of the error positions. Considering the compressed video image, the proposed watermarking scheme is unrelated to the quantization and is able to concurrently embed or extract the watermark. We experimentally verified that the lowest frequency subband(LL4) is not sensitive to the change in the spatial domain, so LL4 subband was selected for the mark space. And the combination of the bitplanes which has the properties of both the minimum degradation of the image and the robustness was chosen as the embedded Point in the mark space in LL4 subband. Since we know the watermark embedded positions and the watermark is embedded by not varying the value but changing the value, the watermark can be extracted without the original image. Also, for the security when exposing the watermark embedded position, we embed the encrypted watermark by the block cipher. The proposed watermark algorithm shows the robustness against the general image manipulation and is easily transplanted into the image or video compressor with the minimal changing in the structure. The designed hardware has 4037 LABs(24％) and 85 ESBs(3％) in APEX20KC EP20K400CF672C7 FPGA of Altera and stably operates in 82MHz clock frequency.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.11
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• pp.497-508
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• 2008

Mobile Multimedia File System, MNFS, is a file system which extensively exploits NAND FLASH Memory, Since general Flash file systems does not precisely meet the criteria of mobile devices such as MP3 Player, PMP, Digital Camcorder, MNFS is designed to guarantee the optimal performance of FLASH Memory file system. Among many features MNFS provides, there are three distinguishable characteristics. MNFS guarantees, first, constant response time in sequential write requests of the file system, second, fast file system mounting time, and lastly least memory footprint. MNFS implements four schemes to provide such features, Hybrid mapping scheme to map file system metadata and user data, manipulation of user data allocation to fit allocation unit of file data into allocation unit of NAND FLASH Memory, iBAT (in core only Block Allocation Table) to minimize the metadata, and bottom-up representation of directory. Prototype implementation of MNFS was tested and measured its performance on ARM9 processor and 1Gbit NAND FLASH Memory environment. Its performance was compared with YAFFS, NAND FLASH File system, and FAT file system which use FTL. This enables to observe constant request time for sequential write request. It shows 30 times faster mounting time to YAFFS, and reduces 95% of HEAP memory consumption compared to YAFFS.

• Journal of The Korean Association For Science Education
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• v.34 no.3
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• pp.295-301
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• 2014

The purpose of this study is to investigate the difficulties of teachers and students on the unit about 'measuring weight.' In this research, we have acquired data about teachers through survey, interview, and self-reflection journals, at the same time we have collected information on the students through survey, assessment test, and interview. We have extracted the difficulties from analysis with constant comparison method. In addition, we have analysed the curriculum of science and mathematics to know the leaning sequence. The analysis had been checked up by experts in science education. The result of the study is as follows: The difficulties of teachers are from the lack of teachers' descriptive knowledge, disorder of conceptual hierarchy in the curriculum, poor experimental instruments, and low psychomotor skill of students. The difficulties of students are from common misconceptions, opaque concepts, lack of manipulation skill, insufficiency of mathematical ability, difficulty of application of principles to the real situation, and lack of problem-solving ability. In addition, teachers have recognized that students face more difficulties in experiment class, while students think that they face more difficulties in conceptual understanding class.