• The Journal of the Acoustical Society of Korea
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• v.28 no.1
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• pp.1-9
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• 2009

This paper deals with the realization of multi-channel live karaoke. In this study, 6-channel MP3 decoding and tempo/key scaling was operated in real time by using the TMS320C6713 DSP, which is 32 bit floating-point DSP made by TI Co. The 6 channel consists of front L/R instrument, rear L/R instrument, melody, and woofer. In case of the 4 channel, rear L/R instrument can be replaced with drum L/R channel. And the final output data is generated as adjusted to a 5.1 channel speaker. The SOLA algorithm was applied for tempo scaling, and key scaling was done with interpolation and decimation in the time domain. Drum channel was excluded in key scaling by separating instruments into drums and non-drums, and in processing SOLA, high-quality tempo scaling was made possible by differentiating SOLA frame size, which was optimized for real-time process. The use of 6 channels allows the composition of various channels, and the multi-channel audio system of this study can be effectively applied at any place where live music is needed.

• Journal of Communications and Networks
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• v.1 no.2
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• pp.89-98
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• 1999

In a synchronization (sync) $network^1$containing N nodes, it is shown (Theorem 1c) that an arbitrarily connected sync network & is the union of a countable set of isolated connecting sync networks${&_i,i= 1,2,.., L}, I.E., & = \bigcup_{I=1}^L&_i$ It is shown(Theorem 2e) that aconnecting sync network is the union of a set of disjoint irreducible subnetworks having one or more nodes. It is further shown(Theorem 3a) that there exists at least one closed irreducible subnetwork in $&_i$. It is further demonstrated that a con-necting sync network is the union of both a master group and a slave group of nodes. The master group is the union of closed irreducible subnetworks in $&_i$. The slave group is the union of non-colsed irre-ducible subnetworks in $&_i$. The relationships between master-slave(MS), mutual synchronous (MUS) and hierarchical MS/MUS ent-works are clearly manifested [1]. Additionally, Theorem 5 shows that each node in the slave group is accessible by at least on node in the master group. This allows one to conclude that the synchro-nization information avilable in the master group can be reliably transported to each node in the slave group. Counting and combinatorial arguments are used to develop a recursive algorithm which counts the number $A_N$ of arbitrarily connected sync network architectures in an N-nodal sync network and the number $C_N$ of isolated connecting sync network in &. EXamples for N=2,3,4,5 and 6 are provided. Finally, network examples are presented which illustrate the results offered by the theorems. The notation used and symbol definitions are listed in Appendix A.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.228-233
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• 2005

The protein side-chain packing problem (SCPP) is known to be NP-complete. Various graph theoretic based side-chain packing algorithms have been proposed. However as the size of the protein becomes larger, the sampling space increases exponentially. Hence, one approach to cope with the time complexity is to decompose the graph of the protein into smaller subgraphs. Some existing approaches decompose the graph into biconnected components at an articulation point (resulting in an at-most 21-residue subgraph) or solve the SCPP by tree decomposition (4-, 5-residue subgraph). In this regard, we had also presented a deterministic based approach called as SPWCQ using the notion of maximum edge weight clique in which we reduce SCPP to a graph and then obtain the maximum edge-weight clique of the obtained graph. This algorithm performs well for a protein of less than 500 residues. However, it fails to produce a feasible solution for larger proteins because of the size of the search space. In this paper, we present a new heuristic approach for the side-chain packing problem based on the maximum edge-weight clique finding algorithm that enables us to compute the side-chain packing of much larger proteins. Our new approach can compute side-chain packing of a protein of 874 residues with an RMSD of 1.423${\AA}$.

• Journal of computational fluids engineering
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• v.5 no.1
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• pp.1-7
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• 2000

In general, FDM(finite difference method) and FVM(finite volume method) are used for analyzing the fluid flow numerically. However it is difficult to apply them to problems involving complex geometries, multi-connected domains, and complex boundary conditions. On the contrary, FEM(finite element method) with coordinates transformation for the unstructured grid is effective for the complex geometries. Most of previous studies have used commercial codes such as KIVA or STAR-CD for the flow analyses in the engine cylinder, and these codes are mostly based on the FVM. In the present study, using the FEM for three-dimensional, unsteady, and incompressible Navier-Stokes equation, the velocity and pressure fields in the engine cylinder have been numerically analyzed. As a numerical algorithm, 4-step time-splitting method is used and ALE(arbitrary Lagrangian Eulerian) method is adopted for moving grids. In the Piston-Cylinder, the calculated results show good agreement in comparison with those by the FVM and the experimental results by the LDA.

• Smart Structures and Systems
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• v.20 no.4
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• pp.427-440
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• 2017

One of the suitable structural damage detection methods using vibrational characteristics are damage-index-based methods. In this study, a damage index for identifying damages in plate structures using frequency response function (FRF) data has been provided. One of the significant challenges of identifying the damages in plate structures is high number of degrees of freedom resulting in decreased damage identifying accuracy. On the other hand, FRF data are of high volume and this dramatically decreases the computing speed and increases the memory necessary to store the data, which makes the use of this method difficult. In this study, FRF data are compressed using two-dimensional principal component analysis (2D-PCA), and then converted into damage index vectors. The damage indices, each of which represents a specific condition of intact or damaged structures are stored in a database. After computing damage index of structure with unknown damage and using algorithm of lookup tables, the structural damage including the severity and location of the damage will be identified. In this study, damage detection accuracy using the proposed damage index in square-shaped structural plates with dimensions of 3, 7 and 10 meters and with boundary conditions of four simply supported edges (4S), three clamped edges (3C), and four clamped edges (4C) under various single and multiple-element damage scenarios have been studied. Furthermore, in order to model uncertainties of measurement, insensitivity of this method to noises in the data measured by applying values of 5, 10, 15 and 20 percent of normal Gaussian noise to FRF values is discussed.

• Science of Emotion and Sensibility
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• v.1 no.1
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• pp.69-78
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• 1998

Sleep deprivation may affect the brain functions such as cognition and consequently, dynamics of the BEG. We examined the effects of sleep deprivation on chaoticity of the EEG. Five volunteers were sleep-deprived over a period of 24 hours They were checked by EEG during two days. thc first day of baseline period and the second day of total sleep deprivation period. EEGs were recorded from 16 channels for nonlinear analysis. We employed a method of minimum embedding dimension to calculate the first positive Lyapunov exponent. Fer limited noisy data, this algorithm was strikingly faster and more accurate than previous ones. Our results show that the sleep deprived volunteers had lower values of the first positive Lyapunov exponent at ten channels (Fp1, F4. F8. T4, T5. C3, C4. P3. P4. O1) compared with the values of baseline periods. These results suggested that sleep deprivation leads to decrease of chaotic activity in brain and impairment of the information processing in the brain. We suggested that nonlinear analysis of the EEG before and after sleep deprivation may offer fruitful perspectives for understanding the role if sleep and the effects of sleep deprivation on the brain function.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.27-39
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• 2023

Detecting greenhouses from the remote sensing datasets is useful in identifying the illegal agricultural facilities and predicting the agricultural output of the greenhouses. This research proposed a methodology for automatically detecting greenhouses from a given Planetscope satellite imagery acquired in the areas of Gimje City using the deep learning technique through a series of steps. First, multiple training images with a fixed size that contain the greenhouse features were generated from the five training Planetscope satellite imagery. Next, the YOLO(You Only Look Once) model was trained using the generated training images. Finally, the greenhouse features were detected from the input Planetscope satellite image. Statistical results showed that the 76.4% of the greenhouse features were detected from the input Planetscope satellite imagery by using the trained YOLO model. In future research, the high-resolution satellite imagery with a spatial resolution less than 1m should be used to detect more greenhouse features.

• The Journal of the Korea Contents Association
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• v.4 no.1
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• pp.55-66
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• 2004

Recently, as the personal computers are supplied rapidly, they formed the nucleus of the computer system. But, because of the easiness that anyone uses them to go near easily, it is the fact that the security of personal computer is weakness. So, in the paper, 1 propose the technical method that minimizes the loss and leakage of important data. This paper implemented a crypto system for security of data file on personal computer and assistance storage medium. The way of encryption/decryption is applied by complexity method which mixed Diffie-Hellman key exchange protocol, a typical RC4(Rivest Cipher version 4) algorithm of stream cipher and a typical MD5(Message Digest version 5) of Hash Function. For valuation implemented crypto system, three criteria is presented, which are crypto complexity, processing time and pattern matching. And according to analysis the three criteria the crypto system is verified the security, efficiency and usefulness. The crypto system is programmed with Visual C++ language of Microsoft. And so, as this is software system, we shall have a technical security system at a minimum cost for all personal computer.

• The KIPS Transactions:PartC
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• v.9C no.2
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• pp.293-296
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• 2002

UP Link is One of the commercial product which converts HTML to HDML convertor in order to show the internet www contents in the mobile environments. When UP browser accesses HTML pages, the agent in the UP Link controls the converter to change the HTML to the HDML, I-Mode, which is developed by NTT-Docomo of Japan, has many contents through the long and stable commercial service. Micro Explorer, which is developed by Stinger project, also has many additional function. In this paper, we designed and implemented WAP convertor which can accept C-HTML contents and mHTML contents. C-HTML format by I-Mode is a subset of HTML format, mHTML format by ME is similar to C-HTML, So the content provides can easily develop C-HTML contents compared with WAP and the other case. Since C-HTML, mHTML and WML are used under the mobile environment, the limited transmission capacity of one page is also similar. In order to make a match table. After that, we apply conversion algorithm on it. If we can not find matched element, we arrange some tags which only can be supported by WML to display in the best shape. By the result, we can convert over 90% contents.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4C
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• pp.386-394
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• 2010

In this paper, we propose an adaptive coordinated Tx-Rx beamforming scheme for inter-user interference cancellation, when a BS communicates with multiple users that each has multiple receive antenna. The conventional coordinated Tx-Rx beamforming scheme uses a fixed multi-stream per user regardless of the instantaneous channel states, that is, both user with ill-conditioned and well-conditioned channels have the same number of data streams. However, in the proposed adaptive coordinated Tx-Rx beamforming scheme, we select the number of streams per user to solve the inefficient problem of the conventional coordinated Tx-Rx beamforming. As a result of applying the adaptive coordinated Tx-Rx beamforming scheme, the BER performance is improved. Simulation results show that the proposed algorithm outperforms the conventional coordinated Tx-Rx beamforming algorithm by 2.5dB at a target BER of $10^{-2}$.