• Journal of Communications and Networks
• /
• 제14권4호
• /
• pp.410-417
• /
• 2012

One of the premier mechanisms used in extracting unobserved signals from observed mixtures in signal processing is employing a blind source separation (BSS) algorithm. Orthogonal frequency division multiplexing (OFDM) techniques are playing a prominent role in the sphere of multicarrier communication. A set of remedial solutions taken to mitigate deteriorative effects caused within the air interface of OFDM transmission with aid of BSS schemes is presented. Four energy functions are used in deriving the filter coefficients. Energy criterion functions to be optimized and the performance is justified. These functions together with iterative fixed point rule for receive signal are used in determining the filter coefficients. Time correlation properties of the channel are taken advantage for BSS. It is tried to remove colored noise and jamming components from themixture at the receiver. Themethod is tested in a slow fading channel with a receiver containing equal gain combining to treat the channel state information values. The importance is that, these are quite low computational complexity mechanisms.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 2002년도 하계학술발표대회 논문집 제21권 1호
• /
• pp.9-14
• /
• 2002

We propose a new algorithm for blind source separation (BSS), in which frequency-domain independent component analysis (FDICA) and time-domain ICA (TDICA) are combined to achieve a superior source-separation performance under reverberant conditions. Generally speaking, conventional TDICA fails to separate source signals under heavily reverberant conditions because of the low convergence in the iterative learning of the inverse of the mixing system. On the other hand, the separation performance of conventional FDICA also degrades significantly because the independence assumption of narrow-band signals collapses when the number of subbands increases. In the proposed method, the separated signals of FDICA are regarded as the input signals for TDICA, and we can remove the residual crosstalk components of FDICA by using TDICA. The experimental results obtained under the reverberant condition reveal that the separation performance of the proposed method is superior to that of conventional ICA-based BSS methods.

• Journal of Magnetics
• /
• 제22권1호
• /
• pp.14-22
• /
• 2017

The NMR's probe consists of the static magnetic field generator (magnetic source) and the RF coil. It is very strict for the homogeneity of the static magnetic field intensity of the magnetic source, so the cost of the magnetic source is more expensive in the entire nuclear magnetic resonance instrument. The magnetic source generally consists of electromagnet, permanent magnet and superconducting magnet. The permanent magnet basically needs not to spend on operation and maintenance and its cost of manufacture is much cheaper than the superconducting magnet. Therefore, the permanent magnet may be the only choice for the static magnetic field device if we want to use the magnetic resonance instrument as an analyzer for production by reducing price. A new probe magnet was developed on the basis of the permanent magnet ring in this paper to provide a technological way for reducing the manufacturing cost, weight and volume of the existing nuclear magnetic resonance instrument (including MRI) probe.

• 한국정보통신학회논문지
• /
• 제26권2호
• /
• pp.317-320
• /
• 2022

This paper studies real-time error in the context of monitoring a symmetric binary information source over a delay system. To obtain the average real-time error, the delay system is modeled and analyzed as a discrete time Markov chain with a finite state space. Numerical analysis is performed on various system parameters such as state transition probabilities of information source, transmission times, and transmission frequencies. Given state transition probabilities and transmission times, we investigate the relationship between the transmission frequency and the average real-time error. The results can be used to investigate the relationship between real-time errors and age of information.

• Journal of Information Processing Systems
• /
• 제17권3호
• /
• pp.537-555
• /
• 2021

Many researchers have carried out studies related to programming languages since the beginning of computer science. Besides programming with traditional programming languages (i.e., procedural, object-oriented, functional programming language, etc.), a new paradigm of programming is being carried out. It is programming with natural language. By programming with natural language, we expect that it will free our expressiveness in contrast to programming languages which have strong constraints in syntax. This paper surveys the approaches that generate source code automatically from a natural language description. We also categorize the approaches by their forms of input and output. Finally, we analyze the current trend of approaches and suggest the future direction of this research domain to improve automatic code generation with natural language. From the analysis, we state that researchers should work on customizing language models in the domain of source code and explore better representations of source code such as embedding techniques and pre-trained models which have been proved to work well on natural language processing tasks.

• 한국정보시스템학회지:정보시스템연구
• /
• 제20권4호
• /
• pp.1-22
• /
• 2011

This study addressed trust to collective intelligence for explaining the affecting factors to the intention to use of collective intelligence by dividing the object of trust into a Web site and an information source group. We explored the factors affecting user's continuance intention toward collective intelligence in the view off trust building. We made a well-structured survey of our proposed model and gained 205 cases. We analyzed the proposed research model empirically using partial least square method. The findings are summarized as follows. First, all key factors (relevance, timeless, completeness, understandability) composing of collective intelligence quality have a positive and significant impact on confirmation. Second, confirmation has a significant impact on trust toward a Web site, as well as toward an information source group. The last is that trust toward a Web site influences on continuance intention, whereas trust toward an information source group doesn't.

• Journal of information and communication convergence engineering
• /
• 제18권1호
• /
• pp.22-27
• /
• 2020

Content centric networking (CCN) is regarded as promising internet architecture because it can provide network efficiency in terms of bandwidth consumption by separating contents from a specific network location and decrease network congestion events. However, the application of a CCN does not widely consider the side effects of mobile devices, particularly mobile content sources. For content source mobility, a full routing update is required. Therefore, in this study, a route optimization scheme is proposed for mobile content sources in a CCN environment to provide low communication overhead, short download time, and low resource consumption. The proposed scheme establishes a direct path between content requesters and a mobile content source for the exchange of interest and data packets using interest-piggybacked data packets. Based on the inherent CCN naming characteristics, the content source does not know the name prefix of the content consumer, and thus the proposed optimized CCN scheme utilizes the content router in the home domain of the content source.

• 복식
• /
• 제51권7호
• /
• pp.123-134
• /
• 2001

The purpose of this study to compare the purchasing behaviour of men's business suits, among custom suits, system order, and ready-made suits, centering around the choice of information source, risk perception and benefits sought. The survey of this study was collected from 450 adult male in Seoul. The data was analyzed by factor analysis and ANOVA. The result of this study were as follows : 1. Custom suits, system order, and ready-made suits consumers have a significant difference in the choice of information source. The consumer attaching most importance to the impersonal information source is the system order users, custom suits users, and ready-made suits users respectively. However there was no significant difference in the personal source among 3 different purchasing behaviour of men's suits. 2. For the risk perception, 1) the group who perceived the highest in economic risk is the system order users, followed by custom suits users, and ready-made suits users. 2) the group who perceived performance risk as being the highest concern is the ready-made suits consumers, followed by system order user, and custom suits user. 3) the group who perceived the socio-psychological risk as the highest is the ready-made suits consumers, and followed by custom suits user and system order users. 4) there is no difference among the three groups with respect to the fashionability loss risk. 5) the group of the highest perceiving the useful loss risk is the ready-made suits consumers, and the next is system order users, custom suits users. 6) the group of the highest perceiving the time and convenience loss risk is ready-made suits users, and the next is system order users, custom suits users. 3. For the benefit sought, the group of the highest perceiving the aesthetics is custom suits consumers, and the next is system order users, ready-made suits users.

• Journal of Information Processing Systems
• /
• 제13권3호
• /
• pp.630-642
• /
• 2017

In this paper, we propose the opportunistic non-orthogonal multiple access (NOMA)-based cooperative relaying system (CRS) with channel state information (CSI) available at the source, where CSI for the source-to-destination and source-to-relay links is used for opportunistic transmission. Using the CSI, for opportunistic transmission, the source instantaneously chooses between the direct transmission and the cooperative NOMA transmission. We provide an asymptotic expression for the average achievable rate of the opportunistic NOMA-based CRS under Rayleigh fading channels. We verify the asymptotic analysis through Monte Carlo simulations, and compare the average achievable rates of the opportunistic NOMA-based CRS and the conventional one for various channel powers and power allocation coefficients used for NOMA.

• 한국BIM학회 논문집
• /
• 제5권2호
• /
• pp.19-25
• /
• 2015

The purpose of this study is to design simple BIM query language for visualizing BIM information as the viewpoint of use-cases by using open source viewer cost-effectively. recently, the studies related to the facility management using BIM are being researched world-widely. In this studies, it's important to develop the BIM query to obtain the needed data from BIM database. To implement it, the trends in related studies were reviewed and the open source-based BIM viewer architecture was analyzed. And then the architecture considering the simple BIM Query Language (sBQL) was designed to represent the geometry and property of the BIM database. Lastly, the system by using the proposed sBQL grammar was developed.