Tenan, South Korea
Tenan, South Korea

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Lee H.-W.,Namseoul University
Journal of Convergence Information Technology | Year: 2012

This paper describes convergence behaviors of acoustic echo canceller with BSS(blind signal separation). Acoustic echo canceller may be deteriorated or diverged during double-talk period. So we use BSS technology to estimate the near-end signal and to get the error signal which is eliminated the near-end signal from the residual signal. We assume that the near-end path is a single channel and the acoustic echo path is multi-channel. And we use a copy of coefficients of the echo canceller for the mixing coefficients of the multi-channel. The blind signal separation method extracts the near-end signal from dual microphones by iterative computations with 2nd-order statistical character in the closed reverberation environment. The acoustic echo canceller using this method operates irrespective of double-talking. We analyzed convergence behaviors of the BSS method inside the acoustic echo canceller. The results show that the BSS technology by iterative computation converges stably, irrelevantly to the echo canceller.


Lee H.-W.,Namseoul University
Journal of Convergence Information Technology | Year: 2012

This paper describes an acoustic echo canceller with BSS(blind signal separation) for doubletalking. Acoustic echo canceller may be deteriorated or diverged during double-talk period. So we use BSS technology to estimate the near-end signal and to get the error signal which is eliminated the near-end signal from the residual signal. We assume that the near-end path is single channel and the acoustic echo path is multi-channel. And we use a copy of coefficients of the echo canceller for the mixing coefficients of the multi-channel. The blind signal separation method extracts the near-end signal from dual microphones by iterative computations with 2nd-order statistical character in the closed reverberation environment. The acoustic echo canceller using this method operates irrespective of double-talking. We verified performances of the proposed acoustic echo canceller by simulations. The results show that the acoustic echo canceller with this method improves ERLE(echo return loss enhancement) of more about 20dB than the normal echo canceller, and operates stably without a divergence of coefficients even double-talk period.


Shin Y.,Namseoul University
Communications in Computer and Information Science | Year: 2012

Considering national greenhouse gas emissions extract from buildings(25%) and transportation(17%), it is important to construct environmentally friendly city that is for modern human life. Urban planning method using TOD as an element of city planning scheme that is proposing sustainable built environment is a key element of low carbon and green city by interconnecting public transit and land use plan to cause high density development around station influence area. The purpose of this study is to explore TOD city revitalization method focusing on Toyama railway station & Surroundings area in Japan in order to find applicable measures in Korea. In Toyama, there are some projects like a revitalization plan of new city center, activation of public transportation, and downtown inhabitation warning project which are developed by effective transportation link with Toyama Railway Station. From this on, it's an important compound to be recognized as an element of urban facilities. © 2012 Springer-Verlag.


Choi S.,Namseoul University
Journal of Computer Virology and Hacking Techniques | Year: 2015

The growing company that provides high quality service to every customer by introducing a cloud system organization. However, the information needs diverse and different cloud systems, so every cloud system can act as a security system that provide appropriate cloud systems. Cloud services are becoming complicated and diversified depending on concerns about cloud security continues, the growing need of professionalism held by the cloud service (CSB : cloud service brokerage) companies. Thus, to analyze the various services, find my support legislation to solve, security and delete compatibility issues, the services of the best new business through service offerings tailored to the environment, and will implement the necessary management services which which is brokerage (CSB). This study presents a brokerage (CSB) development model, and suggests policy measures that apply to the co-operation that I am having difficulties in cloud service business models. © 2015, Springer-Verlag France.


Lee S.,Inha Technical College | Lee B.-J.,Namseoul University
Surface and Coatings Technology | Year: 2012

In the present work, we report the formation of residual oxide layer during chemical-mechanical-planarization (CMP) process in the carbon nanotube (CNT) via interconnects and some feasible solutions for its removal. Residual oxide layer makes electrically poor contact between CNTs and metal resulting in high contact resistance in CNT via interconnects. We adopt post-CMP processes such as hydrofluoric acid (HF) or Ar plasma treatment to remove the residual oxide layer. X-ray photoelectron spectroscopy (XPS) was used to confirm the chemical state of samples before and after the post-CMP process. Silicon and oxygen peaks from silicon-based oxide layer observed after the CMP process were disappeared and reduced in its intensity by the post-CMP process, respectively. Furthermore, via resistance decreased more than 1 order of magnitude after the post-CMP process. It is found that the post-CMP process provides good electrical contact between CNTs and metal by removing the residual oxide layer. © 2011 Elsevier B.V.


Kim J.-G.,Namseoul University
2011 International Conference on Information Science and Applications, ICISA 2011 | Year: 2011

The expansion of the Internet has made web applications become a part of everyday life. As a result the number of incidents which exploit web application vulnerabilities are increasing. A large percentage of these incidents are SQL Injection attacks which are a serious security threat to databases with potentially sensitive information. Therefore, much research has been done to detect and prevent these attacks and it resulted in a decline of SQL Injection attacks. However, there are still methods to bypass them and these methods are too complex to implement in real web applications. This paper proposes a simple and effective SQL Query removal method which uses Combined Static and Dynamic Analysis and evaluates the efficiency through various experiments. © 2011 IEEE.


Park W.,Seoul National University | Park S.,Namseoul University
Ergonomics | Year: 2013

Despite the prevalence of obesity and overweight, anthropometric characteristics of large individuals have not been extensively studied. This study investigated body shapes of large persons (Broca index ≥ 20, BMI ≥ 25 or WHR>1.0) using stature-normalised body dimensions data from the latest South Korean anthropometric survey. For each sex, a factor analysis was performed on the anthropometric data set to identify the key factors that explain the shape variability; and then, a cluster analysis was conducted on the factor scores data to determine a set of representative body types. The body types were labelled in terms of their distinct shape characteristics and their relative frequencies were computed for each of the four age groups considered: the 10s, 20s-30s, 40s-50s and 60s. The study findings may facilitate creating artefacts that anthropometrically accommodate large individuals, developing digital human models of large persons and designing future ergonomics studies on largeness. Practitioner Summary: This study investigated body shapes of large persons using anthropometric data from South Korea. For each sex, multivariate statistical analyses were conducted to identify the key factors of the body shape variability and determine the representative body types. The study findings may facilitate designing artefacts that anthropometrically accommodate large persons. © 2013 Copyright Taylor and Francis Group, LLC.


This paper proposes an inference methodology that can minimize the spreading effect caused by the occurrence of a feeder fault, a feeder overload, a main transformer fault, or a main transformer overload problem in a distribution system under a heavy load condition. First, the load transfer procedure is decomposed into multisteps and multistages. Then, a new inference methodology for searching the goal nodes as well as the fail nodes based on the local minimum tree search is developed. © 2012 IEEE.


Provided are a method of growing carbon nanotubes laterally, including forming catalyst dots to grow carbon nanotubes on a substrate, forming a sacrificial layer including a plurality of nanochannels including regions having the catalyst dots formed therein, and growing carbon nanotubes through the nanochannels, and a field effect transistor using the method.


Provided are a method of growing carbon nanotubes laterally, including forming catalyst dots to grow carbon nanotubes on a substrate, forming a sacrificial layer including a plurality of nanochannels including regions having the catalyst dots formed therein, and growing carbon nanotubes through the nanochannels, and a field effect transistor using the method.

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