• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.4 s.23
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• pp.102-109
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• 2005

In this paper, we propose a new listen-in technique to overcome the problems and the shortcomings which could possibly meet in the previous listen-in methods to deal with the blind signal manually according to operator's decision. In the proposed listen-in method, receiving the signals, classifying the modulation types, and demodulating the signals can be done automatically without operator's intervention. We realize the listen-in technology by developing the high speed frequency tuner, the automatic modulation recognizer, and the signal demodulator. In conclusion, we confirm and show that the developed equipment has a good performance in classifying the modulation type through the computer simulation and the field test.

• Journal of Internet Computing and Services
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• v.8 no.2
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• pp.43-54
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• 2007

The effective power consumption is the primary issue in a sensor network which consists of the sensor nodes with limited battery power. So, most of the MAC protocols in sensor networks have been designed with the consideration of energy efficiency. Generally, these protocols make use of the listen and sleep mode periodically. However, this approach inevitably causes a long transmission delay on the data forwarding path, which is mainly resulted from the sleep time of the receiver node. This paper deals with a design of DT-MAC(Data Transmission centric MAC) protocol, with minimizes the data transmission delay while it forces each node to consume its energy efficiently. Thus, a node received a packet converts its remained sleep time to the pseudo_listen time, in which the node is able to transmit a packet. With benefit of the pseudo_listen period, the data transmission delay along with the data forwarding path will be shortened as much as it possible. Therefore, DT-MAC protocol is very suitable to the various applications which require a real time sensing data such as disaster and fire alarm.

• Journal of IKEEE
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• v.23 no.1
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• pp.91-98
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• 2019

LTE's extension for unlicensed spectrum called Licensed Assisted Access (LAA) is equipped with Listen-Before-Talk (LBT) designed similar with the backoff mechanism of Wi-Fi for coexistence. However, Wi-Fi's backoff mechanism has not evolved from its old design for compatibility with legacy devices, thus LAA's LBT is not efficient either in utilizing spectrum. If LAA operates with no Wi-Fi systems in proximity, it can run more efficient LBT. In this paper, we propose Narrowband Clear Channel Assessment (NCCA) for narrowband transmission. In NCCA, an LAA node performs LBT in either wide or each narrow bandwidth segment. This allows multiple LAA nodes to perform simultaneous transmissions in orthogonal bandwidth segments in the same time slot. We design four variants of NCCA implementation and model their performance using a mathematical model. The coexistence performance of NCCA with conventional wideband nodes and the accuracy of the model are shown via simulation.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10c
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• pp.267-271
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• 2007

디지털 카메라의 보급과 U.C.C. 개념의 등장으로 인하여 개인이 생산하는 사진의 양도 많아지고, 이를 감상하는 시간도 많아졌다. 사진이란 추억을 회상하는데 하나의 포인트 역할을 하는 매체이다. 따라서 인간의 감성적인 부분을 많이 자극되는데, 이 과정에서 추가적인 자극을 줌으로써 사용자의 감성을 더욱 자극할 수 있다. 하지만, 기존의 연구들은 디지털 사진을 검색하고 관리하는데 초점이 맞추어져 있었다. 본 논문에서는 사용자가 사진 앨범을 감상할 때에 개별 사진을 분석하여 전체 사진과 가장 잘 어울리는 배경음악을 추천/재생하는 ListenPhoto 시스템을 제안한다. 그리고, 시스템의 필요성에 대한 평가와 시스템 성능에 대한 평가 두 부분으로 나누어 평가를 진행하였다. 사용자들은 이 시스템을 통하여 풍부하게 디지털 사진 생활을 즐길 수 있게 될 것이다.

• MALSORI
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• no.57
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• pp.1-14
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• 2006

This study examines personal factors that affect Korean speakers' English pronunciation. Personal factors which are examined here are as follows: personality type, cognitive system, motivational orientation type, interest in English, how often they listen to tapes, and academic achievements. Data were collected through MBTI (Myers Briggs Type Indicator) Test, Group Embedded Figural Test, and a Questionnaire. The participants consisted of 65 college students. All the results were statistically analyzed: Korean students' personality type and cognitive system are not related with their pronunciation, but motivational orientation type, how often they listen to tapes, academic achievements, and interest in English study are correlated with their pronunciation.

• RED RIBBON
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• s.28
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• pp.12-14
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• 1999

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7B
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• pp.706-718
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• 2002

In bluetooth system, there are two kinds of interference. One is the frequency static interference, for example 802.11 direct sequence, the interferer uses fixed frequency band. Another is frequency dynamic interference, for example other piconets or 802.11 frequency hopping, the interferer uses dynamic frequency channel and cant be estimated. In this paper we introduce a novel solution of hybrid method of Listen-Before-Talk (LBT) and Adaptive Frequency Hopping (AFH) to address the coexistence of bluetooth and Direct Sequence of wireless local area network (WLAN). Before any bluetooth packet transmission, in the turn around time of the current slot, both the sender and receiver sense the channel whether there is any transmission going on or not. If the channel is busy, packet transmission is withdrawn until another chance. This is the LBT in Bluetooth. Because of asymmetry sense ability of WLAN and bluetooth, AFH is introduced to combat the left front-edge packet collisions. In monitor period of AFH, LBT is performed to label the channels with static interference. Then, all the labeled noisy channels are not used in the followed bluetooth frequency hopping. In this way, both the frequency dynamic and frequency static interference are effectively mitigated. We evaluate the solution through packet collision analysis and a detail realistic simulation with IP traffic. It turns out that the hybrid method can combat both the frequency dynamic and frequency static interference. The packet collision analysis shows it almost doubles the maximal system aggregate throughput. The realistic simulation shows it has the least packet loss.

• CELLMED
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• v.6 no.3
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• pp.20.1-20.3
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• 2016

Changbu-taryung has long been known as a one of the best folksong in Korea. There had been no report for music therapy on stress management. The purpose of this article debates that Changbu-taryung may has beneficial effect on stress management. As a wonderful food can make people recover of disease, listen to delightful music can be a healthy way of healing our emotions. People tend to listen to glad music when they want to progress their mood because peculiar qualities comprised in that music entertain us and promote emotional state. Tae-yong Jeon is a creative destroyer and an out-of-box singer on Changbu-taryung. He has a good command of melody and rhythm. And he was singing with diverse and sweet tunes. That is where he is at his strongest. He rejected the conventional singing that would confine him to particular skill. As if he does enjoy the pleasure of his own cooking. The author recommend you listen to delightful and shapeshifter music when you often feel stressed out. This article indicates that Changbu-taryung may have beneficial effect on stress management.

• Speech Sciences
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• v.14 no.3
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• pp.21-29
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• 2007

The necessity for improving the English listening ability of Korean learners has been emphasized since the ultimate goal of English education converted to CLT(Communicative Language Teaching) in Korea. Verbotonal Approach as an auditory-based strategy has been proved to be effective substantially in maximizing the listening skill of spoken foreign language. The purpose of this study is to find out an efficient way of improving listening ability for Korean middle school students by employing OFH(Optimal Frequency of Hearing) using Tonality Word Sentence Test, before & after using Listen II Verbotonal training unit based on VTS(Verbotonal System). The results of the listening tests showed that the listening ability of the subjects increased by 16.7% on the words and by 5.5% on the sentences after using Listen II, compared with before using Listen II and that the improvement rate of listening ability on the level of words is much higher than that on the level of sentences. From the results, we can come to a conclusion that training the listening skill with words in mid-tonality and low-tonality based on OFH might give a great positive effect in improving listening ability for Korean learners of English.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.493-495
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• 2005

지금까지 무선 센서 네트워크에서 에너지를 효율적으로 사용하기 위한 많은 라우팅 및 MAC 프로토콜들이 개발되어 왔다. 특히 에너지 효율적 센서 MAC 프로토콜들 중 Sensor-MAC (S-MAC) 프로토콜은 listen 시간과 sleep 시간을 주기적으로 반복하여, 데이터 전송이 없을 경우 노드의 통신 모듈을 Sleep시킴으로써 그 만큼의 에너지를 절약한다. 노드의 sleep시간이 길수록 더 많은 에너지를 절약할 수 있으나, 대신 sleep시간에 발생된 데이터는 다시 다음 주기의 listen시간이 시작될 때까지 지연되어야 한다는 단점이 있다. 이러한 데이터 전송 지연은 센서 네트워크에서 다양한 어플리케이션을 지원하기 위해 반드시 개선되어야 할 사항이다. 본 논문에서는 S-MAC의 listen/sleep 주기를 그대로 사용하여 에너지를 절약하면서도, 큰 오버헤드를 발생시키지 않고 데이터 전송시의 지연 시간을 최소화하는 기법에 대해 논의한다. 또한 시뮬레이션을 통해 기존의 S-MAC 및 Adaptive S-MAC 프로토콜과 지연시간 및 에너지 소비량을 비교하여, 제안된 기법이 지연시간을 감소시키면서도 기존 MAC 프로토콜들과 비슷한 에너지 소비량을 갖는다는 것을 증명하였다.