• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.21-24
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• 2000

In this paper, We introduce effective handoff method from W-COMA system of 3$^{rd}$ generation to 15-95 system of 2$^{nd}$ generation. In case of this handoff, Ms should know long code state using traffic channel, timing information and pilot offset of 26 synchronous system during the compressed mode. So We establish additional common channel in order to obtain handoff information. Common channel transmits same information from all base stations and provides MS with timing information of zero offset. long code state and timing of super frame for sync. channel. Therefore during the compressed mode. MS can obtain information for handoff using common channel..

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.64.1-64.1
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• 2016

We study the evolution of a late-type galaxy (LTG) in a rich cluster environment by using N-body/SPH simulations. To do that we perform a set of simulations of a LTG falling in a Coma-like cluster and also the LTG colliding with early-type galaxies (ETGs) multiple times in the cluster environment. We use a catalog of the Coma cluster in order to estimate the typical number of collisions and the closest approach distances that a LTG would experience in the cluster. We investigate the cold gas depletion and star formation quenching of our LTG model influenced by the hot cluster gas as well as the hot halo gas of the colliding ETGs.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.1
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• pp.1-7
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• 2000

In this paper, we proposed a complex multirate filter bank(CMRFB) based adaptive notch filtering technique to solve the co-existence narrowband interference problem of DS-CDMA and TDMA systems. We have discussed error performance of co-existence of DS-CDMA and TDMA system by using complex multirate filter bank in land mobile channel and computer simulation results show that the proposed scheme can eliminate the narrowband interference(TDMA signals) effectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9B
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• pp.771-777
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• 2004

In a COMA system, the capacity is variable and mainly depends on multiple access interference. The multiple access interference has a deep relationship with transmitted or received power. The capacity of COMA2000 system is considered to be limited by the forward link capacity. In this paper, we show that the forward link cell load can be represented by the total transmitted power of base station and we propose a forward link call admission control (CAC) strategy for COMA2000 system. The proposed call admission scheme adopts the rate control algorithm for data call. This call admission scheme enables the system to utilize radio resource dynamically by controlling data rate according to the cell load status, and enhance the system throughput and grade of service (GoS). quality of service(QoS) such as blocking and outage probability.

• Journal of information and communication convergence engineering
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• v.2 no.3
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• pp.139-144
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• 2004

In order to transmit various types of multimedia data (i.e. voice, video, and data) over a wireless channel, the coding and modulation scheme needs to be flexible and capable of providing a variable quality of service, data rates, and latency. In this paper, we study a mobile multimedia COMA network combined with the concatenated Reed-Solomon/Rate Compatible Punctured Convolution code (RS/RCPC). Also, this paper propose the combination of concatenated RS/RCPC coder and COMA RAKE receiver for multimedia COMA traffic which can be sent over wireless channels. From the results, using a frequency selective Rayleigh fading channel model, it is shown that concatenated RS/RCPC coder at the wireless physical layer can be effective in providing reliable wireless multimedia CDMA network. And the proposed scheme that combine concatenated RS/RCPC coder and CDMA RAKE receiver provides a significant gain in the BER performance over multi-user interference and multipath frequency selective fading channels.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.57.4-58
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• 2018

It is interesting to find the best exospheric model that can account for the observed characteristics of the lunar coma and tail simultaneously. Recently, the initial abundances of atomic species near surface are found to be different depending on certain local areas. We will present the influence of different initial conditions of localized sources on the characteristics of the lunar exosphere, and also present time-dependent simulations showing the distributions of atomic species around the lunar coma and the final stage of the lunar tail. Based on our updated 3-D lunar model, we will present resulted physical parameters of the lunar sodium coma and tail.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.988-991
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• 2020

다양한 실세계 응용 분야들에서 공동의 목표를 위해 여러 에이전트들이 상호 유기적으로 협력할 수 있는 행동 정책을 배우는 것은 매우 중요하다. 이러한 다중 에이전트 강화 학습(MARL) 환경에서 기존의 연구들은 대부분 중앙-집중형 훈련과 분산형 실행(CTDE) 방식을 사실상 표준 프레임워크로 채택해왔다. 하지만 이러한 다중 에이전트 강화 학습 방식은 훈련 시간 동안에는 경험하지 못한 새로운 환경 변화가 실전 상황에서 끊임없이 발생할 수 있는 동적 환경에서는 효과적으로 대처하기 어렵다. 이러한 동적 환경에 효과적으로 대응하기 위해, 본 논문에서는 새로운 다중 에이전트 강화 학습 체계인 C-COMA를 제안한다. C-COMA는 에이전트들의 훈련 시간과 실행 시간을 따로 나누지 않고, 처음부터 실전 상황을 가정하고 지속적으로 에이전트들의 협력적 행동 정책을 학습해나가는 지속 학습 모델이다. 본 논문에서는 대표적인 실시간 전략게임인 StarcraftII를 토대로 동적 미니게임을 구현하고 이 환경을 이용한 다양한 실험들을 수행함으로써, 제안 모델인 C-COMA의 효과와 우수성을 입증한다.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.3
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• pp.353-362
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• 2014

Purpose: The present study was aimed to investigate the change of higher-order aberrations induced by aging and the effect of myopic degree on the correlation between age and higher-order aberrations. Methods: The higher-order aberrations in 931 eyes aged from 20 to 60 were measured by using a LADARWave device employing Hartmann-Shack system to analyze the effect of myopic degree measured by manifest refraction test on higher-order aberrations. Results: Coma and vertical coma aberrations were significantly decreased by the increase of myopic degree while vertical astigmatic aberration was significantly increased. The correlations of age and coma, vertical coma, spherical, vertical trefoil, horizontal trefoil, vertical astigmatic, horizontal astigmatic and vertical tetrafoil aberrations depended on the myopic degree, except for horizontal coma and horizontal tetrafoil aberrations. Conclusions: It is suggested to consider the myopic degree for the refractive correction including the laser surgery based on the present result that higher-order aberrations are affected by the myopic degree.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.115-117
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• 2003

본 논문에서는 CDMA S-ALOHA 시스템에서 공평한 패킷 전송을 위한 MAC 프로토콜을 제안한다. CDMA S-ALOHA 시스템에서 동일한 슬롯에 전송되는 패킷들은 다원접속 간섭으로 작용하며, 이는 패킷 전송 실패의 주요 요인이 된다 따라서 최대의 시스템 처리율을 얻기 위하여 동시에 전송되는 패킷의 수를 일정하게 유지시킬 필요가 있다. 제안한 기법에서는 기지국이 망의 부하에 따라 다음 슬롯의 패킷 전송 확률을 계산하여 방송하고, 단말기들은 수신한 전송 확률을 기반으로 패킷 전송을 시도한다.

• The Journal of Internal Korean Medicine
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• v.40 no.6
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• pp.1225-1236
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• 2019

Objective: This is a case report on the effect of Korean traditional medicine on deep stupor to semi-coma with intracerebral and intraventricular hemorrhage. Methods: The patient was treated by Korean traditional medicine such as acupuncture, moxibustion, and herbal medicine. The change of mental state was evaluated by the Glasgow Coma Scale (GCS). We used the Modified Medical Research Council Scale (MRC scale) and the Modified Barthel Index (MBI) to evaluate the effectiveness of the treatment. Results: After treatment, the physical function and ability to perform activities of daily living were improved. The Modified Barthel Index increased from 0 to 40 after treatment with Korean medicine. Conclusions: According to this study, Korean traditional medicine can be effective for the treatment of quadriparesis in patients with deep stupor to semi-coma in intracerebral and intraventricular hemorrhage.