Performance Analysis of Multistage Interference Cancellation for Asynchronous TH-UWB Systems in Multipath Fading Channels

Seungyoup Han,Eunsung Oh,Myeongsu Han,Choongchae Woo,Daesik Hong IEEE 2009 IEEE Transactions on Vehicular Technology VT Vol.58 No.3

<P>In this paper, we present an accurate analytical method for an asynchronous time-hopping (TH) ultrawideband (UWB) system using multistage interference cancellation (MIC) in multipath fading channels. To model the asynchronous transmission, we first investigate the chip-asynchronous case and extend the results of chip-asynchronous transmission into completely asynchronous transmission as a more general environment. Specifically, the approximate closed-form expression is derived for numerically calculating the average bit-error probability (BEP) of the MIC receivers, which are based on the hard-decision (HD) and soft-decision (SD) detections, respectively. In performing the analysis, the effect of multiple-access interference (MAI) is modeled as a Gaussian process. The results of an interference cancellation (IC) receiver as a function of the ratio between the two types of processing gain-1) pulse combining gain <I>N</I> <SUB>s</SUB> and 2) pulse spreading gain <I>N</I> <SUB>c</SUB>-are analyzed and compared under the constraint that the total processing gain of the system is large and fixed. To build up intuitive knowledge, some remarks on the analytic results are presented to describe the design criterion for the interference suppression. In numerical results, the theoretical analysis is verified via comparison with simulation results in terms of the number of IC stages, the set of cancellation parameters, and the number of users.</P>

DS/SS 시스템에서의 병렬 부 필터 구조를 사용한 적응형 확산 코드 동기획득 기법

한명수(MyeongSu Han),류탁기(Takki Yu),강창언(Changeon Kang),홍대식(Daesik Hong) 한국통신학회 2002 한국통신학회 학술대회논문집 Vol.2002 No.11

OFDMA 시스템에서 비율적 전송률 분배를 위한 자원 할당

한승엽(Seungyoup Han),오은성(Eunsung Oh),한명수(Myeongsu Han),홍대식(Daesik Hong) 대한전자공학회 2008 電子工學會論文誌-TC (Telecommunications) Vol.45 No.1

본 논문에서는 직교 주파수 분할 다중 접속 방식 (OFDMA, Orthogonal Frequency Division Multiple Access)에서 전송률의 비율적 제한 조건 (Constraint)이 고려된 자원 할당 방식에 대해 논의한다. 제안된 자원 할당 방식은 비트 오율, 전송 전력 및 전송 비율 등에 관한 제한 조건 하에서 사용자들이 요구하는 다양한 서비스를 만족하면서 최대의 시스템 전송률을 얻기 위한 최적화 문제를 다룬다. 본 문제에 관한 최적의 해 (optimal solution)는 상당히 복잡하므로 부 채널 할당과 전력 할당을 나누어 복잡도를 낮춘 부 최적 해 (Suboptimal solution)를 제안한다. 먼저, 각 사용자에게 할당될 부 채널의 수를 사용자들의 평균 신호 대 잡음비와 전송률 비율을 기반으로 결정한다. 이어서 사용자에게 할당될 부 채널은 변형된 max-min 알고리즘에 따라 결정되고 이를 기반으로 최적화 문제에 대한 Lagrange dual 문제의 해를 구하는 최적의 전력 할당 방식을 제안한다. 또한 보다낮은 복잡도를 갖는 전력 할당을 위해 반복적 전송 비율 검출 알고리즘을 제안한다. 마지막으로 모의실험을 통해 본 논문에서는 제안하는 알고리즘이 사용자 간의 전송률에 관한 공평성 (fairness)을 정확히 만족하면서 시스템의 전송률을 극대화할 수 있음을 분석한다. In this paper, a new adaptive resource allocation scheme is proposed in orthogonal frequency-division multiple access (OFDMA) systems with rate proportionality constraints. The problem of maximizing the overall system capacity with constraints on bit error rate, total transmission power and rate-proportionality for user requiring different classes of service is formulated. Since the optimal solution to the constrained fairness problem is extremely complex to obtain, a low-complexity suboptimal algorithm that separates subchannel allocation and power allocation is proposed. Firstly, the number of subchannels to be assigned to each user is determined based on the users’ average signal-to-noise ratio and rate-proportion. Subchannels are subsequently distributed according to the modified max-min criterion. Lastly, based on the subchannel allocation, the optimal power allocation by solving the Language dual problem is proposed. Additionally, in order to reduce the computational complexity, iterative rate proportionality tracking algorithm is proposed for maximizing the capacity together with maintaining the rate proportionality constraint.

Successful treatment of a severe open wound in a raccoon dog (Nyctereutes procyonoides): antibiotic susceptibility testing supported

Myeongsu Kim,Haerin Rhim,Seulgi Gim,Chang-Eun Lee,Hakyoung Yoon,Jae-Ik Han 대한수의학회 2023 大韓獸醫學會誌 Vol.63 No.3

An adult raccoon dog with extensive, deep, and contaminated wounds on the right hip and multiple fractures was rescued. The open wound was managed daily by debridement and flushing for 3 weeks. Modified active drainage was then performed, and antibiotics administered according to the antibiotic susceptibility test. After 2 weeks, the exudate disappeared and the drain was removed. After monitoring for 1 month, the animal was released in to the wild. This case shows that even if infection remains, rapid wound repair is possible if appropriate antibiotic selection through regular examination and active drainage are combined.

탈부착 타입 굴삭기 원격조작 키트와 5G기반 저지연 영상전송 모듈을 이용한 장거리용 지뢰 제거 시스템에 관한 연구

길명수(Myeongsu Gil),장성훈(Sunghoon Jang),박진철(Jincheol Park),현덕수(Ducksoo Hyun),이종성(Jongsung Lee),유보현(Bo-Hyun Ryu),정상혁(Jeong Sang Hyeok),이원승(Won Seung Lee),한창수(Chang-Soo Han) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

As the idea of making the DMZ a peace zone has been implemented by the Panmunjeom Declaration of Apr. 27, the South-North Korea Military Talks of June 14, and each working meeting, discussions about the landmine removal work have been resumed. It is estimated that the mines on the Korean peninsula have about 1.27 million piles in the South DMZ and about 800,000 piles in the DMZ in the North MDL. Due to floods, typhoons and landslides, it is also distributed to civilian residential areas. These mines resulted in about 66 explosion from 2001 to 2016, and 89 casualties were caused by these accidents. Therefore, the mine removal system developed in Korea such as ROBHAZ, 4-legged Robot Mine Detector, and HUMIR, as well as imported equipment such as Rhiono, MK-4, Mine-Breaker, and bullet-proof excavator and dozer were put into mine removal work. However, it was judged to by unsuitable for carrying out forest and mountain terrestrial DMZ. In this paper, we propose a mid/long distance mine removal system using a detachable excavator remote control kit and a 5G-based low latency image transmission module. The proposed mine removal system can be applied to various types of excavators and it can be expected to improve the operation efficiency through real-time image transmission.

Average SNR and ergodic capacity analysis for opportunistic DFrelaying with outage over rayleigh fading channels

Sungeun Lee,Myeongsu Han,Daesik Hong IEEE 2009 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS Vol.8 No.6

<P>In the paper, we deal with a single-selection opportunistic relaying with the decode-and-forward (DF) protocol over Rayleigh fading channels. The exact end-to-end average signal-to-noise ratios (SNR) and ergodic capacities of both proactive and reactive opportunistic relaying are derived as a closed-form for arbitrary link SNR. In addition, the effective ergodic capacity satisfying the minimum required data rate without outage is also identified for both relaying schemes. The analysis results are used to demonstrate which relaying scheme outperforms the other for given system parameters.</P>

Prevalence of Leukocytozoon spp. in Rescued Wild Birds in Korea

Namhee Kim,Myeongsu Kim,Haerin Rhim,Jae-Ik Han 대한미생물학회 2021 Journal of Bacteriology and Virology Vol.51 No.4

Recent Observations of Micro-earthquakes and Its Implications for Seismic Risk in the Seoul Metropolitan Region, Korea

Kwang-Hee Kim(김광희),Minhui Han(한민희),Jai-Bok Kyung(경재복),Myeongsu Kim(김명수) 한국암석학회 2016 암석학회지 Vol.25 No.3

2010년 2월 9일 수도권에서 모멘트 규모 3.1 지진이 발생했다. 수도권 지역에서는 계기지진 관측이 시작된 후 오랫동안 유감지진 보고가 없었기 때문에, 이 지진은 수도권의 지진 위험성과 위해성을 상기시키는 계기가 되었다. 수도권은 약 2천 5백만 명의 인구밀집지역으로서 인구수 측면에서 본다면 세계에서 가장 큰 대도시 중 하나이다. 이 지진이 발생한 위치에서 규모 6.5의 지진이 발생했음을 가정하여 지진동을 시뮬레이션 해보면, 많은 인구와 구조물의 취약성으로 인하여 서울을 포함한 수도권 지역은 매우 심각한 위해성을 가지고 있을 것으로 생각된다. 본 연구의 동기를 제공한 시흥 지진이 피해를 야기할 수 있는 주요 지진으로 간주될 수는 없지만, 이 지역의 역사적 지진기록과 최근 지진발생 현황에 비추어 볼 때 그 중요성을 간과해서는 안 된다. 또한 수도권처럼 지진발생이 많지 않은 곳에서는 기존의 지진관측망으로 감시하는 지진보다 작은 규모의 지진을 지진위험성 및 위해성 평가에 사용할 것을 제안한다. A moment magnitude 3.1 earthquake occurred in the Seoul metropolitan region (SMR), Korea, on 9 February 2010. The unexpected shaking attracted much attention and raised concerns about the seismic hazards and risks in the SMR, which was regarded as an area safe from any earthquake hazard. The SMR has a population of 25 million and is one of the largest metropolitan areas in the world. A shakemap for a scenario earthquake with magnitude 6.5 and focal depth 12 km implies that the SMR will be exposed to serious risk because of its large population and the high vulnerability of its buildings. Although the instrumentally recorded earthquakes discussed in this article cannot be classified as major events, they should not be discounted as insignificant. Considering the low seismicity, micro-earthquakes below the magnitude of a conventional seismic network can achieve would be used to estimate background information in the evaluation of earthquake hazards and risks.

nArgBP2 regulates excitatory synapse formation by controlling dendritic spine morphology

Lee, Sang-Eun,Kim, Yoonju,Han, Jeong-Kyu,Park, Hoyong,Lee, Unghwi,Na, Myeongsu,Jeong, Soomin,Chung, ChiHye,Cestra, Gianluca,Chang, Sunghoe National Academy of Sciences 2016 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.113 No.24

<P>Neural Abelson-related gene-binding protein 2 (nArgBP2) was originally identified as a protein that directly interacts with synapseassociated protein 90/postsynaptic density protein 95-associated protein 3 (SAPAP3), a postsynaptic scaffolding protein critical for the assembly of glutamatergic synapses. Although genetic deletion of nArgBP2 in mice leads to manic/bipolar-like behaviors resembling many aspects of symptoms in patients with bipolar disorder, the actual function of nArgBP2 at the synapse is completely unknown. Here, we found that the knockdown (KD) of nArgBP2 by specific small hairpin RNAs (shRNAs) resulted in a dramatic change in dendritic spine morphology. Reintroducing shRNA-resistant nArgBP2 reversed these defects. In particular, nArgBP2 KD impaired spinesynapse formation such that excitatory synapses terminated mostly at dendritic shafts instead of spine heads in spiny neurons, although inhibitory synapse formation was not affected. nArgBP2 KD further caused a marked increase of actin cytoskeleton dynamics in spines, which was associated with increased Wiskott-Aldrich syndrome protein-family verprolin homologous protein 1 (WAVE1)/p21-activated kinase (PAK) phosphorylation and reduced activity of cofilin. These effects of nArgBP2 KD in spines were rescued by inhibiting PAK or activating cofilin combined with sequestration of WAVE. Together, our results suggest that nArgBP2 functions to regulate spine morphogenesis and subsequent spine-synapse formation at glutamatergic synapses. They also raise the possibility that the aberrant regulation of synaptic actin filaments caused by reduced nArgBP2 expression may contribute to the manifestation of the synaptic dysfunction observed in manic/bipolar disorder.</P>

상용 굴삭기를 위한 탈부착 로봇 매니퓰레이터 기반의 무인 굴삭시스템 개발

강민성(Min-Sung Kang),길명수(Myeongsu Gil),이승훈(Seunghoon Lee),한창수(Chang-Soo Han) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

Recently, There is a growing interest in automation and remote control of construction machinery in order to reduce of labor costs and safety accident prevention. In particular, the excavators have been most used in earthmoving work and the research for remote control of excavators are being studied. This paper presents a method of unmanned excavation system based on robot manipulator which is easily mount on excavator levers and pedals. The unmanned excavation system is composed of lever control units, pedal control units and main controller which controls these units. The respective control units are designed to span the workspace of excavator’s levers and pedals. Experiments are implemented to verify the feasibility of the proposed methodology.