• 한국산학기술학회논문지
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• 제16권7호
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• pp.4704-4710
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• 2015

본 연구는 가돌리늄 조영제의 T1 shortening effect를 이용하여 말초동맥으로 갈수록 신호강도가 낮아지는 위상영상의 단점을 근본적으로 개선함으로써 진단에 유용한 영상을 획득하고자 하였다. 연구기간은 2014년 10월부터 동년 12월까지 시행하였으며, 심장질환자를 제외한 AVM 환자 30명을 대상으로 하였다. 연구방법은 T1 shortening effect에 따른 신호강도의 차이를 알아보기 위해 가돌리늄 조영제 주입 전 후 자화강조영상을 획득한 다음, 위상영상을 비교평가 하였다. 연구결과, 가돌리늄 조영제 주입 전, 후 뇌실질 내 말초동맥의 신호강도는 가돌리늄 조영제 주입 후가 주입 전에 비해 전두엽 19.45%, 측두엽 23.09%, 두정엽 18.82%, 후두엽 25.45%, 소뇌 20.93%로 증가 하였고 통계적으로 유의하였다. 그러므로 위상영상 획득 시 가돌리늄 조영제의 T1 shortening effect를 이용하면 위상영상의 단점을 보완할 수 있어 진단 및 치료에 유용한 영상을 획득할 수 있으리라 사료된다.

• 한국통신학회논문지
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• 제34권8C호
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• pp.742-749
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• 2009

본 논문에서는 옥내환경의 무선전송을 위한 SDD(Synchronous Digital Duplexing)/OFDMA (Orthogonal Frequency Division Multiple Access) 시스템에서 AP(Access Point)와 SS(Subscriber Station)의 TDoA(Time Difference of Arrival)와 CFO(Carrier Frequency Offset)에 의해 발생하는 상 하향링크 OFDM 심볼의 IBI(Inter Block Interference)와 ICI(Inter Carrier Interference)의 영향을 극복하기 위한 TSF(Time-domain Shortening Filter)와 FSF(Frequency-domain Shortening Filter)를 제안한다. 제안된 TSF와 FSF는 상호 레인정 과정에서 획득한 AP와 각 SS 에 대한 채널응답 및 동기 정보를 이용하여, 시간영역과 주파수영역에서 SIRST(SIR for Shortening in Time)와 SINRSF(SINR for Shortening in Frequency)를 최대화한다. 제안된 TSF와 FSF는 SDD/OFDMA 시스템에서 TDoA에 따른 effective 채널응답과 CFO에 따른 ICI의 영향을 효과적으로 감쇄시키는 것을 모의실험을 통하여 확인한다.

• 한국운동역학회지
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• 제24권1호
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• pp.1-9
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• 2014

The purpose of this study was to investigate the muscle mechanical properties of the pelvic axial pre-rotational movement for the Jireugi in the Taekwondo Juchumseogi stance. Eleven elite Taekwondo Poomsae athletes participated. Each participant performed 5 right hand Jireugi in Juchumseogi stance as fast and strong as possible while their motion was recorded by a 3D motion analysis system and the ground reaction forces by two force plates. The power and work of the muscular group surrounding the waist were analyzed to verify the effect of the stretch-shortening cycle (SSC) theory. The cause of the greater power seems to be the application of the SSC by the muscles surrounding the waist during the preparation phase of the pre-rotation group. For the none pre-rotation group, they only used the concentric contraction of the muscles surrounding the waist. Because the pre-rotation group used the SSC theory, they had the effect of shortening of the range of movement, creating a fast and more powerful rotation, thus anticipating the increase the magnitude of impact.

• 한국전산구조공학회논문집
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• 제21권2호
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• pp.189-197
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• 2008

본 연구에서는 3개 이상의 기둥그룹에 대해서도 일반적으로 적용 가능한 기둥축소량의 최적보정기법을 제안하고, 이를 실제 시공된 건물에 적용하여 그 적용성을 평가하였다. 제안된 최적보정기법은 성능 및 시공상의 제약조건을 만족하면서 보정개소를 최소한으로 할 수 있는 층그룹 및 이때의 보정량을 산정하며, 상대보정뿐만 아니라 절대보정을 고려한 혼합보정도 가능하다. 최적보정에는 시뮬레이티드 어닐링(simulated annealing)이 주요 알고리즘으로 사용되었다. 제안된 기법을 실제 축소량 보정이 수행된 61층 건물에 적용한 결과, 보정량을 쉽게 산출할 수 있고 또한 실무방식보다 보정개소를 줄일 수 있어 적용성이 뛰어남을 확인하였다.

• 토지주택연구
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• 제2권4호
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• pp.355-365
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• 2011

Construction duration is very important as a factor which comprises three axises of construction management with quality and cost in construction project. In general project condition, construction duration is optimized while minimizing construction cost and securing required quality. However, in case of insufficient project time duration or delayed projects, project progress management is different from those of normal projects. These project areas need solutions to complete work within a given completion day. To time shortening the current duration of each typical floor of structural framework in apartment construction is investigated, and a basic time schedule planning for typical floor of structural framework in normal projects is planned. This study proposed 3 ways for time shortening of urgent project or insufficient construction duration project. Also, This study proposed detailed time shortening method and technical solution conditions while time is shortened.

• 대한족부족관절학회지
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• 제25권4호
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• pp.177-180
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• 2021

Pediatric ankle fractures can cause physeal injuries which can lead to the shortening of the fibula. This induces a lateral shift of the talus, valgus tilt, and instability of the ankle joint, which can result in an arthritic change in this joint. Patients with a shortening of the fibula may complain of constant pain and restricted movements in their daily lives and during sports activities. Ankle reconstruction with fibula lengthening Z-osteotomy can provide excellent results if arthritis is absent or minimal, especially in young and active patients. To the best of the authors' knowledge, this is the first report in South Korea regarding the treatment of fibula shortening following a growth arrest due to injury.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1920-1923
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• 2002

This paper proposes an impulse response shortening algorithm applicable to decision feedback equalization of single carrier wideband signal. When he impulse response shortening methods for narrowband signaling are applied to single carrier wideband signals, they result in noise enhancement problem, significantly deterioriting the receiver performance. This problem can be alleviated by educing the eigenvalue spread ratio of the impulse response, which can be achieved by adding additive white noise with small variance to the impulse response of the channel. The performance of the proposed scheme is verified by computer simulation.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (3)
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• pp.31-33
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• 2004

We suggest an enhanced automatic route shortening method for dynamic source routing (DSR) protocol. DSR is a request / response based protocol which has low routing overhead owing to node movement. The original automatic route shortening is performed on the only nodes that belong to the source route of packets. On the contrary, our suggested method allows all neighbor nodes hearing the packet to participate in automatic route shortening. It makes all possible route shortenings be performed. So we maintain maximal short routes of ongoing data connections. Simulation results show that our method pays small extra overhead for ARS, but increases the ratio of packet transmissions and ARS' are performed from 2 to 5 times as much as original ARS.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 봄 학술발표회 논문집(I)
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• pp.397-402
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• 1998

The objectives of this paper are to estimate differential column Shortening and to determine appropreate compensation amount in 52 story Amatapura Apartment in Indonesia. for this, a computer program based on PCA and CEB-FIP code is developed. The results show that Elastic and Creep strain are the main factors of column shortening and the maximum differential shortening is appeared near the middle of the building height. The results between field survey and estimation have some difference, the most influential factor of the difference can be lateral restraints provided by horizontal members, which cannot be handled in this developed program. Hence introducing the modification factors from various field survey, this program can be used properly in design and construction procedures.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.475-480
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• 1997

Highrise concrete buildings are very sensitive to cumulative and differential shortening of their vertical element such as wall and columns. Inelastic deformation due to creep and shrinkage consist of various factors and load history af actual building is very complicated. Therefore, for the accurate prediction and compensation of axial shortening, special efforts in design and construction phase are required to ensure long-term serviceability and strength requirement. In this paper, axial shortening estimation and compensation procedure is presented, which utilized experimentally determined concrete properties and preliminary load history and computerized approach, in case of Plaza Rakyat office tower, 79-story reinforced concrete building under construction in Malaysia.