http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
김흥섭,홍진석,오재응,Kim, Heung-Seob,Hong, Jin-Seok,Oh, Jae-Eung 대한기계학회 1997 大韓機械學會論文集A Vol.21 No.11
This study experimentally demonstrates the use of active muffler attached to the automotive exhaust system to reduce exhaust noise. For improving the signal to noise ratio in the process of estimation of secondary path transfer functions, the on-line algorithm that conventional inverse modeling is combined with adaptive line enhancer is used as the control algorithm. Active muffler is designed that the primary noise and the control sound are propagated as a plane wave in the outlet. Therefore, the error microphone could be placed out of the tail pipe center of a high temperature and the radiation noise to the outside could be reduced in the whole area around the outlet. The control experiment for reducing exhaust noise with active muffler is implemented during run-up at no load. From the experimental results presented, compared with the conventional off-line method, the proposed on-line method is capable to acquire a reduction of exhaust noise above 5 dB in overall sound power level.
배기소음 제어용 능동형 소음기의 제어 성능평가에 관한 연구
김흥섭,손동구,오재응,Kim, Heung-seob,Shon, Dong-Gu,Oh, Jae-Eung 대한기계학회 1998 大韓機械學會論文集A Vol.22 No.2
Active mufflers have been mainly applied in the large industrial engine due to considerable expense for implementation, but a necessity of development has been increased by the tightened regulation of exhaust noise and the request of high power. In this study, the active muffler prototype for installing in an automobile is designed and constructed. The active muffler is designed so that the primary noise and the control sound are propagated as a plane wave in the outlet. Therefore, the error microphone could be placed outside the high temperature centers of the tail pipe, and the noise radiating to the outside could be reduced in the whole areas around the outlet. For evaluating the control performance of the prototype, the control experiments of band-pass filtered random signal and the modulation of sinusoidal signal which are generated from the primary noise speaker as practical exhaust sound level are implemented. And to investigate the radiation pattern from the outlet of tail pipe and the noise reduction level of points placed adjacent to the outlet, the sound level of adjacent points of thirty is measured.
김흥섭,홍진석,오재응,Kim, Heung-Seob,Hong, Jin-Seok,Oh, Jae-Eung 대한기계학회 1997 大韓機械學會論文集A Vol.21 No.8
In the case of the transfer function for the secondary path is dependent on time, the on-line method which can model it is continuously must be applied to the active noise control technique. And the adaptive random noise technique among the on-line methods is effective in the narrow-band control. In this method, the signal to noise ratio between random noise for modeling and primary noise is low. Therefore, the estimations of transfer function will be prone to inaccuracies and the convergence time will be too long. Such imperfections will have an influence upon the performance of an active noise controller. In this study, t enhance the signal to noise ratio, the on-line method that is combined the conventional adaptive random noise technique and the adaptive line enhancer, is proposed. By using proposed on-line method, a rigorous system identification and control of primary noise have been implemented.
자동차 실내 소음저감을 위한 다채널 능동소음 제어에 관한 연구 II : 모의 실험
김흥섭,이태연,신준,오재응,Kim, H.S.,Lee, T.Y.,Shin, J.,Oh, J.E. 한국자동차공학회 1994 한국 자동차공학회논문집 Vol.2 No.6
Active noise control of random noise which propatate in the vehicle cabin as a form of spherical wave is the target of this study. In the previous study, the adaptive algorithm for adaptive controller is presented for the application in active noise control system. And for the preliminary study of adaptive active noise control in vehicle cabin as a real system, a computer simulation is performed on the effectiveness of the adaptive algorithm in the amplitude of the pressure fluctuation. This work studies the implementation of multi-channel feedforward adaptive algorithm for the reduction of the noise inside a vehicle cabin using a number of secondary sources derived by adaptive filtering of reference noise source. Multi-channel adaptive feedforward algorithm are verified in numerical simulation and semi-experimental justification of developed system is made on a domestic passenger car. In the results of semi-experimental study, the noise of specific region in the interior of automobile are reduced for the appreciabe sound pressure level in the operating engine rpm and finally this study suggests the capabilities of the real time active noise control in 3 dimensional acoustic fields.
부가경로 전달함수의 온라인 예측에 의한 능동소음제어의 성능 향상
김흥섭,손동구,오재응,Kim, Heung-Seob,Sohn, Dong-Gu,Oh, Jae-Eung 대한기계학회 1997 大韓機械學會論文集A Vol.21 No.2
In the conventional inverse modeling method for on-line modeling of the secondary path transfer function, the signal to noise ratio between the arbitrary random signal and the plant noise have to keep at -10 - -20 dB. For these reasons, the modeling can't be exactly implemented by the conventional method alone and the convergence time for modeling becomes too long. In this study, by combining the conventional inverse modeling method with an adaptive line enhancer, or with an adaptive noise canceller, a rigorous transfer functions of secondary path modeling and the control of a primary noise have been implemented simultaneously.
동기화한 이산화법을 이용한 능동소음제어의 성능향상에 관한 연구
김흥섭,오재응,신준,Kim, Heung-Seob,Oh, Jae-Eung,Shin, Joon 대한기계학회 1994 대한기계학회논문집 Vol.18 No.10
In this paper, active noise control is performed in a duct system using the periodic pulse train which corresponds to the periodic component of noise source as a reference signal. Control algorithm applied in this study is possible to eliminate the acoustic feedback which occurs in the conventional filtered-x and filtered-u LMS algorithm by using electrical reference signal and has the fast adaptation speed with low filter orders by using synchronous sampling method is discussed via computer simulations and experiments of case studies such as frequency modulation, amplitude modulation and frequency differency between source signal and reference signal.
탄도미사일의 비행특성을 고려한 요격미사일 소요 알고리즘
김흥섭,김기태,전건욱,Kim, Heung-Seob,Kim, Ki-Tae,Jeon, Geon-Wook 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.6
A Ballistic Missile(BM) is a missile that follows a sub-orbital ballistic flightpath with the objective of delivering one or more wardheads to a predetermined target and An Anti-Ballistic Missile(ABM) is a missile designed to destroy a ballistic missile before reaching its target. The main objective of this study is to assess the requirement of ABM by considering both flight characteristic of the SCUD-B/C, Nodong missiles and intercept performance of ABM in the Lower tier Ballistic Missile Defense(BMD). The Ballistic Missile's flight characteristics, such as trajectory, velocity etc., are estimated by simulation using the physical motion equations. The requirement of ABM is calculated by evaluating whether the BMD forces can defend those when the ballistic missiles attack prime facilities.
공격편대군-표적 최적 할당을 위한 수리모형 및 병렬 하이브리드 유전자 알고리즘
김흥섭,조용남,Kim, Heungseob,Cho, Yongnam 한국군사과학기술학회 2017 한국군사과학기술학회지 Vol.20 No.4
For optimizing the operation plan when strike packages attack multiple targets, this article suggests a new mathematical model and a parallel hybrid genetic algorithm (PHGA) as a solution methodology. In the model, a package can assault multiple targets on a sortie and permitted the use of mixed munitions for a target. Furthermore, because the survival probability of a package depends on a flight route, it is formulated as a mixed integer programming which is synthesized the models for vehicle routing and weapon-target assignment. The hybrid strategy of the solution method (PHGA) is also implemented by the separation of functions of a GA and an exact solution method using ILOG CPLEX. The GA searches the flight routes of packages, and CPLEX assigns the munitions of a package to the targets on its way. The parallelism enhances the likelihood seeking the optimal solution via the collaboration among the HGAs.
이정석(Jungsuk Lee),윤문영(Moonyoung Yoon),양갑진(Kapjin Yang),송정훈(Jeonghoon Song),제우성(Woosung Che),부광석(Kwangsuk Boo),김흥섭(Heungseob Kim5) 한국자동차공학회 2016 한국자동차공학회 부문종합 학술대회 Vol.2016 No.5
The fundamental reason of noise in gear system is transmission error due to deflection of gear teeth. The vibration from transmission error moves to shaft and bearing. This vibration generates bearing force which exite gear box and finally radiate as noise outside. Therefore, studying transmission error is the most important to predict which is the fundamental reason of gear noise. In this paper, transmission error due to teeth deflection was predicted and shaft torsion was not considered in order to find only teeth deflection. For this reason, shaft was modeled as rigid, and only gear pair was modeled as flexible body. transmission error was predicted by Abaqus, FEA program, and this was compared for Spur and Helical type.