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Substructure Synthesis Method using Dynamic Reduction
Get PDFSubstructure Synthesis Method using Dynamic Reduction
analysis on structures. In these days, it is a very common method for not only a simple vibration analysis but also the optimization of structures.
However, when we apply that method for the complicated and the huge structures, we should increase the number of elements to get more accurate results. Furthermore, it causes the increase of the degree of freedom and the limitation of calculating time and memory capacity of computer.
The finite element method(FEM) has been developed and applied for dynamic So, many researchers have challenged to find more improved modeling techniques and calculation methods to overcome those hurdles.
The Guyan's reduction method and the substructure synthesis method are typical examples of such methods. Of the substructure synthesis method, the component mode synthesis method(CMS) is widely used for dynamic analysis of structure.
However, as order of natural frequency becomes higher, it causes errors because it implies the Guyan's static reduction and the number of modes taken from each component is deficient.
In this thesis, the substructure synthesis method using dynamic reduction is proposed to obtain accurate results in high order natural frequency range.
Computer simulation of the proposed method, FEM, and the component mode synthesis method(CMS) have been carried out on a rectangular plate to prove the availability of the proposed method.
The results are as follows :
1. The analytical results of the substructure synthesis method using dynamic reduction coincide with those of FEM, and the availability of the proposed method has been verified.
2. The proposed method can overcome the error occurrence which were caused by the defects of the component mode synthesis method using Guyan's static reduction.
3. The natural frequency of the specific frequency range can be obtained without errors. So, it is expected that the proposed method could be applied to the analysis in high frequency range like noise problem
A Study on Design and Implementation of Wideband High Power Amplifier for Digital TV Repeater
Get PDFIn this dissertation, a high power amplifier has been implemented and performed evaluation, which is operating at UHF band (470 ~ 806 MHz) for Digital TV repeater.
The theoretical consideration of 100 Watt power amplifier at UHF band used in Digital TV repeater is studied. After extracting target specification of each part, amplifier is designed and fabricated.
When the driving amplifier stage is flown by bias voltage of 28 V DC and current of 900 mA, it has the gain of more than 53.5 dB, the gain flatness of ±0.5 dB and return loss of less than -12 dB in 470 ~ 806 MHz.
Also, when two signals at 2 MHz frequency interval are input port into the driving amplifier stage with 1 Watt output, it resulted in excellent characteristics to design specification with showing intermodulation distortion characteristics of more than 48 dBc.
The middle amplifier stage using 85 Watt device is fabricated by RO-4003 electric substrate which is 3.38 in dielectric constant and 32 mil-thickness. When the driving amplifier stage and the middle amplifier stage were flown by bias voltage of 28 V DC and current of 4 A, they revealed the gain of more than 66 dB, the gain flatness of ±0.2 dB and return loss of less than -16 dB.
Also, when two signals at 2 MHz frequency interval in using frequency band is input port into the driving amplifier stage with 40 dBm of output power, it showed intermodulation distortion characteristics of more than 38.50 dBc.
The 100 Watt unit power amplifier using temperature independent biasing for Digital TV repeater application is designed and fabricated. The DC operation point of this unit power amplifier at temperature variation from 20 ℃ to 100 ℃ is fixed by active bias circuit. The variation of current consumption in the 100 Watt unit power amplifier has an excellent characteristics of less than 0.6 A. The implemented unit power amplifier has the gain over 12 dB, the gain flatness of less than ±0.5 dB and return loss of less than 15 dB over the DTV repeater frequency range. This unit power amplifier yields intermodulation distortion of more than 32 dBc at 2 MHz offset, which satisfies the IMD at output power of 100 Watt (50 dBm).
The broadband high power 3-way combiner was designed and fabricated for the digital TV repeater. To achieve increase of bandwidth and high power capability, Wilkinson type power divider was adopted in our research. First of all, Wilkinson type power divider of equal-split and unequal-split were combined, the characteristics variation of the same phase four port power combiner was simulated according to the various thicknesses of dielectric substrates. As the results of simulation, the power combiner fabricated by using dielectric substrate of 120 mil-thickness has the characteristics as follows: insertion loss of less than -6 dB, return loss of less than -13 dB, isolation among the output ports of less than -15 dB, and phase difference among the output ports of smaller than 13°. Therefore, this power combiner was possible to improve the limit of microstrip line width due to high impedance, the problems of power loss due to interaction between strip lines in high power combiner and narrow bandwidth simultaneously. Furthermore, since the fabricated 3-way combiner has good characteristics of insertion loss, the return loss, separation between ports and phase difference, making broadband and high power could be achieved.
By using 3-way power divider and power combiner, 100 Watt unit power amplifier stage was designed and fabricated as a type of 3-stage balanced amplifier and to detect the final signal output power with using of 40 dB parallel coupled-line directional coupler. The fabricated 40 dB parallel couled-line directional coupler detects the signal power emitting to the antenna, and then supplies its voltage to the attenuator. In addition, this sets to be changed with a basic attenuation 8 dB, according to the changing of the power amplifier's temperature and 8-VSB modulator's input signal.
Besides, in order to measure the fabricated 100 Watt power amplifier, the estimation technique function which makes equivalent mask by Tektronix RFA-300A was used. As a result of the measurement, the existence of pilot signal is confirmed and the signal transmitted at the rated output power 100 Watt is brought out the flat feature through 6 MHz bandwidth. And it resulted that its value was less than -47 dB at the edge of radiation channel and less than -110 dB at more than 6 MHz position from channel edge. Finally a positive results on the equivalent mask has been complied with related regulations.목차
Abbreviations
Abstract
제1장 서론 = 12
1.1 연구 배경 = 12
1.2 연구 목적 = 14
제2장 디지털 TV 방송 시스템 = 16
2.1 통신 시스템의 형태 = 16
2.2 DTV 시스템 설계 파라미터 = 17
2.3 지상파 DTV 중계기 시스템 = 25
2.4 지상파 DTV HPA 서브 시스템 = 27
제3장 전력증폭기의 설계 및 구현 = 31
3.1 구동증폭단의 설계 및 구현 = 31
3.2 중간증폭단의 설계 및 구현 = 50
3.3 100 Watt 단위 전력증폭기의 설계 및 구현 = 62
3.4 결과 분석 = 75
제4장 100 Watt 전력증폭기의 구성 및 평가 = 77
4.1 3-Way 동위상 고출력 전력결합기 = 77
4.2 전력검출기 및 감쇠기 = 97
4.3 100 Watt 전력증폭기의 구성 및 특성 평가 = 103
4.4 결과 분석 = 115
제5장 결론 = 116
참고문헌 = 11
(A) Study on the Improvement of the Accuracy of the Positioning System for an Intelligent Wheelchair by Multisensor Data Fusion
Get PDFWith the increase of social concern about the disables and elderly people, their participation in social activities is demanded. In this view, an intelligent wheelchair is necessary for giving them better mobility and for saving them a considerable physical effort. To control the motion of the intelligent wheelchair, the current position of the wheelchair must be known as accurately as possible. A well-known method to estimate the current position in the field of wheeled mobile robotics is dead- reckoning. But in the case of the position estimation based on the conventional dead-reckoning for an intelligent wheelchair with pneumatic tires, it is impossible to avoid the position estimation error because of the change of radii of the wheels which depend on an user's weight and a variable environment.
Therefore, this thesis proposes the positioning system which can estimate the error of radii of the wheels using a gyroscope and ultrasonic sensors and can correct the radii of the wheels to reduce the dead-reckoned position error. The extended Kalman filter was used as a method for fusing multisensor data with information on the dead-reckoned position error.
Simulations to verify the effectiveness of the proposed positioning system are performed and they prove good performances demonstrated from the results
Legal Protection of a seaman according to termination of seaman-employment relationship
Get PDFWorld each nation recognizes the importance of the marine that is future resources treasure and is going ahead with various policies. That is, It is not too much to say that ocean power is important because of a geographical position that is a peninsula surrounded by sea on three sides and insufficiency of natural resources to improve nation wealth and quality of people life through securing marine resource to accomplish nation development. In order to recognizes the importance the marine, and to accomplish nation development and growth, various policies and will of people and an administrator are important, but among those, seaman is most important. No matter how much a ship and the capital are healthy, maritime affairs and fisheries industrial cannot be run in case of seaman is not exist, or ability of him is short.
By the way, in spite of the importance of seaman's role how is the real position of seaman in our country? Is because the attraction of a seaman occupation's decline the competitiveness of the marine corporation and nation is getting worse according to an elevation of national income and a change of social sense of value? What is the first policy to resolve these problem? In a word, It is attraction of seaman occupation. That is, before retirement consideration of labor should be compensated by improving employment conditions after retirement. The right of seaman shouted be protected to acquire the base of new life.
This paper purpose of study is the inducement of attraction of seaman occupation by protecting the right to the retirement seamen, inducing a long time boarding to the boarding seamen and seelxing seamen occupation to the retired seamen though indicating the policies of the protection of the seaman's right after retirement the problem related to those, and the reform measures. This paper summary is below
Primarily seaman labor exists structural and quantitative specialty compared with land labor. Thfoerere, seaman must be specially protected employment conditions, continuation guarantee of labor relationship, rights guarantee after labor relationship extinction etc. Also, the same labor must be evaluated the same judge's robe so long as a common denominator called specialty of marine labor exists. Therefore, application range of the existing seaman act must be expanded.
Second it is a special nature of the provision of th termination seaman employment's. It is not simply to mean severance of labor, and it is loss of the opportunity of being provided labor to ship owner, and that of receiving wages to seamen. therefore it has a great influence on parties, it is necessary to regulate the employment relationship and to reform the problem.
1. It is a discharge provision on the seaman act. It is necessary to express clearly the provision of transfer ship and to revise the provision of the time limit of discharge, exception related to a notice of discharge and the permission of labor committee according to assignment of the ship.
2. It is thing about discharge on management. because of inconsistency with the seaman act it is reasonable to revise the provision of the seaman act and to take the legislative measure instead of introducing the discharge on management.
3. It is an exception provision about the termination according to passage of the ship title and official reprimand of leaving a ship. Among these official reprimand of leaving a ship of a captain gives a lot of disadvantage to individual rights of a seaman, but the carries no legal binding force when a seaman does not leave a ship voluntarily. Therefore, it is reasonable to repeal official reprimand of leaving a ship and to provide the leaving a ship that is legal binding to captain. the exceptional provision about the the employment termination according to a charge of ship ownership should be revisied toward the aspect of employment guarantee of a seaman and resolveness of financial difficulties of a shipowner.
4. If it is the exceptional provision of the point of the time of termination in case of on boarding employment relationship is terminated. it is necessary to revise toward taking considerations of the disadvantages of a seaman and the peace of the ship-community.
Thirdly, it is the problem of the legal protection of the seaman according to the seaman employment termination and reform measure. the problem of perfect the retired seaman and his family is important to the boarding seaman, retired seaman and to the reserved seaman. Nonetheless the existing seaman act and a related legal system are short of protecting the right of them the reform measure are below
1. Because the retirement allowance system is not enough for inductance of longtime boarding and protection of a seaman in spite of the existence value of it, it is necessary to introduces an seaman pension system and to revise the provision of the retirement allowance system on the seaman act for the seaman who is not able to receive the pension benefit.
2. overdue wages, rights about unemployment, rights about a disaster compensation are not more enough than a worker on labor standard law. These rights are things related to employment conditions of seamans substantially, and it is proper to revises seaman insurance law and to take legislative actions because it is to be related to a social insurance system of a seaman. A seaman is the same constitutional worker and people as a worker on labor standards law, but seaman is not able to receive the benefit of social security system. A maintenance of these policies is an unconstitutionality and cannot induce attraction of a seaman occupation. Therefore, in consideration of special nature marine labor, it is urgent to amend in order to receive the benefit of seaman insurance law above the level of benefit of the worker on labor standards law.
3. It is the provision about the repatriation of a seaman that is unique only in the seaman employment relationship. The existing seaman act considers specialty of marine labor and is putting a repatriation provision, but it is short to consider the position of a seaman and is not enough for a foreign legislation level. Therefore, the provision about repatriation on the seaman act must be revised toward reflecting the intention of a seaman and preserving the profit of a seaman.
Until now welfare policy about the seaman has a lot of problems as above. if there is not a seaman we are not able to strengthen ocean fisheries industry and the competitiveness of nation. Therefore, special measures about legal protection of seaman according to the termination of seaman employment relationship in order to preserve the right of them and to resolve manpower problem of seaman occupation .목차
ABSTRACT
第1章 序論 = 1
第1節 硏究의 目的 = 1
第2節 硏究의 方法과 範圍 = 4
第2章 船員勤勞關係의 特殊性과 終了의 問題點 = 5
第1節 船員勤勞關係의 特殊性 = 6
I. 勞動行爲의 本質的 特殊性 = 6
II. 勞動行爲의 評價的 特殊性 = 10
第2節 船員勤勞關係 終了의 問題點 = 12
I. 論議의 前提 = 12
II. 船員勤勞關係의 終了事由에 관련된 問題點 = 14
III. 船員勤勞關係 終了後 船員의 法的保護에 관련된 問題點 = 18
第3章 船員勤勞關係의 終了事由 = 22
第1節 民法規定이 適用되는 終了事由 = 23
I. 合意解止 및 辭職 = 24
II. 船員勤勞契約期間의 滿了 = 28
第2節 勤勞基準法과 共通的인 終了事由 = 32
I. 船員勤勞關係에 있어서 解雇의 正當한 事由 = 33
II. 船員法上 解雇規定의 問題點과 改善方向 = 42
第3節 勤勞基準法의 規定에 의한 終了事由 = 51
I. 船員法과 勤勞基準法의 關係 = 52
II. 經營上 解雇의 導入問題와 立法的 對處方案 = 55
第4節 船員法上 獨自的 終了事由 = 58
I. 船長의 下船懲戒權 = 59
II. 船舶所有權의 變更 = 67
第5節 船員法上 船員勤勞關係의 終了時點 = 82
I. 船員勤勞關係의 終了時點에 대한 例外事由 = 83
II. 問題點과 改善方向 = 86
第4章 船員勤勞關係의 終了後 船員의 法的保護 = 88
第1節 一般勤勞關係와 동등한 수준으로 保護되는 權利 = 88
I. 船員法上 退職金制度의 特殊性 = 89
II. 船員法上 退職金制度의 問題點과 改善方向 = 93
第2節 一般勤勞關係보다 미흡한 수준으로 保護되는 權利 = 106
I. 滯拂賃金에 관한 權利 = 107
II. 失業에 관한 權利 = 126
III. 災害補償에 관한 權利 = 140
第3節 船員勤勞關係에서만 인정되는 權利 = 163
I. 船員法上 送還規定의 內容 = 164
II. 船員法上 送還規定의 問題點과 改善方向 = 167
第5章 結論 = 172
參考文獻 = 18
A Study on the Optimal Design and Application of a System Identifier Based on Neural Networks Using Genetic Algorithms
Get PDFThis paper deals with nonlinear system modelling using neural networks and genetic algorithms.
Applications of neural networks to control and identification have been actively studied because of their approximating ability of nonlinear functions. It is important to design the neural network which has optimal structure for minimum error and fast response time. Nowadays, genetic algorithms have been getting more popular because of their simplicity and robustness.
In this paper, We optimize neural network structure using a genetic algorithms. The genetic algorithm uses binary coded chromosomes for neural network structure and searches for an optimal neural network structure of minimizing error and fast response time. Through extensive simulation and practical tests, It is verified that the proposed method is effective for identification of nonlinear system.목차
Abstract = iii
제 1 장 서론 = 1
제 2 장 신경 회로망 기반 시스템 식별 = 4
2.1 다층 퍼셉트론 및 Levenberg-Marquardt 알고리즘 = 4
2.1.1 뉴런 = 4
2.1.2 다층 퍼셉트론(Multilayer Perception:MLP) = 5
2.1.3 Levenberg-Marquardt 알고리즘 = 6
2.2 신경 회로망 기반 시스템 식별 = 11
2.2.1 시스템 식별 절차 = 11
2.2.2 시스템 모델의 구조 = 13
2.2.3 ARX Model = 14
제 3 장 유전알고리즘을 이용한 신경 회로망 기반 시스템 식별기 구조의 최적화 = 16
3.1 유전알고리즘의 구조 및 역할 = 16
3.2 신경 회로망 구조의 부호화 및 적합도 = 18
3.3 시스템 식별기 최적화의 구조 및 연산과정 = 21
제 4 장 시뮬레이션 및 검토 = 24
4.1 최적 구조 신경 회로망 모델 도출 = 24
4.2 최적 구조 신경 회로망을 이용한 시스템 식별 = 29
4.3 Direct Inverse Control = 33
4.4 결과 검토 = 35
제 5 장 실험 및 검토 = 38
5.1 선박용 안정화 위성 안테나의 구조 = 38
5.2 선박용 안정화 위성 안테나의 최적 구조 신경 회로망 모델 도출 = 41
5.3 최적 구조 신경 회로망을 이용한 선박용 안정화 위성 안테나 시스템의 식별 = 46
5.4 결과 검토 = 50
제 6 장 결론 = 51
참고문헌 = 5
Design of Magnetic Fluid Linear Actuator Without Noise and Vibration
Get PDFIn this paper, the magnetic fluid linear actuator is designed. Inside the small tube, magnetic fluid is shielded with thin rubber protector. The magnetic fluid activated by traveling pulses of magnetic field drags the water inside the actuator. The size and weight of the device because there is no gear type parts, we can do reduce. Furthermore, it could be operated without vibration and noise.
The iterative algorithm for the shape of magnetic fluid is presented by using nonlinear finite element method and Navier-Stokes equations. The computed curvatures of fluid under the magnetic field and the gravitational force are agreed well with photographic image. The dimension and electric configurations of the magnetic linear actuator are optimized and the results are compared with the measurements.Abstract
제 1 ？？ 서론 = 1
1.1 연구배경 = 1
1.2 연구내용 및 방법 = 2
제 2 장 자성유체의 구조와 성질 = 3
2.1 자성유체의 물성 = 3
2.2 자성유체의 성질 = 5
2.3 자성유체의 응용 = 6
제 3 장 자성유체의 흐름해석 = 8
3.1 선형운동량 해석 = 8
3.2 Navier-Stokes방정식에 의한 유체해석 = 15
3.3 유한요소법에 의한 자기장 해석 = 19
3.3.1 지배방정식 유도 = 19
3.3.2 유한요소 정식화 = 22
3.4 유체 형태를 결정하는 수치해석 = 23
제 4 장 Linear Actuator의 구조 및 설계 = 29
4.1 Linear Actuator의 구조 = 29
4.2 Linear Actuator의 흐름해석 = 30
제 5 장 Linear의 Actuator의 실험 및 고찰 = 34
5.1 최적 코일거리 = 35
5.2 자성유체의 최적 양 = 37
5.3 최적의 자계의 세기 = 38
제 6 장 결론 = 39
참고문헌 = 4
(A) Study on the Linearity Improvement of Power Amplifier by Predistortion Method
Get PDFAccording to the evolution of existing and new standards of mobile communication systems and wireless multimedia services, the high quality of the signals to be transmitted from a base station is required. The RF(radio frequency) power amplifiers which are used in such systems, have to amplify all types of signals without significant distortion and keep operation capability at potentially high levels of output power.
For this purpose predistortion method was applied. It can reduce the 3rd order intermodulation signal by inserting the predistorter that has opposite characteristics of amplifier in front of the amplifier. The predistortion linearizer consisted of 3dB branch-line coupler, MESFET, attenuator, delayline, 20 dB directional coupler, and Wilkinson power combiner. The phase difference of two input signals into the Wilkinson power combiner was adjusted to maintain out-of phase by monitoring with 20 dB couplers, respectively, and controlling the length of delayline. Thus, the difference of two signals only can be emerged to the output port of the Wilkinson power combiner, and then it is possible to cancel the signals of two path. It is possible to have 180°phase difference between the fundamental signal and the 3rd order intermodulation signal. In addition, the passive attenuator and the phase shifter used for predistorter could minimize phase variation compared with the case of active ones.
The proposed predistorter was designed in the frequency band of 1,885 MHz ∼ 2,025 MHz, and cascaded to 4 W power amplifier, and tested with two-tone spreaded 2.5 MHz at the center frequency of 1.96 GHz. As an experimental result, it was clearly shown that the 3rd order intermodulation distortion characteristics have been improved as much as 17 dB when the output of the power amplifier is 30.67 dBm.Abstract = ⅰ
Nomenclature = ⅱ
제 1 장 서론 = 1
1.1 연구배경 = 1
1.2 연구목적 = 3
제 2 장 전력증폭기의 비선형 특성 = 4
2.1 전력증폭기의 상호변조 왜곡과 교차점 = 4
2.2 전력증폭소자의 분석 = 10
2.3 제작된 전력증폭기의 특성 = 13
제 3장 전치왜곡 선형화기 설계 = 16
3.1 전치왜곡 선형화기의 동작원리 = 16
3.2 선형화기 구성회로 특성 = 18
3.3 전치왜곡 선형화기 실험결과 = 28
제 4 장 선형화기를 포함한 전력증폭기의 측정 결과 = 33
제 5 장 결론 = 38
참고문헌 = 4
Effect of Natural Organic Substrates on Facilitation of Endosulfan Bildegradation in a Soil and Isolation of PCNB degraders
Get PDFEndosulfan and pentachloronitrobenzene (PCNB) are toxic pesticides that were used to control soil-borne plant diseases but are still detected in soils and ediblecrops despite its terminated use. In this study we report a new Endosulfan and PCNB-degrading strains able to grow under ambient aerobic conditions. These strains could readily utilize Endosulfan and PCNB (100ppm) as a sole carbon source respectively and showed a distinctive growth in a week or so. Endosulfan degrader was identified as Klebsiella oxytoca KE-8 and PCNB degrader as Alcaligenes denitrificans based upon 16S rDNA sequence analysis. In this study a PCR-DGGE (denaturing gradient gel electrophoresis) system was developed to specifically monitor endosulfan or PCNB degrader population (Klebsiella oxytoca KE-8 and Alcaligenes denitrificans). The isolation and characterization of the new degraders will be useful in facilitating accelerated bioremediation of Endosulfan and PCNB in the environment and in monitoring the bioremediation processes.목차
List of Tables = iii
List of Figures = iv
ABSTRACT = vi
I. 서론 = 1
II. 문헌연구 = 3
2.1 Endosulfan 및 PCNB의 물리·화학적 성질 및 생물독성 = 3
2.2 Endosulfan 및 PCNB 오염현황 = 6
2.3 Endosulfan 및 PCNB의 생분해경로 = 7
2.4 천연유기물 첨가에 따른 난분해성 유기화합물의 분해 촉진 = 11
2.5 PCR-DGGE기법에 의한 미생물의 군집분석 = 11
III. 실험 = 14
3.1 시험토양의 채취 = 14
3.2 시약 = 14
3.3 Endosulfan 및 PCNB생분해균의 분리 = 14
3.4 Endosulfan 및 PCNB 생분해균주의 성장실험 = 15
3.5 Endosulfan 및 PCNB 분해균주의 동정 = 16
3.6 Endosulfan 분해경로 규명을 위한 돌연변이균 제조 = 17
3.7. 순수배양조건에서의 천연유기물첨가에 의한 Endosulfan 분해촉진 시험 = 17
3.8 토양에서 천연유기물첨가에 의한 Endosulfan 분해촉진 시험 = 18
3.9 PCR-DGGE 기법에 의한 분해미생물의 추적 = 19
IV. 결과 및 고찰 = 21
4.1. Endosulfan 및 PCNB분해균의 분리 및 성장조사 = 21
4.2. Endosulfan 및 PCNB분해균의 동정결과 = 25
4.3. Tn 5 mutagenesis결과 = 31
4.4 천연유기물 첨가 순수배양조건에서의 Endosulfan 및 PCNB분해균의 성장 = 31
4.5. 천연유기물 첨가 토양에서의 Endosulfan분해균의 성장 조사 및 Endosulfan 분해효과 = 33
V. 결론 = 43
VI. 참고문헌 = 4
Speed Control of Marine Diesel Engines Using Fuzzy Gain Scheduling
Get PDFIn marine transportation, one of the most important factors is the energy saving. In order to reduce the fuel oil consumption, ship's propulsion efficiency must be increased as much as possible. The Propulsion efficiency depends upon a combination of an engine and a propeller. This situation led the engine manufacturers to design the engine that has lower speed, longer stroke and a small number of cylinders. Consequently, the variations of rotational torque became larger than before because of the longer time delay in fuel oil injection process and increased output per cylinder. As these new trends the conventional mechanical hydraulic governors for engine speed control have been replaced by digital governors which adopt the PID control or the optimal control algorithm. And the conventional PID controller has been extensively used to speed control of marine diesel engines. However, one of drawbacks is that its control performance can be degraded if the parameters are fixed on whole operating points.
In this paper, a scheme for integrating PID control and the fuzzy technique is presented to control speed of a marine diesel engine on overall operating points. At first, the local PID controller is designed at each speed mode, whose parameters are optimally adjusted using a genetic algorithm. Then, fuzzy "if-then" rules combine the local controllers as a consequence part. To demonstrate the effectiveness of the proposed fuzzy PID controller, a set of simulation works on a marine diesel engine are carried out.목차
Abstract = iii
제1장 서론 = 1
제2장 선박 디젤기관의 모델링 = 4
2.1 선박 디젤기관의 모델링 = 4
2.2 선박 주기관의 운전특성 = 7
2.3 퍼지 모델링 = 8
제3장 PID 제어기의 퍼지 게인 스케쥴링 = 11
3.1 최적화 도구로서의 유전알고리즘 = 11
3.1.1 동조 계수의 염색체 표현 = 12
3.1.2 유전 연산자 = 13
3.1.3 엘리트 전략 = 17
3.1.4 적합도 평가 = 17
3.2 RCGA 기반의 PID 제어기 설계 = 18
3.3 퍼지 게인 스케쥴링 = 21
제4장 모의실험 = 25
4.1 제어대상 시스템 = 25
4.2 제어대상의 퍼지모델 = 26
4.3 PID 계수의 최적동조 = 31
4.4 설정치 변경에 대한 속도추종 실험 = 34
4.5 외란에 대한 속도조절 성능 실험 = 39
제5장 결론 = 42
참고문헌 = 4
Image Segmentation Based on the Fuzzy Clustering Algorithm using Average Intracluster Distance
Get PDFImage Segmentation Based on the Fuzzy Clustering
Algorithm using Average Intracluster Distance
Image segmentation is one of the important processes in the image information extraction for computer vision systems. The fuzzy clustering methods have been extensively used in the image segmentation because it extract feature information of the region. Most of fuzzy clustering methods have used the Fuzzy C-means(FCM) algorithm. This algorithm can be misclassified about the different size of cluster because the degree of membership depends on highly the distance between data and the centroids of the clusters.
This paper proposes a fuzzy clustering algorithm using the Average Intracluster Distance that classifies data uniformly without regard to the size of data sets. The Average Intracluster Distance take an average of the vector set belong to each cluster and increase in exact propotion to it's size and density. The experimental results demonstrate that the proposed approach has the good classication entropy and validity function