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A Study on Flow Zone Development and Botton change gy Propeller Jets from Ships
Get PDFThe flow zone through propeller jets is used in evaluating the environmental and constructional effects of navigation on the waterways. Water in this zone can go through the propellers but not all water in this zone will go through the propellers. It relies on the characteristics of ships and water depth. A numerical model using the momentum theory of the propeller and Shield's diagram was developed in a restricted waterway. Equations for discharge are presented based on thrust coefficients and propeller speed and are the most accurate means of defining discharge. Approximate methods for discharge are developed based on applied ship's power. Equations for discharge are as a function of applied power, propeller diameter, and ship speed. Water depth of the waterway and draft of the ship are also necessary for the calculation of the grain size of the initial motion. The velocity distribution of discharge from the propeller was simulated by the Gaussian normal distribution function. The shear velocity and shear stress were from the Sternberg's formula. Case studies to show the influence of significant factors on sediment movement induced by the ship's propeller at the channel bottom are presented. The first case is for large ships passing through the navigation channel and berthing and unberthing at container terminal at Kwang Yang harbor.
Eleven ships are considered, including naval ship, tanker and bulk carriers.
The second case is for the commercial moving tow and the barge. The combined effects of the propeller jet and the wake flow a moving barge are investigated.목차
ABSTRACT = i
LIST OF TABLES = v
LIST OF FIGURES = vi
NOMENCLATURE = ix
제1장 서론 = 1
1.1 연구의 배경 = 1
1.2 연구의 목적 및 내용 = 2
1.3 연구의 방법 = 2
제2장 기본이론 = 5
2.1 추진기 배수류 이론 = 5
2.1.1 추진기 배수류의 속도분포 = 6
2.1.2 추진기에 의한 운동량 이론 = 16
2.1.3 속도분포 = 23
2.2 표사 수송이론 = 28
2.2.1 이론적 배경 = 28
2.2.2 소류사 수송이론 및 방정식 = 28
2.2.3 부유사 수송이론 및 방정식 = 33
2.2.4 표사이동의 결정이론 = 37
제3장 수치모델수립 및 적용 = 42
3.1 대형선박에 대한 모델 구성 = 42
3.1.1 실제 수역과 제한수로에 대한 적용 = 42
3.1.2 저면전단응력의 산정 = 46
3.2 예인선의 모델 구성 = 50
3.2.1 추진기 제트의 유속 산정 = 51
3.2.2 저면 전단응력의 산정 = 57
제4장 수치실험 결과 및 분석 = 61
4.1 제한수로 및 부두전면에서의 적용 = 61
4.1.1 제한수로에 대한 적용 = 61
4.1.2 부두 전면에 대한 적용 = 79
4.2 예인선에 대한 적용 = 104
4.2.1 대상선박의 특성 및 조건 = 104
4.2.2 수치모형의 검증 = 105
4.2.3 적용결과 및 분석 = 108
4.3 저면변형에 대한 고찰 = 114
제5장 결론 = 120
참고문헌 = 12
A Study on the Fault and Liability in the Ship Collisions
Get PDFWith a gross tonnage exceeding 12 million tons, Korea is currently one of the leading maritime nations of the world. However, approximately 800 marine accidents including ship collisions occur every year, and such frequent accidents result in considerable amounts of property losses and personal injuries. Accordingly, legal provisions governing ship collisions have gradually become very important. Nevertheless, the Commercial Code contains only six articles related to the ship collisions, which are not detailed enough to cover the diversified circumstances of ship accidents.
In particular, the Commercial Code provisions do not address the elements of ship collision, burden of proof or calculation method of negligence ratio, etc. Under the Commercial Code provisions, the ratio of responsibility principle applies with respect to property damage. With respect to loss of life, however, the Commercial Code simply provides for the joint liability principle, and does not mention the calculation method of damages. The Commercial Code invokes the principle of responsibility ratio for both property damages and loss of life as provided in the International Convention for the Unification of Certain Rules of Law with respect to Collisions between Vessels (1910), Article 4, Paragraph (3). However, seriously consideration is necessary as to whether the application of the ratio of responsibility principle is appropriate with respect to loss of life.
Further, in considering the apportionment of responsibility for collisions, the view that both parties to the collision should be responsible (cross liability principle), and the view that only one party to the collision should be responsible as the sole tortfeasor (sole responsibility principle), should be closely compared and analyzed.
The purpose of this thesis is to present various domestic and foreign judicial precedents concerning ship collisions, to serve as a resource for future legislations on the above subjects.
Specifically, Chapter Ⅰ "Introduction" discusses the background of the study and the issues relating to Article 846, Sections 1 and 2 of the Commercial CodeChapter Ⅱ addresses the definition of the "ships" and the elements required for a ship collision, Collision of ships due to force majeure(The Commercial Code, Article 844), Collision of ships due to negligence of one party(The Commercial Code, Article 845). The meaning of "ship" under each separate legislation must be interpreted in accordance with the context of the relevant legislation, where the legislation provides for the meaning of the term ship in accordance with the purpose of legislation. However, in the case of independent legislations and other matters, the concept of ship should be defined by taking into consideration not only the provisions of the legislation, but also the surrounding circumstances including the ability of navigation, function and purpose of the relevant vessel, together with the provisions of the legislation.
In the case of damage to a third party by a tug or tow, the various existing legal principles lacks generality, and further gives rise to the question whether the innocent third party can be fully compensated. Thus, the responsible party for the tort in the course of towing a vessel should be determined, based on the principle that the tug and tow are a single unit and that the master of the tug has primary responsibility. However in this case, the nature of the tow and the circumstances of the towing operation should be fully taken into account.
Chapter Ⅲ deals with the meaning of "Fault" under the civil law, criminal law and collision regulations, the determination and the criteria of negligence in case of collision between ships. The decision of the Marine Accident Adjudication Tribunal in a case of collision between ships only serves as reference material for the purpose of judgement of the court. In order for the Marine Accident Adjudication Tribunal's decision to carry more weight in the future, it is necessary to establish a system to secure the expertise and independence of the Marine Accident Adjudication Tribunal marine judges. In connection with the type of negligence, calculation of the proportion of negligence and burden of proof as to apportionment of liability, domestic and foreign judicial precedents, have been cited for comparison, and would be important materials for assessment of the ratio of negligence in ship collision cases.
Chapter Ⅳ considers the responsibility for compensation for damage caused by ship collisions, which is the main issue in such accidents.
The following issues are considered in Chapter Ⅳ:
- Who is responsible for the collision?
- The Commercial Code, Article 846, Section (1) : Collision of ship due to negligence of both parties.
- Scope of responsibility for compensation for damage in case of collision of ships due to negligence of both parties.
- Comparison between the single liability principle and the cross liability principle.
- Comparison between liability for loss of life and liability for loss of property.
Chapter Ⅴ discusses the invocation of the immunity clause, limitation of shipowner's liability, time bar, jurisdiction and governing law relating to the ship collision.
In case of collision between two ships of different nationality, adoption of the laws of the perpetrating ships nationality is of questionable validity in terms of legislation. In case where the cause of collision cannot be established, it is very difficult to determine which vessel is responsible for the collision. Therefore, if the two vessels collided on the high seas and an action based on such collision is brought before the Korean court, the case would have to be governed by Korean laws pursuant to the principle of lex loci. To resolve this difficulty, it is necessary to consider a revision of the Korean Conflict of Laws Act so as to accord jurisdiction to the Korean courts in case of collision on the high seas involving a Korean ship, and to apply the Korean Commercial Code for determination of issues relating to liability.
It would be difficult to reach a conclusion on any of the aforementioned subjects. Therefore the writer herein presents judicial precedents in various cases that occurred in England, U.S.A and Korea. The Commercial Code, Article 846 provides the basis for calculation of compensation amount for damages arising out of collision between ships due to negligence of both parties. The International Convention on Collision of Ships (1910) provides that the compensation for damage resulting from ship collisions due to negligence of both parties shall be borne by the owners of the ships in proportion to their respective weight of responsibility for the collision, and that in case the weight of responsibility cannot be assessed, the negligence of both parties shall be deemed equal. The above provision apparently takes into consideration the demands of marine underwriters at the time of drafting the Convention.
Almost all compensations for damage resulting from collision of ships in the present day are settled by way of marine insurance. As such insurance coverage is based on liability for ship collision, it is necessary to closely examine the legal principles governing ship collisions. The principles governing compensation for loss of property in case of collision caused by negligence of both parties are modifications of the general principles under the Civil Code. However, liability for loss of lives of third parties in case of collision due to negligence of both parties is imposed jointly on both parties. It is therefore noteworthy that the loss of property due to ship collisions, which can be considered an internal matter, is governed by the principle of proportionate liability, while the loss of lives of third parties is governed by the tort principles under the Civil Code. Thus, it should be noted that notwithstanding the common nature of marine perils, the system of compensation for damage is governed by a dual principle. The writer, therefore, would like to point out that the liability for loss of property as well as for loss of lives of the third party in case of collision due to negligence of both parties, shall be imposed jointly on both parties in line with the Japanese Commercial Code, Article 797, because there is not any any special reason to discriminate the loss of lives and the loss of property of the third parties for the innocent parties' interest.目次 = ⅰ
ABSTRACT = ⅳ
第 1 章 머리말 = 1
第 1 節 硏究의 目的 = 1
第 2 節 硏究의 範圍와 方法 = 4
第 2 章 船舶衝突 損害賠償責任의 槪念과 發展 = 6
第 1 節 船舶衝突의 槪念과 法的 性質 = 6
Ⅰ. 船舶衝突의 槪念 = 6
Ⅱ. 船舶衝突의 成立要件 = 10
Ⅲ. 船舶衝突의 種類 = 22
Ⅳ. 船舶衝突 損害損害賠償責任의 法的 性質 = 28
第 2 節 船舶衝突에서의 過失責任法理의 發展 = 29
Ⅰ. 過失로 인한 損害賠償責任의 基礎 = 29
Ⅱ. 雙方過失衝突의 경우 = 31
Ⅲ. 船舶衝突 損害賠償責任에 관한 立法例 = 34
Ⅳ. 船舶衝突 損害賠償責任 關聯 國際協約의 發達 = 41
Ⅴ. 船舶衝突에 관한 國內法의 規定 = 44
第 3 章 船舶衝突에 있어서의 過失 = 47
第 1 節 過失의 槪念 = 47
Ⅰ. 過失의 一般論 = 47
Ⅱ. 船舶衝突에 있어서 過失 = 54
第 2 節 過失의 判定 = 58
Ⅰ. 海洋安全審判院 = 58
Ⅱ. 法院 = 62
Ⅲ. 過失判定에 대한 海洋安全審判院의 裁決과 法院의 判決과의 關係 = 67
第 3 節 船舶衝突에 있어서의 過失責任 = 71
Ⅰ. 過失責任과 過失의 認定基準 = 71
Ⅱ. 過失의 類型 및 內容 = 73
Ⅲ. 立證責任 및 過失의 推定 = 91
Ⅳ. 小結 = 100
第 4 章 船舶衝突로 인한 損害賠償責任 = 102
第 1 節 損害賠償責任의 主體 = 103
Ⅰ. 船舶所有者 등 = 103
Ⅱ. 導船士 = 105
Ⅲ. 港灣當局 및 海上交通管制官 = 106
Ⅳ. 多數의 責任主體 相互間의 關係 = 107
第 2 節 損害賠償責任의 法理 = 107
Ⅰ. 人的 損害 = 110
Ⅱ. 物的 損害 = 111
第 3 節 損害賠償責任의 範圍 = 125
Ⅰ. 船舶衝突과 損害와의 相當因果關係 = 125
Ⅱ. 損害賠償責任의 範圍 = 128
第 5 章 船舶衝突 損害賠償責任에 있어서 其他 問題 = 135
第 1 節 免責約款 등의 援用 = 135
第 2 節 船舶所有者의 責任制限 = 137
Ⅰ. 船舶衝突과 船舶所有者의 責任制限 = 137
Ⅱ. 過失比率에 의한 責任과 船舶所有者 責任制限節次와의 相互關係 = 138
Ⅲ. 船舶所有者의 責任制限과 기타의 債權과의 關係 = 139
第 3 節 船舶衝突債權의 消滅時效 = 140
Ⅰ. 消滅時效期間 = 140
Ⅱ. 時效의 起算點과 時效의 中斷 = 141
第 4 節 船舶衝突에 관한 裁判管轄權과 準據法 = 142
Ⅰ. 船舶衝突과 裁判管轄權 = 142
Ⅱ. 船舶衝突에 있어서 準據法 = 144
Ⅲ. 各國의 立法例 = 145
第 6 章 맺음말 (立法論) = 154
參考文獻 = 15
A Study on the Channel Estimation in the Underwater communications
Get PDFIn recent years, underwater acoustic communication have received much attention as their applications, have begun to shift from military toward commercial. The growing interest in underwater acoustic communications come as a response to the rapidly growing needs for wireless underwater communications, brought in part by the broadening of applications, such as military and commercial ones. Commercial applications which have received much attention lately are pollution monitoring in environmental systems, remote control in off-shore oil industry, and collection of scientific data recorded at benthic station without the need for retrieving the instruments. Many developing applications include of commercial and military are now calling for real-time communication with submarines and autonomous underwater vehicles, not only in point-to-point links, but also in network configurations.
This research has aimed toward bringing together many of the well established principles of wireless radio communications and re-considering them for application in underwater acoustic channels. However, the adverse effects of underwater propagation has on the digital acoustic signals often require development of specialized communication techniques. Many solutions have been offered, and the extensive research of the past years has established underwater acoustic communications as a new field of applied engineering.
In this thesis, a new method of channel estimation for underwater acoustic communication is considered. Signal transmitted in the underwater has multiple interactions with the sea surface, the bottom, and volume. Multipath propagation in underwater acoustic communication causes distortion to high-speed digital signals. The proposed method reduces distortion of received signal by multipath propagation. The proposed method is similar to the passive phase conjugation technique. However, the difference is that the probe signal is used for underwater communication channel estimation. The underwater channel impulse responses are estimated by eigenvalue decomposition algorithm. The channel vectors are in the null space of the covariance matrix of the received signal at receiver array. The received data signals are convolved with the time-reversed channel impulse responses. The results of this processing reduce distortion of received signal. The performances of the proposed method are evaluated in various environments.목차
그림차례 = ii
표차례 = iii
기호표 = iv
약어표 = v
Abstract = vi
제1장 서론 = 1
제2장 Time-Reversal Mirrors = 5
제2-1절 능동형 TRM = 5
제2-2절 수동형 TRM = 9
제3장 채널 추정을 이용한 디지털 통신 = 19
제4장 시뮬레이션 결과 = 25
제5장 결론 = 31
참고문헌 = 3
(A) Study on the Reactive Power Compensation using Instantaneous Power for Self-Commutated Static Var Compensator
Get PDFA Study on the Reactive Power Compensation using Instantaneous Power for Self-Commutated Static Var Compensator
The static var compensator(SVC) plays an important role in larger and more complex electric power systems. Rapid and continuous reactive compensation by the SVC contributes to voltage stabilization, power oscillation damping, overvoltage suppression, minimization of transmission losses and so on.
The multilevel inverters connected in series are suitable for high voltage systems because of their circuit structure. They are capable of reducing harmonic component in the AC source side currents without requiring high frequency switching to the devices.
The main problem of multilevel inverters without independent DC voltage source is the unbalance of DC capacitor voltage. Problems in using SVC are the voltage unbalance at each stage of DC capacitor and uncontrollability of reactive power in its low region. DC capacitor voltage equalization is required to ensure the even sharing of voltage stresses in the power devices, and to compensate accurately reactive power.
In this paper, harmonic current components were analyzed to solve these problems and it was found that the voltage distortion of the DC capacitor is caused by the harmonics in resistive mode operation and/or low reactive power.
In addition, the zero point of DC capacitor voltage deviation is investigated by analyzing resistive mode operation and/or low reactive power. It gives a control table for DC capacitor voltage equalization. Asymmetrical Pulse Amplitude Modulation(PAM) switching pattern is suggested to equalize DC capacitor voltage. The principle of asymmetrical PAM switching pattern is time shifting of charging or discharging period of DC capacitor by controlling angle.
By using the control table, asymmetrical PAM switching pattern is realized to equalize DC capacitor voltage.
Instantaneous power vector theory which can expresses the instantaneous apparent power vector is proposed to control reactive power. The validity of the proposed method is confirmed by simulation studies and experiments
The Effect of Additives on the Properties of Zn Electrode
Get PDFThe zinc electrode is one of the most widely used as an anode material in alkaline battery systems, and the silver-zinc system has the highest gravimetric energy density and the highest volumetric energy density among all of the rechargeable batteries. Some rechargeable lithium batteries are reported to have better performances. They are, however, still in reserach stage having several defects, for example small size, limited rate capability, moreover, being considered as an obstacle eventual use due to the safety problem and the environmental concern. The advantage of using zinc electrode are low cost, good electrochemical equivalent (820 Ah/Kg) and high open-circuit voltages (OCVs) in most of battery systems. But its cycle life as secondary battery is very short, because the shape change is occurred by the replacement of zinc active material and the dendrite growth causing undesirable morphology .
Generally the methods of improvement of zinc electrode's characteristic are mixing Hg, Cd, As with zinc active materials in manufacturing process, changing their separator or adding small amount of additives into alkaline electrolyte.
In this study, four kinds of experiments were performed in order to investicat the effects of additives by adding four types additives which have been reported to show an effect on improving the performance of silver-zinc secondary battery systems with zinc anode, and Pb₃O₄ to inhibit the dissolution of zinc into KOH electrolyte.
Firstly, the potential versus submerged time as to the variation of the quantity of additives was measured in order to select the most appropriate quantity of Pb₃O₄.
Secondly, executed potentiodynamic polarization test was performed in order to measure the degree of corrosion of zinc electrode.
Thirdly, conducted charge-discharge cycle life test was performed.
And finely the morphology of the surface of zinc electrode was analyzed through SEM (Scanning Electron Microscope) photographs.
The results of this study are as follows :
1) The result of potential vs. submerging time for 21days showed that potential of Zn electrode contained its properties in case of 0.5 wt.% of Pb₃O₄ when Zn electrode was set in 40 wt.% of KOH as to the quantity of Pb₃O₄ 0.5, 1.0 and 2.0 wt.% and four types additives .
2) The result of polarization test in case of 40 wt.% KOH electrolyte with 0.5 wt.% of Pb₃O₄ and the four types additives was that the protection property of Pb₃O₄ showed the best performance and then followed by tartrate. In case that nothing was added(here in after referred to No Addition), it showed the worst performance.
3) The result of charge-discharge cycle life test showed that the property of charge and discharge, when the additives were added, was better case of No Addition. Especially the discharge property of tartrate showed the best result, and the charge property was good also.
4) The result of SEM analysis showed that the shape change and the dendrite growth of Zn electrode surface was noticed with the lowest amount in case of adding tartrate and Pb₃O₄ showed fair performance for three days.목차
Abstract
1. 서론 = 1
2. 이론적 배경 = 4
2.1 알카리 2차 전지용 Zn 전극 = 4
2.2 Zn 전극의 용해 특성 = 9
2.2.1 Zn 전극의 anode 용해와 부동태 = 9
2.2.2 과포화 zincate 용액 = 13
(1) 전해질 내에서의 zincate = 13
(2) 과포화 zincate 용액의 형성 = 14
(3) 과포화 zincate 용액으로부터의 ZnO 석출 = 17
2.3 Zn 전극에 미치는 첨가제의 영향 = 18
2.3.1 수산화 칼슘의 영향 = 18
2.3.2 구연산 나트륨, 주석산 나트륨 칼륨, 포도당 칼슘의 영향 = 21
2.3.3 사삼산화납의 영향 = 23
2.4 충·방전 시 Zn의 용해 및 전착 메커니즘 = 28
2.4.1 KOH용액 중 Zn의 anode 용해 메커니즘 = 28
2.4.2 Zn의 anode 용해, 그리고 Zn(OH)₂및 ZnO의 형성과 재용해 = 31
2.4.3 Zn 전착 시 dendrite와 성장 층의 형성 = 34
3. 실험 방법 = 36
3.1 실험용 극판 제작 = 36
3.1.1 음극판의 제작 = 36
3.1.2 양극판의 제작 = 38
3.2 전해액과 첨가제의 조성 = 41
3.3 성능 분석시험
3.3.1 자연전위 측정(Potential vs. submerged time)시험 = 42
3.3.2 분극특성 시험(Potentiodynamic polarization test) = 42
3.3.3 충·방전 가속 사이클 수명시험 = 43
3.3.4 SEM 측정 = 46
4. 실험결과 및 고찰 = 47
4.1 자연전위 측정 = 47
4.2 분극 곡선 = 50
4.3 충·방전 가속 사이클 수명시험 = 57
4.4 방전 곡선 = 68
4.5 회복 전위 곡선 = 74
4.6 충전 곡선 = 80
4.7 SEM 사진 분석 = 86
5. 결론 = 101
참고문헌 = 10
沿岸貨物船業體의 經營分析에 의한 經營改善方案에 관한 硏究
Get PDFThe purpose of this study is to examine a scheme for growth, management rationalization and reform measure of domestic coastal shipping companies, and Ihope that this will be of some help that coastal shipping companies get ready for a management improvement plan and decision-making
For this study, I investigated not only a financial condition and forms of management of coastal shipping companies but also operating earnings and expenses which several kinds of vessel as well as by regional groups in domestic
On the bases of this study I lay out the schemes how to develop domestic coastal shipping company and the fine parts are as followsThe first, it is necessary to secure a steadying seamen supply plan. In order to make it more rational, the company have to guarantee seamen's real income and the government have to lighten the individual income tax and support medical insurance fee and employment insurance fee, in addition to establish a joint company for seamen's supply
The second, the coastal shipping company has to make ready for measure devised to deal with an extension of electronic commercial transaction and high value added service.
At present, the coastal shipping companies must cope effectively with the change of economic circumstance that is to say, epoch-making development of information technology, the change of economic based on a knowledge-intensive. So that the companies have to introduce the system of electronic commercial transaction as well as a exclusive berth for coastal shipping
The third, it is necessary to establish a control policy for reasonable space of coasting vessel. Private corporations need to organize what is called "the committee for self-control an excess of bottoms" in order to judge what is reasonable space or not
The fourth, this is the point to be specially considered that an old vessel is to be substitute for the latest economic vessel. Ithink this is an epoch-making device to improve coastal shipping system because nowadays the owner of goods wants high-level and various services. The first consideration is the government has to lend money to build a ship at low interest
The fifth, coastal shipping companies have to grow larger and construct mutual aid system in order to cut down the cost and rise competitiveness against another transportation mode.
The sixth, it is necessary that the government take measures to promote top-ranking coastal shipping company. If the government do it that way, management man will make every effort to make a top-ranking company, and so top-ranker will contribute greatly to developcoastal shipping and cut down transportation cost as well as safety voyage, the protection of environment, and so on.목차
Abstract
제1장 서론 = 1
제1절 연구필요성과 연구목적 = 1
제2절 자료수집과 연구방법 = 2
1. 자료수집 = 2
2. 분석방법 = 3
제2장 연안화물선업체의 성장배경과 현황분석 = 6
제1절 해방 후 연안화물선업체의 성장배경 = 6
제2절 연안화물선업의 현황분석 = 8
1. 선종별 및 선령별 선복량 현황 = 8
2. 연안화물선업의 소유구조 = 20
3. 연안화물선박 확보현황분석 = 21
제3절 연안화물선시장의 특성 = 26
1. 연안화물선시장의 구조적 특성 = 26
제4절 연안화물운송시장의 성장 = 32
1. 연안화물 수송물량의 성장추이 = 32
2. 연안화물의 구조변동 = 33
제3장 연안화물선업체의 경영분석과 경영진단 = 39
제1절 연안？？물선업체의 재무제표구조분석 = 39
제2절 연안화물선업체의 재무비율분석 = 43
1. 재무구조비율분석 = 43
2. 수익성분석 = 50
3. 운항수지 분석과 진단 = 54
제3절 연안화물선업체의 경영분석결과와 진단 = 56
1. 대차대조표 구조분석결과와 진단 = 56
2. 손익계산서 구조분석결과와 진단 = 58
3. 연안화물선업체의 재무비율분석과 진단 = 58
4. 운항수지 분석결과와 진단 = 59
제4장 연안화물선업체의 경영문제점과 대응방안 = 62
제1절 연안화물운송의 주요현안과 경영문제점 = 62
1. 연안화물운송사업의 등록제 문제점과 보완 = 62
2. 연안화물운송사업의 수요 독점적 착취와 협업화 부진과 개선방안 = 66
3. 해운환경변화에 대응력강화를 위한 선박금융제도개선 = 70
4. Modal Shift의 추진 = 71
5. 선박안전관리체제의 법제화 = 72
제2절 연안화물선업체의 발전전략 = 74
1. 경영환경여건의 개선방안 = 74
2. 대화주 관계의 개선방안 = 75
3. Modal Shift 정책의 추진 = 76
4. 연안화물터미널의 종합물류기지화 = 77
5. 연안해운업의 집약화 = 78
6. 연안해운 수송시스템의 개선 = 78
7. 연안선박 ？횬喚桓？체제 구축방안 = 79
8. 우량해운기업제도 도입 = 80
9. 면세유 공급방안 = 81
제3절 연안화물선사업의 발전을 위한 정책건의 = 82
1. 연안해운의 21세기 장기발전의 기본방향 = 82
2. 연안해운업계의 정책건의 = 86
제5장 결론과 시사점 = 101
제1절 분석결과의 요약 및 시사점 = 101
1. 경영성과분석과 진단결과 = 101
2. 연안화물선업의 활성화를 위한 경영개선방안 = 103
제2절 연구의 한계 = 105
[참고문헌] = 10
(The) Effective Stabilization of Sewage Sludge Using T.P.A.D(Temperature-Phased Anaerobic Digestion)
Get PDFThe conventional single-stage anaerobic digestion system employed in korea has been limited in an effective stabilization and sewage sludge. This indicates relatively higher management cost for the sewage sludge treatment. Temperature-phased anaerobic bioreactor system could be an alternative technology to circumvent these problems. This system includes a thermophilic (55℃) reactor and a mesophilic (35℃) reactor in sequence. The temperature-phased system employs a thermophilic process where consumption of organics at higher concentration can be performed. This system can be remove pathogen more efficiently and cause little scuming or foaming that has been typical in the conventional sludge treatment system.
The purpose of this study was to compare the performance of the temperature-phased (thermophilic/mesolphilic) sludge treatment system with the conventional single-stage system in treating mixtures of primary sludge and waste activated sludge in terms of sludge stabilization methane production and hydraulic retention time.
For this study, TPAD system comprised a two-stage reactor system which gas composed of a thermophilic anaerobic digestion system (12.6L) and a mesophilic reactor (34.8L) in sequential order while the conventional single-stage system had a working volume of 51L. Both reactor systems were run in various range of hydraulic retention time to comparatively analyze an optimal retention time for each system.
The experimental results were summarized as follows. Little foaming was observed in TPAD system after 18 days of operation while the foaming was significant in the conventional system from the beginning. In terms of volatile solids (VS) removal the TPAD system showed a maximum rate at the HRT of 10 days. However, the conventional system gave a similar effect as in TPAD system after 28 days, indicating TPAD system was almost 3 times as effective as the conventional system in terms of treatment time. COD, VS removal efficiency in the thermophilic reactor of TPAD system was inversely proportional to HRT but this was compensated in the mesophilic reactor in the system. The conventional system, however, needed longer HRT to reach the equivalent removal efficency. pH and VFA/alkalinity ratio in both systems a were generally maintained in a stable range regardless of HRT.
From the above results, it was generally concluded that the TPAD system was more efficient in stabilization of sludge, organics reduction, methane production, and decreased HRT, hence reduced volume in sludge digester.
This study showed contribute to an understanding of TPAD system in view of sludge treatment compared with the convintional system and to development of a TPAD system applicable to a field situation
Development of 3-D Particsl Tracking Velocimetry using Genetic Algorithm
Get PDF충분한 정확도와 신뢰도를 가진 다양한 난류계측에서 열선유속계와 LDV가 계측에 널리적용되어 왔다. 그러나 이러한 계측법은 기본적으로 측정대상공간에 대하여 한 점에 대한 정보밖에 얻을수 없다. 이러한 이유로 동시 다점계측이라는 장점을 가진 PIV계측기법에 의해 얻어내는 연구성과들이 계속 증가 추세에 있으며, 특히 난류에 대한 많은 정보를 얻기 위해서는 3방향의 속도성분을 동시에 계측하는 것이 요구되어지고, 이러한 3차원 계측이 활발히 진행되어지고 있다. 그러나, 기존의 계측방법으로 속도가 빠르거나, 3차원성이 강한 복잡한 유동장에 대한 계측은 어려운 단계에 있다.
본 연구에서는 이러한 단점을 극복하기 위하여 기존의 탐색방법인 시간-공간, 공간-시간방식이 아닌 시ㆍ공간을 동시에 탐색하여, 계측과정을 축소하여 계측시에 존재하는 오차의 영향을 최소화하는 알고리즘을 구축하고자 한다. 이러한 알고리즘의 구축을 위해 자연세계의 진화 현상인 적자생존에 기초한 최적화 알고리즘인 유전알고리즘을 적용하였다. 유전알고리즘을 적용하기위해 3차원 벡터를 기준으로 하는 개체를 정의？臼눗？, 3차원 위치와 유체의 연속의식으로부터 적합도를 선정하여 유전연산자를 적용하는 알고리즘을 개발하였다.
개발된 알고리즘은 채널유동 및 충돌제트유동에 대한 가상영상기법에 의해 알고리즘의 성능평가를 수행하였으며, 기존의 방법보다 우수한 결과를 보임을 알 수 있었다. 나아가 후향단유동장에 계측을 통하여 순간 3차원 속도벡터의 개수가 약 1,100개 이상으로 획득하는데 성공하였으며, 정성적으로 타당한 결과를 얻을 수 있었다.
본 연구에서 개발된 유전알고리즘에 의한 PTV기법이 가상영상 및 채널유동대한 우수한 결과를 얻음으로서 난류유동의 계측법의 유효성을 입증하였다.List of Tables = Ⅰ
List of Figures = Ⅱ
Abstract = Ⅳ
Nomenclature = Ⅴ
제 1 장 서론 = 1
제 2 장 3차원 계측의 원리
2.1 표정요소의 정의 및 계산 = 5
2.2 3차원 위치 결정의 원리 = 6
제 3 장 유전 알고리즘(GA)의 적용
3.1 일반적인 유전 알고리즘 = 12
3.2 PTV에서의 유전 알고리즘 = 12
제 4 장 가상영상에 의한 성능평가
4.1 가상영상의 구현 = 20
4.2 채널 및 제트유동의 가상영상 = 30
4.3 계측오차의 불확실성 = 39
제 5 장 후향단 유동계측
5.1 계측 시스템의 구성 = 41
5.2 실험조건 및 계측결과 = 44
제 6 장 결론 = 61
참고문헌 = 6
(A) Study on the core Detection of Fingerprint Based on the Ridge Direction
Get PDFThe core of fingerprint is a basis for fingerprint identification. widespread algorithms for core detection use the template matching technique. But these methods occasionally extract wrong cores which are not related with the real core of fingerprint.
This paper proposes a core detection method using normal direction information of the ridge. The proposed method extracts a core by calculating deviations of normal directions on the basis that the ridge radiates from its core in every direction. According to the experiment results, it is certain that the proposed method can extract a core more efficiently than the template matching method.제 1 장 서론 = 1
제 2 장 템플릿 매칭에 의한 중심점 추출 = 3
2.1 지문 분류별 중심점 형태 = 3
2.2 템플릿을 이용한 중심점 추출=6
제 3 장 융선 추적을 통한 융선방향 결정과 융선의 법선방향을 이용한 중심점 추출 = 9
3.1 융선 추적방법에 의한 융선의 방향 결정 = 9
3.1.1 융선방향 결정 = 13
3.1.2 프로파일 명암도 분포 조절과 정지조건 = 18
3.2 융선의 법선방향 편차를 이용한 중심점 추출 = 21
3.2.1 방향 성분과 중심점 = 22
3.2.2 법선방향 편차와 중심점 추출 = 24
제 4 장 실험 및 고찰 = 31
제 5 장 결론 = 4
An Implementation of Attitude Stabilizing Controller for 2-Axis Platform using Adaptive Fuzzy Control and DSP
Get PDFIn order to stably receive or transmit the signals of satellite antennas or TV receivers mounted on a moving ship, it is necessary to stabilize the platform of the ship. The motion of the ship is a six degree-of-freedom motion and is composed of surge, sway, heave, roll, pitch and yaw component. Components related to the stabilization of the ship are the very roll and pitch component and they are independent each other.
To stablilize the platform of the ship is to comprise feedback control systems for each rolling and pitching plant, which follow the reference input signals corresponding to the opposite directions of the roll and pitch angle detected from the moving ship.
This adaptive fuzzy control algorithm is especially useful for systems whose mathematical models are not easily found owing to the geometrical complexity, parameter uncertainty and etc. The adaptive fuzzy control algorithm suggested in this paper, is a 2nd/1st-type indirect adaptive fuzzy control algorithm utilizing only the advantages of 1st-type and 2nd-type indirect adaptive fuzzy control algorithm in order for a microprocessor to accomplish control algorithms with a computational efficiency.
There is a great number of on line computational parameters when the fuzzy logics of the adaptive fuzzy control algorithm are accomplished. In order to compute them within a real time sampling period, the TMS320C31 DSPs were adopted and real time controllers were composed using the DSPs as a central instruments.
To prove the effectiveness of the suggested control algorithm computer simulations were accomplished. To test the usefulness and the possibility of the real time control within 10 msec sampling period experiments were executed. According to the results of simulations and experiments, the suggested control algorithm turned out effective and the attitude stabilizing control system of platform of ships exhibited a very good control performance with tracking errors within ±0.5°for each time-varying roll and pitch command angle.목차
Abstract
제1장 서론 = 1
제2장 자세 안정화 제어 알고리즘 = 4
2.1 선박 운동에서의 자세 안정화 = 4
2.2 자세 안정화 제어 알고리즘 = 6
2.3 간접적응퍼지제어기 = 8
2.3.1 인식 모델 = 9
2.3.2 기본제어기 = 10
2.3.3 감독제어기 = 11
2.3.4 적응 규칙 = 14
2.4 2/1형 간접적응퍼지제어기 = 17
제3장 자세 안정화 제어시스템의 구조 = 19
3.1 전체 제어시스템의 구조 = 19
3.2 센서부의 구조 = 22
3.3 구동장치부 = 25
3.4 자세제어부 = 27
제4장 자세 안정화 시스템의 모델링 및 제어기 설계 = 29
4.1 시스템 모델링 = 29
4.2 자세 안정화 적응퍼지제어기 설계 = 31
4.3 시뮬레이션 결과 및 고찰 = 34
제5장 실험 및 결과 = 37
5.1 DSP 기반 제어기의 구조 = 37
5.2 전체 제어시스템의 구성 = 40
5.3 실험 및 결과 고찰 = 45
제6장 결론 = 50
참고문헌 = 5