8090 research outputs found
Sort by
(An) Empirical Study on the Impacts of Management Characteristics of Korean Shipping Companies on the Risk
Get PDFGenerally speaking, shipping companies need enormous funds to purchase or build ships which are their most important assets. Particularly Korean shipping companies which have difficulties in raising funds have high risk because their debt level is very high in relation to the acquisition of the vessels. And besides, it is very difficult for the shipping companies to expect stable freight revenue as shipping market is a complete competition market in which all the prices including freight rate are decided according to the theory of demand and supply between shippers and ship owners not in the domestic market but in the global market. Consequently, the risk of shipping companies is even higher than that of other industries because it is very uncertain for them to obtain stable revenue and sustain their growth rate.
Higher return can be achieved when the risk is high in accordance with conventional economic and financial theory. However, the conventional theory regarding the relationship between profit and risk does not always apply to Korean shipping companies as they cannot get high return despite the high risk confronting Korean shipping companies when compared to other industries. Therefore, it is very useful to analyse factors which have impacts on shipping companies and to take measures to enhance competitiveness of Korean shipping companies. The purpose of this study is to select the shipping-related risk factors and to analyse the relationship between shipping-related risk and those factors in Korean shipping companies for the development of Korean shipping industry.
The field data on the 32 ocean-going shipping companies′ financial statements have been used to get the empirical evidence. Coastal shipping companies were excluded as most of them are too small in size to make reasonable decisions and it is very difficult to collect the related data.
Previous books or documents have been referred to research the conventional theories as to the relationship between risk and return. Statistics analysis has been made based on the collected data to choose factors which influence shipping-related risk. T-test and multiple regression analysis have also been used to test relationship between risk and those factors.
This study has set six hypotheses and research model to examine the shipping -related risk factors and the relationship between shipping-related risk and those factors. Six hypotheses are the followings : Four factors(fluctuation of vessel volume, fluctuation of debt, fluctuation of operation profits, fluctuation of cash flow) have a negative correlation with the shipping risk whereas two factors(fluctuation of charter cost, fluctuation of interest) have a positive correlation with the shipping risk.
These hypotheses have been adopted as a result of multiple regression analysis with a significance level less than 0.01. These results represent that Korean shipping companies′ managers tend to make conservative decisions as to vessel volume if the shipping risk becomes high: Fluctuation of debt becomes low if the shipping risk becomes highManagement techniques and systematic provisions have to be prepared to avoid an exchange rate risk when funds are raised by foreign currency debt.Vessel acquisition contract should reasonably be made in terms of interestCharter related decision should be made reasonably and conservatively to manage the shipping-related riskKorean ocean-going shipping companies have to reduce their debt ratio and increase their equity capital ratio to avoid shipping riskIf the shipping risk becomes high, decision-making regarding cash flow becomes conservative and so Korean ocean-going shipping companies tend to make a reasonable decision to avoid the risk.
Finally, the results of this study hint that Korean ocean-going shipping companies relatively make a non-aggressive and non-offensive but reasonable and conservative decision in preparation against possible shipping risk in their cash flow, vessel volume etcInterest becomes higher when shipping market is depressedKorean shipping companies do not get high profits even if they are faced with relatively high risk when compared to other industriesThe bigger the charter cost, the higher the shipping risk表 目次
그림 차례
英文 抄錄 (Abstract)
第1章 序論 = 1
第1節 問題의 提起 = 1
第2節 硏究의 目的 = 3
第3節 硏究의 方法 = 4
1. 硏究對象과 資料蒐集 = 4
2. 分析方法 = 4
第4節 硏究의 範圍와 內容 = 5
第2章 韓國海運産業의 變遷過程과 經營特性 = 6
第1節 韓國海運産業의 變遷過程 = 6
1. 韓國海運의 準備期 (1945년부터 1960년) = 7
2. 韓國海運의 高度 成長期 (1960년부터 1984년) = 11
3. 韓國海運의 現況 (海運自由化 또는 國際化) = 15
4. 韓國海運의 未來展望 = 19
第2節 海運産業과 市場 特性 = 21
1. 海運自由가 海運市場에 미치는 影響 = 21
2. 需給調節機能의 不安全과 市場의 補完裝置 = 27
3. 世界經濟의 變化와 海運業의 構造的 不況 = 32
第3章 危險要因에 관한 理論的 背景과 先行硏究 = 42
第1節 危險과 관련된 意思決定理論 = 42
1. 企業危險에 대한 經營行態理論 = 42
2. 危險에 대한 經營戰略的 接近 = 44
第2節 海運危險과 海運産業의 特性 = 48
1. 海運經營의 意思決定 分野 = 48
2. 海運危險과 관련된 海運産業의 特性 = 50
第3節 海運經營에 따른 企業危險 = 54
1. 海運企業과 企業危險의 種類 = 54
2. 海運市場別 危險의 具體的 形態 = 57
3. 海運企業의 經營多角化와 危險 = 62
4. 海運危險에 따른 海運産業의 競爭力 强化 必要性 = 63
第4章 韓國海運企業의 經營實態分析과 診斷 = 66
第1節 外航海運의 經營環境 分析 = 66
1. 外航海運企業의 現況 = 66
2. 外航海運産業의 經營環境 = 71
3. 外航船 保有現況 = 73
第2節 韓國海運企業의 經營實態分析 = 78
1. 收益性 分析 = 78
2. 財務構造 分析 = 81
3. 資産 및 資本의 效率性 分析 = 83
4. 生産性 分析 = 85
第5章 海運危險의 關聯要因에 관한 實證硏究 = 88
第1節 變數選定과 硏究假說 設定 = 88
1. 變數選定과 測定 = 88
2. 資料蒐集과 分析方法 = 91
3. 硏究模型과 假設設定 = 92
第2節 外航海運企業의 危險要因分析 및 製造業과 比較 = 98
1. 外航海運 關聯變數들의 趨勢 分析 = 98
2. 外航企業과 製造業間의 危險關聯要因 比較 分析 = 108
第3節 海運危險과 關聯要因間의 關聯性分析과 結果 = 118
1. 分析模型과 分析結果 = 118
2. 假說檢定結果 = 121
第6章 結論 = 123
第1節 分析結果의 要約 = 123
第2節 硏究結果의 示唆點 = 126
第3節 硏究의 限界와 向後 硏究課題 = 128
參考文獻 = 129
1. 國內文獻 = 129
2. 國外文獻 = 13
An Empirical Study on the Size Effect in Korean Shipping Industry
Get PDFThis thesis is aimed to guide ocean shipping companies to reasonable decisions and to increase the competitiveness of Korean shipping industry by clarifying the determinants of size effect of ocean shipping companies, which only depend for the enormous amount of money to introduce the operating fixed assets, or the vessels, upon the supporting policy from the government or the loan from the related financial institutions.
In this study, the size of the shipping industry was measured with sale amounts, and the its political cost measured with the corporation tax, as explicit taxes shown on the financial state- ments, and with tax, public imports and donation as implicit taxes, divided by total sales profit.
As independent variables of the size effect and political costs, 5 elements were composed such as average interest ratio, sales growth ratio, marine risk(sales variance), cash flow and charactering reveune ratio. To verify the relations and the effect level between independent variables and size, the structure equation Model(SEM) was applied using AMOS statistical package(4.0).
The result of the analysis shows significantly positive relations between size variables and political cost of shipping industry. Moreover, average interest ratio and charactering reveune ratio were proved significant related with size effect of shipping industry.
These can be understood that the big company, which hold large vessel numbers, have high debt ratio and the large business have high charactering size with the consideration of fleet policy.
This study indicates that the hypothesis of size is verified, that political costs and size variables have positive relations because shipping industry has much higher debt ratio and marine risks in its nature than any other industry, and the development and maintainment of the business are closely connected to the political matter. Under WTO system, however, Korean shipping industry is considered to continue restructuring and the rationalization of management to survive keen competition of the world shipping market.
It is the limitation in this study that this study can not be free from the influence of sample bias since the study analyzed only the financial statements in research period of the 36 ocean shipping companies. Therefore, when it concerns to the limitation of this thesis, further studies need either to be subdivided on time series or to be compared with other industries.목차
第1章 序論 = 1
第1節 問題의 提起 = 1
第2節 硏究의 目的 = 4
第3節 硏究方法 = 4
1. 硏究對象과 資料蒐集 = 4
2. 分析方法 = 5
第4節 硏究의 範圍와 內容 = 6
第2章 規模效果에 관한 理論的 背景과 先行硏究 = 7
第1節 實證的 會計理論分野에 대한 考察 = 7
第2節 實證的 會計理論에서의 主要 假設 = 21
1. 規模假說(Size Hypothesis) = 22
2. 負債/持分假說(Debt /Equity Hypothesis) = 27
3. 經營補償 計劃假說(Bonus Plan Hypothesis) = 28
第3節 政治的費用과 規模假設에 대한 先行硏究 = 30
第4節 政治的費用 代理變數의 定義 = 35
1. 有效法人稅率의 定義 = 35
2. 準租稅負擔率의 定義 = 38
3. 租稅負擔率의 定義 = 39
第3章 外航船社의 船舶保有와 經營現況 = 40
第1節 外航船社의 一般現況 = 40
1. 外航船社의 現況 = 40
2. 外航船 保有現況 = 45
3. 外航海運의 輸送現況 = 49
4. 外航船社의 經營現況과 問題點 = 55
第2節 外航船社의 經營實態分析 = 60
1. 收益性 分析 = 60
2. 財務構造 分析 = 62
3. 資産 및 資本의 效率性 分析 = 64
4. 生産性 分析 = 65
5. 韓國海運産業 經營實態分析 要約 = 68
第4章 韓國海運産業의 規模效果에 관한 實證硏究 = 69
第1節 硏究假說과 硏究模型 = 69
1. 硏究假說 = 69
2. 硏究模型 = 72
第2節 變數의 定義와 測定方法 = 73
1. 從屬變數의 定義와 測定方法 = 73
2. 獨立變數의 定義와 測定方法 = 74
3. 資料蒐集과 硏究對象 = 77
第3節 規模效果 分析과 結果 = 78
第5章 結論 = 83
第1節 分析結果의 要約 = 83
第2節 硏究結果의 示唆點 = 84
第3節 硏究의 限界와 向後 硏究課題 = 85
參考文獻 = 86
1. 國內文獻 = 86
2. 國外文獻 = 8
Design and Implementation of a Relational Database for Management of UML Models
Get PDFThe UML (Unified Modeling Language) is a modeling language for specifying, visualizing, constructing, and documenting systems. It also supports systematically the design and development of systems. There may be a large number of models to be managed in a real modeling environment. A methodology to save and retrieve the models effectively, therefore, needs to be developed.
This thesis focuses on the class diagram which is the core part of UML. It proposes a database supported methodology for the management of class diagrams. In the proposed methodology, class diagrams are saved in and retrieved from a relational database. To save a class diagram in the database, the constitution of the class diagram is translated in terms of relational tables. To retrieve a class diagram from the database, the user- specified query is translated into the SQL (Structured Query Language), and then the constituent of the class diagram is searched from the tables in the database.
The proposed methodology can exploit the function of the relational database such as managing a large number of models, sharing the models among users, and fast queries. It, therefore, provides a powerful framework for an effective management of UML models and a fast development of systems.Abstract = ⅱ
제 1 장 서론 = 1
제 2 장 UML 및 UML 개발 도구 = 4
2.1 UML의 구성 요소 = 4
2.2 UML 클래스 다이어그램(Class Diagram) = 6
2.2.1 클래스(Class)와 인터페이스(Interface) = 7
2.2.2 관계(Relationship) = 8
2.3 UML 개발 도구 = 10
제 3 장 UML 클래스 다이어그램의 저장 및 검색 = 12
3.1 UML 클래스 다이어그램 변환 = 12
3.2 관계형 데이터베이스 생성 및 저장 = 17
3.3 UML 클래스 다이어그램 검색 = 21
제 4 장 구현 및 기존 시스템과의 비교 = 23
4.1 알고리즘 및 시스템 흐름도 = 23
4.2 데이터베이스 테이블 상세 설계 = 26
4.3 시스템 구현 = 33
4.4 기존 시스템과의 비교 = 35
제 5 장 결론 및 향후 연구과제 = 36
참고 문헌 = 3
(A) Study on the Simulation of Turbocharger Matching through a Performance Characteristics of Compressor and Turbine
Get PDFBasic methods to increase power output of internal combustion reciprocating engine is increasing of engine revolutions and engine displacement. But they have limitations because of reduction of volumetric efficiency, increase of mechanical losses, noise, vibration, size and weight of engine.
For this reason, most of engines have been coupled with a turbo charging system in order to increase engine power. Turbocharging can be defined as the introduction of air into an engine cylinder at a density greater than atmosphere. This allows a corresponding increase in the fuel that can be burned hence raises the available power output.
The engine is designed for variable speed and the operation will usually exhibit some deterioration in performance both at extreme low and high speed. However, the useful speed range can be wide, since engine is well suited to cater for a wide range of mass flow rate.
The performance of turbocharger is directly dependent upon the gas angle at entry of the impeller, diffuser of compressor and turbine rotor. The blade angles are set to match these gas angle, but a correct match will only be obtained when the mass flow rate is correct for a specified rotor speed. Therefore turbocharger is not well suited for operation over a wide flow range.
Turbocharger is not ideally suited to operate in conjunction with a engine. So the combination of diesel engine and turbocharger must be planned with care.
The objective of turbocharger matching is to fit a turbocharger with the most suitable characteristics of an engine in order to obtain the best overall performance. Matching of the correct turbocharger to a diesel engine is very important and is vital for successful operation of a turbocharged diesel engine. It will principally be governed by required performance with engine.
Simulation program used for the optimum calculation of turbocharger matching is very effective method to estimate turbocharged diesel engine performance.
In this paper the author has studied a calculation of turbocharger matching for 4 stroke automotive diesel engine and marine diesel engine through development of simulation program by using performance characteristics of turbocharger, and has estimated effects of efficiency, size of turbine and fuelling on the engine and turbocharger.
It was assured that simulation results agreeed well with experimental results of thermodynamic states at turbocharger and intake, exhaust manifold, and yield correct tendencies of estimation according to efficiency, size of turbine and fuelling.Abstract = Ⅲ
Nomenclature = Ⅴ
제 1 장 서론 = 1
제 2 장 배기가스 터빈과급기 = 3
2.1 배기가스 터빈 과급기의 구조 = 4
2.1.1 과급디젤 기관의 계통도 = 4
2.1.2 압축기 = 6
2.1.3 중간냉각기 = 9
2.1.4 터빈 = 10
2.1.5 Waste Gate Valve = 13
2.2 배기가스 터빈 과급기의 과급방식 = 13
2.2.1 동압과급 = 14
2.2.2 정압과급 = 15
제 3 장 과급기 매칭 계산 방법 = 16
3.1 매칭 계산 FLOW CHAT = 17
3.2 과급기 매칭 계산 방법 = 18
3.2.1 입력데이터 = 18
3.2.2 압축기 계산 방법 = 19
3.2.3 급기상태 계산 방법 = 22
3.2.4 배기상태 계산 방법 = 23
3.2.5 터빈 계산 방법 = 26
제 4 장 예측결과 및 고찰 = 29
4.1 소형 4행정 디젤기관 = 29
4.1.1 실험기관 = 29
4.1.2 과급기 성능 해석 = 30
4.1.3 과급기 성능 예측 분석 = 38
4.2 대형 2행정 디젤기관 = 45
4.2.1 실험기관 = 45
4.2.2 과급기 성능해석 = 46
4.2.3 과급기 성능 예측 분석 = 55
제 5 장 결론 = 58
參考文獻 = 6
(An) Empirical Study on Knowledge Management Utilization for Firm's Competitiveness
Get PDFThe concept of knowledge management(K.M) appeared in the world society, As Europe management conference supported by ILO adapts subject of "Knowledge management(forecast of new opportunity)". recently, Because knowledge management begins to be applied in the whole industrial field. knowledge management has been brought as a best practice that companies can improve and harden their own competitive power basically.
To make KM help for management place, the importance to managers recognition KM and emphasis on company competition are required the gap study of actual use level.
In this study, I will boundly recognition degree of knowledge competition importance with 4 factors, that is there are management renovation and knowledge ability factor, financial factor, customer values factor and inside processor factor.
I did gap analysis between actual competition and these factors.
when I did factor analysis of out side environment factors, that's results consist of complexity of competitive and cooperative companies, change speed of new goods and new tech, variety of customers and simplexity of demand expectation.
Then, I did again T-test of the results, The results of the analysis showed me that korea companies are much interested in KM, and it's appeared that KM is contributing to company competition.
If I conclude with the results of this study, we are interested in the word of KM but do not see the importance of KM. However we have a high level of competition advantages on the contrary korea companies are interested in the change of customer's desire, but don't come up with hold competition advantages so we'll be required much more interest and endeavor in KM and intelligence asset in the future. we find it's important to upgrade inside processor korea is engaged in personnel resource but has to be interested in knowledge share system like KM. In regard to customer value, the understanding of customer's desire has competition advantages and other factors are important nevertheless, we don't have competition of those.제 1 장 서론 = 1
제 1 절 문제의 제기 = 1
제 2 절 연구의 목적 = 3
제 3 절 연구의 방법 = 4
1. 연구대상과 자료 수집 = 4
2. 분석 방법 = 5
제 4 절 연구의 범위와 내용 = 6
제 2 장 지식경영시스템에 관한 배경과 선행연구 = 8
제 1 절 지식, 지식경영과 관련된 이론 = 9
1. 지식 = 9
2. 지식의 분류 = 10
3. 지식경영 = 11
제 2 절 지식경영에 관한 선행연구와 흐름 = 12
1. 개념연구 = 13
2. 전략(strategy) = 15
3. Process = 17
4. 문화=사람(culture=people) = 19
5. 기술(technology) = 20
제 3 장 변수선정과 연구가설 설정 = 23
제 1 절 변수선정과 측정 = 23
제 2 절 연구모형과 연구가설 = 23
1. 연구 가설 = 23
2. 연구모형 = 25
제 4 장 지식경영요인의 중요성 인식과 실제경쟁력 활용수준간의 격차분석에 관한 실증연구 = 27
제 1 절 지식경영요인의 중요성 인식과 실제경쟁력 활용수준간의 격차분석과 결과 = 27
1. 변수의 신뢰성과 타당성 분석 = 27
2. 지식경영 4요인의 격차분석 = 31
제 2 절 환경요인을 고려 후 지식경영중요성 인식과 실제 경쟁력활용 수준간의 T- Test = 40
1. 변수의 신뢰성과 타당성 분석 = 40
2. 외부 환경을 고려한 지식경영요인의 중요성과 실제경쟁력간의 T - Test = 42
제 5 장 결론 = 45
제 1 절 분석결과의 요약 및 시사점 = 45
제 2 절 연구의 한계와 향후 연구방향 = 46
1. 연구의 한계 = 46
2. 향후 연구과제 = 47
參考文獻 = 48
1. 國內文獻 = 48
2. 國外文獻 = 50
3. 인터넷 웹사이트 = 5
Molecular Biological and Ecological Investigation of PCBs Biodegradation Facilitated by Plant Terpenes
Get PDF본 연구에서는 천연적으로 식물에서 합성이 이루어지며 자연계에 광범위하게 존재하는 식물 테르핀 (terpenes) 가 PCBs 및 천연 할로겐화 물질이 호기성 상태의 PCBs로 오염된 토양의 환경친화적 처리에 있어서 이러한 추가기질로서 어떤 역할을 하는지를 분자생물학적 및 생태학적 기법을 이용하여 규명하고자 하였다.
우선적으로, 2종의 PCB 분해균주에서 테르핀 (carvone) 에 의해 PCB 분해경로가 유도된다는 사실을 생화학적 및 분자생물학적 기법들을 이용하여 밝혀내었다. Carvone에 의한 Ralstonia eutropha H850의 bphC 유전자의 발현결과는 H850의 토양내에서의 발현추적에 도움이 될 것이다.
이러한 연구결과를 바탕으로 테르핀 (carvone, limonene, terpinene 등) 를 처리한 토양에 H850 균주를 접종하여 관찰한 결과, 최소한 2개월 이상 존재할 수 있음을 밝혔다. 그리고 처리구별 토양 총 RNA를 추출하여 RT-PCR을 통해 bphC 유전자의 mRNA 발현을 조사한 결과 비페닐 처리구 (4일째)에서 그 유전자가 발현됨을 밝혔다. 그러나 테르핀 처리구에서는 유전자의 발현이 나타나지 않은 것으로 보아 계면활성제의 처리？？ 통한 생물이용율을 증가시킬시 유전자의 발현 촉진, 그리고 지속적 기질 첨가 효과를 검토할 필요가 있었다. 이러한 이유로 계면활성제 sorbitan trioleate의 토양첨가실험을 실시하였다. 그 실험을 통해 sorbitan trioleate는 PCBs 분해균의 성장기질로 사용되어지는 것을 확인할 수 있었으며 또한 그 균주에 대한 독성도 없는 것으로 나타났다. 따라서 본 계면활성제가 분해균의 초기 밀도를 높이고 그 후 테르핀이 PCBs 분해 유전자의 발현을 촉진할 경우 그 분해효과는 극대화될 것으로 판단되며 이는 현장 적용시 상당한 이점으로 작용할 수 있을 것이다.
또한 자연의 성장 기질 또는 유도물질로서 식물 테르핀이 PCB congeners에 어떠한 생분해 영향을 주는가에 대한 연구도 이루어졌다. PCB 분해자인 Rhodococcus sp. P166와 Rhodococcus sp. T104는 비페닐과 테르핀 ((S)-(-)-limonene, p- cymene，α-terpinene)을 성장기질로 이용함을 밝혀내었다. 그리고 congener 분해시험에서 (S)-(-)-limonene, p-cymene와 α-terpinene에서 키운 strain T104가 비페닐에 성장한 분해율의 50% 에 해당하는 30%까지 4,4'-DCBp를 분해시킬 수 있음을 보여주었다. 더구나 (S)-(-) limonene을 이용하여 ？眉？ 균주 T104 또한 2,2'-DCBp를 30%까지 분해시킬 수 있음을 확인하였다. 따라서 본 연구는 자연에 널리 존재하는 테르핀이 PCB 분해균의 성장기질로서 사용되어 그 분해유전자가 유도되며 그 결과 PCB의 congener를 기질 특이적으로 분해할 수 있음을 보여주었다. 이것은 기존의 순수 PCBs 분해 균주의 resting cell assay를 통한 meta ring fission 과 비교해 볼 때 환경시료(부산항 저질자료 제시하지 않음)에서 농화배양으로 분리한 균주의 성장기질로서, 유도체로서 사용됨을 실험으로 확인할 수 있었고 이 연구에서 설정한 가설이 틀리지 않았음을 증명할 수 있었다.목차
Table of Contents = i
List of Tables = iv
List of Figures = v
ABSTRACT = viii
I. INTRODUCTION = 1
II. LITERATURE REVIEW = 4
2.1. PCBs (polychlorinated biphenyls) in the Environment and Their Problems = 8
2.2. PCB Biodegradation = 9
2.3. Biphenyl and Natural Substrates as Growth Substrates in PCB Biodegradation = 11
2.4. Plant Terpenes and Their Relevance to PCB Biodegradation = 12
2.5. Soil Microcosms Undergoing PCB Biodegradation = 15
2.5.1 Role of Surfactants in PCB Biodegradation = 15
2.5.2 PCR-DGGE Fingerprinting for Analysis of Microbial Community = 16
III. MATERIAL AND METHODS = 19
3.1. Chemicals. = 19
3.2. Bacterial Strains, Culture Maintenance and Growth Conditions = 19
3.3. Nucleic Acids Extraction from Pure Cultures = 20
3.3.1 Total DNA extraction = 20
3.3.2 Total RNA extraction = 21
3.4. Utilization Test of Terpenes = 23
3.5. Induction of PCB-degradative Pathway by Terpenes = 23
3.6. Resting Cell Assay of PCB Cometabolism = 23
3.7. Analysis of PCB Biodegradation = 24
3.7.1 Extraction of PCBs = 24
3.7.2 GC Analysis of PCB Degradation = 25
3.7.3 Analysis of Chloride Ions Released from 4,4-DCBp Degraded = 26
3.8. Colorimetric Enzyme Assay (agar plates) = 26
3.9. Soil Microcosm Experiment = 27
3.9.1 Soil Microcosms Set up = 27
3.9.2 Viable Counting of PCB Degraders = 29
3.9.3 Total Soil DNA Extraction and PCR = 30
3.10. Primers Design = 32
3.11. Reverse Transcription PCR (RT-PCR) = 33
3.12. PCR-DGGE for Analysis of Microbial Community = 35
IV. RESULTS AND DISCUSSION = 36
4.1. Growth of PCB Degraders on Biphenyl and Terpenes = 36
4.2. Colorimeric a Assay of PCB Degradation under Different Terpenes-inducing Conditions = 38
4.2.1 Resting Cell Assay = 38
4.2.2 Spray Plate Assay of Dihydroxybiphenyl Dioxygenase = 43
4.2.3 GC analysis of PCB Degradation during Resting Cell Assay = 44
4.3. PCR amplification of bphC gene = 49
4.3.1 PCR monitoring bphC Gene of Rhodococus sp. T104 in Pure Culture = 49
4.4. Monitoring of bph Gene Expression in Pure Culture of Rhodococus sp. T104 through RT-PCR = 51
4.5. Monitoring of PCB Degraders Population and Their Gene Expression in Soil Microcosms = 53
4.5.1 Population Dynamics of PCBs Degrader = 53
4.5.2 Gene expression in soil microcosms = 53
4.5.3 PCR-DGGE fingerprinting for the analysis of microbial community = 62
V. CONCLUSION = 64
VI. FURTHER WORKS = 65
VII. REFERENCES = 66
ACKNOWLEDGEMNET
CURRICULUM AND VITA
Numerical Study on Combustion Charaterestics in a Constant Volume Combustor having a Radical Injector
Get PDFA premixed-compression-ignition engine has been studied to improve the performances of efficiency and exhaust emissions. However those systems have some difficulties for controlling combustion process.
Radical is an activated chemical species formed by a chemical chain reaction between reactant and product. When the chain reactions occur, the energy bond of species is broken easily by the released radical. The combustion chamber of premixed-compression-ingnition engine is consist of a main chamber with lean premixture and a subchamber with rich premixture. Those are connected by narrow cylinderical connections. With ignition start in the subchamber, many different kinds of radical is jetted into the main chamber. The premixed gas in main chamber is quickly burned up by the radical ignition in multi-pionts.
In this thesis, the combustion phenomena in a constant volume combustor having a radical injector are numerically analyzed. The some constants in the reaction rate equation are adjusted by the experimented results tested in the same geometrical chamber. the code is applied on the two combustors in a wide range of equivalence ratio. The results shows that the burning time is much shorter in the combustor having radical injector.목차
ABSTRACT = iii
I. 序論
1.1 연구배경 = 1
1.2 연구내용 = 4
II. 硏究方法
2.1 수학적 모델 = 6
III. 計算條件
3.1 반응률상수 변화에 따른 연소특성 = 9
3.2 부실의 당량비 변화에 따른 연소특성 = 13
IV. 計算結果 및 考察
4.1 반응율상수의 영향 = 16
4.1.1 반응율상수 변화에 따른 연소특성 = 16
4.1.2 당량비변화에 따른 연소특성 = 20
4.1.3 온도분포 및 화학종분포 = 22
4.2 라디칼 인젝터가 장착된 연소실 = 40
4.2.1 실험치와의 비교 = 40
4.2.2 당량비 변화에 따른 특성 = 40
4.2.3 연소실내의 온도 분포 특성 = 40
4.3 라디칼인젝터가 있는 경우와 없는 경우의 비교 = 45
V. 結論
參考文獻 = 5
An Experimental Study on the Sea Water Flow in Bay
Get PDFRecently, the water pollution of coastal sea area including harbor, bay and inland sea has been very serious and it causes various environmental impacts.
Generally the quality of seawater is influenced by the amount of exchanging water volume. Especially, closed water such as the closed harbor or the bay with narrow mouth is likely to be polluted, because the flux of water is limited to the entrance of the harbor or the bay. Hence, the development of prediction technique, which can evaluate the amount of water flux and water circulation system within the closed water, is demanded.
In this study, water flow system of Danghang Bay, which has the narrow and long topographical characteristics with the narrow bay mouth and its flow is influenced principally by the tidal current, is investigated experimentally and numerically.
In order to understand the tidal system of Danghang Bay, harmonic analysis is performed based on measured tidal range and flow velocity. In addition, numerical model for tidal exchange is developed considering conditions of Danghang Bay. Calculated results show good agreement with measurements. Lastly, based on the proposed numerical model, exchange ratio of seawater volume in Danghang Bay is predicted.목차
Abstract = VI
제1장 서론 = 1
제2장 당항만의 환경 = 3
2.1 자연환경 = 3
2.1.1 조석 및 조류 = 4
2.1.2 파랑 = 6
2.1.3 강수량 = 6
2.1.4 바람 = 7
2.2 인위적 환경 = 8
2.2.1 매립 진행 및 계획 = 8
2.2.2 부근의 항만 시설과 개발계획 = 9
2.2.3 선박통항 = 9
2.3 현장실험 = 10
2.3.1 실험개요 = 10
2.3.2 실험결과 = 11
제3장 모델링 = 21
3.1 지배방정식 = 21
3.1.1 좌표계 = 21
3.1.2 연속방정식과 운동방정식 = 21
3.2 수치해석 = 23
3.2.1 안정조건 = 23
3.2.2 격자 = 24
3.2.3 유한차분법 = 26
3.2.4 경계조건 = 28
3.3 모델의 흐름도 = 29
3.4 모델링 결과 = 31
제4장 해수유동추정 = 37
4.1 만내 조석 및 수로유속 = 37
4.2 최대 유속수심 = 43
4.3 해수교환율 = 44
제5장 결론 = 48
참고문헌 = 4
Numerical Analysis of Three-Dimensional Wave Transformation and Dynamic Response of Floating Breakwater Moored by Pier
Get PDFIn general, the salient features of the floating breakwater have excellent regulation of sea-water keeping the marine always clean, up and down free movement with the incoming and outgoing tides, capable of installing without considering the geological condition of sea-bed, and capable of installing at any water depth. This study discussed the three dimensional wave transformation of the floating breakwater moored by pier, and its dynamic response numerically. Numerical method is based on the boundary integral method and eigenfunction expansion method. It is known that pier mooring system. Pier mooring system permits only vertical motion (heaving motion) of floating breakwater, other motions restricted. It was assumed in present study that a resistant force as friction between pier and floating pontoon was not applied for the vertical motion of the floating breakwater. So, the floating breakwater moves freely for vertical direction. According to the numerical results, draft and width of the floating breakwater affected on the wave transformations greatly, and incident wave of long period was well transmitted to the rear of the floating breakwater. And the vertical motion came to be large for the short wave period.목차
ABSTRACT = i
요약 = ii
1. 서론 = 1
1.1 본 연구의 배경과 목적 = 1
1.2 본 연구의 구성 = 4
2. 이론적인 해석 = 5
2.1 기본가정 및 경계조건 = 5
2.2 속도포텐셜의 전개 = 8
2.3 Green함수에 의한 f₁ , f₂^(n):Φ_0 ,Φ_sφ_0 ,φ_v 의 표시 = 10
2.4 부방파제에 작용하는 유체력 = 18
2.5 부방파제의 운동방정식 = 20
2.6 D, D₁, D₂에 있어서 연속조건 = 22
2.6.1 부방파제 I에 대해서 = 23
2.6.2 부방파제 II에 대해서 = 27
2.7 제량의 결정 = 32
3. 수치해석의 결과 = 36
3.1 수치해석의 조건 = 36
3.2 수치해석의 결과 = 36
3.2.1 파랑변형 = 36
(a) 흘수심의 변화 = 36
(b) 입사주기의 변화 = 37
(c) 입사파향각의 변화 = 38
(d) 폭의 변화 = 38
(e) 개구폭의 변화 = 39
3.2.2 연직운동 = 55
4. 결론 = 58
참고문헌 = 5
(The) Function and Economic Effects of Establishing Logistic Free Zone in the Port of Pusan
Get PDFThe Function and Economic Effects of Establishing Logistic Free Zone in the Port of Pusan
This paper probes the necessity and feasibility of establishing a logistic free zone in Port of Pusan. It considers the logistics function of Pusan Port and the economic effects of establishing the logistic free zone, and suggests policy prescriptions for introducing the free zone system and improving the logistics functions of Pusan Port.
Major research findings from this study were as follows.
First, we found that the logistics promotion function of Pusan Port is competitive relatively, and specifically, and Pusan Port needs to make up the foundation for establishing the value-added logistics function and to supplement some of the remaining inadequacy in logistics function.
Second, this study analyzed influences on the Pusan regional economy of the logistic free zone system through a regression analysis. Using input-output table data, the regression analysis was able to provide a quantitative prediction on effects of making the Pusan Port a tariff-free zone. Influence for the regional economy due to the enforcement of the free zone system, we found that a strong positive effects should be expected on the Pusan regional economy once the logistic free zone would be set up at the Port of Pusan.
Third, the positive economic effects on Pusan regional industries might be further strengthened if the value-added logistics function of Pusan Port could be supplemented by linking to the hinterland of Pusan Port