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(An) Empirical Study on the Relationship of Market Orientation, Mediators and Business Performance in the International Logistics Service Industry
Get PDFAn Empirical Study on the Relationship of Market Orientation, Mediators and Business Performance in the International Logistics Service Industry
A positive market orientation-business performance relationship has been reported in the literature. However, many researchers have constantly called for closer examination of the nature of relationship, in particular, how other factors may moderate the relationship. Recent researches have been provided the much needed theoretical framework for the relationship of market orientation and mediators on business performance. Therefore this study is based on this conceptual framework.
The purpose of this study is to shed some light on how market orientation, mediators such as employee satisfaction, service quality and commitment, and business performance are related and to offer important managerial implications for managements or marketing practitioners in the international logistics service industry.
This study suggest that the employee satisfaction, service quality and commitment are moderating the relationship between market orientation and business performance.
Market orientation has a positive effect on employee satisfaction, service quality and commitment as well as business performance. Especially, the results show that commitment has a stronger association with business performance than any other mediators. Thus enhancement of commitment may be a prerequisite of a positive market orientation-business performance linkage.
The findings of this study can be summarized as follows:
1) A higher degree of market orientation is found to be correlated with higher employee satisfaction, better service quality and more enhanced commitment. 2) An improved employee satisfaction bring about greater service quality. 3) Superior service quality enhances commitment between service firm and customer. 4) Market orientation affects positive business performance directly. In summary, all hypotheses except H6 were supported.
The results of this study provide several important managerial implications.
Firstly, market orientation was newly defined.
Market orientation is a entire effort and intention of company in order to create higher and continuous business performance through the appropriate and efficient managerial activity, and immediate and accurate response for every market information including customers' and competitors'.
Secondly, international logistics service firms should be effort for the enhancement of commitment.
Thirdly, a market-oriented service firm maintains its sustainable competitive advantages by continually engaging in market-oriented efforts and making timely modifications that lead to improved business performance.
Finally, managements and marketing practitioners should be remember that market-oriented efforts have latent effects such as an improvement of firm's image or positive change in social recognition
The Effect of Lubricant Containing Copper Alloy Nano-Powder on Engine Lubrication
Get PDFThe characteristic of a lubricant is important under severe running condition.
Especially on diesel engines the better lubrication performance is required due to the extreme condition such as high temperature and pressure by combustion process in a combustion chamber.
Many research works for improving a boundary lubrication performance have been studied by using solid lubricants, and have been tried to apply solid lubricants to an engine. However those general lubricants like MoS2 or PTFE have not been applied on engines due to the extreme conditions such as very high temperature and pressure by combustion process in a cylinder.
Recently, the solid lubricant containing a copper nickel alloy has been introduced and studied.
In this thesis the lubricant containing the alloy particles is applied on a high speed rolling contact wear test machine and a diesel engine. The lubricant is assessed by mechanical characteristic test and by engine performance test. The results by mechanical characteristic test show the decrease of the coefficient of friction and oil temperature. The results by engine test show the decrease of X-axis and Y-axis amplitude which strongly effect on engine vibration and the decrease of torque related strongly to the engine efficiency as well as the improvement of the engine lubrication performance.
It is clear that the lubricant containing the copper nickel alloy nano-powder decreases friction and wear, and it is also expected the increase of the sealing effect between a cylinder and piston rings.목차
ABSTRACT = i
1. 서론
1.1 연구의 배경 및 목적 = 1
2. 윤활유 및 첨가제
2.1 기관의 윤활 = 4
2.1.1 윤활영역의 종류 = 4
2.1.2 윤활작용 = 6
2.1.3 윤활유의 물리·화학적 성질 = 8
2.2 기관의 윤활제 = 9
2.2.1 엔진오일의 역할 = 10
2.2.2 엔진유의 요구성능 = 15
2.2.3 엔진유의 분류기준 = 18
2.3 기관윤활유 첨가제 = 19
2.3.1 첨가제의 종류 = 20
2.3.2 대표적인 첨가제의 특성 = 21
2.3.3 고체윤활제 = 25
2.4 나노구리합금윤활제 = 28
3. 실험장비 및 실험조건
3.1 고속마찰마모시험기 = 30
3.1.1 실험장치 = 30
3.1.2 실험조건 및 실험방법 = 33
3.2 모터구동 디젤기관 = 33
3.2.1 실험장치 = 33
3.2.2 구동장치 = 35
3.2.2 계측장치 = 35
3.2.3 실험조건 및 실험방법 = 40
4. 실험결과 및 고찰
4.1 일반적인 특성 고찰 = 41
4.1.1 마찰특성 = 41
4.1.2 시편마모특성 = 50
4..2 기관진동특성 고찰 = 54
4.3 기관윤활특성 고찰 = 67
4.3.1 과도상태윤활특성 = 67
4.3.2 정상상태의 윤활특성 = 68
5. 결론 = 71
참고문헌 = 7
Effect of Diazinon on Behavior and Tyrosine Hydroxylase Activity as a Biomarker in Japanese Medaka (Oryzias latipes)
Get PDFNowadays environmental pollutants have not only increased in quantity but also changed dramatically in quality. In other words, the release of hazardous waste materials into the environment poses serious risks in humans and ecosystem. In order to minimize their environmental risks caused by the wastes the developed countries have established systems for toxicity evaluation of hazardous chemicals, legislation for their proper management plan, and their efficient administration program. Ecological risk is equivalent to product of exposure and hazard of specific chemical or a mixture of chemicals. The risk assessment, therefore, requires a comprehensive measurement of exposure and hazard of the chemicals that can be achieved by toxicity evaluation using a biological system. The biological system includes biomarkers that are molecular and physiological indicators of chemical stress.
Diazinon[O,O-diethylO-(2-isopropyl-4-methyl-6-pyrimidinyl) phosphorothioate], is an organo-phosphorous insecticide widely used for the control of agricultural and household pests, the toxic effects of which are mainly due to the inhibition of cholinesterase. Diazinon shows a high toxicity to organisms, especially fish and aquatic invertebrates although it has relatively low toxic effects on mammals and humans.
In this study we have tried to develop a biomarker used to elucidate a molecular basis of, and to monitor abnormal behavior caused by diazinon in Japanese medaka (Oryzias latipes) as a model organism. For monitoring experiments at behavioral and molecular biological levels, the fish were treated under different sublethal conditions of diazinon and their behavioral responses were observed.
Organ or tissue-specific detection of TH activity and mRNA as biomarkers will be a useful monitoring tool for neurobehavioral changes in fish influenced by toxic chemicals. Furthermore, quantitative analysis of locomotive patterns and its correlation with the neurochemical and molecular data would be highly useful in measuring toxicity and hazard of various environmental pollutants. This study provides molecular and neurobehavioral bases of a biomonitoring system for toxic chemicals using a model organism such as fish.List of Tables = ⅳ
List of Figures = ⅴ
ABSTRACT = ⅶ
Ⅰ. 서론 = 1
Ⅱ. 연구 배경 및 목적 = 3
2.1 다이아지논의 특징 및 환경독성 = 3
2.2 생태적 위해성 평가에 대한 연구 동향 = 6
2.3 독성물질에 대한 생리·화학적 연구 동향 = 7
2.4 연구 필요성 및 목적 = 8
Ⅲ. 실험 재료 및 방법 = 11
3.1 화학약품 및 실험어류 = 11
3.1.1 화학약품 = 11
3.1.2 실험어류 = 11
3.2 송사리의 행동반응 조사와 이미지 구현 = 11
3.3 AChE 정량 및 신경전달물질(neurotransmitter)의 측정 = 12
3.4 송사리 ovary cDNA library 및 TH 유전자의 cloning = 13
3.5 조직 시료 준비 및 총 RNA 추출 = 13
3.5.1 조직 시료 추출 및 정제 = 13
3.5.2 총 RNA 추출 및 정제 = 14
3.6 비방사성(non-radioactive) DIG 시스템을 이용한 Northern blot 분석 = 14
3.7 TH 유전자의 발현 모니터링 = 16
3.7.1 면역조직화학(immunohistochemistry) = 16
3.7.2 RT-PCR 반응 = 16
3.7.3 Semiquantitative RT-PCR 반응 = 17
3.7.4 In situ 혼성화 반응 = 18
Ⅳ. 연구 결과 및 고찰 = 19
4.1 다이아지논 처리에 따른 송사리 행동변화 = 19
4.1.1 다이아지논 처리 시 ？鵑贊碩？ 관찰 = 19
4.1.2 송사리 반응 행동궤적과 AChE 활성과의 관계 = 21
4.2 송사리의 AChE 효소활성 및 신경전달물질 효소활성의 측정 = 26
4.2.1 AChE 효소활성 = 26
4.2.2 Monoamine oxidase 활성 변화 = 29
4.3 송사리의 TH 효소활성 = 31
4.4 송사리의 TH 유전자의 cloning = 35
4.4.1 TH 유전자 단백질 아미노산 순서 결정 = 35
4.4.2 TH 유전자 발현추적을 위한 RT-PCR primer 디자인 = 35
4.5 송사리의 총 RNA 추출 및 Northern blot = 38
4.5.1 총 RNA 추출 = 38
4.5.2 Northern blot 혼성화 반응에 의한 유전자의 발현조사 = 39
4.6 면역조직화학(immunohistochemistry)에 의한 TH 단백질의 조직별 발현 = 41
4.7 송사리의 TH 유전자의 발현을 추적하기 위한 RT-PCR = 43
4.7.1 Diazinon 처리 농도별 및 시간별 RT-PCR = 43
4.7.2 TH 유전자의 RT-PCR 및 semiquantitative RT-PCR = 46
4.8 In situ 혼성화 반응에 의한 TH 유전자의 조직별 발현의 정량적 검출 = 49
Ⅴ. 결론 = 51
Ⅵ. 향후 연구 과제 = 53
REFERENCE
(The) Computer Simulation Analysis for Urban Logistics Improvement
Get PDFAs a results of the expansion of the urban areas and economic activities, the concerns on freight distribution in urban areas are highly increasing. Main concerns are put on both the increase of transportation cost and the ineffectiveness of urban goods movement. Accordingly, to reduce the traffic of the freight vehicle and the time for loading & unloading, many alternatives are being discussed.
In this respect, this study introduces the concept of urban and CBD(Central Business District) logistics, and analyzes related problems. And then it introduces some cases of improvement of urban logistics. Based on these, several alternatives designed to improve urban logistics are suggested, and computer simulation analyses have been done to evaluate them. The results reveal that among those alternatives converting parking space to on-road loading space is most efficient. It is also suggested that for implementation more broad aspects such as legal and behavioral aspects need to be taken into account.1. 서론 = 1
1.1 연구의 배경 및 목적 = 1
1.2 연구 수행 방법 및 구성 = 2
2. 도시 물류에 대한 이론적 고찰 = 4
2.1 물류와 도시내 물류시스템？？ 정의 = 4
2.2 C.B.D.의 개념 = 10
2.3 도시내 물류 문제의 배경 = 13
2.4 도시내 물류 문제의 현상과 문제점 = 15
2.5 도시 물류 개선을 위한 외국 사례 = 18
2.5.1 뉴욕 의료 도매 상가 Satellite주차 시스템과 화물차 호출 시스템 = 18
2.5.2 Consolidation System = 18
2.5.3 달라스 도심부 물류시스템 = 19
2.5.4 일본 복강천신 지역 공동 집배송 시스템 = 19
2.5.5 공동 물류 Depot계획과 물류 정비 지구의 제안 = 20
2.5.6 포켓 로딩 시스템의 제안 = 21
2.6 도시 물류 관련 선행 연구 = 22
3. 도심 상업 지구의 물류 체계 특성 분석 및 대안 설정 = 25
3.1 대도시에서의 단말 물류 과제 = 25
3.2 단말 물류 문제의 개선 대안 = 26
3.2.1 트럭 주차 및 대기 장소의 확보 = 26
3.2.2 시설 개선 = 30
3.2.3 관리·운영 제도 개선 = 33
4. 대안 평가 = 36
4.1 연구 대상 지역의 현황 = 36
4.1.1 일반 현황 = 36
4.2 각 대안별 시뮬레이션 모형 구축 = 40
4.2.1 개요 = 40
4.2.2 입력 자료 분석 = 41
4.2.3 각 대안별 파라메타 결정 = 45
4.2.4 시뮬레이션 모형 구축 = 45
4.3 시뮬레이션 결과 분석 = 47
4.4 도시 물류 개선 방향 = 48
4.4.1 주체별 개선 방향 = 48
5. 결론 = 5
Export Yard Planning System Integrated with Yard Monitoring System in Contanier Terminal
Get PDFThe container terminal operation systems can be classified by three different parts of major sub systems which are planning system, resource management system, and real-time control system. Especially, for improving the efficiency and productivity of container terminal, the planning system is the most important sub system in the operation systems because of processing highly increased the number of container loaded on board and of getting more important position in competition with other terminal.
The reason of this, the planning system, consists of the ship planning, yard planning and berth planning, is studied and practiced by many kinds of ways. However, the study of the integrated planning with real-time control system is seldom published. In particular, in yard planning system, there are so many ways to get benefits to plan if it could be integrated with real-time yard monitoring such as to get exact location of unexpectedly changed position of containers, to prevent interference of equipment in planed blocks, to consider the planning with loading patterns and so on.
To utilize these benefits in this paper, heuristic algorithms for the export yard planning, operated on monitoring system, one of the real-time control systems, are suggested and integrated export yard planning system are designed and developed.목차
ABSTRACT
표목차, 그림목차
제1장 서론 = 1
1.1 연구의 배경 및 필요성 = 1
1.2 관련 문헌 연구 = 3
1.3 논문의 구성 = 5
제2장 시스템 분석 = 7
2.1 수출입 장치장 내에서의 컨테이너 흐름 = 7
2.1.1 장치장의 구조 및 특성 = 7
2.1.2 수입 컨테이너 흐름 = 9
2.1.3 수출 컨테이너 흐름 = 10
2.2 수입 컨테이너 장치장 계획 = 10
2.2.1 수입 장치장의 블록 배정 = 11
2.2.1 수입 컨테이너별 저장 위치 결정 = 12
2.3 수출 컨테이너 장치장 계획 = 13
2.3.1 수출 장치장의 블록 배정 계획 = 13
2.3.2 수출 컨테이너별 저장위치 결정 = 15
제3장 시스템 설계 = 16
3.1 설계 범위 및 고려사항 = 16
3.2 통합 시스템과 기존 시스템과의 비교 = 17
3.3 시스템의 모형화 = 19
3.3.1 컨테이너, 컨테이너 목록 = 20
3.3.2 장치장 구조 = 21
3.4 Database 설계 = 22
3.4.1 Database 설계 개념 및 고려사항 = 23
3.4.2 Database Design = 25
3.5 수출 장치장 계획 수립을 위한 해법 = 28
3.5.1 문제의 정의 = 28
3.5.2 수출 장치장 계획 수립 규칙 = 29
3.5.3 발견적 해법의 제시 = 33
제4장 시스템 구현 소개 및 모형의 적용 = 40
4.1 시스템 개발 방향 및 특징 = 40
4.2 시스템의 구조 = 41
4.3 시스템의 적용 = 42
4.3.1 적용 자료 = 42
4.3.2 단계별 적용 = 44
제5장 결론 = 49
참고문헌 = 51
부
Bias due to Mismatch and its Sensitivity in Matched Field Processing
Get PDFMatched field processing(MFP) is a parameter estimation technique for localizing the range, depth, and bearing of a point source from the signal field propagating in an acoustic waveguide. MFP involves the correlation of the actual acoustic pressure field measured at a receiver array with a predicted field based on a postulated source position and an assumed ocean model.
A high degree of correlation between the measured field and the predicted field indicates a likely source location. Thus an increased complexity of the ocean's structure provides a greater variability of the acoustic fields, which aids the estimation procedure. When the environmental data are inaccurate or incomplete, a "mismatch" occurs between the measured data and the predicted pressure field, that causes a degradation in MFP correlation and an appreciable bias.
In this thesis, I was concerned with quantitative evaluation of the effects of mismatches arising from inaccuracies in a number of important system and ocean environmental parameters in a shallow water. The motivation for this study is to examine the biases in the source localization and the sensitivities of the matching results from various mismatches.
Using a conventional estimator, I have investigated the bias of range and depth estimates caused by perturbations in array position, as well as ocean environmental parameters through the simulation. Replica fields are calculated using the normal mode methods with the exception of bathymetry case. Also this study examined the sensitivity of MFP to geometric, geoacoustic, and ocean sound speed parameters using the genetic algorithm. And this method is applied to measured data to overcome mismatch and accurately estimate source location with limited a priori environmental information by expanding the parameter search space of MFP to include environmental parameters.
As a result, significant biases can be introduced into the depth and range localization predictions of a MFP through erroneous estimates of environmental parameters. It can also be concluded that the impact of mismatch, both summer sound speed and sensor position in water layer, is more serious than the geoacoustic parameters. This implies that simulations of mismatch which consider only a few errors will provide very misleading results on source position. Water depth and bottom bathymetry errors can be offset significantlyit shifted progressively farther away and deeper from the actual source location as the true water depth became shallower. Errors in estimates of the sediment attenuation and density, and basement parameters appear to be of relatively minor importance.
From an experimental implementation viewpoint, these result should enable resources to be concentrated on obtaining reliable values for those parameters which are important to know accurately, avoiding unnecessary effort to overdetermine relatively unimportant ones. It is also necessary to understand the types of mismatches in MFP that may be introduced by inaccuracies in the various forward modeling parameters, so that specific types of information deficiencies may be identified and attempts can be made to compensate for them.목차
Abstract = i
목차 = iii
List of Figures = vi
List of Tables = viii
List of Symbols = ix
I. 서론 = 1
1.1 연구 배경 = 1
1.2 연구 목적 = 2
1.3 연구 내용 및 구성 = 4
II. 정합장처리 알고리즘 = 6
2.1 해양에서 음파 전달과 모델링 = 6
2.2 정합장처리의 구성 요소 = 8
2.3 정합장 프로세서 = 10
2.3.1 협대역 프로세서 = 10
2.3.2 광대역 프로세서 = 17
2.4 유전자 알고리즘을 이용한 매개변수 역산 = 24
2.4.1 목적함수 = 26
2.4.2 매개변수 초기화 = 27
2.4.3 유전 연산자 = 28
2.4.4 사후 통계 = 29
III. 매개변수 오정합에 대한 수치실험 및 분석 = 32
3.1 오정합 연구 동향 = 32
3.2 수치실험 환경 = 34
3.3 개별 매개변수 오정합 = 36
3.3.1 시스템 매개변수 오정합 = 36
3.3.1.1 주파수 오정합 = 36
3.3.1.2 배열 수심 오정합 = 38
3.3.1.3 배열 경사 오정합 = 40
3.3.2 수층 매개변수 오정합 = 43
3.3.2.1 음속분포 오정합 = 43
3.3.2.2 수심 오정합 = 50
3.3.2.3 해저면 경사 오정합 = 53
3.3.3 해저퇴적층 매개변수 오정합 = 58
3.3.3.1 해저퇴적층 두께 오정합 = 58
3.3.3.2 해저퇴적층 상부음속 오정합 = 61
3.3.3.3 해저퇴적층 하부음속 오정합 = 61
3.3.3.4 해저퇴적층 밀도 오정합 = 63
3.3.3.5 해저퇴적층 감쇠계수 오정합 = 63
3.3.4 저층 매개변수 오정합 = 66
3.3.4.1 저층 음속 오정합 = 66
3.3.4.2 저층 밀도 오정합 = 67
3.3.4.3 저층 감쇠계수 오정합 = 68
3.4 결합된 매개변수 오정합 = 69
3.4.1 수층 수심과 배열 수심과의 오정합 = 70
3.4.2 수층 수심과 배열 경사와의 오정합 = 70
3.4.3 수층 수심과 해저층 음속과의 오정합 = 73
3.4.4 수층 수심과 해저층 밀도와의 오정합 = 73
3.5 종합된 매개변수 오정합 = 76
IV. 오정합에 대한 매개변수의 민감도 분석 = 81
4.1 연구동향 = 81
4.2 매개변수의 민감도 분석 결과 = 82
V. 실측자료의 매개변수 최적화 및 오정합 영향 = 90
5.1 실험 해역의 환경 및 신호 분석 = 90
5.1.1 실험 해역과 음원의 경로 = 90
5.1.2 수직 선배열과 예인 음원 = 91
5.1.3 실험 환경 = 92
5.1.4 신호의 스펙트로그램 분석 = 94
5.2 매개변수 역산과 음원 위치 추적 = 95
5.3 역산된 실험 자료의 오정합 영향 분석 = 101
VI. 결론 = 106
참고 문헌 = 10
(A) Theoretical Study on the Optimum Refrigerant Charge in a Vapor-Compression Air-Conditioner
Get PDFA Theoretical Study on Optimum Charging rate of Refrigerant at the Vapor-Compression Air-Conditioner.
A theoretical model for the transient performance of vapor-compression, air-conditioning system has been developed to evaluate the influence of the refrigerant charge on the system performance. The model is based on a system which has an indoor and an outdoor unit and is rated at 3,500 kcal/h cooling capacity. The major components of the system are an evaporator and a condenser, capillary tube, and a reciprocating compressor.
A set of mass and energy equations for the heat exchangers and the capillary tube and an appropriate model for the compressor are solved numerically based on the finite volume integral method. The momentum equation is not considered in the present model because the pressure drop is typically small compared to the pressure drop across the expansion devise in vapor compression refrigeration.
For a base-case system charged with 750 gram of R-22 refrigerant, the present model successfully predicts the transient behavior of the vapor-compression air-conditioner from the startup. For indoor air of 27oC and outdoor air of 35oC, the evaporating pressure is lowering, the condensing pressure is rising and reaches a steady-state value after about 30 seconds. The refrigerant flow in the compressor is high at the beginning but it gradually decreases, and becomes equal to the capillary flow rate at the steady-state condition. At the steady-state, about 90% of the refrigerant mass is distributed in the condenser and the liquid line.
An estimation of the optimum refrigerant charge is obtained after conducting a set of calculations with different refrigerant charge from 500 grams to 1000 grams. As the refrigerant charge is increased, both the evaporating and condensing pressures increase gradually, but the cooling rate and the COP show a maximum in the range of 750-800 grams of refrigerant charge. This amount of refrigerant mass is determined to be the optimum charge of the system.
The differences between condensing and evaporating pressure are about the same throughout the variation of the refrigerant charge. It implies that it is misleading to use these pressures in seeking the optimum charge. The superheat of refrigerant vapor at the evaporator exit is 1∼6℃ at the range of the optimum charge. The results of the present work suggests that the optimum refrigerant charge in a refrigeration system be determined by examining the variations of cooling rate, COP, and suction vapor superheat, which may vary depending upon the system capacity and the indoor and outdoor operational conditions. Also, the effect of outdoor air temperature on the optimum refrigerant charge is discussed
(A) Study on The Characteristics of Direct Injection LPG Spray
Get PDFLiquefied petroleum gas (LPG) has been used as motor fuel due to its low emissions and low cost. The fuel feeding system has been improved with stringent requirement for exhaust emissions. LPG carburetion system was first introduced, then the system has been changed to a precisely controlled gas injection system, but this gas feeding system has a limitation on improving power output. In order to improve an engine performance, a multi-point port injection system was introduced recently, and a liquid direct injection system into a cylinder was suggested as a next generation system to maximize a fuel economy as well as a power.
This study addresses the analysis of the LPG spray from single hole injector. The spray images are visualized and compared with diesel or gasoline sprays in a wide injection and ambient gas pressure ranges. A short arc strobo having flashing duration of 20micro-s and CCD camera of Pulnix are used to take the images. The injection pressure is generated up to 150MPa by Haskel air driven pump. And the ambient pressure is adjusted by pumping air into a constant volume chamber. Three different test conditions are given, which are the continuous injection case with various injection pressures, the spray development case with various injection pressures and the spray development case with ambient pressure variation. The LPG spray photographs are compared with sprays of gasoline and diesel fuel at the same conditions, and the spray angles and penetration lengths are also compared, then the spray behavior is analyzed.
The LPG spray photos show that the dispersion characteristics depends very sensuously on the ambient pressure soon after injection. The spray angle is very wide in the low ambient pressure conditions until 0.3MPa, but the angle value is quickly reduced at the condition over the pressure. However the down stream of the LPG spray still shows much wider dispersion and less penetration than those of gasoline and diesel sprays due to fast evaporation. That says the LPG fuel in liquid phase by high injection rail pressure at the nozzle tip is quickly evaporated into gas phase in the low ambient pressure cases, but the spray leaving the nozzle is remaining as liquid phase in the high ambient pressure cases. Therefore the spray is dispersed widely with low penetration like LPG gas injection in the low ambient pressure case, and the spray is less dispersed and longer penetrated like liquid gasoline spray in the high ambient pressure cases, but the behavior at the spray tip is much wider and less penetrated than those of gasoline and diesel. It indicates that the behavior of LPG spray might be more dependent on the gas flow motion in cylinder than the spray injection velocity. Therefore, the chamber and intake port shape might be careful to get a suitable flow motion for designing direct injection LPG engines.ABSTRACT
1. 서론 = 1
1.1 연구의 배경 및 목적 = 1
1.2 본 논문의 구성 = 5
2. 연속분사에서의 분무 특성 = 6
2.1 실험장치의 구성 및 실험조건 = 6
2.2 분사압력에 따른 분무 특성 = 8
2.2.1 디젤유 분무 특성 = 8
2.2.2 LPG 분무 특성 = 11
2.2.3 디젤유와 LPG 분무 특성 비교 = 11
3. 분사압력변화에 따른 분무 특성 = 14
3.1 실험장치의 구성 및 실험조건 = 14
3.2 디젤유 분무 특성 = 16
3.3 LPG 분무 특성 = 21
3.4 디젤유와 LPG 분무 특성 비교 = 25
4. 분위기 압력변화에 따른 분무 특성 = 29
4.1 실험장치의 구성 및 실험조건 = 29
4.2 LPG 분무 특성 = 30
4.3 디젤유 분무 특성 = 33
4.4 가솔린 분무 특성 = 36
4.5 LPG, 디젤유와 가솔린 분무 특성 비교 = 39
4.5.1 초기 분무 특성 = 39
4.5.2 분무 진행거리 85mm에서의 분무 특성 = 41
4.5.3 분무 진행거리 및 분무폭 = 43
5. 결론 = 47
참고문헌 = 4
An Electrochemical Study on Corrosion Behaviors of Steel in Rinsing System of Steel Production
Get PDFThe objective of this research is to develop a method to prevent, so-called rinsing rust, in pickling and oiling line (POL) in a steel manufacturing company. In this company, a cascade type rinsing system has been adopted to remove residual acid remaining on the strip after pickling. Although it has shown effective rinsing capability under normal operating condition, rinsing rusts (spray burns) are evident on the strip as the line occur slow downed and stopped. Since the cost down due to rusting is significant(around $80.00/ton), it is necessary to develop a system which will prevent the rusting during rinsing.
First of all in this study, major operation conditions of the existing system were analyzed. The major problem in the existing rinsing system was identified as high acidity of the rinsing solution. Temperature of rinsing solution is 60~65℃, and its pH is 1.5~4. Because rusting is a corrosion process, corrosion behavior of hot rolled strips was investigated. Exposure tests were conducted under the same conditions as the rinsing system (60℃ HCl solution : pH 1.5~4) up to 200 seconds. As the acidity of solution increased, corrosion became severe. This phenomenon could be attributed to fast cathodic reaction of hydrogen evolution at low pH(high acidity). To resolve this low pH problem, the neutralization of rinsing solution by NaOH was considered. The results showed that when pH of solution is higher than 6, corrosion became moderate up to 100 seconds of exposure.목차
Abstract
1. 서론 = 1
2. 이론적 배경 = 3
2.1 금속의 부식 = 3
2.1.1 부식의 발생 = 3
2.1.2 부식 메카니즘 = 6
(1) 전위(potential) = 6
(2) 전위-pH도 = 11
(3) 분극(Polarization) = 16
2.2 수세공정(Rinse system) = 17
2.2.1 원리 = 17
2.2.2 구조 = 17
2.2.3 폭포식(Cascade) 수세공정 = 21
2.3 수세공정에서 부식(Rinsing rust) = 25
2.3.1 수세라인에서 부식반응 = 26
2.3.2 염산용액에서 강의 부식반응 = 26
3. 실험방？？ = 35
3.1 실험용액조건 = 35
3.2 시편종류 = 35
3.3 시편제작 및 실험방법 = 38
3.3.1 부식표면 측정 = 42
3.3.2 분극곡선 측정 = 42
4. 실험결과 및 고찰 = 46
4.1 수세공정조건에서의 부식실험 고찰 = 46
4.2 수세공정조건 변화에 따른 부식실험 고찰 = 78
4.2.1 pH변화에 따른 부식거동 = 78
4.2.2 용존산소 및 온도에 따른 부식거동 = 91
5. 결론 = 106
참고문헌 = 10
Research about management of Korean ocean salvage system, present condition and development aspect
Get PDFIt is expected that the benefits we get from the sea will continue to increase. However, this gifts from the sea can be suddenly disappeared by human's mistake, such as the capsize of a ship(SEA PRINCE). Oil spill happens when the oil leaks from the tanker and covers the sea.
The damage of it is formidable since the oil covers the sea fast in short time. To prevent this kind of disaster we should prevent it before it happens and should it happen, we need to take immediate preemptive action before it gets worse.
In this reason governments are required to establish effective system and salvage operation. In korea, when accidents happen in the sea, most cases rely on overseas companies to deal with the accidents. In this reason, the consequences can be worse lacking of appropriate action against it. Thus the government need to support civil company to have technology and equipments to deal with accidents.
It seems more effective to consign towing, salvage operation, (preemption, response)to citizen companies, while
National Maritime Police Agency concentrates on rescuing and searching.목차
Abstract = I
제1장 서론 = 1
제1절 연구배경 = 1
제2절 연구목적 = 2
제3절 연구의 방법 및 구성 = 4
제2장 구난방제체제의 고찰 = 5
제1절 구난체제 = 5
1. 구난(救難)의 의미 = 5
2. 구난관련 법령 = 5
3. 우리나라의 해상 구난체제 = 12
제2절 해양오염 방제체제 = 19
1. 방제의 의미 = 19
2. 방제관련 법령 = 19
3. 유류오염과 경로 = 22
4. 유출유의 영향 = 26
5. 방제체제 = 29
제3절 외국의 방제체제 = 37
1. 미국 = 37
2. 일본 = 39
3. 영국 = 40
4. 노르웨이 = 40
5. 네덜란드 = 42
6. 독일 = 42
7. 캐나다 = 42
8. 스웨덴 = 43
제4절 해양사고 발생현황 = 43
1. 구난부문 해양사고 발생현황 = 43
2. 방제부문 해양사고 발생현황 = 46
제3장 해양 구난방제체제의 운영 현황 = 49
제1절 우리나라 구난방제업 운영 현황 = 49
1. 구난업 운영 현황 = 49
2. 방제업 운영 현황 = 53
제2절 세계 주요 국가의 구난방제 제도 = 58
1. 미국 = 58
2. 일본 = 59
3. 영국 = 60
제3절 해상방제지원시스템 발전과정 = 62
제4절 구난방제 사례 = 63
1. 엑슨발데즈호 사고 = 63
2. 씨프린스호 사고 = 66
제4장 해양 구난방제체제의 문제점과 발전 방향 = 74
제1절 구난방제체제의 기반 조성 = 74
1. 범국가적 구난방제체제의 구축 = 74
2. 국가 방제 능력 강화 = 75
3. 구난방제 기능의 활성화 = 77
제2절 구난방제 시설투자 = 82
1. 해역특성을 고려한 구난방제장비의 구입 및 방제선 확충 = 82
2. 과학화된 구난방제 시스템 운영 = 83
제3절 구난방제 기술개발 및 능력 향상 = 84
1. 구난방제 기술개발 촉진 = 84
2. 구난방제 기술능력 향상 = 85
제4절 국제 구난방제협력 체제 구축 = 86
제5장 결론 = 88
제1절 연구결과의 요약 = 88
제2절 연구결과의 시사점 = 91
제3절 연구의 한계 및 향후 연구방향 = 92
참고문헌 = 9