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Implementation of Advanced Image Processing Algorithm for Cellular Phone
Full text linkIn this thesis, improvement algorithms of raising the memory efficiency through encoding or decoding the large size image of cellular phones are designed and realized.
Most of cellular phone uses bit mapped image in the memory with the value of hexadecimal, which is proper for rapid change and display of data.
However, It is needed the high quality of graphics in the cellular phone especially in the multimedia era. The improvement in the hardware and software technology made it possible to develope the cellular phone with 256 or 65,000 colors.
On the side of memory as an example, 6.4 Kbytes of memory are needed to store the image of 101 * 80 size with 256 colors.
Data compress technique is of interest, because cellular phone which uses a kind of operation system have limited memory and unit prices of the memory chips have significant effect on marketing.
Therefore, in this thesis, algorithms are proposed to decode LZW data and display image on LCD like a bitmap image through using the LZW compress algorithm which is used in GIF file. As a result of LZW compression of the bitmap image, proposed LZW(Lempel-Ziv-Welch) algorithm show the reduction of memory size as benefit of image size when convert bitmap image to GIF image.목차
Abstract = iv
제1장 서론 = 1
제2장 CDMA 단말기의 이미지 프로세싱 = 4
2.1 CDMA 단말기의 이미지 프로세싱 개요 = 4
2.2 이미지 압축 알고리즘에 대한 개요 = 5
2.3 LZW를 이용한 압축율 개선 및 처리속도의 증가 = 6
제3장 비트맵, GIF와 LZW의 개요 = 8
3.1 비트맵의 구조 = 8
3.2 GIF의 구조 = 13
3.3 LZW 압축 알고리즘의 구조 및 구현 = 18
제4장 개선된 이미지 알고리즘의 구현 = 24
4.1 GIF 이미지에서 LZW 데이터 추출 알고리즘 = 24
4.2 단말기에서 LZW 데이터 복원 알고리즘 = 29
제5장 실험 및 검증 = 32
5.1 LZW 알고리즘 적용시의 메모리 사이즈 비교 = 32
제6장 결론 = 40
참고문헌 = 4
A Study on the Characterization of Carbon Nanotubes by Terahertz Spectroscopy
Full text linkWe have measured the absorption and dispersion of single- walled carbon nanotubes (SWCNTs) films using an optoelectronic THz beam system for THz time-domain spectroscopy (THz- TDS). The angle-dependent conductivities of anisotropically aligned nanotube films, which were prepared by a mechanical squeezing with a bar coater, were also characterized. Samples were prepared raw SWCNT and purified SWCNT, respectively.
As the frequency increases, the power absorption coefficient of SWCNT increases. Also, the power absorption shows maximum at parallel orientation of the film to the THz beam polarization and minimum at perpendicular orientation, which was explained by a 'wire grid' model indicating that SWCNTs were aligned. The refractive indices decrease with increasing frequency. This trend is similar to that yielded by lightly doped semiconductors. The real conductivities increase with increasing frequency in the low frequency ranges. This is not congruent with the simple Drude theory.목차
Abstract
제1장 서론 = 1
1.1 연구 목적 및 배경 = 1
1.2 연구 내용 및 방법 = 3
제2장 테라헤르츠 시간영역 분광법 시스템 = 4
2.1 테라헤르츠 시스템 구성 = 4
2.2 송신부 및 수신부 = 8
2.3 설치 및 조정 = 11
2.4 데이터 수집 = 14
2.5 교류전압을 이용한 테라헤르츠 이진신호 = 16
제3장 측정 = 21
3.1 수분에 의한 테라헤르츠 전자기 펄스 = 21
3.2 Thin 필름 측정 = 22
제4장 탄소 나노튜브 = 25
4.1 탄소 나노튜브 = 25
4.2 탄소 나노튜브의 성장 및 배열 = 27
4.3 탄소 나노튜브의 측정 결과 = 30
제5장 결론 = 42
참고 문헌 = 4
A Study on DCVM forward converter for Power Factor Correction of Wind Power Generator
Full text linkWind power generation would be the most potent alternative energy source in near future with growing concern about the shortage of natural energy resources by a sharp increase in energy consumption and environmental pollution. In wind power generation, wind energy is converted to electrical energy via rotary blades and an alternator. With small size power generation system used in private houses, large scale wind power generators of megawatt range are also commonly under commercial generation. It is said that the price of power electronic device occupy 25%-35% of whole system price. Power conversion device can be divided into two parts, one is AC/DC converter part which converting ac generator voltage into dc voltage and the other is DC/AC converter part linking with utility line. AC/DC converter should meet the various input voltage requirements, and also high power factor should be achieved.
In this paper, high power factor and high efficiency forward converter is suggested by driving it with LC filter in DCVM operation. Being operated by DCVM, the forward converter's loss is dramatically decreased with the presence of voltage zero period when switch is turned off. It suggests that IGBT switch can be used in wind power generator system without further loss in the switching period which is favorable in large power rating system.
Through the experiment, output of 24 [V], 72 [W] is obtained with 90 [Vrms], 110 [Vrms], 260 [Vrms] input voltages. Power factors of 0.998, 0.995 and 0.993 are achieved with input voltage of 90, 220, 260 [Vrms] respectively. Besides simple control circuit without current sensor, it is profitable for miniaturization because the size of inductor and capacitor could be small. Also, THD of the converter is within 10% for the input voltage range from 90 to 260 [Vrms]. So, DCVM forward converter can be the possible AC/DC converter in wind power generation with varying input wind power.목차
Abstract
제1장 서론 = 1
제2장 DCVM 포워드 컨버터 = 3
2.1 포워드 컨버터 = 3
2.2 DCVM 포워드 컨버터의 회로 해석 = 8
2.3 입·출력 특성 = 15
2.4 제안한 포워드 컨버터 설계 = 21
2.4.1 파라미터 설계 = 21
2.4.2 트랜스포머 설계 = 24
제3장 시뮬레이션 = 28
3.1 회로 구성 = 28
3.2 시뮬레이션 결과 및 고찰 = 29
제4장 실험 및 결과 = 32
4.1 실험 구성도 = 32
4.4.1 스위치 구동부 = 34
4.4.2 MOSFET = 34
4.2 결과 및 고찰 = 36
제5장 결론 = 42
참고문헌 = 4
(A) Study on Causes and Effects between Competitive Edge of the Shipping Industry and Ship Financing System in Korea
No full textA Study on Causes and Effects between Competitive Edge of the Shipping Industry and Ship Financing System in Korea
Shipping business belongs to an international and capital-intensive industry and thus shipowners are keen on improving competitiveness over cost factors such as, but not limited to, capital cost, voyage cost, general overhead cost, and so on for its survival, further growth and development in the world shipping market. Shipping cost can be generally classified into two categories, i.e., international and national costs. The costs which may be considered as non-variable between nations can be regarded as international whereas those which may be variable between nations as national.
The capital cost, which has been national one to Korean shipowners, has not been competitive over foreign competitors in the international shipping market over the last five decades because the terms and conditions of ship financing employed by Korean shipowners have not been favourable and the Korean rules and regulations on foreign currency exchange control, taxes, custom duties and depreciation, among others, have been relatively unfavourable for Korean shipowners. This means that their capital and general overhead costs have been comparatively higher than those of foreign shipowners. However, the voyage cost of Korean ship has been similar to foreign shipowners'.
The world shipping market becomes more unfavourable to Korean shipowners because the government policy for protecting them, such as cargo preference and waiver system, has been repealed since Korea joined in WTO and OECD. Furthermore, the international rules and regulations against protective measures and policies have been strengthened and severer than before, and any breach of them will be followed with retaliation and conflicts.
In the meantime, Korean shipowners have recently been strongly required by the Korean government to improve financial situation and to reduce their equity-debt ratio to below 200 percent by the end of 1999. Under such international and domestic circumstances, they have to find out suitable way of ship financing arrangement with better and more favourable terms and conditions to fulfill competitive services.
This study aims to find out the reason why Korean shipowners were in uncompetitive position in the world shipping market during last half century from 1945 to 1997 by historically investigating ship financing sources, Korean rules and regulations related to ship financing and its terms and conditions.
The whole period (1945-1997) considered under the study is divided into five sub-periods for historical review as follows:
- Period of reliance on government provision of ship financing
(1945-1961).
- Period for diversification of ship financing sources(1962-1975).
- Period of expansion of ship financing(1976-1983).
- Period of adjustment of ship financing(1984-1990).
- Period of open ship financing(1991-1997).
The following typical financing sources and Korean owners' ship financing arrangement were reviewed: -
- Bank loans: official export credit, Keihek-Zoseon and general
commercial bank loan.
- Lease financing
- Equity financing
- Special type of ship financing such as K/S ship financing, Shikumisen and mezzanine financing scheme.
Having researched into Korean shipowners' ship financing sources and their availability through historical review of them in this study, five hypotheses are set up to test whether the Korean shipping industry had competitive edge in the world shipping market from 1945 to 1977.
[Hypothesis No. 1] It was one of reasons why some Korean shipowners, especially in the period of expansion of ship financing(1976-1983), were in a bankrupt situation where they failed to generate net cash flow from operating the vessel secured with foreign ship financing.
It was found out that Korean shipowners could not generate net cash flow from even long-term COA and could be presumed same from their general shipping activities, which enable us to assume that Korean shipowners would be in a financial difficulty and eventual bankruptcy. Thus the hypothesis No. 1 has been adopted.
[Hypothesis No. 2] Korean shipowners were not in competitive position on capital cost which was higher than those of foreign competitors' because both the terms and conditions of ship financing were not favorable, and rules and regulations were so much restrictive.
It was confirmed from the study that Korean shipowners were hampered from ship financing contract on a commercial basis due to various government's restrictive rules and regulations. In addition, they failed to contract ship financing with favourable terms and condition. It was further confirmed that Korean shipowners were not in a competitive on capital cost factors due to both reasons above, which make us support on hypothesis No. 2.
[Hypothesis No. 3] Notwithstanding to above, it was possible for Korean shipowners to build up specialized fleet such as iron ore or coal and liquefied natural gas carriers with continuous employment of long-term COA basis, owing to the cargo preference policy and waiver system introduced by the Korean government.
It was confirmed that the government gave first priority to Korean shipping companies to have long-term COA with POSCO, KEPCO, KGC, which enables them to fix the new building order with Keihek-Zoseon or BBHP.
Thus the domestic shipping enterprises were in a competitive for carrying these charterers' cargoes. Thus we can adopt hypothesis No. 3.
[Hypothesis No. 4] The Korean shipowners have not taken a proper measure in order to be competitive under the circumstances that both the rules and regulations related to environmental protection and imposing penalty on breach of them have been strengthened and severer than before under the circumstances of open economic orders.
It was found out that the Korean shipowners failed to meet this kind of requirement for ship financing to be competitive in world shipping market. The hypothesis No. 4, thus, could be supported.
[Hypothesis No. 5] It has been greatly contributed to improving Korean shipowners' competitiveness on capital cost factors in the shipping market that Korean government is revising restrictive rules and regulations and is lifting the ban on ship financing and furthermore the big charterers' are improving terms and conditions on COA freight level to Korean shipowners.
It would be assumed that the recent change and improvement on shipping policy from the government and big charterers such as POSCO, KEPCO and KGC would be greatly helpful for up-grading Korean shipowners' competitiveness considering the reverse action from government and big charterers caused reverse effects in the past. Hypothesis No. 5, therefore, would be adopted.
And the study recommends the following:
First, the restrictive rules and regulations relating to ship financing should be further amended in order for Korean shipowners to be allowed for commercial approach and decision in shipping activity.
Second, the shipowners themselves should prepare and take proper measures for contracting ship financing arrangement with better and favourable terms and conditions under open economic order and severer rules and regulations on maritime environmental matter
Third, the government should newly devise in law any financing scheme, which enables Korean shipowners to save their capital charges and keep eventually them competitive
Am Empirical Study on the Quality Management for Port Services: Primarily on Busan Container Terminals
No full textAs the competition among the ports is recently extreme, the purpose of this study which intends to keep sustainable competitive advantage in Busan Container Terminals through the quality management of port service is shown as the followings.
First, the common factor of quality management activities in the part of domestic container port is to be analyzed. secondly, the efforts for enhancing the standard of quality management is to be confirmed. lastly the relationship of cause-effect among the source of quality management, quality management activities and quality management is to be clarified.
An empirical study was carried out to examine how Busan Container Terminals view quality management activities by the provision of statistical evidence showing the efforts to enhance the standard of quality management, common factors of quality management activities and causal relationship among these factors.
The data investigating the quality management for Busan Container Terminals were collected from 170 persons in charge of quality management for port services in Busan Container Terminals by the use of questionnaire method and personal interviews.
The Cronbach's α coefficient and factor analysis were used to analyze the reliability and the propriety of measured variables.
Furthermore, SEM method using AMOS 4.0 was used to analyze the cause-effet relationship among the source, activities and accomplishments of quality management representing the core concept of quality management system.
The results of hypothesis testing were found to be as follows1) It is shown the leadership - the source of quality management - has the significant effect upon the personnel resource control, service quality strategy, and investment raising plan which are the quality management activities, and the system culture significantly affects the quality management activities of bench marking and quality information system. This suggests which it needs the strong leadership which importantly thinks the customer and the customer-oriented system culture which considers the service importantly in order that the quality management is correctly introduced to the part of domestic container port.
2) It is shown that the personnel resources management, bench marking and quality information system of the quality management activities have the significant effect upon the satisfaction of system member, and thus it is indicated the quality management activities must be progressed , centering around the personnel resources management, bench marking and quality information system. The system suggests the management environment which the whole personnel can take part in the quality management through the effective personnel resources management, and thus must plan the progress of individual and system and the leader must develop the method of delivering the value to the customer, continuously comparing the innovational course of affairs in the other terminal and how it is against the needs of customer, and also will have to own the know-how for the business promotion between the departments within the terminal. Also, the leader will have to plan and operate the quality information management system and to utilize the information on the customer and then to heighten the effectiveness of information management, and also to make the business cooperation with the department through the introduction of information system smoothly.
3) It is shown which the individual rather than the system member has acknowledged to be larger in the change with regard to the environment change degree of container port, and on the other hand, the whole system member has prepared for the environment change well.
The importance of this study is placed in the description of the theoretical and general system on the quality management when the domestic container terminals have activated to promote the quality management, and in suggesting the actual problems and settlement method which are directly helpful to the field, and it can be indicated as having its meaning on future research object.목차
Abstract = 1
제1장 서론 = 1
제1절 연구배경 = 1
제2절 연구목적 = 2
제3절 연구의 방법 및 구성 = 3
제2장 품질경영의 이론적 고찰 = 5
제1절 품질경영의 의의 = 5
1. 품질의 개념 = 5
2. 품질의 배경 및 발전과정 = 8
3. 품질경영의 접근법 = 14
4. 품질경영시스템 및 프로그램 = 21
제2절 품질경영시스템 = 27
1. 전략적인 품질경영 = 27
2. 시스템경영 = 28
3. 품질경영시스템 = 30
제3절 컨테이너항만부문에서의 서비스품질경영 = 41
1. 항만서비스의 개념적 특성 = 41
2. 항만서비스의 특성 = 45
3. 항만고객의 니즈(Needs) = 46
4. 컨테이너항만부문의 품질경영 = 48
제3장 연구설계와 가설설정 = 52
제1절 연구설계 = 52
1. 연구설계 = 52
2. 변수의 조작적 정의와 측정 = 53
3. 표본설계 및 설문지의 구성 = 59
제2절 연구가설의 설정 = 60
1. 품질경영의 원천과 품질경영활동과의 관계 = 60
2. 품질경영활동과 품질성과와의 관계 = 64
제4장 실증분석 = 68
제1절 자료의 분석 = 68
1. 표본의 특성 = 68
2. 측정변수의 신뢰성 검증 = 69
3. 요인분석 = 71
제2절 연구가설의 검정 = 76
1. 모형의 적합도 평가 = 77
2. 품질경영의 원천과 품질경영활동과의 관계에 대한 가설 = 77
3. 분석결과의 요약 = 79
제5장 결론 = 82
1. 연구의 요약 및 시사점 = 82
2. 연구의 한계점 = 83
참고문헌 = 84
= 8
A Study on Sea Waybill
Full text linkThe purpose of this paper is to study Sea Waybill, the new transport document replacing the traditional Bill of Lading in international trade.
In a word, Sea Waybill is considered as a type of shipping document by revolution of transport and communication.
The high speed of ship and delay of document delivery occurs in international Trade and is named by ‘The Crisis of Bill of Lading by Sea'. It results in the appearance, increase and use of Sea Waybill.
After 1970, the use of Sea Waybill have been increased step by step. Sea Waybill was used at first in Europe. In North Atlantic line and Europe line, Sea Waybill use was 80% in 1996.
However, Sea Waybill use of east Asian Line including Korea is sluggish at about 15%.
What does make a difficulty in the use of Sea Waybill?
In the middle of various problems, the problem handling in this paper is concerned with the legislation of Sea Waybill.
In Korea, Any law about Sea Waybill is non-existed. So it is important to investigate this matter and find a lawful solution. This paper is composed of 5 chapters as followsChapterI introduces the purpose and scope of this research.
ChapterII reviews a general outline and kind of Bill of lading by Sea. It also shows the character of Sea Waybill and compares Sea Waybill and other transport document by Sea.
ChapterIII review the lawful situations of other countries and compare various conventions about Sea Waybill.
ChapterIV discuss the problems in using Sea Waybill on the commercial law and investigate the solutions of those problems.
As the conclusion, ChapterV summarizes the contents of each chapter and emphasizes the requirement of legislation relating to Sea Waybill.목차
Abstract = v
第1章 序論
第1節 硏究의 背景 및 目的 = 1
第2節 硏究의 範圍 및 方法 = 3
第2章 船荷證券의 限界와 海上運送狀 導入의 必要性
第1節 海上運送證券의 種類 = 5
I. 船荷證券 = 5
1. 船荷證券의 意義와 種類 = 5
2. 船荷證券의 法的 性質 = 6
II. 複合運送證券 = 9
1. 複合運送證券의 意義와 種類 = 9
2. 複合運送證券의 法的 性質 = 15
III. 海上運送狀(Sea WayBill) = 16
1. 海上運送狀의 意義와 種類 = 16
2. 海上運送狀의 法的 性質 = 24
第2節 船荷證券의 限界와 海上運送狀의 利用效果 = 29
I. 船荷證券의 危機 = 29
II. 船荷證券의 危機에 대한 旣存의 對策과 限界 = 31
1. 船荷證券 原本 1통의 船長託送 = 31
2. 保證渡 = 32
3. 受荷人에 대한 船荷證券 直送 = 36
4. 船荷證券의 元地回收 = 37
5. 船荷證券의 目的地·第3地 發行(on line B/L) = 38
6. 電子式 船荷證券 = 39
(1) 電子式 船荷證券의 意義 = 39
(2) 電子式 船荷證券의 問題點 = 44
7. 스탠드바이 信用狀 = 46
(1) 스탠드바이 信用狀의 意義 = 46
(2) 스탠드바이 信用狀의 問題點 = 51
III. 海上運送狀 利用의 效果 = 54
第3章 海上運送狀에 관한 比較法的 硏究
第1節 各國의 海上運送狀에 관한 立法動向 = 59
I. 英國 = 59
II. 美國 = 60
第2節 海上運送狀에 관한 國際運送規則과 國際協約 = 63
I. 헤이그規則(헤이그 비스비規則) = 63
II. 함부르크規則 = 64
III. UN國際物品複合運送協約 = 65
IV. 國際海法會 海上運送狀 統一規則 = 66
1. 海上運送狀 統一規則의 制定 必要性과 頸圍 = 66
2. 海上運送狀 統一規則의 內容 = 67
V. Incoterms 2000 = 72
VI. 信用狀統一規則 = 73
第4章 海上運送狀 利用을 위한 商法의 解釋 및 立法方案
第1節 解釋論的 解決方法 = 75
I. 解釋論的 方法 = 75
1. 船荷證券 및 貨物相換證 關聯 條項의 準用 範圍 = 75
2. 船荷證券 關聯 條項의 準用 範圍의 檢討 = 75
II. 解釋論的 方法의 限界 = 76
1. C.I.F. 條件에서 運送物轉賣의 問題 = 76
2. 航海 中의 運送物 轉賣의 問題 = 79
3. 擔保力不在의 問題 = 80
4. 送荷人의 運送物處分權 問題 = 81
5. 運送人特定과 保險者代位權行使의 問題 = 83
第2節 立法論的 解決方案 = 84
I. 適用法規 不在의 問題 = 84
II. 立法原則 = 86
III. 商法改正案의 提案 = 88
第5章 結論 = 9
Effect of Thermal Aging on the Strength of Laminate Composites and Honeycomb Sandwich Structures
Full text linkComposites are used in lots of field such as a part of aeronautic space, ship, machinery and so on because can make structure wished for necessary condition by control fiber direction and laminated sequence.
Aerospace industries are widely using honeycomb sandwich structures that it has high specific strength, stiffness, chemical material resistance and fatigue resistance. As the use of advanced composites increase, specific techniques have been developed to repair changed composite structures. In order to repair the damaged part, it is required that the material in the damaged area be removed first by utilizing the proper method, and prepreg be lay up in the area and cured under vacuum using the vacuum-bagging materials. However in curing process, either in an oven or autoclave is to be delamination can be occurred in the sound areas during and/or after the exposure to the elevated curing temperature in case that the repair process is repeated although autoclave curing using the vacuum-bagging becomes virtually mandatory for advanced composite repairs, in order to achieve the required compaction and proper consolidation of the repair materials and prepreg can sometimes be repaired with either or wet materials in field condition, autoclaves for repairs are rarely necessary. In order to repair the damaged part production high quality composites are completed by control the surrounding temperature and pressure in autoclave. The quality is influenced heat exposure degree by chemical reaction for processing.
Therefore, this study was conducted tensile, compressive, interlaminar shear strength tests of the laminate composites structures and flatwise, drum peel, long beam flexural strength tests of honeycomb sandwich structures by affecting thermal aging to evaluate how it affects to the composites materials of aircraft by measure the change of mechanical properties according to heat exposure degree for repairing. As the result, the change of mechanical strength was observed at the honeycomb sandwich structure which is exposed to hear several times, but the laminate composites structure was not .
Consequently, the control of curing cycle times and curing condition is recommended for parts in order to reduce the delamination phenomenon between laminate skin and honeycomb core to the minimum in case that the repair process is repeated.목차
Abstract = 1
제 1 장 서론 = 3
제 2 장 복합재료의 성형 및 수리의 이론적 배경 = 6
2.1 오토클레이브 성형 = 6
2.2 샌드위치 구조 = 14
2.2.1 프리프레그 = 16
2.2.2 코아재료 = 21
2.2.3 하니콤 코어 = 24
2.2.4 폼 코어 = 30
2.3 복합재료의 손상 및 수리 = 32
2.3.1 손상의 종류 = 34
2.3.2 손상의 평가 = 37
2.3.3 수리의 종류 = 40
제 3 장 라미네이트 강도 평가 = 45
3.1 시험재료 = 45
3.2 시험편 제작 = 46
3.3 시험방법 = 50
3.4 실험결과 = 55
제 4 장 하니콤 샌드위치 구조물의 강도 평가 = 59
4.1 시험재료 = 59
4.2 시험편 제작 = 60
4.3 시험방법 = 64
4.4 실험결과 = 67
제 6 장 종합 = 70
제 7 장 결론 = 73
참고문헌 = 7
(A) Study on the Heat Transfer Characteristic of Loop Type Capillary Heat Pipe
Full text linkHeat pipes have a very excellent heat transfer performance. They are utilized latent heat for heat transfer. But existing heat pipes have several defects in spite of excellent heat transfer performance. The Loop type capillary heat pipe is an epoch-making heat pipe and it is removed several defects of existing heat pipes. This study is performed to obtain the foundation materials about the loop type capillary heat pipe.
In this paper, heat transfer characteristics of loop type capillary heat pipe is experimentally investigated for the effect of several charge quantity ratios of working fluid and heat loads. And characteristics of temperature oscillation on looped capillary heat pipe are experimentally analyzed by means of the deterministic's manner on chaotic dynamics. Heat loads and working fluid were changed from 100W to 600W and 20% to 80%. Water was used as working fluid inside heat pipe. This type heat pipe consists of a heating section, a cooling section and an adiabatic section. A heating section is processed a copper block and an electric heater is inserted inside a copper block. An adiabatic section consists of very excellent insulations like ceramic insulation. A cooling section is made a transparent acryl plate. The heat pipe used has a 0.002m internal diameter, a 0.34m length in one turn and consists of 19 turns. Heating and cooling sections each have a length of 0.07m. Adibatic section has a length of 0.2m. Experiments were performed to measure the temperature and the pressure variation of heat pipe. A K-type thermocouple is adhere to a heating section, a cooling section and an adiabatic section. A pressure tranducer adhere to an upper end of the cooling section. And then, After the heat pipe is done a stationary state, Data were sampled 1000, 1000, 4000 by 3, 9, 135Hz respectively. This study was made use of a mean value of each section. Heat transfer performance, effective thermal conductivity, boiling heat transfer and condensation heat transfer coefficients were calculated for various operating conditions of heat pipe and it is found that heat transfer characteristics of this type heat pipe is very excellent. An effective thermal conductivity was thousands as much as that of copper. As this experimental results, this type heat pipe operates by the oscillatory flow caused by the pressure and temperature oscillation. Besides the looped heat pipe was operated by self-excited oscillation and circulation of working fluid, and oscillation of capillary heat pipes assumed chaotic behavior
An Empirical Study of Leadership Style and Empowerment on the Job Satisfaction and Organization Commitment:Primarily on the R. O. K. Navy
Full text linkThe researchers who are more interested in the practical utility than the theoretical study in the organizational behavior recently have used the concept of empowerment, and have investigated it actively.
The limitation on the command leadership by the traditional leadership has been felt by the change of developmental conditions of system urban modernization, up-to-date equipment and variety of awareness structure together with the highest military scientific technical development in the modern war.
In particular, the military has the strict grade structure and thorough conveying system of order & command, and so the study on the leadership was variously attempted, but the sharp progress was not shown and each when the system members caused the social troubles, the military leadership has been criticized.
Notwithstanding these facts, the empirical study on the interactions of cause and effect among system effect, leadership and empowerment in the military system is actually not satisfactory.
In this study, I intended to categorize leadership style into the transformational leadership and transactional leadership and to analyze the relationship of cause and effect among the empowerment, job satisfaction and organization commitment empirically.
Accordingly, in this study, I established the research model being the transactional leadership and the transformational leadership as the independent variable, job satisfaction and organization commitment as the dependent variable and empowerment as the parameter.
For the empirical analysis on the above-stated research model, I carried out the validity analysis, reliability analysis, factor analysis and path analysis based on the sample of 244 copies collected in the subject of naval officers who are in Busan, Jinhae, Pyeongtaek, Donghae and Jeju-do upon the study purpose.
As its analysis result, I could confirm which the empowerment made as the meaning, capacity, self-decision and effect among the leadership style classified as the transactional leadership and the transformational leadership, the job satisfaction and the organization commitment has been acted as the available parameter. As the analysis result of Structural Equation Model, the path coefficient of transformational leadership 0.35 was shown bigger than the transactional leadership's path coefficient 0.213.
When the longitudinal study for the clear presumption on the sample collection and cause & effect course for the expansion of considering the variable and the generalization of study is executed upon the wider agreement on the concept of empowerment from now on, its explanatory power will be increased.목차
Abstract = I
제1장 서론 = 1
제1절 연구의 배경 = 1
제2절 연구의 목적 = 2
제3절 연구방법 및 구？？ = 3
제2장 이론적 배경 = 5
제1절 리더십 = 5
1. 리더십의 정의 = 5
2. 리더십 이론의 전개 과정 = 7
3. 거래적 리더십과 변혁적 리더십 = 8
4. 軍 리더십에 관한 硏究 = 19
제2절 임파워먼트 = 27
1. 임파워먼트의 형성배경 = 27
2. 임파워먼트의 개념 = 28
3. 임파워먼트 理論의 發展 = 31
4. 軍 임파워먼트에 관한 연구 = 41
제3절 조직유효성 = 42
1. 職務滿足에 관한 硏究 = 42
2. 조직몰입에 관한 연구 = 45
제4절 리더십, 임파워먼트와 조직유효성 = 48
1. 리더십과 임파워먼트 = 48
2. 임파워먼트와 직무만족 = 52
3. 임파워먼트와 조직몰입 = 53
제3장 연구설계와 가설설정 = 54
제1절 연구모형과 가설설정 = 54
1. 연구모형 = 54
2. 가설의 설정 = 55
3. 변수의 조작적 정의 = 57
제2절 표본설계 및 설문지의 구성 = 60
1. 표본의 선정과 조사방법 = 60
2. 설문지의 구성 = 61
제4장 실증분석 = 63
제1절 자료의 분석 = 63
1. 표본의 특성 = 63
2. 측정변수의 신뢰성 및 타당성 검정 = 64
제2절 가설검정 = 68
1. 모형의 적합도 평가 = 69
2. 가설 검정 = 70
？？5장 결론 = 72
1. 연구결과의 요약 및 시사점 = 72
2. 연구의 한계점 = 73
참고문헌 = 7
A Experimental Study on the Frequency and Temperature Variation of a Closed-type Thermoacoustic Refrigerator
No full textIn general, the thermoacoustic refrigeration technique employs either the pulse-tube type refrigeration or the resonator type refrigeration. In the resonator type refrigeration technique, it can be classified into the heat-driven type and the speaker-driven type. The purpose of this study is to develope a resonator type thermoacoustic refrigerator driven by a loudspeaker.
In this study, a resonator type thermoacoustic refrigerator is designed and fabricated according to the method suggested by Hofler. The resonator type thermoacoustic refrigerator is composed of a resonator of 4 cm diameter, stack of plates, heat exchangers and cooling part. The fundamental operation frequency of this thermoacoustic refrigerator is 250Hz. Lengthes of the hot heat exchanger the stack of plates and the cold exchanger heat exchanger are 15 mm, 7 cm and 9 mm respectively. Heat exchnger are constructed by the wire cutting method. Stack of plates is of spiral type having a finite spaces of 0.7 mm and is made of Kapton. The total length of the resonator type thermocaoustic refrigerator can be different according to the kind of filling gas and the driving frequency.
Maximum temperature drop of the thermocaoustic refrigerator is observed to be 15。C when it is operated at 250Hz of driving frequency and 161.319dB of sound pressure level. Calculated efficiency(□) of this theramoacoustic refrigerator is 6.78%. It is concluded that the thermoacoustic refrigerator has optimum operation frequency according to the length of resonator and the stack.목차
Abstract
사용기호 = v
I. 서론 = 1
1.1 연구 배경 = 1
2. 연구 내용 = 4
II. 열음향 냉동이론 = 5
2.1 열음향 냉동 기술동향 = 5
2.2 열음향 냉동원리 = 6
2.3 Lagrangian 관점의 열음향 냉동이론 = 8
2.4 Eulerian 관점의 열음향 냉동이론 = 10
2.5 열유동률 = 12
2.6 일유동률 = 15
III. 열음향 냉동장치 = 19
3.1 열음향 냉동기 = 19
3.2 열교환기 = 23
3.3 박판집적체 = 23
3.4 공명관 = 26
3.5 음향 발생장치 = 26
3.6 실험장치의 구성 = 26
3.7 실험내용 및 실험방법 = 30
3.7.1 실험내용 = 30
3.7.2 실험방법 = 30
IV. 실험결과 및 고찰 = 31
4.1 주파수별 온도 측정 결과 = 31
4.2 음압레벨 측정 및 음향 동력 = 47
V. 결론 = 52
참고문헌 = 5