1,219 research outputs found
(A) Research about the Wave Force on Cylinders in Transient Waves
When the very large offshore structures are constructed at sea, the site has a various wave in which the physical phenomena are very complicated. But most research on the wave force of the very large offshore structures are carried out on linear wave force. Because of the complexity of analysis and difficulties of measurement. To get more realistic estimations of force on offshore structures in real sea, it is necessary to consider the effects of nonlinear water waves. Some research has been carried out analysis of transient waves to consider breaking waves. However, almost all of the simulations to transient waves are very complicated and difficult because of taking measurements.
This paper first presents easier simulation to transient wave. Second, It compares wave force based on the 3-D source distribution method and measured in breaking waves. A numerical procedure is described for predicting the wave force of cylinders by the 3-D source distribution method. As well as, to analysis of irregular wave, carried out a convolution integral with a response impulse function which is to take inverse FFT the wave exciting force in frequency domain. And transient wave is solved from linear Airy wave theory and based on combining an energy transmission velocity and a wave phase velocity. This formula applies to any water depth, because this formula includes linear dispersion relationship.
When the 3-D source distribution method is used to calculate the wave force and generated by breaking wave meets the very large floating body, the resulting figures are smaller than the real wave force.Abstract = โ
ฐ
Nomenclature = โ
ณ
List of Tables = โ
ต
List of Figures = โ
ถ
1. ์๋ก = 1
1.1 ์ฐ๊ตฌ ๋ฐฐ๊ฒฝ = 1
1.2 ๊ธฐ์กด์ ์ฐ๊ตฌ = 1
1.3 ์ฐ๊ตฌ์ ๋ด์ฉ = 2
2. ํด์๊ตฌ์กฐ๋ฌผ์ ์์ฉํ๋ ๋น์ ํ ์ ์ฒด๋ ฅ ํด์ = 3
2.1 ๋น์ ํ ์ ์ฒด๋ ฅ ๋ฐ ํ๊ฐ์ ๋ ฅ = 3
2.2 ์์ ํ๋ฉด ๊ฒฝ๊ณ์กฐ๊ฑด = 4
2.3 ๋ฌผ์ฒดํ๋ฉด ๊ฒฝ๊ณ์กฐ๊ฑด = 7
2.4 ๊ฒฝ๊ณ์น ๋ฌธ์ ์ ์ ์ฒด๋ ฅ = 12
2.5 ํ๊ฐ์ ๋ ฅ๊ณผ ์ ๋ฌํจ์ = 15
3. ์๊ฐ ์์ญ์์์ ํ๊ฐ์ ๋ ฅ = 21
4. ์ด๋ก ๊ณ์ฐ ๋ฐ ๋ชจํ = 25
4.1 ๊ณ์ฐ ๋ฐ ์คํ๋ชจํ = 25
4.2 ํน์ด์ ๋ถํฌ๋ฒ์์ํ 1์ฐจ ํ๊ฐ์ ๋ ฅ = 27
4.3 ๊ฐ ๋ชจ๋ธ์ ๋ํ ์ํ์ค ์๋ตํจ์ = 29
5 ์คํ = 30
5.1 ๊ณผ๋์ํ = 30
5.2 ๊ณผ๋์ํ ์ฌํ = 32
5.3 ์คํ ๋ฐ์ดํฐ ์ฒ๋ฆฌ = 34
5.4 ์ค์ ๋ก ์ฌํ๋ ํํ = 35
5.5 ์ธก์ ๋ ํ๋ ฅ๊ณผ ์ด๋ก ์์ ๊ตฌํด์ง ํ๋ ฅ ๋น๊ต = 44
5.5.1 ๋ชจ๋ธโ
= 45
5.5.2 ๋ชจ๋ธโ
ก = 47
5.5.3 ์คํ ๋ถ์ = 49
6. ๊ฒฐ๋ก = 50
References = 51
์ฐธ๊ณ . Haskind ๊ณต์ = 5
็ฌฌ28ๆ
[[abstract]]็ฑๆผ๏ค่ๅฑๆฉๅๅ
ๅไธปๆฌๅตๅธๅ็ช๏ผๅๆฌกๅผ็ผๅฐๆญ็็ถๆฟๆฒป๏งค็้ๆณจใ้ๅฐ็ถๆฟๅ้ก๏ผๆญ็้ซๅณฐๆ่จญ็ฝฎไธไปปๅๅฐ็ตใ2010๏ฆ10ๆ21ๆฅไปปๅๅฐ็ตๅๆญ็้ซๅณฐๆๆๅบไธไปฝๅ ฑๅ๏ผๆๅบๅจไฟๆๅๅฎถ่ฒกๆฟๅ็ถๆฟๆฟ็ญไนๅๆ๏ผๅๆๅกๅ้ๅฐคๅ
ถๆฏๆญๅ
ๅ๏ผ็ถๆฟ็ธไบไพ่ณด๏จๆฅต้ซใไปปๅๅฐ็ตๅปบ่ญฐๆๅผทๅ็ถๆฟๆฒป๏งค๏ผๆน้ฉๆนๅๆๆไบๅ้ขๅ็ผๅฑใ
็ฌฌๅ
ซๅฑไบๆญ้ซๅณฐๆ่ญฐๆผ2010๏ฆ10ๆ4่ณ5ๆฅๅจๆฏ๏งๆๅธ๏คน๏ฅฌ็พ่๏จใไบๆญ้ซๅณฐๆไธปๅธญๆผไธปๆๆ่ญฐๆ่กจ็คบ๏ผๆญคๆฌกๆ่ญฐ็ไธป้กๅจๆผ่จ๏ฅใ็ๆดปๅ่ณชใ๏ผ่ๆญค้ๆๆๆๅ
ฌๆฐ๏คๅฅฝ็็ฆ๏งไธฆ็ตฆไบ๏คๅค็ๅฐๅดใๅจๆญคๆ่ญฐไธญ๏ผๆๆไบๆดฒ่ๆญๆดฒๆๅกๅ็๏ฆดๅฐไบบ็้็ณ้้็ญ๏ฅถๆงๅฐ่ฉฑ่ๅไฝ็่ญฐ้ก๏ผไธฆไธ่้ๅจๅนณ็ญ็ๅคฅไผด้ไฟใ็ธไบ้็ๅฐ้่๏ง็ๅ้
ใ
ไผๆฏๅฆๅ กๆฏไธ็ไธๅฏไธๆฉซ่ทจๆญไบ๏ฅธๆดฒ็ๅๅธ๏ผไธๅจ2010๏ฆ้็ฒ้ธ็บๆญ็็ๆๅไน้ฝใไผๆฏๅฆๅ ก็บไฝๅ
ฅ้ธ๏ผๅ่ณๅ
ถ๏ฅงๆฏ็ฉๆฏ๏งด็ไธ็ๅ๏ผๅ่ณๅ
ถ็บไฝๆณๅ ๅ
ฅๆญ็๏ผไผๆฏๅฆๅ ก็้ญ
๏ฆๅจๅช
Design and Implementation of a Relational Database for Management of UML Models
The 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 = โ
ฑ
์ 1 ์ฅ ์๋ก = 1
์ 2 ์ฅ UML ๋ฐ UML ๊ฐ๋ฐ ๋๊ตฌ = 4
2.1 UML์ ๊ตฌ์ฑ ์์ = 4
2.2 UML ํด๋์ค ๋ค์ด์ด๊ทธ๋จ(Class Diagram) = 6
2.2.1 ํด๋์ค(Class)์ ์ธํฐํ์ด์ค(Interface) = 7
2.2.2 ๊ด๊ณ(Relationship) = 8
2.3 UML ๊ฐ๋ฐ ๋๊ตฌ = 10
์ 3 ์ฅ UML ํด๋์ค ๋ค์ด์ด๊ทธ๋จ์ ์ ์ฅ ๋ฐ ๊ฒ์ = 12
3.1 UML ํด๋์ค ๋ค์ด์ด๊ทธ๋จ ๋ณํ = 12
3.2 ๊ด๊ณํ ๋ฐ์ดํฐ๋ฒ ์ด์ค ์์ฑ ๋ฐ ์ ์ฅ = 17
3.3 UML ํด๋์ค ๋ค์ด์ด๊ทธ๋จ ๊ฒ์ = 21
์ 4 ์ฅ ๊ตฌํ ๋ฐ ๊ธฐ์กด ์์คํ
๊ณผ์ ๋น๊ต = 23
4.1 ์๊ณ ๋ฆฌ์ฆ ๋ฐ ์์คํ
ํ๋ฆ๋ = 23
4.2 ๋ฐ์ดํฐ๋ฒ ์ด์ค ํ
์ด๋ธ ์์ธ ์ค๊ณ = 26
4.3 ์์คํ
๊ตฌํ = 33
4.4 ๊ธฐ์กด ์์คํ
๊ณผ์ ๋น๊ต = 35
์ 5 ์ฅ ๊ฒฐ๋ก ๋ฐ ํฅํ ์ฐ๊ตฌ๊ณผ์ = 36
์ฐธ๊ณ ๋ฌธํ = 3
Development of an Auto-Trim Control System for Ro-Ro Ship Carrying Heavy Cargoes
In Ro-Ro ship carrying heavy cargoes, it is very important to maintain a certain level of aft draft and the proper trim through the entire loading or discharging process. Some kinds of manual ballast control system have been generally applied so far to this practice in Ro-Ro ship. However, there is need to develop a so-called Auto-Trim Control System using some computer technology to improve the operation of those existing systems.
This paper aims at developing an Auto-Trim Control System especially for Ro-Ro ship carrying such heavy cargoes including hot coils and steel plates. The author carried out some systems analysis and design for developing the system by examining and reflecting the practices of the entire loading and discharging process.
Then a user-friendly Auto-Trim Control System has been built by interfacing the Valve Remote Control system and Tank Level & Draft Measuring system with itself. The author also provides some excellent results on the performance of the system by reporting the records of installing the system on board 4 Ro-Ro ships.Abstract
์ 1 ์ฅ ์๋ก = 1
1.1 ์ฐ๊ตฌ์ ๋ฐฐ๊ฒฝ = 1
1.2 ์ฐ๊ตฌ์ ๋ชฉ์ = 2
์ 2 ์ฅ ์์คํ
์ ๊ฐ์ = 3
2.1 ์ค๋ํ๋ฌผ ์ ์ Ro-Ro ์ ํ์ญ ์์
์ ๊ธฐ๋ณธ๊ฐ๋
= 3
2.2 Auto-Trim Control System์ ๊ธฐ๋ณธ๊ฐ๋
= 7
2.3 ์์คํ
๊ตฌ์ฑ๋ = 10
์ 3 ์ฅ ์ ๋ฏธํ์ ๋ฐ ํธ๋ฆผ ์ ์ด ์๊ณ ๋ฆฌ๋ฌ์ ๊ฐ๋ฐ = 11
3.1 ํฑํฌ ๋ฐฐ์น๋ = 11
3.2 ํฑํฌ ๋ฐฐ์ ์ฐ์ ์์ = 11
3.3 ํฑํฌ ์ ํ ๊ท์น = 12
์ 4 ์ฅ Auto-trim Control System ๊ฐ๋ฐ = 15
4.1 ์์คํ
์ํํธ์จ์ด ๊ตฌ์ฑ = 15
4.2 ์์คํ
์ค๊ณ = 16
4.3 ๋ฐธ๋ธ ๋ฐ ํํ ์๋ ์ ์ฐจ = 21
4.4 ์์คํ
๊ตฌํ = 37
์ 5 ์ฅ ํ๋ก๊ทธ๋จ ์คํ ์ = 42
5.1 ํต์ ์ํ ํ์์ค = 42
5.2 ์ ๋ฐ์ํ ํ์์ค = 44
5.3 ํ๋ก๊ทธ๋จ ์๋ = 45
์ 6 ์ฅ ๊ฒฐ๋ก = 58
์ฐธ๊ณ ๋ฌธํ = 6
A Study on Flow Zone Development and Botton change gy Propeller Jets from Ships
The 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.๋ชฉ์ฐจ
ABSTRACT = i
LIST OF TABLES = v
LIST OF FIGURES = vi
NOMENCLATURE = ix
์ 1์ฅ ์๋ก = 1
1.1 ์ฐ๊ตฌ์ ๋ฐฐ๊ฒฝ = 1
1.2 ์ฐ๊ตฌ์ ๋ชฉ์ ๋ฐ ๋ด์ฉ = 2
1.3 ์ฐ๊ตฌ์ ๋ฐฉ๋ฒ = 2
์ 2์ฅ ๊ธฐ๋ณธ์ด๋ก = 5
2.1 ์ถ์ง๊ธฐ ๋ฐฐ์๋ฅ ์ด๋ก = 5
2.1.1 ์ถ์ง๊ธฐ ๋ฐฐ์๋ฅ์ ์๋๋ถํฌ = 6
2.1.2 ์ถ์ง๊ธฐ์ ์ํ ์ด๋๋ ์ด๋ก = 16
2.1.3 ์๋๋ถํฌ = 23
2.2 ํ์ฌ ์์ก์ด๋ก = 28
2.2.1 ์ด๋ก ์ ๋ฐฐ๊ฒฝ = 28
2.2.2 ์๋ฅ์ฌ ์์ก์ด๋ก ๋ฐ ๋ฐฉ์ ์ = 28
2.2.3 ๋ถ์ ์ฌ ์์ก์ด๋ก ๋ฐ ๋ฐฉ์ ์ = 33
2.2.4 ํ์ฌ์ด๋์ ๊ฒฐ์ ์ด๋ก = 37
์ 3์ฅ ์์น๋ชจ๋ธ์๋ฆฝ ๋ฐ ์ ์ฉ = 42
3.1 ๋ํ์ ๋ฐ์ ๋ํ ๋ชจ๋ธ ๊ตฌ์ฑ = 42
3.1.1 ์ค์ ์์ญ๊ณผ ์ ํ์๋ก์ ๋ํ ์ ์ฉ = 42
3.1.2 ์ ๋ฉด์ ๋จ์๋ ฅ์ ์ฐ์ = 46
3.2 ์์ธ์ ์ ๋ชจ๋ธ ๊ตฌ์ฑ = 50
3.2.1 ์ถ์ง๊ธฐ ์ ํธ์ ์ ์ ์ฐ์ = 51
3.2.2 ์ ๋ฉด ์ ๋จ์๋ ฅ์ ์ฐ์ = 57
์ 4์ฅ ์์น์คํ ๊ฒฐ๊ณผ ๋ฐ ๋ถ์ = 61
4.1 ์ ํ์๋ก ๋ฐ ๋ถ๋์ ๋ฉด์์์ ์ ์ฉ = 61
4.1.1 ์ ํ์๋ก์ ๋ํ ์ ์ฉ = 61
4.1.2 ๋ถ๋ ์ ๋ฉด์ ๋ํ ์ ์ฉ = 79
4.2 ์์ธ์ ์ ๋ํ ์ ์ฉ = 104
4.2.1 ๋์์ ๋ฐ์ ํน์ฑ ๋ฐ ์กฐ๊ฑด = 104
4.2.2 ์์น๋ชจํ์ ๊ฒ์ฆ = 105
4.2.3 ์ ์ฉ๊ฒฐ๊ณผ ๋ฐ ๋ถ์ = 108
4.3 ์ ๋ฉด๋ณํ์ ๋ํ ๊ณ ์ฐฐ = 114
์ 5์ฅ ๊ฒฐ๋ก = 120
์ฐธ๊ณ ๋ฌธํ = 12
A Study on the Shock-Safety Assessment for Shipboard Equipments
If main equipments are damaged with the shock wave induced by a non-contact underwater explosion, The warship is able to lose easily its fighting ability. A number of researches have been reported the disability is not caused by the damage of hull but caused by that of equipments.
Therefore, the main shipboard equipments have required the safety ability test using many kinds of theoretical analysis methods or experimental analysis methods to get safety estimation of shock.
So, in this paper the procedure of shock testing and the method of theoretical analysis are investigated. Then, shock ability for starting air compressor in actual shipboard equipment is estimated through the DDAM and the shock testing based on MIL-SPEC standard. Finally, the calculated results and the experimental results are compared to find the reliability of theoretical analysis.
The results of this study can be used as a to design shipboard equipments having shock wave.Abstract
1. ์๋ก = 1
1.1 ์ฐ๊ตฌ ๋ฐฐ๊ฒฝ = 1
1.2 ์ฐ๊ตฌ ๋ชฉ์ = 3
2. ๋ด์ถฉ๊ฒฉ ์ฑ๋ฅํ๊ฐ = 5
2.1 ํจ์ ์ฉํ์ฌ ์ฅ๋น์ ๋ด์ถฉ๊ฒฉ ์๊ตฌ์กฐ๊ฑด = 5
2.2 ์ํ์ ํ๊ฐ๋ฐฉ๋ฒ = 7
2.3 ํด์์ ๋ด์ถฉ๊ฒฉ ์ฑ๋ฅ ํ๊ฐ๋ฐฉ๋ฒ = 17
2.3.1 DDAM = 18
3. ๋์์ฅ๋น์ DDAM์ ์ด์ฉํ ๋ด์ถฉ๊ฒฉ ์ฑ๋ฅ ํด์๊ฒฐ๊ณผ = 43
3.1 ๋์์ฅ๋น ์ฃผ์์ฌ์ = 43
3.2 ๋์์ฅ๋น์ ์ถฉ๊ฒฉํด์ ๊ธฐ์ค = 43
3.3 ๋์์ฅ๋น ๋ชจ๋ธ๋ง = 45
3.4 ์ํ๋ถ์ ์ ์ = 48
3.5 ์์ ์ง๋ ํด์ = 49
3.6 ์ถฉ๊ฒฉ์๋ต ํด์ ๋ฐ ์๋ ฅ๊ณ์ฐ = 51
4. ์คํ์ ๋ฐฉ๋ฒ์ ์ํ ๋์์ฅ๋น์ ๋ด์ถฉ๊ฒฉ ์ฑ๋ฅํ๊ฐ ๊ฒฐ๊ณผ = 57
4.1 ๋ด์ถฉ๊ฒฉ ์ํ์กฐ๊ฑด = 57
4.2 ๋ด์ถฉ๊ฒฉ ์ํ๋ฐฉ๋ฒ = 58
4.3 ๋ด์ถฉ๊ฒฉ ์ฑ๋ฅ์ํ ๊ฒฐ๊ณผ = 60
5. ๊ฒฐ๋ก = 61
์ฐธ๊ณ ๋ฌธํ = 6
A Study on the Fingerprint Recognition Method Directional Feature Detection using Neural Networks
Fingerprint-based identification is known to be used for a very long time. Owing to their uniqueness and immutability, fingerprints are today the most widely used biometric features. Therefore, recognition using fingerprints is one of the safest methods as a way of personal identification.
In this paper, a fingerprint identification method using neural networks and the direction feature vectors based on the directional image extracted from gray-scale fingerprint image without binarization and thinning is proposed.
The basic idea of the above mentioned method is to track the ridge lines on the gray-scale image, by ๏ผailing according to the local orientation of the ridge pattern. A set of starting points are determined by superimposing a grid on the gray-scale image. A labeling strategy is adopted to examine each ridge line only once and locate the intersections between ridge lines. After the direction feature vectors are consisted of vectors by four direction labeling. Matching method used in this paper is four direction feature vectors based matching.
The experiment are used total 124 feature patterns of four fingerprints, and One fingerprint image is consisted of 31 feature patterns. The results is presented excellent recognition capability of learned fingerprint images.Abstract(Korean) = 2
Abstract(English) = 3
Chapter 1 Introduction = 4
Chapter 2 Neural networks = 6
2.1 Introduction of neural networks = 6
2.2 Investigation between biological and artificial neuron = 7
2.3 Learning and structure of multilayer neural network = 10
2.4 Multilayered neural networks used experimental = 14
Chapter 3 Fingerprint recognition = 15
3.1 Direction feature vector detection = 15
3.2 Tangent direction computation = 18
3.3 Four direction labeling and pattern detection = 20
Chapter 4 Experimental results = 25
4.1 Experimental environment and method = 25
4.2 Experimental results = 29
Chapter 5 Conclusion = 40
References = 4
ๅคงๅญธ้ขๅ่ชๆ่ฒ็ง ๆ่ฒ่ชฒ็จ ็ก็ฉถ
ไบบ้์ ์ฑ์ฅ๊ณผ ๋ฐ๋ฌ์ ํน์ ํ ๆนๅ์ผ๋ก ์๋ดํ๊ณ ์ง๋ํ๋ค๋ ์ ์์ ๆ่ฒ์ ๋ถ๋ช
ํ ์๋์ ์ธ ํ๋์ด๋ค. ๊ทธ๋ฆฌ๊ณ ์๋ํ ๊ฒฐ๊ณผ๋ฅผ ๋ณ๊ฒํ๊ธฐ ์ํ์ฌ ๅ
งๅฎน๊ณผ ๆนๆณ๊ณผ ็ฏๆฌก์ ็ต็น์ ๊ตฌ์ ํ๋ค๋ ๆ่ฒ์ ๋ํ ๊ณํ์ ์ธ ํ์๋ค. ๆ่ฒ่
, ์ฆ ๆๅธซ๋ ์ด ํ์์ ์ฃผ๋์์ด๋ฉฐ ๋งก์ ๋ถ์ผ์ ๋ํ์ฌ ๊ทธ ๆ่ฒๅ
งๅฎน ยท ๆนๆณ ยท ็ฏๆฌก ๋ฐ ็ต็น์ ๋ฅํตํด์ผ ํ๋ค. ์ฆ ํน์ ๊ณผ๋ชฉ์ ๆๅธซ๋ ๋ด๋น๊ต๊ณผ ์ ๋ฐ์ ๊ดํ ๊ฐ๊ณ ๋ ๋์ ์ง์๊ณผ ์ด์ ํจ๊ณผ์ ์ ๋ฌ์ ์ํ ๆนๆณ์ ๏งค่ซ๊ณผ ๅฏฆ้์ ์ ํตํด์ผ ํ๋ค๋ ๊ฒ์ด๋ค. ๋ ์ค๋๋ ์ ๆ่ฒ์ด ๋๋ถ๋ถ ๅญธๆ ก๋ผ๋ ๅ
ฌๅผๆ่ฒๆฉ้์ ํตํด ์ด๋ฃจ์ด์ง๊ณ ์๊ณ ์ ๋ถ๊ฐ ๋ง๋ จํ๋ ๆ่ฒๆฟ็ญ์ ์ํด ์ด์๋๊ณ ์๋ ๋ฐ, ๆๅธซ๋ ์ด ๋ถ์ผ์ ๋ํด์๋ ํด๋น ๊ต๊ณผ์ ๊ดํ ํ ์ถฉ๋ถํ ์ง์์ ๊ฐ์ ธ์ผ ํ๋ค. ๆๅธซ๋ ์ถฉ๋ถํ ๅ่ทๆ่ฒ์ ๋ฐ๊ณ ๊ต๋จ์ ์๋ ๆ่ฒๅฐ้ๅฎถ์ด๋ค. ๊ทธ๋ ๅ
ฌๅผๆ่ฒ์ ์ผ๋ถ๋ฅผ ๊ธฐํ ยท ์ค์ฒํ๋ ์ค์ฒ์ธ์ด๋ฉฐ ํ๋๊ฐ์ด๋ค. ๊ทธ๋ ์ค์ฒ์ธ ํ๋์ธ์ผ๋ก์จ ๊ทธ์ ํ๋์ ์ํฅ์ ์ฃผ๋ ์ ๋ฐ ์ฌํญ์ ๊ดํ ํ๋ฌธ์ ยท ๊ธฐ์ ์ ยท ๊ต์์ ๊ธฐ์ด๋ฅผ ๊ฐ์ง๊ณ ์์ด์ผ ํ๋ค. ๊ทธ๋ฌ๋ ์๋ฐํ ๋งํด์ ๊ต์ฌ๋ ์์ ์ด ๊ฐ๋ฅด์น๋ ๊ต๊ณผ์ ๋ด์ฉ์ด๋ ๊ต์๋ฒ ์์ฒด์ ๋ํ ์ ๋ฌธ๊ฐ๋ ์๋๋ค. ์์ฐ์ธ์ผ๋ก์์ ์ด๋ ๊ตญ์ด๊ณผ ๆๅธซ๊ฐ ๆๅญธๆน่ฉ์ด๋ ๆ่ฒๅญธ์ ๅฐ้ๅฎถ์ผ ์๋ ์์ผ๋ ์ด๋ค์ ๊ฐ๊ธฐ ๋ค๋ฅธ ์ญํ ๊ธฐ๋๋ฅผ ๊ฐ๋๋ค. ๋ฐ๊พธ์ด ๋งํด์ ๆๅธซ๋ ์ค๋ฌด์ ์ฑ
์์ ์ง ์์ฉ๊ณผํ์์ธ ์
์ด๋ค. ์ด๊ฐ์ ๆๅธซ์ ์์ฑ์ ์ฑ
์์ง ๊ณณ์ด ๅธซ็ฏๅคงๅญธ์ด๋ค. ํํ ๆ่ฒๆณ์ ์ด๋ธ ๋ค์๊ณผ ๊ฐ์ด ์ ์ํ๊ณ ์๋ ๋ฐ, ๅคงๅญธ้ขๆ่ฒ์ด ๅคงๅญธๆ่ฒ์ ์ฐ์ฅ ยท ์ฌํ ยท ํ๋๋ผ๊ณ ๋ณผ ๋ ๆ่ฒๅคงๅญธ้ข์ ์ค๋ฆฝ ์ทจ์ง ๋ํ ์ด์ ์คํ๋ค๊ณ ๋ณผ ์ ์์ ๊ฒ์ด๋ค.ๆฌ ่ซๆ์ 1980ๅนดๅบฆ ๆๆ้จ ๅญธ่ก็ก็ฉถ ๅฉๆ่ฒป์ ไพํ ็ก็ฉถ่ซๆ์
(A) Study on Fluid Characteristics in the Wake of Bluff Bodies by Multivision PIV
Time-resolved analyses of the wake characteristics of two-dimensional bluff body flows have been executed by applying the multivision PIV to square prism (angle of attacks:0ใ, 30ใ), circular cylinders (rotating speed :0 rpm, 76 rpm) and airfoils (fixed, pitching) submerged in a circulating water channel (Re=10โด). The macroscopic shedding patterns and their dominant frequencies were discussed in terms of instantaneous velocity, vorticity and turbulent quantities such as turbulence intensity, turbulent kinetic energy and three Reynolds stresses.
In this study, more realistic animation of flow patterns has been exploited by adopting the multivision PIV with three input CCD cameras to obtain an expanded measurement wake region. Quantitative frequency analysis was also carried out with the conventional PIV with single CCD camera.
Particularly, the time-averaged distribution of turbulent intensity in all experimental cases revealed separate island-like small regions where the magnitude of turbulent intensity was always strengthened. The dominant shedding frequencies of the turbulent quantities in the wake regions were two times larger than those of the velocity and vorticity.Abstract = โ
ฐ
Nomenclature = โ
ฒ
์ 1์ฅ ์๋ก = 1
1.1 ์ฐ๊ตฌ์ ๋ฐฐ๊ฒฝ ๋ฐ ์ฐ๊ตฌ๋ชฉ์ = 1
1.2 PIV์ ๊ฐ์ = 3
1.3 Multivision PIV์ ๊ฐ์ = 6
์ 2์ฅ ์คํ = 8
2.1 ์คํ์ฅ์น = 8
2.2 ๊ท ์ผ์ ์
์๋ํ์ธ = 14
2.3 PIV ์์คํ
์ ๊ตฌ์ฑ = 16
2.3.1 ์กฐ๋ช
๋ฐ ์ถ์ ์
์ = 16
2.3.2 ์์์
๋ ฅ ๋ฐ ์ ์ฅ์ฅ์น = 17
2.3.3 ์ด๋ฏธ์ง๋ณด์ค๋ = 19
2.3.4 ์ํตํ ๋ ์ฆ = 20
์ 3์ฅ ์์์ฒ๋ฆฌ = 22
3.1 ์ ์ฒ๋ฆฌ = 22
3.2 ๋์ผ์
์ ์ถ์ = 28
3.3 ํ์ฒ๋ฆฌ = 36
์ 4์ฅ ๊ฒฐ๊ณผ ๋ฐ ๊ฒํ = 37
4.1 ์์์ ํฉ์ฑ = 37
4.2 ์๋๋ฒกํฐ, ์ ์ ๋ฐ ์๋ํ๋กํ์ผ = 40
4.3 ๋๋ฅ๊ฐ๋ = 50
4.4 ์ ๋ฐ ์ ๋ํน์ฑ = 55
4.5 ์๊ฐํ๊ท ๋ฐ์ดํฐ ๋ถ์ = 58
4.6 ์ฃผํ์ ๋ถ์ = 63
์ 5์ฅ ๊ฒฐ๋ก = 72
์ฐธ๊ณ ๋ฌธํ = 74
๊ฐ์ฌ์ ๊ธ = 7
ํด๋ผ์ด์คํธ์ ํฌ๊ณก ใํค๋ฅด๋ง์ ์ ์ใ ์ฐ๊ตฌ
ใํค๋ฅด๋ง์ ์ ์ใ(Die Hermannsschlacht. Ein Drama)์ ๊ฒ๋ฅด๋ง ๋ฏผ์กฑ์ ์์
์๋ฅด๋ฏธ๋์ฐ์ค(Arminius)๊ฐ ๊ทธ์ ๋์กฑ์ ๋ก๋ง์ ์ง๋ฐฐ์์ ํด๋ฐฉํ๋ ๊ณผ์ ์ ๋ด๊ณ ์๋ค. ์ด ์ํ์ ํํ ์ฌ๊ทน(ๅฒๅ)์ด๋ผ๊ณ ๋ถ๋ฆฌ์ง๋ง ์ฌ์ค์ ์ถฉ์คํ ๊ฒ์ ์๋๋ค. ์คํ๋ ค ์ด ์ํ์ ๋ํด๋ ์น ์ ์์ผ๋ก ์ธํ ํ๋ก์ด์ผ์ ๊ตญ๋์ ๊ทน๋ณตํ๊ธฐ ์ํด์ ๋
์ผ๋ฏผ์กฑ์ด ๊ฒฐ์ํ ๊ฒ์ ํธ์ํ๋ ์ ์น์ ์ธ ์๋๋ฅผ ๊ฐ๊ณ ์๋ค. ๋ค์ ๋งํ๋ฉด ํด๋ผ์ด์คํธ๋ ๋จ์ํ ์ญ์ฌ๊ทน์ ์ฐ๋ คํ ๊ฒ์ด ์๋๋ผ๏ผ ํ๋ก์ด์ผ์ ๋ํ ๋ํด๋ ์น์ ์ ์น์ ์ผ๋ง์ ๋ถ์ํ๊ณ ๊ทธ์ ๋ํ ์ฆ์ค์ฌ์ ๋ถ๋ฌ์ผ์ผ์ผ ๋
์ผ๊ตญ๋ฏผ์ ์ ๊ตญ์ฌ์ ๊ณ ์ทจ์ํค๋ ค๋ ๊ฒ์ ์ผ๋์ ๋์๋ ๊ฒ์ด๋ค
- โฆ