Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Ocean Engineering and Technology
Journal Basic Information
Journal DOI :
Korean Society of Ocean Engineers
Editor in Chief :
Volume & Issues
Volume 21, Issue 6 - Dec 2007
Volume 21, Issue 5 - Oct 2007
Volume 21, Issue 4 - Aug 2007
Volume 21, Issue 3 - Jun 2007
Volume 21, Issue 2 - Apr 2007
Volume 21, Issue 1 - Feb 2007
Selecting the target year
A Study on the Development of Active Circulating Type Oil Recovery Vessel
Lee, Kji-Joo ; Shugan, Igor V. ; An, Jung-Sun ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 1~6
A study on the new active circulation type oil-water separation system including buoyancy type guidance system was carried out in this paper. Newly developed oil-water separation system is composed of several oil separation steps. In the beginning of these steps, buoy type separation system would be used. Buoy type oil guiding system was developed based on the difference of density of water and oil.
Diagonal Tension Failure Model for RC Slender Beams without Shear Reinforcement Based on Kinematical Conditions (I) - Development
You, Young-Min ; Kang, Won-Ho ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 7~15
A mechanical model was developed to predict the behavior of point-loaded RC slender beams (a/d > 2.5) without stirrups. It is commonly accepted by most researchers that a diagonal tension crack plays a predominant role in the failure mode of these beams, but the failure mechanism of these members is still debatable. In this paper, it was assumed that diagonal tension failure was triggered by the concrete cover splitting due to the dowel action at the initial location of diagonal tension cracks, which propagate from flexural cracks. When concrete cover splitting occurred, the shape of a diagonal tension crack was simultaneously developed, which can be determined from the principal tensile stress trajectory. This fictitious crack rotates onto the crack tip with load increase. During the rotation, all forces acting on the crack (i.e, dowel force of longitudinal bars, vertical component of concrete tensile force, shear force by aggregate interlock, shear force in compression zone) were calculated by considering the kinematical conditions such as crack width or sliding. These forces except for the shear force in the compression zone were uncoupled with respect to crack width and sliding by the proposed constitutive relations for friction along the crack. Uncoupling the shear forces along the crack was aimed at distinguishing each force from the total shear force and clarifying the failure mechanism of RC slender beams without stirrups. In addition, a proposed method deriving the dowel force of longitudinal bars made it possible to predict the secondary shear failure. The proposed model can be used to predict not only the entire behavior of point-loaded RC slender shear beams, but also the ultimate shear strength. The experiments used to validate the proposed model are reported in a companion paper.
Diagonal Tension Failure Model for RC Slender Beams without Shear Reinforcement Based on Kinematical Conditions (II) - Verification
You, Young-Min ; Kang, Won-Ho ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 16~25
In a companion paper, a rational mechanical model to predict the entire behavior of point-loaded RC slender beams (a/d > 2.5) without shear reinforcement was developed. This paper presents the test results of 9 slender shear beams and compares them with analytical results performed by the proposed model. They are grouped by two parameters, which are shear span ratio and concrete strength. Three kinds of concrete strength the 26.5, 39.2, and 58.8 MPa were included as a major experimental parameter together with different shear span ratios ranging from 3 to 6 depending on the test series. Tests were set up as a traditional 3 point bending test. Various measurements were taken to monitor abrupt shear failure. Test results were not only compared with analytical results from the proposed model, but also other formulas, to consider the various aspects of shear failure such as kinematical conditions or shear capacity. Finally, a review of the proposed model is presented with respect to the shear transfer mechanisms and the effect of test parameters. Results show that several assumptions and proposals adopted in the proposed model are rational and reasonable.
Finite Element Simulation of Elastic Wave Propagation in a Concrete Plate - Modeling and Damage Detection
Woo, Jin-Ho ; Kim, Jeong-Tae ; Cho, Hyun-Man ; Na, Won-Bae ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 26~33
Finite element simulation of elastic wave propagation in a concrete plate was carried out to investigate its modeling and damage detection procedures. For the numerical stability three criteria were introduced and tested. With a proper element size and time increment, two different kinds of damage scenarios (crack and deterioration) were applied to verify the feasibility of the finite element simulation. It is shown that the severities of those damages are sensitive to the received displacement signals.
On Damping of Irregular Waves Passing over a Permeable Seabeds
Hur, Dong-Soo ; Choi, Dong-Seok ; Lee, Woo-Dong ; Bae, Ki-Seong ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 34~41
The present study investigates numerically damping characteristics of irregular waves passing over a permeable seabeds. At first, the numerical model, which is able to consider the flow through a porous medium with inertial, laminar and turbulent resistance terms and determine the eddy viscosity with LES turbulent model, is validated by comparing with existing experimental data. And then, the numerical test on irregular wave damping over a permeable seabeds is performed in case that wave and flume conditions are changed. It is revealed from the numerical results that the more porosity and mean grain are increased, the more wave damping is increased. Also, the effect of wave period on damping of irregular waves over a permeable seabed is discussed.
Numerical Simulation of Tsunami Impact Load Using 3-Dimensional Particle Method
Kim, Young-Hun ; Jung, Sung-Jun ; Lee, Byung-Hyuk ; Hwang, Sung-Chul ; Park, Jong-Chun ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 42~46
The impact of a single wave generated by a dam break with a tall structure is modeled with a three-dimensional version of the Moving particle semi-implicit (MPS) method. The particle method is more feasible and effective than methods based on grid connection problems involving violent free surface motions. In the present study, the Tsunami impact load and the change of longitudinal velocity component around the structure, which are obtained from the numerical simulation, are compared to those from experiments.
The Hydraulic Characteristics of a Submerged Breakwater Covered with Multi-Function Blocks
Sohn, Byung-Kyu ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 47~52
This paper presents the design of a submerged breakwater, which functions as an eco-structure in a marine environment. Newly patented blocks were used in the submerged breakwater to both make it stable and provide an inhabitable space for fish. To investigate the wave transmission of the proposed submerged breakwater, parametric studies were conducted through two-dimensional hydraulic tests, which were carried out at the National Fisheries Research and Development Institute (NFRDI) in South Korea. Those parameters are relative crest width (B/L), wave steepness (H/L), relative crest depth (hB/H), and submerged breakwater configuration. The hydraulic experimental results can be used to predict the performance of the proposed submerged breakwater covered with the multi-function blocks.
Numerical Simulation of Non-linear Free-surface Motions Using Moving Particle Semi-implicit(MPS) Method
Lee, Byung-Hyuk ; Jeong, Seong-Jun ; Ryu, Min-Cheol ; Kim, Yong-Soo ; Kim, Young-Hun ; Park, Jong-Chun ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 53~58
A particle method, recognized as one of gridless methods, has been developed to investigate non-linear free-surface motions interacting with structures. This method is more feasible and effective than conventional grid methods for solving flow fieldswith complicated boundary shapes. The method consists of particle interaction models representing pressure gradient, diffusion, incompressibility, and the free-surface boundary conditions without grids. In the present study, broken dam problems with various viscosity values are simulated to validate the developed method.
Geomorphologic Changes in Gwangyang Bay Using Marine Geographic Information System
Kim, Jong-Kyu ; Cho, Ki-Woon ; Kim, Jung-Hyun ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 59~63
This study discusses the spatiotemporal characteristics of the geomorphological changes in Gwangyang Bay. In this study, we analyzed four aerial photos and nautical charts. The geomorphological changes that have occurred over time were identified using an MGIS (Marine geographic information system) overlay analysis. As a result, we were able to identify the geomorphological changes that have resulted from the coastal development and fairway dredging of Gwangyang Bay. This paper demonstrates that the marine geographic information system can be effective in monitoring the geomorphological changes in coastal zones.
Analysis of the Effects on the Southeastern Coast of Korea by a Tsunami Originating from Hypothetical Earthquake in Japan
Kim, Do-Sam ; Kim, Ji-Min ; Lee, Kwang-Ho ; Son, Byoung-Kyu ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 64~71
The hypothetical earthquake located on the fault zone along the western coast of Japan, where sufficient time has elapsed since the last earthquake or an earthquake has not occurred yet, is known to possess significant potential energy. The possibility of earthquake activities occurring here in the future is high. It is expected that the resulting tsunamis will cause great damage to the East Sea coast of Korea and affect parts of the southern coast as well. In this study, tsunami that may be caused by a virtual earthquake that is expected in the hypothetical earthquake, along the western coast of Japan, will be estimated using numerical simulation. From this, the effect of the tsunami originating from the hypothetical earthquake on the southeastern coast of Korea will be evaluated by examining the water level rise due to the maximum water level rise and changing time, for each point along the southeastern coast. It will be possible to use the virtual results obtained like this as important basic materials in future disaster prevention plans and designs, for determining the direction of coastal development, for arranging seashore and harbor structures and to carry out wave resistant design for the southeastern coast of Korea.
Numerical Simulation of Tsunamis that Affected the Coastal Zone of East Sea
Kim, Do-Sam ; Kim, Ji-Min ; Lee, Kwang-Ho ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 72~80
The tsunami that resulted from the Central East sea Earthquake, which registered 7.7 on the Richter scale, that occurred over the entire water region in Akita on May. 26, 1983 and the tsunami that was triggered by the Southwest off Hokkaido Earthquake (7.8 on the Richter scale) that occurred in Southwest off Hokkaido on July 12, 1993 are representative cases that led to considerable damage in life and property, not only in Japan but also in Korea. In this study, multi-grid method was used in order to reproduce sufficiently the shoaling effect that occurs as water depth becomes shallow in the shallow water region and moving boundary condition was introduced to consider the runup in the coastal region. For the tsunamis that exerted considerable effect on the East Sea coast of Korea that were caused by the Central East Sea Earthquake in 1983 and the Southwest off Hokkaido Earthquake in 1993, characteristics like water level rise and propagation in the East Sea coast will be examined using numerical simulations. At the same time, these values will be compared with observed values. In addition, maximum water level rise and change in the water level with respect to time that were caused by the tsunamis were examined at each location along the East sea coast. Usefulness of numerical analysis was verified by comparing with observed values.
An Experimental Study on the Hydration Heat Control of Mass Concrete Using Heat Pipe
BaeK, Dong-Il ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 81~86
In order to eliminate the hydration heat of mass concrete, this paper reports the results of hydration heat control in mass concrete using the OCHP (Oscillating capillary tube heat pipe). In the summarized results of the mock up experiments, distributing the heat pipe at 300 mm intervals based on the center of the test specimen was the most effective. A 200 mm turn interval for the heat pipe was measured to be the most appropriate, taking into account the reinforcement placing at the actual site. Therefore, when the hydration heat control method using the heat pipe developed in this study is applied, not only canconstruction efficiency & a reduction in the necessary construction time be expected, but so can outstanding economical effects.
A Study on the Discharge System of Thermal Waste Water
Kwak, Ki-Su ; Jeon, Yong-Ho ; Kim, Heon-Tae ; Ryu, Cheong-Ro ; Lee, Kyung-Seon ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 87~94
This study used POM (Princeton ocean model) improved for applying to coastal area in order to predict the distribution of thermal waste water. This model was applied to the coastal circulation and the effect of thermal waste water of Cheonsu-Bay. So this study compared the discharge of thermal waste water with each layer and section. The tidal current was about 1.5 m/sec at surface level and 0.9 m/sec on bottom level at flood tide; tidal current was about 1.3 m/sec on surface level and 0.8 m/sec on bottom level at ebb tide. The method discharging the thermal waste water in the nearshore region (case 1) accelerates the diffusion of the thermal waste water in the north-south direction(longshore direction). However, the method discharge the thermal waster water in the offshore region (case 2) reduced the diffusion of the thermal waste water over the coastal region. According th the diffusion region of the thermal waste water with case 1 and case 2 at three different layers (surface, middle, bottom), the diffusion region by case 1 discharge method generally influenced wider region (twice) than the one by case 2 discharge method with lower temperature between
, whereas the case 2 discharge method influenced the deeper region (middle and botton layers) with higher change of the water temperature (
The Effects of
on the Mechanical Properties of Silicon Nitride
Noh, Sang-Hoon ; Moon, Chang-Kwon ; Jeong, Hae-Yong ; Seo, Won-Chan ; Yoon, Han-Ki ; Kim, Bu-Ahn ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 95~100
In the present work, silicon nitride was fabricated with
as a sintering additive and its mechanical properties were investigated. Silicon nitride with 3, 5, and 7wt% of
was prepared and sintered by a Hot Pressing (HP) technique at 1750 and
for 2 h. The process was performed under different process pressures of 30 and 45 MPa. Mechanical properties (density, strength, hardness, and fracture toughness) were investigated as a function of the
ceramics showing similar mechanical properties compared with
ceramics. But its high temperature strength was considerably higher than that of
Study on the Design, Manufacture, and Pressure Test of a Pressure Vessel Model
Joung, Tae-Hwan ; Lee, Jae-Hwan ; Lee, Chong-Moo ; Hykudome, Tadahiro ; Sammut, Karl ; Nho, In-Sik ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 101~106
In this paper, the authors demonstrate a new idea to take the place of the real pressure vessel test, which should be carried out in a high pressure experiment unit before the real sea trial test. The idea is to make a pressure vessel model as a replica of the real pressure vessel test, which can reduce the cost of making a pressure vessel and large pressure experiment unit. The pressure vessel model was designedbased on linear-elastic, buckling equations and Finite Element Analysis. The manufactured pressure vessel model was investigated and monitored while the pressure test was being conducted. After the test, the result and the validity of the pressure vessel model as a replica of the real pressure vessel test was studied.
Torsional and Flexural Behavior Characteristics of Symmetric Pier Copping Beam
Kwon, Min-Ho ; Jung, Hee-Hyo ; Kim, Jin-Woo ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 107~114
The main aim of this study was to evaluate the bending and torsional behaviors of representative regular type cap beams in elevated guideway structures. A1/2 scale model copping beam, excluding the column portion, was designed, constructed, and tested. The copping beam was subjected to horizontal monotonic and cyclic loads with a constant vertical load over the loading stage. The damage was very much dominated by torsion. Experiment results showed that the spiral confinement in the beam helped to restrain the opening of torsional cracks in the column zone. Hence, the torsional strength of the cap beam contributesgreatly to the confinement conditions of the column.
Knowledge Base Construction of Ship Design Using Fuzzy Equalization and Rough Sets
Suh, Kyu-Youl ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 115~119
Inference rules of the knowledge base, generated by experts or optimization, may be often inconsistent and incomplete. This paper suggests a systematic and automatic method which extracts inference rules not from experts' subject but from data. First, input/output linguistic variables are partitioned into several properties by the fuzzy equalization algorithm and each combination of their properties comes to premise of inference rule. Then, the conclusion which is the mast suitable for the premise is selected by evaluating consistent measure. This method, automatically from data, derives inference rules from experience. It is shown through application that extracts new inference rules between hull dimensions and hull performance.
An Experimental Study on the Stability of Artificial Reefs for Shellfish and Seaweed
Sohn, Byung-Kyu ;
Journal of Ocean Engineering and Technology, volume 21, issue 6, 2007, Pages 120~124
The purpose of this study was to investigate the stability of the arched and fan types of artificial reefs, which provide habitats for shellfish and seaweed. According to the Froude similitude, parameters affecting the stability of the artificial reefs were analytically, experimentally studied. First, the design parameters of the artificial reefs in wave and current fields were presented. Then, using dimensionless parameters, such as the surf similarity parameter and water particle speed, the stability of the arched and fan types of artificial reefs was investigated. From the hydraulic experiments, it is shown that the stability heavily depends on the way the artificial reefs are installed. Therefore, the installation of the artificial reefs on the surf zone should be carefully executed.