• Journal of the Korean Society of Marine Environment & Safety
• /
• v.22 no.5
• /
• pp.430-443
• /
• 2016

This paper involves the constitutionality of the restrictive by-laws established by the 'College of Maritime Science' at the 'Korea Maritime and Ocean University' when they affect the cadet's fundamental rights, particularly, in connection with the training system of the 'Merchant Cadet Dormitory.' The issue in question is whether the school regulations may fall within a judicially permissible boundary in light of the general principles of constitutional rights in that the rules are enacted by the school itself in accordance with the Article 31, Section 4 of the Constitution and largely regulate the cadets' living conditions on a campus. However, the general scrutiny standard the courts apply requires the school enactments to pass three tests to be justified: (1) legislative authorization, (2) proportionality and (3) non-infringement on the essential elements of the fundamental rights as articulated under Article 37, Section 2 of the Constitution. The review in this paper shows that, first, the by-laws at issue find themselves statutorily authorized by the 'Higher Education Act' and the 'Decree of the Establishment of National Schools', with the proportionality as a second part observed within a justifiable scope and the essential elements of the fundamental rights as the third point not being marred. In conclusion, the school's dormitory training system is not found to cross the line and, however, the school authorities still need to keep overseeing the overall training course to secure the constitutional proportionality.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.21 no.4
• /
• pp.290-300
• /
• 2009

The existing numerical methods on the vertical membrane breakwater have employed a linear analysis where the variable membrane tension occurring during membrane motions is assumed to be very negligible compared to the initial tension. In the present study, a quasi-nonlinear analysis is attempted such that the temporary tension of the membrane is substituted by the average tension for a wave period that is sought by an iterative calculation. The results showed that with the increase of the wave period the reflection coefficients appeared larger and the transmission coefficients smaller compared to the results of the linear analysis. The application of the quasi-nonlinear analysis also showed that the performance of the structure is closely dependent on the horizontal deformation of the membrane. In order to suppress the horizontal deformation, it may be required to take the larger initial tension of the membrane or to put additional mooring lines in the middle of the vertical faces of the membrane. But for theses methods to be effective, a largely sized surface float should be installed to secure enough buoyancy to support such downward forces.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.31 no.6
• /
• pp.409-422
• /
• 2019

In this study, we carried out the 3D numerical simulation to investigate the hydraulic characteristics of Synchronous Edge wave known as the driving mechanism of beach cusp using the Tool Box called the ihFoam that has its roots on the OpenFoam. As a wave driver, RANS (Reynolds Averaged Navier-Stokes equation) and mass conservation equation are used. In doing so, we materialized short-crested waves known as the prerequisite for the formation of Synchronous Edge waves by generating two obliquely colliding Cnoidal waves. Numerical results show that as can be expected, flow velocity along the cross section where waves are focused are simulated to be much faster than the one along the cross section where waves are diverged. It is also shown that along the cross section where waves are focused, up-rush is moving much faster than its associated back-wash, but a duration period of up-rush is shortened, which complies the typical characteristics of nonlinear waves. On the other hand, due to the water-merging effect triggered by the redirected flow toward wave-diverging area at the pinacle of run-up, along the cross section where waves are diverged, offshore-ward velocity is larger than shore-ward velocity at the vicinity of shore-line, while at the very middle of shoaling process, the asymmetry of flow velocity leaned toward the shore is noticeably weakened. Considering that these flow characteristics can be found without exception in Synchronous Edge waves, the numerical simulation can be regarded to be successfully implemented. In doing so, new insight about how the boundary layer streaming occur are also developed.

• Journal of Korea Multimedia Society
• /
• v.13 no.3
• /
• pp.430-437
• /
• 2010

It is essential for living donor liver transplantation that surgeon must understand the hepatic vessel structure to improve the success rate of operation. In this paper, we extract the liver boundary without other surrounding structures such as heart, stomach, and spleen using the contrast enhanced MDCT liver image sequence. After that, we extract the major hepatic veins (left, middle, right hepatic vein) with morphological filter after review the basic structure of hepatic vessel which reside in segmented liver image region. The purpose of this study is provide the overall status of transplantation operation with size estimation of resection part which is dissected along with the middle hepatic vein. The method of liver extraction is as follows: firstly, we get rid of background and muscle layer with gray level distribution ratio from sampling process. secondly, the coincident images match with unit mesh image are unified with resulted image using the corse coordinate of liver and body. thirdly, we extract the final liver image after expanding and region filling. Using the segmented liver images, we extract the hepatic vessels with morphological filter and reversed the major hepatic vessels only with a results of ascending order of vessel size. The 3D reconstructed views of hepatic vessel are generated after applying the interpolation to provide the smooth view. These 3D view are used to estimate the dissection line after identify the middle hepatic vein. Finally, the volume of resection region is calculated and we can identify the possibility of successful transplantation operation.

• Toxicological Research
• /
• v.20 no.2
• /
• pp.101-108
• /
• 2004

The different social reflections about the benefits and the potential risks of genetically modified (GM) crops have evolved with .different reactions in different countries. Many countries including Korea are working toward setting down new guidelines. Korea requires companies to label all food that contains more than 3% GM ingredients. One of the rapid and convenient detection methods of GM ingredients is amplification of the introduced DNAs by polymerase chain reaction (PCR). Many PCR kits for this purpose are commercially available. The objective of this study was to evaluate performance of commercialized GM crop detection kits. The results showed that 6 out of 15 kits tested did not meet the requirements even purposed by the manufacturers themselves in terms of stability, reproducibility, and detection limits, suggesting a potential quality control problem in their design stage or production line. The evaluation also suggests that, although the duplex and triplex detection kits allowed unambiguous detection in a single PCR reaction, the monoplex detection kits were the most sensitive to the detection of GM ingredients. The detection limits also differ between soybean and corn. Results from this study will be useful in the development of sound qualitative tracking systems of GM ingredients for monitoring throughout the cultivation of GM crops, their trans-boundary movement, and food production using GM grains as well as for complying with government guidelines associated with GM crops.

• Korean Journal of Plant Resources
• /
• v.29 no.1
• /
• pp.110-127
• /
• 2016

This floristic study was conducted from April to September, 2014 in 12 days. The investigated area was Mt. Segeolsan (1,261 m) which is the part of Chirisan National Park and its neighbor region, Goan-ri, Sandeuk-ri. Based on voucher specimens, flora of this area consisted of 108 families, 376 genera, 584 species, 5 subspecies, 73 varieties, and 16 forma, totally 679 taxa. 17 taxa were endemic to Korea such as Carex okamotoi Ohwi, Cimicifuga austrokoreana H.W. Lee & C.W. Park., Thalictrum rochebrunianum var. grandisepalum (H.Lév.) Nakai, Fallopia koreana B.U. Oh & J.G. Kim, Asarum patens (Yamaki) Yamaki ex Y.N. Lee, and Stewartia pseudocamellia Maxim. etc. Among these species, C. austrokoreana, T. rochebrunianum var. grandisepalum, F. koreana, A. patens are considered having a southern boundary line of distribution in the Chirisan National Park region. And so Carex okamotoi has main distribution center in the Chirisan National Park region, this study region is assumed important in phytogeography. The useful plants were 633 taxa, ethonobotanic plants were 359 taxa in this area. Invasive alien species were 61 taxa, which were naturalized rate (9.0%) and urbanized index (17.4%).

• Journal of the Korean Society of Hazard Mitigation
• /
• v.6 no.1 s.20
• /
• pp.59-68
• /
• 2006

Flow separation of recirculation zone by increasing of flow and change of its direction at confluence results in backwater due to conveyance reduction. The hydraulic characteristics of flow separation are analysed by experimental results of flow ratios of tributary and main streams and approaching angles. The boundary of flow separation by dimensionless length and width is defined by the streamline of zero and this definition agrees well to the existing investigation. Because flow separation doesn't appear in small flow ratio and approaching angle of $30^{\circ}$, the equation of flow separation with flow ratio and approaching angle is provided. In flow separation consideration and comparing with previous results, the existing equations of dimensionless length and width ratios by function of approaching angle, flow ratio, and downstream Froude number are modified and also contraction coefficient and shape factor are analysed. Dimensionless length and width ratios are proportional to the flow ratio and approaching angle. In analysis of water surface profiles, the backwater effects are proportional to the flow ratio and approaching angle and the magnitude at outside wall is greater than that of inside wall of main stream. The length, $X_l$ from the beginning of confluence to downstream of uniform flow, where the depth is equal to uniform depth, is characterized by width of stream, flow ratio, approaching angle, and contraction coefficient. The ratios between maximum water depth by backwater and minimum depth at separation are analysed.

• Journal of the Society of Naval Architects of Korea
• /
• v.34 no.1
• /
• pp.11-23
• /
• 1997

This paper contains a new approach to blade section design method for marine propellers. The hydrodynamic characteristics of 2-D section are highly influenced by its geometrical parameters i.e., thickness and camber distributions and leading edge radius etc. To consider fully turbulent flow field near 2-D section. the finite volume method with k-${\varepsilon}$ turbulent model which solve Reynolds time averaged Navier-Stokes(RANS) equation is applied. In this study, O-type grid system that can provide many calculation points on blade surface is used. The results were compared with those of the experiment of NACA0012 to confirm the accuracy of the developed codes. The goal of this study is the development of a blade section with high efficiency and low drag. To achieve this, we carried out the tests of lift, drag and cavitation characteristics in cavitation tunnel. The results of experiment were compared with numerical results in order to validate the proposed blades design method. By comparing the numerical results with the experiments, we found that the new blade section, KH28 allows superior performance in efficiency and cavitation avoidance characteristics. We further investigated the blade section design method and an application study of this section, KH28 to apply to the marine propeller. In order to improve the accuracy of numerical results on prediction of lift and drag, we conclude here that the 2-layer boundary model must be used.

• Nuclear Engineering and Technology
• /
• v.45 no.4
• /
• pp.513-522
• /
• 2013

The ODSCC detected in the TSP position of Ulchin 3&4 SGs are typical ODSCC of Alloy 600MA tubes. The causative chemical environment is formed by concentration of impurities inside the occluded region formed by the tube surface, egg crate strips, and sludge deposit there. Most cracks are detected at or near the line contacts between the tube surface and the egg crate strips. The region of dense crack population, as defined as between $4^{th}$ and $9^{th}$ TSPs, and near the center of hot leg hemisphere plane, coincided well with the region of preferential sludge deposition as defined by thermal hydraulics calculation using SGAP computer code. The cracks developed homogeneously in a wide range of SGs, so that the number of cracks detected each outage increased very rapidly since the first detection in the $8^{th}$ refueling outage. The root cause assessment focused on investigation of the difference in microstructure and manufacturing residual stress in order to reveal the cause of different susceptibilities to ODSCC among identical six units. The manufacturing residual stress as measured by XRD on OD surface and by split tube method indicated that the high residual stress of Alloy 600MA tube played a critical role in developing ODSCC. The level of residual stress showed substantial variations among the six units depending on details of straightening and OD grinding processes. Youngwang 3&4 tubes are less susceptible to ODSCC than U3 and U4 tubes because semi-continuous coarse chromium carbides are formed along the grain boundary of Y3&4 tubes, while there are finer less continuous chromium carbides in U3 and U4. The different carbide morphology is caused by the difference in cooling rate after mill anneal. There is a possibility that high chromium content in the Y3&4 tubes, still within the allowable range of Alloy 600, has made some contribution to the improved resistance to ODSCC. It is anticipated that ODSCC in Y5&6 SGs will be retarded more considerably than U3 SGs since the manufacturing residual stress in Y5&6 tubes is substantially lower than in U3 tubes, while the microstructure is similar with each other.

• Journal of architectural history
• /
• v.28 no.2
• /
• pp.77-90
• /
• 2019

The Sacheonwangsa temple in Silla was completed in 679, just after the unification of the Three Kingdoms. In recent years, we have been critically considering the history of the chronology based on the existence of 'Geumdang of the previous generation', which has emerged through the research report of the Sacheonwangsa temple. It is the one to reconsider the construction process of the Sacheonwangsa temple centering on the re-interpretation of the construction time and the character of the first stage of the foundation which was confirmed from within the Geumdang site. The results of this study are as follows : 1)The "Chang(創) of Sacheonwangsa temple" in [Three Affairs that Queen Seondeok had already known] that it is presumed that the construction of the Sacheonwangsa temple, which was designed by Anham before 640 years ago, will convey the fact that the first of the King Munmu's reign (661 ~) has been finalized after the initial discussion. 2)Although the theories after excavations are predicated on the existence of 'Geumdang of the previous generation', there is no reason to believe that a lasting predecessor building with roof and pillar walls on predecessor buildings is considered to have been built. The foundation was associated with the "build a temple out of coloured silk(以彩帛營寺)" i.e. 'Jochang(祖創)' in 670 years before the construction plan was formally finalized. However, it is presumed that the remains of the platform construction on the premise that it will be used on the construction of Geumdang. 3)The decision to 'rebuilding( ??)' based on a formal construction plan is determined to be from 670 to 672 years. The maintaining of the original cathedral axis line, to the north on the boundary of the southern limit of the foundation flat portion, the result of developing and embodied the relative position of the Geumdang in the newly determined cathedral unfold and embody, the center of the building base and Geumdang, it is presumed that the centers of them are divided into North and south. 4)The completion of the Sacheonwangsa temple in 679 is understood as the conclusion of 'rebuilding' to "build a temple out of coloured silk" i.e. 'Jochang' in 670 years. The pent roof of the Geumdang was initially considered not to be in the plan, but it is judged to be before the completion of the Sacheonwangsa temple.