• Journal of the Society of Naval Architects of Korea
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• v.52 no.4
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• pp.283-289
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• 2015

RGT(Riser Guide Tube) is a part of mooring on the bottom of a turret system to be connected with a production riser, and DBSC(Diverless Bend Stiffener Connector) is a latching component between them. In this paper, appropriate lug arrangement is decided mathematically for the case that a DBSC is lifted and installed on a RGT under the water while FPSO is under construction. Considering asymmetric arrangement & position of RGT and initial lug position, additional lug positions are determined by using an optimization method. The modified installation scheme with new lug points is investigated with a lifting simulation system, SIMSON. The simulation result shows that the installation of DBSC on RGT under the given conditions is quite feasible; therefore the mathematical method is proven to be appropriate.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.255-255
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• 2017

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.174-177
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• 2006

본 논문에서는 리프팅 기반의 DWT 구조의 단점을 개선하고자 플립핑(Flipping)기법과 5 단 파이프라인 구조(5 Stage Pipeline)를 적용하여 임계경로가 획기적으로 줄어든 1 차원 DWT 구조를 제안하고 이를 활용하여 JPEG2000 표준의 손실 압축 모드에서 이용되는 9/7 필터계수의 2 차원 DWT 를 수행 할 수 있도록 열 방향 DWT 처리기를 설계하였다. 2 차원 DWT 는 1 차원 DWT 의 처리 결과에 대해 열상의 열(Column) 방향으로 2 차원 처리를 수행해야 하므로 1 차원 결과를 저장하기 위한 한 영상 사이즈 만큼의 메모리 버퍼를 필요로 한다. 기존 $N^2$이 필요하던 메모리 사이즈를 14N으로 줄인 2차원 구조를 제안한다.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.2
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• pp.135-143
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• 2016

In this study, an embedded system composed of equipment setting, block importing, scenario setting and output reporting is developed in multi-body dynamics program, ADAMS, for conducting dynamic structural analysis of block lifting process. First, equipment used for block lifting process is set in the simulation environment and the shapes and functions of two lifting beams, and six block loaders are provided as the equipment. Second, the modal analysis result of the lifting block is imported from the static structural analysis system, NASTRAN. Third, the lifting scenarios, such as hoisting, waiting, trolley moving, and wire connecting, are set in the system. Finally, output results in the forms of plots, texts and tables, are reported after the dynamic structural analysis. The test examples conducted in a shipyard are applied into the developed system in various condition and scenarios. The loads at the lug points, the stress contours, and the hot spot tables of the developed system are compared with the result of the static analysis system.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.228-231
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• 2001

Construction of roof structure, cable suspended structure, for Pusan main stadium is adapted a lifting method that is VSL lifting system. 5 precesses are practiced for erection of the roof structure including the first lifting process for erection of upper cables and the second lifting process for erection of lower cables. Since all cables of this roof structure with two open speller sockets are determined their length, some cable were wrong length, the roof structure would be unstable. But At complete of erection for the roof structure each cab3e is attained to theoretical tension force with average $4\%$ errors.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.1
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• pp.42-50
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• 2014

Lifting lugs are frequently used in shipyard to transportate and turn over blocks. As the shipbuilding technology develops, blocks has become bigger and bigger, and block management technology takes a more important role in shipbuilding to enhance the productivity. For the sake of economic as well as safe design of lug structure, more rigorous analysis is needed. In this study in order to investigate the strength characteristics of two type of lug, that is, D and T type lugs, non-linear strength analysis has been carried out to compare the ultimate strength characteristics of two types of lug varying in-plane and out-of-plane loading directions. Based on the present numerical analysis results, it can be drawn that T type lug is superior to D type lug from view points of ultimate strength and deformation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.4 s.334
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• pp.19-28
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• 2005

In this paper, we proposed a parallel fast 2-D discrete wavelet transform hardware architecture based on lifting scheme. The proposed architecture improved the 2-D processing speed, and reduced internal memory buffer size. The previous lifting scheme based parallel 2-D wavelet transform architectures were consisted with row direction and column direction modules, which were pair of prediction and update filter module. In 2-D wavelet transform, column direction processing used the row direction results, which were not generated in column direction order but in row direction order, so most hardware architecture need internal buffer memory. The proposed architecture focused on the reducing of the internal memory buffer size and the total calculation time. Reducing the total calculation time, we proposed a 4-way data flow scheduling and memory based parallel hardware architecture. The 4-way data flow scheduling can increase the row direction parallel performance, and reduced the initial latency of starting of the row direction calculation. In this hardware architecture, the internal buffer memory didn't used to store the results of the row direction calculation, while it contained intermediate values of column direction calculation. This method is very effective in column direction processing, because the input data of column direction were not generated in column direction order The proposed architecture was implemented with VHDL and Altera Stratix device. The implementation results showed overall calculation time reduced from $N^2/2+\alpha$ to $N^2/4+\beta$, and internal buffer memory size reduced by around $50\%$ of previous works.

• The Korean Journal of Petroleum Geology
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• v.2 no.2 s.3
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• pp.59-70
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• 1994

The Cenozoic geological structures and the tectonic evolution of the southern Ulleung Basin were studied with seismic profiles and exploration well data. Basement structure of the Korea Strait is distinctly characterized by normal faults trending northeast to southwest. The normal faults of the basement are most likely related to the initial liking and extensional tectonics of Ulleung Basin. Tsushima fault along the west coast of Tsushima islands runs northeastward to the central Ulleung Basin. The Middle Miocene and older sequences in the Tsushima Strait show folds and faults mostly trending northeast to southwest. These folds and faults may be interpreted as a result of compressional tectonics. The Late Miocene to Qauternary sequences are not much deformed, but numerous faults mostly N-S trending are dominated in the Tsushima Strait. The Ulleung Basin was in intial rifting during Oligocene, and then active extension and subsidence from Early to early Middle Miocene. Therefore SW Japan separated from Korea Peninsula and drifted toward southeast, and Ulleung Basin was formed as a pull-apart basin under dextral transtensional tectonic regime. During rifting and extensional stage, Tsushima fault as a main tectonic line separating SW Japan block from the Korean Peninsula acted as a normal faulting with right-lateral strike-slip motion as SW Japan drifted southeastward. During middle Middle Miocene to early Late Miocene, the opening of Ulleung basin stopped and uplifted due to compressional tectonics. The southwest Japan block converging on the Korean Peninsula caused compressional stress to the southern margin of Ulleung Basin, resulting in strong deformation under sinistral transpressional tectonic regime. Tsushima fault acted as thrust fault with left-lateral strike-slip motion. From middle Late Miocene to Quaternary, the southern margin of Ulleung Basin has been controlled by compressional motion. Thus the Tsushima fault still appears to be an active thrust fault by compressional tectonic regime.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.113-116
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• 2001

제로트리 부호화 알고리즘 중 효율적이며 잘 알려진 SPIHT는 높은 메모리 요구로 인해 하드웨어 구현에 큰 어려움을 가지고 있다. 이 논문에서는 저 메모리 사용과 빠른 제로트리 부호화 알고리즘을 제안한다. 메모리를 줄이고 빠른 코딩을 위한 방법으로 다음 3가지를 사용한다. 첫 번째, 리프팅을 이용한 웨이블릿 변환은 기존의 필터뱅크 방식의 변환보다 저 메모리와 계산량의 감소를 가진다. 두 번째, 웨이블릿 변환된 계수들은 블럭으로 나누어져 각각 코딩된다. 여기서 블록은 제로트리 구조가 유지되는 STB(spatial tree-based block)이다. 세 번째, Wheeler 와 Pearlman이 제안한 NLS (no list SPIHT)를 이용한 부호화이다. NLS는 효율성에서 SPIHT와 거의 같으며 작고 고정된 메모리와 빠른 부호화 속도를 보여준다.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.4
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• pp.59-65
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• 2003

With the fast growth of shipbuilding industry, in recent years several hundreds of thousands of lifting lugs for a year have been used. This paper is aimed at maximizing the recovering use of lifting lugs. In this study, we have evaluated the structural strength for present and modified lifting lugs under in-plane and out-of-plane load conditions. For this purpose, the equivalent stresses have been calculated by nonlinear elasto-plastic analysis using the finite element program ABAQUS. At the same time, the contact conditions between lifting lug and shackle pin are also considered.