• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.289-296
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• 2013

To evaluate seasonal variation in fatty acid composition in broccoli, 12 commercial cultivars of broccoli were grown in spring and fall season at the field of NIHHS, and their floret, leaf and stem parts were used for the fatty acid composition analyses. Among 14 fatty acids detected in broccoli, linolenic, palmitic and linoleic acids were major fatty acids comprising more than 80% of total fatty acids in both the seasons and all the parts. Likewise, stearic and oleic acids were also present in considerable amount while remaining fatty acids; caproic, lauric, myristic, pentadecanoic, palmitoleic, heptadecanoic, arachidic, behenic and lignoceric acids showed their minor compositional ratio. Among the three parts, stem exhibited highest SFAs (49.681% in spring and 50.717% in fall season) compared to MUFA and PUFA, while highest compositional ratio of PUFAs were observed in leaves (62.588% in spring and 68.931% in fall season), which indicates leaves as a good source of health beneficial fatty acids. In contrast, floret part exhibited highest SFA (48.786%) and PUFA (57.518%) in spring and fall seasons, respectively. Major fatty acids; palmitic, linoleic and linolenic acid showed lowest cultivar dependent variation (below 10%) and leaf showed least variation in both the seasons compared to floret and stem. Our results suggest that all the fatty acids are significantly influenced by genotype of cultivars (C), plant parts (P) and growing seasons (S). Among the 14 fatty acids, myristic and palmitic acid showed highest positive or negative correlationship with oleic (r=$0.912^{**}$) and linolenic acid (r=-$0.933^{**}$), respectively. The most abundant fatty acid, linolenic acid, showed either negative or no correlation ship with other fatty acids while palmitic acid, a second major fatty acid, exhibited either positive or negative correlation ship.

• Structural Engineering and Mechanics
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• v.23 no.3
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• pp.293-308
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• 2006

This paper presents a complete and consistent formulation to study the seismic response of a free-standing ship supported by an arrangement of n keel blocks which are all located in a dry dock. It is considered that the foundation of the system is subjected to both horizontal and vertical in plane excitation. The motion of the system is classified in eight different modes which are Rest (relative), Sliding of keel blocks, Rocking of keel blocks, Sliding of the ship, Sliding of both keel blocks and the ship, Sliding and rocking of keel blocks, Rocking of keel blocks with sliding of the ship, and finally Sliding and rocking of keel blocks accompanied with sliding of the ship. For each mode of motion the governing equations are derived, and transition conditions between different modes are also defined. This formulation is based on a number of fundamental assumptions which are 2D idealization for motion of the system, considering keel blocks as the rigid ones and the ship as a massive rigid block too, allowing the similar motion for all keel blocks, and supposing frictional nature for transmitted forces between contacted parts. Also, the rocking of the ship is not likely to take place, and the complete ship separation from keel blocks or separation of keel blocks from the base is considered as one of the failure mode in the system. The formulation presented in this paper can be used in its entirety or in part, and they are suitable for investigation of generalized response using suitable analytical, or conducting a time-history sensitivity analysis.

• Structural Engineering and Mechanics
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• v.42 no.4
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• pp.507-530
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• 2012

Age-related problems especially corrosion and fatigue are normally suffered by weatherworn ships and aging offshore structures. The effect of corrosion is one of the important factors in the Common Structural Rule (CSR) guideline of the ship design based on a 20 or 25 years design life. The aim of this research is the clarification of the corrosion effect on ultimate strength of stiffened panels on various types of double hull oil tankers. In the case of ships, corrosion is a phenomenon caused by the ambient environment and it has different characteristics depending on the parts involved. Extensive research considering these characteristic have already done by previous researchers. Based on this data, the ultimate strength behavior of stiffened panels for four double hull oil tankers such as VLCC, Suezmax, Aframax, and Panamax classes are compared and analyzed. By considering hogging and sagging bending moments, the stiffened panels of the deck, inner bottom and outer bottom located far away from neutral axis of ship are assessed. The results of this paper will be useful in evaluating the ultimate strength of an oil tanker subjected to corrosion. These results will be an informative example to check the effect of ultimate strength of a stiffened panel according to corrosion addition from CSR for a given type of ship.

• Journal of Welding and Joining
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• v.14 no.6
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• pp.119-130
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• 1996

Welding is one of the important technologies in shipbuilding industry. Automation and productivity promotion of welding contribute to the cost saving of ship production. The quality and productivity of welding are dependent on the quality and suitability of technical information supplied by engineering parts. This paper describes the research results of welding information system for ship. The system can be used for the development of CIMS for shipbuilding. For this work, the welding information related to the ship Production were analyzed in detail. Object-oriented technique is applied to represent the complex and various welding information. To process the extend amount of the welding information of ship, database system was constructed. A pilot system for the bulk carrier ship was developed and can be used with ease by programming of event-driven method and implementaion of graphical user interlace.

• IE interfaces
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• v.15 no.1
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• pp.26-39
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• 2002

Two key data areas of the integrated production database in computer-integrated manufacturing (CIM) systems are the product structure in the forms of bills of material(BOM) and the process structure in the forms of routings. The great majority of existing information systems regard the BOM and routing as two separate data entities, possibly with some degree of cross-referencing. This paper proposes new information structure called the bills of material and routings(BMR) that logically integrates the BOM and routings for the CIM systems in ship production. The characteristics of ship production are described as: 1) make-to-order production type, 2) combined manufacturing principles (workshop production and construction site production), 3) significant overlapping of design, planning and manufacturing, 4) very long order throughput time, 5) complex product structure and production process. The proposed BMR systematically manages ail parts and operations data needed ship production considering characteristics of ship production. Also, the BMR situated on the integrated production database more efficiently supports interface between engineering and production functions, and integrates a wide variety of functions within production such as production planning, process planning, operation scheduling, material planning, costing etc., and simplifies information flow between sub-systems in CIM systems.

• Journal of Ocean Engineering and Technology
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• v.27 no.1
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• pp.24-30
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• 2013

The Korea Navy has been making constant efforts to apply M&S (modeling and simulation) to naval ship development, and the generalization of M&S for ship development is a trend. M&S for ship design is used for the V&V (verification and validation) of its design and operation, including design verification and ergonomic design that considers the crew using the Naval Ship Product Model. In addition, many parts of this M&S are repeatedly accomplished regardless of the kinds of ships. This study aims to standardize M&S, which repeatedly applies similar verifications for operation scenarios. A congestion assessment simulation for the major spaces of ships was the subject of the standardization based on the leading research results of various researchers, and a simulation automation solution was suggested. An information model using XML was proposed through the simulation automation concept, and a prototype system based on it was implemented. The usability was shown through a case study that verified the operability performance of the crew messroom.

• Journal of Ocean Engineering and Technology
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• v.34 no.1
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• pp.37-45
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• 2020

Unstiffened and stiffened cylindrically curved plates are often used in ship structures. For example, they can be found on a deck with a camber, a side shell at the fore and aft parts, and the circular bilge part of a ship structure. It is believed that such cylindrically curved plates can be fundamentally modelled using a portion of a circular cylinder. From estimations using cylindrically curved plate models, it is known that the curvature generally increases the buckling strength compared to a flat plate under axial compression. The existence of curvature is also expected to increase both the ultimate and buckling strengths. In the present study, a series of finite element analyses were conducted on stiffened curved plates with several varying parameters such as the curvature, panel slenderness ratio, and web height and type of stiffener applied. The results of numerical calculations on stiffened and unstiffened curved plates were examined to clarify the influences of such parameters on the characteristics of their buckling/plastic collapse behavior and strength under an axial compression.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.384-394
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• 2020

This paper proposes an outlier detection model based on machine learning that can diagnose the presence or absence of major engine parts through unsupervised learning analysis of main engine big data of a ship. Engine big data of the ship was collected for more than seven months, and expert knowledge and correlation analysis were performed to select features that are closely related to the operation of the main engine. For unsupervised learning analysis, ensemble model wherein many predictive models are strategically combined to increase the model performance, is used for anomaly detection. As a result, the proposed model successfully detected the anomalous engine status from the normal status. To validate our approach, clustering analysis was conducted to find out the different patterns of anomalies the anomalous point. By examining distribution of each cluster, we could successfully find the patterns of anomalies.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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• pp.227-235
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• 2016

Heavy-weight high speed underwater vehicle(HSUV) is launched from the submerged mother ship. For the safety point of view, it is important to confirm whether the HSUV would touch the launching mother ship. In this paper, the hydrodynamic force and moment were modeled by the polynomials of motion variables and the simple lift and drag acting on a plate and cylinder which consist of the HSUV's several parts. The mother ship was assumed as the Rankine half body to consider the flow field near the moving ship. Such hydrodynamic force and moment were included in the 6 DOF equations of motion of the HSUV and the dynamic simulations for the various conditions of the HSUV until the propeller activation were performed. Developed simulation program is expected to reduce the number of expensive sea trial test to develop safety logic of the HSUV at the initial firing stage.

• Korean Journal of Computational Design and Engineering
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• v.16 no.5
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• pp.323-330
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• 2011

Large number of part design such as for aircraft and automotive development is preceded by functional or sectional design groups for efficiency. With the assembly development of large number of parts, interferences and gaps can be found when the parts and sub-assemblies by those design groups are to be assembled. When rainwater come into the space among parts and is not be drained sufficiently, rainwater within the structure can backflow to gaps or unexpected outlets, which may cause severe problems of part corrosion and electric shock. This research has developed a method and a program to simulate backflow of rainwater within space among parts, which can find unexpected outlets and gaps as in real situation. The developed program can not only simulate up and downstream of liquid, but also the flow with multiple channels of division and joining. The developed method can also be applied to aircraft and ship design process.