• Speech Sciences
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• v.13 no.1
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• pp.43-54
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• 2006

The purpose of this study is to examine temporal structures of English words beginning with an /s/ plus stop sequence through production experiments with native speakers of Korean learning English and native speakers of English. According to the results of our production experiment, both a beginner and an advanced group of Korean English learners produced /s/ shorter than a following stop, while the opposite pattern was observed in English native speakers' production. An advanced group of Korean English learners were good at producing a stop after /s/ as unaspirated, but their production of a stop following /s/ was different from English native speakers' production in that the closure duration of the stop was much longer.

• MALSORI
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• no.52
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• pp.61-84
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• 2004

This study investigates the Korean native speakers' English liquid perception and production. Perception and production experiments were each conducted twice before and after a short period of explicit learning process of phonetic characteristics of English liquids. The results showed that correlation between perception and production varied depending on factors. In both perception and production, word-final position was the most difficult, and cluster position was the easiest. A considerable improvement was observed in word-initial and medial positions in production, whereas no improvement was achieved in word-final position, especially in production. This study is also concerned with the formant structures of Korean native speakers' production of English liquids in order to see what acoustic features are highly correlated with Korean native speakers' production accuracy of English liquids. The results showed that F2 did not show a high correlation while F3 was a strong correlate of the production accuracy.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.10-21
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• 2021

Recently, the demand for atypical structures with functions and sculptural beauty is increasing in the construction industry. Existing mold-based structure production methods have many advantages, but building complex atypical structures represents limitations due to the cost and technical characteristics. Production methods using molding are suitable for mass production systems, but production cost, construction period, construction cost, and environmental pollution can occur in small quantity batch production. The recent trend in the construction industry calls for new construction methods of customized small quantity batch production methods that can produce various types of sophisticated structures. In addition to the economic effects of developing related technologies of 3D Concrete Printers (3DCP), it can enhance national image through the image of future technology, the international status of the construction civil engineering industry, self-reliance, and technology export. Until now, 3DCP technology has been carried out in producing and utilizing residential houses, structures, etc., on land or manufacturing on land and installing them underwater. The final purpose of this research project is to produce marine structures by directly printing various marine structures underwater with 3DCP equipment. Compared to current underwater structure construction techniques, constructing structures directly underwater using 3DCP equipment has the following advantages: 1) cost reduction effects: 2) reduction of construct time, 3) ease of manufacturing amorphous underwater structures, 4) disaster prevention effects. The core element technology of the 3DCP equipment is to extrude the transferred composite materials at a constant quantitative speed and control the printing flow of the materials smoothly while printing the output. In this study, the extruding module of the 3DCP equipment operates underwater while developing an extruding module that can control the printing flow of the material while extruding it at a constant quantitative speed and minimizing the external force that can occur during underwater printing. The research on the development of 3DCP equipment for printing concrete structures underwater and the preliminary experiment of printing concrete structures using high viscosity low-flow concrete composite materials is explained.

• Asian Journal of Turfgrass Science
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• v.9 no.1
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• pp.53-74
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• 1995

This study was made on the relationships among production structures, biomass and Soil proper-ties of grassland types in Chejudo. The results of this investigation were obtained as foolows. The annual productions of the grasslands of Zoysio, Imperata, Themede, Miscanthus and Pteridium types were 40.36~144.00, 168.28~272.44, 58.24~138.44, 156.12 ~714. 12 and 157. 18~398.40g /m$^2$, respectively. The production structures of those grassland types were different from one another. The water contents, organic matter, total nitrogen and available phosphorus were different levels between grasslands had a simple correlation at 5% level and the organic matter contents were a higher significant at the partial correlation. Key words: Production Structure, Biomass, Soil properity, Chejudo.

• Genomics & Informatics
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• v.15 no.4
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• pp.142-146
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• 2017

More effective production of human insulin is important, because insulin is the main medication that is used to treat multiple types of diabetes and because many people are suffering from diabetes. The current system of insulin production is based on recombinant DNA technology, and the expression vector is composed of a preproinsulin sequence that is a fused form of an artificial leader peptide and the native proinsulin. It has been reported that the sequence of the leader peptide affects the production of insulin. To analyze how the leader peptide affects the maturation of insulin structurally, we adapted several in silico simulations using 13 artificial proinsulin sequences. Three-dimensional structures of models were predicted and compared. Although their sequences had few differences, the predicted structures were somewhat different. The structures were refined by molecular dynamics simulation, and the energy of each model was estimated. Then, protein-protein docking between the models and trypsin was carried out to compare how efficiently the protease could access the cleavage sites of the proinsulin models. The results showed some concordance with experimental results that have been reported; so, we expect our analysis will be used to predict the optimized sequence of artificial proinsulin for more effective production.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.106-111
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• 2006

The steel outfitting structures installed in engine room are vibrated by an excitation of the engine and the propeller. Vibration problems such as cracks and fitting breakages are mainly induced at the near range of the resonance. The excitation frequency estimation is possible by engines and propeller specifications, but the natural frequency of a steel outfitting structure is not easily estimated due to the complication and variety of the designed shape. This paper represents natural frequency data of simple steel outfitting structures. As a vibration analysis tool, MSC/NASTRAN was used to calculate natural frequencies. Natural frequencies were compared in case of the shape and boundary condition changes of simple models, and anti-vibration models of the steel outfitting structures were presented on the basis of results.

• Journal of Ocean Engineering and Technology
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• v.22 no.4
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• pp.72-77
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• 2008

General aspects of deepwater petroleum exploration and production were identified and related technical challenges were addressed. Historical perspectives, insight, processes, and engineering applications are reviewed to enhance the design capability of the domestic offshore industry. The technical challenges and unique aspects of deepwater exploration and production were identified. The assessment of deepwater exploration, drilling, and production systems is a key stage for performing the front end engineering design (FEED). The global trends in deepwater development, including the feasibility for Korea, were reviewed.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.3-8
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• 2006

The application of three-dimensional (3-D) CAD has been popularized for design and production and digital manufacturing has been spreading in many industrial fields. By simulation of the production process using 3-D digital models, which are the core of CIM (Computer Integrated Manufacturing) system, the efficiency and safety of production are improved at each stage of work, and optimization of manufacturing can be achieved. This paper firstly describes the concept of "simulation based production" in shipbuilding and also digital manufacturing; the 3-D CAD system is indispensable for effective simulation because ship structure is three dimensionally complex. By simulation, "computer optimized manufacturing" can be possible. The most effective fields of simulation in shipbuilding are in jobs where many parties have to cooperate, while existing two-dimensional drawings are hardly observed the whole structures due to interference between structures or equipment of complex shape. In this paper some examples of the successful application in IHIMU (IHI Marine United Inc.) are shown: assembly of a pipe unit, erection of a complex hull block, carriage of equipment, installation of a propeller, and access in an engine room.

• Special Issue of the Society of Naval Architects of Korea
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• 2015.09a
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• pp.63-68
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• 2015

This paper presents fatigue analysis of helideck structures located in FPSO. After FPSO is moved to the target position where production of resource is performed, FPSO stays at the target position and performs production of resource, storage and off-loading during the design life. Helideck structure is located in FPSO essentially for the movement of personnel and life rescue at emergency situations by using helicopters. Because inertial load induced by FPSO motion and landing and taking-off load of helicopter occur at helideck structures cyclically, helideck structures should be designed to withstand fatigue loads. Therefore, The fatigue assessment of helideck structures should be performed with fatigue loads. Effect of stress concentration due to misalignment between welded plates is considered in fatigue assessment additionally.

• Structural Engineering and Mechanics
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• v.68 no.3
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• pp.299-312
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• 2018

In this paper, an extended finite element method is proposed to analyze both geometric and material non-linear behavior of general Functionally Graded Material (FGM) plate-shell type structures. A user defined subroutine (UMAT) is developed and implemented in Abaqus/Standard to study the elastoplastic behavior of the ceramic particle-reinforced metal-matrix FGM plates-shells. The standard quadrilateral 4-nodes shell element with three rotational and three translational degrees of freedom per node, S4, is extended in the present study, to deal with elasto-plastic analysis of geometrically non-linear FGM plate-shell structures. The elastoplastic material properties are assumed to vary smoothly through the thickness of the plate-shell type structures. The nonlinear approach is based on Mori-Tanaka model to underline micromechanics and locally determine the effective FGM properties and self-consistent method of Suquet for the homogenization of the stress-field. The elasto-plastic behavior of the ceramic/metal FGM is assumed to follow Ludwik hardening law. An incremental formulation of the elasto-plastic constitutive relation is developed to predict the tangent operator. In order to to highlight the effectiveness and the accuracy of the present finite element procedure, numerical examples of geometrically non-linear elastoplastic functionally graded plates and shells are presented. The effects of the geometrical parameters and the volume fraction index on nonlinear responses are performed.