• Fashion & Textile Research Journal
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• v.21 no.5
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• pp.656-664
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• 2019

This study was to develop the patterns based on the study of commercial Cheollik dress pattern analysis that verify the effects of pattern improvement by performing wearing evaluations. The commercial Cheollik dress pattern analysis was divided into A type composed of a traditional hanbok flat sleeve type and B type composed of western three-dimensional sleeves type. The prototype pattern of A type and prototype pattern of B type were fabricated after modifying and supplementing the pattern on the basis of precedent research. Appearance evaluations and mobility evaluations were also conducted. In the evaluations of the appearance, the prototype pattern in both A type and B type rated better than the control pattern in all items, so it can be judged to be a pattern that creates a better appearance in terms of allowance and design ratio. In the evaluations of the mobility, the prototype pattern was more convenient and a functional pattern with better scores in both A type and B type. If the Cheollik dress prototype patterns developed in this study are distributed, the Cheollik dress will be easy and comfortable to wear as a casual wear, which will help to make dailyization and popularization of Hanbok.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.6
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• pp.139-146
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• 2019

The modular building system is a type of prefabricated construction method, and is an industrialized building system that transports, assembles, and completes a three-dimensional module manufactured in a factory to the site. The economics of a modular building system where 50 to 80% of the entire process takes place in a modular factory is dominated by productivity of the factory manufacturing process. Since the building of the module is finished by the combination of unit parts produced by each material, it is necessary to manage the process in each module unit. However, currently marketed process control programs do not reflect the features of these modular methods. In this paper, we introduce Modular Factory Design software(MFD 2019) that can make modular unit production plan which reflects production base(modular factory) and production target(application and number of modular units). In order to verify software compatibility and reliability, two production plans with different production methods were formulated and simulated.

• Journal of the Korea Institute of Building Construction
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• v.21 no.6
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• pp.617-627
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• 2021

In this study, a numerical analysis using a three-dimensional numerical simulation was performed to assess the applicability of foundation reinforcing method using load transfer apparatus which can be used in the remodeling of deteriorated structures. The numerical model was validated through comparison with the real scale experimental results, and then a parametric study was performed to investigate the effect of friction coefficient of load transfer apparatus and axial stiffness of pile on the performance of foundation reinforcing method. It was confirmed that the foundation reinforcing method considered in this study can efficiently control the load applied to an existing foundation.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.659-673
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• 2021

This study aims to investigate the impact of the High Pressure Selective Catalytic Reduction system (SCR-HP) on a large marine two-stroke engine performance parameters by employing thermodynamic modelling. A coupled model of the zero-dimensional type is extended to incorporate the modelling of the SCR-HP components and the Control Bypass Valve (CBV) block. This model is employed to simulate several scenarios representing the engine operation at both healthy and degraded conditions considering the compressor fouling and the SCR reactor clogging. The derived results are analysed to quantify the impact of the SCR-HP on the investigated engine performance. The SCR system pressure drop and the cylinder bypass valve flow cause an increase of the engine Specific Fuel Oil Consumption (SFOC) in the range 0.3-2.77 g/kWh. The thermal inertia of the SCR-HP is mainly attributed to the SCR reactor, which causes a delayed turbocharger response. These effects are more pronounced at low engine loads. This study supports the better understanding of the operating characteristics of marine two-stroke diesel engines equipped with the SCR-HP and quantification of the impact of the components degradation on the engine performance.

• Wind and Structures
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• v.34 no.6
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• pp.525-538
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• 2022

High-rise wooden pagodas generate large displacement responses under wind action. It is necessary and wise to reduce the wind loads and wind-induced responses on the architectural heritage using artificial plants, which do not damage ancient architecture and increase greenery. This study calculates and analyzes the wind loads and wind-induced responses on the Yingxian Wooden Pagoda, in China, using artificial plants via the finite element analysis (FEA). A three-dimensional wind-loading field was simulated using a wind tunnel test. Wind loads and wind-induced responses, including the displacement and acceleration of the pagoda with and without artificial plants, were analyzed. In addition, three types of tree arrangements were discussed and analyzed using the score method. The results revealed that artificial plants can effectively control wind loads and wind-induced displacements, but the wind-induced accelerations are enlarged to some extent during the process. The height of the tree significantly affected the shelter effects of the structure. The distance of trees from the pagoda and arrangement width of the tree had less influence on shelter effects. This study extends the understanding of the nondestructive method based on artificial plants, for controlling the wind base loads and structural responses of wooden pagodas and preserving architectural heritage via FEA.

• Coupled systems mechanics
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• v.11 no.4
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• pp.285-295
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• 2022

Laminated composite plates are utilized extensively in different fields of construction and industry thanks to their advantages such as high stiffness-to-weight ratio. Additionally, they are characterized by their directional properties that permit the designer to optimize their stiffness for specific applications. This paper presents a numerical analysis and optimization study of plates made of composite subjected to low velocity impact. The main aim is to identify the optimum fiber orientations of the composite plates that resist low velocity impact load. First, a three-dimensional finite element model is built using LS DYNA computer software package to perform the impact analyses. The composite plate has been modeled using solid elements. The failure criteria of Tsai-Wu's criterion have been used to control the strength of the composite material. A good agreement has been found between the predicted numerical results and experimental results in the literature which validate the finite element model. Then, an Adaptive Simulated Annealing (ASA) has been used to optimize the response of impacted composite laminate where its objective is to maximize the safety factor by varying the ply angles. The results show that the ASA is robust in the sense that it is capable of predicting the best optimal designs.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1698-1711
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• 2022

A combined safety approach, which uses a best-estimate computer code and adopts conservative assumptions for safety systems availability, is developed and applied to the safety margin evaluation for the Loss of Condenser Vacuum (LOCV) of the 1000 MWe Korean Nuclear Power Plant. The Multi-dimensional Analysis of Reactor Safety-KINS standard (MARS-KS) code is selected as a best-estimate code and the PAPIRUS program is used to obtain different initial operational conditions through random sampling of control variables. During an LOCV event, fuel integrity is not threatened by the increase in Departure from Nuclear Boiling Ratio (DNBR). However, the high pressure in the primary coolant system and the secondary system might affect the system integrity. Thus, the peak pressure becomes a major safety concern. Transient analyses are performed for 124 cases of different initial conditions and the most conservative case, which results in the highest system pressure is selected. It is found the suggested methodology gives similar peak pressures when compared to those predicted from existing methodologies. The proposed approach is expected to minimize the time and efforts required to identify the conservative plant conditions in the existing conservative safety methodologies.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1860-1873
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• 2022

Nuclear thermal-hydraulic system analysis codes have been developed to comprehensively model nuclear reactor systems to evaluate the safety of a nuclear reactor system. For analyzing complex systems with finite computational resources, system codes usually solve simplified fluid equations for coarsely discretized control volumes with one-dimensional assumptions and replace source terms in the governing equations with constitutive relations. Wall boiling heat transfer models are regarded as essential models in nuclear safety evaluation among many constitutive relations. The wall boiling heat transfer models of two widely used nuclear system codes, RELAP5 and TRACE, are analyzed in this study. It is first described how wall heat transfer models are composed in the two codes. By utilizing the same method described in Part 1 paper, heat fluxes from the two codes are compared under the same thermal-hydraulic conditions. The significant factors for the differences are identified as well as at which conditions the non-negligible difference occurs. Steady-state simulations with both codes are also conducted to confirm how the difference in wall heat transfer models impacts the simulation results.

• Steel and Composite Structures
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• v.41 no.5
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• pp.637-648
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• 2021

Nowadays, one of the practical, fast and easy ways to strengthen steel elements is the use of Carbon Fiber Reinforced Polymer (CFRP). Most previous research in the CFRP strengthening of steel members has carried out on straight steel members. The main difference between horizontal curved beams and straight beams under vertical load is the presence of torsional moment in the horizontal curved beams. In the other words, the horizontal curved beams are analyzed and designed for simultaneous internal forces included bending moment, torsional moment, and shear force. The horizontal curved steel beams are usually used in buildings, bridges, trusses, and others. This study explored the effect of the CFRP strengthening on the behavior of the horizontal curved square hollow section (SHS) steel beams. Four specimens were analyzed, one non-strengthened curved steel beam as a control column and three horizontal curved steel beams strengthened using CFRP sheets (under concentrated load and uniform distributed load). To analyze the horizontal curved steel beams, three dimensional (3D) modeling and nonlinear static analysis methods using ANSYS software were applied. The results indicated that application of CFRP sheets in some specific locations of the horizontal curved steel beams could increase the ultimate capacity of these beams, significantly. Also, the results indicated when the horizontal curved steel beams were under distributed load, the increase rate in the ultimate capacity was more than in the case when these beams were under concentrated load.

• Journal of Drive and Control
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• v.19 no.1
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• pp.62-68
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• 2022

Considering the characteristics of industrial machines that lack vehicle-induced wind, forced convection by a cooling fan is mostly required. Therefore, numerical analysis of an engine room is usually performed to examine the cooling performance in the room. However, most engine rooms consist of a number of parts and components at specific positions, leading to high costs for numerical modeling and simulation. In this paper, a new methodology for three-dimensional computer-assisted design simplification was proposed, especially for the pile of components and parts at the engine room outlet. A porous media model and regression analysis were used to derive a meta-model for imitating the flow rate reduction at the outlet by the pile. The results showed that the fitted model was reasonable considering the coefficient of determination. The final numerical model of the engine room was then used to simulate the velocity distribution by changing the mass flow rate at the outlet. The results showed that both velocity distributions were significantly changed in each case and the meta-model was valid in imitating the flow rate reduction by some piles of components and parts.