• Journal of the Korean Institute of Gas
• /
• v.22 no.3
• /
• pp.13-19
• /
• 2018

The exposed pipe requires higher durability because is directly contacted with the outside air unlike the buried pipe. For this purpose, clear detailed technical standards are essential in the design and construction of piping systems. However, the existing technical standards were not able to evaluate the durability considering the characteristics of piping, so many questions were raised in the field. Therefore, through the present study, the existing detailed technical standards are revised to propose measures to secure the durability of exposed piping.

• Journal of Fisheries and Marine Sciences Education
• /
• v.27 no.1
• /
• pp.262-272
• /
• 2015

The aim of this study is to analysis factors that determine the competitiveness of container ports using the KJ and AHP methods. For this, 54 detailed attributing factors were identified both by previous studies and port users. 24 attributing factors were identified by a group of port experts. also, These were grouped 18 detailed attributing factors into 6 attributing factors by a group of port experts using the KJ method. These were made into a model of hierarchical structure with 3 levels, taking 1 goal factor, 6 evaluation factors and 18 detailed evaluation factors. The collected date of questionnaires were analyzed by a group of port experts using the AHP method. The analysis result of the evaluation factors in container port shows that port cargo volume is the most important factor, followed by port location, port cost, port service, port facility and port management. The analysis results of detailed evaluation factors in container port shows that import and export cargo volume is the most important factor, followed by transshipment cargo volume, distance from main trunk, cargo handling cost, distance from the point of importing and exporting, speediness of cargo handling, stability of cargo handling, vessel/cargo cost in port entry and leaving, punctuality in port entry and leaving, number and length of berth, collateral service cost, terminal area, hinterland accessibility, ability of terminal operation company, front depth of berth, etc.

• Proceedings of the KSME Conference
• /
• 2001.11a
• /
• pp.330-335
• /
• 2001

While contacting directly with ground, the tire tread part is in shape of complex patterns of variable ASDs(anti-skid depth) for various tire performances. However, owing to the painstaking mesh generation job and the extremely long CPU-time, conventional 3-D tire analyses have been performed by either neglecting tread pattern or modeling circumferential grooves only. As a result, such simplified analysis models lead to considerably poor numerical expectations. This paper addresses the development of a systematic 3-D mesh generation of tires considering the detailed tread pattern. Basically, tire body and tread meshes are separately generated, and then both are to be combined. For the systematic mesh generation, which consists of a series of meshing steps, we develop in-house subroutines which utilize the useful functions of I-DEAS solid modeler. The detailed pattern mesh can be imparted partially or completely.

• Computers and Concrete
• /
• v.19 no.3
• /
• pp.283-291
• /
• 2017

A large number of residential buildings in regions subjected to severe earthquakes do not have enough load carrying capacity. The most of them have been constructed without receiving any structural engineering attention. It is practically almost impossible to perform detailed experimental evaluation and analytical analysis for each building to determine their seismic vulnerability, because of time and cost constraints. This fact points to a need for a simple evaluation method that focuses on selection of buildings which do not have the life safety performance level by adopting the main requirements given in the seismic codes. This paper deals with seismic assessment of existing reinforced concrete residential buildings and contains an alternative simplified procedure for seismic evaluation of buildings. Accuracy of the proposed procedure is examined by taking into account existing 250 buildings. When the results of the proposed procedure are compared with those of the detailed analyses, it can be seen that the results are quite compatible. It is seen that the accuracy of the proposed procedure is about 80% according to the detailed analysis results of existing buildings. This accuracy percentage indicates that the proposed procedure in this paper can be easily applied to existing buildings to predict their seismic performance level as a first approach before implementing the detailed and complex analyses.

• Journal of Power Electronics
• /
• v.9 no.4
• /
• pp.553-566
• /
• 2009

In-phase control and energy-optimized control are the two major control strategies proposed for series power quality controllers (SPQC). However quantitative analysis and comparison between these two control strategies is quite limited in previous publications. In this paper, an extensive quantitative analysis is carried out on these two control strategies through phasor diagram approach, and a detailed quantitative comparison is conducted accordingly. The load current is used as the reference phasor, and this leads to a simpler and clearer phasor diagram for the quantitative relationship. Subsequently detailed analysis of SPQC using in-phase control and energy-optimized control are provided respectively, under different modes both for under voltage/voltage sag and for over voltage/voltage swell. The closed form analytic expressions and the curves describing SPQC compensation characteristics are obtained. The detailed system power flow is figured out for each mode, and the detailed quantitative comparison between the two control strategies is then carried out. The comparison covers several aspects of SPQC, such as required compensating voltage magnitude, required capacity of energy storage component, and maximal ride-through time. In the end, computer simulation and prototype experimental results are shown to verify the validity of all the analysis and the result of the comparison.

• Journal of Korean Academy of Nursing Administration
• /
• v.17 no.3
• /
• pp.336-348
• /
• 2011

Purpose: This methodological study was done to develop a telephone consultation algorithms and practice guidelines for patient discharged with ophthalmic diseases. Methods: The ophthalmic problems of the patients were identified and expert knowledge on managing the problems was acquired. Algorithms and practice guidelines were developed based on the expert knowledge. The content validity of algorithms and practice guidelines was evaluated by the experts. Results: The preliminary algorithms and practice guidelines were developed from 60 detailed signs and symptoms and 45 nursing interventions. The experts agreed that 57 detailed signs and symptoms linked with nursing interventions were valid, with the content validity index over 80%. Meeting with nurse experts and ophthalmologists was convened to review the rest of the 3 detailed signs and symptoms linked with nursing interventions. Finally, 60 detailed signs and symptoms and 46 nursing interventions were confirmed. Conclusion: This study suggests that the algorithms and practice guidelines are effective decision-making tools and utilization of these algorithms and practice guidelines is expected to improve the quality of clinical nursing and patient satisfaction.

• Journal of architectural history
• /
• v.27 no.3
• /
• pp.59-72
• /
• 2018

The detailed names and meanings of Korean stone pagodas have not yet been properly studied or clearly defined. Therefore, an aim of this report is to compare the detailed names of Korean, Chinese, and Japanese stone pagodas by focusing on content used previously by Ko and his students and content that is currently in use (i.e., since the Japanese colonial era). Additional objectives are to assess the significance of these names and propose an appropriate detailed draft regarding names of stone pagodas. The discussion will proceed by dividing the stone pagoda into three parts: the podium, main structure, and finial. First, the content in Luo Zhewen(羅哲文)'s "Ancient pagodas in China(中國古塔)" (1985) is considered; then, "朝鮮の石塔" (1943)-published by during the Japanese colonial era-is explored. The thesis written by Yu-Seop Ko regarding Korea's first stone pagoda and the content in "A Study of Korean Pagodas(朝鮮塔婆의 硏究)" (1948), which contains Yu-Seop Ko's posthumous works published in book form by his student Su-Yeong Hwang, Heu-Kyoung Kim are examined. to pagodas that are used today, are compared and reviewed. Since Korea, China, and Japan influence each other, pagoda-related terms are shared to some extent. In this study, these were applied to stone pagodas, and names used thus far that have not drawn criticism were studied and proposed as suitable alternatives.

• Advances in aircraft and spacecraft science
• /
• v.6 no.2
• /
• pp.169-187
• /
• 2019

This work presents a practical detailed finite element (FE) approach for the three-dimensional (3D) free-vibration analysis of actual aircraft and spacecraft-type lightweight and thin honeycomb sandwich panels. It consists of calling successively in $MATLAB^{(R)}$, via a developed user-friendly GUI, a detailed 3D meshing tool, a macrocommands language translator and a commercial FE solver($ABAQUS^{(R)}$ or $ANSYS^{(R)}$). In contrary to the common practice of meshing finely the faces and core cells, the proposed meshing tool represents each wall of the actual hexagonal core cells as a single two-dimensional (2D) 4 nodes quadrangularshell element or two 3 nodes triangular ones, while the faces meshes are obtained simply using the nodes at the core-faces interfaces. Moreover, as the same 2D FE interpolation type is used for meshing the core and faces, this leads to an automatic handling of their required FE compatibility relations. This proposed approach is applied to a sample made of very thin glass fiber reinforced polymer woven composite faces and a thin aluminum alloy hexagonal honeycomb core. The unknown or incomplete geometric and materials properties are first collected through direct measurements, reverse engineering techniques and experimental-FE modal analysis-based inverse identification. Then, the free-vibrations of the actual honeycomb sandwich panel are analyzed experimentally under different boundary conditions and numerically using different mesh basic cell shapes. It is found that this approach is accurate for the first few modes used for pre-design purpose.

• Advances in aircraft and spacecraft science
• /
• v.9 no.5
• /
• pp.377-400
• /
• 2022

The aim of this work is a numerical comparison (FEM) between lattice pyramidal-core panel and honeycomb core panel for different core thicknesses. By evaluating the mid-span deflection, the shear rigidity and the shear modulus for both core types and different core thicknesses, it is possible to define which core type has got the best mechanical behaviour for each thickness and the evolution of that behaviour as far as the thickness increases. Since a specific base geometry has been used for the lattice pyramidal core, the comparison gives us the opportunity to investigate the unit cell strut angle giving the higher mechanical properties. The presented work considers a detailed FEM modelling of a standard 3-point bending test (ASTM C393/C393M Standard Practice). Detailed FEM modelling addresses to detailed discretization of cores by means of beam elements for lattice core and shell elements for honeycomb core. Facings, instead, have been modelled by using shell elements for both sandwich panels. On lattice core structure, elements of core and facings are directly connected, to better simulate the additive manufacturing process. Otherwise, an MPC-based constraint between facings and core has been used for honeycomb core structure. Both sandwich panels are entirely built of Aluminium alloy. Prior to compare the two models, the FEM sandwich panel model with lattice pyramidal core needs to be validated with 3-point bending test experimental results, in order to ensure a good reliability of the FEM approach and of the comparison. Furthermore, the analytical validation has been performed according to Allen's theory. The FEM analysis is linear static with an increasing midspan load ranging from 50N up to 500N.

• Structural Engineering and Mechanics
• /
• v.30 no.6
• /
• pp.733-761
• /
• 2008

The failure of reinforced concrete structures in recent earthquakes caused concern about the performance of beam column joints. Confinement of joint is one of the ways to improve the performance of beam column joints during earthquakes. This paper describes an experimental study of exterior beam-column joints with two non-conventional reinforcement arrangements. One exterior beam-column joint of a six story building in seismic zone III of India was designed for earthquake loading. The transverse reinforcement of the joint assemblages were detailed as per IS 13920:1993 and IS 456:2000 respectively. The proposed nonconventional reinforcement was provided in the form of diagonal reinforcement on the faces of the joint, as a replacement of stirrups in the joint region for joints detailed as per IS 13920 and as additional reinforcement for joints detailed as per IS 456. These newly proposed detailing have the basic advantage of reducing the reinforcement congestion at the joint region. In order to study and compare the performance of joint with different detailing, four types of one-third scale specimens were cast (two numbers in each type). The main objective of the present study is to investigate the effectiveness of the proposed reinforcement detailing. All the specimens were tested under reverse cyclic loading, with appropriate axial load. From the test results, it was found that the beam-column joint having confining reinforcement as per IS: 456 with nonconventional detailing performed well. Test results indicate that the non-conventionally detailed specimens, Type 2 and Type 4 have an improvement in average ductility of 16% and 119% than their conventionally detailed counter parts (Type1 and Type 3). Further, the joint shear capacity of the Type 2 and Type 4 specimens are improved by 8.4% and 15.6% than the corresponding specimens of Type 1 and Type 3 respectively. The present study proposes a closed form expression to compute the yield and ultimate load of the system. This is accomplished using the theory of statics and the failure pattern observed during testing. Good correlation is found between the theoretical and experimental results.