• Steel and Composite Structures
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• v.31 no.5
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• pp.453-467
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• 2019

Portal frame structures, made up of cold-formed steel trusses, are increasingly being used for lightweight building construction. A novel pin-jointed moment connector, called the Howick Rivet Connector (HRC), was developed and tested previously in T-joints and truss assemblage to determine its reliable strength, stiffness and moment resisting capacity. This paper presents an experimental study on the HRC, in moment resisting cold-formed steel trusses. The connection method is devised where intersecting truss members are confined by a gusset connected by HRCs to create a rigid moment connection. In total, three large scale experiments were conducted to determine the elastic capacity and cyclic behaviour of the gusseted truss moment connection comprising HRC connectors. Theoretical failure loads were also calculated and compared against the experimental failure loads. Results show that the HRCs work effectively at carrying high shear loads between the members of the truss, enabling rigid behaviour to be developed and giving elastic behaviour without tilting up to a defined yield point. An extended gusset connection has been proposed to maximize the moment carrying capacity in a truss knee connection using the HRCs, in which they are aligned around the perimeter of the gusset to maximize the moment capacity and to increase the stability of the truss knee joint.

• Journal of the Korean Geotechnical Society
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• v.25 no.7
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• pp.11-21
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• 2009

This paper presents a new high-performance supporting system of the shallow tunnel. In order to perform this research the mechanism of new supporting system is suggested and compared with the conventional existing supporting system. It is found that the new supporting system as pre-support system has several advantages such as improvement of ground before tunnel excavation and increment of capacity of the tunnel support. The construction procedures of this supporting system are also reviewed. In addition, the numerical simulation is carried out to evaluate the new supporting system. It is found that the new high-performance supporting system is very applicable in shallow depth tunnel such as portal area, tunnel in soil and weak zone, and so on.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2007.10a
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• pp.63-79
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• 2007

Several remedial works were attempted to stabilize the collapsed area of the inlet slopes of diversion tunnel, but prevention of any further movement was being only carried out at beginning stage by filling the area with aggregates and rock debris, after several cracks had been initiated and developed around the area. The extra specialty developed folding zone is consisted with highly weathered Greywacke and Black shale. The suggested solution is to improve the properties of the rock mass of failed area by choosing the optimum level of reinforcement through the increment of slope rock support design so as to control the movement of slopes during the re-excavation. The Bakun hydroelectric project includes the construction of a hydroelectric power plant with an installed capacity of 2,520MW and a power transmission system connecting to the existing transmission networks in Sarawak and Western Malaysia. The power station will consist of a 210m height Concrete Faced Rockfill Dam. During the construction of the dam and the power facilities the Balui River has to be diverted of the tunnels is 12m and the tunnel width is 16m at the portal area. This paper describes the stability analysis and design methods for the open cut rock slopes in the inlet area of the diversion tunnels. The geotechnical parameters employed in stability calculations were given as a function of four defined Rock Mass Type (RMT) which were based on RMR system from Bieniawski. The stability calculations procedure of the rock slopes are divided into two stages. In the first stage, it is calculated for the stability of each "global" slope without any rock support and shotcrete system. In the second stage, it is calculated for each "local" slope stability with berms and supported with rock bolts and shotcrete. The monitoring instrumentation was performed continuously and some of the design modification was carried out in order to increase the safety of failed area based on the unforeseen geological risks during the open cut excavation.

• Journal of KIISE:Software and Applications
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• v.34 no.2
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• pp.150-159
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• 2007

For the construction of accurate scientific citation information, author disambiguation should be primarily resolved. This study proposes a method that utilizes URI(Uniform Resource Identifier) to create precise author citation networks. The adoption of URIs for representing authors and papers in this study enables us to maintain the integrity of constantly changing citation information and to guarantee the accessibility to the right literature. In experiments, we extracted 2,872 author-centric citation relation pairs from recent major IT-related proceedings written in Korean. From those, 135 citation network groups were discovered. The findings of this study are expected to be applied to a variety of researcher network services and scientific information portal services.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.539-542
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• 2006

According as acceptance an order results of plant industry increases, ability of plant project management is required and necessity about information technology is augmented. For required information technology, developing information present conditions that consist of partial or unit system of domestic plant companies by synthetic system, development of systematic plant information system that supply standard direction presentation, tools and know-how about information technology need. This study achieved basic research that set information strategy and target by reflect trend of such plant industry, analyze future IT technology trend, international information environment, policy trend etc. and execute SWOT analysis of plant information system through this and present confrontation ways. It is presented confrontation ways by SWOT analysis through this research; (1) Development of education contents that can come forth competent person of plant industry, (2) Practical use of communication means that can offer by real time about informations connected with plant, (3) Offer of knowledge contents that supply various and useful inside and outside of the country's plant knowledge

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.1
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• pp.188-201
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• 2016

A Clothing Department is a major fields of specialized vocational high schools. Specialized high schools with clothing related departments are located in Seoul (4 schools), Busan (2), Incheon (3), Daejeon (1), Ulsan (1), Kangwondo (1), Kyungkido (1), Kyungsangbukdo (1) and Chungcheongbukdo (1). In these 15 specialized high schools, 92 classes of clothing departments are run by 72 clothing teachers with 2,459 students enrolled. The range of object of this study is 15 clothing related departments of specialized high schools and their titles are department of Fashion Design, Clothing Design, Clothing Art, Multi Fashion Design, Fashion Textile Design, and Global Design. They were investigated by literature from previous research and education statistics from the Korean Educational Development Institute (KEDI). Websites such as 'School Information', 'portal site of Specialized High School', 'Ministry of Education-Education Statistics and Information' were also searched. The homepages of specialized high schools with clothing department were also investigated respectively. In this study, current scale, employment rate of graduates, major courses, scale of teachers of clothing major of clothing department of specialized high school were analyzed. In 2015, employment rate and college enrollment rate of vocational high schools were 46.6% and 36.6% respectively, whereas employment rate and college enrollment rate of clothing departments four specialized High Schools were 39.9% and 45.8% respectively. The number of major courses of clothing departments are 12-15, and the main subjects of the curriculum were Fashion Design, Construction of Western Clothing, Construction of Korean Clothing, Textile Materials and Mangement and Computer Graphics. Major courses consist of 90-108 weekly lesson-hours for 6 semesters. Thanks to government projects to encourage specialized high schools, the educational environment has improved in areas of practice room equipment, industry connections, field training, internship, and scholarship funds. However, despite government projects to encourage education at specialized high schools, there is a need for a more flexible education system to enhance student creativity at specialized high schools.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.2
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• pp.113-122
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• 2013

Recently there has been increased interest for the portal and shallow tunnel for an eco-friendly tunneling method. Semi cut & cover tunnel excavation techniques applied to concrete slab and construction and a growing number of cases, but there is no load combinations and arch concrete cross section for the applicable standards. Therefore, in this study, ground conditions and tunnel overburden thickness, thickness of backfill, overburden surface slope angle changes to a variety of conditions in order to propose standards for the semi cut & cover method was performed numerical analysis. Regression analysis method to the analysis of the results of numerical analysis, and linear regression equations derived to classify and organize a rational, economical, and safe semi cut & cover tunneling method based proposed.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.153-161
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• 2011

As the problem of GOSST building belongs to NP compete domain, heuristics for the problem ask for immense amount execution time and computations in large scale inputs. In this paper, we propose an efficient mechanism for GOSST construction using space locality PTAS. For 40,000 input nodes with maximum weight 100, the proposed space locality PTAS GOSST with 16 unit areas can reduce about 4.00% of connection cost and 89.26% of execution time less than weighted minimum spanning tree method. Though the proposed method increases 0.03% of connection cost more, but cuts down 96.39% of execution time less than approximate GOSST method (SGOSST) without PTAS. Therefore the proposed space locality PTAS GOSST mechanism can work moderately well to many useful applications where a greate number of weighted inputs should be connected in short time with approximate minimum connection cost.

• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.81-92
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• 2008

Generally the connection of members is defined as hinge or rigid. But, real joints on structure have to be considered semi-rigid connections because this permits relative rotation for members on joints. The purpose of this study is to derive a generalized tangential stiffness matrix of frames with semi-rigid connections and to develop a buckling analysis program. For the exact stiffness matrix, an accurate displacement field is introduced using an equilibrium equation for beam-columns under the bending and axial forces. Also, stability functions that consider sway deformation and force-displacement relations with rotational spring on ends were defined. In order to illustrate the accuracy of this study and the characteristics of semi-rigid for system buckling load, samples of angle-, portal- and 3-story frames with semi-rigid connections are presented, where the proposed approach is found to be in excellent agreement with other research results. Meanwhile, the application of codes such as Eurocode 3 and LRFD led to significant inaccuracies.

• Geomechanics and Engineering
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• v.32 no.1
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• pp.111-123
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• 2023

The slope of an open cut tunnel is located above the exit of the Leijia tunnel on the Changgan high-speed railway. During the excavation of the open cut tunnel foundation pit, the slope slipped twice, a large landslide of 92500 m³ formed. The landslide body and unstable slope body not only caused the foundation pit of the open cut tunnel to be buried and the anchor piles to be damaged but also directly threatened the operational safety of the later high-speed railway. Therefore, to study the stability change in the slope of the open cut tunnel under heavy rain and excavation conditions, a 3D numerical calculation model of the slope is carried out by Midas GTS software, the deformation mechanism is analyzed, anti-sliding measures are proposed, and the effectiveness of the anti-sliding measures is analyzed according to the field monitoring results. The results show that when rainfall occurs, rainwater collects in the open cut tunnel area, resulting in a transient saturation zone on the slope on the right side of the open cut tunnel, which reduces the shear strength of the slope soil; the excavation at the slope toe reduces the anti-sliding capacity of the slope toe. Under the combined action of excavation and rainfall, when the soil above the top of the anchor pile is excavated, two potential sliding surfaces are bounded by the top of the excavation area, and the shear outlet is located at the top of the anchor pile. After the excavation of the open cut tunnel, the potential sliding surface is mainly concentrated at the lower part of the downhill area, and the shear outlet moves down to the bottom of the open cut tunnel. Based on the deformation characteristics and the failure mechanism of the landslides, comprehensive control measures, including interim emergency mitigation measures and long-term mitigation measures, are proposed. The field monitoring results further verify the accuracy of the anti-sliding mechanism analysis and the effectiveness of anti-sliding measures.