• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6D
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• pp.917-926
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• 2006

Transportation Economies of scale are the essential properties of hub networks. One critical property of the hub network design problem is to quantify cost savings which stem from economies of scale, the costs of operating hub facilities and opportunity costs associated with delays stemming from consolidation of traffic flows. Due to the NP-complete property of the hub location problem, however, most previous researchers have focused on the development of heuristic algorithms for approximate solutions. The purpose of this paper is to develop a hub network design model considering transportation economies of scale from the consolidation of traffic flows. The model is designed to consider the uniqueness of hub networks and to determine several cost components. The heuristic algorithms for the developed model are suggested and the results of the model are compared with recently published studies using real data. Results of the analysis show that the proposed model reflects transportation economies of scale due to consolidation of flows. This study can form not only the theoretical basis of an effective and rational hub network design but contribute to the assessment of existing and planned logistics systems.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3D
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• pp.205-213
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• 2010

The unsignalized intersections in a community road in the city of Seoul have 3,753 traffic accidents(9%) of total 41,702 cases in 2008, not high in the occurrence rate of traffic accidents, but seem to have a quite high potential of accidents due to the unreasonable and insufficient operation of systems and facilities in the part of traffic foundations. In particular, the un-signalized intersections in a community road have an insufficient measure for safety as compared to the crossroads with signals, and there are few analysis of traffic accidents and domestic researches on the model of affecting factors. Our country also has no concept of passing priority in operating a crossroad without signals, differently from foreign countries, so the researches and safety measures for improving the safety of a crossroad without signals in a community road are urgent. Therefore, this research has developed a safety model for a crossroad without signals in a community road based on the safety image data collected through individual interviews and questionnaires for the users of unsignalized intersections in a community road, and confirmed that legal systems, road facilities, personal factors, etc. have the biggest effect on the safety of drivers. It was confirmed that the clarity of passing methods, establishment of legal systems, etc. have the biggest effect on safety in order to raise the safety of unsignalized intersections in a community road, which drivers desire.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.4A
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• pp.337-342
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• 2010

Generally most sluice gates are closed and opened by a mechanical winch, a winch using an oil-pressure, or a winch mixing both. Because of their size and structure, they should be safely operated with more than two pulling devices helping each other. At the moment of their opening and closing, there usually occur some additional loads to the structure which cannot be exactly measurable at the stage of designing. Such additional loads can cause the sluice gate to be unbalanced and make it hard to open and close the gate, and by also overloading a winch, they can inflict a significant damage to the safety of the sluice gate. This paper explains a FDC(Force-Displacement Control) system which simultaneously considered the oil-pressure and displacement in order to evenly distribute the force and make a winch balanced at the opening and closing motion. This FDC system was implemented by means of the PID(Proportional Integral Derivative) function of XG 5000 program. It was experimented on a model of the sluice gate winch with the hydraulic oil pressure cylinder. The experiments showed that the developed FDC system made the winch of hydraulic oil pressure cylinder open and close cooperatively in spite of various external loads. Therefore the FDC system is proven effective when it is applied to a winch of sluice gate.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.6
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• pp.417-427
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• 2010

In the ease that a new cross tunnel is constructed under the existing tunnel, development of a longitudinal arching would be influenced by the existing tunnel. But it is not enough to investigate. Especially, the influence of the structure loads on the ground surface on the new tunnel, which the under-passes existing tunnel has been rarely studied. This study, therefore, aimed to clarify the effect of the existing tunnel and the structure on the ground surface on the development of a longitudinal ground arching during the excavation of a cross tunnel under the existing tunnel. Two-dimensional model tests were carried out in the test box, whose dimension was 30 cm (wide) ${\times}$ 113 cm (deep) ${\times}$ 87 cm (high). The existing tunnel was made of S21 steel tube in 16 cm diameter and 1 mm thickness. The ground surface load was 4.9 kPa and was loaded on the model structure in the size with 30 cm width ${\times}$ 16 cm height. New tunnel was excavated in 250 mm height by a bench cut method. As results, the longitudinal arching would be developed but it was severely influenced by not only the existing upper tunnel but also the ground surface load. The influence of the ground surface load on the development of longitudinal ground arching around a new tunnel showed the highest value when the tunnel face located direct under the surface load.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.2
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• pp.199-211
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• 2009

Development of underground space is actively performed globally for better life in the surface, and the scale of the space is increasing. Extreme care should be taken in the construction of the underground space in urban areas in order to avoid damage of adjacent structures and interference with existing underground space. In case of shallow tunnels, reinforcement of ground and structures is necessary to minimize the damage to structures due to excavation but any standard for optimum range of the reinforcement has not been established yet. In this paper, a series of numerical analyses have been performed for a 20 m diameter tunnel excavated underneath a structure to investigate the degree of damage of the structure according to vertical and horizontal spacing between the tunnel and structure. In addition to that, optimum range of reinforcement is presented for each case where reinforcement is required. It has been observed that the reinforcement is necessary for the ground condition adapted in the analyses as follows: (1) if horizontal spacing ($S_{H}$) approaches to 0D (D: equivalent diameter of tunnel) for vertical spacing (Sv) of 0.5D, and (2) if tunnel exists underneath the structure for vertical spacing (Sv) of 0.75D. The reinforcement is not necessary for Sv of 10 regardless of $S_{H}$. It also has been obtained that the optimum ranges of the reinforcement around structure foundation are 7 m in depth and whole width of the structure and 5 m beyond tunnel sidewall. These reinforcememt ranges have been confirmed to be enough for stability of the structure if types of reinforcement method is appropriately selected.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.4
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• pp.372-379
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• 2023

International oil prices are expected to increase from $85 a barrel this year to up to $100 a barrel in the second half of the year; this is likely to increase orders for offshore plants in the global market. One main characteristic of offshore plants is that a large helideck is located on the top side, and aluminum alloys are used as the basic material of the structure for weight reduction and corrosion resistance. Shipowners are increasing the size of helicopters to quickly evacuate lives in the event of an emergency, and the safety use load of devices that can stably secure helicopters to the deck is also required to increase. Owing to the nature of the aluminum material, the structural strength caused by welding is greatly reduced; therefore, the fixing device must be designed by embedding it in the deck and fixing it with bolts. In this study, a model applying aluminum alloy 6082-T6 was developed to develop a helicopter fastening device that can be used for large helidecks (diameter = 28 m). The developed item was verified through nonlinear structural strength calculation to satisfy the load used for the actual fastening condition. The load condition with a 45° showed a lower ultimate strength than the 90° case owing to local plastic collapse. The nonlinear structural collapse behavior showed a result similar to that of the experimental test. The main contents derived from this study are considered to be reference materials when evaluating the structural strength of similar aluminum equipment.

• Women's Studies Review
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• v.29 no.2
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• pp.3-35
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• 2012

This paper attempts to examine complicated relations which the nineteenth-century English novel of female development has with the Bildungsroman genre, and to discuss that the story of female development effectively realizes the potential dynamics of the genre. It looks into the history of discussions on the Bildungsroman which began at the end of the nineteenth-century in Germany and developed among twentieth-century Anglo-American critics, and those on the female development which didn't start until feminist criticism ventured out at the end of 1970s, and have developed into various perspectives ever since in accordance to the progress of feminist criticism. In general, Bildungsroman criticism considers that it portrays the process how the protagonist develops self and achieves an accommodation with society. However, this paper points out that the Bildungsroman is the narrative form which represents conflicts between self and society caused by idealizing the infinitive possibility of self-determination while simultaneously presenting the limited goal of social integration. It argues that the subversive dynamics of the genre can give full play to its potential when it reveals contradictions and tensions between individual subjectivity and integration into society and connects them with criticism of political and social structures. It is the stories of female Bildungshelds depicted by nineteenth-century female writers that exquisitely embody the subversive potential of the Bildungsroman. They acutely experience alienation from society where independency or autonomy is fundamentally impossible because the ideology of separate spheres does not allow them to live a meaningful life economically and sociologically outside the marriage. An example of a female Bildungsheld whose conflicts between development of self and integration with society are doubled by gender is Jane Eyre. Jane Eyre is a representative Bildungsroman with subversive dynamics, which tells the story of female development but splits itself through various techniques inserting contradictory and opposite meanings, thus resignifying female development and questioning social and political structures.

• 지역과문화
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• v.6 no.3
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• pp.29-53
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• 2019

Korean traditional women artists are placed in dual suffering from unequal rights in terms of gender and misrecognition endowed by historical legacy. There has been no clear cut definition but interchangeable adoption of various terms such as Yeo-ak, Yeo-gi, and Gisaeng even in the study of music theory and history itself. Study on female musician has been mostly performed on the basis of music theory and history so that one sided discourse on female traditional artist has survived and aggravated its connotation during the colonial ages and modernization. Envisioning traditional female artist as instrumentalizing their body and status as artist resulted in crucifying victims of sexual harassment is one recent example. This study is an attempt to collect knowledge on the various layers of discourse about the status and role of female traditional artist. This is a first stage of analysis covering the period Joseon dynasty where original and official records regarding female traditional artists remains until today. The findings are that policy discourse are to be classified as politico-ideological layer, music theoretical layer, and socio-political layer. It is to be clarified in the future which layer has the most sustaining influence to the present and why.

• International Area Studies Review
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• v.15 no.1
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• pp.341-365
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• 2011

This study used a non-parametric linear program, Data Envelopment Analysis to compare the efficiency of South Korean and Chinese banks from 2000 to 2008, which is said to be the reformation period of their financial structure. The sample banks were 10 commercial banks and 6 regional banks in Korea, and 4 state-owned commercial banks and 11 stock commercial banks in China. The main objective of our research is to compare their efficiency, as well as the changes in efficiency periodically according to the types of the banks. According to the periodical analysis, both of the countries showed steady increase in efficiency. This shows that finance restructure and merging were positive factors for bank's efficiency during the revolution of finance structure. The study showed that between Korea and China, the bank of Korea has higher efficiency than that of China. Although the reconstruction period happened around the same time, due to the earlier acceleration period to opening Korea's financial market, made the difference in efficiency.

• Journal of The Geomorphological Association of Korea
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• v.18 no.2
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• pp.25-37
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• 2011

The purpose of this study is to investigate the history of phenomenon(hereinafter called mass-movement) of movement of inorganic material originated from hillslope by denudation of hillslope surrounding the watershed during Holocen period in the Chaamgol watershed(hereinafter called study watershed) uppermost stream of Maegokcheon Cheonan-si Chungnam. To do this, for the object of allivium distributed in valley bottom of study watershed, facies analysis, radiocarbon dating and grain size analysis were conducted and geomorphological analysis on study watershed conducted together. The result is like the following. It was confirmed that over around 9,100yrBP~to recent due to a few times of mass-movement occurred in time scale of 10²~10³ years, a large quantity of inorganic material is mixed in organic material layer originated from wetland formed in valley bottom of study watershed or exists between organic material layers. And it was found that in study watershed, mass-movement occurred in instable period of hillslope after the Early Holocen existed at least 8 times (M1 period~M8 period) and wetland environment formed in the stable period of hill slope existed total 4 times (W1 period~W4 period). This analysis result will be used in the future as basic material in research of Holocen climate change of Maegokcheon watershed and in restoration of denudation process of hillslope following this.