• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.3
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• pp.255-280
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• 2024

If there are concerns about the stability of segment lining due to section deficiency or large deformation in shield TBM tunnel, reinforcement can be done through ground grouting outside the tunnel or by using steel plate reinforcement, ring beam reinforcement, or inner double layer lining inside the tunnel. Traditional analyses of shield TBM tunnels have been conducted using a continuum method that does not consider the segmented nature of segment lining. This study investigates the reinforcement mechanism for double layer reinforced sections with internal steel linings. By improving the modeling of segment lining, this study applies Break-joint mode (BJM), which considers the segmented characteristics of segment lining, to analyze the deformation characteristics of double layer reinforced sections. The results indicate that the existing concrete segment lining functioned similarly to ground reinforcement around the tunnel, rather than distribution the load. In general, both the BJM model considering the segmentation of segment lining and the continuum rigid method were similar deformation shapes and stress distributions of the lining under load. However, in terms of deformation, when the load strength exceeded the threshold, the deformation patterns of the two models differed.

• Journal of Service Research and Studies
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• v.7 no.1
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• pp.83-96
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• 2017

The importance of service science is emphasized in the modern economy, and the value and necessity of service research still increasing. Since the service research framework was proposed, it has been studied from various perspectives and incorporated into one framework--service research. The direction of service research has been established and a new baseline of research has been established. However, the modern economic and social environment could be described as a new era, the Fourth Industrial Revolution has changed drastically. More and more systematic research on services has become necessary. Therefore, this study analyzed the field of service research in the existing framework. The study suggested how service research could broaden the horizon of service research by studying the 'what'. To do this, we analyzed recent service research trends by themes. We also identified the shortcomings of previous studies about service, and suggested directions and research themes for future research. Based on this study we developed a general approach to the creation of new models from the viewpoint of service science. The authors were also able to develop a general approach to areas such as service innovation, service inference, service solution, and service design leverage. In addition, it is necessary to extend service research and business model to the utilization of service technology. This approach could contribute to forming the basis of future service development, and to utilize social media to create new value of innovative company. The results of this study could contribute to deepening and expanding service research.

• Convergence Security Journal
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• v.13 no.5
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• pp.107-116
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• 2013

Occur in various parts of the world and the new aspects of the regional conflict is spreading. Nation and civilization, one based on religious ideology, hegemonic tendencies areas of conflict are factors that appear. It has the characteristic that inheritance and conflict between civilizations is spreading. Christian and Islamic books, especially the confrontation and conflict is surfaced in the international political aspects, and a threat to the security of the human race is approaching. To assert the superiority of Western Christianity emerging countries, the salvation of mankind and world peace mission with the historical non-democracy, human rights, women's rights, underdevelopment, nuclear issues, and the spirit of Christian civilization, considered to be linked and reverse, Democracy Launching and human rights issues are forcing Western development model. Islam believes in absolute monotheism that God Lord only determined by the 'slave' and having the determination to serve the religious, political, social and cultural nature ingrained, and closely adjacent to each other geographically, to focus on in quency characteristics higher than the other civilizations are appearing. To assert the doctrine of non-violent Islam 'Koran' and 'knife' became known as the violent images appear in the armed conflict between the culture method. Today the world is facing a clash of civilizations is derived from the religious conflicts and confrontation and friction between the nations appear. In particular, the deep religious roots of Christianity and Islam, the Arab-Israeli conflict, including the right to live in strife confrontation between Christianity and Islam was spread. By a factor of civilization and the spread of terrorism occurred historically proven came here from all over the earth that is being generated is true. Civilization are the symbol of the nation and the species identity.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.10
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• pp.649-657
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• 2017

A rupture in a high-pressure pipe causes the fluid in the pipe to be discharged in the atmosphere at a high speed resulting in a supersonic jet that generates the compressible flow. This supersonic jet may display complicated and unsteady behavior in general. In this study, Computational Fluid Dynamics (CFD) analysis was performed to investigate the compressible flow generated by a supersonic jet ejected from a high-pressure pipe. A Shear Stress Transport (SST) turbulence model was selected to analyze the unsteady nature of the flow, which depends upon the various gases as well as the diameter of the pipe. In the CFD analysis, the basic boundary conditions were assumed to be as follows: pipe of diameter 10 cm, jet pressure ratio of 5, and an inlet gas temperature of 300 K. During the analysis, the behavior of the shockwave generated by a supersonic jet was observed and it was found that the blast wave was generated indirectly. The pressure wave characteristics of hydrogen gas, which possesses the smallest molecular mass, showed the shortest distance to the safety zone. There were no significant difference observed for nitrogen gas, air, and oxygen gas, which have similar molecular mass. In addition, an increase in the diameter of the pipe resulted in the ejected impact caused by the increased flow rate to become larger and the zone of jet influence to extend further.

• Convergence Security Journal
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• v.18 no.2
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• pp.167-177
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• 2018

Major countries, such as the U.S., UK and Germany have reformed their national intelligence systems in the face of transnational, asymmetric and comprehensive threats since September 11, 2001 and have strengthened the intelligence capacity involved in countering terrorism and WMD proliferation, right/left extremism threats. The Korean Moon Jae-in government is preparing a reform plan to eliminate illegal political intervention and abuse of power by the National Intelligence Service(NIS) and to rebuild it as an efficient national intelligence agency for national security. In discussing the reform direction of the NIS, it is necessary to discuss in detail whether adopting a separate model of intelligence agencies to restrict domestic intelligence activities of the NIS and concentrate on foreign intelligence activities or establish new domestic intelligence agencies. Second, as for the issue of transferring anti-Communism investigation authority of the NIS to the police, it needs to be carefully considered in terms of balancing the efficiency and professionalism of intelligence agency activity in the context of North Korea's continuous military provocation, covert operations and cyber threats. Third, it should strive to strengthen the control and supervision functions of the administration and the National Assembly to ensure the political neutrality of the NIS in accordance with the democratization era, to guarantee citizens' basic rights and to improve the transparency of budget execution.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.277-284
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• 2020

This thesis interrogates the term a performer's 'spontaneity' as the key principle to approach and enhance contemporary performer's training and acting. Drawing on a number of problematic issues, this thesis particularly examines the paradigm of the subtle bodily movement inform the experience of a performer's spontaneity as embodied and understood in approaching and adapting through text analysis and action. The in-depth process of the relationship between a performer's action and the transformative effects, is central to understanding and adapting the key principle of acting/training that a specific text would pursue through a specific performance by means of what a performer must do on stage. Following the discussion of acting in training and rehearsal, this thesis argues the necessity of an alternative way(s) and model of the performer's work via how the performer's action is sincerely emerged from the moment-by-moment rather than the performer anticipates what comes in the next and therefore pretend to do/be something/someone. Expanding upon the assumptions mentioned above, this thesis provides some pragmatic and descriptive work(s) from the practitioners' concepts and approaches that invites us to reconsider the nature of acting and its adaptability for contemporary performers.

• 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.

• Journal of The Korean Association For Science Education
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• v.27 no.7
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• pp.645-662
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• 2007

The purpose of this study was to explore the manners in which models are used in secondary science classrooms. A total of thirteen video-recordings of science lessons dealing with the domains of atmospheric and oceanic earth sciences and their verbatim transcripts were analysed both quantitatively and qualitatively. Interviews with three inservice science teachers were also conducted. Six interrelated assertions were generated as the result of the study: 1) The most frequently used models in secondary earth science classrooms include two-dimensional pictorial, symbolic, iconic, and diagrammatic ones; 2) Science teachers employ models as a mode of representation to make the subject matter available to students; 3) In earth science classrooms, teachers use typical forms of models in intensive manners; 4) Students themselves deal with models on a few occasions, but they just follow similar procedures with the same models; 5) Teachers talk rarely about the nature of scientific models and provide few opportunities for students to think about it; and, 6) Teachers in practice think that the value of using models should be appraised in consideration of the pedagogical intentions of the teacher. Implications for science education and science education research were discussed.

• Journal of Gifted/Talented Education
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• v.21 no.3
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• pp.595-610
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• 2011

It is hard to understand the coexistence of giftedness and disorder in an individual, but the twice-exceptional is widely recognized now. Gifted autistic spectrum disorder is one of its subtypes in which giftedness exists with autistic spectrum disorder (ASD) simultaneously. Like other constructs including giftedness, the nature of gifted ASD has not been understood in a fundamental and wholistic manner. This paper suggests a cognitive mechanism of gifted ASD based on the integrated model of human abilities(Song, 2009; Song & Porath, 2005), which explains how giftedness coexists with ASD and interacts with each other, producing the characteristics of gifted individuals with ASD. According to the suggested mechanism, the excessive growth of mental spaces in the brain may cause ASD. The over-grown mental spaces result in excessively strong short-term sensory memory and better facility of processing, promoting internal cognitive activities on one hand, but relative lack of cognitive activities in the real world space results in ASD symptoms on the other hand. The cognitive structure of gifted ASD students also contributes to the presentation of giftedness in specific domains. This study suggests that gifted individuals with ASD need to be discouraged from fully engaging in domains they are interested in or the most confident of, rather to be encouraged to invest their giftedness to overcome their ASD symptoms. This study also provides new perspectives on theoretical and educational approaches for gifted ASD.

• Journal of the Korean GEO-environmental Society
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• v.19 no.10
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• pp.21-26
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• 2018

Soil-water characteristic curve, which is called soil retention curve, is required to explore water flows in unsaturated soils, relative permeability of water in multi-phase fluids flow, and change to stiffness and volume of soils. Thus, the understanding of soil-water characteristic curves of soils help us explore the behavior of soils inclduing fluids. Biopolymers are environmental-friendly materials, which can be completely degraded by microbes and have been believed not to affect the nature. Thus, various biopolymers such as deacetylated power, polyethylene oxide, xanthan gum, alginic acid sodium salt, and polyacrylic acid have been studies for the application to soil remediation, soil improvement, and enhanced oil recovery. PAA (polyacrylic acid) is one of biopolymers, which have shown a great effect in enhanced oil recovery as well as soil remediation because of the improvement of water-flood performance by mobility control. The study on soil-water characteristic curves of sandy soils containing PAA (polyacrylic acid) has been conducted through experimentations and theoretical models. The results show that both capillary entry pressure and residual water saturation dramatically increase according to the increased concentration of PAA (polyacrylic acid). Also, soil-water characteristic curves by theoretical models are quite well consistent with the results by experimental studies. Thus, soil-water characteristic curves of sandy soils containing biopolymers such as PAA (polyacrylic acid) can be estimated using fitting parameters for the theoretical model.