• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.10
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• pp.809-819
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• 2020

In this study, the twist angle and wing planform shapes were selected as design variables and optimized to secure the stability of the flying-wing type UAV. Flying-wing aircraft has no separated fuselage and tails, which has advantages in aerodynamic characteristics and stealth performance, but it is difficult to secure the flight stability. In this paper, the sweep back angle and twist angle were optimized to obtain the lateral stability, the static margin and wing planform shapes were optimized to improve the longitudinal stability of the flying-wing, then effect of the twist angle was confirmed by comparing the stability of the shape with the winglet and the shape with the twist angle. In the optimization formulation, focusing on improving stability, constraints were established, objective functions and design variables were set, then design variable sensitivity analysis was performed using the Sobol method. AVL was used for aerodynamic analysis and stability analysis, and SQP was used for optimization. The CFD analysis of the optimized shape and the simulation of the dynamic stability proved that the twist angle can be applied to the improvement of the lateral stability as well as the stealth performance in the flying-wing instead of the winglet.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.502-507
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• 2016

The transition from a carbon economy based on fossil fuels to a hydrogen economy is necessary to ensure energy security and to combat climate change. In order to pursue the transition to a hydrogen economy while achieving sustainable economic growth, a preliminary study into the establishment of the necessary infrastructure for the future hydrogen economy needs to be carried out. This study addresses the economic and environmental interactions in a dynamic computable general equilibrium (CGE) model focusing on the economic effects of the introduction of renewable energy into the Korean energy system. Firstly, the introduction of hydrogen results in an increase in the investment in hydrogen production and the reduction of the production cost, ultimately leading to GDP growth. Secondly, the mandatory introduction of renewable energy and associated government subsidies bring about a reduction in total demand. Additionally, the mandatory introduction of hydrogen energy into the power sector helps to reduce CO2 emissions through the transition from a carbon economy-based on fossil energy to a hydrogen economy. This means that hydrogen energy needs to come from non-fossil fuel sources in order for greenhouse gases to be effectively reduced. Therefore, it seems necessary for policy support to be strengthened substantially and for additional studies to be conducted into the production of hydrogen energy from renewable sources.

• Cartoon and Animation Studies
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• s.48
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• pp.141-172
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• 2017

The film (2000) and (2016) are based on different time slips from each other. However, these two films have many common elements that make one illusion-based illusion. In the common elements, the main characters (being and thing) are traversed at different times and directed as a cyclical one. Also, among these, the movement link of the time and space has a commonality that it becomes possible through a medium ( - radio, you, there - pill). As a result, a series of scenes expressed in showed that the scene of produced in 2000 was greatly circulated. The reason why two movies have similar structure is that the basic framework of video media based on time slip is similar. Therefore, the purpose of this study is not to analyze the problem of quoting and borrowing of two films as mentioned in the paper. To add up, the material of video media is manifold which is a dynamic object of potential which is unlimited and opened, and by rearranging one media it can be created by escaping from one territory. Also, it is a study of analysis to contribute to producer or researcher as a time slip video creation reference connecting times based on the manifold arrangement from two films.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.4831-4843
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• 2014

Magazines on specific genres have been operating collaborative, co-working and collective production systems for value maximization using an adaptation strategy on the dynamic, complex and uncertain value network of the magazine industry. The study used a case study method, and data collection was performed by observational research, depth interviews and survey research. The subjects of the study were 'magazine industry', 'magazine firm and community', and 'collaboration system within creative users'. According to the research results, the ecosystem of magazines on a specific genre has been evolving into an innovative value network system, which is combined with the magazine firm, community users and magazine platform. Second, the rapid introduction of smart device environment changes the way of the collaborating system, in which an action and interaction came out within the community, creative users and magazine firms. Third, the production agency shows strong action and interaction, which fits the magazine platform within the ecosystem of a magazine on a specific genre well. This model has a similar fractal structure to the game, publishing, drama, movie, comic, and animation contents industry, converging to an innovative technology-based-creative-industry.

• Journal of the Economic Geographical Society of Korea
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• v.20 no.2
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• pp.189-213
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• 2017

This study seeks to critically examine the significance and limits of the cluster adaptive cycle model for analysis of cluster evolution and to propose research issues for future analysis of cluster evolution based on this critical examination. Until the 1980s, research on industrial complexes including clusters was based on a 'static perspective' that focuses on the aspect of economic space at a specific point in time, but the research paradigm has recently shifted to a 'dynamic perspective' focusing on 'evolution' of 'complex adaptive systems'. As a result, the adaptive cycle model has attracted attention as an analysis tool of dynamically evolving clusters. However, the cluster adaptive cycle model has emerged by being appropriately modified and expanded according to the properties of the cluster and its evolution. The cluster adaptive cycle model is a comprehensive analysis framework that identifies the characteristics of cluster evolution in terms of resource accumulation, interdependence, and resilience and classifies cluster evolution paths into six different categories. Nevertheless, there is still a need for further discussion and supplementation in terms of theoretical and empirical research to expand and deepen the model. Therefore, research issues for future analysis of cluster evolution are to specify and elaborate the cluster evolution model, to emphasize the concept of resilience, and to verify the applicability and usefulness of the model through empirical research.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.6
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• pp.120-136
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• 2016

This study, views the color of scenery not as a static state, but rather as a continuous sequence of perceptions that incorporates the concept of time. This study derived techniques to quantitatively analyze the flow and data from this sequence. By utilizing this, urban color trends can be based on openness. This is very close to what would be experienced by an actual viewer: it extracted color data and visual amount from frames at 2-second intervals by shooting a video of the color sequence of the city as seen from both the left and right sides from the inside of the monorail (line 3 of the Daegu urban railway). These images were classified by color group, brightness, chroma, high chroma distribution derived techniques such as openness of space, brightness level, clarity level, high-chroma distribution and code, advantage of visual amount, dominant factor exposure, hot and cold color image and dynamic of sequence rhythm. During the derived sequence, the data determines the openness in the visual amount of sky and it was found that the tendency of the colors of the city was opening regression analysis. The more colorful the city is opening the brightness is lowered, the chroma increased slightly, cold colors significantly increased, which also had a very deep relationship with Lynch enclosed proportion, color change of the city trends through the actual scenery could grasp in more detail.

• Macromolecular Research
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• v.10 no.1
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• pp.2-12
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• 2002

The small-angle X-ray scattering (SAXS) beamline BL4C1 at the 2.5 GeV storage ring of the Pohang Accelerator Laboratory (PAL) has been in its first you of operation since August 2000. During this first stage it could meet the basic requirements of the rapidly growing domestic SAXS user community, which has been carrying out measurements mainly on various polymer systems. The X-ray source is a bending magnet which produces white radiation with a critical energy of 5.5 keV. A synthetic double multilayer monochromator selects quasi-monochromatic radiation with a bandwidth of ca. 1.5%. This relatively low degree of monochromatization is sufficient for most SAXS measurements and allows a considerably higher flux at the sample as compared to monochromators using single crystals. Higher harmonics from the monochromator are rejected by reflection from a flat mirror, and a slit system is installed for collimation. A charge-coupled device (CCD) system, two one-dimensional photodiode arrays (PDA) and imaging plates (IP) are available its detectors. The overall performance of the beamline optics and of the detector systems has been checked using various standard samples. While the CCD and PDA detectors are well-suited for diffraction measurements, they give unsatisfactory data from weakly scattering samples, due to their high intrinsic noise. By using the IP system smooth scattering curves could be obtained in a wide dynamic range. In the second stage, stating from August 2001, the beamline will be upgraded with additional slits, focusing optics and gas-filled proportional detectors.

• Korean Journal of Social Welfare
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• v.63 no.1
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• pp.29-55
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• 2011

This study aims to understand the experiences of rights-based social work practice in a residential facility for people with intellectual disabilities. A representative residential facility practicing a human rights perspective was selected by recommendation of professional groups. Using a qualitative case study method, data was collected and analysed. In detail, it explores the experiences of rights-based social work practice at both organizational and individual levels respectively, and then discusses ethical dilemmas that arise from workers in the process of rights-based social work practice. According to results at the organizational level, rights-based social work practice of the residential facility began from workers' interests in needs of users with intellectual disabilities. Some trials to apply human rights in social work practice resulted in regulations for people with intellectual disabilities and stepped up organizational culture on human rights perspectives. And, at the individual level, self determination and choice of users with intellectual disabilities were stressed among various forms of human rights. As the results of rights-based social work practice, it appeared to be improved for the participation of the users, workers' human rights sensitivity, and qualities of rights-based activities. However, ethical dilemmas still existed. Hence, rights-based social work practice should understand a process of dynamic interaction between users and workers, which require workers to endeavor continuously. This study is significant in that it explored rights-based social work practice, focusing on field experiences for the first time in Korea, and suggested practical tasks to settle it down in the future.

• Journal of Korea Port Economic Association
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• v.28 no.3
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• pp.235-257
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• 2012

Recently the role of ports has been changed to satisfy flexibly needs of demands in global economy. A new concept for ports is not just a place for international trade but an important nodal point in logistics chain. The changing environment like this trend creates a high degree of uncertainty and leaves port managers confused with the question how to respond effectively to dynamic market. The latest studies provide that the port must have a good hinterland to achieve competitive advantages in a logistics chain. Korean Government announced "The Master Development Plan for Port Logistics Parks in Korea" in 2006. This contains the plan of hinterland construction of Busan New Port to achieve the status of logistics hub in Asian market. Previous studies rely solely on traditional DCF(discounted cash flow) analysis for investment of hinterland. However DCF method does not include irreversibility, uncertainty and the choice of timing for investment project. This thesis introduces a ROPM(real options pricing model) which overcomes the limitations of traditional valuation methods. The option valuations in this study utilize the Black-Scholes model, the binomial model and the MonteCarlo simulation to value investment opportunity of a port hinterland. In this thesis, an attempt is made to modify the NPV criterion by incorporating the real options approach, and its application is demonstrated in a hinterland construction investment plan. This research has conducted an empirical analysis by calculating economic value of the investment for a hinterland of Busan New Port.

• Journal of Korean Society of Transportation
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• v.28 no.2
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• pp.99-108
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• 2010

In this paper I tried to find out changed and improved streetscape through the simulation using components of streetscape abstracted by factor analysis after analyzing present situation and problems of the streetscape for housing developments prepared on publis water surface. An analysis object is located in Haeundae Marine City in Busan. As a result of analysing the streetscape of marine city at present, I could see that main problems were discontinuous street space that did not reflect the characteristic of seashore, uncomfortable and insecure passage owing to coexistence street at seashore, insufficient street facilities for pedestrians, and disordered outdoor signboards. Therefore, I put the causal problems of marine city's streetscape in the insufficient street components, disharmony, and discontinuity so analysed the simulation elements applying selected street components and evaluated them to deduce demand factors having common meaning. As the result, the common demand factors were 'street furniture', 'harmonious streetscape with surrounding', 'landscape with natural openness', and 'landscape with dynamic symbol' in the order. So it needs to stress on a plan for proper arrangement of 'street facilities' and symbolic streetscape having continuity and harmony with surrounding so that the plan can proceed more properly for marine city's identity.