• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.51-59
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• 2006

The physical characteristics of autonomic microcapsules manufactured with various agitation speeds in a stirred tank were observed experimentally by a particle size analyzer and an optical microscope. The flow characteristics in a stirred tank were also investigated through a 3-dimensional numerical simulation to understand the manufacturing process of autonomic microcapsules. According to the results, we found that the agitation speed was the important factor to determine the sizes of microcapsules. The impeller-induced flow allowed the jet and tip-vortex pair components in the mixed fluid of a stirred tank. The vorticity around the blades in the impeller was increased as increasing the agitation speed. In addition, the size of autonomic microcapsules was strongly affected on the small scale mixing pattern such as a tip-vortex pair.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.1
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• pp.10-18
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• 2010

The purpose of this paper deals with direct multiple-shooting method (DMS) to resolve helicopter maneuver problems of helicopters. The maneuver problem is transformed into nonlinear problems and solved DMS technique. The DMS method is easy in handling constraints and it has large convergence radius compared to other strategies. When parameterized with piecewise constant controls, the problems become most effectively tractable because the search direction is easily estimated by solving the structured Karush-Kuhn-Tucker (KKT) system. However, generally the computation of function, gradients and Hessian matrices has considerably time-consuming for complex system such as helicopter. This study focused on the approximation of the KKT system using the matrix exponential and its integrals. The propose method is validated by solving optimal control problems for the linear system where the KKT system is exactly expressed with the matrix exponential and its integrals. The trajectory tracking problem of various maneuvers like bob up, sidestep near hovering flight speed and hurdle hop, slalom, transient turn, acceleration and deceleration are analyzed to investigate the effects of algorithmic details. The results show the matrix exponential approach to compute gradients and the Hessian matrix is most efficient among the implemented methods when combined with the mixed time integration method for the system dynamics. The analyses with the proposed method show good convergence and capability of tracking the prescribed trajectory. Therefore, it can be used to solve critical areas of helicopter flight dynamic problems.

• Journal of Navigation and Port Research
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• v.27 no.1
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• pp.63-70
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• 2003

If semi-rigid connections are used for superstructures of very large floating structures (VLFS), the number of rigid connections can be reduced and more economical construction will be possible. In this study, considering service load and wave load in VLFS, the applicability of mixed use of rigid and semi-rigid connections have been studied using three types of connections for a four-bay eight-story frame. Three types of connections are used; top and seat-angle connections with double web-angle(TSD), extended end plate connections, steel tubular column with square external-diaphragm connections. ABAQUS(Finite element analysis program) is used for conducting second order elastic analysis.

• Korean Institute of Interior Design Journal
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• v.23 no.1
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• pp.172-180
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• 2014

A railway station appears in the form of multi-use station building where cultural and commercial elements such as shopping and leisure are mixed, getting out of simple space configuration oriented to the space for station work, where a passenger stays for a little while. Now, a railway station is a place expanded to the inside of city, and builds a relationship with urban fabric, and therefore it should receive the social change in the time together with the surrounding infrastructure, and should inevitably form the urban environment. And it should become the 'Place' so as to be capable of playing a role of buffer and a role of regional gateway landmark by making users included in the inside through various uses with regard to the dispersed urban connection. Hence, this study is intended to examine the planning through the place branding of railway station. In the method of research, the characteristics that place branding had was investigated, and an analysis was made on the basis of 10 place branding strategic elements and 6 railway design guidelines. And it was intended to set a direction in which the existing place branding strategy could be applied to the railway station, and was intended to derive the place branding planning strategic elements of railway station. Hence, the planning can be classified into the following 5 kinds in connection with railway station. First, identity should be embodied through the strategy of constructing the symbolic image of railway station. Second, a role of mediating variously approaching flows in the city should be played. Third, the spatial layout of railway station, which can increase the efficiency of use, should be arranged. Fourth, special characteristics should be intensified through creative storytelling that stimulates emotion. Fifth, an organic change is gradually necessary for sustainability. These planning elements should be applied in harmonious combination. Therefore, a new railway station can be maded by building identity and placeness and by giving the value through these planning directions in the future.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.403-407
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• 2007

Korean Government conducted "a research for establishing the integrated construction information classification system" and suggested the classification system for the first and second level in terms of the complexity in May, 2001. The Ministry of Construction and Transportation announced a standard of the integrated construction information classification system using previous research in August, 2001. Since 2005, many BTL projects have been constructed for the educational facility. However, there is mixed official standard of the system for the educational facility. Moreover, it is difficult for the SPC to use the current "integrated construction information classification system", since the item in the educational facility cannot be easily located in the current system. Thus, this research suggests an efficient maintenance system for the educational facility. Two classification systems, space-oriented and element-oriented systems, are suggested to increase efficiency of the classification system.

• Journal of the Korean Institute of Rural Architecture
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• v.17 no.3
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• pp.1-9
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• 2015

The purpose of this paper is to analysis on periodical changes of rural houses of Korean-Chinese people residing in Yanbian area, China focused on periodical changes of floor plans according to Chinese government's policies and regulations influencing on rural houses. Changes of floor plans are classified into four periods; immigrating settled period, 1960-1970s, 1980-1990s, and after 2000. Total number of 67 cases were analyzed that data was collected 48 cases of literature studies and 19 cases of field study in Yanbian, China. The results are as followings. In immigrating settled period, floor plans of the rural houses have tended to be continued the pattern of the Korean traditional rural houses. Nevertheless China was changed socialism system, rarely floor plans were influenced by the system during this period. From 1960s to 1970s, the livestock and rural mechanization are influenced by the "People's Commune" policy. The "Barn" and "Mill" were converted into "warehouse". The residential part consists of one Jeongji (space mixed dinning and kitchen) and one to three of Ondolbang (room). From 1980s to 1990s influenced by the policies of "Cultural Revolution", "Birth Control" and "Chinese Economic Reform", the Korean traditional customs like "elders first" and "distinction between the male and female have been gradually vanished. Meanwhile, spaces of the rural houses have consisted of Jeongji, big Utppang (room), and warehouse. Each space is opened and mutual. Since 2000, influenced by the policy of a "new Socialist Countryside Construction", the bathroom and kitchen are added in interior spaces, the life style in rural houses has been changed as for both the sedentary style and western style.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.8
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• pp.357-368
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• 2013

Our society has evolved into a fully connected society in a mixed reality environment enabling various knowledge sharing / management / control / creation due to the expansion of broadband ICT infrastructure, smart devices, cloud services and social media services. Therefore cyber threats have increased with the convenience. The society of the future can cause more complex and subtle problems, if you do not have an effective response to cyber threats, due to fusion of logical space and physical space, organic connection of the smart object and the universalization of fully connected society. In this paper, we propose the strategy to build knowledge-base as the basis to actively respond to new cyber threats caused by future various environmental changes and the universalization of fully connected society.

• Korean Journal of Remote Sensing
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• v.30 no.5
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• pp.559-570
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• 2014

Backscatter signal observed from the space-borne Light Detection And Ranging (LIDAR) system is providing unique 3-dimensional spatial distribution as well as temporal variations for atmospheric aerosols. In this study, the continuous observations for aerosol profiles were analyzed during a years of 2012 by using a Cloud-Aerosol LIDAR with Orthogonal Polarization (CALIOP), carried on the Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation (CALIPSO) satellite. The statistical analysis on the particulate extinction coefficient and depolarization ratio for each altitude was conducted according to time and space in order to estimate the variation of optical properties of aerosols over Northeast Asia ($E110^{\circ}-140^{\circ}$, $N20^{\circ}$ $-50^{\circ}$). The most frequent altitudes of aerosols are clearly identified and seasonal mean aerosol profiles vary with season. Since relatively high particle depolarization ratios (>0.5) are found during all seasons, it is considered that the non-spherical aerosols mixed with pollution are mainly exists over study area. This study forms initial regional 3-dimensional aerosol information, which will be extended and improved over time for estimation of aerosol climatology and event cases.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.2
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• pp.178-189
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• 1995

In this pater, authors derive the state - space equiation about the patallel - type inverted pendulum which is adopted as control object, and constitute the control system by $H_\infty$control theory. The modeling error is unavoidably existed by linearization error, and so on. We regard this modeling error which is determined from the identification through frequency response as unstructured model uncertainty. An augmented state - space equiation with frequency weighting function is constructed for application of the $H_\infty$theory, and the mixed sensitivity problem is considered. The weighting functions are determined in consideration of the model uncertainty and the response of system in frequency region. The $H_\infty$controller is designed by using software package for controller design. From results of response simulation, the control system designed with $H_\infty$theory guarantees low sensitivity for disturbance as well as robustness against the model uncertainties.

• Korea Science and Art Forum
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• v.27
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• pp.213-219
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• 2017

This paper aims to approach a spatial furniture for sedentary lifestyle which been has derived and evolved from Korea's traditional 'Ondol' heating system. In this living culture, people has been staid on the floor where people would sit directly on without furniture such as chair and bed. With every changing technological advances, sedentary life culture is transformed and mixed instead of sedentary habit. Most of people lived in western house such as apartment forms. As time go by, western furnitures were used became widespread. However, during the process, it impossible to acclimate ourselves to the new lifestyle such as chair, bed etc. This leads to users feeling uncomfortable on certain points. The researcher suggests a spatial furniture through a new approach to rest-taking that also intersects the cultures of East and West while resolving the a fore-mentioned issues. The study is conducted as follows. Firstly, issues are discovered through a user's lifestyle to exist usage and interplay of house and furniture. Furthermore, the issues was not a fragmentary thing but more related to a culture and a coustom of long standing. Secondly, a design experiment is conducted to conclude a new form and function that is better fit for the Korean culture where sitting on the floor is the norm. New direction for space that intersects the cultures of the East and West while using modules made convenient for contemporary life is presented. Finally, this study is meaningful in that it reinterprets furniture used for rest within the context of sedentary culture, in order to propose a new direction and value for design that overcomes the boundaries between eastern and western applied to resting space.