• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.758-771
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• 2021

This paper presents a novel control scheme for the three-dimensional (3D) path following of underactuated Autonomous Underwater Vehicle (AUVs) subject to unknown internal and external disturbances, in term of the time scale decomposition method. As illustration, two-time scale motions are first artificially forced into the closed-loop control system, by appropriately selecting the control gain of the integrator. Using the singular perturbation theory, the integrator is considered as a fast dynamical control law that designed to shape the space configuration of fast variable. And then the stabilizing controller is designed in the reduced model independently, based on the time scale decomposition method, leading to a relatively simple control law. The stability of the resultant closed-loop system is demonstrated by constructing a composite Lyapunov function. Finally, simulation results are provided to prove the efficacy of the proposed controller for path following of underactuated AUVs under internal and external disturbances.

• Journal of Korean Society of Steel Construction
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• v.10 no.3 s.36
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• pp.487-495
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• 1998

Recently, the space truss has been attracted by many designers because of their ability to support significant loads with a minimum material. And it is relatively flexible to design the configuration of structures. This paper presents a volume optimization for the space truss on the basis of result evaluated from nonlinear analysis. The optimization of the truss is done by nonlinear optimum GINO(General Interactive Nonlinear Optimizer) program. The objective function considered is the volume of the steel bars. The constraints for optimum design are the design limits, such as the axial force strength, maximum slenderness, minimum thickness, allowable deflection and ratio of the external diameter to thickness of the circular tube bars.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.15-23
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• 2008

This paper proposes a CIB framework implementing a ubiquitous smart space. In a ubiquitous smart space, a ubiquitous mobile device recognizes surrounding context, and infers the situation and provides services to users. Ubiquitous mobile devices have a RDF store to manage resources and relevant information efficiently on CIB framework. This store space is flexible on the operations such as addition, modification, deletion of information and response to query by SPARQL. In addition, it provides local information to other ubiquitous mobile devices in the from of XML and stores resource information from other ubiquitous mobile devices into local ubiquitous mobile device for the purpose of discovering external resources.

• International Journal of Aeronautical and Space Sciences
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• v.16 no.2
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• pp.278-294
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• 2015

Considering the guidance and control problem of the near space interceptor (NSI) during the terminal course, this paper proposes a three-channel independent integrated guidance and control (IGC) scheme based on the backstepping sliding mode and finite time disturbance observer (FTDO). Initially, the three-channel independent IGC model is constructed based on the interceptor-target relative motion and nonlinear dynamic model of the interceptor, in which the channel coupling term and external disturbance are regarded as the total disturbances of the corresponding channel. Then, the FTDO is introduced to estimate the target acceleration and control system loop disturbances, and the feed-forward compensation term based on the estimated values is employed to effectively remove the effect of disturbances in finite time. Subsequently, the IGC algorithm based on the backstepping sliding mode is also given to obtain the virtual control moment. Furthermore, a robust least-squares weighted control allocation (RLSWCA) algorithm is employed to distribute the previous virtual control moment among the corresponding aerodynamic fins and reaction jets, which also takes into account the uncertainty in the control effectiveness matrix. Finally, simulation results show that the proposed IGC method can obtain the small miss distance and smooth interceptor trajectories.

• Journal of the Korean housing association
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• v.25 no.5
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• pp.63-71
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• 2014

Recently, many researches on the supply of public rental-housings that utilize modular houses have been conducted for the expanded supply of public rental house and consumer-customized supply. For this reason, a research on recognition and satisfaction of residents who live in modular houses was conducted based on their evaluations on public rental houses utilizing actual modular houses. Consequently planning guidelines that would increase residency satisfaction was drawn. Surveys and interviews of 'The Gongneung Hee-mang Housing' were conducted, and analyses of descriptive statistics, multiple regression analysis and importance-satisfaction analysis were conducted. The post occupancy evaluations inform that to gain extra recognition by promoting advantages of modular houses and engaging in educational activities are needed. Dealing with issues such as external noises and vibrations, proper common facility, interior space plan, taking account of facility plan is also needed. This study would contribute to establish modular house planning, reflecting the residents' practical demands.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.73-76
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• 2005

The advanced information and communication technology gives vehicles another role of the third digital space, merging a physical space with a virtual space in a ubiquitous society. In the ubiquitous environment, the vehicle becomes a sensor node, which has a computing and communication capability in the digital space of wired and wireless network. An intelligent vehicle information system with a remote control and diagnosis is one of the future vehicle systems that we can expect in the ubiquitous environment. However, for the intelligent vehicle system, many issues such as vehicle mobility, in-vehicle communication, service platform and network convergence should be resolved. In this paper, an in-vehicle gateway is presented for an intelligent vehicle information system to make an access to heterogeneous networks. It gives an access to the server systems on the internet via CDMA-based hierarchical module architecture. Some experiments was made to find out how long it takes to communicate between a vehicle's intelligent information system and an external server in the various environment. The results show that the average response time amounts to 776ms at fixec place, 707ms at rural area and 910ms at urban area.

• Korean Institute of Interior Design Journal
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• v.24 no.3
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• pp.3-14
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• 2015

The most important issue of modern cities is a crime. Crime prevention through environmental planning is needed in the urban mixed-use commercial facilities which have an important role of modern urban life, and have a positive elements for local society. The purpose of this study is to propose a direction of crime prevention through environmental planning for the urban mixed-use commercial facilities. In order to accomplish this purpose, a questionnaire survey is performed on users of urban mixed-use commercial facilities to evaluate the importance and satisfaction. The conclusions are as follows; 1) Crime prevention through environmental planning is needed in the public space which forms boundary between urban mixed-use commercial facilities and other urban facilities. 2) Safety support planning is necessary for women and children for crime prevention of urban mixed-use commercial facilities. 3) Crime prevention planning is needed in urban mixed-use commercial facilities of the various isolation space. 4) Crime prevention through environmental planning is needed for facilities of after business hours. 5) Various security alarm system considering the characteristics of the space is needed for crime prevention. 6) Community program is necessary in order to increase the utilization of external public space. 7) A sign is necessary to prevent a criminal act in urban mixed-use commercial facilities. 8) The connection of commercial facilities and activity inducing factors is needed.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2007.05a
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• pp.222-226
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• 2007

Buildings form interior space when part of an external environment is limited by a physical surface. And, the interior space forms an appearance of building when space-defining elements, such as floor, wall, and roof. An appearance or a form of building has a lot of meanings depending on the physical and psychological conditions, as well as symbolism. Especially, the prevailing meaning of form in the modern age was, "Form follows function," was quite different from the meaning of form in the architectural era of Louis I. Kahn, who asserted "Form always supercedes function," when functional modernism was still existed even after some 50 years later. Existing studies on Louis I. Kahn usually analyzed his architectural terminology and philosophical concepts of Centrality, Light, Order, Form, and Design; or they were focused on an overall plane and the principle of composition. The purposes of this study are: (1) to investigate how the formal composition characteristics of building are expressed on skylights; and (2) to demonstrate that the formal composition characteristics of skylights plays an important role in constructing a whole structure of building in relation with other architectural elements.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.9
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• pp.75-81
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• 2003

The longitude and latitude of a geosynchronous satellite are not defined as a point in space because of various external perturbations. To perform the missions of a satellite for a communication and broadcasting, the satellite must be positioned within a predefined station keeping box in given limited space longitude. In this study, we propose east-west station keeping box larger than that of north-south station. By using the derived error equation, we verified the Koreasat station keeping box allocation by assuming one week and two weeks of station keeping cycle.

• KIEAE Journal
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• v.8 no.3
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• pp.93-100
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• 2008

The residents solve a physiological and hygienic craving in the bathroom. Bathroom is a common space in residence. Recently the role of the bathroom with interest augmentation of the wellbeing of the consumers is coming to be important space in residence. The purpose of this research is to investigate the bathroom satisfaction and priority of the apartment resident and to present the bathroom design for the future in apartment. The subjects of this study were residents who live in brand apartments located in Seoul. The results of this study are as following, First, basically the solution of safety problem is necessary in the bathroom. Second, the daylight is necessary in the bathroom and the resident must be possible to see an external view from the bathroom. Third, the space planning for a function convenience is necessary to a bathroom space. The rest support which leads the introduction of health wellbeing and natural friendship element is necessary to the bathroom design for the future. The bathroom design for the future must be safety, must be a bathroom of the high-class finishing material.