• Earthquakes and Structures
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• v.10 no.5
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• pp.1067-1087
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• 2016

In this paper, a decoupled proportional-integral-derivative (PID) control approach for seismic control of smart structures is presented. First, the state space equation of a structure is transformed into modal coordinates and parameters of the modal PID control are separately designed in a reduced modal space. Then, the feedback gain matrix of the controller is obtained based on the contribution of modal responses to the structural responses. The performance of the controller is investigated to adjust control force of piezoelectric friction dampers (PFDs) in a benchmark base isolated building. In order to tune the modal feedback gain of the controller, a suitable trade-off among the conflicting objectives, i.e., the reduction of maximum modal base displacement and the maximum modal floor acceleration of the smart base isolated structure, as well as the maximum modal control force, is created using a multi-objective cuckoo search (MOCS) algorithm. In terms of reduction of maximum base displacement and story acceleration, numerical simulations show that the proposed method performs better than other reported controllers in the literature. Moreover, simulation results show that the PFDs are able to efficiently dissipate the input excitation energy and reduce the damage energy of the structure. Overall, the proposed control strategy provides a simple strategy to tune the control forces and reduces the number of sensors of the control system to the number of controlled stories.

• Archives of Craniofacial Surgery
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• v.22 no.5
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• pp.232-238
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• 2021

Background: Galeal or temporalis muscle flaps have been traditionally used to reconstruct skull base defects after tumor removal. Unfortunately, these flaps do not provide sufficient vascularized tissue for a dural seal in extensive defects. This study describes the successful coverage of large skull base defects using anterolateral thigh (ALT) free flaps. Methods: This retrospective study included five patients who underwent skull base surgery between June 2018 and June 2021. Reconstruction was performed using an ALT free flap to cover defects that included the intracranial space and extended to the frontal sinus and cribriform plate. Results: There were no major complications, such as ascending infections or cerebrospinal leakage. Postoperative magnetic resonance imaging showed that the flaps were well-maintained in all patients. Conclusion: Successful reconstruction was performed using ALT free flaps for large anterior skull base defects. In conclusion, the ALT free flap is an effective option for preventing communication between the nasal cavity and the intracranial space.

• Honam Mathematical Journal
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• v.22 no.1
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• pp.107-111
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• 2000

We study Einstein warped product spaces. As a result, we prove the following: if M is an Einstein warped product space with base a compact 2-dimensional surface, then M is simply a Riemannian product space.

• ETRI Journal
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• v.15 no.3
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• pp.61-69
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• 1994

A new analytical model for the base current of Si/SiGe/Si heterojunction bipolar transistors(HBTs) has been developed. This model includes the hole injection current from the base to the emitter, and the recombination components in the space charge region(SCR) and the neutral base. Distinctly different from other models, this model includes the following effects on each base current component by using the boundary condition of the excess minority carrier concentration at SCR boundaries: the first is the effect of the parasitic potential barrier which is formed at the Si/SiGe collector-base heterojunction due to the dopant outdiffusion from the SiGe base to the adjacent Si collector, and the second is the Ge composition grading effect. The effectiveness of this model is confirmed by comparing the calculated result with the measured plot of the base current vs. the collector-base bias voltage for the ungraded HBT. The decreasing base current with the increasing the collector-base reverse bias voltage is successfully explained by this model without assuming the short-lifetime region close to the SiGe/Si collector-base junction, where a complete absence of dislocations is confirmed by transmission electron microscopy (TEM)[1].The recombination component in the neutral base region is shown to dominate other components even for HBTs with a thin base, due to the increased carrier storage in the vicinity of the parasitic potential barrier at collector-base heterojunction.

• Journal of the Korean Institute of Educational Facilities
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• v.19 no.1
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• pp.13-24
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• 2012

Recently, many middle and high schools are remodeling the buildings and facilities based on departmental system. This study, through analyzing on 10 remodeling cases of high school, is showing the variation before and after remodeling, space organization types, and the types of school management. This also gives us the information on the number of classrooms and teachers' rooms for each subject, the area and number of home base, and the current state of all these facilities. Furthermore, this study is comparing and analyzing the rate of use of specialized classrooms to the type of management. Through this analysis, we reach the following conclusions. l. However all the cases remodeled their buildings to implement departmental system, the methods of space composition, the numbers of the classrooms, and the status of home base are in various forms. 2. Taken as a whole, there are only few spaces used by departmental system. 3. The spaces for practical subjects such as Science and Art are inadequate than the ones for major subjects such as Languages and Mathematics. 4. A system to assign a room for a teacher records the lowest space usage rate. 5. The area of home base per one student is only $0.48m^2$, and even the area is mostly filled with lockers. The present condition of the 10 high schools which we surveyed shortly after remodeled shows that departmental system is not firmly settled down yet.

• Korean Institute of Interior Design Journal
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• v.21 no.3
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• pp.22-30
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• 2012

Nowadays the issue of environmental pollution and ecological destruction is not a simple issue but an important issue to be continuously considered. It is deemed that a study for recycled new materials is immediately required and this study is to analyze features and processing methods of new materials which can be used to interior space. We found the recycled new materials used for space through researching various web sits. And then we analyzed what the base materials are and classified that base materials are whether natural or artificial of the recycled materials. We classified processing methods of the recycled new materials after researching general processing methods. The result of this study would be an important material to the research and development of new finishing materials with consideration of environment and to the research for a guideline of applicable new materials. The results of this study are as follows : First, we could classify widely 2 categories into natural material and artificial material and then 10 subcategories into metal, glass, wood, rubber, stone, plastic, leather or fabric, ceramic, concrete and so on, and analyzed that which material is mostly used and whether it is single material or multiple material. In order to analyze the feature of processing method. Second, we could classify into 4 categories such as junction, surface process, molding, and insert, and found out which processing method is applied based on objects of research. Third, as an analysis result of the recycled new material feature, in order to develop various new materials, it is required to study on combination and application of 2 materials or more rather than single material. Four, as a analysis result of the processing method feature, I would like to suggest that development and application of various processing methods are required. Especially, it is necessary to grope for a way to develop new functional materials for interior space through a systemic research and analysis of processing method of other fields. Furthermore, a way to reuse recycled new materials should be considered in a stage of selection and application of processing method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.11
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• pp.2473-2478
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• 2009

The latest, Digital art is attempt new field's Art, that is utilize variously digital media image, sound, simulation, 3D holography. A large number of Digital Art is contact with the audience in pavilion(limit place and limit period). However, It will be possible, Digital Art can use place digital form media even there are indoor, outdoor, anywhere. Prior to study, I was to analyze the feature of Digital Art in order to using Digital Art, Interactivity make communication between humans and the art as well as cause audience participation, and take a role of bridge between human and space. A study was base on the relationship between human and space, space and Digital Art, Digital Art and human taken the focus interaction between human and space, and Interactivity of Digital Art. This paper analyze reciprocal action for utilize Digital Art in indoor space design, and this paper study expression about indoor design base of interactive.

• Journal of the Korean Institute of Rural Architecture
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• v.17 no.4
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• pp.83-90
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• 2015

The equalization policy needs various factors-standardization of educational environment, standardization of learning method, standardization of teacher ability, etc. Especially the standardization of educational environment is the base of various factors. But the recent educational environment condition of high school is not equal. The purpose of this study is to provide basic data for equal learning environment condition in high school applying departmentalized classroom system. This study has progressed through analyzing on 9 remodelling case of high school in Gangwon-Do. The method of this study is visiting high schools that operate the system, grasping the condition for environment composition, and investigating and analyzing practical use of the environment. The results of this study are summarized as follows: 1) The space compositions for departmentalized classroom system are generally desirable, but some schools take irrational space composition, especially on home base-teacher laboratory, classroom-teacher laboratory. 2) The space area distributions are different in every school. This result is based on not taking standard criterion on space area distribution.

• Journal of the Korean housing association
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• v.27 no.4
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• pp.47-58
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• 2016

As increasing demand for the living environment to promote social health, this study focused on consumers customized rental housing community space. Set the community spatial planning objectives and strategies shown in previous studies to the conceptual model for evaluation of community space. Based on the planning methods and standards of consumers custom community facilities, we analyzed the Seoul consumer customized public rental housing nine cases. Because almost located in the small vacant lot, they had limitations as a base for the local community. Nevertheless, through the arrangement of the building, Child care households increase the chance of contact with the neighbors. In elderly households, welfare facilities strengthen the character of as a base for local community. 1-2 person households situated close to the cultural facilities, by installing a hobby room and gym, was judged to be able to promote the community. Consumer custom rental housing community space evaluation items presented in this study, was set up by analysis of the conceptual model for evaluation of community space and implications of the 9 cases.

• Journal of Astronomy and Space Sciences
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• v.31 no.2
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• pp.177-186
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• 2014

The Immersion Grating Infrared Spectrometer (IGRINS) is a near-infrared wide-band high-resolution spectrograph jointly developed by the Korea Astronomy and Space Science Institute and the University of Texas at Austin. IGRINS employs three HAWAII-2RG Focal Plane Array (H2RG FPA) detectors. We present the design and fabrication of the detector mount for the H2RG detector. The detector mount consists of a detector housing, an ASIC housing, a Field Flattener Lens (FFL) mount, and a support base frame. The detector and the ASIC housing should be kept at 65 K and the support base frame at 130 K. Therefore they are thermally isolated by the support made of GFRP material. The detector mount is designed so that it has features of fine adjusting the position of the detector surface in the optical axis and of fine adjusting yaw and pitch angles in order to utilize as an optical system alignment compensator. We optimized the structural stability and thermal characteristics of the mount design using computer-aided 3D modeling and finite element analysis. Based on the structural and thermal analysis, the designed detector mount meets an optical stability tolerance and system thermal requirements. Actual detector mount fabricated based on the design has been installed into the IGRINS cryostat and successfully passed a vacuum test and a cold test.