SMP Prototype Design and Fabrication for Thermo-responsive Façade Elements

The aim to attain sustainability in the built environment introduced the innovative application of advanced material technologies for low-energy, but aesthetically intriguing, building design strategies. Adaptive and responsive building skins as embedded and intrinsic control systems can be delivered with smart materials, and thus have the potential to minimise the energy consumption of buildings by maximising the natural and passive adjustment of façade components for shading, air-flow, daylight, and view. The dynamic smart material façade, adaptable to changing outdoor environments, is considered to be a holistic design approach that integrates the behavioural performance effects with the appearance and aesthetics of kinetic ability provided by smart materials acting as actuators, by adjusting their properties according to external stimuli. Of the various environmental inputs sensed by, and actuating, active and dynamic building façade systems, this research focuses on temperature as the stimulus to activate a dynamic shading device with the mechanism of opening and closing, specifically considering Seoul’s climate. Among currently available thermo-responsive smart materials, the shape memory polymer (SMP) is investigated as an activator of shading devices to be implemented to adaptive building skin strategies. As the first stage of SMP prototype design and fabrication study toward the thermo-responsive building façade elements, SMP prototypes are proposed in cell types. Among the general thermo-mechanical cycle of thermo-responsive SMP, only programming of the permanent shape via additive manufacturing and recovery at the activation temperature are focused upon in this research. This study proposes a design-to-fabrication workflow integrating computational tools, 3d printing and recalibration of relevant variables in digital design process, G code generation, and manufacturing using commercially available SMP filaments. To verify the 3d printing process, and to demonstrate the shape-changing behaviour of SMP actuators, reproduction of a referenced prototype was conducted, in addition to fabrication experiments of SMP surfaces with various thicknesses and SMP hinges with customised rotating angles. In addition, a base-line prototype combining the static ABS plate and the active SMP hinge is developed to set up the heat test and a digital motion simulation from data of shape changing behaviour acquired from a hands-on model test. After the demonstration of the baseline prototype in design and additive manufacturing process, various SMP prototypes were designed with reference to kinetic prototype researches, but with the consistent 100mm-diameter circular surface, in a scale of 1:3. They were also fabricated with a 3d printer for both open and closed positions to testify to their constructability, and thus to comparatively evaluate the design and fabrication outcomes. Furthermore, after conducting radiation and thermal simulation analysis, shading performance validation is noted for selecting potential prototypes. Lastly, the needs to further develop reversible reiterative shape-changing materials or systems are briefly discussed

Variations in patterns of low fertility in South Korea in 2004: a county level analysis

Since the early 1960s, South Korea has been going through a rapid fertility decline, along with its socioeconomic development and effective family planning programs. After achieving a desired replacement level of fertility in 1984, the total fertility rate (TFR) of Korea has gradually declined to the level of lowest-low fertility. According to 2004 vital statistics, the TFR for Korea was 1.16-below the lowest-low fertility level of 1.3. Also, Korea's fertility rates have fluctuated and varied spatially, even at the level of low fertility. Undoubtedly, Korean family planning programs have been effective in population control through the last 40 years, but since 2000, the shift to pro-natal policies indicates that Korea's fertility transition is no longer a response to family planning policies. Rather, the level of socioeconomic development is still considered to have a significant effect on Korea's fertility decline. Thus, in this thesis, the primary objective is to examine the socioeconomic determinants of fertility differentials and the variation in low fertility among the counties in South Korea in 2004. Using data from the 2000 census and 2004 vital statistics, I tested the hypothesized relationships between the level of socioeconomic development and fertility based on the demographic transition theory (DTT), by estimating several Ordinary Least Square (OLS) multiple regression models. Specifically, socioeconomic predictors, such as agricultural attainment, labor force participation, and educational attainment, were primarily examined to test the validity of the DTT hypotheses. In addition, this thesis also examined the effects of women's status and traditional norms and cultural values on variation in fertility. My results showed that the DTT is applicable to an accounting of the variance in fertility rates among the Korean counties in 2004. Although the levels of fertility are extremely low all across the country, it is apparent that socioeconomic conditions are having an impact on fertility differentials in Korea

What data characteristics are needed for data reuse in the domain of social sciences in Korea?

With the benefits of data sharing and reuse, data reuse have been promoted in various domains. While there are practices and discussions regarding data sharing and reuse, we still have little knowledge on what characteristics of data impact decisions on data reuse. In this sense, we aim to explore data characteristics in the context of data reuse within the domain of social sciences in Korea. For the purpose of this study, we conducted in-depth interviews with twelve re-searchers in the field of social science in terms of six dimensions: data producer, country/language, data type/collection method, procedure, accessibility, size/currency. For the producer dimension, social scientists preferred data that have been produced by an institution rather than an individual researcher. In language used in the data sets, English were more favored because researchers preferred English than any other languages. In terms of data type, quantitative and survey data types are preferred. For the procedure of data, researchers preferred original raw data with plenty of metadata and demographic information for analysis. For accessibility, there was less preference for restricted data. Lastly, for size/currency, researchers showed a preference for big size data and current data. These preliminary findings can provide better understanding about data reuse and guide improved data reuse services

Improving Recall of Browsing Sets in Image Retrieval from a Semiotics Perspective

The purpose of dissertation is to utilize connotative messages for enhancing image retrieval and browsing. By adopting semiotics as a theoretical tool, this study explores problems of image retrieval and proposes an image retrieval model. The semiotics approach conceptually demonstrates that: 1) a fundamental reason for the dissonance between retrieved images and user needs is representation of connotative messages, and 2) the image retrieval model which makes use of denotative index terms is able to facilitate users to browse connotatively related images effectively even when the users' needs are potentially expressed in the form of denotative query. Two experiments are performed for verifying the semiotic-based image retrieval model and evaluating the effectiveness of the model. As data sources, 5,199 records are collected from Artefacts Canada: Humanities by Canadian Heritage Information Network, and the candidate terms of connotation and denotation are extracted from Art & Architecture Thesaurus. The first experiment, by applying term association measures, verifies that the connotative messages of an image can be derived from denotative messages of the image. The second experiment reveals that the association thesaurus which is constructed based on the associations between connotation and denotation facilitates assigning connotative terms to image documents. In addition, the result of relevant judgments presents that the association thesaurus improves the relative recall of retrieved image documents as well as the relative recall of browsing sets. This study concludes that the association thesaurus indicating associations between connotation and denotation is able to improve the accessibility of the connotative messages. The results of the study are hoped to contribute to the conceptual knowledge of image retrieval by providing understandings of connotative messages within an image and to the practical design of image retrieval system by proposing an association thesaurus which can supplement the limitations of the current content-based image retrieval systems (CBIR)

An Electromagnetic Steering System for Magnetic Nanoparticle Drug Delivery

Targeted delivery of pharmaceutical agents to the brain using magnetic nanoparticles (MNPs) is an efficient technique to transport molecules to disease locations. MNPs can cross the blood–brain barrier (BBB) and can be concentrated at a specific location in the brain using non-invasive electromagnetic forces. The proposed EMA consists of two coil-core system. The cores are added in the center of each coil to concentrate the flux in the region of interest. The EMA can enhance the gradient field 10 times compared to only coil system and generate the maximum magnetic field of 160 mT and 5.6 T/m. A 12-kW direct-current power supply was used to generate sufficient magnetic forces on the MNPs by regulating the input currents of the coils. Effective guidance of MNPs is demonstrated via simulations and experiments using 800-nm-diameter MNPs in a Y-shaped channel. The developed EMA system has high potentials to increase BBB crossing of MNPs for efficient drug targeting to brain region

Z-Interop

Final report for the Z39.50 interoperability testbed project, phase 2

Functionalized Magnetic Force Enhances Magnetic Nanoparticle Guidance: From Simulation to Crossing of the Blood-Brain Barrier in vivo

In recent studies, we introduced the concept of functionalized magnetic force as a method to prevent nanoparticles from sticking to vessel walls caused by extensive simulation and in vitro experiments involving a Y-shaped channel. In this study, we further investigated the effectiveness of the functionalized magnetic force with a realistic 3D vessel through simulations. For the simulations, we considered a more realistic continuous injection of particles with different magnetic forces and frequencies. Based on the results from our simulation studies, we performed in vivo mice experiments to evaluate the effectiveness of using a functionalized magnetic force to aid magnetic nanoparticles (MNPs) in crossing the blood-brain barrier (BBB). To implement the functionalized magnetic force, we developed an electromagnetic actuator regulated by a programmable direct current (DC) power supply. Our results indicate that a functionalized magnetic field can effectively prevent MNPs from sticking, and also guide them across the BBB. We used 770-nm fluorescent carboxyl MNPs in this study. Following intravenous administration of MNPs into mice, we applied an external magnetic field (EMF) to mediate transport of the MNPs across the BBB and into the brain. Furthermore, we evaluated the differential effects of functionalized magnetic fields (0.25, 0.5, and 1 Hz) and constant magnetic fields on the transport of MNPs across the BBB. Our results showed that a functionalized magnetic field is more effective than a constant magnetic field in the transport and uptake of MNPs across the BBB in mice. Specifically, applying a functionalized magnetic field with a 3 A current and 0.5 Hz frequency mediated the greatest transport and uptake of MNPs across the BBB in mic