• Journal of the Korean Society of Systems Engineering
• /
• v.14 no.2
• /
• pp.58-66
• /
• 2018

This paper represents a systematic approach aimed at improving the performance of the proportional integral (PI) controller for the Advanced Power Reactor (APR) 1400 Feedwater Control System (FWCS). When the performance of the PI controller offers superior control and enhanced robustness, the steam generator (SG) level is properly controlled. This leads to the safe operation and increased the availability of the nuclear power plant. In this paper, a systems engineering approach is used in order to design a novel PI controller for the FWCS. In the reverse engineering stage, the existing FWCS configuration, especially the characteristics of the feedwater controller as well as the feedwater flow path to each SG from the FWCS, were reviewed and analysed. The overall block diagram of the FWCS and the SG was also developed in the reverse engineering process. In the re-engineering stage, the actual design of the feedwater PI controller was carried out using a genetic algorithm (GA). Lastly, in the validation and verification phase, the existing PI controller and the PI controller designed using GA method were simulated in Simulink/Matlab. From the simulation results, the GA-PI controller was found to exhibit greater stability than the current controller of the FWCS.

• Smart Structures and Systems
• /
• v.29 no.4
• /
• pp.561-576
• /
• 2022

Heritage timber structures represent the history and culture of a nation. These structures have been inherited from previous generations; however, they inevitably exhibit deterioration over time, potentially leading to structural deficiencies. Structural Health Monitoring (SHM) offers the potential to assess operational anomalies, deterioration, and damage through processing and analysis of data collected from transducers and sensors mounted on the structure. This paper reports on the design and implementation of a long-term SHM system on the Feiyun Wooden Pavilion in China, a three-story timber building built more than 500 years ago. The principles and features of the design and implementation of SHM systems for heritage timber buildings are systematically discussed. In total, 104 sensors of 6 different types are deployed on the structure to monitor the environmental effects and structural responses, including air temperature and humidity, wind speed and direction, structural temperatures, strain, inclination, and acceleration. In addition, integrated data acquisition and transmission subsystem using a newly developed software platform are implemented. Selected preliminary statistical and correlation analysis using one year of monitoring data are presented to demonstrate the condition assessment capability of the system based on the monitoring data.

• Computers and Concrete
• /
• v.29 no.5
• /
• pp.347-360
• /
• 2022

Fiber-reinforced cementitious composites (FRCC) have emerged as a response to the calls for strong, ductile and sustainable concrete mixes. FRCC has shown outstanding mechanical properties and ductility where special fibres are used in the mixes to give it the strength and the ability to exhibit strain hardening. With the possibility of designing the FRCC mixes to include sustainable constituents and by-products materials such as fly ash, FRCC started to emerge as a green alternative as well. To be able to design mixes that achieve these conflicting properties in concrete, there is a need to understand the composition effect on FRCC and optimize these compositions. Therefore, this paper aims to investigate the influence of FRCC compositions on the properties of fresh and hardened of FRCC and then to optimize these mix compositions using factorial design approach. Three factors, water-to-binder ratio (w/b), mineral admixtures (total of fly ash and metakaolin by cement content (MAR)), and metakaolin content (MK), were investigated to determine their effects on the properties of fresh and hardened FRCC. The results show the importance of combining both FA and MK in obtaining a satisfactory fresh and mechanical properties of FRCC. Models were suggested to elucidate the role of the studied factors and a method for optimization was proposed.

• The Research Journal of the Costume Culture
• /
• v.32 no.1
• /
• pp.17-37
• /
• 2024

This study examines the rise of the Body Positive Movement on TikTok and its role as a form of online content activism influencing the fashion design and industry. Through a combination of literature review and case study methodology, the study explores the expression techniques and thematic types of Body Positive Movement on TikTok. Reviews of literature, previous studies, online articles, fashion journals, and relevant search terms on TikTok informed a definition of Body Positive Movement and an analysis of its formation and rise. The research findings confirm the impact TikTok content on Body Positive Movement has on the fashion industry in addressing external factors (i.e., 'Appearance', 'Race', 'Aging', 'Physical Disability') and intrinsic factors (i.e., 'Acceptance of Diversity', 'Self-Esteem', 'Rejection of Stereotypes', 'Appropriate Representation', 'Information Provision'). The key external factor , 'Appearance', includes subcategories such as 'Body Shape', 'Body Hair', 'Skin', and 'Facial Features'. TikTok content creators on fashion creatively combine music, emojis, and visual storytelling to exhibit positive self-perception concerning these factors. A significant finding of the study is that short clips predominantly manifesting external factors differentiate into informative or enlightening videos associated with intrinsic factors. The study underscores Body Positive Movement's important influence on the fashion industry from design to presentation.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.20 no.1
• /
• pp.93-107
• /
• 2018

A questionnaire survey was conducted on male and female college students living in Busan in May 2015 to study customer types and purchasing behaviors based on the benefit sought from undergarments. This study used a total of 460 data reports collected from 203 male and 257 female college students. The results of this study were as follows. First, the undergarment benefits sought were divided into material and function, harmony of outerwear and underwear and design. Consumers were categorized into function seekers, brand and design seekers, and undergarment indifferent customers. In addition, while male college students were likely to be function seekers, female college students were mostly brand and design seekers. Second, both male and female respondents showcased significant differences in the undergarment benefits sought depending on their customer type. Based on the customer type, male college students showed a greater difference in the undergarment benefits they sought when compared to their female counterparts, and marked differences were found in male respondents' undergarment material and function factors and female respondents' harmony factor of outerwear and underwear. Based on their sex, a significant difference in the harmony factor of outerwear and undergarments was observed. Third, after examining the purchasing behavior influenced by the customer type, this study found that both male and female students had undergarment purchasing behavior differences depending on their customer type, while function seekers and design seekers were likely to exhibit similar behaviors in purchasing undergarments regardless of their sex, except for their preferred image and purchasing method of undergarments. However, among the indifferent group of customers, there were significant differences depending on their sex.

• Archives of design research
• /
• v.11 no.3
• /
• pp.58-67
• /
• 1998

Exposition primarily reguires the basic understanding of the mutual effect between the conventional culture and the future-oriented change of society.A number of fundamental and general research articles exist which are related to the exhibition planning and design. Unfortunately, the concrete research works dealing with the large-scale international expositions are hardly found in the literature. In this connection, this research was particularly focused on the special exposition display and planning. The International Exposition, the World Design Exposition and the International Garden and Greenery Exposition were chosen in order to examine the conceptual characteristics as the proper examples creating the fantastic space and developing the new exposition display technigue. The Government Pavilion in the Taejon Expo , 93 was chosen as an example for the exposition planning. An overall research concerning the basic direction and structure of the exposition design, the exposition display and the special system technigue was carried out in order to represent the basic spirit and theme with the most efficient way.

• Applied Chemistry for Engineering
• /
• v.20 no.2
• /
• pp.234-240
• /
• 2009

$Mg(OH)_2$ particles were prepared by precipitation and a hydrothermal treatment to examine the effect of $MgCl_2$ concentration, alkali type and concentration, temperature, hydrothermal treatment on the formation of $Mg(OH)_2$ particles using full factorial design, as one of DOE (Design of experiment) methods. The primary particle size is similar to the secondary particle size for the samples after the hydrothermal treatment, where the average particle size of $Mg(OH)_2$ increased with increasing the concentration of $MgCl_2$ and hydrothermal temperature and decreasing alkali/Mg molar ratio. On the other hand, for the samples prepared from precipitation, the secondary particle size is larger than the primary particles due to aggregation. The difference in alkaline source is that the particles prepared from $NH_4OH$ exhibit the larger size with better dispersion than those from NaOH. Low density polyethylene and ethylene-co-vinyl acetate (LDPE-EVA) resin composed of the smaller secondary particle size of $Mg(OH)_2$ shows a higher limited oxygen index (LOI) at 50 and 55% loading, but the smaller primary particle size may result in a better grade in UL-94 tests. At the high loading of 60%, all samples with any preparation methods exhibit V-0 grade but the LOI value depends on not only primary particle size but also dispersion state.

• Korea Science and Art Forum
• /
• v.25
• /
• pp.227-240
• /
• 2016

This study aims to examine how visitors in science centers interact with gesture-based exhibits from embodied cognition perspectives. Four gesture-based exhibits in two science centers were selected for this study. In addition, we interviewed a total of 14 visitor groups to examine how they perceived the property of gesture-based exhibit. We also interviewed four experts to further examine the benefits and limitations of the current gesture-based exhibits in science centers. The research results indicate that the total amount of interaction time between visitors and gesture-based exhibits was not high overall, implying that there was little of visitors' immersive engagement. Both experts and visitors expressed that the current gesture-based exhibits tend to highlight the novelty effect but little obvious impacts linking gestures and learning. Drawing from the key findings, this study suggests the following design considerations for gesture-based exhibits. First, to increate visitor's initial engagement, the purpose and usability of gesture-based exhibits should be considered from the initial phase of design. Second, to promote meaningful interaction, it is important to sustain visitors' initial engagement. For that, gesture-based exhibits should be transformed to promote intellectual curiosity beyond simple interaction. Third, from embodied cognition perspectives, exhibits design should reflect how the mappings between specific gestures and metaphors affect learning processes. Lastly, this study suggests that future gesture-based exhibits should be designed toward promoting interaction among visitors and adaptive inquiry.

• Wind and Structures
• /
• v.14 no.5
• /
• pp.383-411
• /
• 2011

Roof is an integral part of building envelope. It protects occupants from environmental forces such as wind, rain, snow and others. Among those environmental forces, wind is a major factor that can cause structural roof damages. Roof due to wind actions can exhibit either flexible or rigid system responses. At present, a dynamic test procedure available is CSA A123.21-04 for the wind uplift resistance evaluation of flexible membrane-roofing systems and there is no dynamic test procedure available in North America for wind uplift resistance evaluation of rigid membrane-roofing system. In order to incorporate rigid membrane-roofing systems into the CSA A123.21-04 testing procedure, this paper presents the development of a load cycle. For this process, the present study compared the wind performance of rigid systems with the flexible systems. Analysis of the pressure time histories data using probability distribution function and power spectral density verified that these two roofs types exhibit different system responses under wind forces. Rain flow counting method was applied on the wind tunnel time histories data. Calculated wind load cycles were compared with the existing load cycle of CSA A123.21-04. With the input from the roof manufacturers and roofing associations, the developed load cycles had been generalized and extended to evaluate the ultimate wind uplift resistance capacity of rigid roofs. This new knowledge is integrated into the new edition of CSA A123.21-10 so that the standard can be used to evaluate wind uplift resistance capacity of membrane roofing systems.

• Korean Institute of Interior Design Journal
• /
• v.15 no.6 s.59
• /
• pp.213-220
• /
• 2006

Le Corbusier (1887-1965) is known as a great architect ranking with such master architects as Frank Lloyd Wright and Mies van der Rohe who produced great architectural achievements in an era from the dawning to the maturity of the modem architecture. His works are marked for their peculiarity in expressing his architectural concept as perceived through his artistic sensibility. He has brought the form of his architecture to perfect through the influence of Purism. His architectural concept has instigated him to construct the relations between structure, form and the notion of space through the 'Dom-ino' structural system and the 'Five Principles of the Modem Architecture.' As a result, he has become such an architect as has ripened his works by adopting the 'Modulor' for human measurement. During the decade from 1929 to 1939, he made public the 'Museum of Unlimited Growth' programs in an attempt to give a concrete form to his concept of 'unlimited space' spreading to all directions, which was actually visualized by the constructions of three art museums, located Ahmedabad and Chandigarh in India and Tokyo in Japan. Although a number of researches have so far been publicized on the works and the architectural ideas of Le Corbusier, no systematic research has yet been released on the idea of 'Museum of Unlimited Growth' as a matter of fact. Therefore, this study has set its purpose to grasp the peculiarities of his exhibition space design through an analysis on the characteristics of the 'Museum of Unlimited Growth' so designed as to reflect the concept of a space, which is centrifugally growing. With this purpose in mind, this research is also to suggest how the design of the 'Museum of Unlimited Growth' would influence the modem museum exhibit space. The contents of this study comprise the consideration on the early ideas of Le Corbusier, the typical features of the growing museum and the analysis as well as the integration of his works.