Search

Design deliverable quality is one of the most critical factors to the overall performance of a construction project, but achieving it has become difficult due to the ever increasing complexity of the construction environment. Consequently, various technologies are continuously developed and implemented on projects to enhance the efficiency and quality of design and construction processes. The objective of this dissertation is to examine how these emergent complexities—and the technological remedies for these complexities—affect building design quality. To achieve this objective, this dissertation presents three studies in Chapter 2, 3, and 4, respectively. Chapter 2 provides a deep exploration of the types of complexity embedded in design problems. By conducting statistical analyses of leading indicators of design defects, the author determined that problematic deliverables involve technical complexity more than organizational complexity, and that different types of causal factors contribute to different types of complexity. In Chapter 3, the author focused on the current status of technologies aimed at improving design quality. First, after extracting key design quality themes through viii qualitative analysis, the author connected them with applicable BIM functions. Based on this result, a framework of five BIM-based key design processes was developed to show how BIM can be effectively utilized during the design phase. Lastly, the limitations of BIM in terms of design quality are examined in Chapter 4. In the course of a statistical analysis of whether leading indicators are or are not supported by BIM, the author determined that BIM is currently not capable of incorporating constructability, commissioning, and maintenance information during the design phase. This analysis also generated a table presenting the leading indicators not supported by BIM, along with their associated potential defects. These findings also helped the author formulate recommendations for future research to advance BIM use in design quality management. This dissertation fills a gap in the academic body of knowledge by providing a deeper understanding of design quality management on building construction projects. Specifically, through its investigation of the complexity involved in design problems and through its determination of the current capability of BIM to mitigate such design problems, this study has contributed valuable new knowledge on BIM use and design management. Further, by identifying the relationship between design quality and complexity, and by developing a framework and a table of valuable information on design defect leading indicators, this dissertation helps industry practitioners develop proactive strategies for effective defect prevention and design quality management on building projects.

Planar, integrated microscale sensors utilizing prism-coupler type angular interrogation sensing technique have been demonstrated. The main structure of the sensor consists of an optical prism coupled to a built-in waveguide to introduce Fraunhofer diffraction when light ray comes into the prism from the waveguide. The Fraunhofer diffraction creates spectrum of consecutive rays over the sensing edge of the prism such that there is no need for the bulky scanning mechanisms typically used in other macro scale sensing systems. Two types of sensors are presented: (1) total internal reflection based critical point detection (CPD) sensor, and (2) surface plasmon resonance (SPR) based resonance point detection (RPD) sensor.The CPD sensor is fabricated by a simple, two-mask process which creates a right angle prism with three sides with lengths of 1, 0.86, and 1.33 mm, respectively in the prototype design and a waveguide with a cross sectional area of 4~0.25 um2. The 0.25 um-thick core and the 2.5 um-thick cladding layers of the waveguide are made of silicon nitride and silicon dioxide, respectively. The CPD sensing technique measures the shift of the critical point of the total reflection as the results of change of refractive index due to biofouling. Optical simulations are used to validate the working principle and the calculated biofouling sensitivity is comparable to the other optical sensing methods. A baseline measurement has been conducted to verify the operation of the sensor with an error of less than ± 0.002 R.I.U. During a 9-hour biofouling measurement using milk as the media, a change in the refractive index as much as 0.0089 is recorded as the result of biofouling.The RPD sensing technique employs surface plasmon resonance as its sensing mechanism by measuring the shift of the resonance point with respect to the change of the incident angle. The design and fabrication process is similar to the fundamental structure of CPD sensors with an additional deposition of a thin metal layer on the sensing edge of the prism. The theoretical sensitivity is calculated as 90 deg RIU-1, which is comparable with the state-of-the-art optical sensors at 127 deg RIU-1. The refractive index measurement for selected liquids agrees with the values in the literature with an error range of less than ± 0.002 R.I.U. Furthermore, the refractive index change of biofouling formation is measured to be 0.0078 for a 9-hour experiment using milk as the testing media.

This study examined the prospects of Korean reunification. The study explores how the factors of integration affect North and South Korea after the country was divided into the two sides despite its millennium of unity. A sample of both North and South Korean newspapers covering a 47-year period of Korean reunificational efforts were analyzed as a major source of data to discover if there is any evidence of Korean national will to integrate among Koreans in the two countries. Content analysis is a major method of this research. The most obvious findings of this study are that the newspapers in North Korea did not show any significant change in their tones or attitudes throughout 47-year period studied. The North Korean regime which controls what is published in the papers is still fiercely ideological and hostile toward South Korea. The South Korean papers, on the other hand, showed marked changes in their tones and attitudes toward reunification during this period. Korean reunification remains a matter of time because the political development of South Korea, combined with remarkable economic progress, can surely heal the broken unity and national will among Koreans. The enormous financial burden to rebuild the North Korean economy which will fall upon South Koreans is a major challenge. The road to Korean reunification and the future of reunified Korea depend upon the willingness, wisdom, patience, freedom and courage of the South Koreans to assume the tremendous burden to rebuild North Korea and to strengthen diplomatic relations with the United States as well as neighboring countries to develop more positive inter-Korean relations based upon their cultural, social and economic contacts, cooperations and transactions between the two sides. If Koreans have such willingness, wisdom, patience and courage to accomplish their freedom and hope of unity, the divided Korean peninsula will be reunified and will become one nation again.