Auditory discrimination of extent of frequency modulation in vocal vibrato

조양호 University of Colorado - Boulder 1990 국내박사

Rationality and incrementality in decision processes : their relationships with environmental and organizational variables

현선해 University of Colorado, Boulder 1992 해외박사

Absolute strain measurement using fiber bragg gratings

이병하 University of Colorado-Boulder 1996 해외박사

Ge이 첨가된 광섬유의 core는 UV 파장의 빛과 반응하고 광 감응성이라고 불려지는 현상을 통하여 그 굴절률이 변한다. 광섬유를 따라 주기적으로 세기가 변하는 UV 빛을 광섬유에 조사하여 주면 core내에 같은 주기의 위상 격자가 형성된다. 광섬유 격자는 core를 통하여 도파되는 빛 중 Bragg 파장이라 불리는 특별 파장의 빛만 선택적으로 반사하는데 이 파장은 격자의 주기와 core의 유효 굴절률에 의하여 결정된다. 광섬유 격자의 파장 선택성은 광통신에 필요한 필터나 광분산 보정 용 소자를 만드는데 이용된다. 또한 이미 만들어진 광 섬유 격자의 Bragg파장은 외부에서 가해지는 압력, 온도, strain의 변화에 따라 변화되므로 이들의 센서로 사용된다. Core 굴절률의 변화는 조사되는 UV 빛의 세기와 조사량에 의하여 결정되는데 아직 충분한 이론적 해석이 이루어지지 않고 있다. 본 연구에서는 광섬유에 UV를 조사하면서 만들어지는 광섬유 격자의 시간에 따른 반사율의 변화와 Bragg 파장의 이동, 투과 spectrum의 선폭을 동시에 측정함으로써 UV에 의한 core 굴절률의 변화에 대한 실험식을 구하였다. 또한 이 결과를 이용하여 센서 응용에 적합한 광섬유 격자를 만들고 실제 strain 센서로서의 특성들을 조사하였다. 광섬유 격자를 센서로 이용할 때 그 유용성은 격자의 Bragg 파장을 얼마나 정확히 그리고 얼마나 효과적으로 만들 수 있는가에 따라 결정된다. 본 연구에서는 경제적이면서도 해상도가 좋은 센서 시스템을 만들기 위하여 센서 광섬유 격자와 짝을 이루는 또 하나의 광섬유 격자를 가변 필터로 사용하였다. 센서 격자에서 반사된 빛을 필터 격자에 통과 시키면 두 격자의 Bragg 파장이 일치하는 점에서 최대의 투과율을 갖는다. 필터 격자에 가해진 strain을 필터 격자를 통과한 빛의 세기와 연계시켜 closed-loop로 조절함으로써 두 격자의 Bragg 파장이 일치하도록 하고 그 값을 센서 양으로 하였다. 필터 격자에 가해지는 strain은 일반적으로 piezo를 이용하여 조절하는데 piezo는 비교적 큰 비 선형성과 히스테리시스를 가지므로 센서 값으로 사용하기엔 부적합하다. 본 연구에서는 필터 격자를 내재하고 있는 광섬유의 공명 주파수를 현-진동자의 특성을 이용하여 측정함으로써 센서 시스템의 해상도를 향상시켰다. 필터 광섬유 격자와 현-진동자를 이용하여 센서 광섬유 격자에 가해진 strain과 온도를 측정한 결과 strain은 1200με영역에서 0.4 % 이내의 선형성을 보였고 100 Hz 까지 측정이 가능하였다. 온도에 따른 Bragg 파장 변화는 9.6με/℃로 측정 되었다. 또한 준 정체 상태의 해상도는 0.05με과 0.005℃로 각각 측정 되었다.

Test cell experiment for the determination of building thermal system parameters

전홍석 University of Colorado, Boulder 1986 해외박사

건물 열성능시스템 소자의 결정을 위한 시험시설 실험연구를 수행하였다. 건 물 구조요소의 벡타합서(Building Element Vector Anaysis:BEVA)은 열손실계 수, 열저항효과, 실내온도변화, 태양열, 내부열 등을 포함하는 걸물열성능 시스템 소자를 이용한 시간별 분석방법이다. 건물열성능 시스템 소자는 주파수 도면에서의 실수와 허수로 표시되는 두벡타로 표시되며, 건물물성치와 벽체구조의 벡타합성으로 계산된다. 또다른 방법 은 단기측정 테이터로부터 역추정계산할 수 있다. 단기간의 측정테이타 수학 적인 방법으로 역추정하면 시스템소자를 결정하는 계수를 찾을 수 있으며, 이로부터 열성능시스템 소자의 산정이 가능해 진다. 실내실험은 정해진 주파수의 사이커브 열원을 소형시험시설에 공급하고, 그 반응을 측정하여 열성능 시스템 소자를 결정한다. 실외실험은 실내.실외온도와 태양의 일사량 효과를 제로주파수와 24시간 주기의 주파수대에서 측정한다. 실내실험결과 11.1%와 7.5% 범위이내에서 계산일치와 일치되었으며 역추정계 수를 이용한 실외실험결과 3.5%와 10.2%범위내에서 일치하였다. 계산과 실측을 병행하는 시험시설 실험연구를 통하여 건물소자 벡타합성과 건물열성능시스템소자를 이용한 방법이 검증되였으며, 이론과 실제의 정확한 �과가 입증되었다.

Modeling and optimization in slab-on-grade radiant heating floor systems

임병찬 University of Colorado - Boulder 2003 해외박사

Radiant floor panel heating systems have been widely used in several European and Asian countries. Recently, radiant systems have received renewed interest due to their inherent advantages compared to conventional heating systems including low-noise, potential energy savings, uniform temperature distribution within spaces, and superior thermal comfort. The systems may require lower energy use due to lower room setpoint temperature when compared to conventional forced air systems. Similar indoor comfort levels can be accomplished with 3 to 4 °C lower space temperatures. Nowadays, radiant heating systems have a wide range of applications including heating habitable buildings such as residences, office buildings, classrooms, and hospitals, as well as industrial facilities and warehouses. The work presented in this thesis focuses on the analysis of slab-on-grade building foundations and radiant floor heating systems with embedded hot water pipes. In addition, the thesis provides a comprehensive analysis of the thermal interaction between ground and building indoor environment through slab-on-grade floor. To properly modeling ground-coupled heat transfer, the analysis is based on the integration of a two-dimensional transient ground-coupled heat transfer model using implicit finite difference method (FDM) within a state-of-the-art whole building simulation program, EnergyPlus. In particular, the thermal performance of foundation for both conditioned and unconditioned residential buildings is analyzed under various slab insulation configurations including floating space temperatures, temperature distributions within ground, and total slab heat losses/gains. The developed numerical radiant floor model for hot water heating systems is validated against previously reported experimental data. Using the developed radiant floor model, parametric analyses are performed to determine the transient thermal performance of ground-coupled radiant floor heating systems with embedded hot water pipes. Several conventional control strategies are evaluated to operate radiant floor heating systems. Finally, optimal control strategies are developed to reduce heating energy comparing conventional control scheme to both maintain the thermal comfort level of the occupants and reduce heating energy cost.

A theory of incumbent disadvantage

강용순 University of Colorado, Boulder 1995 해외박사

이 논문은 기존의 선책이 사람의 정보처리 및 기억(information processing & memory process)을 통해 미래의 선호(preference sturcture)와 선택에 어 떠한 영향을 미치는가를 연구한 것이다. 이 글에서 현직(incumbent)이라 함은 어떤 개인이 자의든 타의든, 다른 대안들이 배제된 상태에서 현재 소유 혹은 소속하고 있는 객체를 말하며, 그 예로서는 승용차 등 내구성 소비재, 선출적 공직자, 배우자, 직업, 주택, 주거지, 신체조건 등을 들 수 있다. 앞의 예에 서 보듯이 현직의 범주에는 사람들이 평소에 다소 중요하게 생각하고 (high- involvement), 일단 결정되면 한동안 바꾸기 힘든(long-term commitment) 그 래서 선책의 위험이 따르는(high-risk) 대상들이 주로 포함된다. 기존의 사회과학이론들은 다양한 이론적 근거를 들어 현직자(혹은 소비자가 현재 사용하고 있는 브랜드)가 여타 대안들에 비해 차기선택시 월등히 유리 (有利)함을 주장해왔다. (널리알려진 현직유리론으로는 Festinger 1957, Bem 1967, Stigler & Becker 1977, Carpenter & Nakamoto 1989 등을 꼽을 수 있 다. )그러나 이 논문에서는 실제의 사회현상과 소비현상들이 현직유리론 만으 로 잘 설명되지 않음을 인식 (예: 자동차교체, 이혼, 현직자낙선 등), 여타 조건이 동일할 경우에도 현직이 불리할 수 있는 과정은 과연 어떠한 것인가를 모색해 보았다. 그 결과 이 논문에서는 기존의 현직유리론들을 보완하는 새로 운 이론으로 현직불리론을 주장, 그 이론적 체계를 구축하고, 이론의 적용한 계를 설정하였으며, 그 가설들을 실증적, 계량적 분석을 통해 검증하였다. 위의 가설을 검증하기 위해 세 가지의 실증적 연구가 실시되었다. 그 첫번 째로는 42명이 3주간 5회에 걸쳐 참가한 실험실 실험으로, 위 가설의 기본적 주장들에 대한 실증적 증거들을 제시하였고, 둘째로는 82명이 2회에 걸쳐 참 가한 추가적 실험을 통해 첫번째 실험 결과를 보다 현실적인 상황에서 재차 확인하였으며(replication) 특히 컴퓨터를 이용한 응답반응속도(reaction time)측정을 통해서는 기억구조(memory accessibility)에 관한 가설을 뒷받침 하는 증거를 확보하였다. 세번째로는 300명의 자동차 소유주와의 전화 인터뷰 를 통해 수집한 자료를 분석 현직불리론이 실험실에서 뿐만 아니라 실제 사회 에서의 현상도 적절히 예측 설명할 수 있음을 보여 주었다. A dynamic theory of attitude change is proposed. The theory captures regularities over time in attitude change toward high-involvement, multiattribute objects which can be thought of as "incumbents," such as automobiles, houses, spouses, or presidents. The theory posits that individuals repeatedly cornpare and contrast their incumbents Mth altematives on an attribute-by-attribute basis. In such repeated comparisons, the incumbent's relatively superior attributes are perceived as gains, whereas its inferior attributes are felt as losses. Because human beings are more sensitive to negative information than to positive information, and because losses are more paintfu1 than gains, over time, the importance (i.e., memory accessibility) of the attribute dimensions on which the incumbent is inferior, relative to altematives, tends to increase. As a result of the increasing importance of an incumbent's weaknesses, the relative importance of its superior dimensions can also decrease. This change in attribute importance will be disadvantageous to the incumbent in the next election or the next purchase occasion, other things being equaI. This hypothesis explains attitude changes (and the evolution of tastes) over time for which existing theories, including cognitive dissonance theory, may not account adeqmteIy. Three empirical studies, including two laboratory experiments and one field study, were conducted to test the hypotheses. In the first experiment which was conducted in five sessions and lasted three weeks, the fundamental premise of the proposed theory was tested using different types of gambles as stimuli.The second experiment used copy machines as stimuli and focused on the internaI, cognitive mechanisms of the proposed theory. Finally, the third study (interviews with 300 automobiIe owners) documented some real world evidence. 0verall, the empirical evidence supports the proposed theory.

The Wounds of the Wild West: Analysis of the Online Debate about Guns at the Local and National Level

Sindorf, Shannon University of Colorado at Boulder 2014 해외박사(DDOD)

Informal talk between citizens could be considered the glue that holds a deliberative democracy together. In everyday political talk, opinions are formed, formal institutions are criticized so they can be improved, and social change is initiated and advanced. But even informal conversation can be difficult or unproductive when the issue being discussed is heated or controversial, such as debates over gun rights and gun control. National debates over gun issues increased after the elementary school shooting in 2012 in Newtown, Connecticut, and residents of Colorado recalled lingering emotional wounds acquired after the 1999 Columbine school shooting in the suburbs of Denver, Colorado and the 2012 theater shooting in Aurora, Colorado. Colorado has been the site of multiple mass shootings in recent decades, and most Coloradans have historically ascribed to a libertarian philosophy that favors individual gun rights over gun control. The tensions between these two facts make Colorado an intriguing case study in the gun debate. This project was designed to examine online discussion of the gun debate to determine if and which elements of deliberation this discussion contained, whether the amount of those elements of deliberation differed whether discussion happened on a local or national level, and how discussion participants were using and framing expertise. This study employs both content analysis and textual analysis of comments on gun issues in the online comments forums of three Colorado newspapers from July 1, 2012 to June 30, 2013. Though commenting did not amount to actual deliberation, some elements of deliberation, such as respect and the discussion of solutions to problems, were present more often when commenters were discussing issues on a local rather than a national level. Commenters rejected the legitimacy of experts in favor of technological populism, and the only form of expertise pro-gun-rights commenters considered relevant to the debate was personal knowledge and experience with firearms. Wild West mythology informed the gun debate in Colorado, as many commenters tied guns to a Western American Monomythic fantasy, while others insisted that lingering Wild West fantasies were hindering a rational, contemporary conversation about guns.

I'm White? Understanding one's racial identity

Henderson, John Patrick University of Colorado at Boulder 2005 해외박사(DDOD)

The following ethnographic study is about the Leadership Project (LP)---a residential academic program at a large, public university---and the experiences of students and staff who participated in it during the 2003/2004 academic year. This study examined whether or not and to what degree the LP and/or the university encouraged a shift in White racial consciousness during the students' first year at Mountain State University. It is important to note that it was not the expressed purpose of the LP to promote racial consciousness. Rather, the LP at times during the year provided White participants with opportunities to better understand their racial identity. The findings suggest that the LP, more so than the university, challenged White students to shift, from one place to another, along Freire's (1973) stages of social consciousness. Unlike the university, which tended to reproduce (Bourdieu & Passeron, 1990) and reinforce existing structures of racial inequality by not confronting White students about their racial privilege, the LP provided opportunities for first-year White students to become aware of their racial privilege and devise strategies to deconstruct it. This study brings to light the enormous challenges university students and staff face when choosing to confront White privilege. At the same time, it also provides examples of transformation that can add to the existing literature on promoting racial awareness among White students. The study provides empirical research on the impact that academic and social contexts have on promoting or hindering a shift in White racial awareness. It demonstrates the importance of providing numerous opportunities for students and staff to have critical interactions that promote understanding of race and other ascribed identity characteristics.

An evaluation of Colorado's enterprise zone program

Lynch, Devon P University of Colorado at Boulder 2005 해외박사(DDOD)

Since the early 1980s, most states have implemented enterprise zone programs. This thesis examines the impact of Colorado's Enterprise Zone Program with the aim to determine whether or not it is achieving its intended goal of alleviating the economic blight present in the enterprise zone areas. Chapter one examines the impact of the Colorado enterprise zone program on employment and payroll per worker for 73,008 establishments, controlling for establishment and county characteristics. Tobits reveal that enterprise zone designation has positive effects on employment and earnings. Perhaps surprisingly, these effects occur only in rural areas. Consistent with previous research, enterprise zones appear to have no impact in the manufacturing industry. Moreover, the only significant effect observed in urban areas is a negative impact in the Denver County enterprise zone. This is of interest since the urban areas contain most of the target populations. Chapter two looks at the combined effects of agglomeration economies and the enterprise zone program on the birth, death and net birth of establishments as well as their respective levels of employment and payroll. Close examination reveals that Colorado's Enterprise Zone Program (EZP) has no significant impact on the birth, death or net births of establishment as well as their respective levels of employment and payroll. However, the evidence indicates that the concentration of establishments in the same industry is important to the birth, death and net birth of establishments as well as their level of employment. Consequently, the conclusion is that agglomeration economies have no effect on the payroll of establishments. Chapter three examines the welfare effects of the enterprise zone program for the residents of these areas. The evidence suggests that the program is not achieving the desired effect of reducing the economic blight in the zone areas. Statistically, the program has no significant effect on the rate of poverty or per capita income for the residents of the zones relative to those living in similar non-zone areas. However, the only significant effect observed for the unemployment rate is a positive effect for the urban zones; that is, the unemployment rate is higher in urban zones relative to similar non-zones.

The challenges of creating a professional model of teaching: Case studies of four Colorado charter schools

Boettiger, Brigitte University of Colorado at Boulder 2001 해외박사(DDOD)

One of the purposes of charter school policy is to enhance teacher professionalism, yet initial research on charter schools presents conflicting findings on the issue. One of the goals of Colorado's legislation is to provide teachers with “new professional opportunities” and “responsibility for the learning program at a school site” (Senate Bill 93-183, p.2). Yet, there are many inherent contradictions in Colorado's legislation concerning the roles and responsibilities of teachers and little is known about how the policy is playing out. This research project investigates the issue through a comparative case study of four Colorado charter schools. Using qualitative methods, such as document analysis, focused observations, and semi-structured interviews with teachers, parents, and administrators, this study identifies the kinds of professional opportunities available to teachers in charter schools and determines whether a school is more bureaucratic or professional in its model of teaching. Different organizational arrangements, such as group initiating, governance structure, and curricular focus, are analyzed for how they influence the professional control of teachers at the four charter schools. Lastly, specific attributes of a professional model of teaching are also analyzed for their influence on one another. Some of these attributes include decision making, teacher collaboration and talk, opportunities for leadership, and workplace environment. Findings indicate that some Colorado charter schools do provide teachers with a variety of professional opportunities and more closely approximate a professional model of teaching. At these charter schools teachers have extensive professional control and decision making authority and regularly scheduled times for teacher collaboration. They can focus their talk on issues related to student learning and view their workplace as a respectful and supportive place. However, not all charter schools exhibit these characteristics to the same extent. There is a complex interplay between who was involved in developing a charter school, whether or not there are multiple teachers on a school's governing board, opportunities for teacher collaboration, and the flexibility of a school's governance structure. These variables influence the level of professional control afforded teachers, which, in turn, affects how well teachers can take responsibility for the learning program at a school site.