Discourse Functions of the Present Perfect Tense in the English Expository Texts of the CSAT

서영상 부산대학교 대학원 2023 국내석사

This study examined the discourse functions of the present perfect in the English expository texts of the CSAT for the past ten years (2013-2022). It investigated the present perfect in the original texts of the CSAT passages considering three elements: the location, the meaning, and the role of the present perfect in the original text. Through this analysis, this research identified seven discourse functions of the present perfect in the CSAT texts, which were topic introduction, topic transition, topic closing, providing background information, explanation of details, marking an off-the-sequence event, and inquiry about readers’ knowledge. This study also investigated the differences between the discourse functions of the present perfect and those of the preterite at the context level. In order to find the differences, it analyzed the discourse functions of the preterite in the same way it analyzed the present perfect, and then contrasted the discourse functions of the two verb forms in the texts where they occurred together. Through this process, this research found two differences: (1) When the present perfect and the preterite occur together in the same text, the present perfect introduces a topic and the preterite elaborates on the topic. (2) When introducing a topic, the present perfect delivers a general topic, whereas the preterite conveys a general or specific topic. Lastly, this study also examined the differences between the discourse functions of the present perfect in the original texts and those in the CSAT texts, and found three categories of the differences. They were the changes (1) from topic transition to topic introduction, (2) from topic closing to providing background information, and (3) from explanation of details to providing background information. This result shows that when the present perfect is disconnected from previous informative sentences, it might result in having different discourse functions. I hope that this study will help English learners to enhance the understanding of the present perfect and alleviate the confusion caused by the differences of the present perfect and the preterite.

Additional cysteine as a controller of enzymatic dual functions of 2-Cys peroxiredoxin

안병철 Graduate School, Korea University 2010 국내박사

이 논문의 주 목적은 크게 세가지로 나누어진다. 첫째, Pseudomonas putida KT2440 와 Pseudomonas aeruginosa PAO1에서 이전에 알려지지 않은 새로운 2-Cys peroxiredoxin(Prx)들을 분리 동정하는 것이다. 일반적으로 알려진 2-Cys Prx는 이중 효소활성(dual function)을 가지는 것으로 알려져 있고, 이중 효소활성은 퍼옥시다제(peroxidase)와 분자 샤페론(molecular chaperone)으로 알려져 있다. 따라서, Pseudomonad에서 분리 동정된 두 단백질이 앞서 언급한 이중 효소활성을 가지는 새로운 2-Cys Prx 임을 확인하였다. 둘째, 이들의 상동성을 바탕으로 잉여 시스테인(additional cysteine)이 2-Cys Prx의 이중 효소활성에 주는 영향과 구조적 변화에 어떠한 영향을 주는지를 점 돌연변이(site-directed mutagenesis) 방법을 이용하여 잉여 시스테인의 기능을 밝히고 스트레스에 대한 2-Cys Prx의 최적 효소활성과 구조를 제시하는 것이다. 셋째, 앞서 언급한 잉여 시스테인에 의한 2-Cys Prx의 구조적 효소활성적 변화를 바탕으로 2-Cys Prx의 다양한 위치에 점 돌연변이 방법을 이용하여 잉여 시스테인을 삽입하고, 결과적으로 높은 이중 효소활성을 동시에 가지는 슈퍼-Prx를 만드는 방법을 제시하는 것이다. 모든 생물 종의 2-Cys Prx들은 단백질 구조적으로 유사성을 보인다. 티올(Thiol)을 바탕으로 하는 대부분의 2-Cys Prx 단백질들은 외부환경에 의존적인 올리고머(oligomeric) 구조를 형성 하는것으로 알려져 있지만, 아직 박테리아에서는 2-Cys Prx 단백질의 결합 또는 분리의 생리학적인 기작은 불분명하다. 본 연구를 통해 Psudomonad로부터 이황화결합(disulfide bond)을 가지는 단백질들만을 선택적으로 분리 동정하였다. 이들 중, 이황화결합을 가지며, 아미노산 서열이 다른 종의 Prx 단백질과 상동성(homology)을 가지는 PpPrx(PP1084)과 PaPrx(PA3529)을 선별하였고, 특히 이들 두 Prx 단백질간의 아미노산 서열 상동성은 89%로 높게 나타났다. 또한, PpPrx와 PaPrx 단백질의 이중효소활성을 측정하여 두 Prx 단백질이 이중효소활성을 가지는 새로운 Prx 단백질들임을 확인 하였다. 하지만, PpPrx 단백질은 효소적 특징으로 높은 분자 샤페론 활성과 낮은 퍼옥시다제 활성을 나타내며, 반대로, PaPrx 단백질은 낮은 분자 샤페론 활성과 높은 퍼옥시다제 활성을 확인 하였다. 또한, 구조적 특징을로 PpPrx 단백질은 다량의 고분자와 소량의 저분자 구조를 형성하며, 반대로, PaPrx 단백질은 소량의 고분자와 다량의 저분자 구조를 형성하였다. 이와 같은 높은 상동성에도 반대되는 효소적, 구조적 특징의 차이는 잉여 시스테인에 의한 것으로 점 돌연변이 방법을 이용한 잉여 시스테인 삽입으로 잉여 시스테인이 2-Cys Prx 단백질에 있어서 그 효소적 기능과 구조의 전환을 조절하는 중요한 요소임을 확인 하였다. 따라서, 본 연구를 통해 확인된 잉여 시스테인의 조절 기능을 네가지로 구분하여 정리하였다. 첫째, Pseudomonad의 2-Cys Prx 단백질들의 고분자 올리고머화(oligomerization)는 산화-환원 반응에 민감하며, 잉여 시스테인의 산화는 저분자 올리고머들 간의 결합을 강력하게 촉진하고, 이는 2-Cys Prx의 고분자 복합체 구조형성에 중요한 역할을 한다. 둘째, 본 연구에서 잉여 시스테인의 존재 유무에 따라 2-Cys Prx 단백질의 고분자 올리고머 구조형성과 효소활성에 있어서 어떤 영향을 주는지에 대한 명확한 정보를 제공한다. Pseudomonad의 2-Cys Prx 단백질인 WT-PpPrx와 WT-PaPrx의 구조를 비교하면, 잉여 시스테인을 가지고 있는 WT-PpPrx는 다량의 고분자와 소량의 저분자를 형성하며, 반대로 잉여 시스테인이 없는 WT-PaPrx는 소량의 고분자와 다량의 저분자를 형성하게 되는데, 올리고머화를 위한 분자상의 전환에있어 잉여 시스테인의 중요성이 나타난다. 셋째, 본 논문에서 2-Cys Prx에 있어서 잉여 시스테인이 구조적, 기능적 전환에 매우 중요한 요소임을 확인하기 위해 각각의 대조구와 잉여 시스테인이 삽입 또는 제거된 잉여 시스테인 돌연변이체들의 효소기능과 그 구조를 비교 분석을 통하여, 잉여 시스테인의 유무에 따라 효소적, 구조적 경향이 반대로 나타남을 밝혔다. 이러한 사실을 바탕으로, Prx 단백질들은 과산화수소 (H2O2)를 제거하기 위한 퍼옥시다제로 작용하기 위해서 어떻게 저분자 구조로 전환될 수 있는지를 설명할 수 있는 포괄적인 분리(dissociation) 모델을 만들 수 있다. 위의 모델을 이용하여, Pseudomonad의 2-Cys Prx 단백질인 WT-PpPrx와 WT-PaPrx가 퍼옥시다제와 분자 샤페론 활성이라는 이중 효소기능을 어떻게 나타낼 수 있는지를 설명한다. 또한, 이 포괄적인 모델은 2-Cys Prx 단백질들이 고분자에서 저분자로 또는 저분자에서 고분자 구조로 전환이 가능함을 보여준다. 낮은 농도의 활성산소종이 생성되는 일반적인 환경의 Pseudomonad 세포 내에서 두 2-Cys Prx 단백질들은 다수의 고분자와 일부의 저분자 구조를 형성하고 있다. 이러한 두 종류의 구조적 양상으로 존재하는 2-Cys Prx 단백질은 낮은 농도의 활성산소종 제거와 활성산소종에 의한 단백질 변성으로부터 단백질 보호를 위한 퍼옥시다제와 분자 샤페론의 이중 효소활성을 가지고 있다. 그러나, 강한 산화 스트레스 환경에서, Prx 단백질은 고분자 복합체 구조에서 티오레독신(Trx)-티오레독신 리덕타제(TR) 또는 글루타치온(GSH) -글루타치온 리덕타제(GR) 시스템을 이용하여 급격하게 저분자 구조로 바뀌게 된다. 또한, 다른 종의 Prx 단백질들과 WT-PaPrx의 일반적인 구조적인 변화 기작을 고려하면, Prx 단백질의 고분자에서 저분자로의 구조변화는 세포 내의 H2O2를 제거하기 위해 일어 나며, Pseudomonad의 Prx 단백질에 있어서는 퍼옥시다제의 기능을 활성화 시킨다. 그러나, WT-PpPrx 단백질의 올리고머화되는 구조적인 변화는 저분자 형태의 WT-PpPrx 단백질들 사이에 매우 능률적인 결합자로 작동하는 잉여 시스테인인 Cys112의 존재 때문에 가능하다. 이러한, WT-PpPrx 단백질의 구조적인 변화는 퍼옥시다제에서 분자 샤페론 기능으로의 상호 전환과 연관된다. 넷째, 2-Cys Prx는 구조적 특징에 따라 2-Cys Prx의 이중 효소활성에서 저분자일때 퍼옥시다제 그리고 고분자일때 분자 샤페론의 활성이 강하게 나타난다. 따라서, 앞서 언급한 잉여 시스테인에 의한 2-Cys Prx의 효소적, 구조적 변화를 바탕으로 PpPrx의 다양한 위치에 점 돌연변이 방법을 이용하여 잉여 시스테인을 삽입하였고, 이렇게 제작된 다양한 잉여 시스테인 돌연변이체와 WT-PpPrx의 효소적, 구조적 특징을 비교 분석하였다. 결과적으로, 잉여 시스테인 삽입에 의해 높은 이중 효소활성을 동시에 가지는 슈퍼 Prx를 성공적으로 개발하였다. 본 논문의 결론을 내리면, 산화 스트레스 환경에서 잉여 시스테인인 Cys112에 의존적인 조절과 독립적인 조절에 의해 Prx 단백질의 구조적 결합과 분리가 조절된다는 것을 밝혔다. 그리고, 이 모델은 WT-PpPrx 단백질이 어떠한 이유로 WT-PaPrx 단백질 보다 열에 의한 MDH(malic dehydrogenase)의 변성에 대해 월등히 높은 저해 활성을 나타낼 수 있는지 설명할 수 있다. 이 논문의 가장 중요한 결과는 2-Cys Prx 단백질에 있어서 잉여 시스테인이 효소적, 구조적 변화의 핵심 조절인자(regulator)임을 최초로 밝혔다. 그 조절 기작을 설명 설명 할 수 있다. 또한, 다양한 위치에 잉여 시스테인을 삽입하여 이중 효소활성이 동시에 높은 슈퍼 Prx 돌연변이체를 개발하였다. The main objectives of this thesis are divided into three topics. First, the isolation and characterization of novel peroxiredoxin-like proteins from the Pseudomonas putida KT2440 and Pseudomonas aeruginosa PAO1 are a purpose of this thesis. Generally, 2-cysteine peroxiredoxin (2-Cys Prx) display diversity in structure and apparent molecular weight (MW), and can act alternatively as a peroxidase and molecular chaperone. This study has shown that the isolated two proteins (PpPrx and PaPrx as known as PP1084 and PA3529) were typical 2-Cys Prx with dual function as peroxidase and molecular chaperone activities. Second, the comparison of the available 2-Cys Prx structures between wild type (WT)-Prxs and their additional cysteine mutant type (MT)-Prxs, provided the importance of the additional cysteine and led to the identification of the molecular switch responsible for the oligomerization using site-directed mutagenesis. Furthermore, this study has suggested that the optimal enzymatic activity and the structure of 2-Cys Prx against stress. Thrid, this study previously provided that the enzymatic switch of 2-Cys Prx was closely related to their structure changes. To isolate variants with improved enzymatic dual functions, additional cysteine was inserted at various positions (Cys31, Cys112 and Cys192) of Prx protein by site-directed mutagenesis. Consequently, this study suggested that the best position of additional cysteine for super Prx with optimized dual functions. Thiol-based peroxiredoxins (Prxs) are conserved throughout all kingdoms. Most 2-Cys Prxs have been found to form condition-dependent oligomeric structures, although the physiological relevance of the association or dissociation of these proteins has been unclear in bacteria. This study isolated several disulfide bond proteins (DSBPs) involved in the oxidative stress response in Pseudomonads. Among of isolated DSBPs, PpPrx and PaPrx proteins were seleted as candidates, because these proteins contained disulfide bond and shown highly conserved homology with Prx of other organisms. Interestingly, when amino acid sequences of two Prxs were aligned, these proteins exhibited 93% homology in their amino acid sequences. In addition, two Prxs exhibited dual functions as a peroxidase and a molecular chaperone. When dual functions and structural compositions of two Prxs were compared, the high chaperone activity and high molecular weight (HMW) complexes predominated in PpPrx and the high peroxidase activity and low molecular weight (LMW) forms predominated in PaPrx. In contrast, the low peroxidase activity and few LMW forms exhibited in PpPrx and the low chaperone activity and few HMW complexes exhibited in PaPrx. This study was thus able to explain why WT-PpPrx and WT-PaPrx can have completely different functions as either a peroxidase or a chaperone using site-directed mutagenesis, although they exhibited high amino acid sequence homology. Conseqently, this study reports evidence that additional cysteine as a regulatory factor involved in the structural and functional switching of 2-Cys Prx. Initially, this study has suggested four regulation functions of additional cysteine relating to the functional switch in Prx proteins. Firstly, the oligomerization of the Pseudomonad Prxs is primarily redox sensitive, with the additional cysteine residue strongly favoring formation of high molecular weight (HMW) structures, while the oxidation of the additional cysteine promotes the formation of lower order oligomers. Secondly, this study has provided an explanation for the influence of the additional cysteine against the oligomeric structure formation and its enzymatic activity. The comparison of the available 2-Cys Prx structures between WT-PpPrx and WT-PaPrx, revealed the importance of the additional cysteine and led to the identification of the molecular switch responsible for the oligomerization. Thirdly, this study has shown that the additional cysteine is a critical factor in the structural and functional switching. The additional and exclusion cysteine mutants showed opposite tendencies in structural and functional switching, compared to their wild-type homologs. These observations allowed me to formulate a comprehensive dissociation model to explain how Prxs are converted into monomeric structures in order to act as peroxidases against hydrogen peroxide (H2O2). This study was thus able to explain why WT-PpPrx and WT-PaPrx can have completely different functions as either a peroxidase or a chaperone. This model shows that Prxs can alter their protein structures reversibly between HMW complexes and low molecular weight (LMW) species. At low reactive oxygen species (ROS) concentrations, Prxs form mainly LMW and oligomeric protein structures in vivo. Prxs, existing in these two states, possess the dual activities required to remove low levels of ROS and protect proteins from the denaturation. However, under the severe oxidative stress condition, Prxs rapidly undergo structural changes and the HMW complexes are converted into LMW forms with the help of the thioredoxin (Trx)-thioredoxin reductase (TR) or glutathione (GSH)-glutathione reductase (GR) systems. In considering the general structural change mechanism of other Prxs and of WT-PaPrx, the dissociation of the HMW complexes into LMW species occurs to remove H2O2. This structural change turns on the peroxidase function of Prx. However, the oligomeric structural change of WT-PpPrx is due to the presence of Cys112, which acts as a highly efficient combiner among WT-PpPrx proteins. The structural change is associated with a peroxidase-to-chaperone functional switch. Finally, 2-Cys Prx revealed that the enzymatic switch was closely related to their structure changes. 2-Cys Prx exhibited high chaperone activity in HMW complexes, whereas high peroxidase shown in LMW forms. Previously, this study provided evidences that how the additional cysteine could regulate the structural and functional switch of 2-Cys Prx. Thus, to isolate additional cysteine mutant with improvided enzymatic dual functions, additional cysteine was inserted at vrious positions (Cys31, Cys112 and Cys192) of PpPrx protein by site-directed mutagenesis. The comparison of the available structure composition and enzymatic dual functions performed between WT-PpPrx and additional cysteine mutants. Consequently, this study isolated super PpPrx with optimized dual functions and suggested best position of additional cysteine. In conclusion, this study has announced that the association/dissociation of the Prx was regulated by the Cys112-depedent and Cys112-independent mechanisms under oxidative stress. This model may help to explain why Pseudomonad WT-PpPrx has a much greater inhibitory effect on the denaturation of malic dehydrogenase (MDH) than does WT-PaPrx, even under the heat shock conditions. These evidences with respect to Cys112 support the notion that the additional cysteine acts as a controller of enzymatic dual functions of 2-Cys Prx.

Communicative Functions and Argument Structure Constructions in Korean Middle School Students’ English Speaking Interaction

최정윤 서울대학교 대학원 2015 국내석사

This study explored Korean middle school students’ use of communicative functions and argument structure constructions (ASCs) in English speaking interactions. A total of 25 eight graders participated in this study. They carried out five pairs of tasks in Korean and in English. After the students’ oral production was recorded and transcribed, the corpus data were coded in terms of types of utterances, communicative functions and English ASCs. First, all utterances were classified into either fragmental or non-fragmental utterances. Second, they were also categorized by communicative functions provided in the Seventh National Curriculum. Third, the L2 non-fragmental utterances were further analyzed by types of ASCs. The results provided significant findings related to the gap between the use of communicative functions in L1 and L2 interactions and to the use of ASCs in L2 interactions. First, the most frequently occurring function in the L1 interactions was the sharing of information, while the function of expressing emotion appeared most frequently in the L2 interactions. The comparison between the L1 and L2 interactions revealed that the function of sharing information decreased the most dramatically both in the fragmental and non-fragmental utterances. That is, students expressed their communicative intents related to sharing information significantly less frequently in L2 than in L1. Second, as to the use of English ASCs, the students relied on limited types of ASCs, and simple transitive [V+NP] was the most frequently used. The number of English ASC types, however, formed a statistically positive correlation with the number of utterances in a sentential syntactic structure. Lastly, the function in which the most various types of English ASCs were employed was the sharing of information. With regard to these findings, the study concluded with some pedagogical implications and suggestions for future studies.

Topics in the singularities of plurisubharmonic functions

안종봉 서울대학교 대학원 2021 국내박사

Plurisubharmonic functions are fundamental objects in complex analysis with many applications in complex geometry and even in algebraic geometry.Their singularities can be extremely complicated : some of the most important tools one can use to study the singularities include multiplier ideals and approximation theorems.In the first part, based on joint work with Hoseob Seo, we study problems on equisingular approximation. Recently Guan gave a criterion for the existence of decreasing equisingular approximations with analytic singularities, in the case of diagonal type plurisubharmonic functions. We generalize a weaker version of this to arbitrary toric plurisubharmonic functions.In the second part, we study plurisubharmonic singularities on singular varieties. Our main result in this part is a generalization of the Rashkovskii-Guenancia theorem on multiplier ideals of toric plurisubharmonic functions to the normal Q-Gorenstein case. This also generalizes an algebraic result of Blickle to analytic multiplier ideals. 다중조화버금함수는 복소해석학 뿐 아니라 복소기하학, 나아가 대수기하학에서 중요한 연구 대상입니다. 다중조화버금함수의 특이점들은 굉장히 복잡하고 어렵고 직접적인 관찰 대신 이를 연구하기 위한 도구로 승수 아이디얼과 근사 정리를 이용하곤합니다. 첫번째 결과로 서울대학교 수학연구소 소속인 서호섭 박사후 연구원과 equisingular 근사 정리에 대해서 소개하려고 합니다. 최근에 Qi’an Guan에 의해 발표된 해석적 특이점을 갖는 decreasing, equisingular 근사 정리라는 주제를 다중조화버금함수가 toric일 때 부분적으로 일반화할 수 있음을 설명합니다. 두번째 결과는 특이 다양체 위에서의 다중조화버금함수입니다. 기존의 다양체에서와 달리 특이 다양체에서 다중조화버금함수 및 승수 아이디얼이 어떻게 정의되는지 소개합니다. 또한 주요 결과로서, toric 다중조화버금함수의 경우, 승수 아이디얼을 계산하는데 주요 공식 중 하나인 Rashkovskii-Guenancia의 일반화를 제시합니다. 이 결과는 Blickle의 대수적 승수 아이디얼 공식을 해석적으로 일반화한 것이기도 합니다.

Development of a Usefulness Evaluation Model for Smartphone Application Functions

박주환 포항공과대학교 일반대학원 2018 국내박사

Smartphones are becoming a necessity for modern people's lives, and the use of smartphone applications (Apps) is rapidly increasing. Many companies are entering the App market to generate revenue. In smartphone Apps, various functions are implemented to improvethe user experience. However, no research has explained how the function of an App provides usefulness to users, and what criteria the users use to evaluate the usefulness of individual functions. To provide a useful smartphone function, user, a developer must understand the usefulness that it provides. However, App developers do not have systematic ways to understand and improve the level of usefulness of individual functions that make up their App. The purpose of this study is to explain what factors determine the usefulness of each function that composes the App. This study defined Usefulness Factors of the functions of App and validated a model that explains relationships between the Usefulness Factors and usefulness of the functions. The study defined a Usefulness criterion that considers the Value of, Need for and Quality of the provided function. These three elements were also explained by referring to nine Usefulness Factors that were found in the literature. The proposed model was verified by experimentation. First, the study identified and classify the factors of the usefulness of each of the functions that constitute the App, rather than the App itself. The factors that affect usefulness were collected from the literature; nine factors that affect Usefulness, Value, Needs, and Quality were identified. Second, the relationships of the nine Usefulness Factors to the usefulness of function were expressed as structural models. A Full Usefulness Model was proposed; it includes eight Usefulness Factors, plus Value, Need, and Quality. A Reduced Usefulness Model was proposed; it includes three Usefulness Factors, plus Value, Need, and Quality. Third, the study proposed an evaluation tool to quantify the usefulness of individual functions and the related Usefulness Factors. Based on the two proposed usefulness models, two questionnaires were developed. The questionnaire for the Full Usefulness Model consists of 31 questions to evaluate how that the user feels about nine Usefulness Factors, plus Value, Needs, Quality, and Usefulness. The questionnaire for the Reduced Usefulness Model consists of 7 questions when evaluating functions individually. Fourth, the proposed factors and models were verified in experiments on 36 subjects. Usefulness and other factors were evaluated for 18 functions that were derived from three Apps. Thirty-three questionnaire items were used for the evaluation. Based on the data collected in the experiments, the significances of individual paths were examined by confirmatory factor analysis using partial least squares structural equation modeling (PLS-SEM). This process verified the validity of the two models that explain usefulness. It is expected that the Usefulness Factors and models that are proposed in this study will help researchers who study the usefulness of App functions. The proposed usefulness-evaluation tools could help App developers to quantify the usefulness of their Apps’ functions, then identify the cause of the lack of the usefulness, and use this knowledge to improve them.

EXPERIMENTAL EMBEDDED SENSITIVITY FUNCTIONS FOR USE IN MECHANICAL SYSTEM IDENTIFICATION

양철호 Purdue University 2004 해외박사

In applications involving manufactured mechanical vibrating systems such as vehicle components and systems, an experimental technique for determining the forced response sensitivity to changes in mass, damping or stiffness parameters is needed. In order to distinguish physical changes in the system from nonlinear input-output distortion, an experimental sensitivity technique for identifying nonlinear input-output models in mechanical systems is also needed. An experimental sensitivity method for analyzing forced vibration data is developed and applied in this research. It is shown that if a subset of measured mechanical system input-output functions is available in vibrating systems, an appropriate analytical linear parameterization of these functions leads to algebraic relationships between the measured data in the form of so-called ‘embedded sensitivity functions.’ These functions are solely a function of experimental frequency response function data and determine the linear forced response sensitivity to physical perturbations in the system mechanical properties. Applications in three key areas of mechanical dynamic systems are examined to verify and further study the requirements of the embedded sensitivity function approach in experimental sensitivity analysis. First, the embedded sensitivity approach is used to examine the ‘forward problem’ of identifying optimal design modifications for reducing linear vibration resonance problems. Second, embedded sensitivity functions are applied to characterize nonlinear mechanical systems and identify nonlinear input-output models for those systems. Using embedded sensitivity analysis, frequency response functions are measured at multiple input amplitudes and combined to extract spectral patterns for characterizing stiffness and damping nonlinearities. Expressions for estimating nonlinear parameters are derived using Taylor series expansions of frequency response functions. Third, embedded sensitivity functions are applied to examine the ‘inverse problem’ of identifying structural perturbations, which might occur at various stages throughout the development and operation of mechanical systems. By comparing the embedded sensitivity functions with finite difference functions using baseline and modified frequency response functions, perturbations are shown to be properly detected, located and quantified in theory and practice assuming that structures of interest are only perturbed in one location. Demonstrations on the bench top system and exhaust system indicate that the technique is most effective for identifying perturbations when certain frequency ranges in the data are analyzed to avoid low signal-to-noise ratios and distortions in the resulting estimated stiffness reductions.

SOME ENUMERATION PROBLEMS FOR CRYPTOGRAPHIC BOOLEAN FUNCTIONS

천윤환 State University of New York at Buffalo 2006 해외박사

이 논문은 균형된 불 함수(Balanced Boolean functions)의 갯수의 계산과 SAC(n-1) 함수의 갯수의 계산을 내용으로 하고 있다. 안전한 암호에 사용하는 여러가지 특성 중 SAC(Strict Avalanche Criterion), 균형성(Balancedness), 상관면역성(Correlation- Immune) 등은 암호학에서 특별히 중요한 위치를 차지하고 있다. 이러한 특성을 지닌 함수들을 발견하고 설계하는 것은 암호학에서 중요한 사항이다. 따라서 이 논문에서는 이러한 특성을 만족하는 함수의 갯수를 계산하였다. 논문의 첫 번째 부분은 균형된 불 함수의 개수에 대한 상, 하한(Upper and Lower bound)을 계산하는 것으로 부호이론의 리드-뮬러 코드(Reed- Muller Codes)을 이용하여 균형함수의 갯수를 계산하는 중요한 추측들을 제안하였다. 이러한 추측들을 이용하여 균형함수의 갯수에 대한 상,하한 값을 제시하였으면 이 결과는 현재까지 알려진 균형함수에 대한 갯수를 통하여 확인하였으며 이와 관련된 것으로 앞으로 해결해야 할 과제들을 제시하였다. 두 번째 부분은 SAC(Strict Avalanche Criterion)을 살펴보고 일반적인 특성들에 대하여 논하였으며 지금까지 알려진 함수의 갯수에 대하여 알아보고 SAC(n-1)함수의 GF(p)하에서 계산하는 방법을 연구하였으며 여러가지 특성들을 조사하였다. 특별히 SAC(n-1) 함수를 GF(3)에서 계산하는 방법과 갯수를 계산하였다. This dissertation consists of two parts: Counting balanced Boolean functions, and Counting SAC(n-1) functions over GF(p). The Strict Avalanche Criterion (SAC), Balance, and Correlation Immunity are important properties for many types of cryptographic functions. It is of interest to count the functions satisfying these criterions. In the first part of this dissertation, we obtain good upper and lower bounds on the number B^(n)_(k) which is defined as the number of balanced Boolean functions in n variables with degree ≤k. The weight distribution of k-th order Reed-Muller code of length 2^(n) (R(k, n)), is the list of the possible weights of the codewords in R(k, n). We apply the theory of Reed-Muller codes to obtain the number of balanced Boolean functions, since B^(n)_(k) count the codewords of the middle weight 2^(n-1) Also we suggest conjectures for bounds on the number of balanced Boolean functions. The second part of the dissertation addresses counting functions satisfying the strict avalanche criterion functions over finite fields. We extend the SAC concept from GF(2) to GF(p). We describe the important properties of SAC(n-1) functions over GF(p) such as if f is SAC(n-1), then the degree of each x_(i) must be 2. We also count 20,150 SAC(n-1) functions over GF(3) in 3 variables without O(x_(1), x_(2), x_(3)).

Transitional spaces combined with functions in low-rent housing for rural-to-urban migrants (Nongmin gong) in China : analysis of 3 case studies based upon communal Activities

Peng, Xueni 서울대학교 대학원 2017 국내박사

This study investigates planning strategies regarding low-rent housing for Chinese rural-to-urban migrants (Nongmin gong) through an examination of the intermediary spaces combined with functions shared among such Chinese migrants in their urban settlements. Such functions are to help rural migrants with the process of managing their spatial transition from the rural setting to the urban setting. Chinese migrants gradually transfer from their home rural settlements to establish city lives and engage in urban occupations, but their sense of identity and family network remain grounded in a village culture. The high level of communal activities found in the spontaneous urban settlements of Nongmin gong, can be understood as one aspect of the adherence to the lifestyle of their rural settlements. As a result, the main focus of this study is to show that the sharing of certain functions situated in the transitional spaces, namely, in front of the rental room, in front of the rental house and between the rental houses, always provides opportunities for communal activities to take place. This research reveals that low-rent neighborhoods spontaneously-developed by migrants incorporates close-knit communal activities that take place in these transitional spaces. Under the same physical conditions, by contrast, communal activities have been disappearing in modern low-rent high-rise neighborhoods. Based on the analyses of the physical characteristics of the activities carried out by migrant residents and of the interviews of migrants regarding the significance of communal activities, I defend the thesis that the role played by the transitional spaces must be joined with functions that residents can share or must share with each other. The shared functions situated in the transitional spaces actually allow communal activities to take root. In my dissertation, communal activities taking place in the transitional spaces are investigated based on three typical low-rent migrant neighborhoods: Yimuyuan stands as a spontaneously-developed neighborhood of Nongmin Gong or rural-to-urban migrants in Beijing city; Minxin Jiayuan is a government-subsidized low-rent neighborhood in Chongqing city; and Vanke Tulou is an example of private developer-built low-rent housing, in Guangzhou city. For each case study, communal activities are assessed by examining the spatial characteristics of three transitional spaces and through a survey of a sample of forty-five rural-to-urban migrant residents. While questionnaire surveys were also used for data gathering, we could identify descriptive statistics used for comparative analyses of the three low-rent neighborhoods. Analysis of the migrants’spontaneously-developed housing in the Yimuyuan case suggests two points. Firstly, the high level of communal activities occurring in the three transitional spaces mostly appertains to residents using the shared functions. These functions become a given condition that residents can share with other residents. Secondly, all these shared functions provide a medium by which communal activities are actualized. The available shared functions help to build up the relationship of residents to the functions of their choice, and also make it possible to generate communal activities among residents. Therefore, the results of this study lead to the following finding about low-rent neighborhoods for rural-to-urban migrants: Housing typology (low-rise or high-rise) is not fundamental in influencing relations between neighbors and certainly not the real cause of a high or low level of communal activities. If low-rent neighborhoods are rich in communal activities, this is not because they are crowded or are more suitable places, but because they have sufficient functions to allow that sharing to take place. The same can be applied to places which have few communal activities, it is not resulting from a lack of people or open places, but it is caused by the absence of functions that can be shared, thereby preventing the occurrence of communal activities. Finally, this research proposes strategies using shared functions for planning rural-to-urban migrants’ low-rent housing in China. Regarding the strategies using shared functions, the following shared functions comprise the basis for designing low-rent housing for rural-to-urban migrants in China: hygiene and sanitary functions; cooking and dining functions; storage and rest functions; social service and education functions; and recreation and hobby functions. This kind of low-rent housing model, based on a cooperative network or fictive kinship in the community, could facilitate migrant self-support and produce a more humane residential environment. For the migrants’low-rent housing in their destination city, retrieving the ethics of communal activities can be an alternative to controlling individualism and collectivism.

A GENERALIZATION OF REGULAR p-VALENT FUNCTIONS

오승은 이화여자대학교 대학원 1995 국내박사

한국어와 중국어 지시어의 대조 연구 : 담화 기능과 특성을 중심으로

유진 전북대학교 일반대학원 2014 국내석사

Abstract Contrastive Analysis of Korean and Chinese Deictic Terms -Focused on Discourse Functions and Features- Liu, Zhen Major in Korean Language and Literature The Graduate School Chonbuk National University This paper was to compare the single type with the representative combinational type of Korean deictic terms 'i/geu/jeo' and Chinese deictic terms '这/那' focused on discourse functions. In particular, although there were studies on the functions of the single type of Korean deictic terms 'i/geu/jeo' and Chinese deictic terms '这/那', it's unsatisfactory for studies on 'ireotge/geureotge/jeoreotge' and '这么/那么', 'igeot/geugeot/jeogeot and '这个/那个' of the combinational type. Therefore, this study highlighted the discourse functions of the representative combinational type. Deictic terms are inevitable expressions in daily language life in both Korea and China and the analysis on a spoken corpus was performed for comparison of the discourse functions of 'i/geu/jeo' and '这/那/ as their realization shows remarkably in everyday language. The analysis target data are a raw corpus of modern spoken built by 21st century Sejong project and BJKY established by language institute in Beijing language university. In chapter 2, we discussed about the criteria and the analysis system of 'i/geu/jeo type and '这/那' type. First, each analysis criterion was established after dividing the discourse functions of 'i/geu/jeo' and '这/那' expressions into deictic functions and non-deictic functions. As describing the basic system of 'i/geu/jeo type and '这/那', This study investigated causes of the differences among them. Based on this, applicable specific analysis standards were established to analyze the discourse functions of 'i/geu/jeo-type and 'zhe/na'- type expressions. In chapter 3, assuming 'i/geu/jeo' and '这/那' used alone without combining with other words show the most basic discourse functions among their expressions, while doing contrast analysis on the discourse functions of each deictic terms 'i/geu/jeo and Chinese deictic terms '这/那' shown in a single type, we tried to make clear the similarities and differences. In chapter 4, tried to clarify the similarities and differences of the discourse functions by dividing 'ireotge/geureotge/jeoreotge' and '这么/那么', 'igeot/geugeot/jeogeot and '这个/那个' into deictic functions and non-deictic functions. Finally, we examined the differences revealed according to statistics on 'i/geu/jeo type and '这/那' type.