사회간접자본(SOC)투자 평가모형의 개발 및 응용(2단계)(Development and Application of an Evaluation Model for Infrastructure Investment (Phase 2))

노트 : 이 연구보고서의 내용은 국토연구원의 자체 연구물로서 정부의 정책이나 견해와는 상관없습니다

새로운 콜레스테릭 액정 시스템의 제시: 미세 유체 시스템을 이용한 액정 방울과 자가 조립으로 형성된 나노셀룰로오스 필름에 관한 연구

학위논문 (석사)-- 서울대학교 융합과학기술대학원 : 융합과학부(나노융합전공), 2014. 2. Jan Lagerwall.Cholesteric (N*) liquid crystals have attracted much attention over a broad research field thanks to their peculiar optical properties, rendering them exquisite soft photonic materials. The period of their self-assembled helical structure can be tuned to reflect light in any part of the visible spectrum by adjusting chemical composition or temperature. The helical arrangement of the building blocks of the phase also gives the reflected light circular polarization with same handedness as the helix. Here we focus on two modern cholesteric systems and the unique optical properties that they develop: monodisperse cholesteric liquid crystal droplets and dried films of cellulose nanocrystals with a vitrified internal cholesteric structure. With a coaxial microfluidic set-up we produce monodisperse droplets of suitable cholesteric mixtures, dispersed in a dilute aqueous polyvinylalcohol (PVA) and glycerol solution as continuous phase. The droplets are collected at such high volume fraction that they spontaneously organize into a 2D colloidal crystal arrangement. The continuous phase composition ensures planar alignment, i.e. the helix adopts a radial orientation. This leads to omnidirectional selective reflection from the cholesteric droplets giving rise to peculiar and attractive optical phenomena. We demonstrate the specific way of photonic cross communication between droplets, resulting in multicolored and symmetric patterns. Apart from being fascinating from a fundamental optics perspective, the system holds extensive potential for applications, e.g. in sensors or in anti-counterfeiting tags. Cellulose nanocrystal (CNC) is a novel bionanomaterial that currently attracts considerable international attention. It is produced from natural cellulose sources by extracting the smallest structural element in the form of crystalline nanorods. At certain concentrations a CNC suspension develops a cholesteric liquid crystal phase with consequent helical modulation of the nanorods. We developed a new method of drying CNC suspensions under controlled shear flow, yielding a thin CNC film with an unusually high degree of structural control. A key element is to delay and slow down the glass formation which competes with liquid crystalline ordering as the CNC concentration is increased when the water evaporates. Films dried under appropriate conditions exhibit large-scale uniform iridescent properties, a result of a uniformly aligned helix with pitch in the submicron scale. By increasing the circular shear flow the helix can however also be unwound and a uniformly birefringent film is produced.Abstract(국문초록)••••••••••••ⅰ(52) 1. Introduction 1.1 Motivation and Goals •••••••••••••••1 2. Research Background for This Work 2.1 Liquid Crystals ••••••••••••••••••••••••••• 3 2.2 Chirality in Liquid Crystals : Cholesteric phase••••••• 8 2.3 Cellulose Nanocrystals (CNCs) ••••••••••••••••••••••••••••••••••13 3. Cholesteric Liquid Crystal Droplets Produced by Microfluidics 3.1 Used Materials ••••••••••••••••••••••••••15 3.2 Microfluidic Technique •••••••••••••••••••••••16 3.3 Sample Preparation ••••••••••••••••••••••19 3.4 Reflection Phenomena Observed by Polarizing Optical Microscope ••••••••••••••••••••••20 3.5 Optical Analysis •••••••••••••••••••27 4. Controlled Helix Orientation in Dried Cellulose Nanocrystal films 4.1 Used Materials •••••••••••••••••••••••••••••33 4.2 Film Preparation •••••••••••••••••••••••••34 4.3 Optical Characterization •••••••••••••••••••••••35 4.4 Conclusion •••••••••••••••••••••••••44 Appendix A. Cano Lens Calculation ••••••••••••••••45 5. Reference •••••••••••••••••••••••••••••50Maste

Unsteady-state kinetics for Selective Catalytic Reduction of NOx by NH3

Maste

Economic Development and Scientific and Technical Manpower Administration in Korea

革命政府가 經濟開發 5個年計劃을 樹立한지 이미 4個年이 된다. 經濟開發을 爲한 長期計劃에는 資本形成이 必要한 것은 勿論이지만 그것에 못지않게 重要한 것이 또한 技術形成이라 하겠다. 實은 經濟開發에 무엇보다 앞서야 될것이 人的 資源원을 開發해야 되지 않겠는가 본다. 이 問題는 비단 우리 韓國과 같은 新進國 - 所謂 後進國 - 에서만 該當된 것이 아니며 도리혀 美國이나 蘇聯과 같은 先進國에서는 더욱 깊은 關心과 硏究를 거듭하고 있는 것이다. 그런데 우리나라 經濟開發에 따르는 는 어떠한가. 單純한 意味에 있어서의 人力이나 勞動力은 우리나라에 너무 많아서 問題가 된다. 그러나 經濟開發을 爲해서 必要한 專門知識이나 技術을 가진 人力은 너무나 不足하다는 것이다

The Association Between Second-Line Oral Antihyperglycemic Medication on Types of Dementia in Type 2 Diabetes: A Nationwide Real-World Longitudinal Study

Background: There are few reports that evaluated the association between various types of dementia and dual oral therapy with antihyperglycemic medication. Objective: The goal of this study was to investigate the association between treatment of dual antihyperglycemic medication and dementia subclass in type 2 diabetes mellitus using the Korean National Health Insurance System. Methods: This study included 701,193 individuals with diabetes prescribed dual oral therapy between 2009 and 2012 from the Korean National Health Insurance Service Database, which were tracked until 2017. All-cause, Alzheimer's (AD) and vascular dementia (VaD) were investigated by dual oral therapy. Adjustments were made for age, sex, income, diabetes duration, hypertension, dyslipidemia, smoking, drinking, exercise, body mass index, glucose level, and estimated glomerular filtration rate. Results: Dual therapy with metformin (Met) + dipeptidyl peptidase-4 inhibitor (DPP-4i), Met + thiazolidinedione (TZD), and sulfonylurea (SU) + thiazolidinediones (TZD) were significantly associated with all-cause dementia (HR = 0.904, 0.804, and 0.962, respectively) and VaD (HR = 0.865, 0.725, and 0.911, respectively), compared with Met + SU. Met + DPP-4i and Met + TZD were associated with significantly lower risk of AD (HR = 0.922 and 0.812), compared with Met + SU. Dual therapy with TZD was associated with a significantly lower risk of all-cause dementia, AD, and VaD than nonusers of TZD (HR = 0.918, 0.925 and 0.859, respectively). Conclusion: Adding TZD or DPP-4i instead of SU as second-line anti-diabetic treatment may be considered for delaying or preventing dementia. Also, TZD users relative to TZD non-users on dual oral therapy were significantly associated with lower risk of various types of dementia

Changes of soil-water characteristics in unsaturated soil during freezing

학위논문(박사) - 한국과학기술원 : 건설및환경공학과, 2009.2, [ vii, 111 p. ]한국과학기술원 : 건설및환경공학과

A Study on the technologies for the supercomputing infrastructure

funder : 과학기술부agency : 과학기술부agency : Ministry of Science & Technology슈퍼컴퓨터 및 초고속연구망은 기초과학 연구, 산업체의 연구개발 등의 다양한 분야에서 생산성 및 효율성을 획기적으로 높여 국가경쟁력을 향상시키는 중요한 인프라이며, 이러한 인프라를 효율적으로 구축하고 사용하기 위해서 본 과제에서는 그리드 컴퓨팅 기술, 클러스터/가시화 컴퓨팅 기술, 망 엔지니어링 및 응용 기술, 정보 그리드 기술 등에 관한 연구를 수행 하였다. 1. 그리드 컴퓨팅 기술은 분산된 고성능 자원들을 통합하여 사용자 중심의 과학기술 서비스를 제공하는 새로운 고성능 인프라 구축 기술로서 세계적으로 큰 주목을 받고 있다. 본 과제에서는 그리드 서비스의 구축을 위해 3개년의 그리드 서비스 구축 로드맵을 수립하고, 로드맵의 추진 과정의 일환으로서 그리드 MPI 서비스의 개발 및 그리드 파일 관리 시스템의 설계 등을 수행하였다. 2. 클러스터/가시화 컴퓨팅 기술 연구 분야에서는 멀티클러스터 관리 및 파일시스템 설계를 위한 기본 연구를 수행하였으며 특히 클러스터 관리 소프트웨어인 K*Rocks4.1을 개발 배포하였고 고성능 가시화 시스템 도입을 위한 시스템 구축 전략을 수립하였다. 3. 망 엔지니어링/응용 기술 연구 분야에서는 망 사용자에게 안정적인 대역폭 서비스를 제공하기위한 UCLP 시스템의 개발 구축 및 확장 모듈 개발, 응용 연구자가 필요로 하는 망 응용 성능 향상 기술 연구, 시험 및 응용기술 지원, 고성능 망 응용 선도 기술로써 비압축영상 전송 시스템의 개발을 수행하였다. 4. 정보 그리드 기술 연구 분야에서는 개방형 그리드 서비스 구조(OGSA) 위에서 데이터 공유를 위한 미디에이션 서비스 시스템을 설계하여, 그리드 기술 및 그리드 서비스 기술을 정보 및 지식 관리 시스템에 활용하는 국내 독자적 기술을 확보하였다.○ A study on Grid computing technology - Formulation of the roadmap for production-level Grid service - Design of GT4-based Grid file management system - Development of the prototype of GT4-based Grid MPI service ○ A study on cluster/visualization ○ computing technologies - Researches on multiple cluster system management and file system technology - Design of visualization system and set up scientific visualization environments ○ A study on the network engineering and application technologies - Development of additional modules for UCLPv2 system - A study on general bandwidth reservation technologies - A study on network applications performance enhancement technologies and technical support for the applications researches - Testing high performance systems for high bandwidth and high data volume applications and supporting the application technologies - Development of Uncompressed HD image tranceiver system ○ Research on the information Grid - Development of an efficient information-sharing method within a virtual organization by proposing the architecture of OGSA-enabled mediation service systems - Development of a virtual information integration technique by providing a meta data model for retrieval and fusion of disparate and heterogeneous data resources in Grid environment