53,754 research outputs found
Kim, Chul
No full text학위논문(석사)--아주대학교 교육대학원 :국어교육,2006. 2의 작자 연암 박지원의 사상은 실학의 한 주류를 이루고 있었던 이용후생(利用厚生)을 기조로 하고 있었다. 이용후생은 상공업의 발전을 기도하는 입장에서 복고적 경세치용과는 그 성격을 달리하면서 주로 선진 청 문화를 받아들여 조선말의 현실을 개혁하려는 데 주안점을 둔 것이다.
실학파의 북학주의가 시대적 북벌주의와 대립된 것도 바로 이 개혁을 저해하는 정치 현실과 이를 열망하는 이상 정신의 대결로 설명될 수 있을 것이다. 당시의 위정자들의 상공 천시가 빚어 낸 경제적 후진성과 이에 따른 재정의 궁핍 등 빈곤 타개의 대안으로서 상품의 유통과 생산 기구의 개발을 주장했고 훈척, 권귀의 부패, 사치를 비판하고 주자학적 권위주위도 부정의 대상으로 삼았다. 농공상에 이바지하기 위해 적극적 참여를 고취한 그의 사관(士觀)등 작가의 결렬한 실학적 이상 추구가 이 작품의 풍자 정신을 바탕으로 집약된 주체적 실리주의 이다.다. 효종대 이후 무능한 위정자들 사이에 퍼져 있어 사회적 병폐가 되어 온 사대적 북벌주의의 허위성을 폭로하고 현실적 부조리를 비판함으로써, 그의 이상을 제시하고 있다. 은 작가가 이상의 세계관에서 불완전한 현실을 보는 날카로운 풍자를 볼 수 있는 작품이다.
이러한 풍자를 통한 실리주의적 입장에서 볼 때 조선후기 사회가 당면한 가장 절박한 문제는 유통구조의 취약성에서 기인된 경제적 빈곤이며 이는 국내 상업의 활성화와 해외 무역을 통해 충분히 해결될 수 있다. 그런데 당시 집권층들은 이러한 절박한 대내적 경제 현실을 외면한 채 대외적인 정치적 명분만을 내세움으로써 문제 해결의 길을 스스로 막고 있다. 조선후기의 허약한 경제를 회생시키기 위해서는 주체적 실리주의로의 근본적 의식 전환을 통해 청의 발달된 문물을 적극 받아들일 필요가 있는데, 그들은 이를 거부한 채 명분주의만을 고집하고 있었다. 이는 그들에게 현실 문제를 해결하려는 진정한 뜻이 없다는 것을 말해 줄 뿐만 아니라 그들은 진정한 명분론자도 아니면서 다만 자기들의 현실적 이해를 위해 명분을 이용하고 있을 뿐이니, 그들에 의한 현실 문제의 해결은 더 이상 기대할 수 없다.
이러한 풍자와 비판을 통한 주체적 실리주의는 오늘을 사는 학생들에게 시대 현실을 통찰하는 안목과 그러한 생각의 표현에 대한 방법을 길러준다는 점에서 이 작품의 교육적 의의 크다고 하겠다.Ⅰ. 서론 = 1
1. 연구의 필요성 및 목적 = 1
2. 연구방법 = 3
Ⅱ. 의 작품세계 = 5
1. 창작의 시대적 배경 = 5
2. 풍자적 기법 = 6
3. 의 구조 = 13
Ⅲ. 의 교육적 의미 = 17
1. 현실문제의 진단과 해결방안 = 19
2. 기득권층의 태도에 대한 비판 = 28
3. 주체적 실리주의 = 33
4. 오늘날 관점에서의 교육적 의미 = 44
Ⅳ. 결 론 = 49
참고문헌 = 52Maste
Young Chul Kim
No full text학위논문(석사)--아주대학교 일반대학원 :에너지시스템학과,2019. 2I. Introduction 1
II. Background 3
1. Two-dimensional crystalline materials 3
1.1 Molybdenum disulfide (MoS2) 5
1.2 Graphene 5
2. Carrier dynamics in semiconductors 7
3. Device characterization using scanning photocurrent microscopy 9
4. The basic principles of the pump-probe technique including some studies 14
III. Device fabrication and carrier transport measurement setup 18
1. Device fabrication 18
2. SPCM setup 22
3. Femto-second SPCM setup 22
IV. Imaging carrier transport in MoS2/graphene FET 24
1. Device characterization 24
2. Determinization of electronic band alignment in MoS2/graphene FET through SPCM 30
3. Study of Schottky contact through SPCM 36
4. Diffusion lengths of both majority and minority carriers for both MoS2 and graphene layers 40
5. Carrier transport parameters obtained from femtosecond SPCM measurement 46
V. Conclusion 50
References 52MasterWe performed imaging of the MoS2/graphene heterojunction device fabricated by chemical vapor deposition (CVD) method by using scanning photocurrent microscopy (SPCM). We measured the diffusion length, carrier lifetime, and mobility of each layers. The heterostructure device exhibited n-type operation, due to the lower mobility of MoS2 layer than that of graphene layer. The SPCM signal showed the depletion layer at the MoS2 and graphene heterojunction. The graphene edge offered nucleation site for MoS2 growth and an excellent electrical contact for the MoS2 layer without performing rectifying behavior. The potential barrier at the junction have been extracted from the polarity switching of the photocurrent signals as a function of drain–source bias. Bias-dependent SPCM allowed us to simultaneously measure the diffusion lengths of both electron and hole carriers for the respective MoS2 and graphene layers. Combining them with the lifetimes measured by femtosecond SPCM, we determined the localized electron and hole mobilities in MoS2 and graphene layers. The electron mobility (µe) and hole mobility (µh) yielded µe = 8800 cm2 V-1 s-1 and µh = 15000 cm2 V-1 s-1 for graphene. Similarly, the results for MoS2 yielded µe = 160 cm2 V-1 s-1 and µh = 80 cm2 V-1 s-1 for the electron and holes, respectively. Our work will be beneficial to the understanding of the transport phenomenon in two-dimensional materials and nanoscale devices
Sung-Chul Kim
No full text학위논문(박사)--아주대학교 일반대학원 :에너지시스템학과,2017. 2Chapter 1. General introduction 1
1.1. Orthophosphates 1
1.1.1. Structure of orthophosphates 2
1.1.1.1. Tridymite-related structures 2
1.1.1.2. Olivine-type structures 4
1.1.1.3. Glaserite-like structures 5
1.1.2. Current issues in orthophosphates 7
1.1.2.1. Applications to luminescent host 7
1.1.2.2. Applications to lithium ion batteries 7
1.1.2.3. Crystallographic studies 8
1.2. Phase transformations 10
1.2.1. Classification of phase transformation 10
1.2.2. Solid-solid phase transformations 12
1.2.2.1. Nucleation and growth mechanism 14
1.2.2.2. Spinodal decomposition 17
1.2.3. Time-temperature-transformation (TTT) diagram 19
1.3. Powder diffraction techniques for structural analysis 22
1.3.1. Powder vs. single-crystal diffraction 23
1.3.2. Ab initio structure determination 24
1.4. Objectives 30
Chapter 2. Phase transition, spinodal decomposition and reentrant phase formation in LiSrPO4 32
2.1. Introduction 32
2.2. Experimental 33
2.2.1. Synthesis 33
2.2.2. Structural analysis 33
2.2.3. Thermal analysis 34
2.2.4. Microstructural study 34
2.3. Results 34
2.3.1. Crystal structure of new polymorph 34
2.3.2. Thermo-diffractometric study 41
2.3.3. Thermal expansion measurements 42
2.3.4. Phase analysis 46
2.3.5. Thermal analysis 49
2.3.6. Morphology 52
2.4. Discussion 55
2.4.1. Phase transition 55
2.4.2. Reentrant phase formation and coherent behavior 57
2.5. Conclusions 60
Chapter 3. Crystal structure of LiBaPO4: Polymorphism and phase transition 61
3.1. Introduction 61
3.2. Experimental 61
3.2.1. Synthesis 61
3.2.2. Structural analysis 62
3.2.3. Thermal analysis 62
3.3. Results and Discussion 63
3.3.1. Structure description 63
3.3.1.1. Polymorph I: Monoclinic phase 63
3.3.1.2. Polymorph II: Trigonal phase 68
3.3.2. Phase transition 73
3.4. Conclusions 76
Chapter 4. Comparative study on the phase transformations and nonlinear-optical property in LiMPO4 (M = Ca, Sr, Ba) 77
4.1. Introduction 77
4.2. Experimental 79
4.2.1. Synthesis and structural analysis 79
4.2.2. Phase transformation analysis 79
4.2.3. Optical spectroscopy 80
4.3. Results and Discussion 80
4.3.1. Structure refinements 80
4.3.2. Comparison of phase transformation behaviors 84
4.3.3. Raman spectroscopy 90
4.3.4. Second-harmonic generation (SHG) 92
4.4. Conclusions 95
Chapter 5. Synthesis, crystal structure, and ionic conductivity of a new layered metal phosphate, Li2Sr2Al(PO4)3 96
5.1. Introduction 96
5.2. Experimental 97
5.2.1. Synthesis 97
5.2.2. Single-crystal X-ray diffraction 97
5.2.3. Ionic conductivity measurements 98
5.3. Results and discussion 99
5.3.1. Structure determination 99
5.3.2. Structure description 106
5.3.3. Powder synthesis and ionic conductivity 109
5.4. Conclusions 114
REFERENCES 115DoctoralThis thesis focuses on the crystal structures and phase transformations of lithium metal phosphates LiMPO4 (M = Ca, Sr, Ba). It shows that a correlation exists between the nonlinear optical property and the crystal structure. The synthesis of a new complex metal phosphate was also proposed based on the lattice design concept. Each compound was synthesized by solid state reaction or the molten salt method. X-ray diffraction (XRD), thermophysical analysis, field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, measurement of optical second harmonic generation, and impedance analysis were employed for structural analysis and characterization.
Chapter 1 describes the crystal structure and the physical properties of inorganic phosphates, gives an introduction to phase transformation, describes the procedure for crystal structure determination using powder diffraction, and states the purpose of this paper. Spinodal decomposition, which is one of the unique phase transformation phenomena, is described along with the classification according to the phase transition mechanism. ABPO4 (A, B = alkali, alkaline earth metal)-type inorganic phosphates have different coordination bonds between metal ions and PO4 units depending on the sizes of the A and B ions. The structures are closely related to tridymite, olivine, and glaserite minerals. ABPO4 compounds have attracted much attention as phosphors, optical materials, and electrode materials for secondary batteries due to their structural stability. However, the detailed structures remain unclear. The crystal structure, phase transformation and physicochemical properties of lithium metal phosphates, LiMPO4 (M = Ca, Sr, Ba), are discussed. The synthesis, crystal structure, and electrochemical properties of a new lithium metal phosphate Li2Sr2Al(PO4)3, with an intergrowth-type 2-D layered structure, are also discussed.
In Chapter 2, the crystal structure of LiSrPO4 and the phase transformation with temperature are analyzed. LiSrPO4 exists in two polymorphs: a monoclinic phase at room temperature, and a hexagonal phase at high temperatures. In Particular, spinodal decomposition and reentrant phase formation, which are rare in ceramics, have been reported for the first time. Phase decomposition into Sr3(PO4)2 and Li3PO4 occurred at about 650 °C; the separated phases disappeared and returned to the hexagonal LiSrPO4 phase at 830 °C. The phase transformations were influenced by the morphology of the sample. The bulk sample did not show phase decomposition on cooling because it allows larger strain than the powder sample, which is an energy barrier that prevents phase decomposition.
Chapter 3 shows the structural change of LiBaPO4 with temperature. Two kinds of polymorphs were confirmed, which were different from the crystal structures previously assumed to be orthorhombic or hexagonal. LiBaPO4 exhibited a monoclinic to hexagonal phase transition above 600 °C.
In Chapter 4, a comparative study on the crystal structures and the phase trans-formation behavior of LiMPO4 (M = Ca, Sr, Ba) was undertaken. The correlations between the crystal structure and the second harmonic generation (SHG) and Raman scattering were investigated. The phase transformations in LiMPO4 were related to the lattice energy of each phase and can simply be compared by the lattice volumes. Phase separation occurs when the lattice volume difference between M3(PO4)2 and LiMPO4 is sufficiently large. The trend of SHG observed in LiMPO4 was consistent with the structural distortion of the polyhedron calculated using the bond-valence method.
In Chapter 5, the synthesis, crystal structure, and ionic conductivity of the new lithium metal phosphate, Li2Sr2Al(PO4)3, with a layered structure are discussed. Li2Sr2Al(PO4)3 is a new intergrowth-type compound in which two different phosphate units, LiO4 and PO4 groups are alternately stacked. The ionic conductivity of this compound was measured using an impedance analyzer
Perceptual Averaging Does Not Compute a Single Mean but Summarizes a Distribution
No full textThis project provides supplementary materials for "Perceptual Averaging Does Not Compute a Single Mean but Summarizes a Distribution", by MyoungAh Kim and Sang Chul Chong
Perceptual Averaging Does Not Compute a Single Mean but Summarizes a Distribution
No full textThis project provides supplementary materials for "Perceptual Averaging Does Not Compute a Single Mean but Summarizes a Distribution", by MyoungAh Kim and Sang Chul Chong
Perceptual Averaging Does Not Compute a Single Mean but Summarizes a Distribution
No full textThis project provides supplementary materials for "Perceptual Averaging Does Not Compute a Single Mean but Summarizes a Distribution", by MyoungAh Kim and Sang Chul Chong
Implementation of government procurement in the WTO system
No full textThesis(Master) --Master of Strategy & International Management,2000I. Introduction
II. Basic Structure of the WTO GPA
III. Korea’s Accession to the WTO GPA
IV. Dispute in WTO: “Korea-Measures Affecting Government Procurement”
V. Remaining Questions
VI. Conclusionmasterpublishedby Chul Gyu Kim
Fig. 1. Zabelia densipila M.-P. Hong, Y.-C. Kim & B.Y. Lee. A. Habit. B. Inflorescence. C. Fruit. Drawn from the holotype and isotype M.-P. Hong and Y.-C. Kim 2K9-00181 in A new species of Zabelia (Linnaeaceae) from Korea
No full textFig. 1. Zabelia densipila M.-P. Hong, Y.-C. Kim & B.Y. Lee. A. Habit. B. Inflorescence. C. Fruit. Drawn from the holotype and isotype M.-P. Hong and Y.-C. Kim 2K9-00181 (KB).Published as part of Hong, Moon-Pyo, Kim, Young-Chul, Nam, Gi-Heum & Lee, Byoung Yoon, 2012, A new species of Zabelia (Linnaeaceae) from Korea, pp. 1-3 in Journal of Species Research 1 (1) on page 2, DOI: 10.12651/JSR.2012.1.1.001, http://zenodo.org/record/811995
Development and Validation of an Arterial Pressure-Based Cardiac Output Algorithm Using a Convolutional Neural Network: Retrospective Study Based on Prospective Registry Data
No full textBackground: Arterial pressure-based cardiac output (APCO) is a less invasive method for estimating cardiac output without concerns about complications from the pulmonary artery catheter (PAC). However, inaccuracies of currently available APCO devices have been reported. Improvements to the algorithm by researchers are impossible, as only a subset of the algorithm has been released. Objective: In this study, an open-source algorithm was developed and validated using a convolutional neural network and a transfer learning technique. Methods: A retrospective study was performed using data from a prospective cohort registry of intraoperative bio-signal data from a university hospital. The convolutional neural network model was trained using the arterial pressure waveform as input and the stroke volume (SV) value as the output. The model parameters were pretrained using the SV values from a commercial APCO device (Vigileo or EV1000 with the FloTrac algorithm) and adjusted with a transfer learning technique using SV values from the PAC. The performance of the model was evaluated using absolute error for the PAC on the testing dataset from separate periods. Finally, we compared the performance of the deep learning model and the FloTrac with the SV values from the PAC. Results: A total of 2057 surgical cases (1958 training and 99 testing cases) were used in the registry. In the deep learning model, the absolute errors of SV were 14.5 (SD 13.4) mL (10.2 [SD 8.4] mL in cardiac surgery and 17.4 [SD 15.3] mL in liver transplantation). Compared with FloTrac, the absolute errors of the deep learning model were significantly smaller (16.5 [SD 15.4] and 18.3 [SD 15.1], P<.001). Conclusions: The deep learning-based APCO algorithm showed better performance than the commercial APCO device. Further improvement of the algorithm developed in this study may be helpful for estimating cardiac output accurately in clinical practice and optimizing high-risk patient care. © Hyun-Lim Yang, Chul-Woo Jung, Seong Mi Yang, Min-Soo Kim, Sungho Shim, Kook Hyun Lee, Hyung-Chul Lee. Originally published in JMIR Medical Informatics (https://medinform.jmir.org), 16.08.2021. This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in JMIR Medical Informatics, is properly cited. The complete bibliographic information, a link to the original publication on https://medinform.jmir.org/, as well as this copyright and license information must be included.TRU
Book Review: Taxation in the Digital Economy: New Models in Asia and the Pacific, edited by Nella Hendriyetty, Chris Evans, Chul Ju Kim, and Farhad Taghizadeh-Hesary
No full textBook Review: Taxation in the Digital Economy: New Models in Asia and the Pacific, edited by Nella Hendriyetty, Chris Evans, Chul Ju Kim, and Farhad Taghizadeh-Hesar
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