High-throughput roll-to-roll fabrication of flexible thermochromic coatings for smart windows with VO₂ nanoparticles

Kim, Youngkwang,Yu, Sangbae,Park, Jaeseoung,Yoon, Daseob,Dayaghi, Amir Masoud,Kim, Kun Joong,Ahn, Jin Soo,Son, Junwoo The Royal Society of Chemistry 2018 Journal of Materials Chemistry C Vol.6 No.13

<P>VO2-based ‘nanothermochromics’ that utilize the dispersion of VO2 nanoparticles in a passive host matrix have been evaluated as an economic strategy of “smart” windows to reduce energy consumption for heating and air conditioning in buildings. Here, we demonstrate a high-throughput roll-to-roll fabrication of thermochromic coatings for smart windows that can adapt their optical properties in accordance with external temperature. A large quantity (250 g) of VO2 nanoparticles (NPs) was synthesized at one time by controlled thermal treatment of bead-milled V2O5 NPs as a fast and inexpensive method. The amorphous nature of bead-milled V2O5 NPs combined with their nanometer size kinetically facilitates uniform synthesis of high-quality VO2 NPs even under less-reducing conditions than those used to obtain bulk VO2. This mass production of VO2 NPs could be used to fabricate the largest thermochromic coatings with VO2/PVP composites (12 cm × 600 cm) yet produced with excellent infrared modulation ability (∼45%). This scalable and continuous production of large coatings with thermochromic NPs will accelerate the commercialization of thermochromic coatings for smart windows, which will contribute to a large reduction in energy consumption to heat or cool buildings.</P>

Hardware Institutions for Software Technologies - The Japanese Model of Industrial Development in the Personal Computer Industry

Sangbae Kim 서울대학교 국제학연구소 2002 Journal of International and Area Studies Vol.9 No.1

  This paper attempts to explain why Japan has largely failed to meet unique technological challenges in the field of computer software while it has achieved remarkable success in its technological counterpart-s-computer hardware. What makes this research question puzzling is the fact that Japan has employed pretty much the same industrial policies and institutions for promoting both sectors, nevertheless producing divergent results. Existing neo-institutional approaches to industrial competitiveness are inadequate for explaining this puzzle with respect to “sectoral variation” in the effectiveness of industrial policies and institutions. I suggest that the theory of “technological fitness” is more useful for helping us to understand the relevance of industrial institutions-and further institutional adjustment strategies-in relation to the underlying technological conditions of industrial sectors. In this view, Japan has largely failed in computer software because it has continued to rely on its “hardware institutions” in competing for software technologies.

Cyber Security and Middle Power Diplomacy

Sangbae Kim 한국국제정치학회 KJIS 2014 The Korean Journal of International Studies Vol.12 No.2

International Collaboration on Cyber Security

KIM Sangbae 제주평화연구원 2011 JPI Research Series Vol.2011 No.12

Hardware Institutions for Software Technologies : The Japanese Model of Industrial Development in the Personal Computer Industry

Kim, Sangbae SCHOOL OF INTERNATIONAL AND AREA STUDIES SEOUL NAT 2002 Journal of International and Area Studies Vol.9 No.1

This paper attempts to explain why Japan has largely failed to meet unique technological challenges in the field of computer software while it has achieved remarkable success in its technological counterpart-computer hardware. What makes this research question puzzling is the fact that Japan has employed pretty much the same industrial policies and institutions for promoting both sectors, nevertheless producing divergent results. Existing neo-institutional approaches to industrial competitiveness are inadequate for explaining this puzzle with respect to "sectoral variation" in the effectiveness of industrial policies and institutions. I suggest that the theory of "technological fitness" is more useful for helping us to understand the relevance of industrial institutions-and further institutional adjustment strategies-in relation to the underlying technological conditions of industrial sectors. In this view, Japan has largely failed in computer software because it has continued to rely on its "hardware institutions" in competing for software technologies.

An efficient scheme of target classification and information fusion in wireless sensor networks

Kim, Youngsoo,Jeong, Sangbae,Kim, Daeyoung,Ló,pez, Tomá,s Sá,nchez Springer-Verlag 2009 PERSONAL AND UBIQUITOUS COMPUTING Vol.13 No.7

Sonochemical Synthesis of Zeolite A from Metakaolinite in NaOH Solution

Kim, Wantae,Choi, Doyoung,Kim, Sangbae The Japan Institute of Metals 2010 MATERIALS TRANSACTIONS Vol.51 No.9

<P>Sonochemical synthesis of zeolite A has been conducted by ultrasonic irradiation of mixtures of metakaolinite and NaOH solution. The hydrothermal synthesis at conventional synthesis conditions was undertaken to determine the sonochemical reliability. The enhancement of nucleation and crystallization rate of zeolite A was achieved by ultrasound. In the ultrasonic field, zeolite A once formed in the suspension has been converted into hydroxysodalite and losod as sonicating proceeded. Comparing the results with those of conventional methods, this heterogeneous reaction was particularly accelerated by ultrasound, leading to improved reactivity of solid reactant through intensive mixing. The use of ultrasound enables us to prepare well-dispersed fine zeolite A particles with mean particle size of around 1 μm. The cation exchange capacity values of the products increased as the synthesis reaction for zeolite A proceeded. The high solid concentration in the suspension, however, hindered the ultrasound from intense agitating, resulting in the decrease of zeolite A yield.</P>

Immunosuppressive activity of Allergina

Kim HwanMook,Lee ChangWoo,Han SangBae,Yoon PyoungSeoub,Jeong ChanMook,Lee MyoungLyel,Kim KwanMin,Yoon YeoDae,Kim HyungChin,Park SongKyu 大韓藥學會 2002 大韓藥學會 總會 및 學術大會 Vol.2002 No.2

Kinetics of the Oxidative Roasting of Low Grade Mongolian Molybdenite Concentrate

Kim, Byung-Su,Lee, Hoo-In,Choi, Young-Yoon,Kim, Sangbae The Japan Institute of Metals 2009 MATERIALS TRANSACTIONS Vol.50 No.11

<P>Molybdenite concentrate is the major mineral for the molybdenum industry. The industrial processing of molybdenite concentrate is first to convert to technical grade molybdenum trioxide by its oxidative roasting, followed by its purification by distillation or its ammonia leaching. In the present research, detailed experimental results for the oxidative roasting of low grade Mongolian molybdenite concentrate are presented. The experiments were carried out in the temperature range of 778 to 838 K under air atmosphere by using a thermogravimetric analysis technique. The particle size of the molybdenite concentrate was varied between 53 and 103 μm. As an example of the oxidative roasting of low grade Mongolian molybdenite concentrate, more than 95% of 53 μm particle size molybdenite was converted to molybdenum trioxide in 40 min at 823 K. The Jander equation was found to be useful in describing the rates of the oxidative roasting, which had an activation energy of 215.0 to 259.3 kJ/mol (51.4 to 62.0 kcal/mol) for various sizes, such as 53 μm, 67 μm and 103 μm.</P>

비대칭 오차수정모형을 활용한 KOSPI지수와 아파트가격지수의 관계 분석

김상배(Kim, Sangbae),이승아(Lee, Seung-A) 한국경영교육학회 2020 경영교육연구 Vol.35 No.4

[연구목적] 본 연구의 목적은 비대칭 오차수정모형 통해 우리나라 KOSPI지수와 아파트가격지수 사이의 장기 인과관계를 살펴보는데 있다. [연구방법] 본 연구의 방법은 Enders and Siklos(2001)의 임계 자기회귀(TAR: threshold autoregressive)모형과 모멘텀 임계 자귀회귀(MTAR: momentum threshold autoregressive) 모형을 이용한 비대칭 임계 공적분 방법과 비대칭 오차수정모형을 활용한다. 또한, KOSPI지수와 아파트가격지수 사이의 관계는 잔차의 변동성 효과로 인한 비선형성이 나타날 수 있으므로, 이를 통제하기 위해 이변량 BEKK-GARCH모형을 활용한 강건성 검정과 이 모형을 통해 KOSPI지수와 아파트가격지수의 변동성 전이효과와 변동성 충격반응(volatility Impulse Response Function)을 검토한다. [연구결과] 구조적 변화를 고려하여 KOSPI지수와 아파트가격지수의 공적분 관계를 추정한 결과 Johansen 공적분 검정 결과와는 달리 두 변수 사이에는 공적분 관계가 존재하는 것을 확인하였다. 또한, TAR모형과 MTAR모형을 추정한 결과, KOSPI지수와 아파트가격지수는 장기적 관계가 있으며, 장기균형으로부터 이탈한 경우, 다시 균형 상태로 조정되는 과정이 비대칭적인 것을 확인하였다. 비대칭 오차수정모형을 이용하여 아파트가격과 KOSPI지수 사이의 장기 인과관계를 분석한 결과, KOSPI지수의 변화가 아파트가격을 장기적으로 인과하는 것으로 나타났다. 마지막으로 아파트가격지수가 KOSPI지수에 변동성 전이효과가 존재하며, KOSPI지수와 아파트가격지수 사이의 공분산은 글로벌 금융위기의 충격에 지속적으로 영향을 받고 있는 것으로 나타났다. [연구의 시사점] 본 논문의 추정결과는 우리나라의 경우 KOSPI지수와 아파트가격지수가 장기적인 영향이 존재하기 때문에 투자자는 투자를 결정할 때와 정책당국은 부동산정책을 수립하고 실행할 때 주식시장에 대한 고려가 필요하다는 것을 의미한다. [Purpose] This paper examines the dynamic relationship between KOSPI index and apartment price index in Korea by utilizing a asymmetric error correction model. [Methodology] We adopt the threshold cointegration and the asymmetric error correction model using the threshold autoregressive(TAR) model and the momentum autoregressive(MTAR) model proposed by Enders and Siklos(2001). In addition, we adopt a bivariate BEKK-GARCH model to consider the volatility effect, which may cause the nonlinear relationship between KOSPI index and apartment price index. [Findings] While we cannot reject the null hypothesis of no cointegration from the Johansen cointegration approach, the estimation results from the DOLS cointegration method with considering the structural break show a long-run relationship between KOSPI index and apartment price index. This implies that ignoring the presence of structural break leads to spurious results. Further, we found that KOSPI index causes apartment prices in the long-run from the results of the asymmetric error correction model. Finally, the result from the VIRF show that the covariance between KOSPI index and apartment price index is continuously affected by the impact of the global financial crisis. [Implications] Our results suggest that investors and the policy maker should be cautious when implementing real estate policies because they have the long-run impact on the Korean stock market.