근대언론을 통해 본 청말 해외유람기의 상업화(商業化)와 정론화(政論化) ― 왕도(王韜)와 량계초(梁啓超)를 중심으로

김화진 ( Kim¸ Hwajin ) 고려대학교 중국학연구소 2021 中國學論叢 Vol.- No.73

As the Qing Dynasty began to weaken from the early 19th century, the Western powers began to infiltrate into China again, and various Western cultural systems also flowed into China in earnest, one of which was media culture. Westerners published newspapers and magazines in foreign languages in China between 1858 and 1894. This was aimed at Westerners in China, but it also has a significant impact on the formation of modern Chinese media. Western media culture has set the stage for a new presentation of modern overseas abandonment. Twenty years after returning home from a trip to Europe, Wang Tao (王韜) posted ≪Manyousuilu (漫遊隨錄)≫, a travelogue in the form of a combination of writings and paintings, on ≪DianshizhaiHuabao (點石齋畫報)≫, an annex to ≪Shenbao (申報)≫. Through this, Wang Tao was able to more actively spread his political reform ideology, in addition to introducing new and eccentric Western objects. Liang Qichao (梁啓超) sought to bring about a more practical enlightenment effect for the nation and its people through the ≪Xindalu Youji (新大陸遊記)≫ and the late Qing Dynasty media for the realization of a “power” in the public sector.

Characterization of PM2.5 and identification of transported secondary and biomass burning contribution in Seoul, Korea

Kim, Yumi,Seo, Jihoon,Kim, Jin Young,Lee, Ji Yi,Kim, Hwajin,Kim, Bong Mann Springer 2018 Environmental Science and Pollution Research Vol. No.

<P>The chemical and seasonal characteristics of fine particulates in Seoul, Korea, were investigated based on 24-h integrated PM2.5 measurements made over four 1-month periods in each season between October 2012 and September 2013. The four-season average concentration of PM2.5 was 37 mu g m(-3), and the major chemical components were secondary inorganic aerosol (SIA) species of sulfate, nitrate, and ammonium (49%), followed by organic matter (34%). The mass concentration and most of the chemical components of PM2.5 showed clear seasonal variation, with a winter-high and summer-low pattern. The winter-to-summer sulfate ratio and the winter organic carbon (OC)-to-elemental carbon (EC) ratio were unusually high compared with those in previous studies. Strong correlations of both the sulfate level and the sulfur oxidation ratio with relative humidity, and between water-soluble OC (WSOC) and SIA in winter, suggest the importance of aqueous phase chemistry for secondary aerosols. A strong correlation between non-sea salt sulfate and Na+ levels, a high Cl-/Na+ ratio, and an unusual positive correlation between the nitrogen oxidation ratio and temperature during the winter indicate the influence of transported secondary emission sources from upwind urban areas and from China across the Yellow Sea. Despite the absence of local forest fires and the regulation of wood burning, a high levoglucosan concentration and its correlations with OC and WSOC indicate that Seoul was affected by biomass burning sources in the winter. The unusually high water-insoluble OC (WIOC)-to-EC ratio in winter implies additional transported combustion sources of WIOC. The strong correlation between WIOC and levoglucosan suggests the likely influence of transported biomass burning sources on the high WIOC/EC ratio during the winter.</P>

Caloric restriction improves diabetes-induced cognitive deficits by attenuating neurogranin-associated calcium signaling in high-fat diet-fed mice

Kim, Hwajin,Kang, Heeyoung,Heo, Rok Won,Jeon, Byeong Tak,Yi, Chin-ok,Shin, Hyun Joo,Kim, Jeonghyun,Jeong, Seon-Yong,Kwak, Woori,Kim, Won-Ho,Kang, Sang Soo,Roh, Gu Seob SAGE Publications 2016 Journal of cerebral blood flow and metabolism Vol.36 No.6

<P> Diabetes-induced cognitive decline has been recognized in human patients of type 2 diabetes mellitus and mouse model of obesity, but the underlying mechanisms or therapeutic targets are not clearly identified. We investigated the effect of caloric restriction on diabetes-induced memory deficits and searched a molecular mechanism of caloric restriction-mediated neuroprotection. C57BL/6 mice were fed a high-fat diet for 40 weeks and RNA-seq analysis was performed in the hippocampus of high-fat diet-fed mice. To investigate caloric restriction effect on differential expression of genes, mice were fed high-fat diet for 20 weeks and continued on high-fat diet or subjected to caloric restriction (2 g/day) for 12 weeks. High-fat diet-fed mice exhibited insulin resistance, glial activation, blood-brain barrier leakage, and memory deficits, in that we identified neurogranin, a down-regulated gene in high-fat diet-fed mice using RNA-seq analysis; neurogranin regulates Ca<SUP>2+</SUP>/calmodulin-dependent synaptic function. Caloric restriction increased insulin sensitivity, reduced high-fat diet-induced blood-brain barrier leakage and glial activation, and improved memory deficit. Furthermore, caloric restriction reversed high-fat diet-induced expression of neurogranin and the activation of Ca<SUP>2+</SUP>/calmodulin-dependent protein kinase II and calpain as well as the downstream effectors. Our results suggest that neurogranin is an important factor of high-fat diet-induced memory deficits on which caloric restriction has a therapeutic effect by regulating neurogranin-associated calcium signaling. </P>

Analysis of the Bicycle-Sharing Economy : Strategic Issues for Sustainable Development of Society

Hwajin Kim,조윤정 한국유통과학회 2018 유통과학연구 Vol.16 No.7

Purpose - This study posits that sustainable mobility of the sharing economy plays a key role to consider environment benefits. The purpose of this study is to investigate the bicycle-sharing economy as an emerging and alternative mode of transportation service and provide managerial and policy implications. The bicycle-sharing economy is still at an early stage of introduction as a transportation mode, while the governmental sector is promoting public bicycle-sharing to encourage bicycle as a substitute for private cars. Research design, data, and methodology - This study analyzed the current status of bicycle sharing programs through a survey that was distributed randomly to users and non-users across the country. Using factor analysis, satisfaction and loyalty for the existing users and intention to use and expected satisfaction for the potential users were examined in relation to utility factors. Results – The results show that economic utility affects satisfaction for user, while storage, mobility, and economic utility affects intention to use for potential users. The findings of this study indicate that in order to promote a bicycle-sharing scheme, it would be better to focus on the scheme’s economic advantage to be truly effective. Conclusions - The findings of the study could be applicable to future directions of the sharing economy as a means to achieve the sustainable development of society.

Hygroscopic properties of urban aerosols and their cloud condensation nuclei activities measured in Seoul during the MAPS-Seoul campaign

Kim, Najin,Park, Minsu,Yum, Seong Soo,Park, Jong Sung,Song, In Ho,Shin, Hye Jung,Ahn, Joon Young,Kwak, Kyung-Hwan,Kim, Hwajin,Bae, Gwi-Nam,Lee, Gangwoong Elsevier 2017 Atmospheric environment Vol.153 No.-

<P>Aerosol physical properties, chemical compositions, hygroscopicity and cloud condensation nuclei (CCN) activities were measured in Seoul, the highly populated capital city of Korea, during the Megacity Air Pollution Studies (MAPS-Seoul) campaign, in May-June 2015. The average aerosol concentration for particle diameters >10 nm was 11787 +/- 7421 cm(-3) with dominant peaks at morning rush hours and in the afternoon due to frequent new particle formation (NPF) events. The average CCN concentration was 4075 +/- 1812 cm(-3) at 0.6% supersaturation, with little diurnal variation. The average hygroscopicity parameter (K) value determined using a humidified tandem differential mobility analyzer (HTDMA) ranged 0.17-0.27 for a range of particle diameters (30-150 nm). The K values derived using the aerosol mass spectrometer (AMS) data with three different methods were 0.32-0.34, significantly higher than those from HTDMA due to the uncertainties in the hygroscopicity values of different chemical compositions, especially organics and black carbon. Factors affecting the aerosol hygroscopicity seemed to be traffic and chemical processes during the NPF events. The CCN concentration predicted based on HTDMA K data showed very-good agreement with the measured one. Because of the overestimation of K, CCN closure with the predicted CCN concentration based on AMS K data over-predicted CCN concentration although the linear correlation between measured and predicted CCN concentration was still very good. (C) 2017 Elsevier Ltd. All rights reserved.</P>

Chemistry of new particle growth during springtime in the Seoul metropolitan area, Korea

Kim, Hwajin,Zhang, Qi Elsevier 2019 CHEMOSPHERE - Vol.225 No.-

<P><B>Abstract</B></P> <P>New particle formation and growth events (NPEs) were frequently observed (17 out of 60 days) during April 14 to June 15, 2016 in the Seoul metropolitan area (SMA). In this study, we investigated the chemical mechanisms of new particle growth based on measurements conducted using an aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a scanning mobility particle sizer (SMPS). Both instruments were deployed as a part of the KORUS-AQ campaign (Korea-US Air Quality study). NPEs usually started around noon time between ∼11:00 and 14:00 with the appearance of an ultrafine mode peaking between ∼20 and 30 nm (in mobility diameter, <I>D</I> <SUB>m</SUB>, measured by the SMPS operating in the range 18–947 nm) followed by the growth of this modal diameter to 50–100 nm during the next ∼6–18 h. The growth rate of NPEs during the study was on average 4.48 ± 1.39 nm/h. Comparing to the non-NPE days in SMA, NPEs occurred under the conditions of lower concentration of preexisting particles, higher ozone (48 vs 30 ppb), stronger solar radiation (2.53 vs1.20 MJ/m<SUP>2</SUP>), and drier air (34 vs 65%). The HR-ToF-AMS size-resolved aerosol composition measurements show that LV-OOA (low volatility oxidized organic aerosol) and sulfate were major contributors to the growth of new particles at the initial stage of NPE which mostly occurred during daytime and that the later growth which extended into nighttime was mainly contributed by semi-volatile condensable species such as nitrate and SV-OOA (semi-volatile oxygenated organic aerosol). Generally new particles grew to a modal size of ∼80 nm (12 out of 17 NPEs) over the course of an event, however, particles could grow to larger than 100 nm when nitrate concentration was high whereas particle growth was limited to ∼ 50 nm when nitrate, SV-OOA or sulfate were low.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Photochemical formation of sulfate and LV-OOA are important for the initial growth of particles. </LI> <LI> Later growth was extended into nighttime mainly by nitrate and SV-OOA. </LI> <LI> Concentration of condensable species are important for the size of particles. </LI> </UL> </P>

Exendin-4 Improves Nonalcoholic Fatty Liver Disease by Regulating Glucose Transporter 4 Expression in ob/ob Mice

Kim, Seok,Jung, Jaehoon,Kim, Hwajin,Heo, Rok Won,Yi, Chin-Ok,Lee, Jung Eun,Jeon, Byeong Tak,Kim, Won-Ho,Hahm, Jong Ryeal,Roh, Gu Seob The Korean Society of Pharmacology 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.4

Exendin-4 (Ex-4), a glucagon-like peptide-1 receptor (GLP-1R) agonist, has been known to reverse hepatic steatosis in ob/ob mice. Although many studies have evaluated molecular targets of Ex-4, its mechanism of action on hepatic steatosis and fibrosis has not fully been determined. In the liver, glucose transporter 4 (GLUT4) is mainly expressed in hepatocytes, endothelial cells and hepatic stellate cells (HSCs). In the present study, the effects of Ex-4 on GLUT4 expression were determined in the liver of ob/ob mice. Ob/ob mice were treated with Ex-4 for 10 weeks. Serum metabolic parameters, hepatic triglyceride levels, and liver tissues were evaluated for hepatic steatosis. The weights of the whole body and liver in ob/ob mice were reduced by long-term Ex-4 treatment. Serum metabolic parameters, hepatic steatosis, and hepatic fibrosis in ob/ob mice were reduced by Ex-4. Particularly, Ex-4 improved hepatic steatosis by enhancing GLUT4 via GLP-1R activation in ob/ob mice. Ex-4 treatment also inhibited hepatic fibrosis by decreasing expression of connective tissue growth factor in HSCs of ob/ob mice. Our data suggest that GLP-1 agonists exert a protective effect on hepatic steatosis and fibrosis in obesity and type 2 diabetes.

Development of An Intelligent Planner for Heterarchical Shop Floor Control

Hwajin Kim,Hyunbo Cho,Mooyoung Jung 대한산업공학회 1995 대한산업공학회 추계학술대회논문집 Vol.1995 No.10

Chemical processing of water-soluble species and formation of secondary organic aerosol in fogs

Kim, Hwajin,Collier, Sonya,Ge, Xinlei,Xu, Jianzhong,Sun, Yele,Jiang, Wenqing,Wang, Youliang,Herckes, Pierre,Zhang, Qi Elsevier 2019 Atmospheric environment Vol.200 No.-

<P><B>Abstract</B></P> <P>A field study on fog chemistry and aqueous-phase processing of aerosol particles was conducted in Fresno, California's San Joaquin Valley (SJV) during wintertime. Fog droplets were collected while interstitial submicron aerosol was characterized in real time using a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-AMS). The fog samples were later analyzed using HR-AMS, ion chromatography (IC), and total organic carbon analyzer (TOC). Compared to interstitial aerosol, dissolved solutes in fog waters were composed of higher fractions of ammonium, nitrate, sulfate, methanesulfonic acid, and oxygenated organic compounds, likely due to aqueous formation of secondary species as well as enhanced gas-to-particle partitioning of water-soluble gases under humid conditions. The low-volatility dissolved organic matter in fog water (F-OA) was moderately oxidized with an average oxygen-to-carbon (O/C) ratio of 0.42. The chemical composition of F-OA appeared to be overall similar to that of oxygenated organic component in interstitial aerosol (OOA) and the HR-AMS mass spectra of F-OA and OOA are highly similar (r<SUP>2</SUP> > 0.95). However, there are also significant chemical differences as F-OA appeared to contain a larger fraction of carboxylic functional groups than OOA, indicating enhanced organic acid formation through aqueous-phase reactions. In addition, F-OA was composed of substantially more nitrogen-containing compounds, with an average N/C ratio ∼4 times that of OOA. Most strikingly was that the F-OA spectra showed substantial enhancements of the C<SUB>x</SUB>H<SUB>y</SUB>N<SUB>2</SUB> <SUP>+</SUP> (x ≥ 0; y ≥ 0) ions, which were likely contributed by imidazole- and/or pyrazine-based compounds formed from the aqueous reactions of aldehydes with amino compounds. The results of this study demonstrated that aqueous reactions in atmospheric droplets can significantly modify aerosol composition and contribute to the formation of oxygenated and nitrogen-containing organic compounds in atmospheric aerosol particles. This finding is important for understanding aerosol's effects on human health, air quality, and climate.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HR-AMS study of fog processing of PM1 in San Joaquin Valley of CA during winter. </LI> <LI> Fog waters are enriched of secondary inorganic and organic aerosol species. </LI> <LI> Organic residuals in fog waters (FOM) is moderately oxidized (average O/C = 0.42). </LI> <LI> FOM has more abundant carboxylic acid and organic nitrogen compounds than OOA. </LI> <LI> This is evidence for forming imidazole- or pyrazine-based compounds in fog waters. </LI> </UL> </P>

Understanding On Emission Sources And Formation Processes Of Organic Aerosols In The Seoul Atmosphere

Hwajin Kim(김화진) 대한환경공학회 2021 대한환경공학회 학술발표논문집 Vol.2021 No.11