Projections of summertime ozone concentration over East Asia under multiple IPCC SRES emission scenarios

Lee, Jae-Bum,Cha, Jun-Seok,Hong, Sung-Chul,Choi, Jin-Young,Myoung, Ji-Su,Park, Rokjin J.,Woo, Jung-Hun,Ho, Changhoi,Han, Jin-Seok,Song, Chang-Keun Elsevier 2015 Atmospheric environment Vol.106 No.-

<P><B>Abstract</B></P> <P>We have developed the Integrated Climate and Air Quality Modeling System (ICAMS) through the one-way nesting of global–regional models to examine the changes in the surface ozone concentrations over East Asia under future climate scenarios. Model simulations have been conducted for the present period of 1996–2005 to evaluate the performance of ICAMS. The simulated surface ozone concentrations reproduced the observed monthly mean concentrations at sites in East Asia with high R<SUP>2</SUP> values (0.4–0.9), indicating a successful simulation to capture both spatial and temporal variability. We then performed several model simulations with the six IPCC SRES scenarios (A2, A1B, A1FI, A1T, B1, and B2) for the next three periods, 2016–2025 (the 2020s), 2046–2055 (the 2050s), and 2091–2100 (the 2090s). The model results show that the projected changes of the annual daily mean maximum eight-hour (DM8H) surface ozone concentrations in summertime for East Asia are in the range of 2–8 ppb, −3 to 8 ppb, and −7 to 9 ppb for the 2020s, the 2050s, and the 2090s, respectively, and are primarily determined based on the emission changes of NO<SUB>x</SUB> and NMVOC. The maximum increases in the annual DM8H surface ozone and high-ozone events occur in the 2020s for all scenarios except for A2, implying that the air quality over East Asia is likely to get worse in the near future period (the 2020s) than in the far future periods (the 2050s and the 2090s). The changes in the future environment based on IPCC SRES scenarios would also influence the change in the occurrences of high-concentrations events more greatly than that of the annual DM8H surface ozone concentrations. Sensitivity simulations show that the emissions increase is the key factor in determining future regional surface ozone concentrations in the case of a developing country, China, whereas a developed country, Japan would be influenced more greatly by effects of the regional climate change than the increase in emissions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Change in ozone level is determined by the combination of NO<SUB>x</SUB> and NMVOC emissions. </LI> <LI> Ozone level over East Asia would get worse in the near future (the 2020s) than far future. </LI> <LI> A high-concentration event generally increases and more frequently occurs in the future. </LI> <LI> Change in ozone air quality in a developing country depends more on emissions change. </LI> <LI> Change in ozone air quality in a developed country depends more on climate change. </LI> </UL> </P>

공간정보를 이용한 광안리 해안선 변화에 관한 연구

최철웅(Choi Chul Uong),오치영(Oh Che Young),이창헌(Lee Chang Hun) 대한공간정보학회 2009 대한공간정보학회지 Vol.17 No.1

광안리 해수욕장은 해운대 해수욕장과 더불어 부산을 대표하는 해수욕장 중 하나로 2003년 광안대로 완공 이후 관광객이 꾸준히 늘어 2006년에는 1,000만명 이상의 관광객이 찾는 관광명소이다. 관할구청에서는 광안리 해수욕장 관리를 위해 해마다 양빈사업과 자갈제거 작업을 수행하고 있지만 체계적인 모니터링과 침식에 관한 연구는 미비한 실정이다. 본 연구에서는 지난 60년간 항공사진, 조석자료, GPS측량자료를 이용하여 광안리 해수욕장의 해안선의 변화를 분석하고, 광안리 해상에 건설된 광안대교가 해안선변화에 얼마나 영향을 미치는지 알아보았다. 그 결과 지난 60년간 광안리 해변의 면적은 40% 증가하였으며, 광안대교가 해안선 변화에 미치는 영향은 미비한 것으로 나타났다. The Gwangalli Beach, one of beaches representative of Busan together with the Haeundae Beach, is a tourist attraction, having increased tourists since the completion of Gwangandaero Bridge in 2003 and recording more than 10 million tourists in 2006. Although the competent local government office has conducted artificial beach nourishment/gravel removal projects every year to manage it, systematic monitoring and studies of erosion are insufficient. This study analyzed the changes in the coastline of Gwangalli Beach using aerial photos, tidal data, GPS survey data for the last sixty years, and examined how the Gwangandaero Bridge, which had been constructed on the Gwanganlli sea, has affected the changes. The results show that the area of Gwangalli Beach has increased 40% for the last sixty years, and that the effects of Gwangandaero Bridge on the coastline are insignificant.

High-Resolution Capacitive Microinclinometer With Oblique Comb Electrodes Using (110) Silicon

Dae-Hun Jeong,Sung-Sik Yun,Byung-Geun Lee,Myung-Lae Lee,Chang-Auk Choi,Jong-Hyun Lee IEEE 2011 Journal of microelectromechanical systems Vol.20 No.6

<P>We propose a new capacitive microinclinometer where oblique comb electrodes and double-folded suspension springs are aligned parallel to the vertical (111) plane of (110) silicon. The oblique comb utilizes both the overlapped area and the gap between movable and stationary electrodes, resulting in a considerable increase in sensitivity (capacitance change/angle). The resolution becomes even higher by taking advantage of the smooth (111) sidewalls of the oblique comb electrodes, which are fabricated using silicon deep reactive ion etching followed by crystalline wet etching. The surface roughness was reduced from 200 (R<SUB>rms</SUB>) to 20 nm (R<SUB>rms</SUB>), and the verticality was improved from 88.7° to 89.7°. The capacitance change of the fabricated inclinometer experimentally ranges from -0.793 to 0.783 pF for the full range of inclination angle (from -90° to 90°). The estimated worst resolution, which is obtainable at an inclination angle of ±85°, was as low as 0.25°.</P>

Usefulness of Skin Explants for Histologic Analysis after Fractional Photothermolysis

( Gyeong Hun Park ),( Sung Eun Chang ),( Seunghyun Bang ),( Kwang Hee Won ),( Chong Hyun Won ),( Mi Woo Lee ),( Jee Ho Choi ),( Kee Chan Moon ) 대한피부과학회 2015 Annals of Dermatology Vol.27 No.3

Background: Fractional laser resurfacing treatment has been extensively investigated and is widely used. However, the mechanism underlying its effects is poorly understood because of the ethical and cosmetic problems of obtaining skin biopsies required to study the changes after laser treatment. Objective: To evaluate the usefulness of human skin explants for the investigation of fractional photothermolysis. Methods: Full-thickness discarded skin was treated in 4 ways: no treatment (control), fractional carbon dioxide laser, fractional Er:YAG laser, and fractional 1,550-nm erbium- doped fiber laser. Both treated and non-treated skin samples were cultured ex vivo at the air-medium interface for 7 days. Frozen tissue was sectioned and stained with hematoxylin & eosin for histologic examination and nitro blue tetrazolium chloride for viability testing. Results: Skin explants cultured for up to 3 days exhibited histologic changes similar to those observed in in vivo studies, including microscopic treatment zones surrounded by a thermal coagulation zone, re-epithelialization, and formation of microscopic epidermal necrotic debris. However, the explant structure lost its original form within 7 days of culture. The viability of skin explants was maintained for 3 days of culture but was also lost within 7 days. Conclusion: The skin explant model may be a useful tool for investigating the immediate or early changes following fractional photothermolysis, but further improvements are required to evaluate the long-term and dermal changes. (Ann Dermatol 27(3) 283∼290, 2015)

스펙트럼 변이를 이용한 Soft Decision 기반의 음성향상 기법

최재훈(Jae-Hun Choi),장준혁(Joon-Hyuk Chang),김남수(Nam-Soo Kim) 大韓電子工學會 2010 電子工學會論文誌-SP (Signal processing) Vol.47 No.5

본 논문에서는 비정상적인 배경 잡음 환경에서 음성향상을 위한 신호의 스펙트럼 변이 (Spectral Deviation)을 적용한 Soft Decision 기반의 잡음전력 수정 기법을 제안한다. 기존의 Soft Decision 기반의 잡음전력 추정에 있어서 잡음신호의 정상성(Stationarity)을 가정한 스무딩 파라미터를 사용하여 잡음전력을 추정하고 갱신하였지만, 잡음신호의 주파수적인 특성이 상대적으로 빠르게 변하는 비정상적인 환경에서는 강인하지 못한 단점을 가지게 된다. 본 논문에서는 신호의 스펙트럼 변이를 추정하여 정상적인 잡음 환경과 비정상적인 잡음 환경에 따라 적응적으로 잡음전력을 추정하고 갱신하여 잡음신호에 의해 오염된 음성신호를 향상시킨다. 제안된 알고리즘은 다양한 배경 잡음 환경에서 객관적인 음질측정 방법인 ITU-T P.862 perceptual evaluation of speech quality (PESQ)에 의해서 평가되었으며, 기존의 Soft Decision 기반의 음성 향상 기법과 비교하여 보다 향상된 성능을 보여주었다 In this paper, we propose a new approach to noise estimation incorporating spectral deviation with soft decision scheme to enhance the intelligibility of the degraded speech signal in non-stationary noisy environments. Since the conventional noise estimation technique based on soft decision scheme estimates and updates the noise power spectrum using a fixed smoothing parameter which was assumed in stationary noisy environments, it is difficult to obtain the robust estimates of noise power spectrum in non-stationary noisy environments that spectral characteristics of noise signal such as restaurant constantly change. In this paper, once we first classify the stationary noise and non-stationary noise environments based on the analysis of spectral deviation of noise signal, we adaptively estimate and update the noise power spectrum according to the classified noise types. The performances of the proposed algorithm are evaluated by ITU-T P. 862 perceptual evaluation of speech quality (PESQ) under various ambient noise environments and show better performances compared with the conventional method.

가스성분 및 용접와이어의 변화에 따른 SS400소재의 CO₂용접에서 용접부의 상태변화 고찰

김법헌(Bub-Hun Kim),김원일(Won-Il Kim),최창(Chang Choi),박용환(Yong-Hwan Park) 한국기계가공학회 2012 한국기계가공학회지 Vol.11 No.5

On this study, CO₂ gas, net of Ar gas, and mixed gas in solid wire(AWS ER 70S-6) and flux cored wire(AWS E71T-1) were used to weld on Mild steel(SS400). After the progress, the status changes of the welds in Mild steel(SS400) were investigated with compositional changes. For stable experiments, welding was conducted using the automatic feeder. Radiation testing, hardness testing, chemical composition analysis and penetrated cross-section were measured. Through these experiments, shapes of penetrated cross-section, chemical composition changes, and weld defects according to the variation of welding gas were known. Weld defects and weld cross-sectional shapes by the variation of the welding voltage were also detected.

급성 췌장염으로 발현된 낭성 변화를 일으킨 종격동 부갑상선 선종 1예

권태현,박진흥,윤설영,이창렬,이준호,최소진,손성표,허갑도,최영식,박영효 성분도병원 1998 성분도병원논문집 Vol.4 No.-

Interferon-γ Inhibits in vitro Mobilization of Eosinophils by Interleukin-5

Park, Choon-Sik,Choi, Eun Nam,Kim, Jung Sun,Choi, Yun Sung,Rhim, Tai Youn,Chang, Hun Soo,Chung, Il Yup S. Karger AG 2005 International archives of allergy and immunology Vol.136 No.3

<P><I>Background:</I> Th2 cytokines play pivotal roles in allergic inflammation, including eosinophilia, and their actions are antagonized by Th1 cytokines, conferring them therapeutic potential. <I>Methods:</I> In this study, we examined the ability of a number of cytokines to suppress the activation of eosinophils that function as effector cells for allergic airway diseases. <I>Results:</I> Interleukin (IL)-5, IL-6, and tumor necrosis factor (TNF) induced an eosinophil shape change, whereas interferon (IFN)-γ significantly inhibited the shape change. Other cytokines, including IL-1β, IL-4, IL-10 and IL-13, had little or only slightly enhancing or reducing effects on the shape change. We further analyzed the IFN-γ effect, showing that pretreatment with IFN-γ strongly suppressed IL-5-induced eosinophil shape change, and cycloheximide (CHX) abrogated the suppression by IFN-γ, suggesting that new protein synthesis is required for the inhibitory effect by this cytokine. In agreement with these results, IFN-γ blocked the eosinophil migration and ERK phophorylation induced by IL-5, and the addition of CHX restored eosinophil chemotaxis. <I>Conclusions:</I> Collectively, IFN-γ may attenuate eosinophilic inflammation by directly negating eosinophil mobilization.</P><P>Copyright © 2005 S. Karger AG, Basel</P>

부인과 암수술에 있어서 외과의사의 역할

최평화(Pyong Wha Choi),유창식(Chang Sik Yu),정상훈(Sang Hun Jung),김대동(Dae Dong Kim),홍동현(Dong Hyun Hong),김희철(Hee Cheol Kim),김진천(Jin Cheon Kim) 대한외과학회 2008 Annals of Surgical Treatment and Research(ASRT) Vol.74 No.4

Purpose: Resection of the bowel or solid organs may be required for pelvic tumor surgery. The present study was performed to assess combined surgical procedures and determine the role of the general surgeon in gynecologic oncology surgery Methods: We performed a retrospective study of 135 patients with gynecologic malignancy who underwent a combined operation with a general surgeon between January 2000 and December 2005 at Asan Medical Center. The purpose of the combined operation was categorized into 3 groups: a tumor debulking operation, a resolution of intraoperative complications by a gynecologic surgeon, or an intraoperative diagnostic change. Results: The incidence of combined operations for debulking, resolution of intraoperative complications, and intraoperative diagnostic changes were 103 cases (76.3%), 22 cases (16.3%), and 10 cases (7.4%), respectively. Ovarian cancer was the most common gynecologic malignancy (74.1%) and the rate of a combined operation with a general surgeon in ovarian cancer was 18.5% during the time period. Colorectal resection was the most common procedure by a colorectal surgeon (61.5%). Twenty four patients (17.8%) experienced postoperative complications, including ileus, wound infection, pancreas leakage, and stomal necrosis, with no significant differences according to the purpose of combined operation, pathologic diagnosis, or bowel preparation. The rate of a preoperative consultation to a general surgeon by gynecologic surgeons in cases with colorectal or solid organ invasion preoperatively was 53.2%. Conclusion: A general surgeon is an important consultant in a debulking operation of gynecologic malignancies, especially ovarian cancer, or treatment of complications. Thorough preoperative evaluation, bowel preparation, and preoperative consultation to a general surgeon is important in gynecologic oncology surgery.

가강수량의 변화패턴과 기후인자와의 상관성 분석

이다래 ( Darae Lee ),한경수 ( Kyung Soo Han ),권채영 ( Chaeyoung Kwon ),이경상 ( Kyeong Sang Lee ),서민지 ( Minji Seo ),최성원 ( Sungwon Choi ),성노훈 ( Noh Hun Seong ),이창석 ( Chang Suk Lee ) 대한원격탐사학회 2016 大韓遠隔探査學會誌 Vol.32 No.3

수증기는 지구 장파 복사에너지의 주요 흡수인자이다. 따라서 수증기량의 변화를 모니터링하고 변화의 원인을 세밀하게 조사하는 것은 필수적이다. 본 연구에서는 위성관측에 의해 얻어지는 Total Precipitable Water (TPW)자료를 사용하여 가강수량의 변화패턴을 모니터링 하고자 한다. 또한 기후인자들 중 수증기를 통해 생성되어 수증기의 변화패턴을 분석하는데 있어 중요한 역할을 하는 강수량과 다른 기후인 자들에 비해 비교적 주기적으로 나타나는 엘니뇨를 통해 가강수량의 변화패턴과 기후인자와의 상관성분석을 실시하고자 한다. 본 연구에서는 TERRA/AQUA 위성의 Moderate-Resolution Imaging Spectroadiometer (MODIS) 센서를 통해 관측된 TPW의 장기적인 변화와 한반도 중남부지방의 강수량변화를 정량적으로 분석 하고, 이들의 관계를 엘니뇨와 함께 비교하였다. 이를 통해 엘니뇨의 발생이 한반도 중남부지방의 강수량과 TPW의 변화에 영향을 주고 있는 지에 대해 조사하고자 한다. 먼저, 시계열 분석을 통해 TPW와 중남부지방 강수량의 변화를 정량적으로 산출하고 anomaly분석을 통해 이들의 변화를 세밀하게 분석한 결과 서로 반대 의 양상을 띠는 부분이 발견되어 엘니뇨의 anomaly분석결과와 비교하였다. 그 결과 대부분 같은 양상을 띠고 있던 TPW와 강수량이 엘니뇨가 발생한 후 서로 반대의 양상을 띠는 것을 확인하였다. Water vapor is main absorption factor of outgoing longwave radiation. So, it is essential to monitoring the changes in the amount of water vapor and to understanding the causes of such changes. In this study, we monitor temporal variability of Total Precipitable Water (TPW) which observed by satellite. Among climate variables, precipitation play an important part to analyze temporal variability of water vapor because it is produced by water vapor. And El Nino is one of climate variables which appear regularly in comparison with the others. Through them, we analyze relationship between temporal variability of TPW and climate variable. In this study, we analyzed long-term change of TPW from Moderate-Resolution Imaging Spectroadiometer (MODIS) data and change of precipitation in middle area of Korea peninsula quantitatively. After these analysis, we compared relation of TPW and precipitation with El Nino. The aim of study is to research El Nino has an impact on TPW and precipitation change in middle area of Korea peninsula. First of all, we calculated TPW and precipitation from time series analysis quantitatively, and anomaly analysis is performed to analyze their correlation. As a result, TPW and precipitation has correlation mostly but the part had inverse correlation was found. This was compared with El Nino of anomaly results. As a result, TPW and precipitation had inverse correlation after El Nino occurred. It was found that El Nino have a decisive effect on change of TPW and precipitation.