Ambient Fine and Ultrafine Particle Measurements and Their Correlations with Particulate PAHs at an Elementary School Near a Highway

Sanghwan Song,백도명,Young-Mee Lee,Chulwoo Lee,Chunghee Park,Seung-Do Yu 한국대기환경학회 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.2

Ambient particulate matter (PM) and particle-bound polycyclic aromatic hydrocarbon (PAH) concentrations were measured continuously for 70 days at a Korean elementary school located near a highway. The PM10,PM2.5, and PM1 values were measured with a lightscattering,multi-channel, aerosol spectrometer (Grimm, Model 1.107). The number concentrations of the particles were measured using a scanning mobility particle sizer and counter (SMPS+C) which counted particles from 11.1 to 1083.3 nm classified in 44 channels. Particle-bound PAHs were measured with a direct reading, photoelectric aerosol sensor. The daily NO2, SO2, and CO concentrations were obtained from a national air-monitoring station located near the school. The average concentrations of PM10,PM2.5, and PM1 were 75.3, 59.3, and 52.1 μg/m3, respectively. The average number concentration of the ultrafine particles (UFPs) was 46,307/cm3, and the averaged particle-bound PAHs concentration was 17.9ng/m3 during the study period. The ambient UFP variation was strongly associated with traffic intensity, particularly peak concentrations during the traffic rush hours. Particles ⁄100 nm corresponded to trafficrelated pollutants, including PAHs. Additional longterm monitoring of ambient UFPs and high-resolution traffic measurements should be carried out in future studies. In addition, transient variations in the ambient particle concentration should be taken into consideration in epidemiology studies in order to examine the short-term health effects of urban UFPs.

Ecological risk assessment of estrogenic effects of bisphenol A on fish in Korea

Sanghwan Song,Chulwoo Lee,Jisung Ryu,Eung-Roh Park,Soo-Young Park,Eun-Kyoung Kim,Hyun-Mi Kim,KyungHee Choi,Kwang-Soo Choi,Jin-Gyun Na,Deok-Gil Rhee 환경독성보건학회 2004 한국독성학회 심포지움 및 학술발표회 Vol.- No.-

Initial Risk Assessment of Disodium Disulphite in OECD High Production Volume Chemical Program

Sanghwan Song,Yoonho Choi,Hye-Youn Park,Minjeong Kwon,Hyunju Koo,Seong-Hwan Jeon,Jin-Gyun Na,Kwangsil Park 한국독성학회 2002 Toxicological Research Vol.18 No.1

Disodium disulphite, the HPV chemical, was assigned to Korea in order to implement OECD SIDS program in 1999. It was produed about 3,200 ton/year in 1998. This report evaluates the toxic potency of disodium disuphite based on the environmental and mammalian effects as well as human exposure. Oral LD_(50) in rats is 1,540 mg/kg b.w. and effects was observed to the stomach, liver, and the GI track that was filled with blood. For repeated dose toxicity, the predominant effect was the induction of stomach lesions due to local irritation. The no observed adverse effect level for local (stomach irritation) was about 217 mg/kg bw/day. There is no evidence that disodium disulphite is genotoxic in vivo. No reproductive or developmental toxicity of disodium disulphite was observed for the period up to 2 yr and over three generations. In humans, urticaria and asthma with itching, edema, rhinitis, and nasal congestion were reported. Disodium disulphite is unlikely to induce respiratory sensitization but may enhance symptoms of asthma in sensitive individuals. This chemical would be mainly transported to water compartment when released to environmental compartments since it is highly water soluble (470 g/l at 20). Low K_(OC) (2.447) indicates disodium disulphite is so mobile in soil that it may not stay in the terrestrial compartment. The chemical has been tested in a limited number of aquatic species. From acute toxicity test to fish, 96 hr-LC_(50) was > 100 mg/l. For algae, 72hr-EC_(50) was 48.1 mg/l. For daphnid, the acute toxicity value of 48 hr-EC_(50) was 88.76 mg/l, and chronic value of 21day-NOEC was > 10 mg/l. Therefore, PNEC of 0.1 mg/l for the aquatic organisms was obtained from the chronic value of daphnid using the assessment factor of 100. Based on these data the disodium disulphite was recommended as low priority for further post-SIDS work in OECD.

Dynamic Response Analysis of a Jack-up Leg with Pile-Soil Interaction

Sanghwan Heo(허상환),Weoncheol Koo(구원철),Min-Su Park(박민수) 한국신재생에너지학회 2015 한국신재생에너지학회 학술대회논문집 Vol.2015 No.6

DYNAMIC RESPONSE ANALYSIS OF WAVE ENERGY CONVERTER PLATFORM WITH OSCILLATING MULTI-BUOY

Sanghwan HEO,WeonCheol KOO,Min-Su PARK 한국신재생에너지학회 2017 AFORE Vol.2017 No.11

Dynamic Response Analysis of a Bottom-Fixed 5-MW Jacket Foundation Offshore Wind Turbine

Sanghwan Heo,Weoncheol Koo 한국신재생에너지학회 2023 AFORE Vol.2023 No.11

chandelier garden

이상환(Sanghwan Lee) 한국디자인학회 2016 한국디자인학회 국제초대전도록 Vol.2016 No.12

실내 무선 메쉬 네트워크에서의 간섭 최소화를 위한 메쉬 라우터 배치 기법

이상환(Sanghwan Lee) 한국정보과학회 2010 정보과학회 컴퓨팅의 실제 논문지 Vol.16 No.4

무선 메쉬 네트워크는 쉬운 설치와 향상된 커버리지로 인해 많은 관심과 연구가 진행되고 있다. 예를 들면 메쉬 네트워크에서 throughput을 향상시키는 라우팅 프로토콜에 관한 연구나, 메쉬 링크의 품질을 측정하는 방법 등 다양하다. 하지만 이러한 연구들 중 대부분은 메쉬 라우터의 위치가 고정되어있다고 가정한다. 하지만 실내 메쉬 네트워크의 경우 관리자가 메쉬 네트워크를 독점적으로 관리하기 때문에 설치 시에 메쉬 라우터를 설치할 위치를 마음대로 결정할 수 있다. 따라서 처음부터 메쉬 네트워크의 성능을 고려하여 메쉬 라우터를 설치하는 것은 성능향상에 필수적이다. 이 논문에서는 유전자 기반 최적화 알고리즘을 바탕으로 메쉬 네트워크의 특성 (간섭, 패킷 전달 토폴로지 등)을 고려한 메쉬 라우터 위치 선정 기법을 제시한다. 기존에 메쉬 네트워크는 아니지만 다양한 무선 내트워크에서 기지국이나 AP등을 설치하는 문제가 연구되었고, 메쉬 네트워크의 고정된 메쉬 라우터 집합에서 게이트웨이를 선택하는 문제등이 연구되었지만, 메쉬 라우터의 위치를 선택하는데 있어서, 메쉬 라우터들의 위치나 메쉬 라우터 상에서의 패킷 전송 토폴로지에 의한 간섭을 고려한 연구는 없었다. 다양한 시뮬레이션을 통해 이 논문에서 제시된 기법이 랜덤 선택 기법에 비해 30-40%의 향상을 달성하였음을 보였다. Due to the ease of deployment and the extended coverage, wireless mesh networks (WMNs) are gaining popularity and research focus. For example, the routing protocols that enhance the throughput on the WMNs and the link quality measurement schemes are among the popular research topics. However, most of these works assume that the locations of the mesh routers are predetermined. Since the operators in an Indoor mesh network can determine the locations of the mesh routers by themselves, it is essential to the WMN performance for the mesh routers to be initially placed by considering the performance issues. In this paper, we propose a mesh router placement scheme based on genetic algorithms by considering the characteristics of WMNs such as interference and topology. There have been many related works that solve similar problems such as base station placement in cellular networks and gateway node selection in WMNs. However, none of them actually considers the interference to the mesh clients from non-associated mesh routers in determining the locations of the mesh routers. By simulations, we show that the proposed scheme improves the performance by 30-40% compared to the random selection scheme.

Synthesis of Primary-Particle-Size-Tuned Soot Particles by Controlled Pyrolysis of Hydrocarbon Fuels

Cho, Sanghwan,Lee, Seunghoon,Lee, Wonnam,Park, Sunho American Chemical Society 2016 ENERGY AND FUELS Vol.30 No.8

<P>We have developed a pyrolysis-based soot-generating system, which is able to control the primary soot particle size. The system is clean and portable and runs On diverse hydrocarbon fuels of interest. To evaluate the performance of the system, soot was generated from n-hexane and propylene with various conditions of the temperature, fuel mole fraction, and residence time in the heating zone. The results showed that the primary soot particle size was controllable within the range of 20-60 nm, and the soot yield as a function of the residence time followed a logistic curve of different shape depending upon the fuel mole fraction and healing temperature. The system that we developed can be used as a reliable soot-generating source for diverse laboratories to meet the growing demands for fundamental research on soot characteristics and soot formation mechanisms as well as the assessment of health and environmental effects of soot from various sources.</P>

경제위기와 유럽의 좌파 정치

장상환(Sanghwan Jang) 경상대학교 사회과학연구원(마르크스주의 연구) 2010 마르크스주의 연구 Vol.10 No.2

대공황 이후 최대 경제위기에 직면한 유럽 각국은 금융구제와 재정지출 확장 등 경기 부양정책을 폈지만 결국 재정위기라는 새로운 모순을 안게 되었다. 각국 정부가 재정긴축을 추진하면서 계급 간의 대립과 투쟁이 격화되고 있다. 경제위기는 사회주의자, 급진 좌파에게 신자유주의를 수용해 정체성 위기에 빠진 사회민주주의 정당의 왼쪽에 폭넓은 반자본주의 좌파정당을 건설하는 데 좋은 기회를 제공했다. 그러나 각국별로 급진좌파 정당이 거둔 성과는 다양하다. 독일 좌파당과 포르투갈 좌파블록 등은 성공적인 반면에 이탈리아와 영국은 지리멸렬한 상황이다. 프랑스 반자본주의신당의 성과도 향후 기대할만하다. 급진좌파의 정치에는 객관적 조건 못지않게 주체적 조건이 크게 작용함을 보여준다. 폭넓은 좌파정당을 결성하는 것이 핵심과제인데 기존 정당 내지 정치조직을 유지하고 독자적으로 활동하면서 좌파정당을 공동전선 조직으로 간주하고 대응하는 것은 지지부진하거나 분열이 초래되는 등 명확한 한계를 드러냈다. 급진좌파들은 독립적 정당 내지 정치조직을 해소하고 폭넓은 좌파정당 속에서 분파로서 실천함으로써 좌파정당이 사회를 변혁하는 유력한 기반이 될 수 있도록 발전시켜야 할 것이다. 과거 혁명의 전통과의 연결 탓에 유럽의 급진좌파들은 이념적 지향이 강하다. 이념은 과거 사실과 경험을 기반으로 형성된 것으로 시대의 변화를 신속하게 반영하지 못한다. 이에 급진좌파는 현실의 변화를 인식하고 다른 좌파그룹들과 협력하여 효과적으로 대응하는 데 어려움을 겪는다. 급진좌파는 일개 조직이 모든 문제에 대한 해답을 제공할 수 없다는 인식을 바탕으로, 당내 민주주의 확립, 개혁과 혁명의 변증법적 동학의 정치전략, 그리고 유능한 리더십 등을 통해서 폭넓은 좌파정당 건설의 과제를 수행할 수 있을 것이다. Met with the severest economic crisis after Great depression, European countries pushed counter-cyclical policies as financial relief and fiscal expansion, and fell eventually into another contradiction of fiscal crisis. Fiscal austerity policy pursued by most country provoked confrontation between classes and struggles against budget cuts. Economic crisis provided good opportunity for european socialists and radical left to form broad left party beyond the left of social democrat parties fallen into legitimacy crisis by adapting to neoliberalist policy line. However, the performance among countries varies not a little. Left Party of Germany and Left Bloc in Portugal are somewhat successful, Italy and Britain are in a disrupted condition contrastingly. NPA of France deserves future results. It shows that left politics is much conditioned by subjective conditions besides objective environments. Building broad left party is the crucial problem in the current economic crisis. To challenge this task by existing separate political parties and organizations, treating broad left party as an united front, manifested apparent limitations as to be remained irrelevant or to accentuate split among groups. Radical left must dissolve independent political parties or organizations, and act as a group in the broad left party to develop it as an effective base of social transformation. Influenced by past tradition of revolution and in case being parts of it, European radical lefts have been strongly ideological oriented. Ideology have been formulated upon past facts and experiences, and it's difficult for ideology to rapidly correspond to the changed situation. So radical left also have suffered difficulties to recognize changing reality and effectively responding to it upon cooperation with different groups. Accepting the limitation that any group can not provide correct answer to every problem, radical left may approach the task of building broad left party by establishing inner party democracy, political strategy on dialectical dynamics of reform and revolution, and securing competent leadership.