• 자원환경지질
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• 제13권1호
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• pp.51-63
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• 1980

한반도 주위의 새로운 구조력(neotectionics)을 이해하고, 지진 위험을 평가하기 위해서, 한반도와 그 인접지역의 지진활동을 시간적 및 공간적으로 조사 연구한다. 본 연구는 역사적문헌에서 얻은 기술적인 지진자료와 세계지진 관측망 (WWSSN)에서 얻은 기록등을 사용하여 수행되었다. 한반도의 지진 활동은 13 세기부터 17 세기까지에 가장활발하였다. 지진정지기 (seismic quiescence)는 18 세기에 들어와서 시작하여 약 200 년동안 계속되었다. 최근에와서 지진활동dms 다시 활발하다는 것이 발견되었다. 지진의 위험 분포와 지진회복주기 (return period) 는 축적규모진도수에 의한 통계학적 방법에 의해서 결정되었다. 최근 한반도에서 지진 위험지역은 반도의 서남부 및 서부지역에서 더욱 크다는 것이 발견되었다. Focal mechanism에 의한 일본해 부근의 지진잠재력(neotectonic stress)에 관해서 고찰하면, 옛날의 Paleotectonics의 주력은 지구의 crust의 확장설(expanding)에 의해서 큰 지배를 받았지만, 최근은 태평양 plate가 유라시아 대륙이나 필립핀 plate 밑으로 충돌하여 들어가는 subducting motion 에 큰 지배를 받고 있다는 것이 발견되었다.

• 한국환경과학회지
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• 제18권10호
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• pp.1103-1114
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• 2009

In this study, the environmental behavior of malodor pollutants (MPs: $H_2S$, $CH_3SH$, DMS, and DMDS) was investigated around areas influenced by strong anthropogenic processes based on observations and modeling study (a CALPUFF dispersion model). The MP emission concentrations were measured from 8 industrial source regions (tire plants (S1-S3), waste water disposal plant (S4), and oil refinery (S5) in an urban center area and paper mill/incineration plant (S6) and livestock feedlots (S7-S8) in Ungsang area) in Yangsan city during a fall period in 2008 (21 October 2008). Overall, the most MPs emitted from the urban center area were found to affect the malodor pollution in their downwind areas during early morning (06:00 LST) and nighttime (18:00 and 21:00 LST), compared with those in the Ungsang area. For malodor intensity, the most MPs in the urban center area (especially S1 and S2) were found to be a significant contributor, whereas $CH_3SH$ and $H_2S$ in the Ungsnag area (especially S6) were the dominant contributor. The model study showed agreement in the spatial distributions of simulated MPs with those of the observations. The largest impact of MPs in the urban center area on the malodor pollution in its residential areas occurred at S1, S2, and S3 sites during nighttime, while that of MPs in the Ungsang area occurred at S6 and S8 sites. This may be caused mainly by the high MP emissions and in part by wind conditions (prevailing northeasterly winds with low wind speeds of 2-3 m/s).

• 한국대기환경학회지
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• 제22권2호
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• pp.249-257
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• 2006

In this work, the adsorptive and desorptive behavior of reduced sulfur compounds (RSC) was investigated using the combination of the Peltier cooling (PC)/thermal desorption (TD) unit with the gas chromatographic (GC) detection technique. To examine the adsorptive characteristics of RSC on clothing materials, a total of nine experiments were conducted in a stepwise manner. Once small towel pieces are exposed to significant quantities of RSC standards with high concentrations (10 ppm), the desoprtion stage was then induced by deloading RSC with ultrapure $N_2$ at three different flow rates (FR) of 20, 40, and 60 mL/min. At each FR, the total deloading volume of 400, 800, and 1,600 mL were maintained. These results were then compared in terms of odoring efficiency by dividing the total amount of desorption with the total amount used for exposition or RSC loading. The results indicated that desorption reaction of certain compounds ($CH_3SH$ and DMS) can be influenced significantly with the reducing FR, while they are not affected directly by the total deloading volume. In addition, when the extent of adsorption was compared for most S compounds by the odoring efficiency term, the extent of absorption generally occurred at approximately 1/1000 level of original exposition.

• 한국정보과학회논문지:정보통신
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• 제41권4호
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• pp.167-176
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• 2014

본 논문은 이동 환경 위주의 미래 인터넷 환경을 위해 제안된 Mobile Oriented Future Internet (MOFI) 구조에 대하여 OpenFlow 기반 구현 이슈와 KOREN 실험망을 이용한 성능 분석을 논의한다. MOFI 구조는 호스트 식별자(host identifier)와 지역 위치자(local locator) 사용, 데이터 전달을 위한 Query 우선의 데이터 전달(Query-First Data Delivery), 식별자와 위치자간 분산형 매핑 시스템(Distributed Mapping System)을 특징으로 한다. 기존 MOFI 연구에서는 intra-domain 이동성 지원을 위해 6-to-4 터널링 기법 및 리눅스 플랫폼을 활용한 구현 방식을 제안하고 실험실 테스트베드에서 성능분석을 수행하였다. 한편, 본 논문에서는 inter-domain 이동성 지원을 위한 세부 절차를 논의하고 Click Modular Router와 OpenFlow 플랫폼을 활용한 MOFI 구현 방식을 제안한다. 나아가, 실제 KOREN 실험망을 활용한 성능 실험을 통해 MOFI 구조와 기존 이동성 제어 방식인 Proxy Mobile IP (PMIP) 기법을 비교한다. 실험 결과, 이동성 제어를 위한 시그널링 지연 시간 및 처리되는 메시지 수 측면에서 MOFI 구조가 기존 PMIP 이동성 제어 기법에 비하여 더 좋은 성능을 보이고 있음을 확인하였다.

• Journal of Korean Society for Atmospheric Environment
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• 제19권E3호
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• pp.137-148
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• 2003

In this study, we examined the influence of long-range transport of dust particles and air pollutants on the photochemistry of NO$_3$on Jeju Island, Korea (33.17 N, 126.10$^{\circ}$E) during the Asian Dust-Storm (ADS) period of April 2001. Three ADS events were observed during the periods of 10∼12, 13∼14, and 25∼26 April. Average concentration level of nighttime NO$_3$on Jeju Island during the ADS period was estimated to be about 2 x 10$^{8}$ molecules cm$^{-3}$ ( - 9 pptv). Decreases in NO$_3$levels during the ADS period was likely to be determined mainly by the enhancement of the $N_2$O$_{5}$ heterogeneous reaction on dust aerosol surfaces. The reaction of N20s on aerosol surfaces was a more important sink for nighttime N03 during the ADS due to the significant loading of dust particles. The reaction of $N_2$O$_{5}$ with NMHCs and the gas-phase reaction of N20s with water vapor were both significant loss mechanisms during the study period, especially during the NADS. However, dry deposition of these oxidized nitrogen species and a heterogeneous reaction of NO$_3$were of no importance. Short-term observations of $O_3$, NO$_2$, DMS, and SO$_2$in the MBL indicated that concentrations of most of these chemical species were different between the ADS and non - Asian - Dust-Storm (NADS) periods, implying that their levels were affected sensitively by the differences in air mass trajectories.

• 농촌계획
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• 제19권4호
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• pp.319-327
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• 2013

The objective of this research was to develop a relational database management system(RDBMS) to collect, manage and analyze data on agricultural non-point source(NPS) pollution. The system consists of the relational database for agricultural NPS data and data process modules. The data process modules were composed of four sub-modules for data input, management, analysis, and output. The data collected from the watershed of the upper Cheongmi stream and Geunsam-Ri were used in this study. The database was constructed using Apache Derby with meteorological, hydrological, water quality, and soil characteristics. Agricultural NPS-Data Management System(ANPS-DMS) was developed using Oracle Java. The system developed in this study can deal with a variety of agricultural NPS data and is expected to provide an appropriate data management tool for agricultural NPS studies.

• 한국자기학회지
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• 제15권2호
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• pp.92-95
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• 2005

희박자성반도체 물질인 ZnO 산화물 반도체에 $^{57}Fe$를 미량 치환한 $Zn_{1-x}\;^{57}Fe_xO(X=0.01, 0.02, 0.03)$ 물질을 전통적인 고상반응법에 의하여 물질을 합성하였다. 이렇게 합성된 희박자성반도체 물질의 결정학적 및 자기적 특성을 x-선 회절(XRD), 진동시료 자화 측정 (VSM), $M\ddot{o}ssbauer$분광 실험을 통하여 연구하였다. $ZnFe_2O_4$의 스피넬 페라이트에 해당하는 이차상 생성을 진공열처리를 통하여 제거하였으며, 결정구조는 격자상수 ${\alpha}_o=3.252{\AA},\;c_o=5.205{\AA}$를 갖는 단일상의 wurzite hexagonal 구조로 결정하였다. 77 K에서의 VSM 측정결과 상자성상과 강자성상이 공존하는 결과를 확인할 수 있었으며, Fe의 치환량이 증가할수록 강자성상이 증가하는 것을 알 수 있었다. 뫼스바우어 측정 결과 4.2 K에서 강자성상에 해당하는 공명흡수선이 존재하였으며, 상온에서는 상자성에 해당하는 2개의 공명흡수선만이 존재하는 것을 알 수 있었다. 이러한 결과는 VSM 결과와 잘 일치하였다.

• Radiation Oncology Journal
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• 제13권2호
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• pp.121-128
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• 1995

Purpose: The enhanced cytotoxic effect of combined treatment of hyper-thermia and chemotherapy by increasing intracellular acidity with HMA was investigated. Materials and Methods: FSall tumor cells were injected on the hindlegs of female $C_3H$ mice. When the tumor volume reached about 200mm3, experiments were performed on the groups classified as follows: Group I :Control, Group II : Melphalan alone (2.5mg/kg, 5mg/kg, 10mg/kg, 15mg/kg), Group III : Heat alone $(42.5^{\cdot}C$ for 1 hour) Group IV : Melphalan + Heat $(42.5^{\cdot}C$ for 1 hour), Group V : HMA(10mg/kg) + Melphalan(5.0mg/kg) + Heat$(42.5^{\cdot}C$ for 1hour). Each group included 8-12 mice on each experiment HMA (3-amino-6-chloro-5-(1-homopiperidyl )-N-(diaminomethylene) -c-pyrazinecarboxamide), an analog of amiloride which increases intracellular pH(pHi) was dissolved in dimethyl sulfoxide (DMS) and injected into the tumor-bearing mice through the tail vein. 10mg/kg of HMA and each dose of melphalan were injected into peritoneum of the tumor-bearing mice 30 minutes before heating. Tumor growth delay was calculated when the tumor volme reached at $1500mm^3$ Excision assay was performed on each group and repeated 2-4 times. Results : Tumor growth delay of each experimental groups at $1500mm^3$ were 9, 10, 13 and 19 days respectively. In vivo-in vitro excision assay using FSall tumor cells, the cytotoxicity of each experimental groups was $1.2{\times}10^7,\;1{\times}10^7,\;6{\times}10^6,\;1.7{\times}10^6\;and\;1{\times}10^5$ clonogenic cells/gm respectively When HMA was added to the combined treatment of heat and .chemotherapy, the tumor growth was delayed more than combined treatment without HMA i.e., 6 days tumor growth delay at $1500mm^3$ of tumor volume. Conclusion: The combined effect of cytotoxicity by heat and chemotherapy can be much more enhanced by HMA.

• Archives of Pharmacal Research
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• 제29권11호
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• pp.1049-1054
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• 2006

Activation of Sphingosine kinase (Sphk) increases a bioactive lipid, sphingosine 1-phosphate (S1P) and has been observed in a variety of cancer cells. Therefore, inhibition of Sphk activity was an important target for the development of anticancer drugs. As a searching tool for Sphk inhibitor, we developed fluorescent Sphk activity assay combined with high performance liquid chromatography (HPLC). Previously we established murine teraticarcinoma mutant F9-12 cells which lack S1P lyase and stably express Sphk1. By using F9-12 cells, optimal assay conditions were established as follows; $100\;{\mu}M\;of\;C_{17}-Sph\;and\;30\;{\mu}g$ protein of F9-12 cells lysate in 20 min. Sphingosine analog $C_{17}-Sph$ was efficiently phosphorylated by Sphk activity ($K_{m}:67.08\;{\mu}M,\;V_{max}\;:1507.5\;pmol/min/mg$). New product $C_{17}-S1P$ was separated from S1P in reversed-phase HPLC. In optimized conditions, 300 nM of phorbol 12-myristate 13-acetate (PMA) increased Sphk activity approximately twice while $20\;{\mu}M$ of N,N-dimethylsphingosine (DMS) reduced 70% of Sphk activity in F9-12 cells lysate. In conclusion, we established non-radioactive but convenient Sphk assay system by using HPLC and F9-12 cells.

• 한국대기환경학회지
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• 제27권4호
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• pp.454-459
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• 2011

In this study, the recovery rate of Tedlar bag (T) sampler was investigated in comparison to polyester aluminum bag (P) sampler. To derive the comparative data sets for the relative performance between different samplers, a series of calibration experiments were performed by using 1 ppb standard of four offensive reduced sulfur compounds (RSC) odorants ($H_2S$, $CH_3SH$, DMS, and DMDS) along with $SO_2$ and $CS_2$. All the analysis was made by gas chromatography/pulsed flame photometric detector (GC/PFPD) combined with air server/thermal desorber (AS/TD). The measurement data were obtained by loading gaseous standards (1 ppb) at 3 injection volumes (250, 500 and 1,000 mL) at three intervals (0, 24 and 72 hrs). The recovery rates (RR) of P sampler were computed against the slope values of T sampler. According to our analysis, P sampler exhibits slightly enhanced loss relative to T, especially with light RSCs ($H_2S$ and $CH_3SH$). At day 0, RR for the two were 88 and 85%, respectively. Such reduction proceeded rather rapidly in the case of $H_2S$ through time. However, P sampler was more stable to store $SO_2$ unlike others. Despite slightly reduced recovery, P sampler appears as a good replacement of T sampler.