• 한국대기환경학회지
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• 제22권4호
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• pp.468-476
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• 2006

Hazardous air pollutants (HAPs) have high toxicity and bioaccurnulation potentials into human body even inbsmall amount (levels of ng/$m^3$). As the levels of HAPs might be controversial, it has been become essential to establish the analysis method for correct results. In this study, various analysis methods of VOCs and Aldehydes were compared in order to select the proper methods in our condition. Sampling and analysis method of VOCs were followed to EPA TO-14a and TO-17. VOCs were collected in absorption tube and separated by thermal desorption unit then analyzed by GC/MSD. Aldehydes were sampled in DNPH-cartridge and extracted into solution then analyzed by HPLC as the same condition of EPA TO-13a. This study also shows the results of QA/QC system of selected methods. Some experiments could be improving the data assurance blank test, calibration check, repetition precision check, the determination of detection limit and reproducibility of the retention time. Precisions of VOCs and aldehydes were ranged in 2$\sim$9% and 1$\sim$4% RSD, respectively. Recovery rate of VOCs showed variable ranges from 60 to 133.5%. MDL of VOCs and aldehydes were 0.044$\sim$0.284 ppb and 0.14$\sim$1.02 ng, respectively.

• 한국대기환경학회지
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• 제30권5호
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• pp.477-491
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• 2014

This study was carried out to evaluate the concentration variations of volatile organic compounds (VOCs) in the office environments located in a large urban area with respect to seasonality, smoking status, types of ventilation and heating. Indoor air sampling was undertaken in 37 and 30 offices in Daegu city during summer and winter, respectively. The VOC samples were collected using adsorbent tubes, and were determined by thermal desorption coupled with GC/MS analysis. The analytical method was validated for repeatability, method detection limits (MDL), and duplication precision. A total of 34 VOCs of environmental concern were determined, including 15 aromatics and 19 halogenated hydrocarbons. Average concentrations of BTEX appeared to 1.91 ppb, 22.98 ppb, 3.44 ppb, and 3.70 ppb, respectively. These values were relatively higher levels than those measured at homes and outdoor roadsides reported by other researches. In general, the concentrations of VOCs were higher in winter than summer, in smoking offices than non-smoking offices, in forced ventilation type than natural ventilation type, and in combustion heating than non-combustion heating offices. However, such differences were not always significant at a level of 0.05 by statistical tests (t-test and/or Mann-Whitney test) with some exceptions for BTEX and styrene. This study demonstrated that smoking status, ventilation type and presence of combustion sources indoors could be important factors on the elevated concentrations of some VOCs in the office environment.

• 한국물환경학회지
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• 제28권6호
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• pp.843-850
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• 2012

Due to the fast response to algae bloom issue in drinking water treatment plant, very fast determination methodology for algal toxin is required. In this study, column switching technique based online preconcentration method was combined with high resolution full scan mass spectrometer to save sample preparation time and to obtain fast and accurate result. After parameter optimization of online preconcentration, 1mL filtered sample was directly injected to trap column with switching valve system. Next, target toxins are eluted by 98% acetonitrile and analysed with 150 - 1,100 amu scan range at 50,000 resolving power. Method detection limit (MDL) for microcystin-LR, the most toxic isomer, was 0.1 ng/mL and others such as microcystin-YR, microcystin-RR and nodularin were 0.08, 0.03 and 0.04 ng/mL, respectively. This is the best improved sensitivities with 1mL volume in the literature. Furthermore, due to the use of ultra pressure HPLC (UPLC), the whole method run was completed in 4 min. Real sample applications for 173 sample including 55 surface water and 118 treatment plant samples for raw and treated water could be done within 16 hours. In our calculation, this methodology is roughly 80% faster than the previous manual solid-phase extraction with LC-MS/MS method.

• 한국측량학회지
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• 제25권6_1호
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• pp.545-555
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• 2007

3D buildings are the most prominent feature comprising urban scene. A few of mega-cities in the globe are virtually reconstructed in photo-realistic 3D models, which becomes accessible by the public through the state-of-the-art online mapping services. A lot of research efforts have been made to develop automatic reconstruction technique of large-scale 3D building models from remotely sensed data. However, existing methods still produce irregular building polygons due to errors induced partly by uncalibrated sensor system, scene complexity and partly inappropriate sensor resolution to observed object scales. Thus, a geometric regularization technique is urgently required to rectify such irregular building polygons that are quickly captured from low sensory data. This paper aims to develop a new method for regularizing noise building outlines extracted from airborne LiDAR data, and to evaluate its performance in comparison with existing methods. These include Douglas-Peucker's polyline simplication, total least-squared adjustment, model hypothesis-verification, and rule-based rectification. Based on Minimum Description Length (MDL) principal, a new objective function, Geometric Minimum Description Length (GMDL), to regularize geometric noises is introduced to enhance the repetition of identical line directionality, regular angle transition and to minimize the number of vertices used. After generating hypothetical regularized models, a global optimum of the geometric regularity is achieved by verifying the entire solution space. A comparative evaluation of the proposed geometric regulator is conducted using both simulated and real building vectors with various levels of noise. The results show that the GMDL outperforms the selected existing algorithms at the most of noise levels.

• Biomolecules & Therapeutics
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• 제8권4호
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• pp.325-331
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• 2000

The present study was designed to assess the role of spinal adenosine $A_2$ receptor in the regulation of cardiovascular functions such as mean arterial pressure (MAP) and heart rate (HR) in male Sprague-Dawley rats. Rats (250~300 g) were anesthetized with urethane and paralyzed with d-tubocurarine and artificially ventilated. blood pressure and HR were continuously monitored via a femoral catheter connected to a pressure transducer and a polygraph. Drugs were administered intrathecally using injection cannula through guide cannula which was inserted inthrathecally at lower thoracic level through a puncture of an atlantooccipital mombrane. Intrathecal injection of an adenosine $A_2$ receptor agonist, 5'-(N-cyclopropyl)-carboxamaidoadenosine (CPCA; 1, 2 and 3 nmol, respectively), produced a dose-dependent decrease in MAP and HR. Pretreatment with $N^{G}$-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor or 10 nmol of MDL-12,330, an adenylate cyclase inhibitor blocked significantly the depressor and bradycardic effect of 2 nmol of CPCA. But, Pretreatment with 3 nmol of bicuculline, gamma-aminobutyric acid A (GAB $A_{A}$) receptor antagonist, or 50 nmol of 5-aminovaleric acid, GAB $A_{B}$ receptor antagonist did not inhibit the depressor and bradycardic effect of 2 nmol of CPCA. These results indicate that adenosine $A_2$ receptor in the spinal cord plays an inhibitory role in the regulation of cardiovascular function and that the depressor and bradycardic action of adonosine $A_2$ receptor are mediated via the synthesis of nitric oxide and the activation of adenylate cyclase in the spinal cord of rats.s.s.s.

• 생태와환경
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• 제44권1호
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• pp.22-30
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• 2011

This study was purposed to develop an effective LC/MS/MS method for simultaneously determining five pre-treated cyanotoxins (anatoxin-a, microcystins-RR, -YR, -LR and -LA) of cyanobacteria blooms. Cyanobacterial bloom samples were collected from 11 major lakes and three downstream areas of river around Korea during 2005~2009. Cyanotoxins were identified in 38 samples from the lakes. The validity of the method was evaluated and the recovery rates were found ranging from 83~87%. The MDL turned out to be $0.046\;{\mu}g\;L^{-1}$ for anatoxin-a and $0.066\;{\mu}g\;L^{-1}$ for microcystins (RR, YR, LR and LA), which indicates that the method has high sensitivity and accuracy. The most dominant genus of the cyanobacterial blooms was Microcystis, which accounted for 71% of the analysed samples. Microcystis also contained the largest amount of microcystins ($398.5\;{\mu}g\;gDW^{-1}$) among the analyzed cyanobacteria. The analysis of the five cyanotoxins showed that anatoxin-a ranged between $0{\sim}41.833\;{\mu}g\;gDW^{-1}$ and microcystins ranged between $6.311{\sim}2,148.786\;{\mu}g\;gDW^{-1}$. Among the microcystins, micocystin-RR took up 58.3%, the largest portion. Anatoxin-a was found to account for 77.8% of the samples. This study has its significance in that it allowed the establishment of toxin criteria appropriate for the Korean water systems. Further studies may be necessary to conduct for improving water treatment methods.

• 대한화학회지
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• 제36권1호
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• pp.66-74
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• 1992

HPLC로 11종의 티오카바메이트들의 다성분 동시분석법을 연구하였다. 배추시료에 넣은 티오카바메이트는 추출, 분배, 세척, 및 분리-검출이 단계로 분석되는데, 추출용매로서는 아세톤을 선택하였고, 분배용매로서는 50% 염화메틸렌/석유에테르 혼합용매가 좋은 회수율을 보였다. 분배효율은 물층의 pH 영향을 받는데 산성 혹은 중성에서는 영향이 없으나 염기성에서는 감소하였다. 세척단계에서 공추출물의 제거효율은 응고액 처리법 보다는 컬럼 크로마토그래피법이 우수하였다. 흡착제로는 활성탄/마그네시마/셀라이트 1/2/4)의 흡착제가 좋은 효율을 보였으며, 클로로필드 효과적으로 제거되었다. 이 방법으로 배추에 있는 2ppm정도의 티오카바메이트의 동시 분석의 결과는 평균회수율이 91%, 상대표준편차가 약 8%, 검출한계가 2.2${\sim}$9.3ng이었다.

• The Korean Journal of Physiology and Pharmacology
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• 제20권4호
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• pp.407-414
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• 2016

This study was performed to investigate whether the spinal cholinergic and serotonergic analgesic systems mediate the relieving effect of electroacupuncture (EA) on oxaliplatin-induced neuropathic cold allodynia in rats. The cold allodynia induced by an oxaliplatin injection (6 mg/kg, i.p.) was evaluated by immersing the rat's tail into cold water ($4^{\circ}C$) and measuring the withdrawal latency. EA stimulation (2 Hz, 0.3-ms pulse duration, 0.2~0.3 mA) at the acupoint ST36, GV3, or LI11 all showed a significant anti-allodynic effect, which was stronger at ST36. The analgesic effect of EA at ST36 was blocked by intraperitoneal injection of muscarinic acetylcholine receptor antagonist (atropine, 1 mg/kg), but not by nicotinic (mecamylamine, 2 mg/kg) receptor antagonist. Furthermore, intrathecal administration of $M_2$ (methoctramine, $10{\mu}g$) and $M_3$ (4-DAMP, $10{\mu}g$) receptor antagonist, but not $M_1$ (pirenzepine, $10{\mu}g$) receptor antagonist, blocked the effect. Also, spinal administration of $5-HT_3$ (MDL-72222, $12{\mu}g$) receptor antagonist, but not $5-HT_{1A}$ (NAN-190, $15{\mu}g$) or $5-HT_{2A}$ (ketanserin, $30{\mu}g$) receptor antagonist, prevented the anti-allodynic effect of EA. These results suggest that EA may have a significant analgesic action against oxaliplatin-induced neuropathic pain, which is mediated by spinal cholinergic ($M_2$, $M_3$) and serotonergic ($5-HT_3$) receptors.

• 한국통신학회논문지
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• 제32권9A호
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• pp.931-939
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• 2007

본 논문은 SMDL (Sogang Machine Description Language)을 이용한 DSP 프로세서용 인스트럭션 셋 시뮬레이터 자동 생성기 시스템의 설계에 관해 기술한다. SMDL은 DSP 어플리케이션에 최적화된 아키텍처를 포함한 임베디드 코어의 효율적 기술을 위한 머신 기술 언어로서, 구현된 인스트럭션 셋 시뮬레이터 자동 생성 시스템은 타겟 ASIP의 SMDL 기술을 입력으로 하여 인스트럭션들의 파이프라인 스테이지 별 행위 정보를 분석한 후 cycle-accurate 인스트럭션 셋 시뮬레이터를 C++ 파일로 자동 생성한다. 구현된 자동 생성 시스템의 검증을 위해 ARM9E-S, ADSP-TS20x와 TMS320C2x 아키텍처들을 SMDL로 기술하여 시뮬레이터들을 자동 생성하였으며, 생성된 시뮬레이터들을 이용하여 $4{\times}4$ 매트릭스 곱셈, 16비트 IIR 필터, 32비트 곱셈, 그리고 FFT에 연산에 대한 시뮬레이션을 수행하였다. 결과 생성된 시뮬레이터의 정확한 동작을 확인하였다.

• Clinical and Experimental Reproductive Medicine
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• 제32권2호
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• pp.101-111
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• 2005

배 경: Pituitary adenylate cyclase-activating polypeptide (PACAP)은 양의 시상하부에서 추출된 신경펩타이드 호르몬으로 난소에도 존재하여 배양된 과립막 세포에서 스테로이드합성과 cyclic AMP 형성을 촉진함이 보고되었다. 목 적: 흰쥐 난소를 실험 모델로 사용하여 배란시 황체화호르몬 (luteinizing hormone; LH)에 의해 유도된 PACAP과 PACAP 수용체의 유전자 발현양상과 신호 전달경로를 규명하고자 하였다. 재료 및 방법: 미성숙 흰쥐의 배란전 난포를 체외 배양하면서 LH로 처리하고 PACAP 및 PACAP수용체의 유전자 발현을 보기 위해서는 Northern blot 분석과 in situ hybridization (ISH)을, 그리고 단백질 수준의 PACAP 검색을 위해서는 enzyme linked immunosorbent assay (ELISA) 분석을 이용하였다. 결 과: LH 처리 후 Northern blot상의 PACAP 유전자 발현은 6~9시간에 일시적으로 최고치에 도달하였으며 ISH로 보아 과립막 세포에서 발현됨을 알 수 있었다. ELISA 분석 상 PACAP 단백질도 LH처리 후 6~12시간에 최고치를 나타내었으며, PACAP 수용체 mRNA 역시 3~9시간에 최고치로 과립막 세포에서 발현되었다. Adenylate cyclase (AC) 억제제인 MDL12330A 처리시 LH로 발현된 PACAP mRNA가 감소되며, AC의 활성제인 forskolin 처리에는 LH시와 유사한 PACAP mRNA의 발현양상을 나타내었다. 그러나 protein kinase C (PKC)의 억제제인 chelerythrine과 2-0-tetradecanolphorbol-13-acetate (TPA) 처리로는 PACAP 의 유전자 발현에 영향을 주지 못하였다. 5-lipoxygenase의 억제제인 MK886이나 nordihydroguaiaretic acid (NDGA)로 처리한 결과 LH로 유도된 PACAP 유전자의 발현이 감소되었으나, cyclooxygenase의 억제제인 indomethacin은 별로 영향을 주지 못하였다. MEK와 p38의 억제제인 PD98059와 SB203580도 LH로 촉진 된 PACAP의 유전자 발현을 농도 의존적으로 억제하였다. 결 론 : 배란전 난포에서 PACAP과 PACAP 수용체의 유전자 발현은 모두 LH의 폭발적 분비에 의해 유도되어 일시적으로 과립막 세포에서 나타나 배란을 위한 국소적인 조절 작용을 할 것으로 추정되며, LH로 촉진된 PACAP 유전자 발현을 위한 신호전달은 cAMP-PKA, lipoxygenase 및 MAP kinase 경로를 통하는 것으로 사료된다.