• 한국안전학회지
• /
• 제30권1호
• /
• pp.94-103
• /
• 2015

This study analyzes the influence factors on elderly pedestrian accident. Elderly people are easy to be badly injured by car accidents compared to younger people. Therefore, various plans and measures are required to protect elderly pedestrian from accidents. However, pedestrian accidents studies only focused on microscopic factors such as attribute of driver, pedestrian, road design. In order to prevent pedestrian accident and reduce the severity of the accident, not only microscopic factors but macroscopic variables such as urban planning and facility should be considered. In this regard, this study develops an ordered probit model introduced the characteristics of urban facility which were not considered in the previous studies. The result shows that there is higher level of accident severity in such areas as large commercial area, well-developed area with transportation infrastructure service and non-pedestrian safety zone. Thus, various and appropriate countermeasures should be prepared in order that pedestrian accident can be prevented in the areas mentioned above. In addition to the aforementioned variables, it is revealed that other variables including vehicle speed, gender and age of pedestrian, weather condition, type of vehicle, etc. partly affect the severity of pedestrian accident.

• Applied Microscopy
• /
• 제20권2호
• /
• pp.57-70
• /
• 1990

Characterization and electron microscopic visualization of the plasmid and the gene expression of Escherichia coli were carried out. Transcriptional units of active structural genes were observed after lysis of Escherichia coli cells. The ribosomes attached to the E. coli genome on mRNA molecule as polyribosomes. From this gradient of polyribosome length, we estimated location of mRNA synthesis initiation site. In this experiment, a granule is ofen present which may correspond to a RNA polymerase at the promoter site. pOX1, pOX7, pOX7A, $pOX7{\Delta}1$, pSTP36, pSTP21, pBR322, and pJH12 were visualized by way of electron microscope, and their estimated sizes were determined to be $5.70{\pm}0.08{\mu}m,\;2.15{\pm}0.10{\mu}m,\;2.14{\pm}0.12{\mu}m,\;7.39{\pm}0.08{\mu}m,\;4.03{\pm}0.04{\mu}m,\;1.50{\pm}0.03{\mu}m\;and\;1.25{\pm}0.09{\mu}m$ respectively. One micrometer of measured length corresponded to about 3.0 Kb. Mica-press adsorption method that allows selectivs visualization of the plasmid DNA released in situ from the bacterial cell is rapid and useful for visualization of plasmids. The released plasmid DNA was adsorbed preferently on mica in a divalent cation-free solution. Miller chromatin-spreading method was useful to observe the plasmid and transcripts. BAC method and cytochrome C monolayer were useful to observe the plasmid DNA. Our ability to visualize ultrastructural aspects of the expression of E. coli has given us a unique tool with which to study the regulation the level of an individual gene.

• 대한교통학회지
• /
• 제22권2호
• /
• pp.95-102
• /
• 2004

실시간 신호제어시스템은 현장의 교통정보를 수집하여 교통상황에 맞게 자동으로 신호제어를 수행하는 시스템이다. 그러나 현재까지 국내의 실시간 신호제어시스템인 COSMOS를 적절하게 모의실험 할 수 있는 미시적시뮬레이터가 없는 실정이다. 따라서 본 연구에서는 세계적으로 널리 사용되고 있는 미시적 시뮬레이션 모형인 NETSIM모형을 기반으로 하여 COSMOS 시스템을 평가할 수 있도록 통합 시뮬레이션 환경을 개발하였다. 본 논문은 COSMOS 평가시뮬레이터의 모듈 중에서 모의 실험환경 내에서 차량의 이동에 따라 실시간으로 검지기정보를 추출해내는 모듈과 주요 신호변수 중 하나인 COSMOS 녹색현시배분알고리즘모듈을 제시하였다. 개발된 평가시뮬레이터 내의 정보흐름 정확성을 평가해본 결과, 연산과정 및 정보흐름이 정확한 것으로 확인되었다. 그리고 개발된 시뮬레이터를 개선하기 위한 향후과제들을 논문의 마지막에 제시하였다.

• Spatial Information Research
• /
• 제23권4호
• /
• pp.79-89
• /
• 2015

본 연구는 GIS를 이용하여 미시적 수준에서 교통현상을 시뮬레이션 할 수 있는 미시적 수준의 교통모형을 설계 및 구현하는데 목적이 있다. 이를 위해 차량이 GIS 도로 중심선 자료를 차선, 이동속도 등이 반영된 도로 네트워크 자료로 인식하는 방법론을 개발하였으며, 운전자의 주행 행태를 반영하기 위해 환경인식모형, 차두시간분포모형, 차량추종모형 및 차로변경모형으로 행태모형을 설계 및 구현했다. 모형의 정확도 평가는 종로구의 자하문길을 대상으로 관측자료와 예측 자료를 비교하였으며, 그 결과 시간대별 이동 속도를 매우 정확하게 예측한 것을 확인할 수 있었다. 본 연구를 통해 구현된 GIS 기반의 미시적 수준의 교통모형은 교통 탄소 배출량 분석, 교통류 평가 및 도시기반시설 입지 계획등의 다양한 분야에 효과적으로 기여할 수 있을 것으로 판단된다.

• 대한수의학회지
• /
• 제42권2호
• /
• pp.153-162
• /
• 2002

For the induction of arthropathy, 5% hydrogen peroxide($H_2O_2$) was injected for 5 weeks into the intraarticular space of the New Zealand white rabbits to damage articular cartilage. Alginic acid of low molecular weight (2%) made from macromolecular alginate treated with enzyme was administered into articular space at the dose of 5 mg/kg twice a week for 3 and 6 weeks using 1 ml syringe and 26 G needle. Saline was injected for the control. Tissues surrounding the articulation were obtained for the measurements of superoxide dismutase(SOD) activity as a major antioxidant enzyme and malondialdehyde (MDA) as a lipid peroxidation level. Histopathologic examination on the surface of articular cartilage was carried out. Data showed that injection of hydrogen peroxide for 5 weeks had led to the induction of free radical damage and of articular cartilage change as confirmed by microscopic observation. The application of hydrogen peroxide caused a gradual increase in the SODs and MDA. These patterns were similar after 3 and 6 weeks of alginate treatment. Furthermore, microscopic examinations revealed that hydrogen peroxide caused flaking, fibrillation, fissuring, denudation, and hypocellularity in the articular surfaces. In conclusion, lipid peroxidation was demonstrated in the articular cartilage by the administration of hydrogen peroxide in the rabbit model. This lipid peroxidation could be caused by oxygen free radicals. The histologic and enzymatic correlations on lipid peroxidation in the articulation have provided a better understanding of arthropathy. It is possible to take advantage of these findings to evaluate effective alginate dosage more efficiently.

• 한국물환경학회지
• /
• 제20권5호
• /
• pp.506-511
• /
• 2004

Maintaining dissolved oxygen (DO) at sufficiently low concentration in the aeration tank at a wastewater treatment plant (WWTP) is essential for reduction of the costs of operation and maintenance. On the other hand, the low DO level may result in adverse effect on the integrity of the activated sludge, A typical and disastrous outcome frequently experienced is the outgrowth of filamentous microorganisms, which is called as filamentous bulking, In addition to the traditional methods such as sludge settleability and microscopic observation of the culture, molecular techniques including polymerase chain reaction (PCR) amplification followed by 16S rRNA sequencing were applied to identify filamentous bacteria present in bulking sludge under a condition of low DO concentration, Two morphologically distinct groups, presumably consisting of Sphaerofilus nafans, and Eikelboom Type 1701 or Type 1851, were identified through microscopic observation. They were further confirmed by subsequent 16S rRNA sequencing. Dominant filamentous bacteria identified by the molecular techniques were consisted of three major groups. Sequences of partial 16S rRNA cloned showed that the filamentous bulking organisms were closely related to Eikelboom Type 021N and Eikelboom Type 1701, and Sphaerotilus natans, respectively. Molecular methods were found to possess a strong potential of direct examination of the microbial community of an activated sludge system.

• 자원환경지질
• /
• 제30권4호
• /
• pp.353-362
• /
• 1997

P wave velocities of core samples from the Pocheon granite were measured before and after applications of cyclic loading. Then. distribution of the pre-existing microcracks and microcracks developed due to the cyclic loading was investigated by analyzing P wave velocity anisotropies and microscopic observations from thin sections. Anisotropy constants were calculated with three different ways: (1) $C_A$ between the maximum and the minimum velocities, (2) $C_AI$ between velocities measured along the axial direction and the average of six velocities measured in the planes perpendicular to the loading axis (rift plane) and (3) $C_AII$ between the maximum and the minimum velocities measured in the plane perpendicular to the loading axis. Among anisotropy constants. $C_AI$ was the most effective anisotropy constant to identify the rift plane whose orientation is parallel to the pre-existing microcracks as well as the distribution of stress induced microcracks. $C_AI$ decreased after cyclic loading and the relationship between $C_AI$ and number of cycles shows comparatively coherent negative trends. indicating that stress induced microcracks are aligned perpendicular to the orientation of pre-existing microcracks and that the amounts are proportional to the number of loading cycles. The difference of anisotropy constants before and after cyclic loading was effective in delineating the level of cracks and we called it Induced Crack Index. Velocity measurements and microscopic observations show that anisotropy was caused mainly due to microcracks aligned to a particular direction.

• Bulletin of the Korean Chemical Society
• /
• 제30권1호
• /
• pp.214-218
• /
• 2009

Second-order rate constants ($k_N$) have been measured for nucleophilic substitution reactions of S-4-nitrophenyl thiobenzoate with a series of alicyclic secondary amines in $H_2O$ containing 20 mol % DMSO at 25.0 ${\pm}$ 0.1 ${^{\circ}C}$. The Br$\phi$nsted-type plot exhibits a downward curvature, i.e., $\beta_{nuc}$ decreases from 0.94 to 0.34 as the amine basicity increases. The reactions in the aqueous DMSO have also been suggested to proceed through a zwitterionic tetrahedral intermediate (T${\pm}$) with change in the RDS on the basis of the curved Br$\phi$nsted-type plot. The reactions in the aqueous DMSO exhibit larger $k_N$ values than those in the aqueous EtOH. The macroscopic rate constants ($k_N$) for the reactions in the two solvent systems have been dissected into the microscopic rate constants ($k_1\;and\;k_2/k_{-1}$ ratio) to investigate effect of medium on reactivity in the microscopic level. It has been found that the $k_2/k_{-1}$ ratios are similar for the reactions in the two solvent systems, while $k_1$ values are larger for the reactions in 20 mol % DMSO than for those in 44 wt % EtOH, indicating that the larger $k_1$ is mainly responsible for the larger $k_N$. It has been suggested that the transition state is more stabilized in 20 mol % DMSO through mutual polarizability interaction than in 44 wt % EtOH through H-bonding interaction.

• 한국해양공학회지
• /
• 제26권5호
• /
• pp.73-80
• /
• 2012

It is well known that a considerable amount of scatter is shown in experimental results relating to fatigue crack growth even under identical and constant amplitude cyclic loading conditions. Moreover, flux cored arc welding (FCAW) is a common method used to join thick plates such as the structural members of large scale offshore structures and very large container ships. The objective of this study was to investigate the macro- and microscopic observations of the fatigue crack growth (FCG) behavior of the FCAWed API 2W Gr. 50 steel joints typically applied for offshore structures. In order to clearly understand the randomness of the fatigue crack growth behavior in the materials of three different zones, the weld metal (WM), heat affected zone (HAZ), and base metal (BM), experimental fatigue crack growth tests for each of five specimens were performed on ASTM standard compact tension (CT) specimens under constant amplitude cyclic loading. Special focus was placed on the fatigued fracture surfaces. As a result, a different behavior was observed at the macro-level, depending on the type of material property: BM, HAZ, or WM. The variability in the fatigue crack growth rate for WM was higher than that of BM and HAZ.

• 시큐리티연구
• /
• 제16호
• /
• pp.283-304
• /
• 2008

정보통신 기술의 발전은 시민들을 인터넷을 통로로 그들이 원하는 정보와 공공서비스를 요구할 수 있게 되었으며, 정부는 여론을 수렴할 수 있게 됨으로써 시민들이 정부정책의 참여에 중요한 수단이 되고 있다. 따라서, 이 연구에서는 누구나가 쉽게 차여할 수 있는 정보통신 기술을 이용하여 경찰행정에의 시민참여방법으로 PCRM활용 가능성을 제안하고자 한다. 활용방안으로 크게 거시적 측면과 미시적 측면으로 구분할 수 있다. 거시적인 측면으로 첫째, 서비스 접근성과 사용편의성에 대한 고려이다. 둘째, 서비스의 쌍방성이다. 궁극적인 시민참여의 수준은 적극적인 상호참여의 수준으로 가야한다. 미시적인 측면에서는 첫째, 고객분석 및 세분화 전략을 수행해야 한다. 둘째, 정책 서비스 개발 및 홍보전략을 강화해야 한다. 셋째, 고객관리 활동 부분을 강화한다. 넷째, 총체적 고객관리를 수행해야 한다.