• 한국재난관리표준학회지
• /
• 제1권2호
• /
• pp.61-66
• /
• 2008

국토의 70% 이상이 산지로 구성되어 있어서 도로와 철도 건설을 위해 절토사면이 필연적으로 발생한다 우기, 동절기 서리로 인한 지반융기, 그리고 해빙은 암석 탈락과 사면붕괴의 원인이 되며 매년 사면붕괴에 의한 차량파손과 인명피해가 증가하고 있다. 인명과 재산을 보호하기 위해 사연붕괴를 조기에 탐지할 수 있는 실시간 모니터링 시스템이 필요하다. GMG사에서 개발한 병진 회전 침하(TRS) 센서를 사면 내에 설치하여 실시간으로 사면을 모니터링을 할 수 있도록 했으나, 시스템의 데이터 획득체계가 취약하여 순간적인 낙뢰에 의해 전체 시스템이 손상될 수 있다. 따라서 저자들은 USN(Ubiquitous Sensor Network)을 제시하여 낙뢰에 의한 손상을 최소화시키고 신뢰도 높은 사면 변형 모니터링 체계를 구축했다.

• 국제물리치료학회지
• /
• 제1권2호
• /
• pp.107-112
• /
• 2010

The majority of strokes are caused by ischemia and result in brain tissue damage, leading to problems of the central nervous system including hemiparesis, dysfunction of language and consciousness, and dysfunction of perception. The purpose of this study was to investigate the effects of Poly(ADP-ribose) polymerase(PARP) on necrosis in neuronal cells that have undergone needle electrode electrical stimulation(NEES) prior to induction of ischemia. Ischemia was induced in male SD rats(body weight 300g) by occlusion of the common carotid artery for 5 min, after which the blood was reperfused. After induction of brain ischemia, NEES was applied to Zusanli(ST 36), at 12, 24 and 48 hours. Protein expression was investigated using immuno-reactive cells, which react to PARP antibodies in cerebral nerve cells, and Western blotting. The results were as follows: In the cerebral cortex, the number of PARP reactive cells after 24 hours significantly decreased(p<.05) in the NEES group compared to the GI group. PARP expression after 24 hours significantly decreased(p<.05) in the NEES group compared to the GI group. As a result, NEES showed the greatest effect on necrosis-related PARP immuno-reactive cells 24 hours after ischemia, indicating necrosis inhibition, blocking of neural cell death, and protection of neural cells. Based on the results of this study, NEES can be an effective method of treating dysfunction and improving function of neuronal cells in brain damage caused by ischemia.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.1482-1504
• /
• 2007

철도시스템은 열차견인을 위한 고전압시스템, 열차제어를 위한 저전압시스템을 사용하며, 철도를 구성하는 시스템이 지형적으로 광범위하게 분포되어 있다. 철도시스템에서 전차선의 지락에 의한 과대한 고장전류, 낙뢰 등에 의한 이상 고전압이 발생되어 사람의 사상 및 기기의 고장이 발생할 수 있는데, 지락에 의한 고장전류, 낙뢰에 의한 고전압으로부터 기기를 보호하기 위해서 접지를 설치한다. 각 시스템에 대한 단독접지를 하는 경우에는 기기 상호가 폐회로가 형성되어 이상전류가 흐르게 되어 기기를 정상적으로 작동시키지 못하는 경우가 있다. 따라서 이러한 해결책으로 등전위 접지시스템을 채용한다. 이러한 등전위 접지시스템은 매우 낮은 접지저항을 확보하여야 한다. 본 논문에서는 철도시스템에서 기존의 단독접지시스템에서 현재의 공통접지시스템으로의 변화 및 두 시스템의 시뮬레이션 비교분석과 앞으로의 새로운 접지시스템에 대한 방향에 대해 제시하였다.

• 전기학회논문지
• /
• 제61권11호
• /
• pp.1758-1764
• /
• 2012

A large number of wire rope has been used in various inderstiries as Cranes and Elevators from expanding the scale of the industrial market. But now, the management of wire rope is used as manually operated by rope replacement from over time or after the accident.It is caused to major accidents as well as economic losses and personal injury. Therefore its time to need periodic fault diagnosis of wire rope or supply of real-time monitoring system. Currently, there are several methods has been reported for fault diagnosis method of the wire rope, to find out the feature point from extracting method is becoming more common compared to time wave and model-based system. This method has implemented a deterministic modeling like the observer and neural network through considering the state of the system as a deterministic signal. However, the out-put of real system has probability characteristics, and if it is used as a current method on this system, the performance will be decreased at the real time. And if the random noise is occurred from unstable measure/experiment environment in wire rope system, diagnostic criterion becomes unclear and accuracy of diagnosis becomes blurred. Thus, more sophisticated techniques are required rather than deterministic fault diagnosis algorithm. In this paper, we developed the fault diagnosis of the wire rope using probability density estimation techniques algorithm. At first, The steady-state wire rope fault signal detection is defined as the probability model through probability distribution estimate. Wire rope defects signal is detected by a hall sensor in real-time, it is estimated by proposed probability estimation algorithm. we judge whether wire rope has defection or not using the error value from comparing two probability distribution.

• Safety and Health at Work
• /
• 제4권3호
• /
• pp.160-165
• /
• 2013

Background: Occupational accidents are unplanned events that cause damage. The socio-economic impacts and human costs of accidents are tremendous around the world. Many fatalities happen every year in workplaces such as electricity distribution companies. Some electrical injuries are electrocution, electric shock, and burns. This study was conducted in an electricity distribution company (with rotational 12-hour shift work) in Iran during an 8-year period to survey descriptive factors of injuries. Methods: Variables collected included accident time, age of injured worker, employment type, work experience, injury cause, educational background, and other information about accidents. Results: Results indicated that most of the accidents occurred in summer, and 51.3% were during shift work. Worker negligence (malpractice) was the cause of 75% of deaths. Type of employment had a significant relationship with type of injuries (p < 0.05). Most injuries were electrical burns. Conclusion: High rate of accidents in summer may be due to the warm weather or insufficient professional skills in seasonal workers. Shift workers are at risk of sleep complaints leading to a high rate of work injuries. Acquiring knowledge about safety was related to job experiences. Temporary workers have no chance to work all year like permanent workers, therefore impressive experiences may be less in them. Because the lack of protective equipment and negligence are main causes of accidents, periodical inspections in workshops are necessary.

• 한국컴퓨터정보학회:학술대회논문집
• /
• 한국컴퓨터정보학회 2021년도 제64차 하계학술대회논문집 29권2호
• /
• pp.701-702
• /
• 2021

The purpose of the study was to identify fiber changes induced by electrical stimulation of a certain neural substrate in the rat brain. In the stimulation group, the peripheral nerve was injured and the brain area associated to inhibit sensory information was electrically stimulated. There were sham and sham stimulation groups as controls. Then high-field diffusion tensor imaging (DTI) was acquired. 35 features were taken from the DTI measures from 7 different brain pathways. To compare the efficacy of the classification for 3 animal groups, the linear regression analysis (LDA) and the machine learning technique (MLP) were applied. It was found that the testing accuracy by MLP was about 77%, but that of accuracy by LDA was much higher than MLP. In conclusion, machine learning algorithm could be used to identify and predict the changes of the brain white matter in some situations. The limits of this study will be discussed.

• 한국주조공학회지
• /
• 제27권2호
• /
• pp.72-76
• /
• 2007

Contact materials are widely used as electrical parts. Ag-Cd alloy has a good wear resistance and stable contact resistance. But the Cd exists as coarse oxide in alloy so it have an effect on mechanical properties badly. Moreover, the Cd is an injury material to environment. Nowadays, the use of Cd is strictly restricted. Because of these disadvantage, Ag-Sn-In alloy has been developed. In Ag-Sn-In alloy, the Sn : In ratio affects the internal oxidation properties, such as the formation of the oxide layer on the surface. In this work, we changed and optimized the Sn : In ratio variety for good internal oxidation properties. We have shown that a internal oxidation process did not fully completed when the Sn : In ratio is over 4 : 1 because of the Sn oxide layer at surface. The increase of In decelerates the formation of Sn oxide layer.

• The Korean Journal of Physiology and Pharmacology
• /
• 제4권6호
• /
• pp.455-461
• /
• 2000

Zinc contained in the neurons of central nervous system is activity-dependently released and then attenuates NMDA (N-methyl-D-aspartate)-induced neurotoxicity while augmenting non-NMDA-induced neurodegeneration. Zinc also has been reported to produce antinociceptive action on the inflammation- and nerve injury-induced hyperalgesia in the behavioral test. In this study, we investigated the effects of zinc on the responses of dorsal horn cells to NMDA, kainate and graded electrical stimulation of C-fibers. In the majority of WDR cells (70.6%), zinc current-dependently inhibited WDR cell responses to NMDA and in the remaining cells, produced biphasic responses; excitation followed by inhibition. Zinc augmented the responses of WDR cells to iontophoretical application of kainate. The dominant effect of $Zn^{2+}$ on the responses of WDR cells to C-fiber stimulation was excitatory, but inhibition, excitation-inhibition and no change of the responses to C-fiber stimulation were induced. $Ca^{2+}-EDTA$ antagonized the excitatory or inhibitory effects of $Zn^{2+}$ on the WDR cell responses. These experimental findings suggest that $Zn^{2+}$ modulates the transmission of sensory information in the rat spinal cord.

• International Journal of Oral Biology
• /
• 제32권4호
• /
• pp.153-160
• /
• 2007

The superficial dorsal horn, particularly substantia gelatinosa (SG) in the spinal cord, receives inputs from small-diameter primary afferents that predominantly convey noxious sensation. Reactive oxygen species (ROS) are toxic agents that may be involved in various neurodegenerative diseases. Recent studies indicate that ROS are also involved in persistent pain through a spinal mechanism. In the present study, whole cell patch clamp recordings were carried out on SG neurons in spinal cord slice of young rats to investigate the effects of hydrogen peroxide on neuronal excitability and excitatory synaptic transmission. In current clamp condition, tert-buthyl hydroperoxide (t-BuOOH), an ROS donor, depolarized membrane potential of SG neurons and increased the neuronal firing frequencies evoked by depolarizing current pulses. When slices were pretreated with phenyl-N-tert-buthylnitrone (PBN) or ascorbate, ROS scavengers, t-BuOOH did not induce hyperexcitability. In voltage clamp condition, t-BuOOH increased the frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs), and monosynaptically evoked excitatory postsynaptic currents (eEPSCs) by electrical stimulation of the ipsilateral dorsal root. These data suggest that ROS generated by peripheral nerve injury can modulate the excitability of the SG neurons via pre- and postsynaptic actions.

• International Journal of Safety
• /
• 제10권2호
• /
• pp.21-26
• /
• 2011

In 2001, an independent official board was constituted in Japan to investigate aircraft and railway accidents. In the past 10 years, many accidents and serious incidents have been investigated and these official reports were published by the board, on which the author had sat for 9 years as boarding member. In the interim, there were several train disasters which mocked our trust in railways and also many apparent trivial incidents. In recent years, serious incidents, which a door of running rail cars opens suddenly with some trouble, happen 2 or 3 times in a year. For the past 10 years, such incidents have happened 14 times and 13 cases of them were closed by the board mentioned above. In these 13 cases, no one fell off the rail car, so that the death toll was none luckily. In this paper, these 13 serious incidents are picked up among all the reports published by the board and outlined using some tables. Especially, fall accidents of passengers are discussed mainly from the view point of impact force and duration time. Then, the equation of HIC (Head Injury Criteria) and the risk curves in terms of the HIC are dealt with properly.