• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.274-277
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• 2006

This paper describes a lighting warning system (LWS) which consists of a corona needle electrode, a low noise differential amplifier, an A/D converter, an one-chip microprocessor, a LCD and alarm devices. The corona needle electrode is used to measure electric field intensity caused by thunderclouds on the ground level. To evaluate the sensitivity of the LWS, calibration experiment was carried out using a round-shape parallel plate electrode system. The theoretical and experimental results show that the LWS can measure electric field intensity over 2 [kV/m].

• Journal of Biomedical Engineering Research
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• 제18권3호
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• pp.315-323
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• 1997

Driving is a complex vigilance task that includes improper lookout, excessive speed and inattention. The primary objective of this research is to detect driver drowsiness so that the driver can be alerted to an impending traffic accident in performance. We developed the automatic detection and warning system during drowsy driving. A drowsiness detection system must be able to monitor driver status and detect the detrimental changes of a driver performance. Eyeblink has been found to be a reliable factor of drowsiness detection in earlier studies. As an additional parameter, we also considered the yawning which often occurs in a low vigilance state and predicts the drowsy state. We used a computer vision method to extract the eyeblink and yawning in the face image sequences. When the drowsy state was detected, the driver was refreshed by alarming device and menthol scent generator after deciding the warning level by fuzzy logic. For the evaluation of our system, we measured the physiological parameters such as EOG and EEG. The results indicated that it is possible to detect and alert the driver drowsiness temporarily or continuously by using our system.

• Journal of the Korea Institute of Military Science and Technology
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• 제27권2호
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• pp.213-221
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• 2024

Aircraft's operational effectiveness is reduced due to threats from enemy anti-aircraft weapons, which is a weak point. In particular, guided missiles, which pose a threat to aircraft, are rapidly developing due to technological advancements in seekers, and are classified as one of the important technologies in weapon systems. Missile approach warning equipment installed to ensure aircraft survivability detects guided missiles and provides relevant information to respond. Tests were conducted domestically to verify the detection level of missile approach warning equipment, and test results were presented under various test conditions.

• Proceedings of the KSR Conference
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.530-535
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• 2005

To monitor the flood level under heavy rainfall and the scour at railroad bridge, the system, which can effectively collect, store and transmit the data, is developed and applied to the field. The results in this study are as follows. 1) Monitoring for water level and scour depth is well done in view of the recording velocity and the accuracy of data which are measured. 2) This system is based on the web, internet and it is able to collect the realtime data and to analyze the risk. 3) When water level excesses the limit of danger level of a river on which railroad bridge is located, or when scour depth and angle of inclination of pier is increased, the scenario for early warning signal which sends to managers at central traffic control and drivers of trains is automatically made. It is judged that this system secures the safety of railroad and protects lives of train passengers as the warning signal sends to running train in advance at risky situation of railroad bridge under heavy rainfall.

• YAKHAK HOEJI
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• 제54권6호
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• pp.455-460
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• 2010

We evaluated the inappropriateness of metformin use in patients with type 2 diabetes and chronic medical conditions to identify the frequency of the prescription metformin in violation of the food and drug administration (FDA) black box warning. We reviewed medical records of 307 outpatients who received metformin at endocrinology department in a hospital setting between January 1, 2005 and August 30, 2009. Of the 307 outpatients, 25 discontinued treatment of metformin due to elevated serum creatinine level (Scr${\geq}$1.5 mg/dl in male, Scr${\geq}$1.4 mg/dl in female), cancers, and/or liver disease. 5 were lost to follow-up. 89 (29.0%) of the patients had cardiovascular disease, 54.1% for hypertension, 9.8% for liver disease, and 60 (20.8%) for chronic kidney disease. 12 patients (3.9%) with chronic kidney disease and/or elevated serum creatinine level, and 1 patient (0.3%) with lactic acidosis were contraindicated to metformin use. Metformin should be avoided in 7 outpatients (2.3%) with active hepatitis and 1 patient (2.6%) with liver cirrhosis. Of the 307 outpatients, 13 (4.2%) patients who received metformin at the first visit and 16 (8.7%) patients who received metformin at the last visit violated to black box warning. 8 (2.6%) of the patients were in precautionary conditions to metformin use. Adjusted mean difference of serum creatinine was -0.16 mg/dl [95% CI: -0.22 to -0.11 (p<0.05)] and adjusted mean difference of alanine aminotransferase was 4.46 IU/l [95% CI: 2.47 to 6.44 (p<0.05)] between the first visit and the last visit. Critical number of elderly patients who are at the high risks of drug-disease and drug-laboratory interaction is exposed to the inappropriate metformin use in violation of black box warning. The periodic evaluation of metformin use and monitoring prescription through drug utility review (DUR) system is needed to improve patients' safety and to reduce adverse drug events.

• Smart Structures and Systems
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• 제23권2호
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• pp.107-122
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• 2019

As one of the most important parameters in structural health monitoring, structural frequency has many advantages, such as convenient to be measured, high precision, and insensitive to noise. In addition, frequency-change-ratio based method had been validated to have the ability to identify the damage occurrence and location. However, building a precise enough finite elemental model (FEM) for the test structure is still a huge challenge for this frequency-change-ratio based damage detection technique. In order to overcome this disadvantage and extend the application for frequencies in structural health monitoring area, a novel method was developed in this paper by combining the cross-model cross-mode (CMCM) model updating algorithm with the frequency-change-ratio based method. At first, assuming the physical parameters, including the element mass and stiffness, of the test structure had been known with a certain value, then an initial to-be-updated model with these assumed parameters was constructed according to the typical mass and stiffness distribution characteristic of shear buildings. After that, this to-be-updated model was updated using CMCM algorithm by combining with the measured frequencies of the actual structure when no damage was introduced. Thus, this updated model was regarded as a representation of the FEM model of actual structure, because their modal information were almost the same. Finally, based on this updated model, the frequency-change-ratio based method can be further proceed to realize the damage detection and localization. In order to verify the effectiveness of the developed method, a four-level shear building was numerically simulated and two actual shear structures, including a three-level shear model and an eight-story frame, were experimentally test in laboratory, and all the test results demonstrate that the developed method can identify the structural damage occurrence and location effectively, even only very limited modal frequencies of the test structure were provided.

• Journal of Korea Water Resources Association
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• 제43권1호
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• pp.51-65
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• 2010

We suggest a simple and practical flood forecasting and warning system, which can predict change in the water level of a river in a small to medium-size watershed where flash flooding occurs in a short time. We first choose the flood defense target points, through evaluation of the flood risk of dike overflow and lowland inundation. Using data on rainfall, and on the water levels at the observed and prediction points, we investigate the interrelations and derive a regression formula from which we can predict the flood level at the target points. We calculate flood water levels through a calibrated flood simulation model for various rainfall scenarios, to overcome the shortage of real water stage data, and these results as basic population data are used to derive a regression formula. The values calculated from the regression formula are modified by the weather condition factor, and the system can finally predict the flood stages at the target points for every leading time. We also investigate the applicability of the prediction procedure for real flood events of the Jungnang Stream basin, and find the forecasting values to have close agreement with the surveyed data. We therefore expect that this suggested warning scheme could contribute usefully to the setting up of a flood forecasting and warning system for a small to medium-size river basin.

• Journal of Korea Water Resources Association
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• 제41권3호
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• pp.341-351
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• 2008

Since the damage from the torrential rain increases recently due to climate change and global warming, the significance of flood forecasting and warning becomes important in medium and small streams as well as large river. Through the preprocess and main processes for estimating runoff, diverse errors occur and are accumulated, so that the outcome contains the errors in the existing flood forecasting and warning method. And estimating the parameters needed for runoff models requires a lot of data and the processes contain various uncertainty. In order to overcome the difficulties of the existing flood forecasting and warning system and the uncertainty problem, ANFIS(Adaptive Neuro-Fuzzy Inference System) technique has been presented in this study. ANFIS, a data driven model using the fuzzy inference theory with neural network, can forecast stream level only by using the precipitation and stream level data in catchment without using a lot of physical data that are necessary in existing physical model. Time series data for precipitation and stream level are used as input, and stream levels for t+1, t+2, and t+3 are forecasted with this model. The applicability and the appropriateness of the model is examined by actual rainfall and stream level data from 2003 to 2005 in the Tancheon catchment area. The results of applying ANFIS to the Tancheon catchment area for the actual data show that the stream level can be simulated without large error.

• Journal of Korea Water Resources Association
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• 제40권6호
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• pp.447-458
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• 2007

In this study, the coastal urban flood prediction and warning system based on HEC-RAS and SWMM were investigated to evaluate a watershed of On-Cheon stream in Busan which has characteristics of costal area cased by flooding of coastal urban areas. The basis of this study is a selection of various geological data from the numerical map that is a watershed of On-Cheon stream and computation of hydrologic GIS data. Thiessen method was used for analyzing of rainfall on the On-Cheon stream and 6th regression equation, which is Huff's Type II was time-distribution of rainfall. To evaluate the deployment of flood prediction and warning system, risk depth was used on the 3 selected areas. To find the threshold runoff for hydraulic analysis of stream, HEC-RAS was used and flood depth and threshold runoff was considered with the effect of tidal water level. To estimate urban flash flood trigger rainfall, PCSWMM 2002 was introduced for hydrologic analysis. Consequently, not only were the criteria of coastal urban flood prediction and warning system decided on the watershed of On-Cheon stream, but also the deployment flow charts of flood prediction and warning system and operation system was evaluated. This study indicates the criteria of flood prediction and warning system on the coastal areas and modeling methods with application of ArcView GIS, HEC-RAS and SWMM on the basin. For the future, flood prediction and warning system should be considered and developed to various basin cases to reduce natural flood disasters in coastal urban area.

• Korean Journal of Agricultural and Forest Meteorology
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• 제25권3호
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• pp.236-244
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• 2023

The purpose of this study was to examine the economic feasibility of providing services according to the nationwide expansion of early warning services. The net present value method, one of the cost-benefit analysis methods, was applied to the analysis. As a benefit item that constituted the net present value, the damage reduction amount using crop insurance data and the willingness to pay for the use of early warning services were used. The cost items included system construction and maintenance costs, and text transmission costs. As a result of the analysis, it was found that the nationwide expansion of early warning services had economic feasibility, and its economic effect varied depending on the level of text message use (10 % to 40 %, 10 %p interval) of participating farmers. In the future, the economic effect of early warning services is expected to increase further due to the increase in the number of farmers participating in early warning services and the increase in crop damage caused by climate change. It is necessary to further enhance the economic effect of early warning services by actively utilizing information delivery means through apps or the web as well as text messages.