• Journal of the Korean Society of Safety
• /
• v.10 no.3
• /
• pp.106-109
• /
• 1995

Optimum relocation of the brake relative to the accelerator can reduce stopping diatance and may mean the difference between an accident and a near-accident. A driving simulator was used to examine effiency of brake time. Brake time was measured for 30 participants in six conditions. Brake times were shown to improve as a result of moving the brake pedal from its typical heights above the accelerator to positions below the accelerator.

• Bulletin of the Korean Mathematical Society
• /
• v.56 no.5
• /
• pp.1129-1141
• /
• 2019

We propose a stochastic delay financial model which describes influences driven by historical events. The underlying is modeled by stochastic delay differential equation (SDDE), and the delay effect is modeled by a stopping time in coefficient functions. While this model makes good economical sense, it is difficult to mathematically deal with this. Therefore, we circumvent this model with similar delay effects but mathematically more tractable, which is by the backward time integration. We derive the option pricing equation and provide the option price and the perfect hedging portfolio.

• KIPS Transactions on Software and Data Engineering
• /
• v.6 no.5
• /
• pp.223-228
• /
• 2017

SMT is an device that picks up electronic components and does precise placing onto PCBs. In order to do this, it stops in front of a camera installed in the middle to go over vision inspection. And after that it is move for placing. There are 16 different types of routes in this process. This paper compared to the moving time of three methods in the (sLa-Camera-pLa)type. The first method is stopping in front of the camera for vision inspection and placing components onto PCBs(stop-motion). The second method is moving in front of the camera for vision inspection without stopping(fly1-motion). The third method is inspecting the components when the speed of the X axis, the Y axis is the best and is placing components onto PCBs(fly2-motion). This paper shows the moving time of three methods is same. Therefore we proved that the stop-motion method can be placing in the fastest time without changing structure of the device in the (sLa-Camera-pLa)type.

• Journal of Korean Society of Transportation
• /
• v.32 no.5
• /
• pp.441-451
• /
• 2014

This study proposes a novel performance measure, which is referred to as Hazardous Spacing Index (HSI), to be used for evaluating safety of traffic stream on freeways. The basic principle of the proposed methodology is to investigate whether drivers would have sufficient stopping sight distance (SSD) under limited visibility conditions to eliminate rear-end crash potentials at every time step. Both Road Weather Information Systems (RWIS) and Vehicle Detection Systems (VDS) data were used to derive visibility distance (VD) and SSD, respectively. Moreover, the K-Nearest Neighbors (KNN) method was adopted to predict both VD and SSD in estimating predictive HSIs, which would be used to trigger advanced warning information to encourage safer driving. The outcome of this study is also expected to be used for monitoring freeway traffic stream in terms of safety.

• Journal of Korean Society of Transportation
• /
• v.25 no.6
• /
• pp.19-31
• /
• 2007

When estimating the benefits from an investment project in the transportation sector, errors caused by many factors may exist. This study focuses on user equilibrium traffic assignment methods and stopping criteria. According to previous studies, when using a user equilibrium assignment model, the benefits of travel time savings can be effected by the relative gap value. As the stopping criteria decreases, the time needed for traffic assignment increases, so that lowering the criteria cannot be the best solution. Therefore, an effort is necessary to reduce this change rate and thus improve reliability. This paper considers three methods: reducing the links subject to benefit calculation, extracting sub-area O/D tables and networks, and applying the mean value of successive traffic assignment results. The results of the analysis show that the method using the mean value of five results is more proper than the other methods. Using the sub-area analysis method, if the study area is small the benefits of a project might be over- or under-estimated. This paper used a nationwide O/D table and network at peak time as a case study. The resulting patterns can differ according to basic data to be used in analysis. So further analysis using the data from metropolitan areas are needed.

• Fire Science and Engineering
• /
• v.30 no.6
• /
• pp.57-63
• /
• 2016

In this study, the toxicity of combustion products of wood-based materials (MDF, OSB) were analyzed using experimental animal techniques. The average deed stopping time of MDF was shorter than that of OSB. This means that the toxicity of the combustion products of MDF is higher than that of OSB. To analyze the cause of the result quantitatively, Fourier transform infrared spectroscopy (FT-IR) of the gas phase materials was performed. Qualitative analysis result, CO and $CO_2$ were detected. Quantitative analysis results, the gas generation rate was higher in OSB than in MDF. Blood analysis of mice revealed, COHb to be higher in OSB than MDF. A correlation between the gas generation rate and COHb was found. Currently, the toxicity of the combustion products of the materials is being examined using the toxicity index, such as Fractional Effective Dose (FED). The FED is based on the gas emissions. The average deed stopping time decreased with increasing toxicity of exposed material. On the other hand, the result of this study showed that, the CO emissions of OBS were 186.5% that of MDF. The COHb of OSB was > 129.6% that of MDF. Nevertheless, the average deed stopping time of the OSB is 51 seconds longer than that of MDF. Therefore, more toxicity studies on factors other than the gas phase materials in the combustion products will be needed.

• Journal of Korean Society of Transportation
• /
• v.29 no.3
• /
• pp.115-122
• /
• 2011

This paper investigates the accuracy of the vehicle pre-braking speed estimated based upon measured skidding distance. Driver ordinarily takes sudden braking when urgent situation is developed in the front or when the driver is involved in an unexpected situation, and the driver may be inflicted upon an accident depending on the required stopping distance. Among factors influencing the stopping distance of vehicle such as recognition response time of driver, performance of vehicle's braking device, and state of road surface etc, pre-braking speed is seemingly the most important influencing factor. Currently, in the investigating section of traffic accidents, the state of overspeed is determined by the pre-skidding speed calculated based on the length of skid mark. In order to identify the accurate cause of the accident, it is strongly recommended that estimation of pre-braking speed should be estimated taking into account speed reduction during transient time. In this study, we propose a method for estimating more accurate exact speed information of vehicle at the time of traffic accident. The outcomes from this study potentially help better understanding of the characteristics of vehicle for traffic safety in the future.

• Fire Science and Engineering
• /
• v.28 no.6
• /
• pp.8-12
• /
• 2014

Interior finishing materials using noncombustible were regulated by the building codes to prevent the spread of fire and protect occupants. The average deed of stopping time of experimental mouse exposing combustion gas were measured by KS F 2271 gas toxicity test. At that time, The average deed of stopping time under 9 minutes were judged a inconsistence. This experiment method has limit to find out a cause of toxicity effect factor. In this study, particle size analysis were performed for investigate a major factor.

• Journal of Veterinary Clinics
• /
• v.19 no.2
• /
• pp.199-203
• /
• 2002

Cardiovascular effects of propofol, were assessed after premedication with xylazine(1.0 mUkg, IM) under oxygen supply(200 ml/kg/min) via a endotracheal tube. Twelve adult mixed-breed dogs were divided into four groups; 0.2(Group 1), 0.4(Group 2), 0.6(Group 3) and 0.8 mg/kg/min(Group 4) of propofol respectively. Arterial blood pressure and electrocardiogram were monitored with a physiograph after an arterial catheter was inserted into the femoral artery. pH, arterial carbon dioxide tension($PaCO_2$and arterial oxygen tension($PaO_2$) were evaluated with arterial blood collected through the inserted catheter. Diastolic arterial pressure, systolic arterial pressure and mean arterial pressure were decreased slightly in Group I IIand III, but decreased significantly in Group IV. They were increased rapidly after stopping propofol infusion in Group IV pH was maintained in normal range in Group I, II and m, but was decreased in proportion to time passing in Group IV. $PaCO_2$ was increased significantly only in Group IV but $PaO_2$ was maintained in normal range in all groups Although heart rate was recorded in normal range for 90 minutes, arythmia was noted after stopping propofol infusion in all groups. It was concluded that propofol depressed the cardiovascular system in proportion to infusion dosage, and 0.8 mg/kg/min of propofol infusion rate was not appropriated in canine anesthesia with xylazine premedication.

• Journal of the Korean Statistical Society
• /
• v.23 no.1
• /
• pp.89-102
• /
• 1994

A new method for approximating the average run length (ARL) of cumulative sum (CUSUM) chart is proposed. This method uses the conditional expectation for the test statistic before the stopping time and its asymptotic conditional density function. The values obtained by this method are compared with some other methods in normal and exponential case.