• Journal of the Ergonomics Society of Korea
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• v.28 no.4
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• pp.71-76
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• 2009

Effects of dark adaptation have large safety implications. This study was aimed to investigate the effects of varying illuminance and the size of critical detail on visual performance (i.e., time-to-detect) in a dark room environment. While adapting to the dark environment, ten subjects were asked to detect and answer simple numerical expressions under 9 experimental conditions (3 illuminance level $\times$ 3 target size). The ANOVA results revealed that the time-to-detect was significantly affected by both of the illumination level and the size of critical detail. As illumination increased from 10 lux to 20 lux, the time-to-detect was significantly declined. For the size of critical detail, 0.5/min size (i.e., equal to 2 minutes of visual angle) resulted in a shorter time-to-detect, as compared to 0.7/min size (i.e., equal to 1.6 minutes of visual angle). Potential applications of this research include the development of design guidelines for illumination and warning signs in poorly illuminated viewing environments.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.10
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• pp.89-94
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• 2012

This research is to apply the control of neuron networks for the real-time walking control of Multi-articulated robot. Multi-articulated robot is expressed with a complicated mathematical model on account of the mechanic, electric non-linearity which each articulation of mechanism has, and includes an unstable factor in time of walking control. If such a complex expression is included in control operation, it leads to the disadvantage that operation time is lengthened. Thus, if the rapid change of the load or the disturbance is given, it is difficult to fulfill the control of desired performance. This paper proposes a new mode to implement a neural network controller by installing a real object for controlling and an algorithm for this, which can replace the existing method of implementing a neural network controller by utilizing activation function at the output node. The proposed control algorithm generated control signs corresponding to the non-linearity of Multi-articulated robot, which could generate desired motion in real time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.222-224
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• 2022

Korea has more than 2,000 fires and more than 2,000 casualties every year. This study takes measures to facilitate the incorporation of 119 fire trucks by judging vehicles or standing signs using real-time image reading YOLO5 before the fire trucks arrive at the fire site. It is possible to shorten the time to extinguish a fire by photographing a fire site, transmitting the situation of the site, and analyzing the components of smoke to determine the type of fire. As a result, it is expected that it will be able to minimize casualties by keeping the golden time.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.336-338
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• 2015

This research is to propose an applicable framework for real-time health surveillance and safety monitoring at construction sites. First this study aims at finding (1) a framework for health surveillance that is likely to benefit employers and employees in the industry, (2) a valid way to identify factors or conditions with potential health concerns that can occur under particular work conditions, (3) An effective way to apply wireless/mobile sensors to construction workers using real-time/live data transmission methods, and (4) A relationship between a worker's vital signs and job site environment. Biosensors for physiological response and devices for weather/work related data are to collect real-time data. Relationships between jobs and physiological responses are analyzed and factors that touched particularly contributing to certain responses are identified. When data are incorporated with tasks, factors affecting tasks can be identified to estimate the magnitude of the factors. By comparing work and normal responses possible precautionary actions can be considered. In addition, the study would be lead to improving (1) trade-specific dynamic work schedules for workers which would be based on various factors affecting worker health level and (2) reevaluating worker productivity with health status and work schedule, thereby seeking ways to maximize worker productivity. Through a study, the paper presents expected benefits of implementing health monitoring.

• Journal of Information Technology Applications and Management
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• v.23 no.3
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• pp.87-97
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• 2016

This paper proposes a fast sound source localization method using a TDOA sign-based algorithm. We present an L-shaped microphone set-up which creates four major regions in the range of $0^{\circ}{\sim}360^{\circ}$ by the intersection of the positive and negative regions of the individual microphone pairs. Then, we make an initial source region prediction based on the signs of two TDOA estimates before computing the azimuth value. Also, we apply a threshold and angle comparison to tackle the existing front-back confusion problem. Our experimental results show that the proposed method is comparable in accuracy to previous three microphone array methods; however, it takes a shorter computation time because we compute only two TDOA values.

• Macromolecular Research
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• v.17 no.11
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• pp.874-878
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• 2009

Photorefractive polymer composites were synthesized based on poly (N-vinylcazbazole) (PVK) doped with liquid nonlinear optical chromophores and a sensitizer $C_{60}$. PVK/liquid NLO chromophores/$C_{60}$ devices showed no signs of phase separation and did not require a plasticizer, such as ethylcarbazole. The composites showed 69% diffraction efficiency (C3) and a rapid response time of 46 ms (C1) in four-wave mixing experiments at a light intensity of $60\;mW/cm^2$ and a wavelength of 633 nm.

• Toxicological Research
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• v.13 no.1_2
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• pp.139-147
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• 1997

Four-week toxicity of EPO(erythropoietin) was investigated using New Zealand White rabbits according to the established regulations of Korean National Institute of Safety Research. Rabbits were administered intravenously seven days per week for 28 days with dosage of 0, 80, 400 and 2000IU/kg B. W./day. Animals administered with EPO showed no significant changes of body weight, water consumption and feed consumption, and no clinical signs and death. They were not significantly different from the control group in hematological and serum biochemical analysis, urinalysis, prothrombin time, and partial thromboplastin time. In this study, we concluded that EPO had no toxic effect in the New Zealand White rabbits when they were administered intravenously below 2000IU/ kg B.W./ day for 28 days.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.235-242
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• 2008

Due to the lack of judgement in an information processing on road sign, older drivers usually are having a hard time driving than young group. Furthermore, according to increasing in aging population, older drivers in Korea have been growing much faster. That means research for older drivers' characteristics and the number of guide name for road sign should be needed. In accordance with suggestions, this study was carried out the number of guide names for road sign with a variety of ages from the twenties to the seventies. For the sake of this study, statistical verification was conducted to confirm a change of speed, a reading time and a misreading rate with Driving Simulator and Electrooculogram tool. As the results of study, change of speed in the age range has shown that the higher the proportion of age, the lower the rate of velocity. Also reading time in the age range with regression analysis found that the higher the proportion of age, the higher the rate of reading time by 0.106sec. Finally, a binary logistic model was used to find the main factors. As the results, 4 number of guide names for road sign have been the best of them for older driver. The result of this study verified the importance of ideal guide numbers on road sign for older driver and proved itself to be an effective method to determine the road safety for the road signs.

• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.65-79
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• 2006

The ATIS(Advance Traveler Information System), as one part of ITS, is a system aiming to disperse traffic volume on transportation networks by providing traffic information to transportation users on pre-trip and en-route trips. One of tools in ATIS is usage of VMS(Variable Message Signs). It provides to the drivers with direct information about state of processing direction. which is considered as the most effective method in ATIS. The purposes of providing VMS information are classified two categories. One is to provide simple information to drivers for their convenience. The other is to manage traffic demand to improve transportation network performance. However, for more effective and reliable VMS information, several strategies should be taken into account. The main VMS management strategy is "Traffic Diversion Strategy for minimum delay" when traffic congestion or incident are occurred. For effective operation. firstly. reasonable diversion traffic volume is determined by network traffic condition Secondly, it is necessary to make providing information strategy which reflects driver response behavior for controling diversion traffic volume. This paper focuses on the providing real-time route guidance information by VMS when congestion is occurred by the incidents. This sturdy estimates time-dependent system optimal diversion rate that inflects travel time and queue lengths using traffic flow simulation model on base Cellular Automata. In addition, route choice behavior models are developed using binary logit model for traffic information variable by traffic system controller. Finally, this study provides time-dependent VMS massage contents and degree of providing information in order to optimize the traffic flow.

• Journal of Chest Surgery
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• v.26 no.3
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• pp.224-227
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• 1993

We experienced one case of orthotopic cardiac transplantation in a patient with end stage dilated cardiomyopathy. This 50 year-old female recipient was suffered from NYHA functional class IV cardiac failure and dependent upon intravenous inotropic support for 2 months [recipient category 1]. Her preoperative condition was grave with left ventricular ejection fraction of 20% and estimated systolic pulmonary arterial pressure [from Doppler study] was 50mmHg. The brain-dead donor was 31 year-old male with head trauma. The body sizes [weight, height] of the donor/recipient were 70 Kg, 165 cm / 43 Kg, 160 cm and appropriately overmatched. Preoperatively, identical ABO/Rh blood group [A+] and nonreacting HLA crossmatching were confirmed. On November 11 1992 cardiac transplantation was performed without complication. Multiple organ procurement team and heart transplantation team were organized the operation schedule appropriately to minimize the ischemic time. The pump time was 126 minutes and aortic crossclamping time of recipient heart was 73 minutes and, as a result, total ischemic time of the transplanted heart was 75 minutes. Postoperatively, the vital signs were stable with minimal inotropic support. The immunosuppressive therapy was commenced from preoperatively and cyclosporine, azathioprine, and corticosteroid were used as a combination therapy as scheduled and monitored with blood drug concentration, WBC count, renal function and most importantly regular endomyocardial biopsy.Now, 5 months after transplantation, the patient is in NYHA functional class II with minimal cardiac drug support.