• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2D
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• pp.193-201
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• 2011

The provision of traffic information plays an important role in increasing social benefit not only by saving travel time for individuals but also by improving the efficiency of road operation. VMS(Variable Message Sign) helps on-wheel drivers easily understand the road situation, and also provides real-time traffic information to people on the streets. However, it has not been sufficiently studied on how traffic information based on VMS influences on the drivers' selection of route. This study investigated how drivers use VMS traffic information and how they are satisfied with it. Then, the model of drivers' route selection was specified with the types of traffic information and the expected travel time to examine the influence on the selection of drivers' route. The model was estimated and analyzed in three types according to the condition of detour roads, and the rate of route change and the degree of sensitivity was calculated from the estimation. The results of analysis are as follows. the $1^{st}$ type model showed the 10% of route change for the travel time saving of 5minutes, and the 81.6% of route change for the travel time saving of 20minutes. The $2^{nd}$ type led to the range of route change from 14.2% to 92.7% over the 5 through 20 minutes of travel time saving. The $3^{rd}$ model resulted in the 99.1% of route change. The sensitivity of route change showed the highest for the travel time saving of 11 minutes with the $1^{st}$ type model, 9 minutes with the $2^{nd}$ type model, and 5 minutes with the $3^{rd}$ type model respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5D
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• pp.611-617
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• 2009

With advanced technologies applied to transportation, realtime traffic information has been necessary for not only drivers but also agencies. In normal, traffic conditions have been represented to three levels according to congestion: "free", "slow", and "jammed". Those categories and criteria are set up for traffic management even though traffic information is provided for drivers. This study examines how drivers feel current congestion levels and delves into traffic categories and criteria which they recognize. To collect data for drivers' recognition, a survey of freeway travellers is conducted answering the question about traffic flow speed from video image on a freeway section. In the result of the survey, the surveyee preferred a 4-level traffic condition including "delayed" to 3-level traffic condition. As its criteria, 20 km/h, 50 km/h, and 75 km/h were obtained. These results are expected to contribute to building more appropriate traffic information for drivers and providing an operational guideline for Traffic Monitering Centers.

• Journal of the Ergonomics Society of Korea
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• v.27 no.1
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• pp.1-7
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• 2008

Work related musculoskeletal disorders (WMSDs) have become a hot issue within the Korean workplace for the past several years. Recently, the effect of job related stress on WMSDs, cerebro-cardiovascular diseases, and psychiatric disorders has been steadily increasing. The study conducted questionnaire of Korea version job stress model, WMSDs from NIOSH, CES-D (Center for Epidemiologic Studies Depression Scale), and STAI (State-Trait Anxiety Inventory) against train drivers. The results of this study show that the job stress score of the train drivers is high in the areas of physical environment, job latitude, interpersonal conflict, job insecurity, and organization system. The relation between job stress and WMSDs nd, interpersonal conflict, job insecurity and organizational system. The relation between job stress and depressive disorders showed statistical significance in the areas of job demand, job insecurity and low reward. Finally, the relation between job stress and anxiety disorders showed statistical significance in areas of job demand, interpersonal conflict, job insecurity, organizational system and low reward.

• Journal of Auto-vehicle Safety Association
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• v.7 no.3
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• pp.30-34
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• 2015

This study examined the Korean drivers' acceptance of SAS(Speed Assistance systems) and traffic sign conditions in Korea roads for SLIF(Speed Limit Information Function) that is a part of SAS. Exceeding the speed limit is a factor in the severity of many road accidents and SAS would help the driver to observe a speed limit by warning and/or effectively limiting the speed of the vehicle. SAS are in the initial phase in Korea, Korean drivers could not be familiar with automatical speed limiting during driving, SAS interface design would be considered to be more readily acceptable to the public. And advanced SAS have been introduced onto the market which are able to inform the driver of the current speed limit based on camera and/or digital maps based SLIF. These systems are based on external data using sensors, so environmental conditions are an important factor which could cause malfunction of SLIF functions.

• Journal of the Korean Society of Safety
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• v.22 no.1 s.79
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• pp.61-66
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• 2007

Car crashes are the leading cause of death for persons of every age. Specially, human-related factor has been known to be the primary causal factor of such crashes than vehicle-and environmental-related factors. There are various studies to analyze driver's behavior and characteristics in driving for reducing the car crashes in many areas of car engineering, psychology, human factor, etc. However, there are almost no studies which analyze mainly the human errors in driving and estimate their probabilities in terms of human reliability analysis. This study estimates the probability of human error in driving, i.e. driver error probability. First, fifty driver errors are investigated through DBQ (Driver Behavior Questionnaire) revision and the error likelihoods in driving are collected which are judged by skillful drivers using revised DBQ. Next, these likelihoods are converted into driver error probabilities using the results that verbal probabilistic expressions are changed into quantitative probabilities. Using these probabilities we can improve the warning effects on drivers by indicating their driving error likelihoods quantitatively. We can also expect the reduction effects of car accident through controlling especially dangerous error groups which have higher probabilities. Like these, the results of this study can be used as the primary materials of safety education on drivers.

• Journal of the Korean Society of Safety
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• v.34 no.1
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• pp.76-81
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• 2019

In this study, the causes of human error were identified through the survey of the drivers of the three organizations: Seoul Metro, Seoul Metropolitan Rapid Transit Corporation, and Korail. It was started with the aim of finding and eliciting causes in various directions including human factors, job factors, and environmental factors. The Cronbach alpha value was 0.95 for the reliability significance of the stress-induced factors in the operational area. The significance probability for organisational factors was shown to be 0.82, and the significance of the sub-accident experience and the driving skill factors in operation was 0.81 In addition, the analysis results showed that stress-induced in the field of driving is higher than the human factors in the reliability analysis. The results of the analysis confirmed that the reliability of the organizational and operational stress-induced factors was higher than other causes. In order to reduce urban railroad accidents, this paper suggests a method for operating safe urban railroad through the minimization human errors.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.85-85
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• 2022

The world's most extensive and active deltas, Louisiana's wetlands, are deteriorating rapidly due to multiple stressors such as the discharge of the Mississippi River, sea-level rise, and coastal retreat, the substantial but spatially and temporally variable impacts. However, the ecological and anthropogenic histories, the mode of environmental changes on a multi-millennial timescale have not been thoroughly documented. This study, a palynology-based multiproxy analysis, investigates hydrological, geological, geochemical, and anthropogenic impacts on southern Louisiana wetlands and a variety of external forcing agents influencing ecological succession. Sediment cores extracted from a small pond on a mangrove-dominate island near Port Fourchon, Louisiana, USA yielded a 4,000-year record. The site has been transformed from freshwater to saline water environments, to a mangrove dominant island over the late Holocene. The multivariate principal component analysis identified the relative strength of external drivers responsible for each ecological shift. The Mississippi River delta cycle (lobe switching) was the dominant driver of ecosystem changes during the late Holocene, while relative sea-level rise, tropical cyclones, climate, and anthropogenic effects have been the main drivers late in the site's history.

• Journal of environmental and Sanitary engineering
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• v.21 no.1 s.59
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• pp.12-20
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• 2006

This paper was conducted concerning the degree of indoor air quality in public transport vehicles such as taxicabs, buses and subway trains, as sampled through the active participation of drivers and passengers in Seoul between 13th August 2005 and 2nd November 2005. The results were summarized as follows: 1. Among the measured substances especially respirable particulate matters ($PM_{10}$), total bacteria counts (TBC) and carbon dioxide ($CO_2$) exceeded the standard level of $150{\mu}g/m^3,\;800CFU/m^3$ and 1000ppm. 2. The concentration of carbon dioxide ($CO_2$) in taxi recorded 2491ppm, which is more than the standard amount of 1000ppm. This level was comparatively higher than all other public transportation methods. Total bacteria counts (TBC) in bus and subway recorded $1082CFU/m^3\;and\;1856CFU/m^3$, respectively. 3. The drivers who regularly work long hours showed the higher concern about contamination of the air inside the public transport vehicles and they considered it to be worse than the air outside. In contrast, the general public showed less concern about the air quality inside the public transport vehicles. However, they too acknowledged that the quality of the air inside the public transport vehicles was poor. In regards to the degree of indoor air quality in the public transport vehicles, a counterplan must be implemented urgently to effectively combat the excessive levels of $PM_{10}$, microorganism and $CO_2$. We need to gather more conclusive evidence pertaining to other possible contaminants and influencing factors.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.6
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• pp.73-83
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• 2015

The objective of this study is to establish implications for forest restoration planning in North Korea by analyzing spatio-temporal forest changes and detecting bio-physical factors driving forest degraded. We measured the relationship and spatial distribution between shifting cultivation and sparse forest. We also analyzed between degraded forest land and ecological variables by binary logistic regression to find biophysical drivers of forest degradation and deforestation in North Korea. Between the sparse forest and the shifting cultivation, a positive relationship is found (r=0.91) and scattered discontinuously throughout the country (Moran's I = -1, Z score = -13.46 (p=0.000)). The sparse forest showed a negative relationship with the warmest month(bio 9), the coldest month(bio10), and the minimum of soil water contents (swc_min), while the shifting cultivation had a negative relationship with the warmest month(bio 9) and the minimum of soil water contents(swc_min). However, the most critical drivers convert forests into sloping farmland were the three months rainfall in summer(bio8) and the yearly mean of soil water contents. Such results reflect the growth period of crops which overlaps with the rainy season in North Korea and the recent land reclamation of uplands where the soil water contents are maintained with a dense forest. When South Korea aids forest restoration projects in North Korea, in consideration of food shortage due to North Korea's cropland deficiency, terrace farmlands where soil water contents can be maintained should be excluded from the priority restoration area. In addition, an evaluation method for selecting a potential restoration area must be modified and applied based on multiple criteria including altitude and socio-economic factors in the respective regions.

• Journal of environmental and Sanitary engineering
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• v.18 no.4
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• pp.52-63
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• 2003

This paper investigated Taxi drivers physical subjective symptoms and what factors were interviewed caused the symptoms. The 600 owning taxi-drivers in Seoul during four months from August 1st, 2003 to November 30th, 2003. 1. The average age of the owning taxi-drivers was generally quite high 54 years old. It was very high index compared with the Todai Health Index(THI) and Cornell Medical Index(CMI) of health check tables. 2. According to the age in THI health check table, the complains of mental subjective symptom by reason of age was high among 31 to 40 years old. People who belonged that age group showed high fabrication(L), digestion(C) and aggressiveness(F). The results showed the complains of mental subjective symptom. All items except tiredness(I), melancholia(N), and hypersensitivity(P) were commonly reported by people in their sixties. On the other hand, melancholia(N) and hypersensitivity(P), people in their forties were investigated highly. Statistically, the items of heartㆍblood stream(C) and digestion(D) systems were similar between the two ages, but anger(Q) was different. (p<0.05) 3. From the complains of mental and physical subjective symptoms about work satisfaction on the THI health check table, all items except eyeㆍskin trouble(B) showed strong dissatisfaction. From the complains of mental and physical subjective symptoms about work satisfaction on the CMI health check table, the items of respiratory system(B), digestion(D), nervous system(G), miscellaneous(K), inadequancy(M), and anger(Q) showed similar results. Otherwise, heartㆍblood stream(C) showed statistically different. 4. From the complains of mental and physical subjective symptoms on salary satisfaction in the THI health check table, in the case of people receiving around 1 million won, the complains of physical symptoms showed high among all items except for the respiratory(A) and digestion(C) systems. The eyeㆍskin trouble(B) item showed statistical similarity. The complains of mental and physical subjective symptoms according to a salary degree on the CMI health check table was completely different from the above results. In people received around 1~1.5million won, all items except anxiety(O) showed high. The hypersensitivity(P) item showed statistically different.