• Korean Journal of Health Education and Promotion
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• v.13 no.1
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• pp.90-116
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• 1996

The purpose of this study is to provide basic data for the children so as to avoid any accidents and to improve their health through a sound and safe living environment with safety education established through more systematic methods. For the study, the methods used include the questionnaires for collecting data which are distributed among 273 children from 3 to 6 years old. They live in three districts of Seoul (Kangnam and Kangbuk), Kyeonggido (Munsan and Ilsan) and Incheon. The children's general characteristics are investigated and the relationship between the accident-proneness prospects and their results are analyzed assuming that children's health is expected to have an effect on their safety. The findings of the study are as follows: 1. The accident-proneness prospect (for the living safety) has significant difference in sleeping habits and physically weak conditions(p<0.05). 2. The accident-proneness prospect (for the traffic safety) has no significant difference in accordance with the children's health condition. 3. Children's reasoning power has no significant difference in accordance with their health condition. 4. Children's movement speed non-significantly differs in accordance with their health condition. 5. Children's movement stability has a significant difference in accordance with their health conditions such as history of mild disease(p<0.05) and physical work capacity(p<0.05). 6. Children's attention power has no significant difference in accordance with their health condition. 7. Children's characteristic activities show a significant difference in accordance with their health history of mild disease(p<0.05). mental health(p<0.05). eating habits(p<0.05) and others (i.e. auditory abnormality and skin desease)(p<0.05). 8. General assessment of the APP test has no significant difference in accordance with their health condition. 9. The health conditions are a significant difference in the history of mild disease in accordance with sex(p<0.05) and whole family members(p<0.001). Also there are shown significant differences. in accordance with sex(p<0.05). in physical work capacity(p<0.05). Eye sight, blood circulation and skin condition show significant differences in accordance with residence(p<0.05) and whole family members(p<0.01). and the condition of eating habits appeared significant in accordance with age(p<0.05). Also, sleeping habits and physically weak conditions shows significant differences in accordance with age(p<0.001) and housing pattern(p<0.01), and others (i.e. auditory abnormality and skin desease) show significant differences in accordance with residence (p<0.001).

• Journal of the Korean GEO-environmental Society
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• v.21 no.9
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• pp.25-32
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• 2020

The underground utilities installed under the ground is an important civil engineering structure, such as water supply and sewerage pipes, underground power lines, various communication lines, and city gas pipes. Such underground utilities can be exposed to risk due to external factors such as concentrated rainfall and vehicle load, and it is important to select and construct an appropriate backfill material. Currently, a method mainly used is to fill the soil around the underground utilities and compact it. But it is difficult to compact the lower part of the buried pipe and the compaction efficiency decreases, reducing the stability of the underground utilities and causing various damages. In addition, there are disadvantages such as a decrease in ground strength due to disturbance of the ground, a complicated construction process, and construction costs increase because the construction period becomes longer, and civil complaints due to traffic restrictions. One way to solve this problem is to use a liquid filler. The liquid filler has advantages such as self-leveling ability, self-compaction, fluidity, artificial strength control, and low strength that can be re-excavated for maintenance. In this study, uniaxial compression strength test and fluidity test were performed to characterize the mixed soil using marine clay, stabilizer, and in-situ soil as backfill material. A freezing-thawing test was performed to understand the strength characteristics of the liquid filler by freezing, and in order to examine the effect of the filling materials on the corrosion of the underground pipe, an electrical resistivity test and a pH test were performed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.6
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• pp.637-652
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• 2012

The protector with the shape of '${\sqcap}$' in cross section can be set up in the tunnel, which can be constructed for enlargement of cross section, to keep traffic flow in the tunnel. It is impossible to install the rockbolt in the side wall of tunnel due to a limited space between the protector and cutting surface of side wall. The objective of this study is to suggest the optimum thickness of shotcrete lining without rockbolt on the side wall and to evaluate the stability of tunnel enlarged. Numerical analysis was performed to evaluate the displacement at the center of tunnel, the convergence of tunnel, and the stress in shotcrete lining in 4-lane NATM road tunnel enlarged from 3-lane NATM road tunnel. The vertical displacement at the center of tunnel and the convergence of crown in the tunnel with rockbolt in the side wall were almost similar to those in the tunnel without rockbolt in the side wall. The convergence of bench/invert and the stress in shotcrete lining without rockbolt on the side wall were greater maximum 0.57 mm and 1,300 kN/$m^2$ than those with rockbolt in the side wall. The increased convergence and the stress in shotcrete lining can be reduced in incerasing of thickness of shotcrete lining about 20% (5 cm) of standard thickness, 25 cm, of shotcrete lining.

• International Journal of Highway Engineering
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• v.8 no.2 s.28
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• pp.23-30
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• 2006

Emulsified Asphalt Mixture(EAM) is more environmentally-friendly and cost-effective than typical Hot Mix Asphalt (HMA) because EAM does not produce carcinogenic substances, e.g., naphtha, kerosene, during the both of manufacturing and roadway construction process. Also, it does not require heating the aggregates and asphalt binder. However, EAM has some disadvantages. Generally EAM has a less load bearing capacity and more moisture susceptibility than conventional HMA. The study evaluated a Fiber modified EAM (FEAM) to increase load bearing capacity and to decrease moisture susceptibility of EAM. Modified Marshall mix design was developed to find Optimum Emulsion Contents (OEC), Optimum Water Contents (OWC), and Optimum Fiber Contents (OFC). A series of test were performed on the fabricated specimen with OBC, OWC, and OFC. Tests include Marshall Stability, Indirect Tensile Strength, and Resilient modulus test. Comparison analyses were performed among EAM, Fiber modified EAM (FEAM), and typical HMA to verify the applicability of EAM and FEAM in the field. Test results indicated that both of EAM and FEAM have an enough capability to resist medium traffic volume based on the Marshall mix design criteria. Also the study found that fiber modification is effective to increase the load bearing capacity and moisture damage resistance of EAM.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.39-47
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• 2008

With dramatic development of IT technology and start of DMB service, installing the DMB equipment in a vehicle for watching TV programs and literal or pictorial traffic information are increasing. Watching the DMB during driving the vehicle could cause visual and cognitive distraction to drivers as much as eating food, operating radio and using mobile phone. However, there is not much empirical research for this topic and no research examined the effect of watching the DMB on driving behaviors in Korea. So, the present study examined the effect of watching the DMB on the driving behaviors with car simulator experiment. Within subject design was used in the study. That is, all subjects drove the vehicle both in the watching DMB condition and the non-watching DMB condition. The results indicated that subjects in the watching DMB condition took longer time to arrive at the destination and operated accelerator and brake pedal rapidly than subjects in the non-watching DMB condition. That is, their overall driving stability was lower than non-watching subjects'. Additionally, we examined the difference among the DMB control conditions (i.e., keypad condition, touch-pad condition and remote controller condition) in the driving behaviors. Finally, we discussed the limitations and the implications of the present study.

• Journal of the Korea Concrete Institute
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• v.29 no.1
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• pp.23-32
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• 2017

The joints between precast PSC slabs of the intermediate road slab in double deck tunnel are inevitably generated in the road traffic vehicle traveling direction. Therefore, it is important to make the behavior of parts on the joint in one piece. The imtermediate road slab system of double deck tunnel in great depth proposed in this study will be constructed with precast PSC slab in order to minimize the construction period. And the joint connection between the precast slab has been developed in two methods: the 'Transverse tendon reinforcement method' and 'High strength bolts connection method'. Also, the experiments were performed for the full scale model in order to evaluate the performance of the intermediate road deck slab with two type joints systems, the structural stability was verified through the F.E.M analsysis. The results of static loading test and F.E.M analysis investigated a very stable behavior of intermediate road deck slab in double deck tunnel applying the joint methods developed in this study, in the cracks and deflections to satisfy the design standards of Highway Roads Bridges (2011), it was determined that there is no problem even servicebility.

• Journal of Navigation and Port Research
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• v.40 no.1
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• pp.27-34
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• 2016

For the prevention of marine casualties, international bodies have mainly focused on strengthening ship's stability and design, maritime education and training, and improving maritime traffic environment. Statistics analysis on marine casualties showed that most of casualties occurred in coastal waters, especially by human elements. In order to review the conformity of existing prevention measures with the result of the statistics analysis, the IMO's SHELL model was applied to the established measures. As a result, ergonomic approaches were needed for the prevention of human errors in coastal waters, so that the priority should be given to the interface between ship's operator and navigational environment. For this study, Rasmussen's SRK pyramid, which showed decision making mechanism of human, and the US Coast Guard's investigation manual on marine casualties concerning the collapse of safe maritime transportation system were reviewed, and the merits and demerits within the risk assessment tools such as IWRAP, PAWSA, ES model, PARK model, and NURI model were also studied. Although the effectiveness of the existing risk assessment models was proved in ports and approaching channels, it is concluded that the need of new models for converting Korean seafarers' qualitative risk to quantitative risk was proposed so as to print hazard maps which make seafarers instinctively recognize comparative hazard levels of coastal waters.

• Journal of the Korean Institute of Gas
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• v.24 no.2
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• pp.22-28
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• 2020

In this study, quantitative risk assessment was carried out for city gas high-pressure pipelines crossing through urban rivers. The risk assessment was performed based on actual city gas properties, traffic volume and population and weather data in the worst case scenario conditions. The results confirmed that the social and individual risks were located in conditionally acceptable areas. This can be judged to be safer considering that the risk mitigation effect of protecting the pipes or installing them in the protective structure at the time of the construction of the river buried pipe is not reflected in the result of the risk assessment. Also, SAFETI v8.22 was used to analyze the effects of wind speed and pasquil stability on the accident damage and dispersion distances caused by radiation. As a result of the risk assessment, the safety of the pipelines has been secured to date, but suggests ways to improve safety by preventing unexpected accidents including river bed changes through periodic inspections and monitoring.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.60-67
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• 2009

This paper describes a development of system that enables the user to simulate the rockfall and landslide from slopes using physical engine. Until now, it will not be able to accomplish the virtual experiment of three-dimensional interpretation about slope informations, stability evaluation, the rockfall and landslide simulation, etc., because of absence of three-dimensional simulation systems which relates with slopes. With like that reason, this paper developed a simulator which is identical or similar the rockfall and the landslide where the possibility which will occur or occurred from actuality is high very actual condition from virtual experiment. For a simulator development, this paper uses the physical engine which is mainly used from computer game and animation development etc., And it will be show the process where the rockfall and landslide occurs with simulator. This simulator which sees the process where the rockfall and the landslide occur from three-dimension computer graphics theory and the physical engine, is a system which is the possibility of showing actual feeling. Therefore, the result of this paper is applied in vehicle travelling guidance system and intelligence traffic systematic etc., because of creates visual service and three-dimensional application of the slope information database which is developed in existing, and will be able to forecast the upgrade of user benefit planning and a service.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.622-631
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• 2019

The purpose of this study is to establish and apply a public transport valuation system to form required policy for institutionalization. Over the past six years, Jeju has seen a steady increase in the number of cars owned by its population. Also, as the number of tourists has changed from group to individual tourists, the rate of rental car use has increased rapidly. As a result, road congestion in Jeju city is becoming as crowded as Seoul., Jeju Island is said to have created a foundation for faster, more convenient, and cheaper use of transportation through the reorganization of the public transportation system in August 2017. This is also reflected in the Public Transportation Value Assessment. Jeju residents were in favor of strengthening public transportation priority policy. In addition, public transport valuations are highly valued in the order of public transportation fares, public transportation stability, public transportation policies for the common people, public transportation policies for the vulnerable, public transportation policies for residents, environmentally-friendly policies, and public transportation to help ease traffic congestion. This is because public transportation has a wide range of values and should refine the factors that local governments use to evaluate policy. These methods need to be institutionalized and actively utilized through the establishment of a value assessment system for public transport.