• Archives of design research
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• 제17권3호
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• pp.313-322
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• 2004

Product design has direct effects on sales, exciting consumer's interest in purchasing. With the draft bill of Road Traffic Law passing the National Assembly, drivers have been entirely prohibited by the law from using a cell phone while driving since June 30, 2001, As a result, the demand for and the sales of hands-free Kit products for vehicles have been skyrocketing, and more and more of them have been introduced in the market and competing each other in sales. In these situations, the study attempted to present a case study showing the whole process of product design by a small company, which intended to gain an advantage over the competitors in the sector of hands-free products for vehicles with differentiated design. The product whose design development process was presented in the study has many characteristics. Among them it is the most remarkable in removing the connection between the cell phone terminal and the stationary hands-free product. The study was aimed to increase the investment value of design by helping understand that the ultimate goal of technology is commercialization and that how great the role of design is from the beginning to the final stage of product development. It also emphasized the point that one of the goals of design development should lie in providing a more accurate perception of the importance of design to the industry, by establishing a design process throughout the whole stages of product development including initiation, designing and commercialization.

• Korean Journal of Agricultural and Forest Meteorology
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• 제11권4호
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• pp.143-150
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• 2009

Deicing salt is used to melt snow and ice on the road for traffic safety during the winter season, which accumulates in the roadside vegetation and induces visible injuries. The damage may accelerate particularly when it coincides with early spring leaf out. In order to better understand the response mechanisms, C. kousa (3-year-old) was irrigated twice prior to leaf bud in a rhizosphere with solutions of 0.5, 1.0, and 3.0% calcium chloride ($CaCl_2$) concentration, that were made by using an industrial $CaCl_2$ reagent practical deicing material in Seoul. Physiological traits of the mature leaves were progressively reduced by $CaCl_2$ treatment, resulting in reductions of total chlorophyll contents, chlorophyll a:b, photosynthetic rate, quantum yield, stomatal conductance, $F_V/F_M$, and NPQ. On the contrary, light compensation point and dark respiration were increased at high $CaCl_2$ concentration. A decrease in intercellular $CO_2$ concentration by stomatal closure first resulted in a reduced photosynthetic rate and then was accompanied by low substance metabolic rates and photochemical damage. Based on the reduction of physiological activities at all treatments ($CaCl_2$ 0.5%, 1.0%, and 3.0%), C. kousa was determined as one of the sensitive species to $CaCl_2$.

• International Journal of Highway Engineering
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• 제11권1호
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• pp.13-24
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• 2009

This study developed a high strength and performance concrete pavement material with low shrinkage and reflection of sunlight. Based on the literature review, a new mix-design of applying flash ash to improve the strength and performance of the concrete as well as to reduce the dry shrinkage is suggested. In addition, adding black pigment to reduce the reflection and technique of applying OAG (Optimized Aggregate Gradation) is also included. The result of the laboratory experiment indicates that the brightness and the reflection, which depends on the ratio of black pigment addition, did not deviate from the normal range. When OAG is considered for the mix-design, the strength and performance of the concrete improved greatly. In addition, the mix-design using fly ash reduced the dry shrinkage of concrete and improved the resistance to the permeation of chloride ion. Furthermore, the mix-design, which uses fly ash (25% replacement) and black pigment (3% addition) with the application of OAG, is found to be the most effective mix to reduce the shrinkage and reflection as well as improving the strength and performance of the concrete. The result of an economic analysis indicates that the initial construction cost of this proposed mix is more expensive than that of normal concrete pavement material. However, it can be more economic in the long run because the normal concrete pavement material is likely to cost more due to higher probability of maintenance and repair and higher social cost due to traffic accident, etc.

• Journal of Soil and Groundwater Environment
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• 제9권4호
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• pp.15-23
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• 2004

Deicer operations provide traffic safety during winter driving conditions in urban areas. Using large quantities of de-icing chemicals (i.e., $CaCl_2$ and NaCl) can cause serious environmental problems and may change behaviors of heavy metals in roadside sediments, resulting in an increase in mobilization of heavy metals due to complexation of heavy metals with chloride ions. To examine effect of de-icing salt concentration on the leaching behaviors and mobility of heavy metals (cadmium, zinc, copper, lead, arsenic, nickel, chromium, cobalt, manganese, and iron), leaching experiments were conducted on roadside sediments collected from Seoul city using de-icing salt solutions having various concentrations (0.01-5.0M). Results indicate that zinc, copper, and manganese in roadside sediments were easily mobilized, whereas chromium and cobalt remain strongly fixed. The zinc, copper and manganese concentrations measured in the leaching experiments were relatively high. De-icing salts can cause a decrease in partitioning between adsorbed (or precipitated) and dissolved metals, resulting in an increase in concentrations of dissolved metals in salt laden snowmelt. As a result, run-off water quality can be degraded. The de-icing salt applied on the road surface also lead to infiltration and contamination of heavy metal to groundwater.

• Journal of Korean Society of Transportation
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• 제30권2호
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• pp.43-52
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• 2012

A lane departure warning system (LDWS) is an effective technology-based countermeasure for preventing traffic crashes as it provides warning information to drivers. Understanding the characteristics of perception and satisfaction levels on LDWS is fundamental for deriving better performance and functionality enhancements of the system. The purpose of this study is to evaluate the user satisfaction of LDWS. A survey to collect user perception and user preference data was conducted. Both cross-tabulation analysis and binary logistic regression technique were adopted to identify the factors affecting user satisfaction for LDWS. The results revealed that the accuracy and timeliness of warning information was significant for evaluating the effectiveness of LDWS. In particular, the warning accuracy at a curve segment on the road was the most dominant factor affecting user satisfaction. The outcome of this study would be valuable in evaluating and designing LDWS functionalities.

• Journal of Korean Society of Transportation
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• 제35권3호
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• pp.234-246
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• 2017

The Seoul metropolitan government introduced the bus information systems, bus rapid transit to increase travel speed and punctuality but still suffer from insufficiency. This paper delivers a study verifying the external factors at near the bus stops. The dependent variable was set to the standard deviation of (1) travel time and (2) travel time to and from the bus stop in this study. The independent variables were set to (1) the number of routes, (2) traffic volume by bus type, (3) the number of bus bays, (4) the possibility of passing, (5) the distance to crosswalks and intersections, and (5) the presence of residential road. The results showed that the most significant factors included the link section speed, number of bus bay, distance to crosswalk, and the possibility of passing.

• Journal of the Korean Society for Railway
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• 제11권5호
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• pp.441-448
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• 2008

Increasing urban sprawl and climate changes have been causing unexpected high-intensity rainfall events. Thus there are needs to enhance conventional disaster management system for comprehensive actions to secure safety. Therefore long-term and comprehensive flood management plans need to be well established. Recently torrential snowfall are occurring frequently, causing have snow traffic jams on the road. To secure safety and on-time operation of the Bi-modal tram system, well-structured disaster management system capable of analyzing the show pack melt/freezing due to unexpected snowfall are needed. To secure safety of the Bi-modal tram system due to torrential snow-fall, the snow melt simulation capability was investigated. The snow accumulation and snow melt were measured to validate the SWMM snow melt component. It showed that there was a good agreement between measured snow melt data and the simulated ones. Therefore, the Bi-modal tram disaster management system will be able to predict snow melt reasonably well to secure safety of the Bi-modal tram system during the winter. The Bi-modal tram disaster management system can be used to identify top priority area for know removal within the tram route in case of torrential snowfall to secure on-time operation of the tram. Also it can be used for detour route in the tram networks based on the disaster management system prediction.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제20권2호
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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.

• Journal of Korean Society of Rural Planning
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• 제24권4호
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• pp.147-155
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• 2018

The purpose of this study was to identify vulnerable area of emergency medical care. In the existing method, the emergency medical vulnerable area is set as an area that can not reach the emergency room within 30 minutes. In this study, we set up an area that can not reach within 30 minutes including the accessibility of 119 emergency center. To accomplish this, we obtained information on emergency room and 119 emergency center through Open API and constructed road network using digital map to perform accessibility analysis. As a result, 509 emergency room are located nationwide, 78.0% of them are concentrated in the region, 1,820 emergency center are located, and 61.0% of them are located in rural areas. The average access time from the center of the village to the emergency room was analyzed as 15.3 minutes, and the average access time considering the 119 emergency center was 21.8 minutes, 6.5 minutes more. As a result of considering the accessibility of 119 emergency center, vulnerable areas increased by 2.5 times, vulnerable population increased by 2.0 times, and calculating emergency medical care vulnerable areas, which account for more than 30% of the urban unit population, it was analyzed that it increased from 17 to 34 cities As a further study, it will be necessary to continuously monitor and research the real-time traffic information, medical personnel, medical field, and ambulance information to reflect the reality and to diagnose emergency medical care in the future.

• Journal of Korean Tunnelling and Underground Space Association
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• 제21권5호
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• pp.675-687
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• 2019

In recent years, the needs for double deck-tunnels have increased in large cities due to the increase in traffic volume and high land compensation costs. In Korea, a network type tunnel which is smaller than general road tunnels and crosses another tunnel underground is planned. In the shield tunnel joints between the existing shield tunnel and the box-type enlargement section, a partial steel-concrete joint is proposed where the bending moment is large instead of the existing full-section steel joint. In order to analysis the enlargement section of the shield tunnel diverged section to reflect the three-dimensional effect, the two-dimensional analysis model is considered to consider the column effect and the stiffness effect of the longitudinal member. A two-dimensional analysis method is proposed to reflect the stiffness of the longitudinal member and the column effect of the longitudinal point by considering the rigidity of the longitudinal member as the elastic spring point of the connecting part in the lateral model. As a result of the analysis of the model using the longitudinal member, it was considered that the structural safety of the partial steel-concrete joint can be secured by reducing the bending moment of the joint and the box member by introducing the longitudinal member having the stiffness equal to or greater than a certain value.