• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.177-191
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• 2021

One of the major causes of serious air pollution worldwide is emissions from road transportation. A number of countries are working to reduce vehicle emissions, and the Seoul Metropolitan Government is also implementing active policies to reduce emissions by setting a target of 40% by 2030. Implementing these policies requires the introduction of practical indicators. Most of the domestic emissions are calculated by the emission coefficient, a function of speed at the National Institute of Environmental Research under the Ministry of Environment, but the dynamic variable speed is limited to being used as an indicator of the number of eco-friendly vehicles. Therefore, this study calculated the emission rates in Seoul using the vehicle registration data of Seoul and the vehicle inspection data from the Korea Transportation Safety Authority. The tendency of emissions was determined according to key variables such as vehicle type, fuel and mileage. Emissions were based on carbon monoxide, hydrocarbons, nitrogen oxides and particulate matter measured by vehicle inspection from the Korea Transportation Safety Authority. As a result, the emission rates showed a significant trend according to the model year and mileage. This can be used as a policy indicator to preferentially switch commercial vehicles with old model years and long mileage when switching eco-friendly vehicles in Seoul.

• Journal of Internet Computing and Services
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• v.23 no.1
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• pp.77-86
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• 2022

The Republic of Korea is a country in which coastal surveillance is an imperative national task as it is surrounded by seas on three sides under the confrontation between South and North Korea. However, due to Defense Reform 2.0, the number of R/D (Radar) operating personnel has decreased, and the period of service has also been shortened. Moreover, there is always a possibility that a human error will occur. This paper presents specific guidelines for developing an AI learning model for the intelligent coastal surveillance system. We present a three-step strategy to realize the guidelines. The first stage is a typical stage of building an AI learning model, including data collection, storage, filtering, purification, and data transformation. In the second stage, R/D signal analysis is first performed. Subsequently, AI learning model development for classifying real and false images, coastal area analysis, and vulnerable area/time analysis are performed. In the final stage, validation, visualization, and demonstration of the AI learning model are performed. Through this research, the first achievement of making the existing weapon system intelligent by applying the application of AI technology was achieved.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.84-99
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• 2021

As the micro-mobility market grows, the demand for route guidance, that includes uphill information as well, is increasing. Since the climbing angle depends on the electric motor uesed, it is necessary to establish an uphill road DB according to the threshold standard. Although road alignment information is a very important element in the basic information of the roads, there is no information currently on the longitudinal slope in the road digital map. The High Definition(HD) map which is being built as a preparation for the era of autonomous vehicles has the altitude value, unlike the existing standard node link system. However, the HD map is very insufficient because it has the altitude value only for some sections of the road network. This paper, hence, intends to propose a method to generate the road longitudinal slope using currently available data. We developed a method of computing the longitudinal slope by combining the digital elevation model and the standard link system. After creating an altitude at the road link point divided by 4m based on the Seoul road network, we calculated individual slope per unit distance of the road. After designating a representative slope for each road link, we have extracted the very steep road that cannot be climbed with personal mobility and the slippery roads that cannot be used during heavy snowfall. We additionally described errors in the altitude values due to surrounding terrain and the issues related to the slope calculation method. In the future, we expect that the road longitudinal slope information will be used as basic data that can be used for various convergence analyses.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.2
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• pp.58-71
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• 2021

The number of elderly people worldwide is rapidly increasing and the mobility handicapped suffering from inconvenient public transportation service is also increasing. In Korea and abroad, various policies are being implemented to provide high-quality transportation services for the mobility handicapped, and budget support and investment related to mobility facilities are being expanded. The mobility handicapped spends more time for transit transfer than normal users and their satisfaction with transit service is also lower. There exist transfer inconvenience points of the mobility handicapped due to various factors such as long transfer distances, absence of transportation facilities like elevators, escalators, etc. The purpose of this study is to find transfer inconvenience points for convenient transit transfer of the mobility handicapped using Smart card Big data. This study process traffic card transaction data and construct transfer travel data by user groups using smart card big data and analysis of the transfer characteristics for each user group ; normal, children, elderly, etc. Finally, find transfer inconveniences points by comparing transfer patterns between normal users and the mobility handicapped. This study is significant in that it can find transfer inconvenience points for convenient transit transfer of the mobility handicapped using Smart card Big data. In addition, it can be applicated of Smart card Big data for developing public transportation polices in the future. It is expected that the result of this study be used to improve the accessibility of transit transportation for mobility handicapped.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.475-481
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• 2022

Recycled aggregates show high water absorption rate compared to natural aggregates due to microcrack developed during production process and adhered cement pastes at the surface of recycled aggregates. This leads to the deterioration of mechanical properties and slow work flow. Currently it is getting hard to satisfy high demand for natural aggregates. Utilizing recycled aggregate more widely may be a substitutable countermeasure for the shortage of natural resources. In this study, two-stage mixing approach(TSMA) suggested by Tam et al. is used to produce recycled aggregate concrete(RAC) with 100 % replacement of coarse natural aggregate and tests for compressive strength, elastic modulus, and chloride ion diffusion coefficient are conducted to find out the effect of TSMA compared to normal mixing method. According to experimental result compressive strength and elastic modulus of RAC with TSMA was superior to those of RAC with normal mixing irrespective of water-cement ratio, and in some cases mechanical properties of RAC with TSMA approached to those of natural aggregate concrete(NAC). However, chloride ion diffusion coefficient of RAC was higher than that of NAC. This illustrates that TSMA is not an appropriate method in reducing chloride ion diffusion coefficient, resulting in inconsequential contribution of TSMA to the durability of RAC.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.5
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• pp.78-89
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• 2022

Super - Bus Rapid Transit (S-BRT), adding the advantages of urban railroads to BRT, has emerged to solve the problem of low speed and reliability of the existing BRT. Notably, the S-BRT driveway is classified into exclusive lanes and roads, as BRT, in the domestic guidelines. However, S-BRT and BRT have different operating goals and characteristics, so it is necessary to systematize the S-BRT driveway. Therefore, this study classified an S-BRT driveway into exclusive lane, shared lane with overtaking lane, and shared lane without overtaking lane based on domestic conditions. Subsequently, a control strategy for transit signal priority in each driveway was presented by the study based on the characteristics of the driveway to achieve the S-BRT target service level. Finally, the S-BRT target service level was almost achieved, and the travel speed was high and increased in the order respectively in the exclusive lane, shared lane with overtaking lane, and shared lane without overtaking lane in the study. Hence, it is important to operate a transit signal priority considering the characteristics of each driveway when operating the S-BRT. In essence, this study is expected to be used as a reference for driveway design and transit signal priority operation when introducing S-BRT in each local government in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1D
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• pp.41-48
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• 2009

The capacity analysis of signalized intersection usually includes a HCM method used at home and abroad and a ICU method this study presents. The HCM method focuses on operation analysis measuring an intersection's delay in terms of given traffic volume, signal operation, and intersection structure data. This method includes planning and design analysis, but these analyses are complex due to being possible through repetitive operation analysis. However the ICU method is a powerful tool for planning and design analysis, because these are possible through brief traffic volume and geometry structure data and consider minimum green time. In this study, the authors studied the ICU method and compared the HCM and ICU by analyzing traffic volume scenarios. Also to consider effectiveness for application of the ICU method, the authors applied the ICU to capacity analysis of intersections on urban arterial for setting major intersection and effect analysis for changing crosswalk type, the number of lane, lane use and operation form of left turn. The result of the analyses shows that the ICU method can measure correct capacity of intersection consist of a broad road in urban area, and is effective for planning and design analysis. This study is expected that traffic experts can grasp correct intersection's capacity and carry out a proper planning or improvement by applying the ICU method to planning and design analysis.

• Asia Marketing Journal
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• v.10 no.3
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• pp.147-168
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• 2008

Samsung Tesco is a representative company that is successfully enforcing 'sustainable management' through creative, systematic corporate responsibility (CR). The concentration on CR is because of the fact that the modern society expects companies to do a role as a social citizen. For this reason, Samsung Tesco emphasizes that the cost of carrying on CR is an important factor in business which leads to a positive cycle in business, and accordingly is rather an investment than a cost. The reason why Samsung Tesco proclaimed its resolution to make best efforts on CR is because Samsung Tesco thinks CR is a necessary task and responsibility of a company. Samsung Tesco is doing various activities continuously, and is investing by increasing its costs on CR and systemizing the organization. Consequently, Samsung Tesco is being evaluated as the first and best innovative company in the distribution industry. This case study firstly shows the actual conditions of domestic companies in doing CR. Secondly, it analyzes how Samsung Tesco is carrying out the cultural, sharing, and environmental CR. And lastly, it gives some strategic points on successful CR.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.2
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• pp.188-195
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• 2024

Recently, the use of recycled aggregates from construction waste has been introduced as a solution for environmental problems and aggregate shortage. In spite of the various methods to promote recycling of recycled aggregate, the use of recycled aggregate as the structural aggregate has been limited because the quality of recycled aggregate(especially recycled fine aggregate) has been considered lower than that of natural aggregate. In this work, recycled fine aggregate was immersed for an hour in acrylic resin solutions of various concentrations to improve its quality, the appropriate immersion concentration was selected by measuring the absorption capacity and skeletal density of the recycled fine aggregate, and mortar specimens were prepared to evaluate the mechanical performance in order to propose a applicable treatment process to promote the use of recycled fine aggregate. According to the experimental results, as the acrylic resin concentration increased, the absorption capacity and skeletal density of the recycled fine aggregate decreased. The absorption capacity was lowest at acrylic resin concentrations around 6 to 8 %. However, among mortar specimens made of recycled fine aggregate immersed in acrylic resin solution, the compressive strength was the highest at 4 % acrylic resin concentration, suggesting that the use of higher concentration acrylic resin solution can actually lower the compressive strength of mortar.

• Korean Journal of Optics and Photonics
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• v.35 no.4
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• pp.157-163
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• 2024

We developed a 3-channel fiber laser with a common seed and a phase control system for laser beam combining through a diffractive optical element. Beam combining was performed by adjusting the angles of the beams incident on the diffractive optical elements, and the phase of each beam was controlled to maximize the intensity of the combined laser beam. The power of the 3-channel laser before passing through the diffractive optical elements is about 65 mW. The power of the combined beam varied between 2.9 mW and 48.3 mW depending on the phase change of each channel. Through phase control, the output of the combined beam can be maintained at 42 mW for more than 91.8% of the total time. It is expected that higher combining efficiency can be achieved by improving the transmittance of the diffractive optical elements and the performance of the phase control system.