• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제19권1호
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• pp.71-82
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• 2020

The existing transportation system, which is based on internal combustion engines, is rapidly being converted to electrification. Thus, eco-friendly public transportation with high transportation efficiency will continue to spread throughout the market in the near future. The purpose of this study is to compare and analyze the cognitive characteristics of passengers redgarding the technical and social factors of various public transportation means to help a successful introduction of eco-friendly public transit. Through a survey questionnaire (N=485), seven factors of seven transportation modes were evaluated and analyzed using principal component analysis. As a result, it is confirmed that potential passengers have high expectations for the eco-friendliness and city image of the eco-friendly buses. Also, it is confirmed that eco-friendly buses are superior in cleanliness and ride comfort than diesel buses. Given the study's results, this study identifies the cognitive characteristics of passengers regarding eco-friendly public transportation. We hope that these results will be used as basic information for image positioning and improved service with the use of eco-friendly transportation.

• Journal of Korea Port Economic Association
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• 제30권3호
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• pp.121-140
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• 2014

The purpose of this study is to identify economic benefits for analyzing the future port and propose an appropriate estimation model. This research has conducted the empirical analysis in order to examine the developed research model. First of all, several existing economic benefits are reviewed and the list of benefits, are able to quantify and characterizable, is selected for the next step. We test the application possibility of the proposed model applying for the three suggestions(AS/RS, OSS, Sky Rail) which are based on "Development of Smart Green Container Terminal Technology." The results of this paper are as follows: Firstly, all of the alternatives are proved economic validation because the values of B/C analysis are over 1.0. Secondly, sensitive analysis is attempted to test unforeseeable circumstances based on the cost increases. The result of the test is identified economic validation as well. Lastly, we convince that the proposed research model in this study is particularly applicable to future container terminal so-called "eco-friendly and fully automated container terminal with high productivity."

• Journal of Energy Engineering
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• 제24권2호
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• pp.129-143
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• 2015

Increasing concerns on climate change and energy security accelerated policies to reduce green-house gas emission, especially from the transportation sector. Electric vehicle (EV) has been on the spotlight to deal with such environmental issue and V2G (Vehicle-to-Grid) technology began to draw attentions as an alternative to reduce ownership costs while contributing to an efficient and decentralized power grid. This study conducts a scenario analysis on total cost of ownership of EV under V2G scheme and compare with non-V2G EV and Internal Combustion Engine (ICE) vehicle. As result, V2G service is expected to provide an annual average profit of $210 to EV users willing to reverse flow its residual power in the battery. The profit from V2G service leaves a margin of $4,530 over operational lifetime, compared with $2,420 cost of charge for non-V2G EV. In summary, total cost of ownership of V2G-capable EV was 6.2% less than non-V2G EV and 10.2% higher than ICE vehicle. The results confirm a comparative economic advantage of operating EV under V2G scheme. Increased number of EVs with V2G service has shown to provide positive effects to power industry for valley filling in load distribution, thus, favorably increasing the overall economic feasibility.

• Journal of Internet Computing and Services
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• 제19권1호
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• pp.87-95
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• 2018

Due to global warming and increased energy costs around the world, interests of energy saving and efficiency have been increased. In particular, forging factories need methods to save energy and increase productivity because of needing amounts of energy uses. To solve the problem, we propose a system, which includes collection, monitoring, and analysis process, to monitor energy uses each facility in realtime based on the IoT devices. This system insists of worksheets management, facility/energy management, realtime monitoring, history search, data analysis through connecting with existed ERP/MES Systems in manufacturing factories. The energy monitoring process is to present used energy collected from IoT devices connected with installed gasmeter and wattmeter each facility. This system provide the change of energy uses, usage fee, energy conversion, and green gas information in realtime on Web and mobile devices. This system will be enhanced with energy saving technology by analyzing constructed big data of energy uses. We can also propose a method to increase productivity by integrating this system with functions of digitalized worksheets and optimized models for production process.

• Journal of Internet of Things and Convergence
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• 제7권4호
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• pp.85-94
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• 2021

This study verified what differences in screen golf content characteristics, intention to reuse, customer satisfaction and economic value experienced by consumers according to the image feeling, expression method, and image color provided by screen golf graphic content. In addition, the purpose of this study was to analyze what kind of influence the content characteristics of screen golf have on the economic value and what kind of influence the intention to reuse and customer satisfaction have in this process. From September 1, 2021 to September 30, 2021, a survey of 225 copies of consumers using the screen golf course was conducted. For data processing, frequency analysis, factor analysis, reliability analysis, cluster analysis, chi-square analysis and 3-step mediated regression analysis were performed. The research results are as follows. First, the preferred image feeling showed a high level of clean and sophisticated feeling and the preferred expression method showed a high realistic image. In addition, the preferred image color showed a high level of green color. Second, there were differences in competitiveness, ease of use, sense of solidarity and realism according to the degree of consideration of graphic content and differences in consumer's intention to reuse, customer satisfaction, and economic value. Third, in the relationship between screen golf content characteristics and economic value, customer satisfaction and re-use intention had a mediating effect. Through this study, by providing basic data to derive the graphic design model of screen golf, the operating entity suggested a way to improve economic benefits and tried to contribute to the growth of the screen golf industry.

• Journal of the HCI Society of Korea
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• 제14권2호
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• pp.41-47
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• 2019

In this study, a smart assistive device is designed to recognize pedestrian signal and to provide audio instructions for visually impaired people in crossing streets safely. Walking alone is one of the biggest challenges to the visually impaired and it deteriorates their life quality. The proposed device has a camera attached on a pair of glasses which can detect traffic lights, recognize pedestrian signals in real-time using a machine learning algorithm on GPU board and provide audio instructions to the user. For the portability, the dimension of the device is designed to be compact and light but with sufficient battery life. The embedded processor of device is wired to the small camera which is attached on a pair of glasses. Also, on inner part of the leg of the glasses, a bone-conduction speaker is installed which can give audio instructions without blocking external sounds for safety reason. The performance of the proposed device was validated with experiments and it showed 87.0% recall and 100% precision for detecting pedestrian green light, and 94.4% recall and 97.1% precision for detecting pedestrian red light.

• Korean Journal of Environment and Ecology
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• 제35권2호
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• pp.126-134
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• 2021

It is necessary to set a management period by analyzing growth trends for individual species because the time taken for planted trees to become established differs by species. The purpose of this study was to suggest an appropriate management period through the analysis of the annual growth of Pinus densiflora planted in the riverine eco belt. The average annual growth before planting was 0.6cm. The growth after planting showed an increase of 0.3cm in the 1st and 2nd year, 0.5cm in the 3rd and 4th year, and 0.7cm after the 5th year. Since P. densiflora was confirmed to go through poor growth stages in the 1st and 2nd year, a recovery stage in the 3rd and 4th year, and a normal growth stage in the 5th year, management should pay more attention to improve inappropriate environmental conditions until at least the 4th year, unlike the growth of hardwood. Since the period required for activation by species may vary, the management period of each species will need to be set through growth research.

• Journal of Wetlands Research
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• 제24권4호
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• pp.213-223
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• 2022

This study was conducted to establish a Habitat Suitability index (HSI) based on literature research and field surveys on ecology and habitat of 'Hynobius leechii'. And this study will be used as basic data for qualitative evaluation of habitat environment. The survey sites were divided into natural habitats close to the prototype habitat and artificial restoration areas where Hynobius leechii was monitored. So the types of habitats were diversified. Hynobius leechii is a vulnerable species to climate change because it is affected by the microhabitat and has low mobility. HSI variables of Hynobius leechii were extracted through domestic and overseas literature, and standards were extracted from literature research and field survey. The standards were presented as a value of the physical allowable category in consideration of realization. To verify the study, an in-depth consultation was conducted by amphibians experts. HSI variables of Hynobius leechii were included 9 variables such as Overstory canopy cover(%), Understory cover(%), Water-pH, Soil-pH, Soil relative humidity(%), Leaf litter depth(cm), Rock substrates (%), Type of Coarse woody, Distance from Street or Pollutant(m).

• Korean Journal of Environment and Ecology
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• 제35권4호
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• pp.387-397
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• 2021

This study aims to present reference data necessary for developing evaluation indicators to analyze the actual resilience of purchased land by investigating the factors that affect the restoration of the purchased land in the riparian zone and quantitatively calculating its importance. The main results are as follows. Firstly, this study identified 34 potential resilience factors through a literature review encompassing domestic and overseas studies and derived seven ecological responsiveness factors, six physical responsiveness factors, and four managerial responsiveness factors through the Delphi survey. Secondly, reliability analysis and Analytic Hierarchy Process (AHP) analysis derived the following important factors: structural stability of the vegetation restored in the purchased land, species diversity of wildlife, structural stability of wildlife, the size of restored wetland after purchase, number of plant species, and the land cover status adjacent to the purchased land. The study results are expected to be helpful information for ecological restoration and management plans reflecting reinforcing factors for resilience at each stage of land purchase, restoration, and management.

• Applied Chemistry for Engineering
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• 제34권1호
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• pp.36-44
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• 2023

Core-shell TiO₂/Ag nanoparticles were synthesized by a modified sol-gel process and the reverse micelle method using acetoxime as a reducing agent in water/dodecylbenzenesulfonic acid (DDBA)/cyclohexane. The structure, shape, and size of the TiO₂/Ag nanoparticles were investigated using X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), and thermogravimetric analysis (TGA). The size of TiO₂/Ag nanoparticles could be controlled by changing the [water]/[DDBA] molar ratio values. The size and the polydispersity of TiO₂/Ag nanoparticles increased when the [water]/[DDBA] molar ratio rose. The resultant Ag nanoparticles over the anatase crystal TiO₂ nanoparticles exhibited a strong surface plasmon resonance (SPR) peak at about 430 nm. The SPR peak shifted to the red side with the increase in nanoparticle size. Conductive pastes with 70 wt% TiO₂/Ag nanoparticles were prepared, and the pastes were coated on the PET films using a screen-printing method. The printed paste films of the TiO₂/Ag nanoparticles demonstrated greater surface resistance than conventional Ag paste in the range of 405~630 μΩ/sq.