• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.2
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• pp.102-116
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• 2021

For the safe operation of autonomous vehicles, the representative technology of the 4^th industrial revolution era, a combination of various technologies such as sensor technology, software technology and car technology is required. An autonomous vehicle is a vehicle that recognizes current location and situation by using the various sensors, and makes its own decisions without depending on the driver. Perfect recognition technology is required for fully autonomous driving. Since the precise road maps provide various road information including lanes, stop lines, traffic lights and crosswalks, it is possible to minimize the cognitive errors that occur in autonomous vehicles by using the precise road maps with location information of the road facilities. In this study, the definition, necessity and technical trends of the precise road map have been analyzed, and the HD(High Definition) map prototype based on the web GIS has been built in the autonomous driving-specialized areas of Daegu Metropolitan City(Suseong Medical District, about 24km), the Happy City of Sejong Special Self-Governing City(about 33km), and the FMTC(Future Mobility Technical Center) PG(Proving Ground) of Seoul National University Siheung Campus using the MMS(Mobile Mapping System) surveying results given by the National Geographic Information Institute. In future research, the built-in precise road map service will be installed in the autonomous vehicles and control systems to verify the real-time locations and its location correction algorithm.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.3
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• pp.1-19
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• 2021

The domastic hard shoulder running(HSR) System has been gradually expanding since its initial implementation in September 2007 with the aim of increasing capacity and resolving congestion. Hard Shoulder is used as a space for driver's visual comfort and a place for vehicles to evacuate in case of emergency, but it is replaced by a space for driving when the HSR System is implemented. Therefore, it was intended to determine the improvement effect before and after implementation of the HSR system through safety analysis and mobility analysis. The safety analysis analyzed the impact of traffic accidents by comparing HSR sections and similar sections. The mobility analysis was to determine the improvement effect by quantifying the speed and traffic volume changes before and after HSR System implementation. According to safety yanalysis, there is no effect of reducing traffic accidents when implementing the HSR System. In mobility analysis, the implementation of the HSR System significantly improved the speed of traffic during peak hours and significantly reduces slow and delay hours.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.154-164
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• 2011

This study was conducted to develop the semi-crawler type mini-forwarder that can be operated comfortable small-scale logging operation in the steep terrain and also used at a variety of operations such as the civil work in erosion control and forest-road. Considering the minimum turning radius and the width of forest operation road, the total length, width and loading capacity of the semi-crawler type mini-forwarder is 5,750 mm, 1,900 mm and $2.5m^{3}$, respectively. The maximum engine power is 96ps at 3600 rpm. Selected hydraulic pumps are consists of two main pumps and two sub-main pumps. Main hydraulic pumps are utilized to running motor of the front wheel and rear crawler. Sub-main pumps are utilized to the actuation parts such as steering, crane, out-rigger and dump cylinder. The transmission was adapted as the HST (Hydro-Static Transmission) system. The driving parts are designed and manufactured as the front wheel type and the rear crawler type. The steering type was manufactured as the ackerman type. Driving control parts type was designed and manufactured as driver's seat type of normal cars. It is also attached on auxiliary equipments such as winch, log grapple and out-rigger. The traveling speed of the semi-crawler type mini-forwarder in forest road was 5.3 km/hr to 7.7 km/hr.

• International Area Studies Review
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• v.16 no.1
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• pp.29-52
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• 2012

This study investigates the relationship between corporate social responsibility and corporate governance among major US corporations belonging to S&P 500 index during 2000-2008. Specifically, it examines the ways in which firms engage their boards of directors in integrated strategy by establishing a public affairs(PA) or social responsibility(SR) committee at the board level and the effects of this practice on their corporate social performance(CSP). The empirical findings show that negative CSP is the major driver for establishing such a committee, that is, firms suffering from negative CSP as a result of experiencing undesirable social events tend to establish such a committee. On the other hand, such a committee helps the firm increase positive CSP once it is established. In other words, the purpose of establishing such board-level committees is to address problems associated with negative CSP, and once established, they can help enhance positive CSP by enabling the firm to integrate market, non-market, and social responsibility aspects in strategy formulation more effectively. This is evidence that Baron's integrated strategy framework can help firms achieve tangible outcomes.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.341-348
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• 2020

The ATP-binding cassette (ABC) transporter superfamily represents the largest transmembrane protein that transports a variety of substrates across extra- and intra-cellular membranes. In insects, the ABC transporter proteins play crucial roles in insecticide resistance. To date, no studies have investigated the involvement of ABC transporter gene for cross-resistance to insecticide chemistries. Here, we studied such possible mechanisms against six conventional insecticides using transgenic Drosophila melanogaster strains carrying Mdr49 transcript variant A. For the 91-R and 91-C strains of Drosophila melanogaster, although they have a common origin, 91-R has been intensely selected with DDT for over 60 years, while 91-C has received no insecticide selection. Our transgenic analyses showed that overexpression of 91-R-MDR49 transcript variant A along with three amino acid variations can yield a relatively low degree of cross-resistance to carbofuran (2.0~6.7-fold) and permethrin (2.5~10.5-fold) but did not show cross-resistance to abamectin, imidacloprid, methoxychlor, and prothiofos as compared to the Gal4-driver control strain without transgene expression. These results indicate that the overexpression of Mdr49A in itself leads to a cross-resistance and three amino acid changes have additional effects on positive cross-resistance to carbofuran and permethrin.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.6
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• pp.697-705
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• 2021

Currently, roadway operation agencies provide interior zones of tunnels with emergency information including crash, fire, and vehicles' stop, through state-of-the-art technologies such as variable message signs and radio-based broadcast systems. However, when coping with an emergency in tunnel interior zones, such information could be too late for drivers to access. A radio-based emergency alert system at the access zones of freeway tunnels, on the other hand,could be a good alternative for solving this problem. Therefore, the objective of this study is to assess user acceptability of such an alternative system. To carry out this study, an online survey was conducted on 762 drivers, and the survey results were analyzed using a structural equation modeling to identify factors affecting acceptability of the proposed system. As a result, driver characteristics such as age group, driving frequency, and driving career, utilization of conventional traffic information, and usefulness of conventional traffic information have a positive impact on acceptability. It is expected that the findings of the study will be a basis to effectively address and deploy a new emergency alert system at the access zones of freeway tunnels.

• Journal of the Korean Regional Science Association
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• v.38 no.1
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• pp.21-32
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• 2022

The purpose of this study is two things. First, it is to develop and demonstrate a sharong taxi platform. To this end, the implications for platform development were derived by analyzing consumers' perceptions of existing taxi services using IPA. As a result, abnormal business activities and safe services in the maintenance area were found to be safe rides and easy rides in the key improvement area. Safety such as usage fee level and driver information provision were derived in the areas subject to improvement, and friendly response and internal and external cleanliness were derived in the areas of excessive investment. The second purpose of this study is to estimate the value given to users for sharing taxi service platforms using the CVM. As a result of estimating the value of the demonstration service of the shared taxi platform developed through this study, the WTP was 3,621 won/per household/per year when expanding throughout Gimhae-si, and 2,515 won/per household/per year. Compared to the willingness to pay for empirical services, only 69.5% of the willingness to pay for the spread project in Gimhae-si. This is the result of a combination of service spread to an unspecified number of people and concerns about service quality due to spatial expansion. This suggests that it is necessary to build data through continuous demonstration and to carefully build a roadmap for spread by upgrading services based on this.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.44-61
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• 2022

With the increase of truck traffic, roads are becoming more congested and the risk of accidents is also increasing. Since the fatality rate of traffic accidents caused by trucks is about 2 to 3 times higher than that of passenger cars and buses, it is urgent to prepare policies for truck traffic safety. While most of the previous studies focused on factor analysis that contributes to traffic accidents, this study presented traffic safety policies (4 major-criteria and 12 sub-criteria) for trucks through driver interviews and previous studies. Then, the priority of the policies was evaluated by using Fuzzy-AHP. As a result, the improvement of truck drivers' working environment was evaluated as the most important criteria, and followed by the improvement of road traffic conditions. In detail, there is an urgent need to improve the freight car fare system, ensure sufficient rest for drivers, and strengthen the crackdown of illegal parking and stopping along roads. This study is expected to be usefully utilized in preparing traffic flow safety policies in preparation for the continuous increase of truck traffic.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.203-213
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• 2021

A vehicle crash occurs due to various factors such as the geometry of the road section, traffic, and driver characteristics. A safety performance function has been used in many studies to estimate the relationship between vehicle crash and road factors statistically. And depends on the purpose of the analysis, various characteristic variables have been used. And various characteristic variables have been used in the studies depending on the purpose of analysis. The existing domestic studies generally reflect the average characteristics of the sections by quantifying the traffic volume in macro aggregate units such as the ADT, but this has a limitation that it cannot reflect the real-time changing traffic characteristics. Therefore, the need for research on effective aggregation units that can flexibly reflect the characteristics of the traffic environment arises. In this paper, we develop a safety performance function that can reflect the traffic characteristics in detail with an aggregate unit for one hour in addition to the daily model used in the previous studies. As part of the present study, we also perform a comparison and evaluation between models. The safety performance function for daily and hourly units is developed using a negative binomial regression model with the number of accidents as a dependent variable. In addition, the optimal negative binomial regression model for each of the hourly and daily models was selected, and their prediction performances were compared. The model and evaluation results presented in this paper can be used to determine the risk factors for accidents in the highway section considering the dynamic characteristics. In addition, the model and evaluation results can also be used as the basis for evaluating the availability and transferability of the hourly model.

• Journal of the Society of Disaster Information
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• v.18 no.3
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• pp.622-635
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• 2022

Purpose: Due to the change of demography, the ratio of senior drivers has increased and the transition to a super-aged society is expected to make more seniors drive in the future. Method: In this research, we analyzed medical characteristics of the driver's age-specific decline in body function and saw that both the function of the physical as well as mental capacities deteriorates as people age. Among them, various functions are precipitously weakened after reaching 70, implying that those over the age of 70 are classified as seniors in a medical sense. In this context, we also could identify that based on such age criteria, various safety policies for senior drivers should be developed and set up in Korea. Result: We could find a steep fall in the physical function of body after reaching 70 from the chronological change of cognitive function and judgment ability. In particular, it is revealed that the driving license institution and aptitude test for drivers over 70 should be thoroughly examined, as physical functions necessary for driving such as eyesight and hearing ability is not strong enough in many drivers over 70. Conclusion: Focusing on the physical capacity to drive, we tried to find the hazardous age bracket of senior drivers which might influence driving behaviors. Going forward, we expect this work would help to understand the policies for senior drivers and drivers' physical differences.