• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.1-12
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• 2016

This paper is to analyze characteristics of transfer trips and to identify impacts of land use on them. Using the smart transport card data of Seoul on a weekday in April 2013, we explored general characteristics of the transfer trips such as spatial and temporal distributions, transfer types, and geographical patterns of transfer trips. Then, the multiple regression model for the transfer trips was developed, considering land use as well as socio-economic variables as explanatory ones. For the characteristics of the transfer trips, their ratio to the total trips accounts for 26.7%. Nearly 87% of the trips are one-time transferred, and 64.7% are bus-subway transfer trips. In addition, the transfer trips are more likely to appear nearby subway stations and business facilities. The regression model indicates that land use variables such as the floor areas of business facilities and department stores and mixed land use index significantly positively affect the transfer trips. Our results can be used as basic data for choosing feasible locations of multi-modal transfer centers in urban areas.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.40-53
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• 2021

Recently, shared dockless e-scooter usage has rapidly increased, rather than the station-based shared mobility service, because of convenience. This transition leads to new social problems in urban areas such as increased traffic accidents and hindrance of pedestrian environments. In this study, we analyze the usage characteristics of shared e-scooters in Seoul, and identify factors influencing demand for shared e-scooters by developing a negative binomial regression model. As a result, the usage characteristics show that the average trip distance, the average trip duration, and the average trip speed were 1.5km, 9.4min, and 10.3km/h, respectively. Demographic factor, transport facility factors, land use factors, and weather factors have statistically significant impacts on demand for shared e-scooters. The results of this study will be used as basic data for suggesting effective operation strategies for areas with higher shared e-scooter demand and for establishing transport policies for facilitating shared e-scooter usage.

• Health Policy and Management
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• v.32 no.3
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• pp.323-329
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• 2022

Background: This study aimed to identify the characteristics of the referral and return of patients to clinics in the endocrinology and cardiology departments at the National Health Insurance Service Ilsan Hospital to evaluate the "referral and return of patients to clinics" program and reduce the rate of returning patients. Methods: From May 2018 to December 2020, we identified the number of visits to referral hospitals and hospital usage status at Ilsan Hospital after returning to clinics. We also identified the patients who returned to Ilsan Hospital within 6 months, defined as "failure to transport," among those recommended to be transported to clinics of the Medical Cooperation Center. Additionally, we evaluated the characteristics of the "failure to transport" patients. Results: Among the returning patients, the rate of visiting Ilsan Hospital within 6 months was higher in cardiology than in endocrinology (25.1% vs. 16.7%). Older age, more severe disease, and more number of visits to the department were associated with a high rate of failure to transport. The rate of failure to return was low in cases diagnosed with hyperlipidemia/lipoprotein metabolism disorder. With respect to diabetes, the rate of failure to transport differed according to each type of diagnosis of diabetes. Conclusion: The success rate of the "referral and return of patient to clinics" program differed based on each patient's characteristics, department of visit, and diagnosis. Individualizing according to the visit department and diagnosis is required to ensure successful transfers, and infrastructure expansion and institutional arrangements must be facilitated.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.3
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• pp.197-203
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• 2008

This study analyzed the characteristics of sea water transport between Busan New-port and the Nakdong River estuary. Numerical modeling was used to evaluate the characteristics of the tidal current. Numerical simulations of three different topographies were conducted. The results are summarized as follows: 1) The volume of sea water transport was reduced by $0.7{\sim}18.4%$ when water depth was decreased at Busan New-port (10 m); 2) The volume of sea water transport was increased by $3.5{\sim}21.9%$ when a channel (depth 5 m) was constructed in the direction of the Nakdong River estuary.

• Journal of the Korea Convergence Society
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• v.10 no.6
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• pp.191-201
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• 2019

This study aims at understanding the fundamental characteristics of EV consumer based upon user survey and understanding the challenges to promote EV adoption in Korea. Data are obtained from two different surveys. One asked 304 EV buyers in Korea and another asked 905 prospective customer about EV awareness and perception, EV purchase intention, and etc. Analysis is composed of two parts; one is about the general characteristics and purchase intention of general consumers; another is about the intent to repurchase EV owners. We discuss the policy implications to expand EV demand in Korean market based on two purchase and repurchase logit models.

• Journal of Trauma and Injury
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• v.37 no.2
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• pp.106-113
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• 2024

Purpose: Helicopter transport with medical teams has been proven to be effective, with improvements in patient survival rates. This study compared and analyzed the clinical characteristics and treatment outcomes of trauma patients transported by doctor helicopters according to whether patients were transferred after a clinical evaluation or without a clinical evaluation. Methods: This study retrospectively reviewed data from the Korean Trauma Data Bank of trauma patients who arrived at a regional trauma center through doctor helicopters from January 1, 2014, to December 31, 2022. The patients were divided into two groups: doctor helicopter transport before evaluation (DHTBE) and doctor helicopter transport after evaluation (DHTAE). These groups were compared. Results: The study population included 351 cases. At the time of arrival at the trauma center, the systolic blood pressure was significantly lower in the DHTAE group than in the DHTBE group (P=0.018). The Injury Severity Score was significantly higher in the DHTAE group (P<0.001), and the accident to trauma center arrival time was significantly shorter in the DHTBE group (P<0.001). Mortality did not show a statistically significant between-group difference (P=0.094). Surgical cases in the DHTAE group had a longer time from the accident scene to trauma center arrival (P=0.002). The time from the accident to the operation room or from the accident to angioembolization showed no statistically significant differences. Conclusions: DHTAE was associated with significantly longer transport times to the trauma center, as well as nonstatistically significant trends for delays in receiving surgery and procedures, as well as higher mortality. If severe trauma is suspected, air transport to a trauma center should be requested immediately after a simple screening test (e.g., mechanism of injury, Glasgow Coma Scale, or Focused Assessment with Sonography in Trauma), which may help reduce the time to definitive treatment.

• Journal of Korea Port Economic Association
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• v.28 no.2
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• pp.43-59
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• 2012

Recently, there has been a noticeable increase in the number of tourists in islands that are well-known for their natural landscapes. It is expected that this number will go up steadily, due to the increase in per capita income and leisure time. Regarding tourism transportation, utilizing linkage transport between coastal passenger terminal and inland transport system is crucial. However, the existing system does not measure up to the expectations. This is attributable to the fact that the distances between coastal passenger terminals and inland transportation terminals are too far. Also, the current public transportation system lacks support and needs to take the role of connecting the two terminals. This study shows how coast-inland linkage transport system should be reformed in order to promote island tourism. It focuses on building linkage transport system and minimizing walking distance. Also, adjusting passenger ship schedule to the characteristics of island tourism is needed. For the sake of passengers, coastal passenger ship fare should be reduced, and integrated transport information should be provided.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.1088-1091
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• 2001

Temperature-dependent current-voltage characteristics of Organic Light-Emitting Diodes(OLEDs) were studied. The OLEDs were based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1, 1'-diphenyl-4, 4'-diamine (TPD) as a hole transport and trim(8-hydroxyquinoline) alulninum(Alq$_3$) as an electron transport and emissive material. The current-voltage characteristics were measured in the temperature range of 10[K] and 300[K]. A conduction mechanism in OLEDs was interpreted in terms of tunneling and trap-filled limited current.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1B
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• pp.108-113
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• 2002

Short range communications between road-side equipments and on-board equipment is very important for ITS(intelligent Transport System). Roadside communication is for short range communication, and needs performance of high data bit rate and should support the function for very short term communication. In addition to it, a radio propagation characteristics is very different according to a road environment. In this paper, for reliable roadside communication, the radio multi-path propagation profile at roadside is measured and the characteristics is analyzed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.198-201
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• 2002

We have studied the temperature dependence of current-voltage and luminance-voltage characteristics of Organic Light Emitting Diodes(OLEDs). The OLEDS are based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) as a hole transport, tris(8-hydroxyquinolinoline) aluminum(III) (Alq$_3$) as an electron transport, and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as a buffer layer. The current-voltage and luminance-voltage characteristics were measured in the temperature range of 10[K] and 300[K]. A conduction mechanism in OLEDs has been interpreted in terms of space-charge-limited current(SCLC) and tunneling mechanism.