• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.32-38
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• 2006

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. A new concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. Due to such social requirement, technologically advanced countries are making efforts to develop an environment-friendly vehicle engine at the nation-wide level in order to respond to the reinforced emission control. As a core combustion technology among new combustion technologies for the next generation engine, the homogenous charge compression ignition(HCCI) is expanding its application range by adopting multiple combustion mode, catalyst, direct fuel injection and partially premixed combustion. This study used a 2-staged injection method in order to apply the HCCI combustion method without significantly altering engine specifications in the aspect of multiple combustion mode and practicality by referring to the results of studies on the HCCI engine. In addition, this study confirmed the possibility of securing optimum fuel economy emission reduction in the IMEP 8bar range(which could not be achieved with existing partially premixed combustion) through forced charging, exhaust gas recirculation(EGR), compression ratio change and application of DOC catalyst.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.1
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• pp.162-170
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• 2007

Currently, due to the serious world-wide air pollution by substances emitted from vehicles, emission control is enforced more firmly and it is expected that the regulation requirements for emission will become more severe. Anew concept combustion technology that can reduce the NOx and PM in relation to combustion is urgently required. Due to such social requirement, technologically advanced countries are making efforts to develop an environment-friendly vehicle engine at the nation-wide level in order to respond to the reinforced emission control. As a core combustion technology among new combustion technologies for the next generation engine, the homogeneous charge compression ignition (HCCI) is expanding its application range by adopting multiple combustion mode, catalyst, direct fuel injection and partially premixed combustion. This study used a 2-staged injection method in order to apply the HCCI combustion method without significantly altering engine specifications in the aspect of multiple combustion mode and practicality by referring to the results of studies on the HCCI engine. And it is investigated that the effects of the engine rpm and load(or A/F) to emission characteristics.

• Biomolecules & Therapeutics
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• v.23 no.4
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• pp.345-349
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• 2015

Betulinic acid, a pentacyclic triterpene isolated from Jujube tree (Zizyphus jujuba Mill), has been known for a wide range of biological and medicinal properties such as antibacterial, antimalarial, anti-inflammatory, antihelmintic, antinociceptive, and anticancer activities. In the study, we investigated the antiviral activity on influenza A/PR/8 virus infected A549 human lung adenocarcinoma epithelial cell line and C57BL/6 mice. Betulinic acid showed the anti-influenza viral activity at a concentration of $50{\mu}M$ without a significant cytotoxicity in influenza A/PR/8 virus infected A549 cells. Also, betulinic acid significantly attenuated pulmonary pathology including increased necrosis, numbers of inflammatory cells and pulmonary edema induced by influenza A/PR/8 virus infection compared with vehicle- or oseltamivir-treated mice in vivo model. The down-regulation of IFN-${\gamma}$ level, which is critical for innate and adaptive immunity in viral infection, after treating of betulinic acid in mouse lung. Based on the obtained results, it is suggested that betulinic acid can be the potential therapeutic agent for virus infection via anti-inflammatory activity.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.5
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• pp.865-872
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• 2019

In this paper, we describe the Solar Car, Woongbi, which was created to participate in the World Solar Challenge(WSC) at the team NeulHaeRang of Korea National University of Transportation. The WSC is the world's largest solar car racing competition and has a separate automobile regulation and must be manufactured to meet the regulations. Therefore, the key point of the solar car design is to optimize the energy efficiency based on the regulations. The solar car's drive system consists of a solar array to convert solar energy into electric energy, a maximum power point tracker (MPPT) controller to track the converted electric energy to maximum output power, a battery to store the produced electric energy, a BLDC (Brushless DC) motor for driving the vehicle by converting energy into mechanical energy, and a motor controller for controlling the BLDC. The optimal design methods for solar energy conversion and electric driving system of battery, motor are presented in this paper.

• Journal of Trauma and Injury
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• v.31 no.3
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• pp.125-134
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• 2018

Purpose: The interest in the personal mobility started to grow and as the interest increases, there are growing concerns about the safety of it. The purpose of the study is to look at the types and dynamics of patients injured by the personal mobilities. Methods: This was a retrospective 2-year observational study, from January 2016 to December 2017, on the patients who visited the emergency center and the trauma center, with an injury related to driving the personal mobility. Cases of the personal mobility-related accident were collected based on electronic medical records and hospital emergency department-based injury in-depth surveillance data. Results: A total of 65 patients visited the emergency center and the trauma center, during this study period. Six patients of 50 adults admitted the alcohol consumption (12%) and two adult patients wore the helmet as the protection gear (3.1%). The number of the patients in 2017 rises three times more than the number of patients in 2016 (51 vs. 14). Injuries to the head and neck region (67.7%) was the most common, followed by the upper extremity (46.2%). Eleven patients (16.9%) were admitted to the hospital, of whom three were admitted to the intensive care unit due to intracranial hemorrhage. Nine patients underwent surgery. Conclusions: The use of the personal mobility will continue to grow and the accidents, caused by the vehicle, will increase along with it. The study showed the damage is worse than expected. Personal mobility currently has a limited safety laws and the riders are not yet fully aware of its danger. The improvement of the regulation of the personal mobility, safety education is needed.

• Journal of the Society of Disaster Information
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• v.15 no.1
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• pp.49-66
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• 2019

Purpose: This study aims to apply the counter terrorism policy in pertain to malicious drone abuse and the croweded public places in South Korea. And, to improve counter terrorism protection measure, this study suggests an adoptation of Anti UAV technology into counter terrorism related regulation. Method: Compared to nations' operations of counter terrorism prevention and protection activities with the South Korean gov, problems and limitations are suggested. Results: Anti UAV technology could not be applied for Multi-user facilities by any law due to the limitation, so that it is required to amend counte terrporism related policies and law. Conclusion: This study intends to identify various protection methods against UAV threats. To reduce the risk of UAV, the law of public safety and counter terrorism should be promoted and reinforced for the first.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.85-100
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• 2022

Recently, with the widespread expansion of convergence based on digital connectivity, the transportation and mobility fields are rapidly changing, and research related to this is also diversifying. This study aims to analyze the research trends in the mobility field and identify key research areas and topics. Topic modeling analysis has been proved as a useful approach for analyzing the research trends. The abstracts of 142 research papers concerning mobility from the Korean academic citation index were analyzed, derived 9 research topics and linked to 6 key elements of research framework. The result showed that 'Advanced vehicle and transportaion technology' and 'Linkage and integrated services among means for mobility' were most actively studied research fields. It also found that research on insurance, law, regulation for securing user's safety and conflict-resolving with the existing industry has been conducted.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.6
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• pp.1151-1163
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• 2022

As wireless communication functions begin to be installed in vehicles, cyberattacks that exploit vulnerabilities in wireless communication functions are increasing. To respond to this, UNECE enacted the UN R156 regulation to safely distribute the software installed in the vehicle by using the wireless communication function. The regulations specify the requirements necessary to safely distribute the software for vehicles, but only the abstract requirements are presented without information on the components and detailed functions necessary to develop and implement the requirements. Therefore, in this paper, we propose a security evaluation standard that can evaluate whether a safe SUMS is built using threat modeling, a method for systematically analyzing security threats.

• Herbal Formula Science
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• v.30 no.3
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• pp.123-135
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• 2022

Oryeongsan (ORS), a formula composed of five herbal medicines, has long been used to treat impairments of the regulation of body fluid homeostasis. The purpose of this study was to determine the antihypertensive and renal protective effects of ORS in rats with hypertension. Spontaneously hypertensive rats (SHR) were divided into two groups with similar mean baseline systolic blood pressure (SBP). Then, 1 mL/kg of vehicle (distilled water) or 1.5, 3 g/kg of ORS extract were administered orally once a day for 4 weeks. SBP and diastolic blood pressure (DBP) were measured at weeks 1, 2, 3 and 4. At the end of the experiment, blood was collected, and heart were removed for histology. By the 2 weeks after initiation of treatment, the ORS treated group had significantly lower SBP than SHR rats. The ORS treatment significantly improved blood pressure and echocardiogram parameters compared to hypertensive rats. Additionally, the left ventricular (LV) remodeling and LV dysfunction were significantly improved in ORS treated group hypertensive rats. Furthermore, an increase in fibrotic area has been observed in SHR rats compared with Wistar-Kyoto rats (WKY). Furthermore, administration of ORS significantly attenuated cardiac fibrosis in hypertensive rats. Therefore, these findings suggest that ORS has a protective effect on heart failure by alleviating hypertensive heart disease and cardiovascular dysfunction in SHR.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.63-70
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• 2024

Lithium-ion batteries (LIB) are widely used in various sectors, such as transportation (e.g., electric vehicles (EV)) and energy (e.g., energy storage facilities) due to their high energy density, broad operating temperature (-20 ℃ ~ 60 ℃), and high capacities. LIBs are powerful but fragile on external factors, including pressure, physical damage, overheating, and overcharging, that cause thermal runaway causing fires and explosions. During a LIB fire, a large amount of oxygen is generated from the decomposition of ionogenic materials. A water fire extinguisher that helps with cooling and suffocating must be essentially required at the same time. In fact, however, it is difficult to suppress LIB fires in the case of EVs because a LIB is installed with a battery pack housing that interrupts direct extinguishing by water. Thus, this study aims to investigate effective fire extinguishing measurements for LIB fires by using an EV. Relevant documents, including research articles and reports, were reviewed to identify effective ways of LIBs fire extinguishing. A real-scale fire experiment generating thermal runaway was carried out to figure out the combustion characteristics of EVs. This study revealed that the most effective fire extinguishing measurements for LIB fires are applying fire blankets and water tanks. However, there is still a lack of adequate regulation and guidelines for LIB fire extinguishment. Taking this into account, developing functional fire extinguishment measurements and available regulatory instruments is an urgent issue to secure the safety of firefighters and citizens.