• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.81-81
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• 2020

Pneumonia is infection of air sacs in lungs by bacteria, viruses, fungi and abnormal atmosphere condition. That causes to inflammation and fills up with pus and fulid in air sacs. The symptoms of pneumonia are heavy cough, fever, shortness and rapid respiration and sputum with blood. Also, that remains sequela after the recovery. Thymus quinquecostatus (TQ) has a strong antibacterial effect. That has been used a natural medicine for bronchitis, asthma and nervous inflammation. In this study evaluated anti-inflammatory effects of TQ on IFN (interferon)-γ/TNF (tumor necrosis factor)-α (20 ng/ml) stimulation. MRC-5 cells were seeded at 1 × 10⁵ cells/well in a 24-well plate and stabilized overnight at 37℃. The cells were treated with various concentrations of TQ extracts (DW, 30, 50, 70, 95% EtOH, 0.1~100 mg/ml) for 4h, Subsequently IFN-γ/TNF-α (20 ng/ml) was added to each well and incubated over 12h. the production of inflammatory cytokines were measured by Enzyme-linked immunosorbentassay(ELISA) method. The absorbance was measured at 450 nm using microplate reader. The treatment with TQ extract at dose of 0.1 to 100 mg/ml did not show cytotoxicity in MRC-5 cells (showed cytotoxicity at 95% EtOH 100 mg/ml). The results demonstrated that stimulation of TNF-α/IFN-γ significantly increased the production of inflammatory mediators in the MRC-5 cells compared with unstimulated cells. By contrast, treatment with TQ extreats doses of 0.001 to 10 mM significantly suppressed the production of IL-6 and IL-8. Especially. The higher percent of ethyl alcohol extracts suppressed the production of inflammatory cytokines. This results are considered that essential oil of TQ is extracted according to ethyl alcohol percent. Therefore, TQ has potential to mitigate pulmonary disease that can be used a medicine for pneumonia

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.12a
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• pp.65-65
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• 2020

Bakanae disease, caused by Gibberella fujikuroi, is one of the most devastating diseases threatening rice production in Korea. In recent years, the incidence of bakanae disease became alarming due to the mechanical transplanting practice where the spread of bakanae can be amplified during accelerating seeds growth, due to the use of seeding boxes. The development of resistant rice cultivars could be the primary and effective method for controlling bakanae disease. However, the effects of individual resistance genes are relatively small. Therefore, pyramiding of bakane R genes in rice breeding is a promising strategy having a high potential to mitigate the advert effects of bakanae disease. This study employed a gene pyramiding approach to develop bakanae disease resistant rice lines carrying qBK1, qFfR1 introduced from rice line MY299BK and cv. Nampyeong, respectively. The MY299BK carries qBK1 introduced from cv. Shingwang, which was found to have a high resistance compare to Nampyeong. In addition, the pyramiding effect of the qBK1 and qFfR1 resistance genes were investigated, and the presence or absence of these genes helped us investigate their interaction through bioassay method and MAS. Furthermore, the distribution of resistance in the population showed a biased distribution toward resistance in the F6:7 populutions. However, we could not confirm the accumulation effect of the resistance gene, but the difference between the two genes by the SN2 marker was confirmed. Therefore, the qBK1 gene harbored by MY299BK appears to be different from the qFfR1 carried by Nampyeong, suspected to possess a different bakanae disease resistant gene different from those found in MY299BK and Nampyeong.

• Analyses & Alternatives
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• v.7 no.3
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• pp.115-144
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• 2023

Under the Trump administration, the U.S. has made clear that "China is America's strategic competitor, revisionist power and a major challenge to America's prosperity and security." The Biden administration has largely inherited this perception of China. China has also responded without backing down. Therefore, the U.S.-China strategic competition has become the most important background factor in the international system and has a great impact on the security situation in Northeast Asia. Nevertheless, if you look at the recent process of establishing trilateral security cooperation among ROK, the U.S. and Japan, we can find that ROK's foreign strategy adjustment has played a key role. This is because establishing trilateral security cooperation among ROK, the U.S. and Japan depends on improving ROK-Japan relations. And the Yoon Suk Yeol government is pushing for rapid improvement in ROK-Japan relations regardless of domestic political constraints. The trilateral summit at Camp David laid the groundwork for future cooperation among ROK, the U.S. and Japan in security and other broader areas. China is strongly dissatisfied with the formation of trilateral security cooperation among ROK, the U.S. and Japan. However, this paper argues that although ROK agrees to form trilateral security cooperation with the U.S. and Japan, ROK's strategic objectives are not exactly the same as those of the U.S. and Japan. For example, looking back at the development of the U.S.-Japan alliance after the end of the Cold War, both the U.S. and Japan share similar views and perceptions of China's rise. The real goal of the strengthening of the U.S.-Japan alliance in recent years is also how to cope with China's rise. On the other hand, ROK's previous administrations have been negative about trilateral security cooperation with the U.S. and Japan. This is because ROK's main strategic goal is to reduce or eliminate threats from DPRK rather than respond to China. Faced with increasing DPRK's provocations and threats, more than half of South Koreans are in favor of reinforcing trilateral security cooperation with the U.S. and Japan to contain or mitigate threats from DPRK. As a result, if North Korea's nuclear and missile threats to ROK continue, then ROK's foreign strategy is likely to be to strengthen trilateral security cooperation between the U.S. and Japan to ensure its own safety and survival. If China wants to reduce the strategic pressure from the trilateral security cooperation among ROK, the U.S. and Japan, the best way is to reduce DPRK's provocations and threats to ROK and play a more substantive role in getting DPRK to give up its nuclear program.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.555-571
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• 2023

Due to South Korea's concentrated summer rainfall, constituting 70% of the annual total, landslides frequently occur during the rainy season, necessitating accurate prediction methods to mitigate associated damage. In this study, a reduced-scale and full-scale slope was configured using weathered granite soil to find the possibility of establishing measurement management criterias through landslide reproduction. The experiment focused on matric suction, analyzing changes in ground properties and failure patterns caused by rainfall infiltration. Subsequently, an unsaturated infinite slope stability analysis was conducted. By calculating the failure time when the safety factor falls below 1 for each experiment, landslide prediction was demonstrated to be possible, approximately 17 minutes prior for the reduction-scale experiment and 6.5 hours for the full-scale experiment. These findings provide useful data for establishing Korean soil slope measurement management criteria that consider the characteristics of weathered granite soil.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.743-749
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• 2023

Breast ductal carcinoma in situ(DCIS) refers to cases in which breast epithelial cells have become malignant but are still limited to normal ducts, and has been increasing rapidly in recent years. In this case, a two-year follow-up revealed findings on mammography and ultrasonography that indicated a small mass classified as BI-RADS Category 3, However far from typical malignant tumor these findings were. In the second year of follow-up, a hypoechoic mass with an indistinct boundary of the right breast in the 6 o'clock direction, on mammography appeared to be about 2.1×1.3 cm in size, and biopsy diagnosed it as ductal carcinoma. Since ductal endothelial cancer has no characteristic clinical findings and can show positive clinical and imaging findings in the early stages, regular follow-up is considered important for early diagnosis, and detection of ductal endothelial cancer through mammography and ultrasound is important for improving the prognosis of all breast cancer patients. During the initial examination conducted four years ago, we reported cases of intra ductal cancer in which asymmetric shading, microcalcification, and branched mass, indicative of intra ductal cancer, were observed during follow-up. It is advisable to concurrently explore methods for reducing X-ray dosage to mitigate potential side effects of contrast medium.

• Journal of Korean Neurosurgical Society
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• v.66 no.6
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• pp.726-734
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• 2023

Objective : Chronic subdural hematoma (CSDH) patients using antithrombotic agents (AT) at high risk for cardiovascular disease are increasing. The authors aimed to analyze the factors influencing outcome by targeting patients using AT and to establish a desirable treatment strategy. Methods : A retrospective analysis was performed on data from 462 patients who underwent burr hole trephination (BHT) surgery for CSDH at five hospitals from March 2010 to June 2021. Outcomes included incidence of postoperative acute bleeding, recurrence rate, and morbidity or mortality rate. Patients were divided into the following four groups based on their history of AT use : no AT. Only antiplatelet agents (AP), only anticoagulants (AC), both of AP and AC. In addition, a concurrent literature review was conducted alongside our cohort study. Results : Of 462 patients, 119 (119/462, 25.76%) were using AT. AP prescription did not significantly delay surgery (p=0.318), but AC prescription led to a significant increase in the time interval from admission to operation (p=0.048). After BHT, AP or AC intake significantly increased the period required for an in-dwelling drain (p=0.026 and p=0.037). The use of AC was significantly related to acute bleeding (p=0.044), while the use of AP was not (p=0.808). Use of AP or AC had no significant effect on CSDH recurrence (p=0.517 and p=1.000) or reoperation (p=0.924 and p=1.000). Morbidity was not statistically correlated with use of either AP or AC (p=0.795 and p=0.557, respectively), and there was no significant correlation with mortality for use of these medications (p=0.470 and p=1.000). Conclusion : Elderly CSDH patients may benefit from maintenance of AT therapy during BHT due to reduced thromboembolic risk. However, the use of AC necessitates individualized due to potential postoperative bleeding. Careful post-operative monitoring could mitigate prognosis and recurrence impacts.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.6
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• pp.785-791
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• 2023

Risk management is essential for preventing accidents arising from uncertainties in TBM tunnel projects, especially concerning managing the risk of TBM tunnel collapse, which can cause extensive damage from the tunnel face to the ground surface. In addition, prioritizing risks is necessary to allocate resources efficiently within time and cost constraints. Therefore, this study aimed to establish a TBM risk database through case studies of TBM accidents and determine a risk priority for TBM tunnel collapse using the Bayes theorem. The database consisted of 87 cases, dealing with three accidents and five geological sources. Applying the Bayes theorem to the database, it was found that fault zones and weak ground significantly increased the probability of tunnel collapse, while the other sources showed low correlations with collapse. Therefore, the risk priority for TBM tunnel collapse, considering geological sources, is as follows: 1) Fault zone, 2) Weak ground, 3) Mixed ground, 4) High in-situ stress, and 5) Expansive ground. In practice, the derived risk priority can serve as a valuable reference for risk management, enhancing the safety and efficiency of TBM construction. It provides guidance for developing appropriate countermeasure plans and allocating resources effectively to mitigate the risk of TBM tunnel collapse.

• Korean small business review
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• v.42 no.3
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• pp.173-193
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• 2020

This study analyzes the effects of KOSDAQ-listed firms' convertible bonds, which have recently increased rapidly in number and size. Although KOSDAQ companies are called mid-size companies, KOSDAQ companies belong to SMEs. Furthermore, convertible bonds have traditionally been a critical capital raising tool for SMEs in the US and Europe. In Korea, KOSDAQ companies actively employ convertible bonds. Convertible bonds provide investment incentives for hesitant investors, allowing companies to raise capital at low interest rates. This study analyzes whether capital raising through issuance of convertible bonds by KOSDAQ companies affects their financial constraints. Financial constraints result from incomplete capital markets, which are embedded in most companies and countries.. In particular, financial constraints have a significant impact on the growth and survival of SMEs. The seminal study FHP(1988) is the most important and effective study of firm's financial constraints. We find that FHP's financial constraint measures show that convertible bond issuance would mitigate the financial constraints of KOSDAQ companies. However, the significance of the evidence is not strong.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.413-419
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• 2023

Light Emitting Diodes(LEDs) are widely utilized not only in lighting but also in various applications such as mobile phones, automobiles, displays, etc. The integration of LED lighting with communication, specifically Visible Light Communication(VLC), has gained significant attention. This paper presents the direct implementation and experimentation of a Vehicle-to-Vehicle(V2V) Visible Light Communication system using commonly used red and yellow LEDs in typical vehicles. Data collected from the leading vehicle, including positional and speed information, were modulated using Non-Return-to-Zero On-Off Keying(NRZ-OOK) and transmitted through the rear lights equipped with red and yellow LEDs. A photodetector(PD) received the visible light signals, demodulated the data, and restored it. To mitigate the interference from fluorescent lights and natural light, a PD for interference removal was installed, and an interference removal device using a polarizing filter and a differential amplifier was employed. The performance of the proposed visible light communication system was analyzed in an ideal case, indoors and outdoors environments. In an outdoor setting, maintaining a distance of approximately 30[cm], and a transmission rate of 4800[bps] for inter-vehicle data transmission, the red LED exhibited a performance improvement of approximately 13.63[dB], while the yellow LED showed an improvement of about 11.9[dB].

• Journal of the Korean Institute of Gas
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• v.27 no.4
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• pp.12-18
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• 2023

The effective evacuation strategy according to the accident scenario is crucial to minimize human casualties in the event of toxic gas leak accidents. In this study, the effect of the direction of a building and the location of an industrial complex on the increase in indoor concentration and outdoor diffusion was examined under the same leakage conditions, and effective evacuation criteria were established. In addition, the guidelines for building directions were suggested when constructing buildings that would mitigate human damage caused by chemical accidents. Three scenarios where buildings faced the front, side, and rear of the leakage direction were investigated through CFD simulations. The results revealed that when the building faced the industrial complex, both indoor and outdoor average gas concentrations increased significantly, reaching up to 120 times higher than the other two orientations. Moreover, the indoor space was filled with toxic gas substances more than twice in the same time due to the rapid increase of indoor concentration rate. In cases where the building's windows were positioned at the front, toxic gas stagnation occurred around the building due to pressure differences and reduced flow velocities. Based on our findings, the implementation of these guidelines will contribute to safeguarding residents by minimizing exposure to toxic gas during chemical accidents.