• Journal of the Korean Society for Railway
• /
• v.10 no.5
• /
• pp.613-618
• /
• 2007

The performance of the railway bogie is classified into the stability and the steering performance. Testing for the bogie stability is conducted on the roller rig, but testing for the bogie steering performance on test facility is very difficult, so the testing for the vehicle curving performance is conducted on the real curve track. Testing the railway bogie on the full scale test rig is desirable, but it caused many problems relating to test costs and test time. As a possible alternative to overcome these problems, a small scaled test rig is actively used in the field of bogie stability. Thus, in this paper, we have studied a scaled track to test the bogie steering performance. For this purpose, we designed the 1/5 scaled test track equivalent to radius 200 curve and confirmed the validity of the testing for the bogie steering performance on the sealed curve track through the testing using 1/5 scaled bogie.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.24 no.2
• /
• pp.57-69
• /
• 2021

Urban green spaces supply ecosystem services (ESs), which are consumed by city residents and generate demand, to improve air quality. It is important to determine supply and demand for ESs and reduce the gap for efficient management. This study proposed a method to use the concept of supply and demand for ESs in the decision-making process for urban planning or management. PM₁₀ concentrations were converted to weight for demand assessment on PM₁₀ reduction, and PM₁₀ absorption capacity of all green spaces including the forests, and that of urban green spaces excluding forests, was calculated for each supply assessment. The differences in the calculated supply and demand were analyzed to derive the mismatched regions in Suwon. As a result, regions with big forested areas showed sufficient supply, indicating that the degree of mismatch among administrative neighborhoods (dong) varied greatly depending on whether they had a forest. An analysis of only urban green spaces showed that all neighborhoods lacked supply. Forests with high PM₁₀ absorption capacity had a great effect, but urban green spaces can be considered a key element in reducing PM₁₀ in daily life. Considering the mismatch of supply and demand, spatial distribution, and population distribution, it is possible to prioritize the supply of urban green spaces to reduce PM₁₀ and, furthermore, support decision making for priority zones subject to forest conservation and designation and cancellation of green spaces, which gives significance to this study.

• Journal of Cancer Prevention
• /
• v.23 no.4
• /
• pp.183-190
• /
• 2018

Background: As the number of big-cohort studies increases, validation becomes increasingly more important. We aimed to validate administrative database categorized as colorectal cancer (CRC) by the International Classification of Disease (ICD) 10th code. Methods: Big-cohort was collected from Clinical Data Warehouse using ICD 10th codes from May 1, 2003 to November 30, 2016 at Seoul National University Bundang Hospital. The patients in the study group had been diagnosed with cancer and were recorded in the ICD 10th code of CRC by the National Health Insurance Service. Subjects with codes of inflammatory bowel disease or tuberculosis colitis were selected for the control group. For the accuracy of registered CRC codes (C18-21), the chart, imaging results, and pathologic findings were examined by two reviewers. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for CRC were calculated. Results: A total of 6,780 subjects with CRC and 1,899 control subjects were enrolled. Of these patients, 22 subjects did not have evidence of CRC by colonoscopy, computed tomography, magnetic resonance imaging, or positron emission tomography. The sensitivity and specificity of hospitalization data for identifying CRC were 100.00% and 98.86%, respectively. PPV and NPV were 99.68% and 100.00%, respectively. Conclusions: The big-cohort database using the ICD 10th code for CRC appears to be accurate.

• Journal of Korean Neurosurgical Society
• /
• v.66 no.5
• /
• pp.525-535
• /
• 2023

Objective : We performed an expanded multi-ethnic meta-analysis to identify associations between inflammation-related loci with intracranial aneurysm (IA) susceptibility. This meta-analysis possesses increased statistical power as it is based on the most data ever evaluated. Methods : We searched and reviewed relevant literature through electronic search engines up to August 2022. Overall estimates were calculated under the fixed- or random-effect models using pooled odds ratio (OR) and 95% confidence intervals (CIs). Subgroup analyses were performed according to ethnicity. Results : Our meta-analysis enrolled 15 studies and involved 3070 patients and 5528 controls including European, Asian, Hispanic, and mixed ethnic populations. Of 17 inflammation-related variants, the rs1800796 locus (interleukin [IL]-6) showed the most significant genome-wide association with IA in East-Asian populations, including 1276 IA patients and 1322 controls (OR, 0.65; 95% CI, 0.56-0.75; p=3.24#x00D7;10^-9) under a fixed-effect model. However, this association was not observed in the European population (OR, 1.09; 95% CI, 0.80-1.47; p=0.5929). Three other variants, rs16944 (IL-1β), rs2195940 (IL-12B), and rs1800629 (tumor necrosis factor-α) showed a statistically nominal association with IA in both the overall, as well as East-Asian populations (0.01<p<0.05). Conclusion : Our updated meta-analysis with increased statistical power highlights that rs1800796 which maps on the IL-6 gene is associated with IA, and in particular confers a protective effect against occurrence of IA in the East-Asian population.

• Annual Conference of KIPS
• /
• 2022.05a
• /
• pp.48-51
• /
• 2022

정보통신기술의 (ICT) 발전에 따라 기업은 사용자에게 다양한 서비스를 제공하기 위해 클라우드 서비스 공급자의 클라우드를 활용하고 있다. 클라우드 서비스 공급자는 기업에게 전문적이고 효율적인 클라우드 서비스를 제공하고, 기업은 특별한 클라우드 설치 없이 제공받은 서비스를 활용하여 다양한 서비스를 제공할 수 있다. 최근 클라우드 서비스를 이용하는 기업이 세계적으로 증가함에 따라 클라우드 공급자는 효과적인 서비스를 제공하기 위해 다양한 클라우드 컴퓨팅 기술을 적용하고 있다. 클라우드를 사용하는 기업이 증가함에 따라 클라우드 서버의 수가 증가하고 있으며, 그 중에 해킹을 당하기 때문에 악의적인 노드가 되거나 어떤 불가피한 원인으로 저성능 노드가 되는 경우의 수도 증가하고 있다. 악의적인 노드는 사용자의 보안을 위협하며, 저성능 노드는 효과적인 서비스를 사용자에게 제공할 수 없다. 따라서 서비스 사용자는 다양한 클라우드 서버 중 사용자 수요에 최적화 된 클라우드 노드를 선택하는 기술이 필요하다. 본 논문에서는 효율적인 클라우드 컴퓨팅을 위한 스마트 계약 기반의 노드 선택 기법을 제안한다. 제안하는 노드 선택 기법은 스마트 계약에 따라 사용자가 원하는 서비스에 적합한 클라우드 서버를 선택할 수 있도록 하여 최적화된 클라우드 서비스를 제공한다. 동시에 클라우드 서버들에게 명예 등급에 부여하고 명예 등급이 높을수록 선택되는 확률이 증가한다. 결과적으로 사용자는 효과적인 클라우드 서비스를 선택할 수 있어 효과적인 클라우드 서비스 활용이 가능하다.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.2_2
• /
• pp.333-340
• /
• 2023

Environmental regulations are being strengthened worldwide to solve global warming. For this reason, interest in eco-friendly gas fuels such as LNG and hydrogen is continuously increasing. However, when adopting eco-friendly gas fuel, liquefying at a cryogenic temperature is essential to ensure economic feasibility in storage and transportation. Although austenitic stainless steel is typically applied to store cryogenic liquefied gas, structural steel can experience sudden heat shrinkage in the case of leakage in the loading and unloading process of LNG. In severe cases, the phase of the steel may change, so care is required. This study conducted Charpy impact tests on steel material in nine different temperature ranges, from room to cryogenic temperatures, to analyze the effects of cryogenic liquefied gas leaks. As a result of the study, it was not easy to find variations in ductile to brittle transition temperature (DBTT) due to the leakage of cryogenic liquefied gas. Still, the overall impact toughness tended to decrease, and these results were verified through fracture surface analysis. In summary, brittle fracture of the steel plate may occur when a secondary load is applied to steel for hull structural use exposed to a cryogenic environment of -40 ℃ or lower. Therefore, it needs to be considered in the ship design and operating conditions.

• Journal of Ginseng Research
• /
• v.47 no.3
• /
• pp.429-439
• /
• 2023

Background: The incidence and clinical importance of nonalcoholic fatty liver disease (NAFLD) has emerged. However, effective therapeutic strategies for NAFLD have yet to be found. Panax ginseng (P. ginseng) is a traditional herb in Eastern Asia with therapeutic effects in many chronic disorders. However, the precise effects of ginseng extract on NAFLD are currently unknown. In present study, the therapeutic effects of Rg3-enriched red ginseng extract (Rg3-RGE) on the progression of NAFLD were explored. Methods: Twelve-week-old C57BL/6 male mice were fed a chow or western diet supplemented with high sugar water solution with or without Rg3-RGE. Histopathology, immunohistochemistry, immunofluorescence, serum biochemistry, western blot analysis, and quantitative RT-PCR were used for in vivo experiment. Conditionally immortalized human glomerular endothelial cell (CiGEnC) and primary liver sinusoidal endothelial cells (LSECs) were used for in vitro experiments. Results: Eight weeks of Rg3-RGE treatment significantly attenuated the inflammatory lesions of NAFLD. Furthermore, Rg3-RGE inhibited the inflammatory infiltrate in liver parenchyma and the expression of adhesive molecules to LSECs. Moreover, the Rg3-RGE exhibited similar patterns on the in vitro assays. Conclusion: The results demonstrate that Rg3-RGE treatment ameliorates NAFLD progression by inhibiting chemotaxis activities in LSECs.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.27 no.5
• /
• pp.1-12
• /
• 2024

The purpose of this study is to provide basic data for sustainable production by investigating the growth characteristics of the endangered Korean fir (Abies koreana) under shading treatments. It was found that there was a temperature difference of approximately 6℃ between the shading treatment and the control group, and a difference of about 13% in soil moisture content. Only in the shading treatment group did dead individuals of Korean fir appear, and it was confirmed that other individuals also suffered from leaf withering and other physiological damage. The growth response of root diameter was observed in T2, and the growth of seedling height was observed in T3, indicating that satisfactory growth was observed in over 50% of the shading treatment groups. Total Chlrolophyll was higher according to the shading treatment(p<0.05), This trend is thought to be due to the short-term nature of the experiment, and it is expected that statistical significance will be observed after long-term adaptation. It is considered that over 50% shading effect will be beneficial for survival and growth in Abies koreana over 5 years old at the seedling stage.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.5
• /
• pp.430-436
• /
• 2014

The mission objective of STEP Cube Lab. (Cube Laboratory for Space Technology Experimental Project) classified as a pico-class satellite is to verify the technical effectiveness of payloads such as variable emittance radiator, SMA washer, oscillating heat pipe and MEMS based solid propellant thruster researched at domestic universities. In addition, the MEMS concentrating photovoltaic power system and the non-explosive holding and separation mechanism with the advantages of high constraint force and low shock level will be developed as the primary payloads for on-orbit verification. In this study, the feasibility of the mission actualization has been confirmed by the preliminary system design.

• Food Science of Animal Resources
• /
• v.31 no.5
• /
• pp.701-709
• /
• 2011

This study was performed to establish an effective extraction method of pig placenta extract that could be used for a putative functional food supplement with immunomodulatory effects. In the present study, we used different temperatures (4, 37, 60, 80, and $100^{\circ}C$) and different solvents (chloroform, NaOH, and phosphate buffered saline [PBS]) to extract the pig placenta. Among the different placenta extracts yielded by the different extraction methods, placenta extract (PE) in PBS at $80^{\circ}C$ for 30 min (referred to as PE-PBS80) showed a significant increase of nitric oxide production of up to 22.97 ${\mu}M/10^5$ cells at a 1 mg/mL dose (p<0.05 ) in J774A.1 cells than other extracts and control tested. Using PE-PBS80, further animal challenges were performed to identify the immune-enhanced effects. As a result, orally administered PE-PBS80 showed a significant increase in blood T and B cell activities and immunoglobulin (IgG and IgM) production. IgG and IgM levels increased to 41.53 mg/mL at a 20 mg dose on day 7 and to 27.38 mg/mL at a 10 mg dose on day 14, respectively (p<0.05). Furthermore, PE-PBS80 was also able to significantly enhance the immune modulator cytokine levels (p<0.05) compared to the control and vehicle treatments. Among the evaluated cytokines, the tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) level increased to 28.89 pg/mL at extract doses of 20 and 50 mg, the interleukin-$1{\beta}$ (IL-$1{\beta}$) level increased to 21.52 pg/mL at extract doses of 10, 20, 50 and 75 mg and the interferon (IFN)-${\gamma}$ level increased to 18.24 pg/mL at extract doses of 10, 20, and 50 mg. Therefore, this study presents an effective method for extracting pig placenta extracts and also demonstrates that pig placenta extracts had significant immunomodulatory effects not only at the cellular level but also in a mouse model, suggesting that this material could be used as an excellent candidate functional food supplement.