• Korean Journal of Radiology
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• v.23 no.2
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• pp.172-179
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• 2022

Objective: We aimed to evaluate the ostium of right coronary artery of anomalous origin from the left coronary sinus (AORL) with an interarterial course throughout the cardiac cycle on CT and analyze the clinical significance of the ostial findings. Materials and Methods: From January 2011 to December 2015, 68 patients (41 male, 57.3 ± 12.1 years) with AORL with an interarterial course and retrospective cardiac CT data were included. AORL was classified as high or low ostial location based on the pulmonary annulus in the diastolic and systolic phases on cardiac CT. In addition, the height, width, height/width ratio, area, and angle of the ostium were measured in both cardiac phases. After cardiac CT, patients were followed until December 31, 2020 for major adverse cardiac events (MACE). Clinical and CT characteristics associated with MACE were explored using Cox regression analysis. Results: During a median follow-up period of 2071 days (interquartile range, 1180.5-2747.3 days), 13 patients experienced MACE (19.1%, 13/68). Seven (10.3%, 7/68) had the ostial location change from high in the diastolic phase to low in the systolic phase. In the univariable analysis, younger age (hazard ratio [HR] = 0.918, p < 0.001), high ostial location (HR = 4.008, p = 0.036), larger height/width ratio (HR = 5.621, p = 0.049), and smaller ostial angle (HR = 0.846, p = 0.048) in the systolic phase were significant predictors of MACE. In multivariable cox regression analysis, younger age (adjusted HR = 0.917, p = 0.002) and high ostial location in the systolic phase (adjusted HR = 4.345, p = 0.026) were independent predictors of MACE. Conclusion: The ostial location of AORL with an interarterial course can change during the cardiac cycle, and high ostial location in the systolic phase was an independent predictor of MACE.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.280-288
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• 2018

In this study, an approach for the analysis of the five cephalopod species (octopus, long-arm octopus, squid, wet-foot octopus, beka squid) consumed in the Republic of Korea is developed. The samples were collected from the Southeast Asian countries Thailand, Indonesia, Vietnam, and China. The SYBR-green-based real-time qPCR method, based on the mitochondrial DNA genome of the five cephalopods was developed and validated. The intergroup variations in the mitochondrial DNA are evident in the bioinformatic analysis of the mitochondrial genomic DNA sequences of the five groups. Some of the highly-conserved and slightly-variated regions are identified in the mitochondrial cytochrome-c-oxidase subunit I (COI) gene, 16s ribosomal RNA (16s rRNA) gene, and 12s ribosomal RNA (12s rRNA) gene of these groups. To specify each five cephalopod groups, specific primer sets were designed from the COI, 16s rRNA and 12s rRNA regions. The specific primer sets amplified the DNA using the SYBR-green-based real-time PCR system and 11 commercially secured animal tissues: Octopus vulgaris, Octopus minor, Todarodes pacificus, Dosidicus gigas, Sepia esculenta, Amphioctopus fangsiao, Amphioctopus aegina, Amphioctopus marginatus, Loliolus beka, Loligo edulis, and Loligo chinensis. The results confirmed by a conveient way to calculate relative amplification levels between different samples in that it directly uses the threshold cycles (Ct)-value range generated by the qPCR system from these samples. This genomic DNA-based molecular technique provides a quick, accurate, and reliable method for the taxonomic classification of the animal tissues using the real-time qPCR.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.4
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• pp.245-255
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• 2008

Korea Hydro and Nuclear Power Company(KHNP) conducted site investigations for a low and intermediate-level nuclear waste repository in the Gyeong Ju site. The site characterization work constitutes a description of the site, its regional setting and the current state of the geosphere and biosphere. The main objectives of hydogeological investigation aimed to understand the hydrogeological setting and conditions of the site, and to provide the input parameters for safety evaluation. The hydogeological characterization of the site was performed from the results of surface based investigations, i.e geological mapping and analysis, drilling works and hydraulic testing, and geophysical survey and interpretation. The hydro-structural model based on the hydrogeological characterization consists of one-Hydraulic Soil Domain, three-Hydraulic Rock Domains and five-Hydraulic Conductor Domains. The hydrogeological framework and the hydraulic values provided for each hydraulic unit over a relevant scale were used as the baseline for the conceptualization and interpretation of flow modeling. The current hydrogeological characteristics based on the surface based investigation include some uncertainties resulted from the basic assumption of investigation methods and field data. Therefore, the reassessment of hydrostructure model and hydraulic properties based on the field data obtained during the construction is necessitated for a final hydrogeological characterization.

• Applied Chemistry for Engineering
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• v.33 no.5
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• pp.496-501
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• 2022

In this study, an anode material for lithium secondary batteries was manufactured using petroleum-based residual oil, which is a petroleum refining by-product. Among petroleum-based residual oils, pyrolysis fuel oil (PFO), fluidized catalyst cracking-decant oil (FCC-DO), and vacuum residue (VR) were used as carbon precursors. The physicochemical characteristics of petroleum-based residual oil were confirmed through Matrix-assisted laser desorption/ionization Time-of-Flight (MALDI-TOF) and elemental analysis (EA), and the structural characteristics of anode materials manufactured from residual oil were evaluated using X-ray crystallography (XRD) and Raman spectroscopic techniques. VR was found to contain a wide range of molecular weight distributions and large amounts of impurities compared to PFO and FCC-DO, and PFO and FCC-DO exhibited almost similar physicochemical characteristics. From the XRD analysis results, carbonized PFO and FCC-DO showed similar d₀₀₂ values. However, it was confirmed that FCC-DO had a more developed layered structure than PFO in Lc (Length of a and c axes in the crystal system) and La values. In addition, FCC-DO showed the best cycle characteristics in electrochemical characteristics evaluation. According to the physicochemical and electrochemical results of the petroleum-based residual oil, FCC-DO is a better carbon precursor for a lithium secondary battery than PFO and VR.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.396-400
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• 2007

Various ways of automated guideway transit construction are being planned recently owing to the policies of the national government and local municipalities as well as increasing investment from the private sector. Particularly, the increase in the private investment is increasing greatly in SOC (Social Overhead Cost). This trend of promoting private sector investment must be conducted on the basis of a thorough analysis of the economic feasibility of the project from the government and construction companies in the private sector. In other words, an accurate cost analysis of initial investment cost (Construction cost), maintenance/repair cost, profit making through the operation of the concerned facilities, cost of dissolution, etc. in terms of the life cycle is very much in need. Nevertheless, the analysis of uncertainty factors and its probabilistic theory are in need of development so that they can be used in the analysis of the economic feasibility of a construction project. First of all, the actual studies on maintenance/repair cost of automated guideway transit are scarce as of yet, prohibiting an accurate computation of the cost and its economic analysis. Accordingly, this study focused on the uncertainty analysis of the economic feasibility for civil engineering structures among automated guideway transit construction projects based on the rapidly increasing investment on such structures from the private sector. For this research purpose, a cost classification system for the automated guideway transit is proposed, first of all, and the data On the cost cycle of the civil structure facilities and their unit cost are collected and analyzed. Then, the uncertainty in the cost is analyzed from the perspective of LCC. In consideration of the current status with almost no. studies on maintenance/repair of such facilities, it is expected that the cost classification system and the uncertainty analysis technique proposed in this study will greatly enhance LCC analysis and economic feasibility studies for automated guideway transit projects in the future.

• Applied Chemistry for Engineering
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• v.30 no.2
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• pp.226-232
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• 2019

The biological wastewater treatment is more eco-friendly and can be used effectively in wastewater for a variety of purposes than that of the conventional treatment. In particular, the wastewater treatment using microalgae in biological treatment processes has attracted great attention due to its ability to remove economically nutrients from wastewater and have many advantages as a renewable energy source. This study was investigated to establish the optimal growth conditions for microalga Scenedesmus obliquus. Additionally, the removal efficiencies of nutrients (N, P) and heavy metals (Cu, Zn) from the synthetic wastewater were evaluated. As a results, the optimal growth conditions were established at $28^{\circ}C$, pH 7, and light and dark cycle of 14 : 10 h. In the evaluation of nutrient removal efficiencies at each concentrations of 500, 1,000, 5,000, and 10,000 mg/L, the removal rates were 17.6~70% N and 8.4~34% P in the single treatment and 12.0~58.0% N and 3.0~40.3% P in the binary mixture treatment. In addition, the evaluation of heavy metal removal efficiencies at each concentrations of 10, 30 and 50 mg/L, the removal rates were 13.7~40.3% Cu and 10.0~30.0% Zn in the single treatment and 16.0~40.0% Cu and 12.0~20.0% Zn in the binary mixture treatment. Based on the results of the study, it appears that Scenedesmus obliquus can be used for the removal of nutrients and heavy metals from the swine wastewater.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.476-482
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• 2011

Following public expectations from the emergence of an international agreement with greater legal force after the expiration of the 2012 Kyoto Protocol, Korea is also making efforts to effectively and systematically initiate the mitigation policy and enforce the terms of the international climate change agreement. The majority of domestic industries are candidates for greenhouse gas emission regulation, thereby requiring the proposal of a method that effectively reduces environmental contaminate substances released from railway facilities, following the prediction of an increase in railway usage as an environment-friendly transportation method in the future. Accordingly, this study has quantitatively calculated the amount of released environmental contaminates through the life cycle assessment (LCA) on railway facility constructions, and has evaluated the environmental load and the amount of greenhouse gas emissions through the resulting values. The results of the LCA analysis showed that the amount of environmental load was the highest at the early stages of material implementation and construction, and that the value of global warming was viewed as the highest among the effects. As officially announced by the World Meteorological Organization and the United Nations Environment Program that $CO_2$ is the main culprit of global warming, the analytical values confirmed that the amount of $CO_2$ emissions accounted for more than half of the released greenhouse gases at 2.90E+04tons. The environmental load and $CO_2$ emission rates analyzed in this study are judged to be used in the deduction of the optimum environment-friendly method and quantitative environmental effect of railway facility constructions in the future, as the values can be evaluated based on their degree of environment friendliness.

• Journal of the Korean Society for Railway
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• v.15 no.4
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• pp.334-342
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• 2012

It is connected with various gauges existing in Euro-Asian continents. Such differences impedes the operation seriously as on the contact of railway tracks of different gauge the cargo must be either transshipped or the running assemblies of rail vehicles must be exchanged. Those operations are costly, time-consuming and require extended infrastructure together with very expensive storage and transshipment facilities at border-crossing point. Moreover, those operations extend transportation time considerably. Therefore, effectiveness of railway transportation systems significantly depends on track gauge change 1435/1520mm, which connects with complicated handling-shifting operations. The paper concerns assessment of effectiveness in strategical rail systems with gauge changing. The paper presents short description of transport system with gauge changing and initial assessment of shifting technologies. Method of system assessment comparison based on Life Cycle Cost model is described here as well.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.10
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• pp.2431-2438
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• 2013

The paper presents a procedure for how to development and theoretical review on Dissolved Gas Analyzer. the information of abnormal thermal stress on electrical power equipment by testing the gas is validated to easy by the gas analyzer presented in the paper. the analyzed information is used to evaluate the stability of electrical power equipment. the existing and selling DGA(dissolved gas analyzer) is so expensive and vast that all DGA product comes from foreign country. The objective of the paper is to prove that PAS(photoacoustic spectroscopy) based on a compact portable DGA solve the fixed type of DGA in order to eliminate the occurring issue directly or indirectly. the proposed DGA is easy to handle, and this can also analysis in real time for testing electrical power equipment. By applying the proposed portable, DGA be utilized in the currently electrical power equipment that are being implemented to reduce cycle of analysis of dissolved gas, it can contribute to improving safety by providing the agility of the evaluation of degradation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.4
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• pp.116-122
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• 2013

This study develops a dynamic scheduling model for parallel machine scheduling problem based on genetic algorithm (GA). GA combined with discrete event simulation to minimize the makespan and verifies the effectiveness of the developed model. This research consists of two stages. In the first stage, work sequence will be generated using GA, and the second stage developed work schedule applied to a real work area to verify that it could be executed in real work environment and remove the overlapping work, which causes bottleneck and long lead time. If not, go back to the first stage and develop another schedule until satisfied. Small size problem was experimented and suggested a reasonable schedule within limited resources. As a result of this research, work efficiency is increased, cycle time is decreased, and due date is satisfied within existed resources.