• Nuclear Engineering and Technology
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• 제49권3호
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• pp.645-650
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• 2017

This technical note demonstrates the feasibility of using laser ablation inductively coupled plasma mass spectrometry for the characterization of U-7Mo/Ale5Si dispersion fuel. Our measurements show 5.0% Relative Standard Deviation (RSD) for the reproducibility of measured $^{98}Mo/^{238}U$ ratios in fuel particles from spot analysis, and 3.4% RSD for $^{98}Mo/^{238}U$ ratios in a NIST-SRM 612 glass standard. Line scanning allows for the distinction of U-7Mo fuel particles from the Al-5Si matrix. Each mass spectrum peak indicates the presence of U-7Mo fuel particles, and the time width of each peak corresponds to the size of that fuel particle. The size of the fuel particles is estimated from the time width of the mass spectrum peak for $^{98}Mo$ by considering the scan rate used during the line scan. This preliminary application clearly demonstrates that laser ablation inductively coupled plasma mass spectrometry can directly identify isotope ratios and sizes of the fuel particles in U-Mo/Al dispersion fuel. Once optimized further, this instrument will be a powerful tool for investigating irradiated dispersion fuels in terms of fission product distributions in fuel matrices, and the changes in fuel particle size or shape after irradiation.

• Safety and Health at Work
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• 제12권4호
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• pp.462-470
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• 2021

Background: Fatigue is pervasive, under-reported, and potentially deadly where flight operations are concerned. The aviation industry appears to lack a standardized, practical, and easily replicable protocol for fatigue risk assessment which can be consistently applied across operators. Aim: Our paper sought to present a framework, supported by real-world data with subjective and objective parameters, to monitor aircrew fatigue and performance, and to determine the safe crew configuration for commercial airline operations. Methods: Our protocol identified risk factors for fatigue-induced performance degradation as triggers for fatigue risk and performance assessment. Using both subjective and objective measurements of sleep, fatigue, and performance in the form of instruments such as the Karolinska Sleepiness Scale, Samn-Perelli Crew Status Check, Psychomotor Vigilance Task, sleep logs, and a wearable actigraph for sleep log correlation and sleep duration and quality charting, a workflow flagging fatigue-prone flight operations for risk mitigation was developed and trialed. Results: In an operational study aimed at occupational assessment of fatigue and performance in airline pilots on a three-men crew versus a four-men crew for a long-haul flight, we affirmed the technical feasibility of our proposed framework and approach, the validity of the battery of assessment instruments, and the meaningful interpretation of fatigue and work performance indicators to enable the formulation of safe work recommendations. Conclusion: A standardized occupational assessment protocol like ours is useful to achieve consistency and objectivity in the occupational assessment of fatigue and work performance.

• Korean Journal of Radiology
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• 제19권6호
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• pp.1053-1065
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• 2018

Objective: To evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison. Materials and Methods: In this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled. Informed consent was obtained from all patients. Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (${\geq}3mm$) in two separate sessions using either side-by-side visual comparison or non-rigid registration software. Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition. Then, ablative margins were re-assessed using both methods. Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method. Results: The two methods showed 14.8% (13/88) discordance in estimating sufficient ablative margins. On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (66.7% vs. 27.0%, p = 0.004). However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (28.6% vs. 30.5%, p = 0.79). Conclusion: Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.

• Journal of Korean Neurosurgical Society
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• 제62권1호
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• pp.27-34
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• 2019

Objective : Stent-assisted coil embolization of intracranial wide-necked aneurysm requires long-term postoperative antiplatelet therapy to prevent in-stent thrombosis. This study aimed to demonstrate results of temporary stent placement for coiling wide necked small intracranial aneurysms, which eliminated need for antiplatelet agents, and to discuss its feasibility and safety. Methods : Data of 156 patients who underwent stent-assisted coil embolization between 2011 and 2014 were retrospectively analyzed. Thirteen cases of temporary stent-assisted coil embolization were included, and their clinical and radiological results were evaluated. Results : The aneurysms treated were all unruptured except one case. All of them had wide neck with mean dome-to-neck ratio of 0.96 and were small-sized aneurysms with mean maximal diameter of 4.2 mm. There was no technical failure in retrieval of stent after completion of embolization of the target aneurysm. Immediate angiography revealed 11 complete and two partial embolization (one residual neck and one residual aneurysm). Two cases encountered thrombosis complication, and they were managed without neurological sequelae. The mean follow-up period was 43 months, angiographic follow-up revealed two cases with minor recurrence, and clinical outcome was good with modified Rankin scale score of 0. Conclusion : Temporary stent-assisted coil embolization of small wide-necked intracranial aneurysm using fully retrievable stent appears safe and effective. Further application and evaluation of this technique in more cases with larger size aneurysm is warranted.

• Animal Bioscience
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• 제34권4호
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• pp.516-524
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• 2021

Objective: The genetic evaluation of Santa Inês sheep was performed for resistance to gastrointestinal nematode infection (RGNI) and body size using different relationship matrices to assess the efficiency of including genomic information in the analyses. Methods: There were 1,637 animals in the pedigree and 500, 980, and 980 records of RGNI, thoracic depth (TD), and rump height (RH), respectively. The genomic data consisted of 42,748 SNPs and 388 samples genotyped with the OvineSNP50 BeadChip. The (co)variance components were estimated in single- and multi-trait analyses using the numerator relationship matrix (A) and the hybrid matrix H, which blends A with the genomic relationship matrix (G). The BLUP and single-step genomic BLUP methods were used. The accuracies of estimated breeding values and Spearman rank correlation were also used to assess the feasibility of incorporating genomic information in the analyses. Results: The heritability estimates ranged from 0.11±0.07, for TD (in single-trait analysis using the A matrix), to 0.38±0.08, for RH (using the H matrix in multi-trait analysis). The estimates of genetic correlation ranged from -0.65±0.31 to 0.59±0.19, using A, and from -0.42±0.30 to 0.57±0.16 using H. The gains in accuracy of estimated breeding values ranged from 2.22% to 75.00% with the inclusion of genomic information in the analyses. Conclusion: The inclusion of genomic information will benefit the direct selection for the traits in this study, especially RGNI and TD. More information is necessary to improve the understanding on the genetic relationship between resistance to nematode infection and body size in Santa Inês sheep. The genetic evaluation for the evaluated traits was more efficient when genomic information was included in the analyses.

• Journal of Gastric Cancer
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• 제21권2호
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• pp.179-190
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• 2021

Purpose: Reduced port laparoscopic distal gastrectomy (RPLDG) using 3 ports is less invasive than conventional laparoscopic distal gastrectomy (CLDG) using 5 ports. Although RPLDG performed by expert surgeons is safe and feasible, novice surgeons have difficulty performing this procedure. This study evaluated the surgical outcomes and feasibility of RPLDG performed by a novice surgeon. Materials and Methods: The records of 136 patients who underwent laparoscopic distal gastrectomy for gastric cancer performed by a single novice surgeon between May 2016 and December 2018 were retrospectively reviewed. Among these 136 patients, 52 underwent RPLDG and 84 underwent CLDG. The clinicopathological characteristics, operative outcomes, and short-term postoperative outcomes of the 2 groups were compared. Results: The percentage of women was significantly higher in the RPLDG group than in the CLDG group (48.1% vs. 31%; P=0.045), but other baseline characteristics did not differ significantly between the groups. Billroth II anastomosis was performed significantly more frequent (90.4% vs. 73.8%, P=0.015) and operation time was significantly shorter (207.1±43.3 min vs. 225.5±44.6 min, P=0.020) in the RPLDG group than in the CLDG group. The time to first flatus, postoperative pain score, length of postoperative hospital stay, and incidence and severity of complications did not differ significantly between the groups. Analysis of the learning curve based on the operation time showed that performing RPLDG on 20-30 patients was required to achieve technical proficiency. Conclusions: RPLDG is a safe and feasible surgical procedure for the treatment of gastric cancer, even when performed by a novice surgeon.

• Journal of Korean Neurosurgical Society
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• 제64권5호
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• pp.740-750
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• 2021

Objective : Retrograde suction decompression (RSD) is an adjuvant technique used for the microsurgical treatment of large and giant internal carotid artery (ICA) aneurysms. In this study, we analyzed the efficacy and safety of the RSD technique for the treatment of large and giant ICA aneurysms relative to other conventional microsurgical techniques. Methods : The aneurysms were classified into two groups depending on whether the RSD method was used (21 in the RSD group vs. 43 in the non-RSD group). Baseline characteristics, details of the surgical procedure, angiographic outcomes, clinical outcomes, and procedure-related complications of each group were reviewed retrospectively. Results : There was no significant difference in the rates of complete neck-clipping between the RSD (57.1%) and non-RSD (67.4%) groups. Similarly, there was no difference in the rates of good clinical outcomes (modified Rankin Scale score, 0-2) between the RSD (85.7%) and non-RSD (81.4%) groups. Considering the initial functional status, 19 of 21 (90.5%) patients in the RSD group and 35 of 43 (81.4%) patients in the non-RSD group showed an improvement or no change in functional status, which did not reach statistical significance. Conclusion : In this study, the microsurgical treatment of large and giant intracranial ICA aneurysms using the RSD technique obtained competitive angiographic and clinical outcomes without increasing the risk of procedure-related complications. The RSD technique might be a useful technical option for the microsurgical treatment of large and giant intracranial ICA aneurysms.

• Journal of Korean Neurosurgical Society
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• 제65권4호
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• pp.523-530
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• 2022

Objective : To evaluate the safety and efficacy of an overlapped stenting-assisted coiling technique in treating vertebral artery dissecting aneurysm (VADA) via Low-profile Visualized Intraluminal Support (LVIS) stent-within-Neuroform EZ stent. Methods : From January 2017 to June 2019, 18 consecutive patients with VADAs (ruptured : unruptured=5 : 13) were treated with the overlapping stents assisted-coiling technique in our center. The overlapping manner was a Neuroform EZ stent being deployed first, followed by LVIS stents placement using the 'shelf' technique. The patients' clinical characteristics, technical feasibility and safety, and immediate and follow-up angiographic results were retrospectively reviewed. Results : Seventeen (94.4%) procedures were technically successful with an exact deployment of the stents and patent parent or perforator arteries. The immediate angiographies after procedure confirmed Raymond class I, II, and III occlusion of VADAs were in 12 (66.7%), two (11.1%), and four cases (22.2%), respectively. Post-procedural complications developed in one patient (5.6%) with minor brainstem infarctions, which resulted from an in-stent thrombosis during the procedure. Angiographic follow-up at 5.7 months (range 3 to 9 months) demonstrated Raymond class I and II occlusion were in all cases (100%). The modified Rankin Scale scores at 21.3 months (range 15 to 42 months) 0-2 in 17 cases (94.4%) and three in one case (5.6%). Conclusion : Overlapping stents via LVIS stent-within-Neuroform EZ stent combined with coiling is safe and effective for patients with VADA in the midterm results.

• 인간식물환경학회지
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• 제23권1호
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• pp.1-14
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• 2020

The purpose of this research is to strengthen rural community empowerment by creating a tourism farm as a plan to reduce relative poverty and to improve the quality of life by creating jobs and increasing the income of local residents in underdeveloped countries. To do so, literature review, stakeholder interviews, on-site investigations, focus-group interviews, a project meeting for residents and a questionnaire survey were performed and analyzed and the results were as follows. First, Uganda has the potential to increase agricultural production based on its warm climate, fertile land and abundant natural resources. The quality of life of local residents is expected to be improved by realizing high-added values through the convergence of the conventional existing agricultural industry and other industries if the agricultural technology is properly transferred based on abundant labor force and low labor expenses. Opportunities for the success of the project can be spread to other rural villages across the country. Second, since local residents are now cultivating sugar cane, cassava, matoke, banana, coffee and so on as a farm owner, tourism agriculture with high-added values can be promoted by vitalizing communities based on farming technology to be transferred and a cooperative farm. It is also necessary to implement a rural community empowerment project to do so. Third, the university that is the cooperative partner of the project is positively considering to train experts by establishing a community development department, and, if necessary, a technical training center to educate the general public, which is expected to create synergic effects through the convergence of education, agriculture and tourism.

• Geomechanics and Engineering
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• 제28권6호
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• pp.547-557
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• 2022

Dune sands are poorly graded collapsible soils lacking fines. This experimental study explored the technical feasibility of sustainable invigoration of fine waste materials to improve the geotechnical properties of dune sand. The fine waste considered in this study is fine marble waste. The fine waste powder was mixed with dune sand at different contents (5, 10,15, 20, 25, 50%), where the gradation, void ratio, compaction, and shear strength characteristics were assessed for each fine marble waste -dune sand blend. The geotechnical properties of the dune sand-fine marble waste mix delineated in this study reveal the enhancement in compaction and gradation characteristics of dune sand. According to the results, the binary mixture of dune sand with 20% of fine marble waste gives the highest maximum dry density and results in shear strength improvement. In addition, a numerical study is conducted for the practical application of the binary mix in the field and tested for an isolated shallow foundation. The elemental analysis of the fine marble waste confirms that the material is non-contaminated and can be employed for engineering applications. Furthermore, the numerical study elucidated that the shallow surface replacement of the site with the dune sand mixed with 20% fine marble waste gives optimal performance in terms of stress generation and settlement behavior of an isolated footing. For a sustainable mechanical performance of the fine marble waste mixed sand, an optimum dose of 20% fine marble waste is recommended, and some correlations are proposed. Thus, for improving dune sand's geotechnical characteristics, the addition of fine marble waste to the dune sand is an environment-friendly solution.