• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.1
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• pp.69-85
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• 2019

BeiDou navigation satellite system (BDS) is one of the four main types of global navigation satellite systems. The current system has been widely used by the military and by the aerospace, transportation, and marine fields, among others. However, challenges still remain in the BeiDou system, which requires rapid responses for delay-sensitive devices. A differential positioning algorithm called the data center-based differential positioning (DCDP) method is widely used to avoid the influence of errors. In this method, the positioning information of multiple base stations is uploaded to the data center, and the positioning errors are calculated uniformly by the data center based on the minimum variance or a weighted average algorithm. However, the DCDP method has high delay and overload risk. To solve these problems, this paper introduces edge computing to relieve pressure on the data center. Instead of transmitting the positioning information to the data center, a novel method called edge computing-based differential positioning (ECDP) chooses the nearest reference station to perform edge computing and transmits the difference value to the mobile receiver directly. Simulation results and experiments demonstrate that the performance of the ECDP outperforms that of the DCDP method. The delay of the ECDP method is about 500ms less than that of the DCDP method. Moreover, in the range of allowable burst error, the median of the positioning accuracy of the ECDP method is 0.7923m while that of the DCDP method is 0.8028m.

• Clinical and Experimental Pediatrics
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• v.62 no.8
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• pp.307-311
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• 2019

Purpose: Necrotizing enterocolitis (NEC) is one of the most serious complications of prematurity. Many risk factors can contribute to the development of NEC. The epidermal growth factor (EGF) plays a major role in intestinal barrier function, increases intestinal enzyme activity, and improves nutrient transport. The aim of this study was to assess the role of epidermal growth factor in the development of NEC in preterm neonates. Methods: In this study, 130 preterm neonates were included and divided into 3 groups, as follows: group 1, 40 preterm neonates with NEC; group 2, 50 preterm neonates with sepsis; and group 3, 40 healthy preterm neonates as controls. The NEC group was then subdivided into medical and surgical NEC subgroups. The serum EGF level was measured using enzyme-linked immunosorbent assay. Results: Serum EGF levels (pg/dL) were significantly lower in the NEC group (median [interquartile range, IQR], 9.6 [2-14]) than in the sepsis (10.1 [8-14]) and control groups (11.2 [8-14], P<0.001), with no significant difference between the sepsis and control groups, and were positively correlated with gestational age (r=0.7, P<0.001). A binary logistic regression test revealed that low EGF levels and gestational ages could significantly predict the development of NEC. The receiver-operating characteristic curve for EGF showed an optimal cutoff value of 8 pg/mL, with 73.3% sensitivity, 98% specificity, and an area under the curve of 0.92. Conclusion: The patients with NEC in this study had significantly lower serum EGF levels (P<0.001), which indicated that EGF could be a reliable marker of NEC in preterm neonates.

• Geomechanics and Engineering
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• v.17 no.1
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• pp.81-95
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• 2019

Due to the importance of soil reinforcement using geotextiles in geotechnical engineering, study and investigation into long-term performance, design life and survivability of geotextiles, especially due to installation damage are necessary and will affect their economy. During installation, spreading and compaction of backfill materials, geotextiles may encounter severe stresses which can be higher than they will experience in-service. This paper aims to investigate the installation damage of geotextiles, in order to obtain a good approach to the estimation of the material's strength reduction factor. A series of full-scale tests were conducted to simulate the installation process. The study includes four deliberately poorly-graded backfill materials, two kinds of subgrades with different CBR values, three nonwoven needle-punched geotextiles of classes 1, 2 and 3 (according to AASHTO M288-08) and two different relative densities for the backfill materials. Also, to determine how well or how poorly the geotextiles tolerated the imposed construction stresses, grab tensile tests and visual inspections were carried out on geotextile specimens (before and after installation). Visual inspections of the geotextiles revealed sedimentation of fine-grained particles in all specimens and local stretching of geotextiles by larger soil particles which exerted some damage. A regression model is proposed to reliably predict the installation damage reduction factor. The results, obtained by grab tensile tests and via the proposed models, indicated that the strength reduction factor due to installation damage was reduced as the median grain size and relative density of the backfill decreases, stress transferred to the geotextiles' level decreases and as the as-received grab tensile strength of geotextile and the subgrades' CBR value increase.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.4
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• pp.394-400
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• 2019

Noise removal is one of the required step in processing digital video and there are many researches to develop algorithm that fits with its purpose and environment. However, present impulse noise removal methods are lacking in its function in terms of removing noise in edge and high frequency factors. Therefore, this research has Extended range of masks depending on density to determine noise so that high frequency factors can be preserved. The range of resolution is set based on median and standard deviation of inside resolution after removing impulse noise. afterwards, those resolution within the range are calculated by adding weight to have the final output value. The suggested algorithm has an enhanced function in removing noise in various areas with many edge and high frequency factors than present methods and their functions are compared through simulation.

• Journal of Korean Neurosurgical Society
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• v.64 no.2
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• pp.198-206
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• 2021

Objective : The low-profile Neuroform Atlas stent can be deployed directly without an exchange maneuver by navigating into the Gateway balloon. This retrospective study assessed the safety and efficacy of Neuroform Atlas stenting as a rescue treatment after failure of mechanical thrombetomy (MT) for large artery occlusion. Methods : Between June 2018 and December 2019, a total of 31 patients underwent Neuroform Atlas stenting with prior Gateway balloon angioplasty after failure of conventional MT caused by residual intracranial atherosclerotic stenosis (ICAS). Primary outcomes were successful recanalization and patency of the vessel 24 hours after intervention. Secondary outcomes were vessel patency after 14 days and 3-month modified Rankin Scale. Peri-procedural complications, intracerebral hemorrhage (ICH), and 3-month mortality were reviewed. Results : With a 100% of successful recanalization, median value of stenosis was reduced from 79.0% to 23.5%. Twenty-eight patients (90.3%) showed tolerable vessel patency after 14 days. New infarctions occurred in three patients (9.7%) over a period of 14 days; two patient (6.5%) underwent stent occlusion at 24 hours, and the other patient (3.2%) with delayed stent occlusion had a non-symptomatic dot infarct. There were no peri-procedural complications. Two patients (6.5%) developed an ICH immediately after the procedure with one of them is symptomatic. Conclusion : Neuroform Atlas stenting seems to be an effective and safe rescue treatment modality for failed MT with residual ICAS, by its high successful recanalization rate with tolerable patency, and low peri-procedural complication rate. Further multicenter and randomized controlled trials are needed to confirm our findings.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.3
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• pp.348-355
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• 2021

Hantaan virus(HTNV) causes hemorrhagic fever with renal syndrome(HFRS) with a case fatality rate ranging from <1 to 15 % in human. Hantavax^Ⓡ is a vaccine against the Hantavirus, which has been conditionally approved by the Ministry of Food and Drug Safety(MFDS). However, only 50 % of volunteers had neutralizing antibodies 1 year following the boost. Effective antiviral treatments against HTNV infection are limited. Hantaviruses generally cause asymptomatic infection in adult mice. On the other hand, infection of suckling and newborn mice with hantaviruses causes lethal neurological diesease or persistant infection, which is different from the disease in humans. The development of vaccines and antiviral strategies for HTNV has been partly hampered by the lack of an efficient lethal mouse model to evaluate the efficacy of the candidate vaccines or antivirals. In this report, we established a lethal mouse model for HTNV, which may facilitate in vivo studies on the evaluation of candidate drugs against HTNV. The median lethal dose value of HTNV was calculated by probit analysis of deaths occurring within two weeks. Five groups of ten ICR mice were injected intracranially with serial 2-fold dilutions (from 50 to 3.125 PFU/head) of HTNV. Mice injected with HTNV began to die at 8 days post-infection. The lethal dose required to kill 50 % of the mice (LD₅₀) was calculated to be 2.365 PFU/head.

• Journal of Gastric Cancer
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• v.21 no.2
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• pp.122-131
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• 2021

Purpose: To date, there are no promising treatments for gastric carcinoma with peritoneal metastasis. Some researchers have suggested a survival benefit of gastrectomy in select patients. This study investigated the survival of gastric carcinoma patients with stand-alone peritoneal metastasis according to the type of treatment modality. Materials and Methods: We reviewed the data of 132 patients with gastric carcinoma and stand-alone peritoneal metastasis. We performed gastrectomy when the primary tumor was deemed resectable and systemic chemotherapy was administered. We analyzed patient survival according to the type of treatment, and the prognostic value of gastrectomy was evaluated in univariate and multivariate models. Results: Among all patients, 70 underwent gastrectomy plus chemotherapy, 20 underwent gastrectomy alone, 36 underwent chemotherapy alone, and 6 received supportive care. The median patient survival was 13 months. Patients who underwent gastrectomy had significantly longer survival than those who did not undergo gastrectomy (14 vs. 8 months, P<0.001). Patients who received chemotherapy showed significantly longer survival than those who did not (13 vs. 7 months, P=0.032). Patients who underwent gastrectomy plus chemotherapy showed better survival than those who underwent other treatments. In multivariate analysis, gastrectomy was found to be an independent prognostic factor (hazard ratio, 0.52; 95% confidence interval, 0.33-0.82) in addition to chemotherapy. Conclusions: Our study showed that patients who underwent gastrectomy plus chemotherapy had the best survival. Although the survival benefit of gastrectomy remains uncertain, it is a favorable prognostic indicator in patients with stand-alone peritoneal metastasis.

• Journal of Sasang Constitutional Medicine
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• v.32 no.4
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• pp.11-28
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• 2020

Objectives The purpose of this study was to evaluate quality of reporting of intervention studies on Sasang Constitutional diet (SCD) based on the Consolidated Standards for Reporting of Trials (CONSORT) and Transparent Reporting of Evaluations with Nonrandomized Designs (TREND) statements. Methods We searched for Randomized controlled trials (RCT) and Non randomized studies for intervention (NRSI) on SCD in 4 databases and other sources, selected them by the inclusion criteria, and then evaluated quality of reporting of them. Results 1. A total of 10 studies (1 RCT and 9 NRSI) from 1999 to 2006 were selected and evaluated. The detailed items of up to 78%, at least 40%, and median value of 59% in the CONSORT and TREND statements were not reported. 2. One RCT was reporting 4 (11%) sufficiently, and 4 (11%) insufficiently among the 37 detailed items in the CONSORT statement while it was not reporting 29 (78%) items. 3. Nine NRSI were reporting 7 (12%) items sufficiently, and 2 (3%) items insufficiently among the 58 detailed items in the TREND statement while they were not reporting 15 (26%) items. Twenty (34%) items in the TREND statement were reported in some papers but not in more than half. Conclusions The quality of reporting of intervention studies on SCD has been assessed to be generally low. Subsequent researchers are recommended to select an appropriate statement for research design, and use it as a checklist from the time of designing the study to the time of reporting.

• Journal of Pharmacopuncture
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• v.24 no.2
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• pp.84-90
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• 2021

Objectives: Our study aimed to determine the attitudes of second- and final-year medical students and doctors (teaching faculty) of modern medicine towards complementary and alternative medicine (CAM) using the Complementary, Alternative, and Integrative Medicine Attitude Questionnaire (CAIMAQ). Methods: We invited 248 second-year medical students, 245 final-year medical students, and 48 faculty members to participate in the study. The CAIMAQ consists of 30 items, divided into five categories assessing various aspects of CAM, and scored using a 7-point Likert scale. The median scores obtained were compared between groups; a p-value < 0.05 was considered statistically significant. Results: A total of 138 medical students and faculty responded and participated in the study, of which, 24 (17.4%) were faculty, 40 (29%) were final-year medical students and 74 (53.6%) were second-year medical students. The overall attitude towards the various CAM concepts and therapies was positive. In general, the faculty were significantly less likely to consider referring patients for CAIM treatments, integrating them with conventional medicine, referring patients to alternative healthcare providers, considering the use of subtle energy fields as an ethical form of treatment, or considering CAIM treatments to be less invasive and harmful compared with conventional medicine. There was no significant difference in the attitudes of second- and final-year students. Conclusion: The attitude of medical students and doctors towards CAM is positive, and although the medical faculty have reservations in recommending specific types of CAM therapies or integrating them with conventional care, building evidence for supporting CAM therapies in specific diseases is likely to increase its uptake among health care professionals.

• Journal of Gastric Cancer
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• v.21 no.4
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• pp.392-402
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• 2021

Purpose: Type 4 gastric cancer (GC) has a very poor prognosis even after curative resection, and the survival benefit of splenectomy for splenic hilar lymph node (LN; #10) dissection in type 4 GC remains equivocal. This study aimed to clarify the clinical significance of splenectomy for #10 dissection in patients with type 4 GC. Materials and Methods: The data of a total of 56 patients with type 4 GC who underwent total gastrectomy with splenectomy were retrospectively analyzed. Postoperative morbidity, state of LN metastasis, survival outcomes, and therapeutic value index (TVI) of each LN station were evaluated. TVI was calculated by multiplying the incidence of LN metastasis at each nodal station and the 5-year overall survival (OS) of patients who had metastasis to each node. Results: Overall, the postoperative morbidity rate was 28.6%, and the incidence of #10 metastasis in the patients was 28.6%. The 5-year OS rate for all patients was 29.9%, and most patients developed peritoneal recurrence. Moreover, the 5-year OS rates with and without #10 metastasis were 6.7% and 39.1% (median survival time, 20.4 vs. 46.0 months; P=0.006). The TVI of #10 was as low as 1.92. Conclusions: The clinical significance of splenectomy in the dissection of #10 for type 4 GC is limited and splenectomy for splenic hilar dissection alone should be omitted.