• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.74-91
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• 2023

Several that analyzed the effectiveness of traffic safety facilities a method of comparing changes in the number of accidents, accident severity, speed through traffic accident data before and after installation or speed data collected from vehicle detection systems (VDS). , when traffic accident data is used, it takes a long time to collect because must be collected for at least one year before and after installation. , the road environment may change during this period, such as the addition of other traffic safety facilities in addition to the facilities to be analyzed. , the location of the VDSs for speed data is often different from the location where analysis is required, and there is a problem in that the investigators are exposed to the risk of traffic accident during on-site investigation. Therefore, this study a case study by establishing a methodology to determine effectiveness video images with a drone, extracting data using a program, and comparing vehicle driving speeds before and after speed reduction facilities. Vehicle speed surveys using drones are much safer than observational surveys conducted on highways and have the advantage of tracking speed changes along the vehicle, it is expected that they will be used for various traffic surveys in the future.

• Journal of the Korean Geotechnical Society
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• v.40 no.3
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• pp.77-84
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• 2024

Aging and damaged underground utilities cause cavity and ground subsidence under roads, which can cause economic losses and risk user safety. This study used infrared cameras to assess the thermal characteristics of such cavities and evaluate their reliability using a CNN algorithm. PVC pipes were embedded at various depths in a test site measuring 400 cm × 50 cm × 40 cm. Concrete blocks were used to simulate road surfaces, and measurements were taken from 4 PM to noon the following day. The initial temperatures measured by the infrared camera were 43.7℃, 43.8℃, and 41.9℃, reflecting atmospheric temperature changes during the measurement period. The RP algorithm generates images in four resolutions, i.e., 10,000 × 10,000, 2,000 × 2,000, 1,000 × 1,000, and 100 × 100 pixels. The accuracy of the CNN model using RP images as input was 99%, 97%, 98%, and 96%, respectively. These results represent a considerable improvement over the 73% accuracy obtained using time-series images, with an improvement greater than 20% when using the RP algorithm-based inputs.

• Journal of Wetlands Research
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• v.26 no.1
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• pp.32-40
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• 2024

The purpose of this study is to collect basic information about Narrow-mouthed Toad (Kaloula borealis) by analyzing the morphological characteristics of Narrow-mouthed Toad (Kaloula borealis) caught in pitfall traps. The study site is in Godeok-dong, Gangdong-gu, Seoul, and a total of 1,063 individuals were captured using pitfall traps for a total of four years from July 2016 to November 2020. Narrow-mouthed Toad (Kaloula borealis) were classified into adult and immature individuals based on length (SVL), and differences in sex ratio and shape were confirmed for adults. As a result, all adult males had a pair of white bands observed in the abdomen, and females had eggs identified in the abdomen. Through previous studies, a pair of white bands on the abdomen were determined to be male gonads, and were also confirmed in some immature individuals. The sex of the Narrow-mouthed Toad (Kaloula borealis) could be distinguished by the presence or absence of a pair of white bands located on the abdomen, and it is believed that this can be used as a sex classification method that can be confirmed in the field. During the study period, the adult sex ratio was confirmed to be 697 male (65.57%) and 366 female (34.43%), with more males. It is expected that this method of sex ratio and male/female sex ratio will be used not only for species restoration and monitoring of migration and alternative habitats due to development, but also as basic data for various ecological studies.

• Korean Journal of Radiology
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• v.25 no.1
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• pp.55-61
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• 2024

Objective: This study aimed to evaluate the safety and efficacy of intranodal lymphangiography and thoracic duct embolization (TDE) for chyle leakage (CL) after thyroid surgery. Materials and Methods: Fourteen patients who underwent intranodal lymphangiography and TDE for CL after thyroid surgery were included in this retrospective study. Among the 14 patients, 13 underwent bilateral total thyroidectomy with neck dissection (central compartment neck dissection [CCND], n = 13; left modified radical neck dissection (MRND), n = 11; bilateral MRND, n = 2), and one patient underwent left hemithyroidectomy with CCND. Ten patients (76.9%) had high-output CL (> 500 mL/d). Before the procedure, surgical intervention was attempted in three patients (thoracic duct ligation, n = 1; lymphatic leakage site ligation, n = 2). Lymphangiographic findings, technical and clinical successes, and complications were analyzed. Technical success was defined as the successful embolization of the thoracic duct after access to the lymphatic duct via the transabdominal route. Clinical success was defined as the resolution of CL or surgical drain removal. Results: On lymphangiography, ethiodized oil leakage near the surgical bed was identified in 12 of 14 patients (85.7%). The technical success rate of TDE was 78.6% (11/14). Transabdominal antegrade access was not feasible due to the inability to visualize the identifiable cisterna chyli or a prominent lumbar lymphatic duct. Among patients who underwent a technically successful TDE, the clinical success rate was 90.1% (10/11). The median time from the procedure to drain removal was 3 days (with a range of 1-13 days) for the 13 patients who underwent surgical drainage. No CL recurrence was observed during the follow-up period (ranging from 2-44 months; median, 8 months). There were no complications, except for one case of chylothorax that developed after TDE. Conclusion: TDE appears to be a safe and effective minimally invasive treatment option for CL after thyroid surgery, with acceptable technical and clinical success rates.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1175-1183
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• 2020

Purpose To evaluate the technical feasibility and clinical efficacy of percutaneous transgastric stent placement after the failure of treatment attempt with the transoral approach in malignant gastroduodenal obstruction patients. Materials and Methods From October 2008 to April 2016, nine patients (M:F = 4:5; mean age = 66 years) with malignant gastroduodenal obstruction underwent stent placement via a gastrostomy tract, which was attributed to the failure of the transoral approach. The primary etiologies of the obstruction were pancreatic (n = 5), gastric (n = 2), and metastatic (n = 2) cancers. Through percutaneous gastrostomy, dual stents (inner bare metal and outer polytetrafluoroethylene-covered) were deployed at the obstruction site. The technical and clinical success rates, as well as complications were evaluated during the follow-up period. Results Stents were successfully inserted in eight patients (88%). We failed to insert stent in one patient due to the presence of a tight obstruction. After stent placement, symptoms improved in seven patients. Gastrostomy tube was removed 9 to 20 days (mean = 12 days) after the stent insertion. During the mean follow-up of 136 days (range, 3-387 days), one patient developed a recurrent symptom due to tumor overgrowth. However, there were no other major complications associated with the procedure. Conclusion Percutaneous transgastric stent placement appeared to be technically feasible and clinically effective in patients who underwent a failed transoral approach.

• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.348-355
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• 2024

A current source capable of stably supplying current as a measurement medium is required in order to measure and test important facilities that require large-scale measurement current, such as a control element drive mechanism control system(CEDMCS), in case of dismantling a nuclear power plant. However, it can provides only voltage power as a source, not current, although direct voltage controlled constant current source is essential to test major equipment. That kind of source is not available to supply stable constant current regardless of load variation. It is just voltage supplier. Developing current source is not easy other than voltage source. Very large-scale current source up to ampere class more than such ten times of normal current is inevitable to test above mentioned equipment. So, we developed large-scale current source which is controlled by input DC voltage and supplies constant stable current to object equipment according to this requirement. We measured and tested nuclear power plant equipment using given real site data for a long time and afforded long period load test, and then proved its validity and verification. The developed invetion will be used future installed important equipment measuring and testing.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1350-1360
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• 2023

Purpose To evaluate the factors that predict symptomatic dislodgement of a percutaneous transhepatic biliary drainage (PTBD) catheter in patients with malignant biliary obstruction. Materials and Methods This retrospective study included 572 patients with malignant biliary obstruction who underwent 733 PTBD catheter insertions between January 2010 and February 2015. The duration of catheter placement, approach site, location of the catheter tip, insertion angle, presence of a closed-loop pigtail, and tube diameter were evaluated. Results During the follow-up period, 224 PTBD catheter dislodgements (30.56%) were observed in 157 patients. Among them, 146 (19.92%) were symptomatic. The mean duration from catheter insertion until dislodgement was 32 days (range: 1-233 days). Male (odds ratio [OR]: 1.636, 95% confidence interval [CI]: 1.131-2.367, p = 0.009), right-sided approach (OR: 1.567, 95% CI: 1.080-2.274, p = 0.018), increased insertion angle (OR: 1.015, 95% CI: 1.005-1.026, p = 0.005), and incomplete closed-loop pigtail formation (OR: 1.672, 95% CI: 1.098-2.545, p = 0.016) were independent factors predictive of symptomatic dislodgement of a PTBD catheter. Conclusion Factors predictive of symptomatic catheter dislodgement included male sex, a right-sided approach, increased insertion angle, and incomplete closed-loop pigtail formation.

• Journal of Chest Surgery
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• v.36 no.6
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• pp.384-390
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• 2003

Background: Since Ross and Sormeville first reported the use of aortic homograft valve for correction of pulmonary atresia in 1966, homograft valves are widely used in the repair of congenital anomalies as conduits between the pulmonary ventricle and pulmonary arteries. On the basis of these results, we have used it actively. In this report, we describe our experience with the use of cryopreserved valved homograft conduits for infants and children requiring right ventricle to pulmonary artery connection in various congenital cardiac anomalies. Material and Method: Between January, 1996 and December 2001, 27 infants or children with a median age of 16 months(range 9days to 18years) underwent repair of RVOTO using homograft valved conduit by two surgeons. We studied 22 patients who have been followed up at least more than one year. The diagnosis at operation included pulmonary atresia with ventricular septal defect (n=13), truncus arteriosus (n=3), TGA or corrected TGA with RVOTO (n=6). Homograft valved conduits varied in size from 15 to 26 mm (mean, 183.82 mm). The follow-up period ranged from 12 to 80.4 months (median, 48.4 months). Result: There was no re-operation due to graft failure itself. However, early progressive pulmonary homograft valve insufficiency developed in one patient, that was caused by dilatation secondary to the presence of residual distal pulmonary artery stenosis and hypoplasia after repair of pulmonary atresia with ventricular septal defect. This patient was required reoperation (conduit replacement). During follow-up period, there were significant pulmonary stenosis in one, and pulmonary regurgitation more than moderate degree in 3. And there were mild calcifications at distal anastomotic site in 2 patients. All the calcified homografts were aortic in origin. Conclusion: We observed that cryopreserved homograft conduits used in infant and children functioned satisfactorily in the pulmonic position at mid-term follow-up. To enhance the homograft function, ongoing investigation is required to re-establish the optimal strategy for the harvest, preservation and the use of it.

• Korean Journal of Environmental Biology
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• v.35 no.1
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• pp.83-94
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• 2017

Benthic macroinvertebrates were investigated in thermal discharge that flows Buso stream region from December 2015 to February 2016, Korea. Study site was selected for the upstream, downstream relative to the mixing station and mixing station which thermal effluent flows, water quality analysis and benthic macroinvertebrates composition, taxa of EPT-group individuals, analysis of biological water quality. As a result, a total of 4,015 individuals including 50 species, 30 families, 11 orders, 4 classes, and 3 phyla were recognized. Taxa of species is Ephemeroptera 16 species (32.0%) including 6 families, the density composition was highest in 1,848 individuals (46.03%) Diptera. EPT-group occupied during the study period were a total of 1,876 individuals (46.72%) including 32 species and 17 family, lowest in the mixing station for study period. As a results of community analysis, mixing station in the Limnodrilus gotoi and Chironomidae sp.2, which is dominated by the analysis was Ecdyonurus levis, Cincticostella levanidovae, Nemoura KUa. The dominant species showed a difference in the upstream and downstream. In the functional feeding groups, in the upstream and mixing station Gathering-Collectors, downstream it was analyzed that the ratio of the highest Filtering-Collectors and decreased the ratio of Shredders increasing from upstream to downstream. Habitat orientation group is analyzed that accounted for most of the Clingers and Burrowers, from upstream to downstream toward the higher the ratio of Clingers. Biological water quality assessment results were analyzed the worst state in the mixing station with an average 2.73 (${\pm}0.41$). Correspondence analysis, correlation analysis results of water temperature and the cold-water species, as the water temperature increases were analyzed by reducing cold-water species and EPT-group.

• Journal of the Korean earth science society
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• v.27 no.2
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• pp.159-176
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• 2006

Geographic factors and mathmatical location of the Korean Peninsula have great influences on the variation patterns and appearances over a period of ten days of summer precipitation. In order to clarify the influence of several climate factors on precise climate classification in the middle part region of the Korea, weather entropy and the information ratio were calculated on the basis of information theory and of the data of 25 site observations. The data used for this study are the daily precipitation phenomenon over a period of ten days of summer during the recent thirteen years (1991-2003) at the 25 stations in the middle part region of the Korea. It is divided into four classes of no rain, $0.1{\sim}10.0mm/day,\;10.1{\sim}30.0mm/day$, 30.1mm over/day. Their temporal and spatial change were also analyzed. The results are as follows: the maximum and minimum value of calculated weather entropy are 1.870 bits at Chuncheon in the latter ten days of July and 0.960 bits at Ganghwa during mid September, respectively. And weather entropy in each observation sites tends to be larger in the beginning of August and smaller towards the end of September. The largest and smallest values of weather representative ness based on information ratio were observed at Chungju in the beginning of June and at Deagwallyeong towards the end of July. However, the largest values of weather representativeness came out during the middle or later part of September when 15 sites were adopted as the center of weather forecasting. The representative core region of weather forecasting and climate classification in the middle part region of the Korea are inside of the triangle region of the Buyeo, Incheon, and Gangneung.