• Korean small business review
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• v.42 no.4
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• pp.251-283
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• 2020

The purpose of this study is to provide assistance to the establishment of related policies to improve the level of acceptance and use of smart factories for SMEs in Korea. To this end, the Unified Technology Acceptance Model (UTAUT) was extended to select additional factors that could affect the intention to accept technology, and to demonstrate this. To achieve the research objective, a questionnaire composed of 7-point Likert scales was prepared, and a survey was conducted for manufacturing-related companies. A total of 136 questionnaires were used for statistical processing. As a result of the hypothesis test, performance expectation and social influence had a positive (+) positive effect on voluntary use, but effort expectation and promotion conditions did not have a significant effect. As an extension factor, the network effect and organizational characteristics had a positive (+) effect, and the innovation resistance had a negative effect (-), but the perceived risk had no significant effect. When the size of the company is large, the perceived risk and innovation resistance are low, and the level of influencing factors for veterinary intentions, veterinary intentions, and veterinary behaviors are excluded. Through this study, factors that could have a positive and negative effect on the adoption (reduction) of smart factory-related technologies were identified and factors to be improved and factors to be reduced were suggested. As a result, this study suggests that smart factory-related technologies should be accepted.

• Korean Journal of Radiology
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• v.24 no.10
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• pp.1028-1037
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• 2023

Objective: To evaluate the computed tomography (CT) features for diagnosing metastatic cervical lymph nodes (LNs) in patients with differentiated thyroid cancer (DTC) and validate the CT-based risk stratification system suggested by the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) guidelines. Materials and Methods: A total of 463 LNs from 399 patients with DTC who underwent preoperative CT staging and ultrasound-guided fine-needle aspiration were included. The following CT features for each LN were evaluated: absence of hilum, cystic changes, calcification, strong enhancement, and heterogeneous enhancement. Multivariable logistic regression analysis was performed to identify independent CT features associated with metastatic LNs, and their diagnostic performances were evaluated. LNs were classified into probably benign, indeterminate, and suspicious categories according to the K-TIRADS and the modified LN classification proposed in our study. The diagnostic performance of both classification systems was compared using the exact McNemar and Kosinski tests. Results: The absence of hilum (odds ratio [OR], 4.859; 95% confidence interval [CI], 1.593-14.823; P = 0.005), strong enhancement (OR, 28.755; 95% CI, 12.719-65.007; P < 0.001), and cystic changes (OR, 46.157; 95% CI, 5.07-420.234; P = 0.001) were independently associated with metastatic LNs. All LNs showing calcification were diagnosed as metastases. Heterogeneous enhancement did not show a significant independent association with metastatic LNs. Strong enhancement, calcification, and cystic changes showed moderate to high specificity (70.1%-100%) and positive predictive value (PPV) (91.8%-100%). The absence of the hilum showed high sensitivity (97.8%) but low specificity (34.0%). The modified LN classification, which excluded heterogeneous enhancement from the K-TIRADS, demonstrated higher specificity (70.1% vs. 62.9%, P = 0.016) and PPV (92.5% vs. 90.9%, P = 0.011) than the K-TIRADS. Conclusion: Excluding heterogeneous enhancement as a suspicious feature resulted in a higher specificity and PPV for diagnosing metastatic LNs than the K-TIRADS. Our research results may provide a basis for revising the LN classification in future guidelines.

• Korean Journal of Radiology
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• v.21 no.11
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• pp.1256-1264
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• 2020

Objective: Lung segmentation using volumetric quantitative computed tomography (CT) analysis may help predict outcomes of patients with coronavirus disease (COVID-19). The aim of this study was to investigate the relationship between CT volumetric quantitative analysis and prognosis in patients with COVID-19. Materials and Methods: CT images from patients diagnosed with COVID-19 from February 18 to April 15, 2020 were retrospectively analyzed. CT with a negative finding, failure of quantitative analysis, or poor image quality was excluded. CT volumetric quantitative analysis was performed by automated volumetric methods. Patients were stratified into two risk groups according to CURB-65: mild (score of 0-1) and severe (2-5) pneumonia. Outcomes were evaluated according to the critical event-free survival (CEFS). The critical events were defined as mechanical ventilator care, ICU admission, or death. Multivariable Cox proportional hazards analyses were used to evaluate the relationship between the variables and prognosis. Results: Eighty-two patients (mean age, 63.1 ± 14.5 years; 42 females) were included. In the total cohort, male sex (hazard ratio [HR], 9.264; 95% confidence interval [CI], 2.021-42.457; p = 0.004), C-reactive protein (CRP) (HR, 1.080 per mg/dL; 95% CI, 1.010-1.156; p = 0.025), and COVID-affected lung proportion (CALP) (HR, 1.067 per percentage; 95% CI, 1.033-1.101; p < 0.001) were significantly associated with CEFS. CRP (HR, 1.164 per mg/dL; 95% CI, 1.006-1.347; p = 0.041) was independently associated with CEFS in the mild pneumonia group (n = 54). Normally aerated lung proportion (NALP) (HR, 0.872 per percentage; 95% CI, 0.794-0.957; p = 0.004) and NALP volume (NALPV) (HR, 1.002 per mL; 95% CI, 1.000-1.004; p = 0.019) were associated with a lower risk of critical events in the severe pneumonia group (n = 28). Conclusion: CRP in the mild pneumonia group; NALP and NALPV in the severe pneumonia group; and sex, CRP, and CALP in the total cohort were independently associated with CEFS in patients with COVID-19.

• Clinical and Experimental Pediatrics
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• v.52 no.10
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• pp.1153-1160
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• 2009

Purpose:To evaluate the risk factors for mortality and prognostic factors in pediatric hemato-oncology patients admitted to the pediatric intensive care unit (PICU). Methods:We retrospectively reviewed the medical records of pediatric hemato-oncology patients admitted at the PICU of the Asan Medical Center between September 2005 and July 2008. Patients admitted at the PICU for perioperative or terminal care were excluded. Results:Total 88 patients were analyzed. Overall ICU mortality rate was 34.1%. Mean age at PICU admission was $7.0{\pm}5.7$ years and mean duration of PICU stay was $18.1{\pm}22.2$ days. Hematologic diseases contributed to 77.3% of all the primary diagnoses, and the primary cause of admission was respiratory failure (39.8%). The factors related to increased mortality were C-reactive protein level (P<0.01), ventilation or dialysis requirement (P<0.01), and hematopoietic stem cell transplantation (P<0.05). In all, 3 scoring systems were investigated [Number of Organ System Failures (OSF number), the Pediatric Risk of Mortality III (PRISM III) score, and the Sequential Organ Failure Assessment (SOFA) score]; higher score correlated with worse outcome (P<0.01). The Oncological Pediatric Risk of Mortality (O-PRISM) scores of the 21 patients who had received hematopoietic stem cell transplantation were higher among the non-survivors, but not statistically significant (P=0.203). Conclusion:The PRISM III and SOFA scores obtained within 24 hours of PICU admission were found to be useful as early mortality predictors. The highest OSF number during the PICU stay was closely related to poor outcome.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.1
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• pp.225-285
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• 2017

In regard to the regulations related to the RPA(Remotely Piloted Aircraft), which is sometimes called in other countries as UA(Unmanned Aircraft), ICAO stipulates the regulations in the 'RPAS manual (2015)' in detail based on the 'Chicago Convention' in 1944, and enacts provisions for the Rules of UAS or RPAS. Other contries stipulates them such as the Federal Airline Rules (14 CFR), Public Law (112-95) in the United States, the Air Transport Act, Air Transport Order, Air Transport Authorization Order (through revision in "Regulations to operating Rules on unmanned aerial System") based on EASA Regulation (EC) No.216/2008 in the case of unmanned aircaft under 150kg in Germany, and Civil Aviation Act (CAA 1998), Civil Aviation Act 101 (CASR Part 101) in Australia. Commonly, these laws exclude the model aircraft for leisure purpose and require pilots on the ground, not onboard aricraft, capable of controlling RPA. The laws also require that all managements necessary to operate RPA and pilots safely and efficiently under the structure of the unmanned aircraft system within the scope of the regulations. Each country classifies the RPA as an aircraft less than 25kg. Australia and Germany further break down the RPA at a lower weight. ICAO stipulates all general aviation operations, including commercial operation, in accordance with Annex 6 of the Chicago Convention, and it also applies to RPAs operations. However, passenger transportation using RPAs is excluded. If the operational scope of the RPAs includes the airspace of another country, the special permission of the relevant country shall be required 7 days before the flight date with detail flight plan submitted. In accordance with Federal Aviation Regulation 107 in the United States, a small non-leisure RPA may be operated within line-of-sight of a responsible navigator or observer during the day in the speed range up to 161 km/hr (87 knots) and to the height up to 122 m (400 ft) from surface or water. RPA must yield flight path to other aircraft, and is prohibited to load dangerous materials or to operate more than two RPAs at the same time. In Germany, the regulations on UAS except for leisure and sports provide duty to avoidance of airborne collisions and other provisions related to ground safety and individual privacy. Although commercial UAS of 5 kg or less can be freely operated without approval by relaxing the existing regulatory requirements, all the UAS regardless of the weight must be operated below an altitude of 100 meters with continuous monitoring and pilot control. Australia was the first country to regulate unmanned aircraft in 2001, and its regulations have impacts on the unmanned aircraft laws of ICAO, FAA, and EASA. In order to improve the utiliity of unmanned aircraft which is considered to be low risk, the regulation conditions were relaxed through the revision in 2016 by adding the concept "Excluded RPA". In the case of excluded RPA, it can be operated without special permission even for commercial purpose. Furthermore, disscussions on a new standard manual is being conducted for further flexibility of the current regulations.

• Journal of Chest Surgery
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• v.35 no.4
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• pp.261-266
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• 2002

In an attempt to avoid the adverse effects of the cardiopulmonary bypass, off pump coronary artery bypass grafting(Off pump CABG) that has recently been rediscovered and refined. We compared the preoperative risk factors and in-hospital outcomes of patients done Off pump with those done On pump CABG. Material na Method: One hundred seventy eight patients was underwent CABG between January 2001 and July 2001 12 patients whom underwent associated valvular or left ventricular volume reduction surgery were excluded in this study Data were collected for 52 Off pump CABG and 114 On pump CABG for patient and disease risk factors, extent of coronary disease, and in-hospital outcomes. Result: Off pump CABG and On pump CABG groups did not show any differences in their patient and disease risk factors, and extent of coronary disease. Off pump CABG group had significantly lower mean operation time(234 $\pm$ 37 min vs 290 $\pm$ 48 min, p<0.001), lower mean CK-MB level(10.1 $\pm$ 13.5 IU/L vs 33.1 $\pm$ 18.2 IU/L, p<0.001) and mean ventilation time(14.8 $\pm$ 3.5 hours vs 16.2 $\pm$ 4.9 hours, p=0.048) than On pump CABG groups. On pump CABG group had significantly more distal grafts(3.4 $\pm$ 0.9 vs 2.6 $\pm$ 0.8, p<0.001) than Off pump CABG groups. There were no operative mortality in two groups. Off pump) CABG and On pump CABG groups did not show any differences in their postoperative complications and outcomes including perioperative myocardial infarction, stroke, respiratory failure, renal failure, reoperation, the amount of bleeding, the need of intraaortic balloon pump, the need of inotropics, and the stay of intensive care unit and hospital. Two patients were converted to On pump CABG. Conclusion: This study showed that patients having Off pump CABG are not exposed to a greater risks of adverse outcomes and also provided evidence that patients having Off pump CABG have significantly lower operation time, CK-MB, ventilation time and less distal grafts. Although there may be potential benefits to Off pump CABG, further studies must be directed to determine those patients who would benefit from Off pump CABG.

• Journal of Gastric Cancer
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• v.5 no.4 s.20
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• pp.246-251
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• 2005

Purpose: Benign anastomotic stricture after an esophagojejunostomy using EEA stapler following a radical total gastrectomy is one of the most serious complications. The purpose of this study is to evaluate the incidence risk factors, and treatment associated with benign stricture. Materials and Methods: From March 1998 to February 2001, 436 patients underwent an esophagojejunostomy with Roux-en-Y anastomosis using an EEA stapler followed by an endoscopy. Thirty three of the 436 patients(5.5%) developed an anastomotic stricture; included 24 of the 33 patients had a benign stricture. Nine patients with a malignant stricture were excluded. Results: The median age of the 436 patients was 57 years $(23{\sim}85\;years)$. Two hundred ninety two patients were male, and 144 patients were female. The median time to diagnosing the stricture was 1.5 months $(0.5{\sim}6months)$. There was no statistical significance in any of the risk factors, including the diameter of the stapling device, the status of adjuvant treatment, the status of reflux esophagitis, and a clinical history of diabetes and hypertension. The strictured patients were treated with balloon dilatation, one to three times, with symptom relief. Conclusion: There were no statistically significant risk factors. However, further study of the vascularity of anastomoses and benign strictures needs to be considered. In the anastomotic strictured patients endoscopic balloon dilatation appeared to be the first line of treatment.

• Radiation Oncology Journal
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• v.26 no.1
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• pp.1-9
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• 2008

Purpose: To evaluate the impact of postoperative radiotherapy on loco-regional failure in patients with vulvar carcinoma and to determine the treatment strategy for inguinal lymph nodes. Materials and Methods: Sixty-six patients who received treatment for primary vulvar carcinoma at Seoul National University Hospital, from October 1979 through June 2004, were retrospectively analyzed. Sixteen patients were excluded from the analysis due to the following reasons: distant metastases in two patients; palliative intent for six patients; previous radiotherapy given to the pelvis in three patients; follow-up loss after surgery for four patient; insufficient medical records for one patient. Of 50 eligible patients, 35 were treated with surgery alone(S), ten were treated with surgery followed by radiotherapy(S+RT), and five were treated with radiotherapy alone. Results: The 5-year overall survival(OS) and disease-free survival(DFS) rates of all patients were 91% and 78%, respectively. Twelve patients(26%) experienced treatment failures and the sites of initial failure were as follows: a primary site in eight patients; regional lymph nodes in three patients; the lung in one patient. Although risk factors for failure were more common in the S+RT group than the S group of patients(p<0.05), the DFS rates were similar for the two groups(5-year DFS rates, 78% vs. 83%, p=0.66). The incidences of occult lymph node metastases was 10%. Ten of 31 patients with clinically negative lymph nodes did not received inguinal lymph node dissection, but no patient experienced regional failure. Conclusion: Postoperative radiotherapy may have a potential benefit for patients with risk factors for failure. The omission of inguinal dissection or elective radiotherapy to the inguinal lymph nodes may be considered in low-risk patients with clinically negative lymph nodes.

• Journal of Environmental Policy
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• v.4 no.1
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• pp.39-67
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• 2005

In order to properly define the terms such as soil, soil contamination, soil contamination site and remediation, which are the key terms under the Soil Environment Conservation Act(SECA) in Korea, we analyzed the legal definitions of the similar key words in legislations of the developed western countries. The selected countries were the United States of America, the United Kingdom, the Netherlands, Germany, and Denmark. The legal definitions of these keywords were very much diversified due to different levels of soil contamination, as well as different industrial, social, and legal backgrounds in each country. However, fair suggestions for definitions of the key terms in SECA were derived from the comparative analyses of these countries. First and foremost, SECA should provide a definition of 'soil' which includes a concept of the natural soil layer produced from soil mineralization processes. Groundwater and sublayer of the groundwater would. be excluded in the boundary of the soil with regards to the Groundwater Act of Korea. Definition of 'soil contamination' of SECA should include a concept of risk assessment(soil contaminants, pathway, and receptors), purpose of land use, and the acquired limitation levels of soil contaminants. Soil contamination activity either industrial or anthropogenic in SECA article2-1, could be substituted for a concept of soil risk assessment. Definition of 'soil contamination site' could derive from amalgamating the concepts of i) soil contamination in conjunction with contaminants, ii) risk assessment, iii) a concept of land use, and iv) knowing limitation of contamination site designation. Definition of 'remediation of contaminated site' should include the objective, intention, action, methodology and limit of the remediation. These suggested definitions would increase the efficacy of soil environment conservation policies, which includes the survey of the potentially contaminated area, remediation, and removal of the site.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.7-19
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• 2012

After having announced legislation for threatened or endangered species on the List of Endangered and Threatened Wildlife and Plants in 2005, the Korea Ministry of Environment proposed (in June 2011) amending the list, thereby delisting or reclassifying endangered species using new quantitative criteria for two levels (I and II), as well as status reviews. The new legislation included 40 species remained in their original endangered status, but 19 species were delisted, 5 species were proposed as candidates for delisting, 29 species were given a new endangered listing, and 3 species were proposed for an endangered listing in Korea. We assessed the threatened status of 98 plants using the IUCN Red List Criteria (version 3.1) at the global level, and compared the Ministry's revised criteria with the IUCN Red List Criteria and ESA criteria used in the USA. Most species proposed by the Ministry do not qualify as threatened and one of the major difficulties found in applying IUCN Red List Criteria at the global scale was a lack of knowledge on the status of species at broader geographic scales and the perceived difficulty this causes. Under the current classification process, many endangered species, such as Abeliophyllum distichum, Leontice microrhyncha, Echinosophora koreensis, Leontopodium coreanum, Iris odaesanensis, and Corylopsis coreana at global level were excluded here. Knowledge gaps and uncertainties mean that the number of taxa at high risk of extinction may be substantially greater than is currently understood. Due to a lack of information on its taxonomic status, currently there is controversy over the Red List status of Physocarpus insularis. Also, Caragana koreana, which was an invalidly published name, should be excluded here. Although the Korea Ministry of Environment insisted this procedure was conducted by applying the modified IUCN threat categories and definitions, this evaluation has been carried out based only on subjective views and misapplication of the IUCN Red List Criteria. The current listings by the Korea Ministry of Environment should be challenged. We suggest that broad species concepts on endemic species are applied and also criteria that adequately address the proper quantitative knowledge should be used. It is suggested that the highest priorities for the Red List should be given to endemic species at least in the Korean peninsula first at global scale.