• Journal of the Korea Society for Simulation
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• v.30 no.3
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• pp.11-17
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• 2021

The 30mm anti-aircraft gun has been developed with various types of weapon systems such as protective, protective complex, and wheel-type anti-aircraft artillery. The role of this anti-aircraft gun is an important anti-aircraft weapon in charge of air defense. Anti-aircraft weapons are tasked with defending the airspace from aircraft attacks. In particular, anti-aircraft weapons are organized in combination with mechanized units. And anti-aircraft weapons are prone to attack by enemies because they operate on the front lines of the battlefield. The enemy is expected to attack our troops by covering up or concealing as much as possible in order to increase their viability. Therefore, this study analyzed whether our 30mm anti-aircraft bullets could subdue the enemy in cover. This study analyzed the performance of 30mm anti-aircraft bullets using the M&S technique. For this study, live shooting and simulation method by M&S were used for the experiment. In this study, steel plate and plywood were used for the live shooting experiment. In addition, in the simulation process through M&S, this study used the PRODAS model, AUTODYN model, and Split-x model to analyze the trajectory, penetration, and fragmentation capability of 30mm anti-aircraft bullets. According to the experimental results, it has been proven that 30mm anti-aircraft bullets can destroy enemy armored vehicles. 30mm anti-aircraft bullets succeeded in quickly subduing enemies concealed in general buildings or forests. In this way, it was possible to minimize damage to allies in advance.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.1
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• pp.59-71
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• 2019

In the rapidly changing industrial environment, the continuous increase in demand for entrepreneurship emphasizes the effective support of the government for the survival and growth of entrepreneurs and the necessity of establishing systematic initiative promotion policies. To this end, Of the total number of enterprises. The purpose of this study is to establish a new classification system for entrepreneurial industry that reflects the trend of entrepreneurship based on convergence technology that emerged during the 4th Industrial Revolution era in order to establish a systematic initiative upbringing policy. In this paper, we propose a new classification system for entrepreneurial ecosystem by using Delphi technique. As a result of the study, the categories of entrepreneurial industry are classified into technology entrepreneurship and general entrepreneurship. Technology entrepreneurship is divided into ICT services, ICT manufacturing, general manufacturing, cultural contents and biotechnology. The results of this study suggest a meaningful implication in the establishment of effective policies to support entrepreneurship in the future by establishing new standards of industry classification system of entrepreneurs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.918-923
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• 2018

The main function of a fuel tank is to store fuel. On the other hand, the structural soundness of the fuel tank is related directly to the survival of the crew in an emergency situation, such as an aircraft crash, and the relevant performance is demonstrated by a crash impact test. Because crash impact tests have a high risk of failure due to the high impact loads, various efforts have been made to minimize the possibility of trial and error in the actual test at the beginning of the design. Numerical analysis performed before the actual test is a part of such efforts. For the results of numerical analysis to be reflected in the design, however, the reliability of numerical analysis needs to be ensured. In this study, the results of numerical analysis and actual test data were compared to ensure the reliability of numerical analysis for the crash impact test of a rotorcraft fuel tank. For the numerical analysis of a crash impact test, LS-DYNA, crash analysis software, was used and the ALE (arbitrary Lagrangian Eulerian) technique was applied as the analysis method. To obtain actual test data, strain gages were installed on the metal fittings of the fuel tank and linked to the data acquisition equipment. The strain and stress of the fuel tank fitting were calculated by numerical analysis. The reliability of the numerical analysis was enhanced by assessing the error between the strain measurement of the upper fitting obtained from an actual fuel tank and the strain calculated from numerical analysis.

• Journal of Chest Surgery
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• v.54 no.2
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• pp.106-116
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• 2021

Background: We evaluated the mid-term outcomes and angiographic patency of redo coronary artery bypass grafting (CABG). Methods: Of 2,851 patients who underwent isolated CABG at Seoul National University Hospital from 2000 to 2017, 88 underwent redo CABG. Patients' mean age at redo CABG was 66.0±8.0 years. The mean interval between the first-time and redo CABG was 113.0±62.4 months. The mean follow-up duration was 86 months. Early and mid-term clinical outcomes were evaluated. Angiographic patency rates were evaluated early (1-2 days), 1 year, and 5 years after surgery. Comparative analyses between on-pump and off-pump CABG were also performed. Results: The culprits for reoperation were previous grafts (65.6%), native coronary vessels (17.8%), and both (16.7%). Off-pump CABG was performed in 75 cases (85.2%), and the mean number of distal anastomoses was 1.8±0.8. The saphenous vein (39.7%) was used most frequently, followed by the right internal thoracic artery (28.4%), right gastroepiploic artery (21.3%), left internal thoracic artery (7.8%), and radial artery (2.8%). Operative mortality was 1.1%. The overall survival, cumulative incidence of cardiac death, and cumulative incidence of major adverse cardiac events were 71.3%,12.0%, and 23.3% at 5 years after surgery, respectively. The overall angiographic patency rates were 95.7%, 90.1%, and 92.2% on early, 1-year, and 5-year angiograms, respectively. The angiographic patency rates of saphenous vein grafts were 93.1%, 85.6%, and 91.3% on early, 1-year, and 5-year angiograms, respectively. No significant differences in clinical outcomes or angiographic patency rates were observed between the on-pump (n=13) versus off-pump (n=75) groups. Multivariable analysis revealed that age (hazard ratio [HR], 1.07; p=0.005) and chronic kidney disease (HR, 3.85; p=0.001) were risk factors for all-cause mortality. Conclusion: Redo CABG could mostly be performed using the off-pump technique and did not show increased operative mortality and morbidities.

• Journal of Advanced Navigation Technology
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• v.26 no.5
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• pp.304-311
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• 2022

Although the SEAD(suppression to enemy air defenses) mission is a strategically important task in modern warfare, the high risk of direct exposure to enemy air defense assets forces to use of unmanned aerial vehicles. this paper proposes a path planning algorithm for SEAD mission for an unmanned aerial vehicle and a method for calculating the mission effectiveness on the planned path. Based on the RRT-based path planning algorithm, a low-altitude ingress/egress flight path that can consider the enemy's short-range air defense threat was generated. The Dubins path-based Intercept path planning technique was used to generate a path that is the shortest path while avoiding the enemy's short-range anti-aircraft threat as much as possible. The ingress/intercept/egress paths were connected in order. In addition, mission effectiveness consisting of fuel consumption, the survival probability, the time required to perform the mission, and the target destruction probability was calculated based on the generated path. The proposed techniques were verified through a scenario.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.1
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• pp.16-28
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• 2023

Lung adenocarcinoma accounts for about 40% of all lung cancers. With the recent development of gene profiling technology, studies on mutations in oncogenes and tumor suppressor genes, which are important for the development and growth of tumors, have been actively conducted. Companion diagnosis using next-generation sequencing helps improve survival with targeted therapy. In this study, formalin-fixed paraffin-embedded tissues of non-small cell lung cancer patients were subjected to hematoxylin and eosin staining for detecting genetic mutations that induce lung adenocarcinoma in Koreans. Immunohistochemical staining was also performed to accurately classify lung adenocarcinoma tissues. Based on the results, next-generation sequencing was applied to analyze the types and patterns of genetic mutations, and the association with smoking was established as the most representative cause of lung cancer. Results of next-generation sequencing analysis confirmed the single nucleotide variations, copy number variations, and gene rearrangements. In order to validate the reliability of next-generation sequencing, we additionally performed the existing genetic testing methods (polymerase chain reaction-epidermal growth factor receptor, immunohistochemistry-anaplastic lymphoma kinase (D5F3), and fluorescence in situ hybridiation-receptor tyrosine kinase 1 tests) to confirm the concordance rates with the next-generation sequencing test results. This study demonstrates that next-generation sequencing of lung adenocarcinoma patients simultaneously identifies mutation.

• Knowledge Management Research
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• v.24 no.3
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• pp.217-237
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• 2023

Recently, in the face of successive and unexpected global economic risks, ESG(Environmental, Social, and Governance) management has risen as an essential survival strategy for businesses. Particularly, the supply chain disruptions due to the COVID-19 pandemic have added to the uncertainty of risks, heightening the importance of ESG management in the distribution industry. In this context, the role of blockchain technology in strengthening and managing the connection between the distribution industry and ESG management has become increasingly significant. While there have been extensive proposals for business models that integrate blockchain technology into distribution, few studies have specifically focused on the feasibility and effectiveness of applying blockchain to ESG management in this field. Therefore, this study analyzed the relationship between blockchain and ESG management in the distribution industry by employing association analysis, a text mining technique, on Korean academic research. Through this, the study confirmed the possibility of implementing blockchain in the distribution industry's ESG management and presented keywords to guide future research directions. The findings obtained from this study are expected to be utilized as foundational research for future studies in constructing blockchain-based business models for ESG management in the distribution industry.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.28 no.1
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• pp.59-69
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• 2024

Backgrounds/Aims: Pancreaticoduodenectomy (PD) is the only radical treatment for periampullary malignancies. Superior mesenteric artery (SMA) first approach combined with total meso-pancreas (MP) excision was conducted to improve the oncological results. There has not been any previous research of a technique that combines the SMA first approach and total MP excision with a detailed description of the MP macroscopical shape. Methods: We prospectively assessed 77 patients with periampullary malignancies between October 2020 and March 2022 (18 months). All patients had undergone PD with SMA first approach combined total MP excision. The perioperative indications, clinical data, intra-operative index, R0 resection rate of postoperative pathological specimens (especially mesopancreatic margin), postoperative complications, and follow-up results were evaluated. Results: The median operative time was 289.6 min (178-540 min), the median intraoperative blood loss was 209 mL (30-1,600 mL). Microscopically, there were 19 (24.7%) cases with metastatic MP, and five cases (6.5%) with R1-resection of the MP. The number of lymph nodes (LNs) harvested and metastatic LNs were 27.2 (maximum was 74) and 1.8 (maximum was 16), respectively. Some (46.8%) patients had pancreatic fistula, but mostly in grade A, with 7 patients (9.1%) who required re-operations. Some 18.2% of cases developed postoperative refractory diarrhea. The rate of in-hospital mortality was 1.3%. Conclusions: The PD with SMA first approach combined TMpE for periampullary malignancies was effective in achieving superior oncological statistics (rate of MP R0-resection and number of total resected LNs) with non-inferior short-term outcomes. It is necessary to evaluate survival outcomes with long-term follow-up.

• Journal of Chest Surgery
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• v.39 no.1 s.258
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• pp.28-34
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• 2006

Background: There has been an increase in the number of elderly patients considered for coronary artery bypass grafting (CABG). Recently, there were many satisfactory reports of coronary artery bypass grafting (CABG) in old age due to the development in operative technique and postoperative management. We evaluated operative and follow-up results of patients 70 years of age and older compared to 60 years old. Material and Method: We retrospectively studied the cases of 74 consecutive patients 70 years or older (group A) who underwent a elective CABG from January 2000 to December 2003 and compared that of relatively young age group (group B, 60-69 years old). We compared preoperative characteristics, operation technique, postoperative results that effect outcome, also we investigated late mortality and cardiac events at follow-up periods. Result: Preoperative demographic and clinical characteristics of two groups were not different, except preoperative renal dysfunction(serum creatinine: $\geq$1.4 mg/dl) (group A 17, 23$\%$ vs group B 14, 9$\%$) (p=0.024). There was no difference of the mean number of distal anastomosis and the left ventricular ejection fraction in group A decreased significantly from 53.7$\pm$13$\%$ preoperatively to 49.9$\pm$ 12$\%$ postoperatively (p=0.02), but not changed in group B. There was no difference at operative mortality rate and postoperative major morbidity rate, but wound problem of saphenous vein harvest site was significantly higher in group A than group B (6.8$\%$ vs 0.7$\%$, p=0.02). The mean follow up duration was 24.3$\pm$13 months and the cumulative survival were 95.4$\%$ at 2 year and 79.9$\%$ at 4 year in group A and 95.4$\%$ at 2 year and 90.1$\%$ at 4 year in group B (p=ns). Conclusion: We conclude that age is not a factor of determination when we decide about operation because coronary artery bypass grafting in elderly more than 70 years old can be performed with a low mortality rate and acceptable morbidity rate.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.345-359
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• 2006

Loss of maxillary molar teeth leads to rapid loss of crestal bone and inferior expansion of the maxillary sinus floor (secondary pneumatization). Rehabilitation of the site with osseointegrated dental implants often represents a clinical challenge because of the insufficient bone volume resulted from this phenomenon. Boyne & James proposed the classic procedure for maxillary sinus floor elevation entails preparation of a trap door including the Schneiderian membrane in the lateral sinus wall. Summers proposed another non-invasive method using a set of osteotome and the osteotome sinus floor elevation (OSFE) was proposed for implant sites with at least 5-6mm of bone between the alveolar crest and the maxillary sinus floor. The change of grafted material in maxillary sinus is important for implant survival and the evaluation of graft height after maxillary sinus floor elevation is composed of histologic evaluation and radiomorphometric evaluation. The aim of the present study was radiographically evaluate the graft height change after maxillary sinus floor elevation and the influence of the graft material type in height change and the bone remodeling of grafts in sinus. A total of 59 patients (28 in lateral approach and 31 in crestal approach) who underwent maxillary sinus floor elevation composed of lateral approach and crestal approach were radiographically followed for up to about 48 months. Change in sinusgraft height were calculated with respect to implant length (IL) and grafted sinus height(BL). It was evaluated the change of the graft height according to time, the influence of the approach technique (staged approach and simultaneous approach) in lateral approach to change of the graft height, and the influence of the type of graft materials to change of the graft height. Patients were divided into three class based on the height of the grafted sinus floor relative to the implant apex and evaluated the proportion change of that class (Class I, in which the grafted sinus floor was above the implant apex; Class II, in which the implant apex was level with the grafted sinus floor; and Class III, in which the grafted sinus floor was below the implant apex). And it was evaluated th bone remodeling in sinus during 12 months using SGRl(by $Br\ddot{a}gger$ et al). The result was like that; Sinus graft height decreased significantly in both lateral approach and crestal approach in first 12 months (p$MBCP^{TM}$ had minimum height loss. Class III and Class II was increased by time in both lateral and crestal approach and Class I was decreased by time. SGRI was increased statistically significantly from baseline to 3 months and 3 months(p<0.05) to 12 months(p$ICB^{(R)}$ single use, more reduction of sinusgraft height was appeared. Therefore we speculated that the mixture of graft materials is preferable as a reduction of graft materials. Increasing of the SGRI as time goes by explains the stability of implant, but additional histologic or computed tomographic study will be needed for accurate conclusion. From the radiographic evaluation, we come to know that placement of dental implant with sinus floor elevation is an effective procedure in atrophic maxillary reconstruction.