• KIPS Transactions on Computer and Communication Systems
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• v.4 no.4
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• pp.135-140
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• 2015

The WDSS improves defensive capacity against web application layer DDoS attack by using web cache server and L7 switch which are added on the DDoS shelter system. When web DDoS attack occurs, security agents divert traffic from backbone network to sub-network of the WDSS and then DDoS protection device and L7 switch block abnormal packets. In the meantime, web cache server responds only to requests of normal clients and maintains stable web service. In this way, the WDSS can counteract the web DDoS attack which generates small traffic and depletes server-client session resource. Furthermore, the WDSS does not require IP tunneling because it is not necessary to retransfer the normal requests to original web server. In this paper, we validate operation of the WDSS and verify defensive capability against web application layer DDoS attacks. In order to do this, we built the WDSS on backbone network of an ISP. And we performed web DDoS tests by using a testing system that consists of zombie PCs. The tests were performed by three types and various amounts of web DDoS attacks. Test results suggest that the WDSS can detect small traffic of the web DDoS attacks which do not have repeat flow whereas the formal DDoS shelter system cannot.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.10
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• pp.473-478
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• 2017

Drones require altitude holding in order to achieve flight objectives. The altitude holding of the drone is to repeat the operation of raising or lowering the drone according to the altitude information being measured in real-time. When the drones are maintained altitude, the drone's altitude will continue to change due to external factors such as imbalance in thrust due to difference in motor speed or wind. Therefore, in order to maintain the altitude of drone, we have to exactly measure the continuously changing altitude of the drone. Generally, the acceleration sensor is used for measuring the height of the drones. In this method, there is a problem that the measured value due to the integration error accumulates, and the drone's vibration is recognized by the altitude change. To solve the difficulty of the altitude measurement, commercial drones and existing studies are used for altitude measurement together with acceleration sensors by adding other sensors. However, most of the additional sensors have a limitation on the measurement distance and when the sensors are used together, the calculation processing of the sensor values increases and the altitude measurement speed is delayed. Therefore, it is necessary to accurately measure the altitude of the drone without considering additional sensors or devices. In this paper, we propose a measurement algorithm that improves general altitude measurement method using acceleration sensor and show that accuracy of altitude holding and altitude measurement is improved as a result of applying this algorithm.

• The Southeast Asian review
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• v.28 no.2
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• pp.181-212
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• 2018

In 2017, the government of Duterte, in the second year of the ruling, more strongly promoted peace and order policies and expressed independent diplomacy as the chairman of ASEAN. He continued to fight against drugs and tried to increase his political legitimacy through the punishment for corrupt officials. He also declared martial law in the Mindanao region because of the dissolution of the Maute group, a Muslim terrorist organization, and strengthened counterterrorism cooperation externally. In addition, as to Communist militants, he took the initial reconciliation gesture and promoted peace negotiations, however, concluded the peace tide and started the suppression operation due to a series of bloodshed. He still has a strong drive in peace and order issues, backed up by high support rate, but it is becoming a factor of anxiety as the socioeconomically underprivileged and minority groups are increasingly alienated. As the chairman of ASEAN, Duterte has a certain distance from the United States, which is a firm ally, but has turned to increase familiarity with China and Russia, which can take substantial economic benefits. Through diversifying the external economic support and increase of tax revenue, the priority task was to establish the infrastructure. Although the Philippines, which has a high economic growth rate, has a strong expectation that it can establish a solid infrastructure, tax reforms should be successfully completed in order not to repeat the previous failures, which has traditionally increased foreign debt burden by relying on external resources. It seems that it is necessary to find the meeting point of the foreign policy of Duterte and new Korean government's New Southern Policy, and to find possible economic cooperation policies to improve Philippine infrastructure.

• Journal of Korea Entertainment Industry Association
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• v.14 no.7
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• pp.397-408
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• 2020

This study conducted a focus group interview with 15 college freshman from J college to find out their experiences in non-face-to-face lectures with COVID-19. The contents of the interview were recorded and conducted, and the meaning was analyzed according to the focus group interview procedure through repeated listening. Components were 'Operation of non-face-to-face lectures in unprepared situations', 'Loss of orientation in lectures and departure from learning', 'One way listening', 'The convenience of taking a lectures'. The experience of 'Operating non-face-to-face lectures in unprepared situations' included the start of mixed non-face-to-face lectures, cumbersome and inconvenient online systems, and the demand for tuition refunds. The experience of 'Loss of orientation in lectures and departure from learning' has experienced difficulty in concentrating on lectures, Deficiency in the degree of recognition of learning content, and burden of assignments and exams. The experience of 'One way listening' has experienced lack of interaction between professors and learners and non reflection of liveliness in the field. Finally, participants experienced satisfaction with being able to lectures and repeat lectures at anytime and anywhere they wanted with the convenience of taking lectures. Based on this study, participants called for improvements in the quality lecture contents and interaction between professors and learners, and it is thought that universities will need administrative and financial support and education design and system construction to construct high-quality lecture contents.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.350-354
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• 2009

Background: Complicated pleural space occupying lesions (SOL) have been treated by thoracentesis, closed thoracotomy drainage (CTD) or surgical intervention with using a video thoracosocpe or open thoracotomy depending on the extent of the disease. With the development of video assisted thoracoscopic surgery (VATS), VATS pleural adhesiolysis and decortication have revealed good results as compared to those for open thorcotomy. To assess the effectiveness of VATS pleural adhesiolysis and decortication, we retrospectively analyzed the medical record and radiologic findings of the patients with complicated pleural SOL and who were treated by this surgery. Material and Method: From May 1996 to April 2006, 64 patients (mean age: 41.8 years) with complicated pleural SOL underwent 65 VATS. To analyze the surgical outcome, we classified the postoperative findings on the simple chest X-rays into 4 classes as Class I: no or minimal pleural lesion, Class II: blunting of the cardiophrenic angle and mild pleural thickening, Class III: an elevated diaphgram or persistent lung collapse and Class IV: complicated or recurrent effusion. Result: Before VATS, the patients underwent the diagnostic or therapeutic procedures: single or repeat diagnostic tapping for 41, thoracoscotomy drainage for 11, pigtail catheter drainage for 10 and intrapleural fibrinolytics for 10. The mean duration between the onset of symptom and surgery was 18.4 days. There was neither mortality nor severe complications. The surgical outcomes were class 1 for 28, class 2 for 13, class 3 for 19 and class 4 for 5. There were statistically significant differences between the symptom duration and the classes, and between the operation time and the classes. Conclusion: VATS pleural adhesiolysis and decortication are effective, safe treatments for managing complicated pleural SOL, and an earlier operation is needed for obtaining a better surgical outcome.

• Journal of Yeungnam Medical Science
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• v.3 no.1
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• pp.249-260
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• 1986

Recent reports have noted the increase of and questioned the justification for cesarean section rate in the past decade. This study was carried out retrospectively based on the clinical charts of 510 patients who had been performed cesarean section among 3,357 deliveries at Yeungnam University Hospital from May, 9, 1983 through Nov., 30, 1986. The results were as follows : 1. Overall incidence of cesarean section was 15.7% of total deliveries. Of these, 10.9% were by primary cesarean section and 4.7% by repeat operation. There has been a gradual increase in the cesarean section rate. 2. In the distribution of age, the 26-30 aged group was the most prevalent(60.2%). 3. The most common indications for cesarean section were previous cesarean section(30.2%), CPD (26.9%), Malpresentation(22.7%), and fetal distress(3.5%). In primipara, CPD was the most frequent and in multipara malpresentation. 4. A great proportion(31.6%) was done at 40th gestational week. 5. In the weight distribution of infants, the group of 3,000-3,499gm was the most prevalent(39.8%), premature baby was 9.1%, and giant baby was 5.6%. 6. In the type of operation, lower segment transverse cesarean section was the most(97.5%). 7. In the combined surgery, sterilization was the most prevalent and the next was ovarian cystectomy, hysterectomy, and myomectomy in order. 8. In the type of the anesthesia, general anesthesia was 83.5%. 9. Maternal morbidity was 14.7%. Among the causes of this morbidity, wound infection was the most and the next was urinary tract infection, fever of unknown origin, and atonic bleeding in order. 10. It was found that 18.4% was maternal morbidity in the patients below 10gm Hb. In this group, maternal morbidity was markedly increased as the level of Hb was decreased. 11. Maternal morbidity was increased as the duration of ruptured membrane was prolonged. In the group of over 24 hours after rupture of membrane, it was markedly increased(44.4%). 12. Maternal morbidity was increased as the duration of labor was prolonged. In the group of over 12 hours after the onset of labor, it was 24.6%. 13. Maternal morbity of lower segment transverse cesarean section was the least(14.1%). 14. Maternal morbidity of emergency cesarean section was about two times as much as elective cesarean section.

• Journal of Chest Surgery
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• v.43 no.4
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• pp.375-380
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• 2010

Background: Primary cardiac tumors are extremely rare. The most common type are benign myxomas, and these are almost completely curable with early surgery. Malignant tumors, however, such as sarcomas, are difficult to remove surgically, and their prognosis is known to be poor. In this study, data on patients who had undergone surgical treatment of cardiac tumor in the authors' hospital were collected and analyzed. Material and Method: The subjects included 28 patients who had undergone surgical treatment of cardiac tumor from August 1993 to December 2008. Their medical records were reviewed and retrospectively analyzed. Result: The patients were aged from 20 to 76 years (mean age: $54.2{\pm}15.6$), and 11 were male (39%) and 17 female (61%). Fifteen of them (54%) underwent emergency surgery to improve heart failure symptoms. The most common preoperative symptom was dyspnea (15 cases, 54%). Preoperative echocardiography was performed on all the patients. The average size of the tumor as measured during the operation was $7.0{\pm}6.9cm$ (the average length of the long axis was 2∼40 cm), and the sites of tumor attachment were the interatrial septum (18 cases, 64%), the left atrium (9 cases, 32%), the mitral valve annulus (2 cases, 7%), and the left ventricle (2 cases, 7%). The operation was performed with an incision through both atria in all the patients, and a complete excision was made in 25 cases (89%). According to the biopsy results, there were 4 cases of sarcoma (14%), 1 case of lipoma (4%), and 23 cases of myxoma (82%). The three cases in which the tumors were not completely excised were sarcomas. No operative deaths occurred after the operations. Outpatient follow-up was possible for 24 cases (86%), with a mean follow-up period of $46.8{\pm}42.7$ months. Late death occurred in 3 of the 24 patients; each of these patients had sarcomas. Of these patients, the first had undergone two repeat surgeries, the second had metastatic sites removed, and the last had only chemotherapy. The average recurrence time was $12.7{\pm}10.8$ months, and the average metastasis time was $20.5{\pm}16.8$ months. Conclusion: Most cardiac tumors are benign myxomas. In principle, they should be surgically treated because they can create risks such as embolism, and can be radically treated when surgically removed. In most cases, however, malignant sarcomas are already considerably advanced with severe infiltration into the neighboring tissues at the time of diagnosis. The surgical removal of malignant sarcomas is known to be difficult because of the advanced stage and degree of infiltration. We suggest that excision of the removable portion of the tumor sites to alleviate symptoms such as heart failure can improve quality of life.

• The Korean Journal of Archival Studies
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• no.17
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• pp.247-292
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• 2008

Investigations have been started to set the modern history and national spirit to rights after Commissions were established. Those Commissions are established and operated with time limit to finish its own missions. They creates three kinds of records as acquired materials which acquired or are donated for investigation; investigation records as investigation reports; and administrative records that created while supporting organization's operation. The Commissions use more past records to do special tasks asnation's slate clean and uncovering the truth than other agencies. In other words, the commissions take the most advantages of well-managed records, however, their record management environment and operation systems are relatively loose than other permanent machineries. It has three reasons that; first, there is no record management regulations and criteria for machineries that have time limit. This affected each commissions 'systems and 6 Truth Commissions' record management systems are built separately and on the different level; Second, members lack responsibility from frequent sending, reinstatement, change, and restructuring and that makes troubles to produce and manage records; Third, central archives pay less attention to machineries that operated limited period as the truth commissions. The Commissions rather need more systematic control because its records have historical value. To solve these problems, record management regulations have to be prepared first with features of organizations running limited time and commissions' records as acquired materials or investigation records. Furthermore, building up standard record management system for the Commissions, standardizing transfer data, imposing professional record personnel, and setting limits frequent personnel changes would finish practical problems. Besides, those records created to reveal the truth should use for education and research because Truth Commissions are established to set unfortunate history right and not to repeat it again. The records would serve as steppingstone for establishment of the Truth Record Center that does education, information work, publication, and research with the records. The record center would help using the records efficiently and improving knowledge for its people. And, the center should devote people to recognize importance of the records.

• Information Systems Review
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• v.21 no.4
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• pp.143-156
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• 2019

Types of innovation can be categorized into simplification, information, automation, and intelligence. Intelligence is the highest level of innovation, and RPA can be seen as one of intelligence. Robotic Process Automation(RPA), a software robot with artificial intelligence, is an example of intelligence that is suited for simple, repetitive, large-scale transaction processing tasks. The RPA, which is already in operation in many companies in Korea, shows what needs to be done to naturally focus on the core tasks in a situation where the need for a strong organizational culture is increasing and the emphasis is on voluntary leadership, strong teamwork and execution, and a professional working culture. The introduction was considered naturally according to the need to find. Robotic Process Automation, or RPA, is a technology that replaces human tasks with the goal of quickly and efficiently handling structural tasks. RPA is implemented through software robots that mimic humans using software such as ERP systems or productivity tools. RPA robots are software installed on a computer and are called robots by the principle of operation. RPA is integrated throughout the IT system through the front end, unlike traditional software that communicates with other IT systems through the back end. In practice, this means that software robots use IT systems in the same way as humans, repeat the correct steps, and respond to events on the computer screen instead of communicating with the system's application programming interface(API). Designing software that mimics humans to communicate with other software can be less intuitive, but there are many advantages to this approach. First, you can integrate RPA with virtually any software you use, regardless of your openness to third-party applications. Many enterprise IT systems are proprietary because they do not have many common APIs, and their ability to communicate with other systems is severely limited, but RPA solves this problem. Second, RPA can be implemented in a very short time. Traditional software development methods, such as enterprise software integration, are relatively time consuming, but RPAs can be implemented in a relatively short period of two to four weeks. Third, automated processes through software robots can be easily modified by system users. While traditional approaches require advanced coding techniques to drastically modify how they work, RPA can be instructed by modifying relatively simple logical statements, or by modifying screen captures or graphical process charts of human-run processes. This makes RPA very versatile and flexible. This RPA is a good example of the application of digital to intelligence(D2I).

• Journal of Chest Surgery
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• v.43 no.6
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• pp.655-662
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• 2010

Background: Despite the rapid expansion of percutaneous endovascular repair, open surgical repair is still recognized as an option to achieve a cure. We retrospectively analyzed over a 6 year period the surgical outcomes, the complications and the mortality-related factors for patients with abdominal aortic aneurysms. Material and Method: We analyzed 36 patients who underwent surgery for abdominal aortic aneurysms between May 2001 and June 2005, and between April 2007 and November 2009. The indications for surgery were rupture, a maximal aortic diameter > 50 mm, and medically intractable hypertension or pain. Result: The mean patient age was $69.67{\pm}6.97$ years (range: 57 to 84 years). Thirty two patients (88.9%) were males and 4 patients (11.1%) were females. Extension to the iliac artery existed in 28 patients (77.8%). Thirteen patients (36.1%) had ruptured aortic aneurysms. The mean maximal diameter of the aorta was $73.7{\pm}13.3$ mm (60 to 100 mm). Surgery was performed by a midline laparotomy and 10 patients (27.8%) underwent emergency surgery. The mortality rate was 8.3%; the mortality rate for the patients with ruptured aneurysms was 23.1 % and the mortality rate for patients with unruptured aneurysms was 0%. The postoperative complications included wound infection (3 cases), sepsis (2 cases), renal failure (2 cases) and pneumonia (1 case). Unstable vital signs, pre-operative transfusion, ruptured aneurysm, emergency surgery, comorbidity (DM and syncope) and complications (sepsis and renal failure) were the statistically significant mortality-related factors (p < 0.05). Conclusion: Emergency surgery for ruptured aortic aneurysms continues to have high mortality, but the unruptured cases are repaired with relative safety. Even though endovascular aortic repair is the trend for abdominal aortic aneurysms, an elective operation of the unruptured aneurysms could decrease the procedure's morbidity and the inconvenient for repeat evaluation with good surgical results.