• Journal of Chest Surgery
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• v.18 no.4
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• pp.574-581
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• 1985

Surgical treatment for PDA has been pivotal in historical development of surgery for congenital heart disease. A clinical study on 36 cases of operated PDA were performed during period from Aug. 1981 to Jul. 1985 at the Department of Thoracic & Cardiovascular Surgery in Chonbuk University. The following results are obtained. 1. The 8 males and 28 females ranged in age from 2 yrs, to 24 yrs, [mean 11 yrs.] 2. Chief complaints of the patients were dyspnea on exertion in 61%, palpitation in 39%, frequent URI in 12%, and no subjective symptoms in 11%. 3. On auscultation, continuous machinery murmur heard in 94% and systolic in 14%. 4. Radiologic findings of chest P-A showed increased density of pulmonary vascularity in 94%, cardiomegaly in 69%, and within normal limits in 5% of the patients. 5. EKG findings of the patients revealed LVH in 69%, RVH in 6%, BVH in 6%, and within normal limits in 17%. 6. Of the 36 patients, cardiac catheterization was performed in 34 patients. The results showed mean Qp/Qs = 2.25, mean Pp/Ps=0.42, and mean systolic pulmonary arterial pressure=53mmHg. 7. Surgical methods were as followed: The 32 case of ductal ligation and one case of division & suture technique for PDA through the left posterolateral thoracotomy were done. And 2 cases of ductal ligation one suture closure through the pulmonary artery were performed under the cardiopulmonary bypass. 8. Intraoperative complication was ductal rupture with division 8< suture for PDA and transient hoarseness in 1, recanalization in 1, and urethral stricture in 1 case postoperatively. 9. One patient died due to ductal rupture intraoperatively and operative mortality was 2.8%.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.1
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• pp.205-214
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• 2019

Android uses app cache files to improve app execution performance. However, this optimization technique may raise security issues that need to be examined. In this paper, we present a practical design of "Android app cache manipulation attack" to intentionally modify the cache files of a target app, which can be misused for stealing personal information and performing malicious activities on target apps. Even though the Android framework uses a checksum-based integrity check to protect app cache files, we found that attackers can effectively bypass such checks via the modification of checksum of the target cache files. To demonstrate the feasibility of our attack design, we implemented an attack tool, and performed experiments with real-world Android apps. The experiment results show that 25 apps (86.2%) out of 29 are vulnerable to our attacks. To mitigate app cache manipulation attacks, we suggest two possible defense mechanisms: (1) checking the integrity of app cache files; and (2) applying anti-decompilation techniques.

• Journal of the Korea Convergence Society
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• v.10 no.10
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• pp.21-26
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• 2019

At present, it is indispensable to utilize data as an information society. Therefore, the database is used to manage large amounts of data. In real life, most of the data in a database is the personal information of a group of members. Because personal information is sensitive data, the role of the database administrator who manages personal information is important. However, there is a growing number of attacks on databases to use this personal information in a malicious way. SQL Injection is one of the most known and old hacking techniques. SQL Injection attacks are known as an easy technique, but countermeasures are easy, but a lot of efforts are made to avoid SQL attacks on web pages that require a lot of logins, but some sites are still vulnerable to SQL attacks. Therefore, this study suggests effective defense measures through analysis of SQL hacking technology cases and contributes to preventing web hacking and providing a secure information communication environment.

• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.127-134
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• 2020

Recently, Harmful sites, including pornographic videos, drugs, personal information and hacking tool distribution sites, have caused serious social problems. However, due to the nature of the Internet environment where anyone can use it freely, it is difficult to control the user effectively. And the site operator operates by changing the domain to bypass the blockage. Therefore, even once identified sites have low persistence. In this paper, we propose multi-channel domain tracking technology, a technique that can effectively track changes in the domain addresses of harmful sites, including the same or similar content, by tracking changes in these harmful sites. Proposed technology is a technology that can continuously track information in a domain using OSINT technology. We tested and verified that the proposed technology was effective for domain tracking with a 90.4% trace rate (sensing 66 changes out of 73 domains).

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.2
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• pp.171-179
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• 2022

Self-Modifying-Code is a code that changes the code by itself during execution time. This technique is particularly abused by malicious code to bypass static analysis. Therefor, in order to effectively detect such malicious codes, it is important to identify self-modifying-codes. In the meantime, Self-modify-codes have been analyzed using dynamic analysis methods, but this is time-consuming and costly. If static analysis can detect self-modifying-code it will be of great help to malicious code analysis. In this paper, we propose a static analysis method to detect self-modified code for binary executable programs converted to LLVM IR and apply this method by making a self-modifying-code benchmark. As a result of the experiment in this paper, the designed static analysis method was effective for the standardized LLVM IR program that was compiled and converted to the benchmark program. However, there was a limitation in that it was difficult to detect the self-modifying-code for the unstructured LLVM IR program in which the binary was lifted and transformed. To overcome this, we need an effective way to lift the binary code.

• Korean Journal of Hazardous Materials
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• v.2 no.1
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• pp.31-37
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• 2014

Since the unprecedented hydrogen fluoride leak accident in 2012, there has been growing demand for customized technical information for rapid response and chemical accident management agencies including the Ministry of Environment, the National Emergency Management Agency, and the National Police Agency need more information on chemicals and accident management. In this regard, this study aims to provide reliable technical data and guidelines to initial response agencies, similar to accident management technical reports of the US and Canada. In this study, we conducted a questionnaire survey and interviews on initial response agencies like fire stations, police stations, and local governments to identify new information items for appropriate initial response and improvements of current guidelines. We also collected and reviewed the Canada's TIPS, US EPA's hydrogen fluoride documents, domestic and foreign literature on applicability tests of control chemicals, and interview data, and then produced items to be listed in the technical guidelines. In addition, to establish database of on-site technical information, we carried out applicability tests for accident control data including ① emergency shut down devide, safety guard, shut down valve, ground connection, dyke, transfer pipe, scrubber, and sensor; ② literature and field survey on distribution type and transportation/storage characteristics (container identification, valve, ground connection, etc.); ③ classification and identification of storage/transportation facilities and emergency management methodslike leak prevention, chemicals control, and cutoff or bypass of rain drainage; ④ domestic/foreign analysis methods and environmental standards including portable detection methods, test standards, and exposure limits; and ⑤ comparison/evaluation of neutralization efficiency of control chemicals on toxic substances.

• Journal of Chest Surgery
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• v.30 no.3
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• pp.275-281
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• 1997

The radial artery as a graft for myocardial revascularization was introduced by Carpentier in the early 1970s. Mid-term results were unfortunately discoura ing, and the clinical experience with this graft was interrupted. At the end of the 1980s, these authors reproposed the same arterial conduit with more satisfying results, because of improved technique and pharmacological management of the graft. Between October 1994 and July 1995, 36 patients underwent myocardial revascularization with a radial artery graft in Seiong General Hospital. Left internal mammary artery was concomitantly used as a pedicled Vift in 34 patients. Fifteen patients (42%) had a complete arterial waft revascularization. A total of 12) distal anastomoses were performed (average 3.4 per patient), including 36 left internal mammary artery wafts (two sequential in 2 patients), and 23 saphenous vein grafts. The remaining 64 distal anastomoses were perFormed with radial artery grafts (mean 1.8 per patient). The radial arteries were anastomosed to the circumflex (n=38), diagonal (n= 18), right coronary(n=G), and left anterior descending coronary artery(n=2). The percent ge of radial artery graft anastomoses (64) to the total anastomoses(123) was 52%. The radial artery was used as a single graft in 10 patients, as a sequential graft in 25 patients, and two grafts in 1 patient. Twenty patients underwent associated procedures coronary endarterectomy (14), coronary artery patch angioplasty (4), mitral valve repair (1), and repair of ventricular septal rupture (1). One patient died of low cardiac output syndrome and the others had no perioperative myocardial infarction. There are no ischemic and functional complications in the arm or hand aftcr removal of the radial artery. Only 1 patient required reexploration of the am, for the hematoma evacuation, and 2 patients complained transient thumb dysesthesia of the side of the havested arm. This dysesthesia improved within one month. Postoperative angiovaphic controls were obtained in 11 patients(31%) postoperative 79 to 210 days (mean 126 days). The patency rate were as follows : left internal mammary artery (100%), saphcnous vein (100%), and radial artery(95%). We concluded that the radial artery is useful alternative graft, but long term clinical and angiographic studies are required to derterminc whether wider application is warranted.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.573-579
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• 2008

Background: Composite valve graft replacement is currently the treatment of choice for a wide variety of the lesions of aortic root disease. The purpose of this study was to explore the results of aortic root replacement after using the Cabrol technique over a 13-year period at our institution, and we analyzed the results to help surgeons make better decisions when repairing aortic root disease. Material and Method: Between January 1994 and December 2006, twenty-five patients underwent a Cabrol technique operation at our institution. The mean patient age was $43.7{\pm}14.1$ years old (range: $6{\sim}65$ years) and the male and female ratio was 21:4 (84% : 16%). The patients' follow-up was 100% complete, and the mean follow-up period was $60.7{\pm}50.4$ (range:$1{\sim}162$) months. Annuloaortic ectasia (n=18) was the most frequent cause of aortic disease in this series, followed by aortic dissection (n=7). The mean cardiopulmonary bypass time was $177.2{\pm}44.9$ minutes and the mean aortic cross clamping time was $123.4{\pm}34.1$ minutes. Nine patients were checked with MDCT (Multidetector computed tomography) for evaluating a well functioning secondary graft and the coronary anastomosis site. Result: The early mortality rate was 4% (1 of 25 patients). A significant stenosis, kinking or occlusion of the secondary graft was detected by MDCT in 4 patients. The overall survival rate was 88%. Conclusion: The Cabrol technique demonstrated a significant incidence of long-term complications such as secondary graft stenosis or obstruction. It could be used when the modified Bentall technique is not feasible.

• Journal of Chest Surgery
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• v.42 no.6
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• pp.710-718
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• 2009

Background: The Cox maze procedure has been used as a standard surgical treatment for atrial fibrillation for about 20 years. Recently, the creators have used a bipolar radiofrequency electrode (Cox maze IV procedure) instead of the incision and suture (cut-sew) technique to make atrial ablation lesions for persistent atrial fibrillation. We investigated clinical outcomes for the Cox maze procedure with a bipolar radiofrequency electrode and cryoablator in patients with persistent atrial fibrillation, and compared results with clinical outcomes of the cut-sew procedure. Material and Method: Between April 2005 and July 2007, 40 patients with persistent atrial fibrillation underwent Cox maze IV procedure with a bipolar radiofrequency electrode and cryoablator (bipolar radiofrequency group). Surgical outcomes were compared with those of 35 patients who had the cut-sew technique for the Cox maze III procedure. All patients had concomitant cardiac surgery. Postoperatively, the patients were followed up every 1 to 2 months. Result: At 6 months postoperatively, the conversion rate to regular sinus rhythm was not significantly different between the two groups: 95.0% for the bipolar radiofrequency ablation group; 97.1% for the cut-sew technique (p=1.0). At the end of the follow-up period, the conversion rate to regular sinus rhythm was also not significantly different (92.5% vs. 91.6%, p=1.0). In multivariate analysis using a Cox-regression model, the postoperative atrial dimension was an independent determinant of sinus conversion in the bipolar radiofrequency ablation group (hazard ratio 31, p=0.005). In the Cox-regression model for both groups, atrial fibrillation at 6 months postoperatively (hazard ratio 92.24, p=0.003) and the postoperative left atrial dimension (hazard ratio 16.05, p=0.019) were independent risk factors of continuance or recurrence of atrial fibrillation after Cox maze procedures. Aortic cross-clamp time and cardiopulmonary bypass time were significantly shorter in the radiofrequency group than in the cut-sew group. Conclusion: In the Cox maze procedure for patients with persistent atrial fibrillation, the use of bipolar radiofrequency ablation and a cryoablator is as good as the cut-sew technique for conversion to sinus rhythm. The postoperative left atrial dimension is an independent determinant of postoperative continuance and recurrence of atrial fibrillation.

• Journal of Chest Surgery
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• v.35 no.9
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• pp.643-652
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• 2002

As the prevalence of coronay artery disease is increasing, the surgical treatment has been universalized and operative outcome has been improved. We analyzed the short and mid-term results of 292 CABGs performed in Kangdong Sacred Heart Hospital. Material and Method: From June 1994 to December 2001, 292 patients underwent coronary artery bypass grafting. There were 173 men and 119 women and their ages ranged from 39 to 84 years with a mean of $61.8{\pm}9.1$ years. We analyzed the preoperative risk factors, operative procedures and operative outcome. In addition, we analyzed the recurrence of symptoms, long-term mortality and complications via out-patient follow-up for discharged patients. Result: Preoperative clinical diagnoses were unstable angina in 137(46.9%), stable angina in 34(11.6%), acute myocardial infarction in 40(13.7%), non-Q myocardial infarction in 25(8.6%), postinfarction angina in 22(7.5%), cardiogenic shock in 30(10.3%) and PTCA failure in 4(1.4%) patients. Preoperative angiographic diagnoses were three-vessel disease in 157(53.8%), two-vessel disease in 35 (12.0%), one-vessel disease in 11(3.8%) and left main disease in 89(30.5%) patients. We used saphenous veins in 630, internal thoracic arteries in 257, radial arteries in 50, and right gastoepiploic arteries in 2 distal anastomoses. The mean number of distal anastomoses per patient was $3.2{\pm}1.0$ There were 18 concomitant procedures ; valve replacement in 8(2.7%), left main coronary artery angioplasty in 6(2.1%), patch closure of postinfarction ventricular septal defect(PMI-VSD) in 2(0.7%), replacement of ascending aorta in 1(0.3%) and coronary endarterectomy in 1(0.3%) patient. The mean ACC time was $96.6{\pm}35.3 $ minutes and the mean CPB time was $179.2{\pm}94.6$ minutes. Total early mortality was 8.6%, but it was 3.1% in elective operations. The most common cause of early mortality was low cardiac output syndrome in 6(2.1%) patients. The stastistically significant risk factors for early mortality were hypertension, old age($\geq$ 70 years), poor LV function(EF＜40%), congestive heart failure, preoperative intraaortic balloon pump, emergency operation and chronic renal failure. The most common complication was arrhythmia in 52(17.8%) patients. The mean follow-up period was $39.0{\pm}27.0$ months. Most patients were free of symptoms during follow-up. Fourteen patients(5.8 %) had recurrent symptoms and 7 patients(2.9%) died during follow-up period. Follow-up coronary angiography was performed in 13 patients with recurrent symptoms and they were managed by surgical and medical treatment according to the coronary angiographic result. Conclusion: The operative and late results of CABG in our hospital, was acceptable. However, There should be more refinement in operative technique and postoperative management to improve the results.