• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.55-63
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• 2021

Recently, the incidence rate of malicious codes is over tens of thousands of cases, and it is known that it is almost impossible to detect/respond all of them. This study proposes a method for detecting multiple behavior patterns based on a graph database as a new method for dealing with malicious codes. Traditional dynamic analysis techniques and has applied a method to design and analyze graphs of representative associations malware pattern(process, PE, registry, etc.), another new graph model. As a result of the pattern verification, it was confirmed that the behavior of the basic malicious pattern was detected and the variant attack behavior(at least 5 steps), which was difficult to analyze in the past. In addition, as a result of the performance analysis, it was confirmed that the performance was improved by about 9.84 times or more compared to the relational database for complex patterns of 5 or more steps.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.3
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• pp.501-511
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• 2022

In 2021, ransomware attacks became popular, and the number is rapidly increasing every year. Since PowerShell is used as the primary ransomware technique, the need for PowerShell-based malware detection is ever increasing. However, the existing detection techniques have limits in that they cannot detect obfuscated scripts or require a long processing time for deobfuscation. This paper proposes a simple and fast deobfuscation method and a deep learning-based classification model that can detect PowerShell-based malware. Our technique is composed of Word2Vec and a convolutional neural network to learn the meaning of a script extracting important features. We tested the proposed model using 1400 malicious codes and 8600 normal scripts provided by the AI-based PowerShell malicious script detection track of the 2021 Cybersecurity AI/Big Data Utilization Contest. Our method achieved 5.04 times faster deobfuscation than the existing methods with a perfect success rate and high detection performance with FPR of 0.01 and TPR of 0.965.

• Korea journal of population studies
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• v.22 no.2
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• pp.97-119
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• 1999

한국, 일본, 미국의 생명표, UN의 인구연감, WHO의 세계보건통계연감 등 공식통계를 활용하여, 한국 노인의 기대여명 및 사망원인별 사망력을 미국 및 일본과 비교하여 파악하고 있다. 한국 노인의 기대여명은 미일보다 빠른 속도로 증가하고 있는데, 1970년대 중반 이후는 미국처럼 여자보다 남자 노인의 기대여명 증가가 빠르면서, 남녀 노인의 기대여명 차가 감소하고 있다. 1997년 현재 65세시 기대여명은 남자 13.64세, 여자 17.26세로 남녀간 3.62세 차이를 보이며, 출생후 남자 72%, 여자 88%가 65세까지 생존한다. 노인의 주요 사인은 미일과 마찬가지로 순환기계질환 및 악성신생물인데, 순환기계질환중 한일은 뇌혈관질환이, 미국에서는 허혈성 심장질환이 노인의 주된 사망원인이 된다. 한국 남녀 노인의 연령층과 상관없이 허혈성 심장질환 및 폐렴 사망률은 미일보다 낮고, 뇌혈관질환, 고혈압성질환, 위암, 간암, 결핵, 당뇨병, 정신 및 행동장애, 간질환 및 교통사고 사망률은 미일보다 높다. 대부분의 사망원인에서 남자사망률이 여자사망률보다 높지만, 한국의 고혈압성 질환, 간암, 폐암 및 간질환에 의한 성별 사망률 격차가 미일보다 크며, 한미일 모두 75세 이상 노인의 정신 및 행동장애에 의한 여자 사망률보다 남자사망률보다 높게 나타난다. 사망원인 생명표 작성결과를 보면, 1997년 현재 한국의 65세 남성과 여성은 순환기계질환 제거시 각각 3.47년과 2.7년을, 악성신생물 제거시 각각 3.87년과 1.58세의 기대여명 증가를 예상할 수 있고, 일본에 비해 특정 사인을 제거시 상대적으로 많은 기대여명 증가를 기대할 수 있는 사망원인은 남자 노인의 간질환 및 교통사고를 들 수 있다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.5
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• pp.1087-1097
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• 2017

As the penetration rate of smartphones increases, the number of malicious codes targeting smartphones is increasing. I 360 Security 's smartphone malware statistics show that malicious code increased 437 percent in the first quarter of 2016 compared to the fourth quarter of 2015. In particular, malicious applications, which are the main means of distributing malicious code on smartphones, are aimed at leakage of user information, data destruction, and money withdrawal. Often, it is operated by an API, which is an interface that allows you to control the functions provided by the operating system or programming language. In this paper, we propose a mechanism to detect malicious application based on the similarity of API pattern in normal application and malicious application by learning pattern of API in application derived from static analysis. In addition, we show a technique for improving the detection rate and detection rate for each label derived by using the corresponding mechanism for the sample data. In particular, in the case of the proposed mechanism, it is possible to detect when the API pattern of the new malicious application is similar to the previously learned patterns at a certain level. Future researches of various features of the application and applying them to this mechanism are expected to be able to detect new malicious applications of anti-malware system.

• 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 Chest Surgery
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• v.29 no.4
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• pp.414-419
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• 1996

To determine the efficacy of OK-432 as pleural sclerosant, we examined the outcomes in 81 patients (age : 27 to 82 years) with malignant pleural effusion and the outcomes in 64 patients ecieving OK-432 3-10KE(1 Klinische Einheit unit) through a chest tube for malignant pleural effusions. Of 81 patients with malignant pleural effusion, 40 patients had lung cancer. Lung cancer is the most frequent cause of malignant pleural effusion in men and women, in which 57 oyo of it was adenocarcinoma. Eighty seven percent of patient had respiratory symptom. Of the 64 patients with intracavitary injection of OK-432 for malignant pleural effusion, 59 patients had a complete short-term response (no fluid reaccumulation during 1 month after intracavitary injection of OK-432). Five patiens of the non-responders had partial control of effusion, with improvement in respiratory symptoms and these patients underwent thoracentesis. Of the 51 patients who survived longer than 1 month, 48 patients did not have re- accumulation of the fluid during follow up. Fever after intracavitary injection of OK-432 was a majors side effect although but that was easily controlled with non-steroidal anti inflammatory drug therapy, Thus the efficacy of intracavitary OK-4)2 injection for malignant pleural effusion was very helpful.

• Korean Journal of Head & Neck Oncology
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• v.27 no.1
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• pp.22-26
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• 2011

목 적 : 두경부 암은 발생 순위에서 전체 6위에 해당하는 다빈도 암이나 최근 20여년 동안의 노력에도 불구하고 두경부 암의 독톡한 특성상 생존률에서 뚜렷한 향상을 보이지 못하고 있다. 특히, 하인두 암은 원발 부위의 점막하 침윤이 흔하며, 주변 림프절 전이와 원격 전이가 흔하고, 2차 원발 암종 발생이 흔하여 두경부 암 중에서도 가장 불량한 예후를 보이고 있는 악성 종양이다. 최근에 이러한 암을 치료하고 진단하기 위한 방법으로 분자생물학적 접근법들이 많이 시도 되고 있으며, 그 중 하나로 N-myc downstream regulated gene-1(Ndrg-1)이라는 유전자가 유방, 전립선, 방광 암 등의 타 악성 종양에서 종양의 전이 및 진행 양상과 관련되어 있다는 보고가 있었다. 이에 본 연구는 하인두 암에서의 Ndrg-1의 발현 양상을 살펴보고 이와 임상 양상과의 연관관계를 살펴보고자 하였다. 방 법 : 1996년부터 2003년까지 수술 받은 하인두 암 환자 56명을 대상으로 면역조직화학검사를 시행하여 Ndrg-1 발현을 확인하였고, 3명의 신선 조직을 대상으로 RT-PCR, Western blot을 시행하였다. 결 과 : Ndrg-1은 RT-PCR에서 정상 조직과 악성종양 조직 모두에서 비슷한 수준으로 발현되었다. 그러나 Western blot에서는 정상 조직에서 뚜렷한 증가 양상을 보여 타 연구와 동일한 결과를 보였고, 이는 불필요하며 비효율적인 mRNA수준에서의 발현이 있지만 최종적인 단백 산물 발현에서는 암종의 진행과 연계되어 악성 종양 진행군에서 발현이 억제되는 결과로 해석된다. 면역조직화학검사에서는 정상 상피조직에서 Ndrg-1 발현이 확인되었으며, 통계적으로 유의하지는 않으나 불량한 예후를 가진 그룹에서 대체로 발현이 억제되는 악성 종양과의 역 연관 관계를 확인할 수 있었고, 특히 림프절 전이를 보인 그룹과 그렇지 않은 그룹 사이에서는 통계적으로 유의미한 결과가 확인되었다. 결 론 : 즉, 림프절 전이가 없는 그룹에서 Ndrg-1이 종양의 전이에 관여할 것이라는 타 연구와 일관된 결과로 하인두 암에서도 그 역할이 있음을 나타내는 결과라 할 수 있다.

• Journal of Chest Surgery
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• v.31 no.3
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• pp.266-270
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• 1998

The management of malignant pleural effusion is a difficult problem. Tetracycline was probably the most commonly used sclerosing agent, but parenteral tetracycline is no longer available. This prospective study was designed to determine the efficacy of insufflated talc in producing plerodesisin patients with malignant pleural effusions. Fifteen patients managed between March 1995 and March 1997 underwent thoracoscopy and had 4 gm sterile asbestos-free talc insufflation throughout the pleural space. The mean interval between the procedure and last follow-up was 101 days(range: 25-233 days). The results of treatment were clinically and radiologically compared with pre-operative status. The results were as follows: 1. The patients were 6 men and 9 women with a mean age of 55.1 years(range: 31-74 years). The primary tumors were lung cancer in 10 patients, breast cancer in two, hepatoma in one, stomach cancer in one, and adenocarcinoma of unkown origin in one. 2. Cancer cell positive ratio was 36% in sputum cytology study and 100% in thoracoscopic biopsy. 3. Symptoms improved in 94% of patients treated by talc pleurodesis. 4. After 30 days of the procedure, there was radiologically no recurrence of plural fluid in 94% patients. 5. There were wound infection in one, respiratory failure in one. In conclusion, the insufflation of 4 gm sterile asbestos-free talc in the pleural space is an effective method to control malignant pleural effusions and patients selection is important factor for reexpansion the lung.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.634-642
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• 2020

With the proliferation of Internet of Things (IoT) devices, using the Linux operating system in various architectures has increased. Also, security threats against Linux-based IoT devices are increasing, and malware variants based on existing malware are constantly appearing. In this paper, we propose a system where the binary data of a visualized Executable and Linkable Format (ELF) file is applied to Local Binary Pattern (LBP) image processing techniques and a median filter to classify malware in a Convolutional Neural Network (CNN). As a result, the original image showed the highest accuracy and F1-score at 98.77%, and reproducibility also showed the highest score at 98.55%. For the median filter, the highest precision was 99.19%, and the lowest false positive rate was 0.008%. Using the LBP technique confirmed that the overall result was lower than putting the original ELF file through the median filter. When the results of putting the original file through image processing techniques were classified by majority, it was confirmed that the accuracy, precision, F1-score, and false positive rate were better than putting the original file through the median filter. In the future, the proposed system will be used to classify malware families or add other image processing techniques to improve the accuracy of majority vote classification. Or maybe we mean "the use of Linux O/S distributions for various architectures has increased" instead? If not, please rephrase as intended.

• Korea journal of population studies
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• v.22 no.1
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• pp.37-63
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• 1999

한국 사망력의 수준 및 특징을 일본과 비교하고자 양국의 1995년 공식통계를 사용하여 사망원인별로 성·연령·혼인상태별 사망률, 연령표준화사망률, 생존기간손실년수(PYLL) 및 동 측정치의 남녀간 비와 한일간 비를 계산하였다. 사망원인 항목은 모든 사인(총사망), 결핵, 악성신생물, 당뇨병, 고혈압성 질환, 심장 질환, 뇌혈관 질환, 간 진환, 교통사고, 자살을 포함한다. 일본과 비교하여 한국 사망력의 두드러진 특징은 다음과 같다 : (1)자살을 제외한 대부분의 사인에서 한국의 사망률이 일본보다 높은데 , 특히 결핵, 고혈압성 질환, 간 질환 및 교통사고의 경우 한국 생산활동연령층의 사망률이 두드러지게 높다 : (2)결핵, 간질환, 교통사고, 암사망이 한국의 소아에게서도 발생한다 : (3)한국의 생산활동연령층에서 간 질환, 결핵, 교통사고에 의한 성별 사망력 격차가 큰데, 남성의 사망률이 여성의 사망률보다 높기 때문이다 : (4)자살률이 한국생산활동연령층 남성의 경우 일본보다 낮고, 10대와 20대 여성의 자살률은 일본보다 높다 : (5)한국의 45세 미만에서는 사인에 따라 사별이나 이혼상태에서, 45세 이상에서는 모든 사인에 대해 남녀 모두 미혼상태에서 사망력이 가장 높다. : (6)한국은 사별상태에서, 일본은 이혼상태에서 성별 사망력 격차가 가장 크다.