A Methodology for Pre-Validation of Staffing Plan in terms of Human Performance based on Task Network Modelling

Young Do Koo(구영도),Sa Kil Kim(김사길),Kwang Il Jeong(정광일),Joon Ku Lee(이준구) 대한인간공학회 2022 대한인간공학회 학술대회논문집 Vol.2022 No.10

혈소판유래 성장인자 함유 흡수성 차폐막이 치주조직의 재생에 미치는 영향

구영,김정은,한수부,정종평,박윤정,이승진,권영혁,Ku, Young,Kim, Jeong-Eun,Han, Soo-Boo,Chung, Chong-Pyoung,Park, Yoon-Jeong,Lee, Seung-Jin,Kwon, Youg-Hyuk 대한치주과학회 1997 Journal of Periodontal & Implant Science Vol.27 No.1

PDGF-BB has been recognized as a highly potential growth factor for guided tissue regeneration in periodontal defect. This study carried out histologic and histometric evaluation of $200ng/cm^2$ PDGF-BB loaded bioresorbable membrane made from polyglycolic and polylactic acid. It was tested for its biocompatibility, ability to prevent epithelial downgrowth and amount of periodontal regeneration. Without membrane and PDGF-BB unloaded bioresorbable membrane were used as control. Healthy six beagle dogs were used. Each dog was anesthetized and buccal flaps were reflected in the mandibular and maxillary premolar areas. Buccal alveolar bone between the mesiobuccal and distobuccal line angles was surgically removed on the lower 2nd and 4th premolar in mandible, 2nd premolar in maxilla, to a level 4mm apical to the cementoenamel junction with creating a Class II buccal furcation defect for available space. Care was taken not to remove the root cementum layer and rubber impression materials were placed over each surgically created defect. Flaps were repositioned and sutured. Reconstructive surgery was performed 1 month after defect preparation. PDGF-BB loaded membranes and controls were randomly placed on maxillary 2nd premolars and mandibular 2nd and 4th premolars. Plaque control regimen was instituted with daily brushing with a 0.1% chlorhexidine digluconate during experimental periods. The animals were sacrificed 2 and 5 weeks after surgery and undecalcified specimens were prepared for histologic evaluation. The degree of coronal regrowth of new bone, new cementum and the amonut of new bone areas formed on the defected area of the PDGF-BB loaded membrnae turned superior to without membrane and drug unloaded membrane. Experimental membrane could prevent the epithelial downgrowth irrespective of drug loaded or not and showed good biocompatiblity, These results implicated that PDGF-BB loaded bioresorbable membrane could be highly useful tool for guided tissue regeneration of periodontal defects.

한국인 Actinobacillus actinomycetemcomitans 균주의 특이 독성 clone형과 혈청형 및 백혈구독성과의 관계

구영,Ku, Young 대한치주과학회 1995 Journal of Periodontal & Implant Science Vol.25 No.3

Previous studies have demonstrated that not all A. actinomycetemcomitans produced significant level of leukotoxic factor and its leukotoxicity have associated with serotype and genetic variation. Our aim was to investigate on the interrelationship between serotype and leukotoxicity of an A. actinomycetemcomitans consisting of 13 clinically well characterized. Korean isolates and to evaluate if particular virulent clonal types of A. actinomycetemcomitans are associated with periodontal disease. For this study, 13 strains of A. actinomycetemcomitans from 6 patients with periodontal disease were isolated and identified by using a selective medium(tryptic soy agar supplemented with 10% serum, $75{\mu}g$ of bacitracin and $5{\mu}g$ of vancomycin per ml) in 10% C02 incubator for 3days with routine Gram staining, colony morphology and biochemical test..For serotyping, antisera were prepared from reference strains of 5 serotypes. (ATCC 29523,Y4, SUNY aB 67, IDH 781, IDH 1705) and then ammonium sulfate precipitation, immunoabsorption and indirect immunofluoroscent procedures were done. For analysis of leukotoxicity, sonic extract of A. actinomycetemcomitans exposed to PMN, and trypan blue was stained for counting the cell viability. Finally Southern blot analyses of genomic DNA digested with the restriction enzyme Tag I was done and the Southern blots were hybridized with the 530bp fragment, termed delta 530, originating from the ltx promoter of strain 652 and deleted from strain JP2. Also ltxA-3.1 and SC2 probe from strain JP2 were hybridized with genomic DNA fragments. Results reveal that strains isolated showed approximately equal proportions of 3 serotypes(b, d, e) and serotype b was not detected. 2 patients harbored 2 different serotypes in the same disease site. The prevalence of leukotoxic strain was 23% and there was no relationship between serotype, leukotoxicity and clinical observations. Especially virulent clonal types of Actinobacillus actinomycetemcomitan (JP2 strain) could not found. Further studies are necessary on the genetic polymorphism of leukotoxin and its relations to clinical status.

이온 빔 조사 처리된 키토산 스펀지의 세포적합도에 관한 연구

구영,Ku, Young 대한치주과학회 1998 Journal of Periodontal & Implant Science Vol.28 No.2

Chitosan is a biodegradable and non-toxic material with a molecular weight of 800-1,500Kd which can be obtained in various forms with extraordinary chemical structures and biological characteristics of which enables it to be used in many fields as a biomaterial. Ion irradiation is a useful tool to modify chemical structures and physical properties of high molecular weight polymers. The basic hypothesis of this study is that when surface properties of chitosan in a sponge form are modified with ion beam-irradiation and cell adhesion properties of chitosan would improve and thereby increase the regenerative ability of the damaged bone. The purpose of this study was to illuminate the changes in the cytocompatibility of chitosan sponges after ion beam-irradiation as a preliminary research. Argon($Ar^+$) ions were irradiated at doses of $5{\times}10^{13}$, $5{\times}10^{15}$ at 35 keV on surfaces of each sponges. Cell adhesion and activity of alkaline phosphatases were studied using rat fetal osteoblasts. The results of this study show hat ion beam-irradiation at optimal doses($5{\times}10^^{13}\;Ar^+\;ion/cm^2$) is a useful method to improve cytocompatibility without sacrificing cell viability and any changing cell phenotypes. These results show that ion beam-irradiated chitosan sponges can be further applied as carriers in tissue engineering and as bone filling materials.

A Study on HSI Concept Design for Monitoring and Controlling Multi-Module Small Modular Reactors

Young Do Koo(구영도),Sa Kil Kim(김사길),Moon Won Song(송문원),Kwang Il Jeong(정광일),Joon Ku Lee(이준구) 대한인간공학회 2021 대한인간공학회 학술대회논문집 Vol.2021 No.11

Objective: The objective of the study is to elicit a basic concept for a new human-system interface (HSI) for integrated monitoring and controlling multi-module reactors, which is capable of minimizing any negative effects on the safety of the reactors or human performance. Background: Recently the researches on developing a new nuclear reactor system (i.e., small modular reactors (SMRs)) as well as improving the safety of the existing large-scale nuclear power plants (NPPs) are being carried out. In light water SMRs being developed, there are some characteristics in common, which are distinguished from the existing light water reactors: The safety of SMRs is secured through both advanced designs (e.g., passive safety systems, high level of automation, and so on) and proven technologies utilized also in the existing NPPs. Economy of SMRs due to less than 300 MWe production capacity is planning to be usually covered through multi-module SMR operation by one operator using an individual workstation in a single main control room, as well as a high level of automation technology. More works are accompanied because of more than one mission such as electricity generation, which is the conventional mission, and desalination or hydrogen production, which are new ones. According to these characteristics of SMRs, a new human-system interface (HSI) design being able to monitor and control integrated multi-module SMRs, differ from the existing HSI, is needed in common in SMRs. Specifically, in HSI, several essential capabilities are required: operator’s tasks for monitoring and controlling multiple reactors and access to information on reactors should be supported, and explanations for high levels of automation and alarms also have to be provided. Accordingly, a new HSI concept design proper to multi-module SMRs in view of users’ and regulatory requirements and considerations is necessary. Furthermore, competitiveness of SMR being developed in Republic of Korea can be strengthened by drawing a new HSI design. Method: Current HSI designs for a single reactor designed in accordance with standard design process (i.e., NUREG-0700 Rev.3) is expected to be constrained to monitor and control multi-module SMRs. Thus, a new HSI concept should be presented through addressing challengeable considerations or trying a novel approach. Functional requirements needed in providing plant status, alarm, and controls for multiple SMRs are considered from users’ or a regulatory point-of-view to draw a new HSI design concept, beyond addressing a single reactor only. In addition, HSIs in other multi-module SMRs or surrogate facilities are investigated. Results: New HSI concepts for monitoring and controlling multiple SMRs are proposed, and some of the design examples are drawn, which is distinguished for the existing HSI. Conclusion: As this study is a part of developing a new HSI design for multi-module SMRs, additional study will be sequentially performed based on the result drawn in the study. Application: The result of this study will be used as the input to a study for the basic design of the HSI to be available to multi-module reactors in the future.

Opcode와 API의 빈도수와 상관계수를 활용한 Cerber형 랜섬웨어 탐지모델에 관한 연구

이계혁,황민채,현동엽,구영인,유동영,Lee, Gye-Hyeok,Hwang, Min-Chae,Hyun, Dong-Yeop,Ku, Young-In,Yoo, Dong-Young 한국정보처리학회 2022 정보처리학회논문지. 컴퓨터 및 통신시스템 Vol.11 No.10

최근 코로나 19 팬더믹 이후 원격근무의 확대와 더불어 랜섬웨어 팬더믹이 심화하고 있다. 현재 안티바이러스 백신 업체들이 랜섬웨어에 대응하고자 노력하고 있지만, 기존의 파일 시그니처 기반 정적 분석은 패킹의 다양화, 난독화, 변종 혹은 신종 랜섬웨어의 등장 앞에 무력화될 수 있다. 이러한 랜섬웨어 탐지를 위한 다양한 연구가 진행되고 있으며, 시그니처 기반 정적 분석의 탐지 방법과 행위기반의 동적 분석을 이용한 탐지 연구가 현재 주된 연구유형이라고 볼 수 있다. 본 논문에서는 단일 분석만을 이용하여 탐지모델에 적용하는 것이 아닌 ".text Section" Opcode와 실제 사용하는 Native API의 빈도수를 추출하고 K-means Clustering 알고리즘, 코사인 유사도, 피어슨 상관계수를 이용하여 선정한 특징정보들 사이의 연관성을 분석하였다. 또한, 타 악성코드 유형 중 웜과 Cerber형 랜섬웨어를 분류, 탐지하는 실험을 통해, 선정한 특징정보가 특정 랜섬웨어(Cerber)를 탐지하는 데 특화된 정보임을 검증하였다. 위와 같은 검증을 통해 최종 선정된 특징정보들을 결합하여 기계학습에 적용하여, 최적화 이후 정확도 93.3% 등의 탐지율을 나타내었다. Since the recent COVID-19 Pandemic, the ransomware fandom has intensified along with the expansion of remote work. Currently, anti-virus vaccine companies are trying to respond to ransomware, but traditional file signature-based static analysis can be neutralized in the face of diversification, obfuscation, variants, or the emergence of new ransomware. Various studies are being conducted for such ransomware detection, and detection studies using signature-based static analysis and behavior-based dynamic analysis can be seen as the main research type at present. In this paper, the frequency of ".text Section" Opcode and the Native API used in practice was extracted, and the association between feature information selected using K-means Clustering algorithm, Cosine Similarity, and Pearson correlation coefficient was analyzed. In addition, Through experiments to classify and detect worms among other malware types and Cerber-type ransomware, it was verified that the selected feature information was specialized in detecting specific ransomware (Cerber). As a result of combining the finally selected feature information through the above verification and applying it to machine learning and performing hyper parameter optimization, the detection rate was up to 93.3%.

Opcode와 API의 군집화와 유사도 분석을 활용한 랜섬웨어 탐지모델 연구

이계혁 ( Gye-hyeok Lee ),황민채 ( Min-chae Hwang ),구영인 ( Young-in Ku ),현동엽 ( Dong-yeop Hyun ),유동영 ( Dong-young Yoo ) 한국정보처리학회 2022 한국정보처리학회 학술대회논문집 Vol.29 No.1

최근 코로나 19 팬더믹 이후 원격근무의 확대와 더불어 랜섬웨어 팬더믹이 심화하고 있다. 현재 안티바이러스 백신 업체들이 랜섬웨어에 대응하고자 노력하고 있지만, 기존의 파일시그니처 기반 정적분석은 패킹의 다양화, 난독화, 변종 혹은 신종 랜섬웨어의 등장 앞에 무력화될 수 있고, 실제로 랜섬웨어의 피해 규모 지속 증가가 이를 설명한다. 본 논문에서는 기계학습을 기반으로 한 단일 분석만을 이용하여 탐지모델에 적용하는 것이 아닌 정적분석 정보(.text Section Opcode)와 동적 분석 정보(Native API)를 추출하고 유사도를 바탕으로 연관성을 찾아 결합하여 기계학습에 적용하는 탐지모델을 제안한다.

다공질 Calcium Polyphosphate의 생분해성에 관한 연구

양승민,이영규,한은영,김석영,계승법,이승진,이용무,구영,한수부,정종평,최상묵,류인철,Yang, Seung-Min,Lee, Young-Kyoo,Han, Eun-Young,Kim, Seok-Young,Kye, Seung-Beom,Lee, Seung-Jin,Lee, Yong-Moo,Ku, Young,Han, Soo-Boo,Chung, Chong-Pyoung,Ch 대한치주과학회 2001 Journal of Periodontal & Implant Science Vol.31 No.3

The purpose of this study is to evaluate the bioresorbability of Calcium Polyphosphate added with $Na_2O$ and chitosan. Though calcium phosphate ceramics meet some of the needs for bone replacement, they have some limitation of unresorbability and fibrous encapsulation without direct bone apposition during bone remodelling. To solve these problem, we developed a new ceramic, calcium polyphosphate(CPP), and report the biologic response to CPP in extraction sites of beagle dog. Porous CPP granules were prepared by condensation of anhydrous $Ca(H_2PO_4)_2$ to form non-crystalline $Ca(PO_3)_2$. CPP granules added with $Na_2O$ and chitosan were implanted in extraction sockets and histologic observation were performed at 12 weeks later. Histologic observation at 12 weeks revealed that CPP matrix were mingled with and directly apposed to new bone without any intervention of fibrous connective tissue. CPP granules added with chitosan were well adatped without any adverse tissue reaction and resorbed slowly and spontaneously. CPP granules added with $Na_2O$ and chitosan show multinucleated giant cells and osteoblast-like cells around grafted material and newly formed bone. This result revealed that CPP, regardless of its additive component, had a high affinity for bone and had been resorbed slowly. From this results, it was suggested that CPP is promising ceramic as a bone substitute and addition of $Na_2O$ and chitosan help biodegradation. In further study , it will be determined which concentration of $Na_2O$ help biodegradation and the other additive components increase the degradation rate.

후박 및 은행잎 추출물의 향균, 향염 및 세포활성도에 미치는 영향

정종평,구영,배기환,Chung, Chong-Pyuong,Ku, Young,Bae, Ki-Hwan 대한치주과학회 1995 Journal of Periodontal & Implant Science Vol.25 No.3

Periodontal therapy for treatment of periodontitis involves the elimination of bacterial plaque and elimination of the anatomic defects by regenerative procedure. The purpose of this study was to evaluate on the biological effect of magnolia and Ginkgo biloba extract to the antimicrobial, antiinflammatory and cellular activity. Antimicrobial assay was performed with the diffusion method of the extract by measuring of growth inhibitory zone of B. cereus from blood agar plate. Effect of the extract to cellular activity of gingival fibroblast were examined using MTT method and measured the result with optical density on 570nm by ELISA reader. Inhibitory effects of $PGE_2$ production from gingival fibroblast was performed with the addition of $IL-l{\beta}$ and the extract to the well and examined to the product of $PGE_2$ from cell by ELISA reader. In vivo anti-inflammatory effect was performed with injection examined with clinically and histologically for their extent of mecrosis and inflammation. Antimicrobial activity of Magnolia extract showed significantly higher activity than that of control. However, GBE did not showed significant activity to compare with control, and mixture of Magnolia and GBE extract showed significantly higher activity than that of control. The effect of cellular activity to gingival fibroblast showed no significant differences of between control and Magnolia extract. However, GBE showed significantly higher rate of cellular activity to compare with control and even to PDGF-BB, and also showed same degree of cellular activity even though mixed with Magnolia extract. The inhibitory effect of $PGE_2$ production showed significantly reduction of $PGE_2$ production to compare with control, but its inhibitory effect was not much strong to compare with Indomethacin. In vivo, antiinflammatory effect of Magnolia extract to P. gingivalis injection of Hamster buccal check showed significantly reduction of inflammatory cell infiltration and tissue necrosis, but GBE showed no effect on the inhibition of inflammatory process. These results suggested that Magnolia and GBE extract possessed different kind of biological activity and also can be compensated on their activity with each other for elimination of bacterial plaque and anatonical defect.

임산부의 치주 질환 활성도와 조산과의 상관관계에 관한 연구

최은정,구영,류인철,함병도,윤보현,한수부,정종평,최상묵,Choi, Eun-Cheong,Ku, Young,Rhyu, In-Chul,Hahm, Byung-Do,Yoon, Bo-Hyun,Han, Soo-Boo,Chung, Chong-Pyoung,Choi, Sang-Mook 대한치주과학회 2000 Journal of Periodontal & Implant Science Vol.30 No.1

Purpose We designed this study for the purpose of determining the relationship between periodontal disease activity and PLBW, using the evaluation of probing pocket depth, loss of attachment, gingival index, gingival crevicular fluid amount and subgingival microflora. Methods A total of 100 volunteer mothers(mean age 30.44) at the Department of Obstetrics and Gynecology Seoul National University Hospital were selected for this study.Pregnancy outcomes were categorized into cases and controls in two ways. our definition was based on the following; Group 1 : Any PLBW cases Vs. All NBW controls Group 2 : PLBW cases Vs. NBW controls A periodontal exam was performed on the Ramfjord( #16, 21, 24, 36, 41, 44) teeth and Clinical evaluation consisted of probing pocket depth, loss of attachment, gingival index and gingival crevicular fluid amount. Subgingival plaque samples were collected by three sterile #35 paper points. The total number of anaerobic colonies and aerobic bacteria were enumerated after incubation. Antisera to P. gingivalis, P. intermedia, A. actinomycetemcomitans were produced in white rabbits with live whole cells suspensions. The specific fluorescent bacteria obtained by immunofluorescence and total cell counts obtained by dark-field microscopy were counted on four fields. The percent of each specific microorganism in the total cell count was determined. Results Any PLBW and PLBW cases showed significantly greater probing depth and attachment loss than all NBW and NBW controls. Cases group had significantly increased anaerobic bacterial counts compared with control group and no differences in the other microbes. This study confirmed that periodontal disease is a statistically significant risk factor for PLBW by investigating clinical parameters and subgingival plaque analysis.