• 항공우주시스템공학회지
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• 제13권6호
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• pp.60-69
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• 2019

세계 여러 기업에서는 교통체증이라는 심각한 사회 문제를 해결하기 위해 개인용 항공기 PAV(Personal Air Vehicle) 개발이 활발히 이루어지고 있다. PAV는 사람이 탑승하는 유인운송수단이므로 반드시 감항인증이 요구된다. 항공기와 마찬가지로 PAV의 안전 운항에서 치명적인 위협을 가하는 요소는 고온의 열과 자기장을 동반한 낙뢰이다. 현재 PAV 관련 낙뢰 인증 기술, 지침 및 요건 개발이 미비한 실정이기 때문에 PAV 낙뢰 인증은 더욱 중요하다. 본 연구에서는 미연방항공청(FAA)에서 인정하는 국제 표준 인증지침서인 SAE ARP를 분석하여 낙뢰 인증지침을 PAV에 접목하였다. PAV의 낙뢰에 대한 영향성을 전산 소프트웨어를 통해 분석하였고 향후 추진될 PAV 낙뢰 인증을 위한 실무지침 수립의 근거를 제시하고자 한다.

• Journal of Radiation Protection and Research
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• 제37권4호
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• pp.197-201
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• 2012

경수로 사용후핵연료 중간저장시설의 부지면적을 산출하기 위하여 콘크리트 저장시설 개념모델의 연간선량을 계산하였다. 초기농축도 4.5 wt%, 연소도 45,000 MWd/MTU, 냉각기간 10년인 사용후핵연료를 대상으로 ORIGEN-ARP를 사용하여 선원항을 생산하였으며, MCNP 코드를 사용하여 저장시설에 대한 모델링 및 방사선차폐계산을 수행하였다. 연간선량은 저장시설의 용량별로 계산하였으며, 중앙집중식 저장시설의 경우, 반경 700 m 이상에서 10CFR72에서 권고하는 통제구역 경계에서의 연간선량 기준 0.25 mSv를 만족하였다.

• BMB Reports
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• 제40권2호
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• pp.212-217
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• 2007

The chicken oviduct is a dynamic organ that produces secretory proteins such as ovalbumin during the laying period. In this study, we identified oviduct-specific proteins in hens during the egg-laying period by proteomic analysis. Proteins extracted from the magnum of hens of different ages (5, 35, and 65 weeks) were analyzed by two-dimensional gel electrophoresis to compare the intensity of proteins among samples. Approximately 300 spots were detected on each gel. Based on the comparison of image gels, we found that the intensity of eight spots in 35-week magnums was increased at least by 2-fold compared with the others. Five of the eight spots were identified as calumenin, acidic ribosomal phosphoproteins (ARP), prohibitin, heart fatty acid-binding protein, and anterior gradient-2 (AGR-2). In particular, ARP and AGR-2 were highly expressed in 35- week magnums compared with 5- and 65-week magnums. In addition, the level of these proteins was consistent with their RNA levels. Expression of AGR-2 mRNA was detected in the mature magnum, whereas no signal was observed in premature tissue. Among various tissues, expression of AGR-2 mRNA was highest in the magnum, high in the isthmus, and five fold lower in muscle. It was undetectable in the liver and in other tissues (heart and kidney). However, the mRNA levels of other proteins were ubiquitous among tissues. In transcriptional activity of AGR-2, a 3.0 kb fragment of promoter region containing potential estrogen receptor binding sites had enhanced its activity strongly. In conclusion, these results suggest that AGR-2 has functional regulatory roles in the chicken oviduct during the egglaying period.

• 한국가구학회지
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• 제20권6호
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• pp.543-551
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• 2009

The history repeatedly shows that designers have sought their creative inspiration from fine arts. was also influenced by contemporary art such as surrealism or installment works. This thesis aims to examine the inter-relationship between contemporary art and contemporary furniture design with examples of organic modernism and minimalism furniture design. Also, will be analyzed in light of such interdisciplinary relationship, explaining the significances of in scholastic perspective. The previous research analysis of finding out examples of how fine art and design sought mutual exchanges to develop will help to examine the significance of in the context of art history. This analysis could be used as an important academic material to understand the origin and characteristics of modern design furniture. The features of surrealism and minimalism will be discussed in light of their influences on and interactive relationship with organic modernism furniture design. This provides important basic material to further analyze . Furthermore, the artistic language and plastic features of contemporary sculptors and installment artists such as Jean Arp, Richard Serra and Anish Kapoor will be examined to show how integrated and combined main features of those artists. extracted cognitive and phenomenological aspects from Serra's works that overwhelm viewers with their massive scales. Somewhat abstract yet somewhat primitive and dynamic features of Arp's works was also referred to . are made of FRP, composed of three partitions and six stools. This work was analyzed in aspect of form, composition and function. They have organic and flexible formations with free composition availability which endow free disassemble and arrangement. Also, they have cognitive features as of small elements are freely dispersed upon spaces to bestow certain presences. Based on this, this thesis could develop scholastic researches that examine the mutual and interactive relationship between contemporary art and furniture design with much more detailed discussions and examples.

• 시스템엔지니어링학술지
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• 제6권1호
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• pp.1-13
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• 2010

KC-100 is a 4 seats, single piston engine, civil aircraft whose type certificate is applied for KAS 23 (FAR 23) for the first time in Korea. Its system safety assessment and analysis have been conducted to meet the minimum safety requirement in KAS 23 and to verify the safety of equipment, system, and installation in accordance with the requirement of ${\S}$23.1309 and the guidelines in FAA AC 23.1309-1D and SAE ARP 4761. This safety assessment begins with the FHA (Functional Hazard Assessment) at aircraft and system level in preliminary design phase, and all of the safety assessment and analysis reports including the preliminary version of SSA (System Safety Assessment) have been prepared during detail design phase. The revised version of these safety reports will be approved by Airworthiness Authority through the ground and flight test phases. In this paper, the safety assessment requirement in ${\S}$23.1309, safety assessment guideline in AC 23.1309-1D, and safety assessment and analysis methods in ARP 4761 will be explained based on the application example for KC-100 development. The experience and knowledge of this system safety assessment for civil aircraft can be applied to commuter aircraft of FAR 23 class or large transport airplane of FAR 25 class.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제6권6호
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• pp.261-270
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• 2017

최근 스마트 온디바이스 및 정보 통신 기술의 발전으로 인하여, 중단 없는 서비스에 대한 요구가 점차 증가하고 있다. 이에 따라 시스템의 장애 발생 시에도 지속적으로 서비스를 제공할 수 있는 고가용성이 주목받고 있다. 한편, 대부분의 인터넷 서비스는 TCP를 기반으로 제공되기 때문에, 스마트 온디바이스의 고가용성을 위해서는 효율적인 TCP 세션 복구 기술이 필수적이다. 그러나 기존 TCP 세션 복구 기술은 높은 세션 복구비용이 요구되거나 페일오버를 지원하지 않는 문제점이 존재한다. 이러한 문제점을 해결하기 위해, 본 논문에서는 스마트 온디바이스의 고가용성을 위한 TCP 세션 복구 기술을 제안한다. 이를 위해 첫째, 순서 번호와 확인 응답 번호의 보정을 통해 TCP 세션의 재연결 과정 없이 TCP 세션을 복원한다. 둘째, 마스터 서버와 백업 서버 간에 TCP 세션 복구 데이터를 동기화하고, 마스터 서버의 장애 발생 시 페일오버를 수행한다. 마지막으로, 가상 IP 주소와 GARP (Gratuitous ARP) 패킷의 전송을 통해 피어에게 무중단 서비스를 제공한다.

• 한국컴퓨터정보학회지
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• 제14권2호
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• pp.205-214
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• 2006

유비쿼터스 컴퓨팅 시대의 업무를 위하여 인터넷을 통한 원격 접속이 필요하고, 입력되는 ID와 패스워드에 대한 기밀성 무결성의 네트워크 보안을 위하여 OTP를 적용하고 있다. 현재의 OTP는 Token이라는 하드웨어를 보유하고 있어야 하며, 보안에서도 취약점이 있다. 본 논문에서는 OTP 네트워크에 스니핑 도구를 설치하고, Cain을 이용하여 ARP Cache poisoning 공격을 시행하여 사용자 암호에 대하여 스니핑으로 취약점을 확인한다. 새로운 보안 방안으로 Tokenless OTP를 적용할 수 있는 새로운 시스템을 제안하고, 기밀성과 무결성을 보장하고자 한다. 외부에서 원격 접속 시 Tokenless OTP를 활용하여 접근제어를 위한 테스트를 하고, 접속에서 인증시스템과 연동하여 접속제어를 할 수 있었다. 만약 인증과정에서 해킹을 당해도 사용자만이 알고 있는 핀 번호 없이는 접속이 불가능하다는 것이 확인되었다. 이 결과 Tokenless OTP를 적용할 시에 패스워드의 유출 및 오용과 해킹에 대한 방어가 되어 보안성을 강화하고, 안전성을 높이는 보안 시스템으로 평가되었다.

• Journal of Periodontal and Implant Science
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• 제46권6호
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• pp.415-425
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• 2016

Purpose: The present study investigated the impact of 2 different suture techniques, the conventional crossed mattress suture (X suture) and the novel hidden X suture, for alveolar ridge preservation (ARP) with an open healing approach. Methods: This study was a prospective randomized controlled clinical trial. Fourteen patients requiring extraction of the maxillary or mandibular posterior teeth were enrolled and allocated into 2 groups. After extraction, demineralized bovine bone matrix mixed with 10% collagen (DBBM-C) was grafted and the socket was covered by porcine collagen membrane in a double-layer fashion. No attempt to obtain primary closure was made. The hidden X suture and conventional X suture techniques were performed in the test and control groups, respectively. Cone-beam computed tomographic (CBCT) images were taken immediately after the graft procedure and before implant surgery 4 months later. Additionally, the change in the mucogingival junction (MGJ) position was measured and was compared after extraction, after suturing, and 4 months after the operation. Results: All sites healed without any complications. Clinical evaluations showed that the MGJ line shifted to the lingual side immediately after the application of the X suture by $1.56{\pm}0.90mm$ in the control group, while the application of the hidden X suture rather pushed the MGJ line slightly to the buccal side by $0.25{\pm}0.66mm$. It was demonstrated that the amount of keratinized tissue (KT) preserved on the buccal side was significantly greater in the hidden X suture group 4 months after the procedure (P<0.05). Radiographic analysis showed that the hidden X suture had a significant effect in preserving horizontal width and minimizing vertical reduction in comparison to X suture (P<0.05). Conclusions: Our study provided clinical and radiographic verification of the efficacy of the hidden X suture in preserving the width of KT and the dimensions of the alveolar ridge after ARP.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제5권4호
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• pp.489-497
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• 1999

국내의 ATM 기술은 대부분 교환기 시스템 개발에 집중되어 있었고 최근에는ATM 서비스 분야에 대한 개발 요구가 있다. 이러한 가운데 Internet 서비스는 데이타 망의 기본 서비스로 자리잡았으며, ATM망도 기본적으로 Internet 서비스를 지원하여야 한다. IETF의 IPOA (Classical IP and ARP over ATM)는 국내 망 여건 및 구현의 용이성으로 Internet 서비스를 위한 프로토콜중 가장 선호 대상이지만 RFC사양의 허술함, 구현자의 사양에 대한 이해 부족과 초기 외산 장비 제조 업체들의 자체 사양때문에 기존의 IPOA장비들과 상호 운용 시험에서 후발 IPOA 개발자는 시행착오를 겪어야만 한다. 본 논문에서는 기존 외산 IPOA 장비들과 자체 개발한 장비와 상호 운용 시험을 수행하면서 겪은 사례 연구를 정리하였고 이를 기초로 기존의 외산 IPOA와 상호 운용할 수 있는 최종 요구 사항을 제시하였다. 본 논문을 기초로 IPOA 장비를 개발한다면 국내 후발 ATM 장비 업체는 개발의 시간 및 노력을 줄일 수 있고 향후 IP/ATM 국내 기술력 향상에 도움이 될 것이다.Abstract While we have been focusing on development of ATM switching systems, recently the demand on service by use of ATM switching system is increasing rapidly. Among various ATM services, the Internet service should be provided in an ATM network since the Internet service has been the basic data service. Many domestic engineers consider the classical IP and ARP over ATM (IPOA) to be an appropriate method for interworking of IP and ATM because the IP is the network protocol used in most domestic data networks, and the IPOA is simpler and has less overhead than other approaches. However, it is not easy for a developer to implement the IPOA function module interoperable with other existing ones due to the incomplete description of IETF's RFC specifications, misunderstanding of designer and/or developer, and incompatible vendors' specifications. In this paper, we show several case studies undertaken for interoperability tests of IPOA products between our product and other vendor's products, and discuss the implementation requirement of the IPOA software to be interoperable with the existing IPOA equipment.The design and implementation requirements presented in this paper will reduce the effort of IPOA-developing engineers and time required for interoperability test. Also, this contribution will be helpful in IP/ATM interworking areas.

• Journal of Periodontal and Implant Science
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• 제50권3호
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• pp.197-206
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• 2020

Purpose: The aim of this study was to determine the impact of different compressive forces on deproteinized bovine bone mineral (DBBM) particles covered by native bilayer collagen membrane (NBCM) during alveolar ridge preservation (ARP) in the molar area, and to identify any histomorphometric and clinical differences according to the compressive force applied. Methods: Sockets were filled with DBBM after tooth extraction, and different compressive forces (30 N and 5 N, respectively) were applied to the graft material in the test (30 N) and control (5 N) groups. The DBBM in both groups was covered with NBCM in a double-layered fashion. A crossed horizontal mattress suture (hidden X) was then made. A core biopsy was performed using a trephine bur without flap elevation at the implant placement site for histomorphometric evaluations after 4 months. The change of the marginal bone level was measured using radiography. Results: Twelve patients completed the study. The histomorphometric analysis demonstrated that the mean ratios of the areas of new bone, residual graft material, and soft tissue and the implant stability quotient did not differ significantly between the groups (P>0.05). However, the mean size of the residual graft material showed a significant intergroup difference (P<0.05). Conclusions: The application of 2 compressive forces (5 N, 30 N) on particulate DBBM grafts during open-healing ARP in the posterior area led to comparable new bone formation, implant feasibility and peri-implant bone level.