• 한국컴퓨터정보학회논문지
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• 제16권10호
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• pp.23-31
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• 2011

최근 전력소모와 읽기 성능이 우수한 Solid state disk(SSD)가 많이 사용되고 있으나 가격이 고가이고 삭제 및 쓰기 연산의 효율이 낮은 것이 단점이다. 이것을 보완하기 위한 저장장치의 일종이 하이브리드 하드디스크 (H-HDD: Hybrid Hard disk drive)인데 하드디스크 내부에 플래시 메모리(NVCache: Non-volatile Cache)를 장착하여 디스크블록의 캐시로 사용한다. 본 논문에서는 H-HDD의 저전력과 응답시간을 향상시키기 위해 NVCache의 선반입 및 관리 기법을 제안한다. 제안하는 기법은 NVCache를 읽기 캐시를 위주로 사용하고 쓰기캐시는 디스크 헤드와 스핀들의 상황에 따라 쓰기 연산을 지원한다. 읽기 캐시의 경우 시간적, 지역적 지역성을 동시에 고려하여 선반입을 통해 응답시간과 전력 소모를 감소시키고 쓰기 캐시의 경우 디스크 스핀들의 동작 상태에 따라 NVCache에 쓰기를 실시하여 저전력과 응답성을 향상시키고자한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.623-628
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• 2007

도시 대중교통을 주도하는 도시철도에서의 중요한 기능인 신호 연동장치의 주요 논리 회로 중 가장 취약한 3, 4호선의 소형 (Non-Vital) 계전기를 성능이 향상된 전자연동장치(PLC)로 개량함으로서 사전 장애 발생요인을 제거, 열차 안전운행 확보는 물론 설비의 현대화로 업무 향상에 기여하고 신호설비 유지 보수의 합리화 및 효율화를 기할 수 있도록 신호설비의 기능개선 및 발전 방안이 되도록 하였다. 특히 고장 발생 빈도를 낮추기 위한 방안과 설비 보완 및 신설 등 종합적이고 실현 가능한 설비를 구현하고자 하였으며, 기존의 노후된 신호시설이나 교체 예정인 신호 설비들을 효율적으로 개량하기 위한 방안으로 신호 관련기술기준과 표준을 바탕으로 신호시스템의 합리적 발전에 일익을 담당코자 하였다.

• 멤브레인
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• 제24권4호
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• pp.292-300
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• 2014

내염소성을 갖는 염제거공정용 술폰화 폴리아릴렌 에테르 술폰 랜덤 공중합체(SPAES) thin film composite (TFC)막이 모노글라임 용매를 이용하여 제조되었다. 모노글라임은 선택층인 SPAES만을 용해시키며, 다공성 폴리술폰(예 : Udel$^{(R)}$)층에 대해 비용해성을 지녀, TFC 제조를 위한 선택적 용매로 사용될 수 있다. 또한 개미산이나 디에틸글리콜과는 달리, 환경적으로 무해하며, 매우 낮은 끊는점을 지녔다는 점이 또 다른 장점이 될 수 있다. 다공성 Udel$^{(R)}$ 지지체 위에 코팅시, 코팅용액이 기공구조에 침투하여 유수량을 감소시키는 기공투과현상이 발생하는데, 이를 최소화하기 위해 지지체를 이소프로필알콜과 글리세린 혼합액에서 전처리 후에, 코팅-건조 공정을 통해 결함이 없는 SPAES TFC로 제조된다. 또한, SPAES 선택층의 술폰화도, 고정이온의 염상태 및 물리-화학적 가교효과를 SPAES TFC막을 통한 투과거동과 관련하여 관찰하였다.

• 사물인터넷융복합논문지
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• 제7권4호
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• pp.9-14
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• 2021

고신뢰성을 요구하는 컴퓨팅 시스템에서 저장장치의 수명예측방법은 데이터 보호뿐만 아니라 활용성을 극대화 할 수 있기 때문에 시스템 관리하기 위한 중요한 요소 중 한 가지이다. 최근 여러 저장시스템에서 저장장치로 사용되고 있는 SSD(Solid State Drive)의 수명은 이를 구성하고 있는 낸드 플래시 메모리의 수명이 실질적인 수명과 연결된다. 따라서 SSD를 이용하여 구성한 저장시스템에서는 낸드 플래시 메모리의 수명을 정확하고 효율적으로 예측하는 방법이 필요하다. 본 논문에서는 낸드 플래시 메모리 불량 발생빈도를 이용하여 플래시 메모리 기반 저장장치의 수명 예측을 최적화할수 있는 방법을 제안한다. 이를 위해 DWPD(Drive Writes Per Day) 단위로 데이터를 처리할 때 발생하는 불량 발생빈도를 수집하기 위한 비용 매트릭스(Cost Metrix)를 설계한다. 그리고 경사하강법(Gradient Descent)을 이용하여 수명의 마감이 발생하는 경사도까지 남은 비용을 예측하는 방법을 제안한다. 마지막으로 시뮬레이션을 통해 임의의 불량이 발생했을 때 제안하는 방법을 통한 수명예측의 우수성을 증명했다.

• Archives of Plastic Surgery
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• 제49권2호
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• pp.184-194
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• 2022

The face and the external nose define an individual's physical appearance. Nasal deformities can cause facial disfigurement along with unwanted psychological repercussions. Nasal deformities range in severity, with the most severe cases being indications for a rhinectomy, due to the complexity of the nasal defect. According to published literature, there is no consensus among otolaryngologists and plastic surgeons on which technique or flap use is preferred in terms of complications, aesthetic outcome, or patient satisfaction. The goal of this study is to provide a comprehensive analysis of published studies on nasal reconstruction following rhinectomy. Using the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guidelines for writing systematic reviews, a systematic review was conducted. Four databases were searched using a search strategy. These articles were then imported into the COVIDENCE software and went screening and thorough article review. After screening 2,237 articles, 23 studies were then extracted for data collection analysis. We collected data from 12 case series, 4 case studies, 1 prospective case series, and 4 retrospective chart review studies. The most commonly reported flaps were forehead flaps, superior extended nasal myocutaneous island, forearm free flaps, anterolateral thigh (ALT) free flap, medial femoral condyle free flap (n = 8), and zygomaticus implants (n = 6), and retained nasal prosthesis. Although not specifically indicated by a certain number, the most common indication for the rhinectomy was malignancy, followed by traumas, postsurgical complications, radionecrosis, and congenital nasal malformations.

• Restorative Dentistry and Endodontics
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• 제47권4호
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• pp.35.1-35.9
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• 2022

Although the success rates of microsurgery and micro-resurgery are very high, the influence of a recurrent perforation combined with radicular cyst remains unclear. A 21-year-old white female patient had a history of root perforation in a previously treated right maxillary lateral incisor. Analysis using cone-beam computed tomography (CBCT) revealed an extensive and well-defined periapical radiolucency, involving the buccal and palatal bone plate. The perforation was sealed with bioceramic material (Biodentine) in the pre-surgical phase. In the surgical phase, guided tissue regeneration (GTR) was performed by combining xenograft (lyophilized bovine bone) and autologous platelet-rich fibrin applied to the bone defect. The root-end preparation was done using an ultrasonic tip. The retrograde filling was performed using a bioceramic material (Biodentine). Histopathological analysis confirmed a radicular cyst. The patient returned to her referring practitioner to continue the restorative procedures. CBCT analysis after 1-year recall revealed another perforation in the same place as the first intervention, ultimately treated by micro-resurgery using the same protocol with GTR, and a bioceramic material (MTA Angelus). The 2-year recall showed healing and bone neoformation. In conclusion, endodontic micro-resurgery with GTR showed long-term favorable results when a radicular cyst and a recurrent perforation compromised the success.

• Archives of Plastic Surgery
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• 제50권6호
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• pp.601-609
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• 2023

Background The anterolateral thigh (ALT) flap is a preferred option in the reconstruction of a wide variety of defects, enabling multiple tissue components and thicknesses. Methods This study was conducted to investigate the correlation of the thickness of the traditional subfascial ALT flap and superficial fat flap with age, gender, and body mass index (BMI). A total of 42 patients (28 males and 14 females) were included in the study. Results Mean age was 50.2 (range, 16-75) years and mean BMI was 24.68 ± 4.02 (range, 16.5-34.7) kg/m². The subfascial flap thickness was significantly thinner in male patients (16.07 ± 2.77 mm) than in female patients (24.07 ± 3.93 mm; p < 0.05), whereas no significant difference was found between male (4.28 ± 1.15 mm) and female patients (4.85 ± 1.09 mm) regarding superficial fat flap thickness (p = 0.13). The thickness of both flaps had a positive correlation with BMI, and the strongest correlation was found for subfascial ALT thickness in female patients (r = 0.81). Age had no effect on both flap thickness measurements. The anterior thigh is thicker in women than in men, although it varies according to BMI. This shows that flap elevation is important in the superthin plane, especially if a thin flap is desired in female patients in defect reconstruction with the ALT flap. Thus, a single-stage reconstruction is achieved without the need for a defatting procedure after subfascial dissection or a second defatting procedure 3 to 6 months later. Conclusion The appropriate ALT flap plane should be selected considering the gender and BMI of the patient.

• BMB Reports
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• 제44권2호
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• pp.123-128
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• 2011

Leucine-rich repeat containing protein 10 (LRRC10) is characterized as a cardiac-specific gene, suggesting a role in heart development and disease. A severe cardiac morphogenic defect in zebrafish morphants was recently reported but a contradictory result was found in mice, suggesting a more complicated molecular mechanism exists during mouse embryonic development. To elucidate how LRRC10 is regulated, we analyzed the 5'enhancer region approximately 3 kilo bases (kb) upstream of the Lrrc10 start site using luciferase reporter gene assays. Our characterization of the Lrrc10 promoter indicates it possesses complicated cis-and trans-acting elements. We show that GATA4 and MEF2C could both increase transcriptional activity of Lrrc10 promoter individually but that they do not act synergistically, suggesting that there exists a more complex regulation pattern. Surprisingly, knockout of Gata4 and Mef2c binding sites in the 5’enhancer region (-2,894/-2,889) didn't change the transcriptional activity of the Lrrc10 promoter and the likely GATA4 binding site identified was located in a region only 100 base pair (bp) upstream of the promoter. Our data provides insight into the molecular regulation of Lrrc10 expression, which probably also contributes to its tissue-specific expression.

• 한국세라믹학회지
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• 제53권3호
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• pp.317-324
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• 2016

Continued miniaturization and increasingly exact requirements for thin film deposition in the semiconductor industry is driving the search for new effective, efficient, selective precursors and processes. The requirements of defect-free, conformal films, and precise thickness control have focused attention on atomic layer deposition (ALD). ALD precursors so far have been developed through a trial-and-error experimental approach, leveraging the expertise and tribal knowledge of individual research groups. Precursors can show significant variation in performance, depending on specific choice of co-reactant, deposition stage, and processing conditions. The chemical design space for reactive thin film precursors is enormous and there is urgent need for the development of computational approaches to help identify new ligand-metal architectures and functional co-reactants that deliver the required surface activity for next-generation thin-film deposition processes. In this paper we discuss quantum mechanical simulation (e.g. density functional theory, DFT) applied to ALD precursor reactivity and state-of-the-art automated screening approaches to assist experimental efforts leading toward optimized precursors for next-generation ALD processes.

• Computers and Concrete
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• 제14권6호
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• pp.727-743
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• 2014

The management of existing concrete bridges has become a major social concern in many developed countries due to the large number of bridges exhibiting signs of significant deterioration. This problem has increased the demand for effective maintenance and renewal planning. In order to implement an appropriate management procedure for a structure, a wide array of corrective strategies must be evaluated with respect to not only the condition state of each defect but also safety, economy and sustainability. This paper describes a new performance evaluation system for existing concrete bridges. The system evaluates performance based on load carrying capability and durability from the results of a visual inspection and specification data, and describes the necessity of maintenance. It categorizes all girders and slabs as either unsafe, severe deterioration, moderate deterioration, mild deterioration, or safe. The technique employs an expert system with an appropriate knowledge base in the evaluation. A characteristic feature of the system is the use of neural networks to evaluate the performance and facilitate refinement of the knowledge base. The neural network proposed in the present study has the capability to prevent an inference process and knowledge base from becoming a black box. It is very important that the system is capable of detailing how the performance is calculated since the road network represents a huge investment. The effectiveness of the neural network and machine learning method is verified by comparing diagnostic results by bridge experts.