• 한국치위생학회지
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• 제14권4호
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• pp.447-452
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• 2014

With the increase of esthetic demands, most patients want to have restorations which are not only functional but also esthetic. For the esthetic restoration, many ceramic systems have been introduced and applied in dentistry. Among those ceramic restorations, IPS e.max system composed of lithium disilicate glass ceramic is one of the most commonly used systems because it has strength and esthetic characteristics. IPS e.max system is divided into IPS e.max Press and IPS e.max CAD according to the manufacturing methods. IPS e.max Press is fabricated through heat-pressed technique with ceramic ingot, which is very simple. The restorations which are made using IPS e.max system can apply to 3 units restoration for the anterior teeth and premolar, and single posterior tooth restoration. Cementation is one of the most important clinic procedure for the longevity of the restorations. All ceramics are bonded by resin cements, it is classified into three groups including adhesive, self-adhesive, and conventional. Variolink N, which is an adhesive resin cement and manufactured by same company with IPS e.max, is recommended for the bonding of IPS e.max restoration. Conventional and self-adhesive resin cement is also available. The aim of this review article is to provide the understanding of material properties, production procedure and clinical application of IPS e.max system.

• 대한토목학회논문집
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• 제26권1A호
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• pp.163-171
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• 2006

본 논문에서는 프리스트레스를 이용한 가시설 공법(IPS)에 적용되는 띠장을 이용한 굴착면의 해석 및 설계절차에 대한 연구를 수행하였다. 받침대의 갯수에 따라 설계토압을 받는 IPS 띠장의 초기 긴장력 계산식을 유도하였다. IPS 띠장으로 구성된 빌딩 굴착면의 전산해석을 위해 띠장은 뼈대요소, 지반은 압축력 전담요소, 케이블은 인장력 전담요소를 사용하여 등분포토압 및 편토압을 받는 굴착평면의 전산해석을 수행하였다. 긴장력과 설계토압에 의한 축력과 휨모멘트를 계산하여 축응력과 휨응력을 산출하고 합성응력검토를 수행하여 굴착면의 안전성을 검토하였다.

• 시스템엔지니어링학술지
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• 제16권2호
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• pp.87-96
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• 2020

In this paper we proposed the test design method of reliability growth management. First, we presented the process for establishing the reliability growth management test design considering the number of failures and the termination test time. Reliability growth analysis of continuous system was performed in accordance with the test design process presented. In case the reliability test result is not met with the reliability target value after more than three failures occurred, the required test times were analyzed that 1,725 hrs for one corrective action, 1,950 hrs for two corrective actions. If the number of failures is less than three, design a reliability demonstration test according to confidence level 80% and 90% was performed using RGA 11 Software. As a result, it is possible to establish the reliability growth management test design with sufficient use of available resources. The results of this study can be used when establishing a test design for assessment of reliability growth management of all continuous systems.

• 구강회복응용과학지
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• 제22권3호
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• pp.243-250
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• 2006

Due to high esthetic demands from patients, we are driven to fabricate natural-looking(form and color) restorations. In the past decade, the glass-ceramic in dentistry has been used as a material with variable crystals that affects the appearance, characteristics, and mechanical properties of metal-free fixed restoration. The conventional IPS Empress glass-ceramic is a heat-pressed, leucite reinforced material using the "lost wax" principle. This glass-ceramic has been successfully used for esthetic restorations such as all-ceramic crowns, inlays/onlays, and veneers for about 15 years. This article presents that the form and surface texture of clinical crown are duplicated by IPS-Empress system using "lost-wax technique".

• 한국멀티미디어학회논문지
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• 제9권8호
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• pp.1037-1044
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• 2006

실제 대규모 네트워크에서 사이버 공격으로 인한 보안시스템의 성능을 검증하기는 어렵다. 일반적으로 새로운 보안시스템이나 공격기법은 시뮬레이션을 통해 검증을 한다. 본 논문에서는 보안시스템 및 공격기법을 시뮬레이션 하기 위해 SSFNet을 사용하였다. SSFNet은 프로세스 기반 사건 중심 시뮬레이션 시스템이면서, 대규모 네트워크를 쉽게 표현할 수 있는 장점을 가지고 있다. 하지만 보안시스템이나 패킷을 조작할 수 있는 API를 제공하고 있지 않다. 본 논문에서는 보안 시스템으로 주로 사용하고 있는 방화벽과 IPS 클래스를 개발하여 SSFNet 구성요소로 추가하였다. 방화벽은 패킷 필터링 기반 보안 방화벽 시스템을 모델링하였다. IPS는 탐지 기능과 이상 패킷에 대한 드롭 기능을 가지고 있다. 확장된 SSFNet내에 네트워크를 모델링하여 방화벽과 IPS의 기능을 검증하였다. 방화벽은 패킷의 주소와 포트의 규칙을 통해 패킷을 차단하였다. 그리고 라우터에 기술된 IPS의 로그화면을 통해 패킷의 상태와 이상 패킷이 차단되는 것을 확인하였다.

• 한국강구조학회 논문집
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• 제17권5호통권78호
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• pp.627-636
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• 2005

본 논문에서는 프리스트레스를 이용한 가시설 공법(IPS)에 적용되는 중간 버팀보의 거동 해석 및 설계 절차에 대한 연구를 수행하였다. IPS 중간 버팀보는 조립 단면을 갖는 기둥과 같은 구조 부재이므로 이에 대한 안전성 검토가 필요하다. 중간 버팀보에 작용하는 하중은 기존 가시설에 재하되는 토압을 적용하여 IPS 중간 버팀보의 설계를 실시하였고 면내 외 좌굴거동 해석을 위한 전산해석모델을 작성하였다. IPS 중간 버팀보의 좌굴에 대한 고유치를 구한 값과 정적 해석을 통해 계산된 부재력을 이용하여 유효 좌굴장을 계산하였다. 허용 축방향 압축응력과 허용 휨압축응력을 도출해 합성응력 검토를 수행하여 IPS 중간 버팀보의 안전성을 검토하였다.

• 전력전자학회논문지
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• 제22권4호
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• pp.353-359
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• 2017

To take advantage of electric propulsion, several large vessel kinds, namely, cruise vessels, icebreakers, drill ships, and warships, have been generally designed with Integrated Power System (IPS). Although most of these vessels have adopted AC distribution IPS, DC distribution IPS ships have recently emerged as a new promising technology thanks to the availability of the products related to the DC distribution system, in which the system's major advantages over AC distribution are reduced weight and fuel consumption. This paper presents the comparison results of a 10-t class fishing boat for the AC distribution and DC distribution cases. By replacing AC distribution system with DC distribution, 31-41% reduction in the weight of the electrical equipment weight and 20-25% reduction in the fuel consumption are expected.

• 한국강구조학회 논문집
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• 제21권4호
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• pp.393-401
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• 2009

본 논문에서는 혁신적 프리스트레스트 가시설(IPS)에 적용되는 띠장에 대한 휨 강성식을 엄밀히 유도하고, 이를 바탕으로 실제 굴착 설계에 필요한 띠장의 등가 휨강성 설계식을 제시하였다. 횡 토압을 받는 IPS 띠장에 배치된 케이블 장력을 축 변형 효과를 고려한 경우와 무시한 경우에 대하여 각각 엄밀해를 도출하였다. 가상일의 원리를 이용하여 1-Post, 2-Post, 3-Post와 4-Post의 받침대를 갖는 IPS 띠장 중앙부의 수직변위를 유도하였고, 지간장과 케이블 경사각의 변화에 따른 띠장의 휨 거동 특성을 파악하였다. 유도된 중앙부 변위로부터 실제 굴착면 설계시 활용될 수 있는 간략화된 IPS 띠장의 등가 휨강성을 제시하였고, 본 연구에서 도출된 엄밀해 및 범용 유한요소해석 프로그램을 이용한 결과 비교를 통하여 제시된 설계식의 타당성을 입증하였다.

• 대한치과보철학회지
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• 제39권6호
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• pp.641-658
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• 2001

All-ceramic restorations have become an attractive alternative to porcelain-fused-to-metal crowns. In-Ceram, and more recently IPS Empress 2 were introduced as a new all-ceramic system for single crowns and 3-unit fixed partial dentures. But their strength and marginal fit are still an important issue. This study evaluated the fracture resistance and marginal fit of three systems of 3 unit all-ceramic bridge fabricated on prepared maxillary anterior resin teeth in vitro. The 3 all-ceramic bridge systems were: (1) a glass-infiltrated, sintered alumina system (In-Ceram) fabricated conventionally, (2) the same system with copy-milled alumina cores (copy-milled In-Ceram), (3) a heat pressed, lithium disilicate reinforced glass-ceramic system (IPS Empress 2). Ten bridges of each system with standardized design of framework were fabricated. All specimens of each system were compressed at $55^{\circ}$ at the palatal surface of pontic until catastrophic fracture occurred. Another seven bridges of each system were fabricated with standard method. All of the bridge-die complexes were embedded in epoxy resin and sectioned buccolingually and mesiodistally. The absolute marginal discrepancy was measured with stereomicroscope at ${\times}50$ power. The following results were obtained: 1. There was no significant difference in the fracture strength among the 3 systems studied. 2. The Weibull modulus of copy-milled In-Ceram was higher than that of In-Ceram and IPS Empress 2 bridges. 3. Copy-milled In-Ceram($112{\mu}m$) exhibited significantly greater marginal discrepancy than In Ceram ($97{\mu}m$), and IPS Empress 2 ($94{\mu}m$) at P=0.05. 4. The lingual surfaces of the ceramic crowns showed smaller marginal discrepancies than mesial and distal points. There was no significant difference between teeth (incisor, canine) at P=0.05. 5. All-ceramic bridges of three systems appeared to exhibit sufficient initial strength and accept able marginal fit values to allow clinical application.

• 대한치과보철학회지
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• 제40권6호
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• pp.572-576
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• 2002

This investigation was designed to estimate the biaxial flexure strength and fracture toughness of lithium disilicate glass-ceramics of IPS Empress 2 system pressed with as-received ingots and their sprue buttons. Two groups of the lithium disilicate glass-ceramics were prepared as follows: group 1 is ingot-pressed group; group 2 is sprue button-pressed group. A ball-on-three-ball test was used to determine biaxial flexure strength (BFS) of disks in wet environment. Scanning electron microscopy(SEM) analysis was conducted to observe the microstructure of the ceramics. Unpaired t-test showed that there were no differences in the mean biaxial Hem strength (BFS) and KIC values between group 1 and 2 (p > 0.05). Two groups showed similar values in the KIC and the strength at 5% failure probability. The SEM micrographs of the IPS Empress 2 glass-ceramic showed a closely packed, multi-directionally interlocking pattern of numerous lithium disilicate crystals protruding from the glass matrix. The lithium orthophosphate crystals could not be observed on the fracture surface etched. There was no a marked difference of the microstructure between group 1 and 2. Although there were no tests including color stability, casting accuracy, etc., the results of this study implied that we could reuse the sprue button of the pressed lithium disilicate glass-ceramic of IPS Empress 2 system.