• Proceedings of the Safety Management and Science Conference
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• 2009.04a
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• pp.153-165
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• 2009

It is hot issue to get the competitiveness of product through reliability-growth as well as availability and safety in almost high-technology industry including military, chemistry, nuclear, telecommunication, transportation service and so on. In advanced countries, they experienced remarkable growth based on reliability technology in materials&parts industry as well as high-tech industry. It has become a symbol of national competitiveness and created a higher value added. This paper is taking on effectively developing ways to deploy IEC 60300 dependability management system and the base technology that are needed to improve competitiveness of industries in Korea.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.252-257
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• 2010

The availability of the thermal energy has been deeply recognized recently to encourage the cascade usage of thermal energy from combustion. Within the frame work, a 1 kW class Stirling engine based cogeneration system has been proposed for a unit of a distributed energy system. The capacity has been designed to be adequate for the domestic usage, which requires high compactness as well as low emission and noised. To develop a highly efficient system with satisfying these requirements, a premixed slot flame burner has been proposed and a series of numerical simulation has been performed to establish a design tool for the combustion chamber. The thermal radiation model has been found to highly affect the computational results and a proper resolution to analyze the heat transfer characteristics of the high temperature heat exchanger. Finally, the combustion characteristics of the premixed flame with the metal fiber type burner has been studied.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.168-171
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• 1999

A fault-tolerant system should have a high availability and high reliability to maintain a given system stable against sudden faults in the system. In this paper, we propose a new types of fault tolerant system based on a fault detection bus. The fault detection bus is designed and implemented to detect any errors by comparing event-output signals from two processor modules. It employs the hot standby sparing fault detection method〔1〕 to provide continuity of services even if a system fault occurs. The prototype fault tolerant system is currently being implemented on a management system with two processor modules.

• Corrosion Science and Technology
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• v.11 no.5
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• pp.179-183
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• 2012

As one of promising solutions to overcome high oil price and energy crisis, the construction market of high value-added LNG plants is spotlighted world widely. The purpose of this study is to introduce LNG-RBI system to develop risk assessment technology with RAM(Reliability, Availability, Maintainability) modules against overseas monopolization. After analyzing relevant specific features and their technical levels, risk assessment program, non-destructive reliability evaluation strategy and safety criteria unification class are derived as core technologies. These IT-based convergence technologies can be used for enhancement of LNG plant efficiency, in which the modular parts are related to a system with artificial optimized algorithms as well as diverse databases of facility inspection and diagnosis fields.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.84-90
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• 2000

Integrated tools are developed for the analysis of the aerodynamic performance and aeroacoustics of helicopter rotors. Heli-NK(Helicopter Navier-Stokes & Kirchhoff) code is for hovering and heli-PA(Helicopter Panel & Acoustic analogy) for forward flight. The former showed its ability to predict the hovering efficiency and high-speed impulsive noise level. Thrust calculation, noise levels, and noise directivity patterns are investigated to confirm the availability of the latter. With some proper validation and improvements. these codes will be more useful and practical.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.243-246
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• 2008

The Compact Airborne Imaging Spectrometer System (CAISS) was jointly designed and developed as the hyperspectral imaging system by Korea Aerospace Research Institute (KARI) and ELOP inc., Israel. The primary mission of the CAISS is to acquire and provide full contiguous spectral information with high quality spectral and high spatial resolution for advanced applications in the field of remote sensing. The CAISS consists of six physical units; the camera system, the gyro-stabilized mount, the jig, the GPS/INS, the power inverter and distributor, and the operating system. These subsystems shall be tested and verified in the laboratory before the flight. Especially the camera system of the CAISS shall be calibrated and validated with the calibration equipments such as the integrated sphere and spectral lamps. To improve data quality and availability, it is the most important to understand the mechanism of hyperspectral imaging system and the radiometric and spectral characteristics. This paper presents the major characteristics of camera system on the CAISS and summarizes the results of radiometric and spectral experiment during preliminary system verification.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.569-575
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• 2014

Although mammography is the primary imaging modality for the breast, it has its limitations especially with dense breast parenchyma. Breast magnetic resonance imaging (MRI) has evolved into an important adjunctive tool as it is currently the most sensitive technique for breast cancer detection. Despite this high sensitivity, overlap in the appearances of some benign and malignant breast lesions results in additional unnecessary intervention with negative results. These false positives, in addition to high cost and limited availability, necessitate establishing proper indications for breast MRI. The literature was here reviewed for recent clinical trials, meta-analyses and review papers which have studied this important subject. PubMed; the US national library of medicine, was utilized to review the literature in the last twenty years. Using the obtained information, current uses of breast MRI are discussed in this paper to determine the indications which are relevant to clinical practice.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.403-406
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• 2000

최근 통신망 인프라 구축이 늘어나면서 이의 신뢰성(Reliability)과 가용성(Availability)이 경제 주체인조직 전반의 생산성에 미치는 영향이 그 만큼 커지고 있다. 정보 흐름의 파이프 역할을 담당하고 있는 통신망 시설(하드웨어 및 운용 프로토콜)에 일시적인 장애가 발생할 경우 이로 인해 조직은 엄청난 손실을 입을 수 있다. 따라서 통신망을 안정적으로 운용할 수 있는 보다 효과적인 수단이 요구되고 있다. 통신망에서의 장애를 효과적으로 해결하기 위해서는 장애를 추적하는 장애처리티켓시스템(Trouble Ticket System)이 필요하다. 장애처리티켓시스템은 궁극적으로 네트워크 운영 방식을 획기적으로 개선함으로써 통신망 장애로 인한 시간적, 경제적 손실을 최소화할 수 있다. 본 논문에서는 장애추적해결시스템의 설계와 구현을 통해서 국내 실정에 맞는 장애처리티켓시스템 개발에 적극 활용할 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.7
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• pp.1599-1606
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• 1997

The software RAID file system is defined as the system which distributes data redundantly across an aray of disks attached to each workstations connected on a high-speed network. This provides high throughput as well as higher availability. In this paper, we present an efficient caching scheme for the software RAID filte system. The performance of this schmem is compared to two other schemes previously proposed for convnetional file systems and adapted for the software RAID file system. As in hardware RAID systems, small-writes to be the performance bottleneck in softwre RAID filte systems. To tackle this problem, we logically divide the cache into two levels. By keeping old data and parity val7ues in the second-level cache we were able to eliminate much of the extra disk reads and writes necessary for write-back of dirty blocks. Using track driven simulations we show that the proposed scheme improves performance for both the average response time and the average system busy time.

• Nuclear Engineering and Technology
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• v.22 no.4
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• pp.380-388
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• 1990

The MM-22 medical microtron at Korea Cancer Center Hospital is now operational for high energy electron and photon therapy, This microtron is designed to produce 5.3-22.5 MeV electron beams and deliver these to the treatment head through beam transport system with an intensity and stability suitable for cancer treatment. The availability of high quality radiation modalities from the MM-22 shows new possibilities in the treatment of deep seated tumours. Principle of operation, system structures and operating characteristics of the MM-22 are described in this paper.