• International Journal of Aeronautical and Space Sciences
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• v.3 no.2
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• pp.31-39
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• 2002

In this paper, KOMPSAT-2 on-board fault and ground recovery management design is addressesed in terms of hardware and software components which provide failure detection and spacecraft safing for anomalies which threaten spacecraft survival. It also includes ground real time up-commanding operation to recover the system safely. KOMPSAT-2 spacecraft fault and recovery management is designed such that the subsequent system configuration due to system initialization is initiated and controlled by processors. This paper will show that KOMPSAT-2 has a new design feature of CPU SEU mitigation for the possible upsets in the processor CPUs as a part of on-board fault management design. Recovery management of processor switching has two different ways: gang switching and individual switching. This paper will show that the difficulties of using multiple-processor system can be managed by proper design implementation and flight operation.

• Journal of Power Electronics
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• v.9 no.1
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• pp.93-99
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• 2009

A new plasma display panel sustaining driver using single side sustaining technique with a dual resonant method is proposed in this paper. Since this circuit enables to keep device voltage stress same as the prior circuit, it can be a low cost circuit compared to a conventional driver. To integrate the sustaining function into one side with a single power source in the driver, a charge pump method is adopted to make negative sustaining voltage and to achieve dual resonant energy recovery on the sustaining modes.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.105-111
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• 2003

ORVR filler neck check valve, which is one of the essential components of the vapor fuel control system, should diminish the evaporation by maintaining laminar fluid flow on refueling process. This study presents numerical. results of pressure and velocity distributions of the fluid flow in a ORVR filler neck check valve on refueling process. CFD-ACE+ has been employed for numerical analysis based on the information of experimental results of valve position as a function of inlet flow rate. No abrupt pressure change, which may causes vaporization of fuel, has been confirmed to take place on the concave surface of the valve spool. However, it is clear that some possibility exist at the mid-position of surface of valve spool and downstream according to the opening of valve.

• Journal of Aerospace System Engineering
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• v.3 no.2
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• pp.31-38
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• 2009

COMS On-board FDIR(Failure Detection, Isolation and Recovery) functions are implemented on the on-board software to satisfy the autonomy and failure tolerance requirements. This paper presents concepts of COMS Failure Management with hierarchical layers and addresses the characteristics of the FDIR layer from low level to high level. It is aimed at giving the reader the understanding how the COMS FDIR was designed and how works. It first recalls what are the system level applicable requirements, which are based on the COMS mission requirements. Then it describes the philosophy and structure of the FDIR and subsequently breaks it down into the several FDIR layers. It could be used as an important and useful reference of the information to design and develop an automatic FDIR mechanism in the future.

• Clean Technology
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• v.2 no.1
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• pp.47-52
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• 1996

The solvent extraction method was applied on a spent solution containing copper, which was produced in a printed circuit board process, to recover copper and to reuse the etching solution. Lix 64 N ($\alpha$-Hydroxyoxime + $\beta$-Hydroxybenzophenone Oxime) was used as a solvent. The acidic spent copper solution was mixed with and alkaline copper solution to pH=2. The solvent including 30 volume% of Lix 64 N extracted 17.1gr/l of copper from the mixed spent copper solution. In the continuous bench scale experiment, 4 stages for extraction, 2 stages for stripping and 4 stages for washing were used. Recovered copper was recycled as copper sulfate and the raffinate was reused as copper etchant. The percentage of copper recovery and the purity of copper sulfate were higher than 99.9%, respectively.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.446-448
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• 2008

A new plasma display panel sustaining driver using single side sustaining technique with the dual resonant method is proposed. Since this circuit enables to reduce switches in energy recovery circuit with keeping voltage stress like that of prior circuit, it can be low cost circuit comparing with a conventional driver. To integrate sustain function into one side with single power source in the driver, a charge pump method is adopted to make negative sustaining voltage and achieve dual resonant energy recovery on sustaining modes.

• Weed & Turfgrass Science
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• v.5 no.2
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• pp.88-94
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• 2016

Vehicular traffic on turf results in loss of green cover due to direct tearing of shoots and indirect long-term soil compaction. Protection of turfgrass crowns from wear could increase the ability of turf to recover from heavy traffic. Plastic turfpavers have been installed in trafficked areas to reduce soil compaction and to protect turfgrass crowns from wear. The objectives of this study were to evaluate traffic performance of turfgrasses (Zoysia matrella and Axonopus compressus) and soil mixture (high, medium and low sand mix) combinations on turf-paver complex. The traffic performance of turf and recovery was evaluated based on percent green cover determined by digital image analysis and spectral reflectance responses by NDVI-meter. Bulk density cores indicated significant increase in soil compaction from medium and low sand mixtures compared to high sand mixture. Higher reduction of percent green cover was observed from A. compressus (30-40%) than Z. matrella (10-20%) across soil mixtures. Both turf species displayed higher wear tolerance when established on higher sand (>50% sand) than low sand mixture. Positive turf recovery was also supported by complementary spectral responses. Establishment of Zoysia matrella turf on turfpaver complex using high sand mixture will result in improved wear tolerance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.120-126
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• 2013

This paper proposes a novel scheme of fault detection and self-recovery for space-borne dual ring counters subject to transient faults. The considered ring counter is equipped with hardware redundancy, but it has a limited output domain where direct access to the current state is unavailable. We employ the theory of corrective control to detect any transient fault occurring to the counter bits and to realize immediate self-recovery of the ring counter back to the normal state. The structure of the fault-tolerant controller is designed to be minimal regardless of the counter size. To validate the applicability, we implement the proposed system on a commercial FGPA board.

• Journal of the Korea Computer Industry Society
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• v.3 no.8
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• pp.1105-1116
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• 2002

This paper has presented three types of key recovery methods, which are known as key escrow, key encapsulation, and trusted third party scheme. we have analyzed the existing key recovery products, which have been developed by the advanced nations for electronic commerce and electronic government. we have also analyzed the key recovery policies proposed by the advanced nations, such as The United States of America, Great Britain, and Japan. In this paper, several key recovery policies are proposed for the e-commerce and e-government system. And we have proposed key recovery scheme for the e-commerce system utilizing the on-line secret sharing scheme based on the Internet and public bulletin board.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.1
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• pp.29-43
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• 1998

This study was to investigate the effect of .compressive load and cyclic humidity(2$0^{\circ}C$, 65% and 90% RH) on the physical and mechanical properties of corrugated board. Corrugated boards in the study were under compressive load and under cyclic humidity, and their properties were compared to those without load. Results were summarized as follows ; 1 Statistically significant correlation was shown between the ring crush of the boards and the compressive strength of cylinder specimen made from the boards. So we could study the compressive behavior of board with cylinder specimen. 2. The boards under the compressive load increased their moisture content and thickness much more than those without load both in constant and in cyclic RH. 3. The compressive and tensile strength of board samples were inversely and closely proportional to the sheet moisture content regardless of their load and humidity history. 4. The moisture content did not show any significant proportionality to the change of burst strength of boards within this experiment. 5. Board reconditioning in standard condition led to the recovery of the strength loss that had occurred under various load and humidity condition. 6. The handsheets prepared from the boards that had experienced compressive load and cyclic humidity, and those with no-load and 65% RH did not show any significant difference in strength properties. No physical damage or load-carrying properties of the wood fiber were observed by the compressive load and cyclic humidity history.