• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.291-300
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• 2020

The cartridges used for illuminating a desired point or area are virtually limited in tests and evaluations because of limitations, such as noise during launch, the possibility of fires caused by illuminant charge, and the annual testable quantity. Therefore, to solve these problems, a ground fixed test, which replaces the firing test, or an evaluation method to perform limited tests, can be applied more efficiently. In this paper, the results of an 81mm illuminating cartridge, KM series performed in 2019 were analyzed comprehensively to identify the trends in reliability and quality characteristics and to estimate the shelf life. The shelf life was estimated to be at least 10 years based on the time when the lower confidence level reached 80% at a confidence level of 90%. Considering only major defects, the shelf life can be estimated to be approximately 23 years. On the other hand, the shelf life was estimated to be approximately 11 to 15 years and 25 to 28 years according to the effective illuminating time. Finally, an assessment plan of illuminating cartridges for the mortars was also presented as an improvement plan for an assessment method in the future.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.511-513
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• 2001

이동 컴퓨팅 환경에서는 충분하지 못한 자원으로 인해 기존의 분산 알고리즘이 비효과적인 경우가 많다. 특히 이동 호스트의 낮은 가용성으로 인하여 중단 없는 서비스를 보장받기 힘들다. 이들의 원인은 낮은 대역폭과 호스트들의 이동성, 작은 저장공간 및 안전하지 않은 저장장치, 이동 호스트와 기지국간 또는 이동 호스트들 사이의 통신 오버헤드 그리고 충분하지 못한 베터리 수명들을 들 수 있다. 특히 통신 오버헤드(이동 호스트를 찾는 비용, 이동 호스트의 정보를 저장하는 비용 등)로 인해 이동 호스트의 베터리 수명을 단축시키고 통신 비용을 증가시킨다. 이러한 통신 오버헤드를 최소화함으로써 이동 호스트의 베터리 수명을 연장시키고 시스템의 성능을 향상시킬 수 있다. 본 논문에서는 셀룰라 네트워크를 기반으로 하는 이동 컴퓨팅 환경에서 통신비용과 이동 호스트의 작업을 최소화시키는 조정된 체크포인팅(coordinated checkpointing) 알고리즘을 제안하고 수학적으로 비용을 분석하였으며 기존 알고리즘과 성능을 비교하였다.

• Journal of Internet of Things and Convergence
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• v.9 no.3
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• pp.81-86
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• 2023

SSD (solid state disk), which is flash memory-based storage device, has the advantages of high density and fast data processing. Therefore, it is being utilized as a storage device for high-capacity data storage systems that manage rapidly increasing big data. However, flash memory, a storage media, has a physical limitation that when the write/erase operation is repeated more than a certain number of times, the cells are worn out and can no longer be used. In this paper, we propose a method for converting defective multi-bit cells into single-bit cells to reduce the defect rate of flash memory and extend its lifetime. The proposed idea distinguishes the defects and treatment methods of multi-bit cells and single-bit cells, which have different physical characteristics but are treated as the same defect, and converts the expected defective multi-bit cells into single-bit cells to improve the defect rate and extend the overall lifetime. Finally, we demonstrate the effectiveness of our proposed idea by measuring the increased lifetime of SSD through simulations.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.60-60
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• 2020

본 연구는 수확 단계에 따른 작약 주요 품종의 수확후 품질 특성을 조사하여 품종별 적정 수확 시기를 구명하고자 수행하였다. 절화 작약은 '두체스', '레드참', '보울오브크림' 품종을 사용하였으며, 세 품종 모두 1, 2, 3, 4단계로 구분 지어 수확하여 실험에 사용하였다. 수확한 작약은 40cm로 재절단하여 chrysal professional III 용액이 담긴 화병에 꽃아 생체중, 증산량, 수분흡수량, 개화 단계 변화 등을 매일 조사하였고, 이를 통해 수분균형 및 절화 수명 등의 결과를 도출하였다. '두체스' 품종의 품질 특성 변화를 조사한 결과, 1단계에 수확한 절화의 만개소요일수는 5.5일, 만개유지일수는 2.9일, 총 절화수명은 8.4일로 다른 수확단계보다 1~3일 더 긴 것으로 조사되었으며, 생체중증가율 및 화경 변화 결과를 통해 1단계 수확 시에도 개화는 정상적으로 진행되는 것을 확인할 수 있었다. '레드참' 품종의 품질 특성 변화 조사 결과, 1단계에 수확한 절화의 만개소요일수는 7.9일, 만개유지일수는 3.3일, 총 절화수명은 11.2일로 다른 수확단계보다 1~4일 더 긴 것으로 조사되었다. '보울오브크림' 품종의 품질 특성 변화 조사 결과, 1단계 수확한 절화는 30% 수준만 만개하여 조기 수확에 따른 문제점이 확인되었지만, 2단계 수확한 절화는 개화와 만개 모두 100% 진행되었으며, 만개소요일수는 6.4일, 만개유지일수는 4.5일, 총 절화수명은 10.9일로 다른 수확단계보다 1~2일 긴 것으로 조사되었다. 본 연구 결과, '두체스' 와 '레드참' 품종의 적정 수확단계는 1단계, '보울오브크림' 품종의 적정 수확단계는 2단계가 적절할 것으로 판단된다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.996-997
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• 2008

본 논문에서는 마일드 하이브리드 자동차에 적용 가능한 복합형 에너지 저장 장치의 운용 효율 및 수명 개선이 가능한 스위치 제어 알고리즘을 제안하였다. 제안한 제어 알고리즘은 복합형 에너지 저장 장치를 구성하는 축전지와 울트라커패시터의 전압, 전류, 전력 및 SOC의 변화에 따라 스위치를 적절히 제어함으로써, 시스템 전체의 운용 효율을 개선하고, 또한 축전지에 대전류 충/방전 상황 발생을 제한시켜 축전지의 수명저하 현상을 둔화시킨다. 본 논문에서는 마일드 하이브리드 자동차의 운행 조건을 모사한 사이클 프로파일과 차량 시뮬레이터 장비를 활용하여, 단순병렬 구성의 에너지 저장장치와 스위치 제어 알고리즘이 적용된 에너지 저장장치의 운용효율을 비교함으로써 제안한 알고리즘의 유용성을 확인하였다.

• Korean Journal of Food Science and Technology
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• v.21 no.6
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• pp.876-883
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• 1989

In order to investigate the index component and basis for the shelf-life of the grain share improved Meju, the effect of the storage time and package on the quality of Meju and soy sauce were studied during 90 days storage at $30^{\circ}C$. Also, sensory evaluation for the soy sauces from Meju with various storage time were carried out. During the storage period, moisture content, amylase and protease activity were decreased, on the other hand, the contents of amino-nitrogen and ammonia-nitrogen were increased. Among these components, protease activity was found the major index component for quality control because it was the most important component for soy sauce fermentation and the most changeable component of Meju during the storage period. According to the sensory test, the quality of soy sauce was agreed well with the protease activity of Meju, and the soy sauce from longer storage Meju was inferior organoleptic quality to that from shorter Meju. By the storage quality test, protease activity showed the highest value in 15 days storage Meju and decreased gradually with storage time passed. The basis of protease activity for quality control was 200 (O.D. at 660 nm/g). which was 50% of the initial activity And it was known that the shelf-life of the grain shape improved Meju was about 90 days . It was also shown that the storage in package did not affect noticeably to prolong the shelf-life of Meju on this study.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.82-87
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• 1990

To investigate the shelf-life of the brick share improved Meju, the effect of the storage time and packaged storage on the quality of Meju and soy sauce were studied during 90 days storage at $30^{\circ}C$. During the storage period, pretense activity was rapidly increased, and it reached the maximum value after 30 days of storage and then decreased gradually with storage time. By the sensory evaluation, the soy sauce from Meju which was longer storage was increased its brown color but less sensory quality on taste and flavor. The sensory evaluation score of soy sauces were closely related to the value of protease activity of Meju, So, it was shown that the protease activity was also the major index component on the quality control for the brick shape improved Meju. The protease activity of brick shape Meju was lower during Meju making but decreased slowly during storage period than that of grain shape meju. The values of protease of Meju after 30 days storage were 359 (O.D. at 660 nm/g) in non-packaged, 349 in packaged Meju and after 180 days storage were 207,205, respectively. It was shown that the shelf-life of the brick shape improved Meju was about 180 days by the basis (protease activity: 200 O.D. at 660nm/g) for quality control from the grain shape Meju, and it was longer than that of grain shape Meju. It was also shown that the packaged storage did not prolong the shelf-life of the brick shape improved Meju.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.230-238
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• 2014

The purpose of this study was to develop the cost-effective and efficiency seed longevity prediction method of rice (Oryza sativa L.) germplasm for viability monitoring. To find an optimum predicting method for rice seed longevity at genebank, an accelerated ageing (AA) test, a controlled deterioration (CD) test and a dry-heat treatment (DHT) were conducted to the four groups of rice germplasm based on ecotype, such as Indica, Japonica, Javanica and Tongil type. Among the three artificial aging treatments, the dry-heat treatment of 36 hours at $90^{\circ}C$ is suggested as a routine predictive test method of rice germplasm longevity at a genebank. The distribution of germination rate on 3,066 accessions which conserved 26.5 years at $4^{\circ}C$ showed similar trend with the result of distribution by dry-heat treatment at $90^{\circ}C$ on 36 hours using 106 accessions of rice selected samples which composed four ecotype groups. The results show that the dry-heat treatment affect not only predicting the rice seed longevity but also determining effective interval for monitoring germination of rice germplasm in genebanks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1735-1740
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• 2010

The propellant KM10, a single propellant manufactured nitrocellulose, is known to cause natural degradation phenomena at long term storage. The self-life was estimated using generally used high temperature acceleration aging tests to analyze the content of stabilizer and using the Arrhenius equation & Berthelot equation to calculate reaction rate constants. According to the result of this study, self-life of propellant KM10 using the Arrhenius equation & Berthelot equation appear significantly different as 43.73, 16.53years and when compared with the paper of E. R. Bixon, self-life of propellant KM10 predicted using the Arrhenius equation was reasonably determined.

• Journal of the Korean Institute of Gas
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• v.9 no.2 s.27
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• pp.34-37
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• 2005

The membrane for LNG storage tank behaves linearly in macroscopic view, but behaves elasto-plastically in some local areas, and has the structure undergoing both tension and bending. That is, the membrane is not able to be evaluated with the fatigue characteristics of the material, and it is so difficult to evaluate the membrane with a real big model because of the difficulty of imposing complex loads. Therefore, a prediction formula fur the fatigue life of the membrane is proposed to use for the design of LNG storage tank.