• 한국초전도ㆍ저온공학회논문지
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• 제26권1호
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• pp.20-24
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• 2024

Over the past four years, as the COVID-19 pandemic has struck the world, cold chain of COVID-19 vaccination has become a hot topic. In order to overcome the pandemic situation, it is necessary to establish a cold chain that maintains a low-temperature environment below approximately 203K (-70℃), which is the appropriate storage temperature for vaccines, from vaccine suppliers to local hospitals. Usually, cryocoolers are used to maintain low temperatures, but it is difficult for small-scale local distribution to have cryocooler due to budget and power supply issues. Accordingly, in this paper, a cryogenic TSU (Thermal storage unit) system for vaccination cold chain is designed that can maintain low temperatures below -70℃C for a long time without using a cryocooler. The performance of the TSU system according to the energy storage material for using as TSU is experimentally evaluated. In the experiments, four types of cold storage materials were used: 20% DMSO aqueous solution, 30% DMSO aqueous solution, paraffin wax, and tofu. Prior to the experiment, the specific heat of the cold storage materials at low temperature were measured. Through this, the thermal diffusivity of the materials was calculated, and paraffin wax had the lowest value. As a result of the TSU system's low-temperature maintenance test, paraffin wax showed the best low-temperature maintenance performance. And it recorded a low-temperature maintenance time that was about 24% longer than other materials. As a result of analyzing the temperature trend by location within the TSU system, it was observed that heat intrusion from the outside was not well transmitted to the low temperature area due to the low thermal conductivity of paraffin wax. Therefore, in the TSU system for vaccine storage, it was experimentally verified that the lower the thermal diffusivity of the cold storage material, the better low temperature maintenance performance.

• 한국산학기술학회논문지
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• 제20권1호
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• pp.28-34
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• 2019

태양열은 지구에서 가장 풍부한 재생에너지 중의 하나이지만, 일반적으로 태양열이 풍부한 계절과 열부하가 큰 계절이 서로 달라 사용에 제한이 있다. 유럽과 캐나다에서는 하절기의 풍부한 태양열을 저장하고 그 열을 동절기 난방부하에 활용하여 에너지를 절감하는 태양열 계간축열시스템을 활용하고 있다. 최근 물탱크방식 및 지중축열방식의 태양열 계간축열시스템이 국내에 소개되어 실증연구가 활발히 진행 중이다. 본 연구에서는 연간 2,164 GJ의 난방부하를 가진 경기도 화성시의 유리온실 1개동에 $2,000m^2$의 평판형 태양열 집열기, $20,000m^2$의 지중 계간축열조를 사용하고 단기축열조를 사용하지 않는 보어홀 방식의 태양열 지중 계간축열시스템을 모델링하여, 운전제어조건에 따른 태양열 이용률을 평가하였다. 시간에 따른 태양열 지중 계간축열시스템의 동적성능예측을 위하여 TRNSYS 18 프로그램을 이용하여 시뮬레이션 하였다. 결과적으로 본 연구에서 제안한 태양열 지중 계간축열시스템은 태양열 집열과 지중 계간축열조 방열에 각각 차온 제어 하였을 때, 5년간 평균 약 60%의 태양열 이용률을 나타내었다. 본 연구에서 제안된 시스템은 태양열 지중 계간축열시스템의 구성과 제어방법을 단순화하고 성능을 확보하였다.

• 한국안전학회지
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• 제31권4호
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• pp.9-14
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• 2016

STS304L of membrane structure has been used for a LNG storage tank and has exposed long time under the cryogenic temperature. The purposes of this study are to evaluate the mechanical properties of base and used materials for STS304L of membrane. The tensile and high cycle fatigue tests were investigated for STS304L of membrane used over 20 years at room temperature and $-162^{\circ}C$. In addition, the test of base STS304L was performed in order to compare with used material properties. The chemical composition and phase change were investigated from EDS and XRD. From results of tensile test, yield and ultimate tensile strengths of used STS304L are smaller than those of base STS304L. S-N curves were obtained from fatigue tests at both temperatures. Also, P-S-N curves were presented with statistical method recommend by JSME-S002. Fractography was conducted for analysis of fracture mechanisms.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.101-101
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• 2000

MSC(Multispectral Camera), which will be a unique payload on KOMPSAT-II, is designed to collect panchromatic and multi-spectral imagery with a ground sample distance of 1m and a swath width of 15km at 685km altitude in sun-synchronous orbit. The instrument is designed to have an orbit operation duty cycle of 20% over the mission life time of 3 years. MSC electronics consists of three main subsystems; PMU(Payload Management Unit), CEU(Camera Electronics Unit) and PDTS(Payload Data Transmission Subsystem). PMU performs all the interface between spacecraft and MSC, and manages all the other subsystems by sending commands to them and receiving telemetry from them with software protocol through RS-422 interface. CEU controls FPA(Focal Plane Assembly) which contains TDI(Timc Delay Integration) CCD(Charge Coupled Device) and its clock drivers. PMU provides a Master Clock to synchronize panchromatic and multispectral camera. PDTS performs compression, storage and encryption of image data and transmits them to the ground station through x-band.

• Journal of Preventive Medicine and Public Health
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• 제41권3호
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• pp.195-199
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• 2008

Objectives : Malondialdehyde (MDA), a lipid peroxidation by-product, has been widely used as an indicator of oxidative stress. Urinary 2-naphthol, a urinary PAH metabolite, is used as a marker of ambient particulate exposure and is associated with lung cancer and chronic obstructive pulmonary disease. However, the stability and intra-individual variation associated with urinary MDA and 2-naphthol have not been thoroughly addressed. The objective of this study was to assess the stability and intra-individual variation associated with urinary MDA and 2-naphthol. Methods : Urine samples were collected from 10 healthy volunteers (mean age 34, range $27{\sim}42$ years old). Each sample was divided into three aliquots and stored under three different conditions. The levels of urinary MDA and 2-naphthol were analyzed 1) just after sampling, 2) after storage at room temperature ($21^{\circ}C$) for 16 hours, and 3) after storage in a $-20^{\circ}C$ freezer for 16 hours. In addition, an epidemiological study was conducted in 44 Chinese subjects over a period of 3 weeks. The urinary MDA and 2-naphthol were measured by HPLC three times. Results : There was no difference in the levels of urinary MDA and 2-naphthol between the triplicate measurements (n=10, p=0.84 and p=0.83, respectively). The intra-class correlation coefficients (ICC) for urinary MDA and 2-naphthol were 0.74 and 0.42, respectively. However, the levels of PM2.5 in the air were well correlated with the levels of both MDA and 2-naphthol in the epidemiological study. Conclusions : These results suggest that urinary MDA and 2-naphthol remain stable under variable storage conditions, even at room temperature for 16 hours, and indicate that these markers can be used in epidemiological studies involving various sample storage conditions. The intra-CC of urinary 2-naphthol and MDA were acceptable for application to epidemiological studies.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.601-603
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• 2004

Multi-Spectral Camera(MSC) is a payload on the KOMPSAT -2 satellite to perform the earth remote sensing. The instrument images the earth using a push-broom motion with a swath width of 15 km and a ground sample distance (GSD) of 1 m over the entire field of view (FOV) at altitude 685 Km. The instrument is designed to have an on-orbit operation duty cycle of $20\%$ over the mission lifetime of 3 years with the functions of programmable gain! offset and onboard image data compression/storage. MSC instrument has one(1) channel for panchromatic Imaging and four(4) channel for multi-spectral Imaging covering the spectral range from 450nm to 900nm using TDI CCD Focal Plane Array (FPA). In this paper, the configuration, the interface of MSC hardware and the MSC operation concept are described. And the method of the MSC calibration are described and the design of MSC calibration operation to measure the change of MSC after Launch & Early Operation(LEOP) and normal mission operations are discussed and analyzed.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.825-827
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• 2003

Multi-Spectral Camera(MSC) is a payload on the KOMPSAT-2 satellite to perform the earth remote sensing. The instrument images the earth using a push-broom motion with a swath width of 15 km and a ground sample distance (GSD) of 1 m over the entire field of view (FOV) at altitude 685 Km. The instrument is designed to have an on-orbit operation duty cycle of 20% over the mission lifetime of 3 years with the functions of programmable gain/ offset and on-board image data compression/storage. The MSC instrument has one(1) channel for panchromatic imaging and four(4) channel for multi-spectral imaging covering the spectral range from 450nm to 900nm using TDI CCD Focal Plane Array (FPA). In this paper, the architecture and function of MSC hardware including electrical interface and the operation concept which have been established based on the mission requirements are described. And the design and the preparation of MSC system operation are analyzed and discussed.

• Journal of Information Processing Systems
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• 제14권4호
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• pp.989-1009
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• 2018

Rapid advances in science and technology with exponential development of smart mobile devices, workstations, supercomputers, smart gadgets and network servers has been witnessed over the past few years. The sudden increase in the Internet population and manifold growth in internet speeds has occasioned the generation of an enormous amount of data, now termed 'big data'. Given this scenario, storage of data on local servers or a personal computer is an issue, which can be resolved by utilizing cloud computing. At present, there are several cloud computing service providers available to resolve the big data issues. This paper establishes a framework that builds Hadoop clusters on the new single-board computer (SBC) Mobile Raspberry Pi. Moreover, these clusters offer facilities for storage as well as computing. Besides the fact that the regular data centers require large amounts of energy for operation, they also need cooling equipment and occupy prime real estate. However, this energy consumption scenario and the physical space constraints can be solved by employing a Mobile Raspberry Pi with Hadoop clusters that provides a cost-effective, low-power, high-speed solution along with micro-data center support for big data. Hadoop provides the required modules for the distributed processing of big data by deploying map-reduce programming approaches. In this work, the performance of SBC clusters and a single computer were compared. It can be observed from the experimental data that the SBC clusters exemplify superior performance to a single computer, by around 20%. Furthermore, the cluster processing speed for large volumes of data can be enhanced by escalating the number of SBC nodes. Data storage is accomplished by using a Hadoop Distributed File System (HDFS), which offers more flexibility and greater scalability than a single computer system.

• Animal Bioscience
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• 제35권5호
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• pp.670-676
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• 2022

Objective: This study was conducted to examine influence of skimmed milk-based extender (SM), INRA 96 extender and BotuSemen Gold extender on parameters of stallions' ejaculate during storage. Methods: In this study, 14 stallions between 4 and 20 years of age were monitored. Total and progressive motility, viability and morphology of sperm were evaluated at time intervals of 24, 48, and 72 hours after collection. Results: The total motility, progressive motility, and values of sperm with normal morphology were significantly higher in the INRA 96 and BotuSemen Gold extenders than in the SM (p<0.01). The sperm viability differed significantly in all extenders (p<0.01). The highest value of sperm viability was in INRA 96 (64.69%±0.67%) and lowest in SM (59.70%±0.81%). The highest differences occurred at 72 hours of storage. Values of total motility, progressive motility and sperm viability decreased over time (p<0.01). In case of sperm morphology there was no statistically significant decrease between 48- and 72-hour time intervals. Conclusion: It can be concluded that the extenders with a chemically defined composition have shown better indicators of insemination capabilities in ejaculates than the SM. The BotuSemen Gold extender is a suitable alternative to the INRA 96, when used within 48 hours; after 72 hours of storage, however, the INRA 96 showed a higher share of viable spermatozoa.

• 한국약용작물학회지
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• 제25권2호
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• pp.89-94
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• 2017

Background: The purpose of improving the quality of oriental medicinal herbs is to contribute to the improvement of the income of farm. The present study investigated the effect of reasonable drying methods, different storage conditions and packageing materials on quality and stability of Scutellaria baicalensis Georgi and for developing GAP (good agricultural practice) guide book. Methods and Results: Three methods of drying Scutellaria baicalensis roots produced over two years were used to estimate loss rate owing to drying, storage, and packaging. The methods of drying were categorized into natural drying (36 - 60 h by sunshine), drying with heat dryer (2 - 10 h), or drying with gas bulk dryer (2 - 10 h). After cleaning, and initial drying for a few days under controlled temperature conditions, the second phase of drying was carried out at 35, 45 and $55^{\circ}C$. Changes in hunter color values and quality under the two studied storage treatments (at $20^{\circ}C$ indoors and at $4^{\circ}C$ in a refigerator) were evaluated. Storage period for 60, 120, and 180 days in three packaging materials, PE (polyethylene package), PP (polypropylene gunnysack), and WP (watertight packing paper) were studied. Conclusions: Initial cleaning, reasonable gas drying and hot air drying, and drying in an oven at 35 and $45^{\circ}C$ after cutting the roots resulted in the lowest loss rates in S. Baicalensis root. Hunter color valuse indicated that stroage of dry roots at room temperature was better than PP packaging, and that cold stroage was better than PE packaging for long-term stability.