• Journal of KIISE:Databases
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• v.36 no.2
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• pp.99-111
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• 2009

In wireless sensor networks, various schemes have been proposed to store and process sensed data efficiently. A Data-Centric Storage(DCS) scheme assigns distributed data regions to sensors and stores sensed data to the sensor which is responsible for the data region overlapping the data. The DCS schemes have been proposed to reduce the communication cost for transmitting data and process exact queries and range queries efficiently. Recently, KDDCS that readjusts the distributed data regions dynamically to sensors based on K-D tree was proposed to overcome the storage hot-spots. However, the existing DCS schemes including KDDCS suffer from Query Hot-Spots that are formed if the query regions are not uniformly distributed. As a result, it causes reducing the life time of the sensor network. In this paper, we propose a new DCS scheme, called TPDCS(Time-Parameterized DCS), that avoids the problems of storage hot-spots and query hot-spots. To decentralize the skewed. data and queries, the data regions are assigned by a time dimension as well as data dimensions in our proposed scheme. Therefore, TPDCS extends the life time of sensor networks. It is shown through various experiments that our scheme outperform the existing schemes.

• Journal of Korea Multimedia Society
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• v.15 no.8
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• pp.1048-1058
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• 2012

This paper proposes the DDMPF(Distributed Data Management Protocol using FAT) which prevents data loss and keeps the security of self-organized storages by comprising a client, a storage server, and a verification server in clouding environment. The DDMPF builds a self-organized storage server, solves data loss by decentralizing the partitioned data in it in contrast to the centralized problem and the data loss caused by the storage server problems of existing clouding storages, and improves the efficiency of distributed data management with FAT(File Allocation Table). And, the DDMPF improves the reliability of data by a verification server's verifying the data integrity of a storage server, and strengthens the security in double encryption with a client's private key and the system's master key using EC-DH algorithm. Additionally, the DDMPF limits the number of verification servers and detects the flooding attack by setting the TS(Time Stamp) for a verification request message and the replay attack by using the nonce value generated newly, whenever the verification is requested.

• Food Science and Preservation
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• v.4 no.3
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• pp.227-235
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• 1997

The internal breakdown of Fuji apple during CA storage classified as watercore breakdown, low temperature breakdown and CO2 injury. This study was undertaken to investigate the watercore breakdown injury factors of Korean Fuji apple during CA storage. The development of internal breakdown was more increased with the larger size, the later harvest time and the hither CO2 gas level. But in internal breakdown fruit of the titratable acidity and soluble solid decreased significantly, the pH of fruit juice and the production of carbon dioxide was greatly increased. The best gas levels of CA storage was 2% oxygen and 3% carbon dioxide. Thus, the predictable parameters of internal breakdown of fruit were increase in pH on decrease titratable acidity within 2 months of CA storage, increase carbon dioxide. So, it was found that the best CA sotrage for internal breakdown control of fruit during CA storage was delayed CA storage methods after low temperature storage immediate harvest of apple and than took a step. The delayed CA storage after low temperature storage for 2 months was more effective in the prevention of development of internal breakdown than immediate CA storage after harvest.

• Journal of the Korean Ceramic Society
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• v.45 no.10
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• pp.625-630
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• 2008

In the bone cement composed of dense granules of $\beta-Ca_3(PO_4){_2}(\beta-TCP)$ and $Ca(H_2PO_4){_2}H_2O$, the compressive strength, setting time and temperature rise were measured to observe the degradation of cement with respect to the stored days before setting. Decreases of compressive strength and temperature rise were observed, while setting time increased with respect to the stored days. The similar trends were repeated with the increase of temperature of storage. Such a change virtually meant the fading of the character of cement and it took place only when the two starting materials were mixed during storage. The degradation could be mitigated taking advantage of granular $\beta$-TCP instead of powdery one. The formation of $CaHPO_4$, which resulted from reaction with ambient humidity, was attributed to the degradation observed during storage. Dependence of the degradation behavior on mixing and temperature during storage was discussed in terms of the driving force for reaction of cement.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.2
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• pp.143-150
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• 2000

This study was carried out to investigate the effect of storage period on the physico-chemical properties of tobacco leaves expanded by $CO_2$. The flue-cured and burley tobacco leaves produced from 1996 to 1999 were processed, and stored for that year or 3 years in processing plant. As compared with 1996 crop, the expanded rate of flue-cured tobacco leaves in 1999 crop was higher approximately 18%, while that of burley was higher about 10%. The filling capacity of cigarettes was decreased as storage time became shorter, but the combustibility was improved. The rate of large particles (over 3.36mm) of expanded tobacco showed decreasing tendency as the storage period became longer. The change rate of chemical contents in tobacco leaves between before and after expansion had no significant difference among corp years. The tar and CO contents of cigarettes smoke were reduced in the case of flue-cured tobacco leaves as storage time became shorter, while they were slightly increased in the case of burley tobacco leaves. The ammonia content of burley leaves was decreased remarkably in 1996 and 1999 crop.

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.431-438
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• 2008

This study examined the quality characteristics of Sulgitteok samples prepared with different ratios of lotus root powder over 4 days of storage. The moisture contents of the lotus root powder-containing samples ranged from 35.39 to 37.31% and that of the Sulgitteok without lotus root powder control was 35.92%. The results showed that the various samples had the inconsistent changes during the storage period. As the content of lotus root powder increased, the L-values of samples decreased and the a- and b-values increased. However, their L-, a- and b-values did not show large differences with storage. When compared to the control, the hardness, gumminess, and chewiness of samples slowly increased as the amount of lotus root powder increased. Springiness and cohesiveness decreased according to the amount of added lotus root powder. And increasing amounts of lotus root powder and storage time resulted in greater reductions in adhesiveness. In addition, increasing storage time caused cohesiveness to decrease and springiness to increase. The sensory evaluation results showed that the 20% lotus root Sulgitteok received the highest scores, therefore, this samples was deemed superior.

• Journal of Ginseng Research
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• v.22 no.2
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• pp.82-90
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• 1998

In order to stabilize the price of fresh ginseng by extension of seasonal variation and marketing structure, and to reduce the cost of production by works of intensive and short term, studies were carried out. As fresh ginseng of 4 years old by the MA and CA was stored for 12 week at 4$^{\circ}C$, samples were collected after every 1, 2, 3, 4, 6, 8, 12 weeks for processing red ginseng. Color and Sensual characteristics on ginseng steamed red for the quality evaluation are summarized as follows. For the time course of storage with red ginseng, which was processed from fresh one after various treatments, L and b values were decreased, however a value was increased. In particular, absorbance was step-wisely increased. Turbidity was somewhat increased, and non-treatment of preservative were shown 2 times higher of absorbance. Extraction ratio of ethanol-soluble extractives slightly increased by the preservation methods, and as storage period was passed. CA storage and preservative treat merit versus MA and non-preservative treatment gave much stability in ginseng quality. In the sensual characters, sour taste and sweet taste were increased, but fresh taste and rice scorched taste were decreased. Bitter taste was not much changed until end of storage. CA was shown smaller differences than MA in the pH change. Addition of preservative extended the storage time.

• Journal of Food Hygiene and Safety
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• v.12 no.1
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• pp.55-62
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• 1997

This study was carried out to investigate the microbiological and chemical properties of natural water during storage. The water samples were taken at the time of purchase and the opened bottles and unopened bottles stored at the temperature of 4$^{\circ}C$, 18$^{\circ}C$, and 3$0^{\circ}C$. The bacterial content normally rose to 2.06$\times$102 CFU/$m\ell$ for the unopened bottles and 2.91$\times$102 CFU/$m\ell$ for the opened bottles after 2 weeks of storage, and 1.21$\times$102 CFU/$m\ell$ and 2.64$\times$102, respectively, after 24 weeks of storage. The number of viable cells of bacteria peaked more rapidly at the storage temperature of 3$0^{\circ}C$ than 18$^{\circ}C$. But the total samples were found to be negative for coliforms test during the study period. The average range of pH value was from 7.39 to 7.76. The results showed that the nitrates and chlorides satisfied the Korea Drinking Water Quality Standards during the storage period of 24 weeks. However, the undesirable changes of the taste and odor were detected within 2 weeks and 3 weeks, respectively.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.478-483
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• 1996

We investigated the changes of composition in immature green persimmon during cold(7$^{\circ}C$) and freezing (-2$0^{\circ}C$) storage for 30 days. Moisture, protein, fat and carbohydrate were not significantly different by storage temperature and storage days. Crude fiber had little change during freezing storage, but in case of cold storage, as storage time goes by, it slightly deceased. Content of polyphenol was increased during cold and freezing storage, especially during cold storage it was remarkably increased. Content of total pectin was decreased, while content of soluble pectin was increased during cold storage. Content of total pectin and soluble pectin was slightly decreased or increased during freeze storage. Content of tannin had little change during freezing storage but it significantly decreased during cold storage.

• Journal of the Korean Institute of Gas
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• v.10 no.1 s.30
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• pp.7-12
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• 2006

The quantity of gas which can be supplied by LPG storage tank become a standard of selection. In the absence of the maximum evaporation rates from LPG storage tanks by tank capacity, continuation using time, air temperature, it is in a problem for the dissemination of LPG Storage tanks. In this paper, we showed the maximum evaporation rates from LPG storage tanks by tank capacity, air temperature, continuous using time and remaining level.