• Journal of Institute of Control, Robotics and Systems
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• v.16 no.3
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• pp.305-312
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• 2010

The aim of this study is to find an analytic solution to the problem of determining the optimal capacity of a batch-storage network to meet demand for finished products in a system undergoing joint random variations of operating time and batch material loss. The superstructure of the plant considered here consists of a network of serially and/or parallel interlinked batch processes and storage units. The production processes transform a set of feedstock materials into another set of products with constant conversion factors. The final product demand flow is susceptible to joint random variations in the cycle time and batch size. The production processes have also joint random variations in cycle time and product quantity. The spoiled materials are treated through regeneration or waste disposal processes. The objective function of the optimization is minimizing the total cost, which is composed of setup and inventory holding costs as well as the capital costs of constructing processes and storage units. A novel production and inventory analysis the PSW (Periodic Square Wave) model, provides a judicious graphical method to find the upper and lower bounds of random flows. The advantage of this model is that it provides a set of simple analytic solutions while also maintaining a realistic description of the random material flows between processes and storage units; as a consequence of these analytic solutions, the computation burden is significantly reduced. The proposed method has the potential to rapidly provide very useful data on which to base investment decisions during the early plant design stage. It should be of particular use when these decisions must be made in a highly uncertain business environment.

• Steel and Composite Structures
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• v.32 no.1
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• pp.1-19
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• 2019

The aim of the paper is the prediction of the seismic collapse mode of steel storage pallet racks under seismic loads. The attention paid by the researchers on the behaviour of the industrial steel storage pallets racks is increased over the years thanks to their high dead-to-live load ratio. In fact, these structures, generally made by cold-formed thin-walled profiles, present very low structural costs but can support large and expensive loads. The paper presents a prediction of the seismic collapse modes of multi-storey racks. The analysis of the possible collapse modes has been made by an approach based on the kinematic theorem of plastic collapse extended to the second order effects by means of the concept of collapse mechanism equilibrium curve. In this way, the dissipative behaviour of racks is determined with a simpler method than the pushover analysis. Parametric analyses have been performed on 24 racks, differing for the geometric layout and cross-section of the components, designed in according to the EN16618 and EN15512 requirements. The obtained results have highlighted that, in all the considered cases, the global collapse mechanism, that is the safest one, never develops, leading to a dangerous situation that must be avoided to preserve the structure during a seismic event. Although the studied racks follow all the codes prescriptions, the development of a dissipative collapse mechanism is not achieved. In addition, also the variability of load distribution has been considered, reflecting the different pallet positions assumed during the in-service life of the racks, to point out its influence on the collapse mechanism. The information carried out from the paper can be very useful for designers and manufacturers because it allows to better understand the racks behaviour in seismic load condition.

• Journal of Microbiology and Biotechnology
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• v.31 no.12
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• pp.1684-1691
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• 2021

In this study, the physicochemical changes related to fishy smell were determined by storing high hydrostatic pressure (HHP)-treated mackerel (Scomber japonicus) meat in a refrigerator for 20 days. The inhibition of crude urease activity from Vibrio parahaemolyticus using HHP treatment was also investigated. The mackerel meat storage experiment demonstrated that production of trimethylamine (TMA) and volatile basic nitrogen (VBN), the main components of fishy smell, was significantly reduced on the 20th day of storage after the HHP treatment compared to the untreated mackerels. The results demonstrated that the increased ammonia nitrogen rates in the 2000, 3000, and 4000 bar, HHP-treated groups decreased by 23.8%, 23.8%, and 31.0%, respectively, compared to the untreated groups. The enzyme activity of crude urease was significantly reduced in the HHP-treated group compared to that in the untreated group. Measurement of the volatile organic compounds (VOCs) in mackerel meat during storage indicated that the content of ethanol, 2-butanone, 3-methylbutanal, and trans-2-pentenal, which are known to cause off-flavor due to spoilage, were significantly reduced by HHP treatment. Collectively, our results suggested that HHP treatment would be useful for inhibiting the activity of urease, thereby reducing the fishy smells from fish and shellfish.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.512-519
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• 2023

Pacific oysters Crassostrea gigas are a popular shellfish in the Republic of Korea. However, due to their abundant moisture and nutrient content, oysters are susceptible to microbiological growth and biochemical changes, which lead to quality degradation. Therefore, the present study aimed to investigate the effectiveness of modified atmosphere packaging (MAP) in maintaining the quality of raw oysters during storage. Microbiological and physicochemical parameters such as pH, glycogen content, soluble protein, turbidity, and volatile basic nitrogen (VBN) were analyzed for oysters stored under various gas compositions and storage periods. The results showed that there was no significant increase in viable cell count in MAP oysters after six days in MAP oysters. Moreover, the physicochemical quality of non-MAP oysters deteriorated rapidly, whereas the quality of MAP oysters were maintained during storage. This study suggests that MAP can be an effective technique for maintaining the freshness of raw oysters during distribution and storage, and may also be useful for extending the shelf-life and maintaining the quality of other seafood products.

• Korean journal of food and cookery science
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• v.28 no.4
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• pp.399-405
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• 2012

This study was carried out to investigate the effect of safflower seed powder on the physicochemical characteristics of ground pork during refrigerated storage. Three types of ground pork were evaluated: 20% pork fat added (PF, control), 10% pork fat and 10% added safflower seed powder (PFS), and 20% added safflower seed powder (SS). The pH increased during storage, but decreased after 10 days of the storage (p<0.05). The pH was lower in PFS and SS than that in PF after 10 days of storage (p<0.05). The TBARS (2-thiobarbituric acid reactive substances) values increased with longer storage period (p<0.05), and those of PF, PFS and SS were 1.186, 0.686 and 0.577 mg MA/kg, respectively, after 10 days of storage. The $L^*$ values for external color of PF and PFS decreased (p<0.05), but that of SS was not significantly different after a longer storage period. The $a^*$ values decreased (p<0.05), but the $b^*$ values were not significantly different with longer storage period. The $L^*$ values for internal color of PFS and SS decreased (p<0.05), but that of PF was not significantly different with longer storage period. The $a^*$ value of PF decreased (p<0.05), but that of SS increased with longer storage period. The $b^*$ value decreased (p<0.05), but those of PFS and SS were not significantly different with longer storage period. Water holding capacity decreased with longer storage period, and that of SS was the highest (p<0.05). Cooking loss of PFS and SS was not significantly different with longer storage period, and that of PF was the highest (p<0.05). The reduction in diameter of the samples was not significantly different with longer storage period, and that of PF was the highest (p<0.05). Hardness and chewiness of samples increased, but springiness and cohesiveness decreased with longer storage period (p<0.05). Replacing animal fat with safflower seed powder was effective and may be useful as an innovative meat product.

• Korean Journal of Remote Sensing
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• v.34 no.2_1
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• pp.203-211
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• 2018

Dam discharge is carried out for the management of rivers and area around rivers due to rainy season or drought. Dam discharge should be based on an accurate understanding of the flow rate that can be accommodated in the river. Therefore, understanding the allowable storage capacity of river is an important factor in the management of the environment around the river. However, the methods using water level meters and images, which are currently used to determine the allowable flow rate of rivers, show limitations in terms of accuracy and efficiency. In order to solve these problems, this paper proposes a method to automatically calculate the allowable storage capacity of river based on the images taken by drone. In the first step, we create a 3D model of the river by using the drone images. This generation process consists of tiepoint extraction, image orientation, and image matching. In the second step, the allowable storage capacity is calculated by cross section analysis of the river using the generated river 3D model and the road and river layers in the target area. In this step, we determine the maximum water level of the river, extract the cross-sectional profile along the river, and use the 3D model to calculate the allowable storage capacity for the area. To prove our method, we used Bukhan river's data and as a result, the allowable storage volume was automatically extracted. It is expected that the proposed method will be useful for real - time management of rivers and surrounding areas and 3D models using drone.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.785-796
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• 2006

This study was designed to evaluate the changes in sperm motility, viability, HOST(hypo-osmotic swelling test), IVP(in vitro penetration), SCSA(sperm chromatin structure assay) during storage of liquid semen collected from boars with different farrowing rates using AI, and to find the relationship between boar fertility through AI and sperm diagnostic parameters during semen storage. The results of HOST were significantly decreased according to the increasing of in semen storage days and the results of IVP were significantly decreased at 3 days of semen storage (P<0.05). The %Red was significantly different among the >80%, 70󰠏80% and <70% farrowing rate group at semen storage day 6(P<0.05). The correlation coefficients between the %Red and farrowing rate were increased according to the semen storage. In conclusion, these results suggest that the sperm parameters evaluated in these studies may be useful indicators to predict the fertility of AI and evaluate the semen quality in boars.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.3
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• pp.19-34
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• 2018

The purpose of this study is to estimate monthly agricultural reservoir storage with multiple linear regression model(MLRM) based on reservoir storage and meteorological data. The regression model was developed using 15 years(2002 to 2016) of 3,067 reservoirs by KRC(Korea Rural Community) and 63 meteorological stations by KMA (Korean Meteorological Administration), and the MLRM showed the determination coefficient($R^2$) of 0.51~0.95. The MLRM was applied to 9 selected reservoirs among the whole reservoirs and validated with $R^2$ of 0.44~0.81. The ROC(Receiver Operating Characteristics) analysis of Reservoir Drought Index(RDI) classified by comparing the present reservoir storage with normal year(1976~2005 average) reservoir storage showed average value of 0.64 for 2 years(2015~2016) with the highest value of 0.70 for winter period, lowest value of 0.58 for summer period. If 1 to 3 months weather forecasting data such as Glosea5 produced by KMA are applied, the predicted monthly reservoir storage from the MLRM can be a useful information for agricultural drought pre-preparation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.739-745
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• 2015

To maintain quality of Delaware grapes during storage, grape samples were treated with 0.1% chitosan dissolved in 0.5% acetic acid, packaged with low density polyethylene film, and stored at 4 or $20^{\circ}C$ for 12 days. Chitosan treatment reduced initial populations of yeast and molds in grapes by 1.86 log CFU/g compared to that of the control. During storage, oxygen contents in packages of samples decreased, whereas carbon dioxide contents increased. In addition, regardless of storage temperature, changes in oxygen and carbon dioxide concentrations of grapes treated with chitosan were lower than those of the control. Hardness of samples decreased, and Hunter L, a, and b values were not significantly different among treatments. Regarding pH and total soluble content, grapes stored at $4^{\circ}C$ maintained pH and had greater total soluble content than those stored at $20^{\circ}C$. These results suggest that chitosan treatment and low temperature storage can be useful for maintaining microbiological safety and quality of Delaware grapes during storage.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.672-679
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• 2006

Postharvest nut quality, and changes of soluble solids content and kernel hardness during cold storage in 13 Korean prevailing chestnut cultivars were investigated to establish the chestnut grading and standardization for marketing and processing industry. Chestnut quality attributes such as nut weight, soluble solids content, kernel hardness, % with the pericarp split, and % of polyembryonic nuts were measured from 2001 to 2005. There were significant difference among cultivars in quality characteristics, and also annual variation within same cultivar, corresponded to the high genetic and environmental variability. During cold storage at $2^{\circ}C$ for 16 weeks, remarkable changes in soluble solids content were observed, and Isseumo showed the highest increase of 8% at 16 weeks of cold storage compared with postharvest. In case of most cultivars except early ripening cultivars, soluble solids content of chestnut increased until 12 weeks during cold storage, followed by decreased gradually thereafter. Kernel hardness of most cultivars except lshizuchi during cold storage increased slightly, but it was not statistically significant. This work would be a useful reference to the quality of each chestnut cultivar for the growers and breeders alike.