• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.27-34
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• 2014

The paper proposed a sizing method of an energy storage system(ESS) for peak shaving of high-speed railway substations based on load profile patterns of substations. A lithium based battery ESS was selected since it can produce high-power at high speed that peak shaving requires, and also takes up a relatively smaller space for installation. Adequate size of the ESS, minimum capacity which can technically meet a peak shaving target, was determined by collectively considering load patterns of a target substation, characteristics of the ESS to be installed, and optimal scheduling of the ESS. In case study, a local substation was considered to demonstrate the proposed sizing method. Also economic analysis with the determined size of ESS was performed to calculate electricity cost savings of the peak shaving ESS, and to offer pay-back period and return on investment.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.10a
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• pp.9-18
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• 2003

A method for rapid propagation of mature Jack fruit was developed. Four types of explants (mature embryos, apical meristems of young seedlings, apices from mature plants and nodal segments) were used. It has been found 88% of young apical meristems produced shoots in Campbell and Durzan (CD) medium compared to 60% in Murashige and Skoog (MS) medium. Only 1/3 of them produced multiple shoots. Shoot idtiation from nodal segments was very rare. Mature apices produced callus. Although removed of the sheathing cover around mature buds enhanced the shoot initiation but success rate was low in growth regulator free medium. Embryos respond to the CD medium but not to the MS medium. Embryos from seeds soaked in water for 24 hours produced shoots after 8 weeks of incubation and the success rate was 70% while embryos from dry seeds only produced roots. There was no significant effect of cold storage (refrigeration) for 7 days on shoot initiation from mature embryos (65%) but the ability for shoot induction declines with storage time (55% after 21 days of cold storage). Mature axillary buds were established in Modified Campbell and Durzan (CD) medium supplemented with 0.5mg/1 and IBA. There was a significant difference in the growth performance of shoots according to the period of the year in which explants were collected. Highest (60%) was observed in November-January period. It was only 30% when the explants were collected in February-April or May-July and decreased to 20% in August-October. The shoots produced in November-January showed a higher vigor than those produced in other months. Since Jak fruit show seasonal changes in fruit bearing and shedding of leaves, it can be suggested that the difference in growth performances of tissues cultured in artificial culture media would have been affected by endogenous rhythms.

• Food Science of Animal Resources
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• v.43 no.1
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• pp.85-100
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• 2023

The present study aimed to evaluate the effects of high-intensity ultrasound (HIU) application on meat quality traits, sensory parameters, and the microstructure of semitendinosus muscle from Hanwoo cattle. The samples were treated in an ultrasonic bath (35 kHz) at an intensity of 800 W/cm² for 60 min, followed by aging at 1℃ for 0, 3, and 7 days. The application of ultrasound resulted in lower Warner-Bratzler shear force and higher myofibrillar fragmentation index values during the storage period. HIU also enhanced the tenderness, flavor, umami, and overall acceptability of cooked beef muscle. However, the electronic tongue evaluation results showed higher umami values in the control treatment on the seventh day of storage. The microstructure of sonicated meat showed disorganized myofibrillar architecture and swelling in the A-band region of sarcomeres during the storage period, which led to greater meat tenderness. The heatmap illustrated the high abundance of α-linolenic acid (C20:5n3) and eicosapentaenoic acid (C18:3n3) in sonicated meat samples on the third day of the storage. These results showed that HIU is a potential method for tenderizing and improving the sensory attributes of beef without compromising other quality aspects.

• Journal of the Korean Society of Food Culture
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• v.36 no.3
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• pp.265-273
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• 2021

The Chinese Sigyeong records the foods of the Primitive Pickling Period, pickling being a universal vegetable storage method, but does not indicate the origin of the pickled vegetables or the location of the source of transmission. Kimchi mainly used salt and sauce-based soaking materials at the beginning of the Fermented Pickling Period (beginning in the 1st to 3rd centuries A.D.), and it differed from the Chinese method, which used alcohol and vinegar. In the Umami-Flavored Pickling Period (beginning in the 14th and 15th centuries A.D.), jeotgal, fermented seafoods, were added, and pickles with a completely new identity were created, one different from any other pickles in the world. Lastly, entering the Complex Fermentation and Pickling Period (beginning in the 17th and 18th centuries), the technical process evolved using a separate special seasoning containing red pepper as the secondary immersion source after pickling in brine, the primary immersion source. As a result of this, kimchi was transformed into a food with a unique form and taste not found anywhere else. The unique characteristic of kimchi is that the composition of original materials, a combination of salted marine life and vegetable ingredients, is its core identity, and there is a methodological difference in that it is completed through a second process called saesaengchae (生菜)-chimchae (沈菜).

• Food Science of Animal Resources
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• v.33 no.6
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• pp.744-751
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• 2013

The objective of this study was to assess the physicochemical and sensory changes of a kefir manufactured by a two-step fermentation (MTY, $1^{st}$ step: $37^{\circ}C$ for 9 h; $2^{nd}$ step: $24^{\circ}C$ for 15 h) and compare it with kefirs produced by two conventional methods (GTY, fermentation at $37^{\circ}C$ for 24 h; KEY, $22^{\circ}C$ for 24 h). Rapid changes in pH and titratable acidity (TA) were observed in samples from all three manufacturing methods during fermentation process and storage period. Lactic acid bacteria (LAB) counts of MTY increased gradually up to 12 h of fermentation, reaching 9.28 Log CFU/mL, with maximum value observed in this experiment of 9.48 Log CFU/mL. The LAB counts of all samples decreased significantly during storage. The highest viscosity was observed for MTY (1750-1771 cPs), compared with the lowest viscosity observed for KEY (1250-1277 cPs). The viscosity of all samples increased slightly during storage (1250-1805 cPs, p<0.05), as well as carbon dioxide content (0.01-1.36%, p<0.05), except for GTY. The most significant increase in alcohol concentration during storage period was seen in MTY from 0.01% to 1.36% (p<0.05). MTY scored significantly higher in most items of the sensory analysis, indicating that the product manufactured by the two-step fermentation method is more acceptable compared with conventionally produced kefirs.

• Journal of Biosystems Engineering
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• v.39 no.3
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• pp.194-204
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• 2014

Purpose: The aim of this study was to develop long-term storage technology for Chinese cabbage in order to extend the period of availability of freshly harvested products. The scope of the paper deals with the use of a cooler with a remote monitoring and control interface in conjunction with use of packaging film. Methods: A cooler with a real time monitoring system was designed as a low-temperature storage facility to control temperature and relative humidity (RH). The effects of storage in high-density polyethylene (HDPE) plastic boxes, 3% chitosan dipping solution, polypropylene film (PEF) with perforations, and mesh packaging bags on physiological responses were investigated. The optimal storage temperature and humidity for 120 days were below $0.5^{\circ}C$ and 90%, respectively. Physiological and biochemical features of cabbage quality were also analyzed: weight loss, texture, and sugar salinity, chlorophyll, reducing sugar, and vitamin C contents. Results: The cooler with a remote monitoring and control interface could be operated by an HMI program. A $0.5^{\circ}C$ temperature and 90% humidity could be remotely controlled within the cooler for 120 days. Postharvest freshness of Chinese cabbages could be maintained up to 120 days depending on the packaging method and operation of the remote monitoring system. In particular, wrapping the cabbages in PEF with perforations resulted in a less than a 5% deterioration in quality. This study provides evidence for efficient performance of plastic films in minimizing post-harvest deterioration and maintaining overall quality of cabbages stored under precise low-temperature conditions with remote monitoring and a control interface. Conclusions: Packaging with a modified plastic film and storage in a precisely controlled cooler with a remote monitoring and control interface could slow down the physiological factors that cause adverse quality changes and thereby increase the shelf life of Chinese cabbage.

• Food Science and Preservation
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• v.13 no.3
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• pp.279-284
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• 2006

This study was carried out to investigate the qualities of Saururus chinensis Baill. rhizomes and it content of active ingredient accenting to the storage methods. As the storage period increased the rates of weight loss, rotten rhizomes and the number of sprouts increased. Refrigerator storage resulted in the lowest weight reduction and sprouts rates, while storage in soil-filled box in a store-house was most effective in reducing spoilage rate. Five lignans from rhizome were determined by HPLC Retention time ranged $18{\sim}36$ minutes and showed saucernetin sauchinone, manassantin A, saucerneol D, and manassantin B in that order. Regardless of storage methods, the lignan content was lower after 120 days than after 30 days of storage, and increased manassantin B, manassantin A, saucernetin sauchinone, and saucerneol D in that order.

• Food Science and Preservation
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• v.6 no.3
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• pp.270-275
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• 1999

During the storage period of chives(Allium Tubersum fouler) at low temperature(4-5$^{\circ}C$), weight loss in chives by the packages of LDPE, p.p and HDPE film was decreased less than 1%, however that of chives unpacked was remarkably increased as time went by. Soluble solids of unpacked chives was decreased from 6.0 to 4.6 $^{\circ}$Brix after 2 weeks storage and that of LDPE film sealed was lessened to 4.9-5.9 $^{\circ}$Brix, the treatment of deaeration showed a tendency to decrease a lot to 4.5-4.7 $^{\circ}$Brix. The vitamin C content of chives unpacked was 37.1mg% at before storage, but after one week decreased very much to 15.2mg%, and that in chives packed by the different methods was visibly lessened after 2 weeks storage. the Vitamin C content in chives processed by deaeration sealing method was lessened compared to that at chives processed by sealing only. In the bag of chives packed by HDPE film had low CO$_2$ and C$_2$H$_4$ concentration and the gas concentration in the bag of chives processed by P.P. film was increased as storage period went by. Conclusively the freshness of chives packaged by LDPE and HDPE film maintained for 3 weeks, at P.P film for 2 weeks, but the marketability of chives unpacked was degraded in 3-4 days.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.27-32
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• 2008

The present study has been conducted economic analysis of heat storage type ground source heat pump system(HSGSHP) and normal ground source heat pump (GSHP) which are installed at the same building in the shared an apartment house. Cost items, such as initial cost, annual energy cost and maintenance cost of each system are considered to analyze life cycle cost (LCC) and simple payback period (SPP) with initial cost different are compared. The initial cost is a rule to the Government basic unit cost of production. LCC applied present value method is used to assess economical profit of both of them. Variables used to LCC analysis are prices escalation rate and interest rate mean values of during latest 10 years. The LCC result shows that HSGSHP (1,050,910,000won) is more profitable than GSHP by 68.9% initial cost. And SPP appeared 3.0 year overcome the different initial cost by different annual energy cost.

• Journal of the East Asian Society of Dietary Life
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• v.5 no.2
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• pp.39-48
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• 1995

The effects of storage containers and storage temperatures on Kimchi quality were investigated. The results were summarized as follows : 1. Pabix, poly ethylene-back+plastic container, tupper-ware were much better than crock, stainless steel, and plastic container in keeping a Kimchi. However, there was no significant differences between containers in the sensory test for Kimchi. 2. Kimchi stored at 18$\pm$2$^{\circ}C$ was the most delicious, which revealed pH 4.30, acidity 0.45-0.50%, and salt concentration 3.10wt% in the 4th days after storage whereas sensory score for Kimchi quality was very low in the 12th days after storage. 3. pH in Kimchi stored at 5$^{\circ}C$ after fermentation at 18$\pm$2$^{\circ}C$ was slowly decreased as compared to the Kimchi stored at 18$\pm$2$^{\circ}C$, but texture score of Kimchi stored at -5$^{\circ}C$ or -8$0^{\circ}C$ after fermentation at 18$\pm$2$^{\circ}C$, but texture score of Kimchi stored at -5$^{\circ}C$ or -8$0^{\circ}C$ were compared to that of the Kimchi stored at 18$\pm$2$^{\circ}C$ after fermentation. 5. In the group of Kimchi stored at 1$0^{\circ}C$, immediately after picking it took 48days until the best conditions which were pH 4.30 and acidity 0.45-0.50% were matched. 6. The most promising method in keeping good taste and good quality of Kimchi was to store Kimchi at 5$^{\circ}C$ after 4days fermentation at 18$\pm$2$^{\circ}C$. And, for long period preservation of Kimchi, it took would be effective to store at -8$0^{\circ}C$ after fermentation at 18$\pm$2$^{\circ}C$.