• Horticultural Science & Technology
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• v.31 no.2
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• pp.211-218
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• 2013

This study was conducted to investigate the quality characteristics of eight Kimchi cabbage cultivars and the effect of cold storage on the quality of two kinds of cabbage cultivars, such as 'CR-Nongshim', and 'Ryouckgwang'. Early planted and harvested cultivars at July showed that fresh weight was lower than late harvested cultivars at September, because early harvesting time of July was heavy rainy season at highlands of Gangwon province. The firmness was more than 10 N for all cultivars and 'Cheongock', 'Sanjanggoon', and 'Ryouckgwang' cultivars had high value of firmness among them. No differences among the cultivars were found in appearance, freshness, and texture evaluations at harvest. Sweetness and bitterness had statistical differences and showed high value in 'Ryouckgwang' and in 'CR-Nongshim' and 'Sooho'. Two Kimchi cabbage cultivars such as 'CR-Nongshim' and 'Ryouckgwang' were stored at $0^{\circ}C$, $2^{\circ}C$, $5^{\circ}C$, and room temperature ($25^{\circ}C$) with more than 90% RH. Significant difference was found in weight loss during room and low temperature storage. In general, weight loss of the Kimchi cabbages at room temperature was significantly increased by 15% within 3 days, whereas it was delayed at low temperature until 3 weeks on all Kimchi cabbage cultivars. Firmness of 'CR-Nongshim' was higher than 'Ryouckgwang' but there was no difference within low storage temperatures. Appearance among the sensory factors was a critical indicator to estimate storage periods. On the point of appearance, storage period at $0^{\circ}C$ was 1 week and $2^{\circ}C$ and $5^{\circ}C$ was 3 weeks and 1 week in 'CR-Nongshim' cultivar, respectively. The storage period of 'Ryouckgwang' cultivar was 2 weeks, 4 weeks, and 2 weeks, respectively. Conclusively, storage at $2^{\circ}C$ with more than 90% RH was recommended as optimum temperature to maintain quality in both cultivars.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.1
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• pp.13-17
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• 2010

Purpose: Partial volume effect (PVE) is the phenomenon to lower the accuracy of image due to low estimate, which is to occur from PET/CT 3D image acquisition. The more resolution is declined and the lesion is small, the more it causes a big error. So that it can influence the test result. Studied the optimum image reconstruction method by using variation of parameter, which can influence the PVE. Materials and Methods: It acquires the image in each size spheres which is injected $^{18}F$-FDG to hot site and background in the ratio 4:1 for 10 minutes by using NEMA 2001 IEC phantom in GE Discovey STE 16. The iterative reconstruction is used and gives variety to iteration 2-50 times, subset number 1-56. The analysis's fixed region of interest in detail part of image and compute % difference and signal to noise ratio (SNR) using $SUV_{max}$. Results: It's measured that $SUV_{max}$ of 10 mm spheres, which is changed subset number to 2, 5, 8, 20, 56 in fixed iteration to times, SNR is indicated 0.19, 0.30, 0.40, 0.48, 0.45. As well as each sphere's of total SNR is measured 2.73, 3.38, 3.64, 3.63, 3.38. Conclusion: In iteration 6th to 20th, it indicates similar value in % difference and SNR ($3.47{\pm}0.09$). Over 20th, it increases the phenomenon, which is placed low value on $SUV_{max}$ through the influence of noise. In addition, the identical iteration, it indicates that SNR is high value in 8th to 20th in variation of subset number. Therefore, to reduce partial volume effect of small lesion, it can be declined the partial volume effect in iteration 6 times, subset number 8~20 times, considering reconstruction time.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.843-859
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• 2017

The JK-1 isolate which was the best producer of indole-3-acetic acid and carotenoid among the 388 strains isolated from 28 wetlands in Jeju, was identified to be Rhodopseudomonas palustirs belongs to a typical group of non sulfur purple bacteria based on 16S sRNA sequencing. This study investigated the effect of different cultural conditions of pH, temperature, agitation, light and aeration on growth, IAA and carotenoid production of photosynthetic bacterium JK-1 for optimization of IAA and carotenoid production. It was found that growth, IAA, carotenoid, and bacteriochlorophyll production with light (3,000~3,500 Lux) and agitation (100 rpm) showed better results than those with dark/static or dark/agitation (100 rpm) in anaerobic conditions. The optimal pH, temperature and agitation speed for cell growth were 7, $30^{\circ}C$, 150 rpm, for IAA production were 9, $30^{\circ}C$, 150rpm and for carotenoid production were 6, $25^{\circ}C$, 50 rpm, cultured for 72 h under anaerobic light, respectively. The growth and IAA production were high in aerobic culture compared with anaerocic culture, whereas carotenoid and bacteriochlorophyll content were decreased extremely in aerobic condition (0.5~1 vvm). Subsequently, the optimal culture conditions for JK-1 were selected with pH 7, $30^{\circ}C$ and 100 rpm under anaerobic light and the effect on plant growth was tested by pot assay. Inoculation of JK-1 with 3% (v/v) level caused increase in shoot and root dry weigh that varied from 20%~58% to 40%~28% in young radish in camparison to uninoculated treatment at 50 days of growth. The study suggests that the JK-1 isolate may serve as efficient biofertilizer inoculants to promote plant growth.

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.145-157
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• 2004

The cycle length design model of the Korean traffic responsive signal control systems is devised to vary a cycle length as a response to changes in traffic demand in real time by utilizing parameters specified by a system operator and such field information as degrees of saturation of through phases. Since no explicit guideline is provided to a system operator, the system tends to include ambiguity in terms of the system optimization. In addition, the cycle lengths produced by the existing model have yet been verified if they are comparable to the ones minimizing delay. This paper presents the studies conducted (1) to find shortcomings embedded in the existing model by comparing the cycle lengths produced by the model against the ones minimizing delay and (2) to propose a new direction to design a cycle length minimizing delay and excluding such operator oriented parameters. It was found from the study that the cycle lengths from the existing model fail to minimize delay and promote intersection operational conditions to be unsatisfied when traffic volume is low, due to the feature of the changed target operational volume-to-capacity ratio embedded in the model. The 64 different neural network based cycle length design models were developed based on simulation data surrogating field data. The CORSIM optimal cycle lengths minimizing delay were found through the COST software developed for the study. COST searches for the CORSIM optimal cycle length minimizing delay with a heuristic searching method, a hybrid genetic algorithm. Among 64 models, the best one producing cycle lengths close enough to the optimal was selected through statistical tests. It was found from the verification test that the best model designs a cycle length as similar pattern to the ones minimizing delay. The cycle lengths from the proposed model are comparable to the ones from TRANSYT-7F.

• Journal of the Korean Wood Science and Technology
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• v.43 no.6
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• pp.851-860
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• 2015

The objective of this study was to manufacture the wood based roughage using lumber from thinning of oak and pitch pine (Pinus rigida). And the study also aimed to investigate a feed value evaluation of wood based roughages. To investigate the optimization condition of steam-digestion treatment for roughage, the wood chips of oak and pitch pine were steam-digestion treated at $160^{\circ}C$ under pressure 6 atm depending on treatment times (60 min, 90 min and 120 min) followed by the content of essential oils analyzed. The essential oil content of steam-digestion treated roughages for 90 min and 120 min were under 0.1 mL/kg. The evaluation of feed value was carried out from steam-digestion treated roughages for 90 min through feed chemical composition analysis, NRC (National research Council) modeling, ruminal degradability analysis and relative economic value analysis. The feed chemical compositions including DM (dry mater), CP (crude protein), EE (ether extract), NDF (neutral detergent fiber), ADF (acid detergent fiber), ADL (acid detergent lignin), NFC (nonfiber carbohydrate) in oak roughage were 95.4, 1.36, 3.11, 90.05, 83.85, 17.33, 6.50%, respectively, and in pitch pine roughage were 94.37, 1.33, 5.48, 87.89, 86.88, 30.56, 6.32%, respectively. Both roughages showed low level of protein and very high level of NDF. The TDN (total digestible nutrient) levels using NRC (2001) model in oak and pitch pine roughages were 40.55, 31.22%, respectively. The ruminal in situ dry matter degradability was higher in oak roughage (23.84%) than in pitch pine roughage (10.02%). The economic values of oak and pitch pine rough-ages were 235, and 210 \, respectively.

• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.570-578
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• 2012

Compound K(ginsenoside M1) is one of saponin metabolites and has many benefits for human health. This study was to investigate Compound K produced from ginseng crude saponin extract with commercial cellulolytic complex enzyme(cellulase, ${\beta}$-glucanase, and hemicellulase) obtained from Trichoderma reesei. The effect factors(temperature, pH, ginseng crude saponin extract and enzyme concentration, and reaction time) on production of Compound K from ginseng crude saponin extract were determined by one factor at a time method. The selected major factor variables were ginseng crude saponin extract of 2%(w/v), enzyme of 7%(v/v), reaction time of 48 hr. Based on the effect factors, response surface method was proceeded to optimize the enzymatic bioconversion conditions for the desirable Compound K production under the fixed condition of pH 5.0 and $50^{\circ}C$. The optimal reaction condition from RSM was ginseng crude saponin extract of 2.38%, enzyme of 6.06%, and reaction time of 64.04 hr. The expected concentration of Compound K produced from that reaction was 840.77 mg/100 g. Production of Compound K was 1,017.93 mg/100 g and 862.31 mg/100 g, by flask and bench-scale bioreactor($2.5{\ell}$) system, respectively.

• Korean journal of food and cookery science
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• v.29 no.6
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• pp.661-669
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• 2013

This study was performed to determine the optimal composition of Cheonggukjang added with garlic. The experiment utilized a central composite design (CCD). The evaluation was carried out by means of response surface methodology (RSM), which included 18 experimental points with three independent variables : the content of the garlic (1.3~9.7%, $X_1$), the steaming time of garlic (0~15.1 min, $X_2$), and the fermentation time of Cheonggukjang (48.2~71.8 h, $X_3$). The viscous substance ($Y_1$), acidity ($Y_2$), amino-type nitrogen ($Y_3$), ${\gamma}$-GTP activity ($Y_4$) and ABTS radical scavenging activity ($Y_5$). were assessed in four replicates with five dependent variables. The maximum content of the viscous substance was 13.02% at 6.53% ($X_1$), 6.81 min ($X_2$) and 55.18 h ($X_3$). The acidity was increased when the fermentation time was longer, and the minimum acidity point was 0.50% at 7.75% ($X_1$), 3.42 min ($X_2$) and 58.60 h ($X_3$), respectively. The content of the amino-type nitrogen at the experimental range studied was was 80.58~158.82 mg%, and the stationary point was at saddle point. Using ridge analysis, the maximum point was 156.97 mg% at 6.21% ($X_1$), 14.85 min ($X_2$) and 58.04 h($X_3$). The optimum conditions of ${\gamma}$-GTP activity was 5.73% ($X_1$), 6.99 min ($X_2$) and 57.96 h($X_3$), respectively, at the maximum point was 353.66 mU/mL. The maximum point of ABTS radical scavenging activity was 76.43% at 3.78% ($X_1$), 14.28 min ($X_2$) and 57.99 h($X_3$) at the saddle point, when the garlic steaming time was longer.

• Food Science of Animal Resources
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• v.27 no.2
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• pp.171-178
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• 2007

This study was conducted to investigate the effect of ageing temperature(0 and $4^{\circ}C$) and time(2, 7, 14, 21, 28, and 49 days) on the meat quality of longissimus muscle from Hanwoo steer. The pH, Warner-Bratzler shear force(WBSF), myofibrillar fragmentation index(MFI), cooking and purge loss, sensory, morphological changes, and amino acid composition were assessed. The pH of longissimus muscle increased significantly(p<0.05) for 21 days at $0^{\circ}C$ and 14 days at $4^{\circ}C$, but decreased thereafter. Longissimus muscle aged from 14 days to 28 days at $4^{\circ}C$ had a lower WBSF than longissimus muscle aged at $0^{\circ}C$(p<0.05). The WBSF of longissimus muscle decreased significantly(p<0.05) with ageing time. The MFI, cooking and purge loss, tenderness, and juiciness scores were higher for longissimus muscle aged at $4^{\circ}C$ than at $0^{\circ}C$. As ageing time increased, the MFI, cooking and purge loss, tenderness, juiciness, and amino acid composition of longissimus muscle increased significantly(p<0.05) with ageing at 0 or $4^{\circ}C$. Transmission electron microscopy showed Z-disk degradation and morphological changes of the myofibrils correlating with increased tenderness during the ageing time. Based on these results, the proper ageing conditions of longissimus muscle of Hanwoo steer were 14 days of ageing at $0^{\circ}C$ or 7 days of ageing at $4^{\circ}C$. However, further study on the application of ageing technology to this industry is necessary for the optimization of ageing conditions for the sub-primals or muscles from Hanwoo beef.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1206-1212
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• 2010

This study was performed to establish optimum extraction condition of Tricholoma matsutake. A central composite design was applied to investigate the effects of independent variables, extraction temperature ($X_1$), extraction time ($X_2$) and water per sample ($X_3$) on dependent variables such as soluble solids contents ($Y_1$), total phenolics contents ($Y_2$), reducing sugar contents ($Y_3$), electron donating ability ($Y_4$) and nitrite scavenging ability ($Y_5$). The optimum extraction conditions were predicted and monitored by response surface methodology using SAS program based regression analysis. Soluble solids content, electron donating ability and nitrite scavenging ability were highly affected by water per sample. However, the contents of total phenolics and reducing sugar were affected by water per sample and extraction temperature as well. The optimum extraction conditions for soluble solids were 34.84 mL/g (water/sample) at $78.85^{\circ}C$, for 3.33 hr. In contrast, the optimum extraction conditions of electron donating ability were temperature of $91.00^{\circ}C$, time of 1.62 hr and water per sample of 39.42 mL/g. Taken together, the optimum ranges for hot water extraction of Tricholoma matsutake were $70{\sim}90^{\circ}C$, 2~4 hr and 30~50 mL/g.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.9
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• pp.1081-1090
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• 2017

The purpose of this study was to develop a functional porridge prepared with mulberry leaf and mulberry fruit powder, which can ameliorate hypertension. The experiment was designed according to the central composite design. For optimization of the mixture ratio of mulberry leaf powder (MLP) and mulberry fruit powder (MFP), the independent variables were defined as MLP (X1) and MFP (X2) and the dependent variables were defined as K (Y1), Na (Y2), ${\gamma}$-aminobutyric acid (GABA) (Y3), cyanidin-3-glycoside (C3G) (Y4), rutin (Y5), and flavonoid (Y6). The optimal MLP to MFP mixture ratio according to the response surface method were 5.41 g of MLP and 2.65 g of MFP. The amounts of K, Na, GABA, C3G, rutin, and flavonoid in the optimal MLP and MFP mixture were 1,844.22 mg/100 g, 52.74 mg/100 g, 139.98 mg/100 g, 1,134.89 mg/100 g, 101.56 mg/100 g, and 201.28 mg/100 g, respectively. The amounts of Ca, K, Mg, and Na in the functional porridge at this optimal point were 27.66 mg/100 g, 131.32 mg/100 g, 19.57 mg/100 g, and 3.59 mg/100 g, respectively. Overall, this functional porridge can help reduce hypertension.