• Journal of the Korean Magnetic Resonance Society
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• v.9 no.1
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• pp.48-60
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• 2005

Purpose: The purpose of this study was to design and build an optimized birdcage resonator configuration with a low pass filter, which would facilitate the acquisition of high-resolution 3D-image of small animals at 3T MRI system. Methods and Materials: The birdcage resonator with 12-element structures was built, in order to ensure B1 homogeneity over the image volume and maximum filling factor, and hence to maximize the signal to noise ratio (SNR) and resolution of the 3-dimensional images. The diameter and length of each element of a birdcage resonator were as follows: (1) diameter 13 cm, length 22 cm, (2) diameter 15 cm, length 22 cm, (3) diameter 17 cm, length 25 cm. Spin echo pulse sequence and fast spin echo pulse sequence were employed in obtaining MR images. The quality of the manufactured birdcage resonators wes evaluated on the basis of the return loss following matching and tuning process. Results: The experimental MR image of phantoms by the various manufactured birdcage resonators were obtained to compare the SNR in accordance with the size of objects. The size of an object to that of coil was identified by parameters that were estimated from the image of a phantom. First, the diameter of the birdcage resonator was 15cm, and the ratio of the tangerine to the birdcage resonator accounted for approximately 27%. The Q factor was 53.2 and the SNR was 150.7. Second, at the same birdcage resonator, the ratio of the orange was approximately 53%. The SNR and the Q parameter was 212.8 and 91.2, respectively. Conclusion: The present study demonstrated that if birdcage resonators have the same forms, SNR could be different depending on the size of an object, especially when the size of an object to that of coil is approximately 40~80%, the former is bigger than the latter. Therefore, when the size of an object to be observed is smaller than that of coil, the coil should be manufactured in accordance with the size of an object in order to obtain much more excellent images.

• Journal of Nutrition and Health
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• v.39 no.4
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• pp.417-425
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• 2006

The purpose of this study were to a) investigate operation of human resource in contract foodservice management company (CFMC), b) identify the staffing indices for the establishment an labor productivity for CFMC, and c) develop standardized model of staffing demand as foodservice's scale in CFMC. The data was collected using FS intra-net system from 138 contract-managed foodservice operations in A CFMC and statistical analysis was completed using the SAS/win package (ver. 8.0) for description analysis, ANOVA, Duncan multiple comparison, pearson correlation analysis, and regression analysis. The types of operation were included factory (45%), small scale operation (26%), office (11%), department store (10%), training institute (4%), and hospital (3%). The distribution of foodservice scale was classified by meal served was as follows; 'less than 500 meals (47%)', 'from 500 to 1500 meals (25%)', 'from 1500 to 2500 meals (17%)', and 'more than 2500 meals (12%)'. There was two types of contract method, fee-contract (53%) and profit-and-loss contract (46%) Some variables were significantly high operation indices such as selling price, food cost, monthly sales, net profit and others were significantly low operation indices such as labor, meal time a day in the small foodservice on meal scale (p<.001). The more foodservice was large, the more human resource was disposed on dietitian, cook, cooking employee altogether (p<.001). Foodservice in A CFMC was divided into 2 groups by 500 meals a day, according to comparative analysis of labor productivity as meal scale per working hour, meal scale a day and operation indices as meal per foodservice employee, meal per cooking employee (p<.001). The regression equation model was developed as 'the number of employees=1.82+0.014 ${\times}$ meal served' in the operation of less than 500 meals, 'the number of employees=9.42+0.013 ${\times}$ meal scale a day -0.94 ${\times}$ meal scale per working hour' in the operation over 500 meal scale using labor productivity indices and operation indices. Therefore, CFMC could be enhanced efficiency of human resource arrangement using the standardized model of staffing demand and would be increased effectiveness of profit.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.677-681
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• 2015

Aluminum alloy was examined as a material of low weight reactor for hydrolysis of $NaBH_4$. Aluminum is dissolved with alkali, but there is NaOH as a stabilizer in $NaBH_4$ solution. To decrease corrosion rate of aluminum, decrease NaOH concentration and this result in loss of $NaBH_4$ during storage of $NaBH_4$ solution. Therefore stability of $NaBH_4$ and corrosion of aluminum should be considered in determining the optimum NaOH concentration. $NaBH_4$ stability and corrosion rate of aluminum were measured by hydrogen evolution rate. $NaBH_4$ stability was tested at $20{\sim}50^{\circ}C$ and aluminum corrosion was measured at $60{\sim}90^{\circ}C$. The optimum concentration of NaOH was 0.3 wt%, considering both $NaBH_4$ stability and aluminun corrosion. $NaBH_4$ hydrolysis reaction continued 200min in aluminum No 6061 alloy reactor with 0.3 wt% NaOH at $80{\sim}90^{\circ}C$.

• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.45-52
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• 2010

Two different imide oligomers(6FDA-ODA/APA and 6FDA-MDA/MA) having crosslinkable end groups were prepared by using a solution imidization method and their properties were investigated. Also, semi-interpenetrating polymer networks(semi-IPN) were prepared using the blends of imide oligomers with polyetherimide $Ultem^{(R)}$, which is used in dual-ovenable packaging materials. The characteristic properties of semi-IPN films were interpreted by using TGA, Thin Film Diffusion Analyzer, and WAXD. Molecular weights of imide oligomers were successfully controlled utilizing 2-aminophenylacetylene(APA) and maleic anhydride(MA) as an endcapping agent. Exotherm reactions by crosslinking appeared and the amount of exthotherm heat was linearly increased as the content of imide oligomers was increased. For semi-IPNs of $Ultem^{(R)}$ and imide oligomers, 5% and 10% weight loss temperatures increased as the contents of imide oligomers were increased. Diffusion coefficient and water uptake of semi-IPNs decreased as the content of imide oligomers was increased, which might be resulted from hydrophobic fluorine group and high packing density. It was concluded that relatively low thermal stability and hydrolytic stability of polyetherimide $Ultem^{(R)}$ were improved by incorporating new developed imide oligomers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.629-634
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• 2016

In this study, we investigated the effect of factors that influence the measurement of smoke density using synthetic rubber flooring. The characteristics of rolling stock in an enclosed environment can cause enormous loss of life by smoke inhalation during fires inside passenger cars. The amount of smoke generation from interior materials for rolling stock is strictly restricted domestically and in other countries. Precise measurement of smoke density is therefore required to assess the fire performance of interior materials. Major factors that influence the measurement of smoke density include the uniformity of the specimen, the variations in conditions and instruments, and the operational and maintenance environment of the instruments. The contribution of factors was analyzed by estimating the uncertainty to investigate the contribution ratios of the major factors. The results show a contribution ratio of about 86% for the variation from the measurement of light transmission using a photomultiplier tube. Thus, this factor was the most representative for the measurement of smoke density. The contribution ratio of the other factors was low at about 11%, including irradiant flux conditions (${\pm}0.5 kW/m^2$) and the influence of the operational and maintenance environment of the instrument. These results were obtained using specimens with high uniformity.

• Journal of Wetlands Research
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• v.18 no.2
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• pp.173-182
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• 2016

Although the ecosystem extends numerous functions for the benefit of humankind, construction of horticultural facilities can potentially lead to the degeneration of some of these functions owing to the expansion of impervious regions and loss of habitats. Thus, this study aimed to examine the effect of construction of horticultural facilities on plant biodiversity. Analysis of the vegetation distribution characteristics showed that horticultural facilities had significantly lower plant diversity than did rice paddies. Hence, the proposed approach involved low-impact development, arrangement of habitat space, plant preservation, restricted use of chemical fertilizer, habitat creation, and reduced preservation cost. Lifestyle analysis suggested the importance of developing favorable environments for the growth of annual plants and aquatic plants. In all, 20 species of naturalized plants belonging to 10 families were identified. Furthermore, the proportion of these naturalized plants was higher in glass greenhouses and multi-span greenhouses, suggesting the advantages of employing natural soil mulching while avoiding concrete mulching. Statistical analysis was performed to validate the results, which suggested that impervious regions be converted to natural soils. Collectively, the findings of this study are expected to be used for establishing policies for the construction of eco-friendly and ecological horticultural facilities; this may aid the maintenance of sustainable agricultural landscapes and large-scale development of the reclaimed lands.

• Food Science and Preservation
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• v.23 no.2
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• pp.166-173
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• 2016

This study aimed to evaluate the commercialized packaging status of tomato and paprika, and to investigate the effect of different packaging materials on the quality of tomato and paprika during storage. Packaging statuses were surveyed at a department store, wholesale market, and supermarket in Seoul, Korea. Materials used for packaging tomato and paprika were cartons, polypropylene (PP), low-density polyethylene (LDPE), polystyrene (PS), and polyvinyl chloride (PVC). Tomato and paprika were packaged by using corrugated boxes, Styrofoam trays, PP film, and PVC film. The weight loss and hardness of non-packaged tomato and paprika were significantly different after 48 hr to the initial values (p<0.05). Box-packaged tomatoes had the lowest pH values and showed significantly higher soluble solid contents (p<0.05). However, there were no significant differences in among other packaging materials. For paprika, the ${\Delta}E$ values of PVC wrapping were higher than those of other packagings. Hence, the results demonstrated that a corrugated box with PP film and PP film bags with four holes plus wire-tying were most able to maintain the overall qualities of tomato and paprika, respectively, during storage.

• Food Science and Preservation
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• v.19 no.1
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• pp.31-36
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• 2012

Fresh-cut burdock roots were processed at 4 and $25^{\circ}C$, respectively. The fresh-cut burdock roots were treated with different browning inhibitors (3% citric acid, 3% sodium chloride, 0.3% cystein, and 3% sodium acetate solutions), and the changes in their quality and browning characteristics were investigated. The respiration rate and browning index of the cut roots prepared at $4^{\circ}C$ were lower than those of the cut roots prepared at $25^{\circ}C$. The soluble solid content was higher in the cut roots prepared at $4^{\circ}C$ than in those prepared at $25^{\circ}C$. The weight loss and flesh firmness were not affected by the processing temperatures. Among the browning inhibitors, 0.3% cystein showed the best browning-retarding effect. There was no difference in phenolic compound content between the browning-inhibitor-treated roots and the nontreated roots, but the PPO activity was higher in the latter than in the former. Therefore, the processing temperatures of fresh-cut burdock roots affected their quality and browning development, and the combination of a low processing temperature and the use of the proper browning inhibitor should be applied for the higher quality of the produce.

• Food Science and Preservation
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• v.16 no.2
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• pp.147-154
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• 2009

Radish sprout was packaged with different materials. PO and PC are both hard case PET(polyethylenterephthalate) and has 6 holes and no holes, respectively. LO, LM and LH are anti-fogging OPP(oriented polypropylene) film which have different oxygen transmission rates. The oxygen concentration and weight loss rate in PO packaged were higher than any other packages. The soluble solid contents of radish sprouts packaged with PO showed much increased during storage. The pH increased during storage but pH of the samples packaged with high oxygen transmission rate was relatively low. Radish sprouts in LO had lower b value as compared to other samples. The result of ${\Delta}E$ value was generally high during storage period, especially at 7 days storage. The contents of total polyphenolic compounds and free radical scavenging activity of radish sprout packaged with PC and LO were high. Total aerobic bacteria of sprouts in PC and LO was much higher than others. The result of organoleptic qualities showed that the radish sprouts packaged with LM had a good score in terms of overall acceptability until 7 days storage.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8101-8105
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• 2016

Background: This study examined the psychometric properties of the Bahasa Malaysia (BM) version of the European Organization for Research and Treatment of Cancer (EORTC) Colorectal Cancer-specific Quality Of Life Questionnaire (QLQ-CR29). Materials and Methods: We studied 93 patients recruited from University Malaya and Universiti Kebangsaan Medical Centers, Kuala Lumpur, Malaysia using a self-administered method. Tools included QLQ-C30, QLQ-CR29 and Karnofsky Performance Scales (KPS). Statistical analyses included Cronbach's alpha, test-retest correlations, multi-traits scaling and known-groups comparisons. A p vaue ${\leq}0.05$ was considered significant. Results: The internal consistency coefficients for body image, urinary frequency, blood and mucus and stool frequency scales were acceptable (Cronbach's alpha ${\alpha}{\geq}0.65$). However, the coefficients were low for the blood and mucus and stool frequency scales in patients with a stoma bag (${\alpha}=0.46$). Test-retest correlation coefficients were moderate to high (range: r = 0.51 to 1.00) for most of the scales except anxiety, urinary frequency, buttock pain, hair loss, stoma care related problems, and dyspareunia (r ${\leq}0.49$). Convergent and discriminant validities were achieved in all scales. Patients with a stoma reported significantly higher symptoms of blood and mucus in the stool, flatulence, faecal incontinence, sore skin, and embarrassment due to the frequent need to change the stoma bag (p < 0.05) compared to patients without stoma. None of the scales distinguished between patients based on the KPS scores. There were no overlaps between scales in the QLQ-C30 and QLQ-CR29 (r < 0.40). Conclusions: the BM version of the QLQ-CR29 indicated acceptable psychometric properties in most of the scales similar to original validation study. This questionnaire could be used to complement the QLQ-C30 in assessing HRQOL among BM speaking population with colorectal cancer.