• Korean Journal of Microbiology
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• v.47 no.3
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• pp.241-248
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• 2011

The use of synthetic additives for preservation and enhancement of the market quality of food products has been emerging as a societal issue in terms of safety as well as changes in consumption patterns. Various research related to natural additives is being conducted to address these issues. This study examined the antibacterial effects of 79 types of medicinal herbs used as oriental remedies on bacteria isolated from beverages of damaged marketable quality. The antibacterial effects of methanol extracts on 13 Bacillus sp. and three Paenibacillus sp. were evaluated. We found that 43 of the herbal medicines analyzed had antibacterial effects on the isolated bacteria. Of those, eight were selected, and their antibacterial effects were further examined using water, ethanol, methanol, and ethyl acetate as solvents. The results revealed that Prunus mume, Rhus javanica, and Coptis japonica had excellent antibacterial effects against the isolated bacteria. In particular, they exerted greater antibacterial effects when water and ethanol were used as solvents. This result indicates the possibility of developing natural additives using these substances. Since P. mume in particular, has not been sufficiently studied compared to other herbal medicines, it presents an opportunity for additional investigation and the possibility for development as a new product in the future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.5
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• pp.673-678
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• 2003

Changran Jeotgal (aged and seasoned intestine of Alaska pollack) was prepared as the same method as commercial one and irradiated at 0, 2.5, 5.0 and 10 k㏉ by gamma ray for industrial application. Changran Jeotgal using 10 k㏉-irradiated red pepper powder was also prepared to compare with control (0 k㏉). Commercial red pepper powder was already contaminated at 3.8$\times$10$^{6}$ CFU/$m\ell$ level by total plate count and 10k㏉ of irradiation reduced the number about 4 log cycles. Gamma irradiated Changran Jeotgal at 2.5,5.0, and 10k㏉ showed 3 6, and 7 log cycles of reduction compared to the non-irradiated control in the total plate count after 12 weeks of storage at 1$0^{\circ}C$. Using irradiated (10k㏉) red pepper powder reduced the microbial contamination significantly by 2 log cycles compared to the control. Sensory evaluation showed that the sample irradiated at 2.5 k㏉ was the most acceptable, followed by the sample using irradiated red pepper powder and non-irradiated control. Thus, 2.5 k㏉ of irradiation of Changran Jeotgal was effective to improve safety during distribution and storage without change of sensory quality. Furthermore, using the irradiated red pepper powder is also recommended for safety enhancement of the products.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.95-103
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• 2010

Raw files record luminance values corresponds to each pixel of a digital camera sensor. In digital imaging, controlling exposure to capture the first highlight stop is important on linear-distribution of raw file characteristic. This study sought to verify the efficiency of ETTR method and found the optimum over-exposure amount to maintain the first highlight stop to be the largest number of levels. This was achieved by over-exposing a scene with a raw file and converting it to under-exposure in a raw file converting software. Our paper verified the efficiency of ETTR by controlling the exposure range and ISOs. Throughout the results, if exposure increases gradually 6 steps, dynamic range is also increased. And it shows that the optimized exposure value is around + $1\frac{2}{3}$ stop over compared to the normal exposure with the high ISOs simultaneously. We compared visual noise value at $1\frac{2}{3}$ stop to the normal exposure visual noise. Based on the normal exposure's visual noise, we can confirm that visual noise decrement is increased by increasing ISOs. In this experimental result, we confirm that overexposure about + $1\frac{2}{3}$ stop is the optimum value to make the widest dynamic range and lower visual noise in high ISOs. Based on the study results, we can provide the effective ETTR information to consumers and manufacturers. This method will contribute to the optimum image performance in maximizing dynamic range and minimizing noise in a digital imaging.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3023-3029
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• 2012

The purpose of this study was to investigate the effect of the home-based virtual reality (VR) on upper extremity motor function in hemiparetic stroke patients. Two matched subjects with left hemiplegia were volunteered to participate in this study. One subject received the home-based VR whereas the other subject recovered a modified home-based constraint-induced movement therapy (CIMT). Both interventions were given for 4 hours x 5 times a week for 4 weeks. Outcome measures included Fugl-Meyer Assessment (FMA), Motor Activity Log (MAL), and Wolf Motor Function Test (WMFT). The VR-trained subject showed considerable improvement in all the tested motor functions when compared with the home-based CIMT. Specifically, the FMA measure demonstrated that the VR subject showed 17% enhancement whereas the CIMT subject showed 5% increase. Similarly, Amount of Use (AOU) and Quality of Movement (QOM) of the MAL scores of the VR subject showed 40% and 20% increase whereas the CIMT subject showed 0% and 20% increase, respectively. The WMFT scores of the VR subject and CIMT subject showed 20% increase. Our home-based VR was effective in upper extremity motor recovery of chronic hemiparetic patients even when compared with the well-established CIMT approach in stroke victims.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.7364-7371
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• 2014

Construction post-evaluation (CPE) boosts the efficiency of public construction projects by assessing the performance results of public construction projects and using the results to pursue similar projects. This evaluation comprehensively analyzes and assesses the planning of construction work, the estimated and actual construction costs, the construction period, the demand for construction projects, and the effects of construction projects after the construction work to ensure efficiency. The data was used to prevent lax project execution and enhance the quality and efficiency of similar construction projects. On the other hand, CPE results information must be managed systematically to refer to and use CPE data in similar construction projects. Therefore, in this study, the CPE system was developed as a measure of the systematic and comprehensive management and use of the CPE results information of individual ordering agencies. Therefore, the groundwork was laid for the assurance of quality enhancement and efficient project execution in public construction projects. This system is expected to serve as a useful tool for comprehensively analyzing and assessing construction works.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.4
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• pp.17-27
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• 2007

The enhanced distributed channel access (EDCA) of IEEE 802.11e has been standardized for supporting Quality of Service (QoS) in wireless LANs. In the EDCA, support of QoS can be achieved statistically by reducing the probability of medium access for lower priority traffics. In other words, it provides statistical channel access rather than deterministically prioritized access to high priority traffic. Therefore, lower priority traffics affect the performance of higher priority traffics. Consequently, at the high loads, the EDCA does not guarantee the QoS of multimedia applications such as voice and video even though it provides higher priority. In this paper, we propose a simple and effective scheme, called deterministic priority channel access (DPCA), for improving the QoS performance of the EDCA mechanism. In order to provide guaranteed priority channel access to multimedia applications, the proposed scheme uses a busy tone for limiting the transmissions of lower priority traffics when higher priority traffic has data packets to send. Performance of the proposed scheme is investigated by numerical analysis and simulation. Our results show that the proposed scheme outperforms the EDCA in terms of throughput, delay, jitter, and drop under a wide range of contention levels.

• Journal of Bio-Environment Control
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• v.24 no.1
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• pp.27-33
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• 2015

High temperature stress in summer season at plastic house is a limiting factor for tomato fruit set and yield. This study was performed to assess the effects of gibberellic acid ($GA_3$) and 2,4-Dichlophenoxy acetic acid (2,4-D) spray on fruit set, yield, and quality of tomato cv. 'Adoration'(Enza Zaden Co., Ltd.) under the plastic house in Hwacheon, 2011. Four concentrations (0-, 5-, 10- and $15mg{\cdot}L^{-1}$) of $GA_3$, and three concentrations (0-, 5- and $10mg{\cdot}L^{-1}$) 2,4-D were sprayed in early flowering of tomato in the plastic house, and fruit set, yield and quality characters were observed. The results showed that spray of $10mg{\cdot}L^{-1}$ $GA_3$ significantly increased the fruit set by 14.2% than unsprayed. The spray of $GA_3$ significantly increased the marketable fruit number, fruit weight, and yield. The spray of 2,4-D on blossoms significantly affected the fruit set percentage, fruit weight, marketable fruit weight and yield, and the highest fruit set observed as 62.5% in combined spray of $GA_3$ and 2,4-D at each $5mg{\cdot}L^{-1}$. Fruit size and total soluble solids significantly varied with the concentrations of $GA_3$ sprayed. The result indicates that the spray of $10mg{\cdot}L^{-1}$ $GA_3$ and $5mg{\cdot}L^{-1}$ 2,4-D can be more economic and effective to increase the fruit set, and yield in tomato under high temperature condition in plastic house.

• Geophysics and Geophysical Exploration
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• v.12 no.2
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• pp.192-198
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• 2009

Side scan sonar and SBP (sub-bottom profiler) play a very important role in the survey for seafloor imaging and sub-bottom profiling. In this study, we have acquired side scan sonar and SBP data from the artificial reef area. We applied digital image processing techniques to side scan sonar data in order to improve an image quality. For the enhancement of data quality and image resolution, we applied the typical seismic data processing sequence including gain recovery, muting, spectrum analysis, predictive deconvolution, migration to SBP data. We could easily estimate if artificial reef structures were settled properly and their distribution on the seafloor from the integrated interpretation of side scan sonar and SBP data. From the sampling analysis of seabed sediments, texture filtering of side scan sonar data and SBP data interpretation, we could evaluate the sediment type, distribution and thickness of seafloor sediments in detail.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.3
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• pp.67-71
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• 2014

An attempt to grow high quality GaN on silicon substrate using metal organic chemical vapor deposition (MOCVD), herein GaN epitaxial layers were grown on various Si(111) substrates. Thin Platinum layer was deposited on Si(111) substrate using sputtering, followed by thermal annealing to form Pt nano-clusters which act as masking layer during dry-etched with inductively coupled plasma-reactive ion etching to generate nano-patterned Si(111) substrate. In addition, micro-patterned Si(111) substrate with circle shape was also fabricated by using conventional photo-lithography technique. GaN epitaxial layers were subsequently grown on micro-, nano-patterned and conventional Si (111) substrate under identical growth conditions for comparison. The GaN layer grown on nano-patterned Si (111) substrate shows the lowest crack density with mirror-like surface morphology. The FWHM values of XRD rocking curve measured from symmetry (002) and asymmetry (102) planes are 576 arcsec and 828 arcsec, respectively. To corroborate an enhancement of the growth quality, the FWHM value achieved from the photoluminescence spectra also shows the lowest value (46.5 meV) as compare to other grown samples.

• Journal of the Korean earth science society
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• v.26 no.6
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• pp.511-523
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• 2005

The purpose of this study is to analyze the 1st and 2nd Korea Earth Science Olympiad (KESO) items, in order to find informations to enhance item quality. To do this, internal and external item classification frameworks are developed. Item difficulty (P), discrimination index (DI), correlation, and reliability are estimated by using classical test theory. Generalizability is also estimated by applying the generalizability theory. The results of item classification are as follows: (1) ‘Geology’, ‘astronomy’ and ‘data analysis and interpretation’ are dominant in content and inquiry process domain, respectively. Nearly every item has textbook context. (2) There is no difference between the preliminary and final tests in terms of their thinking skills sections. (3) As a whole, the ratio of items with pictures is high in item representation. However, multiple-choice and short answer items are more common in preliminary competition, and essay type items are found more often in final competition. The ratio of simple items is high in middle school section and preliminary competition, but composite items are dominant in high school section and final competition. The findings of item analysis are as follows: (1) In the middle school section, P is low and DI is moderate. But in the high school section, there is a considerable differences between science high schools and other high schools in general. (2) The highest correlation is reported between the scores of meteorology domain and total score in middle school, whereas in high school astronomy domain and total score show the highest correlation. (3) General high school section show the highest Cronbach $\alpha$ and generalizability. (4) General high school section show acceptable generalizability coefficient (> 0.80), but middle and science high school section should increase the number of items to reach acceptable generalizability level.