• Progress in Medical Physics
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• v.21 no.2
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• pp.165-173
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• 2010

In this paper, we evaluated the performance of 3D CRT, IMRT and three kind of RA plannings to investigate the clinical effect of RA with liver cancer case. The patient undergoing liver cancer of small volume and somewhat constant motion were selected. We performed 3D CRT, IMRT and RA plannings such as 2RA, limited triple arcs (3RA) and 3MRA with Eclipse version 8.6.15. The same dose volume objectives were defined for only CTV, PTV and body except heart, liver and partial body in IMRT and RA plannings. The steepness of dose gradient around tumor was determined by the Normal Tissue Objective function with the same parameters in place of respective definitions of dose volume objectives for the normal organs. The approach between the defined dose constraints and the practical DVH of CTV, PTV and Body was the best in 3MRA and the worst in IMRT. The DVHs were almost the same among RAs. Plans were evaluated using Conformity Index (CI), Homogeneity Index (HI) and Quality of coverage (QoC) by RTOG after prescription with dose level surrounding 98% of PTV in the respective plans. As a result, 3MRA planning showed the better favorable indices than that of the others and achieved the lowest MUs. In this study, RA planning is a technique that is possible to obtain the faster and better dose distribution than 3D CRT or IMRT techniques. Our result suggest that 3MRA planning is able to reduce the MUs further, keeping a similar or better targer dose homogeneity, conformity and sparing normal tissue than 2RA or 3RA.

• Investigative Magnetic Resonance Imaging
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• v.18 no.1
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• pp.1-6
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• 2014

Purpose : $T_2{^*}$ relaxation time which includes susceptibility information represents unique feature of tissue. The objective of this study was to investigate $T_2{^*}$ relaxation times of the normal glandular tissue and fat of breast using a 3T MRI system. Materials and Methods: Seven-echo MR Images were acquired from 52 female subjects (age $49{\pm}12 $years; range, 25 to 75) using a three-dimensional (3D) gradient-echo sequence. Echo times were between 2.28 ms to 25.72 ms in 3.91 ms steps. Voxel-based $T_2{^*}$ relaxation times and $R_2{^*}$ relaxation rate maps were calculated by using the linear curve fitting for each subject. The 3D regions-of-interest (ROI) of the normal glandular tissue and fat were drawn on the longest echo-time image to obtain $T_2{^*}$ and $R_2{^*}$ values. Mean values of those parameters were calculated over all subjects. Results: The 3D ROI sizes were $4818{\pm}4679$ voxels and $1455{\pm}785$ voxels for the normal glandular tissue and fat, respectively. The mean $T_2{^*}$ values were $22.40{\pm}5.61ms$ and $36.36{\pm}8.77ms$ for normal glandular tissue and fat, respectively. The mean $R_2{^*}$ values were $0.0524{\pm}0.0134/ms$ and $0.0297{\pm}0.0069/ms$ for the normal glandular tissue and fat, respectively. Conclusion: $T_2{^*}$ and $R_2{^*}$ values were measured from human breast tissues. $T_2{^*}$ of the normal glandular tissue was shorter than that of fat. Measurement of $T_2{^*}$ relaxation time could be important to understand susceptibility effects in the breast cancer and the normal tissue.

• KSBB Journal
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• v.22 no.3
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• pp.162-167
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• 2007

Ammonia gas is one of the major pollutants which cause environmental pollution and damage to the human and the livestock. The objective of this study was to investigate the important parameters for the development of efficient removal of ammonia gas by Bacillius subtilis IB101 and to optimize the medium composition for the mass production of B. subtilis IB101. The ammonia gas removal efficiency was evaluated at different growth phases and by changing culture conditions (temperature, pH). The effect of $(NH_4)_2SO_4$ concentration in preculture medium was examined. Medium optimization for the mass production of B. subtilis IB101 was performed by using Plackett-Burman design and one factor at a time method. The removal of ammonia gas was more efficient at exponential phase by 20% than at stationary phase. The ammonia gas removal was the highest at pH 4 and 30 $^{\circ}C$. There was not any significant influence of concentration of $(NH_4)_2SO_4$ on the removal of ammonia gas. The components of optimized medium for the production of viable Bacillus subtilis IB101 was yeast extract 10 g/l, soluble starch 2.5 g/l, $MgSO_4$ 6 g/l, $CaCl_2$ 1.55 g/l, $(NH_4)_2SO_4$ 5 g/l, $KH_2PO_4$ 0.75 g/l, soy bean meal 8 g/l.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.6
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• pp.647-653
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• 2007

The ultimate objective of this study is to develop a reliable oxygen-enriched combustion techniques especially for the case of the flue gas recycling in order to reduce the $CO_2$ emissions from practical industrial boilers. To this end a systematic numerical investigation has been performed, as a first step, for the resolution of the combusting flame characteristics of lab-scale LNG combustor. One of the important parameters considered in this study is the level of flue gas recycling calculated in oxygen enriched environment. As a summary of flame characteristics, for the condition of 100% pure $O_2$ as oxidizer without any flue gas recycling, the flame appears as long and thin laminar-like shape with relatively high flame temperature. The feature of high peak of flame temperature is explained by the absence of dilution and heat loss effects due to the presence of $N_2$ inert gas. The same reasoning is also applicable to the laminarized thin flame one, which is attributed to the decrease of the turbulent mixing. These results are physically acceptable and consistent and further generally in good agreement with experimental results appeared in open literature. As the level of $CO_2$ recycling increases in the mixture of $O_2/CO_2$, the peak flame temperature moves near the burner region due to the enhanced turbulent mixing by the increased amount of flow rate of oxidizer stream. However, as might be expected, the flue gas temperature decreases due to presence of $CO_2$ gas together with the inherent feature of large specific heat of this gas. If the recycling ratio more than 80%, gas temperatures drop so significantly that a steady combustion flame can no longer sustain within the furnace. However, combustion in the condition of 30% $O_2/70% $ $CO_2$ can produce similar gas temperature profiles to those of conventional combustion in air oxidizer. An indepth analyses have been made for the change of flame characteristics in the aspect of turbulent intensity and heat balance.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.839-846
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• 2007

The objective of the present study was to investigate the effect of dietary supplementation of the ginseng by-product on growth performance and meat quality in finishing pigs. The animals used in the experiment were a total of 24 Landrace×Yorkshire and weighted 65.81±2.02kg. The experimental diets were basal diet(CON) and 2.5% ginseng by-product(GBP), which replaced lupin in basal diet. The pigs were allotted at 4 pigs per pen with three replicate pens per treatment by completely randomized design. In growth performance, ADFI was significantly lower(P<0.0001) in GBP than in CON. In plasma biochemical composition, total protein(P<0.01), blood urea nitrogen(P<0.03), glucose(P<0.01), albumin(P<0.02), calcium(P<0.01) and inorganic phosphate(P<0.01) were significantly higher in GBP than in CON. Carcass and meat quality were not significantly different between treatments. Total ginsenoside content on meat was significantly higher(P<0.0001) in GBP than in CON. TBARs was significantly lower in GBP than in CON for 6 days(P<0.03) and 12 days (P<0.06), respectively. Our research indicates that plasma biochemical composition, total ginsenoside content and TBARs were affected when replaced with ginseng by-product. Ginseng by-product in the pig diet increased pig muscle ginsenoside, indicating that ginseng by-product can be used as a feed additive.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.8
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• pp.759-769
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• 2013

Electronic equipment has been applied to virtually every area associated with commercial, industrial, and military applications. Specifically, electronics have been incorporated into avionics components installed in aircraft. This equipment is exposed to dynamic loads such as vibration, shock, and acceleration. Especially, avionics components installed in a helicopter are subjected to simultaneous sine and random base excitations. These are denoted as sine on random vibrations according to MIL-STD-810F, Method 514.5. In the past, isolators have been applied to avionics components to reduce vibration and shock. However, an isolator applied to an avionics component installed in a helicopter can amplify the vibration magnitude, and damage the chassis, circuit card assembly, and the isolator itself via resonance at low-frequency sinusoidal vibrations. The objective of this study is to investigate the dynamic characteristics of an avionics component installed in a helicopter and the structural dynamic modification of its tray plate without an isolator using both a finite element analysis and experiments. The structure is optimized by dynamic loads that are selected by comparing the vibration, shock, and acceleration loads using vibration and shock response spectra. A finite element model(FEM) was constructed using a simplified geometry and valid element types that reflect the dynamic characteristics. The FEM was verified by an experimental modal analysis. Design parameters were extracted and selected to modify the structural dynamics using topology optimization, and design of experiments(DOE). A prototype of a modified model was constructed and its feasibility was evaluated using an FEM and a performance test.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.58-64
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• 2011

Objective: The 3-dimensional reconstruction method with resolution recovery modeling has advantages of high spatial resolution and contrast because of its precise modeling of spatial blurring according to the distance from detector plane. The aim of this study was to evaluate one of the resolution recovery reconstruction methods (Astonish, Philips Medical), compare it to other iterative reconstructions, and verify its clinical usefulness. Materials and Methods: NEMA IEC PET body phantom and Flanges Jaszczak ECT phantom (Data Spectrum Corp., USA) studies were performed using Skylight SPECT (Philips) system under four different conditions; short or long (2 times of short) radius, and half or full (40 kcts/frame) acquisition counts. Astonish reconstruction method was compared with two other iterative reconstructions; MLEM and 3D-OSEM which vendor supplied. For quantitative analysis, the contrast ratios obtained from IEC phantom test were compared. Reconstruction parameters were determined by optimization study using graph of contrast ratio versus background variability. The qualitative comparison was performed with Jaszczak ECT phantom and human myocardial data. Results: The overall contrast ratio was higher with Astonish than the others. For the largest hot sphere of 37 mm diameter, Astonish showed about 27.1% and 17.4% higher contrast ratio than MLEM and 3D-OSEM, in short radius study. For long radius, Astonish showed about 40.5% and 32.6% higher contrast ratio than MLEM and 3D-OSEM. The effect of acquired counts was insignificant. In the qualitative studies with Jaszczak phantom and human myocardial data, Astonish showed the best image quality. Conclusion: In this study, we have found out that Astonish can provide more reliable clinical results by better image quality compared to other iterative reconstruction methods. Although further clinical studies are required, Astonish would be used in clinics with confidence for enhancement of images.

• Korean Journal of Veterinary Service
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• v.36 no.4
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• pp.263-272
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• 2013

Consistent information on the chemical composition and its seasonal variation of goat udder half milk is limited in Korea. The objective of this study was to analyze the seasonal variation of the chemical composition of goat milk to take establish various parameters into consideration on the pricing of the goat milk. Variations in chemical composition, somatic cell count (SCC) and bacterial count of 1,038 udder half milk samples from 650 heads raised in 7 farms of Jeonnam province were determined by season. Fat, protein, lactose, non-fat solids, milk urea nitrogen (MUN), pH, SCC and bacterial counts were also analyzed. The average composition of the milk was: fat $3.80{\pm}1.36%$, protein $3.23{\pm}0.80%$, lactose $4.39{\pm}0.54%$, total solids $12.18{\pm}1.80%$, non-fat solids $8.38{\pm}0.80%$, and milk urea nitrogen $28.44{\pm}5.00mg/dL$. The average pH was $6.81{\pm}0.24$. The average of SCC and bacterial counts were $2.54{\pm}4.60{\times}10^6cells/mL$ and $1.25{\pm}3.76{\times}10^5CFU/mL$, respectively. Chemical composition, pH, SCC and bacterial counts of dairy goat milk varied widely during the lactation period and by season. The fat concentration was the lowest in spring ($3.39{\pm}1.53%$) and the highest in autumn and winter ($3.98{\pm}1.30%$ and $3.98{\pm}1.48%$). Protein concentration was the lowest during summer ($2.92{\pm}0.48%$) and the highest in winter ($2.92{\pm}0.48%$). Lactose concentration was the lowest in autumn ($4.24{\pm}0.41%$) and the highest in spring ($4.58{\pm}0.35%$). The lowest total solid value was obtained in the spring season ($11.75{\pm}1.80%$) which was then increased in winter ($12.85{\pm}1.96%$). Non-fat solid concentration was the lowest in summer ($8.07{\pm}0.64%$) and the highest in autumn ($8.94{\pm}0.82%$). MUN concentration was the highest in summer ($8.07{\pm}0.64%$), and the pH concentration was the highest in spring at $6.93{\pm}0.27%$. Seasonal variation of SCC and bacterial count were the lowest in spring ($0.94{\pm}1.54{\times}10^6cells/mL$ and $0.22{\pm}0.61{\times}10^5CFU/mL$, respectively) and was the highest in winter ($3.95{\pm}7.14{\times}10^6cells/mL$ and $2.23{\pm}5.54{\times}10^4CFU/mL$, respectively).

• Food Science of Animal Resources
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• v.28 no.2
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• pp.232-239
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• 2008

The objective of this study is to estimate the shelf-life of Tteokgalbi containing dietary fiber extracted from rice bran by using the predictive microbiology. This Tteokgalbi was made with 0%, 1%, 2%, and 3% dietary fiber. The number of total viable cells, anaerobic, psychrotrophic, and heat-stable bacteria and coliforms was calculated during 15 days of storage under $4{\pm}1^{\circ}C$ and the obtained data was applied to Baranyi function. The evaluation of fitness between predicted and observed data showed that these were matched in a satisfactory way. Heat-stable bacteria was detected lower than <1 log CFU/g and coliforms were not detected during the storage. The changes of total viable cells and psychrotrophic bacteria in Tteokgalbi were increased gradually, but dramatically increased after 3 days of storage. The models of total viable cells and anaerobic bacteria showed very similar growth trends and values of growth parameters each other. The estimated shelf-life of each Tteokgalbi was calculated from the predictive model of total viable cells and the estimated shelf-life was 1.7, 2.3, 2.3, and 2.4 days, respectively. The results suggested that the prediction of bacteria growth could be used to evaluate the microbiological safety and determine the shelf-life of Tteokgalbi as ready-to-eat food in the local market.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.145-156
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• 2006

The objective of this study was to evaluate biological health conditions and physicochemical status using multi-metric models at five sites of the Keum-Ho River during August 2004 and June 2005. The research approach was based on a qualitative habitat evaluation index (QHEI), index of biological integrity (IBI) using fish assemblage, and long-term chemical data (1995 ${\sim}$ 2004), which was obtained from the Ministry of Environment, Korea. For the biological health assessments, regional model of the IBI in Korea (An,2003), was applied for this study. Mean IBI in the river was 30 and varied from 23 to 48 depending on the sampling sites. The river health was judged to be "fair condition", according to the stream health criteria of US EPA (1993) and Barbour et al. (1999). According to the analysis of the chemical water quality data of the river, BOD, COD, conductivity, TP, TN, and TSS largely varied epending on the sampling sites, seasons and years. Variabilities of some parameters including BOD, COD, TP, TN, and conductivity were greater in the downstream than in the upstream reach. This phenomenon was evident in the dilution by the rain during the monsoon. This indicates that precipitation is a very important factor of the chemical variations of water quality. Community analyses showed that species diversity index was highest (H=0.78) in the site 1, while community dominance index was highest in the site 3, where Opsariichthys uncirostris largely dominated. In contrast, the proportions of omnivore and tolerant species were greater in the downstream reach, than in the upstream reach. Overall, this study suggests that some sites in the downstream reach may need to restore the aquatic ecosystem for better biological health.