• Korean journal of applied entomology
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• v.26 no.4 s.73
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• pp.251-255
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• 1987

This study was conducted to investigate the effects of cultural methods on infection by Rhizoctonia disease(Rhizoctonia solani $K\"{u}hn$) of potato (Solanum tuberosum L.). Two potato cultivars, i.e., Irish Cobbler and Superior were planted in 1984 at the Alpine Experiment Station and 4 cultural methods were used in Combinations or separately. The deeper planting showed the later germination of sprout. The degree of infection on underground stems didn't show any differences between the treatments, but the yield was higher in deeper planting. When seed tubers were planted on April 28 the underground stems showed severely discolourated epidermis comparing to later planting, consequently the yield was low. The glazed chitting tubers produced healthy sprouts comparing to the untreated tubers, consequently the yield was also increased. The density of sclerotia on tuber skin was remarkably increased between 6 to 15days of delayed digging after haulm killing. Underground stems of Irish Cobbler were easily discolourated by the disease, where-as the density of sclerotia was higher on tuberskin of Superior than of Irish Cobbler.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2648-2656
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• 2011

A simple HPLC-DAD method was developed and validated to determine B group vitamin content (thiamine, riboflavin, nicotinamide, pantothenic acid, pyridoxine and folic acid) in supplemented food samples, i.e., infant formula, cereal, low-calorie food, a multi-vitamin pill and a vitamin drink. In this study, the most significant advantages were simultaneous determination of the six B group vitamins in various food matrices and a small number of sample treatment steps that required only an organic solvent, acetonitrile. Moreover, this method prevents reduction of column durability, because the mobile phase does not contain ion-pairing reagents. Analytes were separated on a Develosil RPAQUEOUS $C_{30}$ (4.6 mm ${\times}$ 250 mm, 5 ${\mu}M$ particle size) column with a gradient elution of acetonitrile and 20 mM phosphate buffer (pH 3.0) at a flow rate between 0.8 and 1.0 mL/min. Detection was performed at 275 nm, except for that of pantothenic acid (205 nm). The calibration curves for all six vitamins showed good linearity with correlation coefficients ($r^2$) higher than 0.995. The developed method was validated with respect to linearity, intra- and inter-day accuracy and precision, limit of quantification (LOQ), recovery and stability. The method showed good precision and accuracy, with intra- and inter-assay coefficients of variation less than 15% at all concentrations. The recovery was carried out according to the standard addition procedure, with yields ranging from 89.8 to 104.4%. This method was successfully applied to the determination of vitamin B groups in supplemented food products.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1378-1385
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• 1999

The antioxidative activity of Fermented Anchovy on linoleic acid autooxidation was investigated in an aqueous system at pH 7.0. All solvent fractions from Fermented Anchovy were exhibited the strong antioxidative activity. Especially, BuOH and aqueous fractions were gained large amounts with strong antioxidative activity. Ultrafiltration, dialysis, heat treatment of aqueous fraction indicated that water-soluble antioxidants of Fermented Anchovy were heat-resistant, amino acid related compounds with smaller molecular weights than 1,000. Unbound fractions from DE-52 anion exchange chromatography were exhibited antioxidative activity with or without $15\;{\mu}M\;Fe^{+++}\;ion$. We were able to purify one methionine derivative from lots of antioxidative substances in Fermented Anchovy aqueous fraction by gel filtration, anion-exchange chromatography, TLC and HPLC, successfully. These data suggest that Fermented Anchovy aqueous fraction is a mixture of fermented small molecules with strong antioxidative activities.

• Journal of the Korean earth science society
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• v.29 no.6
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• pp.506-519
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• 2008

This article explores the potential learning materials and methods of science practice from exhibits, and how those are presented in natural history museums as a feasible science inquiry community. The idea of science inquiry community was offered as a form of science practice that ended with science learning. A grasp of 'scientific practice to learning' is understood as a way to conceive scientific methods as well as facts and understanding knowledge. To get educational implications on the scientific practice of 'earthquake' as a socioscientific topic in the communities, we analyzed 1) the relationship between earth science curriculum and exhibits related to 'earthquake', 2) the educational goals and intentions of educators, and 3) the characteristics of the exhibits in the American Museum of Natural History and in the Smithsonian National Museum of Natural History. The results of this study showed that those museums presented the exhibits consisting of various and practical cases and events of 'earthquakes' as a socioscientific topic related to their curriculum. At the target museum, it was clearly stated that the pursuing educational goals focused on relations with local interests and socioscientific issues. For making earthquakes relevant to visitors, delivering lived experiences with raw data and interactive media was emphasized in exhibit characteristics.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.1
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• pp.19-28
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• 2010

This study was designed to investigate the effect of increased blood and tibia lead on the change of bone mineral density in retired male lead workers. One hundred nine retired male lead workers who worked in 4 different lead industries and 51 nonoccupationally lead exposed male subjects were recruited from March 2004 to October 2004. Bone mineral density(BMD) was measured by broadband ultrasound attenuation(BUA) at left calcaneous bone area with broadband ultrasound attenuation method of QUS-2(Metra Biosystems Inc, USA). Tibia bone lead was measured for skeletal bone lead with K-xray fluorescence(K-XRF) and blood lead was analyzed with flameless atomic spectrophotometer. Hemoglobin, hematocrit, serum calcium and iron were also analyzed. In addition, information for smoking and drinking status and basic personal data such as age and lead exposure were also collected using questionnaire inquiry. Blood lead was correlated with tibia lead (r=0.711) and these two variables were negatively correlated with BUA in bivariate analysis. BUA and tibia lead showed significant main effects on the change of blood lead after adjusting covariates. The effect modification by the level of BMD (low: lower than the median of BUA and high: higher than the median of BUA) was observed between the association of tibia lead and blood lead after adjustment of covariates. The subjects who had higher BMD seemed to have lower blood lead by the increase of tibia lead than those of lower BMD. In the multiple regression analysis of blood lead and tibia lead on BUA after adjustment of covariates, only blood lead showed statistically significant effect on BUA. This study confirmed that BMD and blood lead were significantly associated. To verify the causal association of BMD on blood lead and vice versa, further longitudinal studies are needed.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.3
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• pp.307-326
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• 2004

Statement of problem. The long-term success of implants is the development of a stable direct connection between bone and implant surface, which must be structural and functional. To improve a direct implant fixation to the bone, various strategies have been developed focusing on the surface of materials. Among them, altering the surface properties can modify cellular responses such as cell adhesion, cell motility and bone deposition. Purpose. This study was to evaluate the cellular behaviors on the surface-modified titanium by morphological observation, cellular proliferation and differentiation. Material and methods. Specimens were divided into five groups, depending on their surface treatment: electropolishing(EP) anoclizing(AN), machining(MA), blasting with hydroxyapatite particle(RBM) and electrical discharge machining(EDM). Physicochemical properties and microstructures of the specimens were examined and the responses of osteoblast-like cells were investigated. The microtopography of specimens was observed by scanning electron microscopy(SEM). Surface roughness was measured by a three-dimensional roughness measuring system. The microstructure was analyzed by X-ray diffractometer(XRD) and scanning auger electron microscopy(AES). To evaluate cellular responses to modified titanium surfaces, osteoblasts isolated from neonatal rat were cultured. The cellular morphology and total protein amounts of osteoblast-like cell were taken as the marker for cellular proliferation, while the expression of alkaline phosphatase was used as the early differentiation marker for osteoblast. In addition, the type I collagen production was determined to be a reliable indicator of bone matrix synthesis. Results. 1. Each prepared specimen showed specific microtopography at SEM examination. The RBM group had a rough and irregular pattern with reticulated appearance. The EDM-treated surface had evident cracks and was heterogeneous consisting of broad sheet or plate with smooth edges and clusters of small grains, deep pores or craters. 2. Surface roughness values were, from the lowest to the highest, electropolished group, anodized group, machined group, RBM group and EDM group. 3. All groups showed amorphous structures. Especially anodized group was found to have increased surface oxide thickness and EDM group had titaniumcarbide(TiC) structure. 4. Cells on electropolished, anodized and machined surfaces developed flattened cell shape and cells on RBM appeared spherical and EDM showed both. After 14 days, the cells cultured from all groups were formed to be confluent and exhibited multilayer proliferation, often overlapped or stratified. 5. Total protein amounts were formed to be quite similar among all the group at 48 hours. At 14 days, the electropolished group and the anodized group induced more total protein amount than the RBM group(P<.05). 6. There was no significant difference among five groups for alkaline phosphatase(ALP) activity at 48 hours. The AN group showed significantly higher ALP activity than any other groups at 14 days(P<.05). 7. All the groups showed similar collagen synthesis except the EDM group. The amount of collagen on the electropolished and anodized surfaces were higher than that on the EDM surface(P<.05).

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.31-42
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• 2000

Consolidation and permeability are major engineering properties of soil. In clay, coefficient of permeability and consolidation can be calculated by incremental loading consolidation test. However, it is known that the incremental loading test has several deficiencies including long testing time, non-uniform stress state, very soft clay and problem of back pressure saturation. Specially, it is not performed with horizontal consolidation test. Several methods have been proposed for obtaining reliable values of $C_v$. Among these, the square root of time-fitting method proposed by Taylor(1948) and logarithm of time-fitting method, also called Casagrande's method, are used extensively in soil engineering practice. But these methods are not amenable for the absence of initial linear portion and have the difficulties involved in distinguishing secondary compression from primary compression. Rowecell consolidation tests were carried out in this study with different trimming axis and sample size. The results were compared with those of other methods; Casagrande,$Taylor,\; Casagrande,\; Hyperbolic,\; \delta/t-logt$. From the results, we explained a relationship between horizontal coefficient of permeability and void ratio was obtained. Finally, the directly measured horizontal coefficient of permeability obtained by using the Rowecell was compared with the permeability derived indirectly from the consolidation test result.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.102-110
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• 2004

In this paper, we propose a VLSI structure of real-time image compression and reconstruction processor using 2-D discrete wavelet transform and implement into a hardware which use minimal hardware resource using ASIC library. In the implemented hardware, Data path part consists of the DWT kernel for the wavelet transform and inverse transform, quantizer/dequantizer, the huffman encoder/huffman decoder, the adder/buffer for the inverse wavelet transform, and the interface modules for input/output. Control part consists of the programming register, the controller which decodes the instructions and generates the control signals, and the status register for indicating the internal state into the external of circuit. According to the programming condition, the designed circuit has the various selective output formats which are wavelet coefficient, quantization coefficient or index, and Huffman code in image compression mode, and Huffman decoding result, reconstructed quantization coefficient, and reconstructed wavelet coefficient in image reconstructed mode. The programming register has 16 stages and one instruction can be used for a horizontal(or vertical) filtering in a level. Since each register automatically operated in the right order, 4-level discrete wavelet transform can be executed by a programming. We synthesized the designed circuit with synthesis library of Hynix 0.35um CMOS fabrication using the synthesis tool, Synopsys and extracted the gate-level netlist. From the netlist, timing information was extracted using Vela tool. We executed the timing simulation with the extracted netlist and timing information using NC-Verilog tool. Also PNR and layout process was executed using Apollo tool. The Implemented hardware has about 50,000 gate sizes and stably operates in 80MHz clock frequency.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.4
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• pp.282-287
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• 2016

Recently in order to protect the ocean environment and to reduce energy consumption, shipbuilders have been developing highly economized ships. This research analyzed the possibility of adopting the onshore absorption refrigerator to offshore ships having a cooling system with refrigerant by using the waiste heat of the engine jacket cooling water instead of compression refrigerators. The results showed that R236fa could be a suitable medium for absorbing the heat of the absorber and condenser in an absorption refrigerator. The cooling system using R236fa achieved a high COP of 0.798, which is 15% and 5% higher than an air cooling system with a cooling tower and a water cooling system with a heat exchanger, respectively. The cooling system with R236fa achieved high efficiency with a 25% reduction in flow rate of LiBr solution and only 15.7% flow rate of cooling medium as compared to the water cooling system. The heating of sea water by the engine jacket water flowing out from the generator can prevent the crystallization of LiBr solution due to the low temperature of sea water.

• The Journal of Korean Medicine
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• v.27 no.1 s.65
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• pp.165-183
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• 2006

Objectives : We implemented the Artemisia Extract Moxibustion Method and had the clinical tests for the diabetes with it. Methods : We implemented Artemisia extract made by extracting the vasodilator and antioxidant compounds from Artemisia-CH2C12 fraction and the moxibustion method constructed with DC Power supply, controller, Artemisia pad. single and multiple heating terminal with PTC(Positive Temperature Coefficient) thermistor. And we performed to estimate the efficiency on the questionnaire and the clinical tests with 23 cases of the diabetics. Results : We have estimated the improvement over 60% the symptoms that were the upper and lower limbs pain, frequent urination, spontaneous perspiration, thirst, decrease of body weight, and malaise after the moxibustion treatment on 5 cases among 23 cases. And the 19 cases took the biochemical check-up after the moxibustion treatment. From the results of biochemical check-up, the average HbAlc of before treatment was 8.400%, and after treatment 7.632%. The average HbAlc was decreased significantly after treatment (P<0.001). And the average urinary blood of before treatment was 0.73 and after treatment 0.27. The average urinary blood was decreased significantly after treatment (P<0.001). In addition the average FBS before treatment was 182.64 mg/dl, after treatment 161.77 mg/dl. Conclusions : We could estimate that our proposed moxibustion method was a significant treatment method for the diabetes.