• Journal of the Institute of Convergence Signal Processing
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• v.8 no.2
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• pp.106-112
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• 2007

This paper proposes a hybrid architecture algorithm for fast computation of DCT and DFT via recursive factorization. Recursive factorization of DCT-II and DFT transform matrix leads to a similar architectural structure so that common architectural base may be used by simply adding a switching device. Linking between two transforms was derived based on matrix recursion formula. Hybrid acrchitectural design for DCT and DFT matrix decomposition were derived using the generation matrix and the trigonometric identities and relations. Data flow diagram for high-speed architecture of Cooley-Tukey type was drawn to accommodate DCT/DFT hybrid architecture. From this data flow diagram computational complexity is comparable to that of the fast DCT algorithms for moderate size of N. Further investigation is needed for multi-mode operation use of FFT architecture in other orthogonal transform computation.

• Journal of muscle and joint health
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• v.14 no.1
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• pp.13-25
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• 2007

Purpose: The purpose of the study was to identify the effects of Tai Chi self-help program on glucose control, cardiovascular risks, and quality of life in patients with type II diabetes. Method: The study subjects were 95 adults with type II diabetes recruited from five primary health centers and one outpatient clinic. The Tai chi self-help program was provided twice a week for 6 months. Outcome measures included blood glucose(HbA1c), cardiovascular risk checklist, and quality of life(SF36). Result: At the completion of 6-month program, HbA1c for Tai Chi group dropped from 6.79 to 6.59 without significant group differences. However, cardiovascular risk scores for Tai Chi group has been significantly reduced compared to the control group. In 6 months, quality of life (SF36) was significantly better for Tai Chi group especially in the areas of physical and social functioning. Conclusion: Tai Chi self-help program applied for type 2 diabetes patients has been partially effective to control cardiovascular risk factors, and some dimensions of quality of life. Tai Chi self-help program can be safely and easily applicable to primary care centers for diabetic patients and other people with chronic disease for their symptom management, and health promotion.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.133-138
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• 2002

Microbial Fe (III) reduction is important for the biogeochemical cycle in the sediment of freshwater system. Also, the Fe (III) reducing mechanism make a model of oxidizing organic compounds and reducing toxic heavy metals, such as chrome or uranium. Thirty-seven strains which have Fe (III) reducing activity were isolated from sediments in lake Soyang and Chunho reservoir. The initial concentration of Fe (II) was the highest in sediments of lake Soyang. However, the highest Fe (III) reducing activity was shown in Chunho reservoir. All isolates were tested for Fe (III) reducing activity. Strains C2 and C3, which were isolated from sediments of Chunho reservoir, showed the highest activity. These strains were tested to see if they utilize various electron donors such as glucose, yeast extract, acetate, ethanol and toluene. Significantly, glucose and yeast extract were used as electron donors. Also these strains were conformed to use humid acid and nitrate as electron accepters. The 16S rRNA sequences of strains C2 and C3 were closely related to Aeromonas hydrophila with 95% similarity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1413-1421
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• 2014

This paper realize power control embedded system with one master of Core-A 32-bit RISC processor and several slaves controling power with synchronized digital signals. Core-A platform is consisted of Core-A processor, AMBA bus, SSRAM, AC97, DMA, UART, GPIO etc. Slave is made by both digital part and analog part. The former generates various power control patterns synchronized with master signal. The latter converts 220V power proportional to 4 bit digital signals. design of Embedded system is executed in Flowrian II, in which software is cross-compiled and hardware is verified by simulation. Embedded system is implemented in FPGA board and CPLD chips as well as PCB board for analog power control.

• KCID journal
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• v.14 no.1
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• pp.50-56
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• 2007

In this study, the Soil and Water Assessment Tool (SWAT) model was used to assess spatiotemporal effects on watershed runoff and sediment characteristics due to land uses changes from 1999 to 2002 at the small watershed, located in Chuncheon-si, Gangwon province. The annual average flow rate of Scenario I (long-term simulation using land use of 1990), II (long-term simulation using land use of 1996), III(long-term simulation using land use of 200) and IV(simulation using land use of 1990, 1995, and 2000) in long-term simulation) using the SWAT model were 29,997,043 m3, 29,992,628 m3, 29,811,191 m3 and 29,931,238 m3, respectively. It was shown that there was no significant changes in estimated flow rate because no significant changes in land uses between 1990 and 2000 were observed. The annual average sediment loads of Scenarios I, II, III and IV for 15 year period were 36,643 kg/ha, 45,340 kg/ha , 27,195 kg/ha and 35,545 kg/ha, respectively. The estimated annual sediment loads from Scenarios I, II, and III, were different from that from the scenario IV, considering spatio-temporal changes in land use and meterological changes over the years, by 10%, 127%, and temporal changes in land use and meterological changes over the years, by 10%, 127%, and 77%. This can be explained in land use changes in high soil erosion potential areas, such as upland areas, within the study watershed. The comparison indicates that changes in land uses upland areas, within the study watershed. The comparison indicates that changes in land uses can affect on sediment yields by more than 10%, which could exceed the safety factor of 10% in Total Maximum Daily Loads (TMDLs). It is, therefore, recommended that not only the temporal analysis with the weather input data but also spatial one with different land uses need to be considered in long-term hydrology and sediment simulating using the SWAT model

• Transactions of the Korean hydrogen and new energy society
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• v.34 no.5
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• pp.421-430
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• 2023

Fe-Ni-Pt nanocatalysts were loaded on carbon black powders which were synthesized by a spontaneous reduction reaction of iron (II) acetylacetonate, nickel (II) acetylacetonate and platinum (II) acetylacetonate. The morphology and the loading weight of Fe-Ni-Pt nanoparticles were characterized by transmission electron microscopy and thermogravimetric analyzer. The amount of Fe-Ni-Pt catalyst supported on the carbon black surface was about 6.42-9.28 wt%, and the higher the Fe content and the lower the Pt content, the higher the total amount of the metal catalyst supported. The Brunauer-Emmett-Teller Analysis (BET) specific surface area of carbon black itself without metal nanoparticles supported was 233.9 m²/g, and when metal nanoparticles were introduced, the specific surface area value was greatly reduced. This is because the metal nanocatalyst particles block the pore entrance of the carbon black, and thereby the catalytic activity of the metal catalysts generated inside the pores is reduced. From the I-V curves, as the content of the Pt nanocatalyst increased, the electrolytic properties of water increased, and the activity of the metal nanocatalyst was in the order of Pt > Ni > Fe.

• Journal of the Korean Magnetics Society
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• v.8 no.1
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• pp.6-12
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• 1998

Fe-N(iron-nitrogen) crystal phases were prepared by nitrogen ion implantation into $\alpha$-Fe foil with Plasma Source Ion Implantation (PSII). Ion implantation time of sample is treated 15 minutes(FeN15) and 30 minutes (FeN30). The nitrogen depth profiles measured by Auger electron spectroscopy (AES) were determined to be about 12000 $\AA$ and 4000 $\AA$ for the samples of FeN15 and FeN30, respectively. The results of vibrating sample magnetometer (VSM) show that the saturation magnetization of the samples of as-implanted FeN15 and FeN30 was higher than that of pure $\alpha$-Fe foil, which may be owing to $\alpha$'-$Fe_8N$ or $\alpha$"-$Fe_{16}N_2$ phases. Accordingly this study shows the possibility of the partial formation of $\alpha$' or $\alpha$" phase in iron nitrogen produced by PSII method.II method.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.73-81
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• 2000

The removal of ferrous iron (Fe(II)) in groundwater is generally achieved by simple aeration or the addition of oxidizing agent. Aeration followed by solid-liquid separation is the most commonly used as physico-chemical treatment method for iron removal. In general aeration has been shown to be very efficient in insolubilizing ferrous iron at the pH level greater than 6.5. In this study pH was maintained over 6.5 using limestone granules under constant aeration to oxidize ferrous iron. In batch experiments, oxidation rate of ferrous iron was investigated under different conditions including limestone granule size. initial concentration of the ferrous iron, pH, temperature and ionic strength in groundwater. The pH in groundwater was presumed as the most important factor determining oxidation rate of ferrous iron. According as the size of the limestone granules decreased, the pH of the iron contaminated water increased quickly and oxidation of the ferrous iron was achieved immediately too. The oxidation rate of the ferrous iron was found to be proportion to initial concentration of the iron contaminated water, temperature and ionic strength, respectively.

• Clinical and Experimental Pediatrics
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• v.46 no.9
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• pp.883-888
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• 2003

Purpose : The etiology of hemolytic anemia can be classified as either cellular or extracellular defects of red blood cells. The aim of this study was to investigate the clinical and laboratory findings of hemolytic anemia concerning its etiological classification. Methods : Clinical and laboratory findings of the patients with hemolytic anemia treated from January 1987 to May 2002 at Severance Hospital were analyzed retrospectively. They were divided into two groups based on the types of red cell defects(group I : erythrocytic defect, group II : extraerythrocytic defect). Results : Twenty one cases were included in group I, thirty four cases in group II, and three cases were unclassified. In group I, nineteen cases(90.5%) were diagnosed as hereditary spherocytosis and were proved to have red cell membrane disorders while two cases(9.5%) were shown to have red cell enzyme deficiencies. In group II, thirteen cases(38.2%) were noted as autoimmune hemolytic anemia, eleven cases(32.4%) as traumatic or microangiopathic hemolytic anemia, four cases(11.8%) as drug induced hemolytic anemia, two cases(5.9%) were related with systemic lupus erythematosus and one case(2.9%) with malignancy. Hemoglobin at the time of diagnosis(7.5 g/dL vs. 6.2 g/dL, P<0.05) and the incidence of splenomegaly(85.7% vs. 18.2%, P<0.05) were higher in group I though blood urea nitrogen(9.0/0.4 mg/dL vs. 27.8/1.6 mg/dL, P<0.05) was higher in group II. Conclusion : Comparing the clinical features of pediatric hemolytic anemia, we concluded as following : In cases associated with extraerythrocytic defect, blood tests revealed significant initial lower hematocrit with higher level of BUN and Cr while cases with erythrocytic defect, splenomegaly were more common noted.

• Journal of Chest Surgery
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• v.41 no.4
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• pp.430-438
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• 2008

Background: All the patients with mechanical valves require warfarin therapy in order to prevent them from developing thromboembolic complications. According to the ACC/AHA practice guidelines, after AVR with bileaflet mechanical prostheses in patients with no risk factors, warfarin is indicated to achieve an INR of 2.0 to 3.0. After MVR with any mechanical valve, warfarin is indicated to achieve an INR of 2.5 to 3.5. But in our clinical experience, bleeding complications (epistaxis, hematuria, uterine bleeding, intracerebral hemorrhage etc.) frequently developed in patients who maintained their INR within this value. So, we retrospectively reviewed the patients with bileaflet mechanical heart valve prosthesis and we determined the optimal anticoagulation value. Material and Method: From January 1984 to February 2007, 311 patients have been followed up at a national medical center. We classified the AVR patients (n=60) into three groups as follows: an INR from 1.5 to 2.0 in Group I, an INR from 2.0 to 2.5 in Group II and an INR from 2.5 to 3.0 in Group III. We classified the MVR (n=171) and DVR (n=80) patients into four groups as follows: an INR from 1.5 to 2.0 in Group I, an INR from 2.0 to 2.5 in Group II, an INR from 2.5 to 3.0 in Group III and an INR from 3.0 to 3.5 in Group III. We compared the groups for their thromboembolic and bleeding complications by means of the Kaplan Meier method. Result: In the AVR patients, 2 thromboembolic complications and 4 bleeding complications occurred and the log rank test failed to identify any statistical significance between the groups for thethromboembolic complication rate, but groups I and II had lower bleeding complication rates than did group III. Thirteen thromboembolic complication and 15 bleeding complication occurred in the MVR and DVR patients, and the log rank test also failed to identify statistical significance between the groups for the thromboembolic complication rate, but groups I and II had lower bleeding complication rates that did groups III and IV. Conclusion: The thromboembolic complication rate was not statistically different between groups I and II and groups III and IV, but the bleeding complication rates of groups I and II were lower than those of groups III and IV. So this outcome encouraged us to continue using our low intensive anticoagulation regime, that is, an INR of 1.5 to 2.5.