• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.314-321
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• 2012

Harmful gases which are generated from various rout at growth environment of livestock ban have a direct and indirect bad influence to the livestock and farmers, and also step-up breeding density and long-term exposure to the sealed environment of winter can be fatal. In this paper, we propose a gas measurement system for monitoring gases of ammonia, hydrogen sulfide, volatile organic compounds, etc. which arise from the muck. The measurement system consist of both wireless gas sensor node and gas recognition software using a Fuzzy Min-Max neural network. To evaluate the performance of suggested system, gas measurement experiments are performed in laboratory environment by using the designed wireless gas sensor node. And we show the performance through classification test for the target gases by the designed gas recognition software.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.615-622
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• 2012

The aim of shotcrete is to increase the bearing capacity and to protect the excavated surface from erosion by preventing falling of rock mass. Shotcreting method is divided into two types as dry process and wet process. Since 1997, wet process method has been used more frequently than dry process method in field works. The failure to bond, so called rebound, occurs in many case during shotcrete works. The excess amount of rebound has a significant effect on the total construction cost. For example, material and craft-man cost increases, the shooting time delays due to deceleration of work execution stage, work efficiency of craft-man decreases and additional cost to remove the muck generates. In this study, therefore, the experimental analysis of rebound amount and strength was conducted by analyzing the actual construction data for wet process type of shotcreting method upon accelerator contents. Also, the effective and rational method was suggested, which can be actually implemented in the Korea construction sites.

• Explosives and Blasting
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• v.28 no.1
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• pp.19-26
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• 2010

The paper presents a case study of a limestone quarry of the Philippines, where major problems in terms of improper fragmentation, poor wall control, and poor heave of the muck pile were witnessed. The paper highlights the significant role of switching over from diagonal firing pattern to V-type firing pattern, and also of making suitable adjustments in the stemming column length for improved confinement and gas retention. The study revealed that by making aforesaid design modifications in the blast round, marked improvement in blasting results was registered. Looking at the results, it was further contemplated to expand the mesh area in the subsequent blast rounds. The mesh area was incremented from the existing $8.96m^2$ to $12m^2$. The results were meticulously registered in the field, and clearly depicted definite improvements in the blast results in terms of increased P.F., reduced boulder count, reduced FEL cycle time, reduced dozing hours and improved heave.

• Journal of Nutrition and Health
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• v.18 no.2
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• pp.98-114
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• 1985

In the previous studies, one of our author had observed the obligatory nitrogen losses through urine and feces in young Korean male adults, and utilization of whole egg protein in Korean young adults with ordinary intake of energy as a basic study for estimating protein requirements of Korean. This study has tried to determine the protein requirement and utilization when subjects ate the Korean mixed diet at the energy level of 45 kcal per Kg body weight per day. Six healthy Korean young female adults, college students, aged $20{\sim}25$ years old, and $45{\sim}61Kg$ of body weight participated as the study subjects. They were given isocaloric diets with four different protein levels for five days each successively. These diets contained protein levels of 0.45, 0.60, 0.75 and 0.90g per Kg of body weight per day, respectively. It was attempted to observe energy and protein intake, urinary and fecal nitrogen losses, true digestibility of protein, net protein utilization of protein in the body over last two days of period of eating each diet and nitrogen balances were calculated. The body weight change and hematological observation were also performed. The results obtained were summarized as follows ; 1) True digestibility of protein of Korean mixed diets ranged from 83.1% to 86.5% and the average of which was $84.7{\pm}1.7%$. 2) Net protein utilization rate of Korean mixed diets was range of 49% to 55% and the average of which was $52{\pm}3%.$ 3) The body weight of subjects were slightly increased and the values of hemoglobin and hematocrit of the blood were also little increased during the experimental periods of twenty days. 4) Protein requirements of Korean mixed diet with the energy level of 45 kcal/Kg body weight per day of Korean young female adults were estimated as 1.00g/Kg/day on this experimental condition.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.636-640
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• 2000

Cup-plant (Silphium perfoliatum L.) has potential to produce high biomass and highly digestible forage in the wetlands where other productive forages do not grow or produce well. However, high moisture content at harvest is a considerable disadvantage of cup-plant for the production of high quality silage. This study was conducted to determine the effect of moisture content on the characteristics of cup-plant silage. Harvested cup-plant was ensiled in farm scale plastic bag silos and laboratory silos. In the plastic bag silos, first growth (FG) and regrowth (RG) cup-plant was harvested, wilted and ensiled. Dry matter content of FG and RG was 280 g/kg and 320 g/kg after 48 hr of wilting. The silage made with FG had pH 5.3 and 5.63 g/kg DM of acetate as a major volatile fatty acid. The composition of lactate, butyrate and acetate production was 1.0: 0.9: 2.3. The pH of silage made with RG was 4.5 and lactate was a major fermentation end product (16.8 g/kg DM). In the laboratory silos, wilted and unwilted first growth cup-plant material was ensiled to compare the early fermentation end products at days 2, 4, 11, and 40. Wilting increased dry matter content by 42% in the harvested material. Wilted silage showed about one unit lower pH until day 11. The contents of ammonia nitrogen and acetate were higher in un wilted silage, while that of lactate was higher in wilted silage (p<0.05). Butyrate and propionate were not detected in the wilted silage until day 40. We conclude from the results that moisture control is essential for the production of high quality cup-plant silage and high pH of cup-plant silage is due to low concentrations of fermentation end products.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.2-6
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• 2000

We have developed an extremely sensitive radio frequency amplifier based on the dc superconducting quantum interference device (dc SQUID). Unlike a conventional semiconductor amplifier, a SQUID can be cooled to ultra-low temperatures (100 mK or less) and thus potentially achieve a much lower noise temperature. In a conventional SQUID amplifier, where the integrated input coil is operated as a lumped element, parasitic capacitance between the coil and the SQUID washer limits the frequency up to which a substantial gain can be achieved to a few hundred MHz. This problem can be circumvented by operating the input coil of the SQUID as a microstrip resonator: instead of connecting the input signal open. Such amplifiers have gains of 15 dB or more at frequencies up to 3 GHz. If required, the resonant frequency of the microstrip can be tuned by means of a varactor diode connected across the otherwise open end of the resonator. The noise temperature of microstrip SQUID amplifiers was measured to be between $0.5\;K\;{\pm}\;0.3\;K$ at a frequency of 80 MHz and $1.5\;K\;{\pm}\;1.2\;K$ at 1.7 GHz, when the SQUID was cooled to 4.2 K. An even lower noise temperature can be achieved by cooling the SQUID to about 0.4 K. In this case, a noise temperature of $100\;mK\;{\pm}\;20\;mK$ was achieved at 90 MHz, and of about $120\;{\pm}\;100\;mK$ at 440 MHz.

• Progress in Superconductivity
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• v.2 no.1
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• pp.1-5
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• 2000

We have developed an extremely sensitive radio frequency amplifier based on the dc superconducting quantum interference device (dc SQUID). Unlike a conventional semiconductor amplifier, a SQUID can be cooled to ultra-low temperatures (100 mK or less) and thus potentially achieve a much lower noise temperature. In a conventional SQUID amplifier, where the integrated input coil is operated as a lumped element, parasitic capacitance between the coil and the SQUID washer limits the frequency up to which a substantial gain can be achieved to a few hundred MHz. This problem can be circumvented. by operating the input coil of the SQUID as a microstrip resonator: instead of connecting the input signal between the two ends of the coil, it is connected between the SQUID washer and one end of the coil; the other end is left open. Such amplifiers have gains of 15 dB or more at frequencies up to 3 GHz. If required, the resonant frequency of the microstrip can be tuned by means of a varactor diode connected across the otherwise open end of the resonator. The noise temperature of microstrip SQUID amplifiers was measured to be between 0.5 K $\pm$ 0.3 K at a frequency of 80 MHz and 1.5 K $\pm$: 1.2 K at 1.7 GHz, when the SQUID was cooled to 4.2 K. An even lower noise temperature can be achieved by cooling the SQUID to about 0.4 K. In this case, a noise temperature of 100 mK $\pm$ 20 mK was achieved at 90 MHz, and of about 120 $\pm$ 100 mK at 440 MHz.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.3
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• pp.261-275
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• 2011

To maintain the traffic flow during tunnel expansion, cars must be protected from falling rocks during excavation and to do so, a protector has to be installed inside the tunnel before beginning the excavation. In Korea, tunnel expansion by blasting rather than by mechanical excavation has been widely achieved. For this reason, a series of numerical analysis were performed to analyze the characteristics of impact load according to material behaviour of blasted rock by using Explicit FEA program. From the numerical results, it is found that the impact loads when rock is assumed as an elastic-plastic material appear to be only 7~12% compared with that when it is elastic.

• Biomolecules & Therapeutics
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• v.17 no.1
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• pp.57-61
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• 2009

This study examined whether or not a pretreatment with dehydroepiandrosterone (DHEA) has an effect on indomethacin-induced gastric mucosal damage. The DHEA group, male Sprague-Dawley rats, was administrated with DHEA orally at a dose of 4 mg/day for one week before inducing gastritis with indomethacin (50 mg/kg, p.o.). Histological assay, lipid peroxidation assay, superoxide dismutase (SOD), glutathione peroxidase (GPx) and Catalase activities were determined. Interestingly, it was found that the DHEA pretreatment attenuated the gastric lesion area induced by indomethacin. Rather, the pretreatment with high dose of DHEA led to submucosal edema, leukocyte infiltration in submucosa and mucosal necrosis. The levels of MDA in the DHEA pretreatment were also higher than those in the rats given with vehicle pretreatment. This suggests that the DHEA pretreatment deteriorates severe inflammation in indomethacin-induced gastritis. DHEA supplementation significantly increased SOD activity in the gastric mucosa. However, the catalase and GPx activities were not altered by DHEA. The co-administration of DHEA with an indomethacin might not offer a protective effect against the acute gastritis induced by indomethacin.

• Korean Journal of Head & Neck Oncology
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• v.13 no.2
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• pp.200-205
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• 1997

Background: There is considerable controversy concerning the most appropriate surgical treatment of patients with DTC. Objectives: In order to selection of the appropriate surgical treatment for DTC, we have analyzed the outcome of the different types of surgical treatment in low and high risk groups of DTC. Materials and Methods: From January 1968 through december 1980, a total of 71 patients with DTC were treated surgically at our institution. According to Cady and Rossi's scoring system, the patients were divided into low risk and high risk groups. Results: Seventy percent of patients were defined as low risk group with a 4% death rate whereas 30% of patients at high risk with a death caused by thyroid cancer in 38%(p<0.05). There was no difference in mortality between ipsilateral lobectomy and total thyroidectomy in both low and high risk groups(p>0.1). Conclusion: In our study, total thyroidectomy was not benefit in high risk group. These results suggested that total thyroidectomy must be selected carefully and based on clear evidence of major improvement in outcome or absence of other suitable surgical approaches. However, follow up study of more cases will be needed for accurate determination of the efficacy of total thyroidectomy in high risk group.