• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.835-841
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• 1998

This study was devoted to the manufacturing process of activated carbon(AC) using and anthracite and bituminous coals which were regarded as appropriate for AC manufacturing, and the physcial properties a AC prepared with coal blends were characterized by the ultimate and proximate analysis. Generally, as the fraction of antheracite in AC from anthracite and bituminous coal blends was increased, AC yield was increased whereas iodine value($I_2$) was decreased. Being not related to mixing ratio of coal blends, the apparent density of AC remained constant. Pore development and iodine value of AC based on coal blends(Fushun and Dandong, 75:25 wt. %) were examined, varing carbonization and steam activation conditions. These results showed that the average pore diameter of AC was below $20{\AA}$ in the activation temperature range of 850 to $900^{\circ}C$ and the iodine value was above $1000m^2/g$. When the adsorption capacity of manufactured AC was compared with commercial AC, it is found that the AC from coal blends was comparable to the commercial AC. Therefore, it was confirmed that the characteristics of manufactured AC were changed with manufacturing conditions and the ratios and types of coal blends.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.500-504
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• 2006

Haptoglobin (Hp) is an acute phase protein, and its plasma level increases consistently in response to inflammation. To investigate the biological role of Hp in lung epithelial cells, the gene expressions of cyclooxygenase-2 (COX-2) and inflammatory cytokines were analyzed using human Hp gene-transfected A549 cells. Western blot analysis showed that COX-2 expression was markedly increased in Hp DNA-transfected cells (stable transfection and transient transfection) compared with that in vehicle DNA-transfected cells. When the Hp-expressing cells were treated with $1{\mu}g/ml$ of LPS or 100 U/ml of $IL-1{\beta}$ for 24 hr, the COX-2 expression was synergistically up-regulated. ACP-based PCR data demonstrated the Hp decreased SPARC expression, but increased IL-4 and S100AI expressions. These findings suggest that the Hp acts as a pro-inflammatory mediator in lung inflammation.

• Journal of Preventive Medicine and Public Health
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• v.21 no.1 s.23
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• pp.31-46
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• 1988

In order to designate a present status necessary for establishment of preventive measures and guidelines of health education against hepatitis B in the course of secondary school education, knowledge and practice toward hepatitis B virus infection was surveyed by a questionnare method on total of 4,855 college entrants in the academic year of 1987 and analyzed the data collected using IBM PC(Trigem 88-II) with SAS package program. About two per cent of college entrants had past history of HBV infections not showing any difference between both sexes and geographical regions. About one third(33.7%) of total students had tested hepatitis B surface antigen(HBsAg), only 4% had tested hepatitis B surface antibody(HBsAb) and vaccination rate amounted to 24.6%, one fourth of total subjects. Both serological tests and vaccination were most commonly performed during adolescence, showing higher rates in female students than in male students. The rates also seemed to be higher in those from urban cities than those from rural cities. Students who had acquired correct knowledge that hepatitis B was infected by virus were amounted to 78.5% of college entrants, and remaining 21.5% had misunderstood that rickettsia, bacteria, fungi or parasites were causal agents. Female students were better aware of the causal agents than male students but there was no difference between places of growth. As for mode of transmission of HBV, 51.5% of male students and 47.7% of female students had correct knowledge. A very few student had known that fact that HBV was transmitted by body fluids such as tear(6.9%), nasal discharge(10.1%) and semen or vaginal secretion(19.2%) and majority(75%) of students had misunderstood that hepatitis B virus would be transmitted per os through food ingestion. Approximately one half(48.9%) of college entrants had knew correctly whom to be vaccinated. Approximately one half of the students knew that hepatr;ma(57.8%) and liver cirrhosis(57.4%) might complicate with hepatitis B virus infection, whereas 12.0% of the students responded that bronchitis was one of the complications of hepatitis B infection. In summary of the above results, we highly recommend that health education program for eradication of hepatitis B virus infection should be introduced in curricula of secondary school education in this country.

• Nutritional Sciences
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• v.5 no.4
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• pp.234-244
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• 2002

This study was conducted to compare the rates of hyperlipidemia, hypertension, high blood glucose, and liver dysfunction, between 64 obese children (24 boys and 11 girls who were moderately obese, and 21 boys and 8 girls who were severely obese) and 45 normal weight children (31 boys and 14 girls) from 13 elementary schools in Kangnung city. Among the boys with severe obesity, the levels of serum triglycerides and LDL-cholesterol (133.60 $\pm$ 49.99 mg/dl and 105.00 $\pm$ 41.12 mg/dl( respectively) were significantly higher compared to the normal Weight group (81.16 $\pm$ 23.59 mg/dl and 87.74 $\pm$ 32.095 mg/dl, respectively) of moderately obese group (102.30 $\pm$ 36.03 mg/dl, 89.99 $\pm$ 32.10 mg/이, respectively). In girls, only serum triglycerides were significantly higher in the severely obese group (154.30 $\pm$ 46.84 mg/dl), compared with the normal weight group (80.00 $\pm$ 25.31 mg/dl) or moderately obese group (106.40 $\pm$ 41.73 mg/dl). In boys, blood pressure in the severely obese group (systolic: 120.5 $\pm$ 9.74 mmHg; diastolic: 80.95 $\pm$ 10.44 mmHg) was significantly higher compared with the groups of normal weight or moderately obese children. The rate of hypertriglyceridemia was significantly different among normal weight, moderately obese, and severely obese boys (9.7%, 41.7%, and 76.2%, respectively). The proportion of boys who had an Atherogenic Index(AI) higher than 3 was found to be significantly higher in the severely obese group (28.6%), compared to 6.5% in the normal weight group and 4.1% in the moderately obese group. Among boys, a significantly higher rate of hypertension was found in the severely obese group, which showed high systolic blood pressure and high diastolic pressure (81.0% and 81.0%), compared with the normal weight group (16.1% and 22.6%) and moderately obese group (33.3% and 33.3%). In conclusion, the diagnosis and management of obese children needs to be tailored to gender and the degree of obesity. Furthermore, a systematic management program needs to be developed for early screening and detection of obesity in order to minimize the risk of hyperlipidemia and hypertension, especially in severely obese children.

• Journal for History of Mathematics
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• v.24 no.4
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• pp.1-6
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• 2011

We investigate a method to find the least common multiples of numbers in the mathematics book GuIlJib(구일집(九一集), 1724) written by the greatest mathematician Hong Jung Ha(홍정하(洪正夏), 1684~?) in Chosun dynasty and then show his achievement on Number Theory. He first noticed that for the greatest common divisor d and the least common multiple l of two natural numbers a, b, l = $a\frac{b}{d}$ = $b\frac{a}{d}$ and $\frac{a}{d}$, $\frac{b}{d}$ are relatively prime and then obtained that for natural numbers $a_1,\;a_2,{\ldots},a_n$, their greatest common divisor D and least common multiple L, $\frac{ai}{D}$($1{\leq}i{\leq}n$) are relatively prime and there are relatively prime numbers $c_i(1{\leq}i{\leq}n)$ with L = $a_ic_i(1{\leq}i{\leq}n)$. The result is one of the most prominent mathematical results Number Theory in Chosun dynasty. The purpose of this paper is to show a process for Hong Jung Ha to capture and reveal a mathematical structure in the theory.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.235-243
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• 2002

Ni-base superalloys are used extensively in industry, both in aeroengines and land based turbines. About 60% by weight of most modern gas turbine engine structural components are made of Ni-base superalloys. To satisfy practical demands, the efficiency of gas turbine engines has been steadily and systematically increased by design modifications to handle higher turbine inlet or firing temperatures. However, the increase in operating temperatures has lead to a decrease in the life of components and increase in costs of replacement. Moreover, around 80% of the large frame size industrial/utility gas turbines operating in the world today were installed in the mid-sixties to early seventies and are now 25 to 30 years old. Consequently, there are greater opportunities now to repair and refurbish the older models. Basically, there are two major factors influencing the weldability of the cast alloys: strain-age cracking and liquation cracking. Susceptibility to strain-age cracking is due to the total Ti plus AI content of the alloy; Liquation cracking is due either to the presence of low melting constituents or constitutional liquation of constituents. Though Rene 41 superalloy has 4.5wt.% total Ti and Al content and falls just below the safe limit proposed by Prager et al., controlled grain size and special heat treatments are needed to obtain crack-free welds. Varying heat treatments and filler materials were used in a laboratory study, then the actual welding of service parts was carried out to verity the possibility of crack-tree weld of components fabricated from Rene 41 superalloy. The microstructural observations indicated that there were two kinds of carbides in the FCC matrix. MC carbides were located along the grain boundaries, while M$_{23}$C$_{6}$ carbide was located both inter and intra granularly. Two kinds of filler materials, Rene 41 and Hastelloy X were used to gas tungsten arc weld a patch into the sheet metal, along with varying pre-weld heat treatments. The microstructure, hardness and tensile tests were determined. The service distressed parts were categorized into three classes: with large cracks, with medium cracks and with small or no visible cracks. No significant difference in microstructure among the specimens was observed. Specimens were cut from the corner and the straight edge of the patch repair, away from the corner. The only cracks present were found to be associated with inadequate surface preparation to remove oxidation. Guidelines for oxide removal and the welding procedures developed in the research enabled crack-free welds to be produced.d.

• Korean Journal of Remote Sensing
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• v.36 no.2_2
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• pp.365-377
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• 2020

Continuous monitoring and immediate response is essential to protect the national maritime territory and maritime resources from the activities of illegal ships. Synthetic Aperture Radar (SAR) images with a wide range of images are effective for maritime surveillance asthe weather and day-night conditions rarely affect to image acquisition. However, an effective ship detection is not easy due to the huge data size of SAR images and various characteristics such as the speckle noise. In this study, the Human Visual Attention System (HVAS) algorithm was applied to KOMPSAT-5 to extract the initial targets, and the SAR-Split algorithm depending on the imaging modes was used to remove false alarms. The detected targets were finally selected by the Constant False Alarm Rate (CFAR) algorithm and matched with the ship's Automatic Identification System (AIS) information. Overall, the detected targets were well matched with AIS data, but some false alarms by ship wakes were observed. The detection rate was about 80% in ES mode and about 64% in ST mode. It is expected that the developed ship detection algorithm will contribute to the construction of a wide area maritime surveillance network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.8-15
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• 2020

A forecasting method using deep learning does not have consistent results due to the differences in the characteristics of the dataset, even though they have the same forecasting models and parameters. For example, the forecasting model X optimized with dataset A would not produce the optimized result with another dataset B. The forecasting model with the characteristics of the dataset needs to be optimized to increase the accuracy of the forecasting model. Therefore, this paper proposes novel optimization steps for outlier removal, dataset classification, and a CNN-LSTM-based hyperparameter tuning process to forecast the daily power usage of a university campus based on the hourly interval. The proposing model produces high forecasting accuracy with a 2% of MAPE with a single power input variable. The proposing model can be used in EMS to suggest improved strategies to users and consequently to improve the power efficiency.

• Ecology and Resilient Infrastructure
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• v.2 no.1
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• pp.12-21
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• 2015

Social demand for ecological engineering and technology has increased in tandem with national economic growth in order to improve the environmental capacity of civil infrastructures. To meet this demand, the Korean Society of Ecology and Infrastructure Engineering (KSEIE) was established in January 2013 and has contributed to the development of ecological engineering technologies. However, the establishment of an educational system for human resources training in ecological engineering is still at an early stage, and it is imperative to develop a curriculum for producing the human resources that can understand and apply ecological principles and functions and that is equipped with the abilities required for ecological conservation, restoration, and creation. As part effort, the KSEIE held a forum, entitled Founding the Education for Ecological Engineering, to discuss the establishment of the education system for ecological engineering in Korea. In this paper, based on the discussions and suggestions made during the forum, we analyzed the current status of ecological engineering education in various disciplines - civil and construction engineering, biology and environment, and landscape planning - in domestic universities, and attempted to seek possible solutions based on the cases of foreign universities. Generally, ecology and other application curricula are taught as fragmented subjects and fields in domestic universities. The development of new education strategies and systematic curricula for multidisciplinary education, ecological response to climate change, and the expansion of research fields is required.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.106-121
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• 2007

The purpose of this study was to examine the effects of suggested etching method on the performance of pits and fissures sealant. In the first part, seventy extracted sound human permanent third molars and premolars were used. The teeth were randomly divided and performed in three different groups as follows : conventional etching, enameloplasty, and testing group. Non-pumicing, dye-guidance vigorous brushing-start etching technique was applied on the occlusal of testing group. Then the pit and fissure sealant was applied on all of the specimens. After the thermocycling and immersing in 1% methylene blue, the resin embedded sections were made. The microleakage data on the section were then recorded under the stereoscope and statistic analysis was done. Additional experiments were also performed : direct fissure surface etched pattern experiment, replica study, and micro-shear bond strength testing observation. The second part included two groups. A paired study was designed to evaluate the influence the environment has on the performance of the sealant. After etching, half of each occlusal surface received one of the two following treatments in succession: sealing in laboratory and intraoral condition (group 1), sealing in intraoral condition with and without a single-bonding agent (group 2). The results of present study can be summarized as follows: - The microleakage of testing group was significant different with conventional method (P<.05) and was not different with the enameloplasty group (P>.05). - The quality and quantity of etched enamel were improved. - Microshear bond strength of testing group was higher than control group (p<.05). - The environmental condition was influenced on the performance of the sealant. The testing etching method modified the capacity of the etching agent to penetrate into the pits and fissures, and simultaneous enhance their efficiency in vitro condition.