• Applied Chemistry for Engineering
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• v.31 no.3
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• pp.328-333
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• 2020

In this study, blended feedstock derived pyrolyzed fuel oil (PFO) and coal-tar was prepared to produce a pitch by thermal polymerization reaction for manufacturing artificial graphite materials. The aromaticity value of 0.355 and 0.818 was obtained for PFO and coal-tar, respectively. In addition, PFO and coal-tar exhibited the difference tendency of weight loss curve for thermogravimetric analysis, which is related to the structural stability depending on the aromaticity and functional groups. The production characteristics confirmed that the pitch derived PFO showed lower production yield and higher softening point than that using blended feedstock. In particular, when comparing P360 (138.5 ℃) and B420 (141.4 ℃) having similar softening points, the production yields of both pitches exhibited 29.89 and 49.03 wt%, respectively. This is mainly due to the blending of PFO and coal-tar having high pitch polymerization reactivity including a large amount of alkyl groups and coal-tar having high thermal stability. This phenomenon indicated that the increased production yield is because of a synergic effect of both the high reactivity of PFO and thermal stability of coal-tar.

• Journal of Korean Society of Steel Construction
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• v.23 no.1
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• pp.125-135
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• 2011

To obtain a lower story height with a long span and better fire resistance, a new composite floor system using GFRP (glass-fiber-reinforced plastics) was proposed. This floor system consists of asymmetric steel with a web opening, a hollow core ball, concrete, and GFRP. To evaluate the flexural performance of the new composite floor system, an experiment was conducted. The test parameters were the presence of GFRP, the void ratio in relation to the hollow core balls, and the web opening. The test results showed that the resistance and stiffness of the specimen with GFRP were 10% higher than those of the reference specimen, and that fully composite action was accomplished up to the yielding point. After the attainment of the yield strength, the ductility of the specimen was reduced due to the stress concentration around the web openings. The slip between the concrete and steel beam, however, was small. Thus, in the design of the proposed new floor systems, it is desirable that the calculated resistance be reduced by 15%, for safety.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12A
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• pp.1171-1180
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• 2010

In wireless sensor networks, reliable event detection is one of the most important research issues. For the reliable event detection, previous works usually assume the events are only individual objects such as tanks and soldiers. Recently, many researches focus on detection of continuous objects such as wild fire and bio-chemical material, but they merely aim at methods to reduce communication costs. Hence, we propose a reliable continuous object detection scheme. However, it might not be trivial. Unlike individual objects that could be referred as a point, a continuous object is shown in a dynamic two-dimensional diagram since it may cover a wide area and it could dynamically alter its own shape according to physical environments, e.g. geographical conditions, wind, and so on. Hence, the continuous object detection reliability can not be estimated by the indicator for individual objects. This paper newly defines the reliability indicator for continuous object detection and proposes an error recovery mechanism relying on the estimation result from the new indicator.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.5
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• pp.1071-1077
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• 2008

Hwa-byung is a form of psychogenic illness among people in Korea and is listed as a culture-bound syndrome of Korea in the DSM-IV. Despite increased clinical researches for Hwa-byung in the oriental medicine of Korea, there has been no agreement of pattern identification for Hwa-byung. The purpose of this study is to develop a standard instrument of pattern identification for Hwa-byung which will be applied to clinical research. The items and structure of the instrument were based on review of published literature. The advisor committee on this study was organized by 15 neuropsychiatry professors of 11 oriental medical colleges nationwide. The experts attended 2 consultation meetings and discussed developing the instrument. and we also took professional advices by e-mail. The results were as follows; First, we divided the symptoms and signs of Hwa-byung into five pattern identification - stagnation of liver Qi, flare-up of the liver fire, disharmony between heart and kidney, deficiency of both Qi and blood, malfunction of gallbladder due to phlegm stagnation. Second, we got the mean weights to each symptom of five pattern identification which had been scored on a 5-point scale - ranging from 0 to 4 by the 15 experts. Third, we made out the Korean instrument of the pattern identification for Hwa-byung. It was composed of 34 questions and decided on question-and-answer form. Though there are some limits in this study, the instrument of pattern identification for Hwa-byung is meaningful and expected to be applied to the subsequent research. And also, we hope to improve the instrument and make up for this study through various research and discussion.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.28-38
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• 2004

The Hun-Min-Jeong-Eum(訓民正音) has been created under the political purpose that is to unite politics and cultures through a philosophical harmony of the confucianism as well as the Buddhism under the periodical circumstance that includes the change of a dynasty and a revolution in culture. The creating work has been greatly affected by the theoretical divination, that is the confucian ideas of North-Song dynasty which has been highly elaborated in those days. The shape of the characters of the Hun-Min-Jeong-Eum(訓民正音) has been influenced by the ancient letters existing at the time (especially Ga-Rim-To 加臨多), it has been throughly readjusted and recreated based on the philosophy. The consonant uses the Three-Pillars(三才)(ㅇ, ㅁ, △) in the style of the five elements and each velar-lingual-labial-dental-guttural sounds (牙舌脣齒喉音) is applicable to five elements also a 'ㅇ' is equivalent to the heaven, a 'ㅁ' to the earth. a '△' to the man. The vowel uses the five elements of ㅗ(water). ㅏ(wood), ㅜ(fire), ㅓ(metal), ㆍ(five-soil), ─(ten-soil) in the style of the Three-Pillars(三才) of ㆍ, ㅡ, ㅣ and the first created letters(初出字), and the secondary created letters(再出字) each can be attached to the eight trigrams(八卦). The consonant has 17 letters and the vowel has 11 letters, therefore the total number of the letters is 28. and those are equivalent to the 28 constellation(二十八宿) of the astronomy. Contrary to the underlying principle that has been applied during the time of the creation of the letters, when the consonant and the vowel are used, the consonant refers to the heaven (天), and the vowel refers to the earth(地). a consonant take a part in making a point on the starting place of the pronounce, a vowel take a part in the keeping the energy to the end.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.1
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• pp.12-25
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• 2007

Numerical simulation of the natural gas steam reforming process for on-site hydrogen production in a $H_2$ fueling station was conducted on the basis of process material and heat balances. The effects of reforming parameters on the process efficiency of hydrogen production were investigated, and set-point values of each of the parameters to minimize the sizes of unit process equipments and to secure a stable operability of the reforming process were suggested. S/C ratio of the reforming reactants was found to be a crucial parameter in the reforming process mostly governing both the hydrogen production efficiency and the stable operability of the process. The operation of the process was regarded to be stable if the feed water(WR) as a reforming reactant could evaporate completely to dry steam through HRSG. The optimum S/C ratio was 3.0 where the process efficiency of hydrogen production was maximized and the stable operability of the process was secured. The optimum feed rates of natural gas(NGR) and WR as reforming reactants and natural gas(NGB) as a burner fuel were also determined for the hydrogen production rate of $27\;Nm^3/h$.

• Proceedings of the Korean Reliability Society Conference
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• 2000.04a
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• pp.239-246
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• 2000

This paper presents a new dynamic approach for assessing feasibility associated with the implementation of accident management strategies by the operators. This approach includes the combined use of both the concept of reliability physics and a dynamic event tree generation scheme. The reliability physics is based on the concept of a comparison between two competing variables, i.e., the requirement and the achievement parameter, while the dynamic event tree generation scheme on the continuous generation of the possible event sequences at every branch point up to the desired solution. This approach is applied to a cavity flooding strategy in a reference plant, which is to supply water into the reactor cavity using emergency fire systems in the station blackout sequence. The MAAP code and Latin Hypercube sampling technique are used to determine the uncertainty of the requirement parameter. It has been demonstrated that this combined methodology may contribute to assessing the success likelihood of the operator actions required during accidents and therefore to developing the accident management procedures.

• Journal of Digital Convergence
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• v.13 no.2
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• pp.279-289
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• 2015

The main purpose of this study is to examine the relationship between the safety awareness and safety practice behavior of the college students. We carried out a questionnaire survey that was targeted at 294 college students from November 1st to November 20th, 2014. Data collected were analyzed with SPSS 18.0 statistical program. Analysis methods were t-test, one way ANOVA, Scheffe test, Pearsons correlation coefficient, and Stepwise multiple regression analysis. The findings are as follows. Safety awareness point was an average of 177.5 points which was higher levels. Area showing the highest safety awareness was safety from fire. Safety practice behavior was an intermediate level of an average 63.3 points. Also, there was a positive correlation between safety awareness and safety practice behavior(r=.595. P<.01). The results of this study implies that we need the safety training program for the safety awareness of college students.

• Journal of the Korean Institute of Gas
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• v.15 no.2
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• pp.82-87
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• 2011

Heat transfer oils are used in applications such as heating systems of chemical plant, refinery heat exchange systems, gas plant process, injection molding systems, and pulp and paper processing. These oils are extremely stable and resistance to thermal and oxidative degradation. In the event of a spill or accidental release of heat transfer oils, it can be ignite easily when there is an ignition source. This paper discusses the flammability and thermal stabilities of new and used oils. The flammability of the oils are assessed by measuring changes in flash point and auto ignition temperature. The thermal stability of oils are evaluated by the thermal screening unit ($TS^u$) and the differential scanning calorimeter (DSC). From the experimental results, it is suggested to give fire hazard characteristics to safe precautions for the proper use and treatment of heat transfer oils.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.11a
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• pp.71-74
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• 2007

With the changes of times the building materials tend to extend the demand for application under the special environment. Since high-ductile mortar is developed, the building materials show excellent performance like toughness, compression, tensile, and bending, etc. in the general concrete from the existing brittle point. And, recently they are widely used as repairing and reinforcing materials both at home and abroad because they are recognized as excellence like durability and fire-resistance. However, it is in a situation of creating problems in durability because it frequently happened deterioration of buildings that have already repaired and reinforced at a time when it requires reconstruction of recently deteriorated construction structure recently. Therefore, in this study improved with a more repair Material development and reinforcement of the second high-ductile mortar products for a variety of basic materials were presented want, research plans used include traditional repair materials and the newly developed PCM (polymer cement mortar) structural reinforcement type indicated that comparison. PCM analysis in order to present a rate depending on the types fiber 0, 1.2 and 2.0(%) at three levels and mixture water according to ratios of weight to Plain in the 2.0 and 1.85(kg) at two levels is set, the results were as follows. 1) This study has shown that PCM had excellent strain hardening behavior at the same time that the bending stress increased according to the fiber contents. 2) This study has shown that it had the durability performance due to the high substance transmission according to the fiber contents.