• Journal of the Korean Society for Heat Treatment
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• v.12 no.1
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• pp.55-65
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• 1999

Graphitization of cementite in high carbon steels at subcritical temperature is reported. We have studied about the effects of Ni in these steels on graphitization. The chemical compositions of the specimens were Fe-(0.54, 0.7)%-C-1.0%Si-0.1%Mn-(0.2~1.0)%Ni. After annealing at $650^{\circ}C$, $680^{\circ}C$ and $700^{\circ}C$ during various time the microstructures and hardness change were observed. In order to recover the initial hardness of high carbon steel, dissolution treatment of graphite was performed at $870^{\circ}C$. In case of 0.7%C steel, graphitization was accelerated rather 1.0%Ni addition steel than 0.2% and 0.54%Ni addition steels but the graphite is coarser. In case of 0.54%C-0.2%Ni steel, graphite particles were distributed relatively homogeniously and finely. Nickel addition promotes graphitization of these steels but makes graphite blocky.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.2
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• pp.191-198
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• 2005

Adding hydrogen gas in natural gas leads to stable combustion in internal combustion engine and its performances rely on compression ratio. To analyze the effects of compression ratio and rate of hydrogen addition on the engine performance, the characteristics of overall engine performance including emission were investigated by using the medium duty natural gas fueled engine. As results, it was found that compression ratio occurred knock was nearby compression ratio, $\varepsilon$=14 for the case that hydrogen was enriched in the natural gas fueled engine. But slight knock was occurred at $\varepsilon$=14.7 in the case of neat natural gas. Also HC and $CO_2$ were reduced around 80% and 20% respectively when the rate of hydrogen addition was increased to 50% and compression ratio from $\varepsilon$=13 to $\varepsilon$=14.7.

• Journal of the Korean Geosynthetics Society
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• v.23 no.1
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• pp.49-60
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• 2024

Recently, the frequency and intensity of typhoon-induced wave loading are increasing due to changed marine environments such as climate change. In addition, frequent earthquakes are causing a lot of damage around the world, including in Japan, Chile, Haiti, China, and Indonesia. In Korea, damage from typhoons has also been increasing since the 2000s, and the frequency and intensity of earthquakes are also increasing. Korea is surrounded by sea on three sides, so typhoons can cause a lot of damage to coastal structures, and earthquakes also cause a lot of damage to coastal structures. As such, the frequency and intensity of typhoon-induced wave loading and earthquakes are increasing both domestically and internationally, but there is no research linking typhoons and earthquakes. Therefore, in this study, numerical analysis was performed for a total of four cases by linking typhoon waves and earthquakes to the caisson breakwater. Numerical analysis was performed by applying wave loads in Case 1 and seismic wave in Case 2, seismic wave after wave loads in Case 3, and wave loads after seismic wave in Case 4. As a result of the numerical analysis, it was confirmed that in Case 3 and Case 4, which linked a typhoon and earthquakes, the damage caused by each load increased compared to Case 1 and Case 2 because the load was applied while the existing ground strength was reduced. In addition, it was confirmed that the greatest damage occurred in Case 3, in which seismic wave were applied after the wave loads.

• Journal of the Korean Mathematical Society
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• v.34 no.2
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• pp.371-381
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• 1997

Our basic concern in this paper is to investigate some geometric properties of the graph of a maximal monotone operator in the one dimensional case. Using a well-known theorem of Minty, we answer S. Simon's questions affirmatively in the one dimensional case. Further developments of these results are also treated. In addition, we provide a new proof of Rockafellar's characterization of maximal monotone operators on R: every maximal monotne operator from R to $2^R$ is the subdifferential of a proper convex lower semicontinuous function.

• CELLMED
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• v.4 no.2
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• pp.13.1-13.6
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• 2014

The written case that reflects the course of treatment for a person is central to the East Asian medical tradition. This paper examines the approaches and particularities of producing the actual written account of the clinical encounter, or a particular aspect of a case, that may be required by acupuncture practitioners and researchers. It will discuss the influences that can be brought to bear on the construction and production of these accounts. In addition, it will outline and highlight historical approaches to the case record documentation process as well as debate the value and purpose of these. This paper aims both to assist the production of helpful and authoritative case records for practitioners and researchers, and to highlight the usefulness of such case records. Moreover, it will discuss not only why the case needs to be written and for whom, but also which agencies support and control what is written. How can contemporary requirements and traditional views both be incorporated accurately, with context and with meaning? The essence of this paper is that practitioner/patient interactions need to be documented, and it will explore how this can best be supported.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.11 no.9
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• pp.414-421
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• 2001

If a machine has some faults, we can detect them using vibration or noise signals. However some maintenance engineers who don\`t have export knowledge, need the help of vibration experts for diagnosing the machine. In this paper a case based reasoning (CBR) system is developed which is able to manipulate the past experiences of vibration diagnosis experts. In the CBR system, the maintenance engineers can retrieve the information form previous cases which are most similar to new problem s that they can solve new problem using solutions form the previous cases. In this paper, a new case retrieval method of CBR system using Petri net is proposed and also applied to diagnosis for electric motors as a practical problem.

• Journal of Fashion Business
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• v.8 no.1
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• pp.141-155
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• 2004

Chitosan, the natural biodegradable polymer derived from chitin by de- acetylation, has been widely applied to the textile finishing processes for excellent anti-microbial characteristic and handle improvement of fabric. The purpose of this study is to investigate the change of handle when cotton fabric is treated with chitosan-polyurethane mixed solution. The viscosity values of chitosan solutions were 8cps and 50cps, and the wet-pick-up% was maintained at 90%. In case of mixing with water soluble polyurethane, the mixture ratio of chitosan and polyurethane was settled on the solid content ratio of 1:0, 1:0.5, 1:1, 1:2. Also the change of physical properties by neutralization in NaOH solution was studied. The results can be summarized up as follows : 1. Extensibility(EM) and tensile energy(WT) of cotton fabric treated with chitosan are decreased, but bending rigidity(B) is remarkably increased. With the addition of polyurethane, the decrease of EM and WT is weakened and the increase of B is weakened. The case of neutralization is similar to the case of polyurethane addition. 2. By treating fabric with chitosan, FUKURAMI(Fullness and softness) is decreased, but KOSHI(Stiffness), SHARI(Crispness), HARI(Anti-drape Stiff ness) are increased. With the addition of polyurethane, the decrease of FUKURAMI is diminished and the increase of KOSHI, SHARI, HARI are diminished. 3. As the viscosity of chitosan solution increased, the air permeability value increased. The addition of polyurethane decreased the air permeability.

• Journal of Animal Environmental Science
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• v.14 no.2
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• pp.91-96
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• 2008

The odours from spreading the slurry, manure storage tanks, and the stall are a source of annoyance for the neighbors and sometimes even become a case for civil appeal. Reducing the odourant and ammonia emission is an urgent need to be addressed. It is known that brown coal and oak charcoal have an ability to absorb odour. We designed an experiment set in lab scale and used the brown coal and oak charcoal as additives in the test to reduce odour. The test are divided into two categories; namely aeration and no-aeration. The additives were added to the each sample at a concentration of 5% and 10% of total base solids, besides the control samples. We carried out the Phenate Method for ammonia analyzing. In the non-aerated case, the results showed a reducing efficiency of 23.7% and 26.4% with an addition rate of 5% and 10% of additives, respectively. In the aerated test, the reducing efficiency of ammonia was 17.8% and 21.0% with an addition rate of 5% and 10% of additives, respectively. In case of oak charcoal, non-aeration showed removal efficiencies of ammonia at 15.9% and 16.1% with addition rates of 5% and 10%, respectively, With aeration, they were 11.4% and 26.4% with addition rates of 5% and 10% oak charcoal, respectively. The tests show that brown coal and oak charcoal have a reducing effect on ammonia emissions.

• Human Ecology Research
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• v.60 no.2
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• pp.303-315
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• 2022

The physicochemical properties of traditional kochujang added with naked oat flours (0, 5, 10, 15%) were periodically examined during fermentation for 20 weeks at 25℃(± 2 ℃). The proximate composition of roasted naked oat flours were as follows: water 0.67%, ash 1.63%, fat 10.37%, protein 13.63%, carbohydrates 73.70%. The water contents of traditional kochujang added with naked oat flours decreased gradually according to the addition level. The pH of traditional kochujang added with naked oat flours increased according to the added level, whereas pH decreased gradually during fermentation. The acidity was opposite to pH. The L (lightness), a (redness) and b (yellowness)-values of samples increased according to the amount of added naked oat flours, whereas they decreased gradually during fermentation. The salinity and sweetness of samples decreased according to the amount of added naked oat flours. Amino acid composition of traditional kochujang added with naked oat flours was higher than that of the control during fermentation. Aspartic acid, alanine, leucine, and arginine were high in the case of traditional kochujang added with 0% naked oat flours, and aspartic acid, leucine, alanine, proline. And arginine were high in the case of traditional kochujang added with 15% naked oat flours. The dietary fiber content was 5.38g/100g in the case of 0% addition and 5.75g/100g in the case of 15% addition. As a result of the above results, it was found that the physicochemical properties of traditional kochujang added with naked oat flours could be improved, and the possibility of developing a traditional kochujang beneficial to health was confirmed.

• Journal of the Korean Ceramic Society
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• v.33 no.9
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• pp.1038-1044
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• 1996

The variations of sintering and electrical characteristics of semiconducting BaTiO3 ceramics with sintering agents added were investigated comparing the case of BaB2O4 addition to BN and TiO2 addition. When BaB2O4 added in BaTiO3 ceramics the densitifcation of specimen could be acheived more easily and recvealed the better PTCR characteristics than BN and TiO2 addition. As increase of addition of BaB2O4 in BaTiO3 spec imens the slope of resistivity jump also increased but the temperature of maximum resistivity decreased, It was supposed that addition of BaB2O4 led to increase of Ns (acceptor state density) value at grain boundaries.