• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.644-650
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• 2021

This study characterized the reforming of methane with carbon dioxide, which is a major cause of global warming. The methane decomposition reaction with carbon dioxide was carried out using transition metal catalysts. The reactivity of tin was lower than that of a transition metal, such as nickel and iron. Most of the decomposition reaction occurred in the solid state. The melting point of tin is 505.03 K. Tin reacts in a liquid phase at the reaction temperature and has the advantage of separating carbon produced by the decomposition of methane from the liquid tin catalyst. Therefore, deactivation due to the deposition of carbon in the liquid tin can be prevented. Methane decomposition with carbon dioxide produced carbon monoxide and hydrogen. Ni was used to promote the catalyst performance and enhance the activity of the catalyst and lifetime. In this study, catalysts were synthesized using the excess wet impregnation method. The effect of the reaction temperature, space velocity was measured to calculate the activity of catalysts, such as the activation energy and regeneration of catalysts. The carbon-deposited tin catalyst regeneration temperature was 1023 K. The reactivity was improved using a nickel co-catalyst and a water supply.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.13 no.1
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• pp.129-138
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• 2002

Objectives：In order to treatment guideline of ADHD, present clinical practise of child psychiatrists and their opinion of optimal intervention were evaluated. Methods：Structured questionnaire items about diagnostic workup, drug choice of 5 different situations according to different co-morbid disorders, and non - pharmacological treatment were applied to 32 child psychiatrists working at university and general hospital. we compared the data with Texas Algorithm Project guideline. Results：(1) Intelligence Test, Sentence Completion Test, sustained attention test, and Conner's questionnaire were the basic routine test that must be performed. (2) Main trend of medication in this study was not different from TAP guideline. (3) In case of co-morbid tic disorder, first recommending drug is still psychostimulant in the TAP guideline. But in this study initial psychostimulant prescription was not main trend. (4) In case of MPH non-response co-morbid disruptive behavior disorder, MPH medication combined with other drug were more common than switching to other drug as suggested the TAP guidelines. (5) In non-pharmacological treatment, most child psychiatrists reported the importance of parent management. Conclusion：There were some difference in medication trend in this study compared with TAP guideline. Further study and conference are needed for experts consensus in Korea.

• The Journal of Korean Academy of Sensory Integration
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• v.16 no.1
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• pp.14-24
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• 2018

Objective : The purpose of this study was to identify the effect of Interactive Metronome (IM) training on postural control and hand writing performance of children with Attention Deficit Hyperactivity Disorder (ADHD). Methods : Participant was a third grade elementary school student diagnosed with ADHD. ABA design was used and a total of 30 sessions were held for 3 sessions every week for a total of 10 weeks. In the intervention period, IM training was conducted for 40~50 minutes before intervention for writing, and the writing task was carried out. We evaluated the handwriting legibility and speed. Before baseline A and within a month after A' phase, Clinical Observation of Motor and Postural Skills (COMPS) was evaluated to examine the changes in postural control of the student. Results : After the IM intervention, the postural control of the student improved in the score of slow movement, finger-nose touching, and asymmetrical tonic neck reflex. The handwriting legibility and speed has also tended to increase during the intervention period, but it has not significantly changed. Conclusion : This study could be used as an evidence that the IM training aimed at postural control and handwriting ability could enhance the ability to improve postural control and thereby provide fundamental knowledge for future studies.

• Journal of the Korean Geotechnical Society
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• v.20 no.2
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• pp.15-26
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• 2004

Based on an estimating method for post-cyclic strength and stiffness with cyclic triaxial tests proposed by one of the authors, cyclic Direct Simple Shear (DSS) tests were carried out to confirm whether the method can be adapted to DSS test on fine-grained soils: silty clay, plastic silt, and non-plastic silt. Results from cyclic and post-cyclic DSS tests were interpreted by a modified method as adopted for cyclic and post-cyclic triaxial tests. In particular, influence of plasticity index for fine-grained soils and initial static shear stress (ISSS) was emphasised. Findings obtained from the present study are: (i) liquefaction strength ratio of fine-grained soils decreases with decreasing plasticity index and increasing ISSS; (ii) plasticity index and ISSS did not markedly influence relation between equivalent cyclic stiffness and shear strain relations; (iii) the higher the plasticity index of fine-grained soils is, the less the strength ratio decreases with increment of a normalcies excess pore water pressure (NEPWP); (iv) stiffness ratio of plastic silt has large activity decrease rapidly with increasing excess pore water pressure; and (v) post-cyclic strength and stiffness results from DSS tests agree well with those predicted by the method modified from a procedure used for triaxial test results.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.202.2-203
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• 2003

전통주의 계승발전을 위해 전통주의 개선과 재현의 필요성이 높아짐에 따라 지난날 맛 좋았던 우리의 전통주의 연구와 개발이 활발히 진행되고 있다. 또한 최근 미곡의 과잉생산으로 인한 과잉쌀 생산에 대한 수요체 창출을 위한 쌀가공품의 개발이 매우 시급한 실정이다. 최근 알콜농도가 낮은 술을 선호하는 경향과 전통주의 특수한 풍미로 인하여 현재 전통주는 많은 사람들로부터 각광을 받고 있어서 현재 몇몇 지역에서 민속주와 토속주가 허가되어 시판되고 있다. 진양주는 전남 해남지역의 전통민속주로서 해남지역에서 생산되는 찹쌀을 원료로 하여 상온에서 발효시키는 독특한 방법으로 제조되는데 이 진양주는 발효과정에서 외부환경의 영향을 많이 받게 된다. 그중 외부온도는 진양주의 품질에 직접적인 영향을 미치게 되는데 아직까지는 진양주제조과정에서 최적발효온도에 대한 연구는 보고된 것이 없다. 본 연구에서는 발효온도를 2$0^{\circ}C$와 $25^{\circ}C$로 하였을 때 발효과정에서 술의 품온, pH, 당도, 알콜함량, 총산의 변화를 조사하였으며 관능검사를 통하여 종합적인 기호도를 평가하여 최적의 발효온도를 탐색하고자 했다. 발효과정에서 술의 품온은 온도계를 사용하여 측정하였고 pH는 pH-meter로 측정하였으며 당도는 당도계를 이용하여 측정하였다. 알콜함량과 총산은 국세청의 주류분석규정에 따라 증류법과 중화적정법을 사용하여 측정하였다. 관능검사는 식품공학과 대학원생과 학부생 10명을 대상으로 종합적인 기호도에 대하여 5단계 평점법으로 실시하였다. 2$0^{\circ}C$에서 발효시 품온은 20.2~23.8$^{\circ}C$사이에서, $25^{\circ}C$에서 발효시 품온은 25.2$^{\circ}C$~28.2$^{\circ}C$사이에서 변화되었고 pH는 2$0^{\circ}C$ 발효시 3.47~4.62 사이에서, $25^{\circ}C$ 발효시 pH는 3.28~4.65사이에서 변화되었고 최종 pH는 2$0^{\circ}C$에서 발효시 3.71로써 $25^{\circ}C$ 발효시 3.58보다 높았다. 최종당도는 2$0^{\circ}C$, $25^{\circ}C$ 발효시 각각 10.2。Brix와 8.4。Brix 였고 알콜농도는 2$0^{\circ}C$발효시 13.8%로 $25^{\circ}C$ 발효시 14.8% 낮았으며 총산은 2$0^{\circ}C$ 발효시 1.32%로 $25^{\circ}C$ 발효시 1.62%보다 낮게 나타났다. 관능검사를 통한 종합적인 기호도는 2$0^{\circ}C$에서 발효시킨 진양주가 4.2로써 $25^{\circ}C$에 발효시킨 진양주 3.5보다 높은 것으로 나타났다. 관능검사시 $25^{\circ}C$에서 발효한 진양주는 신맛이 많이 난다는 결과로 볼 때 최종 pH가 3.58로 낮고 총산이 1.62%로 높아서 나온 결과라고 생각된다. 결론적으로 진양주를 제조할 시 발효온도는 2$0^{\circ}C$가 발효온도 $25^{\circ}C$보다 더 적합하다고 생각된다.

• Journal of the Korean Geotechnical Society
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• v.23 no.2
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• pp.71-83
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• 2007

Liquefaction resistance depends strongly upon the degree of saturation, which is expressed in terms of the pore pressure coefficient, B. The B-value has been widely used to quantify the state of saturation of laboratory samples. However, it is practically impossible to determine in situ state of saturation by using the B-value. So, P-wave velocity can be alternatively used as a convenient index for evaluating the in situ state of saturation. In this paper, the Stokoe type torsional shear (TS) testing system was modified to saturate the specimen, with which it is also possible to measure P ($V_p$), S-wave velocity ($V_s$) and the excess pore water pressure buildup In order to examine the effect of B-value for nearly saturated sands. A series of the tests were carried out at 3 relative densities (40%, 50% and 75%) and various B-values using Toyoura sand. Based on the test results, the variations of $V_p\;and\;V_s$ with B-value were analyzed and compared with a existing theoretically derived formula. The normalized pore water pressure, $du/{\sigma}{_0}'$ and cyclic threshold shear strain, ${\gamma}^c_{th}$ with B-value were also analyzed. Additionally the test results related to pore water pressure were analyzed by $V_p$ to apply to the field seismic analysis.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.1-10
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• 2023

Due to the development of the industrial revolution, regulations on exhaust emissions have been continuously strengthened to reduce the rapidly increasing greenhouse gas emissions. The use of environmentally friendly fuels is essential to meet these regulations. Hydrogen has been attracting attention as a future environmentally friendly fuel, but due to its material properties, it faces significant challenges in handling and storage. As an alternative, ammonia has been proposed. Ammonia can be easily liquefied at room temperature compared to hydrogen and has a high energy density. In order to examine the applicability of ammonia as an engine fuel, experiments were conducted to investigate the effects of changes in combustion control parameters in a direct injection ammonia combustion engine. The experiments were conducted by varying two variables: spark timing and excessive air ratio. Observations were made on combustion stability and the trends of exhaust emissions such as nitrogen oxides and unburned ammonia under the conditions of an engine speed of 1,500 rpm and medium to high loads (brake torque of 200 Nm). By optimizing the combustion control parameters, conditions for stable combustion even when using ammonia as the sole fuel were identified, and plans are underway to apply strategies for future expansion of the operating range.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.3
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• pp.129-145
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• 2019

For the design of composite breakwater as representative one of the coastal and harbor structures, it has been widely discussed by the researchers about the relation between the behavior of excess-pore-water pressure inside the rubble mound and seabed caused by the wave load and its structural failure. Recently, the researchers have tried to verify its relation through the numerical simulation technique. The above researches through numerical simulation have been mostly applied by the linear and nonlinear analytic methods, but there have been no researches through the numerical simulation by the strongly nonlinear mutiphase flow analytical method considering wave-breaking phenomena by VOF method and turbulence model by LES method yet. In the preceding research of this study, olaFlow model based on the mutiphase flow analytical method was applied to the nonlinear interaction analysis of regular wave-composite breakwater-seabed. Also, the same numerical techniques as preceding research are utilized for the analysis of irregular wave-composite breakwater-seabed in this study. Through this paper, it is investigated about the horizontal wave pressures, the time variations of excess-pore-water pressure and their frequency spectra, mean flow velocities, mean vorticities, mean turbulent kinetic energies and etc. around the caisson, rubble mound of the composite breakwater and seabed according to the changes of significant wave height and period. From these results, it was found that maximum nondimensional excess-pore water pressure, mean turbulent kinetic energy and mean vorticity come to be large equally on the horizontal plane in front of rubble mound, circulation of inflow around still water level and outflow around seabed is formed in front of rubble caisson.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.1
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• pp.34-42
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• 1997

Enuresis is repeated involuntary or intentional voiding of urine into bed or clothes over age 5. Though it would be a self-remitting disorder, it could be serious problem in emotional and socio-adaptational aspects. The author reviewed the enuretic patients of Child & Adolescence psychiatric section in Chungnam National University Hospital during past 3 years. 46(4.9%) of 936 patients were diagnosed as enuresis in DSM-Ⅳ. The author evaluated their comorbidity by the data of diagnostic review made in two psychiatrists, and emotional aspects(self-concept, anxiety, depression) through the self-rating scales (Piers-Harris children’ self concept scales, RCMAS, state-trait anxiety inventory for children, child’s depresson inventory). Thirty(65.2%) of the 46 enuretic patients had additional diagnoses such as attention deficit hyperactive disorder, mental retardation, encopresis, oppositional defiant disorder, depression, anxiety disorder, autism, somatoform disorder, tic disorder, obsessive-compulsive disorder, sleep disorder, etc. Sixteen enuretic patients had at least one comorbid disorder. Eleven patients had two, and three patients had more than three. Fourteen of 46 enuretic patients were evaluated through self-rating scales of self-concept, anxiety and depression. But we couldn’t obtain meaningful results. Maybe it was due to the small sample size(N＝14) and the influence of the comorbid disorders. Finally, it was an impressive evidence that there exist many comorbid disorders in enuresis(esp. attention deifict/hyperactive disorder). In emotional aspects, the author thought that further evaluation should be needed for more meaningful results.

• Journal of the Korean Chemical Society
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• v.50 no.6
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• pp.486-493
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• 2006

study investigated the relationship between conceptual understanding and mapping errors induced in learning chemistry concept with two analogies presented in current science textbooks. Each of the two groups from 7th graders (N=260) in three middle schools studied with one of the analogies, and then a conception test and a mapping test were administered. Analyses of the results indicated that students conceptual understanding has a significant relationship with their understanding about the mapping. The scores of the conception test and the mapping test for the unshared attributes were lower than those for the shared attributes. Five types of mapping errors were also identified: overmapping, mismapping, failure to map, rash mapping, and artificial mapping. Many representative misconceptions were found to be associated with their mapping errors. Educational implications are discussed.