• Journal of Korean Society of Steel Construction
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• v.12 no.3 s.46
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• pp.291-302
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• 2000

In recent years the development of high modulus, high strength and low density boron and graphite fibers bonded together has brought renewed interestes in structural elements. When a plate with arbitrarily oriented layers and clamped boundary conditions is subjected to uniform loading, it is difficult to analyze and apply, compared with isotropic and orthotropic cases. Therefore the numerical methods, such as finite difference method or finite element method, should be emloyed to analyse such problems. In this study the finite difference technique is used to formulate the bending analysis of symmetric composite laminated skew plates. When this technique is used to solve the problem, it is desirable to reduce the order of the derivatives in order to minimize the number of the pivotal points involved in each equation. The 4th order partial differential equations of laminated skew plates are converted to an equivalent three of 2nd order partial differential equations with three dependant variables.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.143-143
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• 2016

알루미늄 합금은 내구성과 내식성이 우수할 뿐만 아니라 다양한 표면개질을 통해 그 표면 특성을 더욱 향상시킬 수 있다. 특히 Al-Mg계 5083-H321 Al 합금의 경우 가공성 및 용접성이 우수하여 선체 재료로 널리 이용되는데, 이는 선체중량의 경량화가 가능하여 연료비 절감과 빠른 선속 등 다양한 이점을 지니기 때문이다. 그러나 선속의 고속화에 따라 선체에 가해지는 유체충격이 증가하고 정압 저하에 기인하여 캐비테이션-침식 손상이 증가할 뿐만 아니라 해수환경 특성 상염소이온의 존재로 부식이 가속화되는 등 침식 및 부식의 시너지효과로 손상은 크게 증가한다. 이에 대한 방지대책으로 다양한 표면개질 기법이 제안되고 있으나 강한 충격압이 동반된 캐비테이션 침식-부식 복합 손상 환경에서는 표면처리만으로는 불가능할 수 있다. 따라서 본 연구에서는 양극산화된 5083-H321을 대상으로 캐비테이션 환경 하에서 일정 전위를 인가하여 침식-부식 손상이 최소화되는 최적전위를 규명하고자 한다. 이를 위해 먼저 분극 실험을 통해 재료의 전기화학적 거동을 바탕으로 임의의 전위를 선정하고 해당 전위를 인가한 상태에서 캐비테이션 실험을 실시하였다. 이때 분극실험과 캐비테이션-전기화학 복합실험 모두 $25^{\circ}C$의 해수에서 실시하였으며, 전기화학적 분극실험은 유효면적이 $3.24cm^2$인 시편에 2 mV/s의 분극속도로 0 ~ -3 V 까지 인가하였고, Ag/AgCl 기준전극과 백금대극을 사용하였다. 캐비테이션-전기화학 복합 실험은 정전위를 인가한 상태에서 $30{\mu}m$의 진폭으로 20분간 실시하였으며, 혼팁과 시험편 사이의 거리는 1 mm로 일정하게 유지하였다. 실험 후 표면 손상의 정량적 분석을 위해 인가된 전위별 전류밀도를 비교하고, 무게감소량을 측정하였으며, 손상특성 분석을 위해 3D현미경과 주사전자현미경(SEM)을 통해 표면을 분석하였다.

• 한국체육학회지인문사회과학편
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• v.58 no.1
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• pp.271-284
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• 2019

The purpose of this study was to analyze effects of 12 weeks dance sports on body composition, irisin, adiponectin and blood lipids in obesity elderly women. The subjects were 26 obesity elderly women who do not have medically problems. The subjects randomly assigned to two groups; dance sports exercise(n=13), control(n=13). The subjects in dance sports group were participated for 60 minutes/day with two times/wk for 12 weeks, whereas subjects in control group were asked to maintain normal lifestyle during the same intervention period. The results of the present study showed that the blood irisin was significantly increased in the exercise group. The blood adiponectin level tended to increase in the exercise gorup. The blood lipids, TG and LCL-C were significantly decreased in the exercise group. The TC was slightly decreased, and the HDL-C was slightly increased. In conclusion, low irisin and adiponectin level in obese people have a positive effect on obese elderly women after dance sports. Therefore, exercise is thought to be good for the care of elderly obesity.

• The Journal of Engineering Geology
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• v.22 no.1
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• pp.67-81
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• 2012

The physical, chemical, and biological properties of clogging materials formed within groundwater wells in the Mt. Geumjeong area, Busan, Korea, were characterized. The particle size distribution (PSD) of clogging materials was measured by a laser analyzer. XRD, SEM, and TEM analyses were performed to obtain mineralogical information on the clogging materials, with an emphasis on identifying and characterizing the mineral species. In most cases, PSD data exhibited an near log-normal distribution; however, variations in frequency distribution were found in some intervals (bi-or trimodal distributions), raising the possibility that particles originated from several sources or were formed at different times. XRD data revealed that the clogging materials were mainly amorphous ironhydroxides such as goethite, ferrihydrite, and lapidocrocite, with lesser amounts of Fe, Mn, and Zn metals and silicates such as quartz, feldspar, micas, and smectite. Reddish brown material was amorphous hydrous ferriciron (HFO), and dark red and dark black materials were Fe, Mn-hydroxides. Greyish white and pale brown materials consisted of silicates. SEM observations indicated that the clogging materials were mainly HFO associated with iron bacteria such as Gallionella and Leptothrix, with small amounts of rock fragments. In TEM analysis, disseminated iron particles were commonly observed in the cell and sheath of iron bacteria, indicating that iron was precipitated in close association with the metabolism of bacterial activity. Rock-forming minerals such as quartz, feldspar, and micas were primarily derived from soils or granite aquifers, which are widely distributed in the study area. The results indicate the importance of elucidating the formation mechanisms of clogging materials to ensure sustainable well capacity.

• Journal of the Mineralogical Society of Korea
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• v.27 no.2
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• pp.63-72
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• 2014

This study is conducted to investigate mineralogical characteristics and estimate firing temperature and condition of earthenwares in the 5-6th Century which are found at ancient tombs in Gyo-dong, Gyo-ri, Changnyeong-eup, Changnyeong-gun, Gyeongsangnam-do, TKorea by applying petrological methods. For this study, mineralogical analysis, microtexture observation and chemical analysis were conducted. According to observations using a polarization microscope, the potshreds are mainly composed of quartz and feldspar and consist of some felsic volcanics, tempers, opaques and mullite, hematite and spinel were found under XRD and FTIR analysis. The flow pastes are observed in many potshreds, and it indicate that this textures made by the mixing process or the pottery made from the mixture of 2 sorts of clays at least. They dose not show the features of the potshreds firing under temperature of $1,200-1,300^{\circ}C$ rather than the earthenware firing under relatively low temperature of $1,000^{\circ}C$ approximately because of the existence of a number of pores and the crystals of the specific minerals. The growths mostly of mullite on the surface and into the cracks of the potshreds indicate that the firing condition was not uniform to make even temperature and oxidation. Most of the pottery shreds have felsic volcanic fragments and some of them have cristobalite which is formed at the temperature of more than 1,470^{\circ}C$. But considering the estimated firing temperature, these are not formed during firing but included in the original clay.

• Journal of Acupuncture Research
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• v.19 no.3
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• pp.180-191
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• 2002

Objective : This study was performed to evaluate the effect of oriental medical treatment in whiplash injury patients which caused by traffic accident. Methods : The clinical study was carried out 37 cases of whiplash injury patients which had been admitted in Daejon university Cheon-an oriental hospital from June, 2001 to December, 2001. Results : l. In the distribution of sex distinction was female much more than male in the ratio of 3:2 and thirties was most in age distribution. 2. In situation of traffic accident, The most case was rear-ending(70.27%). 3. Except cervical pain or it's reffered pain, there were whole body symptoms as fallow, insomnia in 11cases(29.73%), night pain in 10 cases(27.03%), general body pain in 8cases(21.62), dizziness in 6cases(16.22%). 4. According to Meridian Muscle theory, a injured parts of patient were devided as follows. There were 22cases(59.46%) which have injury in Bladder, Small Intestine Meridian Muscle, 10cases(27.03%) in Gallblader, Triple Energizer Meridian Muscle, 5cases(13.51%) in Stomach, Large Intestine Meridian Muscle. 5. There were 6cases(16.22%) of the grade of complete recovery, 10cases(27.03%) of the grade of excellent, 12cases(32.43%) of the grade of improvement, 6cases(16.22%) of the grade of disimprovement and 3cases(8.11%) of the grade of poor. So 28cases(75.68%) were efficacious. 6. Generally Herb-meds that have efficacy of Geo-Eohyeol were most used(27cases, 72.97%) in early stage. Secondly Herb-med that have efficacy of Yiqi-sunqi were used(20case, 54,05%) in middle stage and Herb-med of Bo-Qiheol were used(l0cases, 27.03%) in latter term. The most used Herb-med was Hoisu-san, Oyaksungi-san(22cases, 54.96%). 7. In l5cases which have Aqua-Acupuncture treatment, There were 3cases of Complete recovery, 5cases of Excellent, 4cases of Improvement, 2cases of Disimprovement, 1cases of Poor. 8cases(53.33%) were above Excellent grade, so it is more efficatious Than simple treatment without Aqua-Acupuncture(36.37%). 8. The improvement of Bladder, Small Intestine Meridian Muscle was 77.27%, Gallblader, Triple Energizer Meridian Muscle was 70% and Stomach, Large Intestine Meridian Muscle was 80%. Additional Aqua-Acupuncture treatment improved to be effective in Bladder, Small Intestine Meridian Muscle(77.78%), in Gallblader, Triple Energizer Meridian Muscle(75%), in Stomach, Large Intestine Meridian Muscle(100%). Conclusions : In this study, Oriental treatment especially Aqua-Acupuncture was effective in whiplash injury patients which caused by traffic accident.

• Journal of Digital Convergence
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• v.15 no.6
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• pp.133-143
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• 2017

Data is the most important asset in the financial sector. On average, 71 percent of financial institutions generate competitive advantage over data analysis. In particular, in the card industry, the card transaction data is widely used in the development of merchant information, economic fluctuations, and information services by analyzing patterns of consumer behavior and preference trends of all customers. However, creation of new value through fusion of data is insufficient. This study introduces the analysis and forecasting of consumption trends of credit card companies which convergently analyzed the social data and the sales data of the company's own. BC Card developed an algorithm for linking card and social data with trend profiling, and developed a visualization system for analysis contents. In order to verify the performance, BC card analyzed the trends related to 'Six Pocket' and conducted th pilot marketing campaign. As a result, they increased marketing multiplier by 40~100%. This study has implications for creating a methodology and case for analyzing the convergence of structured and unstructured data analysis that have been done separately in the past. This will provide useful implications for future trends not only in card industry but also in other industries.

• Journal of the Mineralogical Society of Korea
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• v.29 no.3
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• pp.123-129
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• 2016

This study is conducted to estimate the firing temperature and condition of the 4-6th Century earthenwares excavated from the ancient tombs in the Seonggok-ri, Cheongdo through mineralogical approaches, and to contrast to the characteristics of the earthenware from the Changnyeong the adjacent area to the Cheongdo. The Cheongdo earthenware was mainly composed of quartz, pores and vitric matrix with minor parts of feldspars, felsic volcanic fragments and opaque minerals, of which quartz crystals frequently show embayed texture and pores was partly filled with amorphous quartz. Mullite, hematite and cristobalite were found by XRD spectrometer additionally, and in the SEM image the Mullite contents are evenly distributed from the central part to the marginal part. As a result, the firing temperature of the Cheongdo earthenware could be 1,100 to $1,200^{\circ}C$, which is higher than that of the Changnyeong. Distribution characteristics of mullite in the Cheongdo and the Changnyeong earthenware indicate that the Cheongdo earthenware was under the longer firing time or more homogeneous thermal condition in the kiln than the Changnyeong.

• Journal of Conservation Science
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• v.29 no.2
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• pp.171-185
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• 2013

The purpose of this study were to interpret making characteristics and clay sources for Proto-Three Kingdoms period potteries which were excavated from Bakjimeure site in Tangjeong, Asan, Korea, on the basis of shape types. The pottery samples of the studied included deep bowl pottery, cylinder shaped pottery, duck shaped pottery and rounded based jar with short neck. And the last jar was dominant among them. This is supported in nearby Yongduri Jinter site, Galmaeri site and Baekseokdong site. They vary in terms of color of clay, absorption ratio and mineral classification. Based on the fact that their absorption ratio range was 4.50 to 25.19% and firing temperature range was 850 to $1,150^{\circ}C$, they were thought to be widely used. The equivalence of cylinder shaped pottery, duck shaped pottery and deep bowl pottery was high in terms of material characteristics and their firing temperature range was 850 to $950^{\circ}C$. However, the deep bowl pottery, compared to other pottery shapes, contained great amount of coarse grained quartz and feldspar, and was different from others in terms of function. For soil sample collected from relative plains (area 3) in the southernmost part of the site, their mineralogical and geochemical characteristics were the most similar to those of the potteries excavated from the Bakjimeure site and even most of the potteries collected from different sites.

• Water for future
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• v.24 no.3
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• pp.49-60
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• 1991

As a second part of the study entitled "Field Measurement and Analysis of Fluvial Sediment in the Cheongmi-Strea", this study concerns mineralogical and contaminative characteristics of sediment particles collected at Wonbu-Gyo and Hanpyeong-Gyo in the Cheongmi-Stream. The mineralogical analysis of the bed sediment collected reveals that, in general , quarz is the most abundant mineral found in sands with feldspars and rock fragments in the next, which confirms what is known in the literature. The shape factor of sand particles is about 0.7, which also agrees to what is known in the foreign literature. The analysis also reveals that the clay particles collected are composed mainly of illite, kaolinate, and chlorite. The analysis of contamination reveals that there is no substantial difference between the contents of organic material and heavy metals in the surface water and those in the pore water beneath the river bed. It is because the sampling for this analysis was conducted right after the September flood during which the fresh top soil from the upstream watershed replaced the old bed sediment and pore water that would probably be more contaminated. The contents of geavy metals in the bed sediment of sand particles do not exceed those in the soils adjacent to the river. For fine sediment such as clays, however, the contents of heavy metals, especially of mercury and zinc, far exceed those in the soils adjacent to the river. These fine sediments are transported downstream in the form of wash load and deposited in part on flood plains, which could be a new source of contaminants.taminants.