• Journal of the Korean Child Neurology Society
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• v.26 no.4
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• pp.205-209
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• 2018

Purpose: Several studies have shown that magnesium plays an important role in modulating N-methyl-D-aspartate (NMDA)-related seizures by blocking NMDA ion channel receptors. Clinicians usually measure total serum magnesium levels instead of biologically active ionized magnesium levels. We compared the serum ionized magnesium ($iMg^{2+}$) level between epileptic children with and without a history of fever-triggered seizure (FTS). Methods: All epileptic children who visited the outpatient clinic or pediatric emergency department at Korea University Guro Hospital between January 2015 and July 2017 were included. Only epileptic children aged 1-8 years who were newly diagnosed within 2 years were included. Results: There were 12 children with FTS and 16 without FTS. Median serum $iMg^{2+}$ level was 0.93 (0.85-1.14, quartile) mEq/L. Serum $iMg^{2+}$ level was significantly lower in epileptic children with FTS (0.86 mEq/L) compared to those without FTS (1.10 mEq/L) (P=0.005). No difference was noted in clinical variables between the two groups. Lower serum $iMg^{2+}$ level significantly increased the risk of having FTS in epileptic children based on multivariable logistic regression analysis (odds ratio [OR]=0.028). Conclusion: Serum $iMg^{2+}$ level was significantly lower in epileptic children with FTS than in those without FTS. Measurement of biologically active serum $iMg^{2+}$ level could be considered in epileptic children with recurrent FTS. A large-scale prospective study is warranted.

• Korean Journal of Heritage: History & Science
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• v.49 no.3
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• pp.240-255
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• 2016

In many cities in the East and West during the modern period, historical resources were perceived as obstacles to urban development and were treated as deficiencies calling for development. Korea underwent a process of drastic urbanization and industrialization almost unprecedented in modern history. In this process of turmoil, cities expanded rapidly and went through a series of changes. City development followed a repeated cycle in which resources were concentrated in the city area, which, in turn, led to further development. However, such method of development is reaching its limits. In order to make a city desirable for living, it is crucial to make an effort to build a sustainable city environment where life and history coexist harmoniously. It is now time to consider how to carry forth sustainable development in the city where the past, present, and future coexist. If so, how will the future of our cities look and the form of housing change? To answer this question, we examined Urban Hanok Residential Areas and Hanyangdoseong neighborhood village, which went through rapid changes in the modern period. The Hanok, which was a commonplace sight in the past, has been perceived as an underdeveloped form of housing, easily targeted for redevelopment only a few years ago; so was the case with Hanyangdoseong neighborhood village. Yet now these are being revalued as sustainable housing areas able to coexist with the history of the city. That is, through restoration, their potential of contributing to the history and identity of the city is gaining recognition. In this regard, it holds great implications for us to look at the changes that traditional Korean housing areas and castle villages have undergone.

• Clean Technology
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• v.27 no.2
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• pp.198-204
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• 2021

This study focused on a two-step process using heterogeneous catalysts to produce biodiesel using Nepalese jatropha oil as a raw material. As a first step, the effect of the repetitive regeneration number of Amberlyst-15 on the esterification reaction of FFA in jatropha oil was investigated. Second, the possibility of a transesterification reaction scale-up using a dolomite bead catalyst was tested. Using 120 kg of jatropha seeds from Nepal, 30 L (27 kg) of jatropha oil was obtained, and the jatropha oil yield from the seeds was about 25.0 wt%. The acid value and FFA content of jatropha oil were measured to be 11.3 mgKOH g^-1 and 5.65%, respectively. As a result of the esterification reaction of jatropha oil using the Amberlyst-15 catalyst in the form of beads, the acid value of the reaction product could be lowered to 0.26 mgKOH g^-1 when the fresh Amberlyst-15 catalyst was used. As the regeneration of the Amberlyst-15 catalyst is repeated, the catalyst has been deactivated, and the esterification reaction performance has deteriorated. The cause of the deactivation seems to be due to the catalyst being broken and impurities being deposited. It was confirmed that the Amberlyst-15 catalyst could be reused up to 5 times for the esterification reaction of jatropha oil. In the second step, the transesterification reaction, a dolomite catalyst, was mass-produced and used in the form of beads. By transesterifying the pretreated jatropha oil in a spinning catalyst basket reactor equipped with 90 g of dolomite bead catalyst, 89.1 wt% of biodiesel yield was obtained in 2 hours after the start of the reaction, which was similar to the transesterification of soybean oil under the same conditions.

• Radiation Oncology Journal
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• v.23 no.4
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• pp.223-229
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• 2005

Purpose: In this work we designed and made MPBP(Multi Purpose Brachytherapy Phantom). The MPBP enables one to reproduce the same patient set-up in MPBP as the treatment of the patient and we tried to get an exact analysis of rectal doses in the phantom without need of in-vivo dosimetry. Materials and Methods: Dose measurements were tried at a point of rectum 1, the reference point of rectum, with a diode detector for 4 patients treated with tandem and ovoid for a brachytherapy of a cervix cancer. Total 20 times of rectal dose measurements were made with 5 times a patient. The set-up variation of the diode detector was analyzed. The same patient set-ups were reproduced in self-made MPBP and then rectal doses were measured with TLD. Results: The measurement results of the diode detector showed that the set-up variation of the diode detector was the maximum $11.25{\pm}0.95mm$ in the y-direction for Patient 1 and the maximum $9.90{\pm}4.50mm,\;20.85{\pm}4.50mm,\;and\;19.15{\pm}3.33mm$ in the z-direction for Patient 2, 3, and 4, respectively. Un analyzing the degree of variation in 3 directions the more variation was showed in the z-direction than x- and y-direction except Patient 1. The results of TLD measurements in MPBP showed the relative maximum error of 8.6% and 7.7% at a point of rectum 1 for Patient 1 and 4, respectively and 1.7% and 1.2% for Patient 2 and 3, respectively. The doses measured at R1 and R2 were higher than those calculated except R point of Patient 2. this can be thought to related to the algorithm of dose calculation, whcih corrects for air and water but is guessed not to consider the correction for the scattered rays, but by considering the self-error (${\pm}5%$) TLD has the relative error of values measured and calculated was analyzed to be in a good agreement within 15%. Conclusion: The reproducibility of dose measurements under the same condition as the treatment could be achieved owing to the self-made MPMP and the dose at the point of interest could be analyzed accurately. If a treatment is peformed after achieving dose optimization using the data obtained in the phantom, dose will be able to be minimized to important organs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1244-1255
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• 2011

The purpose of this study was to compare the perception of meals and nutrition knowledge among high school students in Seoul. A survey was carried out on 548 male/female students in general and vocational high schools. The general high school students showed higher frequency of breakfast than the vocational high school students (p<0.001). As for the reasons for eating alone, the general high school students showed high frequency of 'busy', whereas the vocational high school students revealed high frequency of 'irregular meal times' (p<0.001). Concerning the habit of eating alone, 'irregular meal times (25.0%)', 'unbalanced diet (22.4%)', and 'instant food (16.6%)' were observed in that order (p<0.01). The percentage of high school students who regarded family meals as meals eaten with every member of their family was 70.6% (p<0.05). The percentage of general high school students who ate family meals was 61.8% and that of vocational high school students was 50.0% (p<0.01). When agreement with attitudes, environment, and participation in family meals was evaluated using a Likert scale (strongly agree 5 points, strongly disagree 1 point), the general high school students showed a higher level of agreement than the vocational high school students, and the results showed a significantly higher level of agreement as the frequency of family meals increased. Likewise, the groups who scored a higher level of nutrition knowledge had positive attitudes, environment, and participation in family meals with significant differences.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.28 no.3
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• pp.72-84
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• 2010

This study was attempted in order to offer basic data for implementing and applying Samjonseokjo(三尊石造), which is one of traditional stone construction method, by confirming how the constructive principle is expressed such as proportional beauty, which is contained in the modeling of Triad of Buddha Carved on Rock that was formed in the period of the Three States, centering on Triad of Buddha Carved on Rock in Susan. The summarized findings are as follows. 1. As a result of analyzing size and proportion of totally 17 of Triad of Buddha Carved on Rock, the average total height in Bonjonbul(本尊佛) was 2.96m. Right Hyeopsi(右挾侍) was 2.19m. Left Hyeopsi(左挾侍) was 2.16m. The height ratio according to this was 100:75:75, thereby having shown the relationship of left-right symmetrical balance. The area ratio in left-right Hyeopsi was 13.4:13.7, thereby the two area having been evenly matched. 2. The Triad of Buddha Carved on Rock in Seosan is carved on Inam(印岩) rock after crossing over Sambulgyo bridge of the Yonghyeon valley. Left direction was measured with $S47^{\circ}E$ in an angle of direction. This is judged to target an image change and an aesthetic sense in a Buddhist statue according to direction of sunlight while blocking worshipers' dazzling. 3. As for iconic characteristics of Buddha Carved on Rock in Seosan, there is even Hyeopsi in Bangasang(半跏像) and Bongjiboju(捧持寶珠) type Bosangipsang. In the face of Samjon composition in left-right asymmetry, the unification is indicated while the same line and shape are repeated. Thus, the stably visual balance is being shown. 4. In case of Triad of Buddha Carved on Rock in Seosan, total height in Bonjonbul, left Hyeopsi, and right Hyeopsi was 2.80m, 1.66m, and 1.70m, respectively. Height ratio in left-right Hyeopsibul was 0.60:0.62, thereby having been almost equal. On the other hand, the area ratio was 28.8:25.2, thereby having shown bigger difference. The area ratio on a plane was grasped to come closer to Samjae aesthetic proportion. 5. The axial angle of centering on Gwangbae was 84:46:50, thereby having been close to right angle. On the other hand, the axial angle ratio of centering on Yeonhwajwa(蓮華坐: lotus position) was measured to be 135:25:20, thereby having shown the form of inequilateral triangle close to obtuse angle. Accordingly, the upper part and the lower part of Triad of Buddha Carved on Rock in Susan are taking the stably proportional sense in the middle of maintaining the corresponding relationship through angular proportion of inequilateral triangle in right angle and obtuse angle. 6. The distance ratio in the upper half was 0.51:0.36:0.38. On the other hand, the distance ratio in the lower half was 0.53 : 0.33 : 0.27. Thus, the up-down and left-right symmetrical balance is being formed while showing the image closer to inequilateral triangle. 7. As a result of examining relationship of Samjae-mi(三才美) targeting Triad of Buddha Carved on Rock in Susan, the angular ratio was shown to be more notable that forms the area ratio or triangular form rather than length ratio. The inequilateral triangle, which is formed centering on Gwangbae(光背) in the upper part and Yeonhwajwa(lotus position) in the lower part, is becoming very importantly internal motive of doubling the constructive beauty among Samjae, no less than the mutually height and area ratio in Samjonbul.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.21-30
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• 2011

As well known, dowel bars are used to transfer traffic load acting on one edge to another edge of concrete slab in concrete pavement system. The dowel bars widely used in South Korea are round shape steel bar and they shows satisfactory performance under bending stress which is developed by repetitive traffic loading and environment loading. However, they are not invulnerable to erosion that may be caused by moisture from masonry joint or bottom of the pavement system. Especially, the erosion could rapidly progress with saline to prevent frost of snow in winter time. The problem under this circumstance is that the erosion not only drops strength of the steel dower bar but also comes with volume expansion of the steel dowel bar which can reduce load transferring efficiency of the steel dowel bar. To avoid this erosion problem in reasonable expenses, dowers bars with various materials are being developed. Fiber reinforced plastic(FRP) dower that is presented in this paper is suggested as an alternative of the steel dowel bar and it shows competitive resistance against erosion and tensile stress. The FRP dowel bar is developed in tube shape and is filled with high strength no shrinkage. Several slab thickness designs with the FRP dowel bars are performed by evaluating bearing stress between the dowel bar and concrete slab. To calculated the bearing stresses, theoretical formulation and finite element method(FEM) are utilized with material properties measured from laboratory tests. The results show that both FRP tube dowel bars with diameters of 32mm and 40mm satisfy bearing stress requirement for dowel bars. Also, with consideration that lean concrete is typical material to support concrete slab in South Korea, which means low load transfer efficiency and, therefore, low bearing stress, the FRP tube dowel bar can be used as a replacement of round shape steel bar.

• Cartoon and Animation Studies
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• s.33
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• pp.1-29
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• 2013

Surrealism with the excavation of unconsciousness, seeking for the infinity etc. has established views on aesthetics that conflict traditional western rationalism. The main concern of surrealism is problem of identity and difference. They attempted their own mysterious concept such as 'the marvelous', 'convulsive beauty', 'object chance' etc. These unique views on aesthetics was expressed as various style of art. It is the d$\acute{e}$paysemant that exists one of the typical style in surrealism. D$\acute{e}$paysemant means that objects are taken from be originally place. Therefore, The real world's objects is to leave and change environment from real space as use, ability, meaning of origin. or it is the technique to create surreal illusion that combined to a strange place where relates to extraneous attribute of objects. Namely, objects are newly arranged in expression space. Reconstitutive objects by positioning object over the time and space have given us the marvelous and psychological shock and get unfamiliar meaning and feeling over. This paper is tried to look at the way to use the d$\acute{e}$paysemant which applicated in the media, Especially, focusing on animation. Unlike the other media, animation has its unique artistic characters. First, One of the media characteristics of the animation is creativity images of the hand drawn animation by shooting of frame by frame. The animation image which is created through arrangement obtain life force by unique motility. Works of Norman McLaren and Harry Smith are very interesting that the structural characteristics of the d$\acute{e}$paysemant. It consists with abstract forms and various moving images to let audience the feel characteristics of film. We can experience from these cases, numerous illusion fantasy like change over from creature to inanimate object, space and time, creation and extinction, repetition and metamorphosis etc. One of the main apparat is the emphasis of d$\acute{e}$paysemant in space of frame. In conclusion, d$\acute{e}$paysemant is one of the most characteristic expression technique of surrealism while having inevitable linkage with animation.

• The korean journal of orthodontics
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• v.34 no.3 s.104
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• pp.253-260
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• 2004

Frictional force between the orthodontic bracket and arch wire during sliding tooth movement is related to many factors, such as the size, shape and material of both the bracket and wire, ligation method and the angle formed between the bracket and wire. There have been clear conclusions drawn in regard to most of these factors, but as to the effect of bracket width on frictional force there are only conflicting studies. This study was designed to investigate the effect of bracket width on the amount of frictional forces generated during clinically simulated tooth movement. Three different widths of brackets $(0.018{\times}0.025'\;standard)$ narrow (2.40mm), medium (3.00mm) and wide (4.25mm) were used in tandem with $0.016{\times}0.022'$ stainless steel wire. Three bracket-arch wire combinations were drawn on for 4 minutes on a testing apparatus with a head speed of 0.5mm/min and tested 7 times each. To reproduce biological conditions, dentoalveolar models were designed with indirect technique using a material with similar elastic properties as periodontal ligament (PDL). In addition, to minimize the effect of ligation force, elastomer was used with added resin, which was attached to the bracket to make up for the discrepancies of bracket width. The results were as follows: 1. Maximum frictional force for each bracket-arch wire combination was: Narrow (2.40mm): $68.09\pm4.69gmf$ Medium (3.00mm): $72.75\pm4.98 gmf$ Wide (4.25mm): $72.59\pm4.54gmf$ 2. Frictional force was increased with more displacement of wire through the bracket slot. 3. The ANOVA psot-hoc test showed that the bracker width had no significant effect on frictional force when tested under clinically simulated conditions(p>0.05).

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.4
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• pp.38-51
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• 2015

In the maps of the period, there were three large ponds called Dongji(東池), Seoji(西池) and Namji(南池) in Hanyang, the capital of Joseon Dynasty. They were different than the ponds found in the palace, civic buildings, and private dwellings. Dongji, Seoji and Namji were ponds relating to Fortress wall of Seoul, and all had lotuses cultivated in them. The purpose of this paper is to clarify the locational and spatial characteristics of these ponds and to detail the construction and reconstruction process and management conditions through maps, drawings, illustrations, historical records and literary works from the urban environmental perspective. The results are as follows. First, Seoji and Namji were intended for Bibo(裨補) which redeemed the geographical weaknesses of Hanyang, securement of bright court water(明堂水), supplement for fire energy(火氣), fire preventive water and waterscape facilities, while Dongji was emphasized on protecting water mouth(水口) besides Bibo and securement of bright court water. Second, Seoji was connected to mountain streams and Dongji and Namji were to ditches. The ponds connected to ditches had been difficult to fill and maintain. Third, Seoji and Namji were in urban areas, whereas Dongji was in farmlands, and these locational differences had an influence on the use of ponds. Fourth, the shapes of ponds, in contrast to the ponds in palace and civic buildings, which were perfectly square, were either freeform or square with rounded edges. Fifth, lotus ponds could be maintained by continuous management polices, earth filling and reconstructing process were repeated during the Joseon Dynasty. The lotus ponds of Fortress Wall of Seoul which had managed over 500 years, were built in, in accordance with the tenets of Bibo pungsu geomancy; however as time passed, they were maintained not only as public open spaces, but also a cultural attraction for residents and visitors.