• Journal of Radiation Protection and Research
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• v.38 no.2
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• pp.78-90
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• 2013

Recently, the interest on exposure to radiation is rising. The radiation exposure of mammography is higher in absorbed dose than of X-ray, therefore unnecessary exposure needs to be reduced, and higher image quality is needed. Generally, ray quality of the radiation imaging is an important factor that determines image quality and the amount of ray exposure, and they are affected by tube voltage and added filter. The X-ray energy that is exposed from mammography device is generally a continuous spectrum, which includes low energy that has minute influence on the image quality, and high energy that hinders contrast on image. Currently, molybdenum (Mo) and rhodium (Rh) are the most used added filters for mammography device, and they are used differently according to the energy region of X-ray. This study aims to find out the degree of reduction in exposure dose according to the thickness of aluminum (Al), and to study the changes in image quality and dose when the added filter plates that are made with niobium (Nb) or zirconium (Zr) are used, other than molybdenum (Mo) and rhodium (Rh), the two most used added filters that have similar atomic number and K-absorption regions as Nb and Zr. In this study, single-added filters of molybdenum (Mo), niobium (Nb), and zirconium (Zr) are used, and in some cases, Aluminum (Al) is combined with the single filters. In this case, image quality is considered to be improved depending on the type of added filters, and by using Aluminum (Al) filter together with the others, unnecessary X-ray of low energy would be absorbed, therefore the dose is expected to decrease without any influence when the concentration level becomes identical.

• Journal of The Korean Association For Science Education
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• v.31 no.2
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• pp.225-238
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• 2011

The purpose of this study was to investigate the effects of the instruction with question-creation training, compared with traditional science instructions. The instruction with question-creation training is to give students chances to make questions by themselves based on what they learned before the end of the classes. The four effects of the instruction were studied: students' achievement, metacognition, self-efficacy, and the level of the questions created by the students according to different proficiency levels. Research data was gathered from 65 second grade students at a middle school in Busan. The comparative group was instructed in traditional lecture-type teaching method. The experimental group was instructed with questioncreation training. Students in the experimental group were asked to make 3 questions by themselves and then, to solve their peers' questions about 15 minutes before the end of the classes. Both groups were divided into 3 groups by proficiency level according to the results of last semester's science test. Before the research, a metacognition test and a self-efficacy test were conducted. After the research, an achievement test, a question level test, a metacognition test, and a self-efficacy test were conducted and analyzed by t-test. The research data for question level was analyzed by one-way ANCOVA. The results of this study revealed that question-creation training has a positive effect on student's achievement, metacognition, and self-efficiency. It also showed most of the students have gained an ability to make higher-level questions regardless of their proficiency level due to the increased number of students who made higher-level questions. It also showed that most of the students could gain an ability to make higher-level questions regardless of their proficiency level from the fact that the number of students who made higher-level questions increased in every proficiency level.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.3
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• pp.3-37
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• 2020

The aircraft crew operating on international routes performs almost identical tasks as police officials in terms of dealing with the unlawful interference in the aircraft. This means that the liability question which is related to the law enforcement by the police officer may arise regarding the crew's performance of his or her duties. With regard to the carrier's liability due to the crew's unlawful action, there are distinctive characteristics from the liability due to police officers' unlawful action. In case of the claim for damages by the crew's unlawful action, the first question should be whether such action complies with the requirements under the Tokyo Convention 1963. If such action does not conform with the Tokyo Convention 1963, we should examine that claim under the State Compensation Act, the Montreal Convention 1999, and the Civil Act of Korea. The examination under the Tokyo Convention 1963 is not so different from the Korean Court's precedents. However, the court should consider the characteristics of the environment surrounding the crew. The action which is not indemnified under the Tokyo Convention 1963 should be examined under the tort laws. Because the aircraft crew is private persons entrusted with public duties under Korean Law, the State Compensation Act may apply. However, further studies regarding the harmonious interpretation with the Montreal Convention 1999 is needed. With regard to the carrier's liability, the Montreal Convention of 1999 should be applied to the crew's unlawful actions onboard. This is because the Montreal Convention of 1999 preempts the national law for the events that occurred during transportation, and there is no provision which excludes such unlawful actions from the scope of its application. On the other hand, the national law, such as the Civil Act of Korea, applies to unlawful actions taken after transportation. This is because the interpretation that infinitely expands the scope of the Montreal Convention 1999 should not be allowed. Given the foregoing, the standard of the claim for damages due to the crew's unlawful action varies depending on the place where the specific action was taken. As a result, the type of damage recoverable and the burden of proof also varies accordingly. Carriers and crew members must perform their duties with this in mind, but in particular, they should observe the proportionality, and when interpreting the law, it is necessary for the court or lawyer to consider the special characteristics of the work environment.

• Sleep Medicine and Psychophysiology
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• v.22 no.2
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• pp.57-63
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• 2015

Background and Objectives: Internet addiction is an increasing problem in Korea. The previous studies in this area have targeted adolescents and young adults. This study was conducted to examine the risk of internet addiction in Korean adults and the effect of internet addiction on circadian rhythm. Materials and Methods: For this study, 508 subjects were chosen through population proportional sampling to represent the adult population in Korea, 325 of whom were included based on the Alcohol Use Disorder Identification Test-Korea (Audit-K), Zung's Self-Rating Depression Scale (SDS), drug use in the past year, and suicide attempts. In these subjects, sociodemographic factors including age, gender, and residential area were analyzed, and Young's Internet Addiction Scale (IAS), Morningness-Eveningness Questionnaire (MEQ), and an online survey examining sleep onset time on weekdays and weekends, wake-up time, and caffeinated drink intake were executed. Results: Of the 325 subjects, 136 (41.8%) belonged to a high-risk internet addiction group ($IAS{\geq}40$), and 189 (58.2%) belonged to a normal group (IAS < 40). There was a high proportion of male subjects (p = 0.03) in the high-risk group compared to the normal group. There was a high proportion of younger subjects (p = 0.055) in the high-risk group compared to the normal group, but this difference was not statistically significant. Compared to the normal group, there was a high proportion of the evening type ($MEQ{\leq}41$) in the high-risk group (p = 0.024), who also showed a high proportion of caffeinated drink intake (p < 0.001). Also, the high-risk group was found to go to bed and wake up late, but there was no statistically significant difference with the normal group. Conclusion: This study showed that many adults have a high-risk of internet addiction, and there was a significant correlation between internet addiction and sleep in adult, as has been found in adolescents and early adults. In the future, a longitudinal study will be needed to verify the causal relationship between internet addiction and morningness-eveningness.

• Journal of Korean Biological Nursing Science
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• v.7 no.1
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• pp.69-87
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• 2005

Purpose : The purpose of this study was to identify pediatric nurses's knowledge related to children's pain and pediatric nurses' career including educational experience and to examine whether there is a difference of their knowledge according to their career. Method : Subjects of this study was 115 pediatric nurses of one university hospital who understood purpose of this study and accepted to participate in this study. Subjects responded questionnaire by self report. The data were gathered for 7 days during the period from October 20 to October '2:7, 2003. The pediatric nurses' knowledge and attitude survey regarding pain developed by Manworren(2001) was used to identify the knowledge related to children's pain of pediatric nurses. Nurses' career consisted of level of education, presently working ward, duration of experience at clinic, pediatric clinic and presently working ward and educational experience related to children's pain during undergraduate courses, ward orientation and continuing education. Educational experience regarding children's pain was measured by whether they had education related to children's pain during undergraduate courses, ward orientation and continuing education or not and their perception on the contents of education was measured by 5 point Likert type scale. SPSS Windows was used to analyze the data. Scores of the knowledge regarding children's pain and career including educational experience of pediatric nurses were presented as mean and standard deviation. Mean percentage of correct answers responded by the subjects was presented under the category of introduction, assessment, pharmacological and nonpharmacological intervention for children's pain. The difference of scores of the knowledge regarding children's pain according to nurses' career was analyzed using t-test, ANOVA and Tukey as a post hoc. Statistical significance was accepted at the level of p<.05. Result : Pediatric nurses had deficient knowledge related to children's pain on the whole and did not trust pain complaint and underestimated the pain. They were short of concrete practical knowledge about pain assessment and pharmacological and nonpharmacological intervention for children's pain. They were excessively concerned with side effect and addiction of analgesic drugs and had a negative view point on nonpharmacological pain intervention. About 50% of the subjects received education regarding children's pain while their undergraduate courses. The number of nurses who received education regarding children's pain while their undergraduate courses was found to be greater among the recently graduated nurses. In ward orientation and continuing education, only less than 10% of the nurses received education regarding children's pain. Nurses perceived their experienced educational content deficient; experienced educational content consisted of pain introduction, assessment and pharmacological and nonpharmacological intervention for children's pain while their undergraduate course, ward orientation and continuing education. There were no significant differences of the knowledge regarding children's pain of pediatric nurses according to level of education, duration of experience at clinic, pediatric clinic and presently working ward. Scores of the knowledge regarding children's pain of nurses at neonatal ward were significantly greater than those of nurses at pediatric intensive care unit. Scores of the knowledge regarding children's pain of pediatric nurses who received education during their undergraduate course were significantly greater than those who did not receive it during their undergraduate courses. Also scores of the knowledge regarding children's pain of pediatric nurses who received one kind of educational experience were significantly greater than those who had no educational experience. Conclusion : Pediatric nurses had deficient knowledge of children's pain and underestimated the pain of children. Also they were short of concrete practical knowledge on pain assessment and intervention for children's pain.

• Journal of the Korean Society of Costume
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• v.24
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• pp.15-28
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• 1995

This thesis focuses on the study of costume and ornaments of Shilla which had been severely affected by Uighur, and those of Uighur in Uighur self-governing district located in Shin Kang. East Turkestan, in Centrals Asia. This study aims to identifty the way of intergration of Uighur's costume and ornaments into Shilla, and orgins of Shill's costume and ornaments which had amix of internationl elelemnts thoursh cross exchanges, by comparing the differences between the two, and at the same time to clarify the pedigree of Korean costume and ornaments which are said to be udner a severe Chinese influence, by highlingting its uniqueness and originality . The result of the study demonstrates and originality of SHilla by melting foreign cultures into its own style in the process of accepting them. This means that the Shilla has recreated them in t도 form of simplification, and added naturalistic abstratness which is an element of Norther culture. The costume and ornaments are divided into coronets men's costuem, women's costume, and accessories 1. Coroncts A horse-riding man, and the costume type of 유고제 착유지체형 tell the Northern culture's influence on 백화수피기마인물채화담립 and patterns of a lotus flowr and arabesque show the 백화수피기마인물채색답립 has an influence of Buddhism with cluture of bordering countries of Western China , The origin of 뱍회수피제안형건(원정형, 방정형) lies in Northern cultures which can be found in ancient tombs of the Huns in noin-Ila , and stone caves of Jizil in Kochang. The wall paintings in Alexandropol, Murutuk and 돈황 No. 409 cave show that 초화형입식계금관 is under the influence of Northern culture, and Bezerkrick No, 25 cave and 회 번 in Kocho also show 수목녹각형입식관 is under the influence of Northern culture, with its origin in Novecherkaask. In this regard, the transformed coroncts of Shilla has shows a blended culture of Shilla with Nothern, Chinese, and Western cultures. 2. Men's Costume 반령포 derives from cultures of bordering countries of Western China centering around Uighur and Turkey. 연주문 in Uighur prince's costume and in Uighur paintings of Central Asia were reflected into the arts of Shilla in a direct way, and the motive of Uighur was deviatelly expressed at Shilla's arts in the form of simplicity , and naturalistic abstract paintings as in shown at 입수쌍조문 in tiles and brick. Along with this , 고착지체형 costume originates from Eurasia's Northern horseriding costumes as was shown in a golden man in B.C.4-5C which is now possessed by Kazakstan Republic Academy Archelogy Center Museum, and a golden figure from Skitai ancient caves, an the origin is carried away into wall paintings of Kizil No.14. cave in 8c and Astana's early period ancient tomb. No.6. 3. Women's Costume The hair styles of Shilla people are either 변발 or up -style with a lot of hair around it whose origin can be seen in Astana No.216 and No.187 caves of Kochang and Uighur's wall paintings of royal princess's hair style. Astana's middle period No. 206 and No.230 tombs reveal the its origin of 고착장군 while Astana early period No. 6 tomb shows that of 광유풍만형. 4. Accessories The earrings with small golden beads is seen at earring of figure holding a sword in wall painting of figure holding a sword in wall painting of Kizil in about 5 C. and those of a offering people in Sorchuk wall paintings. The earrings with small golden beads originates from a golden pendant of Shivargan, Afganistan, and golden pendants and other golden and metal accessories from Chrioba ancient tombs in Skiti Critia peninsula. Shilla's costume derives from the costume style of horse-ridding man, which proves the fact that Shilla people are horse-ridding peoplewith excellent horse-ridding techniques, and traditions. The people of Shilla are from horse-ridding people of local mounted momads in Northern part of Siberia steppe and this origin of Northern culture had been carried into Uighur in East Turkestan. At the same time , Shilla has a wealth and power since it was rich in gold and iron , thus producing lots of materials made of them. The results of this study emphasizes Shilla's identity and self-control by creating an independent an innovative heterogeneous culture since Shill's active exchanges with East Asia allowed it to accept the most civilized Uighur culture in East Turkestan among Altai languate which had frequent cross contacts with India and Europe.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.1
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• pp.21-30
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• 1985

The tension leg platform (TLP) is a kind of compliant structures, and is also a type of moored stable platform with a buoyancy exceeding the weight because of having tensioned vertical anchor cables. In this paper, among the various kinds of tension leg structures, Deep Oil Technology (DOT) TLP was analyzed because it has large-displacement portions of the immersed surface such as vertical corner pontoons and small-diameter elongated members such as cross-bracing. It also has results of hydraulic model tests, comparable with theorectical analysis. Because of the vertical axes of symmetry in the three vertical buoyant legs and because there are no larger horizontal buoyant members between these three vertical members, it was decided to develop a numerical algorithm which would predict the dynamic response of the DOT TLP using the previously developed numerical algorithm Floating Vessel Response Simulation (FVRS) for vertically axisymmetric bodies of revolution. In addition, a linearized hydroelastic Morison equation subroutine would be developed to account for the hydrodynamic pressure forces on the small member cross bracing. Interaction between the large buoyant members or small member cross bracings is considered to be negligible and is not included in the analysis. The dynamic response of the DOT TLP in the surge mode is compared with the results of the TLP algorithm for various combinations of diffraction and Morison forces and moments. The results which include the Morison equation are better than the results for diffraction only. This is because the vertically axisymmetric buoyant members are only marginally large enough to consider diffractions effects. The prototype TLP results are expected to be more inertially dominated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.115-123
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• 1990

The purpose of this study was to examine the uses of coal ash as a type of construction material. The methods of examination were chemical anlysis, soil laboratory test and the soil vibration test. Materials used were coal ash obtained as a by-product from 5 thermal power plants in Yongdong, Yongwol, Sochon(anthracite coal) and in Samchonpo and Honam (bituminous coal). Over 70% of the coal ash consisted of silica and alumina. The fly ash grain size showed a uniform distribution from fine-sand to silt, and that of the bottom ash showed from sand to gravel. The specific gravity and density of the coal ash were low. The long term strength increased gradually due to the self-setting property resulting from pozzolanic activity. The shear strength was higher than that of general soil. Cohesion and optimum moisture content of anthracite coal ash were higher than bituminous coal ash, whereas the maximum dry density was higher in bituminous coal ash. The coal ash dynamic Young's modulous curve range was similar to that of general soil. Of the results from the soil vibration test by car-running, the size relative acceleration level in the ash pond was higher than that of natural ground, but the damping ratio was lower than that of natural ground near the ash pond. The coal ash has more advantageous engineering properties than general soil with particles of the same size. For example, the California Bearing Ratio of the bottom ash at both Yongdong and Yongwol was 77~137%. Therefore we expect that if further study is done, coal ash can be used as a construction material when reclaiming seashore, construction embankments, road construction, making right-weight aggregate, or as a general construction material.

• Journal of Plant Biotechnology
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• v.38 no.4
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• pp.285-292
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• 2011

In plants, heteroblasty reflects the morphological adaptation during leaf development according to the external environmental condition and affects the final shape and size of organ. Among parameters displaying heteroblasty, leaf index is an important and typical one to represent the shape and size of simple leaves. Leaf index factor is eventually determined by cell proliferation and cell expansion in leaf blades. Although several regulators and their mechanisms controlling the cell division and cell expansion in leaf development have been studied, it does not fully provide a blueprint of organ formation and morphogenesis during environmental changes. To investigate genes and their mechanisms controlling leaf index during leaf development, we carried out molecular-genetic and physiological experiments using an Arabidopsis mutant. In this study, we identified macrophylla (mac) which had enlarged leaves. In detail, the mac mutant showed alteration in leaf index and cell expansion in direction of width and length, resulting in not only modification of leaf shape but also disruption of heteroblasty. Molecular-genetic studies indicated that mac mutant had point mutation in ROTUDIFOLIA3 (ROT3) gene involved in brassinosteroid biosynthesis and was an allele of rot3-1 mutant. We named it mac/rot3-5 mutant. The expression of ROT3 gene was controlled by negative feedback inhibition by the treatment of brassinosteroid hormone, suggesting that ROT3 gene was involved in brassinosteroid biosynthesis. In dark condition, in addition, the expression of ROT3 gene was up-regulated and mac/rot3-5 mutant showed lower response, compare to wild type in petiole elongation. This study suggests that ROT3 gene has an important role in control of leaf index during leaf expansion process for proper environmental adaptation, such as shade avoidance syndrome, via the control of brassinosteroid biosynthesis.

• The Korean Journal of Petroleum Geology
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• v.6 no.1_2 s.7
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• pp.8-19
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• 1998

In the Sinri area located at the mid western boundary of the Jinan basin, the Manduksan Formation which mainly consists of coarse sandstone narrowly intercalated with shale and the alternation of sand and shale and the Dalgil Formation mainly of shale are distributed. It consists of four lithofacies, such as coarse sandstone, interbedded sandstone/shale, shale and volcanic rock lithofacies. All sediments are interpreted to be deposited by turbidity currents and free fallouts in a lacustrine basin. In these rocks many penecontemporaneous defomation structures are observed such as fold and thrust fault at large scale, and swelling, boudin structure, flame structure, load structure, ptygmatic fold and convolute bedding at small scale. All these structures are developed between upper and lower undisturbed sedimentary strata. Two large folds are similar folds, but lower one gradually developed into concentric shape. The swelling structures by convergence of the sediments are observed in the hinge area and the boudin structures are developed in the limb. The thrust faults including minor folds and sandstone lobes show duplex structure with asymmetric and kink fold on and below in front of the detached sandstone layer. Development of the swellings, boudins and lobes indicates the flexbility of the sediments during deformational episodes. The folds and thrust faults rarely contain fractures relative their scales and lithologies. This feature also indicates the retrievability of sediments during deformation. At the flanks of the thrust faults the normal faults are formed contemporaneously. The deformation structures at small scale such as flame structures, load structures, ptygmatic folds and convolute beddings are syndepositional and penecontemporaneous, which show the effects of tectonic movements. All these deformed sedimentary structures of the Sinri area suggest the continuing tectonic movements during and/or after deposition.