• Title/Summary/Keyword: article 30

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Spectroscopic analysis of near colorless/pink/blue synthetic diamonds from Lightbox ('라이트박스' 무색/핑크/블루 합성 다이아몬드의 분광학적 분석)

  • Choi, Hyunmin;Kim, Youngchool;Lee, Minkyoung;Seok, Jeongwon
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.1
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    • pp.21-26
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    • 2020
  • This article reports the result on the spectroscopic analysis of the three Lightbox CVD-grown diamonds. Lightbox Jewelry, a De Beers company, has begun selling CVD laboratory-grown diamonds since September 2018. Recently, we had the opportunity to examine three Lightbox's pendant necklaces. The 0.25 ct, 0.25 ct, and 0.26 ct round brilliant were graded as "H" near colorless, Fancy Vivid orangy pink, and Fancy Vivid blue with cut grades of excellent, respectively. The laser-inscribed Lightbox logo under the table, large enough to be easily visible with a microscope. Based on the spectroscopic techniques, for near colorless sample was not subjected to post-growth HPHT processing to improve its color. For pink sample, optical centers at H3, 3H, 594 nm, NV, and GR1 were recorded. It was speculated that the pink sample have been received irradiation and annealing. In addition, the blue CVD synthetic sample was concluded to be irradiated without annealing.

Mechanical Properties of Graphene-based Polyimide Composites (그래핀 기반 폴리이미드 복합재의 기계적 물성)

  • Nam, Ki-Ho;Yu, Jaesang;You, Nam-Ho;Han, Haksoo;Ku, Bon-Cheol
    • Composites Research
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    • v.30 no.5
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    • pp.261-266
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    • 2017
  • Polymer composites are materials in which various fillers are uniformly dispersed on the basis of organic resin. They have excellent processability and diversity for industrial products. Recently, as carbon nanomaterials are developed, there is a great deal of effort to use them as reinforcing fillers to fabricate high performance composite materials. In order to transfer the inherent properties of fillers into composite materials as much as possible, the good dispersion and orientation of fillers, and favorable interfacial interaction between fillers and matrix are considered to be very important. In this review article, we intent to derive and explain the relationship between surface chemical structure of fillers and physical properties of composites as a strategy of high strength and toughness of graphenebased polyimide composites.

The Background and Current Research Applied to Development of Korean Cosmetics Based on Traditional Asian Medicine (한국 한방화장품 발달 배경 및 연구 현황)

  • Cho, Gayoung;Park, Hyomin;Choi, Sowoong;Kwon, Leekyung;Cho, Sunga;Suh, Byungfhy;Kim, Namil
    • The Journal of Korean Medical History
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    • v.30 no.2
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    • pp.63-71
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    • 2017
  • Traditional Asian medicine has an extensive evidence base built upon thousands of years of experience within Asia, of curing various diseases. Only recently, within the past two centuries, have modern medical scientists developed interest in traditional Asian medicine. Asian Medicine seems to be regarded only as an adjunctive medicine and viewed as alargely un-proven alternative medicine to complement western medicine, used in some cases to establish a new paradigm of "integrative medicine". This article reviews how Korean herbal cosmetics emerged by applying traditional Asian medicine to the science of cosmetics. The characteristics of Korean herbal cosmetics are examined through examples of history, concepts and traditions. With the advancements in biotechnology, studies are now being conducted on the dermatological effects and processing methods of herbal ingredients, including ginseng. The authors explain the current research on the identification on the active ingredients of herbs, extraction methods, and bio-processing of ingredients to improve the biological efficacies of herbs on the skin. A summary of studies focused on modern reinterpretations of ageing theories, such as 'Seven year aging cycle', are provided. In conclusion, the development of Korean cosmetics products are based on the accumulated knowledge of thousands of years of experience including; 1) practical heritage of traditional Asian medicines such as Donguibogam; 2) excellent medicinal plants, such as ginseng, which are native to Korea; and 3) innovative attempts to modernize materials, processes, and principles.

Research Trends on the 'Convergence of Chinese and Western Medicine' in China, and Lessons Learned (중국의 중서의회통파에 대한 연구동향과 한국 한의계가 얻을 수 있는 교훈)

  • Lee, Choong-Yeol
    • The Journal of Korean Medical History
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    • v.30 no.2
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    • pp.13-31
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    • 2017
  • This study investigates research trends on the Convergence of Chinese and Western Medicine (中西醫匯通, CCWM), by first defining the concepts and the scope of this emerging field, identifying different types of convergence, and suggesting methods to evaluate the process. The author investigates the relationship of CCWM to the Self-Strengthening Movement and the doctrine of Zhongtixiyong (中體西用). Lessons that Korean Medicine (KM) can learn from this approachto help establish relationship between Korean and Western Medicine, are investigated. Proponents of CCWM suggest different types of convergence such as Zhongzhongcanxi (衷中參西), Zhongxizhezhong (中西折衷), and ZhongyiKexuehua (中醫科學化), to accommodate the change in the power dynamics between Chinese and Western medicines. The rigid dual medical system in Korea significantly hinders the potential for convergence. The current system is based on the relativistic model in which the scope of practice for the KM doctor and the Western Medicine doctor are mutually exclusive. Philosophically, the convergence of East-West medicine can be supported by pluralism and monism, while relativism sees it as impossible. A conservative pluralistic model might consider Bogu (補救) of Eastern Medicine, while a more progressive pluralistic model might build a New Medicine which combines the knowledge and techniques of Eastern and Western medicines. An example of monistic model is CAM (Complementary and Alternative Medicine), which aims to scientifically verify the efficacy and safety of the Eastern therapeutic practices and integrate them into Western medicine. This article proposes that as communication and fusion between medical disciplines are essential virtues of contemporary scholarly development, a change that enables the convergence of East-West medicine is needed.

A Study on the Change Detection of Multi-temporal Data - A Case Study on the Urban Fringe in Daegu Metropolitan City - (대도시 주변지역의 토지이용변화 - 대구광역시를 중심으로 -)

  • 박인환;장갑수
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.1
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    • pp.1-10
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    • 2002
  • The purpose of this article is to examine land use change in the fringe area of a metropolitan city through multi-temporal data analysis. Change detection has been regarded as one of the most important applications for utilization of remotely sensed imageries. Conventionally, two images were used for change detection, and Arithmetic calculators were generally used on the process. Meanwhile, multi-temporal change detection for a large number of images has been carried out. In this paper, a digital land-use map and three Landsat TM data were utilized for the multi-temporal change detection Each urban area map was extracted as a base map on the process of multi-temporal change detection. Each urban area map was converted to bit image by using boolean logic. Various urban change types could be obtained by stacking the urban area maps derived from the multi-temporal data using Geographic Information System(GIS). Urban change type map was created by using the process of piling up the bit images. Then the urban change type map was compared with each land cover map for the change detection. Dalseo-gu of Daegu city and Hwawon-eup of Dalsung-gun, the fringe area of Daegu Metropolitan city, were selected for the test area of this multi-temporal change detection method. The districts are adjacent to each other. Dalseo-gu has been developed for 30 yeais and so a large area of paddy land has been changed into a built-up area. Hwawon-eup, near by Dalseo-gu, has been influenced by the urbanization of Dalseo-gu. From 1972 to 1999, 3,507.9ha of agricultural area has been changed into other land uses, while 72.7ha of forest area has been altered. This agricultural area was designated as a 'Semi-agricultural area'by the National landuse Management Law. And it was easy for the preserved area to be changed into a built-up area once it would be included as urban area. Finally, the method of treatment and management of the preserved area needs to be changed to prevent the destruction of paddy land by urban sprawl on the urban fringe.

Recovery of Polyethylene Telephthalate Monomer over Cu or Mn/γ-Al2O3 Catalysts (Cu, Mn/γ-Al2O3 촉매상에서 polyethylene telephthalate 단량체의 회수 연구)

  • Sim, Jae-Wook;Kim, Seung-Soo
    • Applied Chemistry for Engineering
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    • v.28 no.4
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    • pp.485-489
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    • 2017
  • Polyethylene terephthalate (PET) has been widely applied in polymers and packaging industries to produce synthetic fibers, films, drink bottles or food containers. Therefore, it has become one of the major plastic wastes. In this article, glycolysis known as one of the main methods in PET chemical recycling was investigated using a glycol to break down the polymer into a monomer. Glycolysis of PET and ethylene glycol was performed in a micro-tubing reactor under various conditions. The effect of glycolysis conditions on the product distribution was investigated at experimental conditions of the EG/PET ratio of 1~4, the reaction time of 15~90 min and the reaction temperature of $250{\sim}325^{\circ}C$ with Mn and Cu catalysts. The highest yield of bis (2-hydroxyethyl) terephthalate monomer (BHET) was obtained as 89.46 wt% under the condition of the reaction temperature of $300^{\circ}C$ and the time of 30 min using 10 wt% $Cu/{\gamma}-Al_2O_3$ catalyst, with the PET and ethylene glycol ratio of 1 : 2.

Examining on the Relationship Between Interdisciplinarity and Research Impact with Analyzing the Journals of Library and Information Science Field (학제성과 연구 영향력의 상관관계에 관한 연구: 문헌정보학 분야 학술지를 대상으로)

  • Park, SoYoon;Chung, EunKyung
    • Journal of the Korean Society for information Management
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    • v.30 no.4
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    • pp.7-29
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    • 2013
  • As interdisciplinary research has been dominant in various fields, the purpose of this study is to analyze the relationship between interdisciplinarity and research impact in the field of Library and Information Science. For a data set, ten journals ranked as the top of 2011 JCR's in terms of JIF (Journal Impact Factor) were selected. The citation data of 1,873 articles from the ten journals were collected from the WoS during the period from 2006 to 2010. In order to achieve the purpose of this study, as network analysis was conducted to investigate the interdisciplinarity of LIS field, interdisciplinarity indicators, and research impact factors were statistically analyzed. The findings of this study confirmed the interdisciplinary knowledge structure of the LIS field as previous studies identified. More importantly, this study demonstrated that a positive correlation existed between interdisciplinarity represented as betweenness centrality and research impact.

UTILITY OF DIGITAL COVERING THEORY

  • Han, Sang-Eon;Lee, Sik
    • Honam Mathematical Journal
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    • v.36 no.3
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    • pp.695-706
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    • 2014
  • Various properties of digital covering spaces have been substantially used in studying digital homotopic properties of digital images. In particular, these are so related to the study of a digital fundamental group, a classification of digital images, an automorphism group of a digital covering space and so forth. The goal of the present paper, as a survey article, to speak out utility of digital covering theory. Besides, the present paper recalls that the papers [1, 4, 30] took their own approaches into the study of a digital fundamental group. For instance, they consider the digital fundamental group of the special digital image (X, 4), where X := $SC^{2,8}_4$ which is a simple closed 4-curve with eight elements in $Z^2$, as a group which is isomorphic to an infinite cyclic group such as (Z, +). In spite of this approach, they could not propose any digital topological tools to get the result. Namely, the papers [4, 30] consider a simple closed 4 or 8-curve to be a kind of simple closed curve from the viewpoint of a Hausdorff topological structure, i.e. a continuous analogue induced by an algebraic topological approach. However, in digital topology we need to develop a digital topological tool to calculate a digital fundamental group of a given digital space. Finally, the paper [9] firstly developed the notion of a digital covering space and further, the advanced and simplified version was proposed in [21]. Thus the present paper refers the history and the process of calculating a digital fundamental group by using various tools and some utilities of digital covering spaces. Furthermore, we deal with some parts of the preprint [11] which were not published in a journal (see Theorems 4.3 and 4.4). Finally, the paper suggests an efficient process of the calculation of digital fundamental groups of digital images.

Influencing factor on the prognosis of arthrocentesis

  • Kim, Yoon Ho;Jeong, Tae Min;Pang, Kang Mi;Song, Seung Il
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.40 no.4
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    • pp.155-159
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    • 2014
  • Objectives: The purpose of this article is to evaluate factors influencing prognosis of arthrocentesis in patients with temporomandibular joint (TMJ) disorder. Materials and Methods: The subjects included 145 patients treated with arthrocentesis at the Dental Center of Ajou University Hospital from 2011 to 2013 for the purpose of recovering mouth opening limitation (MOL) and pain relief. Prognosis of arthrocentesis was evaluated 1 month after the operation. Improvement on MOL was defined as an increase from below 30 mm (MOL ${\leq}30mm$) to above 40 mm (MOL ${\geq}40mm$), and pain relief was defined as when a group with TMJ pain with a visual analog scale (VAS) score of 4 or more (VAS ${\geq}4$) decreased to a score of 3 or more. The success of arthrocentesis was determined when either mouth opening improved or pain relief was fulfilled. To determine the factors influencing the success of arthrocentesis, the patients were classified by age, gender, diagnosis group (the anterior disc displacement without reduction group, the anterior disc displacement with reduction group, or other TMJ disorders group), time of onset and oral habits (clenching, bruxism) to investigate the correlations between these factors and prognosis. Results: One hundred twenty out of 145 patients who underwent arthrocentesis (83.4%) were found to be successful. Among the influencing factors mentioned above, age, diagnosis and time of onset had no statistically significant correlation with the success of arthrocentesis. However, a group of patients in their fifties showed a lower success rate (ANOVA P=0.053) and the success rate of the group with oral habits was 71% (Pearson's chi-square test P=0.035). Conclusion: From this study, we find that factors influencing the success of arthrocentesis include age and oral habits. We also conclude that arthrocentesis is effective in treating mouth opening symptoms and for pain relief.

Immediately loaded dental implants with fixed prostheses using a computer-guided surgery in a mental retardation patient: a case report (정신지체장애환자에서 Computer-Guided Surgery를 이용한 임플란트 식립 및 즉시 보철물 장착: 증례보고)

  • Han, Se-Jin
    • Journal of Dental Rehabilitation and Applied Science
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    • v.30 no.3
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    • pp.246-252
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    • 2014
  • $Br{\aa}nemark^{\prime}s$ original protocol required 4 to 6 months for implant osseointegration before placement of the definitive prosthesis. Although this approach gave very predictable results, it had certain drawbacks. The main disadvantages of this approach were prolonged treatment time, two surgical procedures, placement of a removable prosthesis that required modifications during the course of treatment, and a greater number of appointments. Immediate implant loading is a viable treatment method for selected cases. One of the greatest advantages of this method is the virtual surgery, which precedes the actual clinical treatment and eliminates any need for last minute decisions. The actual surgery time is decreased, since all steps are predetermined. These advantages aren't only more useful for normal patients but also for the mental retardation patients whose cooperation is difficult. This article presents a clinical approach made possible due to the guided implant surgery and CAD/CAM technique.