• Title/Summary/Keyword: Basic Concept

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Influences of direction for hexagonal-structure arrays of lens patterns on structural, optical, and electrical properties of InGaN/GaN MQW LEDs

  • Lee, Kwang-Jae;Kim, Hyun-June;Park, Dong-Woo;Jo, Byoung-Gu;Oh, Hye-Min;Hwang, Jeong-Woo;Kim, Jin-Soo;Lee, Jin-Hong;Leem, Jae-Young
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.153-153
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    • 2010
  • Recently, to develop GaN-based light-emitting diodes (LEDs) with better performances, various approaches have been suggested by many research groups. In particular, using the patterned sapphire substrate technique has shown the improvement in both internal quantum efficiency and light extraction properties of GaN-based LEDs. In this paper, we discuss the influences of the direction of the hexagonal-structure arrays of lens-shaped patterns (HSAPs) formed on sapphire substrates on the crystal, optical, and electrical properties of InGaN/GaN multi-quantum-well (MQW) LEDs. The basic direction of the HSAPs is normal (HSAPN) with respect to the primary flat zone of a c-plane sapphire substrate. Another HSAP tilted by 30o (HSAP30) from the HSAPN structure was used to investigate the effects of the pattern direction. The full width at half maximums (FWHMs) of the double-crystal x-ray diffraction (DCXRD) spectrum for the (0002) and (1-102) planes of the HSAPN are 320.4 and 381.6 arcsecs., respectively, which are relatively narrower compared to those of the HSP30. The photoluminescence intensity for the HSAPN structure was ~1.2 times stronger than that for the HSAP30. From the electroluminescence (EL) measurements, the intensity for both structures are almost similar. In addition, the effects of the area of the individual lens pattern consisting of the hexagonal-structure arrays are discussed using the concept of the planar area fraction (PAF) defined as the following equation; PAF = [1-(patterns area/total unit areas)] For the relatively small PAF region up to 0.494, the influences of the HSAP direction on the LED characteristics were significant. However, the direction effects of the HSAP became small with increasing the PAF.

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Establishing Diagnosis Systems for Impaired Stream Ecosystem using Stream/River Ecosystem Survey and Health Assessment (수생태계 현황 조사 및 건강성 평가결과를 활용한 수생태계 훼손원인 진단체계 구축)

  • Lee, Jong-Won;Lee, Sang-Woo;Hwang, Soon-Jin;Jang, Min-Ho;Won, Doo-Hee;An, Kyung-Jin;Park, Hye-Jin;Lee, Junga
    • Korean Journal of Ecology and Environment
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    • v.53 no.1
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    • pp.1-10
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    • 2020
  • The Stream/River Ecosystem Survey and Health Assessment has been carried out regarding the ecological health of the streams by the Ministry of Environment (MOE), South Korea. However, the sources of impairment of the stream ecosystem and the interactions between the sources, stressors, and the responses of impaired streams have not been taken into consideration. The purpose of this study is to propose the establishment of diagnosis systems for the impaired stream ecosystem because of the need to incorporate the same in the making of the policy to enable the recovery and improvement of the health of the impaired streams or river ecosystem. First, we define the concept of a diagnosis of the impaired stream or river ecosystem through a literature review. Second, through case studies [e.g., US CADDIS (Causal Analysis/Diagnosis Decision Information System), AUS. Eco Evidence, EU WFD (Water Framework Directive)], we try to develop the diagnosis system for the making of policy. In this study, the diagnosis system that is proposed consists of eight steps including the basic data collection, detecting or suspecting impairment, defining the impaired stream reach, identifying the biological impaired cases and listing the candidate causes, illustrating the interactive conceptual diagrams between stressors and responses, investigating the stressors-responses in the field, verifying causes and identifying the probable causes of the impaired cases, and summarizing and proposing the restoration of the streams. The results of this study will support and enable efficient decision-making for sustainable stream restoration and management based on the diagnosis of the probable causes for the impaired complex and the diverse stream ecosystem.

An Exploratory Investigation on Visual Cues for Emotional Indexing of Image (이미지 감정색인을 위한 시각적 요인 분석에 관한 탐색적 연구)

  • Chung, SunYoung;Chung, EunKyung
    • Journal of the Korean Society for Library and Information Science
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    • v.48 no.1
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    • pp.53-73
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    • 2014
  • Given that emotion-based computing environment has grown recently, it is necessary to focus on emotional access and use of multimedia resources including images. The purpose of this study aims to identify the visual cues for emotion in images. In order to achieve it, this study selected five basic emotions such as love, happiness, sadness, fear, and anger and interviewed twenty participants to demonstrate the visual cues for emotions. A total of 620 visual cues mentioned by participants were collected from the interview results and coded according to five categories and 18 sub-categories for visual cues. Findings of this study showed that facial expressions, actions / behaviors, and syntactic features were found to be significant in terms of perceiving a specific emotion of the image. An individual emotion from visual cues demonstrated distinctive characteristics. The emotion of love showed a higher relation with visual cues such as actions and behaviors, and the happy emotion is substantially related to facial expressions. In addition, the sad emotion was found to be perceived primarily through actions and behaviors and the fear emotion is perceived considerably through facial expressions. The anger emotion is highly related to syntactic features such as lines, shapes, and sizes. Findings of this study implicated that emotional indexing could be effective when content-based features were considered in combination with concept-based features.

An Analysis on the Word Problems of the Addition and Subtraction in Mathematics Text Books and its Students' Responses (수학 교과서의 덧셈과 뺄셈 문장제와 그에 대한 학생들의 반응 분석)

  • Lee, Dae-Hyun
    • School Mathematics
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    • v.11 no.3
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    • pp.479-496
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    • 2009
  • Some children can construct a basic concept of addition and subtraction during the preschool years. Children start to experience mathematics via numbers and their of operations and contact with various contexts of addition and subtraction. In special, word problems reflect mathematics which is appliable to real life. In this paper, I analyse the types of word problems in text book and its students' responses. First, I analyse the types of addition word problems which consist of change add-into situations and part-part-whole situations. Second, I analyse the types of subtraction word problems which consist of change take-away situations, compare situations and equalize situations. Third, I analyse the students' responses by the types of word problems in addition and subtraction. And 115 2nd grade elementary school students participated in this survey. The following results have been drawn from this study. First, the proposition of word problems of part-part-whole situations is higher than that of change add-into situations and the proposition of word problems of take-away situations is higher than that of compare situations and equalize situations. According to the analysis about students' responses, It is no difference between change add-into situations and part-part-whole situations. But the proposition of word problems of take-away situations is higher than that of compare situations and equalize situations. This results from word problems which contain unnecessary information in problem. So, we have to present the various word problems to students.

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Botulinum Toxin A Treatment for Cervical Dystonia Resulting in Endoscopic Thyroidectomy: A Case Report (내시경 갑상샘 절제술 후 발생한 경부 근긴장이상증의 보툴리늄 A 독소를 이용한 치료: 증례보고)

  • Oh, Hwa-Young;Choi, Hwan-Jun;Nam, Doo-Hyun;Kim, Jun-Hyuk;Lee, Young-Man
    • Archives of Plastic Surgery
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    • v.38 no.2
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    • pp.207-211
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    • 2011
  • Purpose: Surgery for thyroid gland requires skin incisions that can result in postsurgical neck scar. To overcome this, many surgeons performed a endoscopic thyroidectomy. But, this approach had a some problems. One of postoperative problems, iatrogenic cervical dystonia (CD) may occur. At common, CD is defined as a syndrome characterized by prolonged muscle contraction causing twisting, repetitive movements or abnormal posture. Botulinum toxin A (BTA, Botox$^{(R)}$, Allergan, Irvine, CA, USA) is well known treatment agent in the treatment of CD. So, the authors applied BTA injection in rare case with iatrogenic CD resulting in endoscopic thyroidectomy. Methods: A 43-year-old female had endoscopic subtotal thyroidectomy operation 3 years ago. She had symptoms such as progressive cervical pain, abnormal neck posture, depression, and sleep difficulty. About 1 year later, the patient who had previous myomectomy of the clavicular head of sternocleidomastoid muscle, however, symptoms were not improved. And then the patient received BTA therapy in our department. The 2 units per 0.1 mL solution was administered in a 1 mL tuberculin syringe. Results: The dose of BTA used in the patient was 36 units for vertical platysmal bands, superficially, and 10 units for ipsilateral sternocleidomastoid muscle, intramuscularly. After 2 weeks, additional the dose of BTA used in the patient was 5 points for remained scar bands, superficially. Complications related to injection such as significant swallowing difficulties, neck muscle weakness, or sensory change were not observed. In 9 months follow-up, the patient maintained a good result from the method of BTA injection alone. Conclusion: The basic concept is selective denervation for the hyperactive individual muscles and scar bands. We conclude that BTA is an effective and safe treatment for CD despite the iatrogenic and complex presentation of this complication.

Philological Study on The Mental Cultivation (정신양생(精神養生)에 관한 문헌적(文獻的) 고찰(考察))

  • Keum Jong-Chul;Soh Kyung-Sun;Kim Kwang-Ho
    • Journal of Society of Preventive Korean Medicine
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    • v.1 no.1
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    • pp.59-75
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    • 1997
  • After examining the viewpoints of the mental cultivation of The yellow Emperor's Internal Bible(內徑), from the viewpoints of The yellow Emperor's Internal Bible, I studied the principles and methods of the mental cultivation(精神養生) which the Taoism School, the Confusian School and the past physicians proposed. And I studied the methods of mental cultivation of the child, the woman and the old by the differences of ages and sex. At the subject of health preservation(養生學) on the basis of concept of relevant adaptation of man to nature(天人相應思想), the mental cultivation(精神養生) was regard more important than the body cultivation(肉體養生) and it was considered that the success of health preservation depended on the state of mind. the basic principles of the mental cultivation is achivement of the mental internal keeping(精神內守) through the state of peace and tranquility without avarice and wild fancy(恬憺虛無). The ways of mental cultivation of the Taoism School, the Confusian School and the past physicians were in the category of The yellow Emperor's Internal Bible. 4. In the previous Jin dynasty(先秦時代), the important theoretical bases and practices to mental cultivation were made. In the Han dynasty(漢時代), the physicians attached importance to mental treaments. During the time from Sui dynasty to Tang Dynasty(隋唐時代), the mental cultivation was made perfect theoretically. During the Period from Song dynasty to Yuan Dynasty(宋元時代), Many methods of mental cultivation were newly created. During the Ming and the Qing Dynasties(明淸時代), the theory of health preservation and the methods of mental treaments were embodied. 5. Studying the mental cultivation by the differences of ages, the childhood(小兒期) is the spring of life. So the mental cultivation of this period put importance to the cultivation of Sh ng(養生). And the youth(靑年期) is the summer of life. So the mental cultivation of this period pill importance to the cultivation of Ch'ang(養長). And the middle age(中年期) is the autumn of life. So the mental cultivation of this period put imporance to the cultivation of Shou(養收). And the old age(老年期) is the winter of life. So the mental cultivation of this period put importance to the cultivation of Tsang(養藏). Studying the mental cultivation by the differences of sex, the man must do the mental cultivation through the dynamic nature(性情) of Yang(陽) and the woman must do the mental cultivation through the static nature of Yin(陰).

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A Basic Study for Wind Energy of Building Cladding using Computational Fluid Dynamics (CFD를 이용하여 건물 외피의 바람에너지에 관한 적용연구)

  • Chung, Yung-Bea
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.39.2-39.2
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    • 2011
  • The new and renewable energy today has a great interest in all countries around the world. In special it has need more limit of the fossil fuel that needs of low carbon emission among the social necessary conditions. Recently, the high-rise building demand the structural safety, the economic feasibility and the functional design. The high-rise building spends enormous energy and it satisfied the design in solving energy requirements. The requirements of energy for the building depends on the partly form wind energy due to the cladding of the building that came from the surroundings of the high-rise building. In this study of the wind energy, the cladding of the building was assessed a tentative study. The wind energy obtains from several small wind powers that came from the building or the surrounding of the building. In making a cladding the wind energy forms with wind pressure by means of energy transformation methods. The assessment for the building cladding was surrounded of wind speed and wind pressure that was carried out as a result of numerical simulation of wind environment and wind pressure which is coefficient around the high-rise building with the computational fluid dynamics. In case of the obtained wind energy from the pressure of the building cladding was estimated by the simulation of CFD of the building. The wind energy at this case was calculated by energy transform methods: the wind pressure coefficients were obtained from the simulated model for wind environment using CFD as follow. The concept for the factor of $E_f$ was suggested in this study. $$C_p=\frac{P_{surface}}{0.5{\rho}V^{2ref}}$$ $$E_c=C_p{\cdot}E_f$$ Where $C_p$ is wind pressure coefficient from CFD, $E_f$ means energy transformation parameter from the principle of the conservation of energy and $E_c$ means energy from the building cladding. The other wind energy that is $E_p$ was assessed by wind power on the building or building surroundings. In this case the small wind power system was carried out for wind energy on the place with the building and it was simulated by computational fluid dynamics. Therefore the total wind energy in the building was calculated as the follows. $$E=E_c+E_p$$ The energy transformation, which is $E_f$ will need more research and estimation for various wind situation of the building. It is necessary for the assessment to make a comparative study about the wind tunnel test or full scale test.

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Analysis on Spatiotemporal Variability of Erosion and Deposition Using a Distributed Hydrologic Model (분포형 수문모형을 이용한 침식 및 퇴적의 시.공간 변동성 분석)

  • Lee, Gi-Ha;Yu, Wan-Sik;Jang, Chang-Lae;Jung, Kwan-Sue
    • Journal of Korea Water Resources Association
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    • v.43 no.11
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    • pp.995-1009
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    • 2010
  • Accelerated soil erosion due to extreme climate change, such as increased rainfall intensity, and human-induced environmental changes, is a widely recognized problem. Existing soil erosion models are generally based on the gross erosion concept to compute annual upland soil loss in tons per acre per year. However, such models are not suitable for event-based simulations of erosion and deposition in time and space. Recent advances in computer geographic information system (GIS) technologies have allowed hydrologists to develop physically based models, and the trend in erosion prediction is towards process-based models, instead of conceptually lumped models. This study aims to propose an effective and robust distributed rainfall-sediment yield-runoff model consisting of basic element modules: a rainfall-runoff module based on the kinematic wave method for subsurface and surface flow, and a runoff-sediment yield-runoff model based on the unit stream power method. The model was tested on the Cheoncheon catchment, upstream of the Yongdam dam using hydrological data for three extreme flood events due to typhoons. The model provided acceptable simulation results with respect to both discharge and sediment discharge even though the simulated sedigraphs were underestimated, compared to observations. The spatial distribution of erosion and deposition demonstrated that eroded sediment loads were deposited in the cells along the channel network, which have a short overland flow length and a gentle local slope while the erosion rate increased as rainfall became larger. Additionally, spatially heterogeneous rainfall intensity, dependant on Thiessen polygons, led to spatially-distinct erosion and deposition patterns.

A Framework of Interpretating (de)Centralized Landscape : an Interaction of Power, Subjectivity, and Performativity ((탈)중심화 경관의 해석을 위한 틀 : 권력, 주체성, 수행성)

  • Park, Kyu-Taeg;Ha, Yong-Sam;Bae, Yoon-Gi
    • Journal of the Korean association of regional geographers
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    • v.16 no.4
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    • pp.355-368
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    • 2010
  • This study is to make a framework of newly interpretating the dynamic change of regional or local landscape rapidly occurred after the establishment of the nation state and capitalistic system. The basic concepts of making an interpretative framework are power, subjectivity, and performativity. The framework of closely interrelating the three concepts developed in the near future will be applied to the interpretation of variety of (de)centralized landscapes in regions or locals. A centralized political power under the nation state has destroyed or marginalized the historically developed landscapes, traditional culture, and subjects' values in regions or locals by the political implementation of the nation state, the establishment of national identity, a centralized economic development, and so on. The landscapes produced by the political power of the nation state can take a role as a cause of conflicts in regions or locals in terms of a historical perspective. Landscapes are being made by various subjects, and the produced landscapes also positively or negatively will influence the emotion, cognition, and behavior of the subjects particularly in a performative perspective. The dynamics interrelation between subjects and landscapes has been disguised or marginalized by reason/rationality, totality/collectivity, the separation between reason and emotion mainly made by modernism, the nation state, a capitalistic system. The interrelation between landscapes and subjects is especially emphasized on people's resistibility and creativity. Lastly, landscape is not a concept given as a priori or (re)presented objectively. It is not also a material or an object independently existed from a subject's emotion and cognition. It should be interpreted through a performative relation with subjects. Performativity will take an active role of combining the materiality of landscape, power, and subjectivity. It is also important to understand the active role of landscapes.

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The Study on the Internet-based Virtual Apartment Remodeling and Auto Estimation Simulator (인터넷 기반의 아파트 리모델링 및 자동 내역산출을 위한 시뮬레이터 디자인 연구)

  • 서재은;김성곤
    • Archives of design research
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    • v.15 no.1
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    • pp.191-202
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    • 2002
  • As family types have been diverse, patterns of living and living space became diverse as much as users are. Therefore, it is needed to provide various remodeled design of living space corresponding to changes of users'living patterns, and to provide these remodeling process to users directly on the web. In this paper, use scenario for the Internet-based Virtual Apartment Remodeling Simulator is researched as an export system to remodel space in accordance with users diverse lifestyle paradigm and the website is developed. The study consists of four parts. First, the general concept of remodeling, including the range and types of remodeling, are defined, and the misleading terms in this field are reviewed and organized by secondary research Second, fixed factors and variable factors are differentiated in the complex building for residence and business that was decided as a basic building type in this study. Third, there needed a database for consulting, final material, pre-estimation real estimation for simulation of remodeling. This database was introduced along with floor plan and elevation. Finally, the remodeling simulator is presented by the case study developed on the web. The system structure and use scenario are also presented. In order to present and inspect design alternatives, prototype was produced. The Final simulator was enhanced by defeating problems regarding interface efficiency and missing information of existing online site.

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