• 제목/요약/키워드: observation gap

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Photonic Band Gaps for Surface Plasmon Modes in Dielectric Gratings on a Flat Metal Surface

  • Song, Seok-Ho;Yoon, Jae-Woong;Lee, Gwan-Su;Oh, Cha-Hwan;Kim, Pill-Soo
    • Journal of the Optical Society of Korea
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    • v.6 no.3
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    • pp.76-82
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    • 2002
  • For dielectric gratings on a flat metal surface, photonic band gaps created by Brags scattering of surface plasmon polaritons are observed. The observation result that directly images this gap is compared with that predicted by a numerical model based on a plane wave expansion. Consistency between the experimental and numerical results is also confirmed by comparison with the well-known calculation method of diffraction, the rigorous coupled wave analysis method.

The characteristic study of amorphous chalcogenide As-Ge-Se-S thin film for photonic crystal application (포토닉 크리스탈 응용을 위한 비정질 칼코게나이드 As-Ge-Se-S 박막의 특성 연구)

  • Nam, Ki-Hyeon;Ju, Long-Yun;Choi, Hyuk;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.77-78
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    • 2007
  • In this paper, we suppose that the 1-dimensional photonic crystal using holography lithography. We used Ag doped amorphous AsGeSeS which belongs in the chalcogenide materials have sensitive photoluminescence property. The purpose of this experiment is the process to complete 3-D photonic crystal after making 2-D photonic crystal. The lattice formation was made an observation by irradiating He-Ne laser with the AsGeSeS film leaned obliquely. Then, by measuring formed diffraction beam, the diffraction lattice was calculated.

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UTIS Vitalization Countermeasures Using Traffic Information Use Satisfaction Rate Model (교통정보 이용 만족도 모형을 활용한 UTIS 활성화 대책)

  • Jang, Seok Yong;Jung, Hun Young;Ko, Sang Seon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.2D
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    • pp.199-207
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    • 2009
  • We tried to show the course of UTIS vitalization, promoting to introduce as part of the advanced traveler information system through analysis using traffic information gap model of service and structural equation modeling being used by drivers. The summary of the research is as follows. 1. We could find out the service matters needed to improve and what should be prior that make drivers' use increase through establishing the gap model of service. 2. We could establish the structural equation modeling through using traffic information use satisfaction rate, entire traffic information satisfaction rate as the observation variables. You can say it is the fruit of this research that it was confirmed the entire satisfaction rate of traffic information influenced extension, convenience, accuracy, economical efficiency in order. We could also arrange the base to determine the order of services for vitalization of UTIS in the future through grasping the priority of each service functions classified by factors. 3. It is confirmed that many drivers want multimedia function, driving support function and various functions for the personal convenience in situations except driving, which enable the drivers to enjoy leisures and interests rather than economical functions during driving due to the recent social and economic changes.

The Dynamics of Local Politics in the Philippines: A Case Study on the PBMA in Surigao del Norte Province (필리핀 지방정치의 역동성: 북부 수리가오 주의 토착 기독교 종교단체 (PBMA) 사례 연구)

  • Lew, Seok Choon;Wang, Hye Suk
    • The Southeast Asian review
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    • v.19 no.2
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    • pp.1-56
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    • 2009
  • It is generally acknowledged that Philippines politics has achieved a basic soil for democracy at the macro-level by the two incidents of 'People Power' (1986 & 2001). However, in spite of such an achievement, Philippine politics at the micro-level, does not enjoy the same reputation. Institutionalized 'Bossism' or 'patron/clientelism' political culture has been attributed to make such a gap. This paper aims to bridge the gap by a longitudinal observation on local politics of a particular province in the Philippines. Surigao del Norte is the province picked up for the study. The reason why this particular province attracts special concerns is that there appears to come a very dynamic local politics, led by an indigenous Christian organization, the PBMA (Philippines Benevolent Missionary Association), which was founded in the mid 1960s. With the coming of the organization in the province, the political power of the traditional families has been narrowed. On the other hand, new families, not only the leader family of the PBMA but also the family allied with the PBMA, has expanded political influence. Following steps are adopted to understand the meaning of such a change. First, institutional frame of Philippine politics and elections will be reviewed. Second, demographic changes will be investigated on Surigao del Norte province to find out how popular the PBMA organization is among the people. Third, local election outcomes will be examined to describe the changing nature of political landscape of the province. This will reveal how the relationship between the old and new families has been developed in the province. Lastly, based on the facts discovered by a longitudinal observation, an attempt to evaluate theories on Philippines politics will be made Conclusions are as follows. To understand the dynamics of Philippine politics, 'expectations from the below,' or, 'passions of the people,' suggested by Ileto, needs more attention. Furthermore, 'mutual accommodation' between domination and resistance, coined by Abinales, also demands more appreciation. The case of local politics in the Surigao del Norte, with the coming of the PBMA, is sure to show a concrete example of changing politics in the 'changeless land.'

An Analysis on the State of Adjustment on Mathematical Education for Adolescent North Korean Defectors (새터민 청소년의 수학학습 실태 및 적응 요인 분석)

  • Yeon, Bo-Ra;Kim, Hong-Chan
    • Journal of the Korean School Mathematics Society
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    • v.15 no.3
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    • pp.467-486
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    • 2012
  • By identifying the state of adjustment regarding mathematical education for adolescents who escaped from North Korea and analyzing the relevant factors from multiple perspectives, this study is aimed at finding improvement methods for their math education adoptability. To fulfill such objective, this paper-reviewed the existing literature and research, conducted participatory observation, collected and analyzed survey research on math education adoptability for 43 students who are currently attending an alternative school for North Korean defectors. The results of this research are as follows: There is a serious pattern of maladjustment concerning math education of adolescents who defected from North Korea. The lack of basic skills in mathematical principles due to the gap in their studies results in poor academic performance, particularly in the advanced stages of learning. In the process of defection, environmental challenges, such as the loss of basic study skills which naturally results from the gap in their studies and differences in the educational curriculum between North and South Korea, are posing difficulties for these students.

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The Observation on the Intrinsic Attribute of 'la Différant Images' Expressed the Changeability of Fashion Style (패션스타일의 가변성에 나타난 차연적 이미지들의 특성 고찰)

  • Park, Shinmi
    • Fashion & Textile Research Journal
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    • v.16 no.5
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    • pp.680-688
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    • 2014
  • The aim of this research is to classify intrinsic attribution of 'la diff$\acute{e}$rance images' which are core propositions of changeability of fashion style. The specific questions of this research are; what are the definition of 'changeability of fashion', 'la diff$\acute{e}$rance' and 'supplement' and what are the relationships?, how the la diff$\acute{e}$rance images which are intrinsic of changeability of fashion style exist? and what is intrinsic attribution of 'ultimate la diff$\acute{e}$rant image', 'immediate la diff$\acute{e}$rant image' and 'la diff$\acute{e}$rant image of the trace'? The researchers deployed a qualitative research method providing a systematic review of the previous studies. In conclusion, the 'supplement' phenomenon and 'la diff$\acute{e}$rant images' shown in the changeability of fashion style, covers up the gap between the structural layers through the play led by supplement logic in the subconscious place of la diff$\acute{e}$rance of dialectical frame. They produce styles that have current value and become generalized la diff$\acute{e}$rant images of trace through the play of 'la dissemination.' These images repeat their individual play to reproduce a new different 'la diff$\acute{e}$rant images' and complete the aesthetics of harmony in the state of 'reservation,' 'deferment' and 'postponement'. The images are ready to make history and they create 'ultimate la diff$\acute{e}$rant images' from the demand of different period, and tries to combine with 'supplement' within 'the gap of la diff$\acute{e}$rance.' This process endlessly repeats in the dialectical frame through the la diff$\acute{e}$rant' play led by time and space, and it continuously produces new style that is required by different time and space.

A Study of Nd:YAG Laser Welding in Cold-reduced Carbon Steel and Stainless Steel Sheet (Nd:YAG 레이저를 이용한 냉연강판과 스테인레스강판의 용접)

  • Lee, Chul-Ku;Lee, Woo-Ram;Baek, Un-Hak
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.19 no.2
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    • pp.163-170
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    • 2010
  • We have studied on welding dissimilar materials of cold-reduced carbon steel sheet and stainless steel sheet together by using laser beam. It is well known that stainless steel is so strong againt rust and heat, while cold-reduced carbon steel is widely used in various parts of industry. In this research we have performed some experiments to know the possibility of welding dissimilar materials using laser beam by adjusting the power output of 3kW laser. Other conditions of the experiments were as follows : the welding speed was varied in the range between 2m/min and 7m/min, argon gas and helium gas were used as shield gas, the flow value of shield gas was ranged between $10{\ell}/min$ and $30{\ell}/min$, and the gap of two materials was ranged between 0mm and 0.3mm. In order to ascertain of the welded surface, we have done the tensile strength testing, the hardness testing and the microscope observation. As a result, we have found that tensile strength was the highest at the condition of the welding speed of 4, the flow value of $20{\ell}/min$, the gap of two materials 0, and the use of helium gas. Above testings have also showed that the tensile strength was generally satisfactory since the penetration of welding was almost complete due to the thinness of the materials. In addition, the formation of the welded area was excellent when it had the highest tensile strength.

Preparation of Cadmium-free Buffer Layers for CIGS Solar Cells (CIGS 태양전지용 Cd-Free 버퍼층 제조)

  • Moon, Jee Hyun;Kim, Ji Hyeon;Yoo, In Sang;Park, Sang Joon
    • Applied Chemistry for Engineering
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    • v.25 no.6
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    • pp.577-580
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    • 2014
  • Indium hydroxy sulfide ($In(OH)_xS_y$) as a cadmium (Cd)-free buffer layer for $CuInGaSe_2$ (CIGS) solar cells was prepared by the chemical bath deposition (CBD) and the reaction time was optimized. The band gap energy and transmittance data alongside the thickness results from the direct observation with focused ion beam system (FIB) could be a powerful tool for optimizing the conditions. In addition, X-ray diffractometer (XRD), X-ray photoelectron microscopy (XPS), and scanning electron microscope (SEM) were also employed for the layer characterization. The results indicated that the optimum reaction time for $In(OH)_xS_y$ buffer layer deposition by CBD was 20 min at $70^{\circ}C$ under the conditions employed. At the optimum conditions, the buffer layer thickness was near 57 nm and the band gap energy was 2.7 eV. In addition, it was found that there was no XPS peak shift in between the buffer layers deposited on molybdenum (Mo)/glass and that on CIGS layer.

Synthesis of TiO2-Fe2O3 Nanocomposite Powders for Magnetic Photocatalyst (자성광촉매용 TiO2-Fe2O3 나노복합분말의 합성)

  • Lee Chang-Woo;Kim Soon-Gil;Yun Sung-Hee;Lee Jai-Sung;Choa Yong-Ho
    • Korean Journal of Materials Research
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    • v.15 no.8
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    • pp.508-513
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    • 2005
  • [ $TiO_2-Fe_2O_3$ ] nanocomposite powders for magnetic photocatalyst were synthesized by sol-gel process, in which $TiO_2$ photocatalytic layer was formed on the surface of $\gamma-Fe_2O_3$ magnetic core. Transmission electron microscopy (TEM) observation and X-ray diffractometry (XRD) analysis revealed that$\gamma-Fe_2O_3$ nanoparticles, $10\~20nm$ in diameter, were coated by $TiO_2$ shell of 5nm in thickness and $TiO_2$ was anatase phase. Also hydroxyl group (-OH) used to decompose organic compounds was detected by Fourier transformation infrared spectrometry(FT-IR) analysis. UV-Visible spectrophotometry results showed that light absorption occurred in the wavelength range of $400\~700 nm$, and the band gap energy $(E_g)$ of powder was 1.8 eV. Finally it was found that the coercivity $(H({ci})$ and saturation magnetization $(M_s)$ of the powder were 79 Oe and 14.8 emu/g, respectively as experimental vibrating sample magnetometer (VSM) measurements.

The Characteristics of Tidal Residual Current in Youngil Bay (영일만의 조석잔차류 거동 특성)

  • Kim Jong-Kyu
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.4 no.1
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    • pp.14-23
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    • 2001
  • The characteristics of tidal circulation with Hyungsan River discharges in Youngil Bay by the numerical experiments is elucidated. For the simulation of tidal residual currents related to inflow by the river discharges in Youngil Bay located in the southeastern part of Korean Peninsula, the two-dimensional numerical experiment is peformed. The tidal elevation boundary conditions of the 4 main tidal harmonic constituents (M₂, S₂, K₁ and O₁) on the open boundary and river discharges at the river boundary are considered. The computed results obtained from numerical experiment showed good agreements with the field observation ones. The residual currents generally flow toward the inner bay through the western (Dalman-Gap) and central areas of the bay, and then the currents go toward the outer bay along the eastern shore (Changgi-Gap) of the bay with anti-clockwise circulation. Especially, in the numerical experiment without Hyungsan River discharges, these flow patterns are disappeared. Based on the results, it showed that the Hyungsan River discharges play the dominant role in the patterns of tidal residual currents. This flow pattern of tidal residual currents are important mechanism of water quality, material transport in Youngil Bay.

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