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Immersion grating mount design of IGRINS

  • Moon, Bong-Kon;Wang, Weisong;Park, Chan;Lee, Sung-Ho;Yuk, In-Soo;Chun, Moo-Young;Lee, Han-Shin;Jaffe, Daniel T.
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.153.2-153.2
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    • 2011
  • The IGRINS (Immersion GRating INfrared Spectrometer) is a high resolution wide-band infrared spectrograph developed by Korea Astronomy and Space Science Institute (KASI) and the University of Texas at Austin (UT). Immersion grating is a key component of IGRINS, which disperses the input ray by using a Silicon material with a lithography technology. Opto-mechanical mount for the immersion grating is important to keep the high spectral resolution and the optical alignment in a cold temperature of $130{\pm}0.06K$. The optical performance of immersion grating can maintain within the de-center tolerance of ${\pm}0.05mm$ and the tip-tilt tolerance of ${\pm}1.5arcmin$. The mount mechanism utilizes the flexure and the kinematic support design to satisfy the requirement and the operation condition. When the IGRINS system is cooled down to a cold temperature, three flexures compensate the thermal contraction stress due to the different material between the immersion grating and the mounting part(Aluminum 6061). They also support the immersion grating by an appropriate preload. Thermal stability is controlled by a copper strap with proper dimensions and a heater. Generally structural and thermal analysis was performed to confirm the mount mechanism. This talk presents the opto-mechanical mount design of the immersion grating of IGRINS.

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The Effects of Faculty Trustworthiness on Relational Factors: From the Service Distribution Perspective (서비스 유통 관점에서 교수 신뢰성이 관계적 요인에 미치는 영향)

  • Cho, Hyun-Jin
    • Journal of Distribution Science
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    • v.15 no.3
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    • pp.81-89
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    • 2017
  • Purpose - Universities are fostering the development of closer relationships with students due to the increase in competition among universities. Universities are placing greater emphasis on relationship quality as a source of competitive advantage. Thus relationship marketing has become an important strategic theme in higher education. The purpose of this study is to investigate the effects of faculty trustworthiness on relationship building process in the context of relationship marketing. For this study, faculty trustworthiness is divided into competence, benevolence, and integrity. And relationship development variables are composed of satisfaction, commitment, positive WOM, and negative WOM. Research design, data, and methodology - To empirically evaluate the proposed research model, this study was carried out using the survey with undergraduate students who were taking business courses. The 270 questionnaires were asked, and a total of 245 respondents provided complete and usable data. The sample consisted of 143 males(58.4%) and 102 females(41.6%). The variables of proposed model were measured on a 5-point Likert scale. The structural equation modeling analysis was used for the hypothesis test. Results - The overall fit of the model was acceptable(χ2=579.7(df=264, P=0.00), GFI=0.935, NFI=0.949, CFI=0.956, RMR=0.040). The results supported 6 hypotheses except for

    and

    . First, competence and benevolence were positively related to satisfaction, while integrity was not significant. A key result of the analysis was that benevolence has the strongest effect on satisfaction. Second, satisfaction had a positive impact on commitment and positive WOM but didn't significantly affect negative WOM. Third, commitment significantly enhanced positive WOM and reduced negative WOM. Conclusions - This study emphasizes the role of faculty trustworthiness based on a long-term relationship. And the findings suggest that the dimensions of faculty trustworthiness have differing effects on satisfaction. In particular, benevolence is found to be the most important factor. This study provides university managers with the following managerial implications. In order to increase the satisfaction of the students, university managers should focus on the faculty's competence and benevolence. Also, it is important that university managers take a relationship approach to maximize WOM effect.

Technological Achievements and Economic Development: The Significance of Technological Achievement Gap in Selected East and South Asian Countries

  • Ali, Tariq Mahmood
    • STI Policy Review
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    • v.8 no.1
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    • pp.113-156
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    • 2017
  • Although technological progress is considered a key element for economic growth and development of a country, strong empirical evidence in this regard is not available yet. Therefore, to establish the empirical link between technology progress and economic development, it is advisable to carry out a time series analysis. In this regard, the Technology Achievement Index (TAI) of 100 top economies has been developed to examine the position of countries' technological progress for the 21 years spanning 1995 to 2015. Countries have been ranked on their TAI which is based on four pillars; technology creation, diffusion of older innovations, diffusion of recent innovations, and development of human skills. As well, this current study re-calculates the Humane Development Index (HDI) of 100 top economies for the 21 years from 1995 to 2015. Ranking of countries' HDI values reflects three dimensions: A long lifespan (life expectancy index), knowledge (Education Index) and a decent standard of living (Gross National Income Index, or GNI). The Standard Deviation (SD) technique has been used to investigate the technological gap between individual countries and groups of countries or regions. For a more meaningful assessment, technological gaps from the maximum achievement value (i.e., one of the countries under study) are presented as well. To investigate the impact of technological progress on economic development, this study introduces a model in which the HDI is used as the dependent variable and the TAI and Gross Capital Formation (GCF) are used as independent variables. The HDI, TAI and GCF are used in this model as proxy variables for economic development, technological progress and capital respectively. Econometric techniques have been used to show the impact of technological progress on economic development. The results show that long-term associations exist between technology progress and economic development; the impact of technology progress on economic development is 13.2% while the impact is 4.3% higher in eight selected East South Asian countries, at 13.5%, than in eight selected highly developed countries (9.2%).

The Relationship among Fashion Social Media, Information Usage Behavior, and Purchase Intention (패션 소셜미디어 품질, 정보 이용행동, 구매의도 간 관계 연구)

  • Kim, Naeeun;Kim, Mi-Sook
    • The Journal of Industrial Distribution & Business
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    • v.9 no.11
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    • pp.25-38
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    • 2018
  • Purpose - This study aimed to identify the sub-dimensions of fashion social media quality (information quality, social quality, service quality, system quality) and investigate how they affect purchase intention through fashion information use behavior (information acceptance, information diffusion). Research design, data, and methodology - Data collection was carried out twice for systematic verification of the research model. In the first data collection, the reliability and validity of research variables were verified through 238 respondents and questionnaires were revised and supplemented based on their responses. In March 2018, the final survey was conducted from 755 respondents the age of 20 to 49. Using SPSS 23.0, descriptive statistics, exploratory factor analysis, correlation analysis were performed. In order to test hypotheses, structural equational modeling technique was employed using AMOS 23.0. Results - First of all, fashion Social media quality consists of four factors including information quality, social quality, service quality and system quality. Second, fashion Social media information quality, social quality, and system quality were shown to have a positive(+) effect on information acceptance behavior, and social quality, service quality and system quality were shown to have a positive(+) effect on information diffusion behavior. It was also determined that the acceptance and diffusion behaviors of fashion information through fashion Social media had positive(+) influence on purchase intention. Conclusions - This study holds academic significance in its identification of the components of fashion Social media quality and for conducting an empirical analysis on the causal relationship between fashion information acceptance and diffusion behaviors, and purchase intention. The results of this study indicate that fashion involvement is the key factors in determining the quality of Social media, the acceptance of information through Social media, and, by extension, the purchase of fashion products. Practitioners in the fashion industry may use the findings of this study in order to build more effective Social media strategy.

Current status and Prospects on the Aerial Monitoring (국토 공중모니터링 현황과 발전방향)

  • Shin, Hyu-Seok;Park, Chung-Ki;Kim, Yeon-Mi;Hwang, Sun-Young;Park, Key-Ho
    • Spatial Information Research
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    • v.16 no.2
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    • pp.173-192
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    • 2008
  • Recent climate fluctuation and environmental change at global scale are causing more incidences of disasters and calamities over the world. In a response to this environmental crisis, international collaboration for Earth Observation(EO) is obtaining more significance in order to understand, watch, and forecast changes in the earth system. As such, aerial monitoring based on remotely sensed data, indispensable for EO, is also drawing more attentions. In this context, we discuss diverse aspects of future developments in the Korean domestic system for aerial monitoring. This paper first thoroughly examines current status of national and international collaboration system arid research of aerial monitoring. It then suggests specific development plans for four critical dimensions such as research, organization, institutional systems, and strategies. Our study would facilitate systematically establishing policies for aerial monitoring in Korea and creating a domestic GEOSS(Global Earth Observation System of Systems) in the near future.

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Realization of High Impedance Surface Characteristics Using a Periodically Transformed Artificial Magnetic Conductor Structure and Reduction Technique of Specific Absorption Rate

  • Lee, Seungwoo;Rhee, Seung-Yeop;Kim, Pan-Yeol;Kim, Nam
    • Journal of electromagnetic engineering and science
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    • v.13 no.2
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    • pp.113-119
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    • 2013
  • We developed a transformed, symmetrical, mushroom-like surface without via holes in cells focused on a 2.4-GHz WLAN band. Each slot in the novel type structure plays a key role in modeling at the desired frequencies. The designed artificial magnetic conductor (AMC) has several advantages, including a small size, a wider bandwidth, a short reflecting distance to the antenna, and easy fabrication because there are no via holes. Overall dimensions of the AMC cell are 21 mm $(Width){\times}21mm$ $(Height){\times}2.6mm$ (Thickness), and the bandwidth is about three times wider (11.7%) compared to that of a conventional AMC (4.0%). For evaluating the performance of the proposed structure, a reflector, which periodically consists of the designed AMC cells, was developed. The antenna with the investigated AMC reflector not only works within a quarter of the wavelength because of the extremely high wave impedance generated by the AMC cells on the surface of the structure but also reduces the specific absorption rate (SAR). Electromagnetic field (EMF) exposure to a human phantom was analyzed by applying the designed reflector to the 2.4-GHz dipole antenna in a tablet PC. The calculated peak SAR averaged over 1 g was 0.125 W/kg when the input power was 1 W and the antenna was located at 20 cm from the human phantom. However, the SAR value was only 0.002 W/kg (i.e., 98.4% blocked) when the designed reflector was inserted in front of the antenna.

A Study on the Characteristics of Geometry in Madeleine Vionnet´s Works (마들렌느 비오네의 작품에 나타난 기하학적 특성에 관한 연구)

  • 유수경;김의경
    • The Research Journal of the Costume Culture
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    • v.10 no.6
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    • pp.763-780
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    • 2002
  • The aim of this research is to analyze Vionnet´s geometric features, which can be regarded as the key formative beauty among the external characteristics of her works. and to thereby establish the theory that her works emitted a time-transcending life force because they were patterns designed based on a geometrical frame of mind. To prove such argument, studies to understand the basic geometrical aspects appearing in her works will be made by taking a look at the general features of geometry, viewing Vionnet´s philosophy for designing, and examining the geometric cutting methods. The period covered in this paper will center mainly on dresses Vionnet made from her very active days in the fashion sector, 1919. till when she retired from the fashion industry, around 1939. What's outstanding about Vionnet´s geometric principle expressed in her works is the unique cutting method that acknowledges the silhouette of the human body as a cubic or three-dimensions concept, through insight of the human body, the mechanics of the materials, and geometry. Vionnet introduced a simple and elegant design by combining geometric figure cuts, such as rectan히es. quadrants, and triangles. Moreover, she created a new sewing structure that plans everything about the materials to the tiniest detail, resulting in producing a softer style With this, Vionnet showed the geometrical correlation can bring about harmony and the beauty of ideal proportion, forming the source of eternal beauty. As discussed so fu, the geometrical characteristics appearing in Vionnet´s works are marked such as spirals, zig-zag lines, asymmetries. panels, gradation, golden proportion, and the mobius-band.

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A Study on the Control of the Welding Quality Using a Infrared sensor (적외선센서를 이용한 용접품질 제어에 관한 연구)

  • Kim I.S.;Son S.J.;Kim I.J.;Kim H.H.;Seo J.H.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.754-758
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    • 2005
  • Optimization of process variables such as arc current, welding voltage and welding speed in terms of the weld characteristics desired is the key step in achieving high quality and improving performance characteristics without increasing the cost. Consequently, incorrect settings of those process variables give rise to deviations in the welding characteristics from the desired bead geometry. Therefore, trainee welders are referred to the tabulated information relating different metal types and thickness as to recommend the desired values of process variables. Basically, the bead geometry plays an important role in determining the mechanical properties of the weld. So that it is very important to select the process variables for obtaining optimal bead geometry. However, it is difficult for the traditional identification methods to provide an accurate model because the optimized welding process is non-linear and time-dependent. In this paper, the possibilities of the Infra-red sensor in sensing and control of the bead geometry in the automated welding process are presented. Infra-red sensor is a well-known method to deal with the problems with a high degree of fuzziness so that the sensor is employed to build the relationship between process variables and the quality characteristic the proposed above respectively. Based on several neural networks, the mathematical models are derived from extensive experiments with different welding parameters and complex geometrical features. The developed system enables to select the optimal welding parameters and control the desired weld dimensions during arc welding process.

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Automated Forming Sequence Design System for Multistage Cold Forging Parts (다단 냉간단조품의 자동공정설계시스템)

  • Park, J.C.;Kim, B.M.;Kim, S.W.;Kim, H.K.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.4
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    • pp.77-87
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    • 1994
  • This paper deals with an automated forming sequence design system by which designers can determine desirable operation sequences even if they have little experience in the design of cold forging process. The forming sequence design in the cold forging is very important and requires many kinds of technical and empirical knowledge. They system isproposed, which generates forming sequence plans for the multistage cold forging of axisymmtrical solid products. Since the process of metal forming can be considered as a transformation of geometry, treatment of the geometry of the product is a key in planning process. To recognize the geometry of the product section, section entity representation and primitive geometries were used. Section entity representation can be used for the calculation of maximum diameter, maximum height, and volume. Forming sequence for the part can be determined by means of primitive geometries such as cylinder, cone, convex, and concave. By utilizing this geometrical characteristics (diameter, height, and radius), the product geometry is expressed by a list of the priitive geometries. Accordingly the forming sequence design is formulated as the search problem which starts with a billet geometry and finishes with a given product one. Using the developed system, the sequence drawing with all dimensions, which includes the proper sequence of operations for the part, is generated under the environment of AutoCAD. Based on the results of forming sequence, process variables(strain, punch pressure, die inner pressure, and forming load) are determined.

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An Empirical Study on Moderating Effects of Entrepreneurship between Market Orientation and Performance Relationship of Korean Venture (한국 중소벤처기업의 시장지향성과 해외진출성과간 관계에 있어 기업가정신의 조절효과에 관한 연구)

  • Kim, Jung-Po
    • International Area Studies Review
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    • v.13 no.3
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    • pp.481-500
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    • 2009
  • This paper investigates the Moderating effect of entrepreneurship on the relationship between market orientation and international performance in Korean Ventures. Literature revealed that an appropriate alignment between firm strategic orientation and market positioning is critical because of its impact on firm performance. The alignment is especially crucial for SMEs as a result of their limited resource base. However, studies have not adequately accounted for the joint effect of entrepreneurship and market orientation on firm performance in different environments as foreign markets. Drawing upon a sample of 217 internationalized Korean Venture Business, it presents evidence related to mainly moderating effects of entrepreneurship on market orientation-international performance. The Key conclusion from the evidence is that market orientation, alone and in conjunction with certain entrepreneurship dimensions, is positively related to firm international performance. More specifically innovativeness and proactiveness have positively moderated the relationship between market orientation and international performance in Korean Ventures.