• Title/Summary/Keyword: Ripple Effect

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The Impact of the Incheon Free Economic Zones on Regional Disparities in Incheon (인천 경제자유구역이 인천시 자치구(군)간 지역불균형에 미치는 영향분석)

  • Kim, Bora;Choi, Jinmu
    • Journal of the Economic Geographical Society of Korea
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    • v.17 no.1
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    • pp.86-97
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    • 2014
  • Incheon Free Economic Zone is the first free economic zone specified in 2003 in Korea. Previous research on the Free Economic Zone has focused on the activation of the free economic zone or foreign investment issue at the level of the national economic plan. Related to the development of a free economic zone, studies are currently insufficient on the relevance of the local economy, the development of linkages with hinterland, and the balanced regional development. Therefore, this study tried to investigate the impact of Incheon Free Economic Zone to the local economy through analyzing the causes and characteristics of the imbalance between the regions in Incheon by comparing before (1996~2002) and after (2003~2009) of the Incheon Free Economic Zone legislation (2003). The result shows that development of the free economic zone has not been connected to the local economy activation and the ripple effect on the old town in Incheon. Further, the construction of a large apartment and infrastructure in the free economic zones have increased the disparity between the free zones and the old town.

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The effects of the shape of IDT electrode pair on the characteristics of SFIT filter (IDT형의 전극 형태가 SFIT형 필터의 특성에 미치는 영향)

  • You, Il-Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.12
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    • pp.2662-2670
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    • 2009
  • The effect of the reflector type for the SAW filter on the characteristics of the slanted finger IDT filter have been studied by computer simulation. The IDT was evaporated by Aluminum-Copper alloy. The design condition was optimized by the phase shift of the SAWfilter for WCDMA. We have employed that the number of pairs of the input and output IDT are 50 pairs and the thickness are $5,000{\AA}$, and the width and the space of reflector are $3.6{\mu}m$ and $2.0{\mu}m$, respectively. Frequency response of the fabricated SFIT filter has the property that the center frequency is about 190MHz and bandwidth at the 3dB is probably 8.2MHz. And we could obtain that the return loss is less then 16dB, the ripple characteristics is probably 4dB and the triple transit echo is less then 18dB after when we have matched impedance.

A Study on Flux Barrier of Permanent Magnet Assisted Reluctance Synchronous Motor Design using FEM (FEM을 이용한 영구자석형 릴럭턴스 동기전동기의 자속 장벽 설계에 대한 연구)

  • Kim, Nam-Hun;Nam, Sang-Hyun;Choi, Kyeong-Ho
    • The Transactions of the Korean Institute of Power Electronics
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    • v.13 no.4
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    • pp.295-302
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    • 2008
  • This paper examines the design and the performance of a PMA-RSM(permanent-magnet assisted reluctance synchronous motor) for washing machine. A FEM(finite element method) is used to analyze performance and maximum torque characteristic of the proposed PMA-RSM. The designed motor is a combination of salient poles, which is making reluctance torque, and permanent magnet which are located on the air-gap of rotor to get a enough torque during low speed resign. Typical flux barrier type reluctance synchronous motor and the effects of adding magnet into the flux barrier of the rotor of a PMA-RSM are compared and examined. Also the maximum torque point of the reluctance torque by reluctance and reaction torque by magnetic alignment torque, which is in barrier, of the proposed PMS-RSM are derived through simulation. Using this results, the characteristics analysis of a performance, an average torque and a torque ripple of flux barrier RSM and the proposed PMA-RSM are performed through FEM under the saturation effect respectively.

A Study on Growth and Development Information and Growth Prediction Model Development Influencing on the Production of Citrus Fruits

  • Kang, Heejoo;Lee, Inseok;Goh, Sangwook;Kang, Seokbeom
    • Agribusiness and Information Management
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    • v.6 no.1
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    • pp.1-11
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    • 2014
  • The purpose of this study is to develop the growth prediction model that can predict growth and development information influencing on the production of citrus fruits. The growth model was developed to predict the floral leaf ratio, number of fruit sets, fruit width, and overweight fruits depending on the main period of growth and development by considering the weather factors because the fruit production is influenced by weather depending on the growth and development period. To predict the outdoor-grown citrus fruit production, the investigation result for the standard farms is used as the basic data; in this study, we also understood that the influence of weather factors on the citrus fruit production based on the data from 2004 to 2013 of the outdoor-grown citrus fruit observation report in which the standard farms were targeted by the Agricultural Research Service and suggested the growth and development information prediction model with the weather information as an independent variable to build the observation model. The growth and development model for outdoor-grown citrus fruits was assumed by using the Ordinary Least Square method (OLS), and the developed growth prediction model can make a prediction in advance with the weather factors prior to the observation investigation for the citrus fruit production. To predict the growth and development information of the production of citrus fruits having a great ripple effect as a representative crop in Jeju agriculture, the prediction result regarding the production applying the weather factors depending on growth and development period could be applied usefully.

Analysis of Pole Ratio Effect of Magnetic Reducer (마그네틱 감속기의 극수비 영향 분석)

  • Jung, Kwang Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.277-283
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    • 2020
  • In a concentric magnetic gear, which replaces the teeth of a mechanical gear with a permanent magnet, the polar ratio of the magnet that determines the reduction ratio affects the behavior of the magnetic gear dramatically. This study analyzed the density of transmission torque, the efficiency of torque considering the solid loss, and the torque quality, including the cogging characteristics using finite element analysis. When the pole number on the driving side was changed from two to five, it was confirmed that there was an optimal pole ratio, in which the transmission torque was maximized. Because eddy current generation density is proportional to the magnetic field, the transmission efficiency also shows a similar tendency to the transmission torque density, and the efficiency is more than 95% at a low gear ratio. The cogging characteristics due to the interaction of the permanent magnets with the limited number of poles are inversely proportional to the least common multiple between the number of magnets on the drive side and the number of modulator teeth. A test model was built for the transmission torque evaluation.

Associated Keyword Recommendation System for Keyword-based Blog Marketing (키워드 기반 블로그 마케팅을 위한 연관 키워드 추천 시스템)

  • Choi, Sung-Ja;Son, Min-Young;Kim, Young-Hak
    • KIISE Transactions on Computing Practices
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    • v.22 no.5
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    • pp.246-251
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    • 2016
  • Recently, the influence of SNS and online media is rapidly growing with a consequent increase in the interest of marketing using these tools. Blog marketing can increase the ripple effect and information delivery in marketing at low cost by prioritizing keyword search results of influential portal sites. However, because of the tough competition to gain top ranking of search results of specific keywords, long-term and proactive efforts are needed. Therefore, we propose a new method that recommends associated keyword groups with the possibility of higher exposure of the blog. The proposed method first collects the documents of blog including search results of target keyword, and extracts and filters keyword with higher association considering the frequency and location information of the word. Next, each associated keyword is compared to target keyword, and then associated keyword group with the possibility of higher exposure is recommended considering the information such as their association, search amount of associated keyword per month, the number of blogs including in search result, and average writhing date of blogs. The experiment result shows that the proposed method recommends keyword group with higher association.

A Study on LLCL Filter to Reduce Harmonic Current of Grid Connected Power Inverter (계통연계형 인버터의 고조파 전류저감을 위한 LLCL 필터에 관한 연구)

  • An, Byoung-Woong;Hong, Chang-Pyo;Kim, Hag-Wone;Cho, Kwan-Yuhl;Lim, Byung-Kuk
    • The Transactions of the Korean Institute of Power Electronics
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    • v.19 no.1
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    • pp.64-70
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    • 2014
  • In this paper, the new LLCL filter is proposed for grid connected three-phase PWM inverter for passive damping. LLCL filter inserts a small inductor in the branch of the capacitor of the traditional LCL filter to compose a series resonant circuit to reduce the switching-frequency component on grid current. Using LLCL filter, the switching-frequency current ripple components can be attenuated much better than the LCL filter, leading to a decrease in the total inductance. However, the resonance phenomena caused by zero impedance from the addition of LC branch in LLCL filter can be a big problem. Resonance phenomena of LLCL filter can be a source of grid system instability, so proper damping methods are required. However, it is difficult to apply a passive damping method in the conventional LLCL filter, because the damping resistor increase impedance of the LC branch. Therefore, switching frequency component of grid current can not much attenuated by low Q of LC series resonance effect. In this paper, a new LLCL filter is proposed to overcome the conventional LLCL filter with passive damping. The validity of the proposed method is proven by simulation and experimental result.

The UV Laser Ablation of Cr film on Glass Substrate (UV레이저를 이용한 Cr 박막의 어블레이션)

  • Yoon, Kyung-Ku;Lee, Seong-Kuk;Kim, Jae-Gu;Choi, Doo-Sun;Whang, Kyung-Hyun;Jung, Jae-Kyoung;Jang, Won-Suk;Na, Suck-Joo
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.8
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    • pp.134-139
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    • 2000
  • In order to understand the removal mechanism and seek the optimal conditions. KrF excimer laser ablation of Cr films on glass substrates is investigated. The surface morphology of the laser-irradiated spot is examined by SEM. The measured single-shot ablation rate is found to be about two times the result of numerical analysis based on a surface vaporization model and heat conduction theory. Surface morphology examination indicates that the Cr film is removed by the sequence of melting-surface vaporization-,melt expulsion by plasma recoil and that the outmost ripple of the diffraction pattern gives a strong effect on the morphology of molten Cr during the melting and vaporization processes. To seek the optimal process parameters for micro patterning morphological investigation is carried out experimentally on samples having different chromium film thicknesses. Optimal processing conditions are determined to enhance the accuracy and quality of thin film removal for micro patterning.

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Health Impact Assessment of Free Immunization Program in Jinju City, Korea

  • Kim, Keon-Yeop;Jeon, So-Youn;Jeon, Man-Joong;Lee, Kwon-Ho;Lee, Sok-Goo;Kim, Dong-Jin;Kang, Eun-Jeong;Bae, Sang-Geun;Kim, Jin-Hee
    • Journal of Preventive Medicine and Public Health
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    • v.45 no.4
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    • pp.267-275
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    • 2012
  • Objectives: This study was conducted to assess the potential health impacts and improve the quality of the free immunization program in Jinju City by maximizing the predicted positive health gains and minimizing the negative health risks. Methods: A steering committee was established in September 2010 to carry out the health impact assessment (HIA) and began the screening and scoping stages. In the appraisal stage, analysis of secondary data, a literature review, case studies, geographic information systems analysis, a questionnaire, and expert consultations were used. The results of the data collection and analyses were discussed during a workshop, after which recommendations were finalized in a written report. Results: Increased access to immunization, comprehensive services provided by physicians, the strengthened role of the public health center in increasing immunization rates and services, and the ripple effect to other neighboring communities were identified as potential positive impacts. On the other hand, the program might be inaccessible to rural regions with no private clinics where there are more at-risk children, vaccine management and quality control at the clinics may be poor, and vaccines may be misused. Recommendations to maximize health gains and minimize risks were separately developed for the public health center and private clinics. Conclusions: The HIA provided an opportunity for stakeholders to comprehensively overview the potential positive and negative impacts of the program before it was implemented. An HIA is a powerful tool that should be used when developing and implementing diverse health-related policies and programs in the community.

A Preliminary Study to Determine Comprehensive Research and Development Plans for Promoting Mental Health Services

  • Kim, Chul Eung;Ko, Young-Mi;Lee, Sang-Uk;Choi, SungKu;Han, Kiwan;Park, Se Jin;Jo, MinKyung;Park, Yu Kyong;Lee, Hye Young;Park, Subin
    • Osong Public Health and Research Perspectives
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    • v.9 no.6
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    • pp.314-324
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    • 2018
  • Objectives: The aim of this study was to analyze research and development projects in mental health services in Korea, using priority evaluation of mental health promotion policies to determine direction of the service. Methods: An online survey was conducted that targeted experts in the mental health service regarding promotion of mental health in Korea in 2016. The survey was based on 32 policy projects that resulted from 12 strategies according to 4 policy objectives. Results: Analysis of 32 mental health projects were assessed regarding the possibility of technology development success, magnitude of the ripple effect, and necessity of a national response. It was observed that 3 policy projects relevant to suicide, had a high relative priority. This was followed by policies for improvement of health insurance and the medical benefit cost system, and policies for reinforcement of crisis psychological support such as those for disaster victims. Conclusion: The prioritization of mental health services should place an emphasis on promotion of a healthy mental lifestyle, rehabilitation support for patients with serious mental illness, and reinforcement of social safety networks for suicide prevention.