• Title/Summary/Keyword: Focus distance

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Usage of Waterbirds on the Artificial Floating Islands in Reservoir using UAV (무인항공기를 활용한 저수지 인공식물섬 조류 이용현황 분석)

  • Kim, Kyeong-Tae;Kim, Young;Kim, Hye-Joung;Kim, Seoung-Yeal;Kim, Whee-Moon;Song, Won-Kyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.5
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    • pp.57-67
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    • 2019
  • Water-Birds are the birds that occupy the highest proportion in Korea, inland wetlands and reservoirs provide them with a good environment as habitat, but their habitats have been losing because of thoughtless development. Therefore, artificial plant islands in reservoirs are important for improving habitat environment and providing food resources. However, there are no research and standards on the built and management of artificial plant islands. So this study is to find out the density of bird using artificial plant island as habitat through monitoring using UAV focus on the Cheonho-reservoirs located in Seobuk-gu, Cheonan-si(Middle Chungcheong Province). Further, the correlation analysis with environmental factors was conducted to determine the effect of artificial plant islands as habitats for water-birds. The supervised classification of the three-time images taken by the drone identified 244 white-billed ducks and 46 mandarin ducks. The utilization rate was different for each photographed date, and more individuals were identified in wet artificial plant islands than dry ones. As a result of analyzing the utilization follow environmental factors, the distance from the trail showed a significant correlation, and the other factors did not have a statistically significant effect. This study is the first case of the UAV monitoring method of the water-birds using artificial plant islands in the reservoir, and can be used as the basic data for the built and management.

The Impact of Compact City Indicators and Commuting Network on Commuting time: Focused on Suburban Cities in the Seoul Metropolitan Area (압축지표와 통근 네트워크가 통근시간에 미치는 영향에 관한 연구 - 수도권 경기·인천 지역을 대상으로 -)

  • Shin, Hakcheol;Woo, Myungje
    • Journal of the Korean Regional Science Association
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    • v.37 no.2
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    • pp.49-61
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    • 2021
  • Long-distance commuting is a problem as people living in Gyeonggi-Incheon contitue to commute to Seoul in the Seoul metropolitan area. To solve this problem, policies in the region are aiming for a self-sufficient zone formation plan and a compact city. However, urban problems caused by such long-distance commuting continue. This appears to be due to excessive density and Seoul-dependent networks. However, existing studies have focused on individual cities despite the importance of inter-city interactions, and had limitations in not considering the characteristics of the Seoul-dependent networks. Therefore, the purpose of this study is to empirically analyze the effect of the compactness on commuter travels by comprehensively considering the interactions between cities within the region using multiple regression. As a result of the analysis, it was found that that commuting efficiency increases when a network of more than a certain size is formed, and the results imply that policies should focus on fostering network centers in Incheon and Gyeonggi regions, which are outside the metropolitan area, and consider to expand the transportation networks at the regional level.

The Ethnicity and National Identity among Transmigrant: The Acehnese Community in Jakarta (이주민 집단의 종족과 국가에 대한 인식: 자카르타의 아쩨인 공동체 사례연구)

  • Jeong, Jeonghun
    • The Southeast Asian review
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    • v.22 no.2
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    • pp.133-170
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    • 2012
  • This thesis aims to analyze the political, social, and cultural activities of the Acehnese ethnic group living in Jakarta, Indonesia. Based on analysis, this thesis examines how their ethnicity and national identity have been formed and expressed. For this purpose, this study deals with Taman Iskandar Muda (hereinafter referred to as TIM), a group of Acehnese transmigrants living in Jakarta. The immigration of the Acehnese to Jakarta started in the 1950s and the number of Acehnese people living in Jakarta persently amounts to 100,000. TIM, which was organized by the first generational of immigrants, functions to group Acehnese immigrants of various generations and class. Forum Keprihatinan Untuk Aceh(hereinafter referred to as Forka), an organization designed to solve the political problems of TIM, undertook various activities to maintain the peace of Aceh as the representative of TIM. Through those activities, TIM and Forka were able to confirm the feeling of homogeneity among the Acehnese who were living in their hometown and also strengthen their identity within the organizations. However, the fact that TIM and Forka put their focus on humanitarian activities paradoxically shows the political limitations that they sustain. TIM and Forka take care not to make their humanitarian activities seem as if they intend to openly strengthen their Acehnese identity and deny their Indonesian one. These political characteristics of Forka's identity are commonly found in groups that practice long-distance nationalism, as transmigrants in diaspora circumstances do. In the organization of TIM, there exists the menasah, which is a space where discussions of the ethnicity and the nation are practiced. As it is the space for local exchange, menasah reveals the identity of TIM through educational/social activities and public services. Menasah functions as the public arena where people practice ethnic identity on the basis of national integration. As a minority ethnic group living in Jakarta and its neighborhood, they are accustomed to double and selective political activities, social activities, and cultural practices. In order to adapt themselves to the double circumstance that they are faced with, they should live extemporaneously, and this life may be the fate that minority ethnic and transmigrants should endure.

An Analysis of Productivity and Efficiency in Indian Non-Life Insurance Companies: DEA-Based Approach (DEA를 이용한 인도 손해보험회사의 효율성 및 생산성 분석)

  • Seo, Daigyo;Kwon, Yongjae
    • Journal of the Korea Convergence Society
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    • v.13 no.3
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    • pp.217-225
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    • 2022
  • We analyzed efficiency and productivity of the Indian non-life insurance market affected by the COVID-19 pandemic from 2020. Using data envelopment analysis(DEA), we examined non-life insurance companies selling health insurance products in India from FY2013 to FY2019. We found the followings. First, average efficiency of the entire non-life insurance industry worsened in the beginning yet improved later. Second, analyzing the efficiency measures by group, we found that private insurance companies had the highest efficiency, followed by state-run insurance companies and pure health insurance companies. Third, average annual productivity growth rate of companies operating distance selling channels including telemarketing is higher than that of traditional face-to-face channels. During and after the COVID-19 pandemic, therefore, Indian non-life insurance companies should focus their resources and efforts on the development of distance selling channels when establishing business strategies. Besides, it would be interesting to extend our analysis to the post-coronavirus period and we leave this for future research.

The Effects of Nozzle Shapes and Pressures on Boundary Layer Flashback of Hydrogen-Air Combustor (수소 전소용 연소 노즐 형상과 연소실 압력이 경계층 역화에 미치는 영향)

  • WON JUNE LEE;JEONGJAE HWANG;HAN SEOK KIM;KYUNGWOOK MIN;MIN KUK KIM
    • Journal of Hydrogen and New Energy
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    • v.33 no.6
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    • pp.776-785
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    • 2022
  • Hydrogen combustion in modern gas-turbine engine is the cutting edge technology as carbon-free energy conversion system. Flashback of hydrogen flame, however, is inevitable and critical specially for premixed hydrogen combustion. Therefore, this experimental investigation is conducted to understand flashback phenomenon in premixed hydrogen combustion. In order to investigate flashback characteristics in premixed hydrogen (H2)/air flame, we focus on pressure conditions and nozzle shapes. In general, quenching distance reduces as pressure of combustion chamber increases, causing flashback from boundary layer near wall. The flashback regime for reference and modified candidate configurations can broadly appear with increasing combustion chamber pressure. The later one can improve flashback-resist by compensating flow velocity at wall. Also, improved wall flow velocity profile of suggested contraction nozzle prevents entire flashback but causes local flashback at nozzle exit.

Evaluation of Radiation Dose to Patients according to the Examination Conditions in Coronary Angiography (심장동맥 조영 검사 시 검사 조건에 따른 환자 선량 평가)

  • Yong-In Cho
    • Journal of radiological science and technology
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    • v.46 no.6
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    • pp.509-517
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    • 2023
  • This study analyzed imaging conditions and exposure index through clinical information collection and dose calculation programs in coronary angiography examinations. Through this, we aim to analyze the effective dose according to examination conditions and provide basic data for dose optimization. In this study, ALARA(As Low As Reasonably Achievable)-F(Fluoroscopy), a program for evaluating the radiation dose of patients and the collected clinical data, was used. First, analysis of imaging conditions and exposure index was performed based on the data of the dose report generated after coronary angiography. Second, after evaluating organ dose according to 9 imaging directions during coronary angiography, with the LAO fixed at 30°, dose evaluation was performed according to tube voltage, tube current, number of frames, focus-skin distance, and field size. Third, the effective dose for each organ was calculated according to the tissue weighting factors presented in ICRP(International Commission on Radiological Protection) recommendations. As a result, the average sum of air kerma during coronary angiography was evaluated as 234.0±112.1 mGy, the dose-area product was 25.9±13.0 Gy·cm2, and the total fluoroscopy time was 2.5±2.0 min. Also, the organ dose tended to increase as the tube voltage, milliampere-second, number of frames, and irradiation range increased, whereas the organ dose decreased as the FSD increased. Therefore, medical radiation exposure to patients can be reduced by selecting the optimal tube voltage and field size during coronary angiography, maximizing the focal-skin distance, using the lowest tube current possible, and reducing the number of frames.

Public Service Good Health Advertising: Effects of Elaboration Likelihood and Construal Level on Consumer Attitudes (보건 관련 공익광고에서 정교화가능성과 해석수준이 광고태도에 미치는 영향)

  • Park, Jong-Chul;Kim, Kyung-Jin
    • Journal of Distribution Science
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    • v.12 no.6
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    • pp.67-79
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    • 2014
  • Purpose - This study aims to accomplish three major research goals. First, it strives to change consumers' focus from peripheral routes to a central route of public service advertising related to the good health policy, without problematic effects, by influencing consumers' knowledge or involvement. Second, this study examines the elaboration likelihood model (ELM) and construal level theory (CLT). Specifically, we consider that the central route of ELM might correspond with the focal goal of CLT. Third, this study analyzes ELM through CLT. That is, ELM predicted that low involvement would take the peripheral route, and high involvement would take the central route. Research design, data, and methodology - This study consisted of three experiments. The first experiment had a 2×2 between-subject design. The subjects were university students and the research period was approximately one year. The first independent variable was the involvement of the overweight issue; this variable was measured and split by the median. The second independent variable was the temporal distance (near vs. distant future); this variable was manipulated. The second experiment also had a 2×2 between-subject design. The first variable was the involvement of cervical adenocarcinoma prevention, and was considered already manipulated by sex. Specifically, males had a low involvement of the disease, but females had high involvement. The second independent variable was priming (power vs. submissive). Power priming would induce abstract thinking, but submissive priming would take concrete processing. The third experiment had a 2×2×2 between-subject design. The first variable was cognitive depletion, and was manipulated by memorizing 9-digit numbers. The second and third independent variables were involvement and abstract thinking induction, such as prior experiments. Data were collected through questionnaires, and were analyzed by an SPSS program. Major hypotheses were tested by examining the interaction effects through ANOVA. Results - Major findings are as follows. First, even for low-involved consumers in the overweight category, distant future manipulation induced them to focus not on the peripheral route but on the central route of the public service advertisement. This result does not correspond to the typical ELM prediction. Second, under power priming, low-involved males of the cervical adenocarcinoma category focused on the peripheral route because of the induction to abstract thinking. This result replicated the first experiment, and confirmed the theoretical robustness. Third, high-involved females focused not on the central but on the peripheral route under the mixed condition of cognitive depletion and near future manipulation. Depletion consumed cognitive resources, and the processing mode of consumers changed from systematic to heuristic. Conclusions - ELM needs to be complemented through CLT in context of public service good health advertising. Specifically, the involvement of ELM may impact consumers' thinking mode (abstract vs. concrete), and the interaction effects may influence consumers' focus on advertising (central vs. peripheral route). This study's limitations were bounded subjects, limited stimuli, and somewhat weak external validity.

Changes in School Foodservice during COVID-19 Pandemic Lockdown based on Focus Group Interviews (포커스 그룹 인터뷰를 통한 COVID-19 유행 동안 학교 급식의 변화)

  • Ji, Mirim;Um, Mihyang;Kye, Seunghee
    • Journal of the Korean Society of Food Culture
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    • v.37 no.1
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    • pp.1-12
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    • 2022
  • This qualitative study analyzed various environmental factors and difficulties faced by school foodservices during the COVID-19 pandemic. Focus group interviews were conducted by enrolling 12 nutrition teachers and nutritionists. Data collected were subsequently analyzed for changes implemented during the pandemic, in hygiene management, diet management, and distribution management of the school meal. The content and method of delivery of information related to diet guidance and school foodservice by related organizations were also examined. Results of the survey show that personal hygiene (such as maintaining student-to-student distance, checking students for a fever, and hand disinfection) was duly applied, installation of table coverings and distancing between school cafeteria seats were conducted, and mandatory mask-wearing to prevent droplet transmission was enforced. Depending on the COVID-19 situation, the number of students having school meals was limited per grade, and time-spaced meals were provided. To prevent infection, menus that required frequent hand contact were excluded from the meal plan. Overall, it was difficult to manage the meal plan due to frequent changes in tasks, such as the number of orders and meal expenses. These changes were communicated by nutrition teachers and nutritionists wherein the numbers of school meals were adjusted, depending on situations arising from each COVID-19 crisis stage. Furthermore, in some schools, either face-to-face nutrition counseling was stopped entirely, or nutrition education was conducted online. Parent participation was disallowed in the monitoring of school meals, and the prohibition on conversations inside the school cafeteria resulted in the absence of communication among students, nutrition teachers, and nutritionists. Additionally, confusion in meal management was caused by frequent changes in the school meal management guidelines provided by the Office of Education and the School Health Promotion Center in response to COVID-19. In anticipation of the emergence of a new virus or infectious diseases caused by mutations in the years to come, it is suggested that a holistic, well-thought-out response manual for safe meal operation needs to be established, in close collaboration with schools and school foodservice-related institutions.

Simulations of Capacitively Coupled Plasmas Between Unequal-sized Powered and Grounded Electrodes Using One- and Two-dimensional Fluid Models

  • So, Soon-Youl
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.5
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    • pp.220-229
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    • 2004
  • We have examined a technique of one-dimensional (1D) fluid modeling for radio-frequency Ar capacitively coupled plasmas (CCP) between unequal-sized powered and grounded electrodes. In order to simulate a practical CCP reactor configuration with a grounded side wall by the 1D model, it has been assumed that the discharge space has a conic frustum shape; the grounded electrode is larger than the powered one and the discharge space expands with the distance from the powered electrode. In this paper, we focus on how much a 1D model can approximate a 2D model and evaluate their comparisons. The plasma density calculated by the 1D model has been compared with that by a two-dimensional (2D) fluid model, and a qualitative agreement between them has been obtained. In addition, 1D and 2D calculation results for another reactor configuration with equal-sized electrodes have also been presented together for comparison. In the discussion, four CCP models, which are 1D and 2D models with symmetric and asymmetric geometries, are compared with each other and the DC self-bias voltage has been focused on as a characteristic property that reflects the unequal electrode surface areas. Reactor configuration and experimental parameters, which the self-bias depends on, have been investigated to develop the ID modeling for reactor geometry with unequal-sized electrodes.

Three Dimensional Indoor Location Tracking Viewer

  • Yang, Chi-Shian;Jung, Sang-Joong;Chung, Wan-Young
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.3 no.1
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    • pp.108-118
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    • 2009
  • In this paper we develop an indoor location tracking system and its 3D tracking monitoring viewer, viz., 3D Navigation Viewer (3DNV). We focus on the integration of an indoor location tracking system with the Virtual Reality Modeling Language (VRML), to facilitate a representation of the user's spatial information in virtual indoor environments that is synchronized with the physical location environment. The developed indoor location tracking system employs beacons as active transmitters, and a listener as a passive receiver. The distance information calculated from the difference speeds of RF and Ultrasonic signals is exploited, to determine the user's physical location. This is essential in supporting third parties like doctors and caregivers in identifying the activities and status of a particular individual via 3DNV. 3DNV serves as a unified user interface for an indoor location tracking system, showing the viewpoint and position of the target in virtual indoor environments. It was implemented using VRML, to provide an actual real time visualization of the target's spatial information.