• Title/Summary/Keyword: Reliability

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A Study on Status of Landscape Architecture Industry with National Statistics (국가통계자료를 활용한 조경산업 현황 연구)

  • Choi, Ja-Ho;Yoon, Young-Kwan;Koo, Bon-Hak
    • Journal of the Korean Institute of Landscape Architecture
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    • v.50 no.5
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    • pp.40-53
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    • 2022
  • This study carried out to provide the methodology and basic status material of using Korean national statistics needed to find the actual state of the landscape architecture industry. The landscape architecture industry was classified into 'Design', 'Construction Management', 'construction', 'Maintenance & Management', 'Materials', 'Research', 'Education', and 'Administration' areas. In each field, business types were systemized and associated in accordance with Korean standard industrial classification and legislations pertinent to construction. Among them, the business types directly defined in the construction related legislations under the Ministry of Land, Infrastructure and Transport were focused on, and the establishment, association, integration, distribution, duplication, and omission of national statistics were analyzed. As a result, the business types of statistical analysis were selected. In order for commonality of statistical items and minimized error of interpretation, semantic analysis was conducted. Finally, the number of registered business types, the number of workers, and sales were selected. Based on them, the analysis framework applicable to fundamental analysis and evaluation of the actual state of the industry was proposed. Actual national statical data were applied for analysis and evaluation. In 2019, the number of registered business types related to the landscape architecture industry was 12,160, the number of workers by business type was 106,296, and the sales by business type were 8,308.5 billion KRW. The number of registered business types and the number of workers had been on the rise from 2017, whereas the sales had been on the decrease. It is required to come up with a plan for industrial development. This study was conducted with the national statistics established by multiple public institutions, so that there are limitations in securing consistency and reliability. Therefore, it is necessary to establish systematic and consistent national statistics in accordance with 「Landscaping Promotion Act」. In the future, it will planned to research application and development plans of national statistics according to subjects including park and green.

Evaluation and Verification of the Attenuation Rate of Lead Sheets by Tube Voltage for Reference to Radiation Shielding Facilities (방사선 방어시설 구축 시 활용 가능한 관전압별 납 시트 차폐율 성능평가 및 실측 검증)

  • Ki-Yoon Lee;Kyung-Hwan Jung;Dong-Hee Han;Jang-Oh Kim;Man-Seok Han;Jong-Won Gil;Cheol-Ha Baek
    • Journal of the Korean Society of Radiology
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    • v.17 no.4
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    • pp.489-495
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    • 2023
  • Radiation shielding facilities are constructed in locations where diagnostic radiation generators are installed, with the aim of preventing exposure for patients and radiation workers. The purpose of this study is seek to compare and validate the trend of attenuation thickness of lead, the primary material in these radiation shielding facilities, at different maximum tube voltages by Monte Carlo simulations and measurement. We employed the Monte Carlo N-Particle 6 simulation code. Within this simulation, we set a lead shielding arrangement, where the distance between the source and the lead sheet was set at 100 cm and the field of view was set at 10 × 10 cm2. Additionally, we varied the tube voltages to encompass 80, 100, 120, and 140 kVp. We calculated energy spectra for each respective tube voltage and applied them in the simulations. Lead thicknesses corresponding to attenuation rates of 50, 70, 90, and 95% were determined for tube voltages of 80, 100, 120, and 140 kVp. For 80 kVp, the calculated thicknesses for these attenuation rates were 0.03, 0.08, 0.21, and 0.33 mm, respectively. For 100 kVp, the values were 0.05, 0.12, 0.30, and 0.50 mm. Similarly, for 120 kVp, they were 0.06, 0.14, 0.38, and 0.56 mm. Lastly, at 140 kVp, the corresponding thicknesses were 0.08, 0.16, 0.42, and 0.61 mm. Measurements were conducted to validate the calculated lead thicknesses. The radiation generator employed was the GE Healthcare Discovery XR 656, and the dosimeter used was the IBA MagicMax. The experimental results showed that at 80 kVp, the attenuation rates for different thicknesses were 43.56, 70.33, 89.85, and 93.05%, respectively. Similarly, at 100 kVp, the rates were 52.49, 72.26, 86.31, and 92.17%. For 120 kVp, the attenuation rates were 48.26, 71.18, 87.30, and 91.56%. Lastly, at 140 kVp, they were measured 50.45, 68.75, 89.95, and 91.65%. Upon comparing the simulation and experimental results, it was confirmed that the differences between the two values were within an average of approximately 3%. These research findings serve to validate the reliability of Monte Carlo simulations and could be employed as fundamental data for future radiation shielding facility construction.

Comparative Study on the Independence of Central bank in Transition Countries: Focused on the Russia, Czech Republic, Poland (체제전환기 국가의 중앙은행 독립성 비교 연구 - 러시아, 체코, 폴란드를 중심으로)

  • Kim, Sang Won
    • Journal of International Area Studies (JIAS)
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    • v.14 no.2
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    • pp.499-524
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    • 2010
  • The purpose of this study is to based on review of theoretical and empirical studies to assess the independence of central banks - the former Socialist republics, including the Russian Federation and Czech, Poland. In addition, the work is expected to clarify whether a link exists between independence and the most important economic indicators such as inflation, economic activity, the budget deficit. And The subject of this study are the formal and actual independence of national banks, as well as limiting factors: political and economic. Background investigation of the problem of independence of central banks from the fact that, according to many economists, it is essential to the successful development of a market economy. The effectiveness of any country's economy due to currency volatility, low inflation, high reliability of the banking system, etc. As far as the independence of monetary regulation contributes to these goals - one of the most actively debated issues in the world of economic theory and practice for a long time. The issue of central bank independence is extremely important for Russia, Czech, Poland. In the near future to the central bank has important tasks, among which are the transition to inflation targeting in the rejection of significant intervention in the foreign exchange market, as well as improving the sustainability of the national banking system. Transparency and independence of the Bank of Russia, Czech Republic, Poland, in my view, should be an important factor in achieving these goals. The countries of Czech Republic, Poland have already made a number of steps to bring the status of their banks to the European standards. Many other developing countries are also in the process of reforming their central banks and the improving conditions of their functioning. However, despite the fact that as a model for reform used by the central banks of countries with developed market economies, central banks in developing countries are still yet deprived of the legal, economic and political independence. A different situation exists in transition space. Because of significant differences in the views of the authorities in transition republics at the necessary level of independence of central banks and the exchange rate and monetary policy reform of monetary management in these countries led to different results.

A Study on the Types of Tree Management in Modern Palace Using Photographs and Expert Interviews (사진과 전문가 인터뷰를 통해 추론한 근대 궁궐의 수목관리 판단 연구)

  • Choi, Jin-seo;Kim, Choong-Sik
    • Journal of the Korean Institute of Landscape Architecture
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    • v.51 no.2
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    • pp.94-102
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    • 2023
  • The Florence Charter, established in 1981 by the ICOMOS-IFLA International Commission on Historic Gardens, considered the historic garden as a plant-dominated architectural composition, a perpetual balance between the artist and the artisan's desire to remain unaltered in perpetuity. Trees, the main component of the garden, require continuous management as they repeat their creation and calling according to the cycle of the seasons and accordingly, it is suggested that management to maintain the appearance of trees in Korean palaces was an indispensable element. Although it is an important matter to historically verify the tree management techniques of the palaces of the past, research has been difficult due to the absence of historical records and the disconnection of life due to the Japanese colonial period. In addition, according to the view that trees were not generally managed in the palace, research on palace tree management techniques has not been conducted so far. Therefore, this study aimed to examine whether or not the tree management of the palaces was performed in the past through expert interviews based on photographs taken in modern times. With the identification of tree species and pruning through in-depth interviews with experts using photographs taken in the modern period, the results are as follows. First, it was found that the shapes of trees and leaves could be identified through photographs and by observing the phenomena caused by planting and pruning, it was possible to estimate whether or not the tree management was implemented in the modern palace. Second, as a result of in-depth interviews with 8 experts in 4 fields, it was possible to determine the tree species and pruning status, purpose, and method. There was no significant difference in opinions between groups, and the evidence was clearly presented. Third, the type of management of trees in the palace was mainly found to be determination of the types of tree, removal of hazardous factors of trees, and management of lower vegetation and through the photographs of Jondeokjeong and Gwanwanjeong, it was confirmed that the trees were managed even before the Japanese colonial era, considering the time of filming. Based on the photographs taken, it was possible to estimate whether the trees were managed before the Japanese colonial period through expert interviews. However, it could not be clarified due to lack of historical materials as to whether it was carried out on its own according to the circumstances of the times or by the Japanese Empire. Still, in this study, evidence was obtained to refute the view that trees of the palace were not managed in the past through the collected data. Expert opinions supporting this view were collected to make the conclusion. In addition, based on the general theory of pruning, an empirical review of expert opinions was conducted to secure the reliability of the research results.

Evaluation of estuary reservoir management based on robust decision making considering water use-flood control-water quality under Climate Change (이수-치수-수질을 고려한 기후변화 대응 로버스트 기반 담수호 관리 평가)

  • Kim, Seokhyeon;Hwang, Soonho;Kim, Sinae;Lee, Hyunji;Kwak, Jihye;Kim, Jihye;Kang, Moonseong
    • Journal of Korea Water Resources Association
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    • v.56 no.6
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    • pp.419-429
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    • 2023
  • The objective of this study was to determine the management water level of an estuary reservoir considering three aspects: the water use, flood control and water quality, and to use a robust decision-making to consider uncertainty due to climate change. The watershed-reservoir linkage model was used to simulate changes in inflow due to climate change, and changes in reservoir water level and water quality. Five management level alternatives ranging from -1.7 El.m to 0.2 El.m were evaluated under the SSP1, 2, 3, and 5 scenariosof the ACCESS-CM2 Global Climate Model. Performance indicators based on period-reliability were calculated for robust decision-making considering the three aspects, and regret was used as a decision indicator to identify the alternatives with the minimum maximum regret. Flood control failure increased as the management level increased, while the probability of water use failure increased as the management level decreased. The highest number of failures occurred under the SSP5 scenario. In the water quality sector, the change in water quality was relatively small with an increase in the management level due to the increase in reservoir volume. Conversely, a decrease in the management level resulted in a more significant change in water quality. In the study area, the estuary reservoir was found to be problematic when the change in water quality was small, resulting in more failures.

K-DEV: A Borehole Deviation Logging Probe Applicable to Steel-cased Holes (철재 케이싱이 설치된 시추공에서도 적용가능한 공곡검층기 K-DEV)

  • Yoonho, Song;Yeonguk, Jo;Seungdo, Kim;Tae Jong, Lee;Myungsun, Kim;In-Hwa, Park;Heuisoon, Lee
    • Geophysics and Geophysical Exploration
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    • v.25 no.4
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    • pp.167-176
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    • 2022
  • We designed a borehole deviation survey tool applicable for steel-cased holes, K-DEV, and developed a prototype for a depth of 500 m aiming to development of own equipment required to secure deep subsurface characterization technologies. K-DEV is equipped with sensors that provide digital output with verified high performance; moreover, it is also compatible with logging winch systems used in Korea. The K-DEV prototype has a nonmagnetic stainless steel housing with an outer diameter of 48.3 mm, which has been tested in the laboratory for water resistance up to 20 MPa and for durability by running into a 1-km deep borehole. We confirmed the operational stability and data repeatability of the prototype by constantly logging up and down to the depth of 600 m. A high-precision micro-electro-mechanical system (MEMS) gyroscope was used for the K-DEV prototype as the gyro sensor, which is crucial for azimuth determination in cased holes. Additionally, we devised an accurate trajectory survey algorithm by employing Unscented Kalman filtering and data fusion for optimization. The borehole test with K-DEV and a commercial logging tool produced sufficiently similar results. Furthermore, the issue of error accumulation due to drift over time of the MEMS gyro was successfully overcome by compensating with stationary measurements for the same attitude at the wellhead before and after logging, as demonstrated by the nearly identical result to the open hole. We believe that the methodology of K-DEV development and operational stability, as well as the data reliability of the prototype, were confirmed through these test applications.

Clinical Characteristics and Comparison of the Various Methods Used for the Diagnosis of the New Influenza A Pandemic in Korea (한국에서의 2009 신종 인플루엔자 A의 임상양상과 다양한 진단 방법들의 비교)

  • Kwon, Min Jung;Lee, Chang Kyu;Roh, Kyoung Ho;Nam, Myung Hyun;Yoon, Soo Young;Lim, Chae Seung;Cho, Yun Jung;Kim, Young Kee;Lee, Kap No
    • Laboratory Medicine Online
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    • v.1 no.1
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    • pp.26-34
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    • 2011
  • Background: Laboratory diagnosis of new influenza A (H1N1) is crucial for managing patients and establishing control and prevention measures. We compared the diagnostic accuracies of the real time RT-PCR (rRT-PCR) test recommended for the confirmation of the new flu and the viral culture method used conventionally for viral disease with that of the rapid antigen test (RAT). Methods: We performed RAT, R-mix culture, and real-time PCR by using 861 respiratory samples collected from December 2009 to January 2010 and evaluated the abilities of these methods to detect new influenza A. The relationship among the positive rates of RAT, grades of culture, and the cycle threshold (Ct) values of rRT-PCR was also evaluated. Results: Of the 861 patients, 308 (35.8%) were diagnosed with new influenza A. The sensitivities, specificities, positive predictive values, and negative predictive values of the tests were respectively as follows: 59.7%, 99.5%, 98.4%, and 81.6% for RAT; 93.2%, 100%, 100%, and 96.3% for R-mix culture; and 95.8%, 100%, 100%, and 97.7% for rRT-PCR. Samples with weak positive grade in culture and those with Ct values of 30-37 in rRT-PCR showed positivities as low as 25.3% and 2.3% in RAT, respectively. The hospitalization rate and death rate of the confirmed patients were 3.2% and 0.3%, respectively, and gastrointestinal symptoms were observed in 7.2% of the patients. Conclusions: R-mix culture and rRT-PCR tests showed excellent reliability in the diagnosis of new influenza A and could be very useful, especially for samples with low viral load.

The Effects of Culture and Art Activities and Participation Motivation on Subjective Well-Being of Individuals: Focusing on Mediating Effect of Learning Motivation (문화예술활동과 참여 동기가 개인의 주관적 안녕감에 미치는 영향 - 학습동기의 매개효과를 중심으로 -)

  • Kim, Seung Hyuk
    • Korean Association of Arts Management
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    • no.51
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    • pp.35-73
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    • 2019
  • The purpose of this study is to investigate the effects of culture and arts activities (experience, type, frequency) and participation motivation on subjective well-being and to investigate the mediating effects of learning motivation. For this study, the subject is limited to adults who are leading consumers of culture and art activities can decide what activity to do. By survey, data from 1,000 respondents are used for analysis after applying proportional sampling based on the proportion of sex and age indicated in the population statistics. Exploratory factor analysis and reliability analysis were conducted based on the collected data using SPSS v.22.0. The results obtained from the empirical analysis are as follows. First, regarding culture and art activities (experience, type, frequency) and subjective well-being, the results are as follows. H1. Those who experienced culture and arts activities have higher subjective well-being than non-experienced ones. H2. Participating in culture and art activity increases subjective well-being more than just spectating culture and art programs. H3. Heavy participants in culture and art activities have higher subjective well-being than lighter participants. These results indicate that culture and art activities are important variables that have a positive effect on subjective well-being. Therefore, participating in culture and art activities may be an appropriate way to enhance subjective well-being because they are life experiences that individuals can experience in their daily lives. Second, H4. internal motivation and external motivation, sub-factors of participation motivation in culture and art activities, have a positive effect on subjective well-being, and amotivation has a negative effect on subjective well-being. Therefore, in order to improve subjective well-being, it is important to strive to lower amotivation and increase internal and external motivation. Third, H5. learning motivation has a partial mediating effect on the relationship between participation motivation in culture and art activities and subjective well-being. This result suggests that culture and art activities and education might be helpful for subjective well-being when they are conducted together since participation motivation in culture.

Examining the Influence of Science Museum Service Quality on Customer Satisfaction and Revisit Intention - A Case of Gwacheon National Science Museum - (과학관 서비스 품질이 고객만족도 및 재방문 의도에 미치는 영향 분석 - 국립과천과학관을 중심으로 -)

  • Choi, Jung won;Nam, Tae woo;Cho, Jae min
    • Korea Science and Art Forum
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    • v.27
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    • pp.277-288
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    • 2017
  • The number of science museums in Korea has expanded quantitatively from 72 in 2008 to 128 in 2016. This study started with the fact that the government puts a lot of budget into building a science museum, but there are more than one quarter of science museums with less than 50 spectators per day and many inefficient institutions. The number of visitors is an important factor in improving the efficiency of the science museum operation. The purpose of this study is to analyze the relation between the service quality of the science museum and the customer satisfaction and the intention to revisit and to find out what kind of effort should be concentrated in the science museum to attract more visitors. Questionnaires were written in the exhibition, education, and culture fields of the Gwacheon National Science Museum. The results were derived by frequency analysis, reliability analysis, factor analysis, and multiple regression analysis. The results and contents of the study are as follows. First, in the field of exhibition, the quality of exhibition facilities was expected to affect customer satisfaction and intention to return, but did not have a meaningful relationship. Second, the education sector has been found to affect customer satisfaction and return intention in all aspects of service quality (operation and contents, instructors, educational facilities and environment). Third, in the field of culture (event), the quality of the cultural program influences the visitor satisfaction, but it does not affect the intention to revisit. The science museum can provide satisfaction to visitors by combining activities such as science and arts. Despite the limitations, it is necessary to make efforts to improve the visitor satisfaction and revisit by proceeding with the convergence research on the entire National Science Museum in the future.

Effects of Impact of Climate Change on Livestock Productivity - For bullocks, dairy, pigs, laying hens, and broilers - (기후변화가 축산 생산성에 미치는 영향 -거세우, 낙농, 양돈, 산란계, 육계를 대상으로-)

  • Lee, H.K.;Park, H.M.;Shin, Y.K.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.20 no.1
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    • pp.107-123
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    • 2018
  • The global impact of climate change on agriculture is now increasing. The purpose of this study was to investigate the effect of climate change on livestock productivity. The variables that have the greatest influence on climate change factors were examined through previous studies and expert surveys. We also used the actual productivity data of livestock farmers to investigate the relationship with climate change. In order to evaluate the climate for changes in livestock productivity, national representative data (such as bullocks, dairy, pigs, laying hens, and broilers) were surveyed in Korea. Also, to select and classify evaluation indexes, we selected climate change factor variables as prior studies and studied the weighting factor of climate variable factors. In this study, the researchers of industry, academia, and farmers in the livestock sector conducted questionnaires on the indicators of vulnerability to climate change using experts, and then weighed the selected indicators using the hierarchical analysis process (AHP). In order to verify the validity of the evaluation index, was examined using domestic climate data (temperature, precipitation, humidity, etc.). Correlation and regression analysis were performed. The empirical relationship between climate change and livestock productivity was examined through this study. As a result, we used data with high reliability of statistical analysis and found that there are significant variables.