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Numerical Study on the Stress-distribution Ratio of Grouting Pile for Reinforced Ground (지반보강용 그라우팅 말뚝의 응력분담비에 대한 수치해석적 연구)

  • Yi, Gyeong-Ju;Lee, Joon-Kyu;Zhang Weiwei;Song, Ki-Il
    • Journal of the Korean Geotechnical Society
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    • v.39 no.2
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    • pp.19-30
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    • 2023
  • Underground structures, such as compacted sand piles applied as soft ground countermeasures, are analyzed for settlement and stability by the composite ground design method. The basic principle of the composite ground design method is the arching effect. The reinforcing effect of the pile is evaluated as the stress-distribution ratio. When applying grouting piles with elastic properties using the ground reinforcement method, the existing stress-distribution ratio was only considered when the pile was installed. This study shows that the method of applying the stress-distribution ratio applied in previous studies should be changed when the ground reinforcement pile is installed at an arbitrary location in the ground without raising it to the ground surface. When high strength jet routing is applied, the stress-distribution ratio (n) to the in-situ ground generally ranges from 30 to 50. However, if the pile is located far from the surface and the depth goes down to the boundary depth of the stress sphere, the stress-distribution effect rapidly decreases, and the stress-distribution ratio converges to 1.5.

Exploring the Impact of Library Public Forums on Users' Perception of Libraries: A Study Based on Their Experiences (공공도서관 공론장 경험에 따른 이용자의 도서관 인식 연구)

  • Yeon Ok Lee;Young Ah Kang;Durk Hyun Chang
    • Journal of Korean Library and Information Science Society
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    • v.54 no.1
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    • pp.269-293
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    • 2023
  • The aim of this study is to investigate whether library public forums, which are conducted as a part of the library's information services, affect users' perception of libraries. We analyzed the variations in users' perception of libraries based on their participation in public forums held by the public libraries. Data was collected through a survey of users from the Seongbuk Public Libraries in Seoul, which hold public forums. It was discovered that users' perception of public libraries varied depending on whether they had attended the library's public forums or not. The study revealed that users who participated in library public forums had a better understanding of the public libraries compared to those who did not. Specifically, users who participated in public forums exhibited a deeper comprehension of the library's roles, higher trust in the library, and a greater willingness to visit the library. In addition, we found that users acknowledged the importance of public forums in libraries and expressed a high level of interest and willingness to participate in them. Based on these findings, we discussed the implications of library public forums on users' perception of libraries and highlighted the need for information services that are based on public forums.

Evaluation of Image for Phantom according to Normalization, Well Counter Correction in PET-CT (PET-CT Normalization, Well Counter Correction에 따른 팬텀을 이용한 영상 평가)

  • Choong-Woon Lee;Yeon-Wook You;Jong-Woon Mun;Yun-Cheol Kim
    • The Korean Journal of Nuclear Medicine Technology
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    • v.27 no.1
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    • pp.47-54
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    • 2023
  • Purpose PET-CT imaging require an appropriate quality assurance system to achieve high efficiency and reliability. Quality control is essential for improving the quality of care and patient safety. Currently, there are performance evaluation methods of UN2-1994 and UN2-2001 proposed by NEMA and IEC for PET-CT image evaluation. In this study, we compare phantom images with the same experiments before and after PET-CT 3D normalization and well counter correction and evaluate the usefulness of quality control. Materials and methods Discovery 690 (General Electric Healthcare, USA) PET-CT equiptment was used to perform 3D normalization and well counter correction as recommended by GE Healthcare. Based on the recovery coefficients for the six spheres of the NEMA IEC Body Phantom recommended by the EARL. 20kBq/㎖ of 18F was injected into the sphere of the phantom and 2kBq/㎖ of 18F was injected into the body of phantom. PET-CT scan was performed with a radioacitivity ratio of 10:1. Images were reconstructed by appliying TOF+PSF+TOF, OSEM+PSF, OSEM and Gaussian filter 4.0, 4.5, 5.0, 5.5, 6.0, 6,5 mm with matrix size 128×128, slice thickness 3.75 mm, iteration 2, subset 16 conditions. The PET image was attenuation corrected using the CT images and analyzed using software program AW 4.7 (General Electric Healthcare, USA). The ROI was set to fit 6 spheres in the CT image, RC (Recovery Coefficient) was measured after fusion of PET and CT. Statistical analysis was performed wilcoxon signed rank test using R. Results Overall, after the quality control items were performed, the recovery coefficient of the phantom image increased and measured. Recovery coefficient according to the image reconstruction increased in the order TOF+PSF, TOF, OSEM+PSF, before and after quality control, RCmax increased by OSEM 0.13, OSEM+PSF 0.16, TOF 0.16, TOF+PSF 0.15 and RCmean increased by OSEM 0.09, OSEM+PSF 0.09, TOF 0.106, TOF+PSF 0.10. Both groups showed a statistically significant difference in Wilcoxon signed rank test results (P value<0.001). Conclusion PET-CT system require quality assurance to achieve high efficiency and reliability. Standardized intervals and procedures should be followed for quality control. We hope that this study will be a good opportunity to think about the importance of quality control in PET-CT

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A New Phase of China's Development Against the Background of "Trade War" with the US: View from Russia (Вступление Китая в новую фазу развития на фоне "торговой войны" с США: взгляд из России)

  • Lukonin, Sergey;Ignatev, Sergei
    • Analyses & Alternatives
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    • v.2 no.2
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    • pp.111-141
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    • 2018
  • By the middle of 2018 there are signs of China's entry into a new period of development, characterized by a change in the old model: "market reforms-inner-party democratization - moderate foreign policy" to another: "market reforms - Xi Jinping personality cult - offensive foreign policy." This model contains the risks of arising of the contradiction between economic freedom and political-ideological rigidity which can lead to destabilization of the political life. However, in the current positive economic dynamics, these risks may come out, rather, in the medium and long term. Today, the political situation in China remains stable - despite growing dissatisfaction in scientific expert and educational circles due to increased control over the intellectual sphere by the authorities. The need for a new redistribution of power between central and provincial authorities could potentially disrupt political stability in the medium term, but, at the moment, is not a critical negative factor. The economic situation is positive-stable. Forecasts indicate a possible increase in China's GDP in 2018 at 6.5%. At the same time, there are negative expectations in connection with the Sino-US and potentially Sino-European "trade war". In the Chinese foreign policy, as a response to Western pressure, China increasingly uses the Russian direction of its diplomacy in the expanded version of Russia + SCO. The nuance here is seen in China's adjusted approach to the SCO: first of all, not as a mechanism for cooperation with Russia, but as an organization that allows using Russia's potential for pressure on the US in the Sino-US strategic rivalry. In the second half of 2018, the Chinese economy will continue to develop steadily, albeit with unresolved traditional problems (debts of provinces and state-owned enterprises, ineffective state sector, risks on the financial and real estate market). In politics, discontent with the cult of Xi will accumulate, but without real threats to its power. Weakening in economic opposition between China and the United States is possible due to Beijing's search for compromises on tariffs, intellectual property, trade deficit. To find such trade-offs, Xi will use the so-called. "Personal diplomacy" of direct contacts with Trump.

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An Exploratory Study of Indifference toward Fine Arts among Korean Middle-Class through a Ground Theory Method (순수예술 무관심 현상에 대한 탐색적 연구 - 근거이론 분석방법을 통한 접근법 -)

  • Park, Min-gwon;Hyun, Eunjung
    • Korean Association of Arts Management
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    • no.52
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    • pp.5-37
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    • 2019
  • Despite a copious volume of work on the relationship between social class and cultural consumption, scholars have paid scant attention to the increasingly apparent observation that a vast majority of the population exhibits indifference toward fine arts regardless of one's socio-economic status. Much of the prior literature on cultural consumption has treated the public's indifference to fine arts not as a distinct analytical category that deserves an explanation of its own, but simply as the opposite of "likes" or the act of consumption, let alone being disentangled from the concept of "dislikes" in taste-formation and consumption behavior. In this paper, we suggest that the seemingly increasing trend toward indifference to fine arts, especially among those who are part of the well-educated and economically well-off, merits close scholarly attention on its own term. As an initial step toward this endeavor, we explore the factors behind indifference toward fine arts among Korean middle-class, using the ground theory method. Our interview findings reveal that much of indifference toward fine arts is attributable to the lack of tastes in fine arts and artistic competence. Our results suggest that research drawing on Bourdieu's theory and Peterson's omnivore hypothesis needs to be further revised through an in-depth investigation of the institutional and societal contexts where art education takes place in Korea. We discuss the implications of our findings for policy-making in the cultural and artistic sphere.

Using frequency and needs for walking sphere of neighborhood facilities by the elderly - Focused on the elderly who lived in Busan - (노인의 근린생활시설 이용정도와 도보권 시설요구 - 부산지역 거주 노인을 중심으로 -)

  • Oh, Chan Ohk
    • Korea Science and Art Forum
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    • v.20
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    • pp.279-292
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    • 2015
  • As the aging society is rapidly coming, the needs for the elderly-friendly living environments was also increasing. The purpose of this study was to examine how frequently 25 neighborhood facilities were used by the elderly and what facility they wanted to be arranged within their walking distance. The subject of this study were 158 elderlies who were their ages of more than 65 years and lived in Busan. The data were collected by using an one to one interview method. Findings were as follows; 1) The elderly used very frequently facility for the elderly such as a senior center, walking road, and park and green space. Also, bus stop, traditional market, and resting facilities were used relatively frequently. 2) Some neighborhood facilities were used not frequently, but periodically. 3) Using frequencies of some neighborhood facilities were different by the elderly's characteristics. 4) Among 25 neighborhood facilities, the facilities which the old persons wanted to be arranged within walking distance were medical clinics, facilities for the elderly, subway station, bus stop, traditional market, park and green space, walking road, and food market/convenience store.

Experiments for Pressure Drop of Scrubbing Layer in a Scrubber System (스크러버 내 충진층에서의 압력강하 특성에 관한 실험적 연구)

  • Yong-Shik Han;Kyu Hyung Do;Kyungyul Chung;Byungil Choi;Hwalong You;Changhyun Kim;Minchang Kim;Taehoon Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.60 no.3
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    • pp.186-192
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    • 2023
  • According to the regulation on the pollution of the marine environment, SOx emission from ships has to be reduced. A SOx scrubbing system installed in a funnel of a ship is considered in order to reduce SOx emission. A scrubbing layer with a porous material is present in the funnel to increase the contact area between exhaust gas and water. In this study, experiments on the pressure drop characteristics in the scrubbing layer are conducted to investigate the effect of the scrubber on the engine load. The pressure drop according to flow rate of air instead of exhaust gas was measured for fillers such as sphere, pall ring and saddle in the scrubbing layer. First of all, porosity is experimentally measured for the three types of filler and it is confirmed that the porosity of the saddle-type filler was the largest. The pressure drop according to the change in air flow rate was measured for the three types of fillers in the scrubbing layer. As a result, the pressure drop was the smallest in the scrubbing layer with the saddle-type filler which has the largest porosity. In addition, the effect of spraying water flowing counter flow against air flow is experimentally examined. It is known that the pressure drop is increased because the air flow space is reduced when water is sprayed. In the case of the saddle, the pressure drop is about 1.5 to 2 times greater than that when only air flows at the optimum exhaust gas-water injection ratio.

Analysis of Absorbed Dose on the Nucleus Size Change of Single Cells using Therapeutic Radioisotopes (치료용 방사성동위원소 사용 시 단일 세포의 핵 크기 변화에 따른 흡수선량 분석)

  • Uoo-Soo, Kim;Yong-In, Cho
    • Journal of the Korean Society of Radiology
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    • v.16 no.7
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    • pp.1007-1014
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    • 2022
  • Targeted radionuclide therapy (TRT) is a method of treating tumor cells using radiopharmaceuticals. Cells and nuclei constituting tissues of the human body are composed of spherical and oval shapes, but cancer cells are composed of various cell types. Therefore, this study analyzed the absorbed dose for each organelle according to the change in the size of the cell nucleus for beta-emitting nuclides during targeted radionuclide therapy through the Monte Carlo method. Cells were set in two sphere shapes, 5 ㎛ and 10 ㎛, and the internal structure was divided into cell nucleus, cytoplasm, and cell surface. Next, the absorbed dose according to the increase in the size of the cell nucleus was evaluated. As a result, 177Lu among the target radionuclides showed the highest dose in all cell compartments. As the ratio of the nucleus in the cell increased, the absorbed dose on the cell surface increased, but the absorbed dose in the cytoplasm and nucleus tended to decrease. Accordingly, it is judged that it is important to select a radionuclide considering the size of cancer cells and determine an appropriate amount of radioactivity during targeted radionuclide treatment.

Psychological and Pedagogical Features the Use of Digital Technology in a Blended Learning Environment

  • Volkova Nataliia;Poyasok Tamara;Symonenko Svitlana;Yermak Yuliia;Varina Hanna;Rackovych Anna
    • International Journal of Computer Science & Network Security
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    • v.24 no.4
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    • pp.127-134
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    • 2024
  • The article highlights the problems of the digitalization of the educational process, which affect the pedagogical cluster and are of a psychological nature. The authors investigate the transformational changes in education in general and the individual beliefs of each subject of the educational process, caused by both the change in the format of learning (distance, mixed), and the use of new technologies (digital, communication). The purpose of the article is to identify the strategic trend of the educational process, which is a synergistic combination of pedagogical methodology and psychological practice and avoiding dialectical opposition of these components of the educational space. At the same time, it should be noted that the introduction of digital technologies in the educational process allows for short-term difficulties, which is a usual phenomenon for innovations in the educational sphere. Consequently, there is a need to differentiate the fundamental problems and temporary shortcomings that are inherent in the new format of learning (pedagogical features). Based on the awareness of this classification, it is necessary to develop psychological techniques that will prevent a negative reaction to the new models of learning and contribute to a painless moral and spiritual adaptation to the realities of the present (psychological characteristics). The methods used in the study are divided into two main groups: general-scientific, which investigates the pedagogical component (synergetic, analysis, structural and typological methods), and general-scientific, which are characterized by psychological direction (dialectics, observation, and comparative analysis). With the help of methods disclosed psychological and pedagogical features of the process of digitalization of education in a mixed learning environment. The result of the study is to develop and carry out methodological constants that will contribute to the synergy for the new pedagogical components (digital technology) and the psychological disposition to their proper use (awareness of the effectiveness of new technologies). So, the digitalization of education has demonstrated its relevance and effectiveness in the pedagogical dimension in the organization of blended and distance learning under the constraints of the COVID-19 pandemic. The task of the psychological cluster is to substantiate the positive aspects of the digitalization of the educational process.

Analysis of Finnish Education-related Research Trends in Korean Journals : A Network Text Analysis (핀란드 교육 관련 연구 동향분석 : 네트워크 텍스트 분석을 중심으로)

  • Kim YoungHwan;Kim YoungMin;Kim Hyunsoo;Noh Jihwa;Murphy Odo Dennis;Park Changun;Kim EunJi;Bae JinHee;Shon Mi;Chung JuHun;Lee ChaeYoung
    • Journal of the International Relations & Interdisciplinary Education
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    • v.4 no.1
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    • pp.85-111
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    • 2024
  • Since the release of the 2000 PISA results, Finland's education has consistently been regarded as a competitor or benchmark for South Korea's educational system. However, recent indicators of division, opposition, and discontent within our educational sphere suggest a considerable departure from Finland's ethos of happiness in education. Against this backdrop, this study aims to analyze the trends in Finnish education-related research appearing in Korean academic journals. Utilizing network text analysis, we examined 160 papers indexed in RISS with titles containing "Finland" and "education". Key findings are as follows. Firstly, research on Finnish education has been steadily increasing, albeit showing recent signs of decline. Secondly, the majority of research topics were micro-level, with literature review-based methodologies predominating. Thirdly, a minority of researchers accounted for one-third of the total research output. Fourthly, countries compared with Finland predominantly included neoliberal states such as Japan, the United States, the United Kingdom, Australia, and Singapore. Fifthly, research themes and subjects primarily focused on primary and secondary education, particularly in domains such as mathematics and science, influenced by PISA. Future research on Finnish education should transcend localized and fragmented areas of inquiry, undertaking comprehensive investigations into the processes and history of Finland's happiness-oriented education. Such endeavors are essential for deriving insights crucial for our learning. Particularly, consideration should be given to moving beyond literature-based methodologies, fostering international collaborative discussions facilitated online, and linking the Finnish education community with educators, parents, students, local councils, and governmental stakeholders to collectively discuss and research.