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High-Temperature Cesium (Cs) Retention Ability of Cs-Exchanged Birnessite (세슘(Cs)으로 이온 교환된 버네사이트의 고온에서의 Cs 고정 능력)

  • Yeongkyoo Kim
    • Korean Journal of Mineralogy and Petrology
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    • v.36 no.4
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    • pp.313-321
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    • 2023
  • Numerous studies have investigated the adsorptive sequestration of radioactive cesium in the natural environment. Among these studies, adsorption onto minerals and high-temperature treatment stand out as highly effective, as demonstrated by the use of zeolite. In this study, cesium was ion-exchanged with birnessite and subsequently underwent high-temperature treatment up to 1100℃ to investigate both mineral phase transformation and the leaching characteristics of cesium. Birnessite has a layered structure consisting of MnO6 octahedrons that share edges, demonstrating excellent cation adsorption capacity. The high-temperature treatment of cesium-ion-exchanged birnessite resulted in changes in the mineral phase, progressing from cryptomelane, bixbyite, birnessite to hausmannite as the temperature increased. This differs from the phase transformation observed in the tunneled manganese oxide mineral todorokite ion-exchanged with cesium, which shows phase transformation only to birnessite and hausmannite. The leaching of cesium from cesium-ion-exchanged birnessite was estimated by varying the reaction time using both distilled water and a 1 M NaCl solution. The leaching quantity changed according to the treatment temperature, reaction time, and type of reaction solution. Specifically, the cesium leaching was higher in the sample reacted with 1 M NaCl compared to the sample with distilled water and also increased with longer reaction time. For the samples reacted with distilled water, the cesium leaching initially increased and then decreased, while in the NaCl solution, the leaching decreased, increased again, and finally nearly stopped like the sample in the distilled water for the sample treated at 1100℃. These changes in leaching are closely associated with the mineral phases formed at different temperatures. The phase transformation to cryptomelane and birnessite enhanced cesium leaching, whereas bixbyite and hausmannite hindered leaching. Notably, hausmannite, the most stable phase occurring at the highest temperature, demonstrated the greatest ability to inhibit cesium leaching. This results strongly suggest that high-temperature treatment of cesium-ion-exchanged birnessite effectively immobilizes and sequesters cesium.

Randomized Controlled Clinical Trials of Warm Herbal Foot Bath Therapy for Insomnia: A Literature Review Based on the CNKI (불면증에 대한 한방 족욕요법의 무작위 대조군 임상연구 현황 : CNKI를 중심으로)

  • Chan-Young Kwon;Boram Lee;Kyoungeun Lee
    • The Journal of Internal Korean Medicine
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    • v.44 no.4
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    • pp.726-740
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    • 2023
  • Objectives: This review investigated the research on warm herbal foot bath therapy (WHFT) for insomnia. Methods: A search was conducted on the China National Knowledge Infrastructure (CNKI) database to collect relevant studies published up to August 29, 2023. Randomized controlled trials (RCTs) comparing WHFT and sleeping pills in patients with insomnia were included. The methodological quality of the included studies was assessed using the Cochrane risk-of-bias assessment tool. The results of the meta-analysis were presented as risk ratios (RRs) or mean differences (MDs) and their 95% confidence intervals (CIs). Results: A total of 11 RCTs were included. WHFT as monotherapy resulted in a significantly higher total effective rate (TER) (RR, 1.25; 95% CI, 1.15 to 1.36; I2=25%) and an improved Pittsburgh Sleep Quality Index (PSQI) global sore (MD, -3.10; 95% CI, -4.24 to -1.95; I2=73%) compared to benzodiazepines. Additionally, WHFT as a combined therapy with benzodiazepines resulted in a significantly higher TER (RR, 1.15; 95% CI, 1.04 to 1.27; I2=0%) and an improved PSQI global score (MD, -2.23; 95% CI, -4.09 to -0.38; I2=80%) compared to benzodiazepines alone. In network analysis visualizing the components of HWFT, four clusters were discovered, and Polygoni Multiflori Ramuls and Ziziphi Spinosae Semen were the key herbs used in WHFT. Overall, the methodological quality of the included studies was poor. Conclusions: There was limited evidence that WHFT as a monotherapy or combined therapy was effective in improving insomnia. The findings can be used as basic data for future WHFT research in South Korea.

The effect of economic crisis on success attribution among Korean students and adults: An indigenous psychological analysis (IMF시대 이후 한국 학생과 성인의 성공에 대한 의식: 토착심리학적 분석)

  • Young-Shin Park;Uichol Kim;Soo-Yeon Tak
    • Korean Journal of Culture and Social Issue
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    • v.8 no.1
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    • pp.103-139
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    • 2002
  • Korean society has significantly changed with the onset of a dramatic economic crisis in 1998. From 2000, however, the Korean economy has recovered and currently Korea is enjoying a similar standard of living and economic growth as the pre-1998 levels. This study is a follow-up analysis, comparing the results examining the success attribution of Korean students and adults in 2001 with the results obtained before the economic crisis in 1997. Using the indigenous psychological approach, this study compares the similarities and differences in Korean students and adults' attribution of their personal success before and after the economic crisis. A total of 988 participants, consisting of 481 primary, junior high, senior high and university students and 507 adults (236 fathers and 271 mothers of the students) completed the questionnaire developed by Kim and Park (1998). The results indicate that students perceived their academic achievement and adults perceived successful family life as their most proud achievement. Successful family life included items such as academic success of children, healthy development of their children, and harmonious family life. The person who provided the most significant support for students were parents and for adults, it was their spouse. For students, the importance of friends' social support increased during the high school years. In terms of type of social support, emotional support was reported to be the most important for both students and adults. As for the reason for their success, majority of students and men reported self-regulation and for women, supportive family environment was reported as being the most important. Comparing 2001 results with the 1997 results, the importance of family increased after the economic crisis. Even with the dramatic economic crisis, however, some of the underlying pattern remain strong (such as importance of academic achievement for students, family life for adults, the importance of social support, especially emotional social support from family members, and believing that self-regulation would lead to success). The similar pattern of results obtain before and after the economic crisis indicate that the above results reflect a fundamental values and belief system deeply imbedded in Korean mentality.

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Scientific Study on Clepsydra of Changgyeonggung Palace, National Treasure for Diagnosis on State of Conservation (국보 창경궁 자격루 누기의 보존상태 진단을 위한 과학적 조사)

  • YOU Harim;LEE Jaesung;YU Jia;JO Hanui;PARK Younghwan;RYU Dongwan
    • Korean Journal of Heritage: History & Science
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    • v.56 no.3
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    • pp.138-156
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    • 2023
  • Some of the metal cultural heritage that make up a considerable proportion of Korea's cultural heritage have been installed and displayed outdoors due to their own functions, roles, and scale. Therefore, more diverse and complex damages can occur outdoors than they are in a stable environment. Therefore, it is necessary to combine accurate diagnosis and systematic survey methods in order to utilize basic data obtained from research results as data for the long-term and continuous conservation management as well as to do the research to diagnose the conservation status of outdoor cultural heritage. The clepsydra(hereinafter referred to as Jagyeongnu) of Changgyeonggung Palace, the National Treasure has been installed and displayed outdoors since it was manufactured. Though regular conservation and maintenance of the Jagyeongnu have been carried out, damage still occurred. Therefore, the scientific research on Jagyeongnu to diagnose the state of conservation was conducted prior to the full-scale conservation treatment. First, the state of conservation was investigated with an examination of basic data, macroscopic inspections and past records of repair history according to the purpose of the research. More detailed examinations were also conducted through the 3D scan, surface pattern investigation, and color difference analysis, and the analysis on materials and contaminants were conducted through P-XRF, FT-IR, and Py-GC/MS. The scientific research reveals that squalane and silicone oil have been applied in the past for conservation treatment and directly exposed to outdoor environmental factors, which caused damage to Jagyeongnu and contaminants such as dust adhered thickly to its surface, accelerating severe damage. A greater incidence of damage was found around the part with relatively high exposure effect, which corresponded with the tendency identified by grouping color difference data. As a result of integrating various research methodologies to diagnose the state of conservation and secure basic data, the causes and types of damage were identified. Furthermore, the process of obtaining digital data to be utilized in various ways, and the color difference analysis presenting visible damage as scientific data and identifying the tendency of damage patterns were confirmed to have been effective.

A Systematic Study of the Intervention Effect of Social Stories in Children with Sleep Disorders (수면장애 아동을 위한 사회적 이야기 중재 효과: 체계적 고찰)

  • Kim, Ji-Ho;Yoo, Eun-Young
    • The Journal of Korean Academy of Sensory Integration
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    • v.21 no.2
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    • pp.69-83
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    • 2023
  • Objective : This study sought to systematically examine the intervention effect of social stories when applied in relation to children with sleep disorders. Methods : Studies available in the SCOPUS, ScienceDirect, PsycArticles, and PubMed databases that were published from 2001 to 2022 were searched. The keywords used for the search were as follows: ("social story" OR "social stories") AND ("sleep" OR "sleep disorders" OR "sleep wake disorder bedtimes" OR "sleep initiation and maintenance disorders" OR "sleep wake disorder" OR "sleep arousal disorders"). Based on the selection criteria, six experimental studies were selected and analyzed. Results : The selected studies were two randomized controlled trials, three individual trials, and one case study. The subjects were mostly children diagnosed with autism spectrum disorder who were school-aged or adolescent. The intervention types were often complex interventions, including social stories and other interventions, while the durations of the interventions varied from one day to more than 40 days. The interventions had a positive effect on the subjects' sleep quality, with night wakings, sleep onset delay, and sleep anxiety all being improved. As standardized assessment tools to evaluate the effectiveness of social stories, the Child Sleep Habits Questionnaire and the Child Behavior Checklist were used in two papers each, and were the most commonly used. As non-standardized assessment tools, each of the four papers used turbulence and sleep diaries as assessment tools. Conclusion : The effect of social story mediation can be divided into sleep quality and sleep-related behavior. In terms of sleep quality, studies showing improvements in night wakings, sleep onset delay, and sleep anxiety accounted for a large proportion of the sample. The detailed effect area of sleep quality showed a significant improvement after the interventions in most studies, and in all six studies analyzed in the present study, the continuation of the effect after the intervention was confirmed via follow-up tests. Thus, the findings of this study are expected to be helpful when applying social stories in children with sleep disorders in clinical practice due to presenting the intervention effects, outcome evaluation tools, and intervention periods in children with sleep disorders in prior investigations involving social stories.

The Garden Archaeological Value of Okhojeong through Kim Jo-sun's Punggojip (김조순의 풍고집(楓皐集)을 통해서 본 옥호정의 정원고고학적 가치)

  • Shin, Hyun-Sil
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.41 no.4
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    • pp.49-56
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    • 2023
  • This study analyzes the entirety of Okhojeongdo's content found in the Punggojip, written by Kim Jo-Sun, who created Okhojeong. Through an examination of the literature confirming Okhojeong within the Punggojip, the study compares the existing research with the Okhojeongdo's content. Additionally, it clarifies the relationships between the disciple, the garden, and related historical facts. The results are as follows. First, Kim Jo-Sun, who created Okhojeong, had a strong literary inclination, which made it relatively easy to estimate the original form of the garden, as he expressed detailed content related to the design and management of the garden. Second, the historical dating of the creation of Okhojeong was previously estimated to be around 1815 based on the inscriptions on the Eulhaebyeok. However, it is more appropriate to revise this to 1804, as revealed by Lee Sung-min, who discovered records in Dongseonggyoyeojip, indicating that Kim Jo-Sun purchased the Jang's house. Third, Kim Jo-Sun's literary hobby, as depicted in Punggojip, closely followed Chinese classics. However, the part about creating the garden is supported by factual and garden archaeological records, giving it inherent value. Regarding the expansion of the garden site, it is estimated that the southern boundary of Okhojeong was extended by about half a unit(kan; 間) through a transfer from Kim saeng Saho. Various additions, stone statues, peculiar rocks, ornamental trees, and accompanying elements are found throughout the garden. Particularly noteworthy are the techniques and aesthetics of creating a stone pagoda, and there are mentions of transplanting young pine trees with professional insights. The love for harmony and elegance in the garden is woven throughout the poetry. Additionally, the process of selecting the location for Okhojeong, the understanding of the terrain and topography, the assessment of existing vegetation, the process of cutting down trees and selecting the soil, the construction of houses with tiles and thatched roofs all contribute to demonstrating the comprehensive stages of creating Okhojeong, providing insight into the location and construction process of the Sanbanru pavilion, showcasing the archaeological value of the garden. A follow-up study is needed to excavate more information about the original form of Okhojeong garden through the interpretation of the collections of the literary works of the influential figures introduced in Punggojip in the future.

Earnings Management of Firms Selected as Preliminary Unicorn (예비유니콘 선정기업의 이익조정에 대한 연구)

  • HAKJUN, HAN;DONGHOON, YANG
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.1
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    • pp.173-188
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    • 2023
  • This paper analyzed the Earnings management of firms selected as preliminary Unicorn. If a manager is selected as a preliminary unicorn firm, he can receive financial support of up to 20 billion won, creating a factor in managing the manager's earnings. The motive for management's earnings management is related to the capital market. Accounting information is used by investors and financial analysts, and corporate profits affect corporate value. Therefore, if the accounting earning is adjusted upward, the corporate value will be raised and investment conditions will be favorable. In this paper, earnings quality was measured by the modified Jones model of Dechow et al.(1995) by the ROA control model of Kothari et al.(2005) among the discretionary accruals estimated using an alternative accrual prediction model. Competing similar companies in the same market as the selected companies were formed, and the discretionary accruals were mutually compared to verify the research hypotheses, and only the selected companies were analyzed for the audit year and after the audit year. As a result of the analysis, it was found that the companies selected as preliminary unicorns had higher earnings management compared to the corresponding companies in question, which had a negative impact on the quality of accounting profits. It was found that the companies selected as preliminary unicorns continued to receive incentives for management's earnings management even after being selected. These results indicate that the companies selected as prospective unicorns are recognized for their value in the market through external growth rather than internal growth, and thus, incentives for management's earnings management to attract investment from external investors under favorable conditions are continuing. In the future preliminary unicorn selection evaluation, it was possible to present what needs to be reviewed on the quality of accounting earning. The implication of this paper is that the factors of management's earnings management eventually hinder investors and creditors from judging the reliability of accounting information. It was suggested that a policy alternative for the K-Unicorn Project, which enhances reliability were presented by reflecting the evaluation of earnings quality through discretionary accruals.

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An Exploratory Study on the Success Factors of Silicon Valley Platform Business Ecosystem: Focusing on IPA Analysis and Qualitative Analysis (실리콘밸리 플랫폼 기업생태계의 성공요인에 관한 탐색적 연구: IPA 분석과 질적 분석을 중심으로)

  • Yeonsung, Jung;Seong Ho, Lee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.1
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    • pp.203-223
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    • 2023
  • Recently, the platform industry is rapidly growing in the global market, and competition is intensifying at the same time. Therefore, in order for domestic platform companies to have global competitiveness in the platform market, it is necessary to study the platform business ecosystem and success factors. However, most of the recent platform-related studies have been theoretical studies on the characteristics of platform business status analysis, platform economy, and indirect network externalities of platforms. Therefore, this study comprehensively analyzed the success factors of Silicon Valley's business ecosystem proposed in previous studies, and at the same time analyzed the success factors extracted from stakeholders in the actual Silicon Valley platform business ecosystem. And based on these factors, an IPA analysis was conducted as a way to propose a success plan to stakeholders in the platform business ecosystem. As a result of the analysis, among the success factors collected through previous studies, manpower, capital, and challenge culture were identified as factors that are relatively well maintained in both importance and satisfaction in Silicon Valley. In the end, it can be seen that the creation of an environment and culture in which Silicon Valley can use it to challenge itself based on excellent human resources and abundant capital contributes the most to the success of Silicon Valley's platform business. On the other hand, although it is of high importance to Silicon Valley's platform corporate ecosystem, the factors that show relatively low satisfaction among stakeholders are 'learning and benchmarking among active companies' and 'strong ties and cooperation between members', and it is analyzed that interest and effort are needed to strengthen these factors in the future. Finally, the systems and policies necessary for market autonomous competition, 'business support service industry', 'name value', and 'spin-off start-up' were important factors in literature research, but the importance and satisfaction of these factors were lowered due to changes in the times and environment. This study has academic implications in that it comprehensively analyzes the success factors of Silicon Valley's business ecosystem proposed in previous studies, and at the same time analyzes the success factors extracted from stakeholders in the actual Silicon Valley platform business ecosystem. In addition, there is another academic implications that importance and satisfaction were simultaneously examined through IPA analysis based on these various extracted factors. As for academic implications, it is meaningful in that it contributed to the formation of the domestic platform ecosystem by providing the government and companies with concrete information on the success factors of the platform business ecosystem and the theoretical grounds for the growth of domestic platform businesses.

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A Study on the Relationships Among Learning Orientation, Innovativeness and Organizational Commitment of Entrepreneurs: Focusing on the Mediating Effect of Innovativeness and the Moderating Effect of Career Relevance (학습지향성 및 혁신성과 조직몰입 간의 관계에 관한 연구: 혁신성의 매개효과와 경력연관성의 조절효과를 중심으로)

  • Joo-Heon, Lee
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.6
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    • pp.159-174
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    • 2022
  • Entrepreneurs should continuously invest resource and capital for a long time to get tangible business results. In order to be successful, despite difficulties, it is essential for entrepreneurs to continue entrepreneurial businesses without giving up too early. Thus, it can be said that organizational commitment of entrepreneurs is essential for success. According to previous studies, the organizational commitment of entrepreneurs has a significant effect on organizing, establishments of new firms and new product developments. The purpose of this article is to examine the relationships among learning orientation, innovativeness and organizational commitment of entrepreneurs. Especially, we focus on the mediating effect of innovativeness in the relationship between learning orientation and organizational commitment and the moderating effect of career relevance among the relationships. Based on empirical analysis, we reported the following results. First, learning orientation, innovativeness and career relevance of entrepreneurs had significant positive effects on organizational commitment. Second, it was found that innovativeness of entrepreneurs has a partial mediating effect on the relationship between learning orientation and organizational commitment. Third, using Baron & Kenny's hierarchical multiple regression analysis, we examined the moderating effect of career relevance among the relationships of learning orientation, innovativeness and organizational commitment. Third, because the interaction term was found to be positively significant, it was concluded there is a moderating effect of career relevance between learning orientation and innovativeness. This means, when career relevance was higher than average, the influence of learning orientation on innovation increases even more. Fourth, it was also found there is a moderating effect of career relevance between learning orientation and organizational commitment. However, the results of the mediated moderating effect analysis showed the moderating effect of career relevance between learning orientation and organization commitment is an indirect effect of moderating effect of career relevance between learning orientation and innovativeness mediated by innovativeness.

The Effect of Environmental Factors on Competency and Performance of Venture Companies: The Double Mediating Effect of Venture Firm Confirmation System Benefits and Venture Firm Internal Competencies (벤처기업에 대한 환경적 요소가 역량 및 성과에 미치는 영향: 벤처기업 확인제도 혜택과 벤처기업 내부 역량의 이중매개효과를 중심으로)

  • Park, Dain;Kim, Daejin
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.5
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    • pp.241-253
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    • 2023
  • In the current rapidly changing environment, each country continues to make efforts to create jobs and strengthen technological competitiveness. In particular, support and revitalization policies for venture companies and start-ups are known to play a role in increasing national competitiveness. Companies should make appropriate replacements amid growing uncertainties in the environment in which business life is shortened and customer needs are diversified due to intensifying competition. First of all, it is important for companies to make efforts to strengthen their internal capabilities on their own. However, venture companies lack internal resources and capabilities, so support from the external environment is important enough to lead to the survival of the company(Timmons, 1994). Financial support and certification systems are being operated at the national level to strengthen the competitiveness of companies. However, financial support can lower a company's self-sustainability depending on the situation, so non-financial support such as R&D support and start-up education is considered to be helpful in the long term for venture growth(Aghion et al., 2012; Jeon & Ko, 2021). Non-financial support is divided into commercialization, facilities, space, childcare, manpower, and certification systems, and this study confirmed the benefits of the venture company confirmation system, which is a certification system. To this end, the 2021 venture company precision survey data and venture company sales data were used, and analyzed using the SPSS 26.0 package and SPSS PROCESS MACRO. As a result of the analysis, it was confirmed that the level of the management environment of venture companies has a positive effect on the benefits of the venture confirmation system or increasing the level of venture company capabilities, but it is difficult to lead to actual management performance. In addition, it was confirmed that the level of venture company competency mediates the relationship between the level of the venture company's business environment and management performance. As a result, even if the level of the venture company's business environment is positive or venture-friendly, it can be said that companies with internal capabilities to digest support from the external environment increase management performance.

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