• Title/Summary/Keyword: cross-over studies

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Trends of Nursing Research on Disasters in Korea (재난관련 국내 간호연구 동향 분석)

  • Lee, Ogcheol
    • Journal of Korean Public Health Nursing
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    • v.28 no.3
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    • pp.432-444
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    • 2014
  • Purpose: This descriptive study was conducted in order to investigate the research trends of past nursing studies related to disasters in Korea, and to identify the direction of future research. Methods: Fifty studies conducted from July 1995 to June 2014 were analyzed according to general characteristics, disaster phase, disaster type, and research theme based on the four areas and 10 domains of the ICN Framework of Disaster Nursing Competencies. Results: The majority of studies were designed using quantitative methods (29). In disaster type, 12 studies explored natural disasters, and 14 explored manmade disasters. Disaster responders were the subject of 31 studies. In relation to research topics, the majority of studies were in the area of preparedness competencies of the ICN Framework (26). The studies were concentrated in the domain of education and preparedness (24). Conclusion: The total number of studies on disasters had increased over the years, while the topics failed to deal with all domains of the ICN Framework. The results indicate that the future direction of nursing research on disasters is to be vitalized through the flexibility of research design, systematic approach based on global perspectives, research on emergency responders and vulnerable people, and research relating to community-based disaster nursing.

Reliability and Safety of Cross-Leg Free Latissmus Dorsi Muscle Flap in Reconstruction of Mutilating Leg Injuries Using End-to-Side Anastomosis

  • Ahmed Gaber Abdelmegeed;Mahmoud A. Hifny;Tarek A. Abulezz;Samia Saied;Mohamed A. Ellabban;Mohamed Abdel-Al Abo-Saeda;Karam A. Allam;Mostafa Mamdoh Haredy;Ahmed S. Mazeed
    • Archives of Plastic Surgery
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    • v.50 no.5
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    • pp.507-513
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    • 2023
  • Background Free tissue transfer is considered the gold standard option for the reconstruction of distal leg defects. Free tissue transfer using recipient vessels in the contralateral leg (cross-leg bridge) is a potential option to supply the flap if there are no suitable recipient vessels in the injured leg. Most studies have described this technique using end-to-end anastomosis which sacrifices the main vessel in the uninjured leg. This study evaluated the use of a cross-leg free latissimus dorsi muscle flap for the reconstruction of defects in single-vessel legs, using end-to-side anastomosis to recipient vessels in the contralateral leg without sacrificing any vessel in the uninjured leg. Methods This is a retrospective study that included 22 consecutive patients with soft tissue defects over the lower leg. All the reconstructed legs had a single artery as documented by CT angiography. All patients underwent cross-leg free latissimus dorsi muscle flap using end-to-side anastomosis to the posterior tibial vessels of the contralateral leg. Results The age at surgery ranged from 12 to 31 years and the mean defect size was 86 cm2. Complete flap survival occurred in 20 cases (91%). One patient had total flap ischemia. Another patient had distal flap ischemia. Conclusion Cross-leg free latissimus dorsi muscle flap is a reliable and safe technique for the reconstruction and salvage of mutilating leg injuries, especially in cases of leg injuries with a single artery. As far as preservation of the donor limb circulation is concerned, end-to-side anastomosis is a reasonable option as it maintains the continuity of the donor leg vessels.

Effects of Different Types of Chatbots on EFL Learners' Speaking Competence and Learner Perception (서로 다른 챗봇 유형이 한국 EFL 학습자의 말하기능력 및 학습자인식에 미치는 영향)

  • Kim, Na-Young
    • Cross-Cultural Studies
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    • v.48
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    • pp.223-252
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    • 2017
  • This study explores effects of two types of chatbots - voice-based and text-based - on Korean EFL learners' speaking competence and learner perception. Participants were 80 freshmen students taking an English-speaking class at a university in Korea. They were divided into two experimental groups at random. During the sixteen-week experimental period, participants engaged in 10 chat sessions with the two different types of chatbots. To take a close examination of effects on the improvement of speaking competence, they took the TOEIC speaking test as pre- and post-tests. Structured questionnaire-based surveys were conducted before and after treatment to determine if there are changes in perception. Findings reveal two chatbots effectively contribute to improvement of speaking competence among EFL learners. Particularly, the voice-based chatbot was as effective as the text-based chatbot. An analysis of survey results indicates perception of chatbot-assisted language learning changed positively over time. In particular, most participants preferred voice-based chatbot over text-based chatbot. This study provides insight on the use of chatbots in EFL learning, suggesting that EFL teachers should integrate chatbot technology in their classrooms.

The Effective Cross-sections of a Lensing galaxy: Singular Isothermal Sphere with External Shear

  • Lee, Dong-Wook;Kim, Sang-Joon
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.77.1-77.1
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    • 2015
  • We present our recent work published in the MNRAS (Lee and Kim, 2014). Numerical studies of the imaging and caustic properties of the singular isothermal sphere (SIS) under a wide range of external shear (from 0.0 to 2.0) are presented. Using a direct inverse mapping formula for this lensing system, we investigate various lensing properties for both low-shear (i.e. ${\gamma}$<1.0) and high-shear (i.e. ${\gamma}$ >1.0) cases. We systematically analyse the effective lensing cross-sections of double-lensing and quadruple-lensing systems, based on the radio luminosity function obtained by the Jodrell-VLA Astrometric Survey (JVAS) and the Cosmic Lens All-Sky Survey (CLASS). We find that the limit of a survey selection bias (i.e. between brighter and fainter images) preferentially reduces the effective lensing cross-sections of two-image lensing systems. By considering the effects of survey selection bias, we demonstrate that the long-standing anomaly over the high quads-to-doubles ratios (i.e. 50~70 % for JVAS and CLASS) can be explained by the moderate effective shear of 0.16~0.18, which is half that of previous estimates. The derived inverse-mapping formula could make the SIS + shear lensing model useful for galaxy-lensing simulations.

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Efficient cross-sectional profiling of built up CFS beams for improved flexural performance

  • Dar, M. Adil;Subramanian, N.;Atif, Mir;Dar, A.R.;Anbarasu, M.;Lim, James B.P.
    • Steel and Composite Structures
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    • v.34 no.3
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    • pp.333-345
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    • 2020
  • In the past, many efficient profiles have been developed for cold-formed steel (CFS) members by judicious intermediate stiffening of the cross-sections, and they have shown improved structural performance over conventional CFS sections. Most of this research work was based on numerical modelling, thus lacking any experimental evidence of the efficiency of these sections. To fulfill this requirement, experimental studies were conducted in this study, on efficient intermediately stiffened CFS sections in flexure, which will result in easy and simple fabrication. Two series of built-up sections, open sections (OS) and box sections (BS), were fabricated and tested under four-point loading with same cross-sectional area. Test strengths, modes of failure, deformed shapes, load vs. mid-span displacements and geometric imperfections were measured and reported. The design strengths were quantified using North American Standards and Indian Standards for cold-formed steel structures. This study confirmed that efficient profiling of CFS sections can improve both the strength and stiffness performance by up to 90%. Closed sections showed better strength performance whereas open sections showed better stiffness performance.

Longitudinal Relationships between Academic Achievement and School Satisfaction :Using Fully Autoregressive Cross-Lagged Modeling and Multi-group Analysis by Poverty Status (학업성취와 학교만족도의 종단적 상호 관계 : 빈곤 및 비빈곤 집단 차이를 중심으로)

  • Park, Hyun-Sun;Lee, Hyun-Joo;Chung, Ick-Joong
    • Korean Journal of Social Welfare Studies
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    • v.42 no.3
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    • pp.183-206
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    • 2011
  • This study examined the longitudinal relationship between academic achievement and school satisfaction using a data of the Seoul Panel Study of Children(SPSC). Fully autoregressive cross-lagged analysis and multi-group comparison were performed to measure the longitudinal relationship between two constructs as well as differences between poverty and non-poverty groups. The results showed that both academic achievement and school satisfaction were stable over time in non-poverty group. Academic achievement at the 4th grade significantly affected the school satisfaction at the 6th grade and it subsequently affected on the academic achievement at the 8th grade in non-poverty group. In contrast, academic achievement was not consistent over time in poverty group. Only the school satisfaction at the 6th grade affected the academic achievement at the 8th grade. The findings of this study have various practical implication for school interventions. It is more important to keep supporting the children to maintain the level of academic achievement in non-poverty group. While, in poverty group, it is essential to make school satisfaction and academic motivation increase with school attachment programs.

Sources of Income Polarization in Korea: Globalization and Technological Innovation

  • Shin, Taeyoung
    • STI Policy Review
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    • v.7 no.2
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    • pp.1-15
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    • 2016
  • This study provides empirical evidences for the relationship between income inequality and economic growth, and relationship of income inequality with some of explanatory variables such as technological innovation, trade globalization, financial globalization and fiscal policy. We find out that income inequality has an adverse effect on economic growth, showing its dynamic features, for which we employed the polynomial distributed lags (PDL) model. The effect of income inequality on economic growth lasts over 9 years, and its dynamic effect peaks after 4 years. In addition, we also attempted to find out empirical evidences of sources of income inequality. The results show that income inequality is positively related to technological innovation, financial globalization, and fiscal policy; negatively related to the trade globalization. Many studies employ cross-country data, but it could have serious problems in collecting statistical data. Korean data is used over the time period of 1990-2015 in this study.

A Review of the Literature Using the Korean National Environmental Health Survey (cycle 1-3) (국민환경보건기초조사 1~3기의 연구성과 검토)

  • Lee, Seungho;Kim, Jin Hee;Choi, Yoon-Hyeong;Kim, Sungkyoon;Lee, Kyung mu;Park, Jae Bum
    • Journal of Environmental Health Sciences
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    • v.47 no.3
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    • pp.227-244
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    • 2021
  • Objectives: The Korean National Environmental Health Survey provides representative biomonitoring data for environmental pollutants in South Korea. Over the last decade, there have been various studies published using this data. In this study, we aimed to provide information and implications by reviewing each study. Methods: We searched comprehensive electronic databases from PubMed, Google Scholar, and Naver Academic database using the key words 'Korean National Environmental Health Survey' and 'KoNEHS' through March 2021. A total of 57 studies were selected after reviewing the relevance of the data. Results: The most frequently studied pollutants were heavy metals (10), Cotinine (8), Bisphenol A (7), and Phthalates (6), in that order. In particular, Phthalates, Bisphenol A, and Parabens were often studied together (6). A decline in urinary cotinine and heavy metals in the body was shown over time among studies on exposure association. It was demonstrated that Phthalates and Bisphenol A were significantly related to obesity and diabetes from the studies of health impacts. Cross-section study design, spot urine, and insufficient health status information were mostly reported as limitations of the data. Conclusion: Since research has been focused on adults, further investigations of children and adolescents are required. In this regard, it is necessary to maintain the consistency of the data structure and provide integrated weights for all ages. In addition, it would allow the measurement of several environmental pollutants by considering subsample design. Lastly, integrated studies with multi-cycles and the health effects from co-exposure to multiple chemicals would be expected to provide important knowledge.

Multi-objective optimal design of laminate composite shells and stiffened shells

  • Lakshmi, K.;Rama Mohan Rao, A.
    • Structural Engineering and Mechanics
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    • v.43 no.6
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    • pp.771-794
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    • 2012
  • This paper presents a multi-objective evolutionary algorithm for combinatorial optimisation and applied for design optimisation of fiber reinforced composite structures. The proposed algorithm closely follows the implementation of Pareto Archive Evolutionary strategy (PAES) proposed in the literature. The modifications suggested include a customized neighbourhood search algorithm in place of mutation operator to improve intensification mechanism and a cross over operator to improve diversification mechanism. Further, an external archive is maintained to collect the historical Pareto optimal solutions. The design constraints are handled in this paper by treating them as additional objectives. Numerical studies have been carried out by solving a hybrid fiber reinforced laminate composite cylindrical shell, stiffened composite cylindrical shell and pressure vessel with varied number of design objectives. The studies presented in this paper clearly indicate that well spread Pareto optimal solutions can be obtained employing the proposed algorithm.

A Study on the Standard Provisions of International Franchising Contracts and Unfair Trade Acts (국제프랜차이즈계약의 표준조항과 불공정거래행위)

  • Seo, Jung-Doo
    • Journal of Arbitration Studies
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    • v.22 no.3
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    • pp.165-185
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    • 2012
  • Franchising has proved over many years to be a successful commercial vehicle for the international distribution of products and services. However, there has long been missing a user-friendly model contract that would reflect the diversity of international franchising contracts. Because the ICC has drafted a model form of international franchising contracts, taking into account the most commonly encountered clauses in franchising agreements, their model could be used as a checklist of the core obligations of a cross-border franchise contract. Because there is no internationally agreed-upon uniform legislation on franchising, parties must rely on national laws and regulations applicable to the international franchise (when such laws and regulations exist) and should therefore very carefully draft stipulations for the legal status of the contract. This study has been intended to cite some provisions for striking a fair balance between the interests of the franchisor and those of the franchisee and for avoiding unfair trade acts in international franchising contracts.

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