• Geomechanics and Engineering
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• 제17권3호
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• pp.227-236
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• 2019

In practice, the natural slopes are frequently with soils of spatial properties and irregular features. The traditional limit analysis method meets an inherent difficulty to deal with the stability problem for such slopes due to the normal condition in the associated flow rule. To overcome the problem, a novel technique based on the upper bound limit analysis, which is called the discretization technique, is employed for the stability evaluation of complex slopes. In this paper, the discretization mechanism for complex slopes was presented, and the safety factors of several examples were calculated. The good agreement between the discretization-based and previous results shows the accuracy of the proposed mechanism, proving that it can be an alternative and reliable approach for complex slope stability analysis.

• Natural Product Sciences
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• 제25권1호
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• pp.59-63
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• 2019

Hematopoiesis has a pivotal role in the maintenance of body homeostasis. Ironically, several hematological disorder caused by chemicals, drugs, and other environmental factors lead to severe bone marrow failure. Current treatments like stem cell transplantation and immunosuppression remain ineffective to ameliorate this diseases. Therefore, a newtreatment to overcome this entity is necessary, one of them by promoting the usage of medicinal plants. Thus, this study aimed to evaluate the hematopoiesis potency of S. javanica berries and leaves extracts in chloramphenicol (CMP)-induced aplastic anemia mice model. In this present study, several types of blood progenitor cell such as $TER-119^+VLA-4^+$ erythrocytes lineage, $Gr-1^+$ granulocytes, and $B220^+$ B-cell progenitor cells were evaluated by flow cytometry analysis. Accordingly, we revealed that S. javanica berries and leaves extracts significantly promoted $TER-119^+VLA-4^+$ erythrocytes lineage and $Gr-1^+$ granulocytes after exposed by CMP. Thus, these results suggested that S. javanica berries and leaves extracts might have hematopoiesis activity in CMP-induced aplastic anemia mice model.

• 무역학회지
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• 제44권1호
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• pp.143-158
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• 2019

As the overseas direct purchase market grows rapidly, firms are setting up various strategic directions to attract consumers. However, many previous researches on this issue have focused on consumption behavior based on consumers' motivation and demographic factors, so there is a certain limit to suggest practical implications for firms. Therefore, this study proposed modeling to understand how firm's strategic direction influences consumers' acceptance behavior in order to overcome these limitations. For this purpose, this study conducted a survey on 357 domestic consumers and conducted empirical analysis through structural equation model analysis. As a result, the effort expectancy of overseas direct purchase site has a strong influence on consumer intention as much as performance expectancy. We also found that product variety had the strongest impact on performance expectancy and that web site reputation directly affected consumers' behavioral intention as well as purchasing behavior.

• KDI Journal of Economic Policy
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• 제42권4호
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• pp.91-116
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• 2020

As a project appraisal tool, the preliminary feasibility study (PFS) has contributed to enhancing the efficiency of public investment decision-making in the Republic of Korea over the last two decades. To overcome the limitations of the efficiency-oriented cost-benefit analysis, the PFS accommodates equity concerns among regions, namely balanced regional development (BRD) analysis. This study attempts to gauge the contributions of BRD analysis to PFS results. Specifically, it addresses how effectively policy efforts to promote decision-making have been implemented in the PFS stage while also considering the balance between equity and efficiency in terms of the trade-off between them, the degree to which they influence the results, and whether the consideration of equity is in fact actually reflected in seriously underdeveloped regions as intended. The study finds that the PFS results over the last two decades have been largely in line with the background and policy objectives. Based on the findings of the study, needs for institutional improvement are suggested, including enhancements in the analysis of regional economic ripple effects and taking into account the psychological factors pertaining to the evaluators in the overall judgment.

• 식품과학과 산업
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• 제54권1호
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• pp.2-10
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• 2021

Microplastics with a size of less than 5 mm have emerged as an important environmental and food safety issue, as they have been detected not only in marine but also in terrestrial ecosystem and drinking water. Although many studies have been conducted on the exposure of microplastics and the effects on human health, the lack of standardized experimental methods for microplastics has been reviewed as a major problem. In order to overcome this, European countries such as the Netherlands and Germany are conducting a project to develop detection methods for microplastics as well as to establish the risk assessment methodologies for microplastics. Being the microplastics suggested to have a substantially potential risk on human health, reliable risk assessments should be conducted considering the various sources of microplastics, chemical pollutants and biological factors. In addition, international standards and regulations should be applied.

• Structural Engineering and Mechanics
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• 제82권2호
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• pp.191-204
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• 2022

A three-mass vehicle model including one rigid mass and two unsprung masses is adopted to predict the vehicle-bridge interaction (VBI) and to establish the nonlinear coupled governing equations. To overcome the numerical instability and large computation problems concerning the vehicle-bridge system, the perturbation method is used to convert the nonlinear coupled governing equations into a set of linear uncoupled equations. Formulas for bridge's natural frequencies considering both the VBI and the dynamic responses of bridge and vehicle are proposed. Compared with the numerical results obtained by the Newmark-β method, the theoretical solutions for natural frequencies and dynamic responses are validated. The effects of the important factors of unsprung mass, vehicle damping, surface irregularity on the natural frequencies and dynamic responses of bridge and vehicle are discussed, based on the theoretical solutions.

• 센서학회지
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• 제32권1호
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• pp.1-9
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• 2023

Recently, the digital healthcare technologies including non-invasive diagnostics based on Internet of Things (IOT) are getting attention. Human exhaled breath contains a variety of volatile organic compounds (VOCs), which can provide information of malfunctions of the body and presence of a specific disease. Detection of VOCs in exhaled breath using gas sensors are easy to use, safe, and cost-effective. However, accurate diagnosis of diseases is challenging because changes in concentration of VOCs are extremely small and lots of body factors directly or indirectly influence to the conditions. To overcome the limitations, highly selective nanosensors and artificial intelligent electronic nose (E-nose) systems have been mainly researched in recent decades. This review provides brief reviews of the recent studies for diabetes and lung cancer diagnosis using nanosensors and E-nose systems.

• Journal of Digestive Cancer Research
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• 제6권1호
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• pp.11-15
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• 2018

Chemotherapy and surgical resection are the mainstay of cancer treatment. Particularly for chemotherapy, although it is effective method to care, sometimes cure various cancers, there are many different status of cancer not being controlled by chemotherapy such as recurrence and resistance to chemotherapy. In order to overcome those difficulties during cancer therapy, immunotherapy targeting immune cells and immune associated factors to enhance cancer immunity has been highlighted. Innate immunity plays important roles on initial stage of cancer immunity that are detecting, killing cancer cells and initiating adaptive immunity for cancer. So many basic and clinical studies to manage innate immunity for cancer therapy have been going on, and most of them were to stimulate innate immune cells including dendritic cell, macrophage, monocyte, and natural killer cell in various ways. They showed promising results but still there are many things to be resolved before clinical application. Herein, I review the role of innate immune cells and therapeutic trials for colorectal cancer.

• 대한영상의학회지
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• 제83권4호
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• pp.776-782
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• 2022

영상의학과 의사의 탈진은 최근 이슈로 부각되고 있으며 의사 본인의 건강 문제뿐만 아니라 환자 진료에 악영향을 미칠 수 있어 환자 안전을 위협할 수 있다. 우리나라 대형병원에 근무하는 전문의의 약 84%에서 한 번 이상 탈진을 경험하였다고 응답하였다. 이를 극복하기 위해서는, 적절한 업무량의 확보뿐만 아니라, 전문가로서의 역할을 할 수 있도록 워크플로우의 개선, 마지막으로 업무-휴식 간의 밸런스를 확보할 수 있도록 해야 한다.

• 인터넷정보학회논문지
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• 제12권1호
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• pp.1-10
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• 2011

스펙트럼 검출은 인지 무선 시스템(Cognitive Radios) 구현을 위한 핵심 기술들 중의 하나이다. 스펙트럼 검출에서 문제시되는 점들 중에 하나는 페이딩(Fading) 및 쉐도윙(Shadowing) 등으로 인해서 스펙트럼 검출 성능이 저하된다는 것이다. 이 문제점을 해결하기 위해 제안된 방법 중 하나가 협력 스펙트럼 검출 방법이다. 이 방법을 통해 비협력 스펙트럼 검출 방식의 성능을 개선할 수 있지만, 여전히 큰 장애물과 같은 간섭 요인에 의해 스펙트럼 성능이 영향을 받는다는 단점이 있다. 특히, 기존의 대부분의 연구에서는 고정된 1차 사용자(Primary User, PU)를 고려하고 있지만 향후 유비쿼터스(Ubiquitous) 환경에서는 이동성을 가지는 1차 사용자가 존재하는 시스템을 고려해야 한다. 이러한 환경에서 기존의 협력 스펙트럼 검출 방식은 정확성이 낮은 검출 성능을 보이고 고려하지 않아도 될 2차 사용자(Cognitive User, CR user)의 국부 센싱값을 전송함으로써 많은 에너지를 소비하는 문제점이 있다. 본 논문에서는 이러한 문제를 해결하기 위해서, 무선 인지 시스템에서의 이동성을 가지는 1차 사용자의 위치를 추정하고 이를 기반으로 간섭 영향을 받는 2차 사용자를 검출한다. 또한 검출된 간섭영향을 받는 2차 사용자의 센싱 정보를 융합 결정할 때 배제함으로써 스펙트럼 검출의 정확성을 높이는 방법을 제안하다. 시뮬레이션을 통하여 제안된 알고리즘이 기존 알고리즘 보다 정확한 스펙트럼 검출을 보인다.