• Tribology and Lubricants
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• 제31권6호
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• pp.264-271
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• 2015

Adhesion force of nanomaterials such as nanoparticle, nanowire, and nanorods should be significantly considered for its mechanical applications. However, examination of the adhesion force is limited since it is technically challenging to carry out experiments with such small objects. Therefore, in this work, molecular dynamics simulation (MDS) was conducted to determine the adhesion force between a nanowire and a flat surface, which could not be readily assessed through experiments. The adhesion force of a cylindrical-shaped nanowire was assessed by performing MDS and applying an equation of Van der Waals interaction. Simulation was conducted in two steps: indentation of a spherical tip on the flat surface and indentation of a cylinder on the flat surface, because the purpose of the simulation was comparing the results of the simulation and calculation of the Van der Waals interaction equation. From the simulation, Hamaker constant used for the equation of Van der Waals interaction was determined to be 2.93 °ø 10?18 J. Using this constant, the adhesion force of the nanowire on the flat surface was readily estimated by calculating Van der Waals equation to be approximately 65~89 nN with respect to the diameter of the nanowire. Moreover, the adhesion force of the nanowire was determined to be 52~77 nN from the simulation It was observed that there was a slight discrepancy (approximately 15~25%) between the results of the simulation and the theoretical calculation. Thus, it was confirmed that the calculation of Van der Waals interaction could be utilized to assess the adhesion force of the nanowire.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권5호
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• pp.2044-2062
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• 2018

Information theory progression along with the advancements being made in the field of Vehicular Ad hoc NETworks (VANETs) supports the use of coding-aware opportunistic routing for efficient data forwarding. In this work, we propose and investigate an adaptive coding-aware routing scheme in a specific VANET scenario known as a vehicular platoon. Availability of coding opportunities may vary with time and therefore, the accurate identification of available coding opportunities at a specific time is a quite challenging task in the highly dynamic scenario of VANETs. In the proposed approach, while estimating the topology of the network at any time instance, a forwarding vehicle contemplates the composition of multiple unicast data flows to encode the correct data packets that can be decoded successfully at destinations. The results obtained by using OMNeT++ simulator reveal that higher throughput can be achieved with minimum possible packet transmissions through the proposed adaptive coding-aware routing approach. In addition, the proposed adaptive scheme outperforms static transmissions of the encoded packets in terms of coding gain, transmission percentage, and encoded packet transmission. To the best of our knowledge, the use of coding-aware opportunistic routing has not been exploited extensively in available literature with reference to its implications in VANETs.

• Current Optics and Photonics
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• 제3권1호
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• pp.66-71
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• 2019

Application of liquid crystal (LC) materials to a flexible device is challenging because the bending of LC displays easily causes change in thickness of the LC layer and orientation of LCs, resulting in deterioration in a displayed image quality. In this work, we demonstrate a prototype device combining a flexible polymer substrate and an optically isotropic LC-polymer composite in which the device consists of interdigitated in-plane switching electrodes deposited on a flexible colorless polyimide substrate and the composite consisting of nano-sized LC droplets in a polymer matrix. The device can keep good electro-optic characteristics even when it is in a bending state because the LC orientation is not disturbed in both voltage-off and -on states. The proposed device shows a high potential to be applicable for future flexible LC devices.

• 한국환경보건학회지
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• 제45권4호
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• pp.340-357
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• 2019

The purpose of this paper is to help develop a comprehensive understanding of the humidifier disinfectant disaster from diverse perspectives based on a critical review of the relevant academic research papers published so far in the fields of both natural and social science. The authors reviewed pertinent articles in the six academic areas of law, social science, humanities, medicine, toxicology, and environmental health. A proper understanding of the issue of humidifier disinfectant is a challenging task because diverse aspects of it have become related over the more than two decades since such products were first released to the market in 1994. Technical and esoteric issues such as the complex system for relief and compensation for health damages and the approval of chemical toxicity are known to be major impediments to viewing the bigger picture regarding this tragedy. The authors believe that experts need to consider a comprehensive perspective going beyond their individual research arena to gain a better understanding of this issue, especially since it was an alarm signal on ethics and the role of experts and scholars in Korean society. Besides the two professors arrested by the prosecutor's office, it should be remembered that medical doctors recommended patients use humidifiers and disinfectants, and the media was inactive in reporting on this issue. Furthermore, the current paucity of examination of the social and political implications of this tragedy calls for more active engagement by researchers in the humanities and social sciences. In this regard, this paper is a work of self-examination and self-criticism by the authors that could resonate with the overall academic community.

• Agribusiness and Information Management
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• 제13권1호
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• pp.1-25
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• 2021

농업 기업가의 과학 기술적 경향은 새로운 기회를 식별하고 탐구하기 위해 필요해지고 있다. 최근 연구에 따르면 신기술의 채택은 기업가적 지향(EO)의 광범위한 접근법과 일치한다. 농업의 타당성이 증가하고 있다고 해도, 기업가적 연구는 대체로 이 도전적인 분야를 간과해 왔다. 게다가, 문헌에는 경험적 연구가 상대적으로 부족하고 여전히 연구되어야 하는 부분이며 잠재력이 있다고 논하고 있다. EO의 문헌에서 비롯된 이 연구는 농업 분야인 HEO(Humanine Entrepreneural Orientation)의 접근을 제안한다. 이 논문은 HEO의 다양한 치수가 농가의 신기술 채택 성향에 미치는 영향을 검증하기 위한 경험적 분석을 제안한다. 모든 결과는 기업, 연구 시스템 및 공공 정책에 대한 몇 가지 시사점을 강조한다. 농업이 매우 특이한 분야이고 제조업과 상당히 다르더라도 농민도 기업인으로 볼 수 있으며 기업가정신을 따를 수 있다고 본다. 따라서, 경험적 연구의 상대적 부족인 농업 EO에 대한 문헌을 본 연구를 통해 풍부하게 할 수 있다고 본다.

• Journal of Hospice and Palliative Care
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• 제24권2호
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• pp.130-134
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• 2021

In the era of coronavirus disease 2019 (COVID-19), social distancing and strict visitation policies at hospitals have made it difficult for medical staff to provide high-quality end-of-life (EOL) care to dying patients and their families. There are various issues related to EOL care, including psychological problems of patients and their families, difficulties in EOL decision-making, the complicated grief of the bereaved family, moral distress, and exhaustion of medical staff. In relation to these issues, we aimed to discuss practical considerations in providing high-quality EOL care in the COVID-19 pandemic. First, medical staff should discuss advance care planning as early as possible and use the parallel planning strategy. Second, medical staff should play a role in facilitating patient-family communication. Third, medical staff should actively and proactively evaluate and alleviate dying patients' symptoms using non-verbal communication. Lastly, medical staff should provide care for family members of the dying patient, who may be particularly vulnerable to post-bereavement problems in the COVID-19 era. Establishing a system of screening high-risk individuals for complicated grief and connecting them to bereavement support services might be considered. Despite the challenging and limited environment, providing EOL care is essential for patients to die with dignity in peace and for the remaining family to return to life after the loved one's death. Efforts considering the practical issues faced by all medical staff and healthcare institutions caring for dying patients should be made.

• 한국정보기술학회논문지
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• 제17권9호
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• pp.99-112
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• 2019

도로 포장면의 크랙(crack)은 도로포장 구조의 열화를 입증하는 중요한 신호와 증상이다. 카메라 영상기반 도로포장 크랙 탐지는 강도 비균질성, 위상 복잡성, 낮은 대조도 및 노이즈성의 텍스처 배경 때문에 어려운 문제이다. 본 논문은 흑백영상에 대하여 깊은 신경망(DNN)에 기반하여 픽셀수준의 도로 크랙 탐지 및 분할 문제에 대해 다룬다. 변형된 U-net 네트워크와 고수준 특징 네트워크를 포함하는 새로운 DNN 구조를 제안한다. 본 연구의 중요 기여는 융합 층을 통해 공급되는 이들 네트워크의 결합 방법이다. 우리가 아는 한, 본 연구는 보도블럭 크랙 분할 및 탐지 문제를 결합을 소개한 최초의 논문이다. 크랙 탐지 및 분할의 시스템 성능은 새로운 구조를 사용하여 급격히 향상되었다. 제안된 시스템을 2개의 공개 데이터셋­크랙 포레스트 데이터셋(CFD)와 AigleRN 데이터셋­에 대하여 구현하고 평가하였다. 본 논문의 시스템은 여덟 가지의 최신 알고리즘과 같은 데이터셋으로 실험을 하였을 때, 가장 뛰어난 결과를 보여주었다.

• International Journal of Computer Science & Network Security
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• 제22권10호
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• pp.73-82
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• 2022

Early detection continues to be the mainstay of breast cancer control as well as the improvement of its treatment. Even so, the absence of cancer symptoms at the onset has early detection quite challenging. Therefore, various researchers continue to focus on cancer as a topic of health to try and make improvements from the perspectives of diagnosis, prevention, and treatment. This research's chief goal is development of a system with deep learning for classification of the breast cancer as non-malignant and malignant using mammogram images. The following two distinct approaches: the first one with the utilization of patches of the Region of Interest (ROI), and the second one with the utilization of the overall images is used. The proposed system is composed of the following two distinct stages: the pre-processing stage and the Convolution Neural Network (CNN) building stage. Of late, the use of meta-heuristic optimization algorithms has accomplished a lot of progress in resolving these problems. Teaching-Learning Based Optimization algorithm (TIBO) meta-heuristic was originally employed for resolving problems of continuous optimization. This work has offered the proposals of novel methods for training the Residual Network (ResNet) as well as the CNN based on the TLBO and the Genetic Algorithm (GA). The classification of breast cancer can be enhanced with direct application of the hybrid TLBO- GA. For this hybrid algorithm, the TLBO, i.e., a core component, will combine the following three distinct operators of the GA: coding, crossover, and mutation. In the TLBO, there is a representation of the optimization solutions as students. On the other hand, the hybrid TLBO-GA will have further division of the students as follows: the top students, the ordinary students, and the poor students. The experiments demonstrated that the proposed hybrid TLBO-GA is more effective than TLBO and GA.

• 인간식물환경학회지
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• 제24권6호
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• pp.685-691
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• 2021

Background and objective: Understanding abstract art as an art form requires depth of thought. Moreover, understanding land art as abstract art is challenging, given its focus on the minimalism and abstract concepts. Much focus, research, and work were actively conducted in the 1970s, as it represented an abstract expression of minimalism. The characteristics of minimalism connote abstract meanings in the use of materials. Nevertheless, the original research of works or artists has often been mentioned, but few studies have analyzed the abstract language of land art materials. The aim of this study is to thus determine the abstract meanings of materials in land art from the 1970s to the 2010s. Methods: Art-based research was employed to address the aim. This study classified the land art materials into intangible and tangible materials, where intangible materials focused on lines, circles, and labyrinths, and tangible materials focused on the earth, stones, wood, and snow. Results: Intangible and tangible materials of land art conveyed various abstract meanings. Intangible materials were reflective of connection and symbiosis with nature, delivering abstract languages of 'take-nothing,' 'reflection' and 'opportunity.' Tangible materials reflected the abstract concepts of 'intervention,' 'resistance,' 'unliving,' and 'change,' and conveyed caveats. In other words, taken together, intangible and tangible materials were presented in symbiosis-and with caveats-and delivered messages for the present and the future. Interestingly, intangible materials inherently reflect symbiosis and communicate caveats in works based on a non-contextualized present and future. Conclusion: Interpretation of the abstract languages derived from intangible and tangible materials could imply a symbiosis between humans and nature, while conveying the message that caveats, to humans, are still ongoing. This relationship plays a significant role in an artist's selection of a medium, which is reflective of abstract beliefs reflected in contemporary, nature-based works created on Earth.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권11호
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• pp.3991-4010
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• 2021

The Question Similarity Measurement of Chinese Crop Diseases and Insect Pests (QSM-CCD&IP) aims to judge the user's tendency to ask questions regarding input problems. The measurement is the basis of the Agricultural Knowledge Question and Answering (Q & A) system, information retrieval, and other tasks. However, the corpus and measurement methods available in this field have some deficiencies. In addition, error propagation may occur when the word boundary features and local context information are ignored when the general method embeds sentences. Hence, these factors make the task challenging. To solve the above problems and tackle the Question Similarity Measurement task in this work, a corpus on Chinese crop diseases and insect pests(CCDIP), which contains 13 categories, was established. Then, taking the CCDIP as the research object, this study proposes a Chinese agricultural text similarity matching model, namely, the AgrCQS. This model is based on mixed information extraction. Specifically, the hybrid embedding layer can enrich character information and improve the recognition ability of the model on the word boundary. The multi-scale local information can be extracted by multi-core convolutional neural network based on multi-weight (MM-CNN). The self-attention mechanism can enhance the fusion ability of the model on global information. In this research, the performance of the AgrCQS on the CCDIP is verified, and three benchmark datasets, namely, AFQMC, LCQMC, and BQ, are used. The accuracy rates are 93.92%, 74.42%, 86.35%, and 83.05%, respectively, which are higher than that of baseline systems without using any external knowledge. Additionally, the proposed method module can be extracted separately and applied to other models, thus providing reference for related research.