Vision-Based In-Flight Collision Avoidance Control Based on Background Subtraction Using Embedded System.

The development of high-performance, low-cost unmanned aerial vehicles paired with rapid progress in vision-based perception systems herald a new era of autonomous flight systems with mission-ready capabilities. One of the key features of an autonomous UAV is a robust mid-air collision avoidance strategy. This paper proposes a vision-based in-flight collision avoidance system based on background subtraction using an embedded computing system for unmanned aerial vehicles (UAVs). The pipeline of proposed in-flight collision avoidance system is as follows: (i) subtract dynamic background subtraction to remove it and to detect moving objects, (ii) denoise using morphology and binarization methods, (iii) cluster the moving objects and remove noise blobs, using Euclidean clustering, (iv) distinguish independent objects and track the movement using the Kalman filter, and (v) avoid collision, using the proposed decision-making techniques. This work focuses on the design and the demonstration of a vision-based fast-moving object detection and tracking system with decision-making capabilities to perform evasive maneuvers to replace a high-vision system such as event camera. The novelty of our method lies in the motion-compensating moving object detection framework, which accomplishes the task with background subtraction via a two-dimensional transformation approximation. Clustering and tracking algorithms process detection data to track independent objects, and stereo-camera-based distance estimation is conducted to estimate the three-dimensional trajectory, which is then used during decision-making procedures. The examination of the system is conducted with a test quadrotor UAV, and appropriate algorithm parameters for various requirements are deduced.

Minimizing the Carrier Collection Loss of the Neutral-Color Transparent Crystalline-silicon Solar Modules via Hybrid Electrode Design.

Transparent solar cells can be used where conventional solar cells are inapplicable, such as, in glass windows of buildings; however, reports on modularization, which is essential for their commercialization, are scarce. Here, a novel modularization method has been proposed for the fabrication of transparent solar cells and a 100-cm2 neutral-color transparent crystalline-silicon solar module has been developed using a hybrid electrode comprising a microgrid electrode and an edge busbar electrode. The transparent solar module exhibits a power conversion efficiency (PCE) of 11.94 and 13.14% when connected in series and in parallel, respectively, with an average visible transmittance of 20%. Additionally, the module exhibits negligible losses in PCE (lower than 0.23%) in outdoor, mechanical-load, and damp-heat (at 85°C/85% RH) stability tests, indicating high stability. The transparent solar module proposes here could facilitate the commercialization of transparent solar cells.

Understanding the 2D-material and substrate interaction during epitaxial growth towards successful remote epitaxy: a review.

Remote epitaxy, which was discovered and reported in 2017, has seen a surge of interest in recent years. Although the technology seemed to be difficult to reproduce by other labs at first, remote epitaxy has come a long way and many groups are able to consistently reproduce the results with a wide range of material systems including III-V, III-N, wide band-gap semiconductors, complex-oxides, and even elementary semiconductors such as Ge. As with any nascent technology, there are critical parameters which must be carefully studied and understood to allow wide-spread adoption of the new technology. For remote epitaxy, the critical parameters are the (1) quality of two-dimensional (2D) materials, (2) transfer or growth of 2D materials on the substrate, (3) epitaxial growth method and condition. In this review, we will give an in-depth overview of the different types of 2D materials used for remote epitaxy reported thus far, and the importance of the growth and transfer method used for the 2D materials. Then, we will introduce the various growth methods for remote epitaxy and highlight the important points in growth condition for each growth method that enables successful epitaxial growth on 2D-coated single-crystalline substrates. We hope this review will give a focused overview of the 2D-material and substrate interaction at the sample preparation stage for remote epitaxy and during growth, which have not been covered in any other review to date.

Design, construction, and operation of a 2 T 240 mm conduction-cooled defect-irrelevant winding (RE) Ba2Cu3O7-x magnet.

In order to explore the applicability of superconducting magnets in a magnetic field range of 3 T or less, where superconducting magnets have not been much used so far, a prototype magnet development project has been launched in collaboration with Hanmi Techwin Corporation and Seoul National University. As a result of the project, here we report the design, construction, and operation results of a 2 T 240 mm defect-irrelevant winding (DIW) (RE) Ba2Cu3O7-x (REBCO) magnet. First, design goals were set considering its potential usage in industrial fields, and a 2 T 240 mm-bore multi-width no-insulation high-temperature superconductor magnet was designed accordingly. Based on the design, a total of 15 double pancake (DP) coils were wound, regardless of defects in REBCO tapes, and assembled together. After being installed in a conduction cooling system, the magnet was tested at a temperature of <20 K, and a magnetic field of 2 T at the magnet center was successfully generated with a total of four DP coils containing multiple defects. Based on the experimental results, the additional considerations required for the DIW approach at the magnet level are discussed.

Interplay of sidewall damage and light extraction efficiency of micro-LEDs.

This Letter describes the impact of shape on micro light-emitting diodes (µLEDs), analyzing 400 µm2 area µLEDs with various mesa shapes (circular, square, and stripes). Appropriate external quantum efficiency (EQE) can yield internal quantum efficiency (IQE) which decreases with increasing peripheral length of the mesas. However, light extraction efficiency (ηe) increased with increasing mesa periphery. We introduce analysis of Jpeak (the current at peak EQE) since it is proportional to the non-radiative recombination. Etching the sidewalls using tetramethylammonium hydroxide (TMAH) increased the peak EQE and decreased the sidewall dependency of Jpeak. Quantitatively, the TMAH etching reduced non-radiative surface recombination by a factor of four. Hence, shrinking µLEDs needs an understanding of the relationship between non-radiative recombination and ηe, where analyzing Jpeak can offer new insights.

Does Stocking Density Affect Growth Performance and Hematological Parameters of Juvenile Olive Flounder Paralichthys olivaceus in a Recirculating Aquaculture System?

Olive flounder Paralichthys olivaceus is a representative culture species in South Korea. Recirculating aquaculture systems (RASs) have received increased attention because they can provide sustainable and environmentally friendly productivity. However, to maintain economic sustainability, the system generally requires high productivity, achieved through a high stocking density, which compromises animal welfare. The reduction in growth based on the stocking density may be due to the social hierarchy resulting from the growth suppression of subordinate individuals. Species, size, culture systems, and other management regimes can affect the social hierarchy. Therefore, a more practical approach must be taken to adjust the stocking density for a particular fish species and fish size in a specific culture system. This study investigated the effect of stocking density on juvenile olive flounder in an RAS. Juvenile olive flounder (61.0 ± 0.3 g) were initially stocked at 3.29, 4.84, 7.14, and 8.56 kg/m2 (T1, T2, T3, and T4, respectively). After 8 weeks, growth performance, in terms of feed conversion, specific growth rate, and daily feed intake rate, was measured. In addition, the blood levels of insulin-like growth factor (IGF-1), growth hormone, glucose, glutamic oxaloacetic transaminase, and glutamic pyruvic transaminase and the whole-body composition were evaluated as stress indicators. Growth performance increased as stocking density increased, but fish at the highest stocking density showed signs of growth reduction toward the end of the experiment. In addition, as stocking density increased, IGF-1 decreased, and cortisol increased. The whole-body protein level was significantly lower in T4 compared with the other treatments. Olive flounder seemed to tolerate a stocking density up to 20.16 kg/m2. Based on the growth performance, hematological response, and whole-body composition results in the present study, a final stocking density of 20 kg/m2 (from the initial stocking density of 4.84-7.14 kg/m2) may be desirable for juvenile olive flounder in an RAS for fish weighing ~60-180 g.

The stability of graphene and boron nitride for III-nitride epitaxy and post-growth exfoliation.

A challenging approach, but one providing a key solution to material growth, remote epitaxy (RE)-a novel concept related to van der Waals epitaxy (vdWE)-requires the stability of a two-dimensional (2-D) material. However, when graphene, a representative 2-D material, is present on substrates that have a nitrogen atom, graphene loss occurs. Although this phenomenon has remained a hurdle for over a decade, restricting the advantages of applying graphene in the growth of III-nitride materials, few previous studies have been conducted. Here, we report the stability of graphene on substrates containing oxygen or nitrogen atoms. Graphene has been observed on highly decomposed Al2O3; however, graphene loss occurred on decomposed AlN at temperatures over 1300 °C. To overcome graphene loss, we investigated 2-D hexagonal boron nitride (h-BN) as an alternative. Unlike graphene on AlN, it was confirmed that h-BN on AlN was intact after the same high-temperature process. Moreover, the overgrown AlN layers on both h-BN/AlN and h-BN/Al2O3 could be successfully exfoliated, which indicates that 2-D h-BN survived after AlN growth and underlines its availability for the vdWE/RE of III-nitrides with further mechanical transfer. By enhancing the stability of the 2-D material on the substrate, our study provides insights into the realization of a novel epitaxy concept.

Complementary and Alternative Medicine Use in Amyotrophic Lateral Sclerosis Cases in South Korea.

Patients with amyotrophic lateral sclerosis (ALS) sometimes consider complementary and alternative medicine (CAM) because of ineffective treatment. This study investigated the prevalence and utilization pattern of CAM among patients with ALS in South Korea. Participants were recruited through homecare services for mechanical ventilation in South Korea. This study comprised a face-to-face cross-sectional survey with staff members available to address any queries. Fifty-five participants were included; all had used >1 CAM treatment option for ALS symptoms. Dietary treatments were most common, followed by functional food and massages. Most participants had obtained relevant information from family members or friends. The main reason for CAM use was an expectation that symptoms will improve with CAM; most patients were unsure of the effects. CAM use was previously discontinued by the majority of patients because of unsatisfactory effects. The mean expenditure on CAM was 288,385.28 ± 685,265.14 won per month, and the mean duration of CAM use was 11.54 ± 20.09 months. The results indicate that there is a high prevalence of CAM use among ALS patients. Healthcare providers should inquire about CAM use and openly provide accurate CAM information. Further evidence of CAM efficacy is required, as is specific guidance for consulting ALS patients regarding CAM.

Resilience in Koreans With Cancer: Scoping Review.

Cancer is a major cause of mortality and morbidity in Korea. However, there has been no previous nursing literature review on the phenomenon of resilience among cancer patients in Korea. The purpose of this study was to identify information about theories, instruments, correlates, and outcomes of resilience in the cancer experiences of Korean adults. This was a scoping review that searched Ovid MEDLINE, CINAHL, Google Scholar, DBpia, and the Korean Studies Information Service System between 2000 and 2016 in order to identify English and Korean research reports. The review yielded 17 quantitative studies, including 2 resilience theories and 6 resilience-specific instruments. The factors self-efficacy, hope, social supports, self-esteem, anxiety, and depression were associated with resilience, regardless of the type of cancer. Quality of life and coping were commonly investigated outcome variables for resilience. This review suggests that a nursing theory reflecting Korean culture and qualitative research concerning the phenomenon of resilience should be conducted as research priorities as the foundation for developing culturally appropriate tools for resilience. This will lead to enhanced quality of life among Korean cancer patients, which is the core of palliative nursing care.

Cancer Screening and Diagnostic Tests in Global Contexts: Case Study and Concept Analysis.

OBJECTIVE: Although the purposes and outcomes of screening and diagnostic tests are different, they are often confused. Therefore, it is important to delineate the clinical concept of cancer screening tests to be clear in our communication not only among healthcare professionals but also with client populations. The aim of this study is to both describe and analyze the concept of cancer screening and explain their practical meaning in global contexts. METHODS: Comparative case studies of cervical and liver cancer screening tests were used as the basis for developing an understanding of a specific concept (phenomenon) of cancer screening and for delineating the relationships between factors that cause screening to occur. RESULTS: A cancer screening is defined as an action taken by both the patient and health-care provider to detect a possible pre-cancerous condition among healthy and asymptomatic individuals who are at sufficient risk of a specific disorder to warrant further investigation or treatment. The case study-based concept analysis has been shown to be useful for improving our understanding of the multi-dimensional nature of the concept in global contexts. CONCLUSIONS: New paradigms maximizing participation in cancer screening to detect diseases before symptoms are manifested rather than focusing on diagnosis and treatment of symptomatic infectious diseases need to be developed and implemented.

Role of phospholipase D in the lifespan of Caenorhabditis elegans.

We have previously shown that phospholipase D (PLD) downregulation accelerates cellular senescence, which is widely believed to play an important role in aging, by stimulating reactive oxygen species (ROS) accumulation in human cells. In this study, we examined the role of PLD in aging using the nematode Caenorhabditis elegans. The mRNA level of pld-1 was found to be inversely correlated with aging. RNAi-mediated knockdown of pld-1 expression in nematodes enhanced ROS and lipofuscin accumulation and decreased lifespan, motility, and resistance to stress compared to that in nematodes treated with control RNAi. Pld-1 knockdown repressed the long lifespan of age-1 and akt-1 mutants but did not further reduce the short lifespan of daf-16 mutants, suggesting that PLD functions between AKT-1 and DAF-16. The ROS scavenger N-acetyl-L-cysteine, a PLD effector phosphatidic acid and a possible CK2 activator spermidine attenuated the lifespan shortening and age-related biomarkers triggered by pld-1 knockdown. Pld-1 RNAi downregulated the expression of DAF-16 target genes such as sod-3, dod-11, and mtl-1 in nematodes. In human cells, furthermore, PLD2 downregulation decreased the transcription of FoxO3a target genes (Cu/ZnSOD, MnSOD, catalase, thioredoxin-2, and peroxiredoxin-5), whereas ectopic PLD2 expression elevated the mRNA levels of these antioxidant genes. Taken together, these results indicated that PLD downregulation shortens longevity and induces age-related biomarkers through ROS accumulation by inhibiting the DAF-16/FoxO3a pathway in nematodes.

The Psychometric Validation of the EPDS-K Among Korean Women: Does It Only Measure Depressive Symptoms?

PURPOSE: The purpose of this study was to test the validity of the Edinburgh Postnatal Depression Scale-Korean (EPDS-K) and compare the specified models (one-, two-, three-factor model, and a model in the current study) in pregnant, first-trimester Korean women. DESIGN AND METHODS: The study consisted of two groups of 100 first-trimester Korean women recruited from maternity clinics in Korea. FINDINGS: The results show that the EPDS-K has depression, anxiety, and anhedonia factors, and that the validity of the EPDS-K with Korean women is questionable. PRACTICE IMPLICATIONS: Healthcare providers should test the psychometric properties of tools for screening accuracy, clinical decision-making, and understanding of a phenomenon within different cultural settings.

Cold Isostatic-Pressured Silver Nanowire Electrodes for Flexible Organic Solar Cells via Room-Temperature Processes.

Transparent conducting electrodes (TCEs) are considered to be an essential structural component of flexible organic solar cells (FOSCs). Silver nanowire (AgNW) electrodes are widely used as TCEs owing to their excellent electrical and optical properties. The fabrication of AgNW electrodes has faced challenges in terms of forming large uniform interconnected networks so that high conductivity and reproducibility can be achieved. In this study, a simple method for creating an intimate contact between AgNWs that uses cold isostatic pressing (CIP) is demonstrated. This method increases the conductivity of the AgNW electrodes, which enables the fabrication of high-efficiency inverted FOSCs that have a power conversion efficiency of 8.75% on flexible polyethylene terephthalate with no short circuiting occurring as the CIP process minimizes the surface roughness of the AgNW electrode. This allows to achieve 100% manufacturing yield of FOSCs. Furthermore, these highly efficient FOSCs are proven to only be 2.4% less efficient even for an extreme bending radius of R ≈ 1.5 mm, compared with initial efficiency.

Downregulation of protein kinase CK2 activity induces age-related biomarkers in C. elegans.

Studies show that a decrease in protein kinase CK2 (CK2) activity is associated with cellular senescence. However, the role of CK2 in organism aging is still poorly understood. Here, we investigated whether protein kinase CK2 (CK2) modulated longevity in Caenorhabditis elegans. CK2 activity decreased with advancing age in the worms. Knockdown of kin-10 (the ortholog of CK2ß) led to a short lifespan phenotype and induced age-related biomarkers, including retardation of locomotion, decreased pharyngeal pumping rate, increased lipofuscin accumulation, and reduced resistance to heat and oxidative stress. The long lifespan of age-1 and akt-1 mutants was significantly suppressed by kin-10 RNAi, suggesting that CK2 acts downstream of AGE-1 and AKT-1. Kin-10 knockdown did not further shorten the short lifespan of daf-16 mutant worms but either decreased or increased the transcriptional activity of DAF-16 depending on the promoters of the target genes, indicating that CK2 is an upstream regulator of DAF-16 in C. elegans. Kin-10 knockdown increased production of reactive oxygen species (ROS) in the worms. Finally, the ROS scavenger N-acetyl-L-cysteine significantly counteracts the lifespan shortening and lipofuscin accumulation induced by kin-10 knockdown. Therefore, the present results suggest that age-dependent CK2 downregulation reduces longevity by associating with both ROS generation and the AGE-1-AKT-1-DAF-16 pathway in C. elegans.

Different psychometric properties of the Emotional Reaction Instrument-English (ERI-E) between hospitalized African American and Caucasian children.

PURPOSE: To demonstrate the psychometric properties of the Emotional Reactions Instrument-English (ERI-E) between hospitalized African American and Caucasian children aged 7-12 years. DESIGN AND METHOD: A methodological study was conducted to examine validity and reliability of the ERI-E with 230 hospitalized African American and Caucasian children. Data were collected with sociodemographic and clinical forms, and using the ERI-E, and the Facial Affective Scale (FAS). RESULTS: Different factor structures were found between hospitalized African American and Caucasian children. In psychometric testing of the ERI-E with African American children, four items, alone, lonely, shy, and bored, were removed from the original 16-item ERI-E after exploratory factor analysis. Three factors, including Fear, Anxiety, and Distress, were identified explaining 60.71% of the total variance. Cronbach's alpha coefficient for the revised 12-item scale was 0.85. Six items, happy, sad, afraid, frightened, hurt, and uncomfortable, in the ERI-E were significantly correlated with the FAS (r = 0.20-0.59) as evidence of concurrent validity. In the sample with hospitalized Caucasian children, two items, bored and uncomfortable, were eliminated from the original ERI-E after exploratory factor analysis. Four factors including Fear, Anxiety, Distress, and Loneliness were extracted with 62.61% of total variance. Cronbach's alpha coefficient for the revised 14-item in the ERI-E was 0.84 for hospitalized Caucasian children. As evidence of concurrent validity, 10 items, happy, sad, afraid, frightened, bad, lonely, scary, bored, hurt, and uncomfortable, in the ERI-E were significantly correlated with the FAS (r = 0.20-0.69). PRACTICE IMPLICATION: Because children with different cultural backgrounds understand or use words differently, healthcare providers should assess the cultural norms of pediatric patients and ensure steps have been taken to ensure clear, effective communication with pediatric patients. In addition, healthcare providers should evaluate the meanings of faces in the FAS before using it in a clinical setting because faces have different cultural connotations. The explosive growth of ethnic minority children in the United States makes it paramount for healthcare providers and researchers to consider the measurement equivalence of any measure to better serve different racial and cultural groups.

Experience of complementary and alternative medicine in patients with amyotrophic lateral sclerosis and their families: A qualitative study.

The purpose of this study was to explore the life experience related to complementary and alternative medicine (CAM) use among patients with amyotrophic lateral sclerosis (ALS). Data were collected though semi-structured interviews of nine patients with ALS and seven family members, who have used CAM. Audio recordings of the interviews were transcribed verbatim and checked for accuracy. The Giorgi's method of phenomenology was used for data analysis. Five constituents forming the units of meaning were: facing the limits of conventional medicine; getting to know CAM; recognizing the ineffectiveness of CAM; using CAM for symptomatic treatment; and seeking new CAM endlessly for complete cure. The study results provide an in-depth understanding of experience with CAM among patients with ALS and their family members. Healthcare providers must give accurate information about the efficacy of CAM as well as its safety and possible adverse effects and should offer patient-centred treatment through active communication throughout the process of diagnosis and treatment.

Self-care use patterns in the UK, US, Australia, and Japan: a multinational web-based survey.

BACKGROUND: The trend toward patient- or consumer-centered healthcare has been accelerated by advances in technology, consumer empowerment, and a shift from infectious to chronic diseases. The purpose of this study was to examine the growing self-care market by analyzing self-care patterns. METHODS: We conducted a cross-sectional, web-based survey involving adults from nine major cities in the UK, the USA, Australia, and Japan. This study examined the extent and frequency of self-care, self-care expenditure, sources of self-care information, and reasons for self-care in each country. RESULTS: The results showed that the prevalence of self-care was highest in Japan (54.9%), followed by the UK (43.1%), the USA (42.5%), and Australia (40.4%). The primary reason for practicing self-care was "to manage my healthcare myself" (cited by 45.7%, 59.5%, 49.2%, and 4.1% of participants in Australia, Japan, the UK, and the USA, respectively). Significant linear associations were observed between age and the prevalence of self-care in all countries (p < 0.05), indicating that self-care prevalence decreased with age in the UK, the USA, and Australia, and increased with age in Japan. The frequency with which self-care was practiced was positively correlated with age in the USA (p < 0.05), Australia (p < 0.01), and Japan (p < 0.05). In addition to acquaintances, internet search engines and information obtained from pharmacies were considered reliable and widely used sources of self-care information. CONCLUSION: When developing self-care products or services, healthcare providers and policymakers should consider self-care patterns.

Prevalence of and Risk Factors for Depressive Symptoms in Korean Women throughout Pregnancy and in Postpartum Period.

PURPOSE: Prenatal depression is a significant predictor for postpartum depression. However, there is a lack of research on risk factors for Korean women related to prenatal depression and the relationship between prenatal depression during the three trimesters and postpartum depression. Therefore, aims of this study were (1) to identify the prevalence of depression during all three trimesters and the postpartum period, (2) to evaluate the relationship between prenatal depression in each trimester and postpartum depression, and (3) to identify the relationship and differences in prenatal depression based on sociodemographic factors in Korean women. METHODS: One hundred and fifty three Korean women were recruited from three maternity clinics in Korea. Prenatal and postpartum depressions were evaluated in the first, second (24-26 weeks), third (32-34 weeks) trimester and 4 weeks postpartum with the Edinburgh Postnatal Depression Scale-Korean. RESULTS: The prevalence of depression in the prenatal and postpartum period ranged from 40.5% to 61.4%. Depression in the second and the third trimester was significantly correlated with depression in the postpartum period. Unemployment and household income were risk factors for prenatal depression in the first and second trimesters. CONCLUSIONS: To assist women suffering from postpartum depression and prevent its effects, women should be screened for prenatal depression during all three trimesters. For Korean women with high risk factors for prenatal depression, we suggest that the Korean government establish healthcare policies related to depression screening as routine prenatal care and mental health referral systems.

Examining Validity and Reliability of the Emotional Reactions Checklist with Hospitalized Children.

Fear, anxiety, and emotional upset are common experiences for hospitalized children. To identify and treat children's emotional reactions, health care professionals must be able to differentiate emotional reactions from pain and other symptoms. Clinical assessment of emotions requires the use of valid and reliable instruments in acute care settings. This study examined internal consistency, construct, and concurrent validity of the Emotional Reactions Checklist (ERC). A descriptive correlational design guided the psychometric approach. Children answered a sociodemographic questionnaire and responded to self-generated scenarios of pleasant and unpleasant events using two self-report scales of emotions. The convenience sample comprised 59 children admitted to an inpatient unit in a large children's hospital or to a community hospital emergency department. Construct validity was supported by significantly different ERC mean responses to recalled pleasant prehospitalization experiences and unpleasant hospitalization experiences (p < .001) for both ERC item responses and total scale scores. Children's explanations for seemingly inconsistent item responses further supported their ability to use the ERC to convey their emotions. Concurrent validity was supported by moderate (r = 0.32) to strong (r = 0.70) correlations between the Facial Affective Scale and ERC items and scale scores. Internal consistency was better supported for the recalled unpleasant experience (α = 0.77) than for the pleasant experience (α = 0.60). Results supported construct and concurrent validity and beginning internal consistency reliability for the ERC in an acute care setting. Further research is required to establish feasibility of repeated use with ill children.