• Nuclear Engineering and Technology
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• 제55권1호
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• pp.37-44
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• 2023

Using the Kalman filtering technique, we propose a novel method for estimating the missing video frames to monitor the activities inside the control room of a nuclear power plant (NPP). The purpose of this study is to reinforce the existing security and safety procedures in the control room of an NPP. The NPP control room serves as the nervous system of the plant, with instrumentation and control systems used to monitor and control critical plant parameters. Because the safety and security of the NPP control room are critical, it must be monitored closely by security cameras in order to assess and reduce the onset of any incidents and accidents that could adversely impact the safety of the NPP. However, for a variety of technical and administrative reasons, continuous monitoring may be interrupted. Because of the interruption, one or more frames of the video may be distorted or missing, making it difficult to identify the activity during this time period. This could endanger overall safety. The demonstrated Kalman filter model estimates the value of the missing frame pixel-by-pixel using information from the frame that occurred in the video sequence before it and the frame that will occur in the video sequence after it. The results of the experiment provide evidence of the effectiveness of the algorithm.

• The Journal of Asian Finance, Economics and Business
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• 제9권1호
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• pp.353-362
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• 2022

Small and medium businesses (SMEs) play a critical role in the economy, yet they are plagued by a shortage of finance. Determining the influence of cash sources both inside and outside the firm is critical to the company's survival and growth. As a result, the purpose of this research is to determine the impact of capital on the growth of SMEs in Vietnam. The key factors of this research are equity and liabilities, which are two proxies for a firm's capital. The data is based on the results of a survey conducted every two years from 2005 to 2015, which included over 2,600 SMEs in 20 processing and manufacturing industries in ten provinces and cities, including Hanoi, Hai Phong, Ho Chi Minh City, Ha Tay, Phu Tho, Nghe An, Quang Nam, Khanh Hoa, Lam Dong, and Long An. The findings show that characteristics such as equity capital, total workforce growth rate, and male entrepreneurs have a positive impact on enterprise growth, whereas liabilities, firm age, and export have a negative impact on enterprise growth. The study has demonstrated that equity has a positive impact while liabilities have a negative impact on the growth of Vietnamese SMEs.

• 식물분류학회지
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• 제46권2호
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• pp.129-148
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• 2016

Plant species on oceanic islands comprise nearly 25% of described vascular plants on only 5% of the Earth's land surface yet are among the most rare and endangered plants. Conservation of plant biodiversity on islands poses particular challenges because many species occur in a few and/or small populations, and their habitats on islands are often disturbed by the activity of humans or by natural processes such as landslides and volcanoes. In addition to described species, evidence is accumulating that there are likely significant numbers of "cryptic" species in oceanic archipelagos. Plant systematists, in collaboration with others in the botanical disciplines, are critical to the discovery of the subtle diversity in oceanic island floras. Molecular data will play an ever increasing role in revealing variation in island lineages. However, the input from plant systematists and other organismal biologists will continue to be important in calling attention to morphological and ecological variation in natural populations and in the discovery of "new" populations that can inform sampling for molecular analyses. Conversely, organismal biologists can provide basic information necessary for understanding the biology of the molecular variants, including diagnostic morphological characters, reproductive biology, habitat, etc. Such basic information is important when describing new species and arguing for their protection. Hybridization presents one of the most challenging problems in the conservation of insular plant diversity, with the process having the potential to decrease diversity in several ways including the merging of species into hybrid swarms or conversely hybridization may generate stable novel recombinants that merit recognition as new species. These processes are often operative in recent radiations in which intrinsic barriers to gene flow have not evolved. The knowledge and continued monitoring of plant populations in the dynamic landscapes on oceanic islands are critical to the preservation of their plant diversity.

• Tribology and Lubricants
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• 제33권4호
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• pp.127-133
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• 2017

In order to characterize the adhesive properties and failure mechanisms of diamond-like carbon (DLC) films of two different thicknesses (130 nm and $1.2{\mu}m$), deposited by plasma-enhanced chemical vapor deposition on a Si substrate, scratch testing with a micro-indenter ($12.5{\mu}m$ tip radius) was performed under a linearly increasing load. These scratch tests were conducted under the same test conditions for both films. The critical load of each film was estimated from the scratch test results, based on a sharp increase in the coefficient of friction and a clear distinction of failure modes. The critical load was the basis for evaluating the adhesion strength of the films, and the $1.2{\mu}m-thick$ DLC film had superior adhesion strength. For better understanding of the failure modes, the following analyses were conducted: friction behavior and scratch tracks analysis using scanning electron microscopy, energy-dispersive spectroscopy, and 3-D profilometry. The scratch test results showed that failure modes were related to the thickness of the films. The 130 nm-thick DLC film underwent cohesive failure modes (cracks and chipping) before reaching to a gross failure stage. On the other hand, the thicker DLC film ($1.2{\mu}m-thick$) did not exhibit micro cracks before a sudden gross failure of the film together with the evidence of cracking and chipping of the Si substrate.

• The Korean Journal of Physiology and Pharmacology
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• 제20권6호
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• pp.657-667
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• 2016

Critical limb ischemia (CLI) is one of the most severe forms of peripheral artery diseases, but current treatment strategies do not guarantee complete recovery of vascular blood flow or reduce the risk of mortality. Recently, human bone marrow derived mesenchymal stem cells (MSCs) have been reported to have a paracrine influence on angiogenesis in several ischemic diseases. However, little evidence is available regarding optimal cell doses and injection frequencies. Thus, the authors undertook this study to investigate the effects of cell dose and injection frequency on cell survival and paracrine effects. MSCs were injected at $10^6$ or $10^5$ per injection (high and low doses) either once (single injection) or once in two consecutive weeks (double injection) into ischemic legs. Mice were sacrificed 4 weeks after first injection. Angiogenic effects were confirmed in vitro and in vivo, and M2 macrophage infiltration into ischemic tissues and rates of limb salvage were documented. MSCs were found to induce angiogenesis through a paracrine effect in vitro, and were found to survive in ischemic muscle for up to 4 weeks dependent on cell dose and injection frequency. In addition, double high dose and low dose of MSC injections increased vessel formation, and decreased fibrosis volumes and apoptotic cell numbers, whereas a single high dose did not. Our results showed MSCs protect against ischemic injury in a paracrine manner, and suggest that increasing injection frequency is more important than MSC dosage for the treatment CLI.

• 한국초전도ㆍ저온공학회논문지
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• 제18권4호
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• pp.15-20
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• 2016

The effects of electron beam (EB) irradiation on the superconducting critical temperature ($T_c$) and critical current density ($J_c$) of YBCO films were studied. The YBCO thin films were irradiated using a KAERI EB accelerator with an energy of 0.2 MeV and a dose of $10^{15}-10^{16}e/cm^2$. A small $T_c$ decrease and a broad superconducting transition were observed as the EB dose increased. The value of $J_cs$ (at 20 K, 50 K and 70 K) increased at doses of $7.5{\times}10^{15}$ and $2.2{\times}10^{16}e/cm^2$. However, $J_cs$ decreased as the dose increased further. The X-ray diffraction (XRD) analysis showed that the c axis of YBCO was elongated and the full width at half maximum (FWHM) increased as the dose increased, which is strong evidence of the atomic displacement by EB irradiation. The transmission electron microscopy (TEM) showed that the amorphous layer formed in the vicinity of the surfaces of the irradiated films. The amorphous phase was often present as an isolated form in the interior of the films. In addition to the formation of the amorphous phase, many striations running along the a-b direction of YBCO were observed. The high magnification lattice image showed that the striations were stacking faults. The enhancement of $J_c$ by EB irradiation is likely to be due to the lattice distortion and the formation of defects such as vacancies and stacking faults. The decrease in $J_c$ at a high EB dose is attributed to the extension of the amorphous region of a non-superconducting phase.

• 중환자간호학회지
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• 제14권2호
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• pp.1-11
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• 2021

Purpose : The aim of this study was to propose appropriate nurse staffing of adult intensive care units considering patients' nursing care needs according to the Workload Management System for Critical Care Nurses (WMSCN). Methods : In a cross-sectional survey conducted in September 2017, 1,786 patients' WMSCN scores, surveys from 2,145 nurses, and administrative data from 118 units in 41 hospitals were analyzed. The means (standard deviations) of the aforementioned scores and nursing hours per patient day were presented. Nurse-to-patient ratios and nurse-to bed ratios for staffing to meet patients' nursing care needs were calculated. Results : The mean WMSCN scores were 109.50±17.17 in tertiary hospitals and 96.38±19.26 in general hospitals. Nursing hours per patient day were 12.47±2.80 in tertiary hospitals and 11.01±2.45 in general hospitals. Nursing hours per patient day correlated with WMSCN scores. Nurse-to-bed ratios required for the provision of ICU nursing care ranged from 1: 0.36 to 1: 0.48. Conclusion : Our findings provide evidence that current ICU nurse staffing is insufficient for meeting patients' nursing care needs. We suggest adjusting the legal standards for adequate nurse staffing considering these needs.

• 대한한방소아과학회지
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• 제36권1호
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• pp.65-77
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• 2022

Objectives The purpose of this study was to understand the public's perception of Korean medical treatment for growth disorders to develop Korean medicine clinical practice guidelines and critical pathways for growth disorders in children and adolescents. Methods A survey was conducted using an online platform targeting 252 adults aged 19 years from May 16, 2021 to May 17, 2021. The questionnaire consisted of questions about the demographic characteristics of respondents; overall perception, experience, and satisfaction with Korean medical treatment for growth disorders; willingness to use or recommend Korean medical treatment for growth disorders; and points for improvement. Results The overall perception of treatment for growth disorders was 3.30 ± 0.892 on a 5-point scale. Concerning the negative reasons, 54.4% of the respondents were concerned about safety; regarding the positive reason, expectations for overall health as well as height growth were the highest at 46.5%. Additionally, there was a high demand for information, such as providing safety information on treatment, presenting evidence for the efficacy of treatment, and standardized clinical process, as points requiring improvement. Conclusions To raise public perception of Korean medical treatment for growth disorders, it is necessary to satisfy the opinions of the public identified through this survey. Therefore, the development and utilization of Korean medicine clinical practice guidelines and critical pathways for growth disorders would play an important role.

• Clinics in Shoulder and Elbow
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• 제27권1호
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• pp.26-31
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• 2024

Background: The coracoacromial ligament (CAL) is frequently observed to be damaged during arthroscopy and it is unclear how demographic, anatomic, and radiographic factors are related to CAL degeneration in full-thickness rotator cuff tears. Methods: A prospective study was conducted of patients at a single institution undergoing shoulder arthroscopy for first-time, full-thickness rotator cuff tears. We evaluated preoperative anteroposterior radiographs to obtain critical shoulder angle, glenoid inclination, acromial index, acromiohumeral distance, lateral acromial angle, and acromial morphology. We documented CAL quality, rotator cuff tear size and pattern during arthroscopy. Multiple logistic regression was used to identify predictive factors for encountering severe CAL fraying during arthroscopy. Results: Shoulders had mild CAL degeneration in 58.1% of cases, whereas severe CAL degeneration was present in 41.9% of shoulders. Patients with severe CAL attrition were significantly older (62.0 years vs. 58.0 years, P=0.042). Shoulders with severe CAL attrition had large rotator cuff tears in 54.1% of cases (P<0.001), and tears involving the infraspinatus (63.2% vs. 29.6%, P=0.003). The severe degeneration group was more likely to have a larger critical shoulder angle measurement on preoperative radiographs than those in the mild attrition group (36.1°±3.6° [range, 30°-45°] vs. 34.1°±3.8° [range, 26°-45°], P=0.037). Conclusions: While the clinical impact of CAL degeneration remains uncertain, increased severity of CAL degeneration is associated with older age, larger rotator cuff tear size, presence of infraspinatus tearing, and increased preoperative critical shoulder angle. Level of evidence: III.

• 한국조경학회지
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• 제39권5호
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• pp.111-118
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• 2011

건강과 삶의 질 향상에 대한 관심이 커짐에 따라 도시녹지가 가져다 주는 건강편익이 크게 주목되고 있지만, 이에 관한 객관적이고 과학적인 데이터는 매우 부족한 실정이다. 따라서 본 연구에서는 도시녹지가 가져다 주는 건강편익에 대한 과학적 자료를 얻기 위해 생리적, 심리적 지표를 활용하여 실험을 실시하였다. 과거병력이 없는 20대 남자 대학생 20명이 실험에 참가하였고, 자극은 녹지와 도시에서 실제의 경관을 15분간 감상하는 것으로 하였다. 이번 연구는 충남대학교 의학전문대학원 생명윤리심사위원회의 승인을 받은 후 실시되었다. 녹지와 도시에 대한 생리반응을 분석한 결과, 도시에 비해 녹지에서 심박동수가 현저히 감소하였고, 안정상태에서 증가하는 부교감신경활동이 유의하게 향상되었으며, 스트레스호르몬의 일종인 코티솔 농도가 낮아지는 경향이 보였다. 심리반응에 있어서는 부정적인 감정과 정신상태가 녹지에서 보다 유의하게 낮아진 반면, 활력은 유의하게 증가하였다. 이번 연구의 결과는, 녹지를 접하는 것이 심리적 변화뿐만 아니라 인체의 자율신경계와 내분비계 활동에 긍정적 변화를 가져다 준다는 것을 보여주는 것으로써, 녹지가 도시민의 건강증진과 관련하여 매우 직접적인 환경요인이 될 수 있음을 과학적으로 뒷받침한다고 할 수 있다.