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        검색결과 3,462

        1.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 현재 주목받고 있는 스마트 글라스와 같은 증강현실 기술은 배터리, 발열, 착용감 문제 등으로 사용자의 불편을 야기시킨다. 본 연구는 이러한 문제들을 해결하고 사용자 편의성을 극대화할 수 있는 새로운 NED 광학계 를 설계하고자 한다. 방법 : Waveguide 타입과 비구면 구성을 적용한 허상광학계로 NED 광학계를 설계하였다. Code V 소프트웨어 를 사용하였고, 경량화, 높은 시야각, 낮은 왜곡 수차 및 우수한 이미지 품질을 설계 목표로 하여 비순차 광학계를 구성하였다. 결과 : 설계된 광학계는 배율 증가, 포커싱, 수차 감소에 초점을 맞춘 첫 번째 파트와 빛의 손실을 최소화하는 Waveguide 타입의 두 번째 파트로 구성하여 고효율성과 높은 해상도를 나타내었다. 사용자에게 선명하고 편안한 시각적 경험을 보장하고, 컴팩트한 디자인으로 휴대성과 사용자 편의성이 동시에 고려된 광학계를 설계하였다. 결론 : 본 연구에서 개발된 Waveguide 타입과 비구면 광학계는 빛의 손실을 최소화하여 망막까지 효율적으로 전달함으로써 NED 기술의 성능을 크게 향상시켰다. 이는 사용자에게 더 높은 선명도와 생동감 있는 시각적 경험 을 제공하며, 향후 고해상도 광학 응용 분야에 큰 기여를 할 것으로 판단된다.
        4,000원
        2.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 8세에서 19세의 근시 학생을 대상으로 어린이 근시관리 누진 안경렌즈의 착용실태를 조사하고 착용 후 2년간 근시도의 변화를 확인하고자 하였다. 방법 : 2019년 6월부터 2023년 5월까지 수원 G 안경원에서 어린이 근시관리 누진렌즈를 구매한 110명을 대상 으로 근시 진행완화를 위해 렌즈의 착용을 지속하고 있는지 그리고 중도 포기했다면 그 이유를 조사하였다. 그 후 2차 정기방문으로 안경을 다시 교정받은 기록이 있는 72명을 대상으로 초점렌즈(A그룹, 33명)와 어린이 근시관리 누진렌즈(B그룹, 39명)를 착용한 두 그룹으로 나누어 2년간 추적 조사하였다. 결과 : 어린이 근시관리 누진렌즈를 처방받은 110명의 1차 대상자 중 15명(13.6%)이 근시진행 완화 안경 착용 을 중도 포기했으며 이들 중 남자는 11명(73.3%), 여자는 4명(26.6%) 이었다. 또한, 중도 포기한 이유로는 구매의 편의성과 비용문제가 주된 이유로 조사되었다. 1차, 2차, 3차 방문 시기에 평균 등가구면 굴절력은 A그룹에서는 – 2.09±1.43, –2.78±1.52, –3.31±1.55 D이었고, B그룹은 –2.04±1.08, –2.63±1.06, -2.94±1.08 D로 측정되 었다. 각각의 안경을 2년간 착용한 후에 평균 등가구면 굴절력의 변화량은 A그룹에서 –1.22±0.56 D이었고, B그 룹에서는 –0.90±0.51 D를 보였다(p=0.010). 결론 : 8세에서 19세의 근시가 있는 초중고 학생은 2년 간 어린이 근시관리 누진렌즈를 착용한 후에 단초점렌즈 를 착용한 그룹에 비해 근시 진행이 지연되었다. 근시관리 안경렌즈의 성공적인 시장 정착을 위해서는 더욱 다양한 모집단을 장기 추적 관찰하여 그 효과를 연구한 자료가 필요하다고 생각된다.
        4,300원
        3.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
        4.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Since rice is the main food in Korea, there are no regulations on corn milling yet. Corn is known as one of the world's top three food crops along with wheat and rice, and it is known that 3.5 billion people worldwide use corn for food. In addition, corn mills are not developed or sold in Korea, but the use of corn mills is increasing significantly in many countries in Southeast Asia. In the Philippines, as Korea's rice mill import increases, Korea's KAMICO (Korea Agricultural Machinery Industry Cooperative) and domestic company A agreed to develop a corn mill jointly with PHilMech, an organization affiliated with the Philippine Ministry of Agriculture. However, research on corn milling was very insignificant, so the development was carried out based on the technology of Korea's rice mill. Rice milling is performed by peeling off the skin of rice and producing brown or white rice, so it is carried out by removing the skin and cutting the skin. On the other hand, in the corn mill, the skin of the corn is peeled, pulverized and selected to produce main products suitable for edible use. Therefore, in order to develop a corn mill, processes such as peeling, transfer, grinding, sorting, and by-product separation are required, and suitable parts must be developed. In addition, the performance must be gradually improved through experiments in which corn is repeatedly milled. The Philippines produces 7.98 million tons/year of corn, which is about 100 times that of Korea, and is mostly consumed as a staple food. This is about 10% of the total crop production in the Philippines. In addition, the main cultivation complexes of corn are the mountainous regions of Tarlac or Pangasinan, and the produced corn is 72.4% of the so-called yellow corn called Arabel and Sarangani, and the remaining 27.6% are known as white corn. In this study, it was intended to produce grains of 2.5 mm or less suitable for food for yellow corn and to develop a corn mill for 200 kg per hour. Detailed conditions for development are stipulated as more than 55% of the main product recovery rate, more than 31% of the by-product recovery rate, less than 5% of the raw material loss rate, and more than 80% of the embryo dislocation rate. In this study, to achieve this, the overall process of the corn mill was developed, and the optimal conditions for the corn mill were obtained through the development of parts and empirical tests to improve performance. In addition, it was intended to achieve the development goal by evaluating and analyzing the performance of each part so that it did not conflict.
        4,800원
        5.
        2024.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A force-free field (FFF) is determined solely by the normal components of magnetic field and current density on the entire boundary of the domain. Methods employing three components of magnetic field suffer from overspecification of boundary conditions and/or a nonzero divergence-B problem. A vector potential formulation eliminates the latter issue, but introduces difficulties in imposing the normal component of current density at the boundary. This paper proposes four different boundary treatment methods within the vector potential formulation. We conduct a comparative analysis of the vector potential FFF solvers that we have developed incorporating these methods against other FFF codes in different magnetic field representations. Although the vector potential solvers with the new boundary treatments do not outperform our poloidal-toroidal formulation code, they demonstrate comparable or superior performance compared to the optimization code in SolarSoftWare. The methods developed here are expected to be readily applied not only to force-free field computations but also to time-dependent data-driven simulations.
        4,300원
        6.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Cerebral palsy presents significant challenges in motor function for affected children. While conventional bottom-up approaches are common in physical therapy, there is increasing interest in the efficacy of the top-down approach. Objectives: To investigated the impact of applying the top-down approach in physical therapy for a child diagnosed with cerebral palsy, focusing on functional improvement and quality of life. Design: A single-case study. Methods: The patient was a 15-year-old boy with spastic diplegic cerebral palsy who was entering middle school. Cerebral palsy treatment approach of the top-down method (jumping rope) was used to guide and direct physical therapy. Results: The child improved in muscle strength of lower extremity, gross motor function, participation and self-esteem, but the pattern of his gait seemed to be more severe on tiptoe. When the child participated in a jumping rope class, he was able to do more than 10 jumps. Conclusion: The effectiveness of the top-down approach in enhancing functional outcomes and quality of life in children with cerebral palsy. It highlights the potential of this approach in pediatric physical therapy, warranting further research validation.
        4,000원
        7.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Most studies targeting stroke patients have confirmed improvements in balance and walking using immersive and non-immersive virtual reality training programs. However, to date, there are not many studies targeting brain activation enhancement for the two training programs. Objectives: The purpose of this study is to investigate the effect of a virtual reality training program on the EEG of stroke patients according to differences in immersion. Design: A randomized controlled trial. Methods: A total of 20 stroke patients, with 10 in an immersive virtual reality training programs group (IVRG) and 10 in a non-virtual reality training programs group (NVRG) were randomly assigned to exercise three times a week for 6 weeks. EEG was measured for 2 minutes using DSI-24. Results: The intra-group difference in relative alpha waves of brain waves was not significant for both groups, and the between-group difference was not significant. Differences in EEG relative beta waves in the experiment group were significant in the Fp1, Fp2, Cz, C3, C4, P3, and O2 in the experiment group, and significant in the Cz and O2 in the control group. As a result of comparing the differences between each group before and after, there was a significant difference in the Fp1 area. Conclusion: Virtual reality training programs based on differences in immersion were found to have a positive effect on EEG. Therefore, it is believed that a virtual reality training program based on differences in immersion can be provided as a clinical intervention method for EEG.
        4,500원
        8.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The Nordic hamstring exercise is effective as a representative exercise for strengthening eccentric contraction that can activate the hamstring at high levels, improve eccentric contraction strength and ability, and significantly reduce injury rates. Objectives: To investigated a comparison with the lunge exercise to determine the effect of the Nordic hamstring exercise on muscle activity and balance ability in a sample of adult amateurs and football players. Design: Randomized controlled trials. Methods: The subjects of the study were stratified samples of 28 professional and amateur football players and two groups (Nordic hamstring group and lunge group) of 14 people each were studied. Surface electromyography using, was performed to measure the hamstring muscle activity, and the good morning exercise was selected as the measurement exercise. For balance ability, the surface area ellipse and length were measured with BioRescue, while for static balance, the posture of closing the eyes and single-limb standing was measured, and for dynamic balance the one-legged squat was measured. Results: The %MVIC of the semitendinosus and the biceps femoris improved in the Nordic hamstring exercise group and showed statistically significant increase (P<.05). The static and dynamic balance improved in the Nordic hamstring exercise group and showed statistically significant decrease (P<.05). Conclusion: The Nordic hamstring exercise can be useful as an exercise to improve the hamstring muscle activity and balance ability of professional and amateur football players.
        4,200원
        9.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hypertension is characterized by excessive renin-angiotensin system activity, leading to blood vessel constriction. Several synthetic compounds have been developed to inhibit renin and angiotensin-converting enzyme (ACE). These drugs often have adverse side effects, driving the exploration of plant protein-derived peptides as alternative or supplementary treatments. This study assessed the phenolic compound and amino acid content and the antioxidant and antihypertensive activity of 5 South Korean staple crops. Sorghum had the highest phenolic compound content and exhibited the highest antioxidant activity. Millet grains, particularly finger millet (38.86%), showed higher antihypertensive activity than red beans (14.42%) and sorghum (17.16%). Finger millet was found to contain a large proportion of branched-chain, aromatic, and sulfur-containing amino acids, which are associated with ACE inhibition. In particular, cysteine content was positively correlated with ACE inhibition in the crops tested (r=0.696, p<0.01). This study confirmed that the amino acid composition was more correlated with the antihypertensive activity of grains than the phenolic compound content. Finger millet mainly contained amino acids, which have higher ACE inhibitory activity, resulting in the strongest antihypertensive activity. These findings underscore the antihypertensive potential of select crops as plant-based food ingredients, offering insight into their biological functions.
        4,200원
        10.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Abstract Purpose : To determine the perceptions of soft contact lens wearers regarding contact lens wear and care, and their knowledge of adverse effects of contact lens wear by self-assessment. Methods : An online survey using smartphone was conducted by Naver and Google questionnaires among university students who have experience wearing soft contact lenses. Results : Two hundred twenty-eight soft lens wearers were participated in the study. The average age was 20.9±1.7 years (female 72.8%; male 27.2%) were university students. Approximately 25.4% of respondents did not receive training and practices for safe soft lens wear and 14.1% evaluated themselves as poor at wearing and caring for soft lenses. The most uncomfortable symptom of soft lens wear was dryness at 76.3%, and 36.0% experienced soft lens-related adverse events. The higher type of adverse event was conjunctivitis, and the most common self-reported cause of contact lens-related adverse events was improper lens care and non-compliance to lens wear regimens. Conclusion : Based on the self-assessment of soft lens care that resulted from this survey, we believe that a more proactive approach to intervention by contact lens practitioners is still needed to prevent the risk of adverse events and improve soft lens wearer behavior. Key words : Compliance, Contact lens-related adverse events, Self-assessment, Soft contact lens Authors ORCID:†
        4,500원
        11.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 한국산 미기록속인 이마줄불청객파리속(신칭)과 미기록종인 작은눈이마줄불청객파리(신칭)를 처음으로 보고한다. 우리는 이 종이 포식성 거미의 섭식과정에 관여하는 phoretic relationship의 습성을 갖는 것을 확인하였다. 이 종의 성충에 대한 기재문과 사진 및 DNA바 코드 서열을 제공한다.
        4,000원
        12.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        제충국(Tanacetum cineariaiaefolium), 데리스(Derris elliptica), 고삼(Sophora flavescens) 추출물은 다양한 해충을 방제하는데 사용되고 있다. 하지만, 국내에서 판매되고 있는 식물추춞물 자재는 유효성분의 표기가 없고, 살충농도와 살충시간에 대한 자료가 전무한 상황이다. 본 연구에서는 상 용화된 주요 식물추출물의 살충유효성분의 농도를 결정하고 복숭아혹진딧물에 대해 살충농도와 살충시간을 측정하였다. 식물추출물의 살충활성성분 인 pyrethrins, rotenone, matrine과 oxymatrine의 농도는 액체 크로마토그래피에서 표준물질을 활용하여 질량분석을 통해 측정하였다. 식물추출 물을 농도별로 희석하여 복숭아혹진딧물에 살포하여 살충력을 측정하였다. 표준화합물과 비교한 후 질량분석 및 결정했습니다. Myzus persicae에 대 한 lethal concentation과 lethal time을 조사했다. 살포 후 48시간 후 치사 농도(LC50)는 pyrethrins (20.4 ppm), roteone (34.1 ppm), matrine (29.6 ppm)였고, 100 ppm 살포한 LT50은 pyrethrins (13.4시간), rotenone (15.1시간), matrine (14.4시간)로 측정되었다. Kaplan-Meier 생존분 석 결과, 100 ppm에서 세 가지 식물 추출물의 LT50은 대조구인 화학 살충제인 Sulfoxaflor를 살포 처리구보다 유의하게 빨랐습니다. 본 결과는 복숭 아혹진딧물 방제를 위해 식물추출물의 제형화에 단일 또는 혼합 제제를 개발하는데 기준 살충농도와 살충시간을 제고하는데 의미가 있다.
        4,000원
        13.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cerebral palsy (CP) is a prevalent neurodevelopmental disorder characterized by motor and postural impairments caused by central nervous system dysfunction. It significantly impacts children’s daily functioning and quality of life. Physical therapy is a crucial intervention for children with CP that aims to improve motor skills and functional abilities. This study aimed to provide a comprehensive overview of holistic physical therapy approaches methods specifically designed for children with CP and examine recent research trends and their implications for optimizing outcomes in this population. This study employed a narrative review approach, conducting a comprehensive examination of the current literature pertaining to physical therapy methods for children with CP. The review encompassed studies exploring assessment techniques, evidence-based interventions, and innovative approaches in the field. It was discerned that encompassing physical therapy strategies, which encompass individualized treatment plans, evidence-based interventions, and the integration of innovative techniques, yield a favorable influence on the motor skills and functional capacities of children with CP. This review synthesizes the current knowledge on effective physical therapeutic strategies for children with CP. Furthermore, this review highlights the need for continued research and innovation in the field of pediatric physical therapy for CP.
        4,000원
        14.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Air conditioner filters purify the air of indoor environments by removing air pollutants and supporting the efficiency of the unit’s cooling function. However, an air conditioner filter can become a microenvironment in which some fungi can grow as dust continues to accumulate and favorable humidity conditions are formed. Fungal growth in air conditioner filters could lead to fungal allergies or fungal diseases, in addition to emitting a foul odor. In an effort to understand what species causes this malodorous problem, we investigated the diversity of fungi found in air conditioners. Fungi were sampled from the collected air conditioner filters and grown on DG18 agar media. After purification for pure isolates, species identification was undertaken. Colony morphology was observed on PDA, MEA, CYA, and OA media. Microstructures of fruiting body, mycelia, and spores were examined using a light microscope. Molecular identification was performed by PCR and sequencing of PCR amplicons, and molecular phylogenetic analysis of sequenced DNA markers, including the Internal Transcribed Spacer (ITS), the 28S large subunit of the nuclear ribosomal RNA (LSU rDNA), the β-tubulin (BenA) gene, the Calmodulin (CaM) gene, and the DNA-directed RNA polymerase II subunit 2 (RPB2) gene. Through this identification process, we found two fungal species, Aspergillus miraensis and Dichotomopilus ramosissimus, which are unrecorded species in Korea. We will now report their morphological and molecular features.
        4,200원
        15.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, quantitative analysis is attempted on data collected from Chilgapsan Observatory Star Park in Cheongyang-gun, Chungcheongnam-do. The aim of this experimental study in which quantitative analysis of the Astronomical Science Museum in Korea is conducted is to investigate its current situation and secure basic data. As of July 31, 2023, it has had 283,931 cumulative visitors in total. It had the largest number of visitors when it opened (2009 year), after which their number reduced steadily until the pandemic (COVID-19, 2020–2022). Recently, however, the number of visitors has increased. Generally, the number of visitors is highest in August (20.8$\%$) and least in April (4.1$\%$). The visit rate is higher on weekends (Saturday and Sunday) than on weekdays (Monday–Friday), and groups comprise only about 5.3$\%$ of the total number of visitors. Moreover, it can be confirmed that the number of visitors increases sharply during events. Finally, it was confirmed that the visit rate was unaffected by weather conditions. Considering these results, we propose the following strategies: 1) Establish a special program that reflects “the weekend effect.” 2) Prepare a plan to attract group visitors during the weekdays using “the event effect.” 3) Arrange alternative programs (e.g., experiential activities) that can be conducted indoors regardless of weather conditions. We think that our findings will help establish a roadmap for the direction the Astronomical Science Museum should take and aid in preparing a strategic foundation to preemptively respond to unexpected situations (e.g., pandemics).
        4,500원
        16.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Throughfall (TF)—as a diffusive hydrological water flux—significantly affects ecohydrological and biogeochemical processes within forest ecosystems. Recent investigations have revealed the impact on TF generation processes within unmanaged coniferous plantations of under-canopy structures, particularly those laden with dead branches, as well as upper-canopy structures. However, spatiotemporal variations in TF in such plantations remain unexplored. We investigated these variations in TF in a 33-year-old unmanaged Japanese cypress (Chamaecyparis obtusa Endl.) plantation, laden with dead branches, with a high stand density (SD) of 2,500 stems ha−1. Over a two-year period (May 2017 to May 2019), we conducted weekly TF measurements using 28 manual-type TF collectors. We compared the present TF ratio and canopy water storage capacity (S) with those of previous investigations conducted on Japanese cypress plantations. Moreover, we assessed key indices contributing to spatiotemporal TF variations (canopy cover: CC and distance to the nearest stem: TFd) and potentially influential dead branch indices (number of dead branches: TFdb and vertical spacing length on a stem: TFs) to elucidate TF spatial patterns. The results showed that the TF ratio was notably lower than that in previous studies (n = 13), with SD (r = –0.92, p < 0.001) and S (r = –0.87, p < 0.001) emerging as key influential factors among other stand-structure parameters. Spatial TF patterns exhibited a decreasing trend as the gross rainfall (GR) increased. Temporal stability was not significantly associated with CC (r = 0.120, p = 0.544), TFd (r = 0.068, p = 0.731), TFdb (r = 0.211, p = 0.281), or TFs (r = 0.206, p = 0.292) for any of the TF collectors. These findings underscore the important role of GR in determining the spatial variation of TF. Collectively, our results contribute to an enhanced understanding of TF spatiotemporal heterogeneity in unmanaged Japanese cypress plantations with dead branches.
        4,600원
        17.
        2023.12 구독 인증기관 무료, 개인회원 유료
        In recent years, deaths and missing people have continuously occurred due to man overboard (MOB) and suicide on passenger ships. However, due to the complex deck structure and enlargement of passenger ships, closed-circuit television (CCTV) coverage is limited, and it is difficult to prevent accidents for all passengers with limited crews. Therefore, a real-time system for detecting high-risk blind spots on passenger ships is needed through risk analysis. This study used a combination of the following three risk factors to calculate and evaluate the risk of MOB and suicide by deck area of the passenger ship: 1) distance away from guard rails, 2) the visibility of CCTV, and 3) ship operating conditions. Based on the survey from experts, risk scores of MOB and suicide accidents by deck area on a passenger ship were yielded.
        4,000원
        18.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we examined the antagonistic effects of sprout-borne lactic acid bacteria (LAB) on Salmonella enterica serovar Enteritidis. This antagonism is promoted as a means of controlling contamination during sprout production and provides additional LAB for consumers. We isolated a total of 24 LAB isolates in nine species and five genera from seven popular vegetable sprouts: alfalfa (Medicago sativa), clover (Trifolium pratense), broccoli (Brassica oleracea ssp. italica), vitamin (B. rapa ssp. narinosa), red radish (Raphanus sativus), red kohlrabi (B. oleracea var. gongylodes), and Kimchi cabbage (B. campestris var. pekinensis). Based on 16S rRNA gene sequences, the LAB species were identified as Enterococcus casseliflavus, E. faecium, E. gallinarum, E. mundtii, Lactococcus taiwanensis, Leuconostoc mesenteroides, Pediococcus pentosaceus, and Weissella cibaria, and W. confusa. A total of 16 LAB isolates in seven species including E. faecium, E. gallinarum, E. mundtii, L. taiwanensis, L. mesenteroides, P. pentosaceus, and W. cibaria showed antagonistic activity toward S. enterica. The growth inhibition of sprout LAB on S. enterica was confirmed by co-culture. Unexpectedly, sprout LAB failed to suppress the growth of S. enterica in alfalfa sprouts, whereas all LAB strains stimulate S. enterica growth even if it is not significant in some strains. The findings of this study indicate that S. enterica-antagonistic LAB are detrimental to food hygiene and will contribute to further LAB research and improved vegetable sprout production.
        4,000원
        19.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,000원
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