• 한국전자파학회지:전자파기술
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• 제6권1호
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• pp.17-27
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• 1995

본 논문에서는 시간영역 유한차분법(FDTD)을 이용하여 전자기 결합 광대역 마이크로스트립 안테나의 특성 을 해석하고 파라메타를 최적화 하였다. 전자기 결합 마이크로스트립 안테나는 급전 선로에 짧은 동조 스터브 틀 연결하면 13%정도의 넓은 대역 특성을 가지며, 동조 스터브의 폭, 길이, 위치 둥의 변화에 따라 안테나의 특 성이 변한다. 시간영역에서의 유한차분볍에 의한 수치해석 결과들 푸리어 변환하여, 주파수 영역에서 공진 주 파수, 반사 손실, 전압정재파비 및 입력 임피이던스 동을 계산하였다. 설계 제작한 안테나의 측정 결과와 비교 하여 시간영역 유한차분법의 계산 결과가 잘 일치함을 보였다. 최적화 후 약 15% 정도의 최대 대역폭을 얻었다

• 한국의류학회지
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• 제27권5호
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• pp.588-599
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• 2003

The convenience of TV home shopping is known to provoke compulsive buying, which is chronic and repetitive purchasing behavior that comes about as a response to negative events or feelings. The purpose of this study was to identify whether there is a difference in the degree of compulsive buying between the purchasers of fashion goods and the purchasers of non-fashion goods on TV home shopping shows and the determinants of compulsive buying and their relative importance. Utilizing the convenient sampling method, the sample of the study was composed of women aged over 20 living in the Seoul metropolitan area. Out of 380 distributed questionnaires, 270 useful questionnaires were returned. The data were analyzed using t-test, Pearson correlation, and multiple regression. The results indicated that TV home shoppers who purchased fashion goods showed higher degree of compulsive buying than those who purchased non-fashion goods and the determinants of compulsive buying are sample＇s age, mean age of the sample＇s children, credit usage, expenditure on fashion goods, frequency of purchase of fashion goods on TV home shopping shows, and promotional tools used by TV home shopping retailers. Regarding the relative importance of the determinants, credit usage was the most influential factor followed by expenditure on fashion goods and the length of exposure to TV home shopping shows.

• Journal of Crop Science and Biotechnology
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• 제10권2호
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• pp.106-111
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• 2007

Increasing genetic variability with mutagenic agents has been broadly employed in plant breeding because it has the potential to alter one or more desirable traits. In this study, a molecular analysis assessed by Amplified Fragment Length Polymorphisms(AFLPs) and a morphological analysis based on seedlings subjected to aluminum stress were compared. Also, an analysis of allelic frequencies was performed to observe unique alleles present in the pool. Genetic distances ranging from 0.448 to 0.953 were observed, suggesting that mutation inducing was effective in generating variability. The genetic distances based on morphological data ranged from 0(genotypes 22 and 23) to 30.38(genotypes 15 and 29). In the analysis of allelic frequency, 13 genotypes presented unique alleles, suggesting that mutation inducing was also targeting unique sites. Mutants with good performance under aluminum stress(9, 15, 18 and 27) did not form the same clusters when morphological and molecular analyses were compared, suggesting that different genomic regions may be responsible for their better performance.

• Current Research on Agriculture and Life Sciences
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• 제2권
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• pp.77-90
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• 1984

Results investigated backwater phenomena at Geumho river basin to get a basic data for Daegu basin area development plan are as the follows. 1. It is a A=0.35 L 1.848 (r = 0.97), the relationship between basin area and river length at Geumho river. 2. Dividing the rainfall of Geumho river basin as two parts, a first half rainfall and a second half rainfall, the amount of a first half rainfall appeared 57.5% comparison with total rainfall. 3. The maximum flood discharge appeared 12 hrs. continuous rainfall rather than 24 hrs. continuous rainfall. 4. Results investigated backwater phenomena from Geumho II bridge to chungchun appeared the rising water level of 69 cm, 55 cm, 44 cm, at section III in the starting point water level of 1.8 m, 2.4 m, 4.0 m respectively. 5. Results investigated backwater phenomena by the flood water level appeared a similar form. There was a average rising water level of 30 cm at section III. At the results of this computation, it was confirmed that section III was affected the highest backwater phenomena among the observed river reaches in Geumho river. In addition, this paper should be given a assistance to decide a economic and safe section in construction of bank of river and estuary barrage.

• 한국운동역학회지
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• 제29권3호
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• pp.167-172
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• 2019

Objective: The aim of this study was to investigate the effect of midsole hardness of running shoe on muscle fatigue and impact force during distance running. Method: Ten healthy college recreational runners who were performing distance running at least three times a week participated in this experiment. They were asked to run for 15 minutes in the treadmill at 10 km/h with running shoes having three different types of midsole hardness (Soft, Medium, Hard). EMG signal and insole pressure were collected during the first and last one minute for each running trials. Data were analyzed using a one-way analysis of variance (ANOVA) with repeated measures. Results: Midsole hardness did not affect the consistency of stride length. For the median frequency of the EMG signal, only VL was affected by midsole hardness; that of medium was greater than other midsoles (p<.05). The loading rate of impact forces increased by midsole hardness (p<.01). Conclusion: Although soft midsole could attenuate impact forces at heel contact, it might have a negative effect on the fatigue of muscle which could decelerate the body after heel contact. Therefore, it is necessary to select the optimum hardness of midsole carefully for both reduction impact forces and muscle fatigue.

• Advances in nano research
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• 제7권2호
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• pp.109-123
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• 2019

In this article, the free vibration analysis of annular sandwich plates with various functionally graded (FG) porous cores and carbon nanotubes reinforced composite (CNTRC) facesheets is investigated based on modified couple stress theory (MCST) and first order shear deformation theories (FSDT). The annular sandwich plate is composed of two face layers and a functionally graded porous core layer which contains different porosity distributions. Various approaches such as extended mixture rule (EMR), Eshelby-Mori-Tanaka (E-M-T), and Halpin-Tsai (H-T) are used to determine the effective material properties of microcomposite circular sandwich plate. The governing equations of motion are extracted by using Hamilton's principle and FSDT. A Ritz method has been utilized to calculate the natural frequency of an annular sandwich plate. The effects of material length scale parameters, boundary conditions, aspect and inner-outer radius ratios, FG porous distributions, pore compressibility and volume fractions of CNTs are considered. The results are obtained by Ritz solutions that can be served as benchmark data to validate their numerical and analytical methods in the future work and also in solid-state physics, materials science, and micro-electro-mechanical devices.

• 한국수산과학회지
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• 제53권6호
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• pp.942-953
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• 2020

Achieving optimal sustainable yields (i.e., avoiding overfishing and maximizing fishery harvest at the same time) is one of the main objectives in fisheries management. Generally, management reference points (MRPs) such as fishing mortalities (Fmsy, F0.1, Fx%) have been suggested for the purpose. In this study, we intended to suggest MRPs for Korea chub mackerel Scomber japonicus stock, using a stochastic catch-at-age model (SCAA) and evaluate whether the current fishing intensity on the stock is appropriate. We used length frequency and catch-per-unit-effort data on the Korea chub mackerel stock collected from the large purse-seine fishery, and yields landed by all fisheries from years 2000 - 2019. We calculated yield per recruit and spawning potential ratio, and projected spawning stock biomass (SSB) under different fishing mortality, assuming annual recruitments were solely controlled by environmental effects (i.e., steepness of 1.0). Some of our major findings and suggestions were that the overfishing threshold would be F46%; i.e., the fishing mortality in the terminal year, 2019 was 0.257/year, which corresponded to F46%.

• Journal of Korean Biological Nursing Science
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• 제23권3호
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• pp.208-216
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• 2021

Purpose: The purpose of this study was to identify the factors influencing nurses' caring behavior. Methods: The descriptive study included 178 intensive care unit (ICU) nurses who completed a self-report structured questionnaire. The data were analyzed using descriptive statistics, independent t-test, one-way ANOVA, and Pearson's correlation and multiple regression analysis using the IBM SPSS/WIN 23.0 program. Results: Significant correlation existed between perception of Patient- and Family-Centered Care (PFCC) and nurses' caring behaviors (r=.36, p<.001). Multiple regression analysis showed that perception of support (β=.36, p<.001), total career length (β=.33, p<.001), and familiarity with PFCC (β=.15, p=.018) affected the caring behavior of ICU nurses. These variables explained 30.0% of the variance in caring behavior. Conclusion: Effective strategies are needed to improve perceptions of support as well as to promote PFCC for increasig the frequency of caring behavior among ICU nurses.

• Advances in nano research
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• 제13권2호
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• pp.165-174
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• 2022

In the present study, a hybrid model of artificial neural network (ANN) and internet of things (IoT) is proposed to overcome the difficulties in deriving governing equations and numerical solutions of the dynamical behavior of the nano-systems. Nano-structures manifest size-dependent behavior in response to static and dynamic loadings. Nonlocal and length-scale parameters alongside with other geometrical, loading and material parameters are taken as input parameters of an ANN to observe the natural frequency and damping behavior of micro sensors made from nanocomposite material with piezoelectric layers. The behavior of a micro-beam is simulated using famous numerical methods in literature under base vibrations. The ANN was further trained to correlate the output vibrations to the base vibration. Afterwards, using IoT, the electrical potential conducted in the sensors are collected and converted to numerical data in an embedded mini-computer and transferred to a server for further calculations and decision by ANN. The ANN calculates the base vibration behavior with is crucial in mechanical systems. The speed and accuracy of the ANN in determining base excitation behavior are the strengths of this network which could be further employed by engineers and scientists.

• 식물분류학회지
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• 제52권1호
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• pp.45-53
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• 2022

Halenia coreana is an endangered, endemic species that is distributed in only a few locations in Korea, such as Mts. Hwaaksan and Daeamsan. It has been recently segregated from H. corniculata, broadly distributed in cold temperate regions that include northern Japan, the Russian Far East, northeastern China, Mongolia, and eastern Europe, where population sizes are usually large. To examine the genetic diversity of H. coreana and evaluate the level of genetic differentiation of the species compared with that of H. corniculata, we surveyed 183 candidate simple sequence repeats (SSR) motif markers for H. coreana and H. corniculata from sequence data of amplified fragments of a specific length in the genome. A total of 17 genomic-SSR markers were selected to examine the levels of genetic diversity and differentiation using 17 samples of H. coreana and 60 samples of three populations of H. corniculata. The results here suggest that the genetic diversity of H. coreana is very low with a high frequency of inbreeding within its population. We found that H. coreana is genetically differentiated from H. corniculata, supporting the recognition of the geographically isolated H. coreana as a distinct species.