• Geomechanics and Engineering
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• 제18권6호
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• pp.585-594
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• 2019

In-situ leaching could be one of the promising mining methods to extract the minerals from deep fractured rock mass. Constrained by the low permeability at depth, however, the performance does not meet the expectation. In fact, the rock mass permeability mainly depends on the pre-existing natural fractures and therefore play a crucial role in in-situ leaching performance. More importantly, fractures have various characteristics, such as aperture, persistence, and density, which have diverse contributions to the promising method. Hence, it is necessary to study the variation of fluid rate versus fracture parameters to enhance in-situ leaching performance. Firstly, the subsurface fractures from the depth of 1500m to 2500m were mapped using the discrete fracture network (DFN) in this paper, and then the numerical model was calibrated at a particular case. On this basis, the fluid flow through fractured rock mass with various fracture characteristics was analyzed. The simulation results showed that with the increase of Fisher' K value, which determine the fracture orientation, the flow rate firstly decreased and then increased. Subsequently, as another critical factor affecting the fluid flow in natural fractures, the fracture transmissivity has a direct relationship with the flow rate. Sensitive study shows that natural fracture characteristics play a critical role in in-situ leaching performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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• pp.3708-3728
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• 2021

Indian herbal plants are used in agriculture and in the food, cosmetics, and pharmaceutical industries. Laboratory-based tests are routinely used to identify and classify similar herb species by analyzing their internal cell structures. In this paper, we have applied computer vision techniques to do the same. The original leaf image was preprocessed using the Chan-Vese active contour segmentation algorithm to efface the background from the image by setting the contraction bias as (v) -1 and smoothing factor (µ) as 0.5, and bringing the initial contour close to the image boundary. Thereafter the segmented grayscale image was fed to a leaky capacitance fired neuron model (LCFN), which differentiates between similar herbs by combining different groups of pixels in the leaf image. The LFCN's decay constant (f), decay constant (g) and threshold (h) parameters were empirically assigned as 0.7, 0.6 and h=18 to generate the 1D feature vector. The LCFN time sequence identified the internal leaf structure at different iterations. Our proposed framework was tested against newly collected herbal species of natural images, geometrically variant images in terms of size, orientation and position. The 1D sequence and shape features of aloe, betel, Indian borage, bittergourd, grape, insulin herb, guava, mango, nilavembu, nithiyakalyani, sweet basil and pomegranate were fed into the 5-fold Bayesian regularization neural network (BRNN), K-nearest neighbors (KNN), support vector machine (SVM), and ensemble classifier to obtain the highest classification accuracy of 91.19%.

• 한국콘텐츠학회논문지
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• 제21권8호
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• pp.466-477
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• 2021

본 연구의 목적은 국내 최초로 반려동물 온라인 쇼핑몰 고객의 쇼핑동기요인들의 고객만족에 대한 영향을 국내 최초로 살펴보고 고객들이 양육하는 반려동물 수가 쇼핑동기요인들의 고객만족에 대한 영향력을 조절하는 효과에 대해 분석하는 것이다. 반려동물 쇼핑몰 고객들의 쇼핑동기요인은 요인분석결과 편의적, 경제적, 쾌락적, 제품특성적, 정보지식적 쇼핑동기의 5개 요인으로 구분되었다. 다중회귀분석을 통해 반려동물 온라인 쇼핑몰 고객의 편의적 쇼핑동기와 정보지식적 쇼핑동기는 고객만족에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 위계적 회귀분석결과 지식정보적 쇼핑동기와 고객만족 간의 관계에서 반려동물 수의 조절효과가 있는 것으로 나타났다.

• 한국콘텐츠학회논문지
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• 제22권4호
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• pp.261-272
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• 2022

본 연구는 유튜브 정치동영상 이용자 420명을 대상으로 정치성향의 선택적 노출과 태도극화 및 온라인 정치참여의 관계를 규명하였으며, 선택적 노출과 온라인 정치참여 관계에서 태도극화의 매개효과에 대해 살펴보았다. 자료는 SPSS 21.0 프로그램과 AMOS 21.0 프로그램을 이용하여 탐색적 요인분석과 상관관계분석, 구조모형분석을 실시하여 주요 결과를 도출하였다. 그 결과 첫째, 선택적 노출은 태도극화에 정적 영향을 미치는 것으로 나타났다. 둘째, 선택적 노출은 온라인 정치참여에 정적 영향을 미치는 것으로 나타났다. 셋째, 태도극화는 온라인 정치참여에 정적 영향을 미치는 것으로 나타났다. 넷째, 태도극화는 선택적 노출과 온라인 정치참여의 관계를 매개하는 것으로 나타났다. 요약하면, 유튜브 정치동영상에 대한 선택적 노출은 태도극화와 온라인 정치참여를 높이고 선택적 노출에 의해 태도극화가 강화될수록 온라인 정치참여로 이어진다는 사실을 확인하였다.

• Journal of Astronomy and Space Sciences
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• 제39권2호
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• pp.43-50
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• 2022

The unified scheme of Seyfert galaxies hypothesizes that the observed differences between the two categories of Seyfert galaxies, type 1 (Sy1) and type 2 (Sy2) are merely due to the difference in the orientation of the toroidal shape of the obscuring material in the active galactic nuclei. We used in this paper, a sample consisting of 120 Seyfert galaxies at 1.40 × 10⁹ Hz in radio, 2.52 × 10¹⁷ Hz in X-ray and 2.52 × 10²³ Hz in γ-ray luminosities observed by the Fermi Large Area Telescope (Fermi-LAT) in order to test the unified scheme of radio-quiet Seyfert galaxies. Our main results are as follows: (i) We found that the distributions of multiwave luminosities (L_radio, L_X-ray, and L_γ-ray) of Sy1 and Sy2 are completely overlapped with up to a factor of 4. The principal component analysis result reveals that Sy1 and Sy2 also occupy the same parameter spaces, which agrees with the notion that Sy1 and Sy2 are the same class objects. A Kolmogorov-Smirnov test performed on the sub-samples indicates that the null hypothesis (both are from the same population) cannot be rejected with chance probability p ~ 0 and separation distance K = 0.013. This result supports the fact that there is no statistical difference between the properties of Sy1 and Sy2 (ii) We found that the coefficient of the best-fit linear regression equation between the common properties of Sy1 and Sy2 is significant (r > 0.50) which plausibly implies that Sy1 and Sy2 are the same type of objects observed at different viewing angle.

• Geomechanics and Engineering
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• 제32권1호
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• pp.49-68
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• 2023

The three-dimensional failure criterion is essential for maintaining wellbore stability and sand production problem. The convenient factor for a stable wellbore is mud weight and borehole orientation, i.e., mud window design and selection of borehole trajectory. This study proposes a new three-dimensional failure criterion with linear relation of three in-situ principal stresses. The number of failure criteria executed to understand the phenomenon of rock failure under in-situ stresses is the Mohr-Coulomb criterion, Hoek-Brown criterion, Mogi-Coulomb criterion, and many more. A new failure criterion is the extended Mohr-Coulomb failure criterion with the influence of intermediate principal stress (σ₂). The influence of intermediate principal stress is considered as a weighting of (σ₂) on the mean effective stress. The triaxial compression test data for eleven rock types are taken from the literature for calibration of material constant and validation of failure prediction. The predictions on rock samples using new criteria are the best fit with the triaxial compression test data points. Here, Drucker-Prager and the Mogi-Coulomb criterion are also implemented to predict the failure for eleven different rock types. It has been observed that the Drucker-Prager criterion gave over prediction of rock failure. On the contrary, the Mogi-Coulomb criterion gave an equally good prediction of rock failure as our proposed new 3D failure criterion. Based on the yield surface of a new 3D linear criterion it gave the safest prediction for the failure of the rock. A new linear failure criterion is recommended for the unique solution as a linear relation of the principal stresses rather than the dual solution by the Mogi-Coulomb criterion.

• 한국식생활문화학회지
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• 제32권5호
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• pp.383-393
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• 2017

연구는 중국 소비자들의 식생활라이프 스타일 요인에 따른 인구학적 특성을 구분함으로써 중국소비자들의 식행동의 차별성을 소비자 집단에 따라 세분화 하여 분석하고, 향후 타겟 소비자의 식품과 음식에 대한 속성과 특성 요구를 수용하는 상품개발을 위한 기초자료를 마련함을 그 목적으로 한다. 식생활라이프스타일에 대한 요인분석 결과 음식의 맛과 질을 중요시여기는 미식요인(Gourmet factor), 건강요인(Healthy factor), 편의요인(Convenience factor), 경제요인(Economic factor) 등 4개 요인이 추출되었으며, 식생활라이프스타일 요인점수에 따라 4개의 군집으로 분류되었다. 이들 4개 그룹은 차별화된 식생활라이프스타일 유형으로 특징지을 수 있으며, 그룹 1 미식경제군은 20대의 젊은이들의 구성비율이 높고 자취의 비율이 높으며, 외식횟수가 높으며 하루 세끼 식사를 규칙적으로 하는 비율은 상대적으로 낮았다. 이들은 식생활라이프스타일은 미식요인과 경제적 요인에 민감한 반면 건강요인과 편의요인에의 민감도가 낮았으며, 식행동에서도 규칙적이며 균형잡힌 식생활에 대한 실천이 가장 낮은 것으로 조사되었다. 즉 음식과 식품에 대하여 품질에 있어서 맛을 추구하지만 몸의 건강을 지키기 위한 식생활의 실천은 낮은 것으로 특징지을 수 있다. 그룹 2 두루관심군은 30대 구성 비율이 높았고 고학력층과 고소득층이 다른 그룹에 비해 높았다. 식생활라이프 스타일 요인 전반에 대한 추구성향이 타 그룹들에 비해 높아, 다양하고 새로운 음식, 외식과 삶에 대한 즐거움을 즐기는 미식을 추구하고, 건강과 관련되는 웰빙 식재료와 식품에 대한 추구도 높았다. 그러나 경제적인 요인인 쿠폰 활용, 가성비 등을 따지고 상대적으로 편의 식품을 적게 소비하며, 식행동 및 식습관에서도 다른 그룹보다 규칙적이며, 특히 유제품과 동물성 단백질의 섭취가 높고, 균형 잡힌 건강식을 섭취하는 식생활 고관심의 스마트 컨슈머의 성향을 보인다. 그룹 3 건강경제군은 40대 이상의 남성비율과 주부의 구성 비율이 높으며 소득수준이 다른 그룹에 비해 낮은, 가족형의 소비자군을 구성한다. 즉 식생활라이프스타일에서도 건강식품, 자연식재료 등에 건강성을 추구하고 식품구매에 있어서 경제적인 가성비를 추구하는 성향을 보이나 식행동 및 식습관 분석 결과 가공식품의 섭취가 다른 그룹에 비해 높은 경향을 보였다. 마지막으로 그룹 4는 30대 이상, 여성의 비율이 상대적으로 높았으며, 대학 이상의 교육수준도 다른 그룹에 비해 높았다. 이들은 가격과 편의성보다는 건강과 맛을 추구하는 그룹으로 중국의 중년여성들의 로하스 지향성이 가장 많이 나타나며, 영양지식을 실생활에 직접 활용하는 것으로 조사되었다. 중국인의 식생활은 최근 10년 사이 전통적인 농수산물의 소비에서 간편식이나, 서구식 식사 등으로 변화되고 있으며, 도시거주민 등을 중심으로 웰빙과 건강, 식생활에 대한 관심도도 높아지고 있다. 미식과 웰빙, 가성비와 간편식 등을 추구하는 식생활라이프스타일은 우리나라를 비롯한 일본, 유럽 등에서도 보편적인 식행동 등으로 나타나며 따라서 중국인들은 높아진 소득과 더불어 건강과 미식 등을 지향하는 다양한 식생활 행동패턴이 조사되었다. 본 연구에서 식생활라이프스타일은 유형별 집단으로 구별되며 차별적 특성을 나타내었고, 이들의 식생활라이프스타일에 따라 식행동 및 식습관은 유의적으로 차이를 보였다. 즉 소비자들이 유지하는 식생활은 그들이 유지하는 식생활에 대한 태도, 행동, 의견에 따라 차별됨을 알 수 있다. 이와 같은 식생활관련 라이프스타일은 소비자들의 삶의 가치와 의식이 반영되는 것이며, 그들만의 고유한 특성이 식생활에 반영되는 것을 알 수 있다. 유사한 식생활라이프스타일을 가진 집단은 세분화된 소비자 집단으로 구별될 수 있으며, 세분화된 집단별로 구매행동의 차이를 보이거나, 선호하는 상품의 유형과 특성에 차이를 보이며, 인구통계학적인 특성에 따라서도 구분되어 질 수 있다. 그러므로 향후 중국 소비자들을 대상으로 하는 식품이나 음식 상품의 개발에서 식품과 식생활에 관련된 미식적, 건강적, 편의적, 경제적인 요소가 주요한 차별점이 될 수 있으며, 중국인들은 과거와 다르게 식품의 건강성과 미식성 등을 고려하고 있고, 식생활라이프스타일 요인과 인구학적인 특성, 식행동 등으로 세분화된 타겟 소비자들의 수용성과 욕구를 고려한 본 연구의 결과가 상품개발 마케팅 활동자료로써 의미 있게 사용될 수 있을 것으로 사료된다. 그러나 본 연구는 중국의 지역적인 분류를 고려하지 않은 온라인을 활용하는 소비자들만을 대상으로 실시되어 조사대상자에 대한 연구한계를 가지고 있으므로, 향후 중국의 다양한 지역과 다양한 민족적 특성을 반영하는 연구가 진행되어야 할 것으로 사료된다.

• 한국응급구조학회지
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• 제3권1호
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• pp.43-54
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• 1999

This study is attempted for the purpose of clearly understanding the stressors which emergency medical technology students experience during clinical practice, giving guidance in desirable direction and improvement of clinical practice, and giving the basic materials so that emergency medical technology students may practice effectively. The design of this study was a descriptive survey. The subjects in this study were 59 emergency medical technology students who were 2nd grade in D college. The collection of questionnaires took 3 days from September 1, 1999 to September 3, 1999. This researcher explained the purpose of this study to students, after they agreed to this survey, the researcher gave the questionnaire to them, had them answer the questions and collected the questionnaire immediately. Data analysis included percentage, mean and standard deviation, t-test and ANOVA trough SPSS computer program. The results of this study are, briefly, as follows; 1. In 'satisfaction-degree to specializing in the science of emergency medical technology' 27.1% of the subjects is revealed as 'satisfied' and in 'satisfaction-degree of clinical practice', 8.5% of the subjects is revealed as 'satisfied'. 2. Viewed from each of the categories of stressors which emergency medical technology students experience during clinical practice, 'ideals and values' is the category in which emergency medical technology students experience most severe stress at a mean 3.25 and 'personal relations' is the category in which emergency medical technology students experience mildest stress at a mean 2.82. The total stress degree mean is 3.06, which emergency medical technology students experience during clinical practice is revealed as 'moderate' stress. 3. Considering the stressor involved in each category, the results are as follows; (1) In 'environment', 'orientation to the hospital before clinical practice' is revealed as the most severe stressor at a menu 3.44. (2) In 'personal relations', 'relations with doctor and nurse' is revealed as the most severe stressor at a mean 3.59. (3) In 'role', 'unilaterally when their role is seems to be obscure' is revealed as the most severe stressor at a mean 4.10. (4) In 'ideals and values', 'difference between college practice and hospital practice' is revealed as the most severe stressor at a mean 3.88. (5) In 'activity', 'repetition of simple and functional work during clinical practice' is revealed as the most severe stressor at a mean 3.98. (6) In 'total stress factors', 'unilaterally when their role is seems to be obscure' is revealed as the most severe stress factor at a mean 4.10 and 'relations with comrade students' is revealed as the stress factor causing mildest stress at a mean 2.20. 4. Considering the relationship between the categories of stressors and the general characteristics, the results are as follows; (1) 'Environment' is revealed as being positively correlated with 'satisfaction degree of clinical practice'(F=3.53, p= .0359). (2) 'Ideals and values' is revealed as being correlated with 'sex'(t=-2.31, p= .0240) and 'satisfaction degree of clinical practice'(F=3.31, p= .0438).

• 대한간호학회지
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• 제30권5호
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• pp.1279-1291
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• 2000

The main objectives of this study were to analyze the concept of hope, so to provide basic data to develop a valid instrument to measure hope, and to develop hope enhancing nursing intervention a program for cancer patients. The hybrid model approach was applied in three phases, the theoretical phase, the empirical phase, and the analytic phase. The study was developed on universal attributes explaining generalized hope and specific hope, which were revealed in a comprehensive review of the literature. In the empirical phase, eight cancer patients undergoing chemotherapy were interviewed to reveal causes, motivation, and their resource of hope according to The Hope Assessment Guide (Farren, Herth, & Popovich, 1995). In the analytical phase, the results of the two previous stages of the study were compared. The results were as follows : In the theoretical phase, six dimensions of hope emerged; affective, cognitive, behavioral, affiliative, temporal and contextual dimension. The antecedent of hope was loss, crisis, uncertainity, and stress. The consequences were renewal, development of new methods, safety, peace and transcendental competence. In the empirical phase, these six dimensions emerged as theoretical phases were verified and specified as these descriptive terms: feeling, intention, expectation, activity, relation, future- orientation, reality and goal-setting. The antecedent factor of hope was occurrence or recurrence of cancer. The consequence of hope was ability to cope with real condition, feeling of safety and comfort, peace, development of new strategy and recovery of disease. The major content of hope in this phase was related to specific hope, but it was also influenced on by general hope. In the analytic phase, general and specific hope was renamed as trait and state hope. All attributes emerged at the empirical phases, and also emerged at the theoretical phase. However, cognitive and contextual dimensions were revised and specified. In conclusion, the concept of hope is divided into trait hope and state hope, and state hope is an anticipatory expectation that occurs at the time of a stressful stimulus, such as being diagnosed with cancer. Hope is a multidimensional dynamic energized mental state which has the dimensions of affective, cognitive, behavioral, affiliative, temporal and contextual. There should be further studies to develope the state and trait hope scale according to definition and attributes of hope investigated in this study. In addition, considering results of the empirical phase, the family is very a important factor as a resource of hope, so it is necessary to consider family in implementing a nursing intervention program to enhance hope.

• 한국운동역학회지
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• 제17권2호
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• pp.145-156
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• 2007

The purposes of this study were to investigate kinematic parameters of racket head and upper extremities during squash back hand stroke and to provide quantitative data to the players. Five Korean elite male players were used as subjects in this study. To find out the swing motion of the players, the land-markers were attached to the segments of upper limb and 3-D motion analysis was performed. Orientation angles were also computed for angular movement of each segment. The results were as follows. 1) the average time of the back hand swing (downswing + follow-through) was 0.39s (0.24 s + 0.15 s). 2) for each event, the average racket velocity at impact was 11.17m/s and the velocity at the end of swing was 8.03m/s, which was the fastest swing speed after impact. Also, for each phase, 5.10m/s was found in down swing but 7.68m/s was found in follow-through. Racket swing speed was fastest after the impact but the swing speed was reduced in the follow-through phase. 3) in records of average of joints angle, shoulder angle was defined as the relative angle to the body. 1.04rad was found at end of back swing, 1.75rad at impact and it changes to 2.35 rad at the end of swing. Elbow angle was defined as the relative angle of forearm to upper arm. 1.73rad was found at top of backswing, 2.79rad at impact, and the angle was changed to 2.55rad at end of swing. Wrist angle was defined as the relative angle of hand to forearm. 2.48rad was found at top of backswing, 2.86rad at impact, and the angle changes to 1.96rad at end of swing. As a result, if the ball is to fly in the fastest speed, the body has to move in the order of trunk, shoulder, elbow and wrist (from proximal segment to distal segment). Thus, the flexibility of the wrist can be very important factor to increase ball speed as the last action of strong impact. In conclusion, the movement in order of the shoulder, elbow and the wrist decided the racket head speed and the standard deviations were increased as the motion was transferred from proximal to the distal segment due to the personal difference of swing arc. In particular, the use of wrist (snap) may change the output dramatically. Therefore, it was concluded that the flexible wrist movement in squash was very important factor to determine the direction and spin of the ball.