• Geomechanics and Engineering
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• 제21권6호
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• pp.551-564
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• 2020

High-stress and complex geological conditions impose great challenges to maintain excavation stability during deep underground mining. In this research, large anisotropic deformation and its management by support system at a deep underground mine in Western Australia were simulated through three-dimensional finite-difference model. The ubiquitous-joint model was used and calibrated in FLAC3D to reproduce the deformation and failure characteristics of the excavation based on the field monitoring results. After modeling verification, the roles of mining depth also the intercept angle between excavation axis and foliation orientation on the deformation and damage were studied. Based on the results, quantitative relationships between key factors and damage classifications were presented, which can be used as an engineering tool. Subsequently, the performance of support system installation sequences was simulated and compared at four different scenarios. The results show that, first surface support and then reinforcement installation can obtain a better controlling effect. Finally, the influence of bolt spacing and ring spacing were also discussed. The outcomes obtained in this research may play a meaningful reference for facing the challenges in thin-bedded or foliated ground conditions.

• 한국항공우주학회지
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• 제49권3호
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• pp.167-174
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• 2021

NASA Common Research Model의 29.7% 축소 모형에 대하여 저속 풍동시험 조건으로 수치해석을 수행하였다. 낮은 레이놀즈수 영역인 0.3×106에서 Belly sting 모형 지지부를 장착한 CRM의 공력계수를 측정하는 시험이 수행되었으며, 수치해석 결과와 비교하였다. 해석의 타당성을 검증하기 위해 선행연구 조건으로 전산해석을 수행하여 비교하였다. Belly sting 모형 지지부 유무에 대한 해석 결과 지지부에 의한 간섭 효과로 동체뿐만 아니라 주날개, 꼬리날개까지 공력에 영향이 있음을 확인하였다.

• Asia pacific journal of information systems
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• 제23권1호
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• pp.1-19
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• 2013

The market for commercial open source software (OSS) has been rapidly growing with the proliferation of OSS. One way to commercialize OSS is the support model, which has been adopted by leading OSS firms such as Red Hat and JBoss. Despite the growing interest in OSS commercialization, little research has provided OSS support providers with a pricing guideline. In this paper, we examine the optimal pricing strategies for OSS support providers. Our benchmark is a monopoly case in which we investigate a startup software vendor's incentive to choose the OSS support regime over the proprietary one. Then we extend the model to a duopoly case in which OSS under the support regime competes against proprietary software. We characterize the conditions under which the OSS support model is viable under competition. We believe that our results offer insights to the OSS vendors who consider commercializing their OSS with a support model.

• 대한간호학회지
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• 제30권3호
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• pp.750-763
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• 2000

This study is based on grounded theory methodology by Strauss & Corbin(1998). Ten hospitalized subjects were interviewed for data collection. In the process of data analysis, 'acceptance' is found to be the causal condition, while 'health professionals' skillfulness', 'ward environment', 'history of hospitalization', and 'general conditions' were identified as context, 'felling of relief' as the core phenomenon, 'self-efficacy', 'support of others', and 'life style' as the intermediate situation, 'passive reaction', 'alternative reaction' and 'active reaction' as the strategy and 'stabilization', 'satisfaction', 'hope' and 'carrying out' as consequences. 'Feeling of relief' is found to go through the three stages of recognition-generation-maintenance after the five different patterns. 1) In case the health professionals are skillful, the ward environment is favorable, the general conditions of the patients improved and as a result the feeling of relief is strong, during the first hospitalization, the self-efficacy of the subjects tends to be strong. They proceed toward the goal set for themselves with a renewed hope and active or alternative reaction toward the feeling of relief. 2) The subjects tend to proceed toward the goal set for themselves with a renewed hope and active and alternative reaction toward the feeling of relief in case health professionals are skillful, the ward environment is favorable the general conditions of the subjects improved, self-efficacy is strong, and lifestyle is autonomous, during the second hospitalization even though support of others is merely superficial. 3) The subjects tend to stabilize, and satisfy themselves with the given situation with passive and alternative reaction to the feeling of relief in case health professionals are skillful and the ward environment is favorable but the general conditions worsened and accordingly the feeling of relief, is weak and life style is dependent during the second hospitalization although the subjects' self-efficacy is strong and support of others is specific. 4) The subjects tend to stabilize and satisfy themselves with the given situation with passive and alternative reaction to the feeling of relief in case health professionals are unskillful the ward environment is unfavorable, the general conditions improved, support of others is specific but life style is dependent and self-efficacy is weak during the first hospitalization. 5) The subjects tend to stabilize and satisfy themselves with the given situation in case health professionals are unskillful the ward environment is unfavorable but the general conditions improved support of others is specific and as a result self-efficacy is strong but life style is dependent.

• 한국전문물리치료학회지
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• 제19권1호
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• pp.28-36
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• 2012

This study used an unstable platform to change the support surface type and position of both lower limbs in order to determine changes in weight distribution and muscle including the vastus medialis, tibialis anterior, lateral hamstring, and lateral gastrocnemius of both lower limbs were evaluated during knee joint flexing and extending in a semi-squat movement in 32 hemiplegic patients. The support surface conditions applied to the lower limbs were divided into four categories: condition 1 had a stable platform for both lower limbs; condition 2 had an unstable platform for the non-hemiplegic side and a stable platform for the hemiplegic side; condition 3 had a stable platform for the non-hemiplegic side and an unstable platform for the hemiplegic side; and condition 4 had an unstable platform for both sides. The normalized EMG activity levels of muscles and weight bearing ratio of both sides in the four surface conditions were compared using repeated measures ANOVA. A significant increase was found in the weight support distribution for the hemiplegic side in flexing and extending sessions in condition 2 compared to the other conditions (p<.05). A statistically significant decrease in significant decrease in asymmetrical weight bearing in flexing and extending sessions was observed for condition 2 compared to the other conditions (p<.05). A similar significant decrease was found in differences in muscular activity for both lower limbs in condition 2 (p<.05). The muscular activity of the hemiplegic side, based on the support surface for each muscle showed a significantly greater increase in condition 2 (p<.05). An unstable platform for the non-hemiplegic side and a stable platform for the hemiplegic side therefore increased symmetry in terms of the weight support distribution rate and muscle activity of lower limbs in hemiplegic patients. The problem of postural control due to asymmetry in hemiplegic patients should be further studied with the aim of developing continuous effects of functional training based on the type and position of the support surfaces and functional improvement.

• 한국노년학
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• 제27권2호
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• pp.503-518
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• 2007

노인은 자녀로부터 일방적으로 지원을 받는 것이 아니라 자녀에게 지원을 하기도 하는 호혜적인 교환을 한다. 이러한 세대간 지원교환의 호혜성은 건강, 경제력 같은 노인의 역량뿐만 아니라 노인이 자녀들과 맺고 있는 관계적 속성에 의해서 다양하게 구조화된다. 호혜성의 다양성이 어떤 요인들에 의해서 결정되는지를 설명하기 위해서 구조화된 설문지를 이용하여 수집된 서울의 65세 이상 노인 730명을 분석하였다. 분석결과는 노부모-자녀의 관계적 속성이 지원교환의 호혜성에 독립적인 영향을 미치고, 자녀와 동거여부, 자녀수, 접촉빈도의 순으로 중요하다. 자녀와 동거하지 않는 노부모는 신체적 지원에서는 자녀로부터 지원을 받는 경향을 보이지만, 경제적 지원에서는 오히려 자녀를 지원하는 양상을 보인다. 자녀수와 접촉빈도는 노인이 자녀로부터 지원을 받도록 하는 쪽으로 영향을 미친다. 노인이 선호하는 아들유무는 커다란 관련성이 없는 것으로 나타났다. 노인의 역량 중에서 건강상태는 신체적 지원은 물론이고 정서적 및 재정적 지원교환에도 모두 결정적으로 중요하지만, 경제력은 재정적 지원교환에만 관련되어 있다. 세대지원의 호혜성에 가장 결정적인 요인은 노부모의 건강 상태이며, 노부모는 부모로서의 역할과 의무로 받아들여 자녀에 대한 지원을 계속하게 된다.

• 충청수학회지
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• 제29권4호
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• pp.631-642
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• 2016

This article deals with one-dimension backward heat conduction problem (BHCP). A new approach based on least squares support vector machines (LS-SVM) is proposed for obtaining their approximate solutions. The approximate solution is presented in closed form by means of LS-SVM, whose parameters are adjusted to minimize an appropriate error function. The approximate solution consists of two parts. The first part is a known function that satisfies initial and boundary conditions. The other is a product of two terms. One term is known function which has zero boundary and initial conditions, another term is unknown which is related to kernel functions. This method has been successfully tested on practical examples and has yielded higher accuracy and stable solutions.

• 한국기계가공학회지
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• 제15권3호
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• pp.58-65
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• 2016

This study analyzed the structural weld strength for a door hinge for a field artillery ammunition support vehicle. In order to determine the optimal conditions, we measured the modal analysis and analyzed the leg length of a rear door hinge. From these methods, we acquired the vibration frequency of normal mode and the optimal welding leg length conditions. It was possible to obtain a structural stability for a rear door hinge of the field artillery ammunition support vehicle. In the future, this should be used as a reference source for the weld strength analysis of high vibration and high weight structures for another welding system design.

• Journal of Electrical Engineering and Technology
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• 제3권3호
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• pp.363-372
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• 2008

In this paper, knowledge-based approach using Support Vector Machines (SVMs) are used for estimating the coordinated zonal settings of a distance relay. The approach depends on the detailed simulation studies of apparent impedance loci as seen by distance relay during disturbance, considering various operating conditions including fault resistance. In a distance relay, the impedance loci given at the relay location is obtained from extensive transient stability studies. SVMs are used as a pattern classifier for obtaining distance relay co-ordination. The scheme utilizes the apparent impedance values observed during a fault as inputs. An improved performance with the use of SVMs, keeping the reach when faced with different fault conditions as well as system power flow changes, are illustrated with an equivalent 265 bus system of a practical Indian Western Grid.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.603-607
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• 2008

This paper is to investigate the effects of support conditions on the whirling stability of a supercritical composite driveshaft. Two system parameters are rigorously considered: one is the bending stiffness of the support beam/bearings and the other is the rotating internal damping of the shaft. An analytic model is developed based on finite element methods and an eigenvalue analysis is employed to estimate the shaft stability under supercritical operating conditions. Results show that the internal damping causes the whirling instability at a supercritical speed, as demonstrated in other previous studies. However, the bending stiffness of the support beam is found to affect greatly the stability behaviors of a supercritical shaft and several combinations of the shaft/beam stiffness can be identified to guarantee the stable operation even in a supercritical region.