• Title/Summary/Keyword: external potential

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Validation of a Diagnostic Model for Core Competencies at the Higher Education Institute in Korea

  • Kim, Sung-Wan
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.1
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    • pp.197-206
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    • 2019
  • The purpose of this study is to develop and validate a model for diagnosing core competencies at the higher education level. Based on literature reviews, a potential model for core competencies at university was suggested. A tool for validating the model was composed of 24 items, which were delivered to 226 professors and administrative staffs, 730 students, and 134 graduates & external industrial experts. Five constructs (core competencies) were extracted from the data collected among professors and administrative staff responding to the importance of the items. The results of importance and performance surveys on core competencies with students were respectively 3.28 to 3.66 and 2.68 to 3.28 (4-point Likert scale). Statistical differences between importance level and performance level were found in all the sub-categories of core competencies. Borich priority determination formula and Locus for Focus Model were used for the determination of the priority of needs. Importance survey among graduates and external experts showed that the mean of each items ranged from 2.80 to 3.76 (4-point Likert scale). The overall results of the analyses suggest that the final model is appropriate for measuring the core competencies.

Experimental investigation of natural bond behavior in circular CFTs

  • Naghipour, Morteza;Khalili, Aidin;Hasani, Seyed Mohammad Reza;Nematzadeh, Mahdi
    • Steel and Composite Structures
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    • v.42 no.2
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    • pp.191-207
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    • 2022
  • Undoubtedly, the employment of direct bond interaction between steel and concrete is preceding the other mechanisms because of its ease of construction. However, the large scatter in the experimental data about the issue has hindered the efforts to characterize bond strength. In the following research, the direct bond interaction and bond-slip behavior of CFTs with circular cross-section were examined through repeated load-reversed push-out tests until four cycles of loading. The influence of different parameters including the diameter of the tube and the use of shear tabs were assessed. Moreover, the utilization of expansive concrete and external spirals was proposed and tested as ways of improving bond strength. According to the results section dimensions, tube slenderness, shrinkage potential of concrete, interface roughness and confinement are key factors in a natural bond. Larger diameters will lead to a considerable drop in bond strength. The use of shear tabs by their associated bending moments increases the bond stress up to eight times. Furthermore, employment of external spirals and expansive concrete have a sensible effect on enhancing bonds. Macro-locking was also found to be the main component in achieving bond strength.

Forced vibrations of an elastic circular plate supported by unilateral edge lateral springs

  • Celep, Zekai;Gencoglu, Mustafa
    • Structural Engineering and Mechanics
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    • v.83 no.4
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    • pp.451-463
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    • 2022
  • The present study deals with forced vibrations of an elastic circular plate supported along its circular edge by unilateral elastic springs. The plate is assumed to be subjected to a uniformly distributed and a concentrated load. Under the combination of these loads, equations of motion are explicitly derived for static and dynamic response analyses by assuming a series of the displacement functions of time and other unknown parameters which are to be determined by employing Lagrangian functional. The approximate solution is sought by applying the Lagrange equations of motions by using the potential energy of the external forces that includes the contributions of the edge forces and the external moments, i.e., those of the effects of the boundary condition to the analysis. For the numerical treatment of the problem in the time domain, the linear acceleration procedure is adopted. The tensionless character of the support is taken into account by using an iterative process and, the coordinate functions for the displacement field are selected to partially fulfill the boundary conditions so that an acceptable approximation can be achieved faster. Numerical results are presented in the figures focusing on the nonlinearity of the problem due to the plate lift-off from the unilateral springs at the edge support.

Modeling of SP responses for geothermal-fluid flow within EGS reservoir (EGS 지열 저류층 유체 유동에 의한 SP 반응 모델링)

  • Song, Seo Young;Kim, Bitnarae;Nam, Myung Jin;Lim, Sung Keun
    • Geophysics and Geophysical Exploration
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    • v.18 no.4
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    • pp.223-231
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    • 2015
  • Self-potential (SP) is sensitive to groundwater flow and there are many causes to generate SP. Among many mechanisms of SP, pore-fluid flow in porous media can generate potential without any external current source, which is referred to as electrokinetic potential or streaming potential. When calculating SP responses on the surface due to geothermal fluid within an engineered geothermal system (EGS) reservoir, SP anomaly is usually considered to be generated by fluid injection or production within the reservoir. However, SP anomaly can also result from geothermal water fluid within EGS reservoirs experiencing temperature changes between injection and production wells. For more precise simulation of SP responses, we developed an algorithm being able to take account of SP anomalies produced by not only water injection and production but also the fluid of geothermal water, based on three-dimensional finite-element-method employing tetrahedron elements; the developed algorithm can simulate electrical potential responses by both point source and volume source. After verifying the developed algorithm, we assumed a simple geothermal reservoir model and analyzed SP responses caused by geothermal water injection and production. We are going to further analyze SP responses for geothermal water in the presence of water production and injection, considering temperature distribution and geothermal water flow in the following research.

External pH Effects on Delayed Rectifier $K^+$ Currents of Small Dorsal Root Ganglion Neuron of Rat

  • Kim, Young-Ho;Hahn, Jung-Hyun;Lim, In-Ja;Chung, Sung-Kwon;Bang, Hyo-Weon
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.2
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    • pp.165-172
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    • 1998
  • Under certain pathophysiological conditions, such as inflammation and ischemia, the concentration of H^+$ ion in the tissue surrounding neurons is changed. Variations in H^+$ concentration are known to alter the conduction and/of the gating properties of several types of ion channels. Several types of K^+$ channels are modulated by pH. In this study, the whole cell configuration of the patch clamp technique has been applied to the recording of the responses of change of external pH on the delayed rectifier K^+$ current of cultured DRG neurons of rat. Outward K^+$ currents were examined in DRG cells, and the Charybdotoxin and Mn^{2+}$ could eliminate Ca^{2+}-dependent$ K^+$ currents from outward K^+$ currents. This outward K^+$ current was activated around -60 mV by step depolarizing pulses from holding potential -70 mV. Outward K^+$ currents were decreased by low external pH. Activation and steady-state inactivation curve were shifted to the right by acidification, while there was small change by alkalization. These results suggest that H^+$ could be alter the sensory modality by changing and modifying voltage-dependent K^+$ currents, which participated in repolarization.

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Effect of Added Mass between Male and Female on The Lower Extremity Joints Angular Velocity, Moment, Absorb Energy During Drop Landing (착지 시 외부 무게 부하에 따른 남성과 여성의 하지 관절 각속도, 모멘트, 에너지 흡수에 미치는 영향)

  • Kwon, Moon-Seok
    • Korean Journal of Applied Biomechanics
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    • v.22 no.3
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    • pp.325-332
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    • 2012
  • This study aimed to analyze the effects of external load between male and female on angular velocity, moment, and absorbed energy of the lower-extremity joints during drop landing. The study subjects were 9 male($mass=70.82{\pm}4.64kg$, $height=1.71{\pm}0.04m$, $age=24.5{\pm}1.84years$), 9 female($mass=50.14{\pm}4.09kg$, $height=1.61{\pm}0.03m$, $age=23.6{\pm}2.62years$), without any serious musculoskeletal, coordination, balance, or joint/ligament problems for 1 year before the study. The angular velocity, flexion/extension and abduction/adduction moments, and absorbed energy of the lower-extremity joints were compared between the men and women during drop landing under 4 different conditions of external load(0%, 8%, 16%, and 24%) by using two-way repeated ANOVA(p < .05). The women landed with a greater peak angular velocity of the ankle joint, greater peak inversion moment, and lower peak hip-extension moment than the men did, under all 4 conditions. Additionally, the landing characteristics of the women were distinct from those of the men; the women showed a greater peak knee-adduction moment and greater absorbed energy of the knee joint. These differences indicate that anterior cruciate ligament(ACL) strain was greater in the women than in the men and therefore, women may be at a higher potential risk for noncontact injuries of the ACL with an increase in external load.

An Empirical Study on the Spin-Off into Internet Business - Emphasis on Factors, Expected Benefits, Strategies - (인터넷 비즈니스 사업으로의 효과적인 스핀오프에 관한 실증연구 - 유발요인, 기대효익, 전략을 중심으로 -)

  • Lee, Kun-Chang;Chung, Nam-Ho;Ahn, Kwang-Mi
    • Asia pacific journal of information systems
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    • v.12 no.3
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    • pp.213-233
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    • 2002
  • Recently, a lot of companies intend to make spin-offs as the Internet usage is proliferating in the business area. A spin-off means a small but autonomous company which is thought to show higher profitability rather than it stays under the influence of a mother enterprise. To prove our hypotheses, we collected questionnaire data from 104 companies considering spin-offs. From experiments with Factor Analysis, we found that there exist four factors which decision-makers should consider before deciding spin-offs such as competence of unit, competence of mother company, competence of spin-off company, and support of mother company. After massive experiments with Regression Analysis we also found that there are significant three performance factors such as competence of unit, competence of spin-off company, and support of mother company. The survey also asked about three potential strategies that they may have been following for achieving business objectives: Cost leadership, Focus, and Differentiation, Six benefits factors emerged from this study: External competitiveness, Internal competency, Productivity, Change, Cost saving, and Improvement. External competitiveness was the most important benefit, and it predicted a Differentiation and Focus strategy. Productivity and Improvement also predicted a Differentiation strategy. External competitiveness, Change, and Cost saving predicted a Cost leadership strategy. However, organizations followed Differentiation and Focus strategies significantly more than Cost leadership. The assessment thus sheds light on the link between information strategy and spin off. We hope that based on our results, many companies considering a spin-off can make a right decision and expect higher performance in a turbulent business environment.

Evaluation of Stability in reinforced Earth Retaining Wall by Vehicle Collision (차량 충돌에 의한 보강토 옹벽의 안정성 평가)

  • Ahn, Kwangkuk;Heo, Yol;Hong, Kinam;Ahn, Minsu
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.6
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    • pp.39-46
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    • 2010
  • The past studies on reinforced earth retaining wall have been mostly focused on the internal and external failure of reinforced earth retaining wall, and the research for external impact was limited on earthquake. However, the potential external impact such as vehicle collision to reinforced earth retaining wall near the road are increasing with development of roads. Therefore, in this study, the reinforced earth retaining wall was modeled by using LS-DYNA, which is a general purpose finite element program recognized for its reliability. The behavior of reinforced earth retaining wall by vehicle speed was analyzed with Ford single unit truck offered by NCAC (National Crash Analysis Center), which is 8 tons weight. In addition, in order to obtain stability of reinforced earth retaining wall for vehicle collision, the gravity retaining wall was applied at the bottom of reinforced earth retaining wall. With varying the height of retaining wall (0.5m, 1.0m, 1.5m), the numerical study was performed to analyze the stability and behavior of reinforced earth retaining wall.

Influencing Factors of University Research Grant: Focusing on the Management Capability of Industry-University Collaboration Foundation (대학 연구비 규모의 영향 요인 분석: 산학협력단의 연구비 관리 역량을 중심으로)

  • Jung, Hyejin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.2
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    • pp.483-491
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    • 2019
  • The aim of this study is to shed light on factors that influence securing of university research grants. For this purpose, this study emphasizes the role of management capability of industry-university cooperation foundation in securing research grants. We analyze whether the potential capabilities influence research grants using panel data from 194 universities during 2016 to 2018. The results obtained from the Driscoll & Kraay standard errors (DKSE) indicate that a number of variables including the portion of industry-university collaboration professors, academic performance of professors, and the number of paid researchers are positively associated with the amount of external research grant approved. However, the percentage of employees employed for less than two years is negatively related with securing external research grants. Once the dependent variable is measured by the total university research grants, the negative coefficient of employees with short-term career disappears. Instead, the percentage of employees who are in charge of research planning and management and the total number of employees involved in industry-university collaboration foundations are negatively related with the total university research grant amounts.

Chest Radiography of Tuberculosis: Determination of Activity Using Deep Learning Algorithm

  • Ye Ra Choi;Soon Ho Yoon;Jihang Kim;Jin Young Yoo;Hwiyoung Kim;Kwang Nam Jin
    • Tuberculosis and Respiratory Diseases
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    • v.86 no.3
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    • pp.226-233
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    • 2023
  • Background: Inactive or old, healed tuberculosis (TB) on chest radiograph (CR) is often found in high TB incidence countries, and to avoid unnecessary evaluation and medication, differentiation from active TB is important. This study develops a deep learning (DL) model to estimate activity in a single chest radiographic analysis. Methods: A total of 3,824 active TB CRs from 511 individuals and 2,277 inactive TB CRs from 558 individuals were retrospectively collected. A pretrained convolutional neural network was fine-tuned to classify active and inactive TB. The model was pretrained with 8,964 pneumonia and 8,525 normal cases from the National Institute of Health (NIH) dataset. During the pretraining phase, the DL model learns the following tasks: pneumonia vs. normal, pneumonia vs. active TB, and active TB vs. normal. The performance of the DL model was validated using three external datasets. Receiver operating characteristic analyses were performed to evaluate the diagnostic performance to determine active TB by DL model and radiologists. Sensitivities and specificities for determining active TB were evaluated for both the DL model and radiologists. Results: The performance of the DL model showed area under the curve (AUC) values of 0.980 in internal validation, and 0.815 and 0.887 in external validation. The AUC values for the DL model, thoracic radiologist, and general radiologist, evaluated using one of the external validation datasets, were 0.815, 0.871, and 0.811, respectively. Conclusion: This DL-based algorithm showed potential as an effective diagnostic tool to identify TB activity, and could be useful for the follow-up of patients with inactive TB in high TB burden countries.