• Journal of international Conference on Electrical Machines and Systems
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• 제1권4호
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• pp.419-424
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• 2012

This paper presents a tubular reciprocating translational motion permanent magnet synchronous motor for percussive drilling applications for offshore oil & gas industry. The motor model and rock model are built up by doing force analysis of the motor and analyzing the physical procesof impact. The optimization of input voltage waveforms to maximize the rate of penetration is done by simulations. The simulation results show that the motor can be utilized in percussive drilling applications and achieve a very large impact force. Simulation results for optimization also show that second harmonic input voltage produces a higher rate of penetration than the sine wave and fourth harmonic input voltages.

• 대한간호학회지
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• 제29권5호
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• pp.1123-1133
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• 1999

The concept of empathy was examined In the professional caregiving relationship and its application was extended to the context of informal caregiving. Using the Lazarus and Folkman model, the influence of empathy on the caregiver's experience in the caregiving relationship was illustrated. The effects of the caregiver's empathy on his/her own caregiving outcomes were investigated by examining the relationship between empathy and burnout experience and life satisfaction. Empathy increased emotional exhaustion while increased personal accomplishment and personalization, indicating conflicting relationship between empathy and burnout. This conflict relationship between empathy and burnout can be explained by suggesting the distinct roles of two dimensions of empathy emotional and cognitive. The needs for more research to support the critical roles of empathy in informal caregiving context and to examine the definite roles of two dimensions of empathy were suggested.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.446-449
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• 2006

Several experimental investigations have been carried out to study the behavior of reinforced concrete columns with short lap splices. However, very few analytical models have been developed for the analysis of such columns subjected to earthquakes. As nonlinear analysis procedures become more common in practice (such as those outlined in the Guidelines for Seismic Rehabilitation of Buildings published by the Federal Emergency Management Agency in the United States), the need for an accurate and reliable representation of the nonlinear response of strength degrading systems becomes more important. In this study, an analytical model for estimating the complete response of reinforced concrete columns with short lap splices is presented. The model is based on local bond stress-slip relationships and is validated against independent experimental data from cyclic loading tests on reinforced concrete columns with typical construction details of the 1960s. In this paper a simple equation for calculating the bar stress at splice failure is presented. Use of the proposed equation resulted in excellent agreement between the measured and calculated strength at splice failure.

• Journal of Electrical Engineering and Technology
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• 제3권4호
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• pp.451-459
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• 2008

Accurate load modeling is essential for power system static and dynamic analysis. By the nature of the problem of parameter estimation for power system load modeling using actual measurements, multiple local optimal solutions may exist and local methods can be trapped in a local optimal solution giving possibly poor performance. In this paper, Trust-Tech, a novel methodology for global optimization, is applied to tackle the multiple local optimal solutions issue in measurement-based power system load modeling. Multiple sets of parameter values of a composite load model are obtained using Trust-Tech in a deterministic manner. Numerical studies indicate that Trust-Tech along with conventional local methods can be successfully applied to power system load model parameter estimation in measurement-based approaches.

• Asian-Australasian Journal of Animal Sciences
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• 제10권5호
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• pp.505-509
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• 1997

Data were from four institutional herds and four field data collection centers involved in a progeny testing program for Nili-Ravi buffaloes in Pakistan. The REML with a single trait animal model, employed on 2,353 lactations, from 901 daughters of 66 sires, gave a heritability estimate of 0.18 for milk yield with repeatability (between lactations) of 0.43. Estimated milk yield was highest at 65 months of age for the first parity and 81 months for later parities. Correction factors for age at calving, standardized to 60 months in the second and later parities, were developed.

• Food Science and Biotechnology
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• 제16권6호
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• pp.954-957
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• 2007

Gelation mechanism of xanthan-carob mixture (X/C) was investigated based on thermorheological behavior. Three X/C ratios (1:3, 1:1, and 3:1) were studied. Small amplitude oscillatory shear tests were performed to measure linear viscoelastic behavior during gelation. Temperature sweep ($-1^{\circ}C/min$) experiments were conducted. Using a non-isothermal kinetic model, activation energy (Ea) during gelation was calculated. At 1% total concentration, the Ea for xanthan fraction (${\phi}_x$)=0.25, 0.5, and 0.75 were 178, 159, and 123 kJ/mol, respectively. However, a discontinuity was observed in the activation energy plots. Based on this, two gelation mechanisms were presumed-association of xanthan and carob molecules and aggregation of polymer strands. The association process is the primary mechanism to form 3-D networks in the initial stage of gelation and the aggregation of polymer strands played a major role in the later stage.

• 경영과학
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• 제23권1호
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• pp.135-152
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• 2006

Over the last decade, the field of supply chain management (SCM) and e-business has received an enormous amount of attention from practitioners and academicians. However, little has been known about how and to what extent small- to medium-sized enterprises (SMEs) are implementing SCM initiatives and e-business practices. This paper proposes a comprehensive research model and presents the survey results of these practices of SMEs located in Wisconsin and illinois, U.S., In terms of competitive strategy and priority, value chain activity priority, supply chain and e-business integration focus, SCM best practices implementation focus and challenges, and business performance. The analysis reveals several valuable insights into how SMEs should run their businesses in today's volatile, rapidly changing customer economy.

• ETRI Journal
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• 제36권4호
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• pp.572-580
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• 2014

Mobile operators in saturated markets increasingly favor mobile network sharing (MNS) over facility-based competition. Previous research examining MNS primarily focused on its positive effects, while the negative effects were largely overlooked. This study proposes a decision-making model using an analytic hierarchy process technique to evaluate decision-making criteria among various types of MNS policies. The decision-making model was applied to Wireless Broadband services in Korea to determine the relative importance of both positive and negative evaluation criteria and preference among multiple types of MNS policies. Positive evaluation criteria (that is, efficiency) were far greater in importance than negative evaluation criteria (that is, competition harm). The preference for adopting MNS among five alternative approaches was also revealed. The study findings offer immediate policy insights in Korea and provide a decision-making framework for policy makers in other countries to utilize.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2010년도 한국우주과학회보 제19권1호
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• pp.38.1-38.1
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• 2010

고해상도 위성들로부터 최상의 영상을 획득하기 위해서는 설계 단계에서 운용 조건이 반영된 위성 영상 품질 예측이 필수적이다. 이 발표에서는 실질적인 위성 궤도 및 자세 정보와 정사영상, DEM(Digital Elevation Model)으로부터 공선조건식을 기반으로 하는 Direct Sensor Modeling을 이용하여 고해상도 가상영상을 생성하는 방법을 제시하였다. Target으로 사용된 정사영상은 $19951\times21055$ size의 USA Wisconsin주의 1m 해상도 영상이며, 이 영상으로부터 0.7m 해상도의 가상영상을 생성하였다. 이 연구를 통하여 위성의 설계 단계에서 궤도상 영상 품질 예측할 수 있으며, 운영 과정에서는 실제 촬영된 영상과 비교 분석을 통하여 위성 및 탑재체의 상태 파악 및 보정이 가능할 것으로 기대된다.

• 대한교통학회지
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• 제17권1호
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• pp.141-157
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• 1999

본 논문은 현재 및 가까운 미래에 있을 교통정보의 제공에 관한 일반적인 가능성으로서 교통현상의 기술이 가능한 교통예측모형의 사용에 대한 총체적인 정리를 함과 함께 바람직한 모형의 제시가 주요 목적이다. 이를 위하여 우선 동적교통배정모형, 통계모형, 모의실험모형, 및 휴리스틱모형이 어떵게 교통정보제공을 위해서 사용될 수 있는지를 각 모형별 제반 특성적 측면에서 검토를 한다. 다음에 이러한 모형의 각종 요구사항이 분석되며, 더 나아가 단기간 교통 상황을 예측하기 위한 각 모형의 능력 및 장단점이 서술적인 관점에서 기술되어진다. 마지막으로, 이러한 각각의 장점을 수용할 수 있을 만한 포괄적인 예측모형의 전형이 그러한 모형을 구축함에 있어서 필요로 하는 데이터의 요구조건과 함께 제시된다.