• Management Science and Financial Engineering
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• v.16 no.3
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• pp.49-70
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• 2010

Customer population management models can be classified into three categories: the first category includes the models that analyze the customer population at cohort level; the second one deals with the customer population at aggregate level; the third one has interest in the interactions among the customer populations in the competitive market. Our study proposes a model that can analyze the dynamics of customer population in consumer-durables market at aggregate level. The dynamics of customer population includes the retention curves from the purchase or at a specific duration time, the duration time expectancy at a specific duration time, and customer population growth or decline including net replacement rate, intrinsic rate of increase, and the generation time of customer population. For this study, we adopt mathematical ecology models, redefine them, and restructure interdisciplinary models to analyze the dynamics of customer population at aggregate level. We use the data of previous research on dynamic customer population management at cohort level to compare its results with those of ours and to demonstrate the useful analytical effects which the precious research cannot provide for marketers.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2009.04a
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• pp.119-124
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• 2009

This paper proposes a tuned liquid column sloshing damper(TLCSD) and presents experimental results to evaluate its control performance. The proposed damper acts as a tuned liquid column damper(TLCD) and a tuned liquid damper(TLD), respectively, in both principal axes of building structures. Shaking table test was performed to grasp its dynamic characteristics. Testing results showed that under inclined incident excitations, a TLCSD used in this study have dynamic characteristics coupled by both TLCD and TLD.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.461-468
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• 2005

In this paper, mixed mode magneto-rheological (MR) damper, which is applicable for vibration control of a small scale multi-story structure, is devised. First, the schematic configurations of the shear, flow, and mixed mode MR dampers are described with design constraints and then the analytical models to predict the field-dependent damping forces are derived for each type. Second, an appropriate size of the mixed mode MR damper is manufactured and its field-dependent damping characteristics are evaluated in time domain. Finally, the performance of the manufactured MR damper which is semi-actively applied to a small scale building excited by earthquake load, is numerically evaluated.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.527-532
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• 2010

In this study, vertical and horizontal accelerometers were installed at the both side of car body and tachometer was installed on the bogie, for the purpose of stability analysis of Korail Airport Express Train during driving. By applying the developed algorithm, the peak-to-peaks of horizontal and vertical acceleration which were matched with location by tachometer were found and compared with the threshold values. The threshold values per velocities which were presented in the "Metro Train Performance Criteria" were applied here. The validity of the developed algorithm was shown by comparing the site investigation and the measured values at frost heave locations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.195-200
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• 2007

System identification of real-scale structure is performed using forced vibration test. There exist various techniques available for identifying the dynamic characteristis of structures using dynamic and static measurements. In this study, The finite element(FE) model of the structure is analytically constructed using ANSYS and the model was updated using the results experimentally measured by the forced vibration test. forced vibration tests showed that Hybrid Mass Damper induced floor responses coincided with the earthquake induced ones which was numerically calculated based on the updated FE model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.648-654
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• 2007

This paper presents the result of a comparison study to evaluate the performance of several semi-active control algorithms for use with large-scale MR damper applied to a building structure under seismic excitation using real-time hybrid test method. Recently, a variety of semi-active control algorithm studies are developed and generally evaluated the performance by using numerical analysis. In this paper real-time hybrid test method was applied to performance evaluating of semi-active control algorithms including a clipped optimal algorithm and the modulated homogeneous friction algorithm.

• Journal of Power System Engineering
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• v.16 no.1
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• pp.30-37
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• 2012

공기 양수 펌프는 재생 에너지 분야, 부식 및 마모 특성의 유체의 활용 등 높은 신뢰성과 낮은 유지보수 비용을 필요로 하는 분야에서 그 사용이 증대되고 있다. 본 연구에서는 소형 공기 양수 펌프의 성능 평가 및 기초 데이터를 얻기 위한 연구로, D=0.012~0.019m, L=0.933m인 배관의 침수 깊이(${\beta}$=0.55,0.60,0.65,0.70)에 따른 수치해석을 수행하였다. 수치 해석 및 실험 결과는 유사성을 뛰었으며, 펌프의 사양과 효율은 공기의 질량 유속 비, 침수 깊이 비와 양수 배관의 길이에 관한 함수로 나타났다. 그리고 최대 물과 공기 질량 유속의 비는 각 배관에서 서로 다른 침수 깊이의 비로 나타났으며, 공기 양수 펌프의 최대 효율이 발생되는 운전조건은 슬러그(slug)와 슬러그 교반 정도(slug-churn flow regime)에 따라 나타남을 알 수 있었다.

• Journal of Information Technology Services
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• v.10 no.2
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• pp.21-39
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• 2011

After ten years from the introduction of CRM systems, many companies reevaluate CRM from the perspective of customers. This paper classifies CRM activities at the contact points with customers and investigates the effect of CRM activities on perceived benefits and the effect of perceived benefits on behavioral intention in the Korean cosmetic industry. The result showed that contact management and complaint handling affected social benefits and that customers perceived confidence benefits from contact management, complaint handling, and churn management. Special treatment benefits were affected by all CRM activities including compensation management. Finally, all kinds of benefits had effects on behavioral intention such as recommendation intention and repurchase intention.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.109-110
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• 2013

국내 이동통신 서비스 시장 사업자들은 신규고객 유치에 집중하기 보다는 기존고객 유지에 더 관심을 가지고 있다. 이러한 배경에는 새로운 신규고객의 창출에 소요되는 비용이 기존고객을 유지하는 비용이 적게 들기 때문이다. 따라서 고객이탈을 발생시키는 요인이 무엇인지를 본 연구에서 알아보고자 한다.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2095-2106
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• 2010

In this study, to grasp the stability of train and to identify the track irregularity, the algorithm was proposed. As the track deformation occur due to running train, the dynamic characteristics of train show non-linearity. The representative transfer functions of wheel to car response were calculated from the frequency response functions which were estimated from measured triaxial accelerations. The measured acceleration responses were compared with the estimated responses from filtered acceleration outputs. This result could show the non-linearity of train system at the location of track deformed. The proposed algorithm was verified by matching with the site investigation.