• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2782-2805
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• 2018

We present a legorization framework that produces a LEGO model from user-specified 3D mesh model. Our framework is composed of two stages: voxelization and legorization. In the voxelization, input 3D mesh is converted to a voxel model. To preserve the shape of the 3D mesh, we devise a silhouette fitting process for the initial voxel model. For legorization, we propose three objectives: stability, aesthetics and efficiency. These objectives are expressed in a tiling equation, which builds a LEGO model using layer-by-layer approach. We legorize five models including characters and buildings to prove the excellence of our framework.

• 디지털융복합연구
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• 제10권4호
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• pp.235-241
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• 2012

최근 교육 수월성 제고와 질적 수준 향상을 위해서 대학에서는 정보화를 추진하고 있으나 개인정보를 비롯한 학사행정과 관련된 중요 정보들이 학사 데이터베이스에 집적되어 있어 그에 따른 보호 대책이 필요하다. 이 논문에서는 학사 데이터베이스 구축에 사용되는 DBMS의 접근제어, 기밀성, 무결성 그리고 보안감사 등이 보장되도록 대학의 현실에 적합한 학사 데이터베이스 통합 보안 모델을 제안한다. 제안 모델은 상당 수 대학들이 데이터베이스 보안 제품을 활용하고 있지 못한 여건을 고려하여 DBMS가 제공하는 기능만으로 보안의 가장 핵심 요소인 기밀성 등을 구현하는 세부 방안을 제시하고 있다.

• International Journal of Quality Innovation
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• 제4권2호
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• pp.73-100
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• 2003

The most successful companies today are said to have strong brands. But what is a strong brand\ulcorner What makes a brand strong\ulcorner How do we build a strong brand\ulcorner This paper develops a customer-based brand equity model to help address these important questions. The developed model is a cause-and-effect model linking customer-brand relationships to rational and emotional brand associations, as well as rational and emotional brand evaluations. The customer-brand relationships are characterized by loyalty, based on both behaviour and attitude. As branding is a very complex concept, it is important to determine which of the many branding elements should be included in the model. This paper discusses why a given aspect is important for a brand's equity and which relations exist between the included variables from a theoretical perspective. The model provides insight into the creation of a brand's equity and can thus be used in the brand management process to achieve brand excellence.

• 유통과학연구
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• 제17권11호
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• pp.47-52
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• 2019

Purpose: This study specifically discusses why coffee shop customers want to revisit coffee shops. In addition, we would like to verify the mediated effect of the emotional reaction in relation to the influence of the experience values of the Chinese coffee shop on the re-visit of the coffee shop. Research design, data and methodology: Regression and reliability analyses were conducted. Simple regression was used for stock price verification, and the bootstrap method of model4 of Hayes was performed for the intermediate hypothesis verification. Results: This study confirmed that the experience values of coffee shops (entertainment, aesthetic, economic efficiency, and service excellence) have a significant influence on customers' intention to revisit coffee shops. Conclusions: Managers can check that the level of revisit by customers is increased by increasing the elements of experience value. In addition, studies have shown that the customer's emotional reactions play a significant mediating role in the relationship between the value of the experience and the customer's intention to revisit the coffee shop. This suggests that the coffee shop operator should focus on the emotional response of its customers and devise strategies to ensure that the value of the experience is connected to the intent of revisiting.

• Computers and Concrete
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• 제21권1호
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• pp.55-66
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• 2018

A large main shock may consist of numerous aftershocks with a short period. The aftershocks induced by a large main shock can cause the collapse of a structure that has been already damaged by the preceding main shock. These aftershocks are important factors in structural damages. Furthermore, despite what is often assumed in seismic design codes, earthquakes do not usually occur as a single event, but as a series of strong aftershocks and even fore shocks. For this reason, this study investigates the effect and potential of consecutive earthquakes on the response and behavior of concrete structures. At first, six moment resisting concrete frames with 3, 5, 7, 10, 12 and 15 stories are designed and analyzed under two different records with seismic sequences from real and artificial cases. The damage states of the model frames were then measured by the Park and Ang's damage index. From the results of this investigation, it is observed that the sequences of ground motions can almost double the accumulated damage and increased response of structures. Therefore, it is certainly insufficient to ignore this effect in the design procedure of structures. Also, the use of artificial seismic sequences as design earthquake can lead to non-conservative prediction of behavior and damage of structures under real seismic sequences.

• Industrial Engineering and Management Systems
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• 제14권3호
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• pp.299-311
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• 2015

Nowadays, the distribution centres aim to reduce costs by reducing inventory and timely shipment. Cross docking is a logistics strategy in which products delivered to a distribution centre by inbound trucks are directly unloaded and transferred to outbound trucks with minimum warehouse storage. Moreover, on-time delivery in a distribution network becomes very crucial especially when several distribution centres and customers are involved. Therefore, an efficient truck scheduling is needed to synchronize the delivery throughout the network in order to satisfy all stake-holders. This paper presents a mathematical model of a mixed integer programming for door assignment and truck scheduling in a multiple inbound and outbound doors cross docking problem according to Just-In-Time concept. The objective is to find the schedule of transhipment operations to simultaneously minimize the total earliness and total tardiness of trucks. Then, a multi-objective differential evolution (MODE) is proposed with an encoding scheme and four decoding strategies, called ITSH, ITDD, OTSH and OTDD, to find a Pareto frontier for the multi-door cross docking problems. The performances of MODE are evaluated using 15 generated instances. The numerical experiments demonstrate that the proposed algorithm is capable of finding a set of diverse and high quality non-dominated solutions.

• Earthquakes and Structures
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• 제14권2호
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• pp.129-142
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• 2018

The current paper introduces a new approach for development of damage index to obtain the maximum damage in the reinforced concrete frames caused by as-recorded single and consecutive earthquakes. To do so, two sets of strong ground motions are selected based on maximum and approximately maximum peak ground acceleration (PGA) from "PEER" and "USGS" centers. Consecutive earthquakes in the first and second groups, not only occurred in similar directions and same stations, but also their real time gaps between successive shocks are less than 10 minutes and 10 days, respectively. In the following, a suite of six concrete moment resisting frames, including 3, 5, 7, 10, 12 and 15 stories, are designed in OpenSees software and analyzed for more than 850 times under two groups of as-recorded strong ground motion records with/without seismic sequences phenomena. The idealized multilayer artificial neural networks, with the least value of Mean Square Error (MSE) and maximum value of regression (R) between outputs and targets were then employed to generate the empirical charts and several correction equations for design utilization. To investigate the effectiveness of the proposed damage index, calibration of the new approach to existing real data (the result of Park-Ang damage index 1985), were conducted. The obtained results show good precision of the developed ANNs-based model in predicting the maximum damage of regular reinforced concrete frames.

• Structural Engineering and Mechanics
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• 제37권6호
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• pp.575-592
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• 2011

For seismic resistant design of critical structures, a dynamic analysis, either response spectrum or time history is frequently required. Owing to the lack of recorded data and the randomness of earthquake ground motion that may be experienced by structure in the future, usually it is difficult to obtain recorded data which fit the requirements (site type, epicenteral distance, etc.) well. Therefore, the artificial seismic records are widely used in seismic designs, verification of seismic capacity and seismic assessment of structures. The purpose of this paper is to develop a numerical method using Artificial Neural Network (ANN) and wavelet packet transform in best basis method which is presented for the decomposition of artificial earthquake records consistent with any arbitrarily specified target response spectra requirements. The ground motion has been modeled as a non-stationary process using wavelet packet. This study shows that the procedure using ANN-based models and wavelet packets in best-basis method are applicable to generate artificial earthquakes compatible with any response spectra. Several numerical examples are given to verify the developed model.

• Journal of Power Electronics
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• 제11권5호
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• pp.719-725
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• 2011

This paper describes a novel Direct Torque Control (DTC) method for adjustable speed Doubly-Fed Induction Machine (DFIM) drives which is supplied by a two-level Space Vector Modulation (SVM) voltage source inverter (DTC-SVM) in the rotor circuit. The inverter reference voltage vector is obtained by using input-output feedback linearization control and a DFIM model in the stator a-b axes reference frame with stator currents and rotor fluxes as state variables. Moreover, to make this nonlinear controller stable and robust to most varying electrical parameter uncertainties, a two layer recurrent Artificial Neural Network (ANN) is used to estimate a certain function which shows the machine lumped uncertainty. The overall system stability is proved by the Lyapunov theorem. It is shown that the torque and flux tracking errors as well as the updated weights of the ANN are uniformly ultimately bounded. Finally, effectiveness of the proposed control approach is shown by computer simulation results.

• Journal of Power Electronics
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• 제10권2호
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• pp.115-124
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• 2010

In this paper, a simple yet efficient auto mode-hop ripple control structure for buck converters with light load operation enhancement is proposed. The converter, which operates under a wide range of input and output voltages, makes use of a state-dependent hysteretic comparator. Depending on the output current, the converter automatically changes the operating mode. This improves the efficiency and reduces the output voltage ripple for a wide range of output currents for given input and output voltages. The sensitivity of the output voltage to the circuit elements is less than 14%, which is seven times lower than that for conventional converters. To assess the efficiency of the proposed converter, it is designed and implemented with commercially available components. The converter provides an output voltage in the range of 0.9V to 31V for load currents of up to 3A when the input voltage is in the range of 5V to 32V. Analytical design expressions which model the operation of the converter are also presented. This circuit can be implemented easily in a single chip with an external inductor and capacitor for both fixed and variable output voltage applications.