• Journal of information and communication convergence engineering
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• 제18권2호
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• pp.132-146
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• 2020

Biometric technologies have become widely available in many different fields. However, biometric technologies using existing physical features such as fingerprints, facial features, irises, and veins must consider forgery and alterations targeting them through fraudulent physical characteristics such as fake fingerprints. Thus, a trend toward next-generation biometric technologies using behavioral biometrics of a living person, such as bio-signals and walking characteristics, has emerged. Accordingly, in this study, we developed a bio-signal authentication algorithm using electrocardiogram (ECG) signals, which are the most uniquely identifiable form of bio-signal available. When using ECG signals with our system, the personal identification and authentication accuracy are approximately 90% during a state of rest. When using fingerprints alone, the equal error rate (EER) is 0.243%; however, when fusing the scores of both the ECG signal and fingerprints, the EER decreases to 0.113% on average. In addition, as a function of detecting a presentation attack on a mobile phone, a method for rejecting a transaction when a fake fingerprint is applied was successfully implemented.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권1호
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• pp.90-94
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• 2005

As the structure of the piezoelectric bimorph cantilever becomes increasingly more complicated, a more accurate and efficient analysis of piezoelectric media is needed. In this paper, the piezoelectric transducer is analyzed by using the three-dimensional finite element method. The validity of the three-dimensional finite element routine is confirmed by comparing the experimental result. The resonance characteristics, such as resonance frequency and anti-resonance frequency, of the piezoelectric cantilever are calculated by the experimentally verified three dimensional finite element method. Subsequently, the characteristics, such as mechanical displacement and impedance, are calculated at the resonance frequency. Besides, to design the piezoelectric bimorph cantilever shape that maximizes displacement at the tip, the ES (Evolution Strategy) algorithm is applied. Finally, optimal design for the fan of the piezoelectric cantilever is fulfilled to obtain maximum displacement at the tip. From these results, the application potentiality of the piezoelectric bimorph cantilever fan is identified.

• 통상정보연구
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• 제8권3호
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• pp.343-368
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• 2006

International transactions of digital goods with the abovementioned characteristics are categorized by stages to review the characteristics and illustrate the problems in this study. The problems that may possibly arise during the implementation of the contract on digital goods are divided by stage, such as delivery, payment and insurance cover in preparation for possible diverse risks. International transactions of digital goods are expected to gain more weight in the world trade in the future. Therefore, legal and technical supports in the international level and international commercial custom need to be settled to smoothen and facilitate international transactions of digital goods.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권1호
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• pp.32-36
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• 2003

The three-phase canned induction motor, which consists of a stator and rotor with a seal can, is used for the main coolant pump (MCP) of the System-integrated Modular Advanced Reactor (SMART). The thermal characteristics of the can must be estimated exactly, since the eddy current loss of the can is a dominant parameter in design. Besides the insulation of the motor winding is compared of Teflon, glass fiber, and air, so it is not an easy task to analyze. A FEM thermal analysis was per-formed by using the thermal properties of complex insulation which were obtained by comparing the results of finite element thermal analysis and those of the experiment. As a result, it is shown that the characteristics of prototype canned induction motor have a good agreement with the results of FEM.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제4B권1호
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• pp.6-11
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• 2004

The single phase switched reluctance motor (SRM) has many merits; simple structure and driving circuits, easy operation and speed control, and etc. This paper presents the torque characteristics of disk type single phase SRM by changing the salient pole lengths and pole arcs. The prototype single phase SRM has a three dimensional magnetic flux pattern because of its structure. That is, the radial and axial magnetic flux contributes to torque generation. Thus, 3D analysis is required for computation of its magnetic field. In this paper, 3D FEM is used for analyzing the magnetic flux distribution and magnetic co-energy.

• Asia pacific journal of information systems
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• 제14권2호
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• pp.87-114
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• 2004

This paper empirically examined the relationships between the characteristics of purchasing items and the effective e-procurement strategies. We found that the importance of items has influence on the effective e-procurement, while the complexity of purchasing process has little influence. This fact exhibits the automation of transactional process has little influence on carrying out e-procurement. We also found, companies prefer the horizontal e-marketplace to the vertical e-marketplace. In addition, companies want to purchase through the e-bidding or reverse auction for lower prices.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2005년도 추계 종합학술대회 논문집
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• pp.223-227
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• 2005

인터넷의 대중화는 기업을 둘러싸고 있는 환경의 변화를 가져왔다. 기업들은 인터넷을 기반으로 하는 웹사이트의 구축과 운영에 상당한 관심과 투자를 함으로써 마케팅활동 및 상거래를 수행하기 위한 수단으로 활용하고 있다. 본 연구에서는 웹사이트의 특성과 고객만족, 관계몰입의 영향관계를 살펴보고자 한다.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권4호
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• pp.312-316
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• 2005

The single phase induction motor has been commonly applied to small-sized electrical appliances because of its low cost, but it has low efficiency and large torque ripple, and it is incapable of speed control. However, two-phase induction motors have small torque ripple, high efficiency and variable speed control, because they are inverter fed. In this paper, the dynamic characteristics of the two-phase induction motor, such as the torque ripple, current and speed, are analyzed by using the time-stepping finite element method, and compared with the cage-type single phase induction motor.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제3B권2호
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• pp.74-78
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• 2003

This paper describes the operating characteristic analysis of the PM-type linear oscillatory actuator used as a magnetic circuit breaker for the electromagnetic field, electric circuit, and mechanical motion problems. Transient calculations are based upon a 2D finite element magnetic field solution including non-linearity of materials. Changes of the dynamic characteristics from the eddy current in the plunger are quantified from finite element analysis. A new laminated model is proposed to decrease the eddy current effect.

• 인터넷정보학회논문지
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• 제18권6호
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• pp.127-136
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• 2017

The strategy that using data collection from Netflix uses for its services is different from traditional human interaction and the communication, and it is represented by the systematic algorithm that rooted from intelligent information system based on the human interaction and communication. These characteristics allowed the study to reflect the influence of 'Asset specificity' which affects the continuous consumption of the media services of Netflix users through economic psychological analysis based on transactional cost economics. The result from the survey on actual Netflix users, three types of specificity (Space specificity, time specificity, relational specificity) reduced perceived searching cost whereas perceived instrumentality has increased, eventually reinforces the commitment to the service. This implies that the service characteristics of Netflix, trying to communicate with the individuals based on intelligent information system are distinct from the existing platform services and it gives the significance of work very effective for user's continuous consumption of the media services.