• International Journal of Precision Engineering and Manufacturing
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• v.9 no.3
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• pp.72-74
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• 2008

We investigate the effect of mechanical damping and electrical conductivity on the dynamic performance of a new electromagnetic engine valve actuator that employs a permanent magnet. The key dynamic performance factors are the transition time and the landing velocity of the armature. Two-dimensional dynamic finite element analyses are performed to simulate a coupled system. The results show that mechanical damping and electrical conductivity have similar effects on the dynamic performance of the engine valve actuator. Subsequently, it is possible to replace the role of mechanical damping by controlling the electrical conductivity through the thickness and number of steel core laminations.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.08a
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• pp.165-168
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• 1998

제안하고 있는 CSD17C00 chip은 C&S technology에서 개발한 것으로, 음성 신호 처리를 위해 범용으로 구현되었으며, 16 bit 40 MIPS DSP group OAK DSP Core를 포함, 이에 Miscellaneous Logic, Serial Port, Host Interface, Timer, Compander 의 5가지 Peripherals 과 범용 I/O Ports 로 설계되었다. 1차적으로 CSD17C00 Chip 의 성능을 점검하였다. 그 결과, 응용 프로그램은 28MIPS의 계산속도를 갖으며, 프로그램 ROM 크기는 8.85KWords 이고, 10KWords 의 데이터 ROM 과 4KWords 데이터 RAM을 필요로 한다. CSD17C00 CHIP은 멀티미디어 통신용 VOCODER 개발을 위한 범용성을 갖추고 있으며, VOCODER 용 S/W 개발 환경 및 H/W 구조가 여타 범용 DSP에 비해편의성고 K합리성을 제공하도록 설계되어 있다. 따라서, 이를 이용한다면, 멀티 미디어 통신용 VOCODER, INTERNET PHONE CO-PROCESSOR, DIGITAL RECODER, MPEG AUDIO ENCODER & DECODER 등 다양한 제품으로의 응용이 가능할 것으로 전망된다.

• Journal of Magnetics
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• v.20 no.4
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• pp.387-393
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• 2015

Torque ripple is necessarily generated in interior permanent magnet synchronous motors (IPMSMs) due to the non-sinusoidal distribution of flux density in the air gap and the magnetic reluctance by stator slots. This paper deals with an asymmetric rotor shape to reduce torque ripple which can make sinusoidal flux density distribution in the air gap. Meanwhile the average torque is relatively increased by the asymmetric rotor. Response surface method (RSM) is applied to find the optimum position of the permanent magnets for the IMPSM with improved torque performance. Consequently, an asymmetric structure is the result of RSM and the structure has disadvantage of a mechanical stiffness. Finally, the performance of suggested shape is verified by finite element analysis and structural analysis is conducted for the mechanical stiffness.

• Journal of Magnetics
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• v.20 no.3
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• pp.258-264
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• 2015

In this paper, an adequate B-H curve extrapolation method is proposed and its reliability is verified through experiments. A method is developed to estimate the magnetic saturation induction from the density of the lamination core and electrical resistivity. The magnetic saturation induction of electrical steels measured using a vibration sample magnetometer are compared with the analytical results to validate the accuracy of the proposed estimation method. It is found that the predicted error in the magnetic saturation induction of the electrical steels are approximately 1.2% when the proposed method is used. The performance of interior permanent magnet synchronous motors that applies the proposed method are evaluated via 2D nonlinear finite element analysis and through experiments. Based on the obtained results, the extrapolated B-H curves from the estimated saturation induction can be used for various analyses in saturation region.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.1
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• pp.132-143
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• 2001

The purpose of this study was to observe cospla subculture in 1990s new generation of Korean youth, focused on activity that was reproducing the appearance of individual characters in animation, comic books and computer games, and to understand the representing process and meaning of appearance. The ethnographic methods including in-depth interviews and observation were used to approach such cultural form more closely from the youth generations perspective and their language. The results were as follows: 1. Although the cospla is originated from Japan, the local experience of Koreans make it the special youth subculture of Korea. 2. There are homological features and hierachical structure among group members of cospla subculture. The core values of Korean cospla are that they are realizing their ideal and elevating their own self-esteem. 3. Their appearance has connotation as symbolic resistance. The cultural activity of cospla is non-realistic, non-productive, but cosplayers conform to the social norm, too.

• Korean Management Science Review
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• v.13 no.3
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• pp.115-128
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• 1996

System usage, the utilization of information technology(IT) by individuals, groups or organizations, is a core variable in IS research. Indeed, there is widespread agreement among researchers that system usage is the primary variable through which IT affects white collar performance because it is a requisite, albeit insufficient, for deriving the benefits of IT. Furthermore, system usage has a notable practical value for managers interested in evaluating the impact of IT. Despite the number of studies of targeted at explaining system usage, there are more areas which required for the verification of system usage. The purpose of this paper is to address, using the Technological Acceptance Model (TAM), the usage pattern of AHP toward the various task in group decision (GD). The result showed that, for the all of the task types, perceived usage (PU) has more effect than perceived ease-of-use(PEU) on the AHP usage. However, more researches are required to generalize the result of this study.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.257-263
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• 2002

Test scheduling of SoC becomes more important because it is one of the prime methods to minimize the testing time under limited power consumption of SoCs. In this paper, a heuristic algorithm, in which test resources are selected for groups and arranged based on the size of product of power dissipation and test time together with total power consumption in core-based SoCs is proposed. We select test resource groups which has maximum power consumption but does not exceed the constrained power consumption and make the testing time slot of resources in the test resource group to be aligned at the initial position to minimize the idle test time of test resources.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.61-63
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• 2010

The R&D of Geospatial Information Infrastructure, which is the one of the KLSG(Korean Land Spatialization Group) mian projects, is core project for promotion of digital korean land. It has been conducted during 4 years, and it will be tested and assessed via TestBed in the 5th & 6th years. The application of Testbed for R&D results will make contributions of stability, enhancement and external reliability for R&D results.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.3
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• pp.77-85
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• 2018

Multi-User Multiple-Input Multiple-Output (MU-MIMO) is the core technology for improving the channel capacity compared to Single-User MIMO (SU-MIMO) by using multiuser gain and spatial diversity. Key problem for the MU-MIMO is the user selection which is the grouping the users optimally. To solve this problem, we adopt Extreme Value Theory (EVT) at the beginning of the proposed algorithm, which defines a primary user set instead of a single user that has maximum channel power according to a predetermined threshold. Each user in the primary set is then paired with all of the users in the system to define user groups. By comparing these user groups, the group that produces a maximum sum rate can be determined. Through computer simulations, we have found that the proposed method outperforms the conventional technique yielding a sum rate that is 0.81 bps/Hz higher when the transmit signal to noise ratio (SNR) is 30 dB and the total number of users is 100.

• Genomics & Informatics
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• v.13 no.4
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• pp.152-155
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• 2015

Recently, the Encyclopedia of DNA Elements (ENCODE) Analysis Working Group converted data from ChIP-seq analyses from the Broad Histone track into 15 corresponding chromatic maps that label sequences with different kinds of histone modifications in promoter regions. Here, we publish a frequency profile of the three ChromHMM promoter states, at 200-bp intervals, with particular reference to the existence of sequence patterns of promoter elements, GC-richness, and transcription starting sites. Through detailed and diligent analysis of promoter regions, researchers will be able to uncover new and significant information about transcription initiation and gene function.