• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.155-164
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• 2012

The compression of software development schedule has a limit without regarding to a development manpower. However, the actually developed softwares includes the impossible short time or unreal long time date. Previously suggested models are driving the development schedule from all of the actually developed software without considering these constraints. This paper recommends a standard of minimum and the most suitable development time period. This paper has chosen a criterion that shows the best development schedule among 5 criteria based on the actually performed projects. Moreover, this paper suggests a model that estimates the development schedule based on the best criterion.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.440-445
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• 2002

In this paper, traction system for urban transit maglev system is proposed. Using vector control strategy to control magnitude and frequency of output voltage transiently is general. But in case of traction system for railway vehicle, it is impossible that adapt vector control because there is one-pulse mode in a high speed region. So this paper proposes the control strategy using vector control in a low speed region and slip frequency control in a high speed region. And also proposes overmodulation method that makes to change in one-pulse mode softly. The performance of traction system will be verified by simulation results using ACSL.

• 전기의세계
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• v.18 no.4
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• pp.7-15
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• 1969

In this method the condenser excite winding has the phase angle of 90 electrical degree, with the load winding in stator. The condenser excite wing is connected with the condenser while the load winding is with the full rectifer. Direct and quardrature axis components of rotating field winding are composed, of balanced two phase winding, and each one of them is connected with half wave rectifiers. Initically, small amount of lead current can be induced at the condenser excite winding by residual magnetism of rotor. The induced lead current forces the rotating field winding to be excited by synchronous alternating magnetic field. The speed electromotive force, there for, induced in rotating field winding shall electro magnetize the rotating field pole by rotating half wave rectifiers. In the case of the charging generator directly coupled with engines at the operation of wide range speed, the generated region, such as vehicles, aircraft, ships etc, is occured. In conclusion, we can take the advantage of, omitting of voltage regurator and current limiter for charging load and reducing the consumption of fuel using the generated region which can be devided in to Impossible generated region, Generated region, and suspension generated region.

• Tribology and Lubricants
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• v.8 no.1
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• pp.38-43
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• 1992

In solving the Reynolds equation in dynamically loaded bearing problem, it is almost impossible to find the squeeze velocity and the cavitation region by analytical method. Finite Element Method was applied to the piston-ring lubrication analysis to solve the complementary problem. The method was very efficient and any convergence problem was not encountered.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.349-354
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• 2004

It is impossible to overestimate the importance of the medical examination. The medical examination and treatment method is composed of Mang(inspection)-Moon(listening)-Moon(anammesis & question)-Jeol(pulse feeling, precussion etc.). Among these 4 methods, the Diagnosis of the Abdominal Region, which is one of the JeolJin, is regarded as the most important method along with pulse feeling. The Diagnosis of the Abdominal Region, which includes the examination of the symptoms and their changes in stomach area to understand the pathological progress of the JangFu, Meridian and Qi-Blood, has been highly emphasized in Western and Eastern Medical Science. External trouble, for instance a cold, can be detected by examining pulse, Internal trouble, for instance indigestion, by Diagnosis of the Abdominal Region. Though the Diagnosis of the Abdominal Region was the important part of the JeolJin, it was often devaluated. The Diagnosis of the Abdominal Region will also be composed of 4 kinds of method on Mang-Moon-Moon-Jeol. We thought that the first of the Abdominal Region Diagnosis is a Mangjin(inspection). So we present the new viewpoint of the abdomen of a diagnosis through emphasizing the importance of Mangjin(inspection).

• Journal of Korea Multimedia Society
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• v.22 no.12
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• pp.1347-1355
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• 2019

Deep learning approach based on convolution neural network (CNN) has extensively studied in the field of computer vision. However, periocular feature extraction using CNN was not well studied because it is practically impossible to collect large volume of biometric data. This study uses the ResNet model which was trained with the ImageNet dataset. To overcome the problem of insufficient training data, we focused on the training of multi-layer perception (MLP) having simple structure rather than training the CNN having complex structure. It first extracts features using the pretrained ResNet model and reduces the feature dimension by principle component analysis (PCA), then trains a MLP classifier. Experimental results with the public periocular dataset UBIPr show that the proposed method is effective in person authentication using periocular region. Especially it has the advantage which can be directly applied for other biometric traits.

• Korean System Dynamics Review
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• v.5 no.1
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• pp.111-126
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• 2004

Many countries in the North East Asia are competing with each other in order to become a centre of international logistics activities. The competition to become a hub port in Far East region is now fierce. The anticipated investments on improving port facilities and attracting the mega carriers are immense for all the ports in the region and the extent of the effort could cripple the local ports and region's economy given the limited financial resources. It is, however, impossible to avoid the disastrous possibility that the massive investments could be channeled into the port, which will never become a hub port, as no port is ready to currently admit defeat and settle as a small regional port. In an attempt to minimise such disastrous waste of resources, ports need to verify the eligibility of their own. This paper tests a system dynamics model using the Port of Busan to understand and illustrate the principle guideline of investment decision making for ports.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.86-90
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• 2002

In this paper, traction system for urban transit maglev system is proposed. Using vector control strategy to control magnitude and frequency of output voltage transiently is general. But in case of traction system for railway vehicle, it is impossible that adapt vector control because there is one-pulse mode in a high speed region. So this paper proposes the control strategy using vector control in a low speed region and slip frequency control in a high speed region. And also proposes overmodulation method that makesto change in one-pulse mode softly. The performance of traction system will be verified by simulation results using ACSL.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.4
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• pp.183-190
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• 2000

It is well-known that the poles of a system are closely related with the dynamics of the systems, and the pole assignment problem, which locates the poles in the desired regions, in one of the major problem in control theory. Also, it is always possible to assign poles to specific points for exactly known linear systems. But, it is impossible for the uncertain linear systems because of the uncertainties that originate from modeling error, system variations, sensing error and disturbances, so we must consider some regions instead of points. In this paper, we consider both the analysis and the design of robust pole assignment problem of linear system with time-varying uncertainty. The considered uncertainties are the unstructured uncertainty and the structured uncertainty, and the considered region is the circular region. Based on Lyapunov stability theorem and linear matrix inequality(LMI), we first present the analysis result for robust pole assignment, and then we present the design result for robust pole assignment. Finally, we give some numerical examples to show the applicability and usefulness of our presented results.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.2
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• pp.149-156
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• 2014

This paper proposes the battery charging algorithm for small-scale wind power generator using three phase PWM converter. it is impossible to control output power of the converter in over wind speed region since back EMF of PMSG is higer than battery voltage. Therefore, battery charging algorithm is proposed to expand battery charging over wind speed region. The suggested method is using the q-axis current for battery charging in the rated wind speed region. In the over wind speed region after it lower back EMF of PMSG using d-axis current it can control output power of the converter. The validity of the proposed algorithm are verified by experiments.