• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.11
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• pp.903-917
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• 2012

For transmitting sensed data, wireless sensor networks have been developed and researched for the improvement of energy efficiency, hence, many MAC protocols in WSN employ the duty cycle mechanism. Since the progressed development of the low power transceiver and processor let the high energy efficiency come true, the delivery of the multimedia data which occurs in area of sensor work should be needed to provide supplemental information. In this paper, we design a new scheme for massive transmission of large multimedia data where the duty cycle is used in contention based MAC protocol, for WMSN. The proposed scheme can be applied into the previous duty cycle mechanism because it provides two operation between normal operation and massive transmission operation. Measuring the buffer status of sender and the condition of current radio channel can be criteria for the decision of the above two operations. This paper shows the results of the experiment by performing the simulation. The target protocol of the experiment is X-MAC which is contention based MAC protocol for WSN. And two approaches, both X-MAC which operates only duty cycle and X-MAC which operates combined massive transmission scheme, are used for the comparative experiment.

• Journal of the Korea Society of Computer and Information
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• v.15 no.1
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• pp.167-175
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• 2010

Like most large organizations, there are business rules such as 'separation of duty' and 'delegation' which should be considered in access control. From a SOD point of view, previous SOD models built on the (Administrative) Role-Based Access Control model cannot present the best solution to security problems such as information integrity by the limited constituent units such as role hierarchy and role inheritance. Thus, we propose a new integrated management model of administration role-based access control model and SOD policy, which is called the OS-SoDAM. The OS-SoDAM defines the authority range in an organizational structure that is separated from role hierarchy and supports a decentralized security officer-level SOD policy in which a local security officer can freely perform SOD policies within a security officer's authority range without the security officer's intervention.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.414-417
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• 2012

Recently, there will be many changes that revised emergency medical service with prescribe specialist doctor emergency medical center duty. if emergency patients come emergency medical center, in the existing system, emergency patients receive treatment in order emergency room doctor and 1-2 resident and 3-4 resident and specialist doctor. in improved system, emergency patients receive treatment to emergency room doctor and duty specialist doctor. as a result, the procedure was. simplify. but appling such a system, there should be placed duty specialist doctor about all departments in hospital. So, all hospitals be difficult to place duty specialist doctor about all departments in hospital. In this paper, to use mobile device, there design integrated emergency center management system for revision of the emergency medical service to use emergency medical center service near the user's and specialist doctor service in hospital and the hospital's information service and Emergency room usage service.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.39 no.1
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• pp.16-21
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• 2002

In this paper, a dual type PFD(Phase Frequency Detector) for high speed PLL to improve output characteristics using TSPC(True Single Phase Clocking) circuit is proposed. The conventional 3-state PFD has problems with large dead-zone and long delay time. Therefore, it is not applicable to high-speed PLL(Phase-Locked Loop). A dynamic PFD with dynamic CMOS logic circuit is proposed to improve these problems. But, it has the disadvantage of jitter noise due to the variation of the duty cycle. In order to solve the problems of previous PFD, the proposed PFD improves not only the dead zone and duty cycle but also jitter noise and response characteristics by the TSPC circuit and dual structured PFD circuit. The PFD is consists of a P-PFD(Positive edge triggered PFD) and a N-PFD(Negative edge triggered PFD) and improves response characteristics to increase PFD gain. The Hspice simulation is performed to evaluate the performance of proposed PFD. From the experimental results, it has the better dead zone, duty cycle and response characteristics than conventional PFDs.

• The Korean Society of Law and Medicine
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• v.10 no.1
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• pp.389-420
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• 2009

Main Issue of Supreme Court Decision 2005Da16713 Delivered on June 24, 2005 is about the duty of medical care in the interhospital transfer of patients. According to the above Supreme Court Decision, in the interhospital transfer of patients, the decision to transfer should make from the aspect of medical treatment. The hospitals and doctors keep the duty of medical care. In addition to the duty for hospitals/doctors to check the capacity and availability of the hospital to which the patient is transferred, there are also duties to inform about emergency medical service and to sufficiently explain the need for the transfer, the medical conditions of the patient to be transferred and the hospital from which the patient is transferred. The hospital to which the patient is transferred must be thoroughly informed about matters such as the patient's conditions, the treatment the patient was given and reasons for transfer. including information upon referral, completeness of medical records, patient monitoring and so on. The interhospital transfer requires the consent of doctor belonging to the hospital to which the patient is transferred after the consideration of capacity and availability of the hospital and the informed consent of patients or legal representatives.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.2
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• pp.102-109
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• 2013

In this paper, a new torque predictive control method of interior permanent magnet synchronous motor is developed based on an extended rotor flux. Also, a duty ratio prediction method is proposed and allows the duty ratio of the active stator voltage vector to be continuously calculated. The proposed method makes it possible to relatively reduce the torque ripple under the steady state as well as to remain the good dynamic response in the transient state. With the duty ratio prediction method, the magnitude and time interval of the active stator voltage vector applied can be continuously controlled against the varying operation conditions. This paper shows a comparative study among the switching table direct torque control(DTC), the SVM-DTC, conventional torque predictive control, and the proposed torque predictive control. Simulation results show validity and effectiveness of this work.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.1
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• pp.32-39
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• 2018

A new dc link voltage controller for a three-phase Vienna rectifier is proposed in this study. This method uses load current and duty information to control dc link voltage. The load current affects the capacitor current and varies the output voltage. Existing methods do not perfectly consider the load current. By considering load current with duty compensation in the proposed method, the transient response is improved by the load variation regardless of the input voltage. The effectiveness of the proposed method is compared with other control methods when the load changes rapidly using PSIM simulation and experiment.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.10
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• pp.9-15
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• 2009

In this paper, we invented a new structure of fast ATC(Automatic Threshold Control) circuit. Using the structure we made a new burst-mode limiting amplifier with fast ATC function using commercial $0.8{\mu}m$ BiCMOS technology. It's ATC function worked so fast that even the first bit of burst-data could be detected, which confirmed that the new structure was useful for fast ATC. However, in the beginning of a burst, distortions in duty-cycle occurred and increased up to 59% of duty-cycle as amplitude of input signal increased. But we confirmed that after 10 cycles passed, duty-cycles was staying below 52% of duty-cycle for any magnitude of input signal.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.725-730
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• 2004

Separation of Duty(SOD), with delegation, is one of important security principles in access control area. The role-based access control model adopts SOD principle, but it has some problems; SOD concept is inconsistent with role hierarchy, permissions that have no relation with SOD may be restricted, and delegation may violate SOD. We propose permission-based SOD model on role-based access control. We establishes SOD as a set of permissions instead of role level SOD. Furthermore we propose a principle of role activation. It solves SOD problems of RBAC and supports easy implementation of SOD policy.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.617-621
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• 2001

This paper presents a maximum power point tracking algorithm for Photovoltaic array using only instantaneous output current information. The conventional Hill climbing method of peak power tracking has a disadvantage of oscillations about the maximum power point. To overcome this problem, we have developed a algorithm, that will estimate the duty ratio corresponding to maximum power operation of solar cell. The estimation of the optimal duty ratio involves, finding the duty ratio at which integral value of output current is maximum. For the estimation, we have used the well know Lagrange's interpolation method. This method can track maximum power point quickly even for changing solar insolations and avoids oscillations after reaching the maximum power point.