• Journal of Power Electronics
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• v.2 no.3
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• pp.155-161
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• 2002

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 an 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 isolation and avoids oscillations after reaching the maximum power point.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.605-606
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• 2006

Voltage Controlled Oscillator(VCO) plays an important role in today's communication systems. Especially, a Clock Generator(CG) in phase-locked loop(PLL) is usually realized by the VCO. This paper proposes a new VCO with a controllable duty cycle buffer, that can be adopted in low-power high-speed communication systems. Delay cell of the VCO is implemented with gilbert cell. Frequency dynamic range of the VCO is in the range of approximately $50MHz{\sim}500MHz$. Parameters with N-well CMOS 0.18-um process with 1.8V supply voltage was used for the simulations.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.2
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• pp.139-144
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• 2013

Negative bias temperature instability (NBTI) has become a major factor determining circuit reliability. The effect of the NBTI on the circuit performance depends on the duty cycle which represents the stress and recovery conditions of each device in a circuit. In this paper, we propose an analytical model to perform more accurate duty cycle estimation at the gate-level. The proposed model allows accurate (average error rate: 3%) computation of the duty cycle without the need for expensive transistor-level simulations Furthermore, our model estimates the waveforms at each node, allowing various aging effects to be applied for a reliable gate-level circuit aging analysis framework.

• Convergence Security Journal
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• v.23 no.1
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• pp.35-43
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• 2023

Since the Personal Information Protection Act was enacted in 2011, it has played a role in safely protecting people's personal information and protecting their rights. Personal information controller must comply with the duty of safeguards for safe personal information management. Even though administrative regulation is an accompanying issue, it is not clear to whom, when and how it applies. According to the imposition of duties, the scope, standards, safety measures, procedures, etc. for the target person should be clearly and specifically specified, but the current legal system is insufficient .In this study, problems and reasonable improvement plans were presented for the classification criteria for applicable subjects, the criteria for the criteria for determining the targets, and the criteria for measures to ensure safety. Through this, we intend to contribute to enhancing the effectiveness of the system by presenting reasonable measures by clarifying and specifying the scope and standards of application.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.780-783
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• 2010

Net residual dispersion (NRD) available to transmit RZ formats with different 24 wavelength as a function of duty cycles of RZ format and residual dispersion per span (RDPS) is induced by controlling precompensation only in 960 km optical transmission links of single mode fiber (SMF) with inline dispersion management (DM) for compensating of accumulated dispersion. It is confirmed that effective NRD range for different 24 wavelengths is gradually broadening as RDPS is more smaller, and as duty cycle of RZ format is more larger in the same RDPS.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.5
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• pp.384-390
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• 2022

In this study, a single-stage, four-phase, interleaved, totem-pole AC-DC converter is proposed for a super-fast charger station that requires high power, a wide voltage range, and bidirectional operation capabilities and adopts various types of electric transport vehicles. The proposed topology is based on current-fed push-pull dual active bridge converter combined with the totem-pole operation. Owing to the four-phase interleaving effect, the bridge on the grid side can switch at 0.25, 0.5, and 0.75 to achieve a ripple-free grid current. The input filter can be removed theoretically. Switching methods for the duty of the secondary-side duty cycle are proposed, and they correspond to the primary duty cycle for reducing the circulating power and handling the total harmonic distortion. Therefore, the converter can operate under a wide voltage range. Experimental results from a 7.5 kW prototype are used to validate the proposed concept.

• The Korean Society of Law and Medicine
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• v.17 no.2
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• pp.145-173
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• 2016

A patient's Right to Self-Determination or his/her Right of Autonomy in the Republic of Korea has traditionally been understood as being composed of two elements. The first, is the patient's Right to Know as it pertains to the physician's Duty to Report [the Medical Situation] to the patient; the second, is the patient's Right to Consent and Right of Refusal as it pertains to the physician's Duty to Inform [for Patient's Consent]. The legal and ethical positions pertaining to the patient's autonomous decision, particularly those in the interest of the patient's not wanting to know about his/her own body or medical condition, were therefore acknowledged as passively expressed entities borne from the patient's forfeiture of the Right to Know and Right to Consent, and exempting the physician from the Duty to Inform. The potential risk of adverse effects rising as a result of applying the Informed Consent Dogma to situations described above were only passively recognized, seen merely as a preclusion of the Informed Consent Dogma or a denial of liability on part of the physician. In short, the legal measures that guarantee a patient's 'Wish for Ignorance' are not currently being understood and acknowledged under the active positions of the patient's 'Right Not to Know' and the physician's 'Duty to Consideration' (such as the duty not to inform). Practical and theoretical issues arise absent the recognition of these active positions of the involved parties. The question of normative evaluation of cases where a sizable amount of harm has come up on the patient as a result of the physician explaining to or informing the patient of his/her medical condition despite the patient previously waiving the Right to Consent or exempting the physician from the Duty to Inform, is one that is yet to be addressed; that of ascertaining direct evidence/legal basis that can cement legality to situations where the physician foregoes the informing process under consideration that doing so may cause harm to the patient, is another. Therefore it is the position of this paper that the Right [Not to Know] and the Duty [to Consideration] play critical roles both in meeting the legal normative requirements pertaining to the enrichment of the patient's Right to Self-Determination and the prevention of adverse effects as it pertains to the provision of [unwanted] medical information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.379-382
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• 2013

In conventional solar energy harvesting systems, continuous perturbation techniques of the duty cycle or switching frequency of a power converter have been used to implement MPPT(Maximum Power Point Tracking) control. In this paper, we propose a new MPPT technique to control the duty cycle of a power switch powering a power converter. The proposed circuit is designed in 0.35um CMOS process, and the designed chip area including pads is $770um{\times}800um$.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.24
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• pp.25-49
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• 2004

English contract law has traditionally taken the view that it is not the duty of the parties to a contract to give information voluntarily to each other. In English law, one of the principal distinctions between insurance contract law and general contract law is the existence of the duty of disclosure in insurance law. This article is, therefore, designed to analyse the scope or extent of the duty of disclosure and the remedy for breach of the duty in English marine insurance law. The main purpose of this article is also to seek the alternative remedy for the breach. The results of analysis are as following : First, the scope of the duty of disclosure is closely related to the test of materiality and the concept of a hypothetical prudent insurer. The assured is required to disclose only material circumstances subject to MIA 1906, s. 18(1). The test of materiality, which had caused a great deal of debate in English courts over 30 years, was finally settled by the House of Lords in Pan Atlantic and the House of Lords rejected the 'decisive influence' test and the 'increased risk' test, and the decision of the House of Lords is thought to accept the 'mere influence' test in subsequent case by the Court of Appeal. Secondly, an actual insurer is, in order to avoid contract, required to provide proof that he is induced to enter into the contract by reason of the non-disclosure of the assured. But this subjective test of actual inducement is somewhat meaningless in sense that English court takes the test of materiality as a starting point and assumes the presumption of inducement even in case of no clear proof on the inducement. Finally, MIA 1906, s. 18 provides expressly for the remedy of avoidance of the contract for breach of the duty of disclosure. This means rescission or retrospective avoidance of the entire contract, and the remedy is based upon a fairly crude 'all-or-nothing' approach. The remedy of rescission is too draconian from the point of view of the assured, because he can be deprived of all cover despite he is innocent perfectly. An inadvertent breach from an innocent mistake is as fatal as wilful concealment. What is, therefore, needed in English marine insurance law with respect to remedy for the breach is to introduce a more sophisticated or proportionate remedy ascertaining degrees of fault.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.3
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• pp.220-226
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• 2014

Input current ripple and harmonic components of the power device are main causes of electromagnetic interference (EMI). Although the discontinuous conduction mode (DCM) operation can reduce harmonic components of the power device by reducing reverse recovery current of diode and turn-off voltage spikes of the switch, input current ripple increases due to high peak to peak inductor current. Therefore, in this paper, frequency control algorithm is proposed to reduce the input current ripple of DCM operated interleaved boost converter. In the proposed algorithm, duty ratio is fixed either 0.33 or 0.67 to minimize the input current ripple and the switching frequency is controlled according to operating conditions. 600 W 3-phase interleaved boost converter prototype system is built to verify proposed algorithm.