Earticle

This paper presents an 2 kW commercial Li-ion(lithium-ion) battery model using PSIM simulation. An in-house designed transformer was employed to measure the leakage and magnetic inductance and determine the resonant frequency. The LLC resonant converter’s transfer function was derived using the FHA method, and voltage gain characteristics were analyzed concerning frequency, Q factor, and inductance variations. The CC-CV charge mode was evaluated at different C-rates, targeting the charging voltage for e-bikes. The results demonstrated that battery voltage increased with SOC until reaching the final charging voltage.

본 논문에서는 전기자동차의 핵심부품인 DC-DC 컨버터를 LLC공진형 컨버터에 신소재(Ga-N HEMT) 를 이용하여 설계함으로써 소형화가 가능하며, 공진주파수를 자유롭게 변경할 수 있으며, 2차측 출력부에 SR Topology를 추가하여 전원장치의 동작 시 효율 및 온도특성을 개선하는 설계기법을 제안하였다. 이를 통해 고효율 과 소형화를 얻을 수 있도록 회로를 구성하였으며, 제안된 컨버터는 200[kHz]의 높은 스위칭주파수를 가지고 동작 시키게 됨으로써 스위칭주파수의 변화 및 회로구현의 장점과 스위칭주파수의 극대화로 인해서 LLC 및 PFC의 사 이즈를 40[%] 최소화 할 수 있었으며, 동작온도의 특성이 250W(12V/20A)에서 온도를 측정한 결과 방열판 없이 60~65℃를 나타냄을 확인하였다. 이러한 설계결과를 토대로 향후 1[kW]이상까지 구현하고자 한다.

In this paper, we present a design technique that miniaturises the DC-DC converter, a key component in the electric vehicle system, using the advanced material (Ga-N HEMT) in the LLC resonant converter and freely changes the resonant frequency. This design is also proposed to improve the efficiency and temperature characteristics by adding SR Topology in the secondary side output during the operation of power supply. In this experiment, as a consequence of the constructed circuit with the operation of high switching frequency of 200 kHz, the size of LLC and PFC was able to be minimised by 40[%]. Thus, the characteristics of operating temperature demonstrated 60-65℃ without a heat sink, when the temperature was measured at 250W (12V/20A). The features were all due to the advantages of the change of switching frequency, switching circuits implementation, and the maximisation of switching frequency. Based on these design results, we would like to implement more than 1 [kW].

With the increasing demand for high-power and high-efficiency power conversion systems, LLC resonant converters, which achieve both high efficiency and high power density through soft-switching operation, have attracted significant attention. Accordingly, various topologies based on LLC resonant converters have been proposed; however, studies on topology analysis and selection criteria remain insufficient. Therefore, this paper analyzes device losses, voltage and current stresses, and efficiency characteristics under different output power levels based on PSIM simulations, and proposes a topology selection methodology for the primary- and secondary-side structures of LLC resonant converters.

It is difficult to say that the discussion on fiduciary duty in United States has been clearly and concretely summarized. The fiduciary duty discussed in the LLCs in United States is not the fiduciary duty in social relation. It can be understood that the fiduciary duty is just on the dimension of contract between specific parties. The legislative means to resolve this issue is just a legal measure for the simple resolution of economic demand; while the dispute in concrete legal principle is still ongoing. It can be said that the background of such discussion works important on the discussion of fiduciary duty in Korean Limited Liability Company (LLC). At present, there is no clear applicable provision in LLC-related articles in the revised Korean Commercial Code, by which fiduciary duty can be levied on the internal legal relation. Especially, the provision, which can be a basis for fiduciary duty of Limited Liability Company (LLC), is on the ‘duty of care’ in the delegation provision with a company; therefore, an opposition of theories regarding the application of fiduciary duty dis cussed in United States LLC is unavoidable. Therefore, the Limited Liability Company (LLC) provision in current revised Commercial Code has the issue that it cannot deal with the unique characteristic of Limited Liability Company (LLC) and its dispute in legal principle. A representative issue is that current revised Commercial Code does not have a provision on the operating agreement, which enables the change and exemption of internal member’s fiduciary duty in United States Limited Liability Company (LLC) law. The reality is that Limited Liability Company (LLC) was introduced to Korea before such ‘standardization’ process. Therefore, future discussion should deal with the legal property or status related to operating agreement of Limited Liability Company (LLC), which has impact on the “duty based on standard or duty” such as fiduciary duty. Next, the legal principle on the existence of normativity or contractual duty regarding the fiduciary duty of Limited Liability Company (LLC), which gets impact from operating agreement, should be established. It is suggested that the normativity of fiduciary duty, harmonious interpretation on the Limited Liability Company (LLC) with strong contract property and the disputes in legal principle should be sequentially established in Korean corporation law practice.

컴퓨팅 성능을 향상시키기 위해 다양한 구조적 설계 기법들이 제안되고 있는데 그중에서도 CPU-GPU 융합형 이종 멀티코어 프로세서가 많은 관심을 받고 있다. CPU-GPU 융합형 이종 멀티코어 프로세서는 단일 칩에 CPU와 GPU를 집적하기 때문에 일반적으로 CPU와 GPU가 Last Level Cache(LLC)를 공유하게 된다. LLC 공유는 CPU와 GPU 코어 사이에 심각한 캐쉬 경합이 발생하는 경우 각각의 코어 활용도가 저하되는 문제를 가지고 있다. 본 논문에서는 CPU와 GPU 사이의 캐쉬 경합 문제를 해결하기 위해 단일 LLC를 CPU와 GPU 각각의 공간으로 분할하고, 분할된 공간의 크기 변화가 전체 시스템 성능에 미치는 영향을 분석하고자 한다. 모의실험 결과에 따르 면, CPU는 사용하는 LLC 크기가 커질수록 성능이 최대 21%까지 향상되지만 GPU는 사용하는 LLC 크기가 커져 도 큰 성능변화를 보이지 않는다. 즉, GPU는 LLC 크기가 감소하더라도 CPU에 비하여 성능이 적게 하락함을 알 수 있다. GPU에서의 LLC 크기 감소에 의한 성능하락이 CPU에서의 LLC 크기 증가에 따른 성능향상보다 훨씬 작기 때문에 실험결과를 기반으로 각각의 코어에 LLC를 분할하여 할당한다면 전체적인 이종 멀티코어 프로세서의 성능을 향상시킬 수 있을 것으로 기대된다. 또한, 이러한 분석을 통해 향후 각 코어의 성능을 최대한 높일 수 있는 메모리 관리기법을 개발한다면 이종 멀티코어 프로세서의 성능을 크게 향상시킬 수 있을 것이다.

Recently, CPU-GPU integrated heterogeneous multicore processors have been widely used for improving the performance of computing systems. Heterogeneous multicore processors integrate CPUs and GPUs on a single chip where CPUs and GPUs share the LLC(Last Level Cache). This causes a serious cache contention problem inside the processor, resulting in significant performance degradation. In this paper, we propose the partitioned LLC architecture to solve the cache contention problem in heterogeneous multicore processors. We analyze the performance impact varying the LLC size of CPUs and GPUs, respectively. According to our simulation results, the bigger the LLC size of the CPU, the CPU performance improves by up to 21%. However, the GPU shows negligible performance difference when the assigned LLC size increases. In other words, the GPU is less likely to lose the performance when the LLC size decreases. Because the performance degradation due to the LLC size reduction in GPU is much smaller than the performance improvement due to the increase of the LLC size of the CPU, the overall performance of heterogeneous multicore processors is expected to be improved by applying partitioned LLC to CPUs and GPUs. In addition, if we develop a memory management technique that can maximize the performance of each core in the future, we can greatly improve the performance of heterogeneous multicore processors.

We tide over a difficult situation, IMF as a radical economic change. we try to Artificial Reformation of Corporate Governance for the existence of a Korean Enterprise. Not only our country, but also all countries of the world, keep pace with dramatic change of International Economics, concentrate their efforts on reformation and innovation of various system of every countries, especially Institution and Law in relation of Corporate Law. And also various system of former days are now changing by a trend of the times and each countries present the economic operation policy of their own. Get born on United States, Limited Liability Company is a devised Corporate Entity for the Relevance to Economic Needs of Corporate Constituencies. In America like a Major Economic Power, gives every facility for attracting enterprise. Especially, in Delaware, Corporate Law gives wide Discretionary Powers to parties for the efficient control of contract between Shareholder and Corporation. what is called the realization of Private Ordering, respects party's rights. And salient tendency of Private Ordering is the evidence of Limited Liability Company. Thus, LLC system of United States take aim at realize the efficiency of Private Ordering. This efficiency of LLC system is connected Legislation of Japan, I t established Japanized LLC in 2005, with Modernization Plan of Japan Corporate Law. Limited Liability as a merit of corporations, flexible manage the inner parts of Partnership and a tax privilege, receive recognition that Institutional Availability, utilization is revitalized, after that politic invitation is legislated in Japan, recently. As a matter of fact, there are in substantial agreement between LLC of United States and Japanized LLC, except for a slice of tax parts. However, Limited Liability, Private Ordering and a tax privilege as a trait of the LLC system is suitable to recognition that Institutional Availability. But at the time of Legislation, we don't have to passing over forecasting that these good traits can make bad effects of system, by being a Double-Edged Sword. It is easy to forecast the damage of the Third Parties, as like the Creditor of Corporation by abusing of Limited Liability, in the same manner with Corporation. In Proposals to Amend Comercial Law, Rules in relation to the Third Parties by Mandatory Rules apply the Provision and Rule Regulating Corporations, but it would be enough to use to make indistinct the Scope of Liability by abuse legislation with LLC system's trait, be controled by Private ordering. At the time of Legislation of LLC, at first, company have necessary to clear up the Scope of Liability to the Third Parties, To find the way to protect the Third Parties as the Creditor of Corporation is the object of this inquiry.

대상판결은 미국에서 패션산업의 특성을 고려해 보호기간만 상대적으로 단기로 하되 기본적으로 저작권적 접근방법에 기초한 패션디자인 보호입법 움직임이 활발한 가운데 내려졌다. 대상판결은 실용품의 저작권보호를 위한 분리가능성 판단과 관련하여 1954년 Mazer사건 이래 모처럼 나온 연방대법원 판결이다. 대상 판결은 치어리더 유니폼 디자인에 관한 분쟁으로서 의류 등 패션디자인 제품의 저작권 보호가능성을 열었다는 점에서 우선 주목받을 만하다. 대상판결은 판례법적으로도 오랜 기간 정리되지 못했던 다음과 같은 다양한 법률적 쟁점에 대해 길잡이를 제공하고 있다. 첫째, 치어리더 유니폼 등 실용품의 분리가능성 요건은 순수 법률해석의 문제로 보고 보호연혁과 제도적 취지에 충실한 해석을 시도하면서 실용품의 분리가능성 판단기준을 ‘개별적 인식(separate identification)요건’과 ‘독립적 존재(independent–existence)요건’으로 나누어 구체적 판단기준을 제시한 것에 의의가 있다. 둘째, 당사자 주장한 종래 분리가능성 테스트 방법론을 모두 부인함으로써 그동안 하급심에서 난무하여 오던 분리가능성 테스트 기준을 정리하고 현행 법문이 갖는 객관적 의미해석에 기초한 통일적 기준을 제시한 것도 의의가 있다. 셋째, 실용품의 입체적 디자인 특징뿐만 아니라 평면적 디자인 특징 역시 분리가능성 테스트의 적용 대상이라는 점, 즉 2차원의 실용품도 분리가능성 테스트 적용 대상임을 분명히 하였다. 넷째. 물리적 분리가능성 이론을 포기하고 관념적 분리가능성 판단으로 일원화함으로써 어차피 분리가능성 판단은 상상을 통한 관념적 작업임을 분명히 하였다. 다섯째, 분리가능성 요건은 실용품의 디자인의 창작성 요건과 별개의 요건임을 분명히 하고 실용품 장식 디자인의 보호는 그 특징적 장식의 복제에만 미치고 유니폼 자체의 복제에는 미치지 아니한다고 명시하여 그 보호 범위를 명확히 하였다.

The subject ruling is a U.S federal Supreme Court’s leading case that has come since the Mazer case in 1954 in relation to the separability requirement for the copyright protection of a useful article, It was rendered during discussing the fashion design protection legislations based on the copyright approach considering the characteristics of the fashion industry in the United States. First of all, it deserves attention in that the subject ruling provides guidance on a variety of the following legal issues that have not been laid down for a long time by precedents. First, the separability requirement of useful articles such as cheerleader uniform is considered as a matter of law, and try to interpret faithful to the protection history and literal purpose, and the criterion of separability of useful article is defined as ‘separate identification requirement’ and “independent-existence requirements”. Second, it is also meaningful to present a unified standard based on the objective interpretation of the current law by judging the separability test standard which has been in controversy for a while by denying all the conventional separability test methodology claimed by the parties. Third, it is clear that not only the three-dimensional design characteristics of useful article but also the two-dimensional design features are subject to the separability test. Fourth. abandoning the theory of physical separability and unifying it by judging the separability only in conceptual, it made it clear that separability judgment is a conceptual work through imagination. Fifth, it made clear that separability requirement is another requirement independent from the originality requirement of the design of the useful article, and the scope of protection of the decorative design of the useful article is clarified by stating that it is limited to the copy of the characteristic decoration and not the reproduction of the uniform itself. In addition, there are many specific factors and perspectives of separability settled during the examining the party’s attack and defense.

기업 형태와 관련하여 2011년 4월 14일 개정 상법(법률 제10600호)이 공포되고, 공포 후 1년이 경과한 날부터 시행되었다(부칙 제1항). 개정 내용 가운데 하나가 제3편 회사에서 제3장의 2를 신설하여 도입한 ‘유한책임회 사’ 제도(제287조의 2∼제287조의 45)이다. 유한책임회사 제도를 도입한 배경에 대해 주식회사의 속성을 가지면서도 중소기업에 걸맞은 기업형태가 요구 되었음을 든다. 또 내부적으로는 조합적인 실질을 갖고 외부적으로는 사원의 유한책임이 확보되는 기업형태 가 필요하였음을 이유로 내세운다. 다른 한편에서는 다양한 기업형태를 도입함으로써 국제적 기준에 부합하 는 회사법제로 재편하기 위한 것으로 설명한다. ‘주요내용’으로 새로운 기업 형태 도입에서 최근 인적 자산의 중요성이 높아짐에 따라 인적 자산을 적절히 수용할 수 있도록 공동기업 또는 회사 형태를 취하면서 내부적으 로는 조합의 실질을 갖추고 외부적으로는 사원의 유한책임이 확보되는 기업 형태에 대한 수요가 늘어나고 있 음을 든다. 그 방법론으로는 미국식 유한책임회사 제도와 일본의 합동회사 제도를 참고하였다고 한다. 그리고 유한회사에 비하여 지분 양도가 자유로움을 들어 활용도가 크다고 한다. 개정 상법은 다양한 기업형태에만 치중하였지 활용도는 전혀 예상하지 못한 듯 하고 준비도 역시 허술하였다. 개정법이 시행되고도 오랜 기간 동안 상업등기법에서는 유한책임회사 등기부를 찾을 수 없었음이 그 단적인 예이다. 개정 상법은 유한책임회사의 법적 성질이 외부적으로는 물적회사에 가깝고, 내부적으로는 인적회사에 가깝다 고 보아 여러 부분에서 합명회사에 관한 규정을 준용하도록 하였다. 그러나 법적으로 명문화가 필요한 중요한 부분에서 입법자가 합명회사에 관한 규정의 준용을 염두에 두었는지 침묵하고 있다. 제도의 운영은 그 실효성 에 앞서 규정의 명확성에 크게 의존한다. 적지 않은 사안에 대해 침묵함으로써 학설에만 의존하도록 하는 것 은 입법자의 자세로서는 바람직하지 않다. 업무집행자와 회사와의 관계를 규정하여, 이들의 회사에 대한 책임 을 추궁할 수 있는 근거와 범위를 밝히는 것이 필요하다. 또 회사 채권자를 보호하기 위한 자본금 충실에 대한 규정과 제3자에 대한 책임의 근거와 범위에 대한 규정을 신설하여야 한다. 입법론적으로 유한책임회사와 유사한 유한회사 제도가 있는데도 굳이 유한회사와 유한책임회사 제도를 두어 야 하는지 심각하게 고려하여야 한다.

With regard to corporate form April 14, 2011 amended Commercial Law (Law No. 10600) was promulgated. One of the amendments is the “Limited Liability Company”(Article 287 Article 287 Article 2 to Chapter 45). Introduced the background of a Limited Liability Company(hereinafter referred to as LLC.) system is to provide a corporate form worthy of SMEs while having the properties of the Corporation. Also we need to a combination of internally association substantial and limited liability form externally. Also Internally, the legislators argued that the form with the substance of the associaton of externally secured a limited liability corporate form of the temple is necessary. In addition, by introducing a form of the various enterprise would be described as to change to meet the international standards Corporate Law. In the introduction of the new corporate form was to allow the joint enterprise or corporate form to accommodate appropriate human capital. Nevertheless, except for intangible property such as labor, credit etc. is to dilute the purpose of the introduction of the LLC. system. Revised Law was amended to apply correspondingly with provisions relating to partnership in various parts of the Commercial Code. But legislators were silent in important part of the application of the legal relationship. Namely there is no clear provisions of the legal relation the management and the company. As a result, the issues that should be applied to any obligations. There is no evidence rules relating to liability for the company's managers. And the absence of evidence can be found in the scope of liability for third party managers. Do not entrust theory only to be urgently amend the relevant provisions.

본 논문에서는, 스위칭 손실이 적고 효율이 높은 이점을 갖고 있는 LLC 공진형 컨버터에 대하여 선형화된 수학적 모델을 정립하고 디지털 제어기 설계 과정을 제안한다. LLC 공진형 컨버터의 비선형 모델에 대하여 EDF(Extended Describing Function) 기법을 도입하여 비선형성을 선형 근사화시킨 선형 소신호 모델을 정립하고 Ziegler Nichols 방법을 이용하여 제어기 계수를 선정하였으며 연속시간 제어기를 디지털 제어기로 변환하여 적용한다. 유도된 선형 소신호 모델에 기 반하여 전압 제어기를 설계하고, MATLAB 시뮬레이션을 통하여 제어기의 성능을 검증한다. 또한, 부하 변화 및 모델링 오차 를 고려한 시뮬레이션을 통하여 LLC 공진형 컨버터에 대해 설계된 전압 제어기의 타당성 및 제어성능을 분석한다.

In this paper, we propose a digital controller design methodology for an LLC resonant converter which has been widely used due to the advantages of low switching loss and high efficiency. We establish a mathematical model of an LLC resonant converter using the extended describing function concept and propose a controller design method based on the Ziegler Nichols control parameter tuning criteria. The voltage controller of an LLC resonant converter is designed based on the derived small signal model and the performance of the controller is verified by MATLAB simulations. The validity and the control performance of the designed voltage controller for the LLC resonant converter is analyzed through some simulations for the case of load variations and circuit modeling errors.

In this paper, a modified form of the most efficient resonant LLC series parallel converter configuration (SPRC) is proposed. The proposed system comprises of an additional LC circuit synchronized along with the existing resonant tank of LLC configuration (LLC-LC configuration). With the development of power electronics devices, resonant converters have been proved to be more efficient than conventional converters as they employ soft switching technique. Among the three basic configurations of resonant converter, Series Resonant Converter (SRC), Parallel Resonant Converter (PRC) and Series Parallel Resonant Converter, the LLC configuration under SPRC is proved to be most efficient providing narrow switching frequency range for wide range of load variation, improved efficiency and providing ZVS capability even at no load. The modified LLC configuration i.e., LLC-LC configuration offers better efficiency as well as better output voltage and gain. The efficiency tends to increase with increase in input voltage and hence these are suitable for high input voltage operation. In this paper, LLC topology of SPRC and a modified LLC topology (LLC-LC) of SPRC for the closed loop control of a BLDC motor are simulated and their performances are compared and analyzed.

본 논문은 LLC 공진 컨버터에 적합한 자동화 권선 변압기 설계에 대한 포괄적인 방법에 대해서 나타낸다. 기존의 LLC 공진 변압기는 하나의 보빈에 모든 권선이 감겨져 있기 때문에 자동화 권선 구현이 어렵다는 문제점이 있다. 따라서 본 논문에서는 절연 테이프와 배리어 테이프가 없이 다중 보빈으로 자동 권선이 가능한 LLC 공진 변압기를 제안하였으며 제안한 LLC 공진 변압기의 설계 절차에 대해서도 나타내었다. Maxwell 3D 시뮬레이션 툴을 이용하여 제안한 LLC 공진 변압기의 해석 및 모델링을 상세하게 기술되었으며 또한 3D 모델링에 의해 제작된 제안한 LLC 공진 변압기를 이용하여 프로타입 150W LLC 공진 컨버터를 실험을 통해 확인하였다.

This paper presents the comprehensive transformer design methodology with the winding method of automatic type suitable for LLC resonant converter. The problem with conventional LLC resonant transformer is that it is difficult to implement the winding method of automatic type because all windings are wound in one bobbin. Therefore, the LLC resonant transformer, which is capable of the winding method of automatic type to multiple section bobbin without insulation tape and barrier tape, is proposed in this paper and the design procedure of the proposed LLC resonant transformer is also shown. Modeling and analysis of the proposed LLC resonant transformer using Maxwell 3D simulation tool are described in detail and a protype 150W LLC resonant converter using the proposed LLC resonant transformer manufactured by 3D modelling is also verified through the experimental test.

The LLC is a very popular closely held business structure in the U.S. because it is recognized as the most favorable business structure to owners as it enables the owners to directly manage the business and yet to enjoy the limited liability privilege and to receive the pass through taxation (single taxation). In response to this trend in the U.S., Japan has adopted “goudougaishya”, the so-called Japanese LLC into the new Company Act, that has been in force since 2006. This paper’s aim is to give useful hints in introducing the LLC system into the Korean Commercial code by providing comparison of the Japanese LLC legislation with the U.S. legislation. This paper does not mention the LLC draft in the revision bill of the Korean Commercial Code because it was already dealt with in another paper of mine. The big differences between the Japanese legislation and that of the U.S. are as follows: First, the U.S. legislation gives flexibility in management structure in that it enables to choose between direct management by the owners and indirect management by the third party managers. Second, most states of the U.S. have not adopted the capital maintenance principle in the past and have instead taken insolvency or bankruptcy as tests in distribution. Third, in transferring member's rights, the U.S. LLC distinguishes between financial rights and management rights and allows financial rights alone to be transferred separately. The break-through of the LLC, when compared with the traditional business structures, is that the owners enjoy the limited liability privilege even though they can manage the business themselves. The traditional concept is that, if the owners directly manage the business themselves as in partnership or “hapmyunghoisa”, then they are personally liable for the business and, if the business is run by the third party managers as in corporation, then they are not personally liable for the business debt and are liable only for the agreed contribution to the business structure. Further more, I think it is imminent that a proprietorship comes out where the owner is liable up to the business assets contributed and not with personal assets provided there is a public notice of limited liability and a complete separation of business assets and individual assets. In case of one man LLC’s, I think it already serves this function.

본 실험에서는 항산화 기능성 증진을 위해 녹차를 첨가한 서리태 청국장을 제조한 후 LLC-PK₁ 세포를 이용하여 superoxide anion (O₂^-)을 유도하는 pyrogallol을 처리하여 발생한 세포 독성에 대한 보호 효과를 확인하였다. 대두 대신 항산화능이 우수한 서리태를 청국장의 주재료로 하고, 부재료로 0.5, 2.0, 5.0% 농도의 녹차를 첨가하여 청국장을 각각 제조한 후 O₂^-에 의해 유도된 산화적 스트레스에 대해 녹차 첨가 서리태 청국장의 산화 스트레스에 대한 개선효과를 검토하였다. 녹차 첨가 서리태 청국장은 서리태 청국장보다 세포 생존율을 증가시키고, 지질 과산화를 억제하며, superoxide dismutase 및 glutathione peroxidase의 항산화 효소 활성을 증가시켜 산화적 스트레스에 대한 보호 효과를 나타냈으며, 특히 녹차 첨가 농도가 증가할수록 효과가 높아지는 경향으로 나타났다. 따라서, 녹차 첨가 서리태 청국장은 서리태 청국장 보다 O₂^-에 의해 유발된 산화적 스트레스를 효과적으로 개선하는 항산화제로서 가능성 증진되었음을 확인하였다.

This study evaluated the antioxidative efficacy of Seoritae Chungkukjang (SC) supplemented with green tea powder (SCG) in an LLC-PK₁ oxidative-stress model. Pyrogallol, a superoxide anion (O₂^-)-generating agent, markedly reduced cell viability, promoted lipid peroxidation, and suppressed antioxidant enzyme activities. Treatment with SC extract counteracted these effects by improving cell viability, inhibiting lipid peroxidation, and enhancing the activities of superoxide dismutase and glutathione peroxidase. Building on this baseline activity, the incorporation of green tea powder further amplified the protective responses, conferring stronger resistance to O₂^--mediated oxidative injury. Higher levels of green tea powder supplementation produced progressively greater antioxidant benefits. Collectively, these findings indicate that SCG exhibits enhanced antioxidant potential and more effectively mitigated O₂^--induced oxidative stress in renal epithelial cells compared with SC alone.

본 논문에서는 315W급 65인치 UHD-TV용 LLC DC to DC 공진 컨버터에 사용되고 있는 Slim형 고주파 변압기의 최적화 설계에 대해서 나타낸다. 또한 본 논문에서는 LLC 공진 변압기의 코어 손실 분석, AC 권선 손실 분석 및 권선 배치 최적화 설계를 통해 Slim형 고주파 변압기의 최적화 설계를 수행한다. 특히 본 논문에서는 이론적으로 해석하여 얻어진 결과를 토대로 고효율 및 Slim형 고주파 변압기는 교류 권선 손실 최소화 및 권선 자동화를 위하여 인터리브 및 수직형 권선 구조로 구성한다. 본 논문 제안한 수직형 권선 구조 방식의 Slim형 고주파 변압기의 1차측 권선은 Litz 권선을 2차 권선은 PCB와 동판 권선을 사용하였다. 최종적으로 Maxwell 2D 및 3D Tool을 이용한 시뮬레이션 결과를 토대로 이론 해석의 정당성을 입증하기 위해서 실험 결과를 통해 본 논문에서 제안한 Slim형 고주파 변압기의 최적화 설계를 수행하였다.

This paper presents an optimal design of the slim type high frequency transformer used in the LLC DC to DC resonant converter for 65-inch UHD-TV with the rated power of 315W. This paper also performs an optimal design of the slim type high frequency through core loss analysis, AC winding loss analysis, and optimization design of the winding arrangement of the LLC resonant transformer. Particularly, the high-efficiency and slim type high frequency transformer based on the obtained results from theoretical analysis in this paper is constructed in the interleaved and vertical winding structures of its transformer to realize the winding method of automatic type and minimize AC winding loss. The primary and secondary windings of the slim type high frequency transformer the vertical winding structure proposed in this paper used the Litz-wire windings, PCB and copper plate windings, respectively. Finally, an optimal design of the slim type high frequency transformer proposed in this paper was carried out through the experimental results to confirm the validity of theoretical analysis based on the simulation results using Maxwell 2D and 3D tool.

This paper proposes a three-bridge LLC resonant converter with auxiliary switches for a wide output voltage control range. This converter can be controlled in two ways to achieve a wide controllable output voltage control range of $V_o$ to $3V_o$. The first control mechanism is achieved through the pulse width modulation (PM) of the auxiliary switches and primary switching devices, while the second control mechanism is achieved through the frequency modulation (FM) of the primary switching devices that are configured to operate in the full-bridge switching mode when the auxiliary switches are turned off. The feasibility of using the proposed converter is verified by the results of an experiment with a 2kW prototype.

스위칭 주파수의 대역 확산 (Spread Spectrum) 기법은 전력 변환 장치의 전자 방해 잡음 (Electromagnetic Interference; EMI)를 줄일 수 있다. 하지만 공진형 컨버터는 스위칭 주파수 가변을 통해 출력 전압을 제어하기 때문에 스위칭 주파수의 대역 확산 기법을 적용하게 되면 출력 전압이 크게 흔들리게 된다. 본 논문은 LLC 공진형 컨버터에 대역 확산 기법을 사용함과 동시에 확산된 스위칭 주파수 대역의 위상 제어를 통해 출력 전압을 제어하는 방법을 제시하고자 한다. 제안하는 출력 전압 제어 성능 향상 및 전자방해잡음 감소 성능은 500 W 프로토타입 컨버터를 사용하여 검증하고자 한다.

LLC 컨버터는 1차측 스위치의 ZVS, 2차측 다이오드의 ZCS를 만족하며 높은 Power density로 인해 여러 분야에서 각광 받고 있는 시기이다. 기존의 FHA를 통해 LLC 컨버터를 해석하여 전압이득을 구하고 이를 기반으로 설계를 하지만 실제로는 기본파 성분뿐만 아니라 고조파 성분을 포함하므로 다소 오차가 존재하게 된다. 따라서 이 논문에서는 기존의 FHA에서 반영하지 않았던 출력 캐패시터의 영향을 반영함으로써 보다 정확한 LLC 컨버터의 전압이득 곡선을 제안한다.