• Journal of Power Electronics
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• v.17 no.5
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• pp.1308-1316
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• 2017

The distributed maximum power point tracking (DMPPT) concept is widely adopted in photovoltaic systems to avoid mismatch loss. However, the high cost and complexity of DMPPT hinder its further promotion in practice. Based on the concept of DMPPT, this paper presents an integrated submodule level half-bridge stack structure along with an optimal current point tracking (OCPT) control algorithm. In this full power processing integrated solution, the number of power switches and passive components is greatly reduced. On the other hand, only one current sensor and its related AD unit are needed to perform the ideal maximum power generation for all of the PV submodules in any irradiance case. The proposal can totally eliminate different small-scaled mismatch effects in real-word condition and the true maximum power point of each PV submodule can be achieved. As a result, the ideal maximum power output of the whole PV system can be achieved. Compared with current solutions, the proposal further develops the integration level of submodule DMPPT solutions with a lower cost and a smaller size. Moreover, the individual MPPT tracking for all of the submodules are guaranteed.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1327-1337
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• 2017

Photovoltaic (PV) systems are influenced by disproportionate impacts on energy production caused by frequent mismatch cases. The occurrence of multiple maximum power points (MPPs) adds complexity to the tracking process in various PV systems. However, current maximum-power point tracking (MPPT) techniques exhibit limited performance. This paper introduces an enhanced simulated annealing (ESA)-based GMPPT technique against multiple MPP issues in P-V curve with different PV system structures. The proposed technique not only distinguishes global and local MPPs but also performs rapid convergence speed and high tracking accuracy of irradiance changing and restart capability detection. Moreover, the proposed global maximum power tracking algorithm can be applied in the central converter of DMPPT and hybrid PV system to meet various application scenarios. Its effectiveness is verified by simulation and test results.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1327-1328
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• 2006

Lanthanum oxide was introduced to molybdenum powder by liquid-liquid doping and liquid-solid doping respectively. Mo alloys were prepared by powder metallurgy technology. The size distribution and feature of dopant particles and the fractographs of Mo alloys were investigated by TEM and SEM respectively. The results indicated that liquid-liquid doping method is favorable for refining and dispersing $La_2O_3$ particles uniformly in matrix. Fracture toughness of Mo alloys prepared by liquid-liquid doping showed better results than that of liquid-solid doping. Furthermore, the influences of the size distribution of $La_2O_3$ on properties of Mo alloys was discussed by dislocation pile-up theory.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2009.10a
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• pp.93-102
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• 2009

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.769-773
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• 2015

Fibulin-5 has recently been considered as a potential tumor suppressor in human cancers. Several studies have shown that it is down-regulated in a variety of tumor types and inhibits tumor growth and metastasis. This study was aimed to investigate the clinical significance of fibulin-5 in glioma and its role in cell proliferation and invasion. We found that the expression of fibulin-5 in glioma tissues was significantly lower than those in normal brain (NB) tissues. Negative expression was significantly correlated with advanced clinical stage (grade III+IV). Furthermore, Fibulin-5 negative expression was correlated with a shorter overall survival of glioma patients. Multivariate Cox repression analysis indicated that fibulin-5 was an independent factor for predicting overall survival of glioma patients. Overexpression obviously inhibited cell proliferation in U251 and U87 cells. Furthermore, it significantly reduced the number of migrating and invading glioma cells. In conclusion, impaired expression of fibulin-5 is correlated with the advanced tumor stage in glioma. Otherwise, Fibulin-5 is an independent prognostic marker for predicting overall survival of glioma patients. Mechanistically, it may function as a tumor suppressor via inhibiting cell proliferation and invasion in gliomas.

• The Journal of Korean Philosophical History
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• no.52
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• pp.281-310
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• 2017

This paper is a reflective study of contemporary Korean scholars' claims that they criticize the explanation of Zhu Xi(朱熹, 1130-1200)'s psychology in which he explains that the 24th Hexagram of $F{\hat{u}}$[復卦] shows the state that the mind has not happened yet[未發]. Zhu Xi explains the 24th Hexagram of $F{\hat{u}}$[復卦] with the theory of no mind yet[未發說]. Several scholars in modern Korea, however, raise the question of whether "thoughtless[思慮未萌] but being not dark to perception[知覺不昧]" of the 24th Hexagram of $F{\hat{u}}$ is enough to explain the state of no mind yet. And they think that "thoughtless[思慮未萌]" is appropriate to explain the state in which the mind has not yet occurred, but it is not to "being not dark to perception". In this study, we would like to show that Zhu Xi's interpretation of the 24th Hexagram of $F{\hat{u}}$[復卦] fully explains the fact that "thoughtless[思慮未萌] but being not dark to perception[知覺不昧]" explain the theory of no mind yet[未發說]. Zhu Xi's 'the theory of no mind yet[未發說]' is divided into two periods, a period of 'old theory on $zh{\bar{o}}ngh{\acute{e}}$[中和舊說]' and a period of 'new theory on $zh{\bar{o}}ngh{\acute{e}}$[中和新說]'. He develops 'the theory of no mind yet[未發說]' on the basis of 'the theory that nature is body and mind is action[性體心用說]' during the period of old theory, and develops the theory[未發說] based on 'the theory that mind controls nature and feelings[心統性情說]' during the new theory. Between the two periods, the status of the mind changes from "the mind has already happened[已發]" to "through which the mind has not yet arisen and the mind has already risen[未發已發]". And its role also changes from 'what nature is happened' to 'presiding on nature and emotion.' This change affects the interpretation of the idea that the mind has not yet happened, that thoughts have not budged yet[思慮未萌], perception is not dark[知覺不昧].

• (The)Study of the Eastern Classic
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• no.33
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• pp.385-411
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• 2008

This thesis aims at examining his understandings about the The Great Learning centering on the of the founder of the YiYongHuSaeng School (利用厚生學派: A school who pursued prosperous economy and welfare of people) orthe BukHak School(北學派: A positive school that pursued mercantilism) from the Joseon Dynasty, Dam-Heon Hong Dae Yong (1731-1783). 1) From what is indicated in the , his studies mainly focused on the annotations from DaeHakJangGuDaeJeonJipJu ("大學章句大全集註": A book that edited different phrases from the Great Learning into chapters and paragraphs), Questioning of the Great Learning", and "JuJaUhRyu (朱子語類: A book of Confucian literature written by Yeo Jung Deok" of Zhu Xi who was a representative scholar of the Neo-Confucianism in the Song Dynasty. 2) Acknowledging entirely the arguing points of Zhu Xi, he is taking a critical position in a way that partial doubts are divided into seven chapters and questioned. 3) For the main characteristic and direction of the questioning, he is estimating that Zhu Xi only stressed the 'means' and 'interior' out of the world of 'means and ends' and 'interior and exterior' in Zhu Xi's recognizing and handling cases; instead, he emphasized putting equivalent value on the 'ends' and 'exterior' as well. 4) In fact, such questions raised partially were misconceived since they were not carried out through profound understanding nor systematic logic expansion of what Zhu Xi insisted. 5) Despite this, at the point where Neo-Confucian thoughts were fixed and weakened only with its form left in the late Joseon Dynasty, his perspective on the study of Confucian classics that the 'ends' and 'exterior' should be as equally valued as the 'means' and 'interior' by examining through the core text of the Neo-Confucianism, The Great Learning has its significance in his YiYongHuSaeng dogma that says politicians, by all means, should provide the ruled with economic convenience and welfare and this is their very right virtue.

• Steel and Composite Structures
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• v.43 no.1
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• pp.55-66
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• 2022

To develop high-efficiency lateral force resistance components for high-rise buildings, a novel energy dissipation shear wall with concrete-filled steel tubular (CFST) column elements was proposed. An energy dissipation shear wall specimen with CFST column elements (GZSW) and an ordinary reinforced concrete shear wall (SW) were constructed, and experimented by low-cycle reversed loading. The mechanical characteristics of these two specimens, including the bearing capacity, ductility, energy dissipation, and stiffness degradation process, were analyzed. The finite-element model of the GZSW was established by ABAQUS. Based on this finite-element model, the effect of the placement of steel-plate energy dissipation connectors on the seismic performance of the shear wall was analyzed, and optimization was performed. The experiment results prove that, the GZSW exhibited a superior seismic performance in terms of bearing capacity, ductility, energy dissipation, and stiffness degradation, in comparison with the SW. The results calculated by the ABAQUS finite-elements model of GZSW corresponded well with the results of experiment, and it proved the rationality of the established finite-elements model. In addition, the optimal placement of the steel-plate energy dissipation connectors was obtained by ABAQUS.

• (The)Study of the Eastern Classic
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• no.37
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• pp.249-278
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• 2009

Zhu-zi(朱子) represented the study of The Book of Odes in Song dynasty and Dai-zhen(戴震) was The Book of Odes researcher representing Wan-pai(a kind of party) in Qing dynasty. Especially Dai-zhen took critical position of Zhu-xi. Comparing Zhu-zi with Dai-zhen in the aspect of The Book of Odes interpretation, this thesis intends to review the difference and the reason of both interpretations. Especially this thesis compares Zhu-zi's interpretation with Dai-zhen's about thirty poems Zhu-zi considered filthy poetry, investigating the differences of their interpretation. Regarding the poetry Zhu-zi considered filthy as refined satire, Dai-zhen had a negative position about Zhu-zi's theory of filthy poetry. As Zhu-zi interpreted the poetry in the first person on the literary view in the time when he interpreted the lyrics in the Feng-shi, he regarded the purpose and the usefulness of poetry as feeling of words. But as Dai-zhen interpreted the poetry in the third person under a Confucian classic view, he regarded the purpose and the usefulness of poetry as refined satire. In brief, that is to say that Zhu-zi made literary interpretations of feeling of words but Dai-zhen made Confucian classic interpretations of 'Si-wu-xie'(思無邪). These two men's differences about interpretation of The Book of Odes have much importance on the historical aspects of The Book of Odes. So to speak, Dai-zhen had bibliographical approach and described the meaning of poetry objectively, following Mao-shi(毛詩) theory about the interpretation of meaning of poetry, criticizing Zhu-zi's literarary view. Dai-zhen's interpretation of The Book of Odes mentioned Above was made from long vital power of Mao-shi theory and a Confucian classic method. Considering the historical stream of Zhu-zi and Dai-zhen's interpreting The Book of Odes, The Book of Odes will be interpreted and analyzed from the various views in the future.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1513-1525
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• 2016

Rapid and accurate phase synchronization is critical for the reliable control of grid-tied inverters. However, the commonly used software phase-locked loop methods do not always satisfy the need for high-speed and accurate phase synchronization under severe grid imbalance conditions. To address this problem, this study develops a novel open-loop phase locking scheme based on a synchronous reference frame. The proposed scheme is characterized by remarkable response speed, high accuracy, and easy implementation. It comprises three functional cascaded blocks: fast orthogonal signal generation block, fast fundamental-frequency positive sequence component construction block, and fast phase calculation block. The developed virtual orthogonal signal generation method in the first block, which is characterized by noise immunity and high accuracy, can effectively avoid approximation errors and noise amplification in a wide range of sampling frequencies. In the second block, which is the foundation for achieving fast phase synchronization within 3 ms, the fundamental-frequency positive sequence components of unsymmetrical grid voltages can be achieved with the developed orthogonal signal construction strategy and the symmetrical component method. The real-time grid phase can be consequently obtained in the third block, which is free from self-tuning closed-loop control and thus improves the dynamic performance of the proposed scheme. The proposed scheme is adaptive to severe unsymmetrical grid voltages with sudden changes in magnitude, phase, and/or frequency. Moreover, this scheme is able to eliminate phase errors induced by harmonics and random noise. The validity and utility of the proposed scheme are verified by the experimental results.