• Journal of Power Electronics
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• v.11 no.5
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• pp.713-718
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• 2011

This paper presents an online voltage disturbance estimator to achieve precise torque control of IPMSMs over a high speed operating region. The proposed design has a type of state-filter based on a Luenburger-style closed loop stator current vector observer. Utilizing the frequency response plot (FRF) approach, the estimation accuracy and the parameter sensitivities are analyzed. Accurate torque control and improved efficiency are provided with the decoupling of the effect of the parameter variations. The feasibility of the presented idea is verified by laboratory experiments.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.201-204
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• 2001

In this paper, a single-phase to three-phase PWM converter topology using six switches only for low cost induction motor drive is proposed. The converter topology is of lower cost than the conventional one, which gives sinusoidal input current, unity power factor, dc output voltage control and bidirectional power flow In addition, the source voltage sensor is eliminated by controlling the deviation between the model current and the system current to be zero. The performance of the proposed converter has been demonstrated through the computer simulation.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.223-226
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• 2001

In this paper, dc link ripple currents for three-phase ac/dc/ac PWM converters are analyzed in a frequency domain. The expression of the harmonic currents is developed by using switching functions and exponential Fourier series expansion. The dc link ripple currents with regard to power factor and modulation index are investigated. In addition, the effect of the displacement angle between the switching periods of line-side converters and load-side inverters on the do link ripple current is studied. The result of the do link current analysis is helpful in specifying the dc link capacitor size and its life time estimation.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.125-128
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• 2002

In this paper, a novel on-line do capacitance estimation method for the PWM converter is proposed. At no load, Input current at a low frequency is injected, which causes do voltage ripple. With the ac voltage and current ripple components of the dc side, the capacitance can be calculated. Experimental result shows that the estimation error is less than $2\%$.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.175-177
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• 1994

In the overmodulation region, the operation of the three phase induction motor with a current controller is characterized by a rapid deterioration of the motor torque and speed. It is desirable to use the overmodulation strategy that extends the normal operating range even in this case. In this paper, a new overmodulation strategy is proposed for the high performance motor drives and the comparison study with two conventional methods are also described. In the proposed strategy, considering the motor dynamics, a suitable voltage vector is selected in order to extend the stable operating range in the overmodulation region. With this advanced overmodulation algorithm, the normal operating range can be extended without any extra hardware.

• Journal of the Korean Society of Food Culture
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• v.3 no.2
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• pp.143-151
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• 1988

'On Zu Bub,' written in Korean, is the anonymous old cook book. The kinds of cooking food recorded-Wine 44, Nu Ruk 2, Sauce 2, dessert 6, side dish 2 etc.-are fifty-six items in all. Especially it was written mirutely about brewage. The wines such as Sub Wang Mo You Bok Gyung Hyang Zu, Gu Ga Zu, Sin Bang Zu, Bang Se Hyang Zu, Zuhk Sun So Zu, Gye Dang Zu, Sa Mi Zu, Gwa Ha Jul Mi Zu were not found in other old cook books, 'Eum Sik Di Mi Bang' and 'Zu Bang Moon' and the contents about Gu Gi Za Zu was guoted from Zi Bung You Suhl. The seasonings used were black pepper, ginger, Chun Cho, Cinnamon, Sugar, ect, but red pepper was not used. But, we can find 'Bingsagua' from this book. First 'Bingsagua' has been found in 1789. 'On zu Bub' is guessed developed in late 1700's.

• Journal of Power Electronics
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• v.18 no.6
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• pp.1634-1641
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• 2018

This study focuses on a high-performance direct active and reactive power controller design that is successfully applicable to three-phase pulse width modulation (PWM) AC/DC converters used in renewable distributed energy generation systems. The proposed controller can overcome the sluggish transient dynamic response of conventional controllers to rapid power command changes. Desired active and reactive powers can be thoroughly obtained at the end of each PWM period through a deadbeat solution. The proposed controller achieves an exact nonlinear cross-coupling decoupling of system power without using a predefined switching table or bang/bang hysteresis control. A graphical and analytical analysis that naturally leads to a control voltage vector selection is provided to confirm the finding. The proposed control strategy is evaluated on a 3 kW PWM AC/DC converter in the simulation and experiment.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.284-295
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• 2018

The safe and late marginal heading dates (SMHD, LMHD), cropping probability, and growth duration of rice were assessed using temperature data in the 27 regions of North Korea. The medians of SMHD and LMHD ranged Jul. 16 and Jul. 27 in Hyesan to Aug. 18 and Aug. 28 in Haeju, respectively, except Changjin, Pungsan, and Samjiyon that did not show any of the SMHD and LMHD. The medians of the days from early marginal transplanting date (EMTD) to heading date ranged 51 days in Hyesan to 109 days in Pyongyang for SMHD and those were delayed by 9~15 days for LMHD, compared to SMHD. Nineteen regions (Kaesong, Haeju, Yongyon, Singye, Sariwon, Nampo, Pyongyang, Anju, Kusong, Sinuiju, Changjon, Wonsan, Hamhung, Pyonggang, Yangdok, Huichon, Supung, Sinpo, Kanggye) and additional four regions (Kimchaek, Chongjin, Sonbong, Chunggang) had the rice cropping probability higher than 80% when analyzed based on the SMHD and LMHD, respectively. The representative SMHD ranged Jul. 24 for Pyonggang to Aug. 12 for Haeju. Compared to the days from EMTD to SMHD, those from EMTD to LMHD were delayed by 9~17 days. When applied SMHD, thirteen regions (Yangdok, Kanggye, Huichon, Supung, Yongyon, Kusong, Anju, Sinuiju, Singye, Pyongyang, Kaesong, Nampo, Sariwon) had the appropriate range of cumulative temperature during grain filling (CT) for grain yield and quality. Sinpo, Hamhung, Pyonggang, Wonsan, Changjon, and Haeju had the CT higher than $1,300^{\circ}C$. It is supposed that rice cropping could be extended to the regions where LMHD-applied cropping probability was higher than 80%. Delaying the heading date than SMHD could be also considered in the regions where the days to SMHD is small but CT is large.

• (The)Study of the Eastern Classic
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• no.57
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• pp.383-406
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• 2014

Mi-Am Yu Hee Choon (1513~1577) considered poetry as a part of his life. Therefore, this writer specifically focused on Mi-Am Yu Hee Choon's Chinese poems. The following is the conclusion from the materials discussed in this article. Mi-Am tried to understand literature in ethical perspective. The number of Chinese poems composed by Mi-Am is estimated to be about 300, and the number of pieces that this writer could find was 285. Also, Mi-Am took poem composition seriously, and put emphasis on content more than structure. Among Go Shi, Yul Shi, and Jul gu, Jul gu (especially Chil Un) is the largest in quantity, and it is presumed that he preferred Chil(seven) Un over Oh(five) Un. With regards to Go Shi, there are relatively many Jeon-Go. With regards to Jul gu, which was a poetry composing structure that Mi-Am could make the best use of, they were mostly about the daily lives. And with regards to Yul Shi, there were many poems that expressed his feelings about the real world and self-examination. Mi-Am's poems can be categorized into ones that he wrote when he was on exile, and ones that he wrote while serving for the king again after he got released from exile. During the exile period, self-discipline through learning, friendship, and love for the people were the main themes of his poems, and after being released and started serving for the king again, his poems were mostly about loyalty to the king, interaction with acquaintances, emotions, ancestor worship, self-examination, and conjugal affection through literary communion. Among Mi-Am's poems, there are many that have Eum Song Cha Un included in their titles, and the mainstream of his poems were related to daily lives or experiences. Also, most of them naturally and calmly expressed the fact itself without exaggerating. Mi-Am considered poetry as a part of his life and the fact that he practiced literary communion with his wife by writing poems about the ordinary things happened between him and his wife, Song Duk Bong, is worthy of notice.

• 보존과학연구
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• s.5
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• pp.148-166
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• 1984

The Investigation of organisms damaged to papers and cellulose materials of Cultural Property in the Ch'ang Dok Palace The investigation of the airborne fungi, the attached fungi to the papers and cellulose materials of Cultural Properties in addition to the insects inhabiting at the Ku Sonwon Jon, Shin Sonwon Jon and Yonwa ch'anggo in the Ch'ang Dok Palace carried out from Jul. 10 to Jul. 21,1984.The results are summarized as follows ;1. Isolation and identification of the airborne fungi from the three storages were Cladosporium sp., Alternaria alternata, As pergillus cervinus, A. flavus, A. nidulance, A. oryzae, A. terreus, A. versicolor, A. wentii, Penicillium adametzii, P.albicans, P.canescens, P. citreo-viride, P. citrinums, P. decumbens, P. frequentans, P. funiculosum, P.herquei, P.implicatum, P.multicolor, P.nigricans, P.nonatum,P.purpurogenum, P.roqueforti, P.viridicatum, Trichodema viride, Geotrichumcandidum, Curvvlaria lunata, Torula hebarum, T.thermophila, Itersoniliasalmonicolor, Drechsclera avenue, Candida sp., Acremonium sp., and Botrytis sp., It was found that thirty five species in thirteen genera was isolated. Among them, the dominant species was Cladosporium sp., and the order was Penicillium, Aspergillus, Alternaria and so on.2. The attached fungi directly isolated from the papers and cellulose materials of Cultural Properties were twenty-nine species in fourteen genera, namely, Acremonium sp., Albertiniella sp., Alternaria alternata, Aspergillus clavatus,A.niger, A.ornatus, A.versicolor, Botrytis sp., Bysochlamys sp., Carpenteles sp.,Chaetomium globosum, Cladosporium sp., Eurotium sp., Mucor sp., Penicilliumcanescens, P.chermesium, P.citrinum, P.frequentans, P.funiculosum, P.herqueiP .implicatum, P.javanicum, P.luteum, P.purpurogenum, P.thomii, P.viridicatum, Torula thermophila, Trichoderma koningi and T.viride. Among them, the mostfungi distributed on the surface of the papers and cellulose materials was Penicillium and the order was Aspergillus, Alternaria, Cladosporium, Trichodermaand so on.3. The insects collected the three storages were ten genera and ten species including 916 specimens. By classifying the insects collected, the most species of the insects was Stenoscelodes hayashii of 857 specimens occupied about 93% of the total insect. And the other insects were collected as Microgamme costipennisAnobium pertinax, Xenomimetes alni, Anthrenus verbasci, Holoparmecus signatus,Thermobia domestica, Halyomorpha brevis, Drosophila coracine and Brattaorientalis. As described above, it could be known that the most airborne fungi was Cladosporium and the order was Penicillium, Aspergillus, Alternaria in the three storages. And the most attached fungi distributed on the surface of papers and cellulose materials was Penicillium and the other fungi were Aspergillus, Alternaria Cladosporium, Trichoderma and so on. Accordingly, from the results, itwas assumed that the major part of airborne fungi were attached to the papers and cellulose materials of Cultural Properties. The paper and cellulose materials of Cultural Properties in Ch'ang Dok Palace were chiefly damaged by S.hayashii in Coleoptera.