• 한국발생생물학회지:발생과생식
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• 제17권3호
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• pp.215-220
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• 2013

Recently, the RNA/DNA-binding protein FUS, Fused in sarcoma, was shown to play a role in growth, differentiation, and morphogenesis in vertebrates. Because little is known about Fus, we investigated its expression pattern in murine tooth development. In situ hybridization of mouse mandibles at specific developmental stages was performed with a DIG-labeled RNA probe. During early tooth development, Fus was detected in the dental epithelium and dental mesenchyme at 11 days postcoitum (dpc) and 12 dpc. From 14 dpc, Fus was strongly expressed in the dental papilla and the cervical loop of the dental epithelium. At postnatal day 4 (PN4), Fus expression was observed in the odontoblasts, ameloblasts, the proliferation zone of the pulp, and the cervical loop. At PN14, the expression pattern of Fus was found to be maintained in the odontoblasts and the proliferation zone of the pulp. Furthermore, Fus expression was especially strong in the Hertwig's epithelial root sheath (HERS). Therefore, this study suggests that Fus may play a role in the HERS during root development.

• Journal of Power Electronics
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• 제16권3호
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• pp.1056-1066
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• 2016

Wireless power transfer (WPT) technology is now recognized as an efficient means of transferring power without physical contact. However, frequency detuning will greatly reduce the transmission power and efficiency of a WPT system. To overcome the difficulties associated with the traditional frequency-tracking methods, this paper proposes a Direct Phase Control (DPC) approach, based on the Second-Order Generalized Integrator Phase-Locked Loop (SOGI-PLL), to provide accurate frequency-tracking for WPT systems. The DPC determines the phase difference between the output voltage and current of the inverter in WPT systems, and the SOGI-PLL provides the phase of the resonant current for dynamically adjusting the output voltage frequency of the inverter. Further, the stability of this control method is analyzed using the linear system theory. The performance of the proposed frequency-tracking method is investigated under various operating conditions. Simulation and experimental results convincingly demonstrate that the proposed technique will track the quasi-resonant frequency automatically, and that the ZVS operation can be achieved.

• 디지털콘텐츠
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• 3호통권22호
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• pp.85-96
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• 1995

• Molecules and Cells
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• 제25권3호
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• pp.358-367
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• 2008

The embryonic germ cell (EGCs) of mice is a kind of pluripotent stem cell that can be generated from pre- and post-migratory primordial germ cells (PGCs). Most previous studies on DNA methylation of EGCs were restricted to 12.5 days post coitum (dpc). This study was designed to establish and characterize murine EGC lines from migrated PGCs as late as 13.5 dpc and to estimate the degrees of methylation of their imprinted genes as well as of the non-imprinted locus, Oct4, using an accurate and quantitative method of measurement. We established five independent EGC lines from post migratory PGCs of 11.5-13.5 dpc from C57BL/6 ${\times}$ DBA/2 F1 hybrid mouse fetuses. All the EGCs exhibited the typical features of pluripotent cells including hypomethylation of the Oct4 regulatory region. We examined the methylation status of three imprinted genes; Igf2, Igf2r and H19 in the five EGC lines using bisulfite genomic sequencing analysis. Igf2r was almost unmethylated in all the EGC lines irrespective of the their sex and stage of isolation; Igf2 and H19 were more methylated than Igf2r, especially in male EGCs. Moreover, EGCs derived at 13.5 dpc exhibited higher levels of DNA methylation than those from earlier stages. These results suggest that in vitro derived EGCs acquire different epigenotypes from their parental in vivo migratory PGCs, and that sex-specific de novo methylation occurs in the Igf2 and H19 genes of EGCs.

• Journal of Power Electronics
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• 제9권5호
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• pp.781-790
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• 2009

This paper presents an implementation of a direct active and reactive power control for a doubly fed induction generator (DFIG), which is applied to a wind generation system as an alternative to the classical field-oriented control (FOC). The FOC has a complex control structure that consists of a current controller, a power controller and frame transformations. The performance of the FOC depends highly on parameter variations of the rotor and stator resistances and the inductances. The proposed direct power control (DPC) method produces a fast and robust power response without the need of complex structure and algorithms. One drawback, however, is its high power ripple during a steady state. In this paper, active and reactive power controllers and space-vector modulation (SVM) are combined to replace hysteresis controllers used in the original DPC drive, resulting in a fixed switching frequency of the power converter. Simulation results with the FOC and DPC for a 3kW DFIG are given and discussed, and the experimental results of a test involving identical machines are presented to illustrate the feasibility of the proposed control strategy.

• Journal of electromagnetic engineering and science
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• 제9권3호
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• pp.124-129
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• 2009

Although the maximum sum-rate capacity of multiple-input multiple output(MIMO) broadcast channels(BCs) can be achieved by dirty-paper coding(DPC), the results were obtained without fairness considerations in uncorrelated MIMO channels. In this paper, we propose new multiuser scheduling algorithms, which find a best user set for approaching the maximum sum-rate capacity while maintaining fairness among users. We analyze the performance of the proposed algorithms using zero-forcing dirty paper coding(ZF-DPC) in the correlated MIMO BCs for throughput and delay fairness, respectively. Numerical results demonstrate that a large time window can reduce the average throughput difference between users, but it increases head-of-line(HOL) delay jitters in the case of delay fairness.

• 대기
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• 제27권4호
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• pp.483-498
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• 2017

Sky view factor can quantify the influence of complex obstructions. This study aims to evaluate the best available SVF method that represents an urban thermal condition with land cover in complex city of Korea and also to quantify a correlation between SVF and mean air temperature; the results are as follows. First, three SVF methods comparison result shows that urban thermal study should consider forest canopy induced effects because the forest canopy test (on/off) on SVF reveals significant difference range (0.8, between maximum value and minimum value) in comparison with the range (0.1~0.3) of SVFs (Fisheye, SOLWEIG and 3DPC) difference. The significance is bigger as a forest cover proportion become larger. Second, R-square between SVF methods and urban local mean air temperature seems more reliable at night than a day. And as the value of SVF increased, it showed a positive slope in summer day and a negative slope in winter night. In the SVF calculation method, Fisheye SVF, which is the observed value, is close to the 3DPC SVF, but the grid-based SWG SVF is higher in correlation with the temperature. However, both urban climate monitoring and model/analysis study need more development because of the different between SVF and mean air temperature correlation results in the summer night period, which imply other major factors such as cooling air by the forest canopy, warming air by anthropogenic heat emitted from fuel oil combustion and so forth.

• 디지털콘텐츠
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• 2호통권45호
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• pp.92-96
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• 1997

한국데이터베이스진흥센터는 지난 2월 3일 제6회 정기 이사회를 개최하고 97년도 사업방향 및 96년도 사업 실적에 관한 전반적인 의결을 거쳤다. 이사회의 의결을 거쳐 올해 시행될 사업현황에 대해 간략히 살펴봤다.

• 디지털콘텐츠
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• 2호통권45호
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• pp.60-61
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• 1997

한국데이터베이스진흥센터는 데이터베이스 이용의 편의를 제공하기 위해 97년 3월 1일부터 인터넷 홈페이지(URL : http://www.dpc.or.kr)를 개설한다. 센터의 홈페이지는 센터 안내 정보, 데이터베이스 목록 정보, 데이터베이스 용어 정보로 구성되어 있다. 데이터베이스 용어 정보로 구성되어 있다.

• 한국응용과학기술학회지
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• 제33권4호
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• pp.615-626
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• 2016

약용매에 용해가 가능한 알킬기 변성 에폭시수지를 합성하기 위하여, 1단계에서 당량비 기준 dodecyl phenol (DP)/formaldehyde = 1.25~1.333/1.0로 하여, 합성된 도데실 페놀 노볼락 화합물의 벤젠 고리수가 3.0~5.0가 되도록 합성하였고, 2단계에서는 당량비 기준으로 1단계에서 합성된 도데실 페놀 노볼락 화합물/비스페놀A형 에폭시수지 (YD-128) = 1/2로 합성하였고, 3단계는 지방산을 투입하여 지방산 변성 도데실 페놀 노볼락 에폭시수지를 합성하였다. 합성된 수지의 반응성도, 점성도와 분자량 변화, 약용매 가용성 등을 측정한 결과, 1단계에서 합성된 도데실 페놀 노볼락 화합물의 벤젠고리수가 늘어남에 따라 지방산 변성 도데실 페놀 노볼락 에폭시수지의 점도가 상승하였고, 약용매 가용성이 우수하였다. 도료 제조 후 물성을 측정한 결과, 개환촉매로 triphenylphosphine(TPP)을 사용한 DPFAC-5는 건조속도, 접착성, 도막경도, 내충격성, 내산성 및 저장안정성이 양호하였다.