• 한국음향학회지
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• 제33권6호
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• pp.375-382
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• 2014

많은 실제 능동 소음 제어 분야에서 주요 소음은 다수의 인접한 배음으로 구성된다. 또한 협대역 능동 소음 제어 시스템은 정현파 세트나 혹은 합으로 구성된 기준 신호에 의해 동작하는 적응 필터들로 구성된다. 본 논문은 직접형, 병렬 형, 간소화한 병렬 형의 능동 소음 제어 시스템이 기본 주파수와 인접한 정현파의 주파수 간격에 영향을 받음을 보여주고 이를 분석한다. 또한 본 논문은 기준 주파수에 독립적인 새로운 간소화한 병렬 형 협대역 능동 소음 제어 시스템을 제안한다. 본 논문에서의 제시한 분석을 증명하고 새로운 협대역 능동 소음 제어 시스템을 기존 협대역 능동 소음 제어 시스템과 비교하기 위해 컴퓨터 시뮬레이션을 수행한다.

• 한국통신학회논문지
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• 제29권5A호
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• pp.574-582
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• 2004

본 논문에서는 패킷 데이터 서비스를 지원하는 DS/CDMA 시스템에서 역방향 링크의 대기 패킷 버스트들이 겪는 평균 전송 시간을 최소화하기 위한 여러 가지 패킷 스캐줄링 방식을 비교 분석하였다. 모든 활성화된 데이터 사용자들이 동시에 전송을 하는 경우의 최적의 스케줄링 방식에 대하여 논하고 기존의 여러 가지 다른 전송률 스케줄링 방식들과의 수학적인 비교 분석을 통하여 평균 전송 지연을 고려한 전송률 스케줄링 방식의 효율적인 지표를 제시하였다.

• 약학회지
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• 제48권1호
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• pp.55-59
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• 2004

A PVA-soft hydrogel, which is a semi-solid form in container, whereas after applying on the skin, it formed a thin layer within a few minutes. In this study, we prepared a novel type PVA-soft hydrogel containing 6-methyluracil as active drug, and the therapeutic value was characterized. To evaluate the therapeutic value of the PVA-soft hydrogel containing drug, various animal models, thermal burn model, incision & excision wound rat model were used. We also measured the wound size and breaking strength to calculate the wound healing extent after single or multiple administration. The wound size of soft hydrogel treated group decreased rapidly than that of control group after multiple dosing in excision wound model. And, the breaking strength of the soft hydrogel treated group was greater than that of control group in incision wound model.

• Journal of Power Electronics
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• 제12권6호
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• pp.1003-1010
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• 2012

Recent power electronics and variable-frequency motor drive technologies have been applied to air conditioners to improve efficiency and power density. However, the mechanical vibrations and acoustic noise resulting from the compressor still remain as a serious problem. This paper presents the development and implementation of an online disturbance state-filter for the suppression of multiple unknown and time-varying vibrations of air conditioning systems. The proposed design has a form of the state-filter based on a Luenburger-style closed-loop speed observer. An active vibration decoupling strategy with an estimated disturbance is provided, which manipulates a motor torque command. Since the proposed estimation does not require any additional transducers or hardware for obtaining real-time information upon disturbances, it is suitable for retrofitting industrial air conditioners.

• 한국통신학회논문지
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• 제40권6호
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• pp.997-1004
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• 2015

이 논문에서는 MISO 하향 능동 안테나 시스템에서 수직 분할 기법을 연구하였다. 능동 안테나 시스템에서는 각 섹터에서 안테나 빔 패턴을 조절 가능 할 뿐만 아니라 복수의 수직 안테나 빔을 통해 수직 섹터분할도 가능하다. 수직 섹터 분할을 위한 최적 빔 기울기를 구하기 위해 기존의 전역 탐색 기법은 매우 높은 계산 복잡도를 요구하기 때문에 이 논문에서는 이러한 계산 복잡도를 낮추기 위해 두 가지 알고리즘을 제안하였다. 먼저 불규칙 행렬이론에서의 광범위 시스템 근사치를 이용하여 근사 전송률 합에 기반을 둔 알고리즘을 제안하였다. 또한, 기존의 하나의 섹터 전송 기법에서의 결과를 이용한 폐쇄 형태 표현을 가진 알고리즘도 제안하였다. 실험결과를 통해 제안된 알고리즘들이 기존의 전역 탐색 알고리즘에 비해 복잡도를 매우 감소시킴에도 불구하고 거의 비슷한 성능을 가짐을 확인하였다.

• Journal of Genetic Medicine
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• 제19권1호
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• pp.27-31
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• 2022

X-linked dominant hypophosphatemic rickets are the most common form of familial hypophosphatemic rickets resulting from hypophosphatemia caused by renal phosphate wasting, which in turn is a result of loss-of-function mutations in PHEX. Herein, we report a 39-year-old female with short stature and skeletal deformities and 12-month-old asymptomatic daughter. The female has a history of multiple surgical treatments because of lower limb deformities. Her biochemical findings revealed low serum phosphorus levels with elevated serum alkaline phosphatase activity and normal serum calcium levels, suggesting presence of hypophosphatemic rickets. To identify the molecular causes, we used a multigene testing panel and found a mutation, c.667dup (p.Asp223GlyfsTer15), in PHEX gene. To the best of our knowledge, this is a novel mutation. A heterozygous form of the same variant was detected in daughter, who showed no typical symptoms such as bow legs, frontal bossing, or waddling gate, but presented early signs of impaired mineralization in both X-ray and biochemical findings. The daughter was initiated onto early medical treatment with oral phosphate supplementation and an active vitamin D analog. Because the daughter was genetically diagnosed based on a family history before the onset of symptoms, appropriate medical management was possible from early infancy.

• Journal of information and communication convergence engineering
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• 제14권3호
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• pp.171-176
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• 2016

In this study, we investigate the physical layer secrecy performance of RF energy harvesting (EH) networks over Rayleigh fading channels. The RF-EH system considered here consists of one power transfer station, one source, one destination, and multiple passive eavesdroppers. The source harvests energy from the power transfer station and transmits the information to the destination by using a time switching-based relaying protocol. The eavesdroppers try to extract the transmitted information without an active attack. By using the statistical characteristics of the signal-to-noise ratio (SNR), the exact closed-form expressions of the existence probability of the secrecy capacity and the secrecy outage probability are derived. Further, we analyze the secrecy performance of the system with respect to various system parameters, such as the location of the system elements and the number of eavesdroppers. Finally, the equivalent Monte Carlo simulation results are provided to confirm the correctness of our calculations.

• Journal of Plant Biotechnology
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• 제37권1호
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• pp.57-66
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• 2010

Programmed cell death systems are important for an active type of cell deaths. Among them, a type of programmed cell death, autophagy is activated in cancer cells in response to multiple stresses and has been demonstrated to promote tumor cell survival and drug resistance. Thus, in the area of cancer, over the time frame form around the 1940s to date, of the 155 small molecules, 73% are other than "synthetic", with 47% actually being either "natural products" or "directly derived therefrom". Autophagy has multiple physiological functions in multicellular organisms, including protein degradation and organelle turnover. Genes and proteins that constitute the basic machinery of the autophagic process were first identified in the yeast system and some of their mammalian orthologues have been characterized as well. Numerous oncogenes, including Akt1, Bcl-2, NF1, PDPK1, class I PI3K, PTEN, and Ras and oncosuppressors, inculuding Bec-1, Bif-1, DAPK-1, p53 and UVRAG suppress or promote the autophagy pathway. Regulation of autophagy in tumors is governed by similar principles of the normal cells, only in a much more complicated manner, given the frequently observed abnormal PI3K activation in cancer and the multitude of interactions between the PI3K/AKT/mTOR pathway and other cell signaling cascades, often also deregulated in tumor cells. Autophagy induction by some anticancer agents underlines the potential utility of its induction as a new cancer treatment modality of development for natural medicines.

• 전자공학회논문지D
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• 제35D권8호
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• pp.24-30
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• 1998

A blue LED of $In_{x}Ga_{1-x}N$ multiple quantum well structure which had the blue emission spectrum of donor-acceptor pair transition generated form Si-Zn co-doped $In_{x}Ga_{1-x}N$ active layer, was fabricated. The $In_{x}Ga_{1-x}N$ MQW heterojunction LED structure was grown by MOCVD on the sapphire substrate with (0001) surface orientation at 800.deg. C. The fabricated LED exhibited forward cut-in voltage of 4~4.5V and reverse breakdown voltage of -13V. Its optical chracteristics showed that the center wavelength of peak emission occurred at 460nm and the optical intensity was increased linearly with respect to the injected electrical current above 5mA.

• 전기학회논문지
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• 제58권3호
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• pp.523-530
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• 2009

This paper presents a study on a small scale single-phase UPFC preliminary researches on power quality compensating schemes of electrical railway. As the UPFC is very complicated power-electronic system consisting of grid-connected transformers, four single phase inverters interconnected with dc-link capacitors and various electrical apparatuses, multiple controllers and control algorithms are needed, and entire UPFC has been modelled in the form of block diagrams and simulated by using Simulink. The main purpose of the compensating system is to manage reactive and active powers with the four single phase inverters, so, the control effort has been focused on the power flow control and has been realized through the hysteresis current control of the single phase inverters. And transport-delayed PLL with additional delay-time compensating term has been used to synchronize a grid voltage and the simulation results have shown that the compensating term could improve PLL performance under some frequency variation of the voltage.