• Parasites, Hosts and Diseases
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• v.54 no.4
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• pp.407-414
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• 2016

Malaria remains a serious public health problem in Shandong Province, China; therefore, it is important to explore the characteristics of the current malaria prevalence situation in the province. In this study, data of malaria cases reported in Shandong during 2012-2014 were analyzed, and Plasmodium species were confirmed by smear microscopy and nested-PCR. A total of 374 malaria cases were reported, 80.8% of which were reported from 6 prefectures. Of all cases, P. falciparum was dominant (81.3%), followed by P. vivax (11.8%); P. ovale and P. malariae together accounted for 6.4% of cases. Notably, for the first time since 2012, no indigenous case had been reported in Shandong Province, a situation that continued through 2014. Total 95.2% of cases were imported from Africa. The ratio of male/female was 92.5:1, and 96.8% of cases occurred in people 20-54 years of age. Farmers or laborers represented 77.5% of cases. No significant trends of monthly pattern were found in the reported cases. All patients were in good condition after treatment, except for 3 who died. These results indicate that imported malaria has increased significantly since 2012 in Shandong Province, especially for P. falciparum, and there is an emergence of species diversity.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.11a
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• pp.298-299
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• 2004

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.11a
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• pp.185-188
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• 2008

영상의 화질을 평가하는 방법은 어떤 정보를 기준으로 평가하느냐에 따라서 전체 기준법 (Full Reference), 부분기준법 (Reduced Reference) 그리고 무기준법 (No Reference)으로 나눌 수 있다. 이중 무기준법은 수신 영상만을 가지고 측정하기 때문에, 다른 방법보다 활용범위가 넓다. 또한, 최근 사람의 눈의 특성을 고려한 인지적(Perceptual)화질평가 방법이 많이 논의되어, 사람이 실제 보고 느끼는 바를 객관화 시키는 방법이 개발되어 왔다. 이들 화질평가 방법들에 대해 많은 연구가 수행되고 있으며, 국제기구들을 통하여 이들 지표들에 대한 표준화가 진행되고 있다. 본 논문에서는 휘도, 색차의 분포도를 분석하여 원본의 화질을 예측하는 방법을 통해서, 기존 무기준법의 정확도를 높이고자 한다. 영상신호의 양자화나 부호화로 인해 임계값을 벗어나는 값들이 생기게 되며, 이 값을 휘도, 색차의 분포도 분석으로 예측하여 화질평가를 수행하게 된다. 실험 결과 제안된 방법의 상관도는 다른 방법보다 높은 것으로 나타났다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.183-186
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• 2009

인터넷의 발전과 비디오 압축 코덱의 발전으로 인해 실시간 영상 스트리밍 (Streaming) 서비스가 가능해졌다. 하지만, 패킷 손실로 인한 비디오 화질 열화는 여전히 문제가 되고 있다. 이 때문에 부호화기 에서는 에러에 강한 내성을 가지는 부호화방법으로 압축하며, 복호화기 에서는 에러 은닉기법을 통하여 패킷 손실에 의한 화질열화를 최소화한다. 이런 기법들을 활용하기 위해서는 패킷손실을 보정한 정확한 화질 열화를 측정 할 수 있는 방법이 필요하다. 영상의 화질을 평가하는 방법은 어떤 정보를 기준으로 평가하느냐에 따라서 전체 기준법 (Full Reference), 부분기준법 (Reduced Reference) 그리고 무기준법 (No Reference)으로 나눌 수 있다. 이중에서 무기준법은 수신 영상만을 가지고 측정하기 때문에, 다른 방법보다 활용범위가 넓다. 본 논문에서는 패킷 비디오 네트워크 환경에서의 발생할 수 있는 다양한 패턴의 패킷 손실에 따른 비디오의 화질 열화를 무기준법에 의해 측정하는 방법을 제안한다. 제안한 방법은 수신된 영상의 움직임 정보를 이용하여 패킷 손실에 따른 각 프레임당 초기 에러 값을 예측 한다. 실험 결과를 통하여 제안한 방법이 상당히 높은 피어슨 상관도 (Pearson Correlation)를 보여준다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.5
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• pp.249-257
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• 2002

In this paper, a novel control scheme compensating source voltage unbalance and harmonic currents for the combined system of series active and shunt passive power filter is proposed, where no low/high-pass filters are used in deriving the reference voltage for compensation. The phase angle and the reference voltages compensating for harmonic current and unbalanced voltage are derived from the positive sequence component of the unbalanced voltage set, which is simply obtained by using digital all-pass filters. In order to remove the phase delay in generating the reference voltage for compensation, the reference of 5th and 7th harmonic components is predicted one-sampling ahead. The validity of the proposed scheme has been verified for 3[kVA] proto-type active power filter system.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.398-403
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• 2003

Dynamic Voltage Restorers (DVR)s are known as the best effective and economic means to compensate for voltage sags and swells [1]-[11]. This paper proposes a novel method to generate reference voltages synchronized with the grid whether the line voltages are distorted by a fault or not. The proposed reference wave generator (RWC) looks for the original wave forms from the corrupted line voltages and synthesizes the expected positive sequence reference waves for DVRs. There is no transient problem on the generated reference waves when the line voltages are distorted by the fault.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.49-51
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• 2000

ln this paper, a method by which penalty factors of all generators including slack bus can be directly derived is presented. With a simple re-assignment of angle reference bus to a bus where no generation exists, penalty factors for slack bus is obtained without any physical assumption. While previous Jacobian-based techniques for generator penalty factor calculation have been derived with basis upon reference bus, proposed method are not dependent on reference bus and calculated penalty factors can be substituted directly into the general ELD equation to compute the economic dispatch. Equations for system loss sensitivity, penalty factors and optimal generation allocation are solved simultaneously in normal power flow computation.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.1
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• pp.1-5
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• 2001

In this paper, a new method for calculating the penalty factors of all generators including the slack bus is presented. A simple transposition of the angle reference, from the conventional slack bus to another bus where no generation exists, enables the derivation of the loss sensitivity of the slack bus. Penalty factors are obtained without any physical assumption through a simple substitution of the bus loss sensitivities. Penalty factors calculated by proposed method are not dependent on reference bus and can also be directly substituted into the general ELD equation for computing the optimal dispatch. Equations for loss sensitivities, Penalty factors and ELD are calculated simultaneously in normal power flow computation. A case study on a test system has proved the effectiveness of the proposed' angle reference transposition' method.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1069-1072
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• 1996

In modern control engineering, the model following system is a typical method. The model following system's performance is due to algorithm of control law, accuracy of modeling to the plant, and dynamics of the reference model. But the determination of the reference model depends on knowledge of an expert. Using an expert system, the determination method of the reference model was proposed in this paper. So, the reference model can be selected by user who has no Knowledge of dynamics and parameters.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.5
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• pp.255-265
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• 2013

3DTV is expected to be a promising next-generation broadcasting service. On the other hand, the visual discomfort/fatigue problems caused by viewing 3D videos have become an important issue. This paper proposes a perceptual quality assessment metric for a stereoscopic video (SV-PQAM). To model the SV-PQAM, this paper presents the following features: temporal variance, disparity variation in intra-frames, disparity variation in inter-frames and disparity distribution of frame boundary areas, which affect the human perception of depth and visual discomfort for stereoscopic views. The four features were combined into the SV-PQAM, which then becomes a no-reference stereoscopic video quality perception model, as an objective quality assessment metric. The proposed SV-PQAM does not require a depth map but instead uses the disparity information by a simple estimation. The model parameters were estimated based on linear regression from the mean score opinion values obtained from the subjective perception quality assessments. The experimental results showed that the proposed SV-PQAM exhibits high consistency with subjective perception quality assessment results in terms of the Pearson correlation coefficient value of 0.808, and the prediction performance exhibited good consistency with a zero outlier ratio value.