• Korean journal of applied entomology
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• v.44 no.1 s.138
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• pp.13-20
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• 2005

Thirty-four species of the subfamily Plusiinae were recognized from the lepidopteran expeditions to Mt. Changbai during 2000-2004. Among them, six species (Abrostola ussuriensis Dufay, Polychrysia aurata (Staudinger), P. splendida (Butler), Lamprotes mikadina (Butler), Autographa amurica (Staudinger), and A. v-minus (Oberthur)) are reported for the first time from China. Three previously reported species Antoculeora ornatissima (Walker), Autographa nigrisigna (Walker), and Syngrapha hochenwarthi (Hochenwarth) were not found in this study, Photographic images of adults of the newly known species from China and their male or female genitalia are given, with a check list of the 37 known species of the subfamily in Mt Changbai.

• Journal of Power Electronics
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• v.16 no.3
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• pp.1067-1075
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• 2016

This paper presents an adaptive observer-based approach to estimate voltage parameters, including frequency, amplitude, and phase angle, for single-phase power systems. In contrast to most existing estimation methods of grid voltage parameters, in this study, grid voltage is treated as a dynamic system related to an unknown grid frequency. Based on adaptive observer theory, a full-order adaptive observer is proposed to estimate voltage parameters. A Lyapunov function-based argument is employed to ensure that the proposed estimation method of voltage parameters has zero steady-state error, even when frequency varies or phase angle jumps significantly. Meanwhile, a reduced-order adaptive observer is designed as the simplified version of the proposed full-order observer. Compared with the frequency-adaptive virtual flux estimation, the proposed adaptive observers exhibit better dynamic response to track the actual grid voltage frequency, amplitude, and phase angle. Simulations and experiments have been conducted to validate the effectiveness of the proposed observers.

• ETRI Journal
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• v.38 no.5
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• pp.941-951
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• 2016

In this paper, cognitive radio and simultaneous wireless information and power transfer (SWIPT) are effectively combined to design a spectrum-efficient and energy-efficient transmission paradigm. Specifically, a novel SWIPT-based primary-secondary cooperation model is proposed to increase the transmission rate of energy/spectrum constrained users. In the proposed model, a multi-antenna secondary user conducts simultaneous energy harvesting and information forwarding by means of power splitting (PS), and tries to maximize its own transmission rate under the premise of successfully assisting the data delivery of the primary user. After the problem formulation, joint power splitting and beamforming optimization algorithms for decode-and-forward and amplify-and-forward modes are presented, in which we obtain the optimal PS factor and beamforming vectors using a golden search method and dual methods. Simulation results show that the proposed SWIPTbased primary-secondary cooperation schemes can obtain a much higher level of performance than that of non-SWIPT cooperation and non-cooperation schemes.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.193-195
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• 2015

The Palomar Transient Factory is a project making use of a Schmidt 48 inch telescope located on the Palomar Mountain, which is surveying the sky with dynamical cadences. It was deployed in 2009 and the observed sky region is over 1200 square degrees. We have studied the long-term periodic variabilities of the known galactic cataclysmic variables (CVs). More than 20 of the sources had been found to have long term periodic signals, ranging from several tens of days to several hundreds of days. Some possible scenarios are proposed to explain the results, such as a magnetic field change of the companion star, precession of the accretion disk, triple systems and superoutburst cycles. Some preliminary discussion will be presented in this article.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.587-589
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• 2015

We present the results from analysis of the Hilbert-Huang transform (HHT) for the 4 Hz quasi-periodic oscillations (QPO) around the black hole X-ray binary XTE J1550-564. The resultant Hilbert spectra demonstrate that the QPO is composed of a series of intermittent signals appearing occasionally. From the analysis of the HHT, we further found the distribution of the lifetimes for the intermittent oscillations and the distribution for the time intervals with no significant signal (the break time). The mean lifetime is 1.45 s and 90% of the oscillation segments have lifetimes less than 3.1 s whereas the mean break time is 0.42 s and 90% of break times are less than 0.73 s. We conclude that the intermittent feature of the QPO could be explained by the Lense-Thirring precession model and rules out interpretations of continual frequency modulation.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.07a
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• pp.151-154
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• 2015

본 논문에서는 스마트 기기를 이용하는 아이 엄마를 타겟층으로 정하고 분석하여 육아를 할 때 다양한 정보를 필요로 하는 초보엄마들을 위해서 실생활에서 사용할 수 있는 육아용 모바일 앱을 기획, 설계, 구현하였다. 초보엄마들을 위해 필요한 정보를 제공하며 아이의 이유식 정보를 등록할 수 있는 캘린더 기능과 아이에게 필요한 이유식 레시피를 제공할 뿐만 아니라, 가까운 병원과 편의시설의 위치서비스와 함께 병원의 정보까지 제공하였다. 또한 우리아이 발달사항을 그래프로 보여주면서 아이의 성장발달을 한 눈에 알아 볼 수 있게 하였다. 그리고 음악을 통해 육아로 지친 초보엄마들을 위해서 마음에 정서적 안정감과 편안함을 심어준다. 초보엄마들이 필요로 하는 기능들을 모아 편리성과 가용성을 극대화 하여 구현하였다.

• Journal of Communications and Networks
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• v.15 no.1
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• pp.54-60
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• 2013

In this paper, a novel method called location-based delivery (LBD), which combines the short message service (SMS) and global position system (GPS), is proposed, and further, a realistic system for tracking a target's movement is developed. LBD reduces the number of short message transmissions while maintaining the location tracking accuracy within the acceptable range. The proposed approach, LBD, consists of three primary features: Short message format, location prediction, and dynamic threshold. The defined short message format is proprietary. Location prediction is performed by using the current location, moving speed, and bearing of the target to predict its next location. When the distance between the predicted location and the actual location exceeds a certain threshold, the target transmits a short message to the tracker to update its current location. The threshold is dynamically adjusted to maintain the location tracking accuracy and the number of short messages on the basis of the moving speed of the target. The experimental results show that LBD, indeed, outperforms other methods because it satisfactorily maintains the location tracking accuracy with relatively fewer messages.

• Journal of Power Electronics
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• v.16 no.1
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• pp.182-189
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• 2016

Fault detection is the research focus and priority in this study to ensure the high reliability of a proposed three-level inverter. Kernel principal component analysis (KPCA) has been widely used for feature extraction because of its simplicity. However, highlighting useful information that may be hidden under retained KPCs remains a problem. A weighted KPCA is proposed to overcome this shortcoming. Variable contribution plots are constructed to evaluate the importance of each KPC on the basis of sensitivity analysis theory. Then, different weighting values of KPCs are set to highlight the useful information. The weighted statistics are evaluated comprehensively by using the improved feature eigenvectors. The effectiveness of the proposed method is validated. The diagnosis results of the inverter indicate that the proposed method is superior to conventional KPCA.

• Journal of Information Science Theory and Practice
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• v.7 no.1
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• pp.17-28
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• 2019

Dengue infection is becoming a serious global health threat. Public awareness is a pre-requisite for the successful implementation of dengue prevention programs. The main purpose of this study was to investigate dengue-related information needs and seeking behavior of the general public in Singapore. Some areas covered by this study were: importance of dengue-related information needs, preferred channels for seeking information, and respondents' perceptions of using dengue-related information. A questionnaire was used for data collection and 152 individuals participated in this study. Data analysis showed that the most sought after information concerned: dengue-related medicines, primary symptoms of dengue infection, and different possible treatments. The popular channels for seeking information were: websites of hospitals and other health agencies, the social media, television, and newspapers. Medical staff, such as doctors and nurses, were trusted for providing accurate information. Although credibility of social media was considered low, respondents were using it due to its easy accessibility. The findings of this study will be useful to government health departments in Singapore as well as in other countries suffering from dengue, hospitals, and public welfare agencies involved in public health awareness campaigns.

• Computers and Concrete
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• v.26 no.6
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• pp.515-531
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• 2020

Due to the construction difficulties of steel reinforced concrete (SRC), a new composite structure of steel and steel fiber reinforced concrete (SSFRC) is proposed for solving construction problems of SRC. This paper aims to investigate the bond properties and composition of interfacial bond stress between steel and steel fiber reinforced concrete. Considering the design parameters of section type, steel fiber ratio, interface embedded length and concrete cover thickness, a total of 36 specimens were fabricated. The bond properties of specimens were studied, and three different methods of calculating interfacial bond stress were analyzed. The results show: relative slip first occurs at the free end; Bearing capacity of specimens increases with the increase of interface embedded length. While the larger interface embedded length is, the smaller the average bond strength is. The average bond strength increases with the increase of concrete cover thickness and steel fiber ratio. And calculation method 3 proposed in this paper can not only reasonably explain the hardening stage after the loading end curve yielding, but also can be applied to steel reinforced high-strength concrete (SRHC) and steel reinforced recycled coarse aggregate concrete (SRRAC).