• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1997년도 추계학술발표회논문집
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• pp.11-13
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• 1997

Abstract - An electronic starter using MOSFET has been designed to take advantage of ideal preheating and starting features which can extend the lifetime of fluorescent lamps. The preheating circuit of the developed electronic starter is consisted of four parts - afull-wave rectifier circuit, an FET switching circuit a timer circuit for the gate switching, and a circuit for end-of-life protection. The circuit is analyzed by using PSpice simulation, and is improved to give an appropriate starting-time through control of R-C time constant of the timer circuit. And the circuit is also provided with an end-of-life protection feature, which utilizes the negative resistance characteristics of a thermistor that is thermally linked to FET through a heatsink. This also protects the FET from any overheating problems. From the results of simulation it is possible to obtain an appropriate value on the starting time for proper ignition and also it is verified that the limit for resistance of the thermistor is dependant on the value of resistance is the timer circuit

• 한방안이비인후피부과학회지
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• 제14권2호
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• pp.194-197
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• 2001

Progressive pigmented purpuric dermatosis(Schamberg's disease, purpura simplex) is an uncommon eruption characterized by petechiae and patches of brownish pigmentation, particularly on the lower extremities. Lesions remain for months or years and present only a cosmetic problem. there is no hematologic disease, venous insufficiency, or associated internal disease. The most characteristic feature is orange brown, pinhead-sized "cayenne pepper" spots. It is hard to find similar disease in Oriental Medicine, however it could be though related with 瘀血. We observed and treated a 25 old female with progressive pigmented purpuric dermatosis on her lower extremities, without pain and itching sign. About 1 year after our treatment, herb-medication. acupuncture treatment, negative therapy and applied aroma oil in order to remove the 瘀血(a kind of congestion) & inner heat and promote the circulation of her blood, the area of pigmented purpuric dermatosis was decreased remarkably and the colour was lighter. She is been treated continuously now and satisfied with the efficacy of treatment.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.300.2-300.2
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• 2013

Periodically shaped pillar-arrays and hole-arrays were fabricated on a Si wafer. Geometric features are similar in a periodic length of 4 ${\mu}m$ and a depth of 2 ${\mu}m$. For the hole-array patterns, positive PR processes were performed. UV exposed PR patterns were removed during a developing process to leave shapes of inversely replicated from a glass photomask. Meanwhile, negative PR processes were taken for the pillar-array patterns. UV exposed PR patterns were remained on a Si substrate having a same feature of patterns of a glass photomask. For an electrical aspect, a pillar structure has a short carrier-collection length resulting in the improved open-circuit voltage of 609 mV from 587 mV of a planar device. An improved performance may be achieved to reduce recombination loss along the patterning surface.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권10호
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• pp.5095-5111
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• 2016

The Probability Hypothesis Density (PHD) filter is a suboptimal approximation and tractable alternative to the multi-target Bayesian filter based on random finite sets. However, the PHD filter fails to track newborn targets when the target birth intensity is unknown prior to tracking. In this paper, a dual detection-guided newborn target intensity PHD algorithm is developed to solve the problem, where two schemes, namely, a newborn target intensity estimation scheme and improved measurement-driven scheme, are proposed. First, the newborn target intensity estimation scheme, consisting of the Dirichlet distribution with the negative exponent parameter and target velocity feature, is used to recursively estimate the target birth intensity. Then, an improved measurement-driven scheme is introduced to reduce the errors of the estimated number of targets and computational load. Simulation results demonstrate that the proposed algorithm can achieve good performance in terms of target states, target number and computational load when the newborn target intensity is not predefined in multi-target tracking systems.

• 센서학회지
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• 제27권6호
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• pp.374-379
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• 2018

The piezocomposite transducer is widely used because it is highly efficient in transforming electric energy into mechanical energy, and its frequency range is broader than that of other types of ultrasound transducers. A general piezocomposite transducer is composed of an acoustic lens, impedance matching layers, piezoelectric materials, and backing layers. When an input voltage is applied to a piezoelectric material as an active material, it generates sound waves while vibrating. At that time, an impedance matching layer helps the sound waves to propagate forward while reducing the impedance mismatch that may occur at the interface between the active material and its front material. The impedance mismatch has a negative effect on the signal of an ultrasound transducer; thus, it is important to design a matching layer to overcome the issue. In this study, an optimized feature of a matching layer with gradient properties is studied. An objective function is defined to minimize both the average and the deviation of the reflection coefficients that are functions of the frequencies. As a result, an improvement in the signal characteristics with respect to the sensitivity and bandwidth is reported.

• 영어영문학
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• 제60권2호
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• pp.339-363
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• 2014

This essay reconsiders the subject of Romantic self-consciousness in a post-de Manian perspective. Self-consciousness is an attribute of Romantic lyricism whereby the poetic speaker I remains conscious of how (s)he feels or lives here and now. This self-reflective feature of Romantic poetry has been controversially interpreted either as self-centered solipsism or as self-expressive objectivism. The question is stirring more disputes among Romantic critics after the advent of New Historicism and Feminism. These two historicistic approaches reprove Romantic poetry for a lack of the sense of history and ascribes it to Romantic self-consciousness. They argue that Romantic poets in general displace historical materiality into an object of internal consciousness, so negating absurd social realities "merely to gain their own immortal soul." This essay targets to overcome this negative stance on Romantic self-consciousness with a "subversive" return to Paul de Man's criticism of Romantic internality.

• Journal of the Korean Physical Society
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• 제73권10호
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• pp.1431-1436
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• 2018

We study the scaling of the price fluctuation in the Korean housing market. From the numerical analysis, we show that the normalized return distribution of the housing price, P(r), has a fat-tail and is well approximated by a power-law, $P(r){\sim}r^{-({\alpha}+1)}$, with ${\alpha}{\simeq}3$ for the whole data set. However, if we divide the data into groups based on the trading patterns, then the value of ${\alpha}$ for positive tail and negative tail can be different depending on the trading patterns. We also find that the autocorrelation function of the housing price decays much slower than that of the stock exchange markets, which shows a unique feature of the housing market distinguished from the other financial systems.

• Communications for Statistical Applications and Methods
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• 제29권4호
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• pp.413-420
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• 2022

In this study we adapt discrete weibull regression model for clustered count data. Discrete weibull regression model has an attractive feature that it can handle both under and over dispersion data. We analyzed the eighth Korean National Health and Nutrition Examination Survey (KNHANES VIII) from 2019 to assess the factors influencing the 1 month outpatient stay in 17 different regions. We compared the results using clustered discrete Weibull regression model with those of Poisson, negative binomial, generalized Poisson and Conway-maxwell Poisson regression models, which are widely used in count data analyses. The results show that the clustered discrete Weibull regression model using random intercept model gives the best fit. Simulation study is also held to investigate the performance of the clustered discrete weibull model under various dispersion setting and zero inflated probabilities. In this paper it is shown that using a random effect with discrete Weibull regression can flexibly model count data with various dispersion without the risk of making wrong assumptions about the data dispersion.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.652-654
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• 2021

침입 탐지 시스템에 의해서 DDoS와 같은 공격을 탐지되며 조기에 차단할 수 있다. 의사 결정 트리를 이용하여 DDoS 공격 트래픽을 분석하였다. 중요도가 높은 결정적인 속성(Feature)을 찾아서 해당 속성에 대해서만 의사 결정 트리를 진행하여 정확도를 확인하였다. 그리고 위양성 및 위음성 트래픽의 내용을 분석하였다. 그 결과 하나의 속성은 98%, 두 가지 속성은 99.8%의 정확도를 각각 나타냈다.

• International Journal of Computer Science & Network Security
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• 제23권11호
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• pp.83-92
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• 2023

The majority of product users rely on the reviews that are posted on the appropriate website. Both users and the product's manufacturer could benefit from these reviews. Daily, thousands of reviews are submitted; how is it possible to read them all? Sentiment analysis has become a critical field of research as posting reviews become more and more common. Machine learning techniques that are supervised, unsupervised, and semi-supervised have worked very hard to harvest this data. The complicated and technological area of feature engineering falls within machine learning. Using deep learning, this tedious process may be completed automatically. Numerous studies have been conducted on deep learning models like LSTM, CNN, RNN, and GRU. Each model has employed a certain type of data, such as CNN for pictures and LSTM for language translation, etc. According to experimental results utilizing a publicly accessible dataset with reviews for all of the models, both positive and negative, and CNN, the best model for the dataset was identified in comparison to the other models, with an accuracy rate of 81%.