• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.325-332
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• 2019

This study analyzed the movement of tumors using 4DCT. Appropriate uniform IM were identified using TC, II and CI depending on ITV margins. DVH and NTCP were also compared in each case. Dose analysis on tumors with uniform IM showed that the optimal treatment plan for satisfying all TC, CI, II was evaluated as 2 mm in phase 20 and 3 mm in 40%. That was compared to the dose from the normal tissues of $PTV_{20}$, $PTV_{40}$. In the 20% radiation field, V5, V10, and V20 for the lungs increased 1.49, 1.26, and 0.65%, while 40% increased by 1.9, 2.41 and 1.23%. NTCP had a dose increase of 0.57 to 0.029% from 20% and 40%. There was a dose increase in the spinal cord and heart at uniform IM, but there was no significant difference. These data suggest that the ITV setting of 20%, phase for Respiratory Gated Radiotherapy using Novalis ExacTrac system can be applied with a uniform IM 2 mm and 40% with 3 mm for optimal treatment plan.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2741-2761
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• 2017

With the purpose of copyright protection for digital video, a novel H.264/AVC watermarking algorithm based on JND model is proposed. Firstly, according to the characteristics of human visual system, a new and more accurate JND model is proposed to determine watermark embedding strength by considering the luminance masking, contrast masking and spatial frequency sensitivity function. Secondly, a new embedding strategy for H.264/AVC watermarking is proposed based on an analysis on the drift error of energy distribution. We argue that more robustness can be achieved if watermarks are embedded in middle and high components of $4{\times}4$ integer DCT since these components are more stable than dc and low components when drift error occurs. Finally, according to different characteristics of middle and high components, the watermarks are embedded using different algorithms, respectively. Experimental results demonstrate that the proposed watermarking algorithm not only meets the imperceptibility and robustness requirements, but also has a high embedding capacity.

• Nuclear Engineering and Technology
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• v.43 no.4
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• pp.343-354
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• 2011

It is critically important to identify unexpected loose parts in a nuclear reactor pressure vessel, since they may collide with and cause damage to internal structures. Mass estimation can provide key information regarding the kind as well as the location of loose parts. This study proposes a mass estimation method based on an artificial neural network (ANN), which can overcome several unresolved issues involved in other conventional methods. In the ANN model, input parameters are the discrete cosine transform (DCT) coefficients of the auto-power spectrum density (APSD) of the measured impact acceleration signal. The performance of the proposed method is then evaluated through application to a large-sized plate and a 1/8-scaled mockup of a reactor pressure vessel. The results are compared with those obtained using a conventional method, the frequency ratio (FR) method. It is shown that the proposed method is capable of estimating the impact mass with 30% lower relative error than the FR method, thus improving the estimation performance.

• Journal of Science Education
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• v.33 no.2
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• pp.271-289
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• 2009

The purpose of the research was to analyze the characteristics and the process elements which appeared to the process of designing experiment for biologists and gifted students in science. Four biologists and thirty-two gifted students were participated in this study. The findings indicated that (a) the researcher figured out the process elements could constructed in fifteen elements such as confirming questions, arrange materials, consideration for experimental subjects, searching variables, eliminating variables, selecting variables, planning operation of variables, planning control environmental variables, planning control biological variables, planning the methods of observation and assessment, planning the methods of collecting data, planning the interpretation of data, planning the repetition of experiments, planning the repetition of assessment, safety regulations as well. The biologists concentrated in the particular process elements related with variables, since the science-gifted students concerned the performance whole process elements themselves without deeper consideration, (b) the characteristics of biologists and science-gifted students in the process of designing experiment were as follows; 1) biologists and students showed the process elements which include the domain specific process skills as well, 2) biologists accurately conducted the designing experiments processes with repetition of specific process, since students designed experiments conventionally, and 3) biologists possessed the domain specific skills and know-how about their experiments, but students did not. The results show that the programs of designing experiment activity should be constructed with the process elements which were concentrated by biologists, should provide feedbacks to design experiment more accurately, and should be developed with concern of the process skills and know-hows of biologists.

• Korean Journal of Cognitive Science
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• v.7 no.1
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• pp.57-74
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• 1996

This paper presents a comparison of recognition performance of the features used inthe recent handwritten korean character recognition.This research aims at providing the basis for feature selecion in order to improve not only the recognition rate but also the efficiency of recognition system.For the comparison of feature performace,we analyzed the characteristics of theose features and then,classified them into three rypes:global feature(image transformation)type,statistical feature type,and local/ topological feature type.For each type,we selected four or five features which seem more suitable to represent the characteristics of korean alphabet,and performed recongition experiments for the first consonant,horizontal vowel,and vertical vowel of a korean character, respectively.The classifier used in our experiments is a multi-layered perceptron with one hidden layer which is trained with backpropagation algorithm.The training and test data in the experiment are taken from 30sets of PE92. Experimental results show that 1)local/topological features outperform the other two type features in terms of recognition rates 2)mesh and projection features in statical feature type,walsh and DCT features in global feature type,and gradient and concavity features in local/topological feature type outperform the others in each type, respectively.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.91-91
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• 2001

Nramp2, also known as DMT1 and DCT1, is a 12-transmembrane domain protein responsible for dietary iron uptake as well as metal ions such as lead, manganese, zinc, copper, nickel, cadmium, and cobalt. High expression of DMT1 increase lead uptake, and DMT1-dependent lead transport was H -dependent and inhibited by iron ions. The molecular mechanism of lead transport in CNS is as yet unknown. although interactions between iron and lead at the level of absorption have been known for some time. The process of lead uptake into astrocytes was not known yet. Nramp2 may mediate transport of heavy metal into astrocytes. We investigated whether Nramp2 mediate transport of lead into astrocytes. And we do whether Nramp2 was expressed highly by deprivation of iron in Astrocytes, and lead uptake into astrocytes was influenced by expression of Nramp2. Immortalized human fetal astrocyte(SV-FHA) cells were cultured in medium containing Dulbecco's modified Eagle's medium and treated with Deferoxamine. Northern blot analysis was done for determining mRNA level of DMT1 and lead uptake assay was done in incubation condition of pH 5.5 and 7.4.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.612-617
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• 2009

In a DCT coding, degradations called block artifact and mosquito noise are appeared in reconstructed pictures. They should be reduced in post processing after decoding without superabundant processing. However, an estimation of mosquito noise is rare because of its difficulty. To realize an estimation of mosquito noise level, we extract a block that mosquito noise will be easy to occur. Mosquito noise level is calculated at a selected side of the block. In this processing, only the sides of high probability block are used. Then, a block value is taken by averaging. Finally, the picture value is calculated by averaging of this. Estimation method is evaluated by using the MPEG-4 decoded pictures. Quantization scale of coding and the estimated mosquito noise level are compared. As the results, we recognize the proposed method gives almost reasonable mosquito block and absolute level. Father, adaptive filter is controlled by the estimated mosquito noise level. It is recognized that the high quality of decoded picture is kept and the mosquito noise is reduced effectively at the picture with degradation.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2006.06a
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• pp.29-32
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• 2006

본 논문에서는 기존의 생체인식에서 사용하지 않았던 방법으로 개인의 치열 영상을 이용하는 생체 인식 방법을 제안한다. 제안한 치열 인식 시스템은 데이터의 중복성 제거와 관측벡터의 차원 감소를 위하여 2D-DCT를 특징 파라미터로 사용하고, 음성인식 및 얼굴인식 분야에서 사용하는 EHMM 기술을 사용한다. EHMM은 3개의 super-state로 구성되며 각각의 super-state는 3개, 5개, 3개의 상태를 갖는 1D-HMM으로 구성된다. 치열인증 시스템의 성능 평가는 모델 훈련에 사용하지 않은 치열 영상으로 인식 실험하여 평가한다. 치열인식 실험에는 남자 10명과 여자 10명에 대하여 각각 10개의 이미지로 구성된 총 200개의 치열 영상을 사용한다. 치열인식 실험에서 제안한 치열인식 시스템의 인식률은 98.5%를 보였고, 참고문헌 [4]의 EHMM을 사용한 얼굴인식 시스템이 갖는 98%와 대등한 성능을 나타내는 것을 확인하였다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2007.11a
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• pp.93-114
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• 2007

Vaccinium uliginosum L. (VU) is a flowering plant in the genus Vaccinium has berry fruit. This study was performed to investigate the effect of water extract of Vaccinium uliginosum L. and fractions on inhibition of melanogenesis and wrinkle formation. One hundred grams of the Vaccinium uliginosum L. was extracted with 2,000 mL of water ($90^{\circ}C$, 16h, 2 times). The water extracts were lyophilized and stored at $4^{\circ}C$ until used. Vaccinium uliginosum L. extracts showed scavenger activities on DPPH radical, superoxide anion radical, hydroxyl radical, hydrogen peroxide and singlet oxygen radical, dose dependently. And VU extract and fractions reduced melanin contents on B16F10 melanoma and inhibited the expression of melanogenesis-related proteins, tyrosinase, tyrosinase-related protein (TRP-1) and dapachrometa utomerase (Dct, TRP-2). Moreover VU extract and fractions stimulated procollagen production and inhibited MMP-1 production in human fibroblast. And it decreased degree of wrinkle formation in hairless mouse skin that induced by DVB irradiation for 9 weeks. From the above results, it is possible that Vaccinium uliginosum L. may be developed to be the health functional food and functional cosmetics that have anti-melanogenesis and anti-wrinkle effect.

• Biomolecules & Therapeutics
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• v.32 no.4
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• pp.492-498
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• 2024

Bioassay and HPLC-UV guided fractionations of the crude extract of marine-derived Streptomyces sp. SNA-077 have led to the isolation of a red pigment, undecylprodigiosin (1). The chemical structure of undecylprodigiosin (1) was revealed by the interpretation of NMR and mass spectroscopic (MS) data. Further, anti-melanogenic effects of undecylprodigiosin (1) were investigated. First, the melanin contents of undecylprodigiosin (1)-treated B16 cells were evaluated. Furthermore, undecylprodigiosin (1) significantly inhibited the key enzymes involved in melanogenesis, including tyrosinase, tyrosinase related protein-1 (TYRP-1), and dopachrome tautomerase (DCT). The mRNA and protein expression levels of Microphthalmia-associated transcriptian factor (MiTF), a critical transcription factor for tyrosinase gene expression, were also suppressed by undecylprodigiosin (1) treatment in B16 analyses. Collectively, our results suggest for the first time that undecylprodigiosin (1), a potent component isolated from an extract of marine Streptomyces sp. SNA-077, critically exerts the anti-melanogenic ability for melanin synthesis.