확률정규화와 노이즈가 들어간 환경에서의 신뢰네트웍 학습알고리즘 성능 비교 분석

김현숙(Hyunsuk Kim),조성준(Sungzoon Cho),펑윈(Yun Peng) 한국정보과학회 1996 정보과학회논문지(B) Vol.23 No.10

최근 신뢰네트웍(belief network)의 네트웍 구조와 확률값을 방대한 상황 데이타로부터 학습하는 몇가지 알고리즘이 제안되었다. 이들중 Cooper의 K2 알고리즘등은 전통적인 학습기법에 바탕을 두고 있지만, Neal의 볼츠만 머신(Boltzmann machine) 학습법이나 Peng 의 헤비안(Hebbian) 학습법등은 신경망 학습법의 일종이다. 본 논문에서는 첫째 다양한 학습 알고리즘의 성능을 실제 상황과 흡사한 환경에서 실험적으로 비교할 수 있도록 사전확률과 인과확률의 정규화 개념을 도입한다. 둘째, 노이즈가 들어간 상황에서의 실험 계획을 구성한다. 마지막으로 Cooper, Neal, Peng의 알고리즘을 실제 상황과 흡사한 노이즈가 포함된 정규화 패턴으로 학습시켰을 때의 성능을 비교하고 분석한다. 학습 결과, Cooper와 Peng의 일고리즘은 확률 값을 학습하는 데 있어 Neal의 알고리즘보다 나은 성능을 보였고, Peng의 알고리즘은 노이즈가 섞인 데이타로부터 네트웍의 구조를 학습하는 데 있어 나머지 두 알고리즘보다 우수한 성능을 보였다. Recently, several belief network learning algorithms have been proposed to learn both the network structures and probabilities from the case data. Although most of these methods (e.g., Cooper's K2 algorithm) are based on traditional machine learning techniques, some of them, e.g., Neal's Boltzmann machine method and Peng's extended Hebbian method take neural network learning approaches. We first introduce the notion of normalization of prior and causation probabilities which helps to render the synthetic data more realistic. Second, we design the test simulation where "noise" is added to the case data. Finally, three learning algorithms proposed by Cooper, Neal, and Peng, respectively, are compared in their performance when trained with noisy normalized synthetic data. Simulation results show that Cooper's and Peng's algorithms are superior to Neal's in average error for learning probabilities, while Peng's algorithm performs better in learning network structures from noisy data.

Basic, HCCbasic : PO-19 ; CTHRC1 is a potential biomolecular marker in human hepatocellular carcinoma

( Yun Peng Wang ),( Pei Pei Hao ),( Mi Jin Lee ),( Goung Ran Yu ),( Hua Lee ),( Seong Hun Kim ),( Dae Ghon Kim ) 대한간학회 2012 춘·추계 학술대회 (KASL) Vol.2012 No.1

Background: CTHRC1 is a 30 kDa secreted protein that has the ability to inhibit collagen matrix synthesis. CTHRC1 expression in breast cancer and colorectal cancer is associated with cancer tissue invasion and metastasis. But, the functional significance of CTHRC1 expression in hepatocellular carcinoma (HCC) is unknown. So the purpose of this study is to investigate whether CTHRC1 is a biomolecular marker in human hepatocellular carcinoma. Methods: CTHRC1 protein expression was investigated by Immunoblotting analysis in HCC cell lines and HCC tumor tissues, respectively. The expressions of CTHRC1 in HCC tissues were also evaluated by immunohistochemical staining according to tumor differentiaton and stage. CTHRC1 levels were assessed in serum of HCC patients by Western blot analysis. Colony formation was assessed in SH-J1 and HLK3 cells. Results: Endogenous and ectopic expression of CTHRC1 was mainly localized in the cytoplasm of the tumor cells. The immunohistochemical staining showed that the expression of CTHRC1 was negligible in normal liver tissue, but most tumors were immunoreactive. CTHRC1 was highly expressed in tumor tissues compares with non - tumor tissues, but barely expressed in HCC cells. We also found that secreted CTHRC1 was abundantly present in the serum of the patients with early and advanced HCCs, and absent with normal liver. Colony generation assay revealed that CTHRC1 overexpression increased colony number by two-folds. Conclusions: These results suggest that CTHRC1 protein maybe useful as a potential biomolecular maker for HCC.

Experimental Investigation of Ion Mobility Measurements in Oxygen under Different Gas Pressures

Yun-Peng Liu,Shi-long Huang 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

In this paper, measurements of ion mobility were performed in oxygen at gas pressures of 44.52 - 101.19 kPa using the drift tube method. Over this pressure range, mobility values were within the limits of 1.796 to 3.821 ㎠·V<SUP>-1</SUP>·s<SUP>-1</SUP> were determined and ion mobility shown to decrease nonlinearly with increasing gas pressure towards a certain level of saturation. Ion mobility measured in air was lower than that measured in oxygen at the same gas pressure. Finally, a parameter correction method for calibrating the relationship between the ion mobility and gas pressure in oxygen was proposed.

Aging effect analysis of long period operating composite insulators in different electric field position

Yun-Peng Liu 한양대학교 세라믹연구소 2012 Journal of Ceramic Processing Research Vol.13 No.S1

Electric field distribution is one of the important factors which impact the aging of composite insulators. The electric field of composite insulators was simulated by ANSYS software, and the shed samples in different parts of the composite insulator were analyzed by Fourier transform infrared spectroscopy (FTIR). The characteristic peaks of functional groups in the main chain and side chain of composite insulator material molecular formula were compared. The smaller the characteristic peak area is, the less the corresponding functional group is, that means the facture condition of main chain or side chain is more serious. In this way, the characteristic peaks of samples in different electric field distribution were compared, and the influence of electric field distribution to the aging effect of the composite insulators is gained. The results show that electric field strength is the strongest in the composite insulator high-voltage side, followed by lowvoltage side, and the electric field in the middle of the composite insulator is the lowest. Accordingly, the aging degree in the composite insulator high-voltage side is the most serious, followed by low-voltage side, and the aging degree is weakest in the middle part.

New phenylpropanoids from Bulbophyllum retusiusculum

Yun-Shan Fang,Ming-Hui Yang,Le Cai,Jia-Peng Wang,Tian-Peng Yin,Jing Yu,Zhong-Tao Ding 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.11

Two new phenylpropanoids, retusiusines A (1) and B (2), and a pair of new phenylpropyl enantiomers, (±)-retusiusine C (3a and 3b), together with eight known compounds, dihydroconiferyl dihydro-p-coumarate (4), methyl 3-(4-hydroxyphenyl) propionate (5), 3-(4-hydroxyphenyl)-propanoic acid (6), dihydroferulic acid (7), methyl 3-(4-methoxyphenyl) propionate (8), 3-(3,4-dimethoxyphenyl)-2-propenal (9), trans-p-coumaric acid (10) and dihydroconiferyl alcohol (11), were isolated from the tubers of Bulbophyllum retusiusculum. The absolute configurations of the new compounds were determined by calculating their electronic circular dichroism (ECD), spectra and specific optical rotations and comparing the calculated values with the experimental data. Compound 2 exhibited potent antifungal activity against Candida albicans (16 μg/mL). Compound 3 showed moderate antibacterial activity against Bacillus subtilis (64 μg/mL).

China

Peng Yun-E 대한교통학회 1998 대한교통학회 기타자료 Vol.1996 No.-

Inhibitory Effects of Syk Transfection on Lung Cancer Cell Invasion

Peng, Chuan-Liang,Zhang, Ying,Sun, Qi-Feng,Zhao, Yun-Peng,Hao, Ying-Tao,Zhao, Xiao-Gang,Cong, Bo Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.5

Objective: Spleen tyrosine kinase (Syk) is closely related to tumor invasion and metastasis, and has been shown to have potential inhibitory effects in tumors. In this study, we constructed a eukaryotic expression vector for Syk and analyzed its effects on invasive ability of the A549 non-small cell lung cancer cell line in vitro. Methods: A fragment of Syk was obtained by RT-PCR from human lung cancer cells and cloned into the expression vector pLNCXSyk. After restriction endonuclease digestion, PCR and DNA sequencing confirmation, the recombinant Syk expression plasmid was transfected into A549 human lung cancer cells using lipofectamine protocols. After selection, the cells stably expressed Syk. Detection of Syk expression of the cells by RT-PCR, and invasive ability were examined. Results: The eukaryotic expression plamid pLNCXSyk was constructed and expressed stably in the A549 human lung cancer cells. The RT-PCR results showed that Syk mRNA expression was upregulated significantly (P<0.05). Lower invasion through a basal membrane were apparent after transfection (P<0.05). Conclusions: A eukaryotic expression plasmid to cause Syk expression in lung cancer cells can obviously inhibit their invasive ability in vitro.

Network Design and Implementation of Synchronization Software

Peng Hai-yun,Liu Xin 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.4

The actual demand for network applications, the paper discusses the data backup, real-time data synchronization knowledge; On this basis, considering the multi-user concurrency, the case of multi-user collaboration, to achieve a multi-machine real-time synchronization, proposed a network synchronization system model, describes its design ideas and development methods. The results show that: the system update for the relatively low intensity operations with relatively good efficiency of backup and synchronization synergy.

Influence of Endurance tests on Space Charge Distribution of 160kV HVDC XLPE Cable

Yun-Peng Liu,He-Chen Liu 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.1

The ageing of XLPE cable insulation will lead to the accelerating accumulation of space charge, which will greatly affect the safe operation of the HVDC cable. In order to investigate the influence of different ageing modes on the space charge distribution of the HVDC cable, thermal stressed, electrical stressed and electro-thermal stressed endurance tests were carried out on the XLPE peelings. The tested XLPE peelings were obtained from 160kV HVDC cable insulation. The endurance tests were carried at thermal stress of 363K, electrical stress of 20kV/mm DC and a combination of both. The Pulsed Electro-Acoustic (PEA) method was used to measure the space charge distribution of the samples. The influences of ageing on the trap energy distribution were analyzed based on the isothermal relaxation theory and the decay characteristics of the space charge. The results showed that thermal ageing would help to improve the crystalline morphologies of the XLPE at the early stage. The total amount of space charge decreased compared to the ones before thermal ageing. The long term of electrical stress would result in the cleavage of polymer molecule chains which would intensify the accumulation of space charge and increase the density and depth of electron traps. With a combination of electrical and thermal stress, the injection and migration of space charge were more significant. Besides, the depth and density of electron traps increased rapidly with the increase of endurance time.

Corona generated Radio Interference of the 750 kV AC Bundle Conductors in Sandy and Dusty Weather Condition in the High Altitude Area

Yun-Peng Liu,Lei Zhu,Fang-Cheng Lv,Bao-Quan Wan,Chun-Ming Pei 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.5

Sandy and dusty weather condition often occurs in the high altitude areas of China, which may greatly influence the corona generated radio interference (RI) characteristics of the bundle conductors of 750 kV AC power transmission lines. Corona generated RI of the conductors of the 750 kV AC power transmission lines used in practice is measured by EMI receiver with a coupling circuit and a coupling capacitor connected between the high voltage side and the earth side in fine and sandy and dusty condition. The measuring frequency is 0.5 MHz, and the quasi-peak detection is used. RI excitation function is calculated based on the corona RI current measured by the EMI receiver. Corona generated RI characteristics were analyzed from sand concentration and sand particle size. The test result shows that the corona generated RI excitation function is influenced by the sandy and dusty condition. Corona discharge of the conductors is more serious in sandy and dusty condition with an ultraviolet (UV) detector. Corona generated RI excitation function increases with the increase of sand concentration and also increases with the increase of particle size.