An Enhanced Password Authentication Scheme Providing Password Updating without Smart Cards

Chin-Chen Chang,Hao-Chuan Tsai,Yi-Hui Chen 보안공학연구지원센터 2007 International Journal of Security and Its Applicat Vol.1 No.2

In 2003, Yang, Chang, and Hwang proposed an enhanced scheme of Peyravivan-Zunic’s password authentication scheme by using the Diffie-Hellman scheme. Later, Yoon, Ryu, and Yoo demonstrated that Yang-Chang-Hwang’s scheme is vulnerable to a stolen-verifier attack and a denial-of-service attack, and then proposed an improved scheme. In this paper, we show that Yoon-Ryu-Yoo’s scheme is still vulnerable to a stolen-verifier attack and a server spoofing attack under some reasonable assumption. In addition, we propose an improved scheme to eliminate such security flaws.

APPLICATIONS OF THE HILBERT-HUANG TRANSFORM ON THE NON-STATIONARY ASTRONOMICAL TIME SERIES

HU, CHIN-PING,CHOU, YI,YANG, TING-CHANG,SU, YI-HAO,HSIEH, HUNG-EN,LIN, CHING-PING,CHUANG, PO-SHENG,LIAO, NAI-HUI The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

The development of time-frequency analysis techniques allow astronomers to successfully deal with the non-stationary time series that originate from unstable physical mechanisms. We applied a recently developed time-frequency analysis method, the Hilbert-Huang transform (HHT), to two non-stationary phenomena: the superorbital modulation in the high-mass X-ray binary SMC X-1 and the quasi-periodic oscillation (QPO) of the AGN RE J1034+396. From the analysis of SMC X-1, we obtained a Hilbert spectrum that shows more detailed information in both the time and frequency domains. Then, a phase-resolved analysis of both the spectra and the orbital profiles was presented. From the spectral analysis, we noticed that the iron line production is dominated by different regions of this binary system in different superorbital phases. Furthermore, a pre-eclipse dip lying at orbital phase ~0:6-0:85 was discovered during the superorbital transition state. We further applied the HHT to analyze the QPO of RE J1034+396. From the Hilbert spectrum and the O-C analysis results, we suggest that it is better to divide the evolution of the QPO into three epochs according to their different periodicities. The correlations between the QPO periods and corresponding fluxes were also different in these three epochs. The change in periodicity and the relationships could be interpreted as the change in oscillation mode based on the diskoseismology model.

BRCA1/2 mutation status in patients with metachronous breast and ovarian malignancies: clues towards the implementation of genetic counseling

Angel Chao,Yi-Hao Lin,Lan-Yan Yang,Ren-Chin Wu,Wei-Yang Chang,Pi-Yueh Chang,Shih-Cheng Chang,Chiao-Yun Lin,Huei-Jean Huang,Cheng-Tao Lin,Hung-Hsueh Chou,Kuan-Gen Huang,Wen-Ling Kuo,Ting-Chang Chang,Ch 대한부인종양학회 2020 Journal of Gynecologic Oncology Vol.31 No.3

Objective: The characteristics of patients with metachronous breast and ovarian malignancies and the pathogenic role of BRCA1/2 mutations remain poorly understood. We investigated these issues through a review of hospital records and nationwide Taiwanese registry data, followed by BRCA1/2 mutation analysis in hospital-based cases. Methods: We retrospectively retrieved consecutive clinical records of Taiwanese patients who presented with these malignancies to our hospital between 2001 and 2017. We also collected information from the Data Science Center of the Taiwan Cancer Registry (TCR) between 2007 and 2015. Next-generation sequencing and multiplex ligation-dependent probe amplification were used to identify BRCA1/2 mutations and large genomic rearrangements, respectively. When BRCA1/2 mutations were identified in index cases, pedigrees were reconstructed and genetic testing was offered to family members. Results: A total of 12,769 patients with breast cancer and 1,537 with ovarian cancer were retrieved from our hospital records. Of them, 28 had metachronous breast and ovarian malignancies. We also identified 113 cases from the TCR dataset. Eighteen hospital-based cases underwent BRCA1/2 sequencing and germline pathogenic mutations were detected in 7 patients (38.9%, 5 in BRCA1 and 2 in BRCA2). All BRCA1/2 mutation carriers had ovarian high-grade serous carcinomas. Of the 12 patients who were alive at the time of analysis, 5 were BRCA1/2 mutation carriers. All of them had family members with BRCA1/2-associated malignancies. Conclusions: Our results provide pilot evidence that BRCA1/2 mutations are common in Taiwanese patients with metachronous breast and ovarian malignancies, supporting the clinical utility of genetic counseling.

An Application of Hilbert-Huang Transform on the Non-Stationary Astronomical Time Series: The Superorbital Modulation of SMC X-1

Chin-Ping Hu,Yi Chou,Ming-Chya Wu,Ting-Chang Yang,Yi-Hao Su 한국우주과학회 2013 Journal of Astronomy and Space Sciences Vol.30 No.2

We present the Hilbert-Huang transform (HHT) analysis on the quasi-periodic modulation of SMC X-1. SMC X-1, consisting of a neutron star and a massive companion, exhibits superorbital modulation with a period varying between ~40 d and ~65 d. We applied the HHT on the light curve observed by the All-Sky Monitor onboard Rossi X-ray Timing Explorer (RXTE) to obtain the instantaneous frequency of the superorbital modulation of SMC X-1. The resultant Hilbert spectrum is consistent with the dynamic power spectrum while it shows more detailed information in both the time and frequency domains. According to the instantaneous frequency, we found a correlation between the superorbital period and the modulation amplitude. Combining the spectral observation made by the Proportional Counter Array onboard RXTE and the superorbital phase derived in the HHT, we performed a superorbital phase-resolved spectral analysis of SMC X-1. An analysis of the spectral parameters versus the orbital phase for different superorbital states revealed that the diversity of nH has an orbital dependence. Furthermore,we obtained the variation in the eclipse profiles by folding the All Sky Monitor light curve with orbital period for different superorbital states. A dip feature, similar to the pre-eclipse dip of Her X-1, can be observed only in the superorbital ascending and descending states, while the width is anti-correlated with the X-ray flux.

Analyzing Offshore Wind Power Patent Portfolios by Using Data Clustering

Chang, Shu-Hao,Fan, Chin-Yuan Korean Institute of Industrial Engineers 2014 Industrial Engineeering & Management Systems Vol.13 No.1

Offshore wind power has been extremely popular in recent years, and in the energy technology field, relevant research has been increasingly conducted. However, research regarding patent portfolios is still insufficient. The purpose of this research is to study the status of mainstream offshore wind power technology and patent portfolios and to investigate major assignees and countries to obtain a thorough understanding of the developmental trends of offshore wind power technology. The findings may be used by the government and industry for designing additional strategic development proposals. Data mining methods, such as multiple correspondence analyses and k-means clustering, were implemented to explore the competing technological and strategic-group relationships within the offshore wind power industry. The results indicate that the technological positions and patent portfolios of the countries and manufacturers are different. Additional technological development strategy recommendations were proposed for the offshore wind power industry.

Clinical Significance of Smudge Cells in Peripheral Blood Smears in Hematological Malignancies and Other Diseases

Chang, Chih-Chun,Sun, Jen-Tang,Liou, Tse-Hsuan,Kuo, Chin-Fu,Bei, Chia-Hao,Lin, Sheng-Jun,Tsai, Wei-Ting,Tan, N-Chi,Liou, Ching-Biau,Su, Ming-Jang,Yen, Tzung-Hai,Chu, Fang-Yeh Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.4

Background: It is reported that the percentage of smudge cells in the blood smear could be a prognostic indicator in chronic lymphocytic leukemia. However, the clinical significance of smudge cells in other hematological malignancies, solid tumors or non-malignant diseases is less clear. Hence, this study was conducted to survey the clinical significance of smudge cells in hematological cancers and other disorders. Materials and Methods: From January to November, 2015, the clinical data of patients who received blood examination with differential counts for clinical purpose and were found to have smudge cells in the peripheral blood film in Far Eastern Memorial Hospital were selected. The percentage of smudge cells and patient outcomes were evaluated for further univariate and survival analyses. Results: A total of 102 patients with smudge cells in their blood smears were included. Smudge cells were frequently presented in out-of-hospital cardiac arrest (OHCA; n=30), infections (n=23), hematological cancers (n=23) and solid cancers (n=10). There was no relationship between the percentage of smudge cells and the patient mortality in all diseases (OR: 1.08, 95% CI: 0.47-2.48, P=1.000) as well as the OHCA group (OR: 1.91, 95% CI: 0.38-9.60, P=0.694). It was observed that in patients with all cancers with the percentage of smudge cells less than 50% had a lower mortality rate in comparison with those who had the percentage of smudge cells of 50% or more (OR: 22.29, 95% CI: 2.38-208.80, P<0.001). Additionally, it was seemingly that patients with smudge cells of 50% or more had a lower survival rate than those with smudge cells less than 50% in all cancers with follow-up at 2-month intervals, but without statistical significance (P=0.064). Conclusions: Our survey indicated that in all cancers, those who had higher percentage of smudge cells were prone to have poor outcomes when compared with the subjects with lower percentage of smudge cells. This finding was quite different from the results of previous studies in which the race-ethnicity of most study populations was non-Asian; hence, further investigations are required. Besides, there was no apparent association of the percentage of smudge cells with patient outcomes in all diseases, including OHCA.

ON THE COMPLEX VARIABILITY OF THE SUPERORBITAL MODULATION PERIOD OF LMC X-4

HU, CHIN-PING,LIN, CHING-PING,CHOU, YI,YANG, TING-CHANG,SU, YI-HAO,HSIEH, HUNG-EN,CHUANG, PO-SHENG,LIAO, NAI-HUI The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

LMC X-4 is an eclipsing high-mass X-ray binary exhibiting a superorbital modulation with a period of ~ 30:5 days. We present a detailed study of the variations of the superorbital modulation period with a time baseline of ~ 18 years. The period determined in the light curve collected by the Monitor of All-sky X-ray Image (MAXI) significantly deviates from that observed by the All Sky Monitor (ASM) onboard the Rossi X-ray Timing Explorer (RXTE). Using the data collected by RXTE/ASM, MAXI, and the Burst Alert Telescope (BAT) onboard Swift, we found a significant period derivative, $\dot{P}=(2.08{\pm}0.12){\times}10^{-5}$. Furthermore, the O{C residual shows complex short-term variations indicating that the superorbital modulation of LMC X-4 exhibits complicated unstable behaviors. In addition, we used archive data collected by the Proportional Counter Array (PCA) on RXTE to estimate the orbital and spin parameters. The detected pulse frequencies obtained in small time segments were fitted with a circular orbital Doppler shift model. In addition to orbital parameters and spin frequency for each observation, we found a spin frequency derivative of $\dot{v}=(6.482{\pm}0.011){\times}10^{-13}Hz{\cdot}s^{-1}$. More precise orbital and spin parameters will be evaluated by the pulse arrival time delay technique in the future.

An Application of Hilbert-Huang Transform on the Non-Stationary Astronomical Time Series: The Superorbital Modulation of SMC X-1

Hu, Chin-Ping,Chou, Yi,Wu, Ming-Chya,Yang, Ting-Chang,Su, Yi-Hao 한국우주과학회 2013 Journal of Astronomy and Space Sciences Vol.30 No.2

We present the Hilbert-Huang transform (HHT) analysis on the quasi-periodic modulation of SMC X-1. SMC X-1, consistingof a neutron star and a massive companion, exhibits superorbital modulation with a period varying between ~40 d and ~65 d.We applied the HHT on the light curve observed by the All-Sky Monitor onboard Rossi X-ray Timing Explorer (RXTE) to obtainthe instantaneous frequency of the superorbital modulation of SMC X-1. The resultant Hilbert spectrum is consistent with thedynamic power spectrum while it shows more detailed information in both the time and frequency domains. According to theinstantaneous frequency, we found a correlation between the superorbital period and the modulation amplitude. Combiningthe spectral observation made by the Proportional Counter Array onboard RXTE and the superorbital phase derived in theHHT, we performed a superorbital phase-resolved spectral analysis of SMC X-1. An analysis of the spectral parameters versusthe orbital phase for different superorbital states revealed that the diversity of nH has an orbital dependence. Furthermore,we obtained the variation in the eclipse profiles by folding the All Sky Monitor light curve with orbital period for differentsuperorbital states. A dip feature, similar to the pre-eclipse dip of Her X-1, can be observed only in the superorbital ascendingand descending states, while the width is anti-correlated with the X-ray flux.

Analyzing Offshore Wind Power Patent Portfolios by Using Data Clustering

Shu-Hao Chang,Chin-Yuan Fan 대한산업공학회 2014 Industrial Engineeering & Management Systems Vol.13 No.1

Offshore wind power has been extremely popular in recent years, and in the energy technology field, relevant research has been increasingly conducted. However, research regarding patent portfolios is still insufficient. The purpose of this research is to study the status of mainstream offshore wind power technology and patent portfolios and to investigate major assignees and countries to obtain a thorough understanding of the developmental trends of offshore wind power technology. The findings may be used by the government and industry for designing additional strategic development proposals. Data mining methods, such as multiple correspondence analyses and k-means clustering, were implemented to explore the competing technological and strategic-group relationships within the offshore wind power industry. The results indicate that the technological positions and patent portfolios of the countries and manufacturers are different. Additional technological development strategy recommendations were proposed for the offshore wind power industry.

CHARACTERIZING THE TIME-FREQUENCY PROPERTIES OF THE 4 Hz QUASI-PERIODIC OSCILLATION AROUND THE BLACK HOLE X-ray BINARY XTE J1550-564

SU, YI-HAO,CHOU, YI,HU, CHIN-PING,YANG, TING-CHANG,HSIEH, HUNG-EN,CHUANG, PO-SHENG,LIN, CHING-PING,LIAO, NAI-HUI The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

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.