Showing papers by "Fu Jen Catholic University published in 2002"

Credit scoring using the hybrid neural discriminant technique

Abstract: Credit scoring has become a very important task as the credit industry has been experiencing double-digit growth rate during the past few decades. The artificial neural network is becoming a very popular alternative in credit scoring models due to its associated memory characteristic and generalization capability. However, the decision of network's topology, importance of potential input variables and the long training process has often long been criticized and hence limited its application in handling credit scoring problems. The objective of the proposed study is to explore the performance of credit scoring by integrating the backpropagation neural networks with traditional discriminant analysis approach. To demonstrate the inclusion of the credit scoring result from discriminant analysis would simplify the network structure and improve the credit scoring accuracy of the designed neural network model, credit scoring tasks are performed on one bank credit card data set. As the results reveal, the proposed hybrid approach converges much faster than the conventional neural networks model. Moreover, the credit scoring accuracies increase in terms of the proposed methodology and outperform traditional discriminant analysis and logistic regression approaches.

H/sub /spl infin// tracking-based sliding mode control for uncertain nonlinear systems via an adaptive fuzzy-neural approach

Abstract: A novel adaptive fuzzy-neural sliding-mode controller with H/sub /spl infin// tracking performance for uncertain nonlinear systems is proposed to attenuate the effects caused by unmodeled dynamics, disturbances and approximate errors. Because of the advantages of fuzzy-neural systems, which can uniformly approximate nonlinear continuous functions to arbitrary accuracy, adaptive fuzzy-neural control theory is then employed to derive the update laws for approximating the uncertain nonlinear functions of the dynamical system. Furthermore, the H/sub /spl infin// tracking design technique and the sliding-mode control method are incorporated into the adaptive fuzzy-neural control scheme so that the derived controller is robust with respect to unmodeled dynamics, disturbances and approximate errors. Compared with conventional methods, the proposed approach not only assures closed-loop stability, but also guarantees an H/sub /spl infin// tracking performance for the overall system based on a much relaxed assumption without prior knowledge on the upper bound of the lumped uncertainties. Simulation results have demonstrated that the effect of the lumped uncertainties on tracking error is efficiently attenuated, and chattering of the control input is significantly reduced by using the proposed approach.

Structural diversity of N-heterocyclic carbene complexes of silver(I)

Abstract: Seven N-heterocyclic carbene complexes of silver(I) have been synthesized, five of which were structurally characterized. Polymeric AgI-carbene complexes with a diverse range of structures are formed through extended AgI–AgI interactions, AgI-bridging halides, AgI-bridging dicarbenes, and ring π–π interactions. Compounds having extended AgI–AgI-centered interactions exhibit low energy emission bands at λmax ≈ 540 nm. These bands are assigned to metal-centered transitions involving extended AgI–AgI interactions.

The behavior of Taiwan mutual fund investors—performance and fund flows

Abstract: We examine the investment flow of open-end equity mutual funds. With a unique data from Taiwan, we are able to investigate the buy and sell behavior of mutual investors separately. We find that most investors that invest in large mutual funds are small-amount investors, while those that invest in small funds invest a much larger amount. Small-amount investors of large funds tend to chase past winners and redeem shares once fund performance improves. They are more likely to avoid actively managed funds with high turnover. On the other hand, large-amount investors of small funds appear to be dispassionate buyers whose purchases are not remarkably affected by short-term performance. They are more likely to keep performance-improving funds, redeem the losers, and pay higher management fees.

Managerial Stress in Greater China: The Direct and Moderator Effects of Coping Strategies and Work Locus of Control

Abstract: La presente etude examine les effets directs et moderateurs des strategies de defense (controle et support) et de la perception de controle au travail (exterieure) sur des relations stresseur-tension entre des gestionnaires de la grande Chine (la Republique populaire de Chine, Hong Kong, et Taiwan). Les donnees ont ete recueillies, via un questionnaire autoadministre, aupres de 876 gestionnaires soit 249 (164 hommes, 85 femmes) en Republique populaire de Chine, 280 a Hong Kong (159 hommes, 120 femmes, 1 non classifie), et 347 (191 hommes, 151 femmes, 5 non classifies) au Taiwan. Des effets directs et moderateurs pour les strategies de defense et pour la perception de controle ont ete demontres pour quelques relations stresseur-tension dans les divers echantillons etudies. The present study aims at examining the direct and moderator effects of coping strategies (control and support coping) and work locus of control (externality) on the stressor-strain relationships among managers in Greater China (the People's Republic of China [PRC], Hong Kong, and Taiwan). A self-administered survey method was employed to collect data from 249 (164 male, 85 female) managers in the PRC, 280 (159 male, 120 female, 1 unclassified) managers in Hong Kong, and 347 (191 male, 151 female, 5 unclassified) managers in Taiwan. The direct and moderator effects of control coping, support coping, and work locus of control on some stressor-strain relationships were demonstrated in the studied samples.

Relationship between bilirubin UDP-glucuronosyl transferase 1A1 gene and neonatal hyperbilirubinemia.

Abstract: The variation rate within the coding region of UDP-glucuronosyl transferase 1A1 (UGT1A1) gene in Taiwan Chinese was found to be 29.3%. This study sought to determine whether that high variation rate of UGT1A1 gene is a risk factor for neonatal hyperbilirubinemia. The study subjects consisted of 123 newborn infants suffering from unconjugated hyperbilirubinemia who had no known risk factors for hyperbilirubinemia and 218 healthy control neonates. The promoter area, exons 1 to 4, coding region of exon 5, and the flanking intronic regions in UGT1A1 gene were determined by the PCR in all subjects. Wild UGT1A1 gene, variation in the promoter, variation at nucleotide 211, variation at nucleotide 1091, and compound heterozygous variation of UGT1A1 gene were found. The percentage of neonates with wild UGT1A1 gene and the percentage of neonates with variation at nucleotide 211 were significantly different between the study subjects and controls. The percentages with bilirubin >or=342 micro M (20.0 mg/dL) and with persistent hyperbilirubinemia in the subjects carrying homozygous variation at nucleotide 211 (Gly71Arg) were significantly higher than the neonates carrying wild type or other genotypes. In conclusion, this study has demonstrated that variation at nucleotide 211 of the UGT1A1 gene is a risk factor for the development of neonatal hyperbilirubinemia. Pediatricians should closely follow hyperbilirubinemic newborn infants who carry homozygous 211 G to A variation in UGT1A1 gene.

Automatic thesaurus generation for Chinese documents

Abstract: This article reports an approach to automatic thesaurus construction for Chinese documents. An effective Chinese keyword extraction algorithm is first presented. Experiments showed that for each document an average of 33% keywords unknown to a lexicon of 123,226 terms could be identified by this algorithm. Of these unregistered words, only 8.3% of them are illegal. Keywords extracted from each document are further filtered for term association analysis. Association weights larger than a threshold are then accumulated over all the documents to yield the final term pair similarities. Compared to previous studies, this method speeds up the thesaurus generation process drastically, It also achieves a similar percentage level of term relatedness.

A New Hybrid Case-Based Architecture for Medical Diagnosis.

Abstract: This paper proposes a new hybrid case-based architecture, which supports multiple-disease diagnosis and the learning of new adaptation knowledge. The architecture combines case-based reasoning (CBR), neural networks, fuzzy theory, induction, utility theory, and knowledge-based planning technology together to facilitate medical diagnosis. The basic mechanism is that of CBR. A distributed fuzzy neural network is employed to perform approximate matching and thus to tolerate potential noise in case retrieval. The induction technology along with utility theory is used to select valuable features of the target case and prune unnecessary search space. Knowledge-based planning is a general-purpose mechanism for case adaptation. It creates a case adaptation plan from an adaptation tree, which contains all relevant problem features, satisfies all relevant constraints, and contains all cases whose expected utilities are greater than a threshold. Execution of the case adaptation plan leads to the diagnosis of multiple diseases. The adaptation tree facilitates the reuse of cases and the learning of various types of knowledge-including relationships between disease types and features, case-specific verification knowledge, and differential diagnosis rules. Integrating these techniques in the CBR paradigm can effectively produce a high-quality diagnosis for a given medical consultation.

Kinematic analysis of kicking movements in preterm infants with very low birth weight and full-term infants.

Abstract: Background and Purpose. Study of kicking development provides important information to understand how early spontaneous movements change in infants as they acquire voluntary control. Researchers have investigated the kicking movements of preterm infants; however, the movement patterns that they have described were inconsistent. The purpose of this study, therefore, was to examine the development of kicking movements with kinematic analysis in preterm infants with very low birth weight (VLBW) and full-term infants. Subjects and Methods. Twenty-two infants with VLBW who were divided into low gestational age (gestational age of <30 weeks, n=9) and high gestational age (gestational age of ≥30 weeks, n=13) classes and 22 full-term infants were evaluated during kicking movements using 4 synchronized cameras and 3-dimensional kinematic analysis when the infants were 2 and 4 months of corrected age. Results. The infants with VLBW and a high gestational age showed similar kicking movements compared with the full-term infants. In contrast, the infants with VLBW and a low gestational age exhibited a higher kick frequency and a shorter flexion phase at 4 months of corrected age. They also exhibited a higher hip-knee correlation and lower variability in the interlimb coordination pattern at 2 and 4 months of corrected age. Discussion and Conclusion. The findings indicate that infants with VLBW, particularly those with a low gestational age, have age-related differences in movement organization and coordination of kicking compared with full-term infants.

Orientation dependence and electric-field effect in the relaxor-based ferroelectric crystal (PbMg1/3Nb2/3O3)0.68(PbTiO3)0.32

Abstract: Dielectric permittivities, polarization\char21{}electric-field hysteresis loops, and domain structures have been measured as a function of temperature in relaxor-based ferroelectric single crystals $({\mathrm{PbMg}}_{1/3}{\mathrm{Nb}}_{2/3}{\mathrm{O}}_{3}{)}_{0.68}({\mathrm{PbTiO}}_{3}{)}_{0.32}$ (PMN-32%PT) for $〈110{〉}_{\mathrm{cub}}$ and $〈211{〉}_{\mathrm{cub}}$ orientations. Contrary to the pure ${\mathrm{PbMg}}_{1/3}{\mathrm{Nb}}_{2/3}{\mathrm{O}}_{3}$ (PMN), PMN-32%PT exhibits apparent crystallographic orientation dependences of dielectric permittivities, polarizations, domain structures and phase transitions. With a prior field-cooled treatment, a field-induced state, perhaps of orthorhombic symmetry, is evidenced and coexists with the rhombohedral symmetry in the low-temperature region. This field-induced phase is manifested by an extra dielectric peak observed near 373 K for the $〈211{〉}_{\mathrm{cub}}$ orientation. A relaxation mechanism which is responsible for the so-called diffuse phase transition crosses a wide temperature region of \ensuremath{\sim}340\char21{}400 K and results from fluctuations between rhombohedral and tetragonal states. In order of increasing temperature (without a prior field-cooled treatment), PMN-32%PT undergoes successive phase transformations: rhombohedral $\mathrm{phase}\ensuremath{\rightarrow}\mathrm{coexistence}$ of rhombohedral and tetragonal $\mathrm{phases}\ensuremath{\rightarrow}\mathrm{tetragonal}$ $\mathrm{phase}\ensuremath{\rightarrow}\mathrm{coexistence}$ of tetragonal and cubic $\mathrm{phases}\ensuremath{\rightarrow}\mathrm{cubic}$ phase.

Lifetime principal occupation and risk of cognitive impairment among the elderly.

Abstract: We used a nested case-control design with study participants sampled from two cohorts, for a total of 2, 198 elderly people 65 years or older and completed cognitive tests between 1993 and 1997, to assess the association between an individual's lifetime principal occupation and the subsequent risk of cognitive impairment. Cases consisted of 290 older adults with impaired cognitive functioning. For each case, two controls with comparable age (within 5 years) and sex frequencies were randomly sampled from the seniors free of cognitive impairment. Occupational data were collected through interviews. Individual's job content was coded into one of the occupational categories or the occupationbased social classes. Compared to those who were former legislators, government administrators, or business executives and managers, a significantly elevated risk of cognitive impairment was estimated for those who were employed as agriculture/animal husbandry/forestry/fishing workers (odds ratio (OR)=3.2), craft and related trades workers (OR=2.2), plant and machine operators and assemblers (OR=14.7), workers of elementary occupations (OR=3.2), or housekeepers (OR=2.6). We also observed health inequalities in the risk of cognitive impairment across social classes with a significant doseresponse trend in which unskilled blue-collar workers had the highest risk. After adjustment for education, we still observed an inverse relationship between risk of cognitive impairment and occupational class. This may mean that lifetime longest-held occupation is more intimately involved in the causal pathways leading to cognitive impairment. Further studies that collect information on specific work hazards would help make specific interpretations of the observed effect of lifetime longestheld occupation in early adulthood on risk of cognitive decline in late life.

N-Acetylcysteine, Vitamin C and Vitamin E Diminish Homocysteine Thiolactone-Induced Apoptosis in Human Promyeloid HL-60 Cells

Abstract: We showed previously that homocysteine thiolactone (HcyT) is a potent inducer of apoptosis in HL-60 cells. In the present study, the role of some radical scavengers (N-acetylcysteine, vitamin C, vitamin E and folate) on the reduction of HcyT-induced apoptosis was investigated. Preincubation of HcyT-treated HL-60 cells with vitamin C (Vit C; 100 micro mol/L) or vitamin E (Vit E; 100 micro mol/L) for 2 h significantly reduced the proportion of apoptotic cells with hypodiploid DNA contents or with membrane phosphatidylserine exposure, and attenuated the apoptotic DNA fragmentation. Preincubation of cells with N-acetylcysteine (NAC; 5 mmol/L) for 2 h significantly reduced HcyT-promoted apoptosis measured by membrane phosphatidylserine exposure only. The reduction of HcyT-induced apoptosis by NAC, Vit C or Vit E occurred simultaneously with a significant decrease in intracellular H(2)O(2) levels and reduced caspase-3 enzymatic activity. In contrast, folate had no H(2)O(2) scavenging capacity and did not suppress caspase-3 activity 6 h after HcyT treatment, although folate exhibited antioxidant behavior toward superoxide anions, hydroxyl radicals and peroxynitrite. Preincubation of cells with folate (10 micro mol/L) for 3 d did not affect the extent of HcyT-promoted apoptotic damage. Taken together, our findings suggest that antioxidant pretreatment with NAC, Vit C or Vit E exerts more beneficial effects than folate on reducing apoptotic cell damage induced by homocysteine thiolactone.

An improved method for determination of isoflavones in soybean powder by liquid chromatography

Abstract: Several extraction and separation methods were evaluated and then developed for determination of isoflavone in soybean powder. Results showed that the highest yield of isoflavones was achieved by using defatted soybean powder as raw material, followed by shaking extraction for 2h with a mixture of acetone and 0.1 M hydrochloric acid as solvent. A mobile phase of acetonitrile (A) and water (B) with the following gradient elution was developed: 5% A in B initially, then increased to 10% A in 5 min, 25% A in 15 min, 32% A in 22 min and returned to 5% A in 27 min. Twelve isoflavones in soybean powder were resolved within 20 min using a Vydac 201TP54 column flow rate 20 mL min−1 and detection at 262 nm. The amounts of various isoflavones in soybean powder were also determined.

Alteration of trace element distribution and testis ACE activity in mice with high peritoneal aluminum.

Abstract: The present investigation was conducted to assess the effects of subacute aluminum (Al) exposure on testicular zinc (Zn), copper (Cu), and iron (Fe) distribution in mice. Animals were intraperitoneally exposed to 0, 13, or 35 mg Al/kg body weight/d for a period of 14 d. Al concentrations in serum and testis in Al-treated animals were significantly higher than those of controls. The serum concentrations of Fe were lower, whereas serum Zn and Cu showed a pattern comparable to that of controls. The accumulation of testicular Fe and Cu remarkably increased in Al-exposed groups, whereas the Zn concentration in testis was significantly reduced only at the highest dose of Al exposure. The values of testicular thiobarbituric acid reactive substances (TBARS) were also increased after Al administration, indicating increased lipid peroxidation and oxidative stress. In addition, when the testicular Al was increased, the testis-specific angiotensin-converting enzyme (testis ACE) was noted. The results of this study indicated that part of the effect of Al intoxication on testis might contribute to abnormal metabolism of other minerals, such as Fe, Zn, and/or Cu. It was also suggested that reduced testis ACE activity presumably plays an important role in oxidative damage of Al-induced testicular toxicity.

A tumor cell growth inhibitor from Saposhnikovae divaricata.

Abstract: In the present study, we tested ethanolic extracts from 10 Chinese herbs for their effects on K562, Raji, Wish, HeLa, Calu-1, and Vero tumor cells proliferation. On a percentage basis, panaxynol purified from Saposhnikovae divaricata had the highest inhibitory activity on various tumor cells proliferation. Cell-cycle analysis indicated that panaxynol arrested the cell cycle progression of tumor cells from the G1 transition to the S phase. In an attempt to further localize the point in the cell cycle where arrest occurred, gene expression of cyclin E, a key regulatory event leading to the G1/S boundary was examined. Results indicated that the levels of cyclin E mRNA in various tumor cells were decreased by panaxynol. Thus, the suppressant effects of panaxynol on proliferation of various tumor cells appeared to be mediated, at least in part, through impairments of cyclin E mRNA levels and arresting cell cycle progression in the cells.

Investigating the information content of non-cash-trading index futures using neural networks

Abstract: This study investigates the information content of SGX-DT Nikkei 225 and MSCI Taiwan index futures prices during the non-cash-trading (NCT) period. The lead–lag relationship between the futures market during the NCT period and the cash market during its opening period is first investigated by the generalized methods of moments. The obtained leading futures and previous day's cash market closing index are then used as the input variables to predict the opening cash price index by the backpropagation neural network model. Sensitivity analysis is first employed to address and solve the issue of finding the appropriate setup of the topology of the networks. Extensive studies are then performed on the robustness of the constructed network by using different training and testing sample sizes. To demonstrate the effectiveness of our proposed method, the 5-min intraday data of spot and futures index from a 6-month historical record were evaluated using the designed neural network model. Analytic results demonstrate that the proposed neural network model outperforms the neural network model with previous day's closing index as the input variable, the random walk and GARCH model forecasts. It, therefore, indicates that there is valuable information involved in the futures prices during the NCT period that can be used to forecast the opening cash price index. Besides, the neural network model provides better forecasting results than the commonly discussed GARCH model.

Presynaptic cross-talk of β-adrenoreceptor and 5-hydroxytryptamine receptor signalling in the modulation of glutamate release from cerebrocortical nerve terminals

Abstract: The presynaptic interactions between facilitatory β-adrenoreceptors and inhibitory 5-hydroxytryptamine (5-HT) receptors modulating glutamate release from cerebrocortical nerve terminals were examined 4-Aminopyridine (4-AP, 1 mM)-evoked glutamate release was facilitated by the membrane permeant cyclic-3′,5′-adenosine monophosphate (cAMP) analogue, 8-bromo-cAMP (8-Br-cAMP), used to directly activate cAMP-dependent protein kinase (PKA) The β-adrenoreceptor agonist, isoprenaline (ISO), effected a concentration-dependent potentiation of 4-AP-evoked glutamate release which was abolished by the β-adrenoreceptor antagonist, propranolol, and the PKA inhibitor, Rp-cyclic-3′,5′-adenosine-monophosphothioate (Rp-cAMPS) 5-HT receptor activation by 100 μM 5-HT produced an inhibition of 4-AP-evoked glutamate release in nerve terminals The inhibitory effect of 5-HT could be mimicked by the selective 5-HT1A receptor agonist, 8-hydroxy-dipropylaminotetralin (8-OH-DPAT) and antagonized by 1-(2-methoxyphenyl)-4-(4-phthalimidobutyl)piperazine (NAN-190) When 5-HT (or 8-OH-DPAT) was used in conjunction with ISO or 8-Br-cAMP, the β-adrenoreceptor- and PKA-mediated potentiation of glutamate release was abrogated The inhibitory crosstalk of 5-HT1A receptors to β-adrenoceptor-mediated facilitation of glutamate release was abolished in the presence of NAN-190 Examination of voltage-dependent Ca2+ influx revealed that, while ISO and 5-HT alone caused a respective potentiation and diminution of the 4-AP-evoked increase in [Ca2+]c, the co-presence of 5-HT abolished the ISO mediated potentiation of Ca2+ influx Together, these results suggest that β-adrenoreceptors and 5-HT1A receptors coexist on the cerebrocortical nerve terminals and that the cross-talk between the two receptor signalling pathways occurs at a locus downstream from cAMP production, possibly at the level of voltage-dependent Ca2+ influx British Journal of Pharmacology (2002) 137, 1371–1379 doi:101038/sjbjp0705045

Advantages of open laparoscopic surgery over exploratory laparotomy in patients with tubo-ovarian abscess.

Abstract: Study Objective To compare laparoscopic surgery and conventional laparotomy in managing patients with tubo-ovarian abscess (TOA). Design Retrospective study (Canadian Task Force classification II-2). Setting Regional hospital. Patients Sixty-nine women with clinically suspicious TOA. Intervention Operative laparoscopy or laparotomy Measurements and Main Results Laparoscopic surgery in 19 women had significant advantages over laparotomy in 37 women. It decreased hospital stay (5.37 ±1.38 days vs 8.92 ± 2.59 days, p = 0.0001), had a lower percentage of wound infections, and had a shorter time for fever to subside (25.79 ± 11.45 vs 39.46 ± 17.47 hrs, p = 0.003). Conclusion Although management of TOA consists of conservative medical treatment with antibiotics, it is now widely accepted that surgical intervention should be pursued early after the diagnosis. Open laparoscopy seems to be a good alternative to traditional laparotomy in managing these patients.