Browsing by Author "Lin, TY"

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210-km Bidirectional transmission system with a novel four-port interleaver to facilitate unidirectional amplification
(2006-01-01)
Huang, MF
;
Chen, J
;
Feng, KM
;
Wei, CC
;
Lai, CY
A novel bidirectional transmission system is proposed and experimentally demonstrated using a four-port interleaver to enable unidirectional amplification. Following bidirectional transmission through 210 km of standard single-mode fibers, sensitivity variations of less than 0.2 dB, with a bit-error rate level of 10(-9) at 10 Gb/s, were observed between bidirectional and unidirectional transmissions.
A new BlueRing scatternet topology for Bluetooth with its formation, routing, and maintenance protocols
(2003-06-01)
Lin, TY
;
Tseng, YC
;
Chang, KM
;
資訊工程學系
;
Department of Computer Science
The basic networking unit in Bluetooth is piconet, and a larger-area Bluetooth network can be formed by multiple piconets, called scatternet. However, the structure of scatternets is not defined in the Bluetooth specification and remains as an open issue at the designers' choice. It is desirable to have simple yet efficient scatternet topologies with good supports of routing protocols, considering that Bluetooths are to be used for personal area networks with design goals of simplicity and compactness. In the literature, although many routing protocols have been proposed for mobile ad hoc networks, directly applying them poses a problem due to Bluetooth's special baseband and MAC-layer features. In this work, we propose an attractive scatternet topology called BlueRing, which connects piconets as a ring interleaved by bridges between piconets, and address its formation, routing, and topology-maintenance protocols. The BlueRing architecture enjoys the following fine features. First, routing on BlueRing is stateless in the sense that no routing information needs to be kept by any host once the ring is formed. This would be favorable for environments such as Smart Homes where computing capability is limited. Second, the architecture is scalable to median-size scatternets easily (e.g. around 50 similar to 70 Bluetooth units). In comparison, most star- or treelike scatternet topologies can easily form a communication bottleneck at the root of the tree as the network enlarges. Third, maintaining a BlueRing is an easy job even as some Bluetooth units join or leave the network. To tolerate single-point failure, we propose a protocol-level remedy mechanism. To tolerate multipoint failure, we propose a recovery mechanism to reconnect the BlueRing. Graceful failure is tolerable as long as no two or more critical points fail at the same time. As far as we know, the fault-tolerant issue has not been properly addressed by existing scatternet protocols yet. In addition, we also evaluate the ideal network throughput at different BlueRing sizes and configurations by mathematical analysis. Simulation results are presented, which demonstrate that BlueRing outperforms other scatternet structures with higher network throughput and moderate packet delay. Copyright (C) 2003 John Wiley Sons, Ltd.
A positive charge at position 33 of thioredoxin primarily affects its interaction with other proteins but not redox potential
(2004-02-03)
Lin, TY
;
Chen, TS
;
生物科技學系
;
Department of Biological Science and Technology
Oxidoreductases of the thioredoxin superfamily possess the C-X-X-C motif. The redox potentials vary over a wide range for these proteins. A crucial determinant of the redox potential has been attributed to the variation of the X-X dipeptide. Here, we substitute Lys for Gly at the first X of Escherichia coli thioredoxin to investigate how a positive charge would affect the redox potential. The substitution does not affect the protein's redox potential. The equilibrium constant obtained from pairwise reaction between the mutant and wild-type proteins equals 1.1, indicating that the replacement does not significantly affect the thiol-disulfide redox equilibrium. However, the catalytic efficiency of thioredoxin reductase on the G33K mutant decreases approximately 2.8 times compared to that of the wild type. The mutation mainly affects K-m, with little effect on k(cat). The mutation also inhibits thioredoxin's ability to reduce insulin disulfide by approximately one-half. Whether the mutant protein supports the growth of phages T3/7 and f1 was tested. The efficiency of plating (EOP) of T3/7 on the mutant strain decreases 5 times at 37 degreesC and 3 x 10(4) times at 42 degreesC relative to that of the wild-type strain, suggesting that interaction between phage gene 5 protein and thioredoxin is hindered. The mutation also reduces the EOP of phage f1 by 8-fold at 37 degreesC and 1.5-fold at 42 degreesC. The global structure of the mutant protein does not change when studied by CD and fluorescence spectra. Therefore, G33K does not significantly affect the overall structure or redox potential of thioredoxin, but primarily interferes with its interaction with other proteins. Together with the G33D mutation, the overall results show that a charged residue at the first X has a greater influence on the molecular interaction of the protein than the redox potential.
An adaptive sniff schedliling scheme for power saving in Bluetooth
(2002-12-01)
Lin, TY
;
Tseng, YC
;
資訊工程學系
;
Department of Computer Science
Bluetooth is expected to be an important basic constructing component of smart homes. In a smart home environment, many devices will be portable and battery-operated, making power saving an essential issue. In this article we study the problem of managing the low-power sniff mode in Bluetooth, where a slave is allowed to be awake only periodically. One challenging problem is how to schedule each slave's sniffing period in a piconet so as to resolve the trade-off between traffic and power-saving requirements, to which we refer as the sniff-scheduling problem. We propose an adaptive protocol to dynamically adjust each slave's sniff parameters, with a goal of catching the varying, and even asymmetric, traffic patterns among the master and slaves. Compared to existing works, our work is unique. First, our scheduling considers multiple slaves simultaneously. Existing work only considers one slave, and different slaves are treated independently. Second, our scheduling is more accurate and dynamic in determining the sniff-related parameters based on slaves' traffic patterns. Most work is restricted to a naive exponential adjustment in sniff interval/sniff-attempt window. Third, our proposal includes the placement of sniff-attempt periods of sniffed slaves on the time axis when multiple slaves are involved. This issue is ignored by earlier work. Extensive simulation results are presented. Among many observations, one interesting result is that with proper settings, our protocol can save significant power while achieving higher network throughput than a naive always active round-robin scheme.
An efficient link polling policy by pattern matching for bluetooth piconets
(2004-03-01)
Lin, TY
;
Tseng, YC
;
Lu, YT
;
資訊工程學系
;
Department of Computer Science
Bluetooth has a master-slave configuration called a piconet. Unspecified in the Bluetooth standard, the link polling policy adopted by a master may significantly influence the bandwidth utilization of a piconet. Several works have been dedicated to this issue. However, none of them addresses the asymmetry of traffics between masters and slaves, and the different data packet types provided by Bluetooth are not fully exploited. In this paper, we propose an efficient pattern matching polling (PMP) policy for data link scheduling that properly resolves these deficiencies. A polling pattern is a sequence of Bluetooth packets of different type combinations (e.g. DH1/DH3/DH5/DM1/DM3/DM5) to be exchanged by a master-slave pair that can properly reflect the traffic ratio (i.e. asymmetry) of the pair. By judiciously selecting a proper polling pattern together with polling times for the link, the precious wireless bandwidth can be better utilized. The ultimate goal is to reduce the unfilled, or even null, payloads in each busy slot. In addition, an overflow mechanism is included to handle unpredictable traffic dynamics. Extensive simulations are presented to justify the capability of PMP in handling regular as well as bursty traffics.
An experimental approach characterizing rear bicycle derailleur systems part I: Performance test
(1998)
Lin, TY
;
Tseng, CH
;
機械工程學系
;
Department of Mechanical Engineering
The derailleur system on a bicycle serves the same purpose as transmissions in motor vehicles: they provide different speed ratios for different situations. Cyclists can choose between speed and labour-saving by moving shift levers to complete a series of mechanical motions that change gears. Therefore, the shifting performance of the derailleur system is very important in designing derailleur system components. This paper proposes a systematic procedure for arranging the design steps for the derailleur system. It promises that the derailleur system components will integrate well and operate effectively. The performance test indices in the present paper can be used to judge the shifting performance during the period of shifting gears. Many design and manufacturing imperfections in products can also be found using the experimental results from performance test. Experimental procedures provide an environment that replaces subjective human 'feel' tests used in the past.
An experimental approach characterizing rear bicycle derailleur systems part II: the stability region and its applications
(1998)
Lin, TY
;
Tseng, CH
;
Fong, ZH
;
機械工程學系
;
Department of Mechanical Engineering
An important concept in the design procedure of bicycle derailleur systems called the stability region is presented in this study. The stability region properties are introduced, and experimental procedures for stability region determination are proposed. The stability ratio, which is a performance index for the stability region is also defined. Shift-lever characteristics such as indexed point, over-shifting and under-shifting can be determined from the stability region experiments. Design concepts and skills for shift lever design are proposed, and a case study is given for demonstration.
An improved packet collision analysis for multi-Bluetooth piconets considering frequency-hopping guard time effect
(2004-12-01)
Lin, TY
;
Liu, YK
;
Tseng, YC
;
資訊工程學系
;
Department of Computer Science
Operating in the unlicensed 2.4-GHz ISM band, a Bluetooth piconet will inevitably encounter the interference problem from other piconets. With a special channel model and packet formats, one research issue is how to predict the packet collision effect in a multipiconet environment. In several earlier works, El-Hoiydi (2001), El-Hoiydi and Decotignie (2001), Lim et al. (2001), this problem is studied, but the results are still very limited in that packets are usually assumed to be uniform in lengths and in that time slots of each piconet are assumed to be fully occupied by packets. These assumptions have been successfully removed in the analytical results proposed in Lin and Tseng (2003). In this paper, we further improve the analytical results in Lin and Tseng (2003) by taking into account the frequency-hopping guard time effect in Bluetooth baseband. The result would offer a way to better estimate the network performance in a multipiconet environment.
Anti-HCV activities of selective polyunsaturated fatty acids
(2004-05-21)
Leu, GZ
;
Lin, TY
;
Hsu, JTA
;
生物科技學系
;
Department of Biological Science and Technology
HCV infection can lead to chronic infectious hepatitis disease with serious sequelae. Interferon-alpha, or its PEGylated form, plus ribavirin is the only treatment option to combat HCV. Alternative and more effective therapy is needed due to the severe side effects and unsatisfactory curing rate of the current therapy. In this study, we found that several polyunsaturated fatty acids (PUFAs) including arachidonic acid (AA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) are able to exert anti-HCV activities using an HCV subgenomic RNA replicon system. The EC50 (50% effective concentration to inhibit HCV replication) of AA was 4 muM that falls in the range of physiologically relevant concentration. At 100 muM, alpha-linolenic acid, gamma-linolenic, and linoleic acid only reduced HCV RNA levels slightly and saturated fatty acids including oleic acid, myristic acid, palmitic acid, and steric acid had no inhibitory activities toward HCV replication. When AA was combined with IFN-alpha, strong synergistic anti-HCV effect was observed as revealed by an isobologram analysis. It will be important to determine whether PUFAs can provide synergistic antiviral effects when given as food supplements during IFN-based anti-HCV therapy. Further elucidation of the exact anti-HCV mechanism caused by AA, DHA, and EPA may lead to the development of agents with potent activity against HCV or related viruses. (C) 2004 Elsevier Inc. All rights reserved.
Anti-HCV activities of selective polyunsaturated fatty acids (vol 318, pg 275, 2004)
(2005-04-22)
Leu, GZ
;
Lin, TY
;
Hsu, JTA
;
生物科技學系
;
Department of Biological Science and Technology
Architecture for area-efficient 2-D transform in H.264/AVC
(2005)
Kuo, YT
;
Lin, TY
;
Liu, CW
;
Jen, CW
;
電子工程學系及電子研究所
As the VLSI technology advances continuously, ASIC can easily achieve the required performance and most of them are actually over-designed. Thus, architecture shrinking is inevitable in optimal designs especially when supply voltages are getting lower. However, conventional designs starting from minimization of algorithmic operations (e.g. multiply) may not always lead to optimal architectures, for the wires and the interconnection complexity significantly grow and have become predominant. This paper explores algorithms and architectures for the 2-D transform in H.264/AVC, of which the operations are very simple (i.e. only shift and add). We have shown that fewer operations do not always result in more compact designs. In our experiments with the UMC 0.18 mu m CMOS technology, the most straightforward matrix multiplication without separable 2-D operation or any fast algorithm has the best area efficiency for D1-size (720x480) video at 30fps. It saves 48%, 34% and 16% silicon area of the previous works respectively.
Collision analysis for a multi-Bluetooth picocells environment
(2003-10-01)
Lin, TY
;
Tseng, YC
;
資訊工程學系
;
Department of Computer Science
Operating in the unlicensed 2.4-GHz ISM band, a Bluetooth piconet will inevitably encounter the interference problem from other piconets. With a special channel model and packet formats, one research issue is how to predict the packet collision effect in a multi-piconet environment. In an earlier work by El-Hoiydi in 2001, this. problem is studied, but the result is still very limited, due to the assumptions that packets must be single-slot ones and that time slots of each piconet must be fully occupied by packets. A more general analysis is presented in this work by eliminating these constraints.
Event-driven messaging services over integrated cellular and wireless sensor networks: Prototyping experiences of a visitor system
(2005-06-01)
Tseng, YC
;
Lin, TY
;
Liu, YK
;
Lin, BR
;
資訊工程學系
As one of the killer applications, instant messaging has become a simple yet efficient tool for peer-to-peer communications in data networks. In telephone networks, short message services are gaining more popularity as well. However, this kind of services typically operates in their own respective networks and is triggered by fairly simple events (such as pushing a "send" button or prescheduling the transmission at later time). A promising direction is to trigger instant messages by environmental information from the physical world. In light of this, this paper proposes to establish an event-driven messaging service over a cellular-and-sensor-integrated network. We have prototyped a system which adopts Global System for Mobile Communication (GSM) as the cellular network, and Bluetooth technology as the sensor network. The latter is to realize a Bluetooth surveillance network with location-sensing capabilities to be deployed within an office building area. While using other technologies is possible, GSM and Bluetooth are two dominating technologies in telephone and data networks. So the proposed technology is immediately feasible, given the fact that many handsets are already Bluetooth-enabled. Through this combination, we demonstrate a visitor system (VS) that offers several attractive features/services for visitors arriving at an office. First, messaging services in VS are driven by preconfigured events which can be collected from the Bluetooth surveillance network. Simple events might be a person entering/leaving a space, while complicated events might be a compound logic statement involving multiple users and multiple locations in VS. Second, we believe that the proposed system justifies the potential of cross-network applications and services. Third, the proposed architecture takes a modular approach by dividing the system into several subsystems according to their functionality. Logically dispatching jobs is the key to future extensions and further value-added services. The system architecture and implementation details are reported. Performance analyses are presented to model the detection latency of a Bluetooth sensor network.
G33D mutant thioredoxin primarily affects the kinetics of reaction with thioredoxin reductase. Probing the structure of the mutant protein
(1999-11-23)
Lin, TY
;
生物科技學系
;
Department of Biological Science and Technology
Escerichia coli thioredoxin is a redox-active protein. A mutant protein with an aspartic acid substitution for the largely conserved glycine at position 33 (G33D) in the active site of thioredoxin has been generated to study the effects of a negatively charged residue in the active site of the protein. Despite the close proximity of the negative-charged Asp to the redox active cysteines, the effective concentration of the cysteines does not deviate significantly from that of the wild-type protein. The redox potential (E-o') measured by the equilibrium between NADPH and the mutant thioredoxin is also close to that of the wild-type. Kinetic measurements of the reaction between thioredoxin and thioredoxin reductase show that G33D mutant and the wild-type proteins have identical k(cat) values. However, the K-m for G33D mutant is approximately 10-fold higher than that for the wild-type protein. In vivo assay of the growth of E.coli strain carrying wild-type or G33D mutant thioredoxin on methionine sulfoxide indicates that the G33D mutant protein is a slower electron donor for methionine sulfoxide reductase. Structural stability of the oxidized protein is not altered by the G33D substitution, as illustrated by the same unfolding free energies studied by urea. The substitution does not show significant change of the near UV and far-UV circular dichroic (CD) and the fluorescence spectra for either the reduced or the oxidized protein. Therefore, the global structure of the G33D protein is not changed. However, the surface of the active site has been altered locally by G33D substitution, which accounts for the above kinetically poor behaviors. A model of G33D structure is constructed based on these studies.
Inhibition of hepatitis C virus replication by antimonial compounds
(2005-10-01)
Hwang, DR
;
Lin, RK
;
Leu, GZ
;
Lin, TY
;
Lien, TW
Chronic hepatitis C virus (HCV) infection is a worldwide health problem causing serious complications, such as liver cirrhosis and hepatoma. Alpha interferon (IFN-alpha) or its polyethylene glycol-modified form combined with ribavirin is the only recommended therapy. However, an alternative therapy is needed due to the unsatisfactory cure rate of the IFN-based therapy. Using a modified reporter assay based on the HCV subgenomic-replicon system, we found that sodium stibogluconate (SSG), a compound used for leishmania treatment, suppressed HCV replication. We have previously reported that SSG is effective at inhibiting HCV replication in a cell line permissive for HCV infection/replication and in an ex vivo assay using fresh human liver slices obtained from patients infected with HCV (26). In this study, we show that the SSG 50% inhibitory dose for HCV replication is 0.2 to 0.3 mg/ml (equivalent to 345 to 517 mu M of Sb) in the HCV subgenomic-replicon system. We also found that SSG and IFN-alpha exert a strong synergistic anti-HCV effect in both the traditional isobologram analysis and the median effect principle (CalcuSyn analysis). The combination of SSG and IFN-alpha could sustain the antiviral response better than SSG or IFN-alpha alone. The results suggest that SSG may be a good drug candidate for use in combination with other therapeutics, such as IFN-alpha and ribavirin, to treat HCV infection.
Investigation of the polarity asymmetry on the electrical characteristics of thin polyoxides grown on N+ polysilicon
(1997-01-01)
Wu, SL
;
Chen, CY
;
Lin, TY
;
Lee, CL
;
Lei, TF
The polarity asymmetry on the electrical characteristics of the oxides grown on n(+) polysilicon (polyoxides) was investigated in terms of the oxidation process, the doping level of the lower polysilicon layer, the oxidation temperature and the oxide thickness, It was found that the thin polyoxide prepared by using a low-temperature wafer loading and N-2 preannealing process, has a smoother polyoxide/polysilicon interface and exhibits a lower oxide tunneling current, a higher dielectric breakdown field when the top electrode is positively biased, a lower electron trapping rate and a larger charge-to-breakdown than does the normal polyoxide. The polarity asymmetry is also strongly dependent on the doping level of the lower polysilicon layer, the oxidation temperature and the oxide thickness. It was found that only the thinner polyoxides (less than or equal to 240 Angstrom) grown on the heavily-doped polysilicon film (30 Ohm/sq) by using the higher-temperature oxidation process (greater than or equal to 950 degrees C) conduct a less oxide tunneling current when the top electrode is positively biased.
Mammalian Ste20-like protein kinase 3 (Mst3) plays an important role in spontaneous delivery
(2006-03-06)
Wu, HY
;
Lin, CY
;
Lin, TY
;
Yuan, CJ
;
生物科技學系
Metro add-drop network applications of cascaded dispersion-compensated interleaver pairs using a recirculating loop
(2005-06-01)
Feng, KM
;
Huang, MF
;
Wei, CC
;
Lai, CY
;
Lin, TY
A 50-GHz channel spaced dispersion-compensated interleaver pair for a metro add-drop network application was demonstrated using a recirculating loop. After five cascaded nodes (ten interleavers), a 2.5-dB sensitivity differential at bit-error-rate level around 10(-9) was observed between the compensated and uncompensated pairs within a +/- 10-GHz detuning frequency window.
Optical properties of Zn1-xMnxSe epilayers grown by molecular beam epitaxy
(1998-04-01)
Chou, WC
;
Ro, CS
;
Hong, DY
;
Yang, CS
;
Lin, CY
Zn1-xMnxSe (x less than or equal to 0.78) epilayers were grown on the GaAs (001) substrate with tilt angle 0, 3, 10, and 15 degrees toward [010] by the molecular beam epitaxy. The reflectivity, transmission, and photoluminescence experiments were used to measure the energy gap of the epilayers. A red shift of 4 meV was found as the substrate tilt angle increased from 0 to 15 degrees. The red shift in band gap energy is attributed to the increasing incoporation of smaller Zn ion with the increase in the kink density which results from the increase in the substrate tilt angle. In addition, the lattice vibration of the Zn1-xMnxSe (0 less than or equal to x less than or equal to 0.78) epilayers measured by the Raman scattering was found to follow the intermediate mode behavior of type Ib instead of type Ic. The force constants F-MnSe = 2.81 x 10(6) amu.cm(-2) and F-ZnSe = 3.96 x 10(6) amu.cm(-2) were obtained.
Optimum design for artificial neural networks: an example in a bicycle derailleur system
(2000-02-01)
Lin, TY
;
Tseng, CH
;
機械工程學系
;
Department of Mechanical Engineering
The integration of neural networks and optimization provides a tool for designing network parameters and improving network performance. In this paper, the Taguchi method and the Design of Experiment (DOE) methodology are used to optimize network parameters. The users have to recognize the application problems and choose a suitable Artificial Neural Network model. Optimization problems can then be defined according to the model. The Taguchi method is first applied to a problem to find out the more important factors, then the DOE methodology is used for further analysis and forecasting. A Learning Vector Quantization example is shown for an application to bicycle derailleur systems. (C) 2000 Elsevier Science Ltd. All rights reserved.