Browsing by Author "Lin, PC"

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A priority TCAM IP-Routing lookup scheme
(2003-07-01)
Lin, PC
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Chang, CJ
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電信工程研究所
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Institute of Communications Engineering
A priority TCAM IP-routing lookup scheme, which combines a priority ternary content addressable memory (TCAM) technique with a compact IP-routing lookup scheme, is proposed in this letter. It not only completes an IP-routing lookup with two memory accesses but also achieves small lookup table size and fast table reconstruction time.
An efficient per-VC accounting-based buffer management scheme for GFR services in TCP/IP networks
(2005-06-01)
Lin, PC
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Chang, CJ
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電信工程研究所
;
Institute of Communications Engineering
An efficient per-virtual connection (per-VC) accounting-based scheme with steepest decent weight updating (PASD) algorithm is proposed for buffer management in TCP/IP networks supporting guaranteed frame rate (GFR) services. It can achieve good fairness, high utilization, and low delay. Also it can be implemented by a genuine FIFO architecture and thus easily support up to 10 Gbps STM-64 rate.
Analysis of buffer requirement for ATM-LSRs with partial VC-merging capability
(2002-06-01)
Lin, PC
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Chang, CJ
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電信工程研究所
;
Institute of Communications Engineering
In an Multi-Protocol Label Switching (MPLS) network domain, Asynchronous Transfer Mode-Label Switch Routers (ATM-LSRs) are considered the best candidate for providing the highest forwarding capability. ATM-LSRs implement a VC-merging scheme that allows many IP routes to be mapped into the same VPI/VCI label, hence supporting scalability. The VC-merging requires reassembly buffers to reconstruct an original packet from its segmented but interleaved AAL-5 cells. In this paper, we analyze the performance of an ATM-LSR with partial VC-merging capability and investigate the impact of VC-merging on the requirement of the reassembly and output buffer. The numerical computation complexity of the mathematical analysis can be reduced from O(M-4) to O(M-2), where M is the total number of ON-OFF sources. We also propose a closed-form equation, which approximates the distribution of the output buffer with satisfactory accuracy. Numerical results show that when incoming cells are severely interleaved, the VC-merging needs the reassembly buffer size to be of the same order as the output buffer size, which cannot be ignored.
Assessing process performance based on the incapability index C-pp
(2005-06-01)
Lin, PC
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Pearn, WL
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工業工程與管理學系
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Department of Industrial Engineering and Management
Process incapability index C-pp has been introduced to the manufacturing industry to measure process performance. But all existing methods for testing C-pp require further estimation of the distribution parameters when calculating the p-values and critical values causing additional sampling errors, which is unreliable. In this paper, an efficient SAS computer program is provided to calculate the p-values. Extensive calculations were performed to examine the behavior of the p-values and the critical values c(0) against the distribution parameter. Useful critical values for commonly used capability requirements are also tabulated. A simple but practical step-by-step hypothesis-testing procedure is developed for in-plant applications. Significance: Complicated statistical theory for the uniformly minimum variance unbiased estimator (UMVUE) of C-pp is implemented for testing normal processes. An efficient computer program and useful critical values are given. A practical procedure is developed for the practitioners to determine whether their process meets the preset capability requirement. Since the proposed procedure does not require further estimation of the distribution parameter, the decisions made are more reliable than that using other approaches.
Capability measures for processes with multiple characteristics
(2003-03-01)
Chen, KS
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Pearn, WL
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Lin, PC
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工業工程與管理學系
;
Department of Industrial Engineering and Management
Process capability indices, such as C-p, C-a, and C-pk, have been widely used in the manufacturing industry providing numerical measures on process precision, process accuracy, and process performance. Capability measures for processes with a single characteristic have been investigated extensively. However, capability measures for processes with multiple characteristics are comparatively neglected In this paper, we consider a generalization of the yield index S-pk proposed by Boyles, for processes with multiple characteristics. We establish a relationship between the generalization and the process yield. We also develop a control chart based on the proposed generalization, which displays all the characteristic measures in one single chart. Using the chart, the engineers can effectively monitor and control the performance of all process characteristics simultaneously. Copyright (C) 2003 John Wiley Sons, Ltd.
Computer program for calculating the p-value in testing process capability index C-pmk
(2002-07-01)
Pearn, WL
;
Lin, PC
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Many process capability indices, including C-p, C-pk, and C-pm, have been proposed to provide numerical measures on the process potential and performance. Combining the advantages of these indices, Pearn et al. (1992) introduced a new capability index called C-pmk, which has been shown to be a useful capability index for processes with two-sided specification limits. In this paper, we implement the theory of a testing hypothesis using the natural estimator of C-pmk, and provide an efficient Maple computer program to calculate the p-values. We also provide tables of the critical values for some commonly used capability requirements. Based on the test we develop a simple step-by-step procedure for in-plant applications. The practitioners can use the proposed procedure to determine whether their process meets the preset capability requirement, and make reliable decisions. Copyright (C) 2002 John Wiley Sons, Ltd.
Direct web switch routing with state migration, TCP masquerade, and cookie name rewriting
(2003)
Lin, YD
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Tsai, PT
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Lin, PC
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Tien, CM
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資訊工程學系
Existing layer 4 load balancers are content-blind and often have difficulty in redirecting HTTP requests. to the appropriate server in the session manner. Layer 7 load balancers, also referred to as web switches, are content-aware and support session persistence. However, most web switches employ a bi-direction architecture, which means both request and response traffic must both pass through the load balancer. This makes a web switch become a bottleneck easily. In this paper, we present a direct routing architecture to prevent response traffic from passing through the web switch. Our solution is highly scalable in the number of back-end servers. In addition, two simple but effective mechanisms, one-packet TCP state migration and cookie name rewriting to packet filter, are presented to support persistent connection and session persistence. Through the external benchmark, we prove that our system outperforms existing solutions. The internal benchmark investigates the bottlenecks of our system and suggests the future improvement.
Estimating process capability index C"(pmk) for asymmetric tolerances: Distributional properties
(2001)
Pearn, WL
;
Lin, PC
;
Chen, KS
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Pearn et al. (1999) considered a capability index C"(pmk), a new gener alization of C-pmk, for processes with asymmetric tolerances. In this paper, we provide a comparison between C"(pmk), and other existing generalizations of C-pmk PM on the accuracy of measuring process performance for processes with asymmetric tolerances. We show that the new generalization C"(pmk) is superior to other existing generalizations of C-pmk. Under the assumption of normality, we derive explicit forms of the cumulative distribution function and the probability density function of the estimated index (C) over cap "(pmk). We show that the cumulative distribution function and the probability density function of the estimated index (C) over cap "(pmk) can be expressed in terms of a mixture of the chi-square distribution and the normal distribution. The explicit forms of the cumulative distribution function and the probability density function considerably simplify the complexity for analyzing the statistical properties of the estimated index (C) over cap "(pmk).
Evolution and evaluation of Internet content delivery
(2003)
Tien, CM
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Lin, PC
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Lin, YD
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資訊工程學系
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Department of Computer Science
Internet content delivery has evolved from centralized hosting, Web replication to the recent content delivery network (CDN). Centralized hosting has the problems of high backbone bandwidth consumption and long user-perceived latency, while Web replication leads to high investment and operational costs in deploying servers in several ISP networks. However, a content delivery network acts as a third party to deliver for various content providers into many ISPs. In this paper, we Introduce the evolution of Internet content delivery and evaluate the performance of CDN. In our evaluation, we find that CDN is more cost-effective than Web replication, saves more bandwidth consumption and distribution time than traditional distribution alternatives such as FTP, has shorter user-perceived latency than centralized hosting, and Improves delivery quality of streaming media.
Measuring process yield based on the capability index C-pm
(2004)
Pearn, WL
;
Lin, PC
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Process capability indices C-p, C-a, C-pk and C-pm have been proposed to the manufacturing industry as capability measures based on various criteria including variation, departure, yield, and loss. It has been noted in recent quality research and capability analysis literature that both the C-pk and C-pm indices provide the same lower bounds on process yield, that is, Yield greater than or equal to 2Phi(3C(pk)) - 1 = 2Phi(3C(pm)) - 1. In this paper, we investigate the behaviour of the actual process yield in terms of the number of nonconformities (in ppm) for processes with a fixed index value of C-pk = C-pm, but with different degrees of process centring, which can be expressed as a function of the capability index C-a. The results illustrate that it is advantageous to use the index C-pm over the index C-pk when measuring process capability, since C-pm provides better customer protection.
Nanoprobe-based affinity mass spectrometry for selected protein profiling in human plasma
(2005-09-15)
Chou, PH
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Chen, SH
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Liao, HK
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Lin, PC
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Her, GR
In recent decades, magnetic nanoparticles have emerged as a promising new platform in biomedical applications, particularly bioseparations. We have developed an immunoassay using antibody-conjugated magnetic nanoparticles as an efficient affinity probe to simultaneously preconcentrate and isolate targeted antigens from biological media. We combined this probe with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI MS) to profile proteins in diluted human plasma. The nanoparticles were designed to detect several disease-associated proteins and could be used directly in MALDI MS without an elution step, thereby facilitating multiple antigen screening and the characterization of antigen variants. Plasma antigens bound rapidly (similar to 10 min) to the antibody-conjugated nanoparticles, allowing the assay to be performed within 20 min. With sensitivity of detection in the femtomole range, the nanoscale immunoassay is superior to assays using microscale particles. We applied our method to comparative protein profiling of patients with gastric cancer and healthy individuals and found differential protein expression levels associated with the disease as well as individuals. Given the flexibility of manipulating functional groups on the nanoprobes, their low cost, robustness, and simplicity of the assay, our approach shows promise for targeted proteome profiling in clinical settings.
Quality yield measure for processes with asymmetric tolerances
(2006-08-01)
Pearn, WL
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Lin, PC
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Chang, YC
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Wu, CW
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工業工程與管理學系
Process capability indices provide numerical measures on whether or not a process is able to produce products that meet prespecified quality targets and are often used by manufacturers to evaluate manufacturing performance. Although process yield is the primary focus of the performance criteria, a formula that combines the yield and the average process loss, called the quality yield index, has been developed. This index, the quality yield, can be viewed as the conventional process yield minus the truncated expected relative process loss within the specifications. Although cases with symmetric tolerances dominate in practical situations, cases with asymmetric tolerances can also occur. In this paper, we generalize the quality yield index for asymmetric tolerances. The generalization technique is justified, and some statistical properties of the estimated generalization are investigated. An application example on high-density light emitting diodes is also presented to illustrate the applicability of the generalization.
Testing manufacturing performance based on capability index C-pm
(2005-12-01)
Lin, PC
;
Pearn, WL
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
The loss-based process capability index C-pm, sometimes called the Taguchi index, has been proposed to the manufacturing industry to measure process performance. In this paper, we propose a method to assess the performance of a normally distributed process. We implement the theory of testing hypothesis using the natural estimator of C-pm, and provide an efficient program to calculate the p-values. We also provide tables of the critical values for some commonly used capability requirements. Based on the test, we develop a simple step-by-step procedure for in-plant applications.
Testing process capability for one-sided specification limit with application to the voltage level translator
(2002-12-01)
Lin, PC
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Pearn, WL
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工業工程與管理學系
;
Department of Industrial Engineering and Management
Process capability indices C-PU and C-PL have been widely used in the microelectronics manufacturing industry as capability measures for processes with one-sided specification limits. In this paper, the theory of statistical hypothesis testing is implemented for normal processes, using the uniformly minimum variance unbiased estimators of Cpu and CPL. Efficient SAS computer programs are provided to calculate the critical values and the p-values required for making decisions. Useful critical values for some commonly used capability requirements are tabulated. Based on the test a simple but practical step-by-step procedure is developed for in-plant applications. An example on the voltage level translator manufacturing process is given to illustrate how the proposed procedure may be applied to test whether the process meets the preset capability requirement. (C) 2002 Elsevier Science Ltd. All rights reserved.
Testing process performance based on capability index C-pk with critical values
(2004-12-01)
Pearn, WL
;
Lin, PC
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Process capability index C-pk has been widely used in the manufacturing industry as a process performance measure. In this paper, we investigate the natural estimator of the index C-pk, and show that under the assumption of normality its distribution can be expressed as a mixture of the chi-square and the normal distributions. We also implement the theory of hypothesis testing using the natural estimator of C-pk, and provide efficient Maple programs to calculate the p-values as well as the critical values for various values of alpha-risk, capability requirements, and sample sizes. The behavior of the p-values and critical values as functions of the distribution parameters are investigated to obtain tight critical values for reliable testing. Based on the test, we develop a simple and practical procedure for in-plant applications. The practitioners can use the proposed procedure to determine whether their process meets the preset capability requirement, and make reliable decisions. (C) 2004 Elsevier Ltd. All rights reserved.
Testing process performance based on capability index C-pk with critical values
(2004-12-01)
Pearn, WL
;
Lin, PC
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Process capability index C-pk has been widely used in the manufacturing industry as a process performance measure. In this paper, we investigate the natural estimator of the index C-pk, and show that under the assumption of normality its distribution can be expressed as a mixture of the chi-square and the normal distributions. We also implement the theory of hypothesis testing using the natural estimator of C-pk, and provide efficient Maple programs to calculate the p-values as well as the critical values for various values of alpha-risk, capability requirements, and sample sizes. The behavior of the p-values and critical values as functions of the distribution parameters are investigated to obtain tight critical values for reliable testing. Based on the test, we develop a simple and practical procedure for in-plant applications. The practitioners can use the proposed procedure to determine whether their process meets the preset capability requirement, and make reliable decisions. (C) 2004 Elsevier Ltd. All rights reserved.
The C ''(pk) index for asymmetric tolerances: Implications and inference
(2004)
Pearn, WL
;
Lin, PC
;
Chen, KS
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
The process capability index C-pk has been widely used in the manufacturing industry to provide numerical measures on process performance. Since C-pk is a yield-based index which is independent of the target T, it fails to account for process centering with symmetric tolerances, and presents an even greater problem with asymmetric tolerances. Pearn and Chen (1998) considered a new generalization C-pk" which was shown to be superior to other existing generalizations of C-pk for processes with asymmetric tolerances. In this paper, we investigate the relation between the fraction nonconforming and the value of C-pk", Furthermore, we derive explicit forms of the cumulative distribution function and the probability density function for the natural estimator (C) over cap (pk)" under the assumption of normality. We also develop a decision making rule based on the natural estimator (C) over cap (pk)", which can be used to test whether the process is capable or not.
The characteristics of hole trapping in HfO2/SiO2 gate dielectrics with TiN gate electrode
(2004-10-18)
Lu, WT
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Lin, PC
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Huang, TY
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Chien, CH
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Yang, MJ
The characteristics of charge trapping during constant voltage stress in an n-type metal-oxide-semiconductor capacitor with HfO2/SiO2 gate stack and TiN gate electrode were studied. We found that the dominant charge trapping mechanism in the high-k gate stack is hole trapping rather than electron trapping. This behavior can be well described by the distributed capture cross-section model. In particular, the flatband voltage shift (DeltaV(fb)) is mainly caused by the trap filling instead of the trap creation [Zafar , J. Appl. Phys. 93, 9298 (2003)]. The dominant hole trapping can be ascribed to a higher probability for hole tunneling from the substrate, compared to electron tunneling from the gate, due to a shorter tunneling path over the barrier for holes due to the work function of the TiN gate electrode. (C) 2004 American Institute of Physics.