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In order to protect electronic components on a Printed Circuit Board (PCB) against electromagnetic radiation/wave, a shielding in the form of an electrically conductive shield-can or box is normally attached on the PCB covering the electronic components. The attached shield-can could provide an additional mechanical strength and minimize the out-ofplane deformation especially where the electronic package is located. In this study, both the dynamic responses of PCB and the characteristic life of solder joints with respect to different shield-can designs were investigated.

Mice can discriminate between chemosignals of individuals based solely on genetic differences confined to the major histocompatibility complex (MHC). Two different sets of compounds have been suggested: volatile compounds and non-volatile peptides. Here, we focus on volatiles and review a number of publications that have identified MHC-regulated compounds in inbred laboratory mice. Surprisingly, there is little agreement among different studies as to the identity of these compounds. One recent approach to specifying MHC-regulated compounds is to study volatile urinary profiles in mouse strains with varying MHC types, genetic backgrounds and different diets. An unexpected finding from these studies is that the concentrations of numerous compounds are influenced by interactions among these variables. As a result, only a few compounds can be identified that are consistently regulated by MHC variation alone. Nevertheless, since trained animals are readily able to discriminate the MHC differences, it is apparent that chemical studies are somehow missing important information underlying mouse recognition of MHC odourtypes. To make progress in this area, we propose a focus on the search for behaviourally relevant odourants rather than a random search for volatiles that are regulated by MHC variation. Furthermore, there is a need to consider a ‘combinatorial odour recognition’ code whereby patterns of volatile metabolites (the basis for odours) specify MHC odourtypes.

This paper is to study the combined behavior of plastic encapsulated MEMS package under humid and elevated temperature environments. Although thermal-induced stress for the materials used in the MEMS package is already fully understood, moisture-induced stress is still not well studied. To cope with humidity effects on the MEMS package, the moisture-induced properties of mold compound are obtained from the proposed experiments. From the weight gain/loss measurement, saturated moisture content and diffusivity were obtained by curve fitting following Fick’s law. In addition, using digital image correlation (DIC) together with precision weight scale, coefficient of hygroscopic swelling (CHS) could also be obtained at different temperatures. The experimental results show that the diffusion coefficient of mold compound material follows Arrhenius’s equation well. Also, it is shown that the CHS of mold compound increases as temperature increases. Finally, using these experimentally obtained moisture properties, conjugated behavior (thermo-hygro-mechanical) of MEMS package under high temperature and humid environment could be estimated through numerical analysis by adopting classical analogy method. The numerical result was also validated by comparing with experimentally obtained warpage of MEMS package at elevated temperatures.Copyright © 2010 by ASME

In this contribution, we investigate the applicability of using multiple propagation paths to estimate the temporal auto-correlation function and the coherence time of wireless propagation channels. The Space-Alternating Generalized Expectation-maximization (SAGE) algorithm is applied for extracting the paths from measurement data. It is found that the channel auto-correlation function and coherence time computed based on the path parameters are biased. A simple method is proposed for correction of the biases. Experimental investigations are conducted to evaluate the effectiveness of the method.

This paper presents a coding scheme for the Gaussian wiretap channel based on low-density parity-check (LDPC) codes. The messages are transmitted over punctured bits to hide data from eavesdroppers. The proposed coding scheme is asymptotically effective in the sense that it yields a bit-error rate (BER) very close to 0.5 for an eavesdropper whose signal-to-noise ratio (SNR) is lower than the threshold SNRE, even if the eavesdropper has the ability to use a bitwise maximum a posteriori (MAP) decoder. Such codes also achieve high reliability for the friendly parties provided they have an SNR above a second threshold SNRB . It is shown how asymptotically optimized LDPC codes are designed with differential evolution where the goal is to achieve high reliability between friendly parties while keeping the security gap SNRB/SNRE as small as possible to protect against passive eavesdroppers. The proposed coding scheme is encodable in linear time, applicable at finite block lengths, and can be combined with existing cryptographic schemes to deliver improved data security by taking advantage of the stochastic nature of many communication channels.

We introduce Yarg code, a binary numeral system for QAM symbol mapping designed to yield improved physical layer security. The simulation results show that Yarg code reduces the security gap from 17.33 dB to 9.42 dB for 16 QAM, and from 17.7 dB to 7.18 dB for 64 QAM with respect to the Gray code. The improved security properties come at the cost of increased required SNR by 6~9 dB.

Previous studies have shown that mineralocorticoid receptor (MCR) blocker reduces proteinuria in diabetic nephropathy (DN), but the role of aldosterone in podocyte injury has never been explored in DN. This study was undertaken to elucidate whether a local aldosterone system existed in podocytes and to examine its role in podocyte apoptosis under diabetic conditions. In vitro, immortalized podocytes were exposed to 5.6 mM glucose (NG), NG + 24.4 mM mannitol, and 30 mM glucose (HG) with or without 10−7M spironolactone (SPR). In vivo, 32 Sprague-Dawley rats were injected with diluent (C, n = 16) or streptozotocin intraperitoneally [diabetes mellitus (DM), n = 16], and 8 rats from each group were treated with SPR for 3 mo. Aldosterone synthase (CYP11B2) and MCR mRNA and protein expression were determined by real-time PCR and Western blot, respectively, and aldosterone levels by radioimmunoassay. Western blot for apoptosis-related molecules, Hoechst 33342 staining, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay were performed to determine apoptosis. CYP11B2 and MCR expression were significantly higher in HG-stimulated podocytes and DM glomeruli compared with NG cells and C glomeruli, respectively, along with increased aldosterone levels. Western blot analysis revealed that cleaved caspase-3 and Bax expression was significantly increased, whereas Bcl-2 expression was significantly decreased in HG-stimulated podocytes and in DM glomeruli. Apoptosis determined by Hoechst 33342 staining and TUNEL assay were also significantly increased in podocytes under diabetic conditions. These changes in the expression of apoptosis-related proteins and the increase in apoptotic cells were inhibited by SPR treatment. These findings suggest that a local aldosterone system is activated and is involved in podocyte apoptosis under diabetic conditions.

The paper considers a hybrid ARQ (HARQ) scheme for a linear pre-coding-based closed-loop multiple-input multiple-output (MIMO) system, in which a pre-coding matrix is dynamically selected for every retransmission by taking into account a symbol-level combining gain obtained from the previous receptions. A new retransmission structure with a sequence of multiple codebooks is proposed that are optimized for combining gain, rather than using a single identical codebook for every retransmission. Furthermore, a criterion for selecting a pre-coding matrix for each retransmission can be provided so as to minimize the retransmission error probability. Under the proposed multiple codebook structure for MIMO-HARQ systems, a sequence of optimum codebooks is constructed for the subsequent retransmissions. Simulation results are presented for showing that the proposed scheme achieves significant error performance advantages over conventional schemes with a single codebook and furthermore, a near-optimal performance is achieved as the codebook size chosen is large enough.

The dynamic response of printed circuit board (PCB) is a major concern to electronic manufacturers when it is subjected to drop impact. In this work, more realistic drop condition is achieved through product-level free drop test. A repeatable free-drop system is developed with an adjustable pair of forks to control the impact orientation during the guided free drop. Digital Image Correlation (DIC) technique is applied to measure and produce the full-field dynamic responses of PCB. Air cushion effect between mobile phone and impact surface is found experimentally, which may be considered significant for the product-level free drop test. The rebound test has been performed to measure the actual impact velocity and to provide a better insight into the drop impact event. The effect of impact velocity is investigated to assess dynamic responses of PCB. Along with the drop impact experiments, the 3D FEA models are analyzed using ANSYS/LS-DYNA. The energy loss from the damping is considered by including the Rayleigh damping in this FEA model. Vibration analysis is performed experimentally and numerically to choose the proper damping parameters.

Multilevel modulation schemes have variations in bit-reliabilities and each has different symbol reliabilities. Choosing the modulation scheme which has the greatest symbol reliability at target SNR on retransmissions offers more chances to get higher Hybrid ARQ performance by making the sum of total bit-reliabilities greater in the entire decoding block. This paper presents a novel Hybrid ARQ scheme which is focused on reducing the number of bits whose reliabilities are low and increasing the total sum of reliabilities of transmitted bits. Proposed Hybrid ARQ scheme achieves more performance gain when in combination with modulation level switching.

While the conventional codebook is defined only for the initial transmission in the closed-loop MIMO system, this paper proposes a new retransmission structure with a sequence of multiple codebooks, rather than using a single identical codebook for every retransmission. The pre-coding matrices, in each codebook, are sequentially linked so that each one can be used for a sequential hybrid ARQ transmission attempt, without invoking any index feedback from the receiver. It has been shown that the proposed codebook structure provides a performance gain of more than 3 dB over the conventional scheme in the long-term static channel.

It is a well-known fact that the lasers have wide variety of applications in diverse fields from medicine to communications [1]. Laser packaging involves appropriate materials selection and design to ensure that the laser performance meets the required specifications. In this paper, we present a GaAs based laser diode package design. The package design enables the laser diode chip to withstand the thermo-mechanical strains that are induced during the package assembly process as well as during the operating conditions. Excessive stresses in the chips could causes cracks in the chip. Excessive strains could cause un-desired spectral characteristics in the emitted light [2]. Therefore, the objective is to design a package that is tested and characterized to avoid these failure modes. This study presents numerical and experimental investigation of thermo-mechanical strains induced due to coefficient of thermal expansion (CTE) mismatch between various package components during assembly process. Finite element (FE) analysis is used to predict the displacements, tensile strains and stresses in the chip at various assembly processes. Digital Image Correlation (DIC) technique was used to measure the strains in the laser diode. Earlier, other researchers have used photo-luminescence methods and spectroscopic methods etc to measure packaging induced strains in the laser package [3]–[9]. The authors are not aware of any prior work where the DIC technique is applied on a very small chip for strain measurements Good correlation in displacements and strains was obtained between the model and the measurements, increasing confidence in the model. In addition, experiments were conducted to estimate the fracture strength of the GaAs to predict the chip failure based on the maximum principal stress criterion. The FE model was later used to conduct parametric study to analyze the impact of other factors on the chip stress such as substrate thickness, voids, thermal gradients in the package, surface irregularities in the chip etc. Experiments and model indicated that the designed package was robust enough and does not cause any damage to the chip.Copyright © 2009 by ASME

In this paper, we introduce a new modulation scheme called Spiral QAM, which is optimized for phase noise, and thus robust in the presence of phase noise. Symbol mapping rules for 16 and 64 Spiral QAM are also presented. SER and BER performance of 64 Spiral QAM was compared with the conventional 64 QAM to show the superior performance of Spiral QAM in the presence of phase noise.

Previous in vitro studies suggest that the p38 MAPK pathway may be involved in the pathogenesis of diabetic nephropathy, but the consequences of the inhibition of the p38 MAPK pathway have not been well elucidated in diabetic (DM) glomeruli. This study was undertaken to investigate the effect of p38 MAPK inhibitor, FR167653, on fibronectin expression and apoptosis in DM glomeruli and in high-glucose-stimulated mesangial cells (MC). In vivo, 32 Sprague-Dawley rats were injected with diluent (control, N = 16) or streptozotocin intraperitoneally (DM, N = 16). Eight rats from each group were treated with FR167653 for 3 mo. In vitro, rat MC were exposed to medium containing 5.6 mM glucose or 30 mM glucose [high glucose (HG)] with or without 10−6M FR167653 for 24 h. Fibronectin mRNA and protein expression were determined by real-time PCR and Western blot, respectively. Western blot for apoptosis-related molecules, terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling assay, and Hoechst 33342 staining were performed to determine apoptosis. FR167653 ameliorated the increases in fibronectin-to-GAPDH mRNA ratio and protein expression in DM glomeruli by 89 and 79% and in HG-stimulated MC by 70 and 91%, respectively ( P < 0.05). Under diabetic conditions, Bcl-2 protein expression was decreased, whereas cleaved caspase-3 protein expression was increased ( P < 0.05), and these changes were inhibited by FR167653 treatment. Apoptotic cells were also significantly increased in DM glomeruli and in HG-stimulated MC ( P < 0.05), and FR167653 ameliorated these increases in apoptotic cells, both in vivo and in vitro. In conclusion, these findings suggest that the inhibition of the p38 MAPK pathway has a beneficial effect on the development of diabetic nephropathy by inhibiting the increase in fibronectin expression and apoptosis.

Major histocompatibility complex (MHC) genes influence urinary odors (odortypes) of mice. That volatile odorants are involved is supported by the observation that odortype identity can be detected from a distance. Furthermore, chemical analyses of urines have revealed numerous volatile odorants that differ in relative abundance between mice that differ only in MHC genotypes. In addition, urines from MHC-different mice evoke distinct odor-induced activity maps in the main olfactory bulbs. However, recent studies report that non-volatile MHC class I peptides may directly act as MHC-associated signals and may thereby be seen to call into question the evidence for a volatile MHC signal. To evaluate this question, we designed a procedure to collect peptide-free urinary volatiles and tested these volatiles for their ability to mediate chemosensory discrimination of MHC-congenic mice differing in their MHC genotype. The headspace volatiles from urines of C57BL/6 congenic mice (haplotypes H2(b) and H2(k)) were collected by solid phase microextraction (SPME). These volatiles were then desorbed into a gas chromatograph (GC) and the entire chromatographic eluate was collected into a buffer solution. Our results conclusively demonstrate that mice trained to discriminate between unadulterated urinary signals of the congenic mice generalize the discrimination, without reward or training, to the buffer solution containing the peptide-free urinary volatiles (p0.001, binomial test). Thus volatile signals, perhaps along with non-volatile ones, are capable of mediating behavioral discriminations of mice of different MHC genotypes.

In this work, free drop impact responses of printed circuit boards (PCBs) mounted in cellular phones has been investigated to assess their dynamic responses and investigate the effects of fastening methods. The digital image correction (DIC) method was used in order to measure a full-field deformation of PCBs during drop from a certain height. Three different fastening techniques which have point or edge contact between the PCBs and the casings were considered. Along with the drop impact experiments, the impact response analysis using ANSYS/LS-DYNA has been performed. To validate the numerical model, the impact response has been compared with the experimental one extracted from the DIC of the PCB. The deformations of the numerical model are well matched with the experimental ones. The effects of assembly method are investigated to assess reliability of PCBs.

Board-level drop test has emerged as a key qualification test for assessing the impact reliability of electronic components. JEDEC standards for board level drop test address different test board designs, assembly, materials, constructions, tester setup etc. However, it fails to emphasize the effect of varying boundary conditions on the dynamic response of the PCB assembly. Repeated dropping of boards during statistical reliability testing loosens up the mounting screws after a certain number of drops. Also, different sizes, and materials of mounts and supports can produce a significant variation in the vibration response of the PCB assembly. This paper addresses the effect of such boundary conditions and their influence on the overall dynamic characteristics of the system. A novel optical technique has been developed to measure the whole-field impact dynamic response of the PCB. Pair of synchronized high-speed cameras the images of board assembly at rates upto 15,000 pictures per second. A digital image correlation (DIC) system has been integrated with the cameras to analyze the acquired images to give dynamic deformation, shape and strain over the entire surface of board during impact. These measurements are conducted for different standoff heights, varying tightening torques on mounting screws and for rubber shim placement between the support and the board. Modal analysis has been performed on the finite element model for the board assembly to validate the experimental measurements. Furthermore, using spectral analysis, quantitative evaluation of varying boundary conditions has been done to understand their effect on fundamental modes and harmonics. With significant sensitivity observed as regards to these parameters, the need for accurate accounting of the boundary conditions while analyzing a drop test has been underlined.

Background. Compared to children, adult patients with minimal change disease (MCD) tend to have a slower response to steroids, but little is known about the factors influencing the steroid responsiveness in these patients. In this study, we investigated the difference in the expression of the glomerular glucocorticoid receptor (GCR) according to steroid responsiveness in 28 adult-onset MCD patients. Methods. Based on the response to steroid treatment, the patients were divided into early responders (ER, n ¼ 20) and late responders (LR, n ¼ 8) according to the response to steroids on the basis of 4 weeks of treatment. The clinical and laboratory findings, and the glomerular mRNA and protein expression of GCR and nephrin, assessed by real-time polymerase chain reaction and immunohistochemistry, respectively, were compared between the ER and LR groups. Ten microscopic haematuric patients in whom renal biopsy was performed and revealed no histological abnormalities were included for control (C). Results. The mRNA expression of GCR was significantly lower in the LR than that in the ER group (P < 0.01), whereas it was comparable between the C and ER groups. GCR protein expression was also decreased in the LR compared with the C and ER groups. In contrast, there was no significant difference in nephrin mRNA expression among the three groups. On the other hand, the GCR mRNA expression correlated inversely with the time to complete remission (r ¼� 0.49, P < 0.05), but not with the amount of proteinuria at presentation. Conclusion. In conclusion, the levels of glomerular GCR expression may be a useful predictor of steroid responsiveness in adult-onset MCD patients.

EIED backoff algorithm was proposed in Song et al., (2003) to enhance the performance of the IEEE 802.11 DCF. EIED provides significant performance improvement without additional complexity. In this paper, we applied EIED to the periodic ranging process of IEEE 802.16, where BEB was originally used. As a performance metric, the average number of tries per periodic ranging attempt was used. The performance was shown analytically, which was verified by computer simulation. The performance results of EIED in the periodic ranging process of IEEE 802.16 are compared to those of BEB. The performance results show that EIED provides a significant performance gain over BEB. Using EIED, we can achieve comparable performance as BEB with significantly smaller set of ranging CDMA codes.

Product durability due to drop shock is a critical element for assessment of reliability for handheld devices. So far, no simulation model for a board-level drop has been extensively validated by experiments for its predictions of global (full-field) dynamic response. Accelerometers and strain gages which are traditionally utilized to measure the response at selected locations, fail to assess the global strain gradients and complex mode shapes. In this work, a novel non-contact optical technique has been proposed for measurement of full-field impact response. Pair of synchronized high-speed cameras capture the images of board assembly subjected to JEDEC standard impact, at rates up to 15,000 pictures per second. A digital image correlation (DIC) system has been integrated with the cameras to analyze the acquired images to give dynamic deformation, shape and strain over the entire surface of board during impact. A finite element model for the drop test has been developed using ANSYS/LS-DYNA. The numerical solution has been fully validated against experimental measurements of acceleration, strain and warpage at series of instants of time after impact. Effect of tightening torque at PCB mounts has been studied comprehensively with regards to the eigenvalues and mode shapes, and the necessity for accurate modeling of dynamic contact conditions existing at the supports has been demonstrated. Simulation model has been further used to assess the drop impact reliability of components on the board. Excellent correlation of all simulation results with the measured data validates the experimental and numerical propositions made in this work for analyzing a board-level drop impact.

In this study, the wetting state on hydrophobic and hydrophilic micro-textured surfaces was investigated. High spatial resolution synchrotron X-ray radiography was used to overcome the limitations in visualization in previous research and clearly visualize the wetting state for each droplet under quantified surface conditions. Based on thermodynamic characteristics, a theoretical model for wetting state depending on the chemical composition (intrinsic contact angle) and geometrical morphology (roughness ratio) of the surfaces was developed.

In the event of PNC failure, the event of PNC leaving a piconet without a proper handover procedure, it is critical to have a scheme that allows one of the PNC capable DEVs to take over the role of PNC to minimize the interruption of services. A new proactive coordinator appropriation (PCA) scheme is proposed to prevent piconets from collapsing in the event of PNC failure. PCA is an efficient and reliable scheme that detects PNC failure in a timely manner, while minimizing the probability of false detection. An analytical comparison of PCA with the existing schemes of similar functionality is provided.

In this paper, the two differential detection architectures which are capable of estimating and compensating a large carrier frequency offset of up to above 80 ppm without performance degradation are proposed. The proposed frequency offset estimation and compensation techniques can achieve optimum performance, even if the amount of carrier frequency offset is much larger than the symbol rate. Since the proposed receiver structures are extremely simple, those are appropriate for IEEE 802.15.4 LR- WPAN system with the motto "Low-cost and low-complexity."

Genes of the major histocompatibility complex (MHC) influence the urinary odors of mice. Behavioral studies have shown (1) that mice differing only at MHC have distinct urinary odors, suggesting an MHC odor phenotype or odortype; (2) that the MHC odortype can be recognized across different background strains; and (3) that the MHC odortype is not an additive trait. Very little is known about the odorants underlying this behavioral phenotype. We compared urinary volatile profiles of two MHC haplotypes (H2(b) and H2(k)) and their heterozygous cross (H2(b) x H2(k)) for two different background strains (C57BL/6J and BALB/c) using solid phase micro-extraction (SPME) headspace analysis and gas chromatography/mass spectrometry (GC/MS). Both MHC and background genes substantially influence the volatile profile. Of 148 compounds screened, 108 of them significantly differ between the six genotypes. Surprisingly, for numerous compounds, their MHC associations are moderated by background genes (i.e., there is a significant MHC x background interaction effect in the statistical model relating genotype to relative compound concentration). These interactions account for nearly 30% of the total genetic effect on the volatile profile. MHC heterozygosity further extends the odortype diversity. For many compounds, the volatile expression for the heterozygote is more extreme than the expression for either homozygote, suggesting a heterozygous-specific odortype. The remarkable breadth of effects of MHC variation on concentrations of metabolites and the interaction between MHC and other genetic variation implies the existence of as yet unknown processes by which variation in MHC genes gives rise to variation in volatile molecules in body fluids.

A recent article by Curran et al (J. Chem. Ecol. vol. 31 (7); 1607-1619, 2005) describes the collection and chemical analysis of ''human scent''. Contrary to the authors? claims, a great deal is known about the chemical constituents of human scent, and its measurement. Here we clarify what is known about human scent, and highlight several shortcomings concerning the authors analysis related to (1) the definition of human scent, (2) chemical analysis of human scent, and (3) conclusions about individual differences. More than 15 years of research has presented both organoleptic and analytical evidence that a mixture of C6-C11 normal, branched, hydroxy-and unsaturated acids present in axillary sweat constitute the characteristic axillary odor. (Zeng et al., 1991; 1992; 1996; 1996a; Natsch et al., 2003). In addition to this mixture of major odor constituents are trace amounts of thio-alcohols (Natsch et al., 2004; Troccaz et al., 2004; Hasegawa et al., 2004) with high odor impact (low olfactory threshold). The details of the chemical identification, exact structures and synthesis (of non-commercially available compounds) as well as biogenesis of many of these compounds have been described in the above cited manuscripts.

Exponential Increase Exponential Decrease (EIED) backoff algorithm, a flexible backoff algorithm with a number of adjustable parameters, was proposed by Song et al. to enhance the performance of the IEEE 802.11 DCF, where the performance benefit of EIED was shown by simulation. In this paper, we extend on the previous work, and provide an analysis of EIED backoff algorithm and an optimization methodology of the parameters of EIED based on the analysis.

A new backoff algorithm is proposed to enhance the performance of the IEEE 802.11 distributed coordination function (DCF), which employs binary exponential backoff (BEB) algorithm. The proposed algorithm, called the exponential increase exponential decrease (EIED) backoff algorithm, is quite simple to implement while significantly improving the network performance over BEB. Another backoff algorithm called multiple increase linear decrease (MILD) backoff algorithm is considered for performance comparison. The simulation results show that EIED outperforms BEB and MILD in terms of both throughput and delay. The performance gain of EIED comes from successfully balancing the two extreme backoff policies of BEB and MILD.

New analytic results are given for the stability and performance of the exponential backoff (EB) algorithm. Previous studies on the stability of the (binary) EB have produced contradictory results instead of a consensus: some proved instability, others showed stability under certain conditions. In these studies, simplified and/or modified models of the backoff algorithm were often used to make analysis more tractable. In this paper, care is taken to use a model for backoff that reflects the actual behavior of backoff algorithms. We show that EB is stable under a throughput definition of stability; the throughput of the network converges to a non-zero constant as the offered load N goes to infinity. We also obtain the analytical expressions for the saturation throughput and the medium access delay of a packet for a given number of nodes, N. The analysis considers the general case of EB with backoff factor r, where BEB is the special case with r = 2. The accuracy of the analysis is checked against simulation results.

We investigate the inherent scalability problem of ad hoc networks that originated from the nature of multi-hop networks. First, the expected packet traffic at the center of a network is analyzed. The result shows that the expected packet traffic at the center of a network is linearly related with the network size, that is, the expected packet traffic at the center of a network is O(k), where k is the radius of a network. From the result, the upper bound of the diameter of a network D = 2k, that guarantees the network is scalable, is obtained. The upper hound is given by C/r - 1, where C is the channel capacity available to each node and r is the packet arrival rate at each node.

In this paper, we present a probabilistic shift-reduce parsing model which can overcome low context-sensitivity of previous LR parsing models. Since previous models are restricted by LR parsing framework, they can utilize only a lookahead and a LR state (stack). The proposed model is not restricted by LR parsing framework, and is able to add rich contextual information as needed. To show an example of contextual information designed for applying the proposed model to Korean, we devise a new context scheme named “surface-context-types” which uses syntactic structures, sentential forms, and selective lexicals. Experimental results show that rich contextual information used by our model can improve the parsing accuracy, and our model outperforms the previous models even when using a lookahead alone.

We present two Hammerstein-type models for parametric system identification of the lip seal friction process in a hydraulic actuator. Adaptive algorithms with least squares criteria are derived, and the performances of the two models are evaluated using experimental results.

The convergence speed of the steepest descent (SD) adaptive algorithm is determined by the eigenvalue spread of the correlation matrix. When the correlation matrix is singular, the algorithm will take a long time to converge. The problem can be regularized by adding a small constant to the diagonal, but this comes at the price of introducing bias. This paper introduces a new adaptive algorithm that uses a family of steepest descent iterations which converge quickly while making the bias arbitrarily small. A numerical example discusses in some detail the operation of the new algorithm.

We present a finite-state memory model for parametric system identification of the lip seal friction process in a hydraulic actuator. The performance of the finite-state memory model is compared with two Hammerstein type models using experimental results.

We have explored the abilities of all-electronic DNA-carbon nanotube (DNA-NT) vapor sensors to discriminate very similar classes of molecules. We screened hundreds of DNA-NT devices against a panel of compounds chosen because of their similarities. We demonstrated that DNA-NT vapor sensors readily discriminate between series of chemical homologues that differ by single methyl groups. DNA-NT devices also discriminate among structural isomers and optical isomers, a trait common in biological olfactory systems, but only recently demonstrated for electronic FET based chemical sensors.

Individual mice have a unique odor, or odortype, that facilitates individual recognition. Odortypes, like other phenotypes, can be influenced by genetic and environmental variation. The genetic influence derives in part from genes of the major histocompatibility complex (MHC). A major environmental influence is diet, which could obscure the genetic contribution to odortype. Because odortype stability is a prerequisite for individual recognition under normal behavioral conditions, we investigated whether MHC-determined urinary odortypes of inbred mice can be identified in the face of large diet-induced variation. Mice trained to discriminate urines from panels of mice that differed both in diet and MHC type found the diet odor more salient in generalization trials. Nevertheless, when mice were trained to discriminate mice with only MHC differences (but on the same diet), they recognized the MHC difference when tested with urines from mice on a different diet. This indicates that MHC odor profiles remain despite large dietary variation. Chemical analyses of urinary volatile organic compounds (VOCs) extracted by solid phase microextraction (SPME) and analyzed by gas chromatography/mass spectrometry (GC/MS) are consistent with this inference. Although diet influenced VOC variation more than MHC, with algorithmic training (supervised classification) MHC types could be accurately discriminated across different diets. Thus, although there are clear diet effects on urinary volatile profiles, they do not obscure MHC effects.