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Most living organisms are actually exposed to chemical mixtures rather than individual substances. But current chemical risk assessment frequently focuses on the single chemical substances. The European Union presented some methods in the draft technical guidance notes for deriving DNEL (Derived No Effect Level) and PNEC (Predicted No Effect Concentration) for risk assessment of mixtures. This case study shows that the differences of DNELs and PNECs of mixtures (2 coating materials) based on two methods (KCC and CR methods) and explains why such differences are generated. The differences of DNELs and PNECs of the mixtures based on the two methods were estimated by 1.21 and 2.31 times respectively. Through the theoretical analysis on influence factors affecting DNEL and PNEC, it could be recognized that the difference between two methods can significantly increase in proportion to the number of substances having similar hazard and weight fraction.

Periodic Au nanoparticle arrays, fabricated using electron beam lithography, have been modified by chemical reaction in solutions having various concentrations of a reducing agent. As the nanoparticles enlarge due to the formation of additional Au nanolumps on the surface, both the position and intensity of plasmon absorbance of Au nanoparticle arrays change in proportion to the concentration of the reducing agent. Moreover, the plasmon absorbance is split into dipole and quadrupole modes as conductive connections form between the particles. Our results demonstrate that the changes in both the position and intensity of plasmon absorbance can be employed together as complementary readout values of nanosensors.

Due to multiple side-peaks in the binary offset carrier (BOC) autocorrelation function, BOC signal synchronization is one of the most challenging tasks for global navigation satellite systems (GNSSs) including Galileo and global positioning system (GPS). Recently, a novel correlation function with reduced side-peaks was proposed for BOC signal synchronization by Julien (6); however, Julien's correlation function still has the side-peaks and can be possible only for sine phased BOC( n,n), where n is the ratio of the pseudo random noise (PRN) code rate to 1.023 MHz. In this paper, we propose a new correlation function for BOC signal synchronization, investigating how multiple side-peaks arise in BOC autocorrelation function. The proposed correlation function does not have any side-peaks and can be generated for any type of BOC signal, sine/cosine phase BOC(kn,n), where k is the ratio of a PRN chip duration to the period of a square wave sub-carrier used in BOC modulation. In addition, an efficient correlator structure is presented for generating the proposed correlation function.

Due to its capability to resist jamming signals, chirp spread spectrum (CSS) technique has attracted much attention in the area of wireless communications. However, there has been little rigorous analysis for the performance of the CSS communication system in jamming environments. In this paper, we present analytic results on the performance of a CSS system by deriving symbol error rate (SER) expressions for a CSS M-ary phase shift keying (MPSK) system in the presence of broadband and tone jamming signals, respectively. The numerical results show that the empirical SER closely agrees with the analytic result., {"references":["H. Shen, and A. Papandreou-Suppappola, \"Diversity and channel estimation\nusing time-varying signals and time-frequency techniques,\" IEEE\nTrans. Signal Process., vol. 54, no. 9, pp. 3400-3413, Sep. 2006.","IEEE 802.15 WPAN Low Rate Alternative PHY TG4a. (March 2007),\nretrieved Sep. 2008, from http://www.ieee802.org/15/pub/TG4a.html","IEEE 802.15 WPAN Low Rate Alternative PHY TG4c. (May 2008),\nretrieved Sep. 2008, from http://www.ieee802.org/15/pub/TG4c.html","J. Pinkney, \"Low complexity indoor wireless data links using chirp spread\nspectrum,\" Ph. D. dissertation, Dept. Elect. Comput. Engineer., University\nof Calgary, Calgary, AB, Canada, 2003.","A. Springer, W. Gugler, M. Huemer, R. Koller, and R. Weigel, \"A wireless\nspread-spectrum communication system using SAW chirped delay lines,\"\nIEEE Trans. Micr., Th., and Techn., vol. 49, no. 4, pp. 754-760, Apr.\n2001.","B. Sklar, Digital Communications: Fundamentals and Applications. Upper\nSaddle River, NJ: Prentice-Hall, 2001.","D. L. Schilling, L. B. Milstein, R. L. Pickholtz, and R. W. Brown,\n\"Optimization of the processing gain of an M-ary direct sequence spread\nspectrum communication system,\" IEEE Trans. Commun., vol. 28, no. 8,\npp. 1389-1398, Aug. 1980.","C. A. Balanis, Antenna Theory: Analysis Design. Hoboken, NJ: John\nWiley & Sons, 2005."]}

Binary offset carrier (BOC) signal synchronization is based on the correlation between the received and locally generated BOC signals. Thus, the multiple side-peaks in BOC autocorrelation are one of the main error sources in synchronizing BOC signals. Recently, new correlation functions with no side-peak were proposed for sine and cosine phased BOC signal synchronization, respectively, by the authors [3]. In this paper, we propose new correlation functions with no side-peak for alternative BOC (AltBOC) and composite BOC (CBOC) signals by using the similar approach to the previous work.

The frequency offset estimation is one of the most important tasks in orthogonal frequency division multiplexing (OFDM) systems. To estimate frequency offset, a periodogram-based estimator has been proposed by Ren. The method consists of three estimation steps and gives an accurate result. However, in the second and third estimation steps, the maximum frequency offset range that can be estimated is limited to a subcarrier spacing. This range is insufficient compared with the overall signal bandwidth, making the first estimation step require high complexity. In this paper, we propose a low-complexity frequency offset estimation method, which can efficiently extend the estimation ranges without loss of accuracy.

In ultra-wideband (UWB) systems, conventionally, the synchronization is to align time phases of a locally generated template and any of multipath components to within an allowable range. However, the synchronization with a low-power multipath component could incur significant performance degradation in receiver operation (e.g., detection) after the synchronization. On the other hand, the synchronization with a high-power multipath component can improve the performance in receiver operation after the synchronization. Generally, the first one among multi- path components has the largest power. Thus, the synchronization with the first path component can make better performance than that with a low-power component in receiver operations after the synchronization. Based on which, we first propose an optimal decision rule based on a maximum likelihood (ML) approach, and then, develope a simpler suboptimal decision rule for selecting the first path component. Simulation results show that the optimal and suboptimal decision rules have better performance than the conventional decision rule in UWB multipath channels.

Binary offset carrier (BOC) signal synchronization is based on the correlation between the received and locally generated BOC signals. Thus, the multiple side-peaks in BOC autocorrelation are one of the main error sources in synchronizing BOC signals. Recently, a new correlation function with no side-peaks was proposed for sine or cosine phased BOC signal synchronization by the authors [7]. In this paper, we propose a novel correlation function for composite binary offset carrier (CBOC) signals by using the similar method to that in [7], which has a better power ratio than the CBOC autocorrelation.

A frequency offset estimation scheme is proposed for orthogonal frequency division multiplexing (OFDM) systems. In the conventional scheme, there is a disadvantage that the performance is sensitive to the fractional frequency offset variation. Thus, a novel scheme is employed to estimate the frequency offset. The proposed scheme is robust to the fractional frequency offset variation and the performance is better than the conventional scheme.

Recently, a frequency offset estimation method for orthogonal frequency division multiplexing (OFDM) has been proposed by Ren et al. (REA) [9]. The method can estimate an frequency offset for any training symbol structure. In the REA method, however, the integer frequency offset detection probability is rapidly varying according to the fractional frequency offset.In this paper, we first analyze the REA frequency offset estimation method, and define new detection criteria suitable for integer frequency offset detection. Then, we propose two efficient integer frequency offset estimation methods based on maximum likelihood method. The proposed methods overcome the drawback of the REA method, maintaining its advantage. The numerical results demonstrate that the proposed methods outperform the REA method in terms of the integer frequency offset detection probability.

Binary offset carrier (BOC) signal synchronization is one of the most important steps to recover the transmitted information in a global navigation satellite system (GNSS) such as Galileo and global positioning system (GPS). Generally, BOC signal synchronization is achieved based on the correlation between the received and locally generated BOC signals. Thus, the multiple side-peaks in BOC autocorrelation are one of the main error sources in synchronizing BOC signals. Recently, a novel correlation function with reduced side-peaks was proposed for BOC signal synchronization by Julien [8]; however, Julien's correlation function not only still has the side-peaks, but also is only applicable to sine phased BOC(n, n), where n is the ratio of the pseudo random noise (PRN) code rate to 1.023 MHz. In this paper, we propose a new correlation function for BOC signal synchronization, which does not have any side-peaks and is applicable to general types of BOC signals, sine/cosine phased BOC(kn, n), where k is the ratio of a PRN chip duration to the period of a square wave sub-carrier used in BOC modulation. In addition, an efficient correlator structure is presented for generating the proposed correlation function.

In this paper, a novel integer frequency offset estimation scheme which is not affected by the timing offset is proposed for orthogonal frequency division multiplexing (OFDM) systems. Most of the schemes proposed for the integer frequency offset estimation assume the absence of the timing offset; however, such an assumption is not appropriate in practical systems. In this paper, using differential combining between two successive subcarriers, we propose a novel frequency offset estimation scheme. The simulation results show that the proposed scheme is robust to the timing offset variation, and thus, performs better than the conventional scheme when the timing offset range is not known.

Binary offset carrier (BOC) signal synchronization is one of the most important steps to recover the navigation data in global navigation satellite system (GNSS) including Galileo and global positioning system (GPS). The main error sources in synchronizing BOC signals are the multiple side-peaks in the BOC autocorrelation and the multipath delay. Recently, a novel correlator receiver for the BOC signal was proposed by Garin (shaping correlator receiver), which was shown to shrink the side-peaks and mitigate the multipath effect to a certain degree. However, a shaping correlator receiver cannot completely remove the side-peaks and is affected by a wider multipath delay range than that of the traditional correlator receiver. Moreover, it is applicable to only BOC(n, n) signal. In this paper, we propose a new correlator receiver for BOC signals. The proposed correlator receiver does not have any side-peak in its correlator output, and has smaller multipath delay range that incurs the tracking error than that in the shaping correlator receiver. Furthermore, the proposed correlator receiver is applicable to various types of BOC signals (i.e., BOC(kn, n)) and requires only a half of the number of the correlators used in the shaping correlator receiver.

The timing offset is one of the main error sources in estimating the frequency offset in orthogonal frequency division multiplexing (OFDM)-based wireless local area network (WLAN) systems. Although some works have been done to mitigate the effect of the timing offset on the frequency offset estimation, most of the investigations require the knowledge of the timing offset range, which is not generally available in practical systems. In this paper, we propose a new frequency offset estimation algorithm using differential combining between two successive correlation samples, which does not require the knowledge of the timing offset range, and thus, is robust to the timing offset variation. The simulation results show that the proposed algorithm is not only robust to the timing offset variation, but also generally performs better than the conventional algorithm, in the case of the timing offset range being not known exactly.

We first investigate the effect of the timing offset on the frequency offset estimation in orthogonal frequency division multiplexing (OFDM) systems. Then, we propose an efficient frequency offset estimation scheme using the coherence phase bandwidth (CPB) and a threshold in the presence of the timing offset. The numerical results demonstrate that the proposed scheme has lower computational complexity compared with the conventional schemes and performs robust operation in the presence of the timing offset.

In this paper, a new detector is proposed for code acquisition, which employs the signs and ranks of the received signal samples, instead of their actual values, and so does not require knowledge of the non-Gaussian noise dispersion. The mean acquisition performance of the proposed detector is compared with that of the detector of S. Yoon et al. (2004). The simulation results show that the proposed scheme is not only robust to deviations from the true value of the non-Gaussian noise dispersion, but also has comparable performance to that of the scheme of S. Yoon et al. (2004) using exact knowledge of the non-Gaussian noise dispersion.

We have proposed to characterize the mechanism through which bioactive surgical sutures generate a T(H)1 immune response and to define the immune-stimulating half-life of the sutures.Bioactive sutures of interferon gamma (IFNgamma), interleukin 2 (IL-2), anti-CD3/CD28, anti-CD3/CD28 + IL-2, or anti-CD3/CD28 + IFNgamma sutures were used to stimulate lymphocytes from normal donors and from head and neck cancer patients in vitro over a 24-day period. Cell supernatants were analyzed by ELISA, and T cells were phenotyped to characterize the immune response generated. Intracellular cytokine staining was performed to measure the expansion of flu-specific T cells. Electromobility shift assay and supershift assay were used to measure the intranuclear DNA binding activity of nuclear factor kappaB and its p65 subunit in T cells activated by sutures in the presence and absence of a proteasome inhibitor, MG-132.Anti-CD3/CD28, anti-CD3/CD28 + IL-2, or anti-CD3/CD28 + IFNgamma generated a prolonged T(H)1 immune response for 18 days in vitro. Anti-CD3/CD28 expanded flu-specific T cells. Activated T cells demonstrated enhanced CD40 ligand (CD40L) expression within 72 hours of stimulation, which stimulated other cells to secrete IL-12. Stimulated T cells demonstrated increased intranuclear expression of nuclear factor-kappaB, which was blocked by MG-132, and also reduced CD40L and IL-12 expression.This is the first report to demonstrate that bioactive surgical sutures can generate a prolonged T(H)1 immune response and expand flu-specific T cells. Bioactive sutures, which are primarily a T-cell stimulant, also stimulated other cells to secrete IL-12 and prolonged the immune response. Sutures may provide a novel in situ stimulating strategy for enhancing the immune system of cancer patients.

Problem: Dendritic cells (DCs) are the key antigen-presenting cells (APC) for inducing an antigen-specific immune response. Generating DCs from head and neck squamous cell cancer (HNSCC) patients may be a very important initial step in manipulating the patient’s immune system to fight their cancer. In this study we test our ability to generate functional DCs from advanced-stage HNSCC patients’ peripheral blood mononuclear cells (PBMC) or lymph node mononuclear cells (LNMC). Methods: Mononuclear cells were stimulated for 10 days in vitro with soluble IL-4 (90hg/mL)/GM-CSF (100U/mL), then soluble TNFa (20 hg/mL) for 48 hours. Flow cytometry was performed to measure the population of cells, which were CD1a+, CD14-, CD15-, CD80+, CD83+, CD86+, HLA-DR++, and CD4+. DCs were then pulsed with Flu-peptide at increasing concentrations (25, 50, and 100 mg/mL) and used to stimulate Flu-specific T cells from HLA-A2+ individuals. Expansion of Flu-specific T cells was measured by re-exposing T cells to Flu-peptide for 24 hours and measuring intra-cellular expression of IFNg. Experiments were also performed in parallel with normal HLA-A2 donors PBMC. Results: Mononuclear cells from HNSCC patients were able to generate a population of cells expressing CD1a+, CD14-, CD15-, CD80+, CD83+, CD86+, HLA-DR++, and CD4+, consistent with DCs. DCs were effective at stimulating Flu-specific T cells from HLA-A2 positive individuals and increased the percentage of T cells (CD4/CD8) expressing intracellular IFNg after re-exposure to Flu-peptide. Conclusion: DCs could be generated from HNSCC patients’ mononuclear cells. Functionality of these DCs to induce a Flu-specific immune response was demonstrated by increased intra-cellular expression of IFNg in CD4 and CD8 cell populations after re-priming. Significance: DCs may be useful in generating an antigen-specific anti-cancer immune response in HNSCC patients. Support: None reported.

Problem: Immunosuppression has been well recognized in head and neck squamous cell carcinoma (HNSCC). We have previously identified increased percentages of T regulator cells (T regs or CD4+/CD25+) from peripheral blood lymphocytes (PBLs) of advanced-stage HNSCC patients. T regs have been implicated in playing a very crucial role in immunosuppression. Previously we developed bioactive sutures that can enhance the immune response of cancer patients. In this study we measured the effect that stimulating HNSCC patients PBLs with bioactive sutures has on the percentage of CD4+/CD25+ T cells. Methods: A group of previously untreated advanced-stage HNSCC patients (n = 10) and controls (n = 7) were studied. PBL were drawn from patients prior to surgery and controls. Lymphocytes were purified by Ficoll-hypaque density centrifugation and stimulated in vitro with a variety of bioactive sutures (anti-CD3/28, anti-CD3/28 + IFNg, anti-CD3/28 + IL-2). The percentage of CD3/CD25, CD4/CD25, CD8/CD25, and annexin-V/propidium iodine positive cells was measured prestimulation and 6 days poststimulation. Results: HNSCC patients demonstrated 21- to 26-fold increases in CD8+/CD25+ and 7- to 8-fold increases in CD4+/CD25+ populations after suture stimulations, while controls demonstrated 36- to 40-fold increases in CD8+/CD25+ and 4-fold increases in CD4+/CD25+. Control PBLs expanded significantly higher percentages (P Conclusion: PBL from advanced-stage HNSCC patients demonstrated enhanced responses to bioactive suture stimulations, with greater expansion in the CD8+/CD25+ than CD4+/CD25+. Control PBL stimulated by bioactive sutures demonstrated even greater expansion of CD8+/CD25+ cells and less expansion of CD4+/CD25+ cells. Significance: Bioactive sutures may be useful for expanding the cytotoxic population of T cells in HNSCC patients to fight cancer. Support: California Cancer Research Program Clinician Scientist Development Award (TYS)

We propose a new model for synthesizing fundamental frequency (F0) contours using a stylisation and a neural network learning method. The F0 contour is described as the superposition of 4 layered features; global tune, word pitch bias, lexical tone, and the syllabic pitch pattern. We firstly stylize the F0 contour of speech material, and analyse stylised data by a statistical approach according to grammatical attributes. We then construct a melodic table, and train lexical tone with a neural network. Finally we develop the intonation generation rules for TTS conversion. This model produces a good neutral declarative intonation, and there is little difference between synthesized speech with the original F0 contour and that with the rule generated content when tested with our TD-PSOLA synthesizer.

The objective of our investigation was to prospectively study what the implications of an unresponsive CD3 receptor are on clinical outcome in advanced-stage head and neck cancer patients.Lymph node mononuclear cells were purified from cancer patients and stimulated with immobilized anti-CD3 in vitro for 8 days. Two populations were identified, nonresponders (NRs) with [(3)H]thymidine-counts per min (cpm)3500 and responders (Rs) with cpmor=3500. NRs and Rs were prospectively followed for a minimum of 24 months, and clinical outcomes were compared. Postoperative complications, length of hospitalization, toxicities associated with chemotherapy or radiation therapy, survival, and disease-free status were measured.Twenty-six patients were followed, of which 19 Rs [[(3)H](X) = 37,819 +/- 24,979 cpm (mean proliferative count +/- SD)] and 7 NRs ([(3)H](X) = 1,375 +/- 1,102 cpm) were identified. There were no phenotypic differences in lymph node T-cell subpopulations (CD3, CD4, CD8, CD28, CD45RO) between groups. There was a 71% (5/7) incidence of recurrent cancer in NRs compared with 16% (3/19) in Rs; the median disease-free interval was significantly less in NRs (P = 0.03). The risk ratio of Rs to develop a recurrent cancer was 0.237 (95% confidence interval, 0.057-0.994), much less than for NRs.Patients with an unresponsive CD3 receptor as measured by in vitro response to anti-CD3 monoclonal antibodies had a significantly higher incidence of recurrent cancer. Analyses using Cox proportion hazards models demonstrated that CD3 response was the single greatest predictor of reduced disease-free interval. This is the first prospective study to confirm the importance of regional lymph node mononuclear cell CD3 receptor function in head and neck squamous cell carcinoma patients for tumor control.

A speech understanding apparatus includes: a speech recognition unit for recognizing an input speech to produce a speech recognition result; a sentence analysis unit for performing morpheme analysis on a sentence corresponding to the speech recognition result, extracting additional information, and performing syntax analysis; a hierarchy describing unit for describing hierarchy of the sentence; a class transformation unit for performing class transformation on the sentence; a semantic representation determination unit for marking optional expressions for the sentence, deleting meaningless expressions and the additional information, converting the sentence into its base form, and deleting morphemic tags or symbols to determine a semantic representation; a semantic representation retrieval unit for retrieving the determined semantic representation from an example-based semantic representation pattern database; and a retrieval result processing unit for selectively producing a retrieved semantic representation.

In this paper, we propose an enhancement of Japanese acoustic model which is trained with Korean speech database by using several combination strategies. We describe the strategies for training more than two language combination, which are Cross-Language Transfer, Cross-Language Adaptation, and Data Pooling Approach. We simulated those strategies and found a proper method for our current Japanese database. Existing combination strategies are generally verified for under-resourced Language environments, but when the speech database is not fully under-resourced, those strategies have been confirmed inappropriate. We made tyied-list with only object-language on Data Pooling Approach training process. As the result, we found the ERR of the acoustic model to be 12.8 %.

We report the electrical properties of single-walled carbon nanotube bundles aligned between two electrodes with a gap of 8 µm by the alternating current dielectrophoresis method. The resistance increased exponentially as the number of structural defects increased from the oxygen plasma treatment. However, no noticeable change was observed in the carrier concentration and tube–tube interaction. The resistance dependence on the plasma treatment time was explained on the basis of the localization of electron states at defect sites. The aspects of the defects were examined by measuring the effects of ammonia adsorption on the conductance of the device.

A two stage utterance verification device and a method thereof are provided. The two stage utterance verification method includes performing a first utterance verification function based on a SVM pattern classification method by using feature data inputted from a search block of a speech recognizer and performing a second utterance verification function based on a CART pattern classification method by using heterogeneity feature data including meta data extracted from a preprocessing module, intermediate results from function blocks of the speech recognizer and the result of the first utterance verification function. Therefore, the two state utterance verification device and the method thereof provide a high quality speech recognition service to a user.

We have fabricated freestanding nanogears by selectively etching single crystalline Au nanoplates and assembled them tooth to tooth using an atomic force microscope (AFM). The nanogears, with one center hole surrounded by six teeth, are smaller than 500 nm in overall size and 60–70 nm in thickness. We demonstrate that blunt AFM tips on stiff cantilevers are effective for the nondestructive manipulation of ductile and flat nano-objects having large contact areas with the substrate, and we discuss the results on the basis of nanomechanical aspects. We expect that the precise AFM manipulation combined with the etch-based fabrication techniques for the freestanding nanocomponents will be useful in the development and post-repair of sophisticated nanoelectromechanical systems.

Functionalization of carbon nanotubes (CNTs) with polymers such as polyethyleneimine or nafion was found to not change the adsorption properties of gas molecules on CNTs, although functionalization can remarkably enhance the sensitivity of gas sensors. Charge transfer between adsorbed molecules and single-walled carbon nanotubes (SWCNTs) at defect sites causes a steep and nonlinear conductance change at low gas concentrations, while molecules physically adsorbed on the pristine surfaces result in the linear electrical responses at higher concentrations. In addition, the molecular binding energies at defect sites of SWCNTs were measured to be 0.61eV for NO2 and 0.53eV for NH3.

Voltage sag are the most common and cause more economic losses, which is a serious power quality (PQ) problem. To solve these problems, several topology using an extra battery or back-to-back has been introduced. However, these conventional topologies have drawback in cost effective and system reliability. This paper presents a three-phase voltage sag supporter for power distribute systems known as dynamic voltage restorer (DVR), and is employing direct AC-AC converter using switching cell (SC) structure. The AC-AC converter, in proposed supporter, is highly reliable because they can solve the shoot-through, dead-time, and commutation problem of traditional AC-AC converters without voltage/current sensing devices from SC structure. Moreover, the proposed voltage supporter has a good dynamics because it operates immediately by using interphase voltage when voltage sag is occurred in grid. Simulation and experimental results is provided to verify this.