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In this paper, we propose a HDTV transmission over IEEE802.3ac 4×5 MIMO WLAN System. The proposed system employs the next generation wireless LAN system based on IEEE802.3ac specification. It reaches more than 33 meter propagation distance by using 80MHz of bandwidth on the 5GHz band. In this system, video data is compressed by JPEG 2000 with error resilience tools. These tools improve error performance against wireless channel, and enable very high throughput communication. Computer simulations are used to evaluate the bit error performance's influences to the video quality. Finally, we present RTL design results of the proposed wireless LAN system.

In mobile environment, decode quality is largely influenced by multipath fading and Doppler shift. In this paper, we reported improvement of mobile reception for high-definition television (HDTV) of integrated services digital broadcasting — terrestrial (ISDB-T) by using maximum ratio combining (MRC) diversity and using two-dimensional (2D) filter in channel estimation. From computer simulations, we show that the bit error rate (BER) of the proposed method is improved compared to that of conventional systems. Finally, we verify reception quality of a received movie signal using our proposed system via computer simulation.

The c-met oncogene product is a cell-surface receptor, which ligand is believed to be the hepatocyte growth factor. We studied the expression of c-met oncogene in the regenerating rat liver after either partial hepatectomy or CCl4-induced liver injury. Northern blot analysis showed that after partial hepatectomy the transcripts of c-met decreased at 8 h, reached the minimum at 36 h, and returned to the steady level on the seventh day. In contrast with the hepatectomized liver, the transcripts of c-met increased after CCl4 treatment. These observations suggest that c-met transcription may be regulated differently depending on regeneration signals.

The relationship between plasma hepatitis C virus (HCV) RNA levels, antibody positivity, and hepatocellular damage were studied in 41 patients with non-A, non-B chronic liver disease. The patients were placed into two groups according to the plasma levels of HCV-RNA: plasma HCV-RNA level was estimated as high when detected by a one stage polymerase chain reaction (PCR) and as low when detectable only after a two stage PCR. Anti-HCV (first and second generation assays) and anti-GOR were also measured. The mean alanine aminotransferase (ALT) level of the high HCV-RNA group was 115 +/- 62 IU/l, whereas that of the low HCV-RNA group was 59 +/- 37 IU/l (P < 0.05). Patients with ALT levels above 100 IU/l had invariably a high level of HCV-RNA. There were no differences in clinical features in relation to the presence of anti-GOR or anti-HCV. Circulating HCV-RNA levels but not anti-HCV or anti-GOR antibodies correlated with hepatocellular damage.

To determine the prevalence of hepatitis C viral infection in patients with sporadic non-A, non-B (NANB) acute hepatitis, hepatitis C viral RNA was studied in the plasma of 15 patients by reverse transcription-polymerase chain reaction assay. Plasma samples were sequentially obtained from 15 patients, and polymerase chain reaction was performed with two nested pairs of primers deduced from the 5′-non-coding region of hepatitis C viral sequences. Anti-C100 and anti-GOR antibodies were also measured with an enzyme-linked immunosorbent assay system. Plasma hepatitis C viral RNA was detected transiently in 7 of 15 patients (47%) at an early phase of the clinical course, while anti-C100 antibodies were detectable in only 2 (29%) of hepatitis C viral RNA-positive patients, and in 1 (13%) of the negative patients. Of 7 patients that were positive for plasma hepatitis C viral RNA, 4 (57%) had relapsing or protracted courses. In contrast, in all patients with undetectable hepatitis C viral RNA, hepatitis C viral RNA recovered and remained normal for at least 1 year. Thus, hepatitis C viral infection represents almost half the patients with acute sporadic NANB hepatitis, and detection of hepatitis C viral RNA in an early clinical phase is superior to anti-C100 measurement for diagnosing acute sporadic hepatitis C viral infection.

This paper discusses about feasibility study on global services recognition system for 3GPP GSM, UMTS, LTE, and IEEE 802.16d/e. we investigate the feasibility of preamble and synchronization signals as agents of services availability. To detect those signals, we propose the architecture consists of symmetric based auto-correlation, cross-correlation, filtering, and decision maker. Based on our estimation, the proposed design has reasonable complexity and has high possibility to develop. Moreover, simulations in ITU pedestrian B channel model give a good result where more than 80% services can be correctly detected for SNR 6 dB or higher.

In this paper, we propose a 4K digital cinema transmission over 1.2Gbps wireless LAN system. The proposed system employs the next generation wireless LAN system based on IEEE802.11ac specification. It reaches more than 33 meter propagation distance by using 80MHz of bandwidth on the 5GHz band. In this system, video data is compressed by JPEG 2000 with error resilience tools. These tools improve error performance against wireless channel, and enable very high throughput communication. Computer simulations are used to evaluate the bit error performance's influences to the video quality. Finally, we present RTL design results of the proposed wireless LAN system.

Recently, much progress has been made in the field of hepatitis B, such as natural history of the disease in relation to the amount of hepatitis B virus (HBV) DNA, genotypes of HBV influencing the natural course and treatment effects, mutations of HBV influencing the severity of the disease and development of hepatocellular carcinoma, and antiviral treatment such as nucleos(t)ide analogues and pegylated interferon. To make the consensus for the diagnosis, management and treatment of hepatitis B, a meeting was held during 45th annual meeting of Japan Society of Hepatology (JSH) in June 2009. In the meeting, recommendations and informative statements were discussed on the following subjects: (i) natural history of HBV infection; (ii) clinical implication of HBV genotypes; (iii) HBV mutations and their potential impact on pathogenesis of HBV infection; (iv) indications for antiviral treatment of chronic hepatitis B; (v) nucleos(t)ide analogues for chronic hepatitis B; and (vi) interferon therapy for chronic hepatitis B. The presenters reviewed the data on these subjects and proposed the consensus statements and recommendations. These statements were discussed among the organizers and presenters, and were approved by the participants of the meeting. In the current report, the relevant data were reviewed and the 12 consensus statements and nine recommendations on chronic hepatitis B were described.

Employing OFDMA and scalable bandwidth scheme in Long Term Evolution (LTE) downlink access impact on increasing complexity in frequency domain physical layer identity detection. Therefore, in this paper, we propose time domain detection instead of frequency domain using finite impulse response (FIR) filter and partial cross-correlation. Moreover, we implement RAM based architecture instead of multipliers and registers in filtering and cross-correlation computation. As result, the proposed system complexity is less than 128 point FFT. As addition, more than 95% physical layer identity can be detected correctly in SNR = 0 dB or higher for AWGN channel condition.

In a soft decision Viterbi decoder, the log-likelihood ratio (LLR) metric is used to improve the performance of the error correction. However, this cannot be directly applied in frequency shift keying (FSK) wireless transmission system which uses a frequency discriminator for FSK de-modulation - an inherently non-linear circuit. The LLR for a linear system cannot be used for the FSK wireless transmission system. It is necessary to calculate LLR which considers the non-linear characteristic of the frequency discriminator. In this paper, we derive the modified LLR which considers the non-linear characteristic of the frequency discriminator. Simulation shows the effectiveness of the derived LLR for 4-ary FSK wireless transmission system.

Pegylated interferon and ribavirin (PEG-IFN/RBV) therapy for chronic hepatitis C virus (HCV) genotype 1 infection is effective in 50% of patients. Recent studies revealed an association between the IL28B genotype and treatment response. We aimed to develop a model for the pre-treatment prediction of response using host and viral factors.Data were collected from 496 patients with HCV genotype 1 treated with PEG-IFN/RBV at five hospitals and universities in Japan. IL28B genotype and mutations in the core and IFN sensitivity determining region (ISDR) of HCV were analyzed to predict response to therapy. The decision model was generated by data mining analysis.The IL28B polymorphism correlated with early virological response and predicted null virological response (NVR) (odds ratio=20.83, p0.0001) and sustained virological response (SVR) (odds ratio=7.41, p0.0001) independent of other covariates. Mutations in the ISDR predicted relapse and SVR independent of IL28B. The decision model revealed that patients with the minor IL28B allele and low platelet counts had the highest NVR (84%) and lowest SVR (7%), whereas those with the major IL28B allele and mutations in the ISDR or high platelet counts had the lowest NVR (0-17%) and highest SVR (61-90%). The model had high reproducibility and predicted SVR with 78% specificity and 70% sensitivity.The IL28B polymorphism and mutations in the ISDR of HCV were significant pre-treatment predictors of response to PEG-IFN/RBV. The decision model, including these host and viral factors may support selection of optimum treatment strategy for individual patients.

Early disappearance of serum hepatitis C virus (HCV) RNA is the prerequisite for achieving sustained virological response (SVR) in peg-interferon (PEG-IFN) plus ribavirin (RBV) therapy for chronic hepatitis C. This study aimed to develop a decision tree model for the pre-treatment prediction of response.Genotype 1b chronic hepatitis C treated with PEG-IFN alpha-2b and RBV were studied. Predictive factors of rapid or complete early virological response (RVR/cEVR) were explored in 400 consecutive patients using a recursive partitioning analysis, referred to as classification and regression tree (CART) and validated.CART analysis identified hepatic steatosis (30%) as the first predictor of response followed by low-density-lipoprotein cholesterol (LDL-C) (/=100 mg/dL), age (50 and60 years), blood sugar (120 mg/dL), and gamma-glutamyltransferase (GGT) (40 IU/L) and built decision tree model. The model consisted of seven groups with variable response rates from low (15%) to high (77%). The reproducibility of the model was confirmed by the independent validation group (r(2) = 0.987). When reconstructed into three groups, the rate of RVR/cEVR was 16% for low probability group, 46% for intermediate probability group and 75% for high probability group.A decision tree model that includes hepatic steatosis, LDL-C, age, blood sugar, and GGT may be useful for the prediction of response before PEG-IFN plus RBV therapy, and has the potential to support clinical decisions in selecting patients for therapy and may provide a rationale for treating metabolic factors to improve the efficacy of antiviral therapy.

In this paper, we propose a 4K digital cinema wireless transmission over 1.2 Gbps wireless LAN system. The proposed system employs next generation wireless LAN system based on IEEE802.11TGac. It uses 80 MHz of bandwidth on 5 GHz band. In this system, video data is compressed by JPEG 2000 with added error resilience tools to improve error performance against wireless channel. Computer simulations are used to evaluate the bit error performance's influences to the video quality.

In this paper, we present a model-based Register Transfer Level (RTL) design of a simple joint parameter method for Carrier Frequency Offset and I/Q imbalance estimation. The estimation scheme is based on a proposed algorithm that uses only two short training symbols for faster estimation. The simple yet robust algorithm is then optimized for Field Programmable gate Array (FPGA) implementation. Simulation results show that the performance of the 16-bit fixed-point system approximates that of the ideal performance of the estimation algorithm.

This paper presents a design of Gigabit MIMO WLAN system with international standardization strategy. The proposed preamble supports gaining the throughput while maintaining the backward compatibility with the IEEE 802.11a/n WLAN systems. It has comparable PAPR and preamble efficiency with IEEE 802.11n mixed mode preamble. Run test under residential channel model shows that our system can achieve throughput over 1 Gbps for 45 meter propagation distance with low BER.

This paper deals with the development of 1.2 Gbps MIMO wireless LAN system based on IEEE802.11TGac's functional requirements. It reaches 33 meter propagation distance by using 80MHz of bandiwdth on 5GHz band. 4 × 5 antennas configuration contribute 2{sund|-order diversity gain and maintain both the high throughput and the high performance. The proposed Greenfield format preamble has high preamble efficiency. Novel phase rotation is employed to get low PAPR signal of preamble and data fields. Three different coding rates are examined for 64-QAM constellation which all accomplish over 1 Gbps with maximum throughput 1.266 Gbps. Synthesis results indicate that the the prototype system as the initial development of the proposed system can be implemented in target FPGAs of Xilinx Virtex-5 SX240T and LX330T.

This paper deals with our work in designing a 1.2 Gbps WLAN system. It reaches 33 meter propagation distance by using 80 MHz bandwidth on 5 GHz band. The proposed preamble has backward compatibility with IEEE802.11n system, allows band sharing and avoids collision within 5 GHz band. The proposed preamble has comparable PAPR and preamble efficiency with IEEE802.11n system. The 4 × 5 MIMO configuration contributes 2nd-order diversity gain and maintains both the throughput and performance. Run test for transmitting 90 frames of 4K digital cinema under in-door channel model demonstrates the excellent performance of the proposed system.

We created agent-based models that visually simulate conditions of chronic viral infections using two software. The results from two models were consistent, when they have same parameters during the actual simulation. The simulation results comprise a transient phase and an equilibrium phase, and unlike the mathematical model, virus count transit smoothly to the equilibrium phase without overshooting which correlates with actual biology in vivo of certain viruses. We investigated the effects caused by varying all the parameters included in concept; increasing virus lifespan, uninfected cell lifespan, uninfected cell regeneration rate, virus production count from infected cells, and infection rate had positive effects to the virus count during the equilibrium period, whereas increasing the latent period, the lifespan-shortening ratio for infected cells, and the cell cycle speed had negative effects. Virus count at the start did not influence the equilibrium conditions, but it influenced the infection development rate. The space size had no intrinsic effect on the equilibrium period, but virus count maximized when the virus moving speed was twice the space size. These agent-based simulation models reproducibly provide a visual representation of the disease, and enable a simulation that encompasses parameters those are difficult to account for in a mathematical model.

This paper introduces a novel algorithm for jointly estimating Carrier Frequency Offset and I/Q Imbalance for OFDM systems. The new algorithm is a closed form solution to obtain the frequency offset and I/Q Imbalance parameters in the absence of noise. In the presence of noise, the proposed algorithm uses the least squares algorithm to accurately estimate the parameters. The proposed algorithm is thus very scalable in terms of complexity. While the target system is OFDM, the proposed algorithm applies to any system as long as two identical data blocks are received in the receiver. Simulation results show that given a suitable amount of CFO, the high estimation accuracy of the proposed algorithm makes its BER performance comparable to a system without CFO and I/Q Imbalance.

This paper proposes a simple algorithm for joint estimation of carrier frequency offset and I/Q imbalance. The reduced complexity algorithm is derived from a closed form solution of the carrier frequency offset and I/Q imbalance parameters given two identical training blocks. The proposed algorithm also uses the least squares algorithm to give accurate estimate in the presence of noise. It was shown that for as little as 10 samples each from two identical OFDM symbols, the proposed algorithm can produce accurate estimate of CFO and I/Q imbalance. While the target system is OFDM, the proposed algorithm applies to any system as long as two identical data blocks are received in the receiver. Simulation results show that performance of the proposed algorithm that uses only 10 samples for complexity reduction is only 1dB below a system without CFO nor I/Q imbalance degradation. Index Terms—Carrier Frequency Offset, I/Q Imbalance, Least Squares Estimate

This paper presents our investigation on performance enhancement due to the implementation of low density parity check (LDPC) codes on IEEE 802.11n system and its Application Specific Integrated Circuit design. Simulation result shows that in higher coding rate, LDPC codes gives 6 dB better performance compared to binary convolutional codes. Logic synthesis is succesfully done on 0.13 µm CMOS technology with low-power standard cell library.

In this paper we report our works on designing MIMO wireless LAN system with throughput 600 Mbps for 30 meter propagation range by using Generalized Layered Space Time (GLST) coding and its implementation on field programmable gate array (FPGA) chips. At the receiver we employ our low-complexity GLST decoder to maintain error performance with low computational complexity. A novel packet format is developed that allows compatibility with the IEEE 802.11 a/n system. Our system works on 5,25 GHz carrier frequency with 80 MHz bandwidth, uses 4 transmit antennas and 2 receive antennas and gives superior performance on channel model B TGn. The Register Transfer Level results show that the developed system is synthesized succesfully as well as the implementation on the target FPGA chips.

A 35-year-old woman was admitted to our hospital for right upper quadrant pain and multiple liver tumor were detected by diagnostic imaging. Tumors located near the surface of the liver which accompanied capsular retraction. Diagnostic laparoscopy showed multiple white tone tumors with retraction of the adjacent liver capsule. Tumor targeted biopsy was performed. The pathologic diagnosis of epithelioid hemangioendothelioma (EHE) was made by the positive staining of factor VIII-related antigen. EHE tend to locate in peripheral and extend to the liver capsule. Therefore, we face difficulties in getting biopsy sample safely. Here we report a useful case of laparoscopic examination and biopsy in the diagnosis of EHE.

In this paper we investigate the performance enhancement due to the implementation of low density parity check (LDPC) codes on IEEE 802.11n system under channel model B TGn and its application specific integrated circuit design. Simulation result shows that LDPC codes gives 6 dB better performance compared to binary convolutional codes. Logic synthesis on 0.13 mum CMOS technology with low-power standard cell library shows that the proposed min-sum algorithm-based LDPC decoder is suitable for portable devices.

It has been verified recently that single carrier cyclic prefixed (SC-CP) with frequency domain equalizer (FDE) is a promising system for mobile communication and robust channel estimation is needed to build the equalizer's weight. Conventional SC-CP wireless system uses training sequences that put in every packet to get the channel information. This increases the overhead of the system. Here we propose a new channel estimation technique by employing cyclic prefix (CP) to maintain both system performance and throughput for this SC wireless system, with 300 kHz bandwidth and 1.6 Mbps throughput. The CP, which is inserted between blocked data to avoid inter-block interference (IBI), can be viewed as a source of channel information. If we can estimate the transmitted CP by conventional way, we can continue to estimate the channel adaptively. The simulation results show that the proposed channel estimation technique can maintain the system performance and gives 14,9% higher throughput compared with the conventional one when the number of packet is increased.

In this paper, we present a FPGA implementation of single carrier (SC) wireless system with frequency domain equalization (FDE) to overcome the effects of multipath fading channels. We propose a new packet format for this wireless system to reduce the error of channel estimation that occurs in the last part of the packet caused by time fluctuation of the channel. Our targets are veracity 15 km/h and 3 Mbps data rate under 1 MHz bandwidth. Simulation results show that our proposed system can work in severe multipath fading with 33 Hz Doppler shift (15 km/h) and 6 ppm frequency offset environment. The logic synthesis result meets the specification.

This paper presents a model-based register transfer level (RTL) design of a 4times2 multiple-inputs multiple-outputs (MIMO)-orthogonal frequency domain multiplexing (OFDM) wireless communication systems transmitter and its field programmable gate array (FPGA) implementation. This system provides a maximum of 600 Mbps with 20 meter of propagation distance using 80 MHz baseband bandwidth with 4times2 MIMO scheme.

600 Mbps data rate with 20 m of propagation distance has been achieved in multiple-input multiple-output (MIMO) wireless LAN (WLAN) system by using a group layered space-time (GLST) algorithm [3]. This system needs to transmit many data at one time in order to achieve high throughput. We propose a MAC protocol using technique of aggregation for this system. We can decrease packet error rate (PER) and increase the transmit data if we use technique of aggregation. The computer simulations for MIMO WLAN systems show the effectiveness of technique of aggregation.

In this paper, we present two register-transfer level (RTL) designs of physical layer-baseband (PHY-BB) for IEEE802.11n wireless local area network (WLAN) system. One is two antennas model which is able to achieve 144 Mbps with 20 MHz bandwidth, and the other is four antennas model which is able to achieve 600 Mbps with 40 MHz bandwidth. We engineer them applying a model-based design process (MBDP) which can accelerate and simplify the development. The results of logic synthesis and the implementation experiments on prototyping FPGA board are reported.

Background & Aims: Clinical significance of molecules involving innate immunity in treatment response remains unclear. The aim is to elucidate the mechanisms underlying resistance to antiviral therapy and predictive usefulness of gene quantification in chronic hepatitis C (CH-C). Methods: We conducted a human study in 74 CH-C patients treated with pegylated interferon α-2b and ribavirin and 5 nonviral control patients. Expression of viral sensors, adaptor molecule, related ubiquitin E3-ligase, and modulators were quantified. Results: Hepatic RIG-I, MDA5, LGP2, ISG15, and USP18 in CH-C patients were up-regulated at 2- to 8-fold compared with nonhepatitis C virus patients with a relatively constitutive Cardif. Hepatic RIG-I, MDA5, and LGP2 were significantly up-regulated in nonvirologic responders (NVR) compared with transient (TR) or sustained virologic responders (SVR). Cardif and RNF125 were negatively correlated with RIG-I and significantly suppressed in NVR. Differences among clinical responses in RIG-I/Cardif and RIG-I/RNF125 ratios were conspicuous (NVR/TR/SVR = 1.3:0.6:0.4 and 2.3:1.3:0.8, respectively). Like viral sensors, ISG15 and USP18 were significantly up-regulated in NVR (4-fold and 2.3-fold, respectively). Multivariate and receiver operator characteristic analyses revealed higher RIG-I/Cardif ratio, ISG15, and USP18 predicted NVR. Lower Cardif in NVR was confirmed by its protein level in Western blot. Also, transcriptional responses in peripheral blood mononuclear cells to the therapy were rapid and strong except for Cardif in not only a positive (RIG-I, ISG15, and USP18) but also in a negative regulatory manner (RNF125). Conclusions: NVR may have adopted a different equilibrium in their innate immune response. High RIG-I/Cardif and RIG-I/RNF125 ratios and ISG15 and USP18 are useful in identifying NVR.

Background/Aims Interferon (IFN) therapy leads to regression of hepatic fibrosis in chronic hepatitis C patients who achieve a sustained virologic response (SVR), while the beneficial effect is limited in those who fail to do so. The aim of the present study was to define factors associated with progression of fibrosis in patients who do not achieve a SVR. Methods Fibrosis staging scores were compared between paired liver biopsies before and after IFN in 97 chronic hepatitis C patients who failed therapy. The mean interval between biopsies was 5.9 years. Factors associated with progression of fibrosis were analyzed. Results Fibrosis progressed in 23%, remained unchanged in 47% and regressed in 29%. Steatosis and a high average alanine aminotransferase (ALT) between biopsies were independent factors for progression of fibrosis with risk ratios of 5.53 and 4.48, respectively. Incidence and yearly rate of progression of fibrosis was 64% and 0.22±0.29 fibrosis units per year in those with both risk factors compared to 8% and −0.04±0.17 fibrosis units per year in those negative for both factors. Conclusions Hepatic steatosis and elevated ALT levels are risk factors for progression of fibrosis in chronic hepatitis C patients who fail to achieve a SVR to IFN therapy and therefore may be therapeutic targets to halt the potentially progressive disease.

We investigated channel estimation with scattered pilots (SPs) in digital terrestrial television broadcasting (DTTB) and the performance of a receiver with a two-dimensional (2D) filter. High-accuracy interpolation is necessary because we perform channel equalization with SPs, which are inserted in transmit signals nonrectangularly. This interpolation is performed with a 2D filter that has a nonrectangular spectrum. However, the generation of the 2D filter involves heavy computational complexity. We propose a method of reducing the computational complexity by designing separable 2D filters. In addition, we present simulation results that compare our method with some conventional methods and show its effectiveness.

Group layered space-time can attain a better tradeoff between data rate and diversity gain. In this paper, we propose a generalized detection that is an ordered successive detection employing an extended Gaussian elimination algorithm. The detection algorithm can reduce computational complexity, as low as O(Nt2Nr) per symbol interval, by using the characteristics of the channel matrix. Nt and Nr are the number of transmitter and receiver antennas, respectively. Simulation results show that the proposed detector can achieve low-complexity and better performance over linear MMSE ones. In addition, the effect of spatial correlation in GLST systems is discussed from the BER performance.

We investigated channel estimation with scattered pilots (SPs) in digital terrestrial television broadcasting (DTTB) and the performance of a receiver with a two-dimensional (2D) filter. High-accuracy interpolation is necessary because we perform channel equalization with SPs, which are inserted in transmit signals nonrectangularly. This interpolation is performed with a 2D filter that has a nonrectangular spectrum. However, the generation of the 2D filter involves heavy computational complexity. We propose a method of reducing the computational complexity by designing separable 2D filters. Then the 2D filters are generated from 1D prototype filters. We'll also indicate the effectiveness of some methods of generating 1D prototype filters. In addition, we present simulation results that compare our method with some conventional methods and show its effectiveness.

This paper presents an FPGA implementation of a GLST-MIMO detector for GLST-MIMO wireless communication systems. The proposed system provides a maximum of 600 Mbps using the 80 MHz baseband bandwidth of the 4times2 MIMO scheme. The GLST-MIMO detector adopts a detection algorithm to low-computational complexity, as low as O(MTx 2) = O(42) (MTx : number of transmit antennas) per symbol interval, by using the orthogonality of the channel matrix. The GLST-MIMO detector architecture meets the timing constraints of real-time processing.

This paper presents a mobile radio system for frequency domain equalization (FDE) applied to single carrier (SC) modulation solutions to combat the effects of multipath fading channels. SC modulation has reduced peak-to-average power radio requirements to OFDM, enabling the use of less costly power amplifiers. SC modulation performance with FDE is similar to that of OFDM, even for very long channel delay spread. The channel estimation error due to the channel variation severely degrades demodulator performance. A large channel estimation error occurs a last symbol of packet in a fast-fading channel. We present a new packet format that is against a fading channel. Therefore, we design SC modulation system with FDE.

A field-programmable gate array (FPGA) prototyping board and several IP sets have been developed for the next generation wireless LAN standard, IEEE802.11n. This standard specifies the use of state-of-the-art wireless technologies such as MIMO-OFDM (multiple-input multiple-output orthogonal frequency division multiplexing) and LDPC(low-density parity check code) error correction, which means that larger LSI chips are needed. The board has five large-scale FPGAs with mesh connections, so it can easily implement MIMO-OFDM systems. The report also presents some RTL-based IP for 11n system such as frame synchronization, carrier synchronization, co-channel interference cancellation, LDPC error correction, fast Fourier transformation (FFT), and inverse fast Fourier transformation (IFFT).

Background & Aims The presence of resistance-associated variants (RAVs) of hepatitis C virus (HCV) attenuates the efficacy of direct acting antivirals (DAAs). The objective of this study was to characterize the susceptibility of RAVs to interferon-based therapy. Methods Direct and deep sequencing were performed to detect Y93H RAV in the NS5A region. Twenty nine genotype 1b patients with detectable RAV at baseline were treated by a combination of simeprevir, pegylated interferon and ribavirin. The longitudinal changes in the proportion of Y93H RAV during therapy and at breakthrough or relapse were determined. Results By direct sequencing, Y93H RAV became undetectable or decreased in proportion at an early time point during therapy (within 7 days) in 57% of patients with both the Y93H variant and wild type virus at baseline when HCV RNA was still detectable. By deep sequencing, the proportion of Y93H RAV against Y93 wild type was 52.7% (5.8%– 97.4%) at baseline which significantly decreased to 29.7% (0.16%- 98.3%) within 7 days of initiation of treatment (p = 0.023). The proportion of Y93H RAV was reduced in 21 of 29 cases (72.4%) and a marked reduction of more than 10% was observed in 14 cases (48.7%). HCV RNA reduction was significantly greater for Y93H RAV (-3.65±1.3 logIU/mL/day) than the Y93 wild type (-3.35±1.0 logIU/mL/day) (p

AIM: To study how lymph node metastasis (LNM) risk is stratified in undifferentiated-type early gastric cancer (undiff-EGC) dependent on combinations of risk factors. METHODS: Five hundred and sixty-seven cases with undiff-EGC undergoing gastrectomy with lymphadenectomy were examined retrospectively. Using clinicopathological factors of patient age, location, size, an endoscopic macroscopic tumor form, ulceration, depth, histology, lymphatic involvement (LI) and venous involvement (VI), LNM risk was examined and stratified by conventional statistical analysis and data-mining analysis. RESULTS: LNM was positive in 44 of 567 cases (7.8%). Univariate analysis revealed > 2 cm, protrusion, submucosal (sm), mixed type, LI and VI as significant prognostic factors and > 2 cm and LI-positive were independent factors by multivariate analysis. In preoperatively evaluable factors excluding LVI, sm and > 2 cm were independent factors. According to the depth and size, cases were categorized into the low-risk group [m and ≤ 2 cm, 0% (LNM incidence)], the moderate-risk group (m and > 2 cm, 5.6%; and sm and ≤ 2 cm, 6.0%), and the high-risk group (sm and > 2 cm, 19.3%). On the other hand, LNM occurred in 1.4% in all LI-negative cases, greatly lower than 28.2% in all LI-positive cases, and LNM incidence was low in LI-negative cases even in the moderate- and high-risk groups. CONCLUSION: LNM-related factors in undiff-EGC were depth and size preoperatively while those were LI and size postoperatively. Among these factors, LI was the most significantly correlated factor.

Group Layered Space-Time can attain a better tradeoff between data rate and diversity gain. For the GLST, in this paper we propose a new generalized detection algorithm that is an ordered successive detection employing an extended Gaussian elimination algorithm. The algorithm can reduce computational complexity, as low as O(Nt2Nr) per symbol interval, by using the characteristics of the channel matrix. Nt and Nr are the number of transmitter and receiver antennas, respectively. Simulation results show that the proposed detector can achieve low-complexity and better performance over linear MMSE ones. In addition, the effect of spatial correlation in GLST systems is discussed from the BER performance.

We investigated channel estimation with scattered pilots (SPs) in digital terrestrial television broadcasting (DTTB) and the performance of a receiver with a two-dimensional (2D) filter. High-accuracy interpolation is necessary because we perform channel equalization with SPs, which are inserted in transmit signals nonrectangularly. This interpolation is performed with a 2D filter that has a nonrectangular spectrum. However, the generation of the 2D filter involves heavy computational complexity. We propose a method of reducing the computational complexity by designing separable 2D filters. In addition, we present simulation results that compare our method with some conventional methods and show its effectiveness.

We investigated channel estimation with scattered pilots (SPs) in digital terrestrial television broadcasting (DTTB) and the performance of a receiver with a two-dimensional (2D) filter. High-accuracy interpolation is necessary because we perform channel equalization with SPs, which are inserted in transmit signals nonrectangularly. This interpolation is performed with a 2D filter that has a nonrectangular spectrum. However, the generation of the 2D filter involves heavy computational complexity. We propose a method of reducing the computational complexity by designing separable 2D filters. In addition, we present simulation results that compare our method with some conventional methods and show its effectiveness.

Background and Aim: Combination treatments of interferon-alpha (IFN) and ribavirin (RBV) are more effective than those of IFN alone in hepatitis C virus (HCV) infection. However, mechanisms of the action of the combination regimen are not well understood. To elucidate the viral genetic basis of IFN plus RBV combination therapy, genetic variabilities of HCV-1b were analyzed. Methods: We performed pair-wise comparisons of full-length HCV genomic sequences in three patients’ sera before and after initiation of IFN plus RBV treatment. Subsequently, we analyzed amino acid sequences of the NS5B region, which codes for the viral RNA-dependent RNA polymerase, and compared these with the outcomes of the therapy in 81 patients. Results: Analysis of the entire HCV sequence in patients who received IFN plus RBV therapy did not show consistent amino acid changes between before and after the initiation of the therapy. NS5B sequence analyses revealed that mutations at positions 300–358 of NS5B, including polymerase motif B to E, occurred more frequently in a group of patients exhibiting a sustained viral response (SVR) or an end-of-treatment response (ETR) compared with a group of patients exhibiting a non-response (NR). Closer examination revealed that mutations at aa 309, 333, 338 and 355 of NS5B occurred significantly more frequently in the SVR plus ETR group than in the NR group (P = 0.0004). Multivariate analysis showed that the number of mutations at these four sites was an independent predictor of SVR plus ETR versus NR. Conclusions: Particular amino acid changes in the NS5B region of HCV may correlate with outcomes of IFN plus RBV combination therapy. © 2005 Blackwell Publishing Asia Pty Ltd

In this paper, a packet analyzer for JPEG2000 codestreams is designed and its switching power and cell areas are estimated. This analyzer is intended to treat packets in the PEG2000 codestream, where the packet header and body data are separated from each other for further processing, such as encryption, partial scrambling, data hiding, and error correction. This VHDL-modeled analyzer can work at a bit rate of 50 Mb/s at minimum cost. Thus, it is suitable for real-time applications.

Although the incidence of hepatocellular carcinoma (HCC) has been shown to be reduced after interferon (IFN) monotherapy in chronic hepatitis C, the risk factors for the development of HCC have not been fully understood. The aim of this study is to investigate the risk factors for the development of HCC after IFN in chronic hepatitis C as well as whether the incidence of HCC will be reduced by ribavirin and IFN combination therapy or not.495 patients with chronic hepatitis C and which received IFN monotherapy were followed and the incidence and risk factors for the development of HCC were examined. On the other hand, in the patients which received ribavirin and IFN combination therapy, the sustained response rate was assessed and the reduction rate of HCC development was predicted.Multivariate analysis by the Cox proportional hazard model revealed that the risk factors for HCC development were age, male gender, severe fibrosis and outcome of IFN therapy. On ribavirin and IFN combination therapy, the sustained response rate reached 17.3% in genotype 1b and 74% in genotypes 2a and 2b infection, thus reducing 20% of the estimated incidence of HCC.To reduce the incidence of HCC in chronic hepatitis C, improvement of the sustained response rate is an essential issue, and ribavirin and IFN combination therapy shows to be promising.

The up-regulation of MUC1 protein is associated with malignant phenotype of cancer. We investigated the significance of KL-6, one of the MUC1 antigens, as a tumor marker in hepatitis C virus positive hepatocellular carcinoma (HCC). Serum KL-6 was determined in 203 patients with chronic hepatitis (CH), 47 patients with liver cirrhosis (LC) and 78 patients with HCC. KL-6 was higher in HCC compared to non-HCC (p=0.0005) and was higher in patients with multiple HCC nodules compared to a single nodule (p=0.02). There was no correlation between KL-6 and existent tumor markers for HCC such as alpha-fetoprotein, lens culinaris agglutinin-reactive alpha-fetoprotein or des-gamma-carboxyprothrombin. In the prospective analysis, the cumulative incidence of HCC was significantly greater in CH and LC patients with high initial KL-6 (above 400U/ml) compared to the others (p=0.02). Moreover, in the prospective observation of 25 patients whose HCC was completely cured by radiofrequency ablation therapy, the cumulative incidence of distant recurrences was significantly greater in patients with high initial KL-6 compared to the others (p=0.005). These results suggest that serum KL-6 could be a novel tumor marker in the diagnosis and the prediction of prognosis of HCC that may have additive value to the existent markers.