Molecular aligned naphthacene thins films were fabricated using vacuum evaporation and the rubbing method. The attenuated total reflection (ATR) and emission light properties from surface plasmon (SP) excitation due to molecular luminescence were investigated for these films. The long axis of the rod-like molecule was estimated to align perpendicular to the rubbing direction. The ATR and emission light properties depended on the molecular orientation.

The computational error of the multilevel fast multipole algorithm is studied. The error convergence rate, achievable minimum error, and error bound are investigated for various element distributions. We will discuss the boundary between the large and small buffer cases in terms of machine precision. The needed buffer size to reach double precision accuracy will be clarified.

Multiple-input multiple-output (MIMO) systems using eigenbeam space division multiplexing (E-SDM) perform well and have increased capacities compared with those using conventional space division multiplexing (SDM). However, channel state information (CSI) is required at a transmitter, and the performance of E-SDM systems depends much on the accuracy of the CSI at a transmitter and a receiver. In time-varying fading environments, the channel change between the transmit weight determination time and the actual data transmission time causes the system performance to degrade. To compensate for the channel error, a linear extrapolation method has been proposed for a time division duplexing system. Unfortunately, the system performance still deteriorates as the maximum Doppler frequency increases. Here, two new techniques of channel extrapolation are proposed. One is second order extrapolation, and the other is exponential extrapolation. Also, we propose maximum Doppler frequency estimation methods for exponential extrapolation. Simulation results for 4tx 4rx MIMO systems showed that using the proposed techniques, E-SDM system performs better in a higher Doppler frequency region.

This paper investigates the impact of chip duty factor (DF) in DS-UWB system with Rake receiver over AWGN and UWB indoor multipath environment corresponding to system parameters such as spreading bandwidth and chip length. Manipulating DF in DS-UWB system offers several advantages over multipath channel and thus, capable of improving system performance for better quality of communication. Although employing lower DF generally improves performance, in some exceptional cases on the other hand, degradation can be observed despite decreasing DF. Therefore, the objective of this paper is to clarify the relationship between DF and DS-UWB system performance. We discovered that with constant processing gain and spreading bandwidth, performance improvement can be observed at DF lower than 0.17. Additionally, with spreading bandwidth as tradeoff parameter, significant performance improvement can only be observed below DF of 0.85.

Recently there are various requirements for LSI testing, such as test compaction, test compression, low power dissipation or increase of defect coverage. If test sequences contain lots of don't cares (Xs), then their flexibility can be used to meet the above requirements. In this paper, we propose methods for finding as many Xs as possible in test sequences for sequential circuits. Given a fully specified test sequence generated by a sequential ATPG, the proposed methods produce a test sequence containing Xs without losing stuck-at fault coverage of the original test sequence. The methods apply an approach based on fault simulation, and they introduce some heuristics for reducing the simulation effort. Experimental results for ISCAS'89 benchmark circuits show the effectiveness of the proposed methods.

Several active queue management schemes have been proposed to provide fairness among flows. In particular, BLACK has the best performance among them with respect to simplicity and fairness. However, it can provoke the UDP throughput to fluctuate and worsen the fairness. In this paper, we propose a new active queue management scheme to modify BLACK for better performance. Simulation results illustrate that the performance of our proposal is better than that of BLACK in terms of the fairness and the smooth UDP throughput.

A hard real-time system is one whose correctness depends not only on the logical result, but also when the results are produced. While many techniques have been proposed for single processor real-time systems, multiprocessor systems have not been studied so extensively. In this paper, we mainly propose two variant (DCTS) by using the Early-Release-Fair (ERfair) and Proportionate-fair (Pfair) model with integral assumptions for identical multi-processor real-time systems. ERfair is a scheduling model for real-time tasks on a multiprocessor system. On the different definitions of distance constraint, we propose two efficient scheduling algorithms designed to probe whether the distance constraints of all ER-fair tasks can be guaranteed. If the distance constraints cannot be guaranteed, then the proposed algorithms gather the unfeasible tasks and inflate them with a reweighting function. The proposed algorithms are linear-time and most suitable for dynamic systems. The experimental results reveal that the proposed algorithms increase significantly the ratio of schedulable task sets.

Diversity transmission using space-time block coding (STBC) shows a degraded performance in frequency selective fading (FSF) channel. In this paper, assuming the CSI is unknown at both transmitter and receiver while a pilot signal is available during the training period, we propose a MIMO transmission scheme using STBC by adopting subband adaptive array (SBAA) processing. The receive signal is converted into the frequency-domain and adaptive processing is done at each subband. A novel construction of SBAA is introduced to process received signal based on STBC. Simulation results demonstrate that the proposed scheme has a better performance compare to conventional STBC, and has a better performance and less computational load compare to STBC-TDLAA.

This paper presents a semi-blind algorithm for multiuser interference cancellation and fading amplitude estimation for downlink MIMO DS-CDMA systems with multipath fading channels. Taking advantage of the space-time information of the parametric multipath channel, the proposed algorithm first uses a space-time channel decoupler to suppress multiuser interference and then decomposes the channel into a set of parallel subchannels each containing the signal of the desired user on an individual multipath. Two criteria, the complementary orthogonal projection (COP) and the minimum variance distortionless response (MVDR), are employed by the space-time decoupler to achieve interference suppression and signal separation. The fading amplitudes can then be estimated from the eigen space of the output of the space-time channel decoupler. It follows that the signal of interest can be maximally combined in a pathwise manner and then differentially decoded.

This letter proposed a linear precoding scheme for the V-BLAST system that requires only knowledge of the statistical CSI; the transmitter does not need the instantaneous CSI. Power allocation on the eigenmodes of the transmit correlation matrix is one way to minimize bit error rate (BER). Simulation results show that the proposed precoding V-BLAST system provides a significant reduction in the BER compared with the conventional V-BLAST systems.

This paper proposes a new codec design method based on JPEG for face images and presents its application to face recognition. Quantization table is designed using the R-D optimization for the Yale face database. In order to use in the embedded systems, fast codec design is also considered. The proposed codec achieves better compression rates than JPEG codec for face images. In face recognition experiments using the linear discriminant analysis (LDA), the proposed codec shows better performance than JPEG codec.

We developed an olfactory display to blend 8 component odors at any composition. The solenoid valves controlled by an algorithm with delta sigma modulation showed the sufficient capability. Then, we developed a system for presenting a movie together with scents. We actually made a movie with scents and evaluated it using questionnaire survey. It was found that the scene with smell attracted the experimental subjects' attention and, moreover, the contrast of the pleasant smell with the offensive one emphasized their attention. Furthermore, we established several guidelines for producing movies with scents.

This paper proposes a new per-test fault diagnosis method based on the X-fault model. The X-fault model can represent all possible faulty behaviors of a physical defect or defects in a gate and/or on its fanout branches by assigning different X symbols assigned to the fanout branches. A partial symbolic fault simulation method is proposed for the X-fault model. Then, a novel technique is proposed for extracting more diagnostic information by analyzing matching details between observed and simulated responses. Furthermore, a unique method is proposed to score the results of fault diagnosis. Experimental results on benchmark circuits demonstrate the superiority of the proposed method over conventional per-test fault diagnosis based on the stuck-at fault model.

In [1] the impact of BIST on the chip defect level after test has been addressed. It was assumed in [1] that no measures are taken to ensure that the BIST circuitry is fault-free before launching the functional test. In this paper we assume that a BIST pretest is first conducted in order to get rid of all chips that fail it. Only chips whose BIST circuitry has passed the pretest are kept, while the rest are discarded. The BIST pretest, however, is assumed to have only a limited coverage against its own faults. This paper studies the product quality improvements as induced by the BIST pretest, and provides some insight as to when it may be worthwhile to perform it.

This paper proposes a fast motion estimation algorithm for variable block-sizes by utilizing motion vector bottom-up procedure for H.264. The refined motion vectors of adjacent small blocks are merged to predict the motion vectors of larger blocks for reducing the computation. Experimental results show that our proposed method has lower computational complexity than full search, fast full search and fast motion estimation of the H.264 reference software JM93 with slight quality decrease and little bit-rate increase.

Many applications of OFDM systems require Doppler spread estimation. This is quite difficult in multi-path fading channels with no strong direct path. This letter proposes a novel Doppler spread estimation method, which uses the mean square (MS) value of channel impulse response's time derivative. The proposed method is very simple compared with the previously proposed methods. Simulation results show that it allows easy and precise Doppler spread calculation for OFDM by using the channel estimation based on either pilot tones or pilot symbols.

There is a certain level of requirements for system performance that intrusion detection systems on the Internet need. One of them is to lower the rate of "False Positive" and "False Negative." Another one is to have a convenient user interface so that users can manage system security easily with the detection systems. However, scan detection systems on public domain show a high rate of false detection and have difficulty in detecting various scanning techniques. In addition, since current scan detection systems are based on the command interface, the systems have been poor at user interface and therefore it is difficult to apply them to system security management. Hence, we first propose a set of new filter rules, which detect various scan attacks based on port scanning techniques. Secondly, a set of ABP-Rules derived from attacker's behavioral patterns is proposed in order to minimize the False Positive rate. With these methods, we implement a new real-time scan detection system, overcoming the limitations of current real-time scan detection systems. Also the implemented system contains a GUI interface for user's convenience of managing the network security, which was developed with Tcl/Tk.

An algorithm for encoding low-density parity check (LDPC) codes is investigated. The algorithm computes parity check symbols by solving a set of sparse equations, and the triangular factorization is employed to solve the equations efficiently. It is shown analytically and experimentally that the proposed algorithm is more efficient than the Richardson's encoding algorithm if the code has a small gap.

Watson-Crick automata were introduced as a new computer model and have been intensively investigated regarding their computational power. In this paper, aiming to establish the relations among language families defined by Watson-Crick automata and the family of context-free languages completely, we obtain the following results. (1) F1WK = FSWK = FWK, (2) FWK = AWK, (3) there exists a language which is not context-free but belongs to NWK, and (4) there exists a context-free language which does not belong to AWK.

Effects of wall material on the channel capacity of an indoor multiple input multiple output (MIMO) system are investigated using a hybrid technique of the method of moments (MoM) and the finite difference time domain (FDTD) method with consideration of the Ricean K factor and the effective degrees of freedom (EDOF) of multiple paths.