The coexistence of MPEG-2 and its powerful successor H.264/AVC has created a huge need for MPEG-2/H.264 video transcoding. However, a traditional transcoder where an MPEG-2 decoder is simply cascaded to an H.264 encoder requires huge computational power due to the adoption of a complicated rate-distortion based mode decision process in H.264. This paper proposes a 2-D Sobel filter based motion vector domain method and a DCT domain method to measure macroblock complexity and realize content-based H.264 candidate mode decision. A new local edge based fast INTRA prediction mode decision method is also adopted to boost the encoding efficiency. Simulation results confirm that with the proposed methods the computational burden of a traditional transcoder can be reduced by 20%30% with only a negligible bit-rate increase for a wide range of video sequences.

We demonstrate single electron counting on an alkanethiol-protected Au nanodot in a double-barrier tunneling structure by noncontact atomic-force spectroscopy (nc-AFS). The Coulomb step width dependence on the Au nanodot diameter is observed. Evaluation of fractional charge Q0 and contact potential difference by nc-AFS reveals a Vd-independent voltage shift due to Q0.

In situ observation of the adsorption process and reduction behavior of hemoglobin adsorbed on a bare glass surface was studied using slab optical waveguide (SOWG) spectroscopy. The peak position of the absorption band of hemoglobin adsorbed on the glass surface was almost the same as that of hemoglobin in solution. This result agrees with results previously reported by our group. The adsorbed hemoglobin molecules were also reduced by sodium dithionite solution. The adsorbed hemoglobin molecules still maintained their function in this experimental condition.

In situ observations were mainly performed by using slab optical waveguide (SOWG) spectroscopy synchronized with potential step measurements to investigate the time dependent spectral change of the adsorbed heptyl viologen cation radicals (HV+) in thin deposition layer on indium-tin-oxide (ITO) electrodes. Several absorption bands, which indicated a monomer and dimer of HV+ were co-adsorbed on ITO electrode surface with a monolayer or a few layers deposition, were observed in UV-visible region. The time dependent spectra yielded some important molecular information for the adsorption phenomena of HV+ on the electrode surface. All observed absorption bands disappeared completely when the electrode potential of -200 mV vs. Ag/AgCl was applied, which indicated the adsorbed HV+ species were electrochemically reoxidized on the ITO electrode.

A novel linear transconductor using translinear cells is proposed. It consists of a voltage follower, a resistor, and a current follower. SPICE simulations using an 8 GHz bipolar transistor-array parameter show that the linear transconductor with a transconductance of 1 mS exhibits a linearity error of less than 0.75% over an input voltage range of 1 V for a supply voltage of 2.0 V. The temperature coefficient of the transconductance is less than 124 ppm/. The -3-dB frequency of the transconductance is more than 4.5 GHz. Applying the linear transconductor as a building block, the design of a bandpass filter with center frequency of 85 MHz and Q-factor of 80 is presented.

Gastric cancer is a great part of the cancer occurrence and the mortality from cancer in Korea, and the early detection of gastric cancer is very important in the treatment and convalescence. This paper, for the early detection of gastric cancer, proposes the analysis system of an endoscopic image of the stomach, which detects abnormal regions by using the change of color in the image and by providing the surface tissue information to the detector. While advanced inflammation or cancer may be easily detected, early inflammation or cancer is difficult to detect and requires more attention to be detected. This paper, at first, converts an endoscopic image to an image of the IHb (Index of Hemoglobin) model and removes noises incurred by illumination and, automatically detects the regions suspected as cancer and provides the related information to the detector, or provides the surface tissue information for the regions appointed by the detector. This paper does not intend to provide the final diagnosis of abnormal regions detected as gastric cancer, but it intends to provide a supplementary mean to reduce the load and mistaken diagnosis of the detector, by automatically detecting the abnormal regions not easily detected by the human eye and this provides additional information for diagnosis. The experiments using practical endoscopic images for performance evaluation showed that the proposed system is effective in the analysis of endoscopic images of the stomach.

In this paper, the problem of Redundant Duplicated RREQ Network-wide Flooding (RDRNF), induced by multiple sensor nodes during route discovery in event-driven wireless sensor networks, is described. In order to reduce the number of signaling messages during the route discovery phase, a novel extension, named the Localized Route Discovery Extension (LRDE), to the on-demand ad hoc routing protocol, is proposed. The LRDE reduces energy consumption during route discovery. The heuristically and temporarily selected Path Set-up Coordinator (PSC) plays the role of a route request broker that alleviates redundant route request flooding. The LRDE also sets a route path be aggregation-compatible. The PSC can effectively perform data aggregation through the routing path constructed by the LRDE. The simulation results reveal that significant energy is conserved by reducing signaling overhead and performing data aggregation when LRDE is applied to on-demand routing protocols.

A linear CMOS transconductor is presented. PMOS transistors are employed in the resistor-replacement and voltage-level shifting to avoid the body effect. To annihilate the non-linear voltage terms, the substrate-bias effect of MOS transistors is treated more accurately in our design. Consequently, the non-linearity of the large-signal transconductance is reduced. The fabricated circuit occupies an area of 245 µm176 µm ( ≈approx 0.043 mm2) and dissipates 0.87 mW from a 3.3 V supply. For an input of 1 Vp-p, the measured output total harmonic distortion is less than 1.2%. The transconductance varies by less than 0.5% in the input range.

Video transcoding technique is an efficient mechanism to deliver visual contents to a variety of users who have different network conditions or terminal devices with different display capabilities. In this paper, we propose two types of transcoding methods for adapting the bitrate of streaming video to the bandwidth of the transmission channel; spatial resolution reduction (SRR) transcoding and temporal resolution reduction (TRR) transcoding. The two transcoding methods are alternatively operated according to the requirements of users. Experimental results show that the proposed transcoding methods can preserve image quality while transcoding to the low bitrate.

We have developed a stereoscopic large LED display with parallax barrier for use by the general public and stereoscopic cameras to show real world images in 3D. This paper aims to analyze stereoscopic camera separation and convergence angle to make the most use of a field of interest and the reproducible space provided by the large stereoscopic LED display. We describe the principle of a stereoscopic LED display with a parallax barrier and its reproducible space that is determined by the allowable range of disparity to fuse stereoscopic images. By using a model of stereoscopic imaging and display process, we introduce the formulas of the reproduced positions on our developed stereoscopic LED display. Furthermore, we analyze relationships between the stereoscopic camera separation, the convergence angle, the area of a field of interest, and the depth range of the reproduced space. The results show there are four categories in camera configurations: there are three kinds of camera configurations that have different characteristics and one configuration that is not recommended. Category A configuration reproduces a wide area of the field of interest in a long range of depth. Category B functions as a reduction of the field of interest. Category C functions as a magnification of the field of interest. In Category D, a narrow area of the field is reproduced in a short range of depth. In particular, for use by stereoscopic LED display with a rather low resolution, Category A and Category C are recommended because they fully use the reproducible positions.

This letter presents a new gossip-based ad hoc service discovery protocol that uses a novel decentralized, peer-to-peer mechanism to provide mobile devices with the ability to advertise and discover services in an efficient way. Our performance study shows that the proposed protocol appropriately addresses the need of proximal service discovery over a dynamic wireless medium.

This paper proposes a wideband speech coder in which a G.711 bitstream is embedded. This coder has an advantage over conventional coders in that it has a high interoperability with existing terminals so costly transcoding involving decoding and re-encoding can be avoided. We also propose a partial mixing method that effectively reduces the mixing complexity in multiple-point remote conferences. To reduce the complexity, we take advantage of the scalable structure of the bitstream and mix only the lower band of the signal. For the higher band, the main speaker location is selected among remote locations and is redistributed with the mixed lower-band signal. By subjective evaluations, we show that the speech quality can be maintained even when the speech signals are partially mixed.

Binary sequences with good autocorrelation and crosscorrelation properties are widely used in signal processing. If the autocorrelation properties are optimum, then the sequences are called perfect. In this paper we show, that the calculation of the crosscorrelation between Gordon-Mills-Welch sequences and Dillon-Dobbertin sequences is related to the crosscorrelation of m-sequences and their decimations. Furthermore, we give an upper bound for the maximum crosscorrelation coefficient (in absolute value) for certain perfect sequences.

The correlation between ohmic contact resistivity (ρc) and transconductance (gm) in AlGaN/GaN high-electron-mobility transistors (HEMTs) was investigated. To characterize ρc precisely, we fabricated a circular transmission line model (c-TLM) pattern adjoined to a field-effect transistor (FET) pattern on an HEMT. By measuring ohmic contact resistance and sheet resistance using the adjoined c-TLM, intrinsic transconductance (gm0), which is not influenced by the source resistance, can be estimated. The gm0 thus obtained is between 179 and 206 mS/mm. Then, it became possible to calculate the correlation between gm and (ρc. We found that ρc should be below 10-5 Ωcm2 for the improvement of gm in AlGaN/GaN HEMT when Rsh 400 Ω/.

This paper presents a novel gain boosted and bandwidth enhanced CMOS Op-Amp based on the well-known folded cascode structure. In contrast with the conventional methods which increase output resistance for gain boosting, the transconductance of the circuit is increased, therefore the -3 dB frequency is the same as for folded cascode structure. With negligible extra power consumption, the unity gain bandwidth is increased considerably. In this method, a new node is created in the circuit which introduces a pole to the transfer function with a frequency lower than cascode pole; feed-forward compensation is employed to reduce the effect of this pole on the frequency response. The input common mode range is limited slightly by 0.2-0.3 V with respect to folded cascode which is insensible. HSPICE simulations using level 49 parameters (BSIM3v3) in a typical 0.35 µm CMOS technology result in three times gain boosting and 60% enhancement in unity gain bandwidth compared to folded cascode, while the power consumption is increased by 10%.

Multiple-input multiple-output (MIMO) systems applying macroscopic selection diversity (MSD) are analyzed in composite fading channels through derived expressions of capacity outage probability. The MSD system uses a maximum capacity MIMO base station (BS) selection algorithm, where the results show a significant improvement in outage capacity.

This paper proposes a metric for example matching under the example-based machine translation. Our metric served as similarity measure is employed to retrieve the most similar examples to a given query. Basically it makes use of simple information such as lemma and part-of-speech information of typographically mismatched words. In addition, it uses the contiguity information of matched word units to catch the full context. Finally we show the results for the correctness of the proposed metric.

A baseband transmission scheme for wireless communications has been proposed and examined using a pair of discone antennas for transmission and reception. The wireless baseband transmission scheme radiates a baseband signal stream, such as non-return-to-zero (NRZ), return-to-zero (RZ), or Manchester encoded signals, directly from an antenna. Namely, a carrier in terms of a sinusoidal radio wave or light wave is not used in the transmission. In experiments, baseband pulses generated with a data generator were radiated directly from the discone antenna, and received waveforms were observed with a digital storage oscilloscope. The experiments showed that wireless baseband transmission is realisable when using antennas with a flat amplitude spectrum and a linear phase characteristic, such as discone antennas, over a given band. Manchester encoding is promising for this wireless baseband transmission.

A new method to reduce power consumption of a linear transconductor is proposed in this paper. The minimum tail current for the operation of the transconductor is supplied by a new current source circuit. The proposed circuit is based on a dynamic biasing current technique. Results of SPICE simulation show that the proposed technique is very effective to reduce power consumption of the transconductor.

This paper proposes a linearized multiplier using the MOS transistors. The proposed circuit can be realized by adding two voltage shifters and some current mirrors to the conventional circuit. Especially, these additional voltage shifters can be saved when the proposed circuit is used as a transconductor. The proposed circuit is driven by a controlled tail current source. A technique to reduce the effect of the mobility reduction is proposed. First, the output current of the conventional transconductor is analytically derived and its problem is pointed out. Secondly, the proposed circuit is shown. The proposed method is accomplished by taking the mobility reduction into account. The validity of the proposed method is confirmed through both of Spice simulation and experiment. Finally, the proposed circuit is fabricated in the 1.2 µm CMOS process. The second-order and the third-order distortions are about -55 dB and -64 dB, respectively for a 0.5 Vp-p sinusoidal input signal.