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In this paper, a beam-tracking technique for orthogonal frequency division multiplexing (OFDM)-based millimeter-wave cellular systems is proposed using subarray structures and pilot sequences. In order to track the variations in the angle of departure (AoD) and angle of arrival (AoA), an antenna array is configured into two different subarrays, which allow us to estimate AoD/AoA based on the phase difference between the two subarrays in the received signals. A pilot sequence is designed such that it can distinguish between different subarrays and track a beam for a mobile station in multicell multiuser environments. Two different implementation methods of AoD/AoA estimation are proposed and compared with computer simulations.

Primary effusion lymphoma (PEL), strongly linked with latent infection of Kaposi's sarcoma-associated herpesvirus (KSHV), constitutively expresses cellular interferon regulatory factor 4 (IRF4) while suppressing the expression of B cell lymphoma 6 (BCL6). Recently, it was shown that IRF4, a key transcriptional repressor of BCL6, might be a pivotal regulator of KSHV for balancing between latency and its reactivation in PEL cells. However, the action of the BCL6-IRF4 transcription factor axis during KSHV's life cycle is not clear. Herein we found that the KSHV lytic protein viral interferon regulatory factor 4 (vIRF4) dramatically enhanced the transcriptional activity of the BCL6 through the inhibition of its negative regulator IRF4. Using a chromatin immunoprecipitation (ChIP) assay, we further showed that vIRF4 bound to the specific promoter region of IRF4, contributing to a dramatic suppression of IRF4 gene expression. Correspondingly, we also found BCL6 expression to be positively and inversely correlated with vIRF4 and IRF4 expression, respectively, during KSHV reactivation. Finally, we observed that these processes require efficient KSHV lytic replication. Thus, our findings suggest a crucial role of the BCL6-IRF4 axis in triggering the transition between KSHV latency and lytic reactivation.

The concept of an intelligent reflecting surface (IRS) has recently emerged as a promising solution for improving the coverage and energy/spectral efficiency of future wireless communication systems. However, as the number of reflecting elements in an IRS increase, the beam training protocol in IRS-assisted millimeter-wave (mmWave) cellular systems requires a large beam training time because it needs to find the best beam pairs for the link between the base station (BS) and the IRS, as well as the link between the IRS and the mobile station (MS). In this paper, a fast beam training technique for IRS-assisted mmWave cellular systems with a uniform rectangular array is proposed for detecting the best beam pairs of BS-IRS and IRS-MS links simultaneously. Two different types of beam training signals (BTSs) are proposed to distinguish simultaneously transmitted beams from the BSs in multi-cell multi-beam environments: the Zadoff–Chu sequence based BTS (ZC-BTS) and m-sequence based BTS (m-BTS). The correlation properties of ZC-BTSs and m-BTSs are analyzed in multi-cell multi-beam environments. In addition, the effect of symbol time offset on the ZC-BTS and m-BTS is analyzed. Finally, simulation results reveal that the proposed technique can significantly reduce the beam training time for IRS-assisted mmWave cellular systems.

The beam training protocol in millimeter-wave cellular systems requires a long processing time that is proportional to the product of the number of Tx beams, number of Rx beams, and number of neighbor base stations. In this paper, a preamble design technique that can significantly reduce the processing time for beam training in an orthogonal-frequency-division-multiplexing-based cellular system is proposed by transmitting multiple beams with their corresponding Tx beam IDs (BIDs) and cell ID (CID). The Zadoff-Chu (ZC) sequence, with its length given by a multiplication of two prime numbers, is proposed for an efficient CID and BID (CBID) search in a preamble design. It is shown by computer simulation that the proposed preamble design technique can obtain a 10- to 20-fold computational complexity gain in CBID detection and achieve a performance (0.1-dB signal-to-noise ratio shift) that is close to that of a ZC sequence with a prime length.

A pilot-based beam-tracking technique is proposed for OFDM-based millimeter-wave cellular systems. In order to track the variations in the angle of departure (AoD) and angle of arrival (AoA), an antenna array is configured into two different subarrays which allow us to estimate AoD/AoA based on the phase difference between the two subarrays in the received signals. A pilot sequence is designed such that it can distinguish between different subarrays and track a beam for a mobile station in multi-cell multi-user environments.

In this paper, we propose a femtocell searching technique which can prevent a macrocell UE(user equipment) from losing synchronism to its serving macrocell near closed access femtocells in co-channel deployment due to the leakage of femtocell signals by using a CS(Common Signal). The CS, commonly transmitted by femtocells in a macrocell at the same time, enables the macrocell UEs to be kept synchronized with their serving macrocells since the CINR(Carrier to Interference and Noise Ratio) of base stations in macrocell can be kept high even near closed access femtocells. Also, the CS is designed in such a way that a macrocell UE can recognize the existence of femtocell by using the metric CSCINR(Common Signal Carrier to Interference and Ratio) measured with CS. In addition, the proposed femtocell searching technique can reduce the frequency of femtocell searching trial by using the metric on mobility of a macrocell UE defined in this paper, and the reduction of the frequency of handover trial can be also expected as a byproduct.

The processing time for beam training in millimeter-wave (mmWave) cellular systems can be significantly reduced by a code division multiplexing (CDM)-based technique, where multiple beams are transmitted simultaneously with their corresponding Tx beam IDs (BIDs) in the preamble. However, mmWave cellular systems with CDM-based preambles require a large number of cell IDs (CIDs) and BIDs, and a high computational complexity for CID and BID (CBID) searches. In this paper, a new preamble design technique that can increase the number of CBIDs significantly is proposed, using a preamble sequence constructed by a combination of two Zadoff-Chu (ZC) sequences. An efficient technique for the CBID detection is also described for the proposed preamble. It is shown by simulations using a simple model of an mmWave cellular system that the proposed technique can obtain a significant reduction in the complexity of the CBID detection without a noticeable performance degradation, compared to the previous technique.

In this paper, a new preamble design technique that can increase the number of cell IDs (CIDs) and beam IDs (BIDs) significantly is proposed, using a preamble sequence constructed by a combination of two Zadoff-Chu (ZC) sequences. An efficient technique for the CID and BID (CBID) detection is also described for the proposed preamble. It is shown by simulations using a simple model of an mmWave cellular system that the proposed technique can obtain a significant reduction in the complexity of the CBID detection without a noticeable performance degradation, compared to the previous technique.

The fundamental problem in multi-cell two-way relaying is low uplink achievable rate due to the fact that the uplink signal transmitted by a user is significantly contaminated by the downlink signal transmitted simultaneously by the base station (BS) in the neighboring cell, which has much greater power than the power of the user uplink signal. In this paper, a novel relay precoding optimization scheme is proposed in the two-cell two-way relay channel with only local channel state information in pursuit of reducing the inter-cell interference. The optimization problems for finding the relay precoding coefficients are decoupled at each relay, and can be solved using the parameters which are calculated offline according to the users' locations. Simulation results show that the proposed scheme outperforms the conventional two-way relaying and direct communication without relaying for cell-edge users, owing to reduced inter-cell interference.

Aim: The primary objective of this study was to determine the effects of quorum quenching in the pathogenicity and toxoflavin production of Burkholderia glumae causing bacterial rice grain rot. Methods and Results: An acyl-homoserine lactonase (aiiA) gene from Bacillus sp. was expressed in B. glumae under the control of a constitutive promoter. Acyl-homoserine lactone production in the aiiA-transformants was reduced significantly, and the aiiA-expressing B. glumae strain reduced the severity of soft rot when the strain was co-inoculated with a soft-rot pathogen, Pectobacterium carotovorum ssp. carotovorum SCCI. However, the aiiA-transformant still caused rice seedling rot and rice grain rot. The aiiA-expressing strains had wild-type levels of transcription from the genes in the toxoflavin biosynthetic operon, and as well as wild-type levels of toxin production. Conclusions: Our results show that aiiA-mediated quorum quenching does not affect virulence or toxoflavin production in B. glumae. Significance and Impact of the Study: Indirect quorum quenching may prove an ineffective approach to the control of rice grain rot, because it reduces, but does not eliminate entirely homoserine lactones in B. glumae. Virulence of rice grain rot was retained despite reduction in homoserine lactones by the expression of aiiA in B. glumae.

In this correspondence, an efficient receive-diversity-combining technique is proposed for single-carrier frequency-division multiple access (SC-FDMA)-based cooperative relay systems when discrete Fourier transform (DFT) spreading sizes for mobile stations and relay stations are different. The proposed technique is composed of an adjustment block for the DFT spreading size, a phase rotation block, a resource reallocation block, a channel phase compensation block, a receive-diversity-combining block, a channel gain compensation block, and a resource de-allocation block. The proposed technique is shown to provide a high diversity gain in multipath channel environments with a relatively small computational complexity.

In this paper, a new handover procedure for OFDM-based multi-hop relay systems is proposed to reduce handover overhead by distinguishing an inter-cell handover event from an intra-cell handover event at the level of the physical layer using a preamble with a hierarchical design. A Subcell ID concept used to identify relay station in a cell is proposed in the hierarchical design that works in conjunction with the existing Cell ID used to identify base station. The proposed handover procedure can simplify the scanning procedure and skip/simplify the network re-entry procedure, resulting in a significant reduction in handover overhead.

In this letter, a recursive ICI cancellation technique for cooperative space-time block coded orthogonal frequency division multiplexing (STBC-OFDM) systems is proposed to mitigate the intercarrier interference (ICI) caused by multiple carrier frequency offsets (CFOs) in cooperative transmission. The proposed technique is shown to mitigate the noise enhancement effect on the STBC-OFDM signals caused by multiple CFOs, and to be effective in reducing ICI especially when the system has a large FFT size and multiple CFOs.

In a cellular system, efficient power saving techniques for a mobile station (MS) are necessary because of its inherently limited battery capacity. The paging indicator (PI) transmission scheme in CDMA cellular systems is known to be an effective power saving strategy. However, in OFDM-based cellular systems, the MS has to operate FFT for PI symbol detection, resulting in a significant power consumption. In this letter, a PI transmission technique with reduced power consumption using the preamble in OFDM-based cellular systems, especially for mobile WiMAX systems, is proposed for the MS under power saving mode. Simulations indicate a 30-50% power saving from our proposed PI transmission technique, at the expense of a slight increase in paging response delay.

In this paper, we propose a new digital duplexing scheme, called synchronous digital duplexing (SDD), which can increase data efficiency and flexibility of resource by transmitting uplink signal and downlink signal simultaneously in wireless communication. In order to transmit uplink and downlink signals simultaneously, the proposed SDD obtains mutual information among subscriber stations (SSs) with a mutual ranging symbol. This information is used for selection of transmission time, decision on cyclic suffix (CS) insertion, determination of CS length, and re-establishment of FFT starting point.

A numerical prediction of the transient fuel temperature in an aircraft was made and verified with a flight test. The analysis was studied with the finite difference method. Numerical calculation was performed by an explicit method of the modified Dufort-Frankel scheme. Convective heat transfer coefficients were used in calculating heat transfer between the aircraft surface and the ambient air. For an aircraft on the ground, an empirical equation represented as a function of free-stream air velocity was used. And, the heat transfer coefficient for flat plate turbulent flow suggested by Eckert was employed for in-flight phases. The governing equations used in this analysis are the mass and energy conservation equations on fuel and oils. The analysis was verified with the flight test data of a fuel system with additional fuel supplies and return concept. As a result of the verification, the difference of the fuel temperatures obtained by the analysis from those of the flight test data was relatively small with a tendency to increase in the later phases of the flight.

In this letter, the effect of a propagation delay resulting from the use of an OFDM system with a transparent mobile multi-hop relay (MMR) is initially analyzed. Then, a least square (LS) channel estimation technique for the OFDM system with throughput enhancement (TE) MMR or cooperative MMR is proposed. It is demonstrated by computer simulation that the proposed LS channel estimation technique for OFDM systems with transparent MMR is superior to the conventional technique in terms of mean square error (MSE) and bit error rate (BER).

Heat transfer in linear motor driven stages for surface mounting device applications was investigated. A simple one-dimensional thermal resistance model was introduced. In order to reduce three-dimensional nature to one-dimensional, a few assumptions and simplifications were employed suitably. A good agreement with a finite element heat transfer analysis in temperature profile was obtained. For validation, the analysis was compared with the measurement with respect to motor driving power. Overall discrepancy was less than 7/spl deg/C. The influences of two high thermal resistance parts, insulation sheet and thermal contact between the coil assembly and the mounting plate, were examined through the analysis. Additionally, the thermal resistance analysis was applied to another stage including an internal cooling-air passage, and was found to be available for this system as well. After validation, cooling effect was surveyed in terms of motor power and cooling-air and -water flow rate.

In recent years, e-Commerce is very active on the Internet, especially the World Wide Web alone: with the popularization of Internet using high-speed networks. Especially, Circulation of Multimedia Contents like MP3 data if widely being focused as one of the popular researches. However, the existing models of AOD (Audio On Demand) System lack substantial illegal copy protection or copyright protection. In this paper, we propose an AOD System that guarantees substantial illegal copy protection and copyright protection based on the PKI (Public Key Infrastructure). As transmitting MP3 data using the user`s public key, the proposed .method prevents the attack of dropper during transmitting data. Also, it guarantees the right of users and distributors by prohibiting illegal users from using MP3 data.

Most mobile computing devices use a battery as their main power source. Efficient power use and management are very important in mobile devices. It is necessary to understand the power consumption of the processor in a mobile device. In this paper, we choose to use a PMU (Performance Monitoring Unit) to understand hardware performance. By using a PMU counter, it is possible to analyze mobile AP (Application Processor) quickly and accurately without additional CPU overhead. We built a power consumption model using the number of memory accesses per cycle and the clock frequency of the core of mobile AP. By using the power consumption model that we built, we can easily and quickly calculate the power consumption of each core in a multi-core mobile AP. We measured the power consumption of mobile AP using the Mibench benchmark suite and then compared actual measured power consumption and predicted power consumption using several benchmark applications of the Parmibench benchmark suite. The average RMSE between actual measured power consumption and predicted power consumption was 5.01%.

A benchmark program provides objective and quantitative experimental data that is used in HW architecture design and as performance criteria. For that reason, a benchmark point must be fairly calculated to make a right decision. It is difficult to benchmark with fairness in embedded systems such as smartphones since there are many HW and SW development environments. For example, iOS adopts ObjectC language and Android supports Java and C/C++ to develop applications. Therefore, it is impossible to apply the same native workload without modification to both iOS and Android platforms. Web-based benchmark programs can solve the problem of fairness. If a platform supports a browsing system, then we can run the same web benchmark program on that platform. In this paper, we construct a web-based benchmark program with JavaScript and HTML5 to evaluate an entire HW platform. The JavaScript workload has three components and the HTML5 workload has two components. Experiment shows that similar runtime characteristics are maintained between native and web workloads. Moreover, we use a compared ratio method to relieve result distortion that comes from unexpected system overheads. Finally, we run our benchmark program on the iOS and many Android platforms.

This study was conducted to determine the proper hand position on the sternum for external chest compression to generate a maximal haemodynamic effect during cardiopulmonary resuscitation (CPR).114 patients with cardiac arrest who underwent chest CT after successful resuscitation from January 2006 to August 2009 were included in the study. To evaluate the area of the cardiac chambers subjected to external chest compression, the area of each cardiac chamber under the sternum was measured using cross-sectional CT at three different locations: the internipple line on the sternum (point A), halfway between point A and the sternoxiphoid junction (point B) and at the sternoxiphoid junction (point C).The widest total heart area, total ventricular area and left ventricular area (LVA) were observed most frequently at point C (58%, 85% and 78% of all cases, respectively). Few cases (six in total heart area, one in total ventricular area and one in LVA) were observed as the widest at point A. Predicted compressed areas of the right and left ventricle were wider at point C than at points A or B (right ventricular area: 366±536 mm(2) at point A, 961±653 mm(2) at point B and 1383±689 mm(2) at point C, p0.001; LVA: 65±236 mm(2) at point A, 365±506 mm(2) at point B and 1099±817 mm(2) at point C, p0.001).Only a small proportion of the ventricle is subjected to external chest compression when CPR is performed according to the current guidelines. Compression of the sternum at the sternoxiphoid junction might be more effective to compress the ventricles.

In this paper, a new handover technique for OFDM-based mobile mesh networks (MMNs) is proposed to reduce the handover overhead by distinguishing an inter-cluster handover event from an intra-cluster handover event using a hierarchical design concept of a preamble. The proposed handover procedure can simplify scanning procedure and skip/simplify network entry procedure, resulting in a significant reduction of handover overhead.

In this paper, a Direction-of-Arrival (DoA) estimation scheme with cell searching is proposed for a mobile relay station (MRS) with uniform circular array (UCA) at handover region. The proposed scheme of cell searching and DoA estimation for the MRS with UCA is robust even when there exist symbol timing offsets (STOs). Compared with the previous scheme, the proposed scheme can reduce computational complexity and processing time for cell searching and DoA estimation. Simulation results are included to verify the performance of the proposed scheme under Mobile WiMAX environment.

In a cellular system, efficient power saving techniques for a mobile station (MS) are necessary because of its inherently limited battery of MS. The paging indicator (PI) transmission scheme in CDMA cellular systems is known to be an effective power saving strategy. However, in OFDM-based cellular systems, the MS has to operate FFT for PI symbol detection, resulting in a significant power consumption. In this paper, a reduced power consumptive PI transmission technique using the preamble in OFDM-based cellular systems, especially for mobile WiMAX systems, is proposed for the MS under power saving mode. Simulations indicate a 30∼50% power saving result from our proposed PI transmission technique, at the expense of a slight increase of paging response delay.

In this paper, two receive diversity combining tech- niques are proposed for cooperative relay systems based on single-carrier frequency division multiple access (SC-FDMA) when DFT spreading sizes for a mobile station (MS) and relay station (RS) are different. A simplified-MRC (S-MRC) technique performs diversity combining in the time-domain by using the estimated channel weights and initial estimates obtained by SC-FDMA signal detector. An interference rejection-MRC (IR- MRC) technique performs diversity combining in the frequency- domain by adjusting DFT spreading size at the receiver. It is shown by computer simulation that the proposed receive combining techniques achieve a significant diversity gain over the conventional ones. Index Terms—SC-FDMA, multi-hop relay, cooperative relay, S-MRC, IR-MRC

In this paper, the effect of a propagation delay resulting from the use of an OFDM system with a transparent mobile multi-hop relay (MMR) is initially analyzed. Additionally, a channel estimation technique for the OFDM system with throughput enhancement (TE) MMR or cooperative MMR is proposed. Secondly, the effect of a Doppler shift caused by a mobile MS is analyzed and a compensation technique for the carrier frequency offset (CFO) in the OFDM system with TE MMR is proposed.

In this paper, an iterative decoding technique for cooperative space-time block coded orthogonal frequency division multiplexing (STBC-OFDM) systems is proposed to mitigate the intercarrier interference (ICI) caused by multiple carrier frequency offsets (CFOs) in cooperative transmission. The proposed iterative decoding technique is shown to mitigate the noise enhancement effect on the STBC-OFDM signals caused by multiple CFOs, and be effective in reducing ICI especially when the system has a large FFT size and a large multiple CFOs.

The end-stage dilated cardiomyopathy is usually treated with cardiac transplantation although some limited success have also been obtained in selected patients using dynamic cardiomyoplasty or medical assist devices. Recently, a new surgical alternatives, called partial left ventriculectomy (PLV) was introduced by Randas J. V Batista in 1995. A 40-year-old man who had end-stage dilated cardiomyopathy refractory to optimal doses of medicines underwent partial left ventriculectomy (Batista’s operation), which reduces ventricular volume to improve left ventricular function. The left ventricular ejection fraction increased from 20 % to 58 % at 4 month after operation. (Korean Circulation J 1998;28(7):1211-1215) KEY WORD:Partial left ventriculectomy.

We report a first case of meningitis due to listeria monocytogenes after cardiac transplantation in Korea. This patient is a 40-year-old man with Dilated cardiomyopathy, he presented with intermittent dyspnea and abdominal distension for about 1 year. After cardiac transplantation, he was treated with azathioprine, cyclosporine and prednisolone for graft rejection. He was presented with intermittent fever, headache and lethargy for about 10days after cardiac transplantation. Listeria monocytogenes was isolated from blood culture and CSF culture. He was treated with intravenous penicillin G for 10days successfully and changed with ampicillin for 10days, took oral ampicillin for 10days without any complication after discharge. (Korean Circulation J 1998;28(9): 1616-1619)

Coronary stenting for long complex lesion is effective but associated with complication. We compared the results of stenting between with multiple conventional stenting group (group A and with single long stenting group (group B. Fifty patients were prospectively and randomly enrolled:25 patients for each group. Each group showed no significant differences of clinical characteristics. One patient died of heart failure in each group, not associated with the procedure itself. One patient had cerebrovascular accident in each group. Five patients had major bleeding (2, group A;3, group B. Angiographic success rate was 100% in each group and proce- dural success rate was 96% and 100% in group A and B, respectively. Angiographic and clinical restenosis rate at 6 months follow-up were 60%, 36% in group A and 65%, 44% in group B, respectively (P=NS. Multivariate analysis showed that several factors affected the angiographic restenosis rate as follows;a male gender (M: F=76.9%:25.0%, p

Backgound：The placement of stents in coronary arteries has been shown to reduce acute closure and restenosis in comparison to balloon angioplasty. However, clinical use of intracoronary stents is impeded by the subacute stent thrombosis and hemorrhagic complications associated with the anticoagulant regimen. It’ s known that the complete stent deployment with high pressure inflation and new antiplatelet agents are effective in reduction of subacute thrombosis and hemorrhage. So we evaluated initial results (success and complication rate after high pressure-stent deployment with new anticoagulation protocol. Methods：One hundred and ninety one patients with 201 lesions were treated with 231 stents of various types. The high pressure balloon inflation and antiplatelets agents were used in all cases. Final high pressure balloon inflation guided by IVUS were performed in 23 consecutive cases with incomplete stent deployment according to angiographic findings. Results：1 The indications of stenting (n＝210 were De novo in 124 (59%, bailout procedure in 57 (27%, suboptimal result after PTCA in 19 (8%, and restenosis after PTCA in 14 (6%. The location of lesions were LAD in 101, RCA in 67, circumflex in 28, ramus intermedius in 3, and LMT artery in 2 lesions. Angiographic morphologic characteristics were type A in 2, type B in 158 (B1：57, B2：101, and type C in 22 lesions. 2 The angiographic and clinical success rate was 96% (192/201 and 92% (186/201 respectively. 3 In angiographic analysis, the baseline average reference vessel dirmeter was 3.33±0.35 mm. Baseline minimum lumen diameter(MLD was 0.58±0.29 mm, with baseline percent diameter stenosis of 82.86±8.64%. The final stent diameter was 3.37±0.29 mm, with mean final percent stenosis of 0.63±8.25. The mean MLD after stenting was significantly increased (p 12atm (p