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Lulin Wide-field Telescope (LWT, with Minor Planet Center Observatory Code of D37) is a newly installed telescope at the Lulin Observatory. LWT consist of a 0.4m astrograph, with a focal ratio of 3.8, and a large format CCD, providing a ~2 degree squared field-of-view. LWT is joining the trend of automating telescopes in the world. Software packages that enable automatic observations for LWT include commercial software such as The SkyX, MaxIm DL and ACP Observatory Control Software (ACP), as well as in-house developed python codes. The Se python codes will generate an observing script executed by ACP to perform automatic observations. We presented the measured limiting magnitude of LWT. At an exposure time of 300 second, LWT can reach to a depth of 19.1 magnitude in V-band (under new moon). We also presented our successful efforts of tracking and follow-up observations of one near Earth asteroid, 2004 XP14, with LWT on 03 January 2019.

Frequency error, non-ideal channel estimation (CE) and inefficient seamless road side unit (RSU) service are critical issues occurring in conventional systems that are completely specified by current IEEE 802.11p standards. This study investigates novel techniques for achieving accurate frequency offset compensation and effective CE and RSU selection for handover in signal-overlapping areas. Recently, communications using data-aided orthogonal frequency-division multiplexing (DA-OFDM), such as pseudo-random-postfix OFDM and time-domain-synchronous OFDM (TDS-OFDM), have been actively studied because of their higher effectiveness, efficiency and better transmission quality. This study consists of three parts: (i) derivation of the maximum likelihood estimation for DA-OFDM, (ii) design of an accurate RSU selection scheme and (iii) implementation of a superior TD CE technique. Performance comparisons between the conventional and the proposed techniques are conducted through comprehensive computer simulations.

Wireless network authentication schemes have been researched forabout a decade, and associated security problems explored by manyresearchers. In 2004, Zhu and Ma proposed an authentication schemefor wireless environments. Afterwards other researchers proposedimprovements according to Zhu-Ma scheme. Mutual authentication isone of the most important issues. To the best of our knowledge,there is no scheme that allows a foreign agent to authenticate thehome agent and mobile user at the same time. Towards this purpose,we propose a simultaneous authentication scheme based on chaoticmaps, and describe how our proposed scheme addresses varioussecurity problems while maintain anonymity. DOI: http://dx.doi.org/10.5755/j01.itc.45.2.8875

Next-generation telematics solutions are being driven by the maturation of recently deployed intelligent transportation systems, assisted by the integration of and rapid collaboration with information communication technology markets and the automotive industry. Examples of this trend can be found in DSRC contexts in which Wi-Fi and WiMAX have become very relevant in vehicular environments. Comprehensive field trials were conducted and relevant measurements were collected in physical environments to investigate the possible environmental factors that occur in roadside-unit-to-vehicle communication scenarios. In these carefully controlled automobile experiments, the most representative parameters are measured and analyzed for DSRC in dynamic environments (e.g., packet loss, latency, and delay spread). Using a systematic testing procedure and through measurement analysis, the communication performance and the operating reliability of wireless communications can be effectively verified; insightful improvements and helpful suggestions and contributions may thus be achieved for telematics system designs. Furthermore, a practical, reasonable, and standardized testing procedure is proposed, and it can be utilized in equipment verification and product certification.

Operating up to 5.5 GHz with 1-mW power consumption, a 90-nm CMOS programmable frequency divider with eight stages of new static D-flip-flop-based (2/1) divider cells is presented, where the supply voltage of 1.0 V is employed. The divider achieves a full modulus range from 1 to 256 and operates over a wide range maintaining up to 4 GHz with -30-dBm input power. The divider also accomplishes a power efficiency of 12.8 GHz/mW with 0.5-V supply voltage. It is favorable for advanced processes.

Drawing on both social exchange theory and impression management theory, this study sought to explain how perception of organizational politics (POP) influences organizational citizenship behaviour (OCB) through two contrary psychological processes. We proposed that through the mediation of job satisfaction, POP has an inhibiting effect on OCB; through the mediation of careerism, POP has a nourishing effect on OCB. Data were obtained from 393 police officers and their colleagues from a city police department in northern Taiwan. Results from structural equation modelling (SEM) revealed that the relationship between POP and OCB was negatively mediated by job satisfaction and positively mediated by careerism. Such antithetical psychological processes imply that employees may experience psychological dilemmas over the performance of OCB when they perceive their organization as political. Implications for theory and future research are discussed.

An edge missing compensator (EMC) is proposed to approach the function of an ideal PD with plusmn2 N-1 times 2pi linear range with N-bit EMC. A PLL implemented with a 9-bit EMC achieves 320 MHz frequency hopping within 10 mus logarithmically which is about 2.4 times faster than the conventional design. The reference spur of the PLL is -48.7 dBc and the phase noise is -88.31dBc/Hz at 10 kHz offset with KVCO = - 2 GHz/V.

The ultra-long period Cepheids (ULPCs) are classical Cepheids with pulsation periods exceeding $\approx 80$ days. The intrinsic brightness of ULPCs are ~1 to ~3 mag brighter than their shorter period counterparts. This makes them attractive in future distance scale work to derive distances beyond the limit set by the shorter period Cepheids. We have initiated a program to search for ULPCs in M31, using the single-band data taken from the Palomar Transient Factory, and identified eight possible candidates. In this work, we presented the VI-band follow-up observations of these eight candidates. Based on our VI-band light curves of these candidates and their locations in the color-magnitude diagram and the Period-Wesenheit diagram, we verify two candidates as being truly ULPCs. The six other candidates are most likely other kinds of long-period variables. With the two confirmed M31 ULPCs, we tested the applicability of ULPCs in distance scale work by deriving the distance modulus of M31. It was found to be $\mu_{M31,ULPC}=24.30\pm0.76$ mag. The large error in the derived distance modulus, together with the large intrinsic dispersion of the Period-Wesenheit (PW) relation and the small number of ULPCs in a given host galaxy, means that the question of the suitability of ULPCs as standard candles is still open. Further work is needed to enlarge the sample of calibrating ULPCs and reduce the intrinsic dispersion of the PW relation before re-considering ULPCs as suitable distance indicators., Comment: 13 pages, with 14 Figures and 4 Tables (one online table). AJ accepted

Next-generation telematics solutions are driven by the mature and recently employed intelligent transportation systems (ITSs), which are assisted by integration and rapid collaboration with information communication technology (ICT) markets as well as the automotive industry. ITSs are a rising technology and include many aspects. For ITSs, smart vehicles and wireless communications are promising technologies that may improve driving safety, reduce traffic congestion, and support information services in vehicles; further, green life for a blue planet is our ultimate goal. Despite the recent global economic downturn that has negatively affected the automobile industry, active research continues in these areas, and new technical challenges have emerged that demand research and development. Dedicated short-range communication (DSRC) exemplifies these challenges because wireless communication techniques have become significant and relevant for vehicular environments. The direct link between clean mobility and ITSs includes less gasoline consumption and toxic gas emission. Thus, to maximize ITS efficiency, the population that adopts ITSs for daily transportation should increase as much as possible. To achieve this goal, the ITS design should not be limited by technique; the "user-centric" notion is the most important requirement and should be considered.

This paper presents a novel VLSI architecture for a fully parallel precomputation-based content-addressable memory (PB-CAM) with low-power, low-cost, and low-voltage features. This design is based on a precomputation approach that saves not only power consumption of the CAM system, but also reduces transistor count and operating voltage of the CAM cell. In addition, the proposed PB-CAM word structure adopts the static pseudo-nMOS circuit design to improve system performance. The whole design was fabricated with the TSMC 0.35-/spl mu/m single-poly quadruple-metal CMOS process. With a 128 words by 30 bits CAM size, the measurement results indicate that the proposed circuit works up to 100 MHz with power consumption of 33 mW at 3.3-V supply voltage and works up to 30 MHz under 1.5-V supply voltage.

A low-FOM SAR ADC using the leakage reduction bootstrapped switch (LRBS) to achieve a satisfactory ENOB and using a low-power approach with a low voltage, low sampling rate, and low-DAC-capacitance structure is presented for biomedical applications. LRBS is proposed to alleviate the leakage caused by the low-power approach to increase SNDR and ENOB. From the measurement results, the 0.18µm CMOS prototype chip with the total DAC capacitance of 2.765pF consumes 2.5nW and achieves a SNDR of 53.05dB under a 0.5V supply voltage at 1KS/s with a Nyquist input. The resulting FOM is 6.8fJ/conversion-step.

In a typical wireless LAN application exploiting the OFDM technology, the preamble is usually used to acquire the channel state information in front of data payload. However, if the length of the frame is short, the bandwidth efficiency is restricted by the overhead due to the frame. For such an application that the length of the frame is long, we have to take into account the time-varying effect. In this paper, we study a semi-blind channel estimation method for improving bandwidth efficiency. Although the decision feedback method can be used for channel tracking, the well-known error propagation problem can seriously degrade the system performance. In our work, the semi-blind channel tracking method applies a decision error criterion to adaptively change the use of the error control signal between the constant modulus algorithm and the decision feedback in order to avoid the error propagation problem. Simulation results show that the proposed semi-blind channel tracking scheme has better BER performance than the decision feedback method.

Novel techniques of Road Side Unit (RSU) selection for handover were investigated in this study. It was determined that there are currently no efficient RSU selection schemes, which is a severe issue for conventional techniques following the current IEEE 802.11p standard. Recently, data-aided OFDM (DA-OFDM), such as Pseudo-Random-Postfix-OFDM (PRP-OFDM) and Time Domain Synchronous-OFDM (TDS-OFDM), have received attention because of their capability for higher effectiveness with better transmission quality. This study derived the maximum likelihood (ML) channel estimation for DA-OFDM and evaluated and compared proposed techniques by computer simulations.

Vehicle-to-infrastructure communication for accident avoidance is an important application defined in the IEEE 802.11p. The primary challenge in the current IEEE 802.11p draft standard is the weak performance of channel estimation (CE) in multipath environments due to insufficient pilot density. Therefore, we propose time-domain (TD) CE techniques that can effectively and accurately estimate channel tap-weighting coefficients for solving this problem. Two network traffic types are investigated in this study: periodic transmission and event transmission. In addition, the proposed TD techniques are able to perform remarkably improved CE while completely following the signaling format in the current standard, with the assistance of the symbol prefix.

The PLL implementing with the conventional Phase/ Frequency Detector (C-PFD) with feedback-path approach suffers from a dead-zone problem is generally resulted in slow acquisition time. A reasonably wider concurrent pulse is required to achieve a dead-zone free detection. The wider concurrent pulse implies the slow acquisition time PLL. This study presents a novel forward Phase Detector (fPD). The dead-zone-free fPD is operated in two modes: ON (M=1) and OFF (M=0). Both input signals INT and EXT are fed into both fPD and CP. The fPD determines the operation mode, while the CP performs the operation of charge/discharge. Two steady signals EXT and INT are used to replace the concurrent pulse in the feedback-path in the C-PFD. Thus, it is a “pulse-less” forward phase detecting scheme. A high-speed PLL with the proposed fPD/CP combination can be achieved. Due to the low disturbance to the Voltage Controlled Oscillator (VCO) control line, the PLL achieves a phase noise of -131 dBc/Hz at 1 MHz offset when the PLL is operated at 2.3 GHz. The low power fPD/CP also achieves high sensitivity for detecting both frequency and phase.

Ever since the emergence of Intelligent Transportation System (ITS), there has been a rapid integration of communications and automotive electronics industry, promoting developments and trends for the new generation of telematics. Apart from the development and standardization of telematics, its field test is however attracting less attention while being a most important aspect of the issue. The purposes of this research are to set up software/field tests and propose possible improvements for IEEE 802.11p standard. Then, obtaining information from software simulation to establish a controllable field for ground tests, and analyzing the indicative parameters of packet loss and latency of Dedicated Short Range Communication (DSRC) telematics system under mobile conditions, to complete a systematic testing procedure, statistics analysis as well as a transceiver design that will improve the transmission performance.

This paper presents a novel 2/3 divider cell circuit design for a truly modular programmable frequency divider with high-speed, low-power, and high input-sensitivity features. In this paper, the proposed flip-flop based 2/3 divider cell adopts dynamic E-TSPC circuit that not only reduces power consumption, but also improves operation speed and input sensitivity. The whole design was implemented using the TSMC 0.18 μm 1P6M CMOS process. With an 8-stage 2/3 divider cell, the measurement results indicate that the proposed circuit operates up to 5.8GHz with the power-consumption less than 3.24mW.

This paper describes and resolves the false locking issue in phase-locked loops (PLLs) with π-phase detector. In order to verify the proposed approach for acquisition and capture range performances of π-phase detector, the phase-controlled-current-source (PCCS) using the reversing scheme is implemented in TSMC 0.18um 1P6M CMOS technology. In the simulation results, the locking time of the proposed approach is 6.7X faster than conventional PFD design. Moreover, the measurement results indicate the locking time of testing PLL is less than 2us.

A least-squares (LS) channel estimation technique is investigated to extend pseudo-random-postfix orthogonal-frequency-division multiplexing (PRP-OFDM) techniques onto mobile applications in rapidly time-variant frequency-selective fading environments. The proposed method exploits self-interference cancellation to effectively reduce a variety of interferences; and thus, it can overcome not only frequency-selectivity caused by multipath reception but also time-selectivity caused by mobility; in particular, OFDM communications are often expected to operate in the presence of both wide Doppler spread and long delay spread. As a result, the proposed technique can achieve lower channel estimation errors and lower bit error probabilities than the conventional techniques exploiting a time-averaging method. Since sufficiently long PRP sequences have never been found in the previous works regarding PRP-OFDM, an application of the proposed technique using chirp signals for mobile PRP-OFDM communication is investigated because the chirp signals exhibit good training properties.

An ideal phase detector (PD) produces an output signal whose DC value is linearly proportional to the phase difference (??) between the phases of its two periodic inputs. In practice, however, the transfer curve of the PD may not be linear or even monotonic for large ??. With a nonlinear PD, the transient response of PLL cannot be easily formulated and slow down the acquisition behavior [1].

The star 1SWASP J022727.03+115641.7 was reported as a contact binary with a period shorter than the empirical limit of such systems. Our study shows the star not to be variable. Instead, it is the nearby star, 2MASS 02272637 +1156494, that exhibits variability. The BRI CCD light curves of 2MASS 02272637+1156494 show the system to be a moderate mass ratio (2.154(-0.008)(+0.074)), and shallow contact (10.4(-1.9)(+1.4)%) W-type contact binary. The masses, radii, and luminosities of the binary components are, respectively, M-1 = 0.25(-0.01)(+0.05), M-circle dot, M-2 = 0.54(-0.04)(+0.11) M-circle dot, R-1 = 0.45(-0.01)(+0.02) R-circle dot, R-2 = 0.063(-0.02)(+0.04) R-circle dot, L-1 = 0.038(-0.005)(+0.018) L-circle dot, and L-2 = 0.071(-0.010)(+0.037) L-circle dot, with an estimated distance 326(-46)(+127) pc. These uncertainties mainly come from the errors of the colors used to estimate the temperature of the primary star. A dark spot was introduced on the massive component in the final solution.

In this paper, a novel logic gate design with low leakage is proposed. Traditionally, the subthreshold leakage through a logic gate depends on the applied input vector. In order to reduce leakage power, we stack an extra transistor in the large leakage path. The proposed structure induces low leakage current under all possible inputs. Compared to the conventional CMOS logic circuit design, the simulation results show that the proposed logic circuits not only reduce significant leakage power dissipation, but also keep similar circuit performance as conventional CMOS logic circuits