Chi-Feng Chen

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A novel method for designing multiband bandpass filters has been proposed in this paper. Coupling structures with both Chebyshev and quasi-elliptic frequency responses are presented to achieve dual- and triple-band characteristics without a significant increase in circuit size. The design concept is to add some extra coupled resonator sections in a(More)
Uncertainty is an inevitable source of noise in water quality management and will weaken the adequacy of decisions. Uncertainty is derived from imperfect information, natural variability, and knowledge-based inconsistency. To make better decisions, it is necessary to reduce uncertainty. Conventional uncertainty analyses have focused on quantifying the(More)
An Internet of Things (IoT) system features integration information from heterogeneous sensor devices, allowing them to deliver a variety of sensed information through networks. An IoT broker in the system acts as an information exchange center, relaying periodic messages from heterogeneous sensor devices to IoT clients. As more devices participate in the(More)
Query by Singing/Humming (QBSH) is a most natural way for music recognition. A QBSH system can help find songs by matching a part of melody users sing or hum. Many Music Information Retrieval (MIR) techniques have been used to carry out the QBSH goal. In the past, little studies had ever been revealed about how to design and implement a simple QBSH system.(More)
This paper proposes four-pole quasi-elliptic function bandpass waveguide filters using multilayer low-temperature co-fired ceramic technology. The vertical metal walls of the waveguide resonators are realized by closely spaced metallic vias. Adjacent cavities are coupled by a narrow slot at the edge of the common broad wall or an inductive window on the(More)
A laminated waveguide magic-T with imbedded Chebyshev filter response is developed in a multilayer low-temperature co-fired ceramic technology by vertically stacked rectangular cavity resonators with highly symmetric coupling structures. The cavities provide even- and odd-symmetric field distributions by simultaneously resonating TE<sub>102</sub> and(More)
Net-type resonators with dual- and tri-mode electrical behaviors have been presented and analyzed theoretically in this paper. The proposed net-type resonator is constructed by a short-ended and several open-ended transmission-line sections, which has the advantages of small size and more flexible resonant frequency allocation and is therefore particularly(More)
In water quality management, pollution control strategies have been sought to accord with the assimilative capacity of water bodies so as to preserve water quality. The waste load allocation (WLA) is a useful approach to determine the allowable loading of pollution sources in water quality management. For any WLA, a particular water body condition is needed(More)
Novel compact microstrip cross-coupled bandpass filters realized by miniaturized stepped impedance resonators (SIR’s) are proposed. The cross coupling between non-adjacent resonators is introduced to exhibit a single pair of transmission zeros near the passband at finite frequencies and thus much better selectivity. The optimal design for miniaturized(More)
This study evaluated risks of emergency room visits (ERV) for all causes, circulatory diseases, and respiratory diseases associated with concentrations of particulate matter (PM10 and PM2.5) and Asian dust storms (ADS) from 2000 to 2008 in metropolitan Taipei. Cumulative 4-day (lag 0-3) relative risks (RR) and confidence intervals (CI) of cause-specific ERV(More)