Electromagnetic interference (EMI) is an inevitable issue in power electronics applications. Although many kinds of solutions have been presented to attenuate EMI noise, there is still little research about the EMI suppression scheme utilized in multimode primary-side regulation (PSR) flyback converters. Targeting EMI regulation in multimode PSR flyback converter, a combo EMI suppression scheme comprised of frequency modulation and dual-slope gate driver is adopted to meet stringent EMI requirements, simplifying peripheral components and design of EMI filter. The proposed scheme is implemented in$0.18~\mu $m 5/40 V BCD process and occupies a die size (with pads) of$1.05\times 0.8$mm2. The experimental results show that the conducted EMI waveforms with line/neutral polarity can easily comply with regulations. The deviations of the output voltage are within ±1.3% under different inputs and loads while the peak effciency of 90% is achieved.

The power over Ethernet (PoE) technology has gained intensive attention in networking market owing to the advantages of compactness, flexibility, and cost in application. The automatic maintain power signature (MPS) function specified by IEEE standard extracts the periodic pulsed current to enable applications requiring low power modes. However, a large driving capacity is required due to a large MPS current above 10 mA, sacrificing a certain area. This brief proposes an adaptive MPS scheme, which reuses existing class regulator and delay timer to source a pulsed MPS current to meet the MPS requirements, saving an area of 0.0104 mm2. The proposed MPS scheme has been fabricated in 0.18-$\mu $m 120-V BCD process and the area is$1.37\times 1.00$mm2. The experimental results show that the proposed PoE interface draws a pulsed current with a period of 312 ms and 25.6% duty cycle to address the issue of MPS absence in very low-power standby modes.

For many on-line systems with massive users, to provide services continuously and steadily is vital for business, which requires the anomalies of services should be located and resolved in a timely manner. As a common IT infrastructure, various APM (Application Performance Management) systems/frameworks have been adopted to monitor each call request to a service. Nevertheless, the call request may contain multidimensional attributes (e.g., City, ISP, Platform, etc.), which may further contain multiple values (e.g., ISP could be T-Mobile, CMCC, etc.). As a result, an anomaly such as DSR (Declining Success Rate) to service typically occurs with a combination of such attribute values, which creates major challenges to locate the root cause of the anomaly due to potentially huge numbers of the combinations. In this paper, we propose a novel method, ImpAPTr (Impact Analysis based on Pruning Tree), to identify the combination of dimensional attributes as the clues leading to the root cause of anomalies regarding DSR timely. In the evaluation with the simulated dataset, ImpAPTr detects valid clues in milliseconds with an accuracy of 99.37% (within the top 10 candidate results), 97.72% (top 5), and 94.51% (top 3), respectively, which outperforms previous approaches to a large degree. A field test with a production environment dataset indicates that ImpAPTr is able to detect valid clues in a few seconds.

As a common IT infrastructure, APM (Application Performance Management) systems have been widely adopted to monitor call requests to an on-line service. Usually, each request may contain multi-dimensional attributes (e.g., City, ISP, Platform, etc.), which may become the reason for a certain anomaly regarding DSR (Declining Success Rate) of service calls either solely or as a combination. Moreover, each attribute may also have multiple values (e.g., ISP could be T-Mobile, Vodafone, CMCC, etc.), rendering intricate root causes and huge challenges to identify the root causes. In this paper, we propose a prototype tool, ImpAPTr (Impact Analysis based on Pruning Tree), to identify the combination of dimensional attributes as the clues to dig out the root causes of anomalies regarding DSR of a service call in a timely manner. ImpAPTr has been evaluated in MeiTuan, one of the biggest on-line service providers. Performance regarding the accuracy outperforms several previous tools in the same field.

"5.12" Wenchuan Earthquake occurred in western Sichuan, China on May 12, 2008. Many potential geo-hazards, induced by this earthquake, were developing. Qinglin gully had no recorders of debris flow before the earthquake and has been the most serious one after that. Based on field survey, we studied the characteristics of debris flow in Qinglin gully by using GIS technology. Results show that three large scale landslides with 0.76 million m3, 0.94 million m3and 12 million m3in volume respectively, induced by the earthquake, were main sources of the debris flow. The debris flow, induced by intensive rainfall on 24 September 2008, was a large scale turbulent one. We analyzed the risk of Qinglin debris flow using the debris flow risk assessment model of momentum principle. Results illuminate that Qinglin gully has the characteristics of high frequency and large scale and severe risks after the earthquake. It was also found, even if vegetation was lush, big debris flows could occur due to background changing of disasters in quake-hit area. Consequently, the next researches should focus on potential debris flows, which is of great significance to post-disaster restoration and reconstruction.

The "Rectangle-V" shaped drainage canal is one of the most-widely used engineering measures in debris flow prevention in the west mountain area in China. The cross-section shape and size of the "Rectangle-V" shaped drainage canal are important parameters in the design. How to choose the shape and size to let the drainage canal have the optimal drainage capacity is rarely revolved before. This paper discusses the design of the optimal hydraulic cross-section. First, the parameter of cross-section size (F) and characteristic parameter of cross-section (S) are defined. Then, the calculation formulas of F and S are deduced. It indicates that F and S are only related to the transverse slope coefficient(IC) under the optimal hydraulic condition. At last, the calculation formulas of the optimal hydraulic depth and width of the drainage canal are deduced. Taking Xinqiao gully, a first-order distributaries in the upper Min River after "5.12" earthquake as an example, this paper designs the optimal cross-section of the drainage canal of viscous debris flow. Compared to the other design methods, the method can confirm the shape and the sizes of "Rectangle-V" shaped drainage canal of viscous debris flow. And the calculated result is the only confirmed value, while the calculating method is convenient and efficient and can be adapted to the actual engineering.

The drainage canal is one of the most widely-used engineering measures in preventing debris flow. The cross- section shape and size are important parameters for designing the drainage canal of debris flow. While how to choose the optimal shape and size to make the drainage canal of debris flow have the best discharging ability is a problem few people have researched. The "Rectangle-V" shape is one of the widely-used cross-section shapes of debris flow drainage canal. This paper chooses it as a researching object, analyzes its optimal hydraulic condition, and discusses its optimal cross-section design. The cross-section configuration parameter (M) of "Rectangle-V" shaped debris flow drainage canal is defined as the ratio of wetted perimeter (P) to hydraulic radius(R). Based on the definition, the calculation formula of M is deduced under the optimal hydraulic condition. The formula indicates that M only relates with the bottom transverse slope coefficient under the optimal hydraulic condition. Assuming the discharge of debris flow (Q), the longitudinal gradient of debris flow drainage canal (I) and the gradation of debris flow grain size as known, we deduce the combinatorial calculating formulas of the cross- section size of "Rectangle-V" shaped debris flow drainage canal by using the simultaneous numerical solution method. On the basis of the analysis of the optimal hydraulic condition of "Rectangle-V" shaped debris flow drainage canal, this paper takes the Huoba Gully as an example for the optimal cross- section design of debris flow drainage canal.

The channels of natural viscous debris flows are all compound. The hydraulic characteristics (wetted perimeter, overflowing area and hydraulic radius) are different under different width ratio of beach to groove and different slurry depth of debris flow. By using the hydraulic calculating method of natural river, this paper discusses the hydraulic characteristics in compound channels of viscous debris flow. The results indicate that the width ratio of beach to groove has a great influence on overflowing capacity and discharge distribution of beach and groove. When the width ratio is the same, the groove discharge decreases with the increase of slurry depth, while the beach discharge increases; when debris flow with the same scale passes by channels which have different width ratio, the overflowing capacity in channels with bigger width ratio is much lager than the smaller one’s; the influence between beach and groove in debris flow compound channels can be expressed by COH and it decreases with the increase of debris flow discharge; when debris flow with the same scale passes by compound channels, the bigger the width ratio is the greater the influence between beach and groove is.