Reliability Prediction of Integrated LED Lamps with Electrolytic Capacitor-Less LED Drivers

This chapter investigates the reliability of the integrated LED lamps with electrolytic capacitor-less LED drivers. Firstly, the impact of the interaction between the degradations of the LED light source and the driver on the lumen depreciation is studied. The electronic-thermal simulation was carried out to obtain the history of temperatures of...

CitRec 2017: International Workshop on Recommender Systems for Citizens

The "International Workshop on Recommender Systems for Citizens" (CitRec) is focused on a novel type of recommender systems both in terms of ownership and purpose: recommender systems run by citizens and serving society as a whole.

A novel lifetime prediction for integrated LED lamps by electronic-thermal simulation

In this paper, an integrated LED lamp with an electrolytic capacitor-free driver is considered to study the coupling effects of both LED and driver's degradations on lamp's lifetime. An electrolytic capacitor-less buck-boost driver is used. The physics of failure (PoF) based electronic thermal simulation is carried out to simulate the lamp's...

Effect of Corridor Design on Energy Consumption for School Buildings in the Cold Climate.

This paper discusses the energy impact of corridor design for school buildings in the cold climate of China. Local school buildings were classified into three types in terms of the corridor design patterns. Architectural related parameters of corridors which could have a potential impact on the energy consumption were summarized and discussed,...

MRLR: Multi-level representation learning for personalized ranking in recommendation

Representation learning (RL) has recently proven to be effective in capturing local item relationships by modeling item co-occurrence in individual user's interaction record. However, the value of RL for recommendation has not reached the full potential due to two major drawbacks: 1) recommendation is modeled as a rating prediction problem...

A Reliability Prediction for Integrated LED Lamp with Electrolytic Capacitor-Free Driver

This paper studies the interaction of catastrophic failure of the driver and LED luminous flux decay for an integrated LED lamp with an electrolytic capacitor-free LED driver. Electronic thermal simulations are utilized to obtain the lamp's dynamic history of temperature and current for two distinct operation modes: constant current mode (CCM...

The Effect of Geometry Parameters on Energy and Thermal Performance of School Buildings in Cold Climates of China

This paper discusses the role of geometry parameters including building shape, window to wall ratio, room depth, and orientation on the energy use and thermal comfort of school buildings in cold climates of China. The annual total energy demand and summer thermal discomfort time were compared through computer simulations with DesignBuilder....

A PoF and statistics combined reliability prediction for LED arrays in lamps

In this work, a physics-of-failure (PoF) reliability prediction methodology is combined with statistical models to consider the interaction between the lumen depreciation and catastrophic failures of LEDs. The current in each LED may redistribute when the catastrophic failure occurs in one of LEDs in an array, thus affecting the operation...

Precision Recess of AlGaN/GaN with Controllable Etching Rate Using ICP-RIE Oxidation and Wet Etching

A method for highly controllable etching of AlGaN/GaN for the fabrication of high sensitivity HEMT based sensors is developed. The process consists of cyclic oxidation of nitride with O₂ plasma using ICP-RIE etcher followed by wet etching of the oxidized layer. Previously reported cyclic oxidation-based GaN etching obtained very...

Institute of Poldering: Meadow Under Construction

Booklet of the elective course AR0048 2014/2015 ‘Landscape Architecture ON site - being part of Oerol’, an elective course of the MSc2 - Chair of Landscape Architecture at the TU Delft.

A new robust design for imperfection sensitive stiffened cylinders used in aerospace engineering

A knock-down factor is commonly used to take into account the obvious decline of the buckling load in a cylindrical shell caused by the inevitable imperfections. In 1968, NASA guideline SP-8007 gave knock-down factors which rely on a lower-bound curve taken from experimental data. Recent research has indicated that the NASA knock-down factors...

Chaotic Dynamics in Smart Grid and Suppression Scheme via Generalized Fuzzy Hyperbolic Model

This paper presents a method to control chaotic behavior of a typical Smart Grid based on generalized fuzzy hyperbolic model (GFHM). As more and more distributed generations (DG) are incorporated into the Smart Grid, the chaotic behavior occurs increasingly. To verify the behavior, a dynamic model which describes a power system with DG is...

Steady analysis of viscous flow around ducted propellers: Validation and study on scale effects