The storage capacity of the NAND flash memory has increased rapidly, and accordingly, the error rate for data writing and reading to the flash memory cell has also escalated. Error-correcting code (ECC) modules, such as low-density parity-check (LDPC), have been applied to flash controllers for error recovery. However, since the error rate increases rapidly, compared to the aging factor and program/erase (P/E) cycle, fixed ECCs and parities are inappropriate methods for resolving this proliferating error, according to the P/E cycle. Therefore, the design of a dynamic ECC scheme and a proper ECC parity management system to increase the lifespan of flash memory storage devices remains in great demand. Herein, an LDPC encoding and decoding scheme is designed to obtain a step-by-step code rate according to the P/E cycle by applying a stepwise rate-compatible LDPC. In addition, an ECC parity management scheme for the increasingly excessive stage-wise ECC is proposed to reduce management and read/write operational overheads. The ECC management scheme also includes the ECC cache system. The proposed LDPC, as well as its management system, will improve the recovery ability of the NAND flash storage device according to the P/E cycle, while it can reduce system read and write overheads due to additional parity data growth.

As web apps quickly evolve, for their maintenance it is essential to separately encapsulate independent widgets composing the web pages. Thus, this paper proposes a new approach to restructuring a web app to achieve such encapsulation, which allows independent development and maintenance of widgets. The approach applies the shadow document object model (DOM) and template standards from the World Wide Web Consortium (W3C) Web Components standards. Empirical evaluation shows that our approach can be applicable to restructuring open source web apps and improving their maintainability. We also show that the approach can improve performance of web apps in terms of response time and the amount of transferred data over a network.

One of the major sources of power drain in smartphones is a frame rendering and display process called graphics pipeline, in which power consumption depends largely on frame rendering operations per second (fps), known as the frame rate, and the quantity of UI content to be rendered. We discovered a major problem causing power consumption upon a scrolling operation: The Android graphics pipeline renders all or a large portion of the content displayed most recently at a frame rate of nearly 60 fps. This paper proposes a scrolling-aware rendering (SCAR) scheme to reduce the frame rate caused by a scrolling. When rendering a frame for UI content to be displayed, SCAR pre-renders UI content that is likely to be displayed soon in any subsequent scrolling operation. This frame is extended to place the pre-rendered UI content contiguously with the UI content to be displayed. Upon a subsequent scrolling, SCAR repositions the extended frame on screen by a scrolling distance instead of rendering a new frame. Our experiments on a smartphone show that SCAR reduced frame rates to below one fps in scrolling, thus saving power by up to 30%.