• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.47 no.7
• /
• pp.52-60
• /
• 2010

In this paper, we propose a dynamic power management framework for multi-core systems. We reduced the power consumption of multi-core processors such as Intel Centrino Duo and ARM11 MPCore, which have been used at the consumer electronics and personal computer market. Each processor uses a different technique to save its power usage, but there is no embedded multi-core processor which has a precise power control mechanism such as dynamic voltage scaling technique. The proposed dynamic power management framework is suitable for smart phones which have an operating system to provide multi-processing capability. Basically, our framework follows an intuitive idea that reducing the power consumption of idle cores is the most effective way to save the overall power consumption of a multi-core processor. We could minimize the energy consumption used by idle cores with application-targeted policies that reflect the characteristics of active workloads. We defined some properties of an application to analyze the performance requirement in real time and automated the management process to verify the result quickly. We tested the proposed framework with popular processors such as Intel Centrino Duo and ARM11 MPCore, and were able to find that our framework dynamically reduced the power consumption of multi-core processors and satisfied the performance requirement of each program.

• Journal of KIISE:Computer Systems and Theory
• /
• v.35 no.7
• /
• pp.305-317
• /
• 2008

As a mobile computing environment is rapidly changing, increasing user demand for multimedia-over-wireless capabilities on embedded processors places constraints on performance, power, and sire. In this regard, this paper proposes color media instructions (CMI) for single instruction, multiple data (SIMD) parallel processors to meet the computational requirements and cost goals. While existing multimedia extensions store and process 48-bit pixels in a 32-bit register, CMI, which considers that color components are perceptually less significant, supports parallel operations on two-packed compressed 16-bit YCbCr (6 bit Y and 5 bits Cb, Cr) data in a 32-bit datapath processor. This provides greater concurrency and efficiency for YCbCr data processing. Moreover, the ability to reduce data format size reduces system cost. The reduction in data bandwidth also simplifies system design. Experimental results on a representative SIMD parallel processor architecture show that CMI achieves an average speedup of 6.3x over the baseline SIMD parallel processor performance. This is in contrast to MMX (a representative Intel's multimedia extensions), which achieves an average speedup of only 3.7x over the same baseline SIMD architecture. CMI also outperforms MMX in both area efficiency (a 52% increase versus a 13% increase) and energy efficiency (a 50% increase versus an 11% increase). CMI improves the performance and efficiency with a mere 3% increase in the system area and a 5% increase in the system power, while MMX requires a 14% increase in the system area and a 16% increase in the system power.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.14 no.2
• /
• pp.141-146
• /
• 2014

This paper describes the implementation and algorithm of handwritten character recognition using mobile touch screen. The system is consisted of PXA320 processor, capacitive touch panel and QT4 interface. The proposed algorithm extracts pattern characteristics with straight, left circle, right circle on the inputting character. The definition of character is determined by 3-way tree searching method. The performance of proposed algorithm is verified using alphabet character. It is suitable to apply the mobile touch screen because of simple algorithm.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.10c
• /
• pp.139-141
• /
• 2001

이동 통신 기기의 보급이 급증함에 따라 많은 모바일 응용들이 생겨나고 있다. 모바일 환경은 기존 PC 환경과는 달리 제한된 리소스를 제공하고 있기 때문에 어플리케이션을 제작하는 데에 많은 제약이 따르고 있다. 가장 큰 제약이라 할 수 있는 것은 제공되는 메모리의 양과 프로세서의 속도라 할 수 있다. 이 두가 지는 서로 상반되는 특성을 가지고 있다. 연산 속도를 빠르게 하려면 보다 많은 메모리의 양이 필요로 하게 되고, 메모리를 절약하려면 연산 속도가 더 늦어지는 것이 일반적인 경우이다. 본 논문에서 다루는 것은 이러한 제한된 환경에서 어떻게 이러한 문제들을 해결하느냐에 대한 것이다. 본 논문에서는 메모리가 부족한 이동 단말기론 위한 어플리케이션 작성시 메모리 절약을 위한 자료구조 선정 방법의 예를 설명하고 메모리 사용량을 분석하였다.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2014.01a
• /
• pp.31-34
• /
• 2014

모바일 프로세서와 모바일 운영체제의 발달에 따라 스마트폰에서도 멀티미디어 신호 처리를 실시간으로 처리가 가능해 졌다. 또한 스마트폰의 급격한 보급률의 증가 및 대중의 악기에 대한 관심이 높아졌다. 이러한 흐름에 따라 국내에 특히 많이 보급되어 있는 안드로이드 스마트폰을 이용하여 고비용의 멀티 이펙트를 대체할 수 있는 어플리케이션을 구현했다. 멀티 이펙트에는 디스토션, 오버드라이브, 딜레이, 에코, 플렌저, 코러스 및 비브라토를 포함하였으며, 구현 결과 매틀랩 시뮬레이션과 유사함을 보였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2014.04a
• /
• pp.278-279
• /
• 2014

모바일 시스템은 제한된 하드웨어 리소스로만 구성된다. 예를 들면, 배터리 용량, 네트워크 대역폭, 저장 용량, 프로세서 성능 등이 그것이다. 이러한 제한된 리소스는 클라우드 서버로의 작업분할을 통하여 경감될 수 있다. 계산량이 많은 부분을 리소스가 풍부한 서버에 전송하고, 서버로부터 결과만을 받아 사용함으로써 리소스의 제약에서 벗어날 수 있다. 작업분할 기술들과 관련하여 많은 연구들이 지난 십 여년 간 진행되었다. 본 연구에서는 이와 관련된 기본적인 논의들을 살펴보도록 하겠다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2011.04a
• /
• pp.57-59
• /
• 2011

최근 컴퓨터 시스템을 소프트웨어적으로 모델링하고 시뮬레이션 성능 평가를 할 수 있는 가상 플랫폼(virtual platform) 기술이 등장하고 있다. OVPsim은 오픈 API를 제공하여 쉽게 프로세서와 주변 장치를 모델링 할 수 있는 가상 플랫폼으로서 소프트웨어 시뮬레이터이지만 매우 빠르게 실행되는 장점을 갖고 있다. 본 논문에서는 OVPsim을 사용하여 간단한 모바일 컴퓨터를 모델링하는 예를 소개하고, 모델링한 컴퓨터 플랫폼에서 리눅스 운영체제를 부팅한 결과와 벤치마크 프로그램을 통해 성능 평가를 수행한 사례를 소개한다.

• Journal of Digital Convergence
• /
• v.13 no.12
• /
• pp.367-380
• /
• 2015

This paper proposes a hybrid rendering method which combines pre-computed global illumination results and interactive local illumination techniques and thus could interactively produce photo-realistic visual effects for mobile entertainment applications. The proposed method uses the programmable shading capability of OpenGL, a de facto standard for computer graphics library so that it can be deployed in a real-world development environment. Also, it increases the rendering time by a negligible amount compared to normal rendering time since the pre-computed results are used as operands of plain arithmetic operations. Therefore it is expected to be applicable in practice for mobiles games which require real-time responsiveness to users.

• The Journal of Korean Association of Computer Education
• /
• v.8 no.4
• /
• pp.87-95
• /
• 2005

A large part of the wireless Internet contents which the young people access through their mobile phones is mobile games. However, mobile games currently available in the market are mostly simple entertainment packages, and there are hardly any educational game contents. This research divided the middle school computer education curriculum into five parts-common PC knowledge, operating systems, word processor, Internet, and multimedia-and designed and implemented a crossword puzzles mobile game. The mobile game designed in this research was given an emphasis to allow access of school lesson contents anywhere and anytime through actual mobile telecommunication networks, so that the students may experience less barrier to more fun and entertaining educational contents. The developed educational mobile game was applied on 2nd year middle school students. The mobile game had positive educational effects.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.4
• /
• pp.39-46
• /
• 2009

Many lip region detection methods have been developed in PC environment. But the existing methods are difficult to run on real-time in resource limited mobile devices. To solve the problem, this paper proposes a real-time lip region detection method for lipreading in Mobile device. It detects face region by using adaptive face color information. After that, it detects lip region by using geometrical relation between eyes and lips. The proposed method is implemented in a smart phone with Intel PXA 270 embedded processor and 386MB memory. Experimental results show that the proposed method runs at the speed 9.5 frame/see and the correct detection rate was 98.8% for 574 images.