• Journal of Digital Contents Society
• /
• v.12 no.4
• /
• pp.551-557
• /
• 2011

In this paper, we propose a stack allocation technique of Android Java objects in order to reduce the number of garbage collection which is one of major reason on Android performance degradation when running applications. The proposed technique is to allocate Java objects into stack rather than heap memory. To do so, stacked objects could escape the garbage collection process. We experiment the proposed technique in the latest Android 2.3 version. For the simulation, we take advantage of the well known Java benchmark, Caffeinemark, and our own. The result shows the performance degradation of Dalvik Virtual Machine execution time caused by the stack allocation of Java objects is very slight and the proposed method considerably reduces the frequency of garbage collection. This will increase application performance and give better user interfaces to Android phone users.

• Journal of KIISE:Software and Applications
• /
• v.31 no.6
• /
• pp.840-848
• /
• 2004

Garbage collecting objects in Java makes memory management easier for the programmer, but it is time consuming. Stack allocation may be an alternative which identifies stack-allocatable objects before the execution, without performance degradation. We suggest an escaping analysis recording the interprocedural movement of the method, to detect an object the method of whose creation may have been already deactivated during the access. Our approach is different from prior works, enables us to handle some cases that are missed in the previous variable - oriented approach.

• Journal of the Korea Society of Computer and Information
• /
• v.6 no.4
• /
• pp.100-103
• /
• 2001

The best solution to improve the execution speed of Java program is to make use of the high speed JVM(Java Virtual Machine). The performance of JVM depends on the difference of its implementation. One of the technologies to enhance JVM performance is a JIT(Just-in-Time) code generator. The JIT code generator transforms Java byte code to the native machine code in accordance with computer system platform. The native machine code is faster than the existing interpreter method, since it can reduce the time to analyze the Java byte code. But the JIT code generator have the problem of increasing the traffic between stack and register because of using many register. Therefore, this paper suggests how to reduce the traffic by applying the policy of stack allocation to JIT code generation, as one of the methods to enhance the performance of JVM.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.11
• /
• pp.5404-5424
• /
• 2018

This work is mainly focused on two major topics in cloud platforms by using OpenStack as a case study: management and provisioning of resources to meet the requirements of a service demanded by remote end-user and relocation of virtual machines (VMs) requests to offload the encumbered compute nodes. The general framework architecture contains two subsystems: 1) An orchestrator that allows to systematize provisioning and resource management in OpenStack, and 2) A resource utilization based subsystem for vibrant VM relocation in OpenStack. The suggested orchestrator provisions and manages resources by: 1) manipulating application program interfaces (APIs) delivered by the cloud supplier in order to allocate/control/manage storage and compute resources; 2) interrelating with software-defined networking (SDN) controller to acquire the details of the accessible resources, and training the variations/rules to manage the network based on the requirements of cloud service. For resource provisioning, an algorithm is suggested, which provisions resources on the basis of unused resources in a pool of VMs. A sub-system is suggested for VM relocation in a cloud computing platform. The framework decides the proposed overload recognition, VM allocation algorithms for VM relocation in clouds and VM selection.

• Annual Conference of KIPS
• /
• 2001.10b
• /
• pp.1541-1544
• /
• 2001

Java virtual machine의 성능을 향상시키기 위해 "JIT(Just-in-Time)"code generator가 고안되었다[3], JIT code generator는 스택기반의 자바 바이트 코드를 레지스터 기반의 native machine code로 변환해 주는 역할을 수행하여 바이트 코드의 번역시간을 줄여준다. 그러나 JIT 는 많은 레지스터의 사용을 야기시키므로 효율적인 레지스터 allocation 정책이 필요하고 스택과 레지스터 간의 traffic 을 가중시킨다. 그러므로 본 논문에서는 자바 바이트 코드의 효율적인 stack allocation 정책을 JIT code generator에 적용함으로 레지스터와의 traffic을 줄이는 방법을 제시하였다.

• Proceedings of the IEEK Conference
• /
• 2000.07a
• /
• pp.302-305
• /
• 2000

This paper proposed an optimal register resource allocation algorithm using graph coloring for minimal register at high level synthesis. The proposed algorithm constructed interference graph consist of the intermediated representation CFG to description VHDL. and at interference graph fur the minimal select color selected a position node at stack, the next inserted spill code and the graph coloring process executes for optimal register allocation. The proposed algorithm proves to effect that result compare another allocation techniques through experiments of bench mark.

• 전기의세계
• /
• v.31 no.4
• /
• pp.281-287
• /
• 1982

PASCAL has a recursive nested structure and uses deep binding of identifiers. This paper studies the problems and techniques in storage management for PASCAL on the IBM 370 system, and presents run-time storage administration algorithms which use stack scheme and heap efficiently on the view of storage. The stack-scheme was used to implement the feature of recursive nested structure and the heap was used to implement the feature of the dynamic allocation procedure and pointer variable, allowing an additional dynamic storage recovery procedure.

• Journal of the Korean earth science society
• /
• v.36 no.1
• /
• pp.36-50
• /
• 2015

The purpose of this study is to assign emission source profiles of volatile organic compounds (VOCs) and particulate matters (PMs) for chemical speciation, and to correct the temporal allocation factor and the chemical speciation of source profiles according to the source classification code within the sparse matrix operator kernel emission system (SMOKE) in the Seoul metropolitan area. The chemical speciation from the source profiles of VOCs such as gasoline, diesel vapor, coating, dry cleaning and LPG include 12 and 34 species for the carbon bond IV (CBIV) chemical mechanism and the statewide air pollution research center 99 (SAPRC99) chemical mechanism, respectively. Also, the chemical speciation of PM2.5 such as soil, road dust, gasoline and diesel vehicles, industrial source, municipal incinerator, coal fired, power plant, biomass burning and marine was allocated to 5 species of fine PM, organic carbon, elementary carbon, $NO_3{^-}$, and $SO_4{^2-}$. In addition, temporal profiles for point and line sources were obtained by using the stack telemetry system (TMS) and hourly traffic flows in the Seoul metropolitan area for 2007. In particular, the temporal allocation factor for the ozone modeling at point sources was estimated based on $NO_X$ emission inventories of the stack TMS data.

• Journal of KIISE:Computer Systems and Theory
• /
• v.34 no.11
• /
• pp.572-580
• /
• 2007

Wireless sensor networks are sensing, computing and communication infrastructures that allow us to monitor, instrument, observe, and respond to phenomena in the harsh environment. Generally, the wireless sensor networks are composed of many deployed sensor nodes that were designed to be very cost-efficient in terms of production cost. For example, UC Berkeley's MICA motes have only 8-bit CPU, 4KB RAM, and 128KB FLASH memory space. Therefore, sensor operating systems that run on the sensor nodes should be able to operate efficiently in terms of the resource management. In this paper, we present a dynamic threads stack management scheme for space-constrained and multi-threaded sensor operating systems. In this scheme, the necessary stack space of each function is measured on compile-time. Then, the information is used to dynamically allocate and release each function's stack space on run-time. It was implemented in Nano-Qplus sensor operating system. Our experimental results show that the proposed scheme outperforms the existing fixed-size stack allocation mechanism.

• The Transactions of the Korea Information Processing Society
• /
• v.2 no.3
• /
• pp.364-373
• /
• 1995

We propose a probabilistic design method and performance analysis in the area of dynamic data structures. We assign two stacks to a block which consists of m contiguous memory cells. Frequencies of delete and insert operations are not fixed, but depend on stack heights. We present various probabilistic schema and a rigorous performance analysis for a random memory allocation. Especially, stack coillision problem is studied and exponential increase of the mean of collision time as mlongrightarrow$\infty$is showed. We also present general mathematical schema which can be applied to the performance problems of finite automata and other computer information systems.