• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.5
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• pp.153-164
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• 2010

A program consumes energy by executing its instructions. The amount of cosumed power is mainly proportional to algorithm complexity and it can be calculated by using complexity information. Generally, the complexity of a S/W is estimated by the microprocessor simulator. But, the simulation takes long time why the simulator is a software modeled the hardware and it only provides the information about computational complexity quantitatively. In this paper, we propose a complexity estimation method of analysis of S/W on source code level and produce the complexity metric mathematically. The function-wise complexity metrics give the detailed information about the calculation-concentrated location in function. The performance of the proposed method is compared with the result of the gate-level microprocessor simulator 'SimpleScalar'. The used softwares for performance test are $4{\times}4$ integer transform, intra-prediction and motion estimation in the latest video codec, H.264/AVC. The number of executed instructions are used to estimate quantitatively and it appears about 11.6%, 9.6% and 3.5% of error respectively in contradistinction to the result of SimpleScalar.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6A
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• pp.614-623
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• 2008

A very low complexity QRD-M algorithm based on adaptive search area is proposed for MIMO systems. The conventional QRD-M scheme extends each survivor paths to all constellation symbols at each layer and selects M paths of minimum path metrics. We found that performance will not be degraded even if we adaptively restrict the survivor path extension only to the neighboring points of temporary detection symbol according to the channel condition at each layer. By employing this feature, we propose a new QRD-M algorithm achieving the near MLD performance with a reduced complexity. We employ the channel gain ratio among the layers as a channel condition indicator, which does not require SNR estimation. The simulation results show that the proposed scheme effectively achieves near MLD performance while maintaining the overall average computation complexity much smaller than the conventional QRD-M algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.3
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• pp.1243-1263
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• 2018

The two-stage linear discrimination analysis (TSLDA) is a feature extraction technique to solve the small size sample problem in the field of image recognition. The TSLDA has retained all subspace information of the between-class scatter and within-class scatter. However, the feature information in the four subspaces may not be entirely beneficial for classification, and the regularization procedure for eliminating singular metrics in TSLDA has higher time complexity. In order to address these drawbacks, this paper proposes an improved two-stage linear discriminant analysis (Improved TSLDA). The Improved TSLDA proposes a selection and compression method to extract superior feature information from the four subspaces to constitute optimal projection space, where it defines a single Fisher criterion to measure the importance of single feature vector. Meanwhile, Improved TSLDA also applies an approximation matrix method to eliminate the singular matrices and reduce its time complexity. This paper presents comparative experiments on five face databases and one handwritten digit database to validate the effectiveness of the Improved TSLDA.

• The Transactions of the Korea Information Processing Society
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• v.2 no.3
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• pp.314-323
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• 1995

Recently, as users' understanding about software is raised, software developers devoted all their energy to satisfy users' needs. Accordingly, software is getting increase in volume and becoming complicated. As account of it, development and maintenance costs of software have been increased, and a large number of developers were projected in maintenance and development of new software. Software with good maintenability has a function in a module and is easy to read and simple. In this paper, for effective management of software complexity, I designed and implemented the system which accepts source program by input and measures product metrics and produce measurement value of factor items.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.3
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• pp.291-301
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• 2012

A scalar metric for the assessment of hull surface producibility was known to be useful in estimating the complexity of a hull form of ships or large offshore structures by looking at their shape. However, it could not serve as a comprehensive measuring tool due to its lack of important components of the hull form such as longitudinals, stiffeners, and web frames attached to the hull surface. To have a complete metric for cost estimation, these structural members must be included. In this paper, major inner structural members are considered by measuring the complexity of their geometric shape. The final scalar metric thus consists of the classes containing inner members with various curvature magnitudes as well as the classes containing curved plates with single and double curvature distribution. Those two distinct metrics are merged into a complete scalar metric that accounts for the total cost estimation of complex structural bodies.

• Journal of Semiconductor Engineering
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• v.2 no.3
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• pp.136-141
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• 2021

This paper analyzes the tree expansion for multiple-input multiple-output (MIMO) detection in the viewpoint of hardware implementation. The tree expansion is to calculate path metrics of child nodes performed in every visit to a node while traversing the detection tree. Accordingly, the tree-expansion unit (TEU), which is responsible for such a task, has been an essential component in a MIMO detector. Despite the paramount importance, the analyses on the TEUs in the literature are not thorough enough. Accordingly, we further investigate the hardware complexity of the TEUs to suggest a guideline for selection. In this paper, we focus on a pair of major ways to implement the TEU: 1) a full parallel realization; 2) a transformation of the formulae followed by common subexpression elimination (CSE). For a logical comparison, the numbers of multipliers and adders are first enumerated. To evaluate them in a more practical manner, the TEUs are implemented in a 65-nm CMOS process, and their propagation delays, gate counts, and power consumptions were measured explicitly. Considering the target specification of a MIMO system and the implementation results comprehensively, one can choose which architecture to adopt in realizing a detector.

• The KIPS Transactions:PartD
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• v.10D no.5
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• pp.859-872
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• 2003

Class hierarchies often constitute the backbone of object-oriented software. Their quality is therefore quite crucial. Building class hierarchies with good qualify is a very important and common tasks on the object oriented software development, but such hierarchies are not so easy to build. Moreover, the class hierarchy structure under construction is frequently restructured and refined until it becomes suitable for the requirement on the iterative and incremental development lifecycle. Therefore, there has been renewal of interest in all methodologies and tools to assist the object oriented developers in this task. In this paper, we define a set of quantitative metrics which provide a wav of capturing features of a rough estimation of complexity of class hierarchy structure. In addition to, we suggest a set of algorithms that transform a original class hierarchy structure into reorganized one based on the proposed metrics for class hierarchy structure. Furthermore, we also prove that each algorithm is "object-preserving". That is, we prove that the set of objects are never changed before and after applying the algorithm on a class hierarchy. The technique presented in this paper can be used as a guidelines of the construction, restructuring and refinement of class hierarchies. Moreover, the proposed set of algorithms based on metrics can be helpful for developers as an useful instrument for the object-oriented software development.velopment.

• Journal of Broadcast Engineering
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• v.21 no.2
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• pp.157-168
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• 2016

In image processing and computer vision fields, mean squared error (MSE) has popularly been used as an objective metric in image quality optimization problems due to its desirable mathematical properties such as metricability, differentiability and convexity. However, as known that MSE is not highly correlated with perceived visual quality, much effort has been made to develop new image quality assessment (IQA) metrics having both the desirable mathematical properties aforementioned and high prediction performances for subjective visual quality scores. Although recent IQA metrics having the desirable mathematical properties have shown to give some promising results in prediction performance for visual quality scores, they also have high computation complexities. In order to alleviate this problem, we propose a new fast IQA metric using a simple Laplace operator. Since the Laplace operator used in our IQA metric can not only effectively mimic operations of receptive fields in retina for luminance stimulus but also be simply computed, our IQA metric can yield both very fast processing speed and high prediction performance. In order to verify the effectiveness of the proposed IQA metric, our method is compared to some state-of-the-art IQA metrics. The experimental results showed that the proposed IQA metric has the fastest running speed compared the IQA methods except MSE under comparison. Moreover, our IQA metric achieves the best prediction performance for subjective image quality scores among the state-of-the-art IQA metrics under test.

• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.30-37
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• 2010

Many embedded real - lime systems have adopted processors supported with dynamic voltage scal-ing(DVS) recently. Power is one of the important metrics for Optimization in the design and operation of embedded real-time systems. We can save considerable energy by using slowdown of processor sup-ported with DVS. In this paper, we improved the previous algorithm at a point of view of time complexity to calculate task slowdown factors for an efficient energy consumption in embedded real-time systems with task synchronization. We grasped the properties of the previous algorithm having $O(n^{2})$ time complexity through mathematical analysis and s simulation. Using its properties we proposed the improved algorithms with O(nlogn) and O(n) time complexity which have the same performance as the previous algorithm has.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.5A
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• pp.752-762
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• 2001

소프트웨어의 유지보수 과정에서 효율적인 복잡성 척도와 테스트 경로의 생성은 중요한 문제이다. 대부분의 경우 테스트 경로의 생성과 복잡성 척도의 측정은 독립적인 기법이 필요하다. 본 논문에서는 테스트 경로의 생성과 복잡성 척도를 통합적으로 생성하고 있다. 제안한 기법은 PUT(Program Under Test)를 확장한 페트리네트 그래프(EPG)를 이용하여 모델링하고 이것의 통합적인 분석을 통하여 테스트 경로를 생성하며, 이 과정에서 생성된 실행경로의 제어구조별 평균 발생 빈도수를 이용하여 복잡성 척도 EV(G)를 구하였다. EV(G)는 실제 프로그램의 실행경로에 기반을 두었기 때문에 프로그램의 제어구조별 차이점 외에도 프로그램의 동작 특성을 복잡도에 잘 반영할 수 있다. 본 논문에서 제안한 통합 기법에 의한 테스트 경로 생성 기법과 복잡성 척도를 소프트웨어의 유지보수에 활용한다면 노력과 비용의 절감 및 소프트웨어의 질적 향상을 가져올 것이다.