• Journal of Information Technology and Architecture
• /
• v.10 no.1
• /
• pp.79-91
• /
• 2013

This paper proposes a systematic methodology that could be used to decide which one shows the best performance among space filling curves (SFCs) in applying lower-dimensional transformations to histogram sequences. A histogram sequence represents a time-series converted from an image by the given SFC. Due to the high-dimensionality nature, histogram sequences are very difficult to be stored and searched in their original form. To solve this problem, we generally use lower-dimensional transformations, which produce lower bounds among high dimensional sequences, but the tightness of those lower-bounds is highly affected by the types of SFC. In this paper, we attack a challenging problem of evaluating which SFC shows the better performance when we apply the lower-dimensional transformation to histogram sequences. For this, we first present a concept of spatial locality, which comes from an intuition of "if the entries are adjacent in a histogram sequence, their corresponding cells should also be adjacent in its original image." We also propose spatial locality preservation metric (slpm in short) that quantitatively evaluates spatial locality and present its formal computation method. We then evaluate five SFCs from the perspective of slpm and verify that this evaluation result concurs with the performance evaluation of lower-dimensional transformations in real image matching. Finally, we perform k-NN (k-nearest neighbors) search based on lower-dimensional transformations and validate accuracy of the proposed slpm by providing that the Hilbert-order with the highest slpm also shows the best performance in k-NN search.

• Journal of Information Technology and Architecture
• /
• v.10 no.3
• /
• pp.335-346
• /
• 2013

With the overwhelming development of information technologies, the need for software development that can deal with diversified and complex business processes has increased dramatically. As a result, companies prefer softwares that can handle far more complex processing ability and also it should be stable as well as easier to maintain. These ambivalent requirements keep the software development organizations from assessing the quantitative abilities, so that under the support of the U.S. Department of Defense the Capability Maturity Model (CMM) and Capability Maturity Model Integration (CMMI) have been developed. The CMMI upper levels for the software development companies will be evaluated to be excellent and authenticated, which drives the companies to get and maintain high levels of maturity. In this paper, a case study for a domestic software company has been exploited how to achieve CMMI level 4 and what kind of factors have been played an effective role. These issues at the domestic and international software and maintenance program, can influence the trustworthiness and marketing effects for the global market. In this paper, the company's actual case study will give clues to find out the important factors for the development and maintenance of software companies maturity levels.

• Journal of Information Technology and Architecture
• /
• v.10 no.1
• /
• pp.101-111
• /
• 2013

Internet traffic volume has been increasing rapidly due to popularization of various smart devices and Internet development. In particular, HTTP-based traffic volume of smart devices is increasing rapidly in addition to desktop traffic volume. The increased mobile traffic can cause serious problems such as network overload, web security, and QoS. In order to solve these problems of the Internet overload and security, it is necessary to accurately detect applications. Traditionally, well-known port based method is utilized in traffic classification. However, this method shows low accuracy since P2P applications exploit a TCP/80 port, which is used for the HTTP protocol; to avoid firewall or IDS. Signature-based method is proposed to solve the lower accuracy problem. This method shows higher analysis rate but it has overhead of signature generation. Also, previous signature-based study only analyzes applications in HTTP protocol-level not application-level. That is, it is difficult to identify application name. Therefore, previous study only performs protocol-level analysis. In this paper, we propose a signature generation method to classify HTTP-based traffics in application-level using the characteristics of typical semi HTTP header. By applying our proposed method to campus network traffic, we validate feasibility of our method.

• Journal of Information Technology and Architecture
• /
• v.9 no.3
• /
• pp.287-301
• /
• 2012

Against Nonaka's seminal work in 1999, this study aims to investigate various influencing factors on knowledge-transfer channels of Korean academics. To do this, we surveyed 20,000 Korean academics in science and engineering with regard to factors involved in their formal and informal collaborative activities with firms. In particular, we focus on the individual characteristics of the academics when the channels are changed from informal channels (e.g. consulting) to formal channels (e.g. licensing), as the codification of knowledge is important when it is spilled over. According to the results, male academics with a longer career and in the field of applied disciplines in a big laboratories are likely to join the transformation of the channels. Interestingly, application capacity as measured by the number of patent application is significantly and positively related to the participation of formal channels. In contrast, scientific capacity as measured by the number of papers is significantly and negatively, or in some case weakly, related to the participation. Finally, based on the findings, some policy implications are put forwarded.