• Journal of KIISE:Computing Practices and Letters
• /
• v.6 no.2
• /
• pp.150-160
• /
• 2000

The currently and most widely used client/server architecture is composed of database servers and clients that include both application and presentation logic. To date, due to the rapid growth in WWW, these client/server applications are implemented using Java language, especially in GUI design at client sides and client/server applications development using JDBC. To develop the applications using JDBC, developers should design database schema, code source code for JDBC connection, design report forms to display selected columns from server-side database. In this paper, we propose a development environment based on JavaBeans component for client/server applications development using JDBC. The proposed environment minimizes manual coding and enables developers to develop client/server applications easily with the designed JavaBeans components and their custom property editor.

• KIPS Transactions on Computer and Communication Systems
• /
• v.4 no.1
• /
• pp.23-30
• /
• 2015

Reflection is a feature of the Java programming language that can examine and manipulate components of program itself. If you use the reflection, you can get an obfuscation effect of Java source because it converts sources into complicated structures. However, when using it, strings of components name of program are exposed. Therefore, it cannot prevent static analysis. In this paper, we presents a method and a tool of interfere with static analysis using reflection. And in this case, exposed strings are encoded using Vigen$\acute{e}$re cipher. Experimental results show that this tool is effective in increasing the overall complexity of the source code. Also the tool provides two types decryption method based on server and local. It can be selected based on the importance of the API because it affects the execution speed of the application.

• Journal of KIISE
• /
• v.44 no.11
• /
• pp.1165-1177
• /
• 2017

Many developers utilize specific APIs to develop software, and to identify the use of a particular API, a developer can refer to a website that provides the API or can retrieve the API from the web. However, the site that provides the API does not necessarily provide guidance on how to use it while it can be partially provided in many other cases. In this paper, we propose a novel system JACE (Java AST collocation-pattern extractor) as a method to reuse commonly-used code as a supplement. The JACE extracts the API call nodes, collocation patterns and analyzes the relations between the collocations to extract significant API patterns from the source code. The following experiment was performed to verify the accuracy of a defined pattern: 794 open source projects were analyzed to extract about 15M API call nodes. Then, the Eclipse plug-in test program was utilized to retrieve the pattern using the top 10 classes of API call nodes. Finally, the code search results from reference pages of the API classes and the Searchcode [1] were compared with the test program results.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.3
• /
• pp.833-840
• /
• 2014

This study presents numerical simulation of turbulent flows in a rectangular open-channel that has a width-to-depth ratio of 2 using the source code provided by OpenFOAM. Large eddy simulations are carried out by solving the filtered continuity and momentum equations numerically. For the non-isotropic residual stress term, Smagorinsky's (1963) model is used. The flow in the open-channel whose width-to-depth ratio is 2, from experiment of Tominaga et al. (1989), is simulated numerically. Simulation results are compared with measured data by Tominga et al. (1989) and Nezu and Rodi (1985) and with LES data by Shi et al. (1999). Comparisons revealed that the model simulates the mean flow and turbulence statistics well. Specifically, the model reproduced the inner secondary currents located at the corner of sidewall and free surface successfully. In addition, the vortical component of turbulence intensity shows bulged contours towards the bottom edge.

• Journal of KIISE:Information Networking
• /
• v.32 no.3
• /
• pp.350-358
• /
• 2005

Recently, VoIP technology is being accepted as are the most promising Internet telephony service, due to the substitution effect of traditional telephony service. Two standards, i.e, . H.323 and SIP. have emerged for signaling and control for Intemet telephony, of which SIP provides far lower complexity and rich extensibility. It is important to secure components of SIP in order to develop various services. Generally, open source codes provide basic functions of SIP as well as complicated structure, but are difficult to extend. In this thesis, we focused on offering interface mechanism between application and SIP User Agent to easily extend for various VoIP services. This thesis describes what function is needed for SIP User Agent, how to define the internal data structure, and how to define the internal processing procedure. The check iist derived through participating the interoperability event for stabilized SIP User Agent is also suggested.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.1
• /
• pp.207-212
• /
• 2018

As a data analysis tool which is becoming popular in the Big Data era, R is rapidly expanding its user range by providing powerful statistical analysis and data visualization functions. Major advantage of R is its functional scalability based on open source, but its scale scalability is limited, resulting in performance degrades in large data processing. RHadoop, one of the extension packages to complement it, can improve data analysis performance as it supports Hadoop platform-based distributed processing of programs written in R. In this paper, we evaluate the validity of RHadoop by evaluating the performance improvement of RHadoop in real medical big data analysis. Performance evaluation of the analysis of the medical history information, which is provided by National Health Insurance Service, using R and RHadoop shows that RHadoop cluster composed of 8 data nodes can improve performance up to 8 times compared with R.

• Journal of Digital Convergence
• /
• v.15 no.9
• /
• pp.241-248
• /
• 2017

There are various problems in the process of developing the game. Especially, there is a lot of problems in testing the balance of the value of each object. This causes problems such as an increase in development cost and a delay in development time. Therefore, if there is a tool or simulator that can test the mutual value balance of each object in advance, this problem can be solved. However, currently there are few simulators, tools, and platforms that can analyze and evaluate the mutual value balance between these objects. In this paper, I designed a platform to evaluate and test the mutual value balance between these objects based on mock battle. The designed platform tests and evaluates the abilities of each object according to their attack and defense strengths. So, this reduces development costs and shortens development time.

• Journal of Digital Contents Society
• /
• v.8 no.1
• /
• pp.17-25
• /
• 2007

Recently, the ubiquitous computing environment being able to connect all kinds of computing elements at anytime anywhere becomes widespread in human life. In this paper, we focus on a PC remote control system using cellular phones. Especially, we design and implement an mobile e-mail transmission system using PC remote control technique. By using our remote controller, cellular phone users can login into their own PC, and then send any file to others by e-mail attachment. To show the correct running of our system, real demonstration results are presented. We are sure that by opening our source code to the public our results can play an important role to encourage development of the various mobile remote control functionalities.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.13 no.4
• /
• pp.229-237
• /
• 2013

As demand for IT services increase, which are based on SOA and cloud computing, service level agreements (SLAs) have received more attention in the parties concerned. An SLA is usually a paper contract written in natural language. SLA management tools which are commercially available, implement SLAs implicitly in the application with a procedural language. This makes automation of SLA management difficult. It is also laborious to maintain contract management systems because changes in a contract give rise to extensive modifications in the source code. We see the source of the trouble is the existence of documentary SLAs (paper contracts) and corresponding executable SLAs (contracts coded in the procedural language). In this paper, to resolve the current SLA management problems we propose an active SLM (Active Service Level Management) system, which is based on the active SLA (Active Service Level Agreement). In the proposed system, the separated management and processing of dual SLAs can be unified into a single process with the introduction of active SLAs (ASLAs).

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.4
• /
• pp.129-133
• /
• 2020

In this paper, a temperature compensation circuit is presented in order to mitigate gain variability due to temperature in the W-band low-noise amplifier (LNA). The proposed cascode temperature compensation bias circuit automatically controls gate bias voltages of the common-source LNA in order to suppress variations of small-signal gain. The designed circuit was realized in a 100-nm GaAs pHEMT process. The simulated voltage gain of W-band LNA including the proposed bias circuit is >20 dB with gain variability less than ±0.8 dB in the range of temperatures between -35 to 71℃. We expect that the proposed circuit contributes to millimeter-wave receivers for stable performances in radar applications.