• International Journal of Internet, Broadcasting and Communication
• /
• 제16권3호
• /
• pp.184-191
• /
• 2024

The focus of this paper is secure code development and maintenance. When it comes to safe code, it is most important to consider code readability and maintainability. This is because complex code has a code smell, that is, a structural problem that complicates code understanding and modification. In this paper, the goal is to improve code quality by detecting and removing smells existing in code. We target the encryption and decryption code SEED.c and evaluate the quality level of the code using several metrics such as lines of code (LOC), number of methods (NOM), number of attributes (NOA), cyclo, and maximum nesting level. We improved the quality of SEED.c through systematic detection and refactoring of code smells. Studies have shown that refactoring processes such as splitting long methods, modularizing large classes, reducing redundant code, and simplifying long parameter lists improve code quality. Through this study, we found that encryption code requires refactoring measures to maintain code security.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• 제34S권8호
• /
• pp.37-44
• /
• 1997

We implemented a code searcher which is used for the PN(pseudo noise) code acquisition in CDMA cellular mobile station. To reduce the reuired hardware and the code acquisition time, we used the double dwell structure which is an effective serial code acquisition metho. We designed a code acquisition has acquired within 1/2 PN chip range. The code searcher is implemented using 0.8 micron code searcher is successfully working in CDMA cellular mobile station and it satisfies the code acquisition time specified in IS-95 standard.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• 제32권3C호
• /
• pp.195-204
• /
• 2007

The cyclic redundancy check(CRC) code used to decide retransmission request in hybrid automatic repeat request(HRAQ) system can also be used to stop iterative decoding of turbo code if it is used as an error correcting code(ECC) of HARQ system. Thus a scheme to use CRC code for both iteration stop and repeat request in the HARQ system with turbo code based on the standard of cdma 2000 system is proposed in this paper. At first, the optimum CRC code which has the minimum length without performance degradation due to undetected errors is found. And the most appropriate turbo encoder structure is also suggested. As results, it is shown that at least 32-bit CRC code should be used and a turbo code with 3 constituent encoders is considered to be the most appropriate one.

• The Transactions of the Korea Information Processing Society
• /
• 제4권10호
• /
• pp.2596-2604
• /
• 1997

There are two kinds of backends in ACK:code generator(full-fledged backend) and code expander(fast backend). Code generators generate target code using string pattern matching and code expanders generate target code using macro expansion. ACK translates EM to SPARC code using code expander. The corresponding SPARC code sequences for a EM code are generated and then push-pop optimization is performed. But, there is the problem of maintaining hybrid stack. And code expander is not considered to passes parameters of a procedure call through register windows. The purpose of this paper is to improve SPARC code quality. We suggest a method of SPARC cod generation using EM tree. Our method is divided into two phases:EM tree building phase and code expansion phase. The EM tree building phase creates the EM tree and code expansion phase translates it into SPARC code. EM tree is designed to pass parameters of a procedure call through register windows. To remove hybrid stack, we extract an additional information from EM code. We improved many disadvantages that arise from code expander in ACK.

• Journal of the Institute of Electronics and Information Engineers
• /
• 제50권5호
• /
• pp.121-127
• /
• 2013

When input power is small, nonideal symmetric balance incomplete block design(BIBD) code design is effective in the spectral-amplitude-code(SAC) optical code-division multiple-access (OCDMA) system. But the number of simultaneous users is not sufficient. To overcome this property, we propose 2-D BIBD codes, where nonideal BIBD codes are used as spectral code and ideal BIBD codes are used as spatial codes. Analytical results show that the number of simultaneous users increases significantly.

• Journal of Korea Society of Digital Industry and Information Management
• /
• 제11권2호
• /
• pp.1-10
• /
• 2015

As programs get more complicated and they are developed by various hands, the possibility that there are program bugs in the code has been increasing. And developers usually run unit tests to find these problems in the code. Besides, the developers are at the pain of getting stability of the code when they have to modify a code very often for clients requirements. In the methodlogy of TDD(Test Driven Development), developers write a unit test code first, and then write a program code for passing the unit test. The unit test must include the boundary condition test the reason why the possibility of occurring the bugs is very high. When failed to pass the test because of the value of a function is incorrect, not existed, out of the range or not matched etc, the program code will return the error code or occur the exception. In the document, the system is designed and implemented in order to insert the generated code automatically or suggest it to the developer, when the boundary condition test is failed. In conclusion, it is possible that the developer will get the code stability by searching the code and checking the code to be omitted automatically through this system.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• 제34S권2호
• /
• pp.1-10
• /
• 1997

In this paper, an improved lower bound on the burst-error correcting capability of th ecyclic product code is presented and through the analysis of this new bound clustered cyclic product (CCP abbr.)code is proposed. The CCP code, to improve the burst-error correcting capability, combines the idea of clustering and the transmission method of cyclic product code. That is, a cluster which is defined in this paper as a group of consecutive code symbols is employed as a new transmission unit to the code array transmission of cyclic product code. the burst-error correcting capability of the CCP code is improved without a loss in the random-error correcting capability and performance comparison in the digital video camera records (DVCR) system shows the superiority of the proposed CCP code over conventional product codes.

• Journal of the Korean Society for Precision Engineering
• /
• 제20권10호
• /
• pp.169-176
• /
• 2003

Genetic algorithm (GA), which has a powerful searching ability and is comparatively easy to use and also to apply, is in the spotlight in the field of the optimization for mechanical systems these days. However, it also contains some problems of slow convergence and low efficiency caused by a huge amount of repetitive computation. To improve the processing efficiency of repetitive computation, some papers have proposed paralleled GA these days. There are some cases that mention the use of gray code or suggest using gray code partially in GA to raise its slow convergence. Gray code is an encoding of numbers so that adjacent numbers have a single digit differing by 1. A binary gray code with n digits corresponds to a hamiltonian path on an n-dimensional hypercube (including direction reversals). The term gray code is open used to refer to a reflected code, or more specifically still, the binary reflected gray code. However, according to proposed reports, gray code GA has lower convergence about 10-20% comparing with binary code GA without presenting any results. This study proposes new Full gray code GA (FGGA) applying a gray code throughout all basic operation fields of GA, which has a good data processing ability to improve the slow convergence of binary code GA.

• Nuclear Engineering and Technology
• /
• 제43권1호
• /
• pp.45-62
• /
• 2011

The Korean nuclear industry is developing a thermal-hydraulic analysis code for safety analysis of pressurized water reactors (PWRs). The new code is called the Safety and Performance Analysis Code for Nuclear Power Plants (SPACE). The SPACE code adopts advanced physical modeling of two-phase flows, mainly two-fluid three-field models which comprise gas, continuous liquid, and droplet fields and has the capability to simulate 3D effects by the use of structured and/or nonstructured meshes. The programming language for the SPACE code is C++ for object-oriented code architecture. The SPACE code will replace outdated vendor supplied codes and will be used for the safety analysis of operating PWRs and the design of advanced reactors. This paper describes the overall features of the SPACE code and shows the code assessment results for several conceptual and separate effect test problems.

• The Journal of the Korea institute of electronic communication sciences
• /
• 제8권1호
• /
• pp.65-70
• /
• 2013

In this paper, we propose the construction of Raptor code using LDGM code instead of LDPC code as precode. To see their merits, the simulations are done. The results show that the performance in case of using LDGM code is worse than that of using LDPC code as precode, and the complexity of encoding LDGM code is lower than that of LDPC.