• Journal of Information Management
• /
• v.29 no.3
• /
• pp.1-26
• /
• 1998

The loop is a fundamental for the parallelism exploiting as it has a large portion of execution time for sequential Java program on the parallel machine. This paper proposes the method of exploiting the implicit parallelism through the analysis of data dependence in the existing Java programming language having a single loop structure. The parallel code generation method through the restructuring compiler and the translation method of Java source program into multithread statement, which is supported in the level of the Java programming language, are also proposed here. The performance test of the program translated into the thread statement is conducted using the trip count of loop and the thread count as parameters. The restructuring compiler makes it possible for users to reduce overhead and exploit parallelism efficiently in the Java programming.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.20 no.6
• /
• pp.59-65
• /
• 2010

Since an attacker can occur an error in cryptographic device during encryption process and extract secret key, the fault injection attack has become a serious threat in chip security. In this paper, we show that an attacker can retrieve the 128-bits secret key using fault injection attack on the for statement of final round key addition in AES implementation. To verify possibility of our proposal, we implement the AES system on ATmega128 microcontroller and try to inject a fault using laser beam. As a result, we can extract 128-bits secret key through just one success of fault injection.

• Journal of KIISE:Software and Applications
• /
• v.37 no.4
• /
• pp.311-316
• /
• 2010

Esterel is an imperative synchronous language that is used to develop memories, cache controllers, bus interfaces, and so on. An Esterel statement is called schizophrenic if it is executed more than once in an instant. A schizophrenic statement may cause problems when it is translated to hardware circuits; a circuit performs more than one reaction in a clock. Previous works claim that only local signal declarations and parallel statements may cause schizophrenic problems. However, control signals produced by a trap statement or data signals used by emit statements can cause schizophrenia. They are new schizophrenic patterns. Especially, schizophrenic problems caused by emit statements cannot be solved by a loop unrolling technique that is the key idea of previous curing techniques for schizophrenic problems. In this paper, we introduce and define the two schizophrenic problems.

• The Transactions of the Korea Information Processing Society
• /
• v.5 no.8
• /
• pp.1997-2012
• /
• 1998

It is necessary to find out the parallelism in tlle sequential Java program to execute it on the parallel machine. The loop is a fundamental source to exploit parallelism as it process a large portion of total execution time in sequential Java program on the parallel machine. However, a complete parallel execution can hardly be achieved due to data dependence. This paper proposes the method of exploiting the implicit parallelism by structuring a dependence graph through the analysis of data dependence in the existing Java programming language having a nested loop structure. The parallel code generation method through the restructuring compiler and also the translation method of Java source program into multithread statement. which is supported by the Java programming language itself, are proposed here. The perforance evaluatlun of the program translaed into the thread statement is conducted using the trip cunt of loop and the trip Count of luop and the thread count as parameters The resttucturing compiler provides efficient way of exploiting parallelism by reducing manual overhead conveliing sequential Java program into parallel code. The execution time for the Java program as a result can be reduced un the parallel machine.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.22 no.4
• /
• pp.709-717
• /
• 2012

The round reduction on block cipher is a fault injection attack in which an attacker inserts temporary errors in cryptographic devices and extracts a secret key by reducing the number of operational round. In this paper, we proposed an improved round reduction method to retrieve master keys by injecting a fault during operation of loop statement in the Triple DES. Using laser fault injection experiment, we also verified that the proposed attack could be applied to a pure microprocessor ATmega 128 chip in which the Triple DES algorithm was implemented. Compared with previous attack method which is required 9 faulty-correct cipher text pairs and some exhaustive searches, the proposed one could extract three 56-bit secret keys with just 5 faulty cipher texts.

• The Transactions of the Korea Information Processing Society
• /
• v.1 no.1
• /
• pp.38-49
• /
• 1994

One of the most common problems encountered in the automatic translation of FORTRAN source code to VECTRAN is the occurrence of conditional transfer of control within loops. Transfers of control create control dependencies, in which the execution of a statement is dependent on the value of a variable in another statement. In this paper I propose algorithms involve an attempt to convert statements in the loop into conditional assignment statements that can be easily analyzed for data dependency, and this paper presents a simplification method for conditional assignment statement. Especially, I propose not only a method for simplifying boolean functions but extended method for n-state functions.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.5
• /
• pp.121-129
• /
• 2007

Scalarization is a process that a parallel construct like an array statement of Fortran 90 or FORALL of HPF is converted into sequential loops that maintain the correct semantics. Most compilers of HPF, recognized as a standard data parallel language, convert a HPF program into a Fortran 77 program inserted message passing primitives. During scalariztion, a parallel construct FORALL should be translated into Fortran 77 DO loops maintaining the semantics of FORALL. In this paper, we propose a scalarization algorithm which converts a FORALL construct into a DO loop with improved performance. For this, we define and use a relation distance vector to keep necessary dependence informations. Then we evaluate execution times of the codes generated by our method and by PARADIGM compiler method for various array sizes.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.04b
• /
• pp.22-24
• /
• 2001

A new GIS software Spatial Database Engine(SDE) has been developed to integrated with spatial database that combines conventional and spatially related data. As we known well in the traditional relation database system, the query evaluation techniques are a well-researched subject, many useful and efficient algorithms have been proposed, but in the spatial database system, it is a litter difference with the traditionally ones. Based on the Query Graph Model(QGM), we implemented our own query evaulation plan in the SDE, which can deal with the full functionality query statement SELECT-FROM-WHERE_GROUPBY-HAVING, and treat the spatial data and non-spatial data seamlessly. We proposed a novel multi way join algorithm base on nest loop that may be attractive.

• Journal of Digital Convergence
• /
• v.13 no.8
• /
• pp.1-8
• /
• 2015

This paper focuses on analyzing Korean language learning effect through the STEAM class using a robot which is targeted on multicultural elementary school students. For the purpose of it, the degree of difficulty and interest of how students feel has been measured. By using the programing tool of Korean language entering base, they learn the programming commands like as variable, data type, branching statement, loop statement, etc in Korean, the effect of Korean learning has been measured. It has been examined two interviews at the beginning and the end of the second semester to measure the effect of Korean language learning. As a result of this research, It can be realized that multicultural children who have similar linguistic characteristics and cultural sphere understood Korean language easily when they take the Korean language class by utilizing a robot, and the class had an effect on the acquisition of Korean language for multicultural children.

• International journal of advanced smart convergence
• /
• v.10 no.1
• /
• pp.97-104
• /
• 2021

Securities and investment services had the most data per company on the average, and used the most data. Investors are increasingly demanding to invest through their own analysis methods. Therefore, securities and investment companies provide stock data to investors through open API. The data received using the open API is in text format. Python is effective and convenient for requesting and receiving text data. We investigate there are 22 major securities and investment companies in Korea and only 6 companies. Only Daishin Securities Co. supports Python officially. We compare how to receive stock data through open API using Python, and Python programming features. The open APIs for the study are Daishin Securities Co. and eBest Investment & Securities Co. Comparing the two APIs for receiving the current stock data, we find the main two differences are the login method and the method of sending and receiving data. As for the login method, CYBOS plus has login information, but xingAPI does not have. As for the method of sending and receiving data, Cybos Plus sends and receives data by calling the request method, and the reply method. xingAPI sends and receives data in the form of an event. Therefore, the number of xingAPI codes is more than that of CYBOS plus. And we find that CYBOS plus executes a loop statement by lists and tuple, dictionary, and CYBOS plus supports the basic commands provided by Python.