암호학적 응용을 위한 안전한 난수 시드

表昌祐 弘益大學校 科學技術硏究所 2005 科學技術硏究論文集 Vol.16 No.-

Internet application programs need the capability of encryption for security. Messages and other data are encrypted and decrypted by using keys, which are generated by random number generators. We have shown that some bits taken the difference between two consecutive readings of microprocessors' counter registers are truly random, where the counter registers increase at the speed of system clock. Our hypothesis is confirmed by using the NIST's test package for random number generators. We tested TSC MSR (Time-Stamp Counter Model-Specific Register) in the Pentium processor. Our result implies that TSC MSR can be used as an internal chaotic source for true random number generation with high performance.

전문대학의 NCS 지원 웹서비스 분석

표창우 한국의료정보교육협회 2020 보건의료생명과학논문지 Vol.8 No.2

본 연구는 전문대학의 NCS 지원 웹서비스를 분석하였다. 분석 범위는 국내 2, 해외 1 포털사이트를 NCS지원센터 등으로 검색하였다. 검색 후 도출된 12개의 전문대학의 NCS지원센터 웹서비스 지원을 분석하였다. NCS 지원 웹서비스는 세 가지로 분류하였다. 첫째, NCS 지원서비스 현황분석, 둘째, NCS 지원사업 현황분석, 셋째, 대학별 차별화된 NCS 지원 웹서비스 분석을 실시하였다. 그 결과 NCS 지원서비스는 NCS 지원사업 현황 서비스보다 양적 웹 페이지는 많이 있었다. 하지만 NCS 지원사업 현황 서비스는 NCS 지원서비스 보다 상세하고 실제 활용할 수 있는 자료로 제시되었다. 차별화된 웹서비스는 각 대학마다 NCS 웹서비스 지원을 극대화하기 위한 노력이 포함된 내용을 분석할 수 있었다. 본 연구를 결과를 토대로 전문대학 교육을 위한 NCS 지원 웹서비스의 질적인 향상을 기대해 본다. This study analyzed NCS-enabled Web services at colleges. The search scope was based on the NCS Support Center, etc. of the two domestic and one overseas portal sites. Support for the NCS Support Center web service from 12 Junior Colleges was analyzed after the search. There were three categories of NCS-enabled Web services. First, NCS-enabled service status analysis, second, NCS-enabled project status analysis, and third, junior college-specific differentiated NCS-enabled web service analysis were conducted. As a result, NCS-enabled services had more quantitative web pages than NCS-enabled project status services. However, NCS-enabled project status services have been presented with more detailed and practical data than NCS-enabled services. Differentiated Web services were able to analyze what included efforts to maximize NCS Web service support for each Junior College. Based on the results of this study, we look forward to improving the quality of NCS-enabled web services for Junior College education.

CATV 망 분배 센터 관리를 위한 웹 기반의 사용자 인터페이스

表昌祐,楊韓根 弘益大學校 科學技術硏究所 2001 科學技術硏究論文集 Vol.12 No.-

As CATV network become a part of Internet, CATV Network Management System (CNMS) take an important role of reliable noise control. CATV network is a hybrid fiber coaxical (HFC) network in tree structure. Upward signals are vulnerable to noise, since noise level is aggregated as the signals approache the root of the network. We designed and implemented a CNMS for noise control based on advanced Internet technology. The CNMS is composed of three servers for web, database and communication. Interface and core communication modules were constructed by using web and Java technology. Lower level communication module was developed by using a Linux server. The CNMS can monitor and control remotely each node in the network. We expect the developed CNMS would serve as a platform for advanced intelligent CATV network management.

정규트리 타입 언어의 확장

表昌祐 弘益大學校 科學技術硏究所 1991 科學技術硏究論文集 Vol.1 No.-

Regular trees have been used for flow analysis of programs. Recently, regular trees have been adopted as a language for types, particularly in logic programming. They have rich expressive power in describing structures of terms. We have extended the regular trees to be used as a type language for Prolog, which is the de facto standard of logic programming languages. Primitive types of Prolog such as integer are given formal definition. A logical system for extending the notion of primitive type is also defined. Under this system, users can define types, which in turn, can be used to strengthen the type checking capability of Prolog programs. A feature of the developed system is that recursive type definitons of types can be straightforwardly converted into type inference rules.

[特輯]논리 프로그래밍의 최근 연구 동향

표창우 한국정보과학회 1992 정보과학회지 Vol.10 No.3

프로그램 구조를 이용한 레지스터 할당의 효과

표창우 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.5 No.-

This paper presents a register allocation techniques utilizing program structure. Program structure is identified by finding single-entry-single-exit region in control flow graph. By incorporating program structure into register allocation, basic blocks are prioritized according to their access frequency. That is, frequently accessed basic blocks are processed before sparsely accessed ones in each phase of register allocation. Also an efficient method of graph coloring, based on graph partition, is presented. We have found out that, in particular, graph partitioning is a proper backbone for register allocation considering program structure.

후처리 최적화기의 설계 및 구현

表昌祐 弘益大學校 科學技術硏究所 1992 科學技術硏究論文集 Vol.2 No.-

In compiler systems, optimization is an essential process which improves the efficiency of machine code. Peephole optimization is one of post optimization techniques, which replaces a sequence of instructions appearing in a peephole with a semantically equivalent and more efficient one. Peephole optimization may also be applied to intermediate representation. This paper designs and implements a peephole optimizer for MIPS R2000 machine programs in assembler code. The peephole optimizer consists in three modules for representation of internal structure, rule application, and output. It uses a peephole of size 2. The rules used by the peephole optimizer are composed of pairs of pattern and replacement. Once a pattern is caught, the corresponding replacement is substituted for the pattern. The rules are for constant folding, strength reduction, null sequences, combined operations, and comparisons. Using the peephole optimizer, we could reduce the size of machine code by 19% to 24% approximately. Since the implementation of peephole optimizer is easy, cost-effective optimization can be achieved with a little effort. As a consequence, the burden of optimization on code generator can be alleviated. This implies fast and easy construction of error-free code generators with the aid of peephole optimization.

정규 트리 상에서 내로우잉 기법을 사용한 부등식 해법

표창우 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.4 No.-

Proving including relations between regular trees takes central role in the area of program analysis for logic or functional programming. We have developed a set of inference rules for proving inclusion relations over the regular tree domain, which constitutes a logical framework for solving inequations between regular trees. We also have developed a narrowing technique, called inclusion narrowing, which allows further reduction when the inference rules cannot be applied because of tree variables. The domain of regular trees in which inequation can have solutions is expanded as a result. It is expected that the developed framework and the inclusion narrowing would contribute to enlargement the program classes to which regular tree based program analysis is applicable.

프로그램 구동 시뮬레이션 환경 구축

李竟雨,表昌祐 弘益大學校 科學技術硏究所 1996 科學技術硏究論文集 Vol.7 No.2

We have established an environment for research in microprocessor design and compile time optimization. The environment consists of Vtrace, a memory trace generation tool by our own development, Parafrase2 and SUIF, parallelizing compilers, QPT/EEI, an execution tracing and profiling tool, and Perfect benchmark programs. We measured memeory reference characteristics of some benchmark programs. The effect of loop transformation on the performance of memory system has also been experimented. Program transformation aiming at data spatial locality has been particularly effective. It is expected that evaluation of various program optimization techniques and their effects on memory system can also be analysed in our environment. The results would be used for design of memory system and development of compile time optimization techniques.

[열린논단]프로그래밍 언어 교육 현황 및 개선 방향

표창우 한국정보과학회 1998 정보과학회지 Vol.16 No.9