흐름그래프로부터 DJ-그래프를 이용한 도미네이터 트리의 변환 알고리즘

沈孫權,安熙學 관동대학교 1999 關大論文集 Vol.27 No.2

We present a new algorithm for maintaining the Dominator Tree of an arbitrary flowgraphs. both reducible and irreducible using DJ graphs. The reducible flowgraph implements the Dominator Tree after the dominator calculation. The irreducible flowgraph implements the Join Dominator Graph using the Join Edge Information Table. We safely reduced to the dominator tree by the join edge eliminationalgorithm. We show that the reducible flowgraph the irreducible flowgraph as an example to prove the validity of the algorithm. Therefore. two flowgraphs are precisely reduced to the Dominator Tree.

Miranda 函數 言語의 設計에 관한 硏究

安熙學 관동대학교 1991 關大論文集 Vol.19 No.2

In late 1970s, several new programming paradigms: logical, parallel, and object-oriented programming, which are different from conventional programming languages such as Pascal and Ada, have been appeared to support those fast and parallel computers. In this paper, we study a functional language and concert with the design of the new programming languages based on functional languages such as FP, HOPE, ML, Miranda, Haskell. In order to design the functional languages, this paper considers underlying theories, characteristic, syntax, and semantics of the new programming language. In specialty, we present BNF of Miranda/ subset, and design Miranda/subset language.

正規表現에 의한 確定 有限 오토마타의 確率的 分析에 關한 硏究

安熙學 관농대학교 1986 關大論文集 Vol.14 No.2

Regular expressions define a class of languages which is central in formal language theory and automata theory. The class is known as the class of regular sets(regular languages). The flow-graph technique for transforming a deterministic finite automata into a regular expression was suggested first by Arden and discussed in detailed by Brzozowski and AcCluskey. Solving to equations of regular expressions by Arden`s rule, we find that they muts always describe the same sets. This paper presents a methods for calculating steady state probabilities from state diagram and transition matrix of given regular expressions E=I*ST*.

다중 SNS 채널 자동 스트리밍 서버의 RELAY 모듈 설계

안희학,이대식 (사)디지털산업정보학회 2017 디지털산업정보학회논문지 Vol.13 No.4

Streaming server is that an image produced in real time or a file form of image produced ahead consists of SNS service, and the relay module of streaming server includes output management module that set an output channel more than 2 and control transmission of video content. This thesis intends to suggest how to stream through plural output channel that contains output channel of external streaming server using relay module and do streaming provided to terminal receiving image, and streaming server, streaming system for this. Thus, by extending output channel sending out image to output channel of external streaming server, the scale of streaming server is not limited and the process allotting external streaming server into output channel sending the image becomes simple, so management of output channel becomes efficient even when sending several images.

세미오토마톤을 利用한 커버링 세미오토마톤의 構成에 關한 硏究

安熙學 관동대학교 1985 關大論文集 Vol.13 No.3

The basic properties of sequential machines are of fundamental importance in Semiauto-maton theory. The decomposition problem has many important theoretical as well as prac-tical applications to the problems of sequential machines. Two basic forms of decomposition are serial decomposition and parallel decomposition. The Covering Semiautomaton has been generalized above two forms of decomposition. The structure theory and the study of machine decomposition were originated by Hartm-anis in 1960, and further developed in a series of papers by Hartmanis and Stearns, Karp, Yoeli and Kohavi. Other constructions to the general machine theory include Krohn and Rhodes, Zeiger, and Gill. This paper presents the theory of Covering SEmiautomaton based on the basic theory of Semiautomaton and we make efficient algorithm of Covering Semiautomaton using SPARKS language.

경로 압축을 이용한 DJ 그래프의 지연 감축 알고리즘에 관한 연구

안희학 전자통신기술연구센터 2002 전자통신논문집 Vol.5 No.-

文脈自由文法의 推論 알고리즘 具現

安熙學 관동대학교 1988 關大論文集 Vol.16 No.2

The problem of the inference of context free grammars is studied from both an abstract and practical point of view. The theoretical aspects of grammatical inference are considered. The structural and statistical properties of context free grammars are analyzed. The statistical closeness of approximation of the sample set by the language of the inferred grammar is measured by a chi-square test. This paper presents the graph of word function found from a given sample set. The inference algorithm of context free grammars is implemented using PASCAL.

클라우드 기반 헬스케어 시스템의 보안 기법에 관한 연구

안희학,이병관,정은희 보안공학연구지원센터 2013 보안공학연구논문지 Vol.10 No.6

본 논문에서는 HA(Healthcare Authority), CS(Cloud Server), Users(Patient, Doctor, Hospital)로 구성된 클라우드 기반 헬스 케어 시스템의 보안 기법을 제안 한다. HA는 헬스 케어 시스템의 사용자들의 ID 생성 및 접근권한을 정의하고, CS는 암호화된 헬스 정보 및 메디컬 정보의 무결성을 검증하는 역할을 담당한다. 제안하는 보안 기법은 HA와 CS 사이에는 EC-DH 알고리즘으로 공유 비밀키를 생성하여 메시지 기밀성을 제공하고, CS와 사용자 사이에는 암호키와 AES알고리즘으로 메시지 기밀성을 제공하도록 설계하였다. 또한, 헬스 케어 시스템에서 전달되는 모든 정보에 대한 MAC을 생성하여 데이터 무결성을 제공하고, 이 MAC에 타임스탬프를 추가하여 메시지 재전송공격도 탐지할 수 있도록 설계하였다. 그 결과, 제안하는 보안 기법은 클라우드 기반 헬스 케어 시스템에서 환자의 개인정보에 대한 프라이버시 보호할 뿐만 아니라 메디컬 정보와 헬스 정보의 기밀성, 무결성, 안전성도 보장할 수 있다.

IoT 기반 라돈 측정 제어시스템 설계 및 구현

안희학,구자영,이상윤 (사)디지털산업정보학회 2020 디지털산업정보학회논문지 Vol.16 No.1

This paper is a IoT-based radon meter control system and a radon meter control method using it. The IoT-based radon meter control system is control system for controlling a radon meter by network-connecting radon meter and a user terminal. The radon measuring device may be provided with a radon sensor to measure a radon value of a preset management target area, it collect and store numerical data. The radon meter control system monitors the condition of the radon meter, it includes control center configured to deliver radon meter management information generated to a user terminal. Also radon measurements to determine the exact amount of radon gas. Therefore, the situation-specific actions based on radon numbers can be promptly implemented to ensure adequate protection for those who are vulnerable to radon and those who live in the area. Condition monitoring allows the radon meter to respond quickly to failure or failure of the radon meter. In addition, it is possible to secure a baseline of radon's influence and to obtain research data to cope with radon by establishing big data with radon measurements.

資料 흐름 分析을 위한 알고리즘의 性能 評價에 관한 硏究

安熙學 관동대학교 1990 關大論文集 Vol.18 No.1

A global data flow algorithm gathers information about the definition and use of data in a procedure or a set of programs. Data flow analysis algorithms gather this local information and infer global data flow from it. Data flow analysis information can be used as a debugging and documentation aid. There are two families of global data flow algorithms in use : the elimination methods and iterative methods. The elimination methods include an original algorithm, Allen-Cocke interval analysis, and Hecht-Ullman analysis. The original algorithm, Allen-Cocke interval analysis, establisher a natural partition of the variables and a variable order on each of a sequence of systems that, when used to order the equtions, results in a highly structured coefficient matrix fcilitating the equation-reduction process. The order algorithm, Hecht-Ullman analysis, avoid repeated calculations of common substitution sequences in the equations by delaying certain computtions. The two algorithms vary in their worst case complexity bounds for reducible flow graphs as shown : complexity Allen-Cocke algorithm is O(N) and complexity of Hecht-Ullman algorithm is O(n log n). This paper provides a study in algorithm design, as well as a new view of these algorithms and their interrelationships.