AutoCAD 도면용 원가 산출 시스템의 구현

엄윤섭 경성대학교 생산기술연구소 1995 생산기술연구지 Vol.2 No.-

A manufacturing cost evaluation system for AutoCAD drawing of machine design is implemented. The system consists of an interface manager, an output manager, and a data manager. Information for manufacturing cost evaluation is stored in the file of drawings. A standard database is provided, and used for storing information in to each drawing file. The standard database consists of three tables. They are a part list table, a material data table, and manufacturing data table. The output manager produces part lists, cost estimation sheets, and manufacturing lists. The system operates on serveral PC's connected via LAN, and can be accessed by multiple users simultaneously.

관계합성을 이용한 관계형 데이터베이스의 설계

엄윤섭 경성대학교 공학기술연구소 2002 공학기술연구지 Vol.9 No.-

The process in design of relational database design consists of requirement analysis, conceptual design using ER diagram, and logical design of the database. In logical database design, the conceptual schema is transformed to the logical schema, and logical schema is normalized. However, in this approach since the conceptual design is ambiguous, this method is hard to apply in actual database design process. This paper proposes a logical database design method by removing the conceptual design process. In new approach, we use the structured design methodology to analysis of the system requirement. We can get all attributes from data store of data flow diagram, which is constructed by the structured methodology. We can derive the relational database schema from attributes using relational systhesis method.

관계형 데이타베이스 시스템 GoldLotus의 설계와 구현

엄윤섭 慶星大學校 1995 論文集 Vol.16 No.2

A relational database system, called GoldLotus, was designed and implemented. The purpose of GoldLotus is to educate undergraduate students in the database course. GoldLotus consists of five modules. They are Scanner, Schema Manager, Parser, Storage Manager, and Query Executor. The database language of GoldLotus is a variant of SQL, which is modified in the way used in the object-oriented database systems. Schema Manager reads a specific database schema from the keyboard, and stores in a schema file. When the schema file. Parser parsing mechanism. Query Executor interpretes a parse tree using syntax-directed translation mechanism. Storage Manager manages data files. A data file consists of a file header and a number of fixed-length records.

네트워크 상에서의 기계설계도면의 관리시스템 개발

엄윤섭 경성대학교 생산기술연구소 1997 생산기술연구지 Vol.4 No.-

A mechanical drawings management system for multiple users on network is developed. The system consists of a file server, resource manager, and draft interface manager. The file server has a database containing the information related to drawings. The database is shared over network. The database containing tables for users, user groups, drawings index, etc. The resource manager is installed on a designated computer, and used by a database administrator. The resource manager sets up the system environment. Through the resource manager, the DBA manages users, designs a database schema, and approves the completion or modification of drawings. The draft interface manager is installed on each client computer. This offer the user the interface to get support from file server for draftings.

객체 지향 데이타베이스의 이론적 정립 및 데이타 언어의 설계

엄윤섭 慶星大學校 1995 論文集 Vol.16 No.3

A number of object-oriented database systems are currently under development, but with little mathematical formalizm. Algebraic Data Model (ADM) is an attempt to formalize the object- oriented data model. ADM uses functions as a modeling tool. An algebra is used as a formal theory. An algebra consists of a family of sets and functions on the sets, where the family of sets represents a collection of data, and the functions represent relations between data. This research formalizes the object-orinted data model by the construction of a data algebra and structured data algebra. A data algebra is a formalization of a database system, and provides a high level abstraction of information with pre-defined sets and functions. A structured algebra realizes a notion of generalization by imposing a partial ordering on a family of sets. The design of the database language is based on the formal data model. The syntax and semantics of language is provided by the signature and algebra of an algebraic structure, respectively.

초등학생의 스마트폰 중독이 행복감에 미치는 영향에서 학교적응의 매개효과와 자기통제력의 조절된 매개효과 검증

엄윤섭,최은실 사단법인 인문사회과학기술융합학회 2018 예술인문사회융합멀티미디어논문지 Vol.8 No.2

This study aims to verify a series of negative effects of elementary school students’ smartphone addiction on school adaptation and happiness, and moderating effect on this mediating process. For the purpose of the study, a total of 1,074 students from fourth to sixth grade in elementary schools located in Seoul and 5 Metropolitan Cities completed a questionnaire including measures of smarthphone addiction, school adaptation, happiness, self control. Data analysis was conducted using multiple statistical packages SPSS 21.0, SPSS PROCESS Macro(v. 2.16), Mplus 7. Intercorrelation matrix showed that smartphone addiction showed negative correlations with school adaptation, happiness, self control, which are positively correlated with each other. Mediation effect of school adaptation between smartphone addiction and happiness, moderation effect of self control between smartphone addiction and school adaptation, and moderated mediation effect of self control on the relatonship smartphone addiction-school adaptation-happiness are all significant. Problems and the implications for future research were discussed. 본 연구는 초등학생의 스마트폰 중독이 학교적응과 행복감에 미치는 일련의 부정적인 효과와 이러한 매개과정에 대한 자기통제력의 조절효과를 검증하고자 하였다. 이를 위해서 서울 및 5대 광역시 소재 초등학교 4, 5, 6학년 학생 1,074명을 대상으로 자기보고식 설문지 방법을 통해서 자료를 수집하였다. 자료의 분석은 SPSS 21.0, SPSS PROCESS Macro(v. 2.16), Mplus 7을 혼용하여 사용하였다. 상관분석 결과, 스마트폰 중독은 학교적응, 행복감, 자기통제력과 모두 부적인 상관을 보였으며, 자기통제력, 학교적응, 행복감은 서로 정적인 상관을 보였다. 학교적응은 스마트폰 중독과 행복감 간의 관계에 대해서 부분적인 매개효과를 보이는 것으로 나타났다. 그리고 자기통제력은 스마트폰 중독과 학교적응 간의 관계에 대해서 조절효과를 보였으며, 스마트폰 중독-학교적응-행복감의 매개과정에 대해서도 조절된 매개효과를 보이는 것으로 나타났다. 조절효과의 분석결과를 상세하게 보면, 자기통제력의 수준이 높은 경우 스마트폰 중독의 높고 낮음에 관계없이 자기통제력의 수준이 낮은 경우보다 학교적응의 점수가 더 높은 것으로 나타났다. 연구의 문제점 및 의미는 결론 및 논의 부분에서 기술되었다.

프로펠라 팬과 앞판과의 간격이 팬 성능에 미치는 영향에 관한 연구

엄윤섭,부정숙,윤인철 한국마린엔지니어링학회 2000 한국마린엔지니어링학회지 Vol.24 No.4

A study on performance of a propeller fan according to the distance between the front plate and the fan was conducted experimentally. Different characteristics of performance were found on the performance curve. Flow measurements using the three dimensional LDV system show that the zone of recirculation exists around the fan. The differences of performance in changes of the distance occurs because the zone of recirculation is much wider at the distance of 24mm than at that of 30mm.

냉장고의 냉동실내 냉기 덕트 내부의 유동해석

엄윤섭,부정숙 한국마린엔지니어링학회 2000 한국마린엔지니어링학회지 Vol.24 No.4

A numerical study has been performed to design duct parameters in the freezer of a domestic refrigerator. The visualization results of FDM analysis using the standard k-$\varepsilon$ model with inlet boundary conditions modelled in this paper show good agreements with the experimental ones in prediction overall flow characteristics. Dominant vortex flows are found in the left upper and right lower corners, while there exists large turbulent kinetic energy around the fan and right upper side of the fan. It, in turn, has effects on the performance and noise. It is recommended to locate the outlet far away from the fan in order to reduce the noise level.

단일 사용자를 위한 객체지향 DBMS의 구현

엄윤섭 慶星大學校 1998 論文集 Vol.19 No.1

A prototype of an object-oriented database management system, called Algebraec Data Model(ADM), is developed on the personal computer for a single user. ADM is extended from the functional data model, originated from DAPLEX. ADM is a formally designed object-oriented data model based on an algebra. The basic unit of database language of ADM is an algebraic expression. ADM adopts the object, classification, aggregation, generalization, and association as data modeling primitives. ADM provides a lattice type system which can are Schma Manager, Praser, Storage System, and Query Executor. Parser checks the grammar of a given tree, and generates a parse tree. Query Executor interpretes the parse tree by syntax-directed translation. Storage Manager uses the technique used in Exodus to store multimedia data. This paper describes the data modeling, database language, and implementation of ADM.

개념적 설계를 배제한 관계형 데이터베이스 스키마의 설계

엄윤섭,Um Yoon-Sup 한국정보통신학회 2005 한국정보통신학회논문지 Vol.9 No.2

관계형 데이터베이스의 설계 과정은 요구사항 분석, ER 모델을 이용한 개념적 설계, 논리적 설계, 그리고 물리적 설계 과정으로 구성된다. 논리적 설계과정은 ER 다이어그램으로 구성된 개념적 스키마를 관계형 스키마로 전환하여 정규화시키는 과정으로 이루어진다. 이런 기존의 설계 과정에서 요구사항의 분석 후 개념적 스키마를 도출하는 개념적 설계 과정이 명확치 않음으로 인해서, 실제 데이터베이스 설계현장에서 적용하기 어려운 점이 있다. 본 논문에서는 작업과정이 모호한 개념적 설계를 제거함으로 보다 체계적으로 데이터베이스 스키마를 설계할 수 있는 방법을 제안한다. 구조적 설계 방법을 이용하여 자료 흐름도를 작성하고, 자료흐름도의 자료저장소에 파악된 애트리뷰트를 이용하여 관계합성으로 관계형 스키마를 도출한다. 관계형 스키마를 정규화하고, 정규화된 테이블로부터 데이터의 의미를 파악하여 테이블 관계도를 작성함으로써 최종 논리적 스키마를 결정한다. The design process of a relational database system consists of requirement analysis, conceptual design using ER diagram, logical design, and physical design. In logical design process, the conceptual schema is transformed to relational schema, and relational schema is normalized. This traditional design process is hard to applied in real database design process, since there is an ambiguity in conceptual design process. In this paper, we suggest a new design process, which provides more structural design steps by removing the conceptual design process. In new approach, we produce the data flow diagram by the structural methodology. From the attributes in the data store of data flow diagram, we construct relational table schema, and we normalize relational schema. Finally we produced table relationship diagram in order to figure out relationships between tables.