• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.21 no.5
• /
• pp.127-134
• /
• 2021

Recently, acquisition of high quality data has become an important issue as the expansion of the big data industry. In order to acquiring high quality data, accurate evaluation of data quality should be preceded first. The quality of data can be evaluated through meta-information such as statistics on data, and the task to extract such meta-information is called data profiling. Until now, data profiling software has typically been provided as a component or an additional service of traditional data quality or visualization tools. Hence, it was not suitable for utilizing directly in various environments. To address this problem, this paper presents the development result of data profiling software based on a microservice architecture that can be serviced in various environments. The presented data profiler provides an easy-to-use interface that requests of meta-information can be serviced through the restful API. Also, a proposed data profiler is independent of a specific environment, thus can be integrated efficiently with the various big data platforms or data analysis tools.

• Aerospace Engineering and Technology
• /
• v.4 no.2
• /
• pp.60-64
• /
• 2005

STSAT-2 will demonstrate the scientific mission(acquisition of brightness temperature of the earth at 23.8 GHz and 37 GHz) and spacecraft technologies(laser ranging, frame-type satellite structure, Dual-head star tracker, CCD sun sensor, pulsed plasma thruster, etc.). In this paper STSAT-2 satellite system is described. It includes the definition of the system and the overview of payloads and BUS.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.4B
• /
• pp.783-787
• /
• 2000

A microprocessor, which is used as a CPU for state-of-the-art personal computers, adopts 256KB or 512KB L2(Level 2) cache memory. This cache hires Direct Mapping Procedure, 32B Line Size, and no Write Allocation. In this cache architecture, we can expert about 2.5% hit ratio improvement by using 8-way Set Associative Mapping instead of Direct Mapping, 128B Line Size instead of 32B, and Write Allocation.

• The Mathematical Education
• /
• v.47 no.1
• /
• pp.49-59
• /
• 2008

In this paper, we discuss two representations of a curve. One is a static representation as set of points, the other is a dynamic representation using time parameter. And we suggest needs of designing a computer microword where we can represent a curve both statically and dynamically. We also emphasize the importance of translation activity from a static representation to a dynamic representation. For this purpose, we first consider constructionism and 'computers and mathematics education' as a theoretical backgrounds. We focus the curve of a parabola in this paper since this is common in mathematics curriculum and is related to realistic situation such as throwing ball. And we survey the mathematics curriculum about parabola representation. And we introduce JavaMAL microworld that is integrated microworld between LOGO and DGS. In this microworld, we represent a parabola using a dynamic action, and connect this dynamic parabola action to recursive patterns. Finally, we remake a parabola for a realistic situation using this dynamic representation. And we discuss the educational meaning of dynamic representation and its computer microworld.

• The Journal of Information Technology and Database
• /
• v.6 no.2
• /
• pp.1-18
• /
• 1999

The purpose of this study was to identify the effect of microcomputer networking on user perception of potential threats to security employing user attitudes as a moderating variable. A research model consisting of microcomputer networking as the independent variable, user perception of potential threats to security as the dependent variable, and user attitude toward security control as the moderating variable was developed through literature review. The results of this study provide an empirical evidence of the importance of environmental change(information systems networking) on user perception of potential threats to security. Further-more the result imply that in order to improve security performance through the reinforcement of user perception of threats to security in the organization, user attitudes should be made favorable.

• Journal of the Institute of Electronics Engineers of Korea TE
• /
• v.37 no.4
• /
• pp.27-34
• /
• 2000

A curriculum-building model is presented to achieve a work based curriculum development. It includes a job analysis method called DACUM(Developing A Curriculum) which is designed to accept various requirements of industrial fields fast and faithfully. The model is applied to design our curriculum. By analysis, it is shown that the new curriculum includes some new practical classes, and/or that new practical contents are included even in old classes.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.23 no.2
• /
• pp.66-71
• /
• 1987

Computer is the best versatile machine of the human creatures. Computers are not only applicated in mathematics but also in operation part of control mechanism and measuring system. Commercial computers have many sophisticated pheripherals, therefore they have many restrictions in practical applications such as control or measurement. The author designed a new simple computer that has essentially required component.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2017.04a
• /
• pp.690-693
• /
• 2017

본 연구는 다양한 운영체제와 플랫폼에서 스몰베이직 프로그래밍을 할 수 있는 환경을 제공하고, 라이브러리를 사용하고 확장하는 것을 목표로 진행 중인 연구 내용을 요약한다. 마이크로소프트 스몰베이직은 처음 컴퓨터 프로그래밍을 배우는 사람에게 쉽게 다가갈 수 있는 프로그래밍 언어이다. 단 14개의 키워드로 구성되어 있어 매우 간단하고 배우기 쉽다. 하지만 프로그래밍 환경을 윈도우즈 운영체제에서만 사용해야하는 단점이 있다. 소스 코드가 공개되어 있지 않아 새로운 요구사항을 맞추기도 어렵다. 이러한 문제점을 해결한 다양한 운영체제에서 사용이 가능하며 라이브러리 확장이 가능한 스몰베이직 환경을 설계하고 구현하고자 한다. 또한 마이크로소프트 스몰베이직의 동적 타이핑 구조에 대한 분석을 통해 명확한 규칙을 설명하고자 한다. 다양한 운영체제에서 스몰베이직 프로그램을 작성하고 PC 뿐만 아니라 안드로이드 기반 스마트폰에서 실행할 수 있다.

• Journal of Advanced Marine Engineering and Technology
• /
• v.15 no.2
• /
• pp.53-63
• /
• 1991

This study suggests a new type shaft generator driven by hydraulic power suitable for small size vessels. Since the shaft generator system is very easy to be affected by disturbances such as speed variation of main engine and load variation of the generator, a robust servo control must be implemented to obtain stable electric power with constant frequency. Thus, in this study two types of controller design method-the reference following optimal control method and robust servo control method-are adopted to the controller design. In the experiment, static and dynamic characteristics of the shaft generator system according to the variation of input frequency setting, the speed variation of the pump and the load variation of the generator are investigated. From the considerations on the computer simulation results and experimental results, it is ascertained that the shaft generator system proposed in this study has good control performances.

• Journal of Biosystems Engineering
• /
• v.17 no.3
• /
• pp.223-228
• /
• 1992

This study was conducted to develop an electro-hydraulic three-point hitch control system using an electro-hydraulic servo valve and microcomputer and to investigate the performance of the three-point hitch control system through indoor and field experiments. 1. The results from indoor experiments coincided with those from computer simulation reported in the previous paper. However, the draft control with the value 4 of Kd showed a slight sustained oscillation after it reached the draft set. 2. From the field experiments, it appeared that the RMS errors increased with the ground speed of tractor. In position control, the three-point hitch control system with electro-hydraulic servo valve showed better performance than that with on-off electro-magnetic valve in the ground speed less than 1.6 m/s. In draft control, however, there was no significant differece in performance between those two systems. 3. In depth control, the both types of electro-hydraulic three-point hitch control system showed better performance than the conventional mechanical-hydraulic three-point hitch control system.