• Journal of The Korean Association of Information Education
• /
• v.14 no.1
• /
• pp.123-130
• /
• 2010

In this paper, we introduce a new programming learning system for young students. The programming learning system consists of a LED display kit and a web-based flowchart system. The LED display kit acts as an output device by way of displaying lights while following a set of instructions given through a flowchart programming. In the flowchart system, the students use symbolic variables for the calculation and can get various displays or animations after creating a flowchart by drag-and-drop. Then we describe the survey results of various programming classes using our system between fall 2005 and spring 2009. The programming teaching was conducted with diverse groups such as elementary school students, gifted students, college students, and teachers etc. The responses from our in class surveys were generally positive.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2017.11a
• /
• pp.582-585
• /
• 2017

본 논문에서는 구글 드라이브, 드롭박스 등 여러 회사에서 제공하고 있는 클라우드들을 하나의 플랫폼으로 통합하여 체계적이고 효율적으로 관리할 수 있는 시스템을 제안한다. 또한 해당 시스템을 통한 파일 업로드 및 다운로드를 진행할 경우, 파일을 여러 개의 패킷으로 분할하여 등록 된 클라우드에 각각 저장함으로써, 사용자의 데이터를 안전하게 보호할 수 있는 환경을 구축하고자 한다. 이를 위해 활용된 오픈 API와 독자적으로 구축한 파일 시스템에 대해 설명하고, 실제 구현한 소프트웨어가 정상적으로 작동하는지 실험을 통해 검증하고자 한다. 최근 클라우드 보안 문제가 대두되는 시점에서 제안한 시스템이 향후 데이터를 보호하기 위한 기술로 활용될 수 있기를 기대한다.

• Journal of KIISE:Computer Systems and Theory
• /
• v.26 no.5
• /
• pp.584-594
• /
• 1999

이 논문에서는 CDMA(Code Division Multiple Access)셀룰러 시스템에서 우선순위 큐(Queue)에 기반을 둔 핸드오프채널할당기법의 모델을 제안하였다. 또한 제안한 모델의 성능을 컴퓨터 시뮬레이션을 통해 비우선순위기법 및 FIFO(First In First Out)큐기법과 비교하였다. 제안하는 모델의 핸드오프 채널할당 기법에서는 이동국의 진행방향에 있는 인접 셀(Neighbor Cell)의 파일롯 중에서 임계치가 T-ADD 이상인 파일롯이 있을 경우 기지국이 이 파일롯(Pilot)에 대한 파일롯 세기 측정메시지를 이동국으로부터 수신 한 지점에서 드롭타이머가 종료된후 현재의 셀에서 사용중인 파일롯에 대한 파일롯 세기 측정 메시지를 이동국으로부터 수신한 시점까지 핸드오프 처리가능 영역으로 정의하고 이를 우선순위 큐의 최대큐 대기시간으로 사용하였다. 제안된 기법의 성능을 분석하기 위한 성능평가 척도는 강조종료확률, 호 블록킹 확률, 전체 제공 트래픽에 대한 수행 트래픽 비율, 평균 규크기미치 핸드오프 시 평균 지연시간이다. 성능시뮬레이션결과, 제안된 기법이 전체 시스템 호처리 용량면에서 약간의 단점은 발생하지만 핸드오프 처리에 있어서 높은 성능을 유지함을 알수 있었다.

• Journal of Korea Multimedia Society
• /
• v.9 no.8
• /
• pp.1037-1044
• /
• 2006

It's difficult to check cyber attacks and the performance of a security system in a real large-scale network. Generally, a new security system or the effect of a new security attack are checked by simulation. We use SSFNet to simulate our security system and cyber attack. SSFNet is an event-driven simulation tools based on process, which has a strength to be capable of expressing a large-scale network. But it doesn't offer any API's which can manipulate not only the related function of security but also the packet. In this paper, we developed a firewall and IPS class, used for a security system, and added to them components of SSFNet. The firewall is modelled a security system based on packet filtering. We checked the function of the firewall and the IPS with network modelled as using our SSFNet. The firewall blocks packets through rules of an address and port of packets. The result of this simulation shows that we can check a status of packets through a log screen of IPS installed in a router and confirm abnormal packet to be dropped.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.37 no.1
• /
• pp.19-28
• /
• 2000

The parallel inverter is widely utilized because of its fault-tolerance capability, high-current output at constant voltages and system modularity. The conventional paralled inverter usually employes an active and reactive power control or a frequency and voltage droop control. However, these approaches have the disadvantages that the response time of parallel inverter control is slow against load and system parameter variation to calculate active, reactive power, frequency and voltage. This paper describes novel control scheme for equalization of output power between the parallel connected inverters. The proposed scheme has a fast power balance control response, a simplicity of implementation, and inherent peak current limiting capability since it employes a instantaneous current/voltage control with output voltage and current balance and output voltage regulation. A design procedure for the proposed parallel inverter controller is presented. Futhermore, the proposed constrol scheme is verified through the simulation in various cases such as the system parameter variation, the control parameter variation and the nonlinear load condition.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2021.10a
• /
• pp.147-149
• /
• 2021

The trend of increasing traffic problems due to the explosion in traffic volume in Sejong City has reached a level that cannot be solved by investment in facility infrastructure, so it is essential to establish an intelligent traffic environment based on data. By benchmarking similar cases in the domestic and overseas, and analyzing the traffic information of Sejong City, we propose a plan to provide parking information using Intelligent CCTV, a smart traffic signal control system, and a safe drop zone. It is expected that this study will a basis for establishing policies of the Sejong City traffic safety strategy in the future.

• Journal of Digital Convergence
• /
• v.19 no.11
• /
• pp.17-22
• /
• 2021

In this paper, a machine learning-based automatic infographic recommendation system is proposed to improve the existing infographic production method. This system consists of a part that machine learning multiple infographic images and a part that automatically recommends infographics with artificial intelligence only by inputting basic data from the user. The recommended infographics are provided in the form of a library, and additional data can be input by drag & drop method. In addition, the infographic image is designed to be dynamically adjusted according to the size of the input data. As a result of analyzing the machine learning-based automatic infographic recommendation process, the matching success rate for layout and keyword was very high, and the matching success rate for type was rather low. In the future, a study to improve the matching success rate for the image type for each part of the infographic will be needed.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.7
• /
• pp.143-150
• /
• 2020

Recently, many companies are interested in smart factory services. Because various smart factory services are provided by the combination of mobile devices, cloud computing, and IoT services. However, many workers turn away from these systems because most of them are not implemented from the worker's point of view. To solve this, we implemented a development tool that allows field workers to produce their own services so that workers can easily create smart factory services. Manufacturing data is collected in real time from sensors which are connected to manufacturing facilities and stored within smart factory platforms. Implemented development tools can produce services such as monitoring, processing, analysis, and control of manufacturing data in drag-and-drop. The implemented system is effective for small manufacturing companies because of their environment: making various services quickly according to the company's purpose. In addition, it is assumed that this also will help workers' improve operation skills on running smart factories and fostering smart factory capable personnel.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.24 no.5
• /
• pp.512-517
• /
• 2014

This paper describes the development of new sweeping machine based on Cyclone Technology, which maintains constant suction power and uses it in a industrial applications as a method for dust removed from grinding work. The performance of a cyclone separator is determined by the turbulence characteristics and particle-particle interaction. To achieve this goal, we design cyclone technology based dust separator for sweeping machine has been proposed as a system which is suitable to work utilizing dust suction alternative to conventional manual system. and Numerical analysis with computational fluid dynamics(CFD) was carried out to investigate the working fluid that flow into cyclone dust separator in order to design optimal structure of the sweeping machine. The validation of cyclone model with CFD is carried out by comparing with experimental results.

• Fashion & Textile Research Journal
• /
• v.14 no.5
• /
• pp.853-865
• /
• 2012

This study has analyzed body size of adult women between 20~59 years old in 2010 conducted by Size Korea and the study method is as follow. (1) Distribution ratio of bust circumference per age and distribution ratio of differences of bust drops were analyzed. (2) Analysis of one-way design of experiment was carried out for 20 items of body sizes according to differences of bust drops with regard to age groups of 20 and 40 years old in consideration of tourists who are unspecified target and for the whole ages groups. (3) Comparison analysis of 20 items of body sizes per bust circumference and according to level of differences of bust drops was carried out and (4) t-test of the two groups based on the standard of 12.5 cm of the differences of bust drops was conducted and was analyzed. Tthe differences of bust drops below 10 cm were reduced according to ages. 12.5 cm was the most in the group of ages of 20s and under 7.5 cm was reduced as ages were higher. Body items according to the differences of bust drops per ages had meaningful differences between groups except (acromion height-axilla height), height and shoulder length for the group of ages of 20s and in the whole ages groups, there was meaningful difference between groups in all items except height and shoulder length. Comparisons according to the differences of bust drops per section of 5 cm of bust circumference showed meaningful differences between groups in general in items of BMI, bust point-bust point, neck circumference, bust circumference, underbust circumference, neck point to bust point and weight. As the result of comparing the two groups of the differences of bust drops based on the standard of 12.5 cm, all had meaningful differences except stature and shoulder length.