• East Asian mathematical journal
• /
• 제40권1호
• /
• pp.119-125
• /
• 2024

Predicting the number of ICU patients holds significant importance, serving as a critical aspect in efficiently allocating resources, ensuring high-quality care for critically ill individuals, and implementing effective public health strategies to mitigate the impact of diseases. This research focuses on estimating ICU patient numbers through the development of a simple mathematical model. Utilizing data on confirmed COVID-19 cases and deaths, this model becomes a valuable tool for predicting and managing ICU resource requirements during the ongoing pandemic. By incorporating historical data on infected individuals and fatalities from previous weeks, we establish a straightforward equation. We found the substantial impact of the delay in infected individuals, particularly those occurring more than five weeks earlier, on the accuracy of ICU predictions. Proactively preparing for potential surges in severe cases becomes feasible by forecasting the demand for intensive care beds, ultimately improving patient outcomes and preventing excessive strain on medical facilities.

• 소성∙가공
• /
• 제8권1호
• /
• pp.65-77
• /
• 1999

In recent years, the quality requirements from the customers of hot rolled steel strip have been steadily increasing in diversity and strictness. To meet these quality requirements as well as to improve productivity, steel mills have been doing their efforts for developing high performance Automatic Gauge Control (AGC) system. However, it is very time consuming and also needs a lot of money to develop the new technologies of AGC in actual mill. So, there has been a demand for developing the Dynamic Hot Rolling Simulator since late 80's. It is a kind of software packages and can analyze the dynamic behaviors of hot finishing rolling process without laborious experiments in actual mill. It can also be used as a designing tool of Automatic Gauge Controller. In this work, the Dynamic Hot Rolling Simulator which is applicable to 6 sands hot strip mill rolling was developed. The MATLAB with SIMLINK was used as a software developer for making the main part of simulator because it is very powerful tool for modeling, integrating, controller design, and simulation. In this paper, the structures and the mathematical models of the simulator were briefly described and the results of simulation on the transient phenomena of hot rolling process with actual mill data were also presented.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2006년도 춘계학술발표대회
• /
• pp.1329-1332
• /
• 2006

온디맨드 소프트웨어 스트리밍(On-Demand Software Streaming)이란 서버가 제공하는 소프트웨어를 클라이언트에 설치하지 않고 실행하는 기술로, 서버로부터 필요한 부분만 스트리밍으로 전송 받아 실행하는 기술을 말한다. 이 기술을 이용하면 소프트웨어 제공자는 소프트웨어 관리를 용이하게 할 수 있고, 소프트웨어 사용자는 적은 저장 공간으로 많은 소프트웨어를 사용할 수 있다는 이점을 얻게 된다. 하지만 모바일 환경에서 이를 이용하는 경우에는, 느린 무선 네트워크를 통해 소프트웨어 이미지를 전송해야 하기 때문에 소프트웨어 실행 속도가 매우 느리다는 문제가 생긴다. 이를 해결하기 위해서 본 논문에서는 온디맨드 소프트웨어 스트리밍을 사용하는 시스템의 성능 향상을 위해 효율적인 선인출 기법을 설계하고 실제로 구현하였다. 실험 결과, 애플리케이션이 데이터를 읽을 때 걸리는 시간이 무선랜 환경에서는 평균 50%, CDMA 환경에서는 평균 20% 정도 감소했으며, 특히 네트워크 지연시간이 증가할수록 더 많이 감소하였다.

• 한국멀티미디어학회논문지
• /
• 제8권6호
• /
• pp.807-813
• /
• 2005

The production and authoring of digital multimedia contents are most important fields in multimedia technology. Nowadays web-based technology and related multimedia software technology are growing in the IT industry and these technologies are evolving most rapidly in our life. The technology of digital audio and video processing is utilizing rapidly to improve quality of our life, Also we are more interested in high sense and artistic feeling in the music and entertainment areas by use of three dimensional (3D) digital sound technology continuously as well as 3D digital video technology. The service field of digital audio contents is increasing rapidly through the Internet. And the society of Internet users wants the audio contents service with better quality. Recently Internet users are not satisfying the sound quality with 2 channels stereo but seeking the high quality of sound with 5,] channels such as 3D audio of the movie films. But it might be needed proper hardware equipments for the service of 3D sound to satisfy this demand. In this paper, we expand the simple 3D audio generator developed and propose a web-based music bank by the software development of 3D audio generation player in 3D sound environment with two speakers minimizing hardware equipments, Also we believe that this study would contribute greatly to digital 3D sound service of high quality for music and entertainment mania.

• Journal of Communications and Networks
• /
• 제16권6호
• /
• pp.656-666
• /
• 2014

In delay tolerant networks (DTNs), delay is inevitable; thus, making better use of buffer space to maximize the packet delivery rate is more important than delay reduction. In DTNs, epidemic routing is a well-known routing protocol. However, epidemic routing is very sensitive to buffer size. Once the buffer size in nodes is insufficient, the performance of epidemic routing will be drastically reduced. In this paper, we propose a buffer scheme to optimize the performance of epidemic routing on the basis of the Lagrangian and dual problem models. By using the proposed optimal buffer scheme, the packet delivery rate in epidemic routing is considerably improved. Our simulation results show that epidemic routing with the proposed optimal buffer scheme outperforms the original epidemic routing in terms of packet delivery rate and average end-to-end delay. It is worth noting that the improved epidemic routing needs much less buffer size compared to that of the original epidemic routing for ensuring the same packet delivery rate. In particular, even though the buffer size is very small (e.g., 50), the packet delivery rate in epidemic routing with the proposed optimal buffer scheme is still 95.8%, which can satisfy general communication demand.

• Journal of Information Processing Systems
• /
• 제14권1호
• /
• pp.228-238
• /
• 2018

With the rapid advancement of Internet services, there has been a dramatic increase in services that dynamically provide Internet resources on demand, such as cloud computing. In a cloud computing service, because the number of users in the cloud is changing dynamically, it is more efficient to utilize a flexible network technology such as software-defined networking (SDN). However, to efficiently support the SDN-based cloud computing service with limited resources, it is important to effectively manage the flow table at the SDN switch. Therefore, in this paper, a new flow management scheme is proposed that is able to, through efficient management, speed up the flow-entry search speed and simultaneously maximize the number of flow entries. The proposed scheme maximizes the capacity of the flow table by efficiently storing flow entry information while quickly executing the operation of flow-entry search by employing a hash index. In this paper, the proposed scheme is implemented by modifying the actual software SDN switch and then, its performance is analyzed. The results of the analysis show that the proposed scheme, by managing the flow tables efficiently, can support more flow entries.

• 디지털융복합연구
• /
• 제6권2호
• /
• pp.65-76
• /
• 2008

Recently, software distribution method, along with advent of era of Web 2.0, is rapidly evolving from ASP(Application Service Provider) method into SaaS(Soft as a Service) method due to development in concepts and technologies including SOA(Service Oriented Architecture) Web Service, On Demand and Component. Determining factor in market competitiveness of newly emerging SaaS business model will be analyzed by focusing on Group-Wares, POS(Point of Sale) System, CRM(Customer Relationship Management) and ERP(Enterprise Resource Planning), which are the most representative SaaS business models in Korea. It is anticipated that the outcome of analysis of determining factors for market competitiveness for each of the main SaaS Business Models acquired through questionnaire survey can be utilized as important benchmarking material in setting the direction of cultivating SaaS market by the government as well as new entries into SaaS market.

• 정보기술과데이타베이스저널
• /
• 제8권1호
• /
• pp.67-80
• /
• 2001

Information Systems (IS) auditing has been know to be helpful in developing optimal IS and managing information resources successfully. The public sector of Korea has witnessed the rapidly growing demand for IS auditing. However, there is a dearth of research that evaluate the effects of IS auditing. This study assesses the impacts of IS auditing based on a process perspective. In order to evaluate the effects objectively and properly, the current study collected empirical data from 58 firms. This stuuy confirmed that IS auditing was a very effective tool for successful IS implementation. The results show that IS auditing improves “project management”, “support”, and “engineering” practices while it does not make any impact on “contract” practice. In general, IS auditing has a tremendous impact on facilitating organization’quality improvement efforts.

• 한국IT서비스학회:학술대회논문집
• /
• 한국IT서비스학회 2006년도 춘계학술대회
• /
• pp.393-400
• /
• 2006

An autonomic system management technology is being developed for self-managing during deployment and on an on-going basis for a production environment so that the system may be deployed and managed in production with minimal human intervention. As networks and distributed systems grow and change, system deployment failures, hardware and software issues, and human error can increasingly hamper the performance and capacity of the components in an IT system, driving up overall costs-even as technology component costs continue to decline. Known as the only solution for an on demand IT environment, the architecture of the autonomic system management will be shown and also the corresponding standards on the way will be introduced in this paper.

• 한국인터넷방송통신학회논문지
• /
• 제17권2호
• /
• pp.51-56
• /
• 2017

최근 이동 단말의 급격한 증가와 함께 통신망 구축의 용이성, 단말의 자유로운 이동성 및 세션의 연속성, 유선에 비견되는 데이터 전송 대역폭 등을 제공하는 무선통신 기술에 대한 수요가 급증하고 있다. 그러나 이러한 무선 통신은 신호전달 특성상 도청이나 DOS 공격, 세션 하이재킹, 재밍 등과 같은 악의적 무선 사이버 공격에 취약하다는 단점을 갖는다. 이와 같은 무선 사이버 공격을 막는 다양한 방법 중 최근 많은 연구가 이루어지고 있는 MTD(Moving Target Defense) 기술은 시스템이 공격 받을 수 있는 요소들을 지속적으로 변경시킴으로써 방어 시스템의 보안 능력을 향상시키는 기법이다. 본 논문에서는 자가 방어 및 복원력이 있는 무선 통신 시스템 구축을 위해 변복조 방법, 동작 주파수, 전송 패킷 길이 등을 동적으로 변화시키는 MTD 기법이 적용된 SDR(Software Defined Radio) 무선통신 테스트베드를 개발하고, 악의적 사용자의 공격 성공률에 대한 성능분석 수식을 제안하고, 시뮬레이션을 통해 성능분석 결과의 타당성을 검증하였다.