• Journal of Information Processing Systems
• /
• 제17권3호
• /
• pp.615-629
• /
• 2021

With the development of mobile edge computing, how to utilize the computing power of edge computing to effectively and efficiently offload data and to compute offloading is of great research value. This paper studies the computation offloading problem of multi-user and multi-server in mobile edge computing. Firstly, in order to minimize system energy consumption, the problem is modeled by considering the joint optimization of the offloading strategy and the wireless and computing resource allocation in a multi-user and multi-server scenario. Additionally, this paper explores the computation offloading scheme to optimize the overall cost. As the centralized optimization method is an NP problem, the game method is used to achieve effective computation offloading in a distributed manner. The decision problem of distributed computation offloading between the mobile equipment is modeled as a multi-user computation offloading game. There is a Nash equilibrium in this game, and it can be achieved by a limited number of iterations. Then, we propose a distributed computation offloading algorithm, which first calculates offloading weights, and then distributedly iterates by the time slot to update the computation offloading decision. Finally, the algorithm is verified by simulation experiments. Simulation results show that our proposed algorithm can achieve the balance by a limited number of iterations. At the same time, the algorithm outperforms several other advanced computation offloading algorithms in terms of the number of users and overall overheads for beneficial decision-making.

• 융합경영연구
• /
• 제5권2호
• /
• pp.40-42
• /
• 2017

The purpose of this study was to review and analyze JEMM(The Journal of Economics, Marketing, and Management) of ICMA(The International Convergence Management Association) and all of published articles of 2013 to 2016 and to revise and update the existing publication strategies in order to improve the internationalization and reputation of JEMM. JEMM of ICMA is a new academic journal of Korea Distribution Science Association(KODISA). It is still in its early stage as it is founded in 2013 as an academic journal to increase an recognition through KCI Candidate application under National Research Foundation of Korea(NRF). It endeavors its efforts to be recognized as a reputable international journal. This study was conducted to confirm the current status of JEMM in the current standards and to establish a strategic process to complement the deficiencies and achieve the goals. JEMM of ICMA has three distinguished features of online submission and review system, only English-based papering, reviewing by anonymous refrees. JEMM of ICMA continuously revised and updated its publication standards and practices and adopted technological support systems to enable its journals to remain independent and open access in order to ultimately become one of the most international journals.

• 한국데이타베이스학회:학술대회논문집
• /
• 한국데이타베이스학회 1994년도 DB산업기술 활성화를 위한 학술대회 및 기술 심포지움
• /
• pp.71-103
• /
• 1994

중복데이타 서버(replication server) 는 자주 사용되는 데이타의 부분 또는 전부를 뷰 형태로 여러 지역에 중복하여 저장함으로써 최종 사용자가 원하는 데이터에 빨리 접근할 수 있도록 해준다. 또한 기본 테이블의 변화된 내용을 주기적으로 뷰에 반영함으로써 데이타 동시성의 문제를 완화하며 통신량을 감소시킬 수 있다. 본 연구에서는 기본 테이블에 일어난 변화를 저장뷰(materialized view)에 반영시켜주기 위해 테이블 전체를 읽는 방식을 피하고 일정기간 동안 테이블에 일어난 변화가 기록된 로그(log)를 이용하는 디프런셜 갱신(differential update) 방법을 사용한다. 이 방법은 테이블의 잠금(locking) 을 피함으로 시스템의 성능을 향상시 킬 수 있다. 또한 갱신에 관련된 통신량을 최소화하기 위한 기법들을 제안한다. 위의 방법을 이용하여 분산 상황에서 조인 저장뷰(join materialized view)의 갱신을 효과적으로 지원해 주는 중복데이타 서버(replication server)의 구조에 관해 연구한다.

• 로봇학회논문지
• /
• 제8권4호
• /
• pp.256-265
• /
• 2013

A local map-based exploration algorithm for mobile robots is presented. Segmented frontiers and their relative transformations constitute a tree structure. By the proposed efficient frontier segmentation and a local map management method, a robot can reduce the unknown area and update the local grid map which is assigned to each frontier node. Although this local map-based exploration method uses only local maps and their adjacent node information, mapping completion and efficiency can be greatly improved by merging and updating the frontier nodes. Also, we suggest appropriate graph search exploration methods for corridor and hall environments. The simulation demonstrates that the entire environment can be represented by well-distributed frontier nodes.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2007년도 가을 학술발표논문집 Vol.34 No.2 (C)
• /
• pp.175-178
• /
• 2007

그리드 데이터베이스는 여러 사이트에 데이터베이스의 복사본을 두어 네트워크 전송 지연을 감소시킨다. 그러나 데이터베이스가 갱신될 때마다 모든 복사본들이 갱신되어야 하기 때문에 이로 인해 발생되는 네트워크 대역폭 소모와 시스템 부하 또한 무시할 수 없는 수준이다. 본 논문에서는 그리드에 사용되는 광대역 네트워크인 인터넷의 구조에 적합한 새로운 데이터베이스 갱신 정책을 제안한다. 본 정책은 인터넷의 구성요소인 AS(Autonomous System)와 ISP(Internet Service Provider)의 계층성과 네트워크의 속도 차를 고려하여 네트워크의 병목구간을 최대한 회피하고, 시스템 부하와 네트워크 부하의 균형을 조절함으로써 그리드 데이터베이스의 성능을 향상시킬 수 있다.

• Tuberculosis and Respiratory Diseases
• /
• 제78권3호
• /
• pp.156-160
• /
• 2015

Severe sepsis and septic shock is a life-threatening disease. It is combined with multi-organ failure. In the past decade, early goal directed therapy has been proposed as an effective treatment strategy for better outcome. Recent epidemiologic studies showed that the outcome of sepsis has been improved with the introduction of early goal directed therapy. However, it is unclear which elements of early goal directed therapy contributed to the better outcome. Recent prospective and randomized trials suggested that some elements of early goal directed therapy did not have any effect on the outcome benefit. In this paper, recent articles about early goal directed therapy will be reviewed and the effectiveness of individual elements of early goal directed therapy will be discussed.

• Tuberculosis and Respiratory Diseases
• /
• 제78권3호
• /
• pp.149-155
• /
• 2015

Extracorporeal life support (ECLS) is a type of cardiopulmonary bypass. It is an artificial means of supplying oxygen and removing $CO_2$ on behalf of damaged lungs while patients are recovering from underlying diseases. Recently, the use of ECLS is rapidly increasing as this machine becomes smaller, less invasive and easier to use. In addition, the improvement of clinicians' technique and outcome is increasing their application to patients with acute respiratory distress. In this regard, the purpose of this review is to introduce the physiological principles, risk factors, and advantages of ECLS, clinical rationale for using ECLS, ventilatory strategy during ECLS, which are still causing different opinions, the weaning from ECLS, and the use of anticoagulant.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 C
• /
• pp.1279-1281
• /
• 1999

The learning automaton is an automaton to update systematically the strategy for enhancing the performance in response to the output results, and several schemes of learning automata have been presented. In this paper, S-model learning automata are applied to achieving a best compromise solution between an optimal solution for economic operation and an optimal solution for stable operation of the power system under the circumstance that the loads vary randomly. It is shown that learning automata are applied satisfactorily to the multiobjective optimization problem for obtaining the best tradeoff among the conflicting economy and stability objectives of power systems.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2002년도 ICCAS
• /
• pp.63.5-63
• /
• 2002

In this paper, we are concerned with a maneuver detection algorithm which uses the 'lost' measurements down-sampled for computation load saving when a target is in quiescent motion. In general applications of estimation, measurements are available at a relatively high rate, while the estimation processing equipment can only operate at a lower sampling rate. Furthermore, when a target is in nearly quiescent motion, the update of the tracking filter need not to be implemented with maxim urn process power of the filter since the states of the target vary relatively slowly. This does not give serious degradation on the estimation performance. We consider the maneuver detection problem at the case...

• Clinical and Experimental Pediatrics
• /
• 제49권3호
• /
• pp.229-234
• /
• 2006

Varicella, which is mostly a benign disease, but also can cause considerable health burden in the community, can be prevented by immunization with live attenuated varicella vaccine. Higher uptake of varicella vaccine by universal immunization in North America has apparently been associated with decline in the number of reported cases of varicella, varicella-related hospitalizations, and the number of deaths caused by complications of varicella. On the contrary, there has been some reluctance in endorsing varicella vaccine for universal immunization in most of European countries. Concerns include unanticipated outbreaks of varicella among vaccine recipients, risk of varicella among unvaccinated adults, risk of herpes zoster among vaccinees as well as unvaccinees. Recently developed measles, mumps, rubella, and varicella combination vaccine and herpes zoster vaccine that may be licensed in the upcoming years may be the solution for varicella vaccine to be utilized in a greater scale. In Korea several varicella vaccine products have been utilized since late 1980. The adoption of varicella vaccine for universal immunization since 2005 along with the changing view in varicella prevention strategy mandates more studies for immunogenecity and efficacy of varicella vaccines as well as more surveillance to delineate the changes in epidemiology of varicella in Korea.