• The Journal of Korean Institute of Communications and Information Sciences
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• v.5 no.1
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• pp.54-59
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• 1980

Adaptive version of the delta modulator that is akin to wyllabic companding for telephony is described. A digital technique is used to sense the slope of the input signal and to control the amplitude of the pulses supplied to the RC network in the feed back loop. Thus the development was stimulated by the suitability of delta modulator for low-cost integrated circuits. Analysis are made of the optimum overload characteristics, stability, SNR for improving the frequency range and these results have been esperimentally verfied.

• Annual Conference of KIPS
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• 2002.11a
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• pp.485-488
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• 2002

QoS를 보장하기 위해서는 웹 서버의 용량을 충분히 확보하는 것이 중요하다. 하지만 웹 서버의 용량을 충분히 확보한다고 하더라도 웹 트래픽의 돌발적인 속성으로 인해 서버 과부하는 거의 필연적으로 발생한다. 본 논문에서는 수락 제어 기법과 트래픽 셰이핑 기법을 하이브리드하여 웹 서버의 과부하를 방지하는 커널 레벨 메카니즘을 제안한다. 수락 제어에 의해 웹 서버로 유입되는 트래픽을 제한하고, 지속 연결이 서버 과부하에 미치는 영향에 대해서는 트래픽 셰이핑을 통해 제한하여 웹 서버가 최적의 상태에서 서비스를 계속할 수 있도록 한다.

• Annual Conference of KIPS
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• 2012.11a
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• pp.351-354
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• 2012

본 연구는 LED 조명제어시스템(LMS)을 이용해서 관리자가 원하는 목표전력량과 LED 조명의 구역별 중요도에 따라 Priority 를 설정 후 실시간으로 전력량을 측정해서 Overload(목표전력량 80% 이상 초과 1 단계, 90% 이상 2 단계) 상황 발생 시 자동으로 LED 조명전력을 차단 또는 디밍함으로써 정전에 대비하고 에너지절감도 가능한 알고리즘과 실증결과에 관한 연구내용을 소개한다.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.76-78
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• 2002

Multicasting over mobile IP network becomes more important with the increasing needs of supporting multimedia services in mobile network. The IETF has suggested two approaches which are remote subscription and bidirectional tunneling for supporting mobility management in multicasting over mobile IP. But these protocols have problems - the frequent reconstruction of multicast delivery tree, packet less during handoff, convergence problem, and so on. In this paper, we propose to use preconfiguration of multicast delivery tree when mobile host enters the foreign network. It will decrease the frequency of multicast delivery tree reconstruction, and reduce the packet loss during handoff, Also the multicast delivery tree maintained by Keep Alive messages makes the signaling overload of networks diminished.

• Annual Conference of KIPS
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• 2010.11a
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• pp.1694-1697
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• 2010

지능형 빌딩 시스템은 빌딩을 운영하는 다양한 단위시스템 정보를 통합하여 빌딩 거주자에게 쾌적하고, 안전한 생활을 할 수 있도록 운영하는 시스템을 말한다. 하드웨어적인 방법은 단위시스템에 비례하게 비용이 증가하는 단점이 있다. 소프트웨어적인 방법은 하나의 서버에서 정보를 수집하기 때문에 단위시스템에 통신량 증가로 인한 오류가 발생하면 전체 시스템에 영향을 미치는 단점을 가지고 있다. 본 논문에서는 소프트웨어적인 방법의 단점을 개선하기 위해서 부하 및 오류를 격리화할 수 있는 가상화를 이용하여 통합 관리 시스템과 인터페이스 관리 시스템으로 운영한다. 시스템의 구조는 통합 관리 모듈, 가상 관리 모듈, 구성 관리 모듈, 그리고 단위시스템 관리 모듈로 분리되며 제안 시스템을 사용함으로써 인터페이스 관리 시스템에서 발생하는 오류 및 부하로 인한 전체 시스템 오류를 축소시킬 수 있다.

• Annual Conference of KIPS
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• 2011.11a
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• pp.489-492
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• 2011

SIP (Session Initiation Protocol)는 사용자간의 멀티미디어 세션의 초기화, 변경 및 종료를 위한 응용 계층의 시그널링 프로토콜이다. SIP는 실시간 멀티미디어 서비스 통신에 많이 이용되기 때문에 주로 Unreliable Transport Protocol을 사용한다. 따라서 손실된 SIP 메시지들의 신뢰성을 보장하기 위하여 재전송 메커니즘을 제공한다. 하지만 이러한 재전송 메커니즘은 SIP 프록시 서버가 과부하 상황일 경우 신뢰성보다는 오버헤드가 증가되는 문제점을 가진다. 기존의 여러 SIP 과부하 제어 방법이 제안되었지만 네트워크 혼잡이 증가함에 따라 프록시 서버의 처리율이나 호 설정 시간의 지연 문제를 효율적으로 해결하지 못한다. 본 논문에서는 SIP 시그널링 네트워크에서 프록시 서버가 과부하 상황일 경우 낮은 호 설정 지연시간과 높은 처리율을 위해 우선순위 스케줄링 기반의 과부하 제어 알고리즘을 제안한다. 그리고 기존 과부하 제어에서 사용하는 알고리즘과 제안하는 알고리즘을 비교하여 보았다. 성능 평가 결과 부하에 따른 프록시 서버의 처리율과 호 설정 시간의 지연 측면에서 기존의 과부하 제어 알고리즘보다 향상됨을 보였다.

• Asia pacific journal of information systems
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• v.34 no.2
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• pp.447-469
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• 2024

Despite the maturity of platforms, only some studies have explored the relationships between the working conditions of platform workers and their organization-like responses to these platforms. Thus, this research utilized the Job Demands-Resources Model (JD-R Model) to analyze the effects of job demands and resources on platform workers' job embracing. The data were collected from 182 food delivery riders in South Korea. This study utilized the PLS technique (partial least squares) to examine the research model. Regarding job demands, this study has found that work overload and physical effort significantly affect burnout. Regarding job resources, the results revealed that service technology support and training significantly affect work engagement. In alignment with the Job Demands-Resources literature, the findings offer tangible proof that burnout has a detrimental impact on job embracing, whereas work engagement has a beneficial effect on job embracing. Our findings indicate that work engagement exerts a more substantial beneficial effect on job embracing, and burnout reduces job embracing. Results also provide novel insights to scholars seeking a comprehensive research model on the impact of on-demand workplace conditions to help platforms attract and retain platform workers.

• International Journal of Computer Science & Network Security
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• v.23 no.9
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• pp.65-70
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• 2023

The "information roadway" will give us an impact of new PC based assignments and administrations, yet the unusualness of this new condition will ask for another style of human-PC association, where the PC transforms into a sharp, dynamic and customized partner. Interface administrators are PC programs that use Artificial Intelligence frameworks to give dynamic help to a customer with PC based errands. Operators drastically change the present client encounter, through the similitude that a specialist can go about as an individual collaborator. The operator procures its capability by gaining from the client and from specialists helping different clients. A couple of model administrators have been gathered using this methodology, including authorities that give customized help with meeting planning, electronic mail taking care of, Smart Personal Assistant and choice of diversion. Operators help clients in a scope of various ways: they perform assignments for the client's sake; they can prepare or educate the client, they enable diverse clients to work together and they screen occasions and methods.

• Journal of the HCI Society of Korea
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• v.2 no.1
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• pp.33-39
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• 2007

Because of the cognitive overload which is caused by the complicated information structure, Digital Convergence product interferes with the effective retrieval of the information from the menu. Two methods have been used to alleviate that cognitive overload by making an effective menu structure; physical menu structure method which is related with the width and depth of the menu, semantic menu structure method which is related with the menu title. In this research, we tried to demonstrate the effectiveness of the menu structure designing method by suggesting a new semantic methodology which uses the Fixation and Fixation duration which are accompanied by the visual search. Because the Fixation is automatically processed by the human cognitive model, we could easily recognize whether the information structure is correspond to the cognitive model or not. From this fact we established the hypothesis that the number of cognitively well established menu structures are fewer than that of the wrongly designed menu structures in terms of the Fixation number and Duration. To verify this hypothesis, we compared the Fixation number and Duration of the modified menu structures with those of the original menu structures by using the Eye-Tracking experiment. As a result, we could find the significant decrease of the Fixation number and Duration after modification. Therefore we could recognize that the modified menu structure was more effective than the original menu structure. In sum, the newly suggested menu structure designing methodology which uses the Fixation and Fixation Duration accompanied by the visual search was proved to be a very effective method.

• Journal of the Korea Society of Computer and Information
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• v.16 no.9
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• pp.131-143
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• 2011

Previous alerting service based on LBS was caused severe overload problem of server by using the method to confirm the location of each moving object on server. In this paper, by loading an App on smart moving object, we proposed a novel algorithm named ADAS(Active Disaster Alert Service) for accessing to the server site with oneself location information as needed and implemented the disaster alerting service system with visualization for user. In the proposed method, running App access to the server periodically with the present location coordinate gained from GPS module or network module and the ID of moving object. Then, the server compare the present location coordinate of moving object and the coordinates of disasters registered in DIDB and transmit the n NDIs existed in near distance orderly from the coordinate of present moving object to the client. The App compares the coordinate of present location for moving object and the coordinates of NDI is transmitted from server by real time and executes the service with classifying levels of alert into three steps such as danger, carefulness and safety. And new NDIs are gained by accessing DIDB on Server periodically during running App. Therefore, this will be become a novel method for reducing fundamentally the server overload problem in comparison with previous alerting service that the career of moving object is managed on server.