• Journal of Communications and Networks
• /
• 제6권3호
• /
• pp.245-257
• /
• 2004

Driven by the growing number of the mobile subscribers, efficient channel resource management plays a key role for provisioning multimedia service in the next generation personal communication systems. To reuse limited channel resources, diminishing the coverage areas of cells seems to be the ultimate solution. Thus, however, causes more handover events. To provide seamless connection environment for mobile terminals and applications, this article presents a novel handover scheme called the intelligent channel reservation (ICR) scheme, which exploits the location prediction technologies to accurately reserve channel resources for handover connections. Considering the fact that each mobile terminal has its individual mobility characteristic, the ICR scheme utilizes a channel reserving notification procedure (CRNP) to collect adequate parameters for predicting the future location of individual mobile terminals. These parameters will be utilized by the handover prediction function to estimate the expected handover blocking rate and the expected number of idle channels. Based on the handover prediction estimations, a cost function for calculating the damages from blocking the handover connections and idling channel resources, and a corresponding algorithm for minimizing the cost function are proposed. In addition, a guard channel decision maker (GCDM) determines the appropriate number of guard channels. The experimental results show that the ICR scheme does reduce the handover-blocking rate while keeping the number of idle channels small.

• 정보처리학회논문지C
• /
• 제14C권1호
• /
• pp.81-86
• /
• 2007

다양한 형태의 멀티미디어 서비스들은 서로 다른 QoS를 요구한다. 따라서, 서로 다른 멀티미디어 서비스를 효율적으로 지원하면서 동시에 우선순위가 높은 서비스의 QoS를 보장할 수 있는 효율적인 셀룰러/무선랜 오버레이 네트워크 관리기법에 대한 관심이 증가하고 있다. 본 논문에서는 효율적인 대역폭의 예약과 할당, 그리고 혼잡제어를 위한 통신 프로토콜을 통한 적응적 네트워크 관리기법을 제안하였다. 컴퓨터 시뮬레이션을 통하여 대역폭 관리를 위해 제안된 기존의 타 기법들과의 비곤 분석을 수행하여 제안된 방법이 다양한 네트워크 트래픽 상황에서 우수한 성능을 가지는 것을 확인할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권9호
• /
• pp.3635-3654
• /
• 2015

With the rapid development of smart devices and mobile Internet, the video application plays an increasingly important role on mobile devices. Understanding user behavior patterns is critical for optimized operation of mobile live streaming systems. On the other hand, volume based billing models on cloud services make it easier for video service providers to scale their services as well as to reduce the waste from oversized service capacities. In this paper, the watching behaviors of a commercial mobile live streaming system are studied in a content-centric manner. Our analysis captures the intrinsic correlation existing between popularity and watching intensity of programs due to the synchronized watching behaviors with program schedule. The watching pattern is further used to estimate traffic volume generated by the program, which is useful on data volume capacity reservation and billing strategy selection in cloud services. The traffic range of programs is estimated based on a naive popularity prediction. In cross validation, the traffic ranges of around 94% of programs are successfully estimated. In high popularity programs (>20000 viewers), the overestimated traffic is less than 15% of real happened traffic when using upper bound to estimate program traffic.

• Journal of Communications and Networks
• /
• 제16권2호
• /
• pp.130-139
• /
• 2014

Due to the unpredictable nature of channel availability, carrying delay-sensitive traffic in cognitive radio networks (CRNs) is very challenging. Spectrum leasing of radio resources has been proposed in the so called coordinated CRNs to improve the quality of service (QoS) experienced by secondary users (SUs). In this paper, the performance of coordinated CRNs under fixed-rate with hard-delay-constraints traffic is analyzed. For the adequate and fair performance comparison, call admission control strategies with fractional channel reservation to prioritize ongoing secondary calls over new ones are considered. Maximum Erlang capacity is obtained by optimizing the number of reserved channels. Numerical results reveal that system performance strongly depends on the value of the mean secondary service time relative to the mean primary service time. Additionally, numerical results show that, in CRNs without spectrum leasing, there exists a critical utilization factor of the primary resources from which it is not longer possible to guarantee the required QoS of SUs and, therefore, services with hard delay constraints cannot be even supported in CRNs. Thus, spectrum leasing can be essential for CRN operators to provide the QoS demanded by fixed-rate applications with hard delay constraints. Finally, the cost per capacity Erlang as function of both the utilization factor of the primary resources and the maximum allowed number of simultaneously rented channels is evaluated.

• 한국컴퓨터정보학회:학술대회논문집
• /
• 한국컴퓨터정보학회 2018년도 제57차 동계학술대회논문집 26권1호
• /
• pp.127-128
• /
• 2018

본 프로젝트에서는 IoT를 활용한 스마트한 풋살 대관 예약 시스템이다. 최근 건강 및 취미에 관심이 많아지면서 하나의 국면으로 풋살에 대한 관심이 많아지고 있다. 이러한 관심은 관련 블로그 등과 같은 그룹 활동으로 많은 정보를 공유하고 있다. 하지만 풋살장 예약, 팀매칭, 용병에 구하기 등과 풋살장 관리에도 어려움이 있다. 이러한 문제점들을 해결하기 위해 본 프로젝트는 웹과 앱을 활용한 커뮤니티 제공, 풋살장 관리, 팀매칭, 용병 등을 실시간으로 공유하고 활용할 수 있도록 하였다. 팀매칭 및 용병은 실시간으로 상대팀과 채팅 통해 조율할 수 있고 용병게시판을 이용하여 용병을 구할 수 있다. 앱에서는 상대팀이 예약시간의 지각, 불참석을 하면 도착알림을 오게 해주고 풋살장에 도착하여 구장문을 열거나 닫고, 구장 조명을 키거나 끄거나, 구장 실시간 영상, 구장 실시간 이용현황 등을 볼 수 있는 기능들을 제공하며, IoT를 활용한 스마트하게 풋살장 관리 및 운영, 활용할 수 있는 시스템이다.

• 대한안전경영과학회지
• /
• 제13권2호
• /
• pp.243-249
• /
• 2011

The purpose of the study was to improve of performance for Magnetic Resonance Imaging (MRI) examination in the department of radiology. It was performed DMAIC (Define, Measure, Analyze, Improve, and Control). In the stage of definition, The fifth kinds of CTQ (critical to quality) by the kindness, the waiting time, the examination explanation, the waiting time and the waiting environment were selected by voice of customer. In the stage of measurement, the performed examinations and the reservation waiting time were measured each 1.77 and 1.69 sigma. In the stage of analysis, the potential key causes were determined the limited working hours and the difference of examination time of various entries. In the stage of improvement, MRI were performed with the operating system of 24 hours examination and the optimization of the difference of examination time by among of 30 minutes, 40 minutes, 50 minutes. Finally, the number of examinations and reserved waiting days were measured by each 3.17 and 1.71 sigma in the control stage.

• 대한건축학회논문집:계획계
• /
• 제35권12호
• /
• pp.75-82
• /
• 2019

After 1840 the first opium war, that changed the social nature and living habitats in China. The purpose of this study is to observe the influence of the war on the plan layout of traditional Chinese residential houses in Beijing Siheyuan. To find out the changes that were made after 1840, and reservation of the past, the space syntax model is used to analyze different social contexts and also compare the ancient and modern residential buildings. The result of the study indicate the following: Before the war, the ancient Siheyuan people's way of life strictly abide by the hierarchy system; External emphasis shows the host's status. However, in modern times, the social status became equal, efficient and harmonious relationship internally, while externally, it arranged the orientation and position of buildings to adapt to the natural environment. However, the boundaries between family members and visitors the emphasis on the courtyard and respect for private life remain unchanged.

• International Journal of Internet, Broadcasting and Communication
• /
• 제14권2호
• /
• pp.36-39
• /
• 2022

Medical tourism is recognized as a high value-added industry due to its longer stay and more useful costs than general tourism, and is growing rapidly around the world, especially in Asia. In addition, medical tourism is a new form of tourism that combines medical services with tourism activities such as recreation, leisure, and cultural activities, nowadays, medical tourism is emphasizing the combination of medical and tourism. Although Korea medical system and clinic have excellent medical equipment and infrastructure, it is not consistent with policy support and legislation. That have make it difficult for consumers to choose clinics for medical tourism. Therefore, it is necessary to provide customized information to the clinics that consumers want to match each other's services. In particular, it is aimed at consumers with simple procedures and cosmetic purposes, especially at small hospitals. In this paper, we propose a customized service platform that matches users seeking clinics and also medical tourism. Also we can easy to reservation clinic for medical tour.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2010년도 추계학술발표대회
• /
• pp.1229-1232
• /
• 2010

공인인증서는 10여 년 간 국내 인터넷 뱅킹이나 전자상거래에서 본인인증 수단으로 긴요하게 이용되어 왔다. 그러나 공인인증서는 처음 발급받았던 저장매체에서 사용이 가능하며, 재발급 시에 기존 인증서를 폐기한 후 새로운 인증서를 발급받아야 하는 불편함이 있다. 2010년 행정안전부에서는 2013년부터 하드디스크 내 공인인증서 저장을 금지한다는 방안을 발표하였다. 이에 따라 사용자들은 공인인증서를 이동형 저장매체에 저장한 후 사용이 가능하게 되어 이동형 저장매체의 중요성이 높아지게 되었으며, 분실 위험에 노출되어 있는 이동형 저장매체가 없을 시에도 안전하게 인증서를 사용할 수 있는 시스템이 필요하게 되었다. 본 논문에서는 위와 같은 불편함을 줄이고자 기존에 발급받았던 인증서를 토대로 경량화 된 일회용 인증서를 발급받음으로써 안전하고 효율적인 결제가 가능하도록 하는 시스템을 설계 및 구현하였다.

• 국제학술발표논문집
• /
• The 1th International Conference on Construction Engineering and Project Management
• /
• pp.569-574
• /
• 2005

This paper presents the core technology of Construction Business Process Automation to model and automate construction business processes. Business Process Reengineering (BPR) and Automation (BPA) have been recognized as one of the important aspects in construction business management. However, BPR requires a lot of efforts to identify, document, implement, execute, maintain, and keep track thousands of business processes to deliver a project. Moreover, existing BPA technologies used in existing Enterprise Resource Planning (ERP) systems do not lend themselves to effective scalability for construction business process management. Application of Workflow and Object Technologies would be quite effective in implementing a scalable enterprise application for construction community. This paper present the technologies and methodologies for automating construction business processes by addressing how: 1) Automated construction management tasks are developed as software components, 2) The process modeling is facilitated by dragging-and dropping task components in a network, 3) Raising business requests and instantiating corresponding process instances are delivered, and 4) Business process instances are executed by using workflow technology based on real-time simulation engine. This paper presents how the construction business process automation is achieved by using equipment reservation and cancellation processes simplified intentionally.