• Journal of Broadcast Engineering
• /
• v.27 no.4
• /
• pp.548-560
• /
• 2022

Video based Point Cloud Compression (V-PCC) is one of the compression methods for compressing point clouds, and shows high efficiency in dynamic point cloud compression with movement due to the feature of compressing point cloud data using an existing video codec. Accordingly, V-PCC is drawing attention as a core technology for immersive content services such as AR/VR. In order to effectively service these V-PCC contents through a media streaming platform, it is necessary to encapsulate them in the existing media file format, ISO based Media File Format (ISOBMFF). However, in order to service through an adaptive streaming platform such as Dynamic Adaptive Streaming over HTTP (DASH), it is necessary to encode V-PCC contents of various qualities and store them in the server. Due to the size of the 2D media, it causes a great burden on the encoder and the server compared to the existing 2D media. As a method to solve such a problem, it may be considered to configure a streaming platform based on content obtained through V-PCC content encoding based on SHVC. Therefore, this paper encapsulates the SHVC-based V-PCC bitstream into ISOBMFF suitable for DASH service and proposes a configuration method to service it. In addition, in this paper, we propose ISOBMFF encapsulation and DASH configuration method to effectively service SHVC-based V-PCC contents, and confirm them through verification experiments.

• Culinary science and hospitality research
• /
• v.18 no.4
• /
• pp.1-14
• /
• 2012

The focus of this study is on investigating an appropriate selling strategy for the guests of a fine dining restaurant in deluxe hotels located on seoul. As survey methods, questionnaires were prepared and distributed to the customers who visited the restaurants of five-star hotels in Seoul. The survey was carried out from July 1 to August 30, 2010. Total 223 copies of questionnaire were used for final analysis. Frequency analysis, descriptive statistics, exploration factor analysis, and reliability analysis were conducted through SPSS 18.0 for final analysis, and path analysis was conducted through AMOS 18.0 for verification of hypotheses. The hypothesized relationships among the models were tested simultaneously by using a structure equation model(SEM). The proposed model provided an adequate fit to the date, $X^2$ = 143.934(df=120, p<.001), GFI=0.935. AGFI= 0.907, RMR=0.022, CFI=0.983. The study results are as follows. First, the restaurant employee's adaptive selling strategies consist of persuasion-suggestion, kindness-rapidity. Second, in the result of analysis to understand the influences between customer satisfaction and adaptive selling strategies, customer satisfaction is shown to have an influential relationships with persuasion-suggestion strategy and kindness-rapidity strategy of employee's adaptive selling. Third, all adaptive selling strategies did not affect customer loyalty. Finally, customers who are satisfied with such services have a significant effect on customer loyalty and supports the existing previous studies.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2006.05a
• /
• pp.1393-1396
• /
• 2006

유비쿼터스 환경은 서비스 이동과 자원 상태 변화 등 실행 환경 변화가 빈번히 발생한다. 이러한 가변하는 실행 환경에 적응하고 가용자원의 부족등으로 발생하는 결함까지 복구할 수 있는 적응형 자율 미들웨어 서비스를 통해 서비스의 계속성 및 고가용성을 보장해야 한다. 이 논문에서는 유비쿼터스 환경에 따라 자율적으로 적응하는 서비스 미들웨어에서 결함 감내 서비스를 지원하는 방법을 제시하였고 프로토타입 Wapee(Web-Service based Application Execution Environment)v0.1을 통해 실제 환경에서 적용가능성을 확인하였다.

• Proceedings of the IEEK Conference
• /
• 2003.07d
• /
• pp.1661-1664
• /
• 2003

The transcoding is a method which converts a multimedia stream to an adaptive format, such as frame rate and resolution, that can be played in the mobile devices. Due to the heavy consumption of CPU power for transcoding, the server in charge cannot supply all streams requested from clients if it is already occupied by several streams. The load balancing among proxies is a common approach for solving such problem. In addition to collaborative works for load balancing, the mobility must be taken into account in the mobile environments. Thus, the wired-network based algorithm is not suitable for the streams service in the mobile environments. In this paper, we propose an alternative scheme for cooperative proxy architecture that considers the case in which mobile devices are moving over other zones.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2003.09a
• /
• pp.660-663
• /
• 2003

The advanced computer network technology enables connectivity of computers through an open network environment. There has been growing numbers of security threat to the networks. Therefore, it requires intrusion detection and prevention technologies. In this paper, we propose a network based intrusion detection model using Fuzzy Cognitive Maps(FCM) that can detect intrusion by the Denial of Service(DoS) attack detection method adopting the packet analyses. A DoS attack appears in the form of the Probe and Syn Flooding attack which is a typical example. The Sp flooding Preventer using Fuzzy cognitive maps(SPuF) model captures and analyzes the packet information to detect Syn flooding attack. Using the result of analysis of decision module, which utilized FCM, the decision module measures the degree of danger of the DoS and trains the response module to deal with attacks. The result of simulating the "KDD ′99 Competition Data Set" in the SPuF model shows that the Probe detection rates were over 97 percentages.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.05a
• /
• pp.441-445
• /
• 2004

In this paper, we deal with an inventory model of a multi-stage, serial supply chain system where a single product type and nonstationary customer demand pattern are considered. The retailer and suppliers place their orders according to an echelon-stock based replenishment control policy. We assume that the suppliers can access online information on the demand history and use this information when making their replenishment decisions. Using a reinforcement learning technique, the inventory control parameters are designed to adaptively change as the customer demand pattern is altered, in order to maintain a given target service level. Through a simulation based experiment, we verified that our approach is good for maintaining the target service level.

• Journal of information and communication convergence engineering
• /
• v.14 no.3
• /
• pp.137-146
• /
• 2016

In this paper, we introduce a quality of experience (QoE)-provisioning mobility management scheme. The emphasis is on a mobility-aware QoE solution enabling network components to recognize the mobility pattern of an end-user and to prepare a handover in advance. We further focus on an energy-adaptive QoE solution based on the energy profile providing the preferred pattern of energy consumption and an energy preference check engine determining whether the provision of the service that the end-user requested is suitable to QoE or not. Lastly, we concentrate on a network-based intelligent mobility management scheme adopting the calm service and the balance. Consequently, we conclude that the proposed schemes improve the handover latency, QoE metrics, and energy efficiency simultaneously.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2011.07a
• /
• pp.102-104
• /
• 2011

최근 비디오 스트리밍과 대화형 비디오 서비스 등과 같은 광대역 멀티미디어 서비스를 지원하기 위하여 Wimax와 같은 4G 무선네트워크 시스템 기술이 발전해 왔다. 4G 무선네트워크의 OFDM(Orthogonal Frequency Division Multiplexing)과 MIMO(multi Input Multi Output)은 사용자들에게 매우 유연한 QoS(Quality of Service) 서비스를 제공해 줄 수 있다.[1] 이 논문에서는 다양한 네트워크 상황에서 멀티캐스트 그룹에게 효율적인 방법으로 통신 자원을 할당하기 위해 OFDM 방법을 사용 하였다. 이에 본 논문에서는 한 셀(cell) 내의 서로 다른 멀티캐스트의 그룹의 다른 SNR(Signal to noise Ratio)의 사용자 분포에 따른 적응적인 scalable 비디오 멀티캐스트 방식을 제안한다. 더 나은 수신율을 가진 사용자는 최적의 MCS(Modulation and Coding Scheme) 할당을 통해 서로 다른 화질의 scalable 비디오 계층 중 높은 해상도의 비디오를 받을 수 있다. 논문에서는 전체 전송률을 최적화 하는 대신 전송받은 전체 비디오의 평균 화질을 최적화하는 방법을 제안한다.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.1
• /
• pp.70-75
• /
• 2015

With the development of communication technologies and smartphone, requirements of positioning accuracy for LBS (Location Based Service) are becoming increasingly important. LBS is a service which offers the information or entertainment based on a location to users. Therefore, positioning is very important for LBS. Among many positioning methods, IEEE 802.11 WLAN positioning measures the distance using the RSSI (Received Signal Strength Indicator) attenuation log model. Thus in order to enhance positioning, we modify the IEEE 802.11 RSSI attenuation log model by adaptive weighting method. In this paper, we propose improved IEEE 802.11 RSSI attenuation log model for enhanced indoor positioning.

• Journal of Information Technology Services
• /
• v.11 no.sup
• /
• pp.165-176
• /
• 2012

Context-Awareness system provides an appropriate service to user by recognizing situation from surrounding environment. There are many successful studies on this framework, but still has some limitations. In this paper, we are describing a context-awareness middleware that can enhance the limitation of the previous approaches. We first defined a new concept of context-awareness environment as a social intelligence. This concept implies that intelligent objects can make relationships, can aware of situation from surrounding environment, and can collaborate to accomplish a given task. The significance of the study is as follows. First, the system is capable of multi context-awareness since it is designed with a structure that supports multiple lines of reasoning. Second, the system is capable of context planning by adapting AI planning mechanism. Third, the system is capable of making the intelligent objects as a group for collaboration, and provides adaptive service to user. We have developed a prototype of the system and tested with a virtual scenario.