• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1999년도 추계종합학술대회 논문집
• /
• pp.129-132
• /
• 1999

In this Paper, new congention control schemes using the adaptive rate control for ATM LANs are presented. If is preferable for hosts in LANs to be able to send bursts at the same speed as the interface link speed in a lightly loaded condition, and as the network load increases, to reduce their traffic rate adaptively in order to avaid network congestion. We propose to apply such a rate control concept for two different traffic classed in the ATM LANs. For the first traffic class requiring no bandwidth reservation, i.e, a best effort service class, a combination of the end-to-end adaptive peak rate control with the link-by-link backpressure control is proposed. For the second traffic class, requiring the bandwidth reservation for the burst transmission, i.e. guaranteed burst service class, a combination of he adaptive peak rate control with the fast bandwidth reservation is proposed.

• 유통과학연구
• /
• 제12권10호
• /
• pp.109-121
• /
• 2014

Purpose - Most studies related to emotional labor have been conducted in the low-contact service industry rather than the high-contact service industry. Since the subjects of this study were golf service assistants, working in an industry in which the interaction and contact between customers and employees are considerable and the degree of customization is high, this study is significant. Thus, we would like to focus on the relationship between the humor style of golf service assistants and emotional labor. Humor style was divided into two styles-adaptive humor and maladaptive humor. Emotional labor was divided into two dimensions-surface acting and deep acting. In addition, we identify the relationship between emotional labor, job satisfaction, and turnover intention. Research design, data, & methodology - This study focuses on the humor styles in the golf service industry, among golf service assistants, on their emotion labor, and verifies the relationship between emotion labor and work satisfaction or job turnover intention. Based on the outcome, a total of four hypotheses were set up. To verify the hypotheses, surveys were conducted on the golf service assistants working in two golf fields in the region of Busan as well as its neighboring area. A total of 250 copies of the questionnaire were distributed. Subsequently, a total of 227 valid questionnaire copies, after excluding improper responses, were used in the analysis. After verifying the reliability and feasibility of variances, Amos 18.0 was used to implement the structure method so as to verify the study hypotheses. As a result of this analysis, the suitability of the entire model was considerably appropriate to the standard value, and the level is adequate to accommodate the study model completely. Results - First, it was found that the adaptive humor of golf service assistants had a positive effect on deep acting and maladaptive humor had a positive effect on surface acting. Second, It was found that employees' satisfaction with their job was reduced through surface acting, and those employees who experienced positive emotional labor in the form of deep acting were more satisfied with their job. Third, surface acting among employees increased turnover intention, but deep acting reduced it. Finally, the relationship between job satisfaction and the turnover intention of golf service assistants in the golf service industry was examined. Conclusions - First, the adaptive humor of the golf assistants in the golf service industry had a positive effect on their expression behavior. Second, deep acting increased their job satisfaction while their surface acting had a noticeably negative effect on their job satisfaction. Third, the surface acting of the emotion labor dimensions that the golf service assistants experience increases their turnover intention while their deep acting decreases their turnover intention. Finally, when analyzing the relationship between job satisfaction and turnover intention of the golf service assistants, it was found that the turnover intention decreased when their job satisfaction is increased.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.89-92
• /
• 2005

For the past years, wireless communications environment have developed with explosive demand of internet service and increase of subscriber. Anytime anywhere, we can access internet service and recently, we can access internet with portable terminal using wireless communications. So several schemes have been proposed for the efficient service. In this paper, we may improve performance of wibro system using adaptive antennas scheme at the base station (BS) and mobile station(MS),operating jointly. In wibro system, the joint use of transmit beamforming at BS and receive beamforming at MS is improved the SINR and increased the capacity compared to conventional system[1],[2].

• Journal of Communications and Networks
• /
• 제8권4호
• /
• pp.432-441
• /
• 2006

As the community antenna television (CATV) networks becomes ubiquitous, instead of constructing an entirely new broadband network infrastructure, it has emerged as one of the rapid and economic technologies to interconnecting heterogeneous network to provide broadband access to subscribers. How to support ubiquitous real-time multimedia applications, especially in a heavy traffic environment, becomes a critical issue in modern CATV networks. In this paper, we propose a time guaranteed and efficient upstream minislots allocation algorithm for supporting quality-of-service (QoS) traffic over data over cable service interface specification (DOCSIS) CATV networks to fulfill the needs of realtime interactive services, such as video telephony, video on demand (VOD), distance learning, and so on. The proposed adaptive fast expansion algorithm and the loading statistics with dynamic swapping algorithm have been shown to perform better than that of the multimedia cable network system (MCNS) DOCSIS.

• Journal of Communications and Networks
• /
• 제14권6호
• /
• pp.692-702
• /
• 2012

Supporting quality of service (QoS) guarantees for diverse multimedia services are the primary concerns for WiMAX (IEEE 802.16) networks. A scheduling scheme that satisfies QoS requirements has become more important for wireless communications. We propose a downlink scheduling scheme called adaptive priority-based downlink scheduling (APDS) for providing QoS guarantees in IEEE 802.16 networks. APDS comprises two major components: Priority assignment and resource allocation. Different service-type connections primarily depend on their QoS requirements to adjust priority assignments and dispatch bandwidth resources dynamically. We consider both starvation avoidance and resource management. Simulation results show that our APDS methodology outperforms the representative scheduling approaches in QoS satisfaction and maintains fairness in starvation prevention.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권5호
• /
• pp.2544-2557
• /
• 2019

Adaptive bitrate streaming is a crucial element in the implementation of high-quality streaming of media content over the Internet. Dynamic adaptive streaming over HTTP (MPEG-DASH) has lately emerged as the de facto solution for over-the-top (OTT) video streaming services. In this paper, we perform macro-level analysis on a real-world MPEG-DASH-based Internet live broadcasting service to gain insight into its behavior throughout the end-to-end service-provision chain, from broadcasters to viewers. Based on this analysis, we propose methods to improve the quality-of-experience (QoE) of MPEG-DASH-based services, particularly with regard to reducing broadcasting delays between recording and viewing of videos, as well as synchronizing client terminals.

• 대한임베디드공학회논문지
• /
• 제12권6호
• /
• pp.369-375
• /
• 2017

In this paper, we present a self-adaptive software platform that enables an IoT gateway to perform autonomous operation considering IoT devices connected each other in resource-constrained environments. Based on the oneM2M device software platform publicly available, we have designed an additional part, called SAS (self-adaptive software) consisting of MAM (memory-aware module), NAM (network-aware module), BAM (battery-aware module), DAM (data-aware module), and DH (decision handler). A prototype system is implemented to show the feasibility of the proposed self-adaptive software architecture. Our proposed system demonstrates that it can adaptively adjust the operation of gateway and connected devices to their resource conditions under the desired service scenarios.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
• /
• pp.95-98
• /
• 2003

To provide high-quality media streaming service over the best-effort Internet, an efficient streaming system with a network-adaptive transport is essential. By adopting FEC-based adaptive transport and by matching it to the priority of media packets, in this paper, an enhanced MPEG-4 streaming system is implemented. The implemented adaptive transport can complement the existing MPEG-4 streaming server with components such as elementary stream provider, sync layer and DMIF layer. Sync layer packets of each MPEG-4 elementary stream are prioritized and then selectively dropped at the sender to match the currently available bandwidth. Also, with the proposed adaptive transport module, the level of FEC protection is dynamically adjusted based on the underlying network condition. With preliminary verification over the emulated network testbed, it is shown that the proposed implementation can mitigate the impact of network fluctuation and thus improve the quality of streaming.

• 디지털융복합연구
• /
• 제16권8호
• /
• pp.151-159
• /
• 2018

본 연구는 서비스 접점에서 개별 고객의 욕구에 맞춰 다양한 형태의 감정들을 반응해야 하는 영업사원의 긍정 탐색과 감정노동이 적응적 판매행동 및 고객만족에 미치는 영향을 중심으로 분석하였다. 115명의 자동차 영업사원들과 해당 영업사원으로부터 서비스를 제공받은 고객 2명씩 230명으로부터 이원적(dyadic) 설문자료를 수집하였다. 총 345명을 대상을 구조방정식모형으로 분석하였다. 분석결과, 긍정 탐색은 심층행동과 표면행동에 유의하게 긍정적인 영향을 미치는 것으로 나타났다. 심층행동만 적응적 판매행동에 긍정적인 영향을 미치는 것으로 나타났으며, 표면행동과는 유의미하지 않게 나타났다. 마지막으로 적응적 판매행동은 고객만족에 긍정적인 영향을 미치는 것으로 나타났다. 본 연구는 이론적으로 영원사원의 긍정 탐색(AI) 접근의 본질을 규명하고, 긍정 탐색(AI) 실천과 관련된 감정노동을 통한 적응적 판매행동을 활성화시키는데 기여할 것이다.

• 한국정보과학회논문지:정보통신
• /
• 제35권3호
• /
• pp.227-234
• /
• 2008

무선 네트워크 기술 발달은 다양한 모바일 서비스 환경에서 시간과 장소에 상관없이 끊김 없는 고속의 무선 통신 서비스를 가능하게 해주었다. 하지만 이와 같은 무선 네트워크 기술은 유선 네트워크와는 달리 고가의 제한된 대역폭을 사용한다. IEEE802.16e 표준 기반의 모바일 와이맥스에서 지원하는 MBS(Multicast Broadcast Service) 기술은 다운링크 채널을 공유하여 다수의 사용자에게 효율적인 데이타 서비스를 지원할 수 있기 때문에 이러한 제한된 대역폭의 한계를 극복할 수 있게 해준다. 그럼에도 불구하고 서비스 커버지리나 채널의 상태에 따라 쉽게 영향을 받는 전송률에 관한 문제는 여전히 남아 있다. 본 논문에서는 이러한 문제를 해결하기 위해 모바일 와이맥스의 중계 시스템을 소개하고, AMC(adaptive modulation and coding)을 이용하여 MBS의 성능을 향상 시킬 수 있는 중계 시스템을 제안한다. NS-2 컴퓨터 시뮬레이터를 이용한 실험 결과는 제안하는 MBS 중계 시스템의 성능이 기존의 시스템보다 전송률과 전송시간 측면에서 크게 향상됨을 보여준다.