• Journal of KIISE:Computing Practices and Letters
• /
• v.16 no.10
• /
• pp.990-994
• /
• 2010

Mobile WiMAX does not guarantee the media qualities because it does not consider the characteristics of video coding techniques. In this paper, PC-MCA(Priority-based Combining adaptive Modulation and Coding with ARQ), a priority based channel-adaptive streaming scheme, is proposed to guarantee media qualities. PC-MCA uses QoS scheduler by scheduling priority of the media and differentially controls modulation and coding schemes according to wireless channel condition and frame priorities. It also guarantees multimedia service quality through video decoding reliability.

• Journal of the Korean Society of Food Culture
• /
• v.22 no.6
• /
• pp.794-800
• /
• 2007

The purpose of this study was to measure the tourists' preference for alternative restaurants with different combinations of 4 attribute levels: origin description, food type, price and service guarantee. A total of 210 questionnaires were completed from tourists who visited Kwangyang, Suncheon and Yeosu during Jan. 2 - Jan. 15, 2007. Conjoint experiment method was used to develop hypothetical restaurants. Ordinal probit model was used to measure the effects of attribute levels on the tourists' preference. Results of the study demonstrated that the ordinal probit model analysis result for the data indicated excellent model fit. The effects of attribute levels (origin description, traditional food, fusion food, price, service guarantee) on the tourists' preference were statistically significant. As expected, estimates of marginal willingness to pay for origin description(3.063), food type(2.349), and service guarantee(2.356) were statistically significant. Moreover, tourists were more willing to pay for origin description than other attribute levels. Tourists also considered the origin description as the very important attribute. In conclusion, based on conjoint analysis, a model was proposed of marginal willingness to pay of attribute levels. It should be noted that the original model was modified and should, preferably, be validated in future research.

• Journal of the Korea Society of Computer and Information
• /
• v.7 no.2
• /
• pp.101-114
• /
• 2002

The real multimedia application in wide area communication needs the guaranteed performance of communication service. Therefore, the resource is reserved at the moment of traffic burst and the region of connection admission possibility is widened at the basis of maximum cell rate. This of study shows that the end-to-end traffic delay to the traffic of burst state is guaranteed when the total of maximum transmission rate is higher than link speed by using the region of deterministic delay. The network load rate of connection admission can be improved by the inducement of delay bounds consideration each traffic characteristic to guarantee the end-to-end delay of network from single switch. This suggested buffering system using deterministic service do not give any influence to service quality and can guarantee the bounds of end-to-end delay. And it can also reduce the load of network even if the delay is increased according to the burst traffic characteristic. The above suggested system can be applied effectively to the various kinds of general network specification which admit both real time trafnc service and non-real time traffic service.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.12 no.6
• /
• pp.2680-2696
• /
• 2018

The collaborative content caching system is an effective solution developed in recent years to reduce transmission delay and network traffic. In order to decrease the service end-to-end transmission delay for future 5G ultra-dense networks (UDN), this paper proposes a novel service migration method that can guarantee the continuity of service and simultaneously reduce the traffic flow in the network. In this paper, we propose a service migration optimization model that minimizes the cumulative transmission delay within the constraints of quality of service (QoS) guarantee and network condition. Subsequently, we propose an improved firefly algorithm to solve this optimization problem. Simulation results show that compared to traditional collaborative content caching schemes, the proposed algorithm can significantly decrease transmission delay and network traffic flow.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.39 no.12
• /
• pp.520-528
• /
• 2002

The ATM Forum recently introduced the Guaranteed Frame Rate(GFR) service category GFR service has been designed to support classical best effort traffic such as TCP/IP based traffic. The GFR service not only guarantees a minimum throughput, but also supports fair distribution of available bandwidth to completing VCs. In this paper, we proposed a new buffer management algorithm based on leaky bucket to provide minimum cell rate guarantee and improve fairness. The proposed algorithm reduces complexity and processing overhead of leaky-bucket algorithm to implement easily.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.12
• /
• pp.4356-4371
• /
• 2014

When the load in a multi-cell orthogonal frequency division multiple access (OFDMA) system is allowed to excessively increase in face of frequent handover, the cell area becomes smaller than the designed size, and thus continuity of quality of service (QoS) for handover requests cannot be guaranteed. To efficiently support the mobility of a mobile terminal (MT), we should adaptively cope with the resource demand of handover calls. This paper proposes a twofold resource-reservation scheme for OFDMA systems to guarantee continuity of QoS for various mobile multimedia services during MT handover from lightly to heavily loaded cells. Our twofold scheme attempts to guarantee service continuity for handover and to maximize resource allocation efficiency. We performed a simulation to evaluate our scheme in terms of outage probability, handover failure rate, total throughput, and blocking rate.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 2008.10b
• /
• pp.537-544
• /
• 2008

The purpose of this study is to find essential delivery service quality elements of internet shopping mall and to investigate the relationship among delivery service quality, satisfaction, trust, and loyalty in the area of internet shopping malls. To do so, theoretical literature review and empirical survey accomplished. The empirical results of this study are summarized as follows. Firstly, accuracy, quickness, safety, information providing, and institutional guarantee have a positive influence on satisfaction. Secondly, accuracy, quickness, information providing, and institutional guarantee have a positive influence on trust. Lastly, satisfaction has a positive influence on trust, and both of satisfaction and trust have a positive influence on loyalty in internet shopping malls. From the analyses of this study, we offer several implications both theoretical and practical perspective.

• ETRI Journal
• /
• v.28 no.3
• /
• pp.311-319
• /
• 2006

This paper presents a terminal-assisted frame-based packet reservation multiple access (TAF-PRMA) protocol, which optimizes random access control between heterogeneous traffic aiming at more efficient voice/data integrated services in dynamic reservation TDMA-based broadband access networks. In order to achieve a differentiated quality-of-service (QoS) guarantee for individual service plus maximal system resource utilization, TAF-PRMA independently controls the random access parameters such as the lengths of the access regions dedicated to respective service traffic and the corresponding permission probabilities, on a frame-by-frame basis. In addition, we have adopted a terminal-assisted random access mechanism where the voice terminal readjusts a global permission probability from the central controller in order to handle the 'fair access' issue resulting from distributed queuing problems inherent in the access network. Our extensive simulation results indicate that TAF-PRMA achieves significant improvements in terms of voice capacity, delay, and fairness over most of the existing medium access control (MAC) schemes for integrated services.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.60
• /
• pp.79-106
• /
• 2013

The world is significant increasing investment volume into developing countries from foreign investors. Foreign financial capital is searching in interesting place among the emerging market. However foreign investors put still their experience in the economical and social crisis with political risks in the host countries. MIGA entered into the political risks insurance market which has one of the basic matter of sponsored the private investment guarantee programs. They put guarantee or covering risks of currency inconvertibility, expropriation, breach of contract and political violence. In the case contracts of guarantee concluded between investor and MIGA which are disputes in relation to such MIGA service contract, it should be settled by negotiation, conciliation and arbitration under the convention establishing the Multilateral Investment Guarantee Agency(MIGA). All disputes within the scope to states and investor of MIGA members shall be settled in accordance with the procedure set out in the convention. Recently, MIGA is opening the office in Seoul to strengthen joint efforts between MIGA and Korea. It will be a good chance to consider sustainable improvement and dispute solutions for emerging countries in foreign investment to the korean investors.

• The Journal of Fisheries Business Administration
• /
• v.51 no.3
• /
• pp.49-71
• /
• 2020

A fisher means any person employed to provide his/her labor in a fishing vessel in exchange for a wage. There is no concept of a fisher in Seafarers Act. This act shall not apply to seafarers who are in service on board a fishing vessel the gross tonnage of which is less than 20 tons. However, of the total 63,112 fishing vessels, only 2,829 fishing vessels have a total tonnage of more than 20 tons. Fishermen engaged in fishing vessels with a gross tonnage of which is less than 20 tons are not guaranteed to be paid arrears through the Wage Claim Guarantee Fund for Seafarer (Article 56). In addition, fishermen working on a fishing vessel are excluded from the Wage claim Guarantee Act. The Labor Standards Act shall apply to fishermen engaged in fishing vessels with a gross tonnage of which is less than 20 tons. Fishermen and seafarers are at a higher risk of living security than regular workers. Guaranteeing the payment of wages is essential for fishermen to improve the life and employment stability. In order to guarantee fisher wage claims, the concept of a fisher in the Seafarers Act must be realized by sources such as the Wage Claim Guarantee Fund of Ministry of Oceans and Fisheries, step by step expansion of members in the wage claim guarantee fund for seafarers and interest for delayed payment of wages, etc.