• Journal of Internet Computing and Services
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• v.2 no.2
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• pp.23-36
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• 2001

To support real-time multicast, the existing DS network may use the EF PHB for transmission, However, because of the dynamic characteristics of the multicast flow and the features of the EF PHB. it is very difficult to make a provision of resources or to manage the network when EF multicast flows increase, Also, the existing LBE PHB can not guarantee the transmission delay bounds required for the real-time multicast traffic, In this paper. a new concept of PHB. namely, low-delay multicast PHB, that may guarantee approximately the per-hop delay is proposed, For the low-delay multicast PHB, router architectures are devised, The queue management algorithm on a low-delay multicast queue and a scheduling method are also devised. This new architecture of the LDM AF class is simple to be implemented.

• The KIPS Transactions:PartC
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• v.9C no.2
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• pp.221-226
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• 2002

Cycling Packet Dropping mechanism we proposed in this paper adaptively drops packets, as predicting traffic pattern between each cycle. Therfore the proposed mechanism makes up for the drawback of RIO mechanism and minimizes errors being capable of predicting in Dynamic and Strict Packet Dropping mechanism. And we executed a simulation and analyzed the throughput and packet drop rate based on the Sending Drop Precedence changing dynamically depending on the network traffic. The results show that the proposed mechanism provides better performance on drop precedence levels and stricter drop precedence policy for AF class.

• Journal of Korean Home Economics Education Association
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• v.31 no.1
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• pp.39-58
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• 2019

The purpose of this study was to investigate the home economics pre-service teachers' verbal interactions during their teaching practicum. For this purpose, the class interactions of four pre-service teachers were recorded, and the data were analyzed using advanced Flanders' verbal interaction analysis. The major findings are as follows: First, the item with the highest proportion of occurrences consisted of the pre-service teachers' 'lectures', 'nonverbal conditions' and 'asks questions'. 'forms a positive learning atmosphere' and 'praises or encourages' exhibited fewer occurrences, and there was little 'giving direction', 'criticizing students or justifying authority'. Second, the instances of class interactions appeared in the form of 'asks questions-student talk response' or 'lecture-asks questions', and in the last class were 'ask questions-student talk initiation' and 'accepts or uses ideas of students'. Third, trends of verbal interactions tend to be generally indirect, and students' remarks have appeared acceptable and compassionate. Fourth, according to expert analysis, 'class management questions' and 'diffusion questions' have increased. Pre-service teachers can guide students through their learning activities, and students can expand their thinking through the teachers' questions. As these results demonstrate, self-study analyses of pre-service teachers and active support in field are needed.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.1219-1222
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• 2006

3GPP에서는 단대단 QoS 보장을 위해 정책 기반 망 관리(PBNM:Policy-based Network Management) 방식을 적용할 것을 권고하고 있다. 본 논문에서는 3GPP에서 제시하는 핵심망 구조에 정책 기반 망 관리 기법 중 DiffServ를 적용해서 현재 DSCP(Differentiated Service Code Point)는 8bit 구성되어 있으나 그 중 6bit만 사용되고 있고, 사용하지 않는 이 2bit를 사용하여 DF(Default Forwarding), EF(Expedited Forwarding), AF(Assured Forwarding)의 DSCP에 Service Class Code Point를 부여해서 DiffServ를 서비스하는 망에서 동일한 Diffserv 정책을 설정해서 효율적인 QoS 기법을 제안하고자 한다.

• Journal of Distribution Science
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• v.18 no.9
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• pp.45-53
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• 2020

Purpose: This study aims at investigating consumers' choice in online food purchasing behavior and the impact on repurchase for fresh food delivery which has recently shown rapid growth in Korea. The study focuses on the user experience factors af fecting satisfaction and intention to continuously use the online food market. Research design, data and methodology: The survey was conducted by 309 people who had purchased fresh food online, and the analysis was conducted using SPSS and AMOS. Structural Equation Modeling was used for the analysis for the verification of hypotheses. The factors that consumers value when ordering fresh food delivery services were defined as system quality, service quality, commodity quality, brand characteristics, and economics from the preceding study and the relationship between satisfaction and willingness to repurchase was verified. Results: When consumers purchase fresh food online, system quality, product quality, brand characteristics, and economics have had a significant impact on satisfaction. Meanwhile, of the five optional attributes of consumers, only economic efficiency has been verified to have a statistically significant impact on repurchase intentions. Conclusions: The results of the study suggested factors that consumers consider important when ordering fresh food online, providing basic data for companies to develop related strategies.

• Korean Journal of Clinical Pharmacy
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• v.20 no.2
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• pp.159-164
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• 2010

Radiofrequency ablation (RA) is being used to manage atrial fibrillation (AF) with patients failed at the $1^{st}$-line anti-arrhythmic medications. Patients undergoing this procedure are at increased risk of thromboembolism after ablation, and anticoagulation management surrounding the ablation remains controversial. Although no conclusive recommendations can be made, published guidelines and data support therapeutic anticoagulation with warfarin. The purpose of this study was to analyze effectiveness of current therapy and to find factors fluctuate International Normalized Ratio (INR) values in patients undergone RA followed by anticoagulation service (ACS). Retrospective review was conducted utilizing database in a hospital. Among 110 patients under warfarin around ablation between January 2006 to September 2007, 54 patients were selected and allocated into 2 groups: Group A included 47 who discontinued warfarin after ablation, while 7 in B continued the medication. Information on demographics, amount and length of warfarin dosing, INR values and measuring frequencies, and the causing factors on INR fluctuation were abstracted. Differences were analyzed using chi-squared test, Fisher's Exact test, and unpaired Student t-test. Mean amount of warfarin before and after surgery was 4.0 mg, 4.1 mg in Group A and was 5.1 mg, 4.6 mg in Group B, respectively. Average duration of warfarin doing before ablation was 73.7 days in Group A, 129.9 days in B with no significant difference (p = 0.312). The duration time of warfarin on groups after ablation lasted several months. The number of checking INRs was 4.1 and 7.6, respectively. Inter-individual variability of INR fluctuations were $2.1{\pm}0.6$ in Group A and $2.2{\pm}0.7$ in B which were not significantly different (p = 0.062). 164 cases of decreased INR were: 'omission in taking medication, stressfulness and headache, 'increased intake of high vitamin K foods', 'lifestyle change of increased physical activities', and 'increase of food-intakes'. To the contrary, 36 cases of increased INR were: 'reduce of food-intake', 'use of non-prescription drugs', 'reduction in physical activities', and 'excessive restriction on food-intake', consecutively. In conclusion, the study validated therapeutic outcomes of RA patients who we treated with standard guideline and demonstrated 9 factors of INR fluctuations in the patient. A well-trained, pharmacist-monitored anticoagulation service could reduce the risk of adverse effects and prevent complications in patients with AF around RA operation.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.217-219
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• 2006

This study focused an water quality response to land-based pollution loads and the appropriate pollutant load reduction in Chinhae Bay using an eco-hydrodynamic model. Land-based discharge foam urban areas, industrial complex and sewage treatment plant was the greatest contributor to cause red-tide blooms and summer hypoxia. Tidal currents velocity af the ebb tide was about 10 cm/s stronger than that of the flood tide. A residual current was simulated to. have a slightly complicated pattern with ranging from 0.1 to. 2.7 cm/s. In Masan Bay, pollutant materials cannot flaw from the inner to the outer bay easily because af residual currents flaw southward at surface and northward at the bottom. The simulation results of COD distribution showedhigh concentrations aver 3 mg/L in the inner part of Masan Bay related pollutant discharge, and charge, and lower levels less than 1.5mg/L in the central part of Chinhae Bay. For improvement water quality in Chinhae Bay, it is necessary to reduce the organic and inorganic loads from paint sources by mare than 50% and ameliorate severe polluted sediment.

• Journal of information and communication convergence engineering
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• v.1 no.3
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• pp.123-128
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• 2003

This paper has addressed the implementation of the single rate Rate Adaptive Shaper(srRAS) described in RFC2963. This shaper has been proposed to use at the ingress of differentiated services networks providing Assured Forwarding Per Hop Behavior (AFPHB). srRAS is typically used in conjunction with single rate Three Color Marker(srTCM) described in RFC2697. srRAS itself is the tail-drop FIFO that is drained at a variable rate, and srTCM is the marker with metering function. G-srRAS is the same as srRAS except that RAS receives the green token state information from the downstream srTCM to avoid delaying a packet in RAS although there are sufficient tokens available to color the packet green. In this paper, we have addressed the algorithm and the architecture of srRAS, and the scheme to implement srRAS using VHDL(Very high-speed integrated circuit Hardware Description Language) and its related tools.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.4865-4886
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• 2017

The user experience of practical indoor power line communication (PLC) applications is greatly affected by the system quality-of-service (QoS) criteria. With a general broadcast-and-multi-access (BMA) relay scheme, in this work we investigate the joint source and relay power optimization of the amplify-and-forward (AF) relay systems used under indoor broad-band PLC environments. To achieve both time diversity and spatial diversity from the relay-involved PLC channel, which is time-varying in nature, the source node has been configured to transmit an identical message twice in the first and second signalling phase, respectively. The QoS constrained power allocation problem is not convex, which makes the global optimal solution is computationally intractable. To solve this problem, an alternating optimization (AO) method has been adopted and decomposes this problem into three convex/quasi-convex sub-problems. Simulation results show the fast convergence and short delay of the proposed algorithm under realistic relay-involved PLC channels. Compared with the two-hop and broadcast-and-forward (BF) relay systems, the proposed general relay system meets the same QoS requirement with less network power assumption.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.12
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• pp.141-148
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• 2005

This paper addresses the design of srTCM (single rate Three Color Marker) described in RFC2697. It has proposed for srTCM to be used at the ingress of Differentiated Service network that provides AF PHB (Assured Forwarding Per Hop Behavior). srTCM is the marker with the metering function, and consists of the token updating function and the marking function. The token updating function uses the dual token bucket. The marking function compares the token values with the length of input packet, and then marks the result into IP QoS field (ToS field). This paper designs srTCM function and then implements it in one chip using VHDL and FPGA technology.