• ETRI Journal
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• 제29권5호
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• pp.700-702
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• 2007

We present a relevance feedback approach based on multi-class support vector machine (SVM) learning and cluster-merging which can significantly improve the retrieval performance in region-based image retrieval. Semantically relevant images may exhibit various visual characteristics and may be scattered in several classes in the feature space due to the semantic gap between low-level features and high-level semantics in the user's mind. To find the semantic classes through relevance feedback, the proposed method reduces the burden of completely re-clustering the classes at iterations and classifies multiple classes. Experimental results show that the proposed method is more effective and efficient than the two-class SVM and multi-class relevance feedback methods.

• 한국지반공학회논문집
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• 제19권5호
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• pp.319-326
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• 2003

터널 설계를 위한 조사에 있어서, 요사이 시추공 조사는 물론 탄성파 탐사, 전기 비저항 탐사 등의 물리탐사가 빈번히 행해지고 있는 실정이다. 따라서 암반 등급 등에 의한 최적의 지반평가를 위해 조사에서 얻어지는 모든 자료를 체계적으로 최대한 활용할 수 있는 방법이 절실히 요구되고 있다. 많은 연구자들이 정량적 데이터가 부족한 경우에 대처하기 위해 정성적 데이터의 이용을 제안해 왔다. 본 연구에서는 시추가 되지 않은 구간의 암반등급을 추정하는 방법이 지구통계학 이론 중의 하나인 다분적 지시크리깅 기법에 기초하여 제안되었다. 실제 터널 설계에 있어서, 불확실성이 다른 두 종류의 자료, 예를 들어 시추공 자료와 물리탐사자료 등이 암반등급 산정에 동시에 활용될 수 있음이 제시되었다.

• The Journal of Asian Finance, Economics and Business
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• 제7권8호
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• pp.723-733
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• 2020

The study investigates the effects of online instructional facilitator's qualities on student performance of online class activities. The study explores the roles of instructional facilitators who may influence student performance of online class activities and their academic achievement. The study employs a set of aggregated data from 1,362 subjects and 10 facilitators who participated in multiple online classes. The results of independent samples t-test reveal that the student performance in online classes has no association with facilitators' educational background or academic degree, as well as demographic characteristics, student evaluation records and instructional achievement. The results of multiple regression analysis show that the facilitator engagement has a positive relation to the enhancement of student interaction, reading discussion messages, and the quality of discussion messages in online discussions. The results of correlation analysis show that the facilitator engagement has a positive impact on both increasing the number of reading discussion messages and enhancing the quality of discussion messages. The facilitator engagement increases the quantity of reading discussion postings and enhances the quality of discussion messages, which would be a substantial contribution to student performance by facilitators. The findings suggest that student performance and academic achievement in online classes are not independent of facilitator engagement.

• 대한산업공학회지
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• 제39권2호
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• pp.82-89
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• 2013

Novelty detection (ND) is an effective technique that can be used to determine whether a future observation is normal or not. In the present study we propose a novelty detection algorithm that can handle a situation where the distributions of target (normal) observations are inhomogeneous. A simulation study and a real case with the TFT-LCD process demonstrated the effectiveness and usefulness of the proposed algorithm.

• Journal of Communications and Networks
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• 제7권4호
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• pp.462-470
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• 2005

We propose a multi-rate and multi-BEP transmission scheme using adaptive overlapping pulse-position modulator (OPPM) and optical power controller in optical code division multiple access (CDMA) networks. The proposed system achieves the multi-rate and multi-BEP transmission by accommodating users with different values of OPPM parameter and transmitted power in the same network. The proposed scheme has advantages that the system is not required to change the code length and number of weight depending on the required bit rate of a user and the difference of bit rates does not have so much effect on the bit error probabilities (BEPs). Moreover, the difference of transmitted powers does not cause the change of bit rate. We analyze the BEPs of the four multimedia service classes corresponding to the com­binations of high/low-rates and low/high-BEPs and show that the proposed scheme can easily achieve distinct differentiation of the service classes with the simple system configuration.

• ETRI Journal
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• 제20권2호
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• pp.171-191
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• 1998

In this paper, we propose a new heuristic design algorithm for the virtual path (VP)-based ATM network with multiple traffic classes, in which QoS constraints associated with traffic class are taken into account. The minimum bandwidth of VP required to carry given amount of traffic is obtained by utilizing an equivalent bandwidth concept, and the route of each VP is placed so that the network cost is minimized while the QoS requirement is fulfilled To evaluate our design algorithm, we consider two kinds of traffic: voice traffic as low speed service and still picture traffic as high speed service. Through numerical examples, we demonstrate that our design method can achieve an efficient use of network resources, which results in providing a cost-effective VP-based ATM network.

• 한국통신학회논문지
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• 제33권5B호
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• pp.334-343
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• 2008

In this work we propose a universal pricing machine, which incorporates a universal pricing framework for the future IEEE802.16 WiMAX service with multiple classes of service. A multimedia service is provided by a QoS provisioning scheme in the WiMAX network and universal pricing means that it can compute the price for any type of service in a unified framework. In the proposed pricing framework we incorporate multiple types of services such as the real time and nonreal time services that are supposed to be provided in the WiMAX network. To that purpose, let us first carry out an analysis on the current pricing scheme of Korean WiMAX service which incorporates only the data size. From that analysis we propose a new pricing scheme for the future WiMAX service that provides different service classes in the network. Via numerical experiment, we verify the implication of the work.

• 한국학교보건학회지
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• 제35권1호
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• pp.11-21
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• 2022

Purpose: This study investigated the relationship between satisfaction with fundamental nursing skills practicum, confidence in fundamental nursing skills performance and learning flow, and examined factors influencing satisfaction with practicum programs of fundamental nursing skills in face-to-face and online classes for nursing students amid COVID-19. Methods: The subjects of the study were 229 junior nursing students from two colleges of nursing located in D and C city, respectively. The collected data were analyzed with descriptive statistics, independent t-test, ANOVA, Kruskal-Wallis test, Pearson's correlation and hierarchical multiple regression, using SPSS/WINdows 23.0. Results: The subjects' satisfaction with practicum showed a high positive correlation with confidence in performance (r=.55, p<.001) and learning flow (r=.70, p<.001) in face-to-face classes, and their satisfaction with practicum showed a high positive correlation with confidence in performance (r=.56, p<.001) and learning flow (r=.73, p<.001) in online classes. The factors affecting the subjects' satisfaction with practicum were learning flow (β=.51, p<.001) and confidence in performance (β=.30, p<.001) for face-to-face classes, and motivation for application (β=.14, p=.034), learning flow (β=.58 p<.001) and confidence in performance (β=.19, p=.015) for online classes. These factors explained 53% and 60% of the satisfaction with practicum in face-to-face classes (F=23.07, p<.001) and online classes (F=20.66, p<.001), respectively. Conclusion: Learning flow and confidence in performance should be considered when developing learning strategy programs to improve nursing students' satisfaction with fundamental nursing skills practicum in both face-to-face and online classes.

• 한국산업융합학회 논문집
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• 제27권2_2호
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• pp.425-435
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• 2024

The purpose of this study was to identify factors influencing learning satisfaction of nursing students in online non-face-to-face classes during COVID-19 pandemic. 138 undergraduate nursing students were recruited from C nursing colleges of C city in Gyungnam. Data was collected using a self-reported online-questionnaire from 5 January to 18 January, 2022. Collected data were analyzed by SPSS/WIN 27.0 program using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient, and multiple regression. Factor influencing learning satisfaction among undergraduate nursing students on online non-face-to-face classes during COVID-19 pandemic were teaching presence(presence of teacher)(𝛽=.43, p<.001), instructional quality(content qualities)(𝛽=.41, p<.001), Satisfaction of nursing major(satisfaction)(𝛽=.13, p<.001). instructional quality(interface)(𝛽=.12, p=.036), which explained about 85.3% of total variance(F=192.78, p<.001). Therefore, in order to improve class satisfaction in online non-face-to-face classes, it is necessary to operate classes that prioritize the presence of teacher so that learners can recognize and trust the presence of teacher by passionately professional performing. And, among instructional quality, we should be strengthen the usefulness of learning materials, content factors related to tests and assignments, and strive to improve satisfaction of nursing major. In addition, it is necessary to prepare and operate classes that fully consider the interface factors related to the manual composition and system convenience for online classes among the quality factors of classes.

• 대한전자공학회논문지TC
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• 제40권10호
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• pp.59-66
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• 2003

본 논문에서는 다수 트래픽 클래스들에게 최소 대역폭을 보장해 줄 수 있는 광버스트스위칭 (Optical Burst Switching, OBS) 기법을 제안한다. 현재까지 제안되었던 QoS (Quality of Service) 관련 OBS 기법들은 클래스간 차별화는 가능하였으나 여러 클래스들이 존재하는 경우 하위 우선순위의 트래픽 클래스는 상급 클래스와 충돌로 최소 대역폭을 보장해 주진 못 하였다. 본 논문에서는 클래스별로 데이터 채널의 일정 시간구간을 할당하여, 최소한 그 영역에서는 최상급 클래스보다도 높은 우선순위를 부여하여 최소 대역폭을 보장받도록 하였다. 이런 동작을 효율적으로 가능하게 하기 위해서 새로운 버스트 어셈블리 알고리즘과, 데이터 채널의 시간영역을 관리방법을 제안한다. 또한 제안된 기법의 단대단 지연시간과 성능을 시뮬레이션을 통해 검증하였다.