• Journal of The Korean Association For Science Education
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• v.24 no.2
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• pp.408-415
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• 2004

The purpose of this study is to investigate the effect of the delayed resolution of cognitive conflict on middle school students' conceptual change in learning the concept of the action and reaction with cognitive conflict strategy. The subjects were divided into 3 groups according to the time in which teacher tried to resolve cognitive conflict: instant resolution group, 2-day delay resolution group, and 7-day delay resolution group. Pretest, just before test, posttest, and delayed posttest were examined to measure the degree of conceptual change. Delay resolution groups' students answered the questionnaire asking what they had done to resolve cognitive conflict during the period which had been delayed resolution of cognitive conflict. The results of this study were as follows. First, instant resolution group showed significantly more scientific conceptual change than delay resolution groups. Secondly, most of delay resolution groups' students who tried to resolve cognitive conflict interacted with their peers. Also, delayed resolution of cognitive conflict was not helpful to resolve cognitive conflict. Thirdly, in delay resolution groups, we found the tendency that students who spent more than 30 minutes trying to resolve cognitive conflict altered their preconceptions into scientific concepts more easily than the others did. According to the results of this study, instant resolution of cognitive conflict is more effective on scientific conceptual change than delayed resolution of cognitive conflict.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.127-135
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• 1984

Personal and social characteristics, disease status, reason of delay of receiving drug from City Health Center and knowledge and attitude on the pulmonary tuberculosis were compared between the faithful group in treatment and the unfaithful group among the patients for pulmonary tuberculosis registered in a City Health Center in order to analyze the factors which influenced the faithfulness to treatment. Record as well as interview survey was done toward all patients of 247 who were registered and being cared during over 6 months in a City Health Center from April 1, 1982 to March 31, 1983, and results were as follows; 1. There was no statistically significant difference in sex and age distribution between the faithful group in treatment and the unfaithful group. 2. There was no statistically significant difference in marital status distribution between the faithful group and unfaithful group in treatment. 3. The lower education group comprised higher proportion than the higher education group among the faithful group in treatment. 4. The proportion of the emlployed was higher than unemlpoyed among the unfaithful group in treatment. 5. The proportion of mild case was higher than severe case among the unfaithful group in treatment. 6. As for the onset of delay of receiving drug, 'less than 3 month after starting treatment' was 59.5% among the unfaithful group in treatment. 7. The reasons of delay of receiving drug were 'no time' (42.2%). 'being away from home' (25.0%), 'being sick' (13.8%), and 'forgot the appointed date' (12.0%). 8. There was no statistically significant difference in the knowledge on the communicability of the tuberculosis between the faithful groups in treatment and the unfaithful group. 9. There was no statistically significant difference in the knowlege on B.C.G. as vaccination drug of tuberculosis between the faithful group and the unfaithful group in treatment. 10. There was no statistically significant difference in the satisfaction on the treatment of health center between the group of faithful and unfaithful in treatment. 11. There was no statistically significant difference in the belief on the complete recovery of tuberculosis between the faithful group and the unfaithful group in treatment. 12. The rate of consulting on tuberculosis treatment with life partner was higher among the faithful group in treatment than the unfaithful group.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.100-100
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• 2004

• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.4
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• pp.24-30
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• 1984

Group delay distortion (phase distortion) is a characteristic which is of no account from a standpoint of voice transmission. But this distortion becomes the major source of distortion in wave form transmission such as data, FAX and others over the public switching telephone network (voice band transmission) so that it must be drastically studied. This paper makes analysis of group deray distortion of the telephone network, describs experimental and measuring results and refers also to the improvement of distortion for the purpose of opening the public switching telephone network to data transmission.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.506-515
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• 2015

In this paper, we propose a group playback synchronization method using adaptive synchronization delay time by the bit rate of media to synchronize a play position of streaming media between mobile smart devices. This method consists of streaming server-side and client-side synchronization algorithms based on synchronization delay time which includes connection time, control packet transmission time, streaming data buffering time, and synchronization processing time. We implement the Android media player application with synchronization support using the proposed algorithms and present the result of performance evaluation.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.82-86
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• 2015

Construction delay is a common problem worldwide, which is considered as one of the main reasons for project failure. Bangladesh construction industry is no exception. This study investigated the main causes of delay in large building construction projects in Bangladesh. A questionnaire survey was conducted to determine the causes of delay from owners, consultants, and contractors of large building construction projects. About 70 respondents participated in the survey. Using the importance index analysis, the study identified 10 most important causes of delay from a list of 30 different causes. Ten most important causes were: (1) lack of experienced construction manager, (2) lowest bidder selection, (3) funding shortage by owner, (4) lack of proper management, (5) improper planning and scheduling, (6) lack of skilled workers, (7) site constraints, (8) contractors' cash flow problems during construction, (9) escalation of resources price, and (10) contractors' excessive workload. Furthermore, Kruskal-Wallis test indicates that there is no significant variation exists among the three group of respondents, ie owners, consultants and contractors.

• ETRI Journal
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• v.22 no.4
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• pp.1-12
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• 2000

Designing a reliable multicast-based network that scales to the size of a multicast group member is difficult because of the diversity of user demands. The loss inferences of internal nodes by end-to-end measurements do not require the use of complete statistics because of the use of maximum likelihood estimation. These schemes are very efficient and the inferred value converges fast to its true value. In the theoretical analysis, internal delay estimation is possible but the analysis is very complex due to the continuity property of the delay. In this paper, we propose the use of a bottleneck location estimator. This can overcome the analytical difficulty of the delay estimation using the power spectrum of the packet interarrival time as the performance metric. Both theoretical analysis and simulation results show that the proposed scheme can be used for bottleneck location inference of internal links in scalable multicasting.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.3
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• pp.65-75
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• 1998

We consider connection-oriented wireless cellular networks such as the second generation wireless cellular networks and wirelss ATM networks. In these networks, a separate forward signaling channel is provided for the transmission of paging and channel allocation packets. When a call destined to a user is requested, all the base stations in the user's current location area broadcast the corresponding paging packet across forward signaling channels. By slot mode operation and paging group allocation for fusers in a location area, we can reduce relative power consumption level at battery-operated terminals. However, a sthe number of paging groups is increased for lowering relative power consumption level, a paging packet experiences higher delay to access the forward signaling channel. For the pre-negotiated quality-of-service level, paging packet delay level must be limited. In this paper, we consider static and dynamic multiplexing schemes for paging packets, and develop an analytical method for calculating paging packet delay and relative power consumption levels. Using this analytial method, we investigate the effect of network parameters on the paging packet delay and relative power consumption levels.

• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1369-1378
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• 2017

Pub/Sub (Publish/Subscribe) paradigm is a simple and easy to use model for interconnecting applications in a distributed environment. In general, subscribers register their interests in a topic or a pattern of events and then asynchronously receive events matching their interest, regardless of the events' publisher. In order to build a low latency lightweight pub/sub system for Internet of Things (IoT) services, we propose a GQSFPS (Group Quorum System-based Fog Pub/Sub) system that is a core component in the event-driven service oriented architecture framework for IoT services. The GQSFPS organizes multiple installed pub/sub brokers in the fog servers into a group quorum based P2P (peer-to-peer) topology for the efficient searching and the low latency accessing of events. Therefore, the events of IoT are cached on the basis of group quorum, and the delay-sensitive IoT applications of edge devices can effectively access the cached events from group quorum fog servers in low latency. The performance of the proposed GQSFPS is evaluated through an analytical model, and is compared to the GQPS (grid quorum-based pud/sub system).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.1 s.92
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• pp.19-25
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• 2005

This paper describes a synthesis method for a self-equalized dual-passband filter. Compared to conventional dual-passband filter, a self-equalized dual-passband filter can reduce BER(bit error rate) in digital data communications and does not need an external equalizer for group-delay equalization. To validate the synthesis technique, a 10-pole dual-mode dual-passband filter which has two self-equalized 5-pole elliptic response passband is synthesized.