• Fisheries and Aquatic Sciences
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• v.27 no.1
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• pp.23-34
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• 2024

While scientific information on the spatial variation of soda lake Microalgae is important to limnological studies, little information was reported from the Ethiopian Rift Valley Lake, Lake Chitu. This study aimed to understand the spatial distribution of the dominant Microalgae taxa in Lake Chitu, Ethiopia. The collection of samples and in situ measurements of some physico-chemical parameters were recorded at three sites for one cycle in November 2021. Fourteen species or genera of Microalgae were identified. Among those, Bacillariophyta were the most important with regard to species abundance and the rarest in species richness. Cyanophyta were the second-most important group in terms of species richness and rarity. Comparatively, all microalgae taxa were rare at both the anthropogenic areas (AA) and the flooding area (FA), which could be mainly due to intensive human and animal intervention and associated with extreme turbidity. Among Cyanophyta, Chroococcus minutus, Microcystis aeruginosa, and Spirulina platensis/fusiformis were predominant at both AA and FA, revealing their adaptation to less clear water and pollution. But S. platensis/fusiformis attained the highest abundance at the FA, indicating their preference for water in a highly nutrient-enriched area. We concluded that the spatial variation of microalgae diversity in relation to water quality parameters has implications for the importance of microalgae as a baseline indicator of water quality assessment tools in lakes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2A
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• pp.119-127
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• 2006

In this two-part paper, we consider dynamic resource allocation in orthogonal frequency division multiple access(OFDMA). To reduce the reverse link overhead for channel quality information(CQI) feedback, a set of sub-carriers are tied up to a sub-channel to be used as the unit of CQI feedback, user-multiplexing and the corresponding power/rate allocation. Specifically, we focus on two sub-channel structures, either aggregated or distributed, where the SNR distribution over a sub-channel is modeled as Ricean in general, and the channel quality of a sub-channel is summarized as the mean and variance of channel gain envelop divided by noise standard deviation. Then, we develop a generalized two step channel/resource allocation algorithm, which uses the two statistical measurements, and analyze the spectral efficiency of the OFDMA system in terms of average frequency utilization. An extension to proportional fair algorithm will also be addressed. As confirmed by numerical results, the aggregated structure is preferred especially when intending aggressive link adaptation.

• The Journal of the Korean dental association
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• v.52 no.3
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• pp.153-163
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• 2014

3-dimensional information for anatomic stucture plays a role as integral part in clinical aspect of dental practice. CBCT(cone beam computed tomography) has been accepted as useful diagnostic tool offering Volume data and images for evaluating teeth and jaws in lower radiation dose than conventional CT. CBCT equipment is essential for the quality assurance of it to ensure continued satisfactory performance and result of adequate images. Dental practitioner and oral and maxillofacial radiologist should have a responsibility and critical thinking to deliver this technology to patients in a responsible way, so that diaganostic value is maximised and radiation doses kept as low as resonably achievable. CBCT imaging modality should be used only after a review of the patient's health and imaging history and the completion of a thorough clinical examination. Clinical guidelines are systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances Dental practitioners should prescribe CBCT imaging only when they expect that the diagnostic yield will benefit patient care, enhance patient safety or improve clinical outcomes significantly. Knowledge of patient dose is essential for clinicians who are making the decision regarding the justification of the exposure. There are some limitation in the measurement of patient dose in CBCT for the approval and adaptation of conventinal methodolgy in CT. It is also important to ensure that doses are optimised and in line with any national and international guidelines. The higher radiation doses of CBCT compared with conventional radiography, mean that high standards must be maintained. The Quality Assurance(QA) programme should entail surveys and checks that are performed according to a regular timetable. QA programme should be maintained by staff to ensure adherence to the programme and to raise its importance among staff.

• Journal of Korea Multimedia Society
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• v.19 no.7
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• pp.1166-1178
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• 2016

In Internet of Things (IoT) environments, billions of interconnected devices and multimedia sensors generate a huge amount of multimedia traffic. Since the environment are in general deployed as a server-centric architecture wireless sensor networks could be bottlenecks between IoT gateways and IoT devices. The bottleneck causes high power consumption of the device and triggers very heavy network overload by transmission of sensing data. The deterioration could decrease the quality of multimedia streaming service due to delay, loss, and waste of device power. Thus, in this paper, we propose a context-based adaptive multimedia streaming scheme to support enhanced QoS and low power consumption in IoT environments. The goal of the scheme is to increase quality score per voltage of the streaming service, given an adaptation algorithm with context that are classified network and hardware such as throughput, RTT, and CPU usage. From the both context, the quality score per voltage is used in the comparison of a only network context-based adaptive multimedia streaming scheme, a fixed multimedia streaming and our scheme. As a result, we achieves a high improvement that means the quality score per voltage is increased up to about 4, especially in case of resolution change.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.7
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• pp.945-951
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• 2007

Noise cancellation is essential for the devices which use speech as an interface. In real environments, speech quality and recognition rates are degraded by the auditive noises coming near the microphone. In this paper, we propose a noise cancellation algorithm using stereo microphones basically. The advantage of the use of multiple microphones is that the direction information of the target source could be applied. The proposed noise canceller is based on the Wiener filter. To estimate the filter, noise and target speech frequency responses should be known and they are estimated by the spectral classification in the frequency domain. The performance of the proposed algorithm is compared with that of the well-known Frost algorithm and the generalized sidelobe canceller (GSC) with an adaptation mode controller (AMC). As performance measures, the perceptual evaluation of speech quality (PESQ), which is the most widely used among various objective speech quality methods, and speech recognition rates are adopted.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.14 no.2
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• pp.43-50
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• 2010

Background and Objectives: Cardiff Acne Disability Index(CADI) is one tool used internationally to measure the quality of life of acne sufferers. There, however, is a necessity of developing Korean version of CADI, as the questionnaires of the original one are written in English, making it hard to apply for Korean patients. So as a first step, we conducted a cross-cultural translation of CADI into Korean and verification of face validity. Methods: After properly translating CADI questionnaires into Korean up to guidelines for cross-cultural adaptation of health related quality-of-life measures, we conducted a survey with 122 undergraduates to get face validity, using the translated questionnaires. Results: About the translated CADI questionnaires, 86 out of 107 undergraduates replied that they had no difficulty understanding them, while 21 offered ideas about ambiguous expressions of them. Upon further examination of two oriental doctors, two sentences were additionally modified in the translated version. Conclusions: Firstly, we created the Korean version of CADI, one of the most effective methods in the world to measure acne sufferers' quality of life, by properly translated the original version into Korean. Then we conducted a survey for face validity with the translated questionnaires and gathered opinions from those questioned. After going through some examining and correcting procedures based on the opinions, we finalized the Korean version of CADI. It will also require a follow-up verification process to prove credibility and validity of the final version of Korean CADI.

• Human Ecology Research
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• v.60 no.2
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• pp.163-176
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• 2022

The purpose of this study is to understand the changes in the daily life and quality of life of the elderly due to the spread of COVID-19. This study attempted to supplement the limitations of quantitative analysis by performing both quantitative and qualitative analysis. A large-scale representative data, the Elderly Survey 2017 and 2020, were analyzed, and in-depth interviews were conducted with a total of 16 elderly people in Gwangju and Seoul. As a result, it was found that the overall quality of life was positively changed compared to before Corona. The frequency of contact and visits with family members decreased whereas the time spent watching TV increased. The elderly's adaptation to daily life has a series of processes since the first outbreak of COVID-19. At the beginning of the outbreak, there were fear, anxiety, and depression due to isolation, but gradually made efforts to adapt to the new situation. They reported that they realized the importance of human relationships, especially spouses, in a crisis situation and that there were some positive aspects as well. Finally, in all these results a difference was found between single-person households and multi-person households. Through the above research results, academic and policy measures were discussed.

• Restorative Dentistry and Endodontics
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• v.47 no.4
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• pp.36.1-36.17
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• 2022

Objectives: This study aimed to evaluate the effect of aging on the marginal quality of glass hybrid (GH) material used to elevate dentin gingival margins, and to analyze the consistency of the results obtained by 3 in vitro methods. Materials and Methods: Ten teeth received compound class II cavities with subgingival margins. The dentin gingival margins were elevated with GH, followed by resin composite. The GH/gingival dentin interfaces were examined through digital microscopy, scanning electron microscopy (SEM) using resin replicas, and according to the World Dental Federation (FDI) criteria. After initial evaluations, all teeth were subjected to 10,000 thermal cycles, followed by repeating the same marginal evaluations and energy dispersive spectroscopy (EDS) analysis for the interfacial zone of 2 specimens. Marginal quality was expressed as the percentage of continuous margin at ×200 for microscopic techniques and as the frequency of each score for FDI ranking. Data were analyzed using the paired sample t-test, Wilcoxon signed-rank test, and Pearson and Spearmen correlation coefficients. Results: None of the testing techniques proved the significance of the aging factor. Moderate and strong significant correlations were found between the testing techniques. The EDS results suggested the presence of an ion-exchange layer along the GH/gingival dentin interface of aged specimens. Conclusions: The marginal quality of the GH/dentin gingival interface defied aging by thermocycling. The replica SEM and FDI ranking results had stronger correlations with each other than either showed with the digital microscopy results.

• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.482-489
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• 2013

The purpose of this study was to identify the relationship of instructional design, perceived learning transfer, and satisfaction. The data were collected using questionnaire from the sample of 239 nursing students. The level of learning transfer was explained by introduction with learning context & providing guidance and initial attention. The level of learning transfer was explained by learning object with motivation, learning goal alignment, accessibility and feedback & adaptation. The level of program satisfaction was explained by introduction with learning context & providing guidance and initial attention. The level of program satisfaction was explained by learning object with motivation, presentation design, interaction availability, feedback & adaptation, learning goal alignment and contents quality. The findings serve as basic data to design e-Learning program to improve learning transfer and satisfaction.

• Journal of Intelligence and Information Systems
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• v.9 no.2
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• pp.121-133
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• 2003

Due to the rapid growth of Internet, means of communication with customers in a traditional customer support environment such as telephone calls are being replaced by mainly e-mail in a Web-based customer support system. Although such a Web-based support is efficient and promises potential benefits for firms, including reduced transaction costs, reduced time, and high quality of support, there are some difficulties associated with responding to many types of customer's inbound e-mails appropriately. As many types of e-mail are received, considerable attention is being paid to methods for increasing the efficiency of managing and responding e-mails. This research proposes an intelligent system for managing customer's inbound e-mails in organizations by applying case based reasoning technique for responding to various customers' inbound e-mails more effectively. In this approach, a case is represented as a frame-typed data structure corresponding to an inbound e-mail, keywords, and its reply e-mail. In the retrieval procedure, keywords and affinity set is developed to index a case, and then the case is represented as a vector, a case vector. Also, cosines value is calculated to measure the similarity between a new inbound e-mail and the cases in the case base. In the adaptation procedure, we provide several adaptation strategies to adapt and modify the retrieved case. The strategies guide to make an outbound e-mail using product databases, databases for customer support, etc. Additionally, the Web-based system architecture is proposed to implement our methodology. The proposed methodology and system will be helpful for developing more efficient Web-based customer support.