• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.1
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• pp.87-91
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• 2019

Effects of feeding frequency on the growth performance of juvenile starry flounder Platichthys stellatus were investigated. One thousand fifty fishes were distributed into 15 of 500-L flow-through tanks. Triplicate groups of were fed experimental diet with five feeding frequency (one meal every two days, one meal a day, two meals a day, three meals a day and four meals a day) for 9 weeks. Weight gain and specific growth rate (SGR) of fish fed two meals a day were higher than those of fish fed one meal 2 days and one meal a day, but not different from those of fish fed three meals a day and four meals a day. Feed consumption of fish fed two meals a day was not different from that of fish fed three meals a day and four meals a day. Feed efficiency (FE) and protein efficiency ratio (PER) of fish fed two meals a day were higher than those of fish fed all other diets, except for three meals a day. These results suggest that the optimal feeding frequency is two meals a day for the optimum growth performance of juvenile starry flounder under the experimental conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.319-327
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• 2022

An eight-week feeding trial was conducted to evaluate the effects of a diet consisting of different onion juice processing by-product (OJPB) levels on juvenile black rockfish Sebastes schlegelii growth, feed utilization, and, lysozyme and antioxidant enzymes activities. Juvenile rockfish (2.2 g) were randomly distributed into 15 flow-through tanks (30 fish/tank). Five experimental diets were prepared in triplicate. The experimental diets were supplemented with OJPB at different levels of 0 (control), 0.25, 0.5, 0.75 and 1% (designated as OJPB0, OJPB0.25, OJPB0.5, OJPB0.75 and OJPB1, respectively). At the end of the feeding trial, the results revealed that the fish that were fed the OJPB0.75 and OJPB1 diets showed enhancement in growth (weight gain and specific growth rate) and feed utilization (feed efficiency and protein efficiency ratio) compared with the fish that were fed other diets. Plasma lysozyme, glutathione concentration, and superoxide dismutase and catalase activities significantly increased in the fish that were fed the OJPB0.75 and OJPB1 diets. In conclusion, dietary supplementation of 0.75-1% OJPB in juvenile rockfish diet improved the growth performance and antioxidant status.

• The Korean Journal of Franchise Management
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• v.13 no.4
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• pp.39-48
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• 2022

Purpose: COVID-19 has negatively influenced the financial performance of restaurant firms. Previous literature suggests that the franchising strategy effectively helps restaurant firms recover from difficult business conditions through various methods for expanding business size and enhancing business efficiency. According to risk-sharing theory, restaurant franchisors may minimize operational risks by sharing the risks with their franchisees. For instance, restaurant franchisors could generate more stable cash flow using franchise fees from their franchisees. However, research on the effect of franchise's risk reduction factor on business performance during pandemic is scarce. Thus, this study aims to examine the positive moderating effect of franchising between COVID-19 and restaurants' financial performance. Research design, data, and methodology: Panel data including financial information and franchising status of restaurant firms were collected for analysis. In order to control for unobserved firm-specific factors, generalized least squared estimation in fixed effects model was conducted. Huber-White robust standard errors were used to deal with heteroscedasticity issues. Results: It was found that COVID-19 pandemic has a negative effect on the restaurants' financial performance such as ROA (return on assets), ROE (return on equity), and PM (profit margins), which confirms the findings from existing literature. More importantly, results show that the degree of franchising has a positive moderating effect on the relationship between COVID-19 and financial performance of restaurant firms. This suggests that more active engagement in franchising may decrease negative impacts of COVID-19 on the restaurants' financial performance. Conclusions: The study supports existing literature related to risk-sharing theory, by confirming that pandemics, such as COVID-19, negatively affect financial performance of the restaurants. Furthermore, it was found that franchising strategy can help lessen negative impacts of pandemics on the firm performance. These findings can contribute to the franchise and restaurant management literature by suggesting the role of franchising in reducing business risks, thereby positively affecting financial performance. Moreover, this study offers business managers of franchisors and franchisees insights for utilizing franchising in restaurant risk management. Policymakers may also gain information on aiding restaurant firms during global crisis, such as COVID-19.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.5
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• pp.541-548
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• 2022

Biofloc technology (BFT) systems provides an additional protein source for fish by converting waste in microbial flocs. Therefore, we aimed to determine the difference in the protein levels of the diet of Far Eastern catfish Silurus asotus reared in BFT and FW systems. We applied a two-way (six protein levels × two aquaculture systems) ANOVA design. We formulated six experimental diets to contain different protein levels (CPs)- 20%, 25%, 30%, 35%, 40% and 45%-referred to as the CP20, CP25, CP30, CP35, CP40 and CP45 diets, respectively. We randomly distributed 900 fish into 36 (18 each for BFT and FW), 300 L tanks (25 fish/tank) with three replications of each diet for 4 weeks. The weight gain (WG) and specific growth rate (SGR) considerably improved as the dietary protein level increased in the formulated diets. The BFT fish showed higher growth performance with any experimental diet than the FW fish. The growth performance of the fish fed the BFT-CP35 diet was higher than that of the fish fed the FW-CP45 diet. In conclusion, the cultivation of Far Eastern catfish (S. asotus) in BFTs can be carried out under reduced dietary protein levels.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.319-319
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• 2023

Flows of water in the environment (e.g. in a river or estuary) generally occur in complex conditions. This complexity can hinder a general understanding of flows and their related sedimentary processes, such as erosion and deposition. To gain insight in simplified, controlled conditions, hydraulic flumes are a popular type of laboratory research equipment. Linear flumes use pumps to recirculation water. This isn't appropriate for the investigation of cohesive sediments as pumps can break fragile cohesive sediment flocs. To overcome this limitation, the rotating annular flume (RAF) was developed. While not having pumps, a side-effect is that unwanted secondary circulations can occur. To counteract this, the top and bottom lid rotate in opposite directions. Furthermore, a larger flume is considered better as it has less curvature and secondary circulation. While only a few RAFs exist, they are important for theoretical research which often underlies numerical models. Many of the first-generation of RAFs have come into disrepair. As new measurement techniques and models become available, there is still a need to research cohesive sediment erosion and deposition in facilities such as a RAF. New RAFs also can have the advantage of being automatic instead of manually operated, thus improving data quality. To further advance our understanding of cohesive sediment erosion and deposition processes, a large, automatic RAF (1.72 m radius, 0.495 m channel depth, 0.275 m channel width) has been constructed at the Hydraulic Laboratory at Chungnam National University (CNU), Korea. The RAF has the ability to simulate both unidirectional (river) and bidirectional (tide) flows with supporting instrumentation for measuring turbulence, bed shear stress, suspended sediment concentraiton, floc size, bed level, and bed density. Here we present the current status and future prospect of the CNU RAF. In the future, calibration of the rotation rate with bed shear stress and experiments with unidirectional and bidirectional flow using cohesive kaolinite are expected. Preliminary results indicate that the CNU RAF is a valuable tool for fundamental cohesive sediment transport research.

• Journal of Korea Water Resources Association
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• v.56 no.2
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• pp.125-137
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• 2023

In marine environments, plastics have become more abundant due to increasing plastic use. Especially, in coastal regions, particles may remain for a long time, and they interact with flows, wind, sand and human activities. This study aimed thus to observe how plastic debris interacts with and escape from sediments. A series of experiments were conducted in order to gain a better understanding of particle release from coastal sediments into water body. An oscillating water tunnel was built for the experiments, and used to generate oscillatory flows of relatively high Reynolds number and induce sediment transport. Spherical plastic particles of three different sizes was used in lieu of plastic debris in environments. It was observed that release of the particles was directly related to change of bedform, which is in turn determined by the flow condition. Also smaller particles tend to escape the sediment more readily. Critical values for dimensionless parameters are proposed.

• Journal of Practical Engineering Education
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• v.16 no.1_spc
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• pp.95-103
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• 2024

With the rapid decline of the school-age population, the competition for admissions has increased and marketing through digital channels has become more important, so universities are investing more resources in online promotion and communication to recruit new students. This study uses Google Analytics, a web log analysis tool, to track the visitor behavior of a university admissions website and establish a digital marketing strategy based on it. The analysis period was set from July 1, 2023, when Google Analytics 4(GA4) was integrated, to January 10, 2024, when the college admissions process was completed. The analysis revealed interesting patterns such as geographical information based on visitors' access location, devices(operating systems) and browsers used by visitors, acquisition channels through visitors traffic, conversions on pages and screens that visitors engaged with and visitor flow. Based on this study, we expect universities to find ways to strengthen their admission promotion through digital marketing and effectively communicate with applicants to gain a competitive edge.

• Tuberculosis and Respiratory Diseases
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• v.56 no.5
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• pp.450-464
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• 2004

Background : The FHIT (fragile histidine triad) gene is a frequent target of deletions associated with abnormal RNA and protein expression in lung cancer. Previous studies have shown FHIT gene transfer into lung cancer cell line lacking FHIT protein expression resulted in inhibition of tumor cell growth attributable to the induction of apoptosis and reversion of tumorigenecity. However, the mechanism of the tumor suppressor activity of the FHIT gene and the cellular pathways associated with its function are not completely understood. Methods : To gain insight into the biological function of FHIT, we compared the NCI-H358 cell line with its stable FHIT transfectants after treatment with cisplatin or paclitaxel. We investigated the effects of FHIT gene expression on cell proliferation, apoptosis, and activation of caspase system and Bcl-2 family. The induction of apoptosis was evaluated by using DAPI staining and flow cytometry. Activation of caspases and Bcl-2 members was evaluated by Western blot analysis. Results : A significantly increased cell death was observed in FHIT transfectants after cisplatin or paclitaxel treatment and this was attributable to the induction of apoptosis. Remarkable changes in caspases and Bcl-2 family were observed in the transfected cells as compared with the control cells after treatment with paclitaxel. Activation of caspase-3 and caspase-7 was markedly increased in cells expressing FHIT. Expression level of Bcl-2 and Bcl-xL protein was significantly decreased and that of Bax and Bad protein was significantly increased in the transfected cells. Conclusion : FHIT gene delivery into lung cancer cells results in enhanced apoptosis induced by treatment with cisplatin or paclitaxel. The data suggest that apoptosis in FHIT-expressing cells could be related to activation of caspase pathway and Bcl-2 family.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.7-15
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• 2010

Research of this paper focused on developing and demonstrating of algorithm with the figures of difference between historical traffic pattern data and real-time traffic data to decide on what the incident is. The aim of this dissertation is to develop incident detection algorithm which can be understood and modified easier to operate. To establish traffic pattern of this algorithm, weighted moving average method was applied. The basis of this method was traffic volume and speed of the same day and time at the same location based on 30-second raw data. The model was completed by a serious of steps of process-screening process of error data, decision of the traffic condition, comparison with pattern data, decision of incident circumstances, continuity test. A variety of parameter value was applied to select reasonable parameter. Results of application of the algorithm came out with figures of average detection rate 94.7 percent, 0.8 percent rate of misinformation and the average detection time 1.6 minutes. With these following results, the detection rate turned out to be superior compared with result of existing model. Applying the concept of traffic patterns was useful to gain excellent results of this study. Also, this study is significant in terms of making algorithm which theorized the decision process of actual operators.

• Land and Housing Review
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• v.3 no.3
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• pp.241-248
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• 2012

Although infrastructure cost comprises the great proportion of residential development cost, all of it tends to be borne by land developers which develop large area. This brings about free-riding by adjacent small development or built-up area, followed by the equity problem in terms of infrastructure development cost sharing and the privatization of development gain. This study aims to establish the method to analyze free-riding on the transportation infrastructure(roads) and investigate empirically how much the free-riding occurs. It sets several development scenarios to calculate the part generated by Bucheon Sangdong district, the case area of this study, of all the traffic flow on the roads. The Network analysis is used to estimate the proportion, by development scenarios, of traffic flow, travel time, and travel cost. As a result, the developer of Bucheon Sangdong district is responsible for 83% of the construction cost of selected roads. The methodology and empirical result of this study would contribute to determine who are liable for the infrastructure facilitation and to estimate how much of the cost the obligators have to share.